Optical print head, image forming apparatus, and method of manufacturing optical print head

文档序号：1524907 发布日期：2020-02-11 浏览：27次中文

阅读说明：本技术 光学打印头、成像设备及光学打印头的制造方法 (Optical print head, image forming apparatus, and method of manufacturing optical print head ) 是由乙黑康明冈田雄太有贺泰祐岩井齐细井慎一郎今井雄一郎百家俊树大坪庆贵后于 2018-06-15 设计创作，主要内容包括：本发明的保持构件505包括与透镜阵列506的侧壁表面相对的第一相对部分(第一内壁表面)和第二相对部分(第二内壁表面)。透镜阵列的在相对于透镜阵列的纵向方向的相对的端部侧上的侧壁表面从第一相对部分的相对的端部和第二相对部分的相对的端部暴露。(The holding member 505 of the present invention includes a first opposing portion (first inner wall surface) and a second opposing portion (second inner wall surface) opposing the side wall surface of the lens array 506. The side wall surfaces of the lens array on opposite end sides with respect to the longitudinal direction of the lens array are exposed from opposite ends of the first opposing portion and opposite ends of the second opposing portion.)

1. An optical printhead included in an image forming apparatus, the optical printhead comprising:

a light emitting portion in which a plurality of light emitting elements for emitting light that exposes a photosensitive drum included in the image forming apparatus are arranged in a longitudinal direction of the optical print head;

a lens array in which a plurality of lenses for condensing light emitted from the plurality of light emitting elements on a surface of the photosensitive drum are arranged along the longitudinal direction;

a holding member for holding the light emitting portion and the lens array;

a first opposing portion formed by protruding from the holding member toward an exit direction of light with respect to an optical axis direction of the lens, and opposing a first sidewall surface that is a sidewall surface of the lens array on a side with respect to a perpendicular direction perpendicular to both the longitudinal direction and the optical axis direction, wherein the first sidewall surface is adhesively fixed to the first opposing portion; and

a second opposing portion formed by protruding from the holding member toward the exit direction and opposing a second side wall surface that is a side wall surface of the lens array on the other side with respect to the perpendicular direction, wherein the second side wall surface is adhesively fixed to the second opposing portion,

wherein the first sidewall surface at least on the one of one end side and the other end side of the lens array with respect to the longitudinal direction is exposed from an end portion of the first opposing portion with respect to the longitudinal direction, and the second sidewall surface at least on the other of the one end side and the other end side of the lens array with respect to the longitudinal direction is exposed from an end portion of the second opposing portion with respect to the longitudinal direction.

2. The optical print head of claim 1, wherein a portion of the lens array protrudes more in the exit direction than the first opposing portion and the second opposing portion.

3. The optical print head according to claim 2, wherein the one end side with respect to the longitudinal direction of the first sidewall surface and the other end side with respect to the longitudinal direction of the first sidewall surface are exposed from the end portion with respect to the longitudinal direction of the first opposing portion, and the one end side with respect to the longitudinal direction of the second sidewall surface and the other end side with respect to the longitudinal direction of the second sidewall surface are exposed from the end portion with respect to the longitudinal direction of the second opposing portion.

4. The optical print head according to claim 2, wherein a length from one end portion with respect to the longitudinal direction of the lens array to the other end portion with respect to the longitudinal direction of the lens array is longer than both a length from one end portion with respect to the longitudinal direction of the first opposing portion to the other end portion with respect to the longitudinal direction of the first opposing portion and a length from one end portion with respect to the longitudinal direction of the second opposing portion to the other end portion with respect to the longitudinal direction of the second opposing portion.

5. The optical print head according to claim 4, wherein the lens array is held with respect to the vertical direction by a holding mechanism for holding the lens array, and

wherein, in order to adjust the position of the lens array with respect to the holding member, an opposite end side with respect to the longitudinal direction of the first sidewall surface is exposed from an opposite end with respect to the longitudinal direction of the first opposing portion, and an opposite end side with respect to the longitudinal direction of the second sidewall surface is exposed from an opposite end with respect to the longitudinal direction of the second opposing portion.

6. An optical printhead included in an image forming apparatus, the optical printhead comprising:

a holding member for holding the light emitting portion and the lens array;

a first opposing portion that is formed by protruding from the holding member toward an exit direction of light with respect to an optical axis direction of the lens, and to which a side wall surface of the lens array on a side with respect to a perpendicular direction that is perpendicular to both the longitudinal direction and the optical axis direction is adhesively fixed; and

a second opposing portion that is formed by protruding from the holding member toward the exit direction and to which a side wall surface of the lens array on the other side with respect to the vertical direction is adhesively fixed,

wherein the side wall surface of the lens array with respect to the vertical direction is exposed from any one of an opposite end portion with respect to a longitudinal direction of the first opposing portion and an opposite end portion with respect to a longitudinal direction of the second opposing portion.

7. The optical print head of claim 6, wherein a portion of the lens array protrudes more in the exit direction than the first opposing portion and the second opposing portion.

8. The optical print head according to claim 7, wherein a length from one end portion with respect to the longitudinal direction of the lens array to the other end portion with respect to the longitudinal direction of the lens array is longer than any of a length from one end portion with respect to the longitudinal direction of the first opposing portion to the other end portion with respect to the longitudinal direction of the first opposing portion and a length from one end portion with respect to the longitudinal direction of the second opposing portion to the other end portion with respect to the longitudinal direction of the second opposing portion.

9. An optical printhead according to claim 8, wherein the lens array is held with respect to the vertical direction by a holding mechanism for holding the lens array, and

wherein, in order to adjust the position of the lens array with respect to the holding member, the side wall surface of the lens array with respect to the longitudinal direction is exposed from either one of an opposite end portion with respect to the longitudinal direction of the first opposing portion and an opposite end portion with respect to the longitudinal direction of the second opposing portion.

10. An optical printhead included in an image forming apparatus, the optical printhead comprising:

a holding member for holding the light emitting portion and the lens array;

wherein the holding member comprises a plurality of holding members,

a first opposing portion that opposes a sidewall surface of the lens array on a side with respect to a perpendicular direction perpendicular to both a longitudinal direction and an optical axis direction of the lens, and to which the sidewall surface on the side is adhesively fixed; and

a second opposing portion that opposes a sidewall surface of the lens array on the other side with respect to the vertical direction and to which the sidewall surface on the other side is adhesively fixed,

wherein in at least one of the first opposing portion and the second opposing portion, at least a part of the opposing portion is provided with a recessed portion along the vertical direction, and a part of the sidewall surface of the lens array with respect to the vertical direction is exposed from the recessed portion.

11. The optical print head of claim 10, wherein a portion of the lens array protrudes more in the exit direction than the first opposing portion and the second opposing portion.

12. The optical print head according to claim 11, wherein the first opposing portion is provided with a plurality of recessed portions along the vertical direction, the side wall surface of the lens array opposite the first opposing portion is exposed from the plurality of recessed portions of the first opposing portion, and the second opposing portion is provided with a plurality of recessed portions along the vertical direction, the side wall surface of the lens array opposite the second opposing portion is exposed from the plurality of recessed portions of the second opposing portion.

13. The optical print head according to claim 12, wherein the recessed portions formed on the first opposing portions are respectively formed on opposing end sides of the first opposing portions with respect to a longitudinal direction, and the recessed portions formed on the second opposing portions are respectively formed on opposing end sides of the second opposing portions with respect to the longitudinal direction.

14. An optical printhead according to claim 13, wherein the lens array is held with respect to the vertical direction by a holding mechanism for holding the lens array, and

wherein, in order to adjust the position of the lens array with respect to the holding member, a part of the sidewall surface of the lens array is exposed from each of the concave portion formed on the first opposing portion and the concave portion formed on the second opposing portion.

15. An imaging apparatus, comprising:

a photosensitive drum; and

an optical print head is provided with a plurality of optical printing heads,

wherein the optical print head comprises a plurality of optical print heads,

a holding member for holding the light emitting portion and the lens array;

16. The imaging device of claim 15, wherein a portion of the lens array protrudes more in an exit direction than the first opposing portion and the second opposing portion.

17. An apparatus according to claim 16, wherein said one end side with respect to the longitudinal direction of said first sidewall surface and said other end side with respect to the longitudinal direction of said first sidewall surface are exposed from said end portion with respect to the longitudinal direction of said first opposing portion, and said one end side with respect to the longitudinal direction of said second sidewall surface and said other end side with respect to the longitudinal direction of said second sidewall surface are exposed from said end portion with respect to the longitudinal direction of said second opposing portion.

18. The imaging apparatus according to claim 17, wherein a length from one end portion with respect to the longitudinal direction of the lens array to the other end portion with respect to the longitudinal direction of the lens array is longer than both a length from one end portion with respect to the longitudinal direction of the first opposing portion to the other end portion with respect to the longitudinal direction of the first opposing portion and a length from one end portion with respect to the longitudinal direction of the second opposing portion to the other end portion with respect to the longitudinal direction of the second opposing portion.

19. The imaging apparatus according to claim 18, wherein the lens array is held with respect to a vertical direction by a holding mechanism for holding the lens array, and

20. An imaging apparatus, comprising:

a photosensitive drum; and

an optical print head is provided with a plurality of optical printing heads,

wherein the optical print head comprises a plurality of optical print heads,

a holding member for holding the light emitting portion and the lens array;

21. The imaging device of claim 20, wherein a portion of the lens array protrudes more in an exit direction than the first opposing portion and the second opposing portion.

22. The imaging apparatus according to claim 21, wherein a length from one end portion with respect to a longitudinal direction of the lens array to the other end portion with respect to the longitudinal direction of the lens array is longer than any of a length from one end portion with respect to the longitudinal direction of the first opposing portion to the other end portion with respect to the longitudinal direction of the first opposing portion and a length from one end portion with respect to the longitudinal direction of the second opposing portion to the other end portion with respect to the longitudinal direction of the second opposing portion.

23. The imaging apparatus according to claim 22, wherein the lens array is held with respect to a vertical direction by a holding mechanism for holding the lens array, and

24. An imaging apparatus, comprising:

a photosensitive drum; and

an optical print head is provided with a plurality of optical printing heads,

wherein the optical print head comprises a plurality of optical print heads,

a holding member for holding the light emitting portion and the lens array;

wherein the holding member comprises a plurality of holding members,

25. The imaging device of claim 24, wherein a portion of the lens array protrudes more in an exit direction than the first opposing portion and the second opposing portion.

26. The imaging apparatus according to claim 25, wherein the first opposing portion is provided with a plurality of recessed portions along the vertical direction, the side wall surface of the lens array opposite to the first opposing portion is exposed from the plurality of recessed portions of the first opposing portion, and the second opposing portion is provided with a plurality of recessed portions along the vertical direction, the side wall surface of the lens array opposite to the second opposing portion is exposed from the plurality of recessed portions of the second opposing portion.

27. An apparatus according to claim 26, wherein said recessed portions formed on said first opposing portions are respectively formed on opposite end sides of said first opposing portions with respect to a longitudinal direction, and said recessed portions formed on said second opposing portions are respectively formed on opposite end sides of said second opposing portions with respect to the longitudinal direction.

28. The imaging apparatus according to claim 27, wherein the lens array is held with respect to the vertical direction by a holding mechanism for holding the lens array, and

29. A method of manufacturing an optical print head included in an image forming apparatus, the optical print head comprising:

a lens array in which a plurality of lenses are arranged in the longitudinal direction, each of the plurality of lenses having an incident surface that allows light emitted from the plurality of light emitting elements to be incident thereon and having an exit surface that allows light emitted from the incident surface to be incident thereon, and each of the plurality of lenses condensing light on a surface of the photosensitive drum,

a holding member for holding the light emitting portion and the lens array,

wherein opposite end sides of the first sidewall surface with respect to a longitudinal direction are exposed from end portions of the first opposing portions with respect to the longitudinal direction, respectively, and opposite end sides of the second sidewall surface with respect to the longitudinal direction are exposed from end portions of the second opposing portions with respect to the longitudinal direction, respectively, the manufacturing method of the optical print head includes:

a holding step in which the sidewall surfaces on opposite end sides of the lens array with respect to a longitudinal direction are held with respect to a vertical direction by the holding mechanism;

an arranging step of inserting the lens array held by the holding mechanism between the first opposing portion and the second opposing portion so that the incident surface and the light emitting portion are opposed to each other, and arranging with respect to the holding member so that the portion held by the holding mechanism is in a state where the portion is exposed from an end portion with respect to the longitudinal direction of the first opposing portion and from an end portion with respect to the longitudinal direction of the second opposing portion;

a light receiving step in which the light emitting element is caused to emit light, and light that enters the incident surface and is emitted from the exit surface is received by a light receiving device;

an adjustment step of moving the lens array in a state where the lens array is held by the holding mechanism based on a light reception result in the light reception step; and

a bonding step of adhesively fixing the lens array adjusted in the interval between the incident surface and the light emitting portion to the first opposing portion and the second opposing portion.

30. The method of manufacturing an optical print head according to claim 31, wherein in the holding step, both side wall surfaces of the lens array with respect to the vertical direction are clamped while being pushed in the vertical direction.

31. A manufacturing method of an optical print head according to claim 31, wherein in the holding mechanism, both side wall surfaces of the lens array with respect to the vertical direction are held while being attracted in the vertical direction.

32. A method of manufacturing an optical print head included in an image forming apparatus, the optical print head comprising:

a holding member for holding the light emitting portion and the lens array,

wherein at least the first sidewall surface on the one end side out of one end side and the other end side with respect to the longitudinal direction of the lens array is exposed from an end portion in the longitudinal direction of the first opposing portion, and at least the second sidewall surface on the other end side out of the one end side and the other end side with respect to the longitudinal direction of the lens array is exposed from an end portion in the longitudinal direction of the second opposing portion, the manufacturing method of the optical print head includes:

a holding step in which the side wall surface of the lens array with respect to the longitudinal direction is held by the holding mechanism;

an adjustment step of moving the lens array in a state where the lens array is held by the holding mechanism based on a light reception result in the light reception step; and

a bonding step of adhesively fixing the lens array adjusted in the interval between the incident surface and the light emitting portion to the first opposing portion and the second opposing portion.

33. A manufacturing method of an optical print head according to claim 32, wherein in the holding mechanism, the side wall surface of the lens array with respect to the vertical direction is held while being attracted in the vertical direction.

34. A method of manufacturing an optical print head included in an image forming apparatus, the optical print head comprising:

a holding member for holding the light emitting portion and the lens array,

wherein the side wall surface of the lens array with respect to a vertical direction is exposed from any one of an opposite end portion with respect to a longitudinal direction of the first opposing portion and an opposite end portion with respect to a longitudinal direction of the second opposing portion, the manufacturing method of the optical print head including:

a holding step in which the side wall surface of the lens array with respect to a vertical direction is held by the holding mechanism;

an arrangement step of inserting the lens array held by the holding mechanism between the first opposing portion and the second opposing portion so that the incident surface and the light emitting portion are opposed to each other, and arranging with respect to the holding member so that the portion held by the holding mechanism is in a state in which the portion is exposed from either one of an opposite end portion with respect to the longitudinal direction of the first opposing portion and an opposite end portion with respect to the longitudinal direction of the second opposing portion;

an adjustment step of moving the lens array in a state where the lens array is held by the holding mechanism based on a light reception result in the light reception step; and

a bonding step of adhesively fixing the lens array adjusted in the interval between the incident surface and the light emitting portion to the first opposing portion and the second opposing portion.

35. A manufacturing method of an optical print head according to claim 34, wherein in the holding mechanism, the side wall surface of the lens array with respect to the vertical direction is held while being attracted in the vertical direction.

36. A method of manufacturing an optical print head included in an image forming apparatus, the optical print head comprising:

a holding member for holding the light emitting portion and the lens array,

wherein the holding member comprises a plurality of holding members,

a first opposing portion on which a plurality of concave portions are formed in a vertical direction and which opposes a sidewall surface of the lens array on a side with respect to the vertical direction perpendicular to both the longitudinal direction and the optical axis direction of the lenses, wherein the sidewall surface on the side is adhesively fixed to the first opposing portion; and

a second opposing portion on which a plurality of concave portions are formed along a vertical direction and which opposes a sidewall surface of the lens array on the other side with respect to the vertical direction, wherein the sidewall surface on the other side is adhesively fixed to the second opposing portion,

wherein a part of the sidewall surface of the lens array with respect to the vertical direction is exposed from a concave portion formed on the first opposing portion and a concave portion formed on the second opposing portion, the manufacturing method of the optical printhead including:

a holding step in which the side wall surface of the lens array with respect to the longitudinal direction is held by the holding mechanism;

an arrangement step of inserting the lens array held by the holding mechanism between the first opposing portion and the second opposing portion so that the incident surface and the light emitting portion oppose each other, and arranging with respect to the holding member so that the portion held by the holding mechanism is in a state where the portion is exposed from a recessed portion formed on the first opposing portion and a recessed portion formed on the second opposing portion;

an adjustment step of moving the lens array in a state where the lens array is held by the holding mechanism based on a light reception result in the light reception step; and

a bonding step in which the lens array adjusted in the interval between the incident surface and the light emitting portion is adhesively fixed to the holding member.

37. The method of manufacturing an optical print head according to claim 36, wherein in the holding step, both side wall surfaces of the lens array with respect to the vertical direction are clamped while being pushed in the vertical direction.

38. A method of manufacturing an optical print head according to claim 36, wherein in the holding step, the two side wall surfaces of the lens array are held while being attracted in the vertical direction.

39. A method of manufacturing an optical print head included in an image forming apparatus, the optical print head comprising:

a holding member for holding the light emitting portion and the lens array,

wherein the holding member comprises a plurality of holding members,

a first opposing portion opposing a sidewall surface of the lens array on a side with respect to a perpendicular direction perpendicular to both the longitudinal direction and an optical axis direction of the lens, wherein the sidewall surface on the side is adhesively fixed to the first opposing portion; and

a second opposing portion opposing a sidewall surface of the lens array on the other side with respect to the vertical direction, wherein the sidewall surface on the other side is adhesively fixed to the second opposing portion,

wherein in at least one of the first opposing portion and the second opposing portion, at least a part of the opposing portion is provided with a recessed portion along a vertical direction, and a part of the sidewall surface of the lens array with respect to the vertical direction is exposed from the recessed portion, the manufacturing method of the optical print head includes:

a holding step in which the side wall surface of the lens array with respect to the longitudinal direction is held by the holding mechanism;

an adjustment step of moving the lens array in a state where the lens array is held by the holding mechanism based on a light reception result in the light reception step; and

a bonding step in which the lens array adjusted in the interval between the incident surface and the light emitting portion is adhesively fixed to the holding member.

40. A method of manufacturing an optical print head according to claim 39, wherein in the holding mechanism, the two sidewall surfaces of the lens array with respect to the vertical direction are held while being attracted in the vertical direction.

Technical Field

The present invention relates to an optical printhead, an image forming apparatus including the same, and a method of manufacturing the same.

Background

An image forming apparatus, such as a printer and a copying machine, includes an optical print head provided with a plurality of light emitting elements for exposing a photosensitive drum to light. As the optical print head, there are an optical print head including an LED (light emitting diode), an organic EL (electroluminescence) device, and the like as an example of a light emitting element (device), and an optical print head in which a plurality of light emitting elements are arranged in one row (line) or two rows (lines) in a staggered pattern in a rotation axis direction of a photosensitive drum is known. Further, the optical print head includes a plurality of lenses for converging light beams emitted from the plurality of light emitting elements onto the photosensitive drum. The plurality of lenses are disposed opposite to the surface of the photosensitive drum so as to extend along the arrangement direction of the light emitting elements between the light emitting elements and the photosensitive drum. Light beams emitted from the plurality of light emitting elements are condensed on the surface of the photosensitive drum by the lens. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum.

The photosensitive drum is one of consumables, and is therefore replaced periodically. An operator, such as a user or a maintenance person, can perform maintenance of the image forming apparatus by replacing the replacement unit including the photosensitive drum. The replacement unit is detachable from the image forming apparatus main assembly by being drawn out of the image forming apparatus main assembly, and is mountable in the image forming apparatus main assembly by being inserted into the image forming apparatus main assembly. When the optical print head exposes the photosensitive drum to light, the spacing between the lens and the photosensitive drum surface is only about 3 mm. Therefore, during replacement of the replacement unit, if the optical print head is moved in a direction away from the photosensitive drum, there is a possibility of contact between the optical print head and the photosensitive drum. Therefore, the image forming apparatus employs a configuration in which, in some cases, the optical print head is reciprocated between an exposure position during exposure of the photosensitive drum to light and a separation position at which the optical print head is farther from the photosensitive drum than at the exposure position for mounting and dismounting the replacement unit.

Here, in the image forming apparatus, an exposure device such as an optical print head is provided between the charging device and the developing device in some cases. In order to achieve miniaturization of the image forming apparatus, it is effective to minimize the distance between the photosensitive drum, the optical print head, the charging device, the developing device, and the like. However, at the periphery of the optical print head, toner scatters from the photosensitive drum and the developing device. Therefore, when the scattered toner or the like enters the inside of the optical head, the light emitting element is contaminated, so that there is a possibility that light emitted from the light emitting element is partially blocked. This is one of the causes of the image quality degradation of the output image. Therefore, it is desirable that the lens is mounted on the optical head main body without a gap. As ｃA mounting method between the lens and the optical head main body, for example, there is ｃA configuration disclosed in japanese laid-open patent application (JP- ｃA) 2012-51250.

As shown in fig. 3 of JP-a 2012-51250, the lens array 56 is held by the housing 58 so as to be opposed to the light emitting diode array 62. As shown in fig. 3, the lens array 56 and the housing 58 are adhesively bonded by an encapsulant 70. This prevents toner and the like scattered around the outer periphery from entering the optical head through the gap between the lens array 56 and the housing 58. In a state where the lens array 56 is inserted into the frame, the sealant 70 is applied along the contact portions 78A and 78B, so that the lens array 56 is mounted into the housing 58.

Disclosure of Invention

[ problems to be solved by the invention ]

However, in the structure shown in JP-A2012-51250, there are problems as described below. When the lens array 56 is mounted to the holding member (housing 58), it is necessary to adjust the positioning (arrangement) position of the lens array 56 between the light exit surface of the light emitting element and the photosensitive drum surface. Therefore, in a state where the lens array 56 is held by some holding mechanism, the mounting position of the lens array 56 on the holding member is finely adjusted, and thereafter, the lens array 56 and the holding member are mounted by an adhesive or the like. When the lens array 56 is held, if the lens array 56 is held with respect to the longitudinal direction of the lens array 56, there is a possibility that the lens array 56 is broken. Further, in the method of holding the lens array 56 with respect to the optical axis direction of the lenses, when the lens array 56 is mounted to the holding member, a portion holding the lower surface of the lens array 56 interferes with the upper surface of the holding member. It is necessary to hold a part of both side wall surfaces of the lens array (surfaces intersecting with a direction perpendicular to the rotational axis direction of the photosensitive drum and the optical axis direction of the lens) by some holding mechanism, but in the configuration disclosed in JP-a 2012-51250 (see fig. 1), it is difficult to say that the area of the part of the side wall surface of the lens array exposed from the holding member is sufficient.

Therefore, when the lens array and the holding member are mounted, it is not easy to finely adjust the mounting position thereof in a state where a part of the lens array 56 is held.

[ means for solving problems ]

In view of the above problem, an optical print head of the present invention is an optical print head included in an image forming apparatus, the optical print head including: a light emitting portion in which a plurality of light emitting elements for emitting light that exposes a photosensitive drum included in the image forming apparatus are arranged in a longitudinal direction of the optical print head; a lens array in which a plurality of lenses for condensing light emitted from the plurality of light emitting elements on a surface of the photosensitive drum are arranged along the longitudinal direction; a holding member for holding the light emitting portion and the lens array; a first opposing portion formed by protruding from the holding member toward an exit direction of light with respect to an optical axis direction of the lens, and opposing a first sidewall surface that is a sidewall surface of the lens array on a side with respect to a perpendicular direction perpendicular to both the longitudinal direction and the optical axis direction, wherein the first sidewall surface is adhesively fixed to the first opposing portion; and a second opposing portion formed by protruding from the holding member toward the emission direction, and is opposite to a second side wall surface that is a side wall surface of the lens array on the other side with respect to the vertical direction, wherein the second side wall surface is adhesively fixed to the second opposing portion, wherein the first side wall surface at least on the one end side of one end side and the other end side of the lens array with respect to the longitudinal direction is exposed from an end portion of the first opposing portion with respect to the longitudinal direction, and the second sidewall surface on at least the other one of one end side and the other end side of the lens array with respect to the longitudinal direction is exposed from an end portion of the second opposing portion with respect to the longitudinal direction.

Further, an optical print head of the present invention is an optical print head included in an image forming apparatus, the optical print head including: a light emitting portion in which a plurality of light emitting elements for emitting light that exposes a photosensitive drum included in the image forming apparatus are arranged in a longitudinal direction of the optical print head; a lens array in which a plurality of lenses for condensing light emitted from the plurality of light emitting elements on a surface of the photosensitive drum are arranged along the longitudinal direction; a holding member for holding the light emitting portion and the lens array; a first opposing portion that is formed by protruding from the holding member toward an exit direction of light with respect to an optical axis direction of the lens, and to which a side wall surface of the lens array on a side with respect to a perpendicular direction that is perpendicular to both the longitudinal direction and the optical axis direction is adhesively fixed; and a second opposing portion formed by protruding from the holding member toward the exit direction, and to which a side wall surface of the lens array on the other side with respect to the vertical direction is adhesively fixed, wherein the side wall surface of the lens array with respect to the vertical direction is exposed from any one of an opposite end portion with respect to the longitudinal direction of the first opposing portion and an opposite end portion with respect to the longitudinal direction of the second opposing portion.

Further, an optical print head of the present invention is an optical print head included in an image forming apparatus, the optical print head including: a light emitting portion in which a plurality of light emitting elements for emitting light that exposes a photosensitive drum included in the image forming apparatus are arranged in a longitudinal direction of the optical print head; a lens array in which a plurality of lenses for condensing light emitted from the plurality of light emitting elements on a surface of the photosensitive drum are arranged along the longitudinal direction; a holding member for holding the light emitting portion and the lens array; wherein the holding member includes a first opposing portion that opposes a side wall surface of the lens array on a side with respect to a perpendicular direction that is perpendicular to both a longitudinal direction and an optical axis direction of the lens, and the side wall surface on the side is adhesively fixed to the first opposing portion; and a second opposing portion that opposes a sidewall surface of the lens array on the other side with respect to the vertical direction and to which the sidewall surface on the other side is adhesively fixed, wherein, in at least one opposing portion of the first opposing portion and the second opposing portion, at least a part of the opposing portion is provided with a recessed portion along the vertical direction, and a part of the sidewall surface of the lens array with respect to the vertical direction is exposed from the recessed portion.

Further, an image forming apparatus of the present invention is an image forming apparatus including: a photosensitive drum; and an optical head, wherein the optical head includes a light emitting portion in which a plurality of light emitting elements for emitting light that exposes a photosensitive drum included in the image forming apparatus are arranged in a longitudinal direction of the optical head; a lens array in which a plurality of lenses for condensing light emitted from the plurality of light emitting elements on a surface of the photosensitive drum are arranged along the longitudinal direction; a holding member for holding the light emitting portion and the lens array; a first opposing portion formed by protruding from the holding member toward an exit direction of light with respect to an optical axis direction of the lens, and opposing a first sidewall surface that is a sidewall surface of the lens array on a side with respect to a perpendicular direction perpendicular to both the longitudinal direction and the optical axis direction, wherein the first sidewall surface is adhesively fixed to the first opposing portion; and a second opposing portion formed by protruding from the holding member toward the emission direction, and is opposite to a second side wall surface that is a side wall surface of the lens array on the other side with respect to the vertical direction, wherein the second side wall surface is adhesively fixed to the second opposing portion, wherein the first side wall surface at least on the one end side of one end side and the other end side of the lens array with respect to the longitudinal direction is exposed from an end portion of the first opposing portion with respect to the longitudinal direction, and the second sidewall surface on at least the other one of one end side and the other end side of the lens array with respect to the longitudinal direction is exposed from an end portion of the second opposing portion with respect to the longitudinal direction.

Further, an image forming apparatus of the present invention is an image forming apparatus including: a photosensitive drum; and an optical head, wherein the optical head includes a light emitting portion in which a plurality of light emitting elements for emitting light that exposes a photosensitive drum included in the image forming apparatus are arranged in a longitudinal direction of the optical head; a lens array in which a plurality of lenses for condensing light emitted from the plurality of light emitting elements on a surface of the photosensitive drum are arranged along the longitudinal direction; a holding member for holding the light emitting portion and the lens array; a first opposing portion that is formed by protruding from the holding member toward an exit direction of light with respect to an optical axis direction of the lens, and to which a side wall surface of the lens array on a side with respect to a perpendicular direction that is perpendicular to both the longitudinal direction and the optical axis direction is adhesively fixed; and a second opposing portion formed by protruding from the holding member toward the exit direction, and to which a side wall surface of the lens array on the other side with respect to the vertical direction is adhesively fixed, wherein the side wall surface of the lens array with respect to the vertical direction is exposed from any one of an opposite end portion with respect to the longitudinal direction of the first opposing portion and an opposite end portion with respect to the longitudinal direction of the second opposing portion.

Further, an image forming apparatus of the present invention is an image forming apparatus including: a photosensitive drum; and an optical head, wherein the optical head includes a light emitting portion in which a plurality of light emitting elements for emitting light that exposes a photosensitive drum included in the image forming apparatus are arranged in a longitudinal direction of the optical head; a lens array in which a plurality of lenses for condensing light emitted from the plurality of light emitting elements on a surface of the photosensitive drum are arranged along the longitudinal direction; a holding member for holding the light emitting portion and the lens array; wherein the holding member includes a first opposing portion that opposes a side wall surface of the lens array on a side with respect to a perpendicular direction that is perpendicular to both a longitudinal direction and an optical axis direction of the lens, and the side wall surface on the side is adhesively fixed to the first opposing portion; and a second opposing portion that opposes a sidewall surface of the lens array on the other side with respect to the vertical direction and to which the sidewall surface on the other side is adhesively fixed, wherein, in at least one opposing portion of the first opposing portion and the second opposing portion, at least a part of the opposing portion is provided with a recessed portion along the vertical direction, and a part of the sidewall surface of the lens array with respect to the vertical direction is exposed from the recessed portion.

Further, a manufacturing method of an optical print head of the present invention is a manufacturing method of an optical print head included in an image forming apparatus, the optical print head including: a light emitting portion in which a plurality of light emitting elements for emitting light that exposes a photosensitive drum included in the image forming apparatus are arranged in a longitudinal direction of the optical print head; a lens array in which a plurality of lenses are arranged along the longitudinal direction, each of the plurality of lenses having an incident surface that allows light emitted from the plurality of light emitting elements to be incident thereon and having an exit surface that allows light emitted from the incident surface to be incident thereon, and each of the plurality of lenses condensing light on a surface of the photosensitive drum; a holding member for holding the light emitting portion and the lens array; a first opposing portion formed by protruding from the holding member toward an exit direction of light with respect to an optical axis direction of the lens, and opposing a first sidewall surface that is a sidewall surface of the lens array on a side with respect to a perpendicular direction perpendicular to both the longitudinal direction and the optical axis direction, wherein the first sidewall surface is adhesively fixed to the first opposing portion; and a second opposing portion formed by protruding from the holding member toward the exit direction and opposing a second sidewall surface that is a sidewall surface of the lens array on the other side with respect to the perpendicular direction, wherein the second sidewall surface is adhesively fixed to the second opposing portion; wherein opposite end sides of the first sidewall surface with respect to a longitudinal direction are exposed from end portions of the first opposing portions with respect to the longitudinal direction, respectively, and opposite end sides of the second sidewall surface with respect to the longitudinal direction are exposed from end portions of the second opposing portions with respect to the longitudinal direction, respectively, the manufacturing method of the optical print head includes: a holding step in which the sidewall surfaces on opposite end sides of the lens array with respect to a longitudinal direction are held with respect to a vertical direction by the holding mechanism; an arranging step of inserting the lens array held by the holding mechanism between the first opposing portion and the second opposing portion so that the incident surface and the light emitting portion are opposed to each other, and arranging with respect to the holding member so that the portion held by the holding mechanism is in a state where the portion is exposed from an end portion with respect to the longitudinal direction of the first opposing portion and from an end portion with respect to the longitudinal direction of the second opposing portion; a light receiving step in which the light emitting element is caused to emit light, and light that enters the incident surface and is emitted from the exit surface is received by a light receiving device; an adjustment step of moving the lens array in a state where the lens array is held by the holding mechanism based on a light reception result in the light reception step; and a bonding step of adhesively fixing the lens array adjusted in the interval between the incident surface and the light emitting portion to the first opposing portion and the second opposing portion.

Further, a manufacturing method of an optical print head of the present invention is a manufacturing method of an optical print head included in an image forming apparatus, the optical print head including: a light emitting portion in which a plurality of light emitting elements for emitting light that exposes a photosensitive drum included in the image forming apparatus are arranged in a longitudinal direction of the optical print head; a lens array in which a plurality of lenses are arranged along the longitudinal direction, each of the plurality of lenses having an incident surface that allows light emitted from the plurality of light emitting elements to be incident thereon and having an exit surface that allows light emitted from the incident surface to be incident thereon, and each of the plurality of lenses condensing light on a surface of the photosensitive drum; a holding member for holding the light emitting portion and the lens array; a first opposing portion formed by protruding from the holding member toward an exit direction of light with respect to an optical axis direction of the lens, and opposing a first sidewall surface that is a sidewall surface of the lens array on a side with respect to a perpendicular direction perpendicular to both the longitudinal direction and the optical axis direction, wherein the first sidewall surface is adhesively fixed to the first opposing portion; and a second opposing portion formed by protruding from the holding member toward the exit direction and opposing a second sidewall surface that is a sidewall surface of the lens array on the other side with respect to the perpendicular direction, wherein the second sidewall surface is adhesively fixed to the second opposing portion; wherein at least the first sidewall surface on the one of one end side and the other end side of the lens array with respect to the longitudinal direction is exposed from an end portion in the longitudinal direction of the first opposing portion, and at least the second sidewall surface on the other of the one end side and the other end side of the lens array with respect to the longitudinal direction is exposed from an end portion in the longitudinal direction of the second opposing portion; the manufacturing method of the optical printing head comprises the following steps: a holding step in which the side wall surface of the lens array with respect to the longitudinal direction is held by the holding mechanism; an arranging step of inserting the lens array held by the holding mechanism between the first opposing portion and the second opposing portion so that the incident surface and the light emitting portion are opposed to each other, and arranging with respect to the holding member so that the portion held by the holding mechanism is in a state where the portion is exposed from an end portion with respect to the longitudinal direction of the first opposing portion and from an end portion with respect to the longitudinal direction of the second opposing portion; a light receiving step in which the light emitting element is caused to emit light, and light that enters the incident surface and is emitted from the exit surface is received by a light receiving device; an adjustment step of moving the lens array in a state where the lens array is held by the holding mechanism based on a light reception result in the light reception step; and a bonding step of adhesively fixing the lens array adjusted in the interval between the incident surface and the light emitting portion to the first opposing portion and the second opposing portion.

Further, a manufacturing method of an optical print head of the present invention is a manufacturing method of an optical print head included in an image forming apparatus, the optical print head including: a light emitting portion in which a plurality of light emitting elements for emitting light that exposes a photosensitive drum included in the image forming apparatus are arranged in a longitudinal direction of the optical print head; a lens array in which a plurality of lenses are arranged in the longitudinal direction, each of the plurality of lenses having an incident surface that allows light emitted from the plurality of light emitting elements to be incident thereon and having an exit surface that allows light emitted from the incident surface to be incident thereon, and each of the plurality of lenses condensing the light on a surface of the photosensitive drum; and a holding member for holding the light emitting portion and the lens array; wherein the holding member comprises: a first opposing portion on which a plurality of concave portions are formed in a vertical direction and which opposes a sidewall surface of the lens array on a side with respect to the vertical direction perpendicular to both the longitudinal direction and the optical axis direction of the lenses, wherein the sidewall surface on the side is adhesively fixed to the first opposing portion; and a second opposing portion on which a plurality of concave portions are formed along a vertical direction and which opposes a sidewall surface of the lens array on the other side with respect to the vertical direction, wherein the sidewall surface on the other side is adhesively fixed to the second opposing portion, wherein a portion of the sidewall surface of the lens array with respect to the vertical direction is exposed from the concave portion formed on the first opposing portion and the concave portion formed on the second opposing portion, the manufacturing method of the optical printhead including: a holding step in which the side wall surface of the lens array with respect to the longitudinal direction is held by the holding mechanism; an arrangement step of inserting the lens array held by the holding mechanism between the first opposing portion and the second opposing portion so that the incident surface and the light emitting portion oppose each other, and arranging with respect to the holding member so that the portion held by the holding mechanism is in a state where the portion is exposed from a recessed portion formed on the first opposing portion and a recessed portion formed on the second opposing portion; a light receiving step in which the light emitting element is caused to emit light, and light that enters the incident surface and is emitted from the exit surface is received by a light receiving device; an adjustment step of moving the lens array in a state where the lens array is held by the holding mechanism based on a light reception result in the light reception step; and a bonding step of adhesively fixing the lens array adjusted in the interval between the incident surface and the light emitting portion to the holding member.

Further, a manufacturing method of an optical print head of the present invention is a manufacturing method of an optical print head included in an image forming apparatus, the optical print head including: a light emitting portion in which a plurality of light emitting elements for emitting light that exposes a photosensitive drum included in the image forming apparatus are arranged in a longitudinal direction of the optical print head; a lens array in which a plurality of lenses are arranged in the longitudinal direction, each of the plurality of lenses having an incident surface that allows light emitted from the plurality of light emitting elements to be incident thereon and having an exit surface that allows light emitted from the incident surface to be incident thereon, and each of the plurality of lenses condensing the light on a surface of the photosensitive drum; and a holding member for holding the light emitting portion and the lens array, wherein the holding member includes: a first opposing portion opposing a sidewall surface of the lens array on a side with respect to a perpendicular direction perpendicular to both the longitudinal direction and an optical axis direction of the lens, wherein the sidewall surface on the side is adhesively fixed to the first opposing portion; and a second opposing portion opposing a sidewall surface of the lens array on the other side with respect to the vertical direction, wherein the sidewall surface on the other side is adhesively fixed to the second opposing portion, wherein, in at least one opposing portion of the first opposing portion and the second opposing portion, at least a part of the opposing portion is provided with a recessed portion along the vertical direction, and a part of the sidewall surface of the lens array with respect to the vertical direction is exposed from the recessed portion, the manufacturing method of the optical print head including: a holding step in which the side wall surface of the lens array with respect to the longitudinal direction is held by the holding mechanism; an arrangement step of inserting the lens array held by the holding mechanism between the first opposing portion and the second opposing portion so that the incident surface and the light emitting portion oppose each other, and arranging with respect to the holding member so that the portion held by the holding mechanism is in a state where the portion is exposed from the recessed portion; a light receiving step in which the light emitting element is caused to emit light, and light that enters the incident surface and is emitted from the exit surface is received by a light receiving device; an adjustment step of moving the lens array in a state where the lens array is held by the holding mechanism based on a light reception result in the light reception step; and a bonding step of adhesively fixing the lens array adjusted in the interval between the incident surface and the light emitting portion to the holding member.

[ Effect of the invention ]

According to the optical print head and the imaging apparatus of the present invention, the lens array can be inserted between the first opposing portion and the second opposing portion in a state where both side wall surfaces on both end portions sides of the lens array with respect to the longitudinal direction of the lens array are sandwiched (held) by the sandwiching (holding) mechanism. Therefore, in a state where the lens array is held by the holding mechanism, the mounting position of the lens array with respect to the holding member can be arranged.

Drawings

Fig. 1 is a schematic sectional view of an image forming apparatus.

Fig. 2 includes a perspective view illustrating a drum unit and its outer periphery in the image forming apparatus.

Fig. 3 includes a schematic perspective view of the exposure unit.

Fig. 4 includes a schematic diagram illustrating a substrate, LED chip, or lens array of an optical printhead.

Fig. 5 includes a schematic view for illustrating the holding member, in which the lens array and the substrate are not illustrated.

Fig. 6 includes schematic views of features for respectively showing the shapes of the lens mounting portions.

Fig. 7 is a schematic view for illustrating a method of applying an adhesive to a holding member.

Fig. 8 includes an enlarged view of the lens mounting portion on one end side.

Fig. 9 is a view for illustrating a protrusion of an adhesive for holding a holding member.

Fig. 10 includes a side view of an optical printhead.

Fig. 11 includes views showing states in which the optical print head contacts or retracts from the drum unit, respectively.

Fig. 12 is a perspective view of the bush attached to the rear side of the drum unit.

Fig. 13 includes perspective views of the first support portion and the third support portion.

Fig. 14 includes perspective views of the second supporting portion, the rear side plate, and the exposure unit mounted to the second supporting portion.

Fig. 15 includes a perspective view of the moving mechanism, in which the first support portion is not shown.

Fig. 16 includes a side view of a first linkage of the lambda type.

Fig. 17 includes a schematic perspective view of the exposure unit.

Fig. 18 includes views for illustrating the moving mechanism.

Fig. 19 includes views for illustrating the X-type moving mechanism.

Fig. 20 includes views for illustrating a moving mechanism using a cam mechanism.

Fig. 21 includes a perspective view of the cover.

Fig. 22 includes a perspective view of the cover for illustrating the operation when the cover is closed.

Fig. 23 includes a perspective view of the cover for illustrating an operation when the cover is closed.

Fig. 24 includes a perspective view of the cover for illustrating an operation when the cover is opened.

Fig. 25 includes a perspective view of the cover for illustrating an operation when the cover is opened.

Fig. 26 includes perspective views for illustrating structures on both ends of the holding member.

Fig. 27 is a perspective view for illustrating a structure on the other end portion of the holding member.

Detailed Description

(examples)

(image forming apparatus)

First, a schematic structure of the image forming apparatus 1 will be described. Fig. 1 is a schematic sectional view of an image forming apparatus 1. The image forming apparatus 1 shown in fig. 1 is a color printer (SFP: small function printer) that does not include a reading device, but may be a copying machine that includes a reading device. Further, the present embodiment is not limited to a color image forming apparatus including a plurality of photosensitive drums 103. The present embodiment may also be a color image forming apparatus including a single photosensitive drum 103 or an image forming apparatus for forming a monochrome image.

The image forming apparatus 1 shown in fig. 1 includes four image forming portions 102Y, 102M, 102C, and 102K (hereinafter also collectively referred to simply as "image forming portions 102") for forming toner images of yellow, magenta, cyan, and black. The image forming portions 102Y, 102M, 102C, and 102K include photosensitive drums 103Y, 103M, 103C, and 103K (hereinafter also collectively referred to simply as "photosensitive drums 103"). Further, the image forming portions 102Y, 102M, 102C, and 102K include charging devices 104Y, 104M, 104C, and 104K (hereinafter also collectively referred to simply as "charging devices 104") for charging the photosensitive drums 103Y, 103M, 103C, and 103K. The image forming portions 102Y, 102M, 102C, and 102K further include LED (light emitting diode, hereinafter described as LED) exposure units 500Y, 500M, 500C, and 500K (hereinafter also collectively referred to simply as "exposure units 500") as light sources for emitting light (beams) to which the photosensitive drums 103Y, 103M, 103C, and 103K are exposed. Further, the image forming portions 102Y, 102M, 102C, and 102K include developing devices 106Y, 106M, 106C, and 106K (hereinafter also collectively referred to simply as "developing devices 106") each for developing an electrostatic latent image on the photosensitive drum 103 with toner into a toner image of an associated color on the photosensitive drum 103. Y, M, C and K added to the reference numerals represent colors of the toner.

The image forming apparatus 1 includes an intermediate transfer belt 7 to which a toner image formed on the photosensitive drum 103 is to be transferred, and primary transfer rollers 108(Y, M, C, K) for successively transferring the toner image formed on the photosensitive drum 103 of the corresponding image forming portion 102 onto the intermediate transfer belt 107. The image forming apparatus 1 further includes a secondary transfer roller 109 for transferring the toner image from the intermediate transfer belt 107 onto the recording paper P fed from the sheet (paper) feeding portion 101, and a fixing device 100 for fixing the secondary-transferred toner image on the recording paper P.

(Drum Unit)

Next, a drum unit 518(Y, M, C, K) and a developing unit 641(Y, M, C, K), which are examples of replacement units that can be mounted in and dismounted from the image forming apparatus 1 according to the present embodiment, will be described. Part (a) of fig. 2 is a schematic perspective view of the outer peripheries of the drum unit 518 and the developing unit 641. Part (b) of fig. 2 is a view showing a state in which the drum unit 518 is inserted into the image forming apparatus 1 from the outside of the apparatus main assembly.

As shown in part (a) of fig. 2, the image forming apparatus 1 includes a front side plate 642 and a rear side plate 643 formed of metal plates. The front side plate 642 is a side wall disposed on the front (surface) side of the image forming apparatus 1. On the other hand, the rear side plate 643 is a side wall provided on the rear (surface) side of the image forming apparatus 1. As shown in part (a) of fig. 2, a front side plate 642 and a rear side plate 643 are disposed opposite to each other, and a metal plate, not shown, as a beam is bridged between the front side plate and the rear side plate. Each of the front side plate 642, the rear side plate 643 and a beam not shown constitutes a part of the frame of the imaging apparatus 1.

The front side plate 642 is provided with an opening through which the drum unit 518 and the developing unit 641 can be inserted and extracted. The drum unit 518 and the developing unit 641 are mounted at a predetermined position (mounting position) of the main assembly of the image forming apparatus 1 through an opening. Further, the image forming apparatus 1 includes a cover 558(Y, M, C, K) for covering the front side of the drum unit 518 and the developing unit 641 mounted at the mounting position. One end portion of the cover 558 is fixed to the main assembly of the image forming apparatus 1 by a hinge, whereby the cover 518 is rotatable relative to the main assembly of the image forming apparatus 1. An operator for performing maintenance opens the cover 558 and takes out the drum unit 518 or the developing unit 641 from the image forming apparatus 1, and then inserts a new drum unit 518 or a new developing unit 641 into the image forming apparatus 1 and closes the cover 558, thereby completing the unit replacement operation. The cover 558 will be described in further detail below.

As shown in fig. 2 (a) and (b), in the following description, a front side panel 642 side and a rear side panel 643 side are defined as a front side and a rear side, respectively. Further, when the position of the photosensitive drum 103K on which the electrostatic latent image relating to the black toner image is formed is taken as a reference (position), the side on which the photosensitive drum 103Y on which the electrostatic latent image relating to the yellow toner image is formed is disposed is defined as the right side. Further, when the position of the photosensitive drum 103Y is taken as a reference (position), the side on which the photosensitive drum 103K is disposed is defined as the left side. Further, with respect to the directions perpendicular to the front-rear direction and the left-right direction, an upward direction in the vertical direction is defined as an upward direction, and a downward direction in the vertical direction is defined as a downward direction. The above-defined front, rear, right, left, upper and lower directions are shown in part (b) of fig. 2. Further, in the following description, with respect to the rotational axis direction of the photosensitive drum 103, one end side represents a front side, and the other end side represents a rear side. Further, one end side and the other end side with respect to the front-rear direction also correspond to the front side and the rear side, respectively. Further, with respect to the left-right direction, one end side represents a right side, and the other end side represents a left side.

In the image forming apparatus 1 of the present embodiment, a drum unit 518 is mounted. The drum unit 518 is a cartridge to be replaced. Drum unit 518 of the present embodiment includes photosensitive drum 103 rotatably supported by a housing of drum unit 518. The drum unit 518 includes the photosensitive drum 103, the charging device 104, and a cleaning device not shown. When photosensitive drum 103 reaches the end of its life, for example, due to abrasion by cleaning by a cleaning means, an operator for performing maintenance takes out drum unit 518 from the apparatus main assembly as shown in part (b) of fig. 2, and replaces photosensitive drum 103. The drum unit 518 may also have a configuration in which the charging device 104 and the cleaning device are not provided and the photosensitive drum 103 is provided.

In the image forming apparatus 1 of the present embodiment, a developing unit 641, which is a member separated from the drum unit 518, is mounted. The developing unit 641 includes the developing device 106 shown in fig. 1. The developing device 106 includes a developing sleeve, which is a developer carrying member for carrying a developer. The developing unit 641 is provided with a plurality of gears for rotating a screw for stirring the toner and the carrier. When these gears are aged and damaged, the operator for performing maintenance takes out the developing unit 641 from the apparatus main assembly of the image forming apparatus 1. The developing unit 641 of the present embodiment is a cartridge which is an integrally assembled unit of the developing device 106 including the developing sleeve and the toner containing portion provided with the screw. In addition, the embodiment of the drum unit 518 and the developing unit 641 may also be a process cartridge as an integrally assembled unit of the drum unit 518 and the developing unit 641 described above.

(image formation Process)

Next, an imaging process will be described. An optical print head 105Y described later exposes the surface of the photosensitive drum 103Y charged by the charging device 104Y to light. Thereby, an electrostatic latent image is formed on the photosensitive drum 103Y. Then, the developing device 106Y develops the electrostatic latent image formed on the photosensitive drum 103Y with yellow toner. The yellow toner image into which the electrostatic latent image is developed on the photosensitive drum 103Y is transferred onto the intermediate transfer belt 107 by the primary transfer roller 108Y at the primary transfer portion Ty. Magenta, cyan, and black toner images are also transferred onto the intermediate transfer belt 107 by a similar image forming process.

The toner images of the respective colors transferred on the intermediate transfer belt 107 are conveyed to the secondary transfer portion T2 by the intermediate transfer belt 107. A transfer bias for transferring the toner image onto the recording paper P is applied to a secondary transfer roller 109 provided at the secondary transfer portion T2. The toner image conveyed to the secondary transfer portion T2 is transferred onto the recording paper P fed from the sheet (paper) feeding portion 101 by a transfer bias applied to the secondary transfer roller 109. The recording paper P to which the toner image is transferred is conveyed to the fixing device 100. The fixing device 100 fixes the toner image on the recording paper P by heat and pressure. The recording paper P subjected to the fixing process by the fixing device 100 is discharged onto a sheet (paper) discharge portion 111.

(Exposure apparatus)

Next, the exposure unit 500 including the optical print head 105 will be described. Here, as an example of an exposure type employed in an image forming apparatus of an electrophotographic type, there is a laser beam scanning exposure type in which a photosensitive drum is scanned with a light beam emitted from a semiconductor laser by a rotating polygon mirror or the like, and the photosensitive drum is exposed to the light beam by an f- θ lens or the like. The "optical print head 105" described in the present embodiment is used for an LED exposure type in which the photosensitive drum 103 is exposed to light by using a light emitting element such as an LED or the like arranged along the rotational axis direction of the photosensitive drum 103, and thus is not used for the above-described laser beam scanning exposure type. Part (a) of fig. 3 is a schematic perspective view of the exposure unit 500 provided in the imaging apparatus 1 of the present embodiment. Part (b) of fig. 3 is a view of the exposure unit 500 shown in part (a) of fig. 3 as viewed from the lower side. Fig. 4 includes a schematic cross-sectional view of the exposure unit 500 shown in fig. 3 and the photosensitive drum 103 disposed on the upper side of the exposure unit 500 cut along the surface perpendicular to the rotational axis direction of the photosensitive drum 103. The exposure unit 500 includes the optical print head 105 and the moving mechanism 640. The optical print head 105 includes a lens array 506, a substrate 502 (light emitting portion), a holding member 505 for holding the lens array 506, contact pins 514, and contact pins 515. The moving mechanism 640 includes a link member 651, a link member 652, a slidable portion 525, a first support portion 527, a second support portion 528, and a third support portion 526. Here, in the present embodiment, the contact pins 514 and 515 are cylindrical pins, but the shape is not limited to a cylindrical shape, and may be, for example, a prism shape, a conical shape, or the like in which the diameter is reduced toward the end portion thereof. Further, one of the contact pin 514 and the contact pin 515 may be a member having a function similar to that of a pin, instead of a pin, or may be, for example, a protrusion protruding toward the upper side and the lower side of the holding member 505.

First, the holding member 505 will be described. The holding member 505 is a holder that holds the substrate 502, the lens array 506, the contact pins 514, and the contact pins 515. In the present embodiment, as an example, the length of the contact pin 514 protruding from the upper surface of the holding member 505 is 7mm, the length of the contact pin 515 protruding from the upper surface of the holding member 505 is 11mm, the length of the contact pin 514 protruding from the lower surface of the holding member 505 is 22mm, and the length of the contact pin 515 protruding from the lower surface of the holding member 505 is 22 mm. As shown in fig. 4, the holding member 505 includes a lens mounting portion 701 on which the lens array 506 is mounted and a substrate mounting portion 702 on which the substrate 502 is mounted. Further, although described later specifically, the holding member 505 includes a spring mounting portion 661(662) and a pin mounting portion 632 (633). The holding member 505 is a mold made of resin prepared by integrally injection-molding the lens mounting portion 701, the substrate mounting portion 702, the spring mounting portion 661, and the spring mounting portion 662. In addition, the material of the holding member is not limited to resin, but may be made of metal, for example.

As shown in part (b) of fig. 3, the spring mounting portion 661 on which the link member 651 is mounted is provided on the more front side than both the front side end portion of the lens array 506 and the front side end portion of the substrate 502, and is provided on the more rear side than the pin mounting portion 632. Further, the spring mounting portion 662 on which the link member 652 is mounted is provided on the more rear side than both the rear-side end portion of the lens array 506 and the rear-side end portion of the substrate 502, and is provided on the more front side than the pin mounting portion 633. That is, the holding member 505 is supported by the link member 651 between the lens array 506 and the contact pins 514 in the front-rear direction, and is supported by the link member 652 between the lens array 506 and the contact pins 515 in the front-rear direction. A portion in which the urging force is applied to the holding member 505 by the link member 651 and the link member 652 does not overlap with the lens array 506 with respect to the up-down direction, and therefore, flexure of the lens array 506 due to the urging force is reduced.

Fig. 4 includes a schematic cross-sectional view of the exposure unit 500 shown in fig. 3 and the photosensitive drum 103 disposed on the upper side of the exposure unit 500 cut along the surface perpendicular to the rotational axis direction of the photosensitive drum 103.

The lens mounting portion 701 is formed to protrude upward from the holding member 505. In other words, the lens mounting portion 701 is formed to protrude in the optical axis direction of the lens from the holding member 505 toward the exit direction of light emitted from the light emitting element. The lens mounting portion 701 includes a first inner wall surface 507 (first opposing portion) and a second inner wall surface 508 (second opposing portion). The first inner wall surface 507 extends in the longitudinal direction of the holding member 505, and the second inner wall surface 508 extends in the longitudinal direction of the holding member 505. The first inner wall surface 507 is provided on one side of the holding member 505 with respect to the vertical direction (the direction perpendicular to both the longitudinal direction of the lens array 506 and the optical axis direction of the lenses), and the second inner wall surface 508 is provided on the other side of the holding member 505 with respect to the vertical direction (the direction perpendicular to both the longitudinal direction of the lens array 506 and the optical axis direction of the lenses). That is, when the lens array 506 is detached from the lens mounting portion 701, the first inner wall surface 507 and the second inner wall surface 508 are opposed to each other in the left-right direction. During assembly of the optical print head 105, the lens array 506 is inserted between the first inner wall surface 507 and the second inner wall surface 508. Then, an adhesive is applied between the first inner wall surface 507 and a side wall surface (first side wall surface) of the lens array 506 opposite to the first inner wall surface 507, and an adhesive is applied between the second inner wall surface 508 and a side wall surface (second side wall surface) of the lens array 506 opposite to the second inner wall surface 508. Thereby, the lens array 506 is fixed to the holding member 505. The exposure unit 500 is disposed on a side below the rotation axis of the photosensitive drum 103 with respect to the vertical direction, and the LED503 of the optical print head 105 exposes the photosensitive drum 103 to light from below. In addition, the exposure unit 500 may also have a configuration in which the exposure unit 500 is disposed on a side above the rotation axis of the photosensitive drum 103 with respect to the vertical direction, and the LED503 of the optical print head 105 exposes the photosensitive drum 103 to light from above. Further, the adhesive referred to herein may also be an adhesive having a sealing function for preventing powder such as toner or dust from entering the inside of the holding member 505. That is, the adhesive in the present embodiment may also be an adhesive whose main purpose is to seal the gap between the lens array 506 and the holding member 505 and adhesively bond the lens array 506 and the holding member 505 to each other as auxiliary functions thereof.

Next, the substrate 502 held by the holding member 505 will be described. Part (a) of fig. 4 is a schematic perspective view of the substrate 502. Part (b1) of fig. 4 is a schematic diagram showing the arrangement of the plurality of LEDs 503 provided on the substrate 502, and part (b2) of fig. 4 is an enlarged view of part (b1) of fig. 4.

An LED chip 639 is mounted on the substrate 502. As shown in part (a) of fig. 4, an LED chip 639 is provided on one surface of the substrate 502, and a connector 504 is provided on the back surface side of the substrate 502. Electrical wiring for supplying signals to the respective LED chips 639 is provided on the substrate 502. One end of a Flexible Flat Cable (FFC), not shown, is connected to the connector 504. A substrate is provided in the main assembly of the image forming apparatus 1. The substrate 502 includes a controller and a connector. The other end of the FFC is connected to a connector. Control signals are input to the substrate 502 from a controller of the main assembly of the image forming apparatus 1 through the FFC and the connector 504. The LED chips 639 are driven by control signals input to the substrate 502.

The LED chip 639 mounted on the substrate 502 will be described in further detail. As shown in parts (b1) and (b2) of fig. 4, a plurality of LED chips 639-1 to 639-29(29 LED chips) in which a plurality of LEDs 503 are arranged are provided on one surface of a substrate 502. On each of the LED chips 639-1 to 639-29, 516 LEDs (light emitting elements) are arranged in a row along the longitudinal direction of the LED chip 639. With respect to the longitudinal direction of the LED chips 639, the center distance k2 between adjacent LEDs corresponds to the resolution of the imaging device 1, the resolution of the imaging device 1 is 1200dpi, and therefore, in the longitudinal direction of the LED chips 639-1 to 639-29, the LEDs are arranged in rows such that the center distance of the LEDs is 21.16 μm. Therefore, in the present embodiment, the exposure range of the optical print head 105 is about 316 mm. The photosensitive layer on the photosensitive drum 103 is formed to have a width of 316mm or more. The length of the long side of the a 4-size recording paper and the length of the short side of the A3-size recording paper are 297mm, and therefore, the optical head 105 in this embodiment has an exposure range in which images can be formed on the a 4-size recording paper and the A3-size recording paper.

The LED chips 639-1 to 639-29 are alternately arranged in two rows along the rotational axis direction of the photosensitive drum 103. That is, as shown in part (b1) of fig. 4, odd-numbered LED chips 639-1, 639-3,. 639-29 counted from the left side are mounted on the substrate 502 in line with the longitudinal direction, and even-numbered LED chips 639-2, 639-4,. 639-28 counted from the left side are mounted on the substrate 502 in line with the longitudinal direction. By disposing the LED chips 639 in this manner, as shown in part (b2) of fig. 4, with respect to the longitudinal direction of the LED chips 639, a center distance k1 between one end portion of one of the adjacent (different) LED chips 639 (e.g., 639-1) and the other end portion of the other of the adjacent LED chips 639 (e.g., 639-2) may be equal to a center distance k2 between the adjacent LEDs on one of the LED chips 639 (e.g., 639-1).

In addition, in the present embodiment, a configuration using an LED as an exposure light source is described as an example, but an organic EL (electroluminescence) device may also be used as an exposure light source.

Next, the lens array 506 will be described. Part (c1) of fig. 4 is a schematic diagram of the lens array 506 viewed from the photosensitive drum 103 side. Further, part (c2) of fig. 4 is a schematic perspective view of the lens array 506. As shown in part (c1) of fig. 4, the plurality of lenses are arranged in two rows in the arrangement direction of the plurality of LEDs 503. The lenses are alternately arranged such that one of the lenses arranged in the other row contacts both of the adjacent lenses arranged in the arrangement direction of the lenses arranged in the above-indicated one row with respect to the arrangement direction of the lenses arranged in the one row. Each lens is a cylindrical rod lens made of glass, and has an incident surface into which light emitted from the LED503 enters and an exit surface from which light entering from the incident surface is emitted. In addition, the material of the lens is not limited to glass, but may be plastic. Further, the shape of the lens is not limited to a cylindrical shape, but may also be a polygonal prism shape such as a hexagonal prism shape.

A broken line Z shown in part (c2) of fig. 4 indicates the optical axis of the lens. The optical print head 105 is moved by the above-described moving mechanism 640 in a direction substantially along the optical axis of the lens indicated by the broken line Z. The optical axis of the lens referred to herein refers to a line connecting the center of the light emitting (exit) surface of the lens and the focal point of the lens. As shown in fig. 4, emitted light emitted from the LEDs enters the lenses of the lens array 506. The light entering the lens is condensed on the surface of the photosensitive drum 103. During assembly of the optical print head 105, the mounting position of the lens array 506 with respect to the lens mounting portion 701 is adjusted so that the distance between the light emitting surface of the LED and the light incident surface of the lens and the distance between the light emitting surface of the lens and the surface of the photosensitive drum 103 are substantially equal to each other.

Next, using fig. 5 to 8, a mounting method between the substrate 502, the lens array 506, and the holding member 505 will be specifically described.

First, a mounting method between the lens array 506 and the holding member 505 will be described.

Part (a) of fig. 5 is a view of the front side of the holding member 505 as viewed from the lower side. The substrate 502 and the lens array 506 are not shown. As shown in part (a) of fig. 5, a through hole 906 extending in the longitudinal direction of the holding member 505 is formed in the holding member 505. In other words, the holding member 505 is provided with the through hole 906 in which the lens array 506 is engaged. Although described in detail later, in a state where the lens array 506 is inserted into the through hole 906, the mounting position of the lens array 506 with respect to the holding member 505 is adjusted. Thereafter, an adhesive 907 is applied to a boundary portion between the lens array 506 and the holding member 505, so that the lens array 506 and the holding member 505 are adhesively fixed to each other. At this time, it is not necessary to apply an adhesive in the entire area of the boundary portion, but the lens array 506 and the holding member 505 may also be fixed by being discretely bonded at several portions.

Part (b1) of fig. 5 is a schematic perspective view of the front side of the holding member 505, in which the lens array 506 is not shown, and part (b2) of fig. 5 is a view of the holding member 505 as viewed from the front side in a cross-sectional view of the holding member 505 cut along a surface perpendicular to the rotational axis direction of the photosensitive drum 103, in which the lens array 506 is not shown. Further, part (c1) of fig. 5 is a schematic perspective view of the front side of the holding member 505 in which the lens array 506 is adhesively fixed, and part (c2) of fig. 5 is a view of the holding member 505 as viewed from the front side in a cross-sectional view of the holding member 505 cut along a surface perpendicular to the rotational axis direction of the photosensitive drum 103 in which the lens array 506 is adhesively fixed. As shown in parts (b1) and (b2) of fig. 5, a lens mounting part 701, on which the lens array 506 is mounted, is formed on the upper side of the holding member 505. The lens mounting portions 701 are formed in the front-rear direction along the edges of the through holes 906 at positions opposite to each other with respect to the left-right direction across the through holes 906. Further, as shown in parts (b1) and (b2) of fig. 5, the lens mounting portion 701 includes a first inner wall surface 507, a second inner wall surface 508, a first inclined surface 703, and a second inclined surface 704. The first inner wall surface 507 and the second inner wall surface 508 are arranged at opposite positions with respect to the left-right direction. On the other upper side of the first inner wall surface 507 and the second inner wall surface 508, the first inclined surface 703 and the second inclined surface 704 are inclined outward with respect to the left-right direction toward the upper side. As shown in parts (c1) and (c2) of fig. 5, the lens array 506 is inserted into the through hole 906 from the upper side such that the right side (one side) side wall surface (first side wall surface) is in a position opposite to the first inner wall surface 507 and such that the left side (other side) side wall surface (second side wall surface) is in a position opposite to the second inner wall surface 508. That is, two side wall surfaces of the lens array 506 with respect to the left-right direction (short side direction) are opposed to the first inner wall surface 507 and the second inner wall surface 508, respectively. The lens array 506 inserted into the through hole 906 is adhesively fixed in a state where a part thereof protrudes upward from the lens mounting portion 701. Bonding between the lens array 506 and the lens mounting portion 701 of the holding member 505 is performed by applying an adhesive 907 to the first inclined surface 703 and the second inclined surface 704 in a state where the lens array 506 is inserted into the through hole 906. Therefore, the surface to which the adhesive 907 is applied is inclined so as to approach the sidewall surface of the lens array 506 toward the lower side, so that the applied adhesive 907 flows toward the lens array 506 along the first inclined surface 703 (the second inclined surface 704) due to its own weight. Therefore, the lens array 506 and the lens mounting portion 701 of the holding member 505 are easily coupled to each other.

Here, in the present embodiment, the first inner wall surface 507 (the second inner wall surface 508) and the first inclined surface 703 (the second inclined surface 704) are described as continuous surfaces, but as shown in part (d) of fig. 5, other surfaces may be provided between the first inner wall surface 507 (the second inner wall surface 508) and the first inclined surface 703 (the second inclined surface 704).

Part (d) of fig. 5 is a view for illustrating a structure in which the lens mounting portion 701 of the holding member 505 is provided with a first bottom portion 715 between the first inclined surface 703 and the first inner wall surface 507 and a second bottom portion 716 between the second inclined surface 704 and the second inner wall surface 508. The first bottom portion 715 is a surface substantially perpendicular to the optical axis direction of the lens, and is formed from an upper end portion of the first inner wall surface 507 to a lower end portion of the first inclined surface 703. Further, the second bottom portion 716 is also a surface perpendicular to the optical axis direction of the lens, and is formed from the upper end of the second inner wall surface 508 to the lower end of the second inclined surface 704. In a state where the lens array 506 is inserted into the through hole 906, an adhesive 907 is applied to the first bottom portion 715 and the second bottom portion 716, so that the lens array 506 and the lens mounting portion 701 of the holding member 505 are adhesively fixed. Therefore, by providing the first bottom portion 715 and the second bottom portion 716, a space in which the adhesive 907 flows is widened as compared with a case where these portions are not provided, and therefore, the adhesive 907 can easily flow into the space.

Next, a mounting method between the substrate 502 and the holding member 505 will be described using parts (a) and (b2) of fig. 5. As shown in part (a) of fig. 5, an opening 908 for allowing insertion of the substrate 502 is formed in the lower side of the holding member 505. A substrate contact portion 911, with which a portion of the substrate 502 contacts when the substrate 502 is inserted into the opening 908 from the lower side of the holding member 505, is formed inside the opening 908. As shown in part (b2) of fig. 5, substrate contact portions 911 are formed on the substrate mounting portions 702 formed on the left and right sides of the holding member 505, respectively. The width with respect to the left-right direction between the substrate contact portions 911 at the two portions (sides) is narrower than the width with respect to the left-right direction of the substrate 502. Therefore, when the substrate 502 is inserted into the opening 908 from the lower side of the holding member 505, the end portions of the substrate 502 on both sides with respect to the left-right direction contact the substrate contact portion 911, so that the mounting position of the substrate 502 with respect to the holding member 502 is determined.

In a state where the substrate 502 whose mounting position is determined contacts the substrate contact portion 911, an adhesive 907 is applied to a boundary portion between the substrate 502 and the substrate mounting portion 702. Thereby, the substrate 502 and the substrate mounting portion 702 are adhesively fixed to each other.

Next, a method of adjusting the mounting position of the lens array 506 with respect to the lens mounting portions 701 when the lens array 506 is mounted between the lens mounting portions 701 of the holding member 505 will be described using portions (a) - (c) of fig. 6.

Parts (a) - (c) of fig. 6 are schematic views of the holding member 505 in a state where the lens array 506 is inserted into the through hole 906 as viewed from the right side of the holding member 505.

Part (a) of fig. 6 is a schematic view of the holding member 505 in the present embodiment. According to part (a) of fig. 5, the distance from the front side end portion to the rear side end portion of the lens mounting portion 701 is shorter than the distance from the front side end portion to the rear side end portion of the lens array 506. Thus, the lens array 506 inserted into the through hole 906 of the holding member 505 is exposed from the lens mounting portion 701 on the front and rear sides (exposed portion 912). Further, as shown in part (a) of fig. 6, the front and rear sides of the lens mounting portion 701 have an inclined structure such that the lens mounting portion 701 is inclined downward toward the end portion. The tilt structure will be described later in detail.

The reason why the exposed portion 912 is provided is that when the lens array 506 is moved for positional adjustment of the lens array 506 with respect to the holding member 505, an area for reliably holding the lens array 506 is ensured. The distance from the light emitting point of the LED503 provided on the substrate 502 to the incident surface of the LED503 of the lens array 506, where the light enters, is determined at the completion of lens manufacturing, and when manufacturing errors and the like are taken into consideration, it is difficult to say that all lenses provide the same value with respect to their values. Therefore, during the assembly of the optical print head 105, the mounting position of the lens array 506 needs to be adjusted so that the distance from the light emitting point of the LED503 to the incident surface of the lens array 506 where the light of the LED503 enters is an appropriate distance. Thus, for example, in a state where the exposed portion 912 of the lens array 506 is held by a holding mechanism of an assembly device or the like, the lens array 506 is inserted into the through hole 906, and the mounting position of the lens array 506 with respect to the holding member 505 is adjusted. As an example of the holding mechanism, there is a structure in which both side wall surfaces of the lens array 506 are sandwiched by being pressed from the left-right direction or a structure in which both side wall surfaces of the lens array 506 are attracted from the left-right direction. In the case where the lens array 506 is held by attraction, only one of the two sidewall surfaces of the lens array 506 may also be held by attraction. That is, both sidewall surfaces of the lens array 506 do not necessarily need to be exposed. For example, a configuration may also be adopted such that the side wall surface of the lens array 506 on one side is exposed from the first inner wall surface 507 and the side wall surface of the lens array 506 on the other side is not exposed from the second inner wall surface 508. Further, a configuration may also be adopted in which the side wall surface of the lens array 506 on one side is exposed only from the front side end portion out of the front side end portion and the rear side end portion of the first inner wall surface 507, and the side wall surface of the lens array 506 on the other side is exposed only from the rear side end portion out of the front side end portion and the rear side end portion of the second inner wall surface 508.

Next, a manufacturing method of the optical print head 105 will be specifically described. First, the exposed portion 912 of the lens array 506 is gripped from the left-right direction by the holding mechanism (holding step). The clamped lens array 506 is inserted into the through hole 906 of the holding member 505 from the upper side (arranging step). At this time, the exposed portion 912 is exposed from both the front end portion and the rear end portion of the lens mounting portion 701, and thus the holding mechanism and the holding member 505 are not in contact with each other. Then, the LED503 provided on the substrate 502 arranged at the position in contact with the substrate contact portion 911 emits light in a state where the lens array 506 is inserted into the through hole 906. The light emitted from the lens array 506 is received by a light receiving device or the like (light receiving step), and according to the light receiving result, the interval (gap) between the lens array 506 and the substrate 502, that is, the mounting position of the lens array 506 with respect to the holding member 505 is adjusted while moving the lens array 506 in the up-down direction (adjusting step). After the adjustment is finished, the lens array 506 and the holding member 505 are adhesively fixed to each other with an adhesive 907.

In addition, the exposed portion 912 is not limited to the portion shown in the portion (a) of fig. 6, but may also be a portion shown by a dotted line in the portion (b) of fig. 6.

In part (b) of fig. 6, both the front end side and the rear end side of the lens mounting portion 701 are stepped portion shapes, and the upper surface of the lens mounting portion 701 is spaced farther from the photosensitive drum 103 at a position closer to the end portion. Thereby, a part of the lens array 506 is exposed on each of the front end side and the rear end side of the lens mounting portion 701 (exposed portion 922). The exposed portion 922 is sandwiched from the left-right direction by the holding mechanism, and the mounting position of the lens array 506 with respect to the holding member is finely adjusted. Thereafter, the lens array 506 and the holding member 505 are adhesively fixed to each other with an adhesive 907.

Further, part (c) of fig. 6 is a configuration in which a concave portion is formed in the left-right direction on the upper surface of the lens mounting portion 701. Thus, as shown in part (c) of fig. 6, the side wall surfaces of the lens array 506 on the left and right sides are exposed from the concave portion (exposed portion 932). The exposed part 932 is held from the left-right direction by the holding mechanism, so that the mounting position of the lens array 506 with respect to the holding member 505 is finely adjusted. Thereafter, the lens array 506 and the holding member 505 are adhesively fixed to each other by the adhesive 907. Here, the concave portion is not necessarily formed on both the first inner wall surface 507 and the second inner wall surface 508. For example, a plurality of concave portions may be formed only on the first inner wall surface 507. The side wall surface of the lens array 506 exposed from the concave portion is held by the holding mechanism by suction.

Next, an application method of the adhesive 907 when the lens array 506 is mounted between the lens mounting portions 701 will be described using fig. 7.

Fig. 7 is an example of a state in which the lens array 506 is inserted into the through hole 906 of the holding member 505. As shown in fig. 7, when the lens array 506 is adhesively fixed between the lens mounting portions 701, the tip of the dispenser 645 for ejecting (discharging) the adhesive 907 is directed between the lens array 506 and the first inclined surface 703 and between the lens array 506 and the second inclined surface 704. In addition, as in the example of the holding member 505 shown in fig. 7, in the case where the holding member 505 includes a first bottom portion 715 and a second bottom portion 716, the top end of the dispenser 645 may also be directed toward the first bottom portion 715 and the second bottom portion 716. In this state, the dispenser 645 moves in the longitudinal direction (arrow direction in the drawing) of the lens array 506 while spraying the adhesive. Thereby, the adhesive 907 is made to flow between the sidewall surface of the lens array 506 and the first inclined surface 703 and between the sidewall surface of the lens array 506 and the second inclined surface 704. In addition, the movement of the dispenser 645 may be performed automatically by the assembly device, or may be performed manually by an assembly operator.

In a state where the lens array 506 is interposed between the first inner wall surface 507 and the second inner wall surface 508, a gap of about 0.2mm may be formed between the first inner wall surface 507 and a sidewall surface (first sidewall surface) of the lens array 506, and a gap of about 0.2mm may also be formed between the second inner wall surface 508 and a sidewall surface (second sidewall surface) of the lens array 506. That is, the holding member 505 is designed such that the difference between the width of the space between the first inner wall surface 507 and the second inner wall surface 508 and the thickness of the lens array 506 is about 0.4 mm. In other words, the first inner wall surface 507 and the side wall surface (first side wall surface) are opposed to each other with a gap of 0.2 mm. Further, the second inner wall surface 508 and the side wall surface (second side wall surface) of the lens array 506 are opposed to each other with a gap of 0.2 mm. As described above, the first inner wall surface 507 and the side wall surface (first side wall surface) of the lens array 506 and the second inner wall surface 508 and the side wall surface (second side wall surface) of the lens array 506 are respectively close to and opposite to each other. Thereby, the adhesive sprayed between the lens array 506 and the first inclined surface 703 and between the lens array 506 and the second inclined surface 704 does not fall down in the vertical direction from between the first inner wall surface 507 and the side wall surface (first side wall surface) of the lens array 506 and from between the second inner wall surface 508 and the side wall surface (second side wall surface) of the lens array 506.

Part (a) of fig. 8 is an enlarged view of the front side of the lens mounting portion 701 of the holding member 505 in the present embodiment. As described above, the front side of the lens mounting portion 701 is inclined downward toward the end portion (inclined portion 904). Although not shown in part (a) of fig. 8, the rear side of the lens mounting portion 701 also has the same structure. By providing the inclined portion 904, the adhesive 907 flows obliquely along the inclined portion 904 under its own weight. Thus, on the front and rear sides of the lens mounting portion 701, an effect of preventing application (coating) failure of the adhesive 907 can be expected.

Further, as shown in part (b) of fig. 8, a groove portion 903 is formed at a portion of the upper surface of the holding member 505 that overlaps with the exposed portion 912 of the lens array 506. The groove portion 903 is formed and extends in a direction intersecting the front-rear direction of the holding member 505. The groove portion 903 is provided directly below the inclined portion 904, so that the adhesive 907 flowing and falling along the inclination is accumulated in the groove portion 903. Thereby, the adhesive 907 can be prevented from flowing and falling from the holding member 505 toward the outer periphery thereof.

Further, as a configuration in which the adhesive 907 is held on the holding member 505, a configuration shown in fig. 9 may also be considered. As shown in fig. 9, on the upper side surface of the holding member 505, on the right and left sides of the through hole 906, there are formed protruding portions 913 protruding upward. The adhesive 907 overflowing between the lens array 506 and the first inclined surface 703 (second inclined surface 704) stays between the lens array 506 and the protrusion 913. In order to cause the adhesive 907 overflowing between the lens array 506 and the first inclined surface 703 (second inclined surface 704) to reliably stay on the holding member 505, it is desirable that the upper end portion of the protrusion 913 is at a position closer to the photosensitive drum 103 than the light emitting surface of the lens array 506.

From here on, the necessity of movement of the optical print head 105 will be described. As described with reference to fig. 2, when the drum unit 518 is replaced, the image forming apparatus 1 of the present embodiment slides (moves) the drum unit 518 toward the front side of the apparatus main assembly in the rotational axis direction of the photosensitive drum 103. When the drum unit 518 is moved in a state where the optical print head 105 is positioned near the surface of the photosensitive drum 103, the optical print head 105 contacts the photosensitive drum 103 that is slid (moved), so that the surface of the photosensitive drum 103 to be mounted is damaged. Further, the lens array 506 contacts the frame of the drum unit 518, so that the lens array 506 is damaged. For this reason, a structure is adopted in which the optical head 105 reciprocates between an exposure position (part (a) of fig. 10) where the photosensitive drum 103 is exposed to light and a retracted position (part (b) of fig. 10) where the photosensitive drum 103 is retracted more from the replacement unit than the exposure position. When the slidable portion 525 slides (moves) in the arrow a direction in a state where the optical head 105 is in the exposure position (part (a) of fig. 10), the optical head 105 moves in a direction toward the retracted position (part (b) of fig. 10). On the other hand, when the slidable portion 525 slides (moves) in the direction of the arrow B in a state where the optical head 105 is in the retracted position (part (B) of fig. 10), the optical head 105 moves in a direction toward the exposure position (part (a) of fig. 10). Details will be described later.

Part (a1) of fig. 11 is a perspective view showing the rear side of the optical print head 105 positioned at the exposure position and the bushing 671 provided on the rear side of the drum unit 518. Part (a2) of fig. 11 is a sectional view showing the second support portion 528 and the bushing 671 provided on the rear side of the drum unit 518 when the optical print head 105 is positioned at the exposure position. Part (b1) of fig. 11 is a perspective view showing the rear side of the optical print head 105 positioned at the retracted position and the bushing 671 provided on the rear side of the drum unit 518. Part (b2) of fig. 11 is a sectional view showing the second support portion 528 and the bushing 671 provided on the rear side of the drum unit 518 when the optical print head 105 is positioned at the retracted position.

Using fig. 11, a state in which the contact pin 515 disposed on the rear side of the optical print head 105 contacts the bushing 671 disposed on the drum unit 518 side will be described. Further, a part corresponding to the bushing 671 with which the contact pin is contacted is provided on the front side of the drum unit 518, and the structure thereof is similar to that of the bushing 671, and the function thereof is also substantially the same as that of the bushing 671. Here, only a state where the contact pin 515 contacts the bushing 671 provided on the drum unit 518 side will be described.

According to part (a1) of fig. 11 and part (b1) of fig. 11, the portion of the link member 652 mounted on the holding member 505 is closer to the photosensitive drum 103 side than the end portion on the side opposite to the replacement unit side (the side where the replacement unit 518 is arranged) of the two ends (end portions) of the contact pin 515 with respect to the up-down direction (the direction in which the optical head 105 moves between the exposure position and the retracted position: the reciprocating direction). The spring mounting portion 662 on which the link member 652 is mounted is provided so as not to intersect the contact pin 515 with respect to the up-down direction. Further, although not shown in this drawing, the portion of the link member 651 mounted on the holding member 505 is closer to the photosensitive drum 103 side than the end portion on the opposite side to the exchange unit side (the side where the exchange unit 518 is arranged) of the two end portions (end portions) of the contact pins 514 with respect to the up-down direction (the direction in which the optical head 105 moves between the exposure position and the retracted position: the reciprocating direction). The spring mounting portion 661 on which the link member 651 is mounted is provided not to cross the contact pin 514 with respect to the up-down direction. Thereby, the increase in the size of the exposure unit 500 with respect to the vertical direction is suppressed.

As shown in part (a2) of fig. 11 and part (b2) of fig. 11, the second support portion 528 includes a second support surface 587, the regulating portion 128, a first wall surface 588, and a second wall surface 589. A second support surface 587 is provided on the underside of the holding member 505. The lower side of the holding member 505 that moves from the exposure position toward the retracted position contacts the second support surface 587 and a later-described first support surface 586 of the first support portion 527 from the upper side with respect to the vertical direction, so that the optical head 105 is in the retracted position. The regulating portion 128 is a U-shaped concave portion that is formed in the second support portion 528 and opens toward the front side, and is provided on the side opposite to the side where the drum unit 518 is positioned with respect to the holding member 505, and is engaged in the second support portion 528 from the rear side of the contact pin 515 so that the contact pin 515 is movable in the up-down direction. The contact pin 515 protruding from the lower side of the holding member 505 moves up and down together with the holding member 505 while moving in the gap formed by the regulating portion 128. Although not shown in this drawing, the first support portion 527 further includes a regulating portion 127. The regulating portion 127 is a U-shaped concave portion that is formed in the first support portion 527 and opened toward the front side, and is provided on the side opposite to the side where the drum unit 518 is positioned with respect to the holding member 505, and is engaged in the second support portion 528 from the front side of the contact pin 514 so that the contact pin 514 is movable in the up-down direction. The contact pin 514 protruding from the lower side of the holding member 505 moves up and down together with the holding member 505 while moving in the gap formed by the regulating portion 127. The regulating portion 127 has a tapered shape so as to reduce friction force due to contact with the contact pin 514 as much as possible. Thereby, the contact pin 514 can smoothly move up and down in the gap of the regulating portion 127. Therefore, the movement of the holding member 505 integrated with the contact pins 515 and 514 in the direction intersecting both the front-rear direction (the rotational axis direction of the photosensitive drum 103) and the up-down direction (the direction in which the optical head 105 moves between the exposure position and the retracted position: the reciprocating direction) is regulated (restricted). Further, the regulating portion 127 may also regulate the movement of the contact pin 514 from the rear side toward the front side, and the regulating portion 128 may also regulate (restrict) the movement of the contact pin 515 from the rear side toward the front side.

The first wall surface 588 and the second wall surface 589 are disposed at opposite positions with respect to the left-right direction and form a gap. When the optical head 105 reciprocates between the exposure position and the retracted position, the holding member 505 moves in the up-down direction in the gap formed by the first wall surface 588 and the second wall surface 589. During the movement, the holding member 505 regulates (restricts) the movement in a direction intersecting both the front-rear direction (the rotational axis direction of the photosensitive drum 103) and the up-down direction (the direction in which the optical head 105 moves between the exposure position and the retracted position: the reciprocating direction) by the first wall surface 588 and the second wall surface 589.

With the above configuration, the optical head 105 is moved between the exposure position and the retracted position in a state where it is moved in a direction intersecting both the front-rear direction (the rotational axis direction of the photosensitive drum 103) and the up-down direction (the direction in which the optical head 105 is moved between the exposure position and the retracted position: the reciprocating direction). In addition, at least one of the regulating portion 127 and the regulating portion 128 may be provided in the first support portion 527 or the second support portion 528. That is, it is sufficient if the regulating portion 127 is provided in the first supporting portion 527 as an example of the supporting portion or the regulating portion 128 is provided in the second supporting portion 528.

As shown in part (a1) of fig. 11 and part (a2) of fig. 11, a position where the contact pin 515 contacts the bushing 671 provided on the rear side of the drum unit 518 and a position where the contact pin 514 (not shown) contacts the component corresponding to the bushing 671 provided on the front side of the drum unit 518 are exposure positions of the optical print head 105. By the contact pins 514 and 515 being in contact with the bushing 671 and the component corresponding to the bushing 671, respectively, the distance between the lens array 506 and the photosensitive drum 103 is a design nominal value.

On the other hand, as shown in part (b1) of fig. 11 and part (b2) of fig. 11, the position at which the contact pin 515 is retracted from the bushing 671 provided on the rear side of the drum unit 518 corresponds to the retracted position of the optical print head 105. By positioning the optical head 105 at the retracted position shown in part (b1) of fig. 11 and part (b2) of fig. 11, the drum unit 518 that slides (moves) for replacement is in a non-contact state with the optical head 105.

Here, the bushing 671 provided to the drum unit 518 will be described. In fig. 12, a perspective view of the bushing 671 is shown. The bushing 671 is a member fixed to the housing of the drum unit 518 by screws or adhesive. As shown in fig. 12, the bushing 671 is provided with an opening 916. The shaft member on the other end side of the photosensitive drum 103 is rotatably inserted into the opening 916. That is, the bushing 671 rotatably supports the photosensitive drum 103.

In the photosensitive drum 103, a photosensitive layer is formed on the outer wall surface of the hollow cylindrical aluminum pipe. Flanges 673 are press-fitted on both ends of the aluminum pipe. In an opening 916 formed in the bushing 671, a flange 673 on the other end side of the photosensitive drum 103 is rotatably inserted. The flange 673 rotates while sliding with the inner wall surface of the opening 916. That is, the bushing 671 rotatably supports the photosensitive drum 103. Further, also at the central portion of the component corresponding to the bushing 671 with which the contact pin 514 is in contact and provided on the front side of the drum unit 518, an opening is formed similarly to the bushing 671. In an opening formed in a member corresponding to the bushing 671, a flange 673 on one end side (front side) of the photosensitive drum 103 is rotatably inserted. The flange 673 rotates while sliding with the inner wall surface of the opening. That is, similarly to the rear side of the drum unit 518, the bushing 671 rotatably supports the photosensitive drum 103 on the front side.

The bushing 671 includes an engagement portion 685 in which the contact pin 515 is engaged. The engagement portion 685 includes a contact surface 551, a rear sidewall surface 596, and a tapered portion 585. The engagement portion 685 may be recessed relative to the bushing 671 or may be upright relative to the bushing 671. The contact pin 515, which is moved in the direction from the retracted position toward the exposure position, contacts the contact surface 551. A tapered portion 585 having a tapered shape is formed at a lower end edge of the engagement portion 685. The tapered portion 585 guides movement of the contact pin 515 in a direction from the retracted position toward the exposed position such that the contact pin 515 contacts the contact surface 551. The contact between the rear sidewall surface 596 and the contact pin 515 will be described later.

The movement of the contact pin 515, which is in contact with the contact surface 551 of the engagement portion 685, in a direction intersecting both the front-back direction (the rotational axis direction of the photosensitive drum 103) and the up-down direction (the direction in which the optical head 105 moves between the exposure position and the retracted position: the reciprocating direction) is restricted by the engagement portion 685. That is, in the optical print head 105 positioned at the exposure position (see part (a2) of fig. 11), the movement of the upper end portion of the contact pin 515 in the direction intersecting both the front-back direction and the up-down direction is restricted by the engagement portion 685, and the movement of the lower end portion of the contact pin 515 in the direction intersecting both the front-back direction and the up-down direction is restricted by the regulating (restricting) portion 128. Here, the difference between the diameter of the engagement portion 685 with respect to the left-right direction and the diameter of the upper end portion of the contact pin 515 with respect to the left-right direction and the difference between the diameter of the regulating portion 128 with respect to the left-right direction and the diameter of the lower end portion of the contact pin 515 with respect to the left-right direction are smaller than the difference between the clearance of the first and second side wall surfaces 588 and 589 with respect to the left-right direction and the holding member 505 positioned between the first and second side wall surfaces 588 and 589. Therefore, when the optical print head 105 is in the exposure position, the first wall surface 588 and the second wall surface 589 do not involve restriction of movement of the optical print head 105 in a direction intersecting both the front-rear direction and the up-down direction of the holding member 505.

(moving mechanism)

Next, the moving mechanism 640 for moving the optical print head 105 will be described.

First, the first support portion 527 will be described. Part (a) of fig. 13 is a schematic perspective view of the first support portion 527. At the first support portion 527, there are formed a first support surface 586 as an example of an abutment portion (stopper mechanism), an opening 700 as an example of an insertion portion, a contact portion 529, a regulating portion 127, a projection 601, a screw hole 602, a positioning boss 603, a positioning boss 604, and a screw hole 605. Here, the first support portion 527 may also be a molded product prepared by integrally subjecting the opening 700 and the first support surface 586 to injection molding, or may also be a separate member of these portions.

The first supporting surface 586 is a portion with which the lower side of the holding member 505 moving from the exposure position toward the retracted position is in contact from the upper side with respect to the vertical direction, and is fixed to the image forming apparatus 1 main assembly. The underside of the retaining member 505 contacts the first support surface 586 such that the optical print head 105 is in the retracted position.

A cleaning member 572 for cleaning the light emitting surface of the lens array 506 contaminated by toner or the like is inserted in the opening 700 from the outside of the main assembly of the image forming apparatus 1. The cleaning member 572 is an elongated rod-like member. In the present embodiment, as an example of the opening 700, a through hole through which the cleaning member 572 passes in the front-rear direction is shown, but the opening 700 is not limited to this through hole and, for example, a slit may be formed in an upper portion. The contact portion 529 is a rear side surface of the first support portion 527 shown by hatching in part (b) of fig. 13, and includes upper and lower sides with respect to the opening 700. The function of the contact portion 529 will be described in detail later.

As shown in part (a) of fig. 13, the regulating portion 127 is a U-shaped concave portion formed in the first support portion 527 and opened toward the rear side. The portion of the contact pin 514 protruding from the lower side of the holding member 505 moves up and down together with the holding member 505 in the gap formed by the regulating portion 127. The regulating portion 127 has a tapered shape for reducing friction force due to contact with the contact pin 514 as much as possible, and is thinned toward the contact pin 514 with respect to the thickness in the up-down direction. Thereby, the contact pin 514 can smoothly move up and down in the gap of the regulating portion 127.

The first support portion 527 is fixed to a front side surface of the front side plate 642. The front side plate 642 is provided with a plurality of holes corresponding to the positioning bosses 603, the positioning bosses 604, and the fixing screws (not shown), respectively. The positioning bosses 603 and the positioning bosses 604 are inserted into the provided plurality of holes, and in this state, the first support portion 527 is fixed to the front side plate 642 by screws passing through screw holes of the first support portion 527.

The third support portion 526 described later is a metal plate bent into a U-shape. Part (b) of fig. 13 shows a view for explaining a state in which one end portion of the third support portion 526 with respect to the longitudinal direction is to be inserted into a portion surrounded by a broken line shown in part (a) of fig. 13, and part (c) of fig. 13 shows a view in which one end portion of the third support portion 526 with respect to the longitudinal direction is in a portion surrounded by a broken line shown in part (a) of fig. 13. As shown in parts (b) and (c) of fig. 13, one end portion of the third support portion 526 is provided with a cut-away portion, and the projection 601 on the first support portion 527 side is engaged with the cut-away portion of the third support portion 526. The position of the third support portion 526 with respect to the first support portion 527 with respect to the left-right direction is determined by the engagement of the protrusion 601 with the cut-away portion of the third support portion 526. The third support portion 526 is pressed from the lower side of the portion (c) of fig. 13 by a screw inserted through the screw hole 602, and is fixed to the first support portion 527 by its contact with the contact surface 681 of the first support portion 527.

Next, the second support portion 528 will be described. Part (a) of fig. 14 is a schematic perspective view of the second support portion 528. A second support surface 587, a first wall surface 588, a second wall surface 589 and the regulating portion 128 are formed at the second support portion 528.

As described above, the second support surface 587 is a portion which the lower side of the holding member 505 that moves from the exposure position toward the retracted position contacts. The second supporting surface 587 is fixed to the image forming apparatus 1 main assembly. The underside of the retaining member 505 contacts the second support surface 587 so that the optical print head 105 is in the retracted position.

As shown in part (b) of fig. 14, the second support portion 528 is fixed to a front side surface of the rear side plate 643. The second support portion 528 is fixed to the rear side plate 643 by positioning bosses and screws, similar to the method of fixing the first support portion 527 to the front side plate 642. Part (c) of fig. 14 shows a state in which the other end side (rear side) of the third support portion 526 with respect to the longitudinal direction of the third support portion 526 is inserted into a portion surrounded by a broken line shown in part (a) of fig. 14. That is, the third support portion 526 is supported at one end portion by the first support portion 527 and at the other end portion by the second support portion 528, and the first support portion 527 and the second support portion 528 are fixed to the front side plate 642 and the rear side plate 643, respectively. Thus, the third supporting portion 526 is fixed to the image forming apparatus 1 main assembly.

In addition, the second support portion 528 may also have a configuration in which the second support portion 528 is fixed to the third support portion 526 by a screw or the like without being screwed with the rear side plate 643. In this case, for example, the second support portion 528 has a structure in which a concave portion is formed and the concave portion is engaged with a protrusion formed on the rear side plate 643 and determines the position of the second support portion 528 with respect to the rear side plate 643. The first wall surface 588 and the second wall surface 589 of the second support portion 528 will be described later.

As shown in part (a) of fig. 14, the regulating portion 128 is a U-shaped concave portion that is formed in the second support portion 528 and opens toward the front side. The portion of the contact pin 515 protruding from the lower side of the holding member 505 moves up and down together with the holding member 505 in the gap formed by the regulating portion 128. The regulating portion 128 has a tapered shape for reducing friction force due to contact with the contact pin 515 as much as possible, and is thinned toward the contact pin 515 with respect to the thickness in the up-down direction. Thereby, the contact pin 515 can smoothly move up and down in the gap of the regulating portion 128.

Next, the third support portion 526 and the slidable portion 525 will be described using fig. 15. The third supporting portion 526 and the slidable portion 525 are arranged on the side opposite to the photosensitive drum 103 with respect to the holding member 505.

Part (a) of fig. 16 is a schematic perspective view of the moving mechanism 640 when the front side of the moving mechanism 640 is viewed from the left side, in which the first support portion 527 is not shown, and part (b) of fig. 16 is a schematic perspective view of the moving mechanism 640 when the rear side of the moving mechanism 640 is viewed from the right side, in which the first support portion 527 is not shown. The moving mechanism 640 includes a link member 651, a slidable portion 525, and a third support portion 526. The third support portion 526 includes a support shaft 531 and an E-shaped stopper ring 533. As shown in fig. 15, the support shaft 531 is inserted through openings provided in the surfaces (left and right side surfaces) of the third support portion 526 processed into a U-letter shape with respect to the left-right direction. The support shaft 531 penetrates left and right side surfaces of the third support portion 526. As shown in fig. 15, the support shaft 531 is held by an E-shaped stopper ring 533 on the outer side of the left side surface so as not to come out of the opening of the third support portion 526 to fall off to be disconnected.

On the other hand, as shown in part (a) of fig. 15, the slidable portion 525 is provided with an elongated hole 691 extending in the front-rear direction. The support shaft 531 is inserted into the elongated hole 691 of the slidable portion 525, and is loosely engaged in the elongated hole 691 with a clearance of, for example, about 0.1-0.5mm with respect to the up-down direction. Therefore, the movement of the slidable portion 525 in the up-down direction with respect to the third support portion 526 is restricted, and the slidable portion 525 is slidable (movable) with respect to the third support portion 526 in correspondence with the length of the elongated hole 691 with respect to the front-rear direction. (20:53 timing)

Further, a slide assistance member 539 including an accommodation space 562 ranging from the left side to the lower side is mounted at one end side of the slidable portion 525. The slide assist member 539 is fixed to the slidable portion 525 from the left side by fastening with a screw. In the accommodating space 562, a pressing portion 561 provided in a cover 558 described later is accommodated. The relationship between the accommodating space 562 and the pressurizing portion 561 and their structural features will be described together with the description of the cover 558 described later.

The moving mechanism 640 will be described below using fig. 3, 15, and 16.

Fig. 3 is a schematic perspective view of the exposure unit 500 including the moving mechanism 640. As shown in fig. 3, the moving mechanism 640 includes a first link mechanism 861, a second link mechanism 862, a slidable portion 525, a first support portion 527, a second support portion 528, and a third support portion 526. The first link mechanism 861 includes a link member 651 and a link member 653, and the second link mechanism 862 includes a link member 652 and a link member 654. As shown in fig. 3, link members 651 and 653 and link members 652 and 654 constitute λ -type link mechanisms, respectively.

Part (a) of fig. 15 is a schematic perspective view of the front side of the moving mechanism 640 as viewed from the left side, in which the first support portion 527 is not shown. Further, part (b) of fig. 15 is a schematic perspective view of the front side of the moving mechanism 640 as viewed from the right side, in which the first support portion 527 is not shown.

Hereinafter, the first link mechanism 861 will be described using fig. 15 (a), part (b) of fig. 15, part (a) of fig. 16, and part (b) of fig. 16. Fig. 12 (a) is a schematic diagram of a cross-sectional view of the first link mechanism 861 viewed from the right side, the cross-sectional view being taken along the rotation axis direction. First link mechanism 861 includes link member 651 and link member 653. Each of link member 651 and link member 653 is a single link member, but may be constituted by combining a plurality of link members.

As shown in parts (a) and (b) of fig. 16, the length of link member 653 with respect to the longitudinal direction is shorter than the length of link member 651 with respect to the longitudinal direction.

The link member 651 includes a bearing portion 610, a projection 655 and a connecting shaft portion 538. The support portion 610 is provided on one end side of the link member 651 with respect to the longitudinal direction. The protrusion 655 is a cylindrical protrusion provided on the other end side of the link member 651 with respect to the longitudinal direction and standing in the rotational axis direction of the link member 651, and is a protrusion for deforming a spring provided on the holding member 505 side of the optical print head 105. The connecting shaft portion 538 is disposed between the bearing portion 610 and the projection 655 with respect to the longitudinal direction of the link member 651. In addition, the link member 651 is not limited to the link member including the projecting portion 655, but may also have a structure in which the link member 651 is curved with respect to the rotational axis direction on one end side with respect to the longitudinal direction.

The support portion 610 is provided with a hollow hole extending in the left-right direction of part (a) of fig. 16. The slidable portion 525 is provided with an engagement shaft portion 534. The engaging shaft portion 534 is a cylindrical protrusion standing from the slidable portion 525 in the left direction of the portion (a) of fig. 16. The engaging shaft portion 534 forms a first connecting portion by being rotatably engaged in the hole of the bearing portion 610. That is, the link member 651 can rotate about the first connecting portion with respect to the slidable portion 525. Here, a configuration may also be adopted in which the engaging shaft portion 534 is formed on the link member 651 side and the bearing portion 610 is formed on the slidable portion 525 side.

The link member 653 includes a connecting shaft portion 530. The connecting shaft portion 530 is provided on one end side of the link member 653 with respect to the longitudinal direction of the link member 653. The connecting shaft portion 530 is a cylindrical protrusion standing from the link member 653 toward the left side of part (a) of fig. 16. The connecting shaft portion 530 is rotatably inserted into a hole formed in the third support portion 526, and forms a second connecting portion. Here, the connecting shaft portion 530 may also be formed on the third support portion 526 instead of the link member 653. That is, the connecting shaft portion 530 formed on the third support portion 526 may also be inserted into a hole provided in the link member 653.

The link member 653 is provided with a circular hole that extends in the left-right direction of the portion (a) of fig. 16, and is formed on the other end side thereof with respect to the longitudinal direction. The connecting shaft portion 538 of the link member 651 is rotatably inserted in the hole, so that the connecting shaft portion 538 and the hole of the link member 653 form a fourth connecting portion. That is, link member 653 may rotate about the third connecting portion with respect to third support portion 526, and may rotate about the fourth connecting portion with respect to link member 651. Here, the connecting shaft portion 538 may also be formed on the link member 653 instead of the link member 651. That is, connecting shaft portion 538 formed on link member 653 may also be rotatably inserted into a hole formed in link member 651.

In addition, the structure of the second link mechanism 862 is also similar to that of the first link mechanism 861 described above. The link members 652 and 654 of the second link mechanism 862 correspond to the link members 651 and 653 of the first link mechanism 651, respectively. Corresponding to the first connecting portion, a connecting portion between one end side portion with respect to the longitudinal direction of the link member 652 and the slidable portion 525 constitutes a second connecting portion. In the moving mechanism 640, either one of the link members 653 and 654 may be omitted.

With the above configuration, when the slidable portion 525 slides from the front side toward the rear side with respect to the third support portion 526, the bearing portion 610 engaged with the engaging shaft portion 534 slides from the front side toward the rear side with respect to the third support portion 526 together with the slidable portion 525. Thereby, as shown in part (a) of fig. 16, when the first link mechanism 861 is viewed from the rear side, the first link mechanism 861 rotates in the clockwise direction about the engagement shaft portion 534, and the link member 653 rotates in the counterclockwise direction about the connecting shaft portion 530. Thus, the projection 655 moves from the exposure position toward the retracted position.

On the other hand, when the slidable portion 525 slides (moves) from the rear side toward the front side with respect to the third support portion 526, the link member 651 and the link member 653 move in the direction opposite to the arrow direction shown in part (a) of fig. 16. When the slidable portion 525 slides from the rear side toward the front side with respect to the third support portion 526, the bearing portion 610 engaged with the engaging shaft portion 534 slides from the rear side toward the front side with respect to the third support portion 526 together with the slidable portion 525. As a result, as shown in part (a) of fig. 16, when the first link mechanism 861 is viewed from the rear side, the first link mechanism 861 rotates in the counterclockwise direction about the engagement shaft portion 534, and the link member 653 rotates in the clockwise direction about the connection shaft portion 530. Thus, the projection 655 moves from the retracted position toward the exposure position.

In addition, (1) the distance between the rotational center axis of the connection shaft portion 538 and the rotational center axis of the bearing portion 610 is L1, (2) the distance between the rotational center axis of the connection shaft portion 538 and the rotational center axis of the connection shaft portion 530 is L2, and (3) the distance between the rotational center axis of the connection shaft portion 538 and the rotational center axis of the projection 655 is L3. In the moving mechanism 640, the first link member 641 forms a Scot-Russel mechanism in which L1, L2, and L3 are equal to each other (part (b) of fig. 16). The distances L1, L2, and L3 are set equal to each other, whereby the projecting portion 655 vertically moves (along the broken line a in part (b) of fig. 16) with respect to the sliding (moving) direction of the engaging shaft portion 534, and therefore, in the above-described link mechanism, the optical head 105 can move substantially in the optical axis direction of the lens.

Here, a configuration may also be adopted in which a structure is used in which the first link mechanism 861 and the second link mechanism 862 are reversed with respect to the front-rear direction, and when the slidable portion 525 slides from the front side toward the rear side, the optical head 105 is moved from the retracted position toward the exposure position, and when the slidable portion 525 slides from the rear side toward the front side, the optical head 105 is moved from the exposure position toward the retracted position. In this case, a cover 558, which will be described later, pushes the slidable portion 525 from the front side toward the rear side when the cover 558 moves from the open state toward the closed state, and pulls the slidable portion 525 from the rear side toward the front side when the cover 558 moves from the closed state toward the open state.

The mechanism for moving the optical print head 105 is not limited to the moving mechanism 640, but may also be the moving mechanism 140 shown in fig. 17, and the moving mechanism 140 will be described below using fig. 17 and 18. In addition, members having substantially similar functions to those constituting the moving mechanism 640 are described by adding the same reference numerals or symbols thereto, and duplicate description will be omitted in some cases.

Hereinafter, a mechanism of the moving mechanism 140 moving the holding member 505 will be described. Part (a) of fig. 18 is a sectional view of the holding member 505 and the moving mechanism 140 shown in part (b) of fig. 18, taken along a plane of the rotation axis of the photosensitive drum 103.

As shown in parts (a) and (b) of fig. 17, the link member 151 includes a support portion 110 and a projection 155. The support portion 110 is provided on one end side of the link member 151 with respect to the longitudinal direction. As shown in parts (a) and (b) of fig. 18, the protrusion 155 is a cylindrical protrusion provided on the other end side of the link member 151 with respect to the longitudinal direction and standing in the rotational axis direction of the link member 151, and is a protrusion for deforming a spring provided on the holding member 505 side of the optical print head 105. Here, the link member 151 is not limited to a link member including the protrusion 155, but may be a structure in which the link member 151 is bent with respect to the rotational axis direction of the link member 151 on one end side with respect to the longitudinal direction of the link member 151.

The support portion 110 is provided with a hollow hole extending in the left-right direction. As shown in parts (a) and (b) of fig. 18, the slidable portion 525 is provided with an engaging shaft portion 534. The engaging shaft portion 534 is a cylindrical protrusion standing from the slidable portion 525 in the left direction of the portion (a) of fig. 16. The hole of the support portion 110 forms a first connecting portion by being rotatably engaged with the engaging shaft portion 534. That is, the link member 151 may rotate about the first connection portion with respect to the slidable portion 525. Here, a configuration may also be adopted in which the engaging shaft portion 534 is formed on the link member 151 side and the supporting portion 110 is formed on the slidable portion 525 side.

In addition, a shaft similar to the support shaft 531 is provided on the rear side of the third support portion 526, an elongated hole similar to the elongated hole 691 is formed on the rear side of the slidable portion 525, and the rear side of the moving mechanism 140 has a structure similar to the front side. Further, the link member 152 has a structure corresponding to that of the link member 151. Further, the connecting portion between the one end side of the link member 152 with respect to the longitudinal direction and the slidable portion 525 constitutes a second connecting portion, corresponding to the first connecting portion.

A contact portion 529 of the first support portion 527 (not shown) is provided on one side of the front of one end portion of the holding member 505. Thus, when the slidable portion 525 slides (moves) from the rear side toward the front side with respect to the third support portion 526, the bearing portion 110 engaged with the engagement shaft portion 534 slides (moves) from the rear side toward the front side with respect to the third support portion 526 together with the slidable portion 525. In this way, the holding member 505 mounted with the protrusion 155 will move toward the front side, but one end of the holding member 505 contacts the contact portion 529, so that the movement of the holding member 505 toward the protrusion side is restricted. The link member 151 is arranged to intersect the rotational axis direction of the photosensitive drum 103 such that one end side provided with the protruding portion 155 is positioned closer to the drum unit 518 side than the other end side provided with the bearing portion 110, and therefore, when the link member 151 is viewed from the right side as shown in part (a) of fig. 18, the link member 151 rotates counterclockwise (rotationally moves) about the engagement shaft portion 534 as the rotational center. Thus, the holding member 505 is moved from the retracted position toward the exposure position while contacting the contact portion 529 at one end thereof.

On the other hand, when the slidable portion 525 slides (moves) from the front side toward the rear side with respect to the third support portion 526, the bearing portion 110 engaged with the engaging shaft portion 534 slides (moves) from the rear side toward the front side with respect to the third support portion 526 together with the slidable portion 525. Thereby, the link member 151 rotates clockwise about the engaging shaft portion 534 as viewed from the right side as shown in part (a) of fig. 18. Therefore, the projection 155 moves in the direction from the exposure position toward the retracted position. Although described later specifically, the slidable portion 525 moves from the rear side toward the front side in association with the closing operation of the cover 558, and moves from the front side toward the rear side in association with the opening operation of the cover 558. That is, when the cover 558 is moved from the open state toward the closed state, the holding member 505 is moved in the direction from the retracted position toward the exposure position, and when the cover 558 is moved from the closed state toward the open state, the holding member 505 is moved in the direction from the exposure position toward the retracted position.

When the optical print head 105 moves substantially in the optical axis direction of the lens, the rear side of the holding member 505 moves in the gap formed by the first wall surface 588 and the second wall surface 589 provided in the above-described second support portion 528. This prevents the holding member 505 from being inclined with respect to the left-right direction.

The link member 151 and the link member 152 may also be arranged such that the other end portion side is arranged further to the front side than the one end portion side, and the contact portion 529 may also be arranged further to the rear side than the other end portion of the holding member. That is, when the slidable portion 525 slides (moves) from the front side toward the rear side with respect to the third support portion 526, the bearing portion 110 engaged with the engaging shaft portion 534 slides (moves) from the front side toward the rear side with respect to the third support portion 526 together with the slidable portion 525. In this way, the holding member 505 mounted with the protruding portion 155 will move toward the rear side, but the other end portion of the holding member 505 contacts the contact portion 529, so that the movement of the holding member 505 toward the protruding portion side is restricted. When the link member 151 is viewed from the right side, the link member 151 and the link member 152 rotate clockwise (rotationally move) about the engaging shaft portion 534 as a rotation center, so that the holder member 505 moves from the retracted position toward the exposed position while being in contact with the contact portion 529 at the other end portion thereof. In this case, the cover 558 pushes the slidable portion 525 from the front side toward the rear side during its movement from the open state toward the closed state, and pulls the slidable portion 525 from the rear side toward the front side during its movement from the closed state toward the open state.

The mechanism for moving the optical print head 105 is not limited to the moving mechanism 640 and the moving mechanism 140, but may also be the moving mechanism 840 shown in fig. 19. The moving mechanism 840 will be described below using fig. 19. In addition, members having substantially the same functions as those constituting the moving mechanism 640(140) will be described by adding the same reference numerals or symbols thereto, and duplicate descriptions will be omitted in some cases.

Part (a1) of fig. 19 and part (a2) of fig. 19 are the moving mechanism 840. As shown in part (a1) of fig. 19 and part (a2) of fig. 19, the moving mechanism 840 includes a first link mechanism 858, a second link mechanism 859, a slidable portion 825, and a third support portion 526. First linkage 858 includes link member 843 and link member 844, and second linkage 859 includes link member 845 and link member 846. As shown in fig. 19, link members 843 and 844, and link members 845 and 846 rotatably cross each other and constitute an X-shaped link mechanism, respectively. The protruding portion 847 of the link member 843, the protruding portion 848 of the link member 844, the protruding portion 849 of the link member 845, and the protruding portion 850 of the link member 846 are rotatably mounted on the unillustrated holding member 805. In the portion (a1) of fig. 19, when the slidable portion 825 slides (moves) in the direction of the arrow a, the link members 843 and 846 rotate relative to the slidable portion 825 so that the protrusions 847 and 850 move toward the lower side (the portion (a2) of fig. 19). On the other hand, in the portion (a2) of fig. 19, when the slidable portion 825 slides (moves) in the direction of the arrow B, the link member 843 + 846 rotates relative to the slidable portion 825, so that the protruding portions 847 + 850 move toward the upper side (portion (a1) of fig. 19).

Part (b) of fig. 19 is a view showing the front side of the combined moving mechanism 840 and the front side of the holding member 805.

Next, using part (b) of fig. 19, a mechanism in which the moving mechanism 840 moves the holding member 805 will be described. Here, the operations of the first link mechanism 858 and the second link mechanism 859 are substantially the same, and therefore, the first link mechanism 858 will be described here using part (b) of fig. 19. First linkage 858 includes link member 843 and link member 844. Each of the link member 843 and the link member 844 constituting the first link mechanism 858 is a single link member, but the first link mechanism 858 may also be constituted by combining a plurality of link members.

The moving mechanism 840 in part (b) of fig. 19 includes a first link mechanism 858 and a slidable portion 825. As shown in part (b) of fig. 19, the slidable portion 825 is provided with an elongated hole 863 which is an elongated opening that penetrates in the left-right direction and extends in the front-rear direction.

The link member 843 includes a projection 810, a projection 847, and a connecting shaft portion 538. The protrusion 810 is provided on one end side with respect to the longitudinal direction. The protrusion 847 is a cylindrical protrusion that is provided on the other end side of the link member 843 with respect to the longitudinal direction, and stands toward the right side with respect to the rotational axis direction of the link member 843. The connecting shaft portion 538 is disposed between the protrusion 810 and the protrusion 847 with respect to the longitudinal direction of the link member 843. Further, the link member 843 is not limited to a link member including the protruding portion 847, and may have a structure in which one end portion side of the link member 843 with respect to the longitudinal direction is bent with respect to the rotation axis direction.

The projection 810 forms a first connecting portion by being loosely rotatably engaged with respect to the elongated hole 863 of the slidable portion 825. That is, the link member 843 may rotate about the first connection portion with respect to the slidable portion 825. Further, the protrusion 810 may move in the front-rear direction within the range of the elongated hole 863 (in the opening) with respect to the front-rear direction in the elongated hole 863. Between the rear side edge of the elongated hole 863 and the projection 810, a coil spring 860 is provided.

The link member 844 includes a connecting shaft portion 530 and a projection 848. The connecting shaft portion 530 is provided on one end side of the link member 844 with respect to the longitudinal direction. The connecting shaft portion 530 is a cylindrical protrusion that stands from the link member 844 toward the right side of portion (b) of fig. 19. The connecting shaft portion 530 is rotatably inserted into a hole formed in the third support portion 526, and forms a third connecting portion. Here, the connecting shaft portion 530 may also be formed on the third support portion 526 instead of the link member 844. That is, the connecting shaft portion 530 formed on the third support portion may also be inserted into a hole formed in the link member 844.

The protrusion 848 is a cylindrical protrusion that is provided on the other end side of the link member 844 with respect to the longitudinal direction, and is erected toward the right side with respect to the rotational axis direction of the link member 844.

Further, between the protruding portion 848 of the link member 844 and the third connecting portion, a circular hole extending in the left-right direction of part (b) of fig. 19 is formed. The connecting shaft portion 538 of the link member 843 is inserted into the hole such that the connecting shaft portion 538 and the holes of the link member 844 form a fourth connecting portion. That is, the link member 844 may rotate with respect to the third support portion 526, and may rotate with respect to the link member 843 around the fourth connecting portion as a rotation center. Here, the connecting shaft portion 538 may also be formed on the link member 844 instead of the link member 843. That is, the connecting shaft portion 538 formed on the link member 843 may also be inserted into a hole formed in the link member 844.

In addition, in the embodiment of the moving mechanism 840, either one of the link member 843 and the link member 844 may be omitted.

Retaining member 805 includes lens array 506, link mounting portion 851, link mounting portion 852, and pin mounting portion 855. Both the link mounting portion 851 and the link mounting portion 852 are disposed between the lens array 506 and the pin 514 mounted in the holding member 805. In addition, although not shown in the drawings, both the link mounting portion 853 and the link mounting portion 854 on which the link member 845 and the link member 846 constituting the second link mechanism 859 are provided between the lens array 506 and the pin 515 mounted on the other end side of the holding member 805. The link mounting portion 851 is a hole formed in the holding member 805 between the lens array 506 and the pin mounting portion 855 and penetrating in the left-right direction. Further, the link mounting portion 852 is an elongated hole extending in the front-rear direction, penetrating in the left-right direction, formed in the holding member 805 between the lens array 506 and the link mounting portion 851.

Projection 847 of link member 843 is rotatably mounted on link mounting portion 851, and projection 848 of link member 844 is rotatably mounted on link mounting portion 852. Further, the projection 848 is mounted to be movable in the front-rear direction with respect to the link mounting portion 851. Therefore, the link member 844 can slide (move) in the front-rear direction within a range of the link mounting portion 852 with respect to the front-rear direction while rotating around the protruding portion 848 as a rotation center.

With the above configuration, when the slidable portion 825 slides (moves) with respect to the third support portion 526 from the front side toward the rear side, the protrusion 810 slides (moves) with respect to the third support portion 526 from the front side toward the rear side together with the slidable portion 825. Thus, when the first link mechanism 858 is viewed from the right side as shown in part (a1) of fig. 19, the link member 843 rotates clockwise about the protruding portion 810 as a rotation center, and the protruding portion 848 moves from the front side toward the rear side at the link mounting portion 852 while the link member 844 rotates counterclockwise about the connecting shaft portion 530. Thus, the protrusion 847 and the protrusion 848 move in the direction from the exposure position toward the retracted position.

On the other hand, when the slidable portion 825 slides (moves) from the rear side toward the front side with respect to the third support portion 526, the protrusion 810 slides (moves) from the rear side toward the front side with respect to the third support portion 526 together with the slidable portion 825. Thus, when the first link mechanism 858 is viewed from the right side as shown in part (a2) of fig. 19, the link member 843 rotates counterclockwise about the protruding portion 810 as a rotation center, and the protruding portion 848 moves from the rear side toward the front side at the link mounting portion while the link member 844 rotates counterclockwise about the connecting shaft portion 530. Therefore, the protrusion 847 and the protrusion 848 move in the direction from the retracted position toward the exposure position. As shown in part (b) of fig. 19, in a state where the contact pin 514 contacts the contact surface 550, when the slidable portion 825 is further slid (moved) toward the front side, the coil spring 860 is contracted by being sandwiched between the rear side edge of the elongated hole 863 and the projection 810. The protrusion 810 is pushed toward the front side by the restoring force of the contracted coil spring 860. Thereby, a pressing force in a direction toward the upper side is applied to the holding member 805.

Here, a configuration may also be adopted in which a structure is used in which the first link mechanism 858 and the second link mechanism 859 are reversed with respect to the front-rear direction, and when the slidable portion 825 slides from the front side toward the rear side, the optical print head 105 is moved from the retracted position toward the exposure position, and when the slidable portion 825 slides from the rear side toward the front side, the optical print head 105 is moved from the exposure position toward the retracted position. In this case, the cover 558, which will be described later, pushes the slidable portion 825 from the front side toward the rear side during the movement of the cover 558 from the open state toward the closed state, and pulls the slidable portion 825 from the rear side toward the front side during the movement of the cover 558 from the closed state toward the open state.

Further, the mechanism for moving the optical print head 105 is not limited to the moving mechanism 640, the moving mechanism 140, and the moving mechanism 840, but may also be a moving mechanism 940 shown in fig. 20, and the moving mechanism 940 will be described below using fig. 20. In addition, members having substantially similar functions to those constituting the moving mechanism 640 (including 140 and 840) are described by adding the same reference numerals or symbols thereto, and duplicate description will be omitted in some cases.

As shown in fig. 20, the first cam portion 112 and the second cam portion 113 are provided on the front and rear sides of the slidable portion 525, and the movement support portion 114 and the movement support portion 115 are provided on the front and rear sides of the lower side of the holding member 905. The first cam portion 112 and the second cam portion 113 have inclined surfaces that descend from the rear side toward the front side on the holding member 905 side.

Part (a) of fig. 20 is a schematic diagram of the moving mechanism 940 and the optical print head 105 located in the exposure position as viewed from the right side. When the optical print head 105 is in the exposure position, when the slidable portion 525 slides from the front side toward the rear side with respect to the third support portion 526, the first cam portion 112 and the second cam portion 113 provided on the slidable portion 525 move from the front side toward the rear side with respect to the third support portion 526 together with the slidable portion 525. Thereby, the lower end portions of the movement supporting portion 114 and the movement supporting portion 115 provided on the holding member 905 contact the first cam portion 112 and the second cam portion 113, and the movement supporting portion 114 and the movement supporting portion 115 move along the first cam portion 112 and the second cam portion 113 in the direction from the exposure position toward the retracted position.

Part (b) of fig. 20 is a schematic diagram of the moving mechanism 940 and the optical print head 105 in the retracted position as viewed from the right side. When the optical print head 105 is in the retracted position, when the slidable portion 525 slides from the rear side toward the front side with respect to the third support portion 526, the first cam portion 112 and the second cam portion 113 provided on the slidable portion 525 move from the rear side toward the front side with respect to the third support portion 526 together with the slidable portion 525. Thereby, the lower end portions of the movement supporting portion 114 and the movement supporting portion 115 provided on the holding member 905 are pushed upward and moved in the direction from the retracted position toward the exposure position along the first cam portion 112 and the second cam portion 113.

Here, a configuration may also be adopted in which a configuration is used in which the first cam portion 112 and the second cam portion 113 are provided and the inclination direction of the inclined surface is inclined downward from the front side toward the rear side, and when the slidable portion 525 slides from the front side toward the rear side, the optical head 105 is moved from the retracted position toward the exposure position, and when the slidable portion 525 slides from the rear side toward the front side, the optical head 105 is moved from the exposure position toward the retracted position. In this case, a cover 558, which will be described later, pushes the slidable portion 525 from the front side toward the rear side during movement of the cover 558 from the open state toward the closed state, and pulls the slidable portion 525 from the rear side toward the front side during movement of the cover 558 from the closed state toward the open state.

Next, the cover 558 will be described with reference to fig. 21, and the cover 558 is a member that slides (moves) the slidable portion 525 as described above. In addition, the configuration for sliding (moving) the slidable portion 525 is not limited to the cover 558. For example, a configuration may also be adopted in which the slidable portion 525 slides (moves) in association with opening and closing of a front door, not shown. Further, a configuration may also be adopted in which the slidable portion 525 slides (moves) in association with rotation of a rotatable member such as a rod (instead of a cover member such as the cover 558 or a door).

Part (a) of fig. 21 is a perspective view of the cover 558. As shown in part (a) of fig. 21, the cap 558 includes a rotation shaft portion 559 and a rotation shaft portion 560. The rotation shaft portion 559 is a cylindrical protrusion protruding in the right direction of the cap 558. On the other hand, the rotating shaft portion 560 is a cylindrical protrusion protruding in the left direction of the cover 558.

Part (b) of fig. 21 shows an enlarged view of a portion where the cover 558 is mounted on the front side plate 642. Further, part (c) of fig. 21 is a perspective view of the cover 558 attached to the front side plate 642. As shown in part (b) of fig. 21, the front side plate 642 includes a support member 621 engageable with a rotation shaft portion 559 of the cover 558, and includes a support member 622 engageable with a rotation shaft portion 560 of the cover 558. As shown in part (c) of fig. 21, the rotation shaft portion 559 of the cover 558 is rotatably engaged with the support member 621 of the front side plate 642, and the rotation shaft portion 560 of the cover 558 is rotatably engaged with the support member 622 of the front side plate 642. As shown in part (a) of fig. 21, the rotation axis of the rotation shaft portion 559 and the rotation axis of the rotation shaft portion 560 are located on the rotation axis 563. The cover 558 is opened and closed with respect to the main assembly of the image forming apparatus 1 around the rotation axis 563 as a rotation center. The closed cover 558 is positioned on the insertion and extraction passage of the developing unit 641. Therefore, when the cover 558 is in the closed state, the operator cannot perform the replacement operation of the drum unit 518 and the developing unit 641. The operator can replace the drum unit 518 by opening the cover 558 and close the cover 558 after the operation.

Next, using fig. 22 to 25, a configuration in which the slidable portion 525 slides (moves) in the rotational axis direction of the photosensitive drum 103 in association with the opening and closing operation of the cover 558 will be specifically described.

Parts (a) - (d) of fig. 22 are perspective views showing the rotation of the cover 558 from the open state toward the closed state. Parts (a) - (d) of fig. 23 are sectional views showing the rotation of the cover 558 from the closed state toward the open state. Part (a) of fig. 22 and part (a) of fig. 23 show an open state of the cover 558. Part (d) of fig. 22 and part (d) of fig. 23 show a closed state of the cover 558. Part (b) of fig. 22 and part (b) of fig. 23, and part (c) of fig. 22 and part (c) of fig. 23 are views showing the cover 558 transitioning from the open state to the closed state. In addition, the cover 558 in the closed state shown in part (d) of fig. 22 and part (d) of fig. 23 is maintained in the closed state by a snap mechanism, a rotation prevention stopper, or the like.

As shown in parts (a) - (d) of fig. 22, the cover 558 rotates about the rotation axis 563 as a center with respect to the main assembly of the image forming apparatus 1. Thereby, as shown in the rotation locus 564 of the parts (a) - (d) of fig. 23, the pressing part 561 is also rotated around the rotation axis 563. The cover 558 includes a cylindrical pressurizing portion 561 protruding from the left side toward the right side. As shown in fig. 22, the pressurizing portion 561 is positioned in the accommodating space 562 installed at one end of the slidable portion 525.

The action of the pressing portion 561 on the slidable portion 525 will be described below using portions (a) to (d) of fig. 23. When the cover 558 is rotated clockwise from the state of part (a) of fig. 23, the pressing portion 561 is positioned on the rotation locus 564 and contacts the contact surface 566 (part (b) of fig. 24) intersecting the rotation locus 564. When the cover 558 is further rotated clockwise from this state, the pressing portion 561 presses the contact surface 566 toward the front side while sliding on the contact surface 566. Thereby, the slide assist member 539 moves toward the front side. The slide assist member 539 is fixed to the slidable portion 525, and therefore, the slidable portion 525 also slides (moves) toward the front side in association with the movement of the slide assist member 539.

Further, when the cover 558 is rotated clockwise, the pressing portion 561 moves from the contact surface 566 to the contact surface 567 (part (c) of fig. 23). The contact surface 567 forms a curved surface having a shape that substantially follows the rotation locus 564 of the pressing section 561. Therefore, in the case where the cover 558 is further rotated clockwise from the state of the portion (c) of fig. 23, the pressing portion 561 is moved toward the upper side in contact with the contact surface 567, but a force for sliding (moving) the slide assistance member 539 toward the more front side is not applied from the pressing portion 561.

According to part (c) of fig. 22 and part (c) of fig. 23, immediately after the holding member 505 is in the exposing position by rotating the cover 558 from the open state to the closed state, the pressing part 561 contacts the front side contact surface 567 of the accommodating space 562. The contact surface 567 has a shape substantially following the rotation locus 564 of the pressing portion 561, that is, has an arc shape with the rotation axis 563 as a center. Therefore, in the case where the cover 558 is further rotated clockwise from the state of part (c) of fig. 23, the pressing part 561 is moved while sliding in a state where the pressing part 561 contacts the surface 567. However, a force for sliding (moving) the slide assistance member 539 toward the more front side is not applied from the pressing portion 561. Therefore, during the movement of the pressing portion 561 on the contact surface 567, the slide assistance member 539 is prevented from moving from the rear side toward the front side. That is, the moving mechanism 640 of the present embodiment is constituted such that the slidable portion 525 slides (moves) in association with the movement of the pressing portion 561 when the cover 558 rotates in a state where the pressing portion 561 is in contact with the contact surface 566, but such that the slidable portion 525 does not slide (move) even when the cover 558 rotates in a state where the pressing portion 561 is in contact with the contact surface 567. When the cover 558 is further rotated clockwise from the state of part (c) of fig. 23, the cover 558 is in a closed state shown in part (d) of fig. 23.

Parts (a) - (d) of fig. 24 are perspective views showing the rotation of the cover 558 from the closed state toward the open state. Parts (a) - (d) of fig. 25 are sectional views showing the rotation of the cover 558 from the open state toward the closed state. Part (a) of fig. 24 and part (a) of fig. 25 show a closed state of the cover 558. Part (d) of fig. 22 and part (d) of fig. 23 show an open state of the cover 558. Part (b) of fig. 24 and part (b) of fig. 25, and part (c) of fig. 24 and part (c) of fig. 25 are views showing the cover 558 transitioning from the closed state to the open state.

In the closed state of the cover 558 shown in part (a) of fig. 25, a force that slides (moves) the slidable portion 525 from the front side toward the rear side via the first link mechanism 861 and the second link mechanism 862 by the self weight of the optical print head 105 and a restoring force of a spring described later acts on the slidable portion 525. However, the cover 558 in the closed state is fixed to the image forming apparatus 1 main assembly so as not to rotate, and the pressing portion 561 restricts the movement of the slide assistance member 539 toward the rear side, and therefore, the slidable portion 525 does not slide (move) toward the rear side.

When the cover 558 is rotated counterclockwise from (state of) part (a) of fig. 25, the pressing portion 561 contacts the contact surface 568 as shown in part (b) of fig. 25. When the cover 558 is further rotated counterclockwise from the state of part (b) of fig. 25, the pressing portion 561 presses the contact surface 568 from the front side toward the rear side as shown in parts (b) and (c) of fig. 25, and thus, the slidable portion 525 moves toward the rear side. Thereafter, when the cover 558 is further rotated counterclockwise, the cover 558 is in an open state as shown in part (d) of fig. 25.

The mechanism in which the pressing portion 561 presses the contact surface 568 is provided for the following reason. Even if the movement restriction of the slide assistance member 539 by the pressing portion 561 is released by rotating the cover 558 counterclockwise from the state of part (a) of fig. 24, when the frictional force between the respective link members, the frictional force between the link member 651 or the link member 653 and the slidable portion 525, and the frictional force between the link member 652 or the link member 654 and the third support portion 526 are large, a case where the slidable portion 525 does not slide (move) toward the rear side will be considered. That is, a case where the slidable portion 525 does not slide (move) even if the cover 558 is opened will be considered. On the other hand, in order to move the slidable portion 525 toward the rear side by opening the cover 558, the moving mechanism 640 of the present embodiment includes a mechanism in which the pressing portion 561 presses the contact surface 568.

With the above configuration, the operator for performing maintenance opens and closes the cover 558, so that the slidable portion 525 slides (moves) relative to the third support portion 526 in association with the movement of the cover 558.

Next, a connecting mechanism between the holding member 505 and the link member 651 will be described. Parts (a) and (c) of fig. 26 are perspective views showing one end side of the holding member 505 with respect to the front-rear direction. Parts (b) and (d) of fig. 26 are perspective views showing the other end side of the holding member 505 with respect to the front-rear direction.

As shown in part (a) of fig. 26, the holding member 505 includes a lens mounting portion 701 on which the lens array 506 is mounted, a spring mounting portion 661 in which a coil spring 547 is mounted, a spring mounting portion 662 in which a coil spring 548 is mounted, a pin mounting portion 632 in which the contact pin 514 is mounted, and a pin mounting portion 633 in which the contact pin 515 is mounted. The holding member 505 is a molded product obtained by integrally injection molding the lens mounting portion 701, the substrate mounting portion 702 (not shown), the spring mounting portion 661, and the spring mounting portion 662, and is made of a resin material. The spring mounting portion 661 is arranged on one end portion side of the lens mounting portion 701 with respect to the front-rear direction, and the pin mounting portion 632 is arranged closer to the end portion side of the holding member 505 than the spring mounting portion 661. Further, the spring mounting portion 662 is arranged on the other end portion side of the lens mounting portion 701 with respect to the front-rear direction, and the pin mounting portion 632 is arranged closer to the other end portion side of the holding member 505 than the spring mounting portion 662. In the holding member 505, when portions forming the lens mounting portion 701, the spring mounting portion 661, and the pin mounting portion 632 are shown in the drawing, in a portion (a) of fig. 26, these portions are portions shown by a C region, a B region, and a region. On the side in front of the lens array 506 and behind the contact pins 514, an urging force is applied to the holding member 505 from the lower side toward the upper side via the coil spring 547 by the projecting portion 655 of the link member 651. Further, using part (C) of fig. 26, when parts forming the lens mounting part 701, the spring mounting part 662, and the pin mounting part 633 are shown in the drawing, these parts are parts shown by a region C, a region D, and a region E, respectively. On the side behind the lens array 506 and in front of the contact pin 515, an urging force is applied to the holding member 505 from the lower side toward the upper side by the coil spring 548 through the protrusion 656 of the link member 652.

First, the spring mounting portion 661 will be described. The spring mounting portion 661 includes a first wall portion 751, a second wall portion 752, a first engagement portion 543, and a second engagement portion 544. The first wall portion 751 is arranged on one end side of the holding member 505 with respect to the left-right direction, and the second wall portion 752 is arranged on the other end side of the holding member 505 with respect to the left-right direction. In the present embodiment, the first wall portion 751 and the second wall portion 752 are arranged on both sides of the contact pin 514 with respect to the left-right direction. As shown in part (a) of fig. 26, the first wall portion 751 and the second wall portion 752 include inner wall surfaces that are opposed to each other. An opening 755 is formed in the first wall portion 751, and an opening 756 is formed in the second wall portion 752. The opening 755 and the opening 756 are elongated holes extending in the up-down direction. The projections 655 are inserted in the openings 755 and 756. The projection 655 is not engaged with the opening 755 and the opening 756, and is inserted at the narrowest portion with respect to the front-rear direction with a gap of about 0.5 mm. Therefore, the moving direction of the projecting portion 655 is guided by the opening 755 and the opening 756 with respect to the up-down direction without receiving a large frictional force from the inner wall surfaces of the opening 755 and the opening 756.

Part (b) of fig. 26 is a view in which the first wall portion 751 is removed from part (a) of fig. 26. The first engagement portion 543 and the second engagement portion 544 are arranged between the first wall portion 751 and the second wall portion 752 with respect to the left-right direction. Further, the first engagement portion 543 and the second wall portion 544 are disposed between the opening 755 and the opening 756. In the present embodiment, the first engagement portion 543 is arranged closer to the end portion side of the holding member 505 than the second engagement portion 544. The first engaging portion 543 and the second engaging portion 544 are projections projecting downward from a connecting portion connecting the first wall portion 751 and the second wall portion 752 of the holding member 505. One end portion of the coil spring 547 is engaged with the first engagement portion 543, and the other end portion of the coil spring 547 is engaged with the second engagement portion 544. The first engaging portion 543 and the second engaging portion 544 are arranged on the spring mounting portion 661 such that the coil spring 547 engaged with the first engaging portion 543 and the second engaging portion 544 traverses the opening 755 and the opening 756.

The first engaging portion 543 and the second engaging portion 544 are arranged at different positions with respect to the up-down direction. In the present embodiment, the first engagement portion 543 is arranged closer to the photosensitive drum 103 side than the second engagement portion 544. In addition, the first engagement portion 543 and the second engagement portion 544 may be provided at the same height with respect to the up-down direction, and the second engagement portion 544 may be arranged closer to the photosensitive drum 103 side than the first engagement portion 543.

As shown in part (b) of fig. 26, the protrusion 655 is inserted into the opening 756 from the outer wall surface side of the second wall portion 752, and passes under the coil spring 547 bridged between the first engagement portion 543 and the second engagement portion 544, and is inserted into the opening 755 of the first wall portion 751.

Next, the spring mounting portion 662 will be described. As shown in part (c) of fig. 26, the spring mounting portion 662 includes a third wall portion 753, a fourth wall portion 754, a third engaging portion 545, and a fourth engaging portion 546. The third wall portion 753 is disposed on one end side of the holding member 505 with respect to the left-right direction, and the fourth wall portion 754 is disposed on the other end side of the holding member 505 with respect to the left-right direction. In the present embodiment, the third wall portion 753 and the fourth wall portion 754 are arranged on both sides of the contact pin 515 with respect to the left-right direction. The first wall portion 751 and the third wall portion 753 are disposed on the same side with respect to the left-right direction, that is, the first wall portion 751 and the third wall portion 753 are disposed on the right side of the holding member 505. The second wall portion 752 and the fourth wall portion 754 are arranged on the same side with respect to the left-right direction, that is, the second wall portion 752 and the fourth wall portion 754 are arranged on the left side of the holder member 505.

As shown in part (c) of fig. 26, the third wall portion 753 and the fourth wall portion 754 include inner wall surfaces that are opposite to each other. An opening 757 is formed in the third wall portion 753, and an opening 758 is formed in the fourth wall portion 754. The opening 757 and the opening 758 are elongated holes extending in the up-down direction. The protrusions 656 are inserted in the openings 757 and 758. The protrusion 656 is not engaged with the opening 757 and the opening 758, and is inserted at the narrowest portion with respect to the front-rear direction with a gap of about 0.5 mm. Therefore, the moving direction of the protruding portion 656 is guided by the openings 757 and the openings 758 with respect to the up-down direction without receiving a large frictional force from the inner wall surfaces of the openings 757 and the openings 758.

Part (d) of fig. 26 is a diagram in which the third wall part 753 is removed from part (c) of fig. 26. The third engaging portion 545 and the fourth engaging portion 546 are arranged between the third wall portion 753 and the fourth wall portion 754 with respect to the left-right direction. Furthermore, the third engagement portion 545 and the fourth wall portion 546 are arranged between the opening 757 and the opening 758. In the present embodiment, the fourth engaging portion 546 is arranged closer to the end portion side of the holding member 505 than the third engaging portion 545. The third engaging portion 545 and the fourth engaging portion 546 are protrusions that protrude downward from a connecting portion that connects the third wall portion 753 and the fourth wall portion 754 of the holding member 505. One end portion of the coil spring 548 is engaged with the third engaging portion 545, and the other end portion of the coil spring 548 is engaged with the fourth engaging portion 546. The third and fourth engaging portions 545 and 546 are arranged on the spring mounting portion 662 such that the coil spring 548 engaged with the third and fourth engaging portions 545 and 546 traverses the openings 757 and 758.

The third engaging portion 545 and the fourth engaging portion 546 are arranged at different positions with respect to the up-down direction. In the present embodiment, the third engaging portion 545 is arranged closer to the photosensitive drum 103 side than the fourth engaging portion 546. In addition, the third engaging portion 545 and the fourth engaging portion 546 may be provided at the same height with respect to the up-down direction, and the fourth engaging portion 546 may be arranged closer to the photosensitive drum 103 side than the third engaging portion 545.

As shown in part (d) of fig. 26, the protruding portion 656 is inserted into the opening 758 from the outer wall surface side of the fourth wall portion 754, and passes under the coil spring 548 bridging between the third engaging portion 545 and the fourth engaging portion 546, and is inserted into the opening 757 of the third wall portion 753.

In addition, in the present embodiment, as examples of the coil spring 547 and the coil spring 548, a coil-shaped spring is shown, but a plate spring may be used.

Next, the action of the projecting portion 655 provided on the link member 651 on the coil spring 547, and the action of the projecting portion 656 provided on the link member 652 on the coil spring 548 will be described using fig. 27. The action of the projection 655 on the coil spring 547 and the action of the projection 656 on the coil spring 548 are substantially similar to each other, and therefore in fig. 27, the action of the projection 656 on the coil spring 548 will be illustrated by way of example.

Part (a) of fig. 27 is a view showing a state in which the contact pin 515 provided in the holding member 505 is retracted from the contact surface 551 of the drum unit 518. Part (b) of fig. 27 is a view showing a timing when the contact pin 515 contacts the contact surface 551 of the drum unit 518. Part (c) of fig. 27 is a view showing a state in which the link member 652 is rotated counterclockwise from the state of part (b) of fig. 27.

In the state of part (a) of fig. 27, when the slidable portion 525 slides (moves), the link member 652 rotates counterclockwise in association therewith, so that the protruding portion 656 moves to the upper side. At this time, the protrusion 656 presses the coil spring 548 upward. When the protrusion 656 presses the coil spring 548 toward the upper side, a force acts on the holding member 505 toward the upper side via the third engaging portion 545 and the fourth engaging portion 546. The contact pin 515 is not in contact with the drum unit 518. There is no force against the force with which the protrusion 656 presses the coil spring 548, other than the gravitational force acting on the optical print head 105. Therefore, when the force acting on the third engaging portion 545 and the fourth engaging portion 546 toward the upper side becomes greater than the gravitational force acting on the optical print head 105, the holding member 505 is moved toward the upper side by the force acting on the third engaging portion 545 and the fourth engaging portion 546. Here, when the holding member 505 is in the retracted position, the lower end portion of the contact pin 515(514) and the holding member 505 are supported by the apparatus main assembly, so that the projecting portion 656(655) of the link member 652(651) may not be in contact with the coil spring 548(547) as well.

When the holding member 505 is moved to the upper side, as shown in part (b) of fig. 27, the contact pin 515 contacts the contact surface 551 of the drum unit 518. In part (b) of fig. 27, the optical print head 105 is disposed at the exposure position, but the urging force acting on the optical print head 105 for urging the optical print head 105 toward the drum unit 518 is insufficient. For this reason, in order to apply the above-described urging force to the optical print head 105, the moving mechanism 640 of the present embodiment has a configuration in which the link member 652 can further rotate from the state of part (b) of fig. 27.

Even when the link member 652 is further rotated counterclockwise from the state of part (b) of fig. 27, the contact pin 515 contacts the contact surface 551 of the drum unit 518, and therefore, the position of the holding member 505 does not change. On the other hand, the protruding portion 656 moves in an upper direction. For this reason, the coil spring 548 is pressed between the third engaging portion 545 and the fourth engaging portion 546 by the protrusion 656 and is elongated by bending, as shown in part (c) of fig. 27.

The state of part (c) of fig. 27 corresponds to the state of the cover 558 in parts (c) and (d) of fig. 23. That is, the slidable portion 525 is in a state where the slidable portion 525 does not slide (move) further toward the upper side. Therefore, the slidable portion 525 does not slide (move), and therefore, the link member 652 does not rotate counterclockwise from the state shown in part (c) of fig. 27, and the protruding portion 656 is stationary at the position of part (c) of fig. 27 without moving toward the upper side. In this state, the contraction force of the coil spring 548 acts on the third engaging portion 545 and the fourth engaging portion 546. The component of the contraction force of the coil spring 548 acting on the third engaging portion 545 and the fourth engaging portion 546 is directed in the upward direction, and therefore, an urging force for urging the holding member 505 toward the drum unit 518 side acts on the holding member 505, so that the holding member 505 is urged toward the drum unit 518 via the contact pin 515.

As described above, the third engaging portion 545 is arranged closer to the photosensitive drum 103 side than the fourth engaging portion 546, and therefore, the resistance (reaction force) in the arrow N direction acts on the coil spring 548 from the protruding portion 656. The component of the resistance force in the direction of arrow N acts on the holding member 505. Therefore, a force toward the rear side with respect to the front-rear direction acts on the contact pin 515, so that the contact pin 515 contacted to the contact surface 551 is pressed to and contacted to the rear side wall surface 596 on the rear side of the engaging portion 685. The reason why the first engaging portion 543 is arranged closer to the photosensitive drum 103 side than the second engaging portion 544 is also similar to the above-described reason.

As described above, the lens mounting portion 701 is formed on the holding member 505 provided in the optical print head 105 according to the present embodiment described above, and the lens mounting portion 701 includes the opposing surfaces (the first inner wall surface 507 and the second inner wall surface 508) opposing the side wall surfaces of the lens array 506 and the inclined surfaces (the first inclined surface 703 and the second inclined surface 704) provided closer to the photosensitive drum 103 side than the opposing surfaces, the inclined surfaces being inclined to extend away from the side wall surfaces of the lens array 506 toward the photosensitive drum 103 side, and the filling agent is filled in the grooves formed by the inclined surfaces and the side wall surfaces of the lens array 506.

[ Industrial Applicability ]

According to the present invention, it is possible to provide an optical print head and an imaging apparatus including a lens array in which a mounting position of the lens array with respect to a holding member can be adjusted in a state where the lens array is held by a holding mechanism.

[ expression of symbol ]

502 substrate

505 holding member

506 lens array

507 first inner wall surface (first opposing portion)

508 second inner wall surface (second opposing portion)

701 lens mounting part

702 substrate mounting part

703 first inclined surface

704 second inclined surface

906 through hole

907 adhesive

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Optical print head, image forming apparatus, and method of manufacturing optical print head

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