阅读说明：本技术 显影盒 (Developing box ) 是由 深町泰生 田口和奈 神田卓也 于 2015-09-01 设计创作，主要内容包括：提供一种显影盒,即使肋设在靠近显影辊的位置,也能使联结构件、惰轮和第一搅拌器齿轮旋转而不被阻碍。具有显影辊(7)的显影盒(3)包括：显影辊齿轮(68),连接到显影辊(7)；显影联结(67),与显影辊齿轮(68)啮合；惰轮(70),与显影联结(67)啮合；搅拌器齿轮(71),与惰轮(70)啮合,连接到搅拌器(11)；以及突起(60L),位于壳体(51)的左壁(53L)。突起(60L)的长度(D2)比左壁(53L)的左表面与搅拌器齿轮(71)之间的长度(D1)短。(Provided is a developing cartridge which can rotate a coupling member, an idler gear, and a first agitator gear without being hindered even if a rib is provided at a position close to a developing roller. A developing cartridge (3) having a developing roller (7) includes: a developing roller gear (68) connected to the developing roller (7); a developing coupling (67) that meshes with the developing roller gear (68); an idler (70) meshed with the developing coupling (67); a stirrer gear (71) engaged with the idle gear (70) and connected to the stirrer (11); and a protrusion (60L) located on a left wall (53L) of the housing (51). The length (D2) of the projection (60L) is shorter than the length (D1) between the left surface of the left wall (53L) and the agitator gear (71).)

1. A developing cartridge comprising:

a housing configured to accommodate a developer inside the housing;

a developing roller extending in a first direction;

a developing roller gear mounted to the developing roller to be rotatable together with the developing roller, the developing roller gear being located at an outer surface (53L) of the casing;

a coupling member rotatable about a first axis extending in the first direction, located at the outer surface, the coupling member including a coupling gear that meshes with the developing roller gear, the coupling gear being rotatable together with the coupling member;

a first idler gear meshed with the coupling gear and rotatable about a second axis extending in the first direction, the first idler gear being located on the outer surface;

a second idler rotatable with the first idler about the second axis, the second idler being located at the outer surface and being further from the outer surface than the first idler, the second idler having a diameter smaller than a diameter of the first idler;

an agitator extending in the first direction;

a first agitator gear mounted to the agitator to be rotatable with the agitator about a third axis extending in the first direction, the first agitator gear being located on the outer surface and meshing with the second idler gear; and

a protrusion extending in the first direction, the protrusion being located between the first axis and the third axis in a second direction connecting the first axis and the third axis, the protrusion being located on the outer surface, the protrusion being located on an outer side of a tip circle of the developing roller gear, an outer side of a tip circle of the coupling gear, an outer side of a tip circle of the first idle gear, and an outer side of a tip circle of the second idle gear,

the first agitator gear is spaced from the projection in the first direction.

2. A developing cartridge according to claim 1, wherein an edge portion of said first agitator gear is apart from said projection in said first direction.

3. A developing cartridge according to claim 2, wherein an edge portion of said first agitator gear facing said outer surface is spaced apart from said projection.

4. A developing cartridge according to claim 1, wherein an edge portion of said first agitator gear is farther from said outer surface than said projection in said first direction.

5. A developing cartridge according to claim 1, wherein a length between said outer surface and said first agitator gear in said first direction is greater than a length of said projection extending from said outer surface in said first direction.

6. A developing cartridge according to claim 1, wherein a length between said outer surface and an edge portion of said first agitator gear in said first direction is larger than a length of said projection extending from said outer surface in said first direction.

7. A developing cartridge according to claim 1, wherein a length between said outer surface and an edge portion of said first agitator gear facing said outer surface in said first direction is larger than a length of said projection extending from said outer surface in said first direction.

8. A developing cartridge according to any one of claims 1 to 7, wherein said projection is mounted on said outer surface.

9. A developing cartridge according to any one of claims 1 to 8, wherein said projection projects from said outer surface.

10. A developing cartridge according to any one of claims 1 to 9, wherein said first idle gear is located on one side with respect to a virtual plane connecting said developing roller and said agitator,

the protrusion is located on an opposite side of the first idler wheel with respect to the imaginary plane.

11. A developing cartridge according to any one of claims 1 to 10, wherein said projection includes a curved surface curved in a direction from said developing roller toward said projection.

12. A developing cartridge according to any one of claims 1 to 10, wherein said projection includes a surface for receiving a pressing force.

13. A developing cartridge according to any one of claims 1 to 10, wherein said projection receives a pressing force from said drum cartridge in response to mounting of said developing cartridge to the drum cartridge.

14. A developing cartridge according to claim 13, wherein said projection receives a pressing force directed to the photosensitive drum of said drum cartridge in response to mounting of said developing cartridge to said drum cartridge.

15. A developing cartridge according to any one of claims 1 to 14, further comprising:

a supply roller extending in the first direction and configured to supply the developer to the developing roller; and

a supply roller gear mounted to the supply roller to be rotatable together with the supply roller, the supply roller gear being engaged with the coupling gear and located at the outer surface,

the protrusion is located outside an addendum circle of the supply roller gear.

16. A developing cartridge according to any one of claims 1 to 15, wherein said casing includes said outer surface and a second outer surface spaced from said outer surface in said first direction,

the developing roller gear, the coupling member, the first idler gear, the second idler gear, the first agitator gear, and the protrusion are located on the outer surface.

17. A developing cartridge according to claim 16, further comprising a second protrusion extending in the first direction, located at the second outer surface,

at least a portion of the protrusion is aligned with at least a portion of the second protrusion in the first direction.

18. A cartridge according to claim 17, wherein the second projection is mounted to the second outer surface.

19. A developing cartridge according to claim 17, wherein said second protrusion protrudes from said second outer surface.

20. A developing cartridge according to any one of claims 17 to 19, wherein said projection includes a curved surface curved in a direction from said developing roller toward said projection,

the second protrusion includes a curved surface curved in a direction from the developing roller toward the second protrusion.

21. A developing cartridge according to any one of claims 17 to 19, wherein said projection includes a surface for receiving a pressing force,

the second protrusion includes a surface for receiving pressure.

22. A developing cartridge according to any one of claims 17-21, wherein said projection and said second projection receive a pressing force from said drum cartridge in response to mounting said developing cartridge to the drum cartridge.

23. A developing cartridge according to claim 22, wherein said projection and said second projection receive a pressing force directed to the photosensitive drum of said drum cartridge in response to mounting of said developing cartridge to said drum cartridge.

24. A developing cartridge according to any one of claims 16 to 23, wherein said agitator includes:

a mixer body located between the outer surface and the second outer surface; and

an agitator shaft extending in the first direction, an end of the agitator shaft penetrating the outer surface,

the first agitator gear is mounted at the one end of the agitator shaft.

25. A developing cartridge according to any one of claims 16 to 24, wherein said developing roller includes:

a developer roller body located between the outer surface and the second outer surface; and

a developing roller shaft extending in the first direction, an end portion of the developing roller shaft penetrating the outer surface,

the developing roller gear is mounted at the one end portion of the developing roller shaft.

26. A developing cartridge according to claim 25, wherein a length between said developing roller body and said first agitator gear in said first direction is larger than a length between an end of said projection and said first agitator gear in said first direction.

27. A developing cartridge according to claim 26, further comprising a supply roller extending in said first direction and configured to supply said developer to said developing roller, said supply roller comprising:

a feed roller body located between the outer surface and the second outer surface;

a supply roller shaft extending in the first direction, an end portion of the supply roller shaft penetrating the outer surface; and

a supply roller gear installed at the one end portion of the supply roller shaft, the supply roller gear being rotatable together with the supply roller, the supply roller gear being located at the outer surface, being engaged with the coupling gear,

the protrusion is located outside an addendum circle of the supply roller gear.

28. A developing cartridge according to claim 25, further comprising a bearing, said bearing being located on said outer surface, said one end portion of said developing roller shaft penetrating through said bearing,

the bearing includes a coupling shaft extending from the bearing in the first direction,

the coupling member is rotatable relative to the coupling shaft,

the developing roller gear is mounted at the one end portion of the developing roller shaft.

29. A developing cartridge according to claim 28, further comprising a supply roller extending in said first direction and configured to supply said developer to said developing roller, said supply roller comprising:

a feed roller body located between the outer surface and the second outer surface;

a supply roller shaft extending in the first direction, an end portion of the supply roller shaft penetrating the outer surface and the bearing; and

a supply roller gear installed at the one end portion of the supply roller shaft, the supply roller gear being rotatable together with the supply roller, the supply roller gear being located at the outer surface, being engaged with the coupling gear,

the protrusion is located outside an addendum circle of the supply roller gear.

30. A developing cartridge according to any one of claims 1 to 29, further comprising a gear cover covering at least a portion of at least one of said developing roller gear, said coupling member, said first idle gear, said second idle gear and said first agitator gear.

31. A developing cartridge according to claim 30, wherein at least a part of said projection is located outside said gear cover.

32. A developing cartridge according to any one of claims 1 to 31, wherein at least a part of said projection is located inside a tip circle of a gear of said first agitator.

33. A developing cartridge according to claim 32, wherein an edge portion of said projection facing said first agitator gear is spaced apart from said first agitator gear in said first direction.

34. A developing cartridge according to any one of claims 1 to 33, further comprising:

a second agitator gear rotatable with the first agitator gear about the third axis, the second agitator gear being closer to the outer surface than the first agitator gear, the second agitator gear having a diameter smaller than a diameter of the first agitator gear;

a friction wheel engageable with the second agitator gear, the friction wheel being located on the outer surface; and

a protrusion that protrudes in the first direction farther from the outer surface than the friction wheel, the protrusion being movable in the first direction in response to rotation of the friction wheel,

the protrusions are located outside of a addendum circle of the gear of the second agitator and outside of a addendum circle of the friction wheel.

35. A developing cartridge according to any one of claims 1 to 34, wherein the agitator includes an agitator shaft extending along the third axis,

the first agitator gear is mounted on the agitator shaft for rotation therewith,

the protrusion is located between the coupling member and the agitator shaft in a second direction connecting the coupling member rotatable about the first axis and the agitator shaft extending along the third axis.

Technical Field

The present invention relates to a developing cartridge.

Background

A developing cartridge mountable to a drum cartridge is known in the art. One such drum cartridge includes a photosensitive drum.

The developing cartridge has a rib at a side surface of the developing cartridge. When the developing cartridge is mounted to the drum cartridge, the rib is pressed by a rotating arm provided at the drum cartridge. By this operation, the developing roller provided at the developing cartridge is pressed toward the photosensitive drum of the drum cartridge.

Patent document 1: japanese patent laid-open No. 2013-50493

Disclosure of Invention

In the above-described conventional developing cartridge, the coupling member is engaged with the idle gear, and the idle gear is engaged with the agitator gear. In some cases, the rib is provided at a position closer to the developing roller than the above-described prior art position.

In the above case, since the rib may contact a gear (e.g., an idler gear or an agitator gear) located on the developing cartridge side surface, the rib may interfere with the rotation of the gear, for example.

In view of the above, it is an object of the present invention to provide a developing cartridge capable of rotating a coupling member, an idler gear, and an agitator gear even when a rib is provided at a position close to a developing roller.

In order to achieve the above and other objects, according to one aspect of the present invention, there is provided a developing cartridge comprising: a housing configured to accommodate a developer inside the housing; a developing roller extending in a first direction; a developing roller gear mounted to the developing roller to be rotatable together with the developing roller, the developing roller gear being located at an outer surface of the casing; a coupling member rotatable about a first axis extending in the first direction, located at the outer surface, the coupling member including a coupling gear that meshes with the developing roller gear, the coupling gear being rotatable together with the coupling member; a first idler gear meshed with the coupling gear and rotatable about a second axis extending in the first direction, the first idler gear being located on the outer surface; a second idler rotatable with the first idler about the second axis, the second idler being located at the outer surface and being further from the outer surface than the first idler, the second idler having a diameter smaller than a diameter of the first idler; an agitator extending in the first direction; a first agitator gear mounted to the agitator to be rotatable with the agitator about a third axis extending in the first direction, the first agitator gear being located on the outer surface and meshing with the second idler gear; and a protrusion extending in the first direction, the protrusion being located between the first axis and the third axis in a second direction connecting the first axis and the third axis, the protrusion being located on the outer surface, the protrusion being located on an outer side of a addendum circle of the developing roller gear, an outer side of a addendum circle of the coupling gear, an outer side of a addendum circle of the first idle gear, and an outer side of a addendum circle of the second idle gear. The first agitator gear is spaced from the projection in the first direction.

With this structure, the projection is located between the first axis and the third axis, on the outer surface, and outside the addendum circles of the developing roller gear, the coupling gear, the first idle gear, and the second idle gear. The first agitator gear is spaced from the projection in a first direction.

Therefore, even if the protrusion is located at a position close to the developing roller (specifically, between the first axis and the third axis), the coupling member, the first idle gear, the second idle gear, and the first agitator gear can be rotated without being hindered.

(2) Preferably, an edge of the first agitator gear is spaced apart from the protrusion in the first direction.

(3) Preferably, an edge of the first agitator gear facing the outer surface is spaced apart from the projection.

(4) Preferably, an edge of the first agitator gear is farther from the outer surface than the projection in the first direction.

(5) Preferably, a length between the outer surface and the first agitator gear in the first direction is greater than a length of the projection extending from the outer surface in the first direction.

(6) Preferably, a length between the outer surface and an edge of the first agitator gear in the first direction is greater than a length of the projection extending from the outer surface in the first direction.

(7) Preferably, a length between the outer surface and an edge of the first agitator gear facing the outer surface in the first direction is greater than a length of the projection extending from the outer surface in the first direction.

(8) Preferably, said protrusion is mounted on said outer surface.

(9) Preferably, the protrusion protrudes from the outer surface.

(10) Preferably, the first idle roller is located on one side with respect to a virtual plane connecting the developing roller and the agitator, and the protrusion is located on an opposite side of the first idle roller with respect to the virtual plane.

(11) Preferably, the protrusion includes a curved surface curved in a direction from the developing roller toward the protrusion.

(12) Preferably, the protrusion comprises a surface for receiving pressure.

(13) Preferably, the projection receives pressure from the drum cartridge in response to mounting the developing cartridge to the drum cartridge.

(14) Preferably, the projection receives a pressing force of the photosensitive drum directed to the drum cartridge in response to mounting of the developing cartridge to the drum cartridge.

(15) Preferably, the method further comprises the following steps: a supply roller extending in the first direction and configured to supply the developer to the developing roller; and a supply roller gear mounted to the supply roller to be rotatable together with the supply roller, the supply roller gear being engaged with the coupling gear and located on the outer surface, the protrusion being located outside an addendum circle of the supply roller gear.

(16) Preferably, the housing includes the outer surface and a second outer surface spaced apart from the outer surface in the first direction, the developing roller gear, the coupling member, the first idle gear, the second idle gear, the first agitator gear, and the projection being located on the outer surface.

(17) Preferably, a second protrusion is included, the second protrusion extending in the first direction and located on the second outer surface, at least a portion of the protrusion being aligned with at least a portion of the second protrusion in the first direction.

(18) Preferably, the second protrusion is mounted on the second outer surface.

(19) Preferably, the second protrusion protrudes from the second outer surface.

(20) Preferably, the protrusion includes a curved surface curved in a direction from the developing roller toward the protrusion, and the second protrusion includes a curved surface curved in a direction from the developing roller toward the second protrusion.

(21) Preferably, the protrusion comprises a surface for receiving pressure and the second protrusion comprises a surface for receiving pressure.

(22) Preferably, the projection and the second projection receive pressure from the drum cartridge in response to mounting the developing cartridge to the drum cartridge.

(23) Preferably, the projection and the second projection receive a pressing force of the photosensitive drum directed to the drum cartridge in response to mounting of the developing cartridge to the drum cartridge.

(24) Preferably, the agitator comprises: a mixer body located between the outer surface and the second outer surface; and an agitator shaft extending in the first direction, an end of the agitator shaft penetrating the outer surface, the first agitator gear being mounted at the end of the agitator shaft.

(25) Preferably, the developing roller includes: a developer roller body located between the outer surface and the second outer surface; and a developing roller shaft extending in the first direction, an end portion of the developing roller shaft penetrating the outer surface, the developing roller gear being installed at the end portion of the developing roller shaft.

(26) Preferably, a length between the developing roller body and the first agitator gear in the first direction is greater than a length between an end of the projection and the first agitator gear in the first direction.

(27) Preferably, the developing device further includes a supply roller extending in the first direction and configured to supply the developer to the developing roller, the supply roller including: a feed roller body located between the outer surface and the second outer surface; a supply roller shaft extending in the first direction, an end portion of the supply roller shaft penetrating the outer surface; and a supply roller gear mounted at the one end portion of the supply roller shaft, the supply roller gear being rotatable together with the supply roller, the supply roller gear being located at the outer surface and engaged with the coupling gear, the protrusion being located outside an addendum circle of the supply roller gear.

(28) Preferably, a bearing is further included, the bearing being located at the outer surface, the one end portion of the developing roller shaft penetrating the bearing, the bearing including a coupling shaft extending from the bearing in the first direction, the coupling member being rotatable relative to the coupling shaft, the developing roller gear being mounted at the one end portion of the developing roller shaft.

(29) Preferably, the developing device further includes a supply roller extending in the first direction and configured to supply the developer to the developing roller, the supply roller including: a feed roller body located between the outer surface and the second outer surface; a supply roller shaft extending in the first direction, an end portion of the supply roller shaft penetrating the outer surface and the bearing; and a supply roller gear mounted at the one end portion of the supply roller shaft, the supply roller gear being rotatable together with the supply roller, the supply roller gear being located at the outer surface and engaged with the coupling gear, the protrusion being located outside an addendum circle of the supply roller gear.

(30) Preferably, the developing device further includes a gear cover that covers at least a portion of at least one of the developing roller gear, the coupling member, the first idle gear, the second idle gear, and the first agitator gear.

(31) Preferably, at least a portion of the protrusion is located outside the gear cover.

(32) Preferably, at least a portion of the projection is located inside a tooth top circle of the first agitator gear.

(33) Preferably, an edge of the protrusion facing the first agitator gear is spaced apart from the first agitator gear in the first direction.

(34) Preferably, the method further comprises the following steps: a second agitator gear rotatable with the first agitator gear about the third axis, the second agitator gear being closer to the outer surface than the first agitator gear, the second agitator gear having a diameter smaller than a diameter of the first agitator gear; a friction wheel engageable with the second agitator gear, the friction wheel being located on the outer surface; and a protrusion that protrudes in the first direction farther from the outer surface than the friction wheel, the protrusion being movable in the first direction in response to rotation of the friction wheel, the protrusion being located outside of a addendum circle of the second agitator gear and outside of a addendum circle of the friction wheel.

(35) Preferably, the agitator comprises an agitator shaft extending along the third axis, the first agitator gear is mounted on the agitator shaft for rotation therewith, and the projection is located between the coupling member and the agitator shaft in a second direction connecting the coupling member rotatable about the first axis and the agitator shaft extending along the third axis.

The developing cartridge of the present invention can rotate the coupling member, the idle gear, and the first agitator gear even if the protrusion is located at a position close to the developing roller.

Drawings

Fig. 1 is an example of a perspective view of a developing cartridge according to a first embodiment;

fig. 2 is an example of a perspective view of the developing cartridge according to the first embodiment, with a gear cover omitted;

fig. 3 is an example of an exploded perspective view of the developing cartridge in fig. 2;

fig. 4 is an example of a bottom view of the developing cartridge in fig. 1;

FIG. 5 is an example of a cross-sectional view A-A of FIG. 4, with the gear cover omitted;

FIG. 6 is an example of a cross-sectional view B-B of FIG. 5;

fig. 7 is an example of a perspective view of the developing cartridge in fig. 1 viewed from the right;

fig. 8 is an example of a perspective view of the developing cartridge in fig. 1 from below;

fig. 9 is an example of a perspective view of a drum cartridge according to the first embodiment;

fig. 10 is an example of a perspective view showing the developing cartridge according to the first embodiment mounted on the drum cartridge;

fig. 11 is an example of a top view of the process cartridge shown in fig. 10;

FIG. 12 is an example of a cross-sectional view C-C of FIG. 11;

FIG. 13 is an example of the cross-sectional view D-D of FIG. 11, with the locking lever in the locked position;

FIG. 14 is an example of a cross-sectional view D-D of FIG. 11, with the locking lever in an unlocked position;

fig. 15 is an example of a central sectional view of an image forming apparatus to which a process cartridge according to the first embodiment is mounted;

fig. 16A is an example of a perspective view seen from the rear upper side of an agitator gear provided at the developing cartridge according to the second embodiment, and fig. 16B is an explanatory view showing the developing cartridge according to the second embodiment;

fig. 17 is an example of a perspective view of a detection unit according to the third embodiment;

fig. 18A is an example of a perspective view from the left of the partially-toothless gear shown in fig. 17, and fig. 18B is a perspective view from the right of the partially-toothless gear shown in fig. 18A;

fig. 19A is an example of a perspective view seen from the left side of the detecting member shown in fig. 17, and fig. 19B is an example of a perspective view seen from the right side of the detecting member shown in fig. 19A;

fig. 20A shows an example of the detecting unit in fig. 17, in which a partially-toothless gear is located at an initial position, and fig. 20B is an example of a perspective view seen from below of the detecting unit in fig. 20A;

fig. 21A shows an example of a state in which a rib provided on the agitator gear is in contact with a boss provided on the partially-toothless gear, and fig. 21B shows an example of a state in which the partially-toothless gear is located at the drive transmission position;

fig. 22 shows an example of a state where a partially-toothless gear is located at a final position;

fig. 23 is an example of an explanatory view showing a developing cartridge according to a modification of the second embodiment; and

fig. 24 is an example of an explanatory diagram showing a developing cartridge according to a modification of the third embodiment.

Detailed Description

[ first embodiment ]

1. Developing cartridge summary

As shown in fig. 1, 2, 3, and 15, the developing cartridge 3 includes a casing 51, a supply roller 8, a developing roller 7, a thickness regulating sheet 9, a bearing 50, a gear train 65, and a gear cover 66. The developing roller 7 extends in a predetermined direction. In the first embodiment, the predetermined direction in which the developing roller 7 extends is the left-right direction. When referring to the drawings, the up-down direction and the front-rear direction defined based on the left-right direction are shown by arrows in fig. 1.

< toner containing portion 10>

As shown in fig. 6, the toner accommodating portion 10 is provided inside the developing cartridge 3. Specifically, the toner containing portion 10 is a space provided inside the housing 51. The toner containing portion 10 is for containing toner. Toner is an example of a developer.

< Agitator 11>

The agitator 11 is provided inside the housing 51. Specifically, the agitator 11 is provided in the toner containing portion 10. The agitator 11 is rotatably supported in the toner accommodating portion 10. The agitator 11 includes an agitator shaft 11A and a blade 11B. In the first embodiment, the agitator 11 includes a plurality of blades 11B. The plurality of blades 11B can stir the toner in the toner containing portion 10. The blade 11B may be made of resin. The blade 11B may be made of a thin sheet.

The agitator shaft 11A has a columnar shape extending in the left-right direction. That is, the central axis a2 of the agitator 11 extends in the left-right direction. The central axis a2 of the beater 11 is an example of a third axis.

Each of the plurality of blades 11B extends radially outward from the outer peripheral surface of the agitator shaft 11A. The plurality of blades 11B are located inside the toner accommodating portion 10. The plurality of blades 11B are located between a left wall 53L and a right wall 53R of the housing 51, which will be described later, inside the toner containing portion 10. The portion of the agitator 11 provided with the plurality of blades 11B is an example of an agitator body.

< supply roll 8>

As shown in fig. 3 and 15, the supply roller 8 is a roller for supplying toner from the toner containing portion 10 to the developing roller 7. The feed roller 8 includes a feed roller shaft 8A and a feed roller body 8B.

The supply roller shaft 8A has a columnar shape. The supply roller shaft 8A is made of metal. The supply roller shaft 8A extends in the left-right direction.

The supply roller main body 8B is cylindrical. The supply roller main body 8B extends in the left-right direction. The supply roller body 8B is made of, for example, a conductive sponge material. The supply roller body 8B covers a central region of the supply roller shaft 8A in the left-right direction. In the first embodiment, the supply roller body 8B does not cover the left and right end portions of the supply roller shaft 8A. In other words, in the first embodiment, the supply roller shaft 8A is inserted through the supply roller body 8B in the left-right direction. The supply roller main body 8B is located between a later-described left wall 53L and a right wall 53R of the housing 51 in the left-right direction. The surface of the supply roller body 8B is in contact with the surface of the developing roller body 7B.

Although the supply roller shaft 8A is inserted through the supply roller body 8B in the left-right direction in the first embodiment, the supply roller shaft 8A may extend from the left and right ends of the supply roller body 8B in the left-right direction.

< developing roller 7>

As shown in fig. 1, the developing roller 7 includes a developing roller shaft 7A and a developing roller body 7B.

The developing roller shaft 7A is columnar. The developing roller shaft 7A is made of metal. The developing roller shaft 7A extends in the left-right direction. That is, the central axis a1 of the developing roller 7 extends in the left-right direction.

The developing roller body 7B is cylindrical. The developing roller body 7B extends in the left-right direction. The developing roller body 7B is made of, for example, conductive rubber. The developing roller body 7B covers a central region of the developing roller shaft 7A in the left-right direction. In the first embodiment, the developing roller body 7B does not cover the left and right end portions of the developing roller shaft 7A. In other words, in the first embodiment, the developing roller shaft 7A is inserted through the developing roller body 7B in the left-right direction. The developing roller body 7B is located between a later-described left wall 53L and a right wall 53R of the casing 51 in the left-right direction.

Although the developing roller shaft 7A is inserted through the developing roller body 7B in the left-right direction in the first embodiment, the developing roller shaft 7A may extend from the left and right ends of the developing roller body 7B in the left-right direction.

< thickness-regulating sheet 9>

The thickness regulating blade 9 is located on the front upper side of the developing roller 7. The thickness regulating blade 9 contacts the surface of the developing roller body 7B.

2. Shell body

The housing 51 has a box shape. The housing 51 includes a left wall 53L, a right wall 53R, a bottom wall 54, a front wall 55, and an upper wall 56. The toner accommodating portion 10 (refer to fig. 6) is a space defined by the left wall 53L, the right wall 53R, the bottom wall 54, the front wall 55, and the upper wall 56. In the first embodiment, the side of the housing 51 on which the toner containing portion 10 is provided is defined as the inside of the housing 51, and the side of the housing 51 opposite to the toner containing portion 10 is defined as the outside of the housing 51. The surface of the housing 51 is an example of an outer surface.

< left wall 53L >

As shown in fig. 1 and 3, the left wall 53L is located at one end of the developing roller 7 in the left-right direction. Specifically, the left wall 53L is located at one end of the developing roller body 7B in the left-right direction. The left wall 53L is located at the left end of the housing 51. The left wall 53L is plate-shaped extending in the front-rear direction and the up-down direction. The left wall 53L has an insertion hole 77, the agitator gear shaft 59, the idler shaft 58, and the projection 60L. The outer surface of the left wall 53L is an example of an outer surface.

< insertion hole 77>

The left end portion 7C of the developing roller shaft 7A is inserted through the insertion hole 77. Specifically, the left end portion 7C of the developing roller shaft 7A is inserted into the insertion hole 77 in a state where the developing roller shaft 7A is mounted on a bearing 50 described later. At this time, the bearing 50 is mounted on the outer surface of the left wall 53L. The insertion hole 77 is located at the rear end portion of the left wall 53L. The insertion hole 77 penetrates the left wall 53L in the left-right direction. Further, the insertion hole 77 is cut rearward from the rear edge of the left wall 53L.

< stirrer gear shaft 59>

An agitator gear shaft 59 is located on the surface of the housing 51. Specifically, the agitator gear shaft 59 extends outward from the surface of the housing 51, and the agitator gear shaft 59 has a cylindrical shape. An agitator gear shaft 59 is located on the outer surface of the left wall 53L. The agitator gear shaft 59 extends from the outer surface of the left wall 53L in the left-right direction. A through hole 59A extending in the left-right direction is formed inside the agitator gear shaft 59. More specifically, the through hole 59A penetrates the inside of the agitator gear shaft 59 in the left-right direction. The left end portion 11C of the agitator shaft 11A is inserted through the through hole 59A and exposed to the outer surface of the left wall 53L. An agitator gear 71 described later is attached to the exposed left end portion 11C of the agitator shaft 11A.

< idler shaft 58>

An idler shaft 58 is located on a surface of the housing 51. Specifically, the idler shaft 58 extends outwardly from the surface of the housing 51 and is cylindrical. An idler shaft 58 is located on the outer surface of the left wall 53L. The idler shaft 58 extends leftward from the outer surface of the left wall 53L, and is cylindrical. That is, the center axis a4 of the idler shaft 58 extends in the left-right direction. The idler shaft 58 is located between the bearing 50 and the agitator gear shaft 59 in the front-rear direction. The central axis a4 of the idler shaft 58 is an example of a second axis.

< position of projection 60L >

The projection 60L is located on the surface of the housing 51. Specifically, the projection 60L extends outward from the surface of the housing 51. The projection 60L is located on the outer surface of the left wall 53L. The projection 60L extends leftward from the outer surface of the left wall 53L. The projection 60L is located on the opposite side of the agitator gear shaft 59 from the idler shaft 58 in the up-down direction. Further, as shown in fig. 5, the projection 60L is located on the opposite side of the idler shaft 58 of a virtual plane L passing through the central axis a1 of the developing roller shaft 7A and the central axis a2 of the agitator shaft 11A. In the first embodiment, the protrusion 60L extends from the outer surface of the left wall 53L, but is not limited to this structure. For example, the projection 60L may be mounted as a separate member on the outer surface of the left wall 53L. Alternatively, the projection 60L may be mounted on the outer surface of the left wall 53L by another member. The projection 60L may be fixed to the left wall 53L.

< shape of projection 60L >

The projection 60L has a U-shape when viewed in the left-right direction. The projection 60L has a shape capable of receiving pressure. Specifically, the projection 60L has a surface for receiving pressure. More specifically, the protrusion 60L has a curved surface 61. The curved surface 61 is curved in a direction from the developing roller 7 to the protrusion 60L. When the pressing member 26L described later contacts the curved surface 61, the curved surface 61 can appropriately receive the pressure from the pressing member 26L to the photosensitive drum 4. The projection 60L is an example of a projection.

< Right wall 53R >

As shown in fig. 7, the right wall 53R is located at the other end of the developing roller 7 in the left-right direction. The other end of the developing roller 7 is spaced from one end of the developing roller 7 in the left-right direction. Specifically, the right wall 53R is located at the other end of the developing roller body 7B in the left-right direction. The right wall 53R is located at the right end of the housing 51. The right wall 53R has a plate shape extending in the front-rear direction and the up-down direction. The right wall 53R includes a projection 60R, a lift projection 63, and a lock projection 64. The outer surface of the right wall 53R is an example of the second outer surface.

< position of projection 60R >

The projection 60R is located on the surface of the housing 51. Specifically, the projection 60R extends outward from the surface of the housing 51. The projection 60R is located on the outer surface of the right wall 53R. The projection 60R extends rightward from the outer surface of the right wall 53R. At least a part of the projection 60R is aligned with at least a part of the projection 60L (see fig. 3) in the left-right direction. In the first embodiment, the protrusion 60R extends from the outer surface of the right wall 53R, but is not limited to this structure. For example, the projection 60R may be mounted as a separate member on the outer surface of the right wall 53R. Alternatively, the projection 60R may be mounted on the outer surface of the right wall 53R by another member. The projection 60R may be fixed to the right wall 53R.

< shape of projection 60R >

The projection 60R has a U-shape when viewed in the left-right direction. The projection 60R has a shape capable of receiving pressure. Specifically, the protrusion 60R has a surface for receiving pressure. More specifically, the protrusion 60R has a curved surface 62. The curved surface 62 is curved in a direction from the developing roller 7 to the projection 60R. The projection 60R is an example of a second projection. When the pressing member 26R described later contacts the curved surface 62, the curved surface 62 can appropriately receive the pressure from the pressing member 26R to the photosensitive drum 4.

< lifting projection 63>

The lift projection 63 is located between the front end portion of the right wall 53R and the projection 60R in the front-rear direction. The lifting projection 63 is located on the outer surface of the right wall 53R. More specifically, the lift projection 63 is a projection extending rightward from the outer surface of the right wall 53R, and is L-shaped when viewed in the rightward and leftward direction.

< locking projection 64>

The locking projection 64 is located between the front end portion of the right wall 53R and the projection 60R in the front-rear direction. The locking projection 64 is located on the outer surface of the right wall 53R. More specifically, the locking projection 64 is a projection extending rightward from the outer surface of the right wall 53R, and has a prismatic shape.

< bottom wall 54>

As shown in fig. 4 and 8, the bottom wall 54 has a plate shape extending in the front-rear direction. Bottom walls 54 extend from left wall 53L and right wall 53R, respectively.

< front wall 55>

A front wall 55 extends upwardly from the front edge of the bottom wall 54. The front wall 55 is plate-shaped. Front walls 55 extend from left wall 53L and right wall 53R, respectively. A developer cartridge handle 76 is provided on the front wall 55.

The developer cartridge handle 76 is located in the center area of the front edge of the front wall 55 in the left-right direction. The developer cartridge handle 76 projects forward from the front edge of the front wall 55.

< Upper wall 56>

As shown in fig. 3, the upper wall 56 has a rectangular plate shape. The front edge of the upper wall 56 is fixed to the upper edge of the front wall 55. The left edge of the upper wall 56 is fixed to the upper edge of the left wall 53L. The right edge of the upper wall 56 is fixed to the upper edge of the right wall 53R.

< bearing 50>

The bearing 50 is located on the outer surface of the left wall 53L. The bearing 50 is located leftward of the insertion hole 77 and is mounted on the outer surface of the left wall 53L. The bearing 50 has a through hole (not shown) through which the left end portion 7C of the developing roller shaft 7A is inserted. A through hole through which the left end portion 7C of the developing roller shaft 7A is inserted is formed to be aligned with the insertion hole 77 in the left-right direction. With this structure, the bearing 50 can rotatably support the developing roller shaft 7A. The bearing 50 also has a through hole (not shown) through which the left end portion 8C of the supply roller shaft 8A is inserted. With this structure, the bearing 50 rotatably supports the supply roller shaft 8A. The bearing 50 includes a coupling shaft 57.

< coupling shaft 57>

The coupling shaft 57 is located between the developing roller shaft 7A and the idler shaft 58 in the front-rear direction. The coupling shaft 57 is located on the outer surface of the left wall 53L. The coupling shaft 57 extends leftward from the left surface of the bearing 50. The coupling shaft 57 is cylindrical. That is, the central axis a3 of the coupling shaft 57 extends in the left-right direction. The center axis a3 of the coupling shaft 57 is an example of the first axis. Although the coupling shaft 57 extends from the bearing 50 in the first embodiment, the coupling shaft 57 may be mounted to the bearing 50 as a separate member. Alternatively, the coupling shaft 57 may extend from the left wall 53L. In this case, the bearing 50 has a through hole, and the coupling shaft 57 extends leftward through the through hole of the bearing 50.

3. Gear train

As shown in fig. 2, 3, and 5, the gear train 65 is located on the outer surface of the left wall 53L. The gear train 65 includes a developing coupling 67, a developing roller gear 68, a supply roller gear 69, an idle gear 70, and an agitator gear 71. The developing coupling 67 is an example of a coupling member.

< development bond 67>

The development coupling 67 has a columnar shape extending in the left-right direction. The developing coupling 67 is rotatably supported on the coupling shaft 57. Specifically, the developing coupling 67 is mounted on the coupling shaft 57, and the developing coupling 67 is rotatable about the coupling shaft 57. In other words, the developing coupling 67 is rotatable about the center axis a3 of the coupling shaft 57. When the developing coupling 67 is mounted on the coupling shaft 57, the developing coupling 67 is located on the outer surface of the left wall 53L of the housing 51 through the bearing 50. The development coupling 67 includes a gear portion 72 and a coupling portion 73. More specifically, the gear portion 72 is located at one end portion of the development coupling 67 in the left-right direction, and the coupling portion 73 is located at the other end portion of the development coupling 67 in the left-right direction. One end of the developing coupling 67 is mounted on the coupling shaft 57.

< Gear part 72>

The gear portion 72 is located at the right end portion of the development coupling 67. The gear portion 72 is formed integrally with the development coupling 67. The gear portion 72 is rotatable together with the development coupling 67. The gear portion 72 has a plurality of gear teeth. A plurality of gear teeth are provided around the circumference of rotation of the developer coupling 67. The addendum circle C9 of the gear portion 72 is spaced apart from the protrusion 60L. In other words, the projection 60L is located outside the addendum circle C9 of the gear portion 72. The gear portion 72 is an example of a coupling gear.

< connecting part 73>

The coupling portion 73 has a structure for receiving a driving force from the outside of the developing cartridge 3. For example, when the image forming apparatus includes a drive input unit for inputting a driving force into the coupling portion 73, the drive input unit is engaged with the coupling portion 73 so that the coupling portion 73 can receive the driving force. More specifically, one end of the coupling portion 73 is concave with respect to the developing coupling 67. More specifically, the coupling portion 73 has a circular concave shape at one end of the developing coupling 67. In the following description, a space recessed from one end of the development coupling 67 is referred to as a space 73B. The coupling portion 73 has a contact portion 73A and a contact portion 73C. Each of the contact portion 73A and the contact portion 73C is located in the circular concave space 73B. Each of the contact portion 73A and the contact portion 73C is apart from each other in the radial direction of the space 73B. Each of the contact portions 73A and 73C protrudes inward in the radial direction of the circular space 73B, and has a rectangular shape. When the contact portions 73A and 73C are engaged with the drive input unit of the image forming apparatus to receive the driving force, the developing coupling 67 can rotate about the coupling shaft 57.

< developing roller gear 68>

The developing roller gear 68 meshes with a gear portion 72 of the development coupling 67. The developing roller gear 68 has a disk shape having a thickness in the left-right direction. The developing roller gear 67 has a plurality of gear teeth formed around the outer peripheral surface of the developing roller gear 68. The developing roller gear 68 is located leftward of the bearing 50, and is supported at the left end portion 7C of the developing roller shaft 7A so as not to be rotatable relative to the developing roller shaft 7A. More specifically, the left end portion 7C of the developing roller shaft 7A penetrates the bearing 50, and the developing roller gear 68 is mounted on the left end portion 7C of the developing roller shaft 7A. The developing roller gear 68 has, for example, a D-shaped through hole 68A formed in a central region of the developing roller gear 68. Further, a part of the peripheral surface of the left end portion 7C is cut off when viewed in the left-right direction, thereby forming a D-shape. By inserting the D-shaped left end portion 7C into the through hole 68A, the developing roller gear 68 cannot rotate relative to the developing roller shaft 7A. With this structure, the developing roller shaft 7A can rotate together with the developing roller gear 68. When the developing roller gear 68 is mounted on the left end portion 7C, the developing roller gear 68 is located on the outer surface of the left wall 53L of the housing 51. The addendum circle C10 of the developing roller gear 68 is separated from the protrusion 60L. The projection 60L is located outside the addendum circle C10 of the developing roller gear 68.

< feed roller gear 69>

The supply roller gear 69 is located below the developing coupling 67. The supply roller gear 69 meshes with the gear portion 72 of the development coupling 67. The supply roller gear 69 has a disk shape having a thickness in the left-right direction. The supply roller gear 69 has a plurality of gear teeth formed around an outer circumferential surface thereof. The addendum circle C4 of the supply roller gear 69 is separated from the protrusion 60L. In other words, the projection 60L is located outside the addendum circle C4 of the supply roller gear 69. The supply roller gear 69 is located leftward of the bearing 50, and is supported by the left end portion 8C of the supply roller shaft 8A so as not to be rotatable with respect to the supply roller shaft 8A. More specifically, the left end portion 8C of the supply roller shaft 8A penetrates the bearing 50, and the supply roller gear 69 is mounted on the left end portion 8C of the supply roller shaft 8A. The supply roller gear 69 has a D-shaped through hole 69A formed in a central region of the supply roller gear 69, for example. Further, a part of the peripheral surface of the left end portion 8C is cut off when viewed in the left-right direction, thereby forming a D-shape. By inserting the D-shaped left end portion 8C into the through hole 69A, the supply roller gear 69 cannot rotate relative to the supply roller shaft 8A. With this configuration, the supply roller shaft 8A can rotate together with the supply roller gear 69. When the supply roller gear 69 is mounted on the left end portion 8C, the supply roller gear 69 is located on the outer surface of the left wall 53L of the housing 51.

< idler 70>

The idler gear 70 is rotatably supported on the idler shaft 58. Specifically, the idler gear 70 is rotatably mounted to the idler shaft 58. The idler gear 70 is spaced from the projection 60L. The idler gear 70 is located above a virtual plane L passing through the central axis a1 of the developing roller shaft 7A and the central axis a2 of the agitator shaft 11A. The idler pulley 70 has a D-shaped through hole 70C formed, for example, in a central region of the idler pulley 70. By inserting the idler shaft 58 through the through bore 70C, the idler 70 is able to rotate about the central axis a4 of the idler shaft 58. When the idler pulley 70 is mounted on the idler shaft 58, the idler pulley 70 is located on the outer surface of the left wall 53L of the housing 51. The idler gear 70 includes a large-diameter gear 70A and a small-diameter gear 70B. The large-diameter gear 70A and the small-diameter gear 70B are integrally formed. Therefore, the small diameter gear 70B can rotate together with the large diameter gear 70A. The small-diameter gear 70B is farther from the left wall 53L in the left-right direction than the large-diameter gear 70A.

< Large diameter Gear 70A >

The large diameter gear 70A has a disk shape having a thickness in the left-right direction. The large diameter gear 70A has a plurality of gear teeth formed around the outer circumferential surface of the large diameter gear 70A. The addendum circle C1 of the large-diameter gear 70A is spaced apart from the protrusion 60L. In other words, the projection 60L is located outside the addendum circle C1 of the large-diameter gear 70A in the front-rear direction. The large-diameter gear 70A meshes with a gear portion 72 of the development coupling 67. The large diameter gear 70A is an example of a first idle gear.

< Small diameter Gear 70B >

The small-diameter gear 70B has a disk shape having a thickness in the left-right direction. The small diameter gear 70B has an outer diameter smaller than that of the large diameter gear 70A. The small-diameter gear 70B has a plurality of gear teeth formed around the outer peripheral surface of the small-diameter gear 70B. The addendum circle C2 of the small-diameter gear 70B is spaced apart from the projection 60L. In other words, the protrusion 60L is located outside the addendum circle C2 of the small-diameter gear 70B in the front-rear direction. The small-diameter gear 70B is an example of a second idle gear.

< stirrer Gear 71>

The agitator gear 71 is mounted to the left end portion 11C of the agitator shaft 11A. The agitator gear 71 is supported at the left end portion 11C of the agitator shaft 11A so as not to be rotatable relative to the agitator gear shaft 59. The agitator gear 71 has a gear portion 71A and a cylindrical portion 71B.

< cylindrical section 71B >

The cylindrical portion 71B extends in the left-right direction. The cylindrical portion 71B has a D-shaped through hole 71C formed in a central region of the cylindrical portion 71B. A part of the peripheral surface of the left end portion 11C of the agitator shaft 11A is cut off when viewed in the left-right direction, thereby forming a D-shape. When the D-shaped left end portion 11C is inserted into the through hole 71C, the agitator gear 71 cannot rotate relative to the agitator shaft 11A. With this structure, the agitator gear 71 can rotate together with the agitator shaft 11A. When the agitator gear 71 is mounted on the left end portion 11C, the agitator gear 71 is located on the outer surface of the left wall 53L of the housing 51. The cylindrical portion 71B is located diagonally above and forward of the projection 60L, and the cylindrical portion 71B is spaced apart from the projection 60L.

< Gear part 71A >

The gear portion 71A is provided at the left end of the cylindrical portion 71B. The gear portion 71A meshes with a small-diameter gear 70B of the idle gear 70. The gear portion 71 has an outer diameter larger than that of the cylinder portion 71B. The gear portion 71A has a disk shape having a thickness in the left-right direction. The gear portion 71A has a plurality of gear teeth formed around an outer circumferential surface of the gear portion 71A. The gear portion 71A and the cylindrical portion 71B are integrally formed. Therefore, the gear portion 71A rotates together with the rotation of the cylindrical portion 71B.

< relative arrangement of the projection 60L and the gear train 65 >

As shown in fig. 5, the projection 60L is located between the central axis a4 of the idler shaft 58 and the central axis a2 of the agitator 11 in the front-rear direction. At least a part of the protrusion 60L is located inside the addendum circle C3 of the gear portion 71A in the front-rear direction. As shown in fig. 6, the edge of the gear portion 71A facing the left wall 53L is apart from the projection 60L in the left-right direction. Specifically, the edge of the gear portion 71A facing the left wall 53L is separated from the projection 60L in the left-right direction. The edge of the gear portion 71A facing the left wall 53L is farther from the left wall 53L than the projection 60L. In the first embodiment, the left wall 53L is separated by a distance D1 from the edge of the gear portion 71A facing the left wall 53L. The length that protrusion 60L extends from left wall 53L is length D2. Distance D1 is greater than length D2. Therefore, even if the projection 60L is located within the addendum circle C3 of the gear portion 71A in the front-rear direction, the projection 60L does not obstruct the rotation of the gear portion 71A. The gear portion 71A is an example of a first agitator gear.

4. Gear cover

As shown in fig. 1 and 8, a gear cover 66 covers the gear train 65. A gear cover 66 may cover at least a portion of the gear train 65. A gear cover 66 is located on the outer surface of the left wall 53L. The gear cover 66 is supported on the outer surface of the left wall 53L. The gear cover 66 has a coupling boss 74 and an opening 75.

The coupling boss 74 has a cylindrical shape extending in the left-right direction. The coupling boss 74 has a through hole 74A penetrating the gear cover 66 in the left-right direction. The inner diameter of the through hole 74A is sized to fit the coupling portion 73 of the developer coupling 67. The coupling portion 73 of the development coupling 67 is rotatably attached to the through hole 74A.

As shown in fig. 8 and 12, when the gear cover 66 is attached to the left wall 53L, the opening 75 is located on the opposite side of the projection 60L from the idle gear 70 in the up-down direction. A part of the projection 60L is exposed to the outside of the gear cover 66 through the opening 75. In other words, the gear cover 66 covers a portion of the projection 60L in the left-right direction.

5. Drum box

The above-described developing cartridge 3 can be mounted to the drum cartridge 2. As shown in fig. 10, 11, the developing cartridge 3 is mounted on the drum cartridge 2. In this case, the developing cartridge 3 and the drum cartridge 2 constitute the process cartridge 1. Hereinafter, the state of the developing cartridge 3 mounted on the drum cartridge 2 will be described with reference to fig. 9 to 15.

(1) Drum box summary

As shown in fig. 9, 15, the drum cartridge 2 includes a photosensitive drum 4, a corona-type (scorotron) charger 5, a transfer roller 6, and a drum frame body 21.

The photosensitive drum 4 is cylindrical and extends in the left-right direction. The photosensitive drum 4 is rotatably supported by the drum frame 21.

The corona charger 5 charges the surface of the photosensitive drum 4. The corona charger 5 is located on one side of the photosensitive drum 4. The corona charger 5 is separated from the photosensitive drum 4.

The transfer roller 6 is a roller for transferring the toner attached to the surface of the photosensitive drum 4 to the paper. The surface of the transfer roller 6 contacts the surface of the photosensitive drum 4. The transfer roller 6 is located on the opposite side of the photosensitive drum 4 from the corona charger 5.

(2) Detailed description of the drum Cartridge

< Drum frame 21>

The drum frame body 21 includes a support frame body 48 and a mounting frame body 49. The drum frame 21 will be described with reference to fig. 9 to 14.

< support frame 48>

The supporting frame 48 is formed to support the photosensitive drum 4, the corona charger 5, and the transfer roller 6.

< mounting frame 49>

The mounting frame 49 includes a left wall 24L, a right wall 24R, and a bottom wall 25. The left wall 24L and the right wall 24R are apart from each other in the left-right direction. Each of the left wall 24L and the right wall 24R has a plate shape. The bottom wall 25 is plate-shaped extending in the left-right direction. The bottom wall 25 is connected to the left wall 24L and the right wall 24R.

< pressing members 26L, 26R >

The pressing member 26L and the pressing member 26R are provided in the mounting frame 49. The pressing member 26L and the pressing member 26R are located between the left wall 24L and the right wall 24R in the left-right direction. The pressing member 26L is located at one end portion of the bottom wall 25 in the left-right direction. The pressing member 26R is located at the other end portion of the bottom wall 25 in the left-right direction. The pressing member 26L and the pressing member 26R are located at the same position in the front-rear direction.

< pressing member 26L >

As shown in fig. 12, the pressing member 26L includes a support member 34L, a compression spring 39L, and a pressing surface 40.

The support member 34L is fixed to the mounting frame 49.

The compression spring 39L is a spring for pressing the developing cartridge 3 toward the photosensitive drum 4. One end of the compression spring 39L is mounted on the support member 34L.

The pressing surface 40 is planar extending in the vertical direction. The pressing surface 40 is attached to the other end of the compression spring 39L.

When the developing cartridge 3 is not mounted to the drum cartridge 2, the compression spring 39L has a length L1. When the developing cartridge 3 is not mounted to the drum cartridge 2, the compression spring 39L urges the pressing surface 40 toward the photosensitive drum 4. When the developing cartridge 3 is mounted on the drum cartridge 2, the pressing surface 40 contacts the projection 60L, and the length of the compression spring 39L is shorter than the length L1. More specifically, when the developing cartridge 3 is mounted on the drum cartridge 2, the pressing surface 40 contacts the curved surface 61 of the projection 60L, and the length of the compression spring 39L is shorter than the length L1. Hereinafter, a region where the pressing surface 40 and the protrusion 60L are in contact is referred to as a contact region CL. By this contact, the compression spring 39L urges the pressing surface 40, thereby pressing the projection 60L toward the photosensitive drum 4.

< pressing Member 26R >

As shown in fig. 13, the pressing member 26R includes a support member 34R, a compression spring 39R, and a pressing surface 41.

The support member 34R is fixed to the mounting frame 49.

The compression spring 39R is a spring for pressing the developing cartridge 3 toward the photosensitive drum 4. One end of the compression spring 39R is mounted on the support member 34R.

The pressing surface 41 is a flat surface extending in the vertical direction. The pressing surface 41 is attached to the other end of the compression spring 39R.

When the developing cartridge 3 is not mounted to the drum cartridge 2, the compression spring 39R has a length L2. When the developing cartridge 3 is not mounted to the drum cartridge 2, the compression spring 39R urges the pressing surface 41 toward the photosensitive drum 4. When the developing cartridge 3 is mounted on the drum cartridge 2, the pressing surface 41 contacts the projection 60R, and the length of the compression spring 39R is shorter than the length L2. More specifically, when the developing cartridge 3 is mounted to the drum cartridge 2, the pressing surface 41 contacts the curved surface 62 of the projection 60R, and the length of the compression spring 39R is shorter than the length L2. Hereinafter, a region where the pressing surface 41 and the projection 60R are in contact is referred to as a contact region CR. By this contact, the compression spring 39R urges the pressing surface 41, thereby pressing the projection 60R toward the photosensitive drum 4. Because the projection 60L and the projection 60R are located at the same position when viewed in the left-right direction, a distance D3 (refer to fig. 12) between the contact region CL and the central axis a1 of the developing roller shaft 7A is equal to a distance D4 between the contact region CR and the central axis a1 of the developing roller shaft 7A.

< guide surfaces 29L, 29R >

As shown in fig. 9 and 11, the left wall 24L has a guide surface 29L. Similarly, the right wall 24R has a guide surface 29R. Each of the guide surface 29L and the guide surface 29R guides the developing cartridge 3 when the developing cartridge 3 is mounted to the drum cartridge 2. In other words, each of the guide surface 29L and the guide surface 29R guides the surface of the developing roller 7 toward the surface of the photosensitive drum 4. The guide surface 29L and the guide surface 29R are located at the same position in the front-rear direction. The developing cartridge 3 is guided by a guide surface 29L and a guide surface 29R described later, and the developing cartridge 3 is in a mounted state in which the developing cartridge 3 is mounted on the drum cartridge 2.

< guide surface 29L >

The guide surface 29L is located between the photosensitive drum 4 and the pressing member 26L in the front-rear direction. The guide surface 29L is sized to guide the developing cartridge 3.

< guide surface 29R >

The guide surface 29R is located between the photosensitive drum 4 and the pressing member 26R in the front-rear direction. The guide surface 29R is sized to guide the developing cartridge 3.

< locking lever 27>

As shown in fig. 9, 13, and 14, the lock lever 27 is located on the opposite side of the pressing member 26R from the photosensitive drum 4 in the front-rear direction. The lock lever 27 is located between the left wall 24L and the right wall 24R in the left-right direction. The lock lever 27 is rotatably supported on the right wall 24R. The lock lever 27 is rotatable about an axis extending in the left-right direction. The lock lever 27 is rotatable between a lock position (see fig. 13) and a unlock position (see fig. 14). In the following description, lock lever 27 is described based on the lock position. The lock lever 27 includes a rotation shaft 42, a lock portion 43, an operation portion 44, and a lift portion 45.

The rotary shaft 42 has a columnar shape extending in the left-right direction. The rotation shaft 42 is rotatably supported on the right wall 24R.

The locking portion 43 can lock the locking projection 64. The locking portion 43 has a locking surface 43A. As shown in fig. 13, when the developing cartridge 3 is mounted on the drum cartridge 2, the locking surface 43A locks the locking projection 64 with respect to the mounting frame 49.

The operation portion 44 has a plate shape. The operation portion 44 is held by an operator. When the operator rotates the operation portion 44, the operation portion 44 rotates between the lock position and the unlock position.

The lifting portion 45 has a lifting surface 45A. As shown in fig. 14, when lock lever 27 is located at the unlock position, lift surface 45A contacts lift projection 63.

More specifically, when the developing cartridge 3 is mounted to the drum cartridge 2, the locking projection 64 of the developing cartridge 3 contacts the lifting surface 45A. Therefore, when the operator urges the developing cartridge 3 toward the drum cartridge 2, the lock lever 27 rotates about the rotation shaft 42, and the lock surface 43A locks the lock projection 64 with respect to the drum cartridge 2. As a result, the developing cartridge 3 is mounted on the drum cartridge 2, as shown in fig. 12, 13. In this case, the pressing member 26L presses the projection 60L toward the photosensitive drum 4, and the pressing member 26R presses the projection 60R toward the photosensitive drum 4.

When the operator rotates the lock lever 27 from its lock position to its unlock position, the lock surface 43A releases the locked state of the lock projection 64, and the lift surface 45A releases the lift projection 63. Next, the lifting face 45A lifts the lifting projection 63. As a result, the locked state of the developing cartridge 3 with respect to the drum cartridge 2 is released.

6. Advantageous effects of the first embodiment

In the first embodiment described above, the developing roller gear 68 meshes with the gear portion 72 of the development coupling 67 on one side of the development coupling 67, and the large diameter gear 70A of the idler gear 70 meshes with the gear portion 72 of the development coupling 67 on the other side of the development coupling 67. This structure allows the developing coupling 67 to be stably rotated. Further, since the small-diameter gear 70B of the idle gear 70 meshes with the gear portion 71A of the agitator 11, the circumferential speed of the agitator 11 can be adjusted. Further, the projection 60L is located between the development coupling 67 and the agitator 11. Therefore, the projection 60L can reliably receive the pressing force from the pressing member 26L toward the photosensitive drum 4 without hindering the gear portion 71A from rotating.

More specifically, the protrusion 60L is located between the idler shaft 58 and the agitator gear shaft 59 in the front-rear direction, and the protrusion 60L is located outside both the addendum circle C1 of the large-diameter gear 70A and the addendum circle C2 of the small-diameter gear 70B in the front-rear direction. The projection 60L is located inside the addendum circle C3 of the gear portion 71A in the front-rear direction. The edge of the gear portion 71A facing the left wall 53L in the left-right direction is spaced apart from the projection 60L. Specifically, the edge of the gear portion 71A facing the left wall 53L is farther from the left wall 53L than the projection 60L. In the first embodiment, the left wall 53L is separated from the edge of the agitator gear 71 facing the left wall 53L by a distance D1. The length that protrusion 60L extends from left wall 53L is length D2. Thus, distance D1 is greater than length D2. Therefore, even if the protrusion is located within the addendum circle C3 of the gear portion 71A in the front-rear direction, the protrusion 60L can reliably receive the pressing force from the pressing member 26L toward the photosensitive drum 4 without hindering the rotation of the gear portion 71A.

Further, when the curved surface 61 contacts the pressing member 26L, the curved surface 61 can appropriately receive the pressing force from the pressing member 26L toward the photosensitive drum 4. Similarly, when the curved surface 62 contacts the pressing member 26R, the curved surface 62 can appropriately receive the pressing force from the pressing member 26R toward the photosensitive drum 4.

7. Usage mode of processing box

As shown in fig. 15, the process cartridge 1 is mounted on the image forming apparatus 81.

The image forming apparatus 81 is a monochrome printer of an electrophotographic system. The image forming apparatus 81 includes an apparatus body 82, a scanner unit 83, and a fixing unit 84.

The apparatus body 82 has a box shape. The apparatus body 82 includes an opening 85, a front cover 86, a paper tray 87, and a discharge tray 88.

The opening 85 is located at the front end of the apparatus body 82. The process cartridge 1 is inserted into the apparatus body 82 through the opening 85.

The front cover 86 is located at the front end of the apparatus body 82. The front cover 86 has a plate shape. The front cover 86 is used to open and close the opening 85.

The paper tray 87 is used to accommodate a plurality of sheets P.

The scanner unit 83 is located above the process cartridge 1. The scanner unit 83 is for irradiating a laser beam toward the photosensitive drum 4.

The fixing unit 84 is located behind the process cartridge 1. The fixing unit 84 includes a heating roller 89 and a pressure roller 90.

When the image forming apparatus 81 starts an image forming operation, the corona charger 5 uniformly charges the surface of the photosensitive drum 4. The scanner unit 83 exposes the surface of the photosensitive drum 4 to the laser beam. As a result, an electrostatic latent image based on the image data is formed on the surface of the photosensitive drum 4.

By rotating the agitator shaft 11A, the agitator 11 agitates the toner in the toner housing 10 to supply the toner to the supply roller 8. The supply roller 8 supplies the toner received from the agitator 11 to the developing roller 7. At this time, the toner is positively charged between the developing roller 7 and the supply roller 8, and the charged toner is carried on the developing roller 7. The thickness regulating sheet 9 regulates the toner carried on the developing roller 7 to a layer having a uniform thickness.

The toner carried on the developing roller 7 is supplied to the electrostatic latent image on the surface of the photosensitive drum 4, so that the photosensitive drum 4 can carry a toner image on the surface thereof.

By the rotation of the various rollers, one sheet P of the plurality of sheets P is fed one at a time from the paper tray 8 to a position between the photosensitive drum 4 and the transfer roller 6 at a predetermined timing. When the sheet P passes between the photosensitive drum 4 and the transfer roller 6, the toner image carried on the surface of the photosensitive drum 4 is transferred to the sheet P.

Next, the sheet P is fed and pressed while passing between the heating roller 89 and the pressing roller 90. At this time, the toner image on the sheet P is thermally fixed on the sheet P. Then, the sheet P is discharged to the discharge tray 88.

Although the projection 60L is located inside the addendum circle C3 of the gear portion 71A in the front-rear direction in the above-described first embodiment, the projection 60L may be located outside the addendum circle C3 of the gear portion 71A in the front-rear direction. Even if the protrusion 60L is located outside the addendum circle C3 of the gear portion 71A in the front-rear direction, the protrusion 60L can reliably receive the pressing force from the pressing member 26L toward the photosensitive drum 4 without hindering the rotation of the gear portion 71A.

8. Second embodiment

Next, the developing cartridge 3 according to the second embodiment is explained with reference to fig. 16A, 16B, and parts similar to those of the first embodiment are given the same reference numerals to avoid duplicate explanation.

In the first embodiment, the gear portion 71A of the agitator gear 71 meshes only with the small-diameter gear 70B of the idle gear 70. However, for example, as shown in fig. 16B, the detected rotary body 101 described in japanese patent application laid-open No. 2011-. In the second embodiment, as shown in fig. 16A, 16B, the driving force can be transmitted from the agitator gear 71 to the detected rotating body 101.

In this case, as shown in fig. 16A, the agitator gear 71 includes a second gear part 71D in addition to the gear part 71A.

The second gear portion 71D is located between the gear portion 71A and the cylindrical portion 71B in the left-right direction. The second gear portion 71D is cylindrical extending rightward from the right surface of the gear portion 71A. The second gear part 71D is arranged coaxially with the gear part 71A. The outer diameter of the second gear portion 71D is smaller than the outer diameter of the gear portion 71A. The second gear portion 71D has a plurality of gear teeth formed on an outer peripheral surface of the second gear portion 71D. The addendum circle C5 of the second gear portion 71D is located inward of the addendum circle C3 of the gear portion 71A and is spaced apart from the protrusion 60L. In other words, the projection 60L is located outside the addendum circle C5 of the second gear portion 71D.

The detected rotating body 101 has a disk shape having a thickness in the left-right direction. The detected rotary body 101 includes a tooth portion 101A, a tooth-missing portion 101B, and a detection protrusion 102.

The tooth portion 101A occupies approximately two thirds of the circumferential direction of the detected rotary body 101, that is, a sector region where the center angle of the detected rotary body 101 is about 240 degrees. The tooth 101A has a plurality of gear teeth along the circumferential surface of the detected rotating body 101. The addendum circle C6 of the tooth portion 101A is separated from the protrusion 60L. In other words, the projection 60L is located outside the addendum circle C6 of the tooth portion 101A.

The missing tooth portion 101B occupies about one third of the circumferential direction of the detected rotary body 101, excluding the area occupied by the tooth portion 101A. The toothless portion 101B is a sector region in which the center angle of the detected rotating body 101 is about 120 degrees. The missing tooth portion 101B has no gear teeth.

The detection protrusion 102 is located at a position displaced from the center of the detected rotating body 101 to the outside in the radial direction. The detection protrusion 102 has a prism shape protruding leftward from the left surface of the detected rotary body 101.

When the developing cartridge 3 in an unused (fresh) state is mounted to the apparatus body 82 of the image forming apparatus 81, the detected rotary 101 can be rotated for a predetermined length of time because the tooth portion 101A is engaged with the second gear portion 71D of the agitator gear 71. When the tooth portion 101A is not engaged with the second gear portion 71D of the agitator gear 71, the rotation of the detected rotating body 101 is stopped.

As described in japanese patent application laid-open No. 2011-. After the detected rotating body 101 moves leftward, the detected rotating body 101 moves rightward. When the detected rotary body 101 moves rightward, the detection protrusion 102 is retracted into the gear cover 66 through an opening formed in the gear cover 66.

When the detected rotary body 101 moves leftward, a sensor (not shown) provided in the apparatus body 82 detects the detection protrusion 102. By this detection, the image forming apparatus 81 determines that the developing cartridge 3 is unused (new product).

In the second embodiment, the second gear part 71D of the agitator gear 71 is an example of the second agitator gear, and the addendum circle C5 of the second gear part 71D is an example of the addendum circle of the second agitator gear. The gear portion 71A of the agitator gear 71 is an example of a first agitator gear, and the addendum circle C3 of the gear portion 71A is an example of an addendum circle of the first agitator gear. The detected rotor 101 is an example of a friction wheel, and the addendum circle C6 of the tooth portion 101A of the detected rotor 101 is an example of an addendum circle of a friction wheel. The detection protrusion 102 is an example of a protrusion. The friction wheel is, for example, a gear that is driven to rotate when contacting other gears by meshing or the like. Further, the friction wheel is, for example, a rotary body that is driven to rotate when contacting other gears by meshing or the like.

In the second embodiment described above, the second gear portion 71D of the agitator gear 71 can transmit the driving force to the detected rotating body 101.

The second embodiment can obtain the same advantageous effects as those described above in the first embodiment.

3. Third embodiment

Next, the developing cartridge 3 according to the third embodiment will be described with reference to fig. 17 to 22, and the same reference numerals are given to the components similar to those of the first and second embodiments to avoid redundant description.

In the third embodiment, a detection unit 238 is used instead of the detected rotary body 101 of the second embodiment.

As shown in fig. 17, the detecting unit 238 includes a partially-toothless gear 251 as an example of a friction wheel, a detecting member 252, and a compression spring 253.

As shown in fig. 18A and 18B, the partially-toothless gear 251 is integrally provided with a gear cylinder portion 255, a slide rib 256, a gear flange portion 254, and a boss 257.

The gear cylindrical portion 255 is cylindrical and extends in the left-right direction. More specifically, the gear cylindrical portion 255 includes a peripheral wall 255A and a contact wall 255B.

The peripheral wall 255A is cylindrical and extends in the left-right direction. The contact wall 255B is located at the right edge of the peripheral wall 255A. The contact wall 255B has a disk shape having a thickness in the left-right direction. The contact wall 255B has an insertion hole 255C.

The insertion hole 255C is located in a central region of the contact wall 255B. The insertion hole 255C is a circular hole. The insertion hole 255C penetrates the contact wall 255B in the left-right direction. The center of the insertion hole 255C corresponds to the center of the contact wall 255B. The diameter of the insertion hole 255C is slightly larger than the outer diameter of the partially-toothless gear shaft 236.

As shown in fig. 18A, the slide rib 256 is located on the left surface of the contact wall 255B apart from the insertion hole 255C. The slide rib 256 has a plate shape extending in the radial direction of the gear cylindrical portion 255. The slide rib 256 protrudes leftward from the left surface of the contact wall 255B. The left-right dimension of the slide rib 256 is larger than the left-right dimension of the peripheral wall 255A.

The gear flange portion 254 flares radially outward from the left edge of the peripheral wall 255A. The gear flange portion 254 includes a tooth portion 254A and a tooth-missing portion 254B.

The tooth portion 254A is plate-shaped extending in the circumferential direction of the peripheral wall 255A, and the tooth portion 254A is C-shaped when viewed from the side. The tooth 254A extends radially outward from the left edge of the peripheral wall 255A in a region having a central angle of about 240 degrees. In addition, the tooth 254A has a plurality of gear teeth 258. The tip circle C8 of the tooth 254A is spaced apart from the projection 60L. In other words, the protrusion 60L is located outside the tip circle C8 of the tooth portion 254A.

The tooth missing portion 254B is separated from the leading edge of the tooth portion 254A and the trailing edge of the tooth portion 254A in the circumferential direction of the circumferential wall 255A. The tooth missing portion 254B is plate-shaped extending in the circumferential direction of the peripheral wall 255A. The tooth-missing portion 254B flares radially outward from the left edge of the peripheral wall 255A in a region having a center angle of about 45 degrees. The radius of curvature of the missing tooth 254B is smaller than the radius of curvature of the tooth 254A. The tooth-missing portion 254B does not have gear teeth on the circumferential surface of the tooth-missing portion 254B. Thus, the partially toothless gear 251 has a peripheral portion provided with a plurality of gear teeth 258, and the remaining peripheral portion has no gear teeth.

The boss 257 is located on the left surface of the tooth-missing portion 254B away from the sliding rib 256. The boss 257 has a columnar shape extending in the left-right direction. The boss 257 projects leftward from the left surface of the tooth-missing portion 254B at a radially outer portion of the tooth-missing portion 254B.

The partly-toothless gear shaft 236 is inserted into the insertion hole 255C in a state where the partly-toothless gear 251 is rotatable with respect to the partly-toothless gear shaft 236, with the result that the partly-toothless gear 251 is supported on the partly-toothless gear shaft 236 provided in the housing 51. With this structure, the partially-toothless gear 251 can rotate about the partially-toothless gear shaft 236. When the driving force is transmitted from the agitator gear 71 to the partially-toothless gear 251, the partially-toothless gear 251 is irreversibly rotated from the initial position to the final position via the drive transmission position.

As shown in fig. 17, the detecting member 252 is located on the left side of the partially toothless gear 251. As shown in fig. 19A and 19B, the detection member 252 is integrally provided with a detection cylindrical portion 266, a detection flange portion 261, a detection protrusion 262 as an example of a protrusion portion, and a displacement portion 263.

The detection cylinder portion 266 has an outer cylinder portion 266A, an inner cylinder portion 266B, and a connecting wall 266C.

The outer tube portion 266A is cylindrical and extends in the left-right direction.

The inner tube portion 266B is cylindrical and extends in the left-right direction. The inner tube portion 266B has a through hole extending in the left-right direction. The through hole penetrates the inner cylindrical portion 266B in the left-right direction. The inner cylindrical portion 266B has an outer diameter smaller than the inner diameter of the outer cylindrical portion 266A, and the inner diameter of the inner cylindrical portion 266B is equal to the outer diameter of the partially-toothless gear shaft 236. Further, the dimension of the inner tube portion 266B in the left-right direction is equal to the dimension of the outer tube portion 266A in the left-right direction. The inner cylindrical portion 266B is located inside the outer cylindrical portion 266A such that the central axis of the inner cylindrical portion 266B is aligned with the central axis of the outer cylindrical portion 266A.

The connecting wall 266C connects the inner peripheral surface of the right end of the outer cylinder portion 266A and the outer peripheral surface of the right end of the inner cylinder portion 266B. The connecting wall 266C is annular.

The detection flange 261 has a ring shape. The detection flange 261 expands radially outward from the left end of the outer cylinder 266A.

As shown in fig. 19A, the upper end portion of the detection projection 262 is located on the left surface of the detection flange portion 261. The detection protrusion 262 has a plate shape extending in the left-right direction. The detection protrusion 262 extends leftward from the detection flange portion 261.

As shown in fig. 19B, the displacement portion 263 is located on the right surface of the detection flange portion 261 along the peripheral edge of the detection flange portion 261. The displacement portion 263 has a cam portion 283. The cam portion 283 protrudes rightward from the detection flange portion 261. In the third embodiment, a plurality of cam portions 283, specifically, three cam portions are provided. The plurality of cam portions 283 are arranged one after another along the circumferential direction of the detection flange portion 261. Each of the cam portions 283 has a first inclined surface 283A, a parallel surface 283B, and a second inclined surface 283C. At least one cam portion 283 may be provided.

The first inclined surface 283A is located on the upstream side of the cam portion 283 in the rotation direction of the partially-toothless gear 251. The first inclined surface 283A is inclined rightward as it goes to the downstream end in the rotation direction of the partially-toothless gear 251. In other words, the first inclined surface 283A is inclined rightward in the rotational direction of the partially-toothless gear 251. More specifically, the distance between the detection flange portion 261 and the first inclined surface 283A becomes gradually longer in the rotation direction of the partially-toothless gear 251.

The parallel surface 283B is formed continuously with the first inclined surface 283A, and extends downstream in the rotational direction of the partially-toothless gear 251. The parallel surface 283B is parallel to the detection flange portion 261 so that the distance in the left-right direction from the detection flange portion 261 is kept constant.

The second inclined surface 283C is located on the downstream side in the rotational direction of the partially-toothless gear 251. The second inclined surface 283C is formed continuously with the parallel surface 283B. The second inclined surface 283C is inclined leftward as it goes to the downstream end in the rotation direction of the partially-toothless gear 251. In other words, the second inclined surface 283C is inclined leftward in the rotational direction of the partially-toothless gear 251. More specifically, the distance between the detection flange portion 261 and the second inclined surface 283C gradually becomes shorter in the rotation direction of the partially-toothless gear 251.

When the displacement portion 263 has a plurality of cam portions 283, the second inclined surface 283C of one cam portion 283 is formed continuously with the first inclined surface 283A of the next cam portion 283. In this way, the plurality of cam portions 283 are provided along the detection flange portion 261.

As shown in fig. 20A, the partially-toothless gear shaft 236 penetrates through a through hole formed in the inner cylindrical portion 266B, and the detecting member 252 is located to the left of the partially-toothless gear 251.

As shown in fig. 17, the compression spring 253 is located leftward of the detecting member 252. The compression spring 253 has a hollow spiral structure extending in the left-right direction. The inner diameter of the compression spring 253 is equal to the outer diameter of the inner cylinder portion 266B. The inner tube portion 266B is inserted into the right end portion of the compression spring 253, and as a result, the compression spring 253 is supported by the detection member 252.

Further, the compression spring 253 is sandwiched between the connecting wall 266C of the detecting member 252 and the gear cover 66 in a compressed state. With this structure, the compression spring 253 always urges the detecting member 252 rightward.

Next, a state of the detection unit 238 before the first use of the developing cartridge 3 (when the developing cartridge 3 is not used) is explained.

In the new-product developing cartridge 3, the partly-toothless gear 251 is located at the initial position, as shown in fig. 20A.

When the partially-toothless gear 251 is located at the initial position, the downstream edge portion of the tooth portion 254A in the rotational direction R of the partially-toothless gear 251 is located apart from the second gear portion 71D, the toothless portion 254B faces the second gear portion 71D, and the toothless portion 254B is slightly apart from the second gear portion 71D.

Therefore, when the partially-toothless gear 251 is located at the initial position, the gear teeth 258 of the partially-toothless gear 251 are not meshed with the second gear part 71D.

Further, the end 256A of the slide rib 256 is located rearward of the first inclined surface 283A of one of the cam portions 283, and contacts the right surface of the detection flange portion 261, as shown in fig. 20B. The detecting member 252 is located at the retracted position due to the force applied by the compression spring 253.

As shown in fig. 2, when the developing coupling 67 rotates in a predetermined rotational direction, the developing roller gear 68, the supply roller gear 69, and the idle gear 70 rotate in a direction opposite to the rotational direction of the developing coupling 67. At this time, the developing roller 7 rotates together with the rotation of the developing roller gear 68, and the supply roller 8 rotates together with the rotation of the supply roller gear 69. Further, when the idle gear 70 rotates, the agitator gear 71 rotates in the direction opposite to the rotation direction of the idle gear 70, as shown in fig. 20A.

As shown in fig. 21A, when the agitator gear 71 rotates, the rib 71E provided on the inner surface of the gear portion 71A of the agitator gear 71 rotates together with the agitator gear 71, contacts the boss 257 of the partially toothless gear 251 at the initial position, and then presses the boss 257 diagonally forward and downward. The partially-toothless gear 251 is rotated in the rotational direction R about the center axis a6 of the partially-toothless gear shaft 236 from the initial position by the pressing force of the rib 71E against the boss 257.

Thereby, the partially-toothless gear 251 reaches the drive transmission position, as shown in fig. 21A, 21B. Next, the gear teeth 258 of the tooth portion 254A mesh with the second gear portion 71D. That is, when the partially-toothless gear 251 is located at the drive transmission position, the gear teeth 258 of the partially-toothless gear 251 are meshed with the second gear part 71D, and the second gear part 71D is located within the tip circle C8 of the tooth part 254A.

As the partially toothless gear 251 continues to rotate in the rotational direction R, the slide rib 256 of the partially toothless gear 251 moves in the rotational direction R together with the rotation of the partially toothless gear 251, as shown in fig. 20B.

At this time, the end 256A of the slide rib 256 slides along the first inclined surface 283A of one of the cam portions 283 in the rotational direction R, pushing the first inclined surface 283A leftward. Thereby, the detecting member 252 is gradually moved leftward from the retracted position against the urging force of the compression spring 253. In other words, the detecting member 252 is moved leftward by the rotation of the partially toothless gear 251, and the detecting protrusion 262 is moved leftward together with the movement of the detecting member 252. As the partly-toothless gear 251 continues to rotate, the end 256A of the slide rib 256 moves from the first inclined surface 283A to the parallel surface 283B of one of the cam portions 283, contacting the parallel surface 283B. At this time, the sensing member 252 is located at the advanced position, i.e., advanced to the farthest left against the force applied by the compression spring 253.

When the detecting member 252 is located at the advanced position, the detecting projection 262 is advanced leftward through a slit 275 formed in the gear cover 66 (refer to fig. 1). When the detection protrusion 262 advances leftward through the slit 275, the detection protrusion 262 contacts an actuator (not shown) provided at the image forming apparatus 81. The contact causes the actuator to move from the non-detection position to the detection position. A light receiving element provided in a photosensor of the image forming apparatus 81 receives the detection light when the actuator is moved to the detection position, and the photosensor outputs a light receiving signal. As the partly-toothless gear 251 continues to rotate, the end 256A of the slide rib 256 moves from the parallel surface 283B to the second inclined surface 283C of one of the cam portions 283, contacting the second inclined surface 283C. The end 256A of the slide rib 256 slides along the second inclined surface 283C in the rotation direction R. Therefore, the detecting member 252 is gradually moved rightward by the urging force of the compression spring 253. As a result, the detection projection 262 gradually recedes into the gear cover 66. When the detection projection 262 is separated from the actuator of the image forming apparatus 81, a biasing member (not shown) provided at the image forming apparatus 81 returns the actuator from the detection position to the non-detection position. That is, the actuator of the image forming apparatus 81 moves to a position between the light emitting element and the light receiving element of the photosensor, the actuator blocks the light receiving element of the photosensor from receiving the detection light, and the output of the light reception signal from the photosensor is interrupted.

As the partially-toothless gear 251 continues to rotate, the detecting member 252 moves again from the retracted position to the advanced position and then from the advanced position to the retracted position, and this movement is performed twice for the remaining two cam portions 283. Therefore, the actuator of the image forming apparatus 81 moves from the non-detection position to the detection position and then from the detection position to the non-detection position, and this movement is performed twice. Thereby, the light sensor outputs two light reception signals. In other words, in the third embodiment, the light sensor outputs three light reception signals in total during the detection operation.

As described above, the detecting member 252 may be provided with at least one cam portion 283. Therefore, the detecting member 252 can perform the movement from the retracted position to the advanced position and then from the advanced position to the retracted position once for each of the remaining two cam portions 283.

When the tooth portion 254A of the partially-toothless gear 251 is subsequently separated from the second gear portion 71D, the partially-toothless gear 251 stops rotating, as shown in fig. 22. When the operation of rotating the partially-toothless gear 251 is completed, the partially-toothless gear 251 reaches the final position.

In this way, the image forming apparatus 81 can not determine whether the developing cartridge 3 is unused (new product) by detecting the detecting member 252.

10. Modification of the embodiment

Next, the developing cartridge 3 according to a modification of the second embodiment will be described with reference to fig. 23, and the same reference numerals are given to the components similar to those of the second embodiment, thereby avoiding the duplicate description.

The detected rotary body 101 according to the second embodiment described above has the tooth portion 101A, and the tooth portion 101A has gear teeth on its circumferential surface. However, in the modification of the second embodiment shown in fig. 23, the detected rotary body 111 is configured as a friction rotary body without gear teeth.

In this case, the detected rotary body 111 includes a contact portion 111A, a non-contact portion 111B, and a detection protrusion 112.

The contact portion 111A occupies approximately two thirds of the circumferential direction of the rotating body 111 to be detected, that is, a sector region having a central angle of approximately 240 degrees in side view of the rotating body 111 to be detected. The contact portion 111A has a rubber layer 111C formed on the entire circumferential surface of the contact portion 111A. The peripheral portion C7 of the contact portion 111A is spaced apart from the projection 60L. In other words, the protrusion 60L is located outside the peripheral portion C7 of the contact portion 111A.

The non-contact portion 111B occupies approximately one third of the circumferential direction of the detected rotary body 111, excluding the area occupied by the contact portion 111A. The non-contact portion 111B is a sector region having a central angle of about 120 degrees in a side view of the detected rotating body 111. The non-contact portion 111B has no rubber layer.

The detection protrusion 112 is located at a position shifted from the center of the detected rotating body 111 to the outside in the radial direction. The detection protrusion 112 has a prism shape protruding leftward from the left surface of the detected rotation body 111.

When the developing cartridge 3 in an unused (fresh) state is mounted to the apparatus body 82 of the image forming apparatus 81, the rubber layer 111C of the contact portion 111A comes into contact with the second gear portion 71D of the agitator gear 71, and this contact causes the detected rotary 111 to rotate for a predetermined length of time. When the contact portion 111A does not contact the second gear portion 71D of the agitator gear 71, the rotation of the detected rotating body 111 is stopped.

In the present modification, the detected rotary body 111 is an example of a friction wheel. The peripheral portion C7 of the contact portion 111A of the detected rotor 111 is an example of an addendum circle of a friction wheel.

The modification of the second embodiment can obtain the same advantageous effects as those described above of the second embodiment.

Next, the developing cartridge 3 according to a modification of the third embodiment will be described with reference to fig. 24, and parts similar to those of the third embodiment are given the same reference numerals to avoid duplicate explanation.

In a modification of the third embodiment, the partially-toothless gear 251 may be a gear that is driven to rotate when contacting other gears by meshing or the like. For example, the partially-toothless gear 251 may be a rotating body without gear teeth 258, or a friction wheel without gear teeth. More specifically, the partially-toothless gear 251 may be provided with the resistance applying member 320 instead of the gear teeth 258. The resistance applying member 320 is made of a material having a relatively high friction coefficient, such as rubber, and is provided around at least an outer peripheral surface of the partially toothless gear 251. The second gear portion 71D is located within the rotation circumference of the resistance applying member 320. In this case, the frictional force generated between the resistance applying member 320 and the second gear part 71D transmits the driving force to the partially toothless gear 251, thereby rotating the partially toothless gear 251. The material and shape of the resistance applying member 320 are not particularly limited as long as the resistance applying member 320 can generate a sufficient frictional force with the second gear part 71D for rotating the partially-toothless gear 251.

The modification of the third embodiment can obtain the same advantageous effects as those described above of the third embodiment.

Although the present invention has been described in conjunction with the specific embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit of the invention.

Description of the reference numerals

2: drum box

3: developing box

4: photosensitive drum

7: developing roller

7A: developing roller shaft

7B: developing roller body

7C: left end part

8: supply roller

8A: supply roller shaft

8B: supply roller body

8C: left end part

11: stirrer

11A: stirrer shaft

11B: blade

11C: left end part

50: bearing assembly

51: shell body

53L: left wall

53R: right wall

60L: protrusion

60R: protrusion

66: gear cover

67: development coupling

68: developing roller gear

69: supply roller gear

70: idler wheel

70A: large-diameter gear

70B: small diameter gear

71: stirrer gear

71A: gear part

71D: second gear part

101: detected rotating body

111: detected rotating body

A1: central axis

A2: central axis

A3: central axis

C1: addendum circle

C2: addendum circle

C3: addendum circle

C4: addendum circle

C5: addendum circle

C6: addendum circle

C7: peripheral part of the body

D1: distance between two adjacent plates

D2: length of

D3: distance between two adjacent plates

D4: distance between two adjacent plates

L: virtual plane