阅读说明：本技术 光反射装置、导光装置以及光扫描装置 (Light reflection device, light guide device, and optical scanning device ) 是由 中泽睦裕 于 2020-03-31 设计创作，主要内容包括：本发明的光反射装置(20)具备反射部件(42),该反射部件具有平面状的反射面。反射面用以反射入射光。反射部件(42)同时进行公转和自转。反射部件的公转方向与自转方向相同。反射部件(42)的公转角速度等于自转角速度的2倍。(A light reflection device (20) is provided with a reflection member (42) having a planar reflection surface. The reflecting surface is used for reflecting incident light. The reflecting member (42) revolves and rotates simultaneously. The revolution direction and the rotation direction of the reflecting member are the same. The revolution angular velocity of the reflecting member (42) is equal to 2 times of the rotation angular velocity.)

1. A light reflection device is characterized by comprising:

a reflecting member having a planar reflecting surface for reflecting incident light and revolving and rotating simultaneously,

the revolution direction and the rotation direction of the reflecting component are the same,

the revolution angular velocity of the reflecting member is equal to 2 times of the rotation angular velocity.

2. The light reflection device according to claim 1, wherein the reflection surfaces are arranged in pairs with an axis of rotation of the reflection member interposed therebetween.

3. The light reflection device according to claim 1 or 2, wherein a plurality of the reflection members are provided,

a plurality of the reflecting members have common axes which are coincident with each other, and

the plurality of reflecting members are arranged so as to divide a circle having the first rotation axis as a center at equal angular intervals.

4. The light reflecting device according to any one of claims 1 to 3, wherein a planetary gear set is provided for revolving and rotating the reflecting member.

5. The light reflecting device according to any one of claims 1 to 4, wherein the reflecting member reflects light in a manner deflected in a plane perpendicular to an axis of rotation, and

the plane is offset in the direction of the rotation axis with respect to the incident light incident on the reflection member.

6. The light reflecting device according to claim 5, wherein the reflecting surface comprises:

a first reflecting surface formed in a planar shape inclined with respect to a plane perpendicular to the rotation axis; and

a second reflecting surface formed in a planar shape inclined with respect to a plane perpendicular to the rotation axis,

a direction in which the first reflection surface is inclined with respect to a plane perpendicular to the rotation axis is opposite to a direction in which the second reflection surface is inclined with respect to a plane perpendicular to the rotation axis,

the incident light is reflected by the second reflecting surface after being reflected by the first reflecting surface, and

the first reflection surface and the second reflection surface are formed so as to be symmetrical with each other with respect to a symmetry plane,

a mirror image of the symmetry plane with respect to the first reflection plane and a mirror image of the symmetry plane with respect to the second reflection plane are coplanar with each other,

The spinning axis is included in the plane of the mirror image.

7. The light reflecting device according to claim 6,

the first reflecting surface is inclined at an angle of 45 DEG with respect to a plane perpendicular to the rotation axis,

the second reflecting surface is inclined at an angle of 45 ° with respect to a plane perpendicular to the rotation axis.

8. A light guide device, characterized in that:

is provided with a light reflection device according to any one of claims 1 to 7, and

the incident light is deflected by the light reflecting device to scan an irradiated object.

9. The light guide device according to claim 8, wherein a scanning lens is provided, and wherein

The scanning lens is disposed on an optical path from the reflecting member to the irradiation target.

10. An optical scanning device characterized in that:

comprising a plurality of light-guiding devices according to claim 8 or 9, and

in each of the light guide devices, the reflection member of the light reflection device revolves and rotates simultaneously, and the light guide device is switched between a reflection state in which the incident light is irradiated onto the reflection surface and reflected and a passage state in which the incident light passes through without being irradiated onto the reflection surface, and the light guide device

The timing of becoming the reflecting state is different among the plurality of light guiding means,

one linear scanning line is formed by a set of scanning regions corresponding to the plurality of light guide devices.

11. An optical scanning device is characterized by comprising:

rotating the reflector;

a driving device that rotates the rotating mirror; and

an irradiation device for irradiating light onto the rotating mirror,

the rotating mirror includes:

a first regular polygonal pyramid;

a second regular polygon cone disposed opposite to the first regular polygon cone with its axis aligned with the axis of the first regular polygon cone,

the side surfaces of the first regular polygon pyramid and the second regular polygon pyramid are planar light reflecting surfaces,

the number of sides of the regular polygon is equal between the first bottom surface of the first regular polygon cone and the second bottom surface of the second regular polygon cone, and

the first bottom surface and the second bottom surface are both arranged perpendicular to the axis,

the first regular polygon pyramid and the second regular polygon pyramid are configured such that the phase of the regular polygon of the first bottom surface and the phase of the regular polygon of the second bottom surface coincide with each other and are rotated integrally with each other by the driving device with the shaft as a rotation axis,

A base angle when the first regular polygon cone is cut by a plane including the axis and passing through a midpoint of one side of the first base surface is α °,

a base angle when the second regular polygon pyramid is cut by a plane including the axis and passing through a midpoint of one side of the second base face is (90-a) °,

the distance between the first base surface and the second base surface is equal to the sum of a value obtained by multiplying the distance between the center point of one side of the regular polygon of the first base surface and the rotation axis by Tan alpha and a value obtained by multiplying the distance between the center point of one side of the polygon of the second base surface and the rotation axis by Tan (90-alpha),

the irradiation device irradiates light to a position intersecting the rotation axis of the rotating mirror.

12. The optical scanning device according to claim 11, wherein the base angle α is 45 °.

Technical Field

The present invention relates generally to a light reflection device that deflects and reflects incident light.

Background

Conventionally, a technique of scanning light from a light source along a linear scanning line has been widely used in a laser processing apparatus, an image forming apparatus, and the like. Patent documents 1 and 2 disclose devices provided in such devices.

The mirror rotating device of patent document 1 includes a light projecting means and a light reflecting means. The light projecting means includes a mirror rotating device having a plurality of plane mirrors arranged in a regular polygon, and reflecting light incident from a predetermined direction by one of the rotating mirror rotating devices, and the plane mirror rotating device emits light while angularly moving at a constant speed. And a light reflection means for reflecting the light emitted from the light projection means by the plurality of reflection portions and guiding the light to an arbitrary irradiated point on a predetermined scanning line.

The polygon mirror rotating apparatus of patent document 2 includes a light projecting means and a light reflecting means. The light projecting means includes a polygon mirror that emits light while angularly moving at a constant speed by reflecting light incident from a predetermined direction with a reflection surface of each side of a regular polygon of a rotating polygon mirror. And a light reflection means for reflecting the light emitted from the light projection means by the plurality of reflection portions and guiding the light to an arbitrary irradiated point on a predetermined scanning line.

In the mirror rotating apparatus of patent document 1, in the light projecting means having only the mirror rotating apparatus, the reflection position of light on each plane mirror of the mirror rotating apparatus fluctuates with the rotation of the mirror rotating apparatus, and distortion of scanning or the like occurs. In the polygon mirror rotating apparatus of patent document 2, in the light projecting means including only the polygon mirror rotating apparatus, the reflection position of light on the reflection surface of each side of the regular polygon of the polygon mirror fluctuates according to the rotation of the polygon mirror, and distortion of scanning or the like occurs.

Therefore, the mirror rotating apparatus of patent document 1 includes a reciprocating mechanism that sequentially reciprocates the plane mirror, and suppresses the change in the reflection position of light by reciprocating the plane mirror. The polygon mirror rotating apparatus disclosed in patent document 2 includes a support member that rotatably supports the polygon mirror, and a reciprocating mechanism that reciprocates the support member, and the polygon mirror and the support member are reciprocated together to suppress variation in the reflection position of light.

As the aforementioned device, a device including a galvanometer mirror (galvano mirror) having a structure in which a movable portion including a mirror is reciprocated and swung is also known. In this device, the movable portion of the galvanometer mirror is oscillated while adjusting the oscillation speed, thereby preventing the variation in the reflected position of the light.

[ Prior art documents ]

[ patent document ]

Patent document 1: japanese patent laid-open publication No. 2018-105903

Patent document 2: japanese patent laid-open publication No. 2018-97055

Disclosure of Invention

Technical problem to be solved by the invention

In the mirror rotating device of patent document 1 and the polygon mirror rotating device of patent document 2, although the fluctuation of the reflection position of light can be suppressed, it cannot be completely prevented. In addition, in the device including the galvanometer mirror, in order to prevent the change of the reflection position of the light, it is necessary to accelerate or decelerate the movable portion of the galvanometer mirror when the movable portion is oscillated, and therefore, the scanning area scanned by the device is narrowed, and the workable range of the irradiated object irradiated with the light is reduced.

Therefore, an object of the present invention is to prevent a change in the reflected position of light and to prevent a reduction in the workable range of an object to be irradiated with light, in a device for deflecting light incident from a predetermined direction.

Technical scheme for solving problems

The problems to be solved by the present invention are as described above, and means for solving the problems and effects thereof will be described below.

According to a first aspect of the present invention, there is provided a light reflecting device of the following structure. That is, the light reflection device includes a reflection member that has a planar reflection surface that reflects incident light and that simultaneously rotates and revolves. The rotation direction of the reflecting member is the same as the revolution direction. The revolution angular velocity of the reflecting member is equal to 2 times of the rotation angular velocity.

According to a second aspect of the present invention, there is provided an optical scanning device having the following structure. That is, the optical scanning device includes a rotating mirror, a driving device, and an irradiation device. The driving device rotates the rotary mirror. The illumination device illuminates light toward the rotating mirror. The rotating mirror includes a first regular polygon cone and a second regular polygon cone. The second regular polygon cone is disposed so that its axis is aligned with the axis of the first regular polygon cone and faces the first regular polygon cone. Each side surface of the first regular polygon pyramid and the second regular polygon pyramid is a planar light reflection surface. The number of sides of the regular polygon is equal to the number of sides of the first bottom surface of the first regular polygon pyramid and the second bottom surface of the second regular polygon pyramid. The first bottom surface and the second bottom surface are both arranged perpendicular to the axis. The first regular polygon pyramid and the second regular polygon pyramid are configured such that the phase of the regular polygon of the first bottom surface and the phase of the regular polygon of the second bottom surface coincide with each other, and are integrally rotated with each other by the driving device with the shaft as a rotation axis. Wherein a base angle when the first regular polygon cone is cut by a plane including the axis and passing through a midpoint of one side of the first base face is α °. A base angle when the second regular polygon pyramid is cut by a plane including the axis and passing through a midpoint of one side of the second base face is (90- α) °. The distance between the first bottom surface and the second bottom surface is equal to the sum of the distance between the middle point of one side of the regular polygon of the first bottom surface and the rotation axis multiplied by tan alpha and the distance between the middle point of one side of the regular polygon of the second bottom surface and the rotation axis multiplied by tan (90-alpha). The irradiation device irradiates light to a position intersecting with a rotation axis of the rotating mirror.

Thus, the reflecting position of the light with respect to the incident light is constant on the reflecting member, and therefore, the reflecting position of the light can be prevented from varying. Therefore, distortion can be prevented when scanning is performed.

Effects of the invention

According to the present invention, in the light reflection device that deflects light incident from a predetermined direction, it is possible to prevent the reflection position of the light from being changed.

Drawings

Fig. 1 is a perspective view showing a laser processing apparatus including a light guide device according to a first embodiment of the present invention;

FIG. 2 is a schematic view showing an example in which the light guide device is provided with one reflection unit;

fig. 3 is a perspective view of the reflection unit;

FIG. 4 is a cross-sectional view of the reflection unit;

fig. 5 is a diagram illustrating a state in which the reflecting member rotates by 180 ° while revolving by 360 °;

fig. 6 is a diagram illustrating a state when incident light is reflected by the reflecting member;

fig. 7 is a sectional view of the reflecting unit cut in a plane perpendicular to the revolution axis of the reflecting member;

fig. 8 is a diagram illustrating a relationship between a position where incident light is irradiated on the reflecting member and an angle of revolution and an angle of rotation;

fig. 9 is a sectional view showing a first modification of the reflection unit;

fig. 10 is a sectional view showing a second modification of the reflection unit;

Fig. 11 is a diagram showing a state in which the first reflecting means is in a reflecting state in the light guide device of the second embodiment;

fig. 12 is a diagram showing a state in which the first reflecting unit changes from the state of fig. 11 to the passing state, and the second reflecting unit changes from the state of fig. 11 to the reflecting state; and

fig. 13 is a perspective view of a rotating mirror of the third embodiment.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. First, the configuration of a laser processing apparatus (optical scanning apparatus) 1 including a light guide device 13 according to a first embodiment of the present invention will be described with reference to fig. 1. Fig. 1 is a perspective view of a laser processing apparatus 1.

The laser processing apparatus 1 shown in fig. 1 can process a workpiece (irradiation object) 200 by irradiating the workpiece 200 with a laser beam and performing optical scanning.

In the present embodiment, the laser processing apparatus 1 can perform non-thermal processing. The non-thermal processing includes, for example, ablation processing. Ablation processing is processing in which a part of the workpiece 200 is vaporized by irradiating a part of the workpiece 200 with laser light. The laser processing apparatus 1 may be configured to perform thermal processing, that is, to melt the workpiece 200 by the heat of the laser beam to perform processing.

The workpiece 200 is a plate-like member. The workpiece 200 is made of, for example, CFRP (carbon fiber reinforced plastic). The workpiece 200 is not limited to a plate-like member, and may be a block-like member, for example. Further, the workpiece 200 may be made of other materials.

The laser beam used in the laser processing apparatus 1 may be visible light or electromagnetic wave having a wavelength band other than visible light. In the present embodiment, not only visible light but also various electromagnetic waves including a relatively wide wavelength band are also referred to as "light".

As shown in fig. 1, the laser processing apparatus 1 includes a conveying unit 11, a laser generator 12, and a light guide device 13.

The conveying unit 11 can convey the workpiece 200 in a direction (sub-scanning direction) substantially orthogonal to the main scanning direction of the laser processing apparatus 1. Then, the laser processing is performed while the workpiece 200 is conveyed by the conveying unit 11.

In the present embodiment, the conveying portion 11 is a belt conveyor. The conveying unit 11 is not particularly limited, and may be a roller conveyor or a structure for conveying the workpiece 200 by gripping it. In addition, the conveying portion 11 may be omitted, and the workpiece 200 may be processed by irradiating the laser beam thereto.

The laser generator 12 is a light source of laser light, and is capable of generating a short-duration and wide-pulse laser by pulse oscillation. The time width of the pulse laser is not particularly limited, and may be, for example, a short time interval of nanosecond, picosecond, or femtosecond. The laser generator 12 may be configured to generate CW laser light by continuous wave oscillation.

The light guide device 13 guides the laser beam generated by the laser generator 12 so as to irradiate the workpiece 200. The laser beam guided by the light guide device 13 is irradiated to an irradiated point 202 on a scanning line 201 defined on the surface of the workpiece 200. As will be described in detail later, the irradiated point 202 on the workpiece 200 irradiated with the laser beam is moved along the linear scanning line 201 at a substantially constant speed by the operation of the light guide device 13. Thereby, optical scanning can be realized.

Next, the light guide device 13 will be described in detail with reference to fig. 2. Fig. 2 is a schematic diagram showing the configuration of the light guide device 13.

As shown in fig. 2, the light guide device 13 includes at least one reflection unit (light reflection device) 20. In the present embodiment, the light guide device 13 includes one reflection unit 20. The reflection unit 20 is disposed inside the housing 17 provided in the light guide device 13.

When the laser light emitted from the laser generator 12 is incident, the reflection unit 20 reflects the laser light to guide toward the workpiece 200. In the following description, the laser beam incident on the reflection unit 20 from the laser generator 12 is also referred to as incident light. The reflection unit 20 is disposed at a predetermined distance from the workpiece 200.

The reflection unit 20 can perform light scanning by reflecting and deflecting incident light. Fig. 1 and 2 show a scanning area 31, and the scanning area 31 is an area where the workpiece 200 is optically scanned by the reflection means 20. The scanning line 201 is constituted by the scanning region 31. The scanning area 31 is scanned by the reflection unit 20.

Next, the reflection unit 20 will be described in detail with reference to fig. 2 to 4. Fig. 3 is a perspective view of the reflection unit 20. Fig. 4 is a sectional view of the reflection unit 20.

As shown in fig. 2, the reflection unit 20 includes a support plate (support member) 41, a reflection member 42, a motor 44, a prism 51, and a scanning lens 53.

The support plate 41 is a disk-shaped member and is rotatable with respect to a housing 63 described later. The first rotation shaft 61 is rotatably supported on the housing 63. The support plate 41 is fixed to one axial end of the first rotating shaft 61. An output shaft of the motor 44 is connected to the other axial end of the first rotating shaft 61.

As shown in fig. 4, the reflection unit 20 includes a housing 63 that houses a drive transmission mechanism of the reflection unit 20. The housing 63 is fixed to a suitable portion of the housing 17 shown in fig. 2.

The housing 63 is formed in a hollow cylindrical shape having one axial side opened. The support plate 41 is disposed so as to close the open side of the case 63. The first rotation shaft 61 is disposed to penetrate the housing 63.

The reflecting member 42 is a member formed in a block shape. The reflecting member 42 is rotatable with respect to the support plate 41. The second rotation shaft 62 is rotatably supported on the support plate 41. The second rotation shaft 62 is oriented in a direction parallel to the first rotation shaft 61 and is disposed so as to penetrate the support plate 41.

The reflecting member 42 is supported on the support plate 41 via the base 71 and the second rotation shaft 62.

As shown in fig. 3, the base portion 71 is formed in a small circular plate shape. As shown in fig. 4, the base 71 is fixed to one axial end of the second rotating shaft 62. The other axial end of the second rotating shaft 62 is located inside the housing 63.

The reflective member 42 is fixed to the base 71. Therefore, the reflecting member 42 can rotate together with the base 71 and the second rotating shaft 62.

The reflecting member 42 is rotatable (revolves) about the first rotation shaft 61 together with the support plate 41 and also rotatable (rotates) about the second rotation shaft 62. In the following description, the axial center of the first rotating shaft 61 is also referred to as a revolution shaft, and the axial center of the second rotating shaft 62 is also referred to as a rotation shaft. The driving mechanism of the reflecting member 42 will be described later.

In the present embodiment, 3 reflecting members 42 are provided. And 3 reflecting members 42 disposed on the surface of the support plate 41 on the side away from the case 63.

As shown in fig. 2, 3 reflecting members 42 are arranged on the support plate 41 so as to equally divide a circle having the first rotation axis 61 as the center. Specifically, 3 reflecting members 42 are arranged at equal intervals (intervals of 120 °) in the circumferential direction of the support plate 41.

The reflection member 42 reflects light and guides the light to the scanning area 31. As shown in fig. 4, the reflecting member 42 includes a first reflecting portion 81 and a second reflecting portion 82. The first reflection portion 81 and the second reflection portion 82 are arranged in a pair with the second rotation shaft 62 (rotation shaft) therebetween.

Specifically, the reflecting member 42 is formed in a rectangular parallelepiped block shape. In the reflecting member 42, the first reflecting portion 81 is disposed on one surface of 2 surfaces facing each other with the rotation axis therebetween, and the second reflecting portion 82 is disposed on the other surface. The first and second reflection portions 81 and 82 are formed symmetrically to each other.

As will be described in detail later, the rotational angular velocity of the support plate 41 is driven to be equal to 2 times the rotational angular velocity of the reflecting member 42. Therefore, during the rotation of the support plate 41 by 360 °, the reflecting member 42 is rotated by 180 °.

When the reflecting member 42 is viewed in the direction along the rotation axis, the first reflecting portion 81 and the second reflecting portion 82 are arranged so as to face opposite sides to each other.

Fig. 5 shows the revolution and rotation of one reflecting member 42 of the 3 reflecting members 42 in the case where the reflecting member 42 is focused. In fig. 5, the edge of the reflective member 42 on the side closer to the first reflective portion 81 is hatched to facilitate understanding of the direction of the reflective member 42. In fig. 5, the revolving direction and the rotating direction of the reflecting member 42 are both counterclockwise.

As shown in fig. 5, as the support plate 41 rotates 360 °, the reflecting member 42 rotates 180 ° in conjunction with the rotation. Therefore, the reflecting member 42 rotates by 180 ° for every 360 ° revolution so as to change the directions of the first and second reflecting units 81 and 82. In this way, every time the support plate 41 rotates 360 °, the surface reflecting the incident light is alternately switched between the first reflecting portion 81 and the second reflecting portion 82.

The first reflection unit 81 and the second reflection unit 82 include a first reflection surface 85 and a second reflection surface 86, respectively. Since the first reflection unit 81 and the second reflection unit 82 have substantially the same configuration, the following description will be given by taking the configuration of the first reflection unit 81 as a representative example.

Specifically, the reflecting member 42 is provided with a groove having a V-shaped cross section, which is opened on the side away from the rotation axis. The long side direction of the groove faces to the direction vertical to the rotation shaft. A first reflecting surface 85 and a second reflecting surface 86 are formed on the inner wall of the groove. The first reflection unit 81 includes a first reflection surface 85 and a second reflection surface 86.

The first reflecting surface 85 and the second reflecting surface 86 are formed in a planar shape. The first reflecting surface 85 is disposed to be inclined with respect to a virtual plane perpendicular to the second rotation axis 62. The second reflecting surface 86 is disposed to be inclined with respect to a virtual plane perpendicular to the second rotation axis 62.

As shown in fig. 6, the first reflecting surface 85 and the second reflecting surface 86 are inclined in opposite directions at equal angles θ (specifically, 45 °) with respect to a virtual plane perpendicular to the second rotation axis 62. Therefore, the first reflecting surface 85 and the second reflecting surface 86 are formed symmetrically with respect to the symmetric surface 87 perpendicular to the second rotation axis 62. The first reflecting surface 85 and the second reflecting surface 86 are arranged so as to form a V-shape with an angle of 90 °.

With this configuration, the incident light guided to the light guide device 13 is bent by the prism 51 and then travels in a direction approaching the reflection unit 20 along the first optical path L1. The first optical path L1 is directed in a direction orthogonal to the direction of the common axis of the reflecting member 42.

The 3 reflecting members 42 are driven by the motor 44 to revolve and rotate, and move so as to sequentially cut off the first optical path L1. Therefore, the 3 reflection members 42 sequentially contact the incident light incident along the first light path L1 to reflect the light.

The first reflecting surface 85 of the first reflecting part 81 or the second reflecting part 82 is disposed so as to overlap the first optical path L1 as shown in fig. 3, in the vicinity of the timing when the revolving reflecting member 42 comes to the position closest to the upstream side of the first optical path L1. Therefore, the incident light is reflected by the first reflection surface 85 and then reflected by the second reflection surface 86.

As shown in fig. 4, when the reflecting member 42 revolves and rotates in a state where the incident light is irradiated on the reflecting member 42, the directions of the first reflecting surface 85 and the second reflecting surface 86 continuously change. Therefore, the direction of the light emitted from the second reflecting surface 86 changes smoothly as indicated by the hollow arrow in fig. 3. In this way, the deflection of the radiated light can be achieved.

Since the first reflecting surface 85 and the second reflecting surface 86 are arranged in a V shape, the light emitted from the reflecting member 42 is deflected along a plane perpendicular to the rotation axis in accordance with the revolution and rotation of the reflecting member 42. This plane is offset in the direction of the second rotation axis 62 (in other words, the first rotation axis 61) with respect to the first optical path L1. Thus, the light reflected by the second reflecting surface 86 can be guided toward the workpiece 200 by the second optical path L2 that is offset from the first optical path L1.

The incident light is incident on the reflection unit 20 in a direction perpendicular to the rotation axis and the revolution axis. When the revolution phase of the reflecting member 42 completely matches the direction of the incident light, the first reflecting surface 85 and the second reflecting surface 86 are orthogonal to the incident light when viewed along the second rotation axis 62. Thus, at this time, the incident light is reflected by the reflecting member 42 2 times in a folded manner as shown in fig. 3, and is emitted along the second light path L2 in a direction parallel to and opposite to the direction of the first light path L1.

Thus, the incident light is reflected by the first reflecting surface 85 and the second reflecting surface 86 and deflected. Here, as shown in fig. 6, a mirror image of the symmetry plane 87 with respect to the first reflection plane 85 and a mirror image of the symmetry plane 87 with respect to the second reflection plane 86 are considered. The 2 mirror images are all planar surfaces 88 located on the interior of the reflective member 42. From the viewpoint of the optical path length, the case where the incident light is reflected while being shifted by the first reflecting surface 85 and the second reflecting surface 86 is equivalent to the case where the incident light is reflected by the plane 88 without being shifted. In this sense, the virtual plane 88 can be said to be a formally reflective surface.

Plane 88 is illustrated from another perspective. In the following description, an optical path from when the incident light is reflected by the first reflecting surface 85 to when the incident light is reflected by the second reflecting surface 86 is referred to as an intermediate optical path L3. The bisector point of the intermediate optical path L3 is located on the symmetry plane 87.

As shown by the broken line in fig. 6, a case where the first optical path L1 of the incident light is extended so as to protrude from the first reflection surface 85 into the reflection member 42 is considered. A point 77 of the front end of the extension line 76, which extends the first light path L1 of the incident light by the length D1 half the intermediate light path L3, is located on the plane 88.

Similarly, a case where the second optical path L2 of the incident light is extended so as to protrude from the second reflection surface 86 into the reflection member 42 is considered. A point 79 at the front end of the extension line 78 extending the second light path L2 of the incident light by the length D1 half the intermediate light path L3 is located on the plane 88.

Fig. 6 shows a state where the direction of the second light path L2 is in the center of the deflection angle range. However, in any case of deflecting the incident light in any direction by the reflecting member 42, the leading ends of the extension lines 76, 78 are always located on the plane 88.

The plane 88 also serves as a reference plane for symmetrically arranging the first reflecting portion 81 and the second reflecting portion 82. Therefore, although the plane 88 is shown in relation to the first reflecting portion 81 in fig. 6, the plane 88 is common to both the first reflecting portion 81 and the second reflector 82. In the present embodiment, the rotation axis of the reflecting member 42 (in other words, the axis of the second rotation axis 62) is arranged so as to be included in the plane 88.

Thus, the case of deflecting incident light by the first reflection unit 81 and the second reflection unit 82 of the reflection member 42 is substantially the same as the case of deflecting incident light by disposing the reflection surfaces on the front and back surfaces of the zero-thickness plane 88 that rotates and revolves together with the reflection member 42. Fig. 2 shows the relationship of the rotating and revolving reflective member 42 to the plane 88.

The prism 51 is formed of an appropriate optical element. The prism 51 is disposed on the upstream side of the reflecting member 42 on the first optical path L1. The prism 51 can guide the laser beam from the laser generator 12 to the reflecting member 42.

The scanning lens 53 is a free-form lens, and a known f θ lens can be used, for example. The scanning lens 53 is disposed between the reflecting member 42 and the scanning area 31. The scanning lens 53 can keep the focal length constant in the central portion and the peripheral portion of the scanning range.

The motor 44 generates a driving force to revolve and rotate the reflecting member 42. The driving force of the motor 44 is transmitted to the planetary gear set via an output shaft of the motor 44, so that the support plate 41 and the reflecting member 42 are rotated. In the present embodiment, the motor 44 is a motor, but is not limited thereto.

Next, a driving mechanism for rotating the support plate 41 and the reflecting member 42 will be described with reference to fig. 4 and 7. Fig. 7 is a sectional view of the reflection unit 20 cut in a plane perpendicular to the revolution axis.

As shown in fig. 4, the support plate 41 is fixed at its center portion to one axial end portion of the first rotary shaft 61. An output shaft of the motor 44 is connected to the other axial end of the first rotating shaft 61.

Further, a second rotation shaft 62 is disposed radially outward of the center portion of the support plate 41. The second rotation shaft 62 is rotatably supported by the support plate 41. One axial end of the second rotating shaft 62 is disposed outside the housing 63 and fixed to the base 71. The other axial end of the second rotating shaft 62 is disposed inside the housing 63.

As shown in fig. 7, the planetary gear 91 is fixed to the second rotation shaft 62 inside the housing 63. The planetary gear 91 meshes with a sun gear 92 provided around the first rotation shaft 61 via an intermediate gear 93. The sun gear 92 is fixed to the housing 63. The intermediate gear 93 is rotatably supported on the support plate 41.

Thereby, when the motor 44 is driven, the driving force of the motor 44 is transmitted to the first rotation shaft 61 to rotate the support plate 41. By the rotation of the support plate 41, the shaft of the intermediate gear 93 and the shaft of the planetary gear 91 (second rotation shaft 62) move around the sun gear 92. At this time, the intermediate gear 93 meshing with the sun gear 92 rotates, and the planetary gears 91 meshing with the intermediate gear 93 also rotate. Therefore, the reflection member 42 fixed to the planetary gear 91 via the second rotation shaft 62 revolves and rotates.

Since the sun gear 92 is fixed to the housing 63 and the intermediate gear 93 is interposed between the planetary gears 91 and the sun gear 92, the rotation direction of the carrier, i.e., the support plate 41, is the same as the rotation direction of the second rotation shaft 62 (the reflection member 42). The number of teeth of the planetary gear 91 is 2 times the number of teeth of the sun gear 92. Thus, the revolution angular velocity of the reflecting member 42 is equal to 2 times the rotation angular velocity of the reflecting member 42.

Next, the relationship between the revolution angular velocity and the rotation angular velocity of the reflecting member 42 will be described in detail with reference to fig. 8.

In fig. 8, a trajectory of the second rotation shaft 62 following the rotation of the support plate 41 is shown as a revolution circle 101. The center of the revolution circle 101 is located at an intersection (origin O) of the X axis and the Y axis extending in the mutually perpendicular directions. The origin O corresponds to the revolution axis of the reflecting member 42. As described above, the deflection of light on the reflecting member 42 can be considered to be substantially the same as the deflection caused by reflecting light by the plane 88. Therefore, in fig. 8, the reflecting member 42 is represented by a straight line showing a plane 88 which is an equivalent virtual reflecting surface.

The rotation axis of the reflecting member 42 is located at an arbitrary point on the revolution circle 101. Here, a state is considered in which the rotation axis of the reflecting member 42 is located at the point P and the direction of the reflecting surface of the reflecting member 42 is perpendicular to the X axis. At this time, the light incident on the origin O in the X-axis direction is reflected by the reflecting member 42 at the point P. When two-dimensional observation is performed as shown in fig. 8, the optical path of the reflected light coincides with the optical path of the incident light.

It is assumed that the position of the rotation axis of the reflecting member 42 changes by the angle θ and moves from the point P to the point Q with the rotation of the support plate 41. Considering what relation the rotation angle of the reflecting member 42 is in relation to the revolution angle, the point where the incident light is irradiated on the reflecting member 42 can be prevented from changing from the point P even when the revolution is performed.

In order to reflect the incident light at the point P even when the rotation axis of the reflecting member 42 is located at the point Q, the reflecting member 42 must be oriented in the same direction as the straight line drawn from the point Q to the point P.

The midpoint of the straight line connecting point P and point Q is assumed to be M. Further, a straight line passing through the point Q and extending parallel to the Y axis is assumed, and the intersection of the straight line and the X axis is assumed to be N.

Since the points P and Q are located on the circumference of the revolution circle 101, the triangle OPQ is an isosceles triangle. Thus, the angle OPM formed by the straight line OP and the straight line PM is equal to the angle OQM formed by the straight line OQ and the straight line QM. The straight line OM is orthogonal to the straight line PQ. The straight line OP is orthogonal to the straight line QN.

When looking at the triangle OQM and triangle NQP, as described above, 2 angles of the triangle are equal. Thus, triangle OQM is similar to triangle NQP.

Therefore, the angle QOM formed by the straight line QO and the straight line OM is equal to the angle PQN formed by the straight line PQ and the straight line QN. The angle QEP formed by the straight line QO and the straight line OP is theta. Thus, the angle QOM is θ/2, and the angle PQN is also θ/2.

As is clear from the results, if the revolution and the rotation are performed simultaneously so that the revolution angular velocity of the reflecting member 42 is 2 times the rotation angular velocity, the reflecting member 42 cuts the optical path so as to always contact the incident light at the point P, and therefore the length of the optical path can be made constant.

As described above, in the present embodiment, incident light is reflected and deflected by rotating the reflecting member 42 having the reflecting surfaces 85, 86. Since the reflecting member 42 is rotationally driven at a constant angular velocity without performing a reciprocating motion (acceleration/deceleration) like a galvanometer mirror, it is possible to avoid narrowing the scanning region 31 in which the moving speed of the irradiated point 202 can be kept constant, and to suppress a decrease in the workable range of the workpiece 200 due to light. Further, since the fluctuation of the point at which the reflecting member 42 contacts the incident light can be prevented by the combination of the revolution and the rotation of the reflecting member 42, the light can be guided to the scanning lens 53 in an ideal state, as in the galvanometer mirror. Thus, the optical reflection device can be obtained which has both a high irradiation rate, which is a characteristic of the polygonal mirror, and a difficulty in variation of the reflection point, which is a characteristic of the galvanometer mirror.

As described above, the reflection unit 20 of the present embodiment includes the reflection member 42, and the reflection member 42 has the planar reflection surfaces 85 and 86. The reflecting surfaces 85, 86 reflect incident light. The reflecting member 42 performs revolution and rotation at the same time. The revolving direction and the rotating direction of the reflecting member 42 are the same. The revolution angular velocity of the reflecting member 42 is equal to 2 times the rotation angular velocity.

This makes the reflecting position of the light with respect to the incident light constant in the reflecting member 42, thereby preventing the reflecting position of the light from varying. Therefore, distortion of the scanning can be reduced. Compared with a galvanometer mirror, since the deflection can be achieved by the rotation of the reflecting member 42 rather than the reciprocating movement, the scanning can be performed easily at a constant speed.

In the reflection unit 20 of the present embodiment, the reflection surfaces 85 and 86 are arranged in pairs with the rotation axis of the reflection member 42 interposed therebetween.

The reflecting member 42 rotates by 180 ° every 360 ° revolution to change its direction. Therefore, by arranging the pair of reflecting surfaces 85, 86 having directions different from each other by 180 ° in the reflecting member 42, when the reflecting member 42 cuts the optical path of the incident light, one of the reflecting surfaces can efficiently reflect the light. Therefore, the incident light can be efficiently guided to the workpiece 200.

The reflection unit 20 of the present embodiment includes 3 reflection members 42. The revolution axes of the 3 reflecting members 42 coincide. The 3 reflecting members 42 are arranged so as to divide a circle having a revolution axis as a center at equal angular intervals.

This enables incident light to be guided to the workpiece 200 more efficiently.

The reflection unit 20 of the present embodiment includes a planetary gear set that performs revolution and rotation of the reflection member 42.

This allows a simple configuration to realize a cutting operation in which the revolution and rotation of the reflecting member 42 are combined.

In the reflection unit 20 of the present embodiment, as shown in fig. 3, the reflection member 42 reflects light so as to deflect along a plane perpendicular to the rotation axis. The plane is shifted in the direction of the rotation axis with respect to the incident light on the reflecting member 42.

Thereby, a layout can be achieved in which the reflected light reflected by the reflecting member 42 does not interfere with an optical member or the like for guiding the incident light to the reflecting unit 20.

In the present embodiment, the reflecting member 42 is provided with a first reflecting surface 85 and a second reflecting surface 86. The first reflecting surface 85 is formed in a planar shape inclined with respect to a plane perpendicular to the rotation axis of the reflecting member 42. The second reflecting surface 86 is formed in a planar shape inclined with respect to a plane perpendicular to the rotation axis of the reflecting member 42. The direction in which the first reflecting surface 85 is inclined with respect to the plane perpendicular to the rotation axis is opposite to the direction in which the second reflecting surface 86 is inclined with respect to the plane perpendicular to the rotation axis. The incident light is reflected by the first reflecting surface 85 and then reflected by the second reflecting surface 86. The first reflecting surface 85 and the second reflecting surface 86 are formed to be symmetrical with each other with respect to the symmetrical surface 87. The mirror image of the plane of symmetry 87 with respect to the first reflecting surface 85 and the mirror image of the plane of symmetry 87 with respect to the second reflecting surface 86 are in the same plane 88 with each other. The axis of rotation of reflective element 42 is contained within a mirrored plane 88.

Thus, a simple configuration can be realized: the reflecting member 42 deflects the incident light while reflecting the incident light, and the reflecting position of the light with respect to the incident light is constant in the reflecting member 42.

In the light guide device 13 of the present embodiment, the first reflecting surface 85 is inclined at an angle θ of 45 ° with respect to a plane perpendicular to the rotation axis. The second reflecting surface 86 is inclined at an angle θ of 45 ° with respect to a plane 88 perpendicular to the rotation axis.

This enables a simple configuration of the reflecting member 42.

The light guide device 13 of the present embodiment includes the reflection unit 20 having the above-described configuration. The incident light is deflected by the reflection unit 20 to scan the workpiece 200.

This enables scanning with less distortion.

The light guide device 13 of the present embodiment includes a scanning lens 53. The scanning lens 53 is disposed on the optical path from the reflecting member 42 to the scanning area 31.

This makes it possible to make the focal length uniform over the entire scanning area. In addition, the light can be guided to the scanning lens 53 in an ideal state.

Next, a first modification of the driving mechanism of the support plate 41 and the reflecting member 42 will be described. In the description of the present modification, the same reference numerals are used in the drawings for the same or similar members as those of the above-described embodiment, and the description thereof will be omitted.

In the modification shown in fig. 9, a ring gear 94 is fixed near the outer periphery of the support plate 41. The ring gear 94 meshes with a drive gear 95 fixed to an output shaft of the motor 44. The other structure is substantially the same as that of fig. 4.

In the present modification, the support plate 41 can be rotated by driving the motor 44 to perform revolution and rotation of the reflecting member 42.

Next, a second modification of the driving mechanism of the support plate 41 and the reflecting member 42 will be described. In the description of the present modification, the same reference numerals are used in the drawings for the same or similar members as those of the above-described embodiment, and the description thereof will be omitted.

In the modification shown in fig. 10, as in fig. 9, a ring gear 94 is fixed to the vicinity of the outer periphery of the support plate 41.

A 2-stage gear 96 is rotatably supported inside the housing 63. The 2-stage gear 96 includes a large-diameter gear 96a and a small-diameter gear 96 b. The large-diameter gear 96a and the small-diameter gear 96b rotate integrally with each other. The large-diameter gear 96a meshes with a drive gear 95 fixed to the output shaft of the motor 44. The small-diameter gear 96b meshes with the ring gear 94.

A transmission gear 97 is rotatably supported inside the housing 63. The transmission gear 97 meshes with a large-diameter gear 96a provided in the 2-stage gear 96.

Unlike the above-described embodiment and the like, the sun gear 92 is rotatably supported by the housing 63. The transmission gear 97 is coupled to the sun gear 92 via a transmission shaft 98. The sun gear 92 rotates integrally with the transmission shaft 98.

In the present modification, the intermediate gear 93 is omitted. The sun gear 92 directly meshes with the planetary gears 91 without interposing the intermediate gear 93.

With this configuration, when the motor 44 is driven, the 2-stage gear 96 rotates. As a result, the ring gear 94 is driven by the small-diameter gear 96b to rotate the support plate 41. At the same time, the transmission gear 97 is driven by the large diameter gear 96a to rotate the sun gear 92.

The sun gear 92 rotates in the same direction as the support plate 41 at a greater angular velocity than the support plate 41. As a result, the planetary gear 91 can be rotated in the same direction as the revolution. Further, by specifying the number of teeth of the 2-stage gear 96 and the like according to a known formula, the revolution and the rotation can be performed simultaneously so that the revolution angular velocity of the reflecting member 42 becomes 2 times the rotation angular velocity.

Next, a second embodiment of the light guide device 13 will be described with reference to fig. 11 and 12. In the description of the present embodiment, the same or similar components as those of the above-described embodiment are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

The present embodiment is different from the first embodiment in that the light guide device 13 includes a plurality of reflection units 20. This embodiment is used, for example, to process a workpiece 200 that is longer in the main scanning direction than in the first embodiment.

As shown in fig. 11 and 12, the light guide device 13 includes a plurality of reflection units 20. In the light guide device 13 of the present embodiment, 2 reflection units 20 are arranged. Each reflection unit 20 reflects the laser light incident from the laser generator 12 and guides to the workpiece 200.

The 2 reflection units 20 are arranged linearly in the main scanning direction. The arrangement direction of the reflection units 20 also coincides with the longitudinal direction of the scanning line 201. The 2 reflection units 20 are disposed at positions having distances substantially equal to the distances from the scanning lines 201.

Hereinafter, regarding the plurality of reflection units 20, the reflection unit 20 located on the upstream side (the side closer to the laser generator 12) in the traveling direction of the incident light may also be referred to as a first reflection unit 21. The reflection unit 20 located on the downstream side (the side away from the laser generator 12) in the traveling direction of the incident light can also be referred to as a second reflection unit 22.

Each reflection unit 20 can perform optical scanning by reflecting and deflecting the laser beam. An area (scanning area) 181 where the workpiece 200 is optically scanned by the first reflecting unit 21 is different from the scanning area 182 of the second reflecting unit 22. The 2 scanning regions 181 and 182 are arranged in a linear array. The scanning line 201 is constituted by a set of 2 scanning regions 181, 182.

Each reflecting unit 20 can be repeatedly switched between a reflecting state in which incident light is reflected and scanned and a passing state in which incident light is not reflected and passes through the downstream side. When the reflection unit 20 is in the reflection state, the light scans a corresponding scanning area (for example, the scanning area 181 in the case of the first reflection unit 21). When the reflection unit 20 is in the passing state, the reflection unit 20 does not perform light scanning.

The timing at which each reflection unit 20 is brought into the reflection state differs among the plurality of reflection units 20. Therefore, the plurality of scanning areas are scanned by the reflection unit 20 switched to the reflection state.

In the present embodiment, 2 reflecting members 42 are provided for one reflecting unit 20. The 2 reflecting members 42 are disposed on the support plate 41 so as to be equally divided by 360 °. Specifically, the 2 reflecting members 42 are arranged at positions where one reflecting member 42 is shifted by 180 ° in the circumferential direction of the support plate 41 with respect to the other reflecting member 42.

On the support plate 41, 2 reflecting members 42 are arranged at positions corresponding to mutually opposing sides of a regular polygon (specifically, a regular quadrangle). Thus, in the 2 reflection members 42, the center angle of one reflection member 42 is 90 °. The reflecting member 42 is not disposed at a position corresponding to a side other than the facing side.

When the 2 reflection members 42 are respectively moved with the rotation of the support plate 41, the state where the reflection members 42 contact the laser light incident on the reflection unit 20 and traveling along the first optical path L1 and the state where they do not contact are alternately switched. As shown in the first reflection unit 21 of fig. 11, a state in which any one of the 2 reflection members 42 contacts incident light is the reflection state. As shown in the first reflection unit 21 of fig. 12, the state in which none of the 2 reflection members 42 contacts the incident light is the pass state.

The first optical path L1 is orthogonal to the first rotation axis 61 and the second rotation axis 62. The 2 reflecting members 42 are arranged so as to be shifted in phase by 180 ° from each other. Therefore, of the 2 reflecting members 42 arranged with the first rotation shaft 61 interposed therebetween, only the reflecting member 42 positioned on the upstream side closer to the first optical path L1 contacts the incident light.

The 2 reflection units 20 configured as described above are provided for incident light entering from the laser generator 12 via an appropriate prism 51, thereby configuring the light guide device 13 according to the present embodiment. In the 2 reflection units 20, the revolution axis and the rotation axis of the reflection member 42 are parallel to each other. The reflecting member 42 revolves in the same direction. The revolution angular velocity of the reflecting member 42 is equal to 2 times the rotation angular velocity.

The reflecting members 42 revolve around each other at an angular velocity equal to the revolution of the reflecting member 42 of the other reflecting unit 20 and in the same direction, while having a rotational phase (90 ° in the present embodiment) shifted by a predetermined angle. This makes it possible to vary the timing at which the reflecting member 42 contacts the incident light among 2 reflecting units 20.

The revolution and rotation of the reflecting member 42 in the plurality of reflecting units as described above can be realized by controlling motors, not shown, provided in the 2 reflecting units 20 so as to rotate in synchronization, for example. However, for example, it is also possible to drive 2 reflection units 20 by a common motor.

Fig. 11 shows a case where the first reflecting unit 21 is in the reflecting state and the second reflecting unit 22 is in the passing state among the 2 reflecting units 20. Fig. 12 shows a case where the first reflecting unit 21 becomes the passing state and the second reflecting unit 22 becomes the reflecting state as a result of the revolution and rotation of the reflecting member 42 of each reflecting unit 20 from the state of fig. 11. In this way, the reflection units 20 for performing optical scanning can be sequentially switched, and optical scanning along the scanning line 201 longer than that in the first embodiment can be achieved as a whole.

As described above, in the laser processing apparatus 1 of the present embodiment, the reflecting member 42 of the reflecting unit 20 revolves and rotates simultaneously, and switches between the reflecting state in which the incident light is irradiated onto the reflecting surface 85 and reflected and the passing state in which the incident light passes without being irradiated onto the reflecting surface 85. The timing of the reflection state differs among the plurality of light guide devices 13. One linear scanning line 201 is formed by a set of scanning regions 181 and 182 corresponding to the plurality of light guide devices 13.

This enables scanning along a long scanning line.

Next, referring to fig. 13, a rotating mirror 250 as a reflecting member having a special shape will be described. In the description of the present embodiment, the same or similar components as those of the above-described embodiment are denoted by the same reference numerals in the drawings, and the description thereof will be omitted.

The rotating mirror 250 includes a first regular polygonal pyramid 251 and a second regular polygonal pyramid 252. In the present embodiment, the 2 regular polygonal cones 251 and 252 are formed as regular octagonal cones, but are not limited thereto.

The 2 regular polygonal cones 251, 252 are arranged opposite to each other with their axes 260 aligned with each other. The 2 regular polygonal cones 251, 252 are joined to each other by an intermediate portion 255. Therefore, the 2 regular polygonal cones 251 and 252 are substantially formed in a polygonal frustum shape.

A transmission shaft 259 is attached to the rotating mirror 250. The rotating mirror 250 is rotated by transmitting a driving force of a driving device (specifically, a motor), not shown, to the transmission shaft 259. The reflecting device for reflecting and deflecting light is composed of a rotating mirror 250 and a driving device. The rotation axis at this time coincides with the axes 260 of the 2 regular polygonal cones 251 and 252.

The side surfaces of the 2 regular polygonal cones 251 and 252 are planar light reflecting surfaces 257. The light reflecting surfaces 257 are arranged around the axis 260. Each light reflecting surface 257 is inclined with respect to the axis 260.

The first regular polygonal pyramid 251 has a first bottom surface 261. The second regular polygonal pyramid 252 has a second bottom surface 262. The first bottom surface 261 and the second bottom surface 262 are regular polygons and are arranged perpendicular to the axis 260.

In the present embodiment, the first regular polygonal pyramid 251 and the second regular polygonal pyramid 252 have the same shape. Since the 2 regular polygonal cones 251 and 252 are regular octagonal cones, the first bottom surface 261 and the second bottom surface 262 are both regular octagons. Thus, the number of sides of the regular polygon of the first bottom surface 261 and the second bottom surface 262 is the same.

The 2 regular polygonal cones 251 and 252 are coupled by the intermediate portion 255 so that phases of regular octagons of the 2 bottom surfaces 261 and 262 coincide with each other.

Fig. 13 shows a virtual plane 270 with the rotating mirror 250 switched off. The virtual plane 270 includes the axis 260 and is defined by the midpoints 271, 272 of one side of the regular octagon of the bottom surfaces 261, 262.

Assuming that α is a base angle when the first regular polygon pyramid 251 is cut by the virtual plane 270 and β is a base angle when the second regular polygon pyramid 252 is cut by the virtual plane 270, the rotating mirror 250 of the present embodiment satisfies a relationship of α + β being 90 °. In the present embodiment, α ═ β ═ 45 °, but is not limited thereto. For example, α may be set to 30 ° or β may be set to 60 °.

In the present embodiment, when the distance between the first bottom surface 261 and the second bottom surface 262 is D2, the distance between the center point 271 of one side of the regular polygon of the first bottom surface 261 and the axis 260 is D3, and the distance between the center point 272 of one side of the regular polygon of the second bottom surface 262 and the axis 260 is D4, the relationship of D2 — D3 × tan α + D4 × tan β is satisfied.

With the above configuration, when the outline obtained by cutting the rotating mirror 250 with the virtual plane 270 is considered, the straight line 281 corresponding to the light reflecting surface 257 of the first regular polygon pyramid 251 and the straight line corresponding to the light reflecting surface 257 of the second regular polygon pyramid 252 are in a mutually perpendicular relationship.

Since the distances D2, D3, and D4 satisfy the above-described relation, if the 2 straight lines 281 and 282 are extended as shown by the chain line in fig. 13, the intersection of the 2 straight lines 281 and 282 is located on the axis 260. This is evident by considering the relationship between 2 right triangles and tan α and tan β.

Incidentally, in the reflecting member 42 of fig. 6 in the embodiment, its rotation axis is arranged so as to be included in the virtual plane 88, i.e., the reflecting plane in the form of light. The configuration of the rotating mirror 250 in fig. 13 is obtained by enlarging the assumed mirror to a regular polygonal cone shape.

In the rotating mirror 250 of fig. 13, a case where light is irradiated from the irradiation device to the light reflection surface 257 so as to intersect with the axis 260 is considered. The incident light (e.g., laser beam) is reflected by the light reflecting surface 257 of the first regular polygonal pyramid 251, and then reflected by the light reflecting surface 257 of the second regular polygonal pyramid 252 to be emitted.

The light reflecting surfaces 257 arranged on the side surfaces of the rotating mirror 250 can correspond to the sides of the regular polygon of the bottom surfaces 261 and 262, respectively. In the following description, the side of the regular polygon corresponding to the light reflecting surface 257 irradiated with light may be referred to as a corresponding side.

Here, assuming a case of a plane 290 having a thickness of zero, the plane 290 is disposed so as to include the shaft 260 and rotates together with the rotating mirror 250. The plane 290 is disposed parallel to the corresponding side. The case where the incident light is deflected by being reflected 2 times by the rotating mirror 250 having a pair of regular polygonal tapered portions is equivalent to the case where the incident light is deflected by being reflected once by the plane 290.

Thereby, the reflection position of light with respect to the incident light on the rotating mirror 250 becomes constant. As a result, the reflected position of the light can be prevented from being changed.

In the present embodiment, the rotary mirror 250 is simply rotated by the transmission shaft 259, and the shaft 260 as the rotation center is not moved. In the present embodiment, since a large-sized rotating device that combines revolution and rotation is not required, simplification and downsizing of the configuration can be easily achieved.

The rotating mirror 250 can be used together with the motor 44, the housing 17, the scanning lens 53, the laser generator 12, and the like to configure the light guide device 13 and the laser processing device 1 shown in fig. 1, for example. As described above, in this laser processing apparatus, the reflection position of light on the rotating mirror 250 is substantially constant. Therefore, by using an f θ lens as the scanning lens 53, the focal point can be scanned at a constant speed over the irradiated point 202. In comparison with the galvanometer mirror, since deflection is achieved by rotation of the rotating mirror 250 instead of reciprocating movement, scanning is easily performed at a constant speed.

As described above, the laser processing apparatus according to the present embodiment includes the rotating mirror 250, the motor, and the irradiation device. The motor rotates the rotating mirror 250. The irradiation device irradiates light toward the rotating mirror 250. The rotating mirror 250 includes a first regular polygonal pyramid 251 and a second regular polygonal pyramid 252. The second regular polygonal pyramid 252 is disposed so that the axis 260 is aligned with the axis of the first regular polygonal pyramid 251 and faces the first regular polygonal pyramid 251. The side surfaces of the first regular polygon pyramid 251 and the second regular polygon pyramid 252 are planar light reflecting surfaces 257. The number of sides of the regular polygon is equal on the first bottom surface 261 of the first regular polygon pyramid 251 and the second bottom surface 262 of the second regular polygon pyramid 252. The first bottom surface 261 and the second bottom surface 262 are disposed perpendicular to the shaft 260. The first regular polygon pyramid 251 and the second regular polygon pyramid 252 are integrally rotated with each other by a motor using the shaft 260 as a rotation axis while matching the phase of the regular polygon of the first bottom surface 261 with the phase of the regular polygon of the second bottom surface 262. The base angle when the first regular polygon cone 251 is cut by a virtual plane 270 including the axis 260 and passing through the midpoint 271 of one side of the regular polygon of the first base surface 261 is α °. A base angle when the second regular polygon pyramid 252 is cut by a virtual plane 270 including the axis 260 and passing through a midpoint 272 of one side of the regular polygon of the second bottom surface 262 is β ═ 90- α °. The distance D2 between the first bottom surface 261 and the second bottom surface 262 is equal to the sum of the value obtained by multiplying the distance D3 between the midpoint 271 of one side of the regular polygon of the first bottom surface 261 and the axis 260 by Tan α and the value obtained by multiplying the distance D4 between the midpoint of one side of the polygon of the second bottom surface 262 and the axis 260 by Tan (90- α). The irradiation device irradiates light in a direction crossing the axis 260 of the rotating mirror 250.

This makes the reflection position of the light with respect to the incident light on the rotating mirror 250 constant, and prevents the light reflection position from varying with rotation. Therefore, distortion of the scanning can be reduced.

In the light guide device of the present embodiment, the base angle α is 45 °.

This allows the rotary mirror 250 to have a simple shape. In addition, a concise light path layout can be realized.

The preferred embodiment and the modified examples of the present invention have been described above, but the above configuration can be modified as follows, for example.

The number of the reflecting members 42 on the reflecting unit 20 with respect to the support plate 41 is not limited to 3 as in the first embodiment, and can be 4 or 5, for example.

The number of the reflection units 20 may be set according to the shape of the irradiation target, for example, 3, 4, or 5 instead of 2 in the second embodiment.

The first reflection unit 81 and the second reflection unit 82 of the reflection member 42 may be implemented by a prism.

The optical scanning device to which the light guide device 13 is applied is not limited to the laser processing device 1, and may be an image forming device, for example.

In the third embodiment, as the first regular polygonal pyramid 251 and the second regular polygonal pyramid 252, for example, a regular hexagonal pyramid, a regular nonagonal pyramid, or the like can be used instead of the regular octagonal pyramid. The dimensions of the first bottom surface 261 and the second bottom surface 262 may be different from each other.

In the rotating mirror 250 according to the third embodiment, a free shape can be adopted for a portion that does not reflect light. The first regular polygon pyramid 251 and the second regular polygon pyramid 252 shown in fig. 13 are actually regular polygon frustums, but are included in the regular polygon pyramid as long as the portion that reflects light is a regular polygon pyramid. The names "bottom surface" and "bottom angle" do not limit the direction of the regular polygonal cone. Rotating the mirror 250, its axis 260 can be used in any direction.

Obviously, the present invention can take many modifications and variations, as long as they are within the scope of the present invention. Therefore, it is to be understood that the present invention may be practiced by methods other than those described in the present specification within the scope of the appended claims.

Description of the reference numerals

1 laser processing device (optical scanning device)

13 light guide device

20 reflection unit (light reflection device)

31 scan area

42 reflective member

53 lens for scanning

61 first rotation axis (rotation axis of the support plate)

62 second rotation axis (rotation axis of reflection component)

81 first reflection part (reflection part)

82 second reflection part (reflection part)

85 first reflecting surface

86 second reflecting surface

200 workpiece (irradiated object)

201 scan line

202 irradiated point

250 rotating mirror (reflection component)

251 first regular polygonal pyramid

252 second regular polygonal pyramid

257 light reflecting surface

260 shaft (rotating shaft)

261 first bottom surface

262 second bottom surface

Bottom angles of alpha and beta.