Polygon mirror

Abstract

To prevent damage to a polygon mirror.SOLUTION: A connecting plate 33 is connected to side faces 12a-12d and is positioned substantially perpendicular to a rotary shaft. A bearing 34 protrudes toward a driving unit from the connecting plate 33 and is engaged with the rotary shaft. Mounting parts 35a-35d protrude toward the driving unit from the connecting plate 33 and are fixed to a fixed plate. Ribs 37a-37d connect between the mounting parts 35a-35d.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a polygon mirror. [Background technology]

[0002] Patent Document 1 discloses a polygon mirror formed from a resin body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-182640 Summary of the Invention [Problem to be solved by the invention]

[0004] Since the polygon mirror rotates at high speed, it is necessary to prevent deformation and breakage due to stress and heat caused by the rotation. The present invention aims to solve such problems, for example. [Means for solving the problem]

[0005] The polygon mirror has a main body integrally formed from synthetic resin and a reflecting portion that reflects light. The main body has a side portion on which the reflecting portion is provided and a support portion that supports the side portion. The support portion is fixed to a fixed plate of a drive unit having a rotation axis and a fixed plate fixed to the rotation axis approximately perpendicular to the rotation axis. The fixed plate rotates with the rotation of the rotation axis, thereby rotating around the rotation axis and rotating the side portion. The support portion has a connecting plate portion connected to the side portion and arranged approximately perpendicular to the rotation axis, a bearing portion that protrudes from the connecting plate portion toward the drive unit and engages with the rotation axis, multiple mounting portions that protrude from the connecting plate portion toward the drive unit and are fixed to the fixed plate, and at least one rib portion connecting the multiple mounting portions. [Effects of the Invention]

[0006] In the polygon mirror, the ribs connect the mounting portions, preventing stress from concentrating on the mounting portions and preventing deformation or damage to the polygon mirror. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is an exploded perspective view showing an example of an optical deflector. [Figure 2] FIG. 2 is a perspective view showing an example of a main body of a polygon mirror. [Figure 3] FIG. 2 is a plan view showing an example of a main body of a polygon mirror. [Figure 4] FIG. 3 is a cross-sectional view taken along line AB showing an example of a main body of a polygon mirror. [Figure 5] FIG. 2 is a bottom view showing an example of a main body of the polygon mirror. [Figure 6] FIG. 2 is a perspective view cut away from line CDE showing an example of a main body of a polygon mirror. [Figure 7] FIG. 10 is a bottom view showing another example of the main body of the polygon mirror. [Figure 8] FIG. 10 is a bottom view showing another example of the main body of the polygon mirror. [Figure 9] FIG. 10 is a bottom view showing another example of the main body of the polygon mirror. [Figure 10] FIG. 10 is a bottom view showing another example of the main body of the polygon mirror. [Figure 11] FIG. 10 is a bottom view showing another example of the main body of the polygon mirror. [Figure 12] FIG. 10 is a bottom view showing another example of the main body of the polygon mirror. DETAILED DESCRIPTION OF THE INVENTION

[0008] The optical deflector 80 will be described with reference to FIG. The optical deflector 80 includes, for example, a polygon mirror 10, a driving unit 81, and screws 89a to 89d.

[0009] The polygon mirror 10 has, for example, a main body 11 and reflecting portions 19a to 19d. The main body 11 is integrally formed by injection molding or the like using synthetic resin such as polycarbonate, acrylic resin, cycloolefin polymer (COP), or cycloolefin copolymer (COC). The reflecting portions 19a to 19d are, for example, planar and reflect light emitted from, for example, a laser light source, etc. The reflecting portions 19a to 19d each have a reflecting layer formed by vacuum-depositing a metal such as aluminum, copper, or silver on the surface of the main body 11, and a protective layer formed on the reflecting layer to protect the reflecting layer. The polygon mirror 10 is attached to the driving section 81 by fixing means such as screws 89a to 89d.

[0010] The driving unit 81 is, for example, a motor, and rotates the polygon mirror 10 . The driving unit 81 includes, for example, a driving body 82, a rotating shaft 83, and a fixed plate 84. The rotation shaft 83 is, for example, cylindrical and has a center axis parallel to the ±Z directions.

[0011] The fixed plate 84 is, for example, a circular plate that is centered on the central axis of the rotation shaft 83 and is perpendicular to the ±Z directions, for example, and is fixed to the rotation shaft 83 by being formed integrally with the rotation shaft 83, for example. The fixing plate 84 has, for example, an upper surface 85 and a plurality of screw holes 86a to 86d. The upper surface 85 is the surface on the +Z side of the fixed plate 84 and is, for example, a circular plane perpendicular to the ±Z directions. The upper surface 85 is an example of a fixed plate abutting plane, and abuts against the polygon mirror 10. The screw holes 86a to 86d are, for example, through-holes that penetrate the fixing plate 84 perpendicular to the ±Z directions. The screw holes 86a to 86d are an example of fixing plate screw holes, and have female threads on the inner surfaces that screw into the screws 89a to 89d.

[0012] The driving body 82 rotates the rotary shaft 83 and the fixed plate 84 around the central axis of the rotary shaft 83 . When light emitted from a laser light source or the like is directed onto the reflecting portions 19a to 19d of the polygon mirror 10, the reflecting portions 19a to 19d reflect the light. Because the driving portion 81 rotates the polygon mirror 10, the direction in which the reflecting portions 19a to 19d reflect the light changes depending on the timing, making it possible to scan a predetermined range within a predetermined plane. Furthermore, by changing the angle of the light incident on the reflecting portions 19a to 19d with respect to the XY plane, the plane scanned by the light reflected by the reflecting portions 19a to 19d changes. For example, by simultaneously irradiating the reflecting portions 19a to 19d with multiple lights with different angles with respect to the XY plane, multiple planes can be scanned simultaneously. By measuring the time it takes for the scanned light to reflect off an object and return, the distance to the object can be measured, which makes it possible to grasp the situation of obstacles present around a vehicle equipped with the optical deflector 80, for example.

[0013] The main body 11 of the polygon mirror 10 will be described in more detail with reference to FIGS. The main body 11 has, for example, side surfaces 12a to 12d and a support portion 13. The side surface portions 12a to 12d are, for example, rectangular plate-like shapes that are substantially parallel to the ±Z directions, and reflecting portions 19a to 19d are provided on the outer surfaces thereof.

[0014] Support portion 13 supports side surface portions 12a to 12d. Support portion 13 is fixed to fixed plate 84 of drive portion 81, and when fixed plate 84 rotates in conjunction with the rotation of rotation shaft 83, support portion 13 rotates around rotation shaft 83, causing side surface portions 12a to 12d to rotate. The support portion 13 includes, for example, a connection plate portion 33, a bearing portion 34, attachment portions 35a to 35d, and rib portions 37a to 37d.

[0015] The connecting plate portion 33 has, for example, a substantially square plate shape and is disposed perpendicular to the ±Z direction. The outer periphery of the connecting plate portion 33 is connected to the side surface portions 12a to 12d. The connecting plate portion 33 has, for example, an upper surface 31 and a lower surface 32 . The upper surface 31 is the surface on the +Z side of the connecting plate portion 33, and has an outer periphery that is, for example, substantially square. The lower surface 32 is the surface on the −Z side of the connecting plate portion 33, and has an outer periphery that is, for example, substantially square.

[0016] The bearing portion 34 has, for example, a substantially cylindrical shape with its central axis parallel to the ±Z directions, and is disposed in the center of the connecting plate portion 33. The bearing portion 34 protrudes in the −Z direction relative to the connecting plate portion 33, and engages with the rotation shaft 83 of the driving portion 81. The bearing portion 34 has, for example, a shaft hole 41 and a lower surface 42 . The shaft hole 41 is a through-hole that passes through the bearing portion 34 in the ±Z direction along the central axis of the bearing portion 34, and the rotation shaft 83 of the drive portion 81 is inserted into the shaft hole 41. The lower surface 42 is the surface on the −Z side of the bearing portion 34 and has, for example, a substantially annular flat surface. The lower surface 42 is located on the −Z side of the lower surface 32 of the connecting plate portion 33.

[0017] The mounting portions 35a to 35d are disposed at positions spaced a predetermined distance from the center of the connecting plate portion 33, and protrude in the −Z direction relative to the connecting plate portion 33. The mounting portions 35a to 35d are fixed to a fixed plate 84 of the driving portion 81. The attachment portions 35a to 35d have, for example, base portions 51a to 51d and end portions 53a to 53d.

[0018] The base portions 51a to 51d are, for example, substantially truncated cones whose central axes are parallel to the ±Z directions, and protrude from the connecting plate portion 33 in the −Z direction. The base portions 51a to 51d have, for example, recesses 52a to 52d. The recesses 52a to 52d are recessed in the -Z direction from the upper surface 31 of the connecting plate portion 33 toward the base portions 51a to 51d. The recesses 52a to 52d are, for example, substantially truncated cones whose central axes are parallel to the ±Z directions.

[0019] The end portions 53a to 53d are, for example, substantially cylindrical with their central axes parallel to the ±Z directions, and protrude further in the −Z direction from the −Z side surfaces of the base portions 51a to 51d. The end portions 53a to 53d have, for example, screw holes 54a to 54d and lower surfaces 55a to 55d. The screw holes 54a to 54d are through holes that pass through the end portions 53a to 53d in the −Z direction from the bottom surfaces of the recesses 52a to 52d. The screw holes 54a to 54d are an example of mounting screw holes, and the screws 89a to 89d are inserted into the screw holes. The lower surfaces 55a to 55d are surfaces on the -Z side of the end portions 53a to 53d and have, for example, a substantially annular planar shape. The lower surfaces 55a to 55d are located on the -Z side of the lower surface 32 of the connecting plate portion 33 and are located on the -Z side of the lower surface 42 of the bearing portion 34. The lower surfaces 55a to 55d are an example of a mounting abutment plane and abut against the upper surface 85 of the fixing plate 84.

[0020] The rib portion 37a connects the mounting portion 35a and the mounting portion 35b. The rib portion 37b connects the mounting portion 35b and the mounting portion 35c. The rib portion 37c connects the mounting portion 35c and the mounting portion 35d. The rib portion 37d connects the mounting portion 35d and the mounting portion 35a. The ribs 37a to 37d are, for example, in the shape of an annular sector column (a shape obtained by cutting out a part of a cylinder by two planes passing through the central axis) centered on the central axis of the bearing part 34. The +Z side ends of the ribs 37a to 37d are connected to the lower surface 32 of the connecting plate part 33. The rib portions 37a to 37d have, for example, lower surfaces 72a to 72d. The lower surfaces 72a to 72d are surfaces on the -Z side of the rib portions 37a to 37d and have, for example, a circular sector planar shape (a shape obtained by cutting out a portion of a circle along two straight lines passing through the center). The lower surfaces 72a to 72d are located on the -Z side of the lower surface 32 of the connecting plate portion 33 and are flush with the lower surfaces 55a to 55d of the mounting portions 35a to 35d. The lower surfaces 72a to 72d are an example of a rib abutment plane and abut against the upper surface 85 of the fixing plate 84.

[0021] When the driving unit 81 rotates the rotary shaft 83 and the fixed plate 84, the rotational movement of the fixed plate 84 is transmitted to the polygon mirror 10 via the screws 89a to 89d. As a result, stress is concentrated on the mounting portions 35a to 35d. In particular, when multiple laser beams are applied to reflecting portions 19a-19d simultaneously to scan multiple planes simultaneously, the lengths of side portions 12a-12d in the ±Z directions are increased to distribute the areas where the laser beams are applied, which increases the weight of main body 11. This increases the force applied to mounting portions 35a-35d and the generated stress, making mounting portions 35a-35d more susceptible to deformation or damage.

[0022] The polygon mirror 10 has ribs 37a to 37d connecting the mounting portions 35a to 35d, which prevents stress from concentrating on the mounting portions 35a to 35d, thereby increasing the strength of the support portion 13 and preventing deformation or damage to the polygon mirror 10.

[0023] Because the lower surfaces 72a to 72d of the ribs 37a to 37d are flush with the lower surfaces 55a to 55d of the mounting portions 35a to 35d, the contact area of the support portion 13 with the fixed plate 84 increases, enabling the force to be dispersed. Also, there is no step between the mounting portions 35a to 35d and the ribs 37a to 37d, preventing stress from concentrating on the step portion and thereby preventing deformation or damage to the polygon mirror 10.

[0024] Since the rib portions 37a to 37d are in the shape of a circular sector column, there is little resistance when the polygon mirror 10 rotates, and the force applied to the mounting portions 35a to 35d can be reduced, thereby preventing the polygon mirror 10 from being deformed or damaged.

[0025] The main body 11A will be described with reference to FIG. The polygon mirror 10 may have a main body 11A instead of the main body 11. The main body 11A is similar to the main body 11, but differs in that it has ribs 37e to 37h instead of the ribs 37a to 37d. The rib portions 37e to 37h connect the attachment portions 35a to 35d in the same manner as the rib portions 37a to 37d. However, unlike the rib portions 37a to 37d, the rib portions 37e to 37h are flat and connect the attachment portions 35a to 35d in a straight line.

[0026] The main body 11B will be described with reference to FIG. The polygon mirror 10 may have a main body 11B instead of the main body 11. The main body 11B is similar to the main body 11, but differs in that it has ribs 37i to 37l instead of the ribs 37a to 37d. The ribs 37i to 37l connect the attachment portions 35a to 35d in the same manner as the ribs 37a to 37d. However, unlike the ribs 37a to 37d, the ribs 37i to 37l are curved flat plates, and connect the attachment portions 35a to 35d in a broken line.

[0027] In this way, the shape of the rib portion is not limited to a circular sector columnar shape, and may be other shapes.

[0028] The main body 11C will be described with reference to FIG. The polygon mirror 10 may have a main body 11C instead of the main body 11. The main body 11C is similar to the main body 11, but differs in that it further has rib portions 37m to 37p. The ribs 37m to 37p are an example of side ribs, and connect the attachment portions 35a to 35d and the side portions 12a to 12d. In this way, by connecting the mounting portions 35a to 35d together, as well as connecting the mounting portions 35a to 35d and the side surfaces 12a to 12d, the strength of the mounting portions 35a to 35d can be further increased.

[0029] The main body 11D will be described with reference to FIG. The polygon mirror 10 may have a main body 11D instead of the main body 11. The main body 11D is similar to the main body 11, but differs in that it further has rib portions 37q to 37t. The rib portions 37q to 37t are an example of rib side surface rib portions, and connect the rib portions 37a to 37d and the side surface portions 12a to 12d. In this way, by connecting the mounting portions 35a to 35d with the ribs 37a to 37d and also connecting the ribs 37a to 37d and the side surfaces 12a to 12d, the strength of the mounting portions 35a to 35d can be further increased.

[0030] Referring to FIG. 11, the main body 11E will be described. The polygon mirror 10 may have a main body 11E instead of the main body 11. The main body 11E is similar to the main body 11, but differs in that it further includes rib portions 37u to 37x. The ribs 37u to 37x are an example of bearing ribs, and connect the attachment portions 35a to 35d and the bearing portion . In this way, by connecting the mounting portions 35a to 35d with the ribs 37a to 37d and also connecting the mounting portions 35a to 35d and the bearing portion 34, the strength of the mounting portions 35a to 35d can be further increased.

[0031] The main body 11F will be described with reference to FIG. The polygon mirror 10 may have a main body 11F instead of the main body 11. The main body 11F is similar to the main body 11, but differs in that it further includes vertical wall portions 38a to 38t. The vertical wall portions 38a to 38t are flat plate-shaped extending in the ±Z direction, and protrude from the attachment portions 35a to 35d in directions approximately perpendicular to the ±Z direction. In this way, not only are the mounting portions 35a to 35d connected by the ribs 37a to 37d, but also the vertical walls 38a to 38t protrude from the mounting portions 35a to 35d, thereby further increasing the strength of the mounting portions 35a to 35d.

[0032] As described above, by further increasing the strength of the attachment portions 35a to 35d, it is possible to prevent the attachment portions 35a to 35d from being damaged.

[0033] The above-described embodiment is an example for facilitating understanding of the present invention. The present invention is not limited thereto, and includes various modifications, changes, additions, or omissions without departing from the scope defined by the appended claims. This can be easily understood by those skilled in the art from the above description.

[0034] For example, the number of side surfaces is not limited to four, but may be three, or may be five or more. The number of attachment portions is not limited to four, but may be three, or may be five or more, and may be different from the number of side surfaces. Furthermore, the lower surface of the attachment portion may be flush with the lower surface of the bearing portion, rather than being located on the -Z side of the lower surface of the bearing portion. [Explanation of symbols]

[0035] 10 polygon mirror, 11, 11A to 11F main body, 12a to 12d side portion, 13 support portion, 19a to 19d reflecting portion, 33 connecting plate portion, 34 bearing portion, 35a to 35d mounting portion, 37a to 37x rib portion, 38a to 38t vertical wall portion, 31, 85 upper surface, 32, 42, 55a to 55d, 72a to 72d lower surface, 41 shaft hole, 51a to 51d base portion, 52a to 52d recessed portion, 53a to 53d end portion, 54a to 54d, 86a to 86d screw hole, 80 optical deflector, 81 drive portion, 82 drive main body, 83 rotating shaft, 84 fixing plate, 89a to 89d screw.

Claims

1. a main body integrally formed from synthetic resin; A reflective part that reflects light Equipped with The body includes: a side surface portion on which the reflecting portion is provided; a support portion that supports the side surface portion; and The support portion is a drive unit having a rotation shaft and a fixed plate fixed to the rotation shaft substantially perpendicular to the rotation shaft, The fixing plate rotates in accordance with the rotation of the rotation shaft, thereby rotating around the rotation shaft and rotating the side surface portion, The support portion is a connecting plate portion connected to the side surface portion and disposed substantially perpendicular to the rotation axis; a bearing portion that protrudes toward the drive portion with respect to the connection plate portion and engages with the rotary shaft; a plurality of mounting portions that protrude toward the drive unit relative to the connection plate portion and are fixed to the fixing plate; At least one rib portion connecting the plurality of mounting portions; having Polygon mirror.

2. Each of the mounting portions is a mounting screw hole through which a screw that threads into a fixing plate screw hole provided in the fixing plate is inserted; an attachment abutment plane that abuts against the fixed plate abutment plane of the fixed plate that is substantially perpendicular to the rotation axis; and The rib portion is a rib abutment plane that abuts against the fixed plate; The rib abutment plane is The mounting surface is flush with the mounting abutment surface. The polygon mirror of claim 1.

3. The rib portion is The bearing portion has a circular sector columnar shape centered on the central axis thereof.

3. The polygon mirror according to claim 1 or 2.

4. The support portion is A bearing rib portion connecting the mounting portion and the bearing portion Further comprising:

3. The polygon mirror according to claim 1 or 2.

5. The support portion is A side rib portion connecting the mounting portion and the side portion Further comprising:

3. The polygon mirror according to claim 1 or 2.

6. The support portion is Rib side rib portion connecting the rib portion and the side portion Further comprising:

3. The polygon mirror according to claim 1 or 2.

7. The support portion is a vertical wall portion extending in a direction substantially parallel to the central axis of the bearing portion and protruding from the mounting portion in a direction substantially perpendicular to the central axis; Further comprising:

3. The polygon mirror according to claim 1 or 2.

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