JP2018155869A - Optical deflector, optical scanner, image formation apparatus, and manufacturing method for optical deflector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical deflector which can easily form a reflection surface and improve accuracy in a reflection direction.SOLUTION: A reflection surface 611A can be easily formed since a protrusion part 612 is located at an inner side in a radial direction with respect to a reflection surface 611A so as not to interfere with a cutting tool 104. Since the protrusion part 612 is integrally formed with a body part 611, the reflection surface 611A hardly causes angle deviation and positional deviation with respect to the protrusion part 612. Also, since the protrusion part 612 holds a rotor magnet 64, rotational force is applied to the protrusion part 612 with respect to a mirror rotor 61 due to electromagnetic interaction between the rotor magnet 64 and a drive coil 632. Accuracy in a reflection direction can be improved due to suppression of deviation between a portion applied with the rotational force and the reflection surface 611A.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an optical deflector, an optical scanning device, an image forming apparatus, and a method for manufacturing the optical deflector.

  In general, an image forming apparatus is provided with an optical scanning device for forming an electrostatic latent image on a photosensitive drum. Such an optical scanning device includes an optical deflector having a movable mirror and a laser light source, and irradiates the movable mirror with laser light from the laser light source, and rotates or linearly moves the movable mirror in the optical deflector. By doing so, the laser beam is scanned.

  As such an optical deflector, an optical deflector having a rotor unit having a plate-like polygon mirror and a stator unit that pivotally supports the rotor unit has been proposed (for example, Patent Document 1). In the optical deflector described in Patent Document 1, a polygon mirror having a reflective surface is bonded to a rotor boss while adjusting the tilt of the reflective surface. A rotating shaft is fixed to the rotor boss.

  By the way, the optical deflector has been desired to increase the area of the reflecting surface in order to cope with the multi-beam laser light and to divide each area of the reflecting surface. The same applies to an optical deflector used in a laser processing apparatus or an object detection apparatus in addition to the image forming apparatus. In the optical deflector described in Patent Document 1, when the area of the reflecting surface is increased, the entire mirror is enlarged and the strength of the bonded portion may be insufficient. For this reason, the angle and position of the reflection surface are likely to change, and the accuracy (surface accuracy) of the light reflection direction by the reflection surface may be reduced. Therefore, it is conceivable to form a reflective surface on the polygon mirror after firmly fixing the rotor boss and the polygon mirror. However, the cutting member for mirror finishing tends to interfere with the rotor boss, and the reflective surface is formed after fixing. It is difficult.

  The objective of this invention is providing the optical deflector which can improve the precision of a reflection direction while being able to form a reflective surface easily.

  In order to solve the above problems, the invention according to claim 1 is a mirror rotor having a plate-like main body part having a reflecting surface formed on one side or both sides, and fixed so as to protrude from the end face with respect to the mirror rotor. And a stator unit that adjusts the angle of the reflecting surface by rotating the mirror rotor about the shaft member, the mirror rotor including the main body portion The stator unit is formed integrally and has a protruding portion protruding from the end face so as to surround the shaft member from the outside in the radial direction, and the stator unit faces the bearing portion that supports the shaft member and the protruding portion. And the projecting portion holds the rotor magnet and is located on the inner side in the radial direction than the reflecting surface. .

  According to the optical deflector of the present invention, since the projecting portion is located on the inner side in the radial direction from the reflecting surface, the cutting member for mirror finishing hardly interferes with the projecting portion, and the reflecting surface is easily formed. can do. By forming such a protruding portion integrally with the main body portion, the reflective surface is less likely to cause an angular shift or a positional shift with respect to the protruding portion. Further, the protrusion holds the rotor magnet, and the mirror rotor is rotated by electromagnetic interaction between the rotor magnet and the drive coil. At this time, a rotational force is applied to the protrusion with respect to the mirror rotor, and the deviation between the portion to which the rotational force is applied and the reflection surface is suppressed, so that the accuracy in the reflection direction can be improved.

1 is a cross-sectional view illustrating an outline of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective view illustrating an outline of an optical scanning device of the image forming apparatus. It is sectional drawing which shows the optical deflector of the said optical scanning device. It is another sectional view showing the optical deflector. It is a perspective view which shows the mirror rotor of the said optical deflector. It is a perspective view which shows a mode that a reflective surface is formed in the said mirror rotor. It is sectional drawing which shows a mode that a reflective surface is formed in the said mirror rotor. It is sectional drawing which shows the optical deflector of the image forming apparatus which concerns on 2nd Embodiment of this invention. It is another sectional view showing the optical deflector. It is a perspective view which shows the mirror rotor and disk member of the said optical deflector. It is sectional drawing which shows the optical deflector of the image forming apparatus which concerns on 3rd Embodiment of this invention. It is a perspective view which shows the mirror rotor of the said optical deflector.

  Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In the second and third embodiments, the same constituent members as those described in the first embodiment and the constituent members having the same functions are denoted by the same reference numerals as those in the first embodiment and the description thereof is omitted.

[First Embodiment]
As shown in FIG. 1, the image forming apparatus 10 according to the present exemplary embodiment includes a monochrome unit including an image forming unit 1, an optical scanning device 2, a fixing device 3, a paper feed tray 4, and a paper discharge tray 5. Printer.

  The image forming unit 1 includes a photosensitive drum 11 as a photosensitive member, a charging device 12 provided around the photosensitive drum 11, a developing device 13, a transfer device 14, and a cleaning device 15. Each of these apparatuses is housed in a process cartridge, and the process cartridge is configured to be detachable from the apparatus main body 20 of the image forming apparatus 10.

  In such an image forming apparatus 10, the optical scanning device 2 irradiates the photosensitive drum 11 with a light beam to form an electrostatic latent image, and the electrostatic latent image is supplied from the developing device 13. To form a toner image. This toner image is transferred onto the recording paper supplied from the paper feed tray 4 by the transfer device 14, and the fixing device 3 fixes the toner image on the recording paper with heat and pressure. It is supposed to be discharged.

  As shown in FIG. 2, the optical scanning device 2 includes a light source 21, a collimator lens 22, a cylinder lens 23, an optical deflector 6A, an fθ lens 24, a mirror 25, and a toroidal lens 26. The laser light generated by the light source 21 is shaped by passing through the collimator lens 22 and the cylinder lens 23, and then enters the optical deflector 6A. As will be described later, the optical deflector 6A is configured so that the angles of the reflecting surfaces 611A and 611B can be changed, and the laser light incident on the optical deflector 6A is scanned linearly on the photosensitive drum 11. Reflected.

  Hereinafter, details of the optical deflector 6A will be described with reference to FIGS. Here, the axial direction of rotation of the optical deflector 6 is defined as a Z direction, and two directions substantially orthogonal to the Z direction are defined as an X direction and a Y direction.

  The optical deflector 6 </ b> A is an inner rotor type brushless motor including a mirror rotor 61, a shaft member 62, a stator unit 63, and a rotor magnet 64, and is configured to rotate the mirror rotor 61 by the stator unit 63. Has been.

  The mirror rotor 61 has a plate-like main body 611 having reflecting surfaces 611A and 611B formed on both surfaces thereof, and is integrally formed with the main body 611 and protrudes from an end surface 611C (surface along the XY plane) of the main body 611. Projecting portion 612.

  The main body 611 is disposed so that the reflecting surfaces 611A and 611B are directed in any direction substantially orthogonal to the Z direction. In the illustrated example, the reflecting surfaces 611A and 611B are directed in the X direction. That is, the reflecting surfaces 611A and 611B are in a state along the YZ plane.

  The main body 611 is formed in a thin plate shape by using, for example, an aluminum-based metal material. At this time, the main body 611 is preferably formed by forging. According to such a configuration, the dimensional accuracy can be increased, the high-speed rotation can be withstand, and the shaft member 62 can be firmly attached. Can be fixed.

  A through hole 611 </ b> D into which the shaft member 62 is inserted and fixed is formed at the center of the main body 611. The through-hole 611D extends along the Z direction, and is disposed at the approximate center of the main body 611 in the X direction and the Y direction. On the upper surface (surface opposite to the end surface 611C) of the main body portion 611, a concave portion 611E that is continuous with the through hole 611D and has a larger diameter than the through hole 611D is formed.

  The protruding portion 612 is formed in a cylindrical shape having a larger diameter than the through hole 611D, and surrounds the shaft member 62 inserted and fixed in the through hole 611D from the outside. Further, the diameter of the protruding portion 612 is smaller than the plate thickness (X-direction dimension) of the main body 611 and the widths (Y-direction dimensions) of the reflecting surfaces 611A and 611B. Accordingly, the protruding portion 612 is located on the inner side in the radial direction (on the shaft member 62 side) than either of the reflecting surfaces 611A and 611B. That is, the protrusion 612 is concave with respect to the main body 611 when viewed from a direction substantially orthogonal to the Z direction.

  The protruding portion 612 is formed with a step so that the outer diameter on the distal end side is smaller than the proximal end side, and this small diameter portion serves as a holding portion 612A that holds the rotor magnet 64 on the outer peripheral surface thereof. The rotor magnet 64 may be fixed to the holding portion 612A with an adhesive, or may be press-fitted and fixed to the holding portion 612A by being formed of a material having the same linear expansion coefficient as that of the mirror rotor 61. If it is configured to be press-fitted and fixed, it is possible to suppress misalignment between the rotor magnet 64 and the holding portion 612A when rotating at high speed or in a high temperature environment, and to maintain a good balance during rotation of the mirror rotor 61.

  The rotor magnet 64 is formed in an annular shape (including a part having a notch formed therein) and is magnetized in the radial direction, and is radially inward and in the height direction (Z direction). The magnetic path is open.

  A mounting recess 611 </ b> F having a circular shape in the Z direction is formed inside the cylindrical protrusion 612. The mounting recess 611F is continuous with the through hole 611D and has a larger diameter than the through hole 611D.

  The shaft member 62 is inserted into the through hole 611D of the main body 611 and fixed by shrinkage fitting. The shaft member 62 is preferably made of martensitic stainless steel. According to such a structure, quenching is possible, and the surface hardness is increased and good wear resistance is obtained. The shaft member may be made of an appropriate material according to the fixing method, required characteristics, and the like.

  The shaft member 62 is fixed to the main body 611 so as to protrude from the end surface 611C. The protruding tip 621 is spherically processed so that it contacts a thrust receiving member 631C described later and functions as a pivot bearing.

  The stator unit 63 adjusts the angles of the reflecting surfaces 611A and 611B by rotating the mirror rotor 61 about the shaft member 62. The stator unit 63 includes a bearing housing 631, a drive coil 632, a hall element 633, a drive IC 634, and a connector 635, which are provided on the substrate 630.

  The bearing housing 631 is provided so as to penetrate the substrate 630 extending along the XY plane, and has a bearing concave portion 631A that is circular in the Z direction as viewed in the mirror rotor 61 side. A cylindrical oil-impregnated bearing 631B as a bearing portion is provided on the inner peripheral surface of the bearing recess 631A, and a thrust receiving member 631C is provided on the bottom surface. The oil-impregnated bearing 631B is composed of a sintered body. In addition, a seal washer 631D for preventing lubricant from flowing out is provided at the opening of the bearing recess 631A.

  A part of the bearing housing 631 on the mirror rotor 61 side is accommodated in the mounting recess 611F of the main body 611. Further, the shaft member 62 fixed to the main body 611 is inserted into the oil-impregnated bearing 631B and comes into contact with the inner peripheral surface, and the tip 621 comes into contact with the thrust receiving member 631C. The mirror rotor 61, the shaft member 62, and the stator unit 63 are assembled in this way, and the shaft member 62 is supported, whereby the mirror rotor 61 fixed to the shaft member 62 is attached to the shaft member 62 by the bearing housing 631. It is supported rotatably about a rotation axis O1 extending along the axis.

  The drive coil 632 includes a plurality of stator cores 632A and a plurality of coil portions 632B provided around the stator core 632. The drive coil 632 is disposed outside the protrusion 612 and the rotor magnet 64 and faces the protrusion 612. By energizing the coil portion 632B, the rotor magnet 64 tries to rotate by electromagnetic interaction, and a rotational force is applied to the protruding portion 612 of the mirror rotor 61.

  In the configuration in which the shaft member 62 is supported by the oil-impregnated bearing 631B, in order to efficiently circulate the impregnated oil and obtain a suitable bearing rigidity, a bearing gap (a gap between the oil-impregnated bearing 631B and the shaft member 62) is: The diameter (the sum of both sides of the shaft member 62) is preferably 10 μm or less. A dynamic pressure generating groove is formed on the outer peripheral surface of the shaft member 62 or the inner peripheral surface of the oil-impregnated bearing 631B. At this time, from the viewpoint of workability, it is preferable that a dynamic pressure generating groove is formed in the oil-impregnated bearing 631B.

  The hall element 633 is disposed in the open magnetic path of the rotor magnet 64 and detects a magnetic field generated by the rotor magnet 64.

  The drive IC 634 controls the drive coil 632 while referring to the detection result by the Hall element 633. That is, when the drive IC 634 switches excitation of the drive coil 632, the rotation of the mirror rotor 61 to which the rotor magnet 64 is fixed is controlled.

  The connector 635 is supplied with power from the outside by connecting a harness or the like, and inputs and outputs signals for rotation control (stopping rotation, changing the number of rotations, etc.).

  In the optical deflector 6A as described above, the drive IC 634 excites the drive coil 632 based on the signal input from the outside and the detection result by the Hall element 633, whereby the mirror rotor 61 rotates and the reflection surfaces 611A and 611B. The angle of changes. Thereby, the laser beam is scanned in the optical scanning device 2.

  When the mirror rotor 61 rotates as described above, an imbalance (displacement between the center of gravity of the rotating body 65 and the rotation axis O1) occurs in the rotating body 65 constituted by the mirror rotor 61, the shaft member 62, and the rotor magnet 64. Vibration may occur. When such an imbalance occurs, it may be corrected by applying a balance adhesive to the rotating body 65. The balance adhesive may be applied to the concave portion 611E formed in the mirror rotor 61 and the portion of the protruding portion 612 that does not hold the rotor magnet 64.

  In addition, when it is difficult to correct the balance due to adhered matter, or when the adhesive force is weak and peeling or scattering occurs during high-speed rotation, the balance may be corrected by cutting the rotating body 65 with a drill or laser. .

  Hereinafter, an optical deflector manufacturing method for manufacturing the optical deflector 6A will be described with reference to FIGS. 6 and 7, the direction in which the shaft member 62 extends is defined as the Z direction, the direction in which the side surface on which the reflective surface 611A is formed faces is the X direction, and the thickness direction of the main body 611 is defined as the Y direction.

  First, the shaft member 62 is fixed to a mirror rotor 61 (hereinafter referred to as a pre-processing rotor 60) before being mirror-finished. Although the rotor 60 before processing is not formed with the reflecting surfaces 611A and 611B, the other shapes are the same as those of the mirror rotor 61 after processing, and the protrusion 612, the through hole 611D, the recess 611E, and the mounting recess 611F are provided. Is formed.

  Next, the reflecting surfaces 611A and 611B are formed on the rotor 60 before processing using the mirror surface processing apparatus 100. The mirror surface processing apparatus 100 includes a fixing unit 101 and a cutting unit 102.

  The fixing means 101 includes a holding recess 101A that holds the tip 621 of the shaft member 62 and the vicinity thereof, and a holding cylindrical portion 101B that holds the protruding portion 612 from the outside. The pre-processing rotor 60 and the shaft member 62 Is fixed and held. The holding cylindrical portion 101 </ b> B has a diameter smaller than the plate thickness of the unprocessed rotor 60, and is located on the radially inner side (on the shaft member 62 side) than the side surfaces 601 and 602 of the unprocessed rotor 60. Further, the fixing means 101 has an angle adjusting mechanism capable of positioning the angle of the side surface 601 of the fixed pre-processing rotor 60.

  The cutting means 102 includes a cutting disk 103, a cutting tool 104 as a cutting member, a rotating means, and a parallel moving means. The plate thickness direction of the cutting disc 103 extends along the X direction, that is, substantially orthogonal to the axial direction of the shaft member 62 fixed to the fixing means 101.

  The cutting disk 103 is rotated by a rotating means about the cutting rotation axis O2 along the X direction through the substantially center thereof, and is parallel in a plane (YZ plane) substantially orthogonal to the cutting rotation axis O2. It is translated by the moving means. The cutting disk 103 is arranged so that one surface thereof faces the side surface 601 of the rotor 60 before processing.

  The cutting tool 104 protrudes from one surface of the cutting disk 103 toward the pre-processing rotor 60 and has a sharp protrusion at the tip. The cutting tool 104 is configured to cut the side surface 601 to be mirror-finished by moving along the in-plane direction with the tip thereof being in contact with the side surface 601 of the rotor 60 before processing. The cutting tool 104 is disposed on the outer peripheral portion (near the outer peripheral edge) of the cutting disc 103.

  An example of the locus of the tip of the cutting tool 104 when the cutting disk 103 is rotated around the cutting rotation axis O2 by the rotating means is shown in FIG. The cutting disk 103 is rotated and translated by the translation means in the YZ plane (the vertical direction and the horizontal direction in FIG. 6) which is a plane orthogonal to the cutting rotation axis O2, and the entire side surface 601 is moved by the cutting tool 104. The reflective surface 611A is formed on the side surface 601 by cutting.

  At this time, the protruding portion 612 and the holding cylindrical portion 101B are located on the inner side in the radial direction than the side surface 601 on which the reflecting surface 611A is formed, and thus do not interfere with the cutting tool 104.

  After the reflective surface 611A is formed on the side surface 601, the pre-processing rotor 60 is rotated, for example, 180 ° by the angle adjusting mechanism of the fixing means 101, and the opposite side surface 602 is opposed to the cutting tool 104. If the reflecting surface 611A and the reflecting surface 611B are not completely opposite to each other and are desired to intersect at a predetermined angle, the pre-processing rotor 60 may be rotated by an appropriate angle by the angle adjusting mechanism. .

  Then, the reflective surface 611B is formed on the side surface 602 by rotating and translating the cutting disk 103 in the same manner as described above. In addition, the optical deflector may have a mirror rotor in which a reflecting surface is formed only on one side. In this case, only one side surface needs to be mirror-finished.

  As described above, the mirror rotor 61 is formed by performing mirror processing on the rotor 60 before processing. The rotor magnet 64 is held by the projecting portion 612 of the mirror rotor 61 to form the rotating body 65, and the optical deflector 6A is assembled by assembling with the stator unit 63 so that the oil-impregnated bearing 631B as the bearing portion supports the shaft member 62. Is completed.

  According to this embodiment, there are the following effects. That is, since the protrusion 612 is located on the radially inner side with respect to the reflective surface 611A (side surface 601) and does not interfere with the cutting tool 104, the reflective surface 611A can be easily formed. Since the protruding portion 612 is formed integrally with the main body portion 611, the reflective surface 611A is less likely to cause an angular shift or a positional shift with respect to the protruding portion 612. Further, since the protrusion 612 holds the rotor magnet 64, a rotational force is applied to the protrusion 612 with respect to the mirror rotor 61 due to electromagnetic interaction between the rotor magnet 64 and the drive coil 632. Since the deviation between the portion to which the rotational force is applied and the reflection surface 611A is suppressed, the accuracy in the reflection direction can be improved.

[Second Embodiment]
The image forming apparatus of the present embodiment includes an optical deflector 6B as shown in FIGS. 8 and 9 instead of the optical deflector 6A as described above.

  As shown in FIG. 10, the optical deflector 6B further includes a disk member 66 with respect to the optical deflector 6A. That is, in the present embodiment, the rotating body 67 is configured by the mirror rotor 61, the shaft member 62, the rotor magnet 64, and the disk member 66. The disk member 66 is attached between the rotor magnet 64 and the main body 611 with respect to the protrusion 612 of the mirror rotor 61.

  The disk member 66 is made of, for example, a resin member or a metal member. The disk member 66 is preferably made of the same material as that of the mirror rotor 61. According to such a configuration, the linear expansion coefficient is substantially equal to that of the mirror rotor 61, and even when thermal stress is applied to the mirror rotor 61. Therefore, the position of the mirror rotor 61 is difficult to be displaced, and the balance during rotation of the mirror rotor 61 can be kept good.

  The disc member 66 has a through hole 661 at its center and is formed in an annular shape, and has an outer diameter (diameter) larger than the plate thickness (dimension in the X direction) of the main body 611 and a reflecting surface 611A, It is smaller than the width (dimension in the Y direction) of 611B. The disk member 66 is fixed to the mirror rotor 61 by inserting the protruding portion 612 through the through hole 661. In the present embodiment, the inner diameter of the through hole 661 is formed to be equal to or slightly larger than the outer diameter of the holding portion 612A, and the base end side (larger diameter portion) than the holding portion 612A is not inserted.

  The disk member 66 is disposed so as to abut on a step formed on the proximal end side of the holding portion 612A, and is sandwiched and fixed by the rotor magnet 64 and the large-diameter portion of the protruding portion 612. The disk member may have an inner diameter that is the same as or slightly larger than the outer diameter of the large-diameter portion of the protruding portion 612 and may be fixed so as to contact the end surface 611C of the main body portion 611.

  On the upper surface (the surface opposite to the substrate 630) of the disk member 66, a bowl-shaped recess 662 along the outer peripheral edge is formed as a recess extending along the circumferential direction. When correcting the unbalance of the rotating body 67 as described above, a balance adhesive may be provided also in the bowl-shaped recess 662.

  According to this embodiment, in addition to the effects of the first embodiment, there are the following effects. That is, by attaching the disk member 66 having the bowl-shaped recess 662 to the mirror rotor 61, a balance adhesive can be provided on the bowl-shaped recess 662, and the unbalance of the rotating body 67 can be easily corrected.

  Further, since the outer diameter of the disk member 66 is larger than the width of the main body 611 and the hook-shaped recess 662 is formed along the outer peripheral edge, the balance adhesive can be provided at a position away from the rotation axis O1. Can be corrected with a small amount of balance adhesive.

[Third Embodiment]
The image forming apparatus according to the present embodiment includes an optical deflector 6C as shown in FIG. 11 instead of the optical deflector 6A as described above.

  As shown in FIG. 12, the optical deflector 6 </ b> C has a pair of lightening portions 613 formed on the main body 611 of the mirror rotor 61 in the optical deflector 6 </ b> A.

  The pair of lightening portions 613 are arranged so as to sandwich the shaft member 62 from the Y direction, and are formed at symmetrical positions with the shaft member 62 as the center. In other words, the pair of thinned portions 613 has two-fold rotational symmetry about the shaft member 62. Moreover, the lightening part 613 is formed in the through-hole shape extended along a Z direction.

  Such a lightening portion 613 is formed by cutting the main body portion 611 prior to forming the reflection surfaces 611A and 611B by mirror finishing as in the first embodiment. Thereby, the fall of the precision of the reflection direction by forming the thinning part 613 is suppressed.

  According to this embodiment, in addition to the effects of the first embodiment, there are the following effects. That is, the mirror rotor 61 can be reduced in weight by forming the thinned portion 613 in the main body portion 611. Thereby, the moment of inertia at the time of rotating the rotating body 65 by the stator unit 63 can be reduced, and the driving load of the motor can be reduced. Accordingly, the time required for the optical deflector 6C to reach the rated rotational speed can be shortened, and the first print time can be shortened in the image forming apparatus.

  In addition, since the pair of thinned portions 613 are formed at symmetrical positions with the shaft member 62 as the center, it is possible to prevent the rotating body 65 from being unbalanced.

  In addition, this invention is not limited to the said 1st-3rd embodiment, The other modification etc. which can achieve the objective of this invention are included, and a deformation | transformation etc. which are shown below are also contained in this invention.

  For example, in the first embodiment, the mirror rotor 61 has the plate-shaped main body 611. However, the mirror rotor may be a polygon mirror having a polygonal columnar or polygonal main body. At this time, it is only necessary that at least one of the outer peripheral surfaces of the polygonal columnar or polygonal main body has a reflecting surface.

  In the second embodiment, the disk member 66 has the bowl-shaped recess 662 on the surface on the main body 611 side. However, the disk member has a recess on the surface opposite to the main body 611. Alternatively, it may have recesses on both sides, or may have recesses on the outer end surface (outer peripheral surface).

  Moreover, in the said 3rd Embodiment, although a pair of thinning part 613 shall be formed in the symmetrical position centering on the shaft member 62, three or more thinning parts may be formed. For example, two or more pairs of lightening portions may be formed at symmetrical positions about the shaft member 62. Moreover, when the main body part of a mirror rotor is a polygonal column or a polygonal cylinder shape, you may form a hollow part so that it may correspond to each side and each vertex of a polygon.

  Moreover, in the said 3rd Embodiment, although the thickness reduction part 63 shall be a through-hole shape, a thickness reduction part may be concave.

  In the first to third embodiments, the optical scanning device having the optical deflector is provided in the image forming apparatus. However, the optical scanning device is provided in a laser processing device, an object detection device, or the like. Laser light may be scanned.

  In addition, the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the present invention has been illustrated and described primarily with respect to particular embodiments, but the present invention is not limited to the embodiments described above without departing from the scope of the technical idea and object of the present invention. The trader can add various modifications.

  Therefore, the description which limited the shape, the material, etc. disclosed above is exemplary for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of some or all of those shapes, materials, etc. is included in this invention.

10 Image forming apparatus 11 Photosensitive drum (photosensitive member)
2 Optical Scanning Device 21 Light Source 6A to 6C Optical Deflector 61 Mirror Rotor 611 Main Body 611A, 611B Reflecting Surface 611C End Surface 612 Protruding Portion 613 Thinning Section 62 Shaft Member 63 Stator Unit 631B Oil-Retaining Bearing (Bearing)
632 Drive coil 64 Rotor magnet 66 Disk member 662 Hook-shaped recess (recess)

JP-A-9-127453

Claims (7)

A mirror rotor having a plate-like main body part having a reflecting surface formed on one side or both sides, a shaft member fixed so as to protrude from the end surface with respect to the mirror rotor, and the mirror rotor around the shaft member. A stator unit that rotates and adjusts the angle of the reflecting surface; and an optical deflector comprising:
The mirror rotor is formed integrally with the main body and has a protruding portion protruding from the end surface so as to surround the shaft member from the outside in the radial direction.
The stator unit includes a bearing portion that supports the shaft member, and a drive coil that is disposed to face the protrusion.
The projecting portion holds a rotor magnet and is located on the inner side in the radial direction than the reflecting surface. A mirror rotor having a polygonal columnar or polygonal tube-shaped main body having a reflective surface formed on at least one of the outer peripheral surfaces, a shaft member fixed to the mirror rotor so as to protrude from the end surface, and the shaft member A stator unit that adjusts the angle of the reflecting surface by rotating the light deflector,
The mirror rotor is formed integrally with the main body and has a protruding portion protruding from the end surface so as to surround the shaft member from the outside in the radial direction.
The stator unit includes a bearing portion that supports the shaft member, and a drive coil that is disposed to face the protrusion.
The projecting portion holds a rotor magnet and is located on the inner side in the radial direction than the reflecting surface. A disk member is attached to the protrusion between the rotor magnet and the main body,
The optical deflector according to claim 1, wherein the disk member has a concave portion extending along a circumferential direction.   The said main-body part is formed in the symmetrical position centering | focusing on the said shaft member, The some thinning part extended along an axial direction is formed, The any one of Claims 1-3 characterized by the above-mentioned. Light deflector.   An optical scanning device comprising: a light source; and the optical deflector according to claim 1.   An image forming apparatus comprising: the optical scanning device according to claim 5; and a photosensitive member. An optical deflector manufacturing method for manufacturing the optical deflector according to any one of claims 1 to 4,
In a state where at least one of the shaft member and the protruding portion is held, the cutting member is rotated around a cutting rotation axis orthogonal to the shaft member, and the cutting rotation axis is moved within the orthogonal plane. After forming the reflective surface on the mirror rotor,
Holding the rotor magnet on the protrusion,
A method of manufacturing an optical deflector, wherein the shaft member is supported by the bearing portion.

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