JPH06123846A - Rotary polygon mirror - Google Patents

Abstract

PURPOSE:To suppress the influence of distortion imparting to a rotary polygon mirror due to tightening force in the case of holding plural rotary polygon mirrors in a laminated state at the time of storage transportation and manufacture, and in the case of attaching the rotary polygon mirror to a motor. CONSTITUTION:In the rotary polygon mirror 21 formed with an insertion hole 24 loaded on the rotary shaft of the motor at the enter part and formed with a reflection surface 2 on a side surface, plural attaching holes 5 to be attached to the motor are formed on the circumference of the insertion hole 24 of the rotary polygon mirror 21, and a flat tightening base 23 being brought into surface contact with each other in the vicinity of the circumference of individual attaching hole 5 when plural pieces of rotary polygon mirrors 21 are superposed on the same axis is projected and formed on at least one side of both end surfaces 22, 22a orthogonally intersecting with the reflection surface 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary polygon mirror which deflects and scans a light beam emitted from a light source.

[0002]

2. Description of the Related Art First, a first conventional example of a rotary polygon mirror is shown in FIG.
Shown in (a) and (b). The rotary polygon mirror 1 has a plurality of reflecting surfaces 2 formed on its side surface, and a fitting hole 3 formed at the center for fitting with a rotating shaft of a motor. Such a rotary polygon mirror 1 is fixed to the rotation surface of the motor with the end face 4 as a reference and driven to rotate.

On the other hand, the rotary polygon mirror 1 is laminated and processed by a jig in the manufacturing process, or packed in a laminated state even during transportation and storage. In this case, if foreign matter such as dust is caught on the superposed surface of the rotary polygon mirror 1, both will be flawed. When the rotary polygon mirror 1 is attached to the rotary surface of the motor with the scratched end surface 4 as a reference surface, surface tilt occurs at each reflecting surface 2 and the irradiation position of the beam light is displaced.

From the above, there is an invention described in Japanese Patent Publication No. 2-34010 as a second conventional example. The contents are shown in FIGS. 6 to 8. Rotating polygon mirror 1
Has six reflecting surfaces 2, a fitting hole 3 to be fitted to the rotation shaft of the motor, and a plurality of mounting holes 5 arranged around the fitting hole 3, and one end surface 4 has a circular protrusion 6 And a recess 8 slightly smaller than the outer diameter of the protrusion 6 is formed on the other end surface 7. Therefore, as shown in FIG. 7, the shaft 9 is passed through the fitting holes 3 of the plurality of rotary polygon mirrors 1, and the plurality of rotary polygon mirrors 1
When the two are fixed in a laminated state, the contact area of each rotary polygon mirror 1 can be reduced, whereby the end faces 4, 7
It becomes difficult to get scratches. During storage, transportation, grinding of the reflection surface 2, etc., the plurality of rotary polygon mirrors 1 are maintained in a laminated state as shown in FIG. 7, and when assembled as an optical scanning device as shown in FIG. , The rotary shaft 11 of the motor 10 is fixedly fitted with the mounting member 12, the rotary shaft 11 is fitted with the fitting hole 3 of the rotary polygon mirror 1, and the plurality of screws 14 inserted in the mounting member 13 are rotated with the rotary face By being inserted into each of the mounting holes 5 of the mirror 1 and screwed into the mounting member 12 below,
The rotary polygon mirror 1 is fixed.

Next, as a third conventional example, Japanese Patent Publication No. 4-3
There is an invention described in Japanese Patent No. 1370. The contents are shown in FIGS. 9 and 10. According to the present invention, a blank of the rotary polygon mirror 15 is formed with a large mounting hole 16 located at the center, a plurality of screw holes (mounting holes) 5 arranged around the large mounting hole 16, and a recess 8 located on one end surface. , A plurality of blanks of the rotary polygon mirror 15 are laminated, the mounting holes 16 are fitted into the jigs 18, respectively, and the presser spring 19 contacting the outer peripheral portion of the rotary polygon mirror 15 at the uppermost stage is tightened and fixed by the screw 20, In this state, the reflecting surface 2 is mirror-finished on the side surface of the blank of the rotary polygon mirror 15. As a result, the area of the surface on which the rotary polygon mirrors 15 overlap is limited by the formation of the recesses 8 to improve the accuracy of parallel flatness, and dust or cutting dust may enter between the rotary polygon mirrors 15. Is an invention that prevents

[0006]

[Problems to be Solved by the Invention] Japanese Patent Publication No.
In the invention described in the publication, when a plurality of rotary polygon mirrors 1 are stacked, a gap is formed between the rotary polygon mirrors 1 as shown in FIG. The polygonal mirror 1 may be distorted, which may impair the scanning accuracy of light. In addition, as shown in FIG.
When the screw 14 is mounted on the rotating surface (mounting member) 0 of 0, if the tightening force of the screw 14 is too large, distortion occurs around the mounting hole 5, and this distortion affects the reflecting surface 2, so that the scanning accuracy of light is reduced. Since it decreases, the rotary polygon mirror 1 must be fixed to the motor 10 via the mounting member 13, and there is a problem that the number of parts required for mounting increases.

In the invention disclosed in Japanese Patent Laid-Open No. 4-31370, when a plurality of blanks of the rotary polygon mirror 15 are laminated in the mirror finishing of the reflecting surface 2, the recesses 8 are formed between the blanks. Since a gap is created, it is necessary to apply the tightening force of the screw 20 to the outer peripheral portion of the blank where no gap is created via the pressing spring 19, which increases the number of fixing members to the jig 18. In the rotary polygon mirror 15 formed in this way, the screw threaded through the mounting hole 5 formed inside the recess 8 is provided on the rotating surface of the motor (the mounting member 12 in FIG. 8).
However, due to the tightening force of the screw, the rotary polygon mirror 1 is fixed in the same manner as the conventional example.
There is a problem that partial distortion occurs around the mounting hole 5 of No. 5.

[0008]

According to the present invention, there is provided a rotary polygonal mirror having a fitting hole for mounting a rotary shaft of a motor formed in a central portion thereof and a reflecting surface formed on a side surface of the rotary polygonal mirror. A plurality of mounting holes to be mounted on the motor are formed around the joint hole, and when a plurality of the rotating polygon mirrors are coaxially stacked, the flat tightening seats are in surface contact with each other in the vicinity of the periphery of each mounting hole. Was formed so as to project on at least one end surface of both end surfaces orthogonal to the reflection surface.

[0009]

According to the present invention, in the case where a plurality of rotary polygon mirrors are stacked in the manufacturing process, a plurality of screws inserted through the mounting holes formed in each rotary polygon mirror are screwed into the jig to form a plurality of rotary polygon mirrors. The rotary polygon mirror can be held, and the number of parts for fixing the plurality of rotary polygon mirrors in a stacked state can be reduced. In this case, since the periphery of the mounting hole of each rotary polygon mirror can be brought into close contact with each other without opening a gap, it is possible to prevent the rotary polygon mirror from being distorted. Further, when fixing each rotating polygon mirror to the rotation surface of the motor, the screw passed through the mounting hole is screwed onto the rotation surface of the motor, but a tightening seat is formed in the vicinity of the periphery of the mounting hole so as to project. Therefore, the distortion due to the tightening force of the screw can be kept within the range of the stop seat to prevent the influence on others, and thus the scanning accuracy can be improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1A is a plan view of the rotary polygon mirror 21, and FIG.
(B) is the vertical side view. A plurality of reflecting surfaces 2 are formed on the outer circumference of the rotary polygon mirror 21, and a fitting hole 24 fitted to the rotary shaft 11 of the motor 10 shown in FIG. A plurality of mounting holes 5 are formed concentrically around the fitting hole 24. On the end face (upper face) 22 of the rotary polygon mirror 21, an annular tightening seat 23 passing through the center of the mounting hole 5 is formed so as to project. This tightening seat 23
Has a width (thickness) dimension larger than the inner diameter of the mounting hole 5.

When a plurality of rotary polygon mirrors 21 are stacked in such a structure, as shown in FIG. 2, the fitting hole 24 formed in each rotary polygon mirror 21 is inserted into the shaft 26 of the jig 25.
, And the screws 27 that have passed through the mounting holes 5 formed in the respective rotary polygon mirrors 21 are screwed into the jig 25. Thereby, the number of parts for fixing the plurality of rotary polygon mirrors 21 in a laminated state can be reduced. In this case, since the periphery of the mounting hole 5 of each rotary polygon mirror 21 can be brought into close contact with each other without opening a gap, it is possible to prevent the rotary polygon mirror 21 from being distorted. In this state, the rotating diamond bite 28 is brought into contact with the outer surface of the rotating polygon mirror 21, whereby the reflecting surface 2 is mirror-finished. The reflective surface 2 of each rotary polygon mirror 21 in a state of being mounted on the jig 25.
Then, a reflective film of Al, Cu, Au, Ag, SiO ₂ , MgF ₂ or the like can be deposited.

When assembling the individual rotary polygon mirrors 21 as an optical scanning device, as in the case described with reference to FIG. 8, the screw 14 passed through the mounting hole 5 is attached to the rotating surface of the motor 10 (mounting member). ) 12, but since the tightening seat 23 is formed in a protruding manner including the vicinity of the periphery of the mounting hole 5,
Distortion due to the tightening force of the screw 14 can be kept within the range of the tightening seat 23 to prevent other influences. Further, as described above, even when the reflective film is vapor-deposited, the reflective film is not vapor-deposited on the overlapping portion of the rotary polygon mirror 21, that is, the contact surface with respect to the rotating surface (mounting member) 12 of the motor 10, so that the reflective surface is not deposited. It is possible to prevent the occurrence of trouble of No. 2. Thereby, the scanning accuracy of light can be improved.

During storage or transportation, a plurality of rotary polygon mirrors 21 are stacked, and a plurality of rotary mirrors are held by screwing nuts onto the tips of the screws 27 that are inserted through the mounting holes 5 of the rotary polygon mirrors. can do.

Next, a modification of the tightening seat formed on the rotary polygon mirror 21 will be described. In FIG. 3A, a plurality of laminated rotary polygon mirrors 21 are closely attached around the mounting hole 5 by forming annular tightening seats 23 on both end surfaces (upper and lower surfaces) 22 and 22a of the rotary polygon mirror 21. It was made. In FIG. 3B, an annular tightening seat 23 is formed on the upper surface of the rotary polygon mirror 21, and a recess is formed on the lower surface with a depth larger than the outer diameter of the tightening seat 23 and smaller than the protruding size of the tightening seat 23. 29 is formed so that the laminated rotary polygon mirrors 21 are brought into close contact with each other near the periphery of the mounting hole 5.

In FIG. 4A, the width of the annular tightening seat 23 is set to be slightly smaller than the inner diameter of the mounting hole 5. This can obtain the same effect as that shown in FIG. In FIG. 4B, the fastening seats 30 that concentrically project around the individual mounting holes 5 are independently formed. In FIG. 4C, a tightening seat 31 formed by arranging a plurality of protrusions radially around each mounting hole 5 is independently formed.

[0016]

According to the present invention, in a rotary polygonal mirror having a fitting hole for mounting on a rotary shaft of a motor formed in a central portion and a reflecting surface formed on a side surface, the circumference of the fitting hole of the rotary polygonal mirror is improved. To form a plurality of mounting holes to be attached to the motor,
When a plurality of the rotary polygon mirrors are coaxially stacked, a flat tightening seat which is in surface contact with each other in the vicinity of the periphery of each of the mounting holes is formed to project on at least one end surface of both end surfaces orthogonal to the reflection surface. Therefore, when stacking a plurality of rotary polygon mirrors during manufacturing, transportation, storage, etc., screw the screws inserted into the mounting holes formed in each rotary polygon mirror into the jig, or It is possible to hold a plurality of rotary polygon mirrors by screwing a nut on the tip, and this makes it possible to reduce the number of parts for fixing a plurality of rotary polygon mirrors in a stacked state. Since the periphery of the mounting hole of the rotary polygon mirror can be brought into close contact without opening a gap, it is possible to prevent the rotary polygon mirror from being distorted, and the individual rotary polygon mirrors can be attached to the rotary surface of the motor. Place to fix The screw that has passed through the mounting hole is screwed onto the rotating surface of the motor, but since a tightening seat is formed in the vicinity of the periphery of the mounting hole, distortion due to the tightening force of the screw is stopped and the range of the seat It can be kept inside to prevent the influence on the other, and thus, there is an effect that the scanning accuracy can be improved.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, in which (a) is a plan view and (b) is a vertical side view.

FIG. 2 is a side view showing a state in which a reflecting surface is mirror-finished with a part thereof as a cross section.

FIG. 3 is a side view showing a modified example of a tightening seat with a part of which is a cross section.

FIG. 4 is a plan view showing a modified example of the tightening seat.

FIG. 5 is a vertical sectional side view showing a first conventional example.

FIG. 6 shows a second conventional example, (a) is a plan view,
(B) is a vertical side view.

FIG. 7 is a vertical sectional side view showing a state in which a plurality of rotary polygon mirrors are stacked.

FIG. 8 is a side view showing a state in which a rotary polygonal mirror is attached to a motor with a part of which is a cross section.

FIG. 9 shows a third conventional example, (a) is a plan view,
(B) is a vertical side view.

FIG. 10 is a vertical sectional side view showing a state in which a plurality of rotary polygon mirrors are stacked.

[Explanation of symbols]

 2 Reflective Surface 5 Mounting Hole 10 Motor 11 Rotating Shaft 22, 22a End Face 23 Tightening Seat 24 Fitting Hole 30, 31 Tightening Seat

Claims (1)

[Claims] 1. A rotary polygonal mirror having a fitting hole for mounting on a rotary shaft of a motor formed in a central portion thereof and a reflecting surface formed on a side surface of the rotary polygonal mirror, wherein the motor is provided around the fitting hole of the rotary polygonal mirror. A plurality of mounting holes to be mounted are formed, and flat fastening seats that are in surface contact with each other in the vicinity of the periphery of each of the mounting holes when the plurality of rotary polygon mirrors are coaxially overlapped with each other. A rotary polygon mirror characterized in that it is formed so as to project on at least one end face of the surface.