JPH11212017A - Rotary polygon mirror device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily set the surface of a polygon mirror at a prescribed angle with high accuracy by producing the outer peripheral surface of a rotary shaft and the hole of the polygon mirror to be force-fitted with high accuracy by force-fitting and fixing the polygon mirror into the rotary shaft of a motor and rotating the polygon mirror integrally with the rotary shaft. SOLUTION: Concerning a polygon mirror 2, a force-fitting hole 2b is formed at its axial center part and by force-fitting that force-fitting hole 2b into a large diameter shaft part 6b of a shaft 6 of a motor 1, the polygon mirror is fixed on the shaft 6 so as to disable rotating and axial moving. Therefore, when the outer peripheral surface of the shaft 6 and the force-fitting hole 2b of the polygon mirror 2 are produced with high accuracy, a surface 2a of the polygon mirror 2 can be set at the prescribed angle. Namely, since the polygon mirror 2 is not contacted with a rotor 7, it is not necessary to grind the rotor 7 after the rotor 7 and the shaft 6 are assembled, and it is enough only to highly accurately produce the shaft 6 and the polygon mirror 2 as components.

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 device used for laser scanning and the like, and more particularly to a structure for supporting a polygon mirror (polygon mirror) mounted on a motor.

[0002]

2. Description of the Related Art As a conventional rotary polygon mirror device, there is, for example, a device provided with an outer rotor type motor 50, a polygon mirror (hereinafter, referred to as a polygon mirror) 51 and a mirror fixing spring 52 as shown in FIG.

A shaft 54 is rotatably supported in a central shaft hole 53a of the stator 53 of the motor 50. The tip end 54a of the shaft 54 is exposed from the center shaft hole 53a of the stator 53, and a cup-shaped rotor 55 is press-fitted and fixed to the tip end 54a. More specifically, the rotor 55 is formed with a press-fit cylindrical portion 55a corresponding to the tip portion 54a of the shaft,
A disk portion 55b extending radially outward is formed on the stator 53 side of the press-fit cylinder portion 55a, and a magnet cylinder extending in the axial direction opposite to the press-fit cylinder portion 55a is provided on an outer peripheral end of the disc portion 55b. A portion 55c is formed. A plurality of rotor magnets 56 are provided on the inner peripheral surface of the magnet cylinder 55c in the circumferential direction. The press-fit cylinder 55a is press-fitted and fixed to the distal end 54a of the shaft 54 so that the rotor magnet 56 covers the drive coil 57 provided on the stator 53.

[0004] The polygon mirror 51 is attached to the rotor 55.
Is pressed and fixed by the mirror fixing spring 52. The polygon mirror 51 is formed in a plate shape, and its plane cross section is formed in a polygonal shape. Each outer surface is finished to a mirror surface 51a.
The polygon mirror 51 has a fitting insertion hole 51b formed at the center of the shaft. Further, the polygon mirror 51
On one side surface, an annular supporting projection 51c is formed. By inserting the press-fitting cylindrical portion 55a into the insertion hole 51b, the polygon mirror 51 is
Attached to. On the other hand, at this time, the annular support protrusion 51
c has its convex surface in contact with the disk portion 55b of the rotor 55. The other side surface of the polygon mirror 51 is fixed by a mirror fixing spring 52 fitted to the press-fitting cylindrical portion 55a so that the polygon mirror 51 cannot rotate and cannot move in the axial direction with respect to the rotor 55. .

In the rotating polygon mirror device thus configured, when the motor 50 is driven, the rotor 55 rotates and the polygon mirror 51 rotates integrally with the rotor 55. Then, the mirror surface 5 of the rotating polygon mirror 51
1a, when laser light is emitted at a predetermined cycle from a laser emitting device (not shown) provided at a predetermined position, the laser light is reflected on each mirror surface 51a of the rotating polygon mirror 51, and the reflected light is reflected on a target object. Go towards. Then, the laser beam further reflected from the target is received by a light receiving device (not shown), and the time during which the laser light is received is calculated. Is to be measured.

[0006]

The surface A of the disk portion 55b of the rotor 55, which is in contact with the convex surface of the annular supporting convex portion 51c of the polygon mirror 51, is perpendicular to the shaft 54 of the motor 50 with high precision. Must. or,
Rotor 55 into which fitting hole 51b of polygon mirror 51 fits
The outer peripheral surface B of the press-fitting cylindrical portion 55a must be parallel to the shaft 54 of the motor 50 with high precision. This is because if the accuracy of either one of the surfaces A and B is poor, when the polygon mirror 51 rotates together with the rotor 55, the mirror surface 51a rotates while swinging (shaking and rotating).
As a result, the laser light is not always reflected at a certain angle, which causes an erroneous measurement.

In this rotary polygon mirror device, even if the shaft 54 and the rotor 55 as components are manufactured with high precision, the accuracy of the two surfaces A and B may be reduced at the stage of assembling the shaft 54 and the rotor 55. There is. Therefore, in this rotary polygon mirror device, in addition to manufacturing each contact surface of the shaft 54, the rotor 55, and the polygon mirror 51 with high accuracy, the two surfaces A of the rotor 55 are assembled after the shaft 54 and the rotor 55 are assembled. , B are polished to maintain the angles of both surfaces A, B with high precision.

However, the shaft 54 and the rotor 55
Polishing the surfaces A and B with high precision after the assembly is complicated and requires several steps, which increases the manufacturing cost of the rotary polygon mirror device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary polygon mirror device capable of easily and highly accurately setting a mirror surface of a polygon mirror at a predetermined angle and reducing cost.

[0010]

According to a first aspect of the present invention, there is provided a rotary polygon mirror apparatus comprising: a polygon mirror having a plurality of reflection surfaces; and a motor for rotating the polygon mirror. Is press-fitted and fixed to the rotating shaft of the motor, and is rotated integrally with the rotating shaft.

According to a second aspect of the present invention, in the rotary polygon mirror device according to the first aspect, the rotary shaft has a large-diameter shaft portion, and the polygon mirror is press-fitted and fixed to the large-diameter shaft portion. The main point is that

[0012] The invention according to claim 3 is the invention according to claim 1 or 2.
Wherein the polygon mirror has a press-fitting collar, and is press-fitted and fixed to the rotary shaft via the press-fitting collar.

According to the first aspect of the present invention, since the polygon mirror is press-fitted and fixed to the rotating shaft of the motor and is rotated integrally with the rotating shaft, the outer peripheral surface of the rotating shaft and the polygon mirror are press-fitted. If the holes in the portions are manufactured with high accuracy, the mirror surface of the polygon mirror can be set at a predetermined angle with high accuracy.

According to the second aspect of the present invention, the rotating shaft has a large-diameter shaft portion, and the polygon mirror is press-fitted and fixed to the large-diameter shaft portion. Fixed to
According to the invention described in claim 3, the polygon mirror has a press-fitting collar, and is press-fitted and fixed to the rotary shaft via the press-fitting collar. Therefore, in the material of the polygon mirror, a portion other than the press-fitting collar can be, for example, a resin or the like.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a rotary polygon mirror device used in a cruise control system of a vehicle will be described below with reference to FIG.

FIG. 1 is a sectional view of a principal part of a rotary polygon mirror device. The rotary polygon mirror device includes an outer rotor type motor 1 and a polygon mirror (hereinafter, referred to as a polygon mirror) 2. The stator 3 of the motor 1 includes a substantially cylindrical shaft support 4 and a drive coil 5 provided on the outer peripheral side of the shaft support 4. Central shaft hole 4 of the shaft support 4
The shaft 6a is rotatably supported by a. The shaft 6 is composed of a support shaft 6a having substantially the same diameter as the central shaft hole 4a, and a large-diameter shaft 6b formed at the tip thereof with a diameter larger than the support shaft 6a. . The support shaft 6a is rotatably supported by the central shaft hole 4a of the shaft support 4.

In the support shaft 6a, the large-diameter shaft 6
The end 6c on the b side is exposed from the central shaft hole 4a of the shaft support 4, and a cup-shaped rotor 7 is press-fitted and fixed to the end 6c. More specifically, the rotor 7 has a disk portion 7b having a through hole 7a corresponding to the diameter of the support shaft portion 6a.
And a magnet cylinder portion 7c extending in a cylindrical shape from the outer peripheral end of the disk portion 7b. The magnet cylinder 7
On the inner peripheral surface of c, a rotor magnet 8 divided into a plurality in the circumferential direction is provided. The through-hole 7a is press-fitted and fixed to the end 6c of the support shaft 6a so that the rotor magnet 8 covers the drive coil 5 of the stator 3.

The polygon mirror 2 is formed in a plate shape from an aluminum alloy, and has a polygonal cross section. Each outer surface is finished as a mirror surface 2a as an anti-slope surface.
The polygon mirror 2 has a press-fit hole 2 at its axial center.
b is formed. The polygon mirror 2 is fixed to the shaft 6 so that it cannot rotate and cannot move in the axial direction by press-fitting the press-fit hole 2b into the large-diameter shaft portion 6b of the shaft 6. At this time, the polygon mirror 2 is in contact only with the large-diameter shaft portion 6b of the shaft 6, and is not in contact with the rotor 7.

In the rotary polygon mirror device thus configured, when the motor 1 is driven, the rotor 7 and the shaft 6
Rotates, and the polygon mirror 2
And rotate together. When laser light is emitted from a laser emitting device (not shown) provided at a predetermined position on the mirror surface 2a of the rotating polygon mirror 2 at a predetermined cycle, the laser light is reflected on each mirror surface 2a of the rotating polygon mirror 2. The reflected light travels toward the target. Then, the laser beam further reflected from the target is received by a light receiving device (not shown), and the time during which the laser light is received is calculated. Is measured. Since the rotary polygon mirror device according to the present embodiment is used for a cruise control system of a vehicle, the target is a vehicle, and the laser light is mainly reflected from a reflector of the vehicle.

Next, the characteristic effects of the rotary polygon mirror device configured as described above will be described below. (1) In the present embodiment, the polygon mirror 2 is prevented from rotating with respect to the shaft 6 and being unable to move in the axial direction by pressing the press-fit hole 2b into the large-diameter shaft portion 6b of the shaft 6. Fixed. Accordingly, if the outer peripheral surface of the shaft 6 and the press-fit hole 2b of the polygon mirror 2 are manufactured with high accuracy, the mirror surface 2a of the polygon mirror 2 can be set at a predetermined angle with high accuracy. That is, since the polygon mirror 2 does not come into contact with the rotor 7 as in the related art, there is no need to grind the rotor 7 after assembling the rotor 7 and the shaft 6, and only the shaft 6 and the polygon mirror 2 as parts are raised. If it is manufactured with high accuracy, the mirror surface 2a of the polygon mirror 2 can be held at a predetermined angle with respect to the shaft 6 with high accuracy. As a result, the number of manufacturing steps of the rotary polygon mirror device can be reduced, and the manufacturing cost of the rotary polygon mirror device and the cruise control system of the vehicle can be reduced. Further, unlike the related art, there is no need for a mirror fixing spring for fixing the polygon mirror, so that the material cost is reduced.

(2) In this embodiment, the portion of the polygon mirror 2 into which the press-fitting hole 2b is press-fitted is the large-diameter shaft portion 6b of the shaft 6. That is, the large-diameter shaft portion 6b having a larger diameter than the support shaft portion 6a having a necessary diameter as the rotation shaft of the motor 1
The press-fit hole 2b of the polygon mirror 2 was press-fitted and fixed. Therefore, the polygon mirror 2 is firmly press-fitted and fixed to the shaft 6. As a result, even if the centrifugal force is increased by rotating the polygon mirror 2 at high speed, the press-fitted and fixed portion is securely held.

The above embodiment may be modified and implemented as follows. In the above embodiment, the large-diameter shaft portion 6b having a larger diameter than the support shaft portion 6a is formed on the shaft 6, and the press-fit hole 2b of the polygon mirror 2 is press-fitted into the large-diameter shaft portion 6b. As shown in FIG. 2, a shaft 11 having a uniform diameter is provided with a press-fit hole 1 of a polygon mirror 12 at a tip 11a.
2a may be press-fitted. Even if you do this,
The same effect as the effect (1) of the above embodiment can be obtained.

In the above embodiment, the polygon mirror 2
Is made of an aluminum alloy, but if it has an anti-slope surface (mirror surface 2a), its material may be changed to resin. In this case, as shown in FIG. 3, the plate-shaped polygon mirror 13 needs to have a metal press-fitting collar 13a formed by insert molding at the center thereof. And
The polygon mirror 13 is fixed to the shaft 6 by press-fitting the press-fit hole 13b of the press-fit collar 13a into the large-diameter shaft portion 6b of the shaft 6. A mirror surface 13c is formed on each surface of the outer periphery of the polygon mirror 13 by, for example, aluminum plating. Even in this case, effects similar to the effects (1) and (2) of the above embodiment can be obtained. Moreover, the polygon mirror 13 is provided with a press-fit collar 13.
Since it is resinous except for a, it is possible to reduce the amount of metal used and to reduce the cost.

The polygon mirror 2 of the above embodiment
As shown in FIG. 4, the shaft 6 may be a resin-made polygon mirror 14 and a shaft 15 having a uniform diameter over the entire shaft. In this case, the plate-shaped polygon mirror 14 is provided with a metal press-fitting collar 14 which is insert-molded at the center thereof.
a must be provided. Even in this case, the same effect as the effect (1) of the above embodiment can be obtained. Moreover, since the polygon mirror 14 is made of resin except for the press-fit collar 14a, it is possible to reduce the amount of metal used and to reduce the cost.

In the rotary polygon mirror device of the above embodiment,
Although the outer rotor type motor 1 is used, an inner rotor type motor may be used as long as the polygon mirror 2 is press-fitted and fixed to the shaft 6 (rotary shaft).

In the above embodiment, the method of manufacturing the shaft 6 is not specifically described, but a metal rod may be manufactured by a lathe. In addition, you may manufacture by sintering or forging, for example. In this case, the manufacturing cost of the shaft 6 can be reduced.

Next, technical ideas other than the claims that can be grasped from each of the above embodiments will be described together with their effects. In a polygon mirror having a plurality of reflection surfaces (13c) on the outer peripheral surface, the rotation axis (6, 6)
Press-fit collar (13a, 1) for press-fitting and fixing to 15)
A polygon mirror comprising: 4a). In this case, the material of the polygon mirrors 13 and 14 is changed to the press-fit collar 13.
Portions other than a and 14a can be made of, for example, resin.

A cruise control system for a vehicle provided with the rotary polygon mirror device according to any one of claims 1 to 3. By doing so, the mirror surfaces 2a and 13c of the polygon mirrors 2 and 12 to 14 can be easily and accurately set to a predetermined angle, and the cost of the cruise control system of the vehicle can be reduced.

[0029]

As described in detail above, according to the present invention,
It is possible to provide a rotary polygon mirror device that can easily and highly accurately set the mirror surface of the polygon mirror at a predetermined angle and reduce the cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a rotary polygon mirror device according to an embodiment.

FIG. 2 is a longitudinal sectional view of a rotary polygon mirror device in another example.

FIG. 3 is a longitudinal sectional view of a rotary polygon mirror device in another example.

FIG. 4 is a longitudinal sectional view of a rotary polygon mirror device in another example.

FIG. 5 is a longitudinal sectional view of a rotary polygon mirror device according to the related art.

[Explanation of symbols]

1 ... motor, 2,12-14 ... polygon mirror, 6,1
1, 15: shaft, 2a, 13c: mirror surface, 6b: large-diameter shaft portion, 13a, 14a: press-fit collar.

Claims (3)

[Claims] 1. A polygon mirror (2, 12 to 14) having a plurality of reflection surfaces (2a, 13c), and a motor (1) for rotating the polygon mirror (2, 12 to 14). In the rotary polygon mirror device, the polygon mirror (2, 12 to 14) is press-fitted and fixed to a rotation shaft (6, 11, 15) of the motor (1), and is fixed to the rotation shaft (6, 11, 15). A rotary polygon mirror device which is integrally rotated. 2. The rotary polygon mirror device according to claim 1, wherein the rotary shaft has a large-diameter shaft portion, and the polygon mirror has a large-diameter shaft portion. (6b) A rotary polygon mirror device, which is press-fitted and fixed to (6b). 3. The rotary polygon mirror device according to claim 1, wherein the polygon mirror is a press-fit collar.
14a), and the press-fitting collars (13a, 14a)
A rotary polygon mirror device, which is press-fitted and fixed to the rotary shaft (6, 15) via a rotary shaft.