JPH05134202A - Deflection scanning device - Google Patents

Abstract

PURPOSE:To reduce the size of a housing and to reduce the weight and decrease the number of components and processes by catching an elastic member, fitted below an optical box, in a groove of the housing, and supporting the elastic member by the optical box. CONSTITUTION:A motor shaft 6 is fitted in the inner ring of a ball bearing pressed in the motor part housing 8. The housing 8 is formed normally of metal such as brass and a flange 10 and the groove 11 are integrally formed. The reverse surface of the flange 10 is made to abut on the optical box 9, thereby positioning the housing 8. A linear spring 12 formed of a wire material is mounted from below in the groove 11 formed in the housing 8 after the housing 8 is fitted to the optical box 9, and both the ends of the spring 12 are supported on projections 13 formed integrally with the optical box 9. Consequently, the housing 8 is pressed as shown by A and fixed to the optical box 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection scanning device using a rotating device such as a polygon mirror supported by a bearing such as a ball bearing. For example, a deflection scanning device used for laser beam deflection in a laser beam printer or the like. Regarding the device.

[0002]

2. Description of the Related Art FIG. 8 shows a conventional example of a deflection scanning device of a laser beam printer. Here, an enlarged sectional view of the deflector portion is shown.

In the figure, a rotary polygon mirror (hereinafter referred to as a polygon mirror) 101 is fixed on a washer 103 fixed to a rotor 102 by caulking or the like. Washer 1
The motor shaft 106 is press-fitted into 03. A driving magnet 104 is fixed to the inner surface of the rotor 102 with an adhesive or the like, and a stator coil 105 provided below the driving magnet 104 rotationally drives the polygon mirror 101 and the like fixed to a motor shaft 106. ..

The motor shaft 106 is fitted in an inner ring of a ball bearing 107 which is press-fitted in a motor housing 108. The housing 108 is fixed to the optical box 109 with screws 110.

Here, the optical box 109 also houses optical means (not shown) for condensing the light beam deflected and scanned by the polygon mirror 101 onto the surface to be scanned.

[0006]

However, in the above-mentioned conventional example, the screw 110 is used to fix the housing 108 to the optical box 109, and the screw is provided on the outside of the rotor 102 so as not to interfere with the rotation of the rotor 102. The screw 110 is arranged. Therefore, the housing 108
Will increase in size, and increase in weight and cost. Moreover, since 4 to 5 screws 110 are normally used, the number of parts, the number of steps, and the cost increase.

[0007]

According to the present invention, in a deflection scanning device for deflecting and scanning a laser beam by rotating a polygon mirror by a drive motor, as a means for fixing a housing containing a ball bearing to an optical box. , The elastic member mounted from below the optical box instead of the screw is hooked in the groove provided in the housing and the elastic member is supported by the optical box, so that the housing can be downsized and the housing can be made smaller. Since the screw for fixing to the optical box can be abolished, weight reduction,
The number of parts and the number of processes can be reduced, and the cost of the deflection scanning device can be reduced.

[0008]

FIG. 1 is a plan view for explaining the structure of a first embodiment of a deflection scanning device of the present invention for scanning a photosensitive member with a light beam, which is used in a laser beam printer. FIG. 1 is a diagram for explaining a function in a cross section parallel to a deflecting surface (a ray bundle surface formed by a light beam changed by a deflecting / reflecting surface of a deflector over time).

The deflection scanning device is a scanner body (optical box) 9
FIG. 1 shows a plan view with the lid removed, which is housed inside. The deflection scanning device is a semiconductor laser device 4.
1, a collimator lens 42 that makes a light beam generated from the semiconductor laser device 41 into a parallel light beam, a cylindrical lens 43 that linearly collects the parallel light beam from the collimator lens 42, and a light beam that is condensed by the cylindrical lens 43. The polygon mirror 1, which is a rotary polygonal mirror having a deflective reflection surface 44a in the vicinity of the line image, and the fθ lens 50, etc. are included. The light beam deflected and reflected by the deflecting / reflecting surface 44 a enters the reflecting mirror 47 through the fθ lens 50, is reflected by the reflecting mirror 47, and
Irradiate a photoconductor (not shown).

The fθ lens 50 is designed so that the light beam reflected by the deflecting / reflecting surface 44a is condensed so as to form a spot on the photosensitive member, and the scanning speed of the spot is kept constant. There is. In order to obtain such characteristics of the fθ lens 50, the fθ lens 50 is composed of two lenses, a spherical lens 45 and a toric lens 46.

The rotation of the rotary polygon mirror 1 causes main scanning by the light beam on the photosensitive member, and sub-scanning by rotationally driving the photosensitive member around the axis of the cylinder. In this way, an electrostatic latent image is formed on the surface of the photoconductor.

Around the photosensitive member, a corona discharger for uniformly charging the surface of the photosensitive member, and a visible image for developing an electrostatic latent image formed on the surface of the photosensitive member into a toner image. Device,
A transfer corona discharger (not shown) for transferring the toner image onto the recording paper is arranged, and by these functions, recording information corresponding to the luminous flux generated by the semiconductor laser device 41 is printed on the recording paper. It

As shown in FIG. 1, the irradiation position of the scanner body 9 is adjusted by positioning pins 51 and 52 provided on the outside of the scanner body 9. Reference numeral 53 is a guide hole for the positioning pin 51, and 54 is a guide hole for the positioning pin 52. The adjustment of the irradiation position of the scanner body 9 in the x direction is performed by moving both the positioning pins 51 and 52 in the same x direction. The adjustment of the scanner body 9 in the θ direction in FIG.
By rotating the and positioning pins 52 in the opposite directions of x, rotational movement in the θ direction is performed.

FIG. 2 shows an enlarged sectional view of the polygon mirror portion shown in FIG.

In the figure, reference numeral 1 denotes a polygon mirror, which is fixed on a washer 3 which is fixed to a rotor 2 by caulking or the like. A motor shaft 6 is press-fitted into the washer 3. A drive magnet 4 is fixed to the inner surface of the rotor 2 with an adhesive or the like, and the rotor 2 is rotationally driven by a stator coil 5 provided below the drive magnet 4. The motor shaft 6 is fitted in an inner ring of a ball bearing 7 which is press-fitted in a motor housing 8. Same housing 8
Is usually made of metal such as brass, and the flange 10 and the groove 11 are integrally formed. The housing 8 is positioned by abutting the lower surface of the flange 10 against the optical box 9. A wire spring 12 formed by a wire as shown in FIG. 3 is attached to the groove 11 provided in the housing 8 from below after the housing 8 is attached to the optical box 9, and both ends of the spring 12 are attached. Optical box 9
The housing 8 is pressed in the direction A in the figure and fixed to the optical box 9 by being supported by the protrusion 13 formed integrally with the housing 8 as shown in the figure. The diameter of the flange 10 may be slightly larger than the body diameter B of the housing 8.

In the description of the present embodiment, the ball bearing is taken as an example of the bearing, but it goes without saying that the present embodiment can be applied to various other known bearings.

As described above, according to this embodiment, as a method of fixing the motor section housing to the optical box, the housing is attached to the optical box and then the wire spring is attached from below, whereby the housing is attached to the optical box. Since it is not necessary to use a screw, it is possible to reduce the size and weight of the housing, simplify the assembly process, reduce the number of parts, and reduce the cost of the deflection scanning device.

[Other Embodiments] FIG. 4 shows a second embodiment of the deflection scanning device of the present invention. In the figure, members having the same functions as those in the first embodiment are designated by the same reference numerals, and a repetitive description will be omitted.
Further, here, an enlarged cross-sectional view of the polygon mirror portion is shown.

In the first embodiment, the wire spring 12 is used to fix the housing 8 to the optical box 9, but in this embodiment, the leaf spring 20 as shown in FIG. 5 is used. A hole 21 and a claw 22 are integrally formed in the spring 20.

The diameter of the hole 21 is slightly larger than the outer diameter B of the housing 8 and the inner diameter of the claw 22 is smaller than the outer diameter B and slightly larger than the diameter of the groove 11.

After attaching the housing 8 to the optical box 9,
When the leaf spring 20 is mounted from below, the claw 22 bends downward due to the entrance of the housing 8 and returns to its original shape at the groove 11 and acts as a retainer for the spring 20. Both ends of the spring 20 are supported by the protrusions 13, and the housing 8 is fixed to the optical box 9 by pressing the housing 8 in the A direction in the figure.

The effect of this embodiment is the same as that described in the first embodiment, but there is also an effect that it is suitable for mass production by replacing the wire spring with a leaf spring.

FIG. 6 shows a third embodiment of the deflection scanning device of the present invention.

In the figure, members having the same functions as those in the above-mentioned embodiment are designated by the same reference numerals, and their re-explanation will be omitted. Also here,
The partial enlarged view of a polygon mirror part is shown.

In the second embodiment, both ends of the leaf spring are supported by the projections, but in this embodiment, as shown in FIG.
The foot 31 is integrally formed on the upper part of the foot so that the load can be applied by bending the foot. The spring 30 has a hole 32
And the claw 33 is integrally formed. The relationship between the diameter of the hole 32 and the inner diameter of the claw 33 with respect to the outer diameter B of the housing 8 is the same as that in the second embodiment. The assembling method and effect of the spring 30 are also the same as those in the second embodiment, and the repetitive description will be omitted.

[0026]

As described above, according to the present invention, in the deflection scanning device for deflecting and scanning the laser beam by rotating the polygon mirror by the drive motor,
By using a housing containing a ball bearing as a means for fixing the optical box, the elastic member attached from below the optical box instead of the screw is hooked in the groove of the housing, and the elastic member is supported by the optical box. Since it is possible to reduce the size and eliminate the screws for fixing the housing, the weight can be reduced, the number of parts can be reduced, the number of processes can be reduced, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view illustrating the configuration of a deflection scanning device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a polygon mirror unit in FIG.

FIG. 3 is a perspective view illustrating a configuration of a wire spring.

FIG. 4 is a sectional view illustrating a polygon mirror portion of a second embodiment of the deflection scanning device of the present invention.

FIG. 5 is a perspective view illustrating a configuration of a leaf spring.

FIG. 6 is a sectional view illustrating a polygon mirror portion of a third embodiment of the deflection scanning device of the present invention.

FIG. 7 is a perspective view illustrating a configuration of a leaf spring.

FIG. 8 is a sectional view illustrating a conventional polygon mirror section.

[Explanation of symbols]

 1 polygon mirror 2 rotor 6 motor shaft 7 ball bearing 8 housing 9 optical box 12 wire spring

Claims (4)

[Claims] 1. A deflector for deflecting a beam from a light source is rotated by a drive motor supported by a bearing to deflect and scan the beam, and the deflector, the drive motor and the beam are converged on an object to be scanned. A deflection scanning device having a container for accommodating optical means, wherein a bearing supporting member is fixed to the container by an elastic member, wherein a groove is formed on the outer periphery of the member for supporting the bearing, and the outside of the container is formed. Hook the elastic member mounted from the above into the groove, and
A deflection scanning device characterized in that a member for supporting the bearing is fixed to the container by supporting the elastic member in the container. 2. The deflection scanning device according to claim 1, wherein a wire spring is used as the elastic member. 3. The deflection scanning device according to claim 1, wherein a leaf spring is used as the elastic member. 4. The deflection scanning device according to claim 1, wherein the elastic member is supported by a protrusion provided on the container.