JPH10239611A - Deflecting scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce vibrations of an optical box due to the vibration of a deflector. SOLUTION: A laser unit which emits laser beam, a polygon mirror 13 which deflects the laser beam from the laser unit, a driving motor 14 which supports and rotates the polygon mirror 13, and an image forming lens 15 which forms an image of laser beam from the polygon mirror 13 on a rotating drum 18 are provided in an optical box 10 made of a synthetic resin, and a groove 31 is formed in the outside surface of a bottom 24 of the optical box 10, and a metallic plate 32 having a rigidity is attached to the groove 31.

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 used for an image forming apparatus such as a laser printer and a laser facsimile.

[0002]

2. Description of the Related Art In a conventional deflection scanning apparatus of this type, a laser unit (not shown) for emitting a laser beam and a laser beam from the A cylindrical lens (not shown) that condenses the laser light, a polygon mirror 3 that is supported by the drive motor 2 and deflects the laser light from the cylindrical lens, an imaging lens 5 that forms the laser light from the polygon mirror 4 on the photosensitive drum 4, and the like. Is arranged. The optical box 1 is provided with a light detection lens and a light detection sensor (not shown) for detecting a part of the laser light from the polygon mirror 3 for synchronization, so that the scanning start position of the laser light is corrected. I have.

The optical box 1 is formed of a synthetic resin material reinforced by glass fiber, and an upper portion of the optical box 1 has an opening 1a. On a part of the side wall 1b of the optical box 1,
There is provided a window 1c through which laser light passes from the imaging lens 5 to the photosensitive drum 4. Bottom wall 1 of optical box 1
At d, a mounting hole 1e for positioning and mounting the drive motor 2 and a mounting base 1f are provided, and a mounting base 1g for the imaging lens 5 is formed. The drive motor 2 is fixed to the optical box 1 by screws 6, and the optical box 1 is fixed to the main body stay 7 of the image forming apparatus by screws 8.

In recent years, the number of rotations of the polygon mirror 3 has been increased in order to increase the definition of an image. At this time, since the vibration of the drive motor 2 also increases, the vibration causes the members 11 to 17 to vibrate via the bottom wall 1 d of the optical box 1.
A problem of deteriorating image quality occurs. As a countermeasure against this problem, the rigidity of the optical box 1 is improved by providing ribs on the optical box 1 or molding the optical box 1 with a synthetic resin material reinforced with a large amount of glass fiber. A weight is attached to adjust the dynamic balance when the polygon mirror 3 rotates at a high speed.

[0005]

However, the above-mentioned prior art has the following problems. (a) Optical box 1 made of synthetic resin material reinforced with glass fiber
Mold, the optical box 1 cannot be recycled. (b) When the rigidity of the optical box 1 is improved, the elasticity of the optical box 1 decreases. For this reason, the member 11 is made using the elasticity of the optical box 1.
It becomes impossible to attach to 17 or the like, and the degree of freedom in design is reduced. (c) When the rigidity of the optical box 1 is improved, the mold for molding the optical box 1 is easily worn, and the life of the mold is shortened. (d) The work of adjusting the dynamic balance of the polygon mirror 3 is not easy, and the work efficiency is poor.

An object of the present invention is to solve the above-mentioned problems and to provide a deflection scanning device capable of easily reducing the vibration of the optical box.

[0007]

In order to achieve the above object, the present invention provides a deflection scanning apparatus comprising: a laser unit for emitting laser light; a deflector for deflecting laser light from the laser unit; In a deflection scanning apparatus provided with an optical box made of a synthetic resin and an imaging lens for forming an image of a laser beam from a container, a vibration reducing member for reducing vibration of the optical box is provided on a bottom wall of the optical box. It is characterized by.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. FIG. 1 is a plan view of the first embodiment, and FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1. A semiconductor laser light source is provided at a predetermined position of the optical box 10 to emit laser light. A laser unit 11 is attached. In the traveling direction of the laser light emitted from the laser unit 11, a cylindrical lens 12 for condensing the laser light linearly and a polygon mirror 13 for deflecting the laser light are sequentially arranged. The polygon mirror 13 is supported by a drive motor 14 having a lower fitting portion 14a and a circuit board 14b, thereby forming a deflector.

In the direction in which most of the laser light deflected by the polygon mirror 13 travels, an imaging lens 15 that forms an image of the laser light and scans the laser light at a constant speed is arranged. Are provided with a synchronization light detection lens 16 and a light detection sensor 17 for correcting the scanning start position of the laser light. And
Outside the optical box 10 in the traveling direction of the laser light transmitted through the imaging lens 15, a photosensitive drum 18 that forms an electrostatic latent image by the laser light is disposed.

The optical box 10 is formed of a synthetic resin material, and an upper portion of the optical box 10 has an opening 21. A window 23 through which laser light passes is formed on the side of the photosensitive drum 18 on the side wall 22 of the optical box 10, and flanges 25 and 26 are provided at the bottom of the outer surface of the side wall 22. The bottom wall 24 of the optical box 10 is provided with a mounting hole 27 for mounting the drive motor 14 and a mounting base 28, and the mounting base 28 is provided with a screw hole 29. In addition, a mounting base 30 for mounting the imaging lens 15 is provided on the bottom wall 24.

At this time, the drive motor 14 is
4a is fitted into the mounting hole 27 of the bottom wall 24 and the circuit board 14
b is placed on the mount 28 and the screw 31 is screwed into the screw hole 29 to be fixed to the optical box 10. And
A groove 32 is provided on the outer surface of the bottom wall 24.
For example, a metal plate 33 is attached by insert molding when the optical box 10 is molded. in this way,
The optical box 10 in which the various members 11 to 17 are arranged is fixed to the main body stay 34 by screws 35.

With such a configuration, the laser light emitted from the laser unit 11 is condensed linearly by the cylindrical lens 12 and enters the polygon mirror 13. The polygon mirror 13 is driven to rotate at a high speed by a drive motor 14, and most of the laser light deflected by the polygon mirror 13 is imaged as a spot image scanned at a constant speed on the photosensitive drum 18 by the imaging lens 15. You. Then, a part of the laser light deflected by the polygon mirror 13 is detected by the light detection lens 16 and the light detection sense 17, and the photosensitive drum 1 of the laser light
8 is corrected. At this time, the metal plate 3
3 reduces the vibration of the bottom wall 24 of the optical box 10 and reduces the propagation of the vibration around the drive motor 14.

As described above, in the first embodiment, the metal plate 33 is used.
Is mounted on the bottom wall 24 of the optical box 10 at a position opposite to the mounting portions of the various members 11 to 17.
The following effects can be obtained without adversely affecting the accuracy of the mounting position.

(1) Vibration of the position of the image formed on the photosensitive drum 18 can be prevented, and the image quality is improved. (2) The standard for the dynamic balance adjustment of the polygon mirror 3 can be relaxed, the work efficiency can be improved, and the manufacturing cost can be reduced. (3) Since the amount of glass fiber added to the synthetic resin material used for the optical box 10 can be reduced, the recycling of the optical box 10 becomes easy. (4) Since the elasticity of the optical box 10 can be maintained, the degree of freedom in designing the optical box 10 can be improved. (5) Since the amount of glass fiber added to the synthetic resin material can be reduced, the life of a mold for molding the optical box 10 can be improved.

FIG. 3 is a cross-sectional view of the second embodiment. In the optical box 10 ', the screw hole 29 of the first embodiment is an insertion hole 29a for inserting a screw 31a, and the metal plate 33 has a screw 3
A screw hole 33a for screwing 1a and a ground plate 36 contacting the main body stay 34 are extended.

In the second embodiment, the same effects as those of the first embodiment can be obtained. In addition, the ground portion (not shown) of the circuit board 14b is connected via the screw 31a, the metal plate 33, and the ground plate 36. The circuit board 14b can be electrically connected to the main body stay 34, the circuit board 14b can be easily grounded, and the noise resistance of the circuit board 14b can be improved. In addition, it is possible to omit the cumbersome work of fastening a lead wire and an earth plate together with the screw 31a conventionally required, circling them in the optical box 10, and then connecting them to the main body stay 34, thereby reducing assembly workability. It can be improved.

FIG. 4 is a cross-sectional view of the third embodiment. The optical box 40 has the same openings 41 and side walls 42 as those in the first embodiment.
A window 43, a bottom wall 44, and flanges 45 and 46 are provided. A window 47 is provided on the bottom wall 44, and a metal plate 48 is fitted into the window 47. The metal plate 48 has a mounting hole 48a for mounting the lower body 14a of the drive motor 14 and a screw hole 48b for screwing the screw 31b.
The mounting table 49 of No. 4 and the mounting table 50 of the imaging lens 15 are formed of synthetic resin. The metal plate 48 is attached when the optical box 40 is formed. At this time, the attachment base 49 and the attachment base 50 are also formed.

In the second embodiment, the same effects as in the first embodiment can be obtained, and the heat of the circuit board 14b can be radiated to the outside of the optical box 40 via the metal plate 48. .

[0019]

As described above, in the deflection scanning apparatus according to the present invention, the vibration reducing member for reducing the vibration of the optical box is provided on the bottom wall of the optical box. The vibration can be easily reduced, and the image quality can be improved by preventing the vibration of the image forming position of the laser beam.

In addition, since the amount of glass fiber added to the synthetic resin can be reduced, the optical box can be recycled and the design flexibility of the optical box and the life of the mold of the optical box can be improved. Becomes

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view of a second embodiment.

FIG. 4 is a sectional view of a third embodiment.

FIG. 5 is a sectional view of a conventional example.

[Explanation of symbols]

 10, 10 ', 40 Optical box 11 Laser unit 13 Polygon mirror 14 Drive motor 15 Imaging lens 24, 47 Bottom wall 27, 48a Mounting hole 28, 30, 49, 50 Mounting base 32 Groove 33, 48 Metal plate 33a, 48b Screw hole 34 Body stay 47 Window

Claims (9)

[Claims] 1. An optical box made of a synthetic resin comprising: a laser unit for emitting laser light; a deflector for deflecting the laser light from the laser unit; and an imaging lens for imaging the laser light from the deflector. The deflection scanning device according to claim 1, wherein a vibration reducing member for reducing vibration of the optical box is provided on a bottom wall of the optical box. 2. The deflection scanning device according to claim 1, wherein the vibration reducing member has a size extending below the laser unit, the deflector, and the imaging lens. 3. The deflection scanning device according to claim 1, wherein the vibration reducing member is attached to a groove formed in a bottom wall of the optical box. 4. The deflection scanning device according to claim 1, wherein the vibration reducing member is attached to a window formed on a bottom wall of the optical box. 5. The deflection scanning device according to claim 4, wherein the vibration reducing member is provided with a mounting reference portion for mounting the laser unit, the deflector, and the imaging lens at predetermined positions. 6. The deflection scanning apparatus according to claim 1, wherein the vibration reducing member is attached when the optical box is molded. 7. The deflection scanning device according to claim 5, wherein the attachment reference portion is formed when the optical box is molded. 8. The deflection scanning device according to claim 1, wherein the vibration reducing member is a metal plate. 9. The deflection scanning device according to claim 8, wherein the deflector and the metal plate are electrically connected, and the metal plate is provided with a conductive member that is electrically connected to an assembly.