JPH07199108A - Optical scanning device - Google Patents

Abstract

PURPOSE:To surely mount a rotary polygon mirror, a laser light source and a synchronization detecting sensor on each prescribed position in a housing with high precision and by an easy work. CONSTITUTION:As for a composite substrate 40, a motor substrate part 41 with a coil and a control circuit for a polygon motor 30, etc., mounted, a laser light source substrate part 42 with a laser light source 14 and a control circuit for the laser light source 14), etc., mounted and a synchronization detecting sensor substrate part 43 with the synchronization detecting sensor 18 and a control circuit for the synchronization detecting sensor 18, etc., are integrally molded. A holder is molded so that it may be brought into tight contact with the housing 44 without leaving a space between them by applying insert-molding, or outsert-molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device which is applied to an electrophotographic recording device and which scans a photosensitive member with laser light.

[0002]

2. Description of the Related Art FIG. 5 is a schematic configuration diagram of a laser printer to which an optical scanning device is applied.

Reference numeral 1 is a photosensitive drum, 2 is a developing device, 3 is a charging device, 4 is a discharging lamp, 5 is a cleaning device, 6 is a transfer device, 7 is a paper feeding cassette, 8 is a fixing device, and 10 is an optical scanning device. Is.

The charger 3 uniformly charges the photosensitive drum 1,
The optical scanning device 10 scans the photosensitive drum 1 with laser light corresponding to image information to form an electrostatic latent image on the photosensitive drum 1. The electrostatic latent image is developed into a toner image by the developing device 2, and the toner image is transferred by the transfer device 6 to the recording paper P that is synchronously conveyed from the paper feeding cassette 7, and then the recording paper P by the fixing device 8. Fixed on top. Also,
After the transfer of the photoconductor drum 1 is completed, the cleaning device 5 removes and collects the residual toner, and the static eliminator 4 neutralizes the charge.

FIG. 6 is a perspective view showing an example of a conventional optical scanning device.

Reference numeral 11 is a housing, 12 is a housing cover attached to the housing 11 to close the opening, 13 is a rotary polygon mirror, 14 is a laser light source composed of a laser diode, 15 is an fθ lens, 16 is a first mirror, Reference numeral 17 is a second mirror, 18 is a synchronous detection sensor, and 20 is a polygon motor screwed to the housing 11 with screws 19.

The rotary polygon mirror 13 rotated at a constant speed by the polygon motor 20 reflects the laser light emitted from the laser light source 14. The laser light reflected by the rotary polygon mirror 13 and moving at a constant angular velocity is incident on the fθ lens 15, the moving speed is converted from the constant angular velocity to the constant velocity, and the laser light is incident on the first mirror 16 or the second mirror 17.

The laser light incident on the first mirror 16 scans the photosensitive drum 1 at a constant speed to form an electrostatic latent image. Further, the laser light incident on the second mirror 17 is reflected by the light receiving portion of the synchronization detection sensor 18 and detected by the synchronization detection sensor 18. The synchronization detection sensor 18 outputs a synchronization detection signal for controlling the output timing of image information and the rotation of the photosensitive drum 1.

FIG. 7 is a side sectional view showing a schematic structure of a polygon motor in the optical scanning device shown in FIG.

Reference numeral 21 denotes a rotary shaft that is connected to the center of rotation of the rotary polygon mirror 13 to support the rotary polygon mirror 13, and reference numeral 22 denotes a radial bearing 22a that rotatably supports the rotary shaft 21 and a holder 22b to which the radial bearing 22a is fixed. Bearing member constituted by 23, 23 is a motor substrate on which a coil 24 and a control circuit (not shown) are mounted, 25 is a disk-shaped rotor fixed to the rotating shaft 21, 26 is a coil 24 fixed to the rotor 25. Is a magnet facing. In such an apparatus, a brushless DC motor is generally used as the polygon motor 20.

[0011]

In the optical scanning device as described above, a fitting portion such as an opening is formed in the housing 11, and the fitting portion is fitted in the vicinity of the lower end portion of the holder 22b of the bearing member 22. Then, the polygon motor 20 is positioned, and the motor substrate 23 is screwed by the screw 19 to fix the polygon motor 20 to the housing 11.

However, the amount of surface tilt of the rotary polygon mirror 13 and the accuracy of the mounting position have a great influence on the image quality. Therefore, it is necessary to position and fix the polygon motor 20 within a margin of error of about 30 μm ± 8 μm with respect to a predetermined position of the housing 11. Further, it is necessary to fix the polygon motor 20 to the bottom surface of the housing 11 so that the inclination of the rotating shaft 21 is about several minutes to several tens of minutes or less.

Further, in order to prevent the polygon motor 20 from moving due to vibration or the like after being fixed to the housing 11, it is necessary to securely fix the polygon motor 20, and further, the laser light source 14 and the synchronization detection sensor 18 are required. In order to prevent the deviation of the optical axis, it is necessary to fix the housing 11 at a predetermined position with high accuracy and reliability.

As described above, the work of positioning the polygon motor 20, the laser light source 14, and the synchronization detection sensor 18 with high precision with respect to the housing 11 and attaching them with the screws 19 or the like is time-consuming and causes a cost increase. .

In order to solve the above-mentioned problems, an object of the present invention is to attach a rotary polygon mirror, a laser light source and a synchronization detection sensor to a predetermined position of a housing with high accuracy and surely by simple work. An object is to provide an optical scanning device.

[0016]

In order to solve the above problems, the first means of the present invention is to provide a rotary polygon mirror for reflecting laser light and a rotary shaft connected to the rotary polygon mirror via a bearing member. In the optical scanning device including a polygon motor for rotatably supporting the rotating polygon mirror during scanning, and a metal housing for housing and supporting the polygon motor and the rotating polygon mirror, the housing and the bearing member are provided. And are integrally formed.

Further, the second means is that a motor substrate fixed to the housing in the polygon motor and a laser light source substrate on which a laser light source for emitting the laser light is mounted are integrally formed. Is characterized by.

Further, the third means integrally forms a motor substrate fixed to the housing in the polygon motor and a synchronization detection sensor substrate on which a synchronization detection sensor for detecting the laser light is mounted. It is characterized by having done.

Further, the fourth means is characterized in that the motor substrate fixed to the housing in the polygon motor and the housing are integrally formed.

Further, a fifth means is characterized in that the motor substrate and a laser light source substrate on which a laser light source for emitting the laser light is mounted are integrally formed.

Further, a sixth means is characterized in that the motor substrate and a synchronous detection sensor substrate on which a synchronous detection sensor for detecting the laser light is mounted are integrally formed.

[0022]

According to the first means, the housing and the bearing member are integrally formed, so that the bearing member is formed at a predetermined position of the housing and the bearing member is fixed to the housing with high strength. Therefore, the positioning work of the polygon motor is simplified, and the polygon motor is prevented from being displaced from the fixed position due to vibration or the like.

Further, according to the second means, the motor substrate fixed to the housing in the polygon motor and the laser light source substrate on which the laser light source for emitting the laser light are mounted are integrally formed. The positioning and fixing work of the laser light source in the housing becomes easy.

Further, according to the third means, the motor substrate fixed to the housing in the polygon motor and the synchronous detection sensor substrate on which the synchronous detection sensor for detecting the laser beam is mounted are integrally formed. By
Positioning and fixing work of the synchronization detection sensor in the housing becomes easy.

According to the fourth means, the motor board fixed to the housing in the polygon motor and the housing are integrally formed, so that the motor board is formed at a predetermined position of the housing. Moreover, the motor board is fixed to the housing with high strength.

Further, according to the fifth means, since the motor substrate and the laser light source substrate on which the laser light source for emitting the laser light is mounted are integrally formed, the laser light source substrate is a predetermined motor substrate. The laser light source substrate is formed at a position and is fixed to the motor substrate with high strength.

Further, according to the sixth means, the motor board and the synchronous detection sensor board on which the synchronous detection sensor for detecting the laser beam is mounted are integrally formed,
The synchronization detection sensor board is formed at a predetermined position on the motor board, and the synchronization detection sensor board is fixed to the motor board with high strength.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. It should be noted that members corresponding to the members described in FIGS. 1 to 4 based on FIGS. 5 to 7 are denoted by the same reference numerals and the description thereof will be omitted.

FIG. 1 is a perspective view showing an embodiment of the optical scanning device of the present invention, and FIG. 2 is a side sectional view showing the main part of this embodiment.

Reference numeral 30 is a polygon motor, and 40 is a composite substrate. The composite substrate 40 includes a coil 24 and a polygon motor 30.
The motor board portion 41 on which the control circuit (not shown) of FIG.
And a laser light source board portion 42 on which a laser light source 14 and a control circuit (not shown) for the laser light source 14 are mounted, and a synchronization detection sensor 18 and a synchronization circuit for mounting a control circuit (not shown) for the synchronization detection sensor 18 The detection sensor board portion 43 is integrally molded. The motor mounting hole 44a penetrates through the housing 44 formed of a metal plate.

The rotating shaft 21 of the polygon motor 30 is a bearing member.
32 thrust bearings 32a are rotatably supported, and the thrust bearings 32a are fixed in a cylindrical holder 32b. This holder 32b is attached to the motor mounting hole 44a of the housing 44.
It is fixed in such a manner that it is inserted into and is held by the upper and lower surfaces of the housing 44. The holder 32b is formed by, for example, insert molding or outsert molding without gaps between the upper and lower surfaces of the housing 44 and the inner surface of the motor mounting hole 44a.
Also, the housing 44 and the holder 32b can be integrally molded by one mold.

The composite substrate 40 is placed and fixed on the stepped portion 32c formed on the outer peripheral surface of the holder 32b and the plurality of protrusions 44b formed on the lower surface of the housing 44.

According to the optical scanning device of this embodiment described above, the bearing member 32 is formed at a predetermined position of the housing 44 with the motor mounting hole 44a as a reference, and the bearing member 32 is fixed to the housing 44 with high strength. Therefore, the positioning work of the polygon motor 30 in the housing 44 becomes unnecessary, the rotary polygon mirror 13 is arranged at a predetermined position with high accuracy and without inclination, and is displaced from the fixed position by vibration or the like. Is prevented.

Further, since the laser light source substrate portion 42 and the synchronization detection sensor substrate portion 43 are integrally formed with the motor substrate portion 41 in the composite substrate 40, the laser light source 14 and the synchronization detection sensor 18 in the housing 44 are positioned and fixed. Work becomes easy.

FIG. 3 and FIG. 4 are side sectional views showing another example of the main part of the optical scanning device of this embodiment.

The composite substrate 50 shown in FIG. 3 is formed on the bottom surface of the housing 44 by printing. A motor substrate 41, a laser light source substrate 42, and a synchronization detection sensor substrate 43 are integrally formed on this composite substrate 50 as well as the composite substrate 40 shown in FIGS. As a result, the composite substrate 50 is formed at a predetermined position of the housing 44, and the composite substrate 50 is formed.
Is fixed to the housing 44 with high strength,
Positioning and fixing work of the laser light source 14 and the synchronization detection sensor 18 in 44 is simplified, and the laser light source 14 and the synchronization detection sensor 18 are arranged at a predetermined position with high accuracy and can be displaced from the fixed position by vibration or the like. To be prevented.

Further, since the housing 44 is made of metal, the composite substrate 50 forms a closed magnetic field with respect to the coil 24, so that the magnetism from the coil 24 can be prevented from leaking to the outside, and the polygon motor 30 can be prevented. Performance is improved.

A holder portion 51a is bent and formed by pressing or the like on a housing 51 formed of a metal plate shown in FIG. In the holder 51a, the rotary shaft 21
A thrust bearing 32a that axially supports is fixed. As a result, the number of parts and the number of processing steps can be reduced, so that the cost of the device can be reduced.

[0039]

As described above, according to the first means of the present invention, the bearing member is formed at the predetermined position of the housing, and the bearing member is fixed to the housing with high strength. Since the positioning work is simplified and the displacement from the fixed position due to vibration or the like is prevented, the rotary polygon mirror can be easily and accurately arranged at a predetermined position, and the rotary polygon mirror is displaced due to vibration or the like. Can be prevented.

Further, according to the second means, the work for positioning and fixing the laser light source in the housing is simplified, so that the assembly of the device is facilitated.

Further, according to the third means, since the work for positioning and fixing the synchronization detecting sensor in the housing is simplified, the assembly of the device is facilitated.

Further, according to the fourth means, the motor board is formed at a predetermined position of the housing, and the motor board is fixed to the housing with high strength, so that the work of fixing the motor board is simplified. It is possible to arrange the motor board at a predetermined position with high accuracy and prevent the motor board from being displaced from the fixed position due to vibration or the like.

Further, according to the fifth means, the laser light source substrate is formed at a predetermined position on the motor substrate, and the laser light source substrate is fixed to the motor substrate with high strength. In addition, the laser light source is arranged at a predetermined position with high accuracy and is prevented from being displaced from the fixed position due to vibration or the like.

Further, according to the sixth means, the synchronization detection sensor is formed at a predetermined position on the motor board, and the synchronization detection sensor board is fixed to the motor board with high strength, thereby positioning the synchronization detection sensor. The fixing work is simplified, the synchronization detection sensor is arranged at a predetermined position with high accuracy, and displacement from the fixed position due to vibration or the like is prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an optical scanning device of the present invention.

FIG. 2 is a side sectional view showing a main part of the present embodiment.

FIG. 3 is a side sectional view showing another example of the main part of the optical scanning device of the present embodiment.

FIG. 4 is a side sectional view showing another example of the main part of the optical scanning device of the present embodiment.

FIG. 5 is a schematic configuration diagram of a laser printer to which an optical scanning device is applied.

FIG. 6 is a perspective view showing an example of a conventional optical scanning device.

7 is a side sectional view showing a schematic configuration of a polygon motor in the optical scanning device shown in FIG.

[Explanation of symbols]

13 ... Rotating polygon mirror, 14 ... Laser light source, 18 ... Synchronous detection sensor, 32 ... Bearing member, 40, 50 ... Composite substrate, 41 ... Motor substrate part, 42 ... Laser light source substrate part, 43 ... Synchronous detection sensor substrate part, 44, 51 ... Housing.

Claims (6)

[Claims] 1. A polygonal motor which reflects a laser beam, a rotary shaft which is rotatably connected to the rotary polygonal mirror through a bearing member, and rotates the rotary polygonal mirror during scanning, and a polygon motor. An optical scanning device comprising: a housing made of metal for accommodating and supporting the rotary polygon mirror; wherein the housing and the bearing member are integrally formed. 2. The motor substrate fixed to the housing in the polygon motor and a laser light source substrate on which a laser light source for emitting the laser light is mounted are integrally formed. 1. The optical scanning device according to 1. 3. A motor substrate fixed to the housing in the polygon motor and a synchronous detection sensor substrate on which a synchronous detection sensor for detecting the laser light is mounted are integrally formed. The optical scanning device according to claim 1. 4. The optical scanning device according to claim 1, wherein a motor substrate fixed to the housing and the housing are integrally formed in the polygon motor. 5. The optical scanning device according to claim 4, wherein the motor substrate and a laser light source substrate on which a laser light source for emitting the laser light is mounted are integrally formed. 6. The optical scanning device according to claim 4, wherein the motor substrate and a synchronization detection sensor substrate on which a synchronization detection sensor for detecting the laser light is mounted are integrally formed.