JPH09127451A - Bearing structure for rotary polygon mirror scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing structure which prevents a bad influence due to scattering of foreign matters in a wide temperature range and is inexpensive. SOLUTION: A rotary polygon mirror 5 is provided which reflected light while being rotated to a base part 1. A fixed shaft 2 is provided on the base part 1 side, and bearings 3 and 4 are provided on the rotary polygon mirror 5 side, and at least parts contacting with bearing parts 3 and 4 of the fixed shaft are made of metallic materials. At least parts contacting with the fixed shaft 2 of bearing parts 3 and 4 are made of resin materials, and worn particles generated by friction between the fixed shaft 2 and bearing parts 3 and 4 are stuck to the fixed shaft 2 or bearing parts 3 and 4 by triboelectrification.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing structure of a rotary polygon mirror scanning device used in an electrophotographic device such as a laser printer.

[0002]

2. Description of the Related Art A rotary polygon mirror scanning device is known in which a laser beam is reflected on a photosensitive member for scanning. The rotary polygon mirror of this rotary polygon mirror scanning device has a polygonal prism shape whose outer surface (side surface) is a mirror surface, and is configured to rotate about an axis. When a slide bearing is used in this rotary polygon mirror scanning device, scattered materials from the slide bearing, such as oil mist of the oil dynamic pressure bearing and abrasion powder of the slide bearing, are reflected on the reflection surface of the rotary polygon mirror or fθ. There is a possibility that the particles may adhere to a laser scanner optical system lens such as a lens and impair the optical characteristics.

In order to solve such a problem, it is possible to use an air dynamic pressure bearing or an oil dynamic pressure bearing.

In the air dynamic pressure bearing, the radial bearing is an air dynamic pressure bearing, the thrust bearing is a magnetic bearing, both bearings are non-contact bearings, and both the radial bearing and the thrust bearing are non-contact air dynamic pressure bearings. , Radial bearings are pneumatic bearings, thrust bearings are contact type sliding bearings using jewels such as sapphire, radial bearings are not pneumatic bearings or thrust bearings, and magnets and cores of circumferentially opposed motors are not provided. It has been proposed that it is levitated by the suction force of. In these air dynamic pressure bearings, the amount of abrasion powder generated can be suppressed.

For the oil dynamic pressure bearing, it has been proposed that a labyrinth structure, a magnetic fluid seal, and a rotating body have a cup shape to complicate an air flow path to a rotating polygon mirror or a lens. In these oil dynamic pressure bearings, oil and abrasion powder mixed in oil can be blocked in the middle of the outflow route to the outside of the motor.

[0006]

However, in the case of a pneumatic bearing, since the rotating body has to be levitated, in order to obtain sufficient thrust rigidity and levitating position accuracy, a magnet or a fine magnetic characteristic Costly because it requires expensive parts such as precision parts with hydrodynamic groove processing.

Further, although the position accuracy of the air dynamic pressure bearing is high due to the thrust contact, the cost is increased because an expensive material such as jewelry is used.

Further, in the oil dynamic pressure bearing, a contact type sliding bearing such as an inexpensive resin or oil-impregnated metal is used for the thrust bearing, and the positioning accuracy in the thrust direction is good, but in the labyrinth or the magnetic fluid holding mechanism. Precise and microfabricated parts are required, resulting in cost increase, and because properties of oil and magnetic fluid change greatly with temperature, it is difficult to guarantee reliability in a wide temperature range against mist scattering.

In the case of an oil dynamic pressure bearing, it is actually difficult to completely prevent mist from adhering to a rotary polygon mirror, a lens, or the like.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bearing structure for a rotary polygon mirror scanning device, which is capable of preventing adverse effects due to foreign matter scattering in a wide temperature range and is inexpensive.

[0011]

In order to achieve the above object, the present invention employs the following means. That is,
The bearing structure of the rotary polygon mirror scanning device according to claim 1, wherein the bearing structure of the rotary polygon mirror scanning device includes a rotary polygon mirror body that reflects light while rotating with respect to the base portion. A fixed shaft is provided, and a bearing portion is provided on the rotary polygon mirror side, and at least a contact portion of the fixed shaft with the bearing portion is made of a metal material, and at least a contact portion of the bearing portion with the fixed shaft is provided. It is characterized in that it is made of a resin material, and wear powder generated by friction between the fixed shaft and the bearing portion is adhered to the fixed shaft or the bearing portion by frictional charging.

According to a second aspect of the present invention, there is provided a bearing structure for a rotary polygon mirror scanning device comprising a rotary polygon mirror body for reflecting light while rotating with respect to a base portion. A fixed shaft is provided on the base part side, a bearing part is provided on the rotary polygon mirror side, and at least a contact portion of the fixed shaft with the bearing part is made of a resin material, and at least the fixed shaft of the bearing part is provided. The contact portion is made of a metal material, and abrasion powder generated by friction between the fixed shaft and the bearing portion is attached to the fixed shaft or the bearing portion by frictional charging.

According to a third aspect of the present invention, there is provided a bearing structure for a rotary polygon mirror scanning device, which comprises a rotary polygon mirror scanning device for reflecting light while rotating with respect to a base portion. A rotary shaft is provided on the rotary polygon mirror side, a bearing part is provided on the base part side, and at least a contact portion of the rotary shaft with the bearing part is made of a metal material, and at least the rotary shaft of the bearing part. It is characterized in that the contact portion with is made of a resin material, and the abrasion powder generated by the friction between the rotating shaft and the bearing portion is adhered to the rotating shaft or the bearing portion by frictional charging.

According to a fourth aspect of the present invention, there is provided a bearing structure for a rotary polygon mirror scanning device, the bearing structure for a rotary polygon mirror scanning device comprising a rotary polygon mirror body for reflecting light while rotating with respect to a base portion. A rotary shaft is provided on the rotary polygon mirror side, a bearing part is provided on the base part side, and at least a contact portion of the rotary shaft with the bearing part is made of a resin material, and at least the rotary shaft of the bearing part. It is characterized in that the contact portion with is made of a metal material, and the abrasion powder generated by the friction between the rotary shaft and the bearing portion is adhered to the rotary shaft or the bearing portion by frictional charging.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view showing a bearing structure of a rotary polygon mirror scanning device according to a first embodiment. As shown in the figure, a base member 1 made of an insulating material
A fixed shaft 2 is fixed to the shaft by projecting upward. Further, the fixed shaft 2 is formed with a groove 2a for generating an air dynamic pressure. The groove 2a can improve the stability of rotation of the fixed shaft 2. A rotary polygonal mirror body 5, which is a flange member including a thrust bearing 4 and a radial bearing 3, is rotatably supported on the fixed shaft 2.

The thrust bearing 4 is composed of a thrust bearing plate 4 which is a slide bearing, and the thrust bearing plate 4 is in sliding contact with the top of the fixed shaft 2. Further, the radial bearing 3 is formed so as to have a slight gap between the side surface of the fixed shaft 2 and the side face of the fixed shaft 2, for example, a gap of about 5 μm. 3 and the fixed shaft 2 are configured to be in a non-contact state.

In the first embodiment, the fixed shaft 2 is made of a metal material, and the thrust bearing 4 and the radial bearing 3 are made of a resin material. As the metal material forming the fixed shaft 2,
Stainless steel was used and its diameter was 4.5 mmφ. As the resin material forming the thrust bearing 4 and the radial bearing 3, a mixture of polyimide resin for enhancing heat resistance, graphite for enhancing abrasion resistance, and Teflon for enhancing lubricity was used. .

The operation of the first embodiment will be described. When the motor is rotating, the radial bearing 3 is brought into a non-contact state with the fixed shaft 2 due to the effect of pneumatic pressure, and the thrust bearing 4 is brought into contact rotation with the fixed shaft 2. At this time, the resin thrust bearing 4 is worn due to contact rotation with the metal fixed shaft 2, and abrasion powder 6 (see FIG. 3) continues to be gradually generated with the lapse of use time.

At the same time, the thrust bearing 4 and the fixed shaft 2 are rotated by the contact rotation between the resin thrust bearing 4 and the metal fixed shaft 2.
Generates static electricity, and the rotary polygonal mirror body 5 is electrically insulated from other parts, so that the rotary polygonal mirror body 5 is charged. The abrasion powder 6 generated from the thrust bearing 4 by this static electricity is attracted to the vicinity of the contact portion between the thrust bearing 4 and the fixed shaft 2, as shown in FIG.

When the motor is stopped, both the radial bearing 3 and the thrust bearing 4 are in contact with the fixed shaft 2. However, since the contact points are metal and resin, they are electrically insulated. Therefore, the charged static electricity is not discharged in a short time, and the suction action time of the abrasion powder 6 due to the static electricity becomes sufficiently longer than the motor rotation stop time, and the abrasion powder 6 is absorbed by the thrust bearing 4 and the fixed shaft 2. Stay near the contact area of.

Therefore, the rotary polygon mirror scanning device is rotated and
Even after repeated stoppages, the abrasion powder 6 generated from the thrust bearing 4 remains in the vicinity of the contact portion between the thrust bearing 4 and the fixed shaft 2, and is reflected on the reflecting surface 5a of the rotary polygon mirror 5 and the laser scanner optical system lens such as the fθ lens. There is no scattering to impair the optical characteristics.

That is, in the structure in which the bearing formed by the combination of the air dynamic pressure radial bearing 3 and the contact type slide thrust bearing 4 is supported by the fixed shaft 2, the bearings 3 and 4 are made of a resin material, and the fixed shaft 2 is made of a metal material. Since it is composed of, it is possible to prevent the abrasion powder due to the contact abrasion of the thrust bearing 4 from scattering to the outside of the bearings 3 and 4.

Further, the thrust bearing 4 is an inexpensive resin plate having a simple shape and does not require any particular component for preventing the abrasion powder 6 from scattering, so that the bearing can be manufactured at a low cost.

In the first embodiment described above, since the metal fixed shaft 2 is fixed to the base member 1 side, the rigidity of the rotary shaft is higher than that of the other embodiments.

Further, resin material products (radial bearing 3, thrust bearing 4) which are replaced by abrasion as in the first embodiment.
Is on the side of the rotary polygon mirror that can be easily removed, so that the effect of facilitating replacement can be obtained.

FIG. 2 is a longitudinal sectional view showing the bearing structure of the rotary polygon mirror scanning device according to the second embodiment. As shown in the figure, a fixed shaft 2 is fixed to a base member 1 made of an insulating material so as to project upward. Then, the fixed shaft 2 is provided with fins or grooves for generating air dynamic pressure as required. A rotary polygonal mirror body 5 including a thrust bearing 4 and a radial bearing 3 is rotatably supported on the fixed shaft 2.

The thrust bearing 4 is composed of a thrust bearing plate 4 which is a slide bearing, and the thrust bearing plate 4 is in sliding contact with the top of the fixed shaft 2. Further, the radial bearing 3 is formed so as to have a slight gap with the side surface of the fixed shaft 2, for example, a gap of about 5 μm,
When the rotary polygon mirror body 5 is rotating, the radial bearing 3 and the fixed shaft 2 are brought into non-contact with each other due to air dynamic pressure.

In the second embodiment, the thrust bearing 4 and the radial bearing 3 are made of a metal material, and the fixed shaft 2 is made of a resin material. Stainless steel was used as the metal material forming the thrust bearing 4 and the radial bearing 3. As the resin material forming the fixed shaft 2, a mixture of polyimide resin for increasing heat resistance, graphite for increasing abrasion resistance, and Teflon for increasing lubricity was used.

Explaining the operation of the second embodiment, as in the first embodiment, when the motor is rotating, the radial bearing 3 is brought into non-contact with the fixed shaft 2 due to the air dynamic pressure effect, and the thrust bearing 4 is fixed. And contact rotation. At this time, the fixed shaft 2 made of resin is worn by contact rotation with the thrust bearing 4 made of metal, and wear powder 6 continues to be gradually generated with the lapse of use time.

At the same time, the contact rotation between the metal thrust bearing 4 and the resin fixed shaft 2 causes the thrust bearing 4 and the fixed shaft 2 to rotate.
Generates static electricity, and the rotary polygon mirror 15 is charged with the rotary polygon mirror 15 because it is insulated from other components. The abrasion powder 6 generated from the thrust bearing 4 due to the static electricity is attracted to the vicinity of the contact portion between the thrust bearing 4 and the fixed shaft 2 as in the first embodiment.

When the motor is stopped, both the radial bearing 3 and the thrust bearing 4 are in contact with the fixed shaft 2. However, since the contact points are metal and resin, they are electrically insulated. Therefore, the charged static electricity is not discharged in a short time, and the suction action time of the abrasion powder 6 due to the static electricity becomes sufficiently longer than the motor rotation stop time, and the abrasion powder 6 is absorbed by the thrust bearing 4 and the fixed shaft 2. Stay near the contact area of.

Therefore, the rotary polygon mirror scanning device is rotated and
Even after repeated stoppages, the abrasion powder 6 generated from the thrust bearing 4 remains in the vicinity of the contact portion between the thrust bearing 4 and the fixed shaft 2, and is reflected on the reflecting surface 5a of the rotary polygon mirror 5 and the laser scanner optical system lens such as the fθ lens. There is no scattering to impair the optical characteristics.

That is, in the structure in which the fixed shaft 2 supports the bearing formed by the combination of the air dynamic radial bearing 3 and the contact type slide thrust bearing 4, the bearings 3 and 4 are made of a metal material and the fixed shaft 2 is made of a resin material. Since it is constituted by, it is possible to prevent the abrasion powder due to the contact abrasion of the fixed shaft 2 from scattering to the outside of the bearings 3 and 4.

Further, the thrust bearing 4 is an inexpensive metal plate having a simple shape and does not require any particular component for preventing the abrasion powder 6 from scattering, so that the bearing can be manufactured at a low cost.

FIG. 4 is a longitudinal sectional view showing the bearing structure of the rotary polygon mirror scanning device according to the third embodiment. As shown in the figure, a thrust bearing 14 and a radial bearing 13 are fixed to a base member 11 made of an insulating material. The thrust bearing 14 and the radial bearing 13 include a rotary shaft 12
A rotary polygon mirror body 15 including is supported rotatably.

The thrust bearing 14 is composed of a thrust bearing plate 4 which is a sliding bearing, and the thrust bearing plate 4 is in sliding contact with the top of the rotary shaft 12.
Further, the radial bearing 13 is formed so as to have a slight clearance, for example, a clearance of about 5 μm, between the radial bearing 13 and the side surface of the rotary shaft 12, and when the rotary polygon mirror body 15 is rotating, the radial bearing is driven by air dynamic pressure. The rotary shaft 12 and the rotary shaft 13 are not in contact with each other.

In the third embodiment, the rotary shaft 12 is made of a metal material, and the thrust bearing 14 and the radial bearing 13 are made of a resin material. Stainless steel is used as the metal material of the rotating shaft 12, and its diameter is 4.5 mm.
φ. Further, the thrust bearing 14 and the radial bearing 1
As the resin material constituting 3, a mixture of polyimide resin for enhancing heat resistance, graphite for enhancing abrasion resistance, and Teflon for enhancing lubricity was used.

The operation of the third embodiment will be described. When the motor is rotating, the radial bearing 13 is brought into non-contact with the rotary shaft 12 due to the air dynamic pressure effect, and the thrust bearing 14 is rotated in contact with the rotary shaft 12. At this time, the resin thrust bearing 14 is worn due to contact rotation with the metal rotary shaft 12,
Abrasion powder 6 continues to be generated gradually with the lapse of use time.

At the same time, static electricity is generated in the thrust bearing 14 and the rotary shaft 12 due to contact rotation between the resin thrust bearing 14 and the metal rotary shaft 12, and the rotary polygon mirror 15 is insulated from other parts. Then, the rotary polygon mirror 15 is charged. The abrasion powder 6 generated from the thrust bearing 14 due to this static electricity is attracted to the vicinity of the contact portion between the thrust bearing 14 and the rotary shaft 12, as shown in FIG.

When the motor is stopped, both the radial bearing 13 and the thrust bearing 14 are in contact with the rotary shaft 12, but since the contact points are metal and resin, they are electrically insulated. Therefore, the charged static electricity is not discharged in a short time, the suction action time of the abrasion powder 6 due to the static electricity becomes sufficiently longer than the motor rotation stop time, and the abrasion powder 6 is absorbed by the thrust bearing 14 and the rotary shaft 12. Stay near the contact area of.

Therefore, the rotary polygon mirror scanning device is rotated and
Even after repeated stoppages, the abrasion powder 6 generated from the thrust bearing 14 remains near the contact portion between the thrust bearing 14 and the rotary shaft 12, and is reflected on the reflecting surface 15a of the rotary polygon mirror 15 and the laser scanner optical system lens such as the fθ lens. There is no scattering to impair the optical characteristics.

That is, in the structure in which the rotary shaft 12 is supported by the bearing formed by the combination of the air dynamic pressure radial bearing 13 and the contact type slide thrust bearing 14, the bearings 13 and 14 are made of resin material, and the rotary shaft 12 is made of metal material. Since the bearings 13 and 14 are composed of
It can be prevented from scattering to the outside.

Further, the thrust bearing 14 is an inexpensive resin plate having a simple shape and does not require any particular component for preventing the abrasion powder 6 from scattering, so that the bearing can be manufactured at low cost.

FIG. 5 is a longitudinal sectional view showing the bearing structure of the rotary polygon mirror scanning device according to the fourth embodiment. As shown in the figure, a thrust bearing 14 and a radial bearing 13 are fixed to a base member 11 made of an insulating material. The thrust bearing 14 and the radial bearing 13 include a rotary shaft 12
A rotary polygon mirror body 15 including is supported rotatably.

The thrust bearing 14 is composed of a thrust bearing plate 4 which is a slide bearing, and the thrust bearing plate 4 is adapted to make sliding contact with the top of the rotary shaft 12.
Further, the radial bearing 13 is formed so as to have a slight clearance, for example, a clearance of about 5 μm, between the radial bearing 13 and the side surface of the rotary shaft 12, and when the rotary polygon mirror body 15 is rotating, the radial bearing is driven by air dynamic pressure. The rotary shaft 12 and the rotary shaft 13 are not in contact with each other.

In the fourth embodiment, the thrust bearing 14 and the radial bearing 13 are made of a metal material, and the rotary shaft 12 is made of a resin material. Stainless steel was used as the metal material forming the thrust bearing 14 and the radial bearing 13. As the resin material forming the rotating shaft 12, a mixture of polyimide resin for enhancing heat resistance, graphite for enhancing abrasion resistance, and Teflon for enhancing lubricity was used.

Explaining the operation of the fourth embodiment, as in the third embodiment, when the motor is rotating, the radial bearing 13 is brought into non-contact with the rotary shaft 12 due to the air dynamic pressure effect, and the thrust bearing 14 is rotated by the rotary shaft 12. And contact rotation. At this time, the rotary shaft 12 made of resin is worn by contact rotation with the thrust bearing 14 made of metal, and wear powder 6 continues to be gradually generated with the lapse of use time.

At the same time, contact rotation between the metal thrust bearing 14 and the resin rotary shaft 12 causes static electricity to be generated in the thrust bearing 14 and the rotary shaft 12, and the rotary polygon mirror 15 is insulated from other parts. Then, the rotary polygon mirror 15 is charged. The abrasion powder 6 generated from the thrust bearing 14 due to the static electricity is attracted to the vicinity of the contact portion between the thrust bearing 14 and the rotary shaft 12 as in the third embodiment.

When the motor is stopped, both the radial bearing 13 and the thrust bearing 14 are in contact with the rotary shaft 12, but since the contact points are metal and resin, they are electrically insulated. Therefore, the charged static electricity is not discharged in a short time, the suction action time of the abrasion powder 6 due to the static electricity becomes sufficiently longer than the motor rotation stop time, and the abrasion powder 6 is absorbed by the thrust bearing 14 and the rotary shaft 12. Stay near the contact area of.

Therefore, the rotary polygon mirror scanning device is rotated and
Even after repeated stoppages, the abrasion powder 6 generated from the thrust bearing 14 remains near the contact portion between the thrust bearing 14 and the rotary shaft 12, and is reflected on the reflecting surface 15a of the rotary polygon mirror 15 and the laser scanner optical system lens such as the fθ lens. There is no scattering to impair the optical characteristics.

That is, in the structure in which the rotary shaft 12 is supported by the bearing formed by the combination of the air dynamic radial bearing 13 and the contact type slide thrust bearing 14, the bearings 13 and 14 are made of metal material, and the rotary shaft 12 is made of resin material. Since it is composed of
4 can be prevented from scattering.

Further, since the thrust bearing 14 is an inexpensive, simple-shaped metal plate and does not require any particular component for preventing the abrasion powder 6 from scattering, the bearing can be manufactured at low cost.

The bearing structure of the rotary polygon mirror scanning device described above is particularly suitable for high-speed rotation of 20000 rpm or more.

In the above embodiment, one of the bearing (radial bearing and thrust bearing) and the fixed shaft is made of a metal material and the other is made of a resin material. However, at least the contact portion of the bearing with the fixed shaft and At least one of the contact portions of the fixed shaft with the bearing may be made of a metal material and the other may be made of a resin material. For example, the fixed shaft or the rotary shaft may be covered with a resin material around the metal rod.

[0055]

As described above, according to the first aspect of the invention, the fixed shaft on the fixed side is made of a metal material and the bearing on the rotation side is made of a resin material. It is possible to prevent the abrasion powder from being attracted due to the static electricity charged in the contact portion of and to be scattered. Further, since it is not necessary to use expensive parts as in the prior art, it is possible to provide an inexpensive bearing structure for a rotary polygon mirror scanning device.

According to the second aspect of the invention, since the fixed shaft on the fixed side is made of a resin material and the bearing on the rotating side is made of a metal material, the contact portion between the fixed shaft and the bearing is charged. It is possible to prevent the abrasion powder from being attracted by the static electricity and scattered. Further, since it is not necessary to use expensive parts as in the prior art, it is possible to provide an inexpensive bearing structure for a rotary polygon mirror scanning device.

According to the third aspect of the invention, since the rotating shaft on the rotating side is made of a metal material and the bearing on the stationary side is made of a resin material, the contact portion between the rotating shaft and the bearing is charged. It is possible to prevent the abrasion powder from being attracted by the static electricity and scattered. Further, since it is not necessary to use expensive parts as in the prior art, it is possible to provide an inexpensive bearing structure for a rotary polygon mirror scanning device.

Further, according to the invention of claim 4, since the rotating shaft on the rotating side is made of the resin material and the bearing on the stationary side is made of the metal material, the contact portion between the rotating shaft and the bearing is charged. It is possible to prevent the abrasion powder from being attracted by the static electricity and scattered. Further, since it is not necessary to use expensive parts as in the prior art, it is possible to provide an inexpensive bearing structure for a rotary polygon mirror scanning device.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing a bearing structure of a rotary polygon mirror scanning device according to a first embodiment of the invention.

FIG. 2 is a longitudinal sectional view showing a bearing structure of a rotary polygon mirror scanning device according to a second embodiment of the invention.

FIG. 3 is an enlarged view of a main part of FIG. 1 showing a state in which wear powder is attached.

FIG. 4 is a longitudinal sectional view showing a bearing structure of a rotary polygon mirror scanning device according to a third embodiment of the invention.

FIG. 5 is a vertical sectional view showing a bearing structure of a rotary polygon mirror scanning device according to a fourth embodiment of the invention.

FIG. 6 is an enlarged view of an essential part of FIG. 4 showing a state in which wear powder is attached.

[Explanation of symbols]

 1 Base Part 2 Fixed Shaft 3 Radial Bearing 4 Thrust Bearing 5 Rotating Polyhedral Mirror 6 Wear Particles 11 Base Part 12 Rotating Axis 13 Radial Bearing 14 Thrust Bearing 15 Rotating Polyhedral Mirror

Claims (4)

[Claims] 1. A bearing structure of a rotary polygon mirror scanning device comprising a rotary polygon mirror body that reflects light while rotating with respect to a base portion, wherein a fixed shaft is provided on the base portion side, and the rotary polygon mirror is provided. A bearing portion is provided on the body side, and at least a contact portion of the fixed shaft with the bearing portion is made of a metal material,
At least a contact portion of the bearing portion with the fixed shaft is made of a resin material, and abrasion powder generated by friction between the fixed shaft and the bearing portion is adhered to the fixed shaft or the bearing portion by frictional charging. Bearing structure of rotary polygon mirror scanning device. 2. A bearing structure of a rotary polygon mirror scanning device comprising a rotary polygon mirror body that reflects light while rotating with respect to a base portion, wherein a fixed shaft is provided on the base portion side, and the rotary polygon mirror side is provided. A bearing portion is provided on the fixed shaft, at least a contact portion of the fixed shaft with the bearing portion is made of a resin material, and at least a contact portion of the bearing portion with the fixed shaft is made of a metal material. A bearing structure of a rotary polygon mirror scanning device, characterized in that abrasion powder generated by friction with a portion is attached to a fixed shaft or a bearing portion by triboelectrification. 3. A bearing structure of a rotary polygon mirror scanning device comprising a rotary polygon mirror body that reflects light while rotating with respect to a base portion, wherein a rotary shaft is provided on the rotary polygon mirror body side, and the base portion is provided. A bearing portion is provided on the side, and at least a contact portion of the rotating shaft with the bearing portion is made of a metal material,
At least a contact portion of the bearing portion with the rotating shaft is made of a resin material, and abrasion powder generated by friction between the rotating shaft and the bearing portion is adhered to the rotating shaft or the bearing portion by frictional charging. Bearing structure of rotary polygon mirror scanning device. 4. A bearing structure of a rotary polygon mirror scanning device comprising a rotary polygon mirror body that reflects light while rotating with respect to a base portion, wherein a rotary shaft is provided on the rotary polygon mirror body side, and the base portion is provided. A bearing portion is provided on the side, and at least a contact portion of the rotating shaft with the bearing portion is made of a resin material,
At least a contact portion of the bearing portion with the rotating shaft is made of a metal material, and abrasion powder generated by friction between the rotating shaft and the bearing portion is attached to the rotating shaft or the bearing portion by frictional charging. Bearing structure of rotary polygon mirror scanning device.