JP2002267978A - Light deflector and light deflecting and scanning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light deflector and a light deflecting and scanning device capable of restraining a vibration caused in a light deflecting member. SOLUTION: A vibration restraining plate 12 is arranged on the opposite side to a reflection surface being the light deflecting surface of a reflecting mirror 6 with respect to the central axis of the mirror 6 and a mirror holder 7, and the moment in direction B is normally generated to reduce the moment in direction A generated in the conventional manner, thereby, rotational vibration is restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical deflecting device such as a folding mirror unit used in an image forming apparatus such as a copying machine and an optical deflecting scanning device having the same.

[0002]

2. Description of the Related Art Conventionally, a laser scanner unit as a light deflection scanning device used in an image forming apparatus is shown in FIGS.
This will be described with reference to FIG. FIG. 4 is a schematic diagram of the laser scanner unit, and FIG. 5 is a schematic diagram of the mirror unit in FIG.

In FIG. 4, an optical stay 1 is fixed between front and rear plates of an image forming apparatus. In the optical stay 1,
Each optical unit is loaded. On the optical stay 1, a laser light emitting unit 2, a cylindrical lens 3, a laser light emitting unit 2, a polygon mirror 4, a rotary reflecting unit for deflecting the laser light emitted from the laser light emitting unit 2 in the main scanning direction, and an fθ lens 5, A folding mirror unit (hereinafter, referred to as a mirror unit) as a light deflecting device having a folding mirror 6 as a light deflecting member is provided.

The folding mirror 6 of the mirror unit deflects the laser beam scanned by the polygon mirror 4 to a photosensitive drum (not shown) as shown in FIG. In the mirror unit, the folding mirror 6 is held by a mirror holder 7 which is a holding member, and the mirror holder 7 is supported by a support plate 8 which is a support member.
Is fixed on the optical stay 1.

Here, the folding mirror 6 and the mirror holder 7 are fixed by a fixing plate 9. Further, the mirror holder 7 has a plate spring 10 as an urging means at both ends in the longitudinal direction.
Urged by the support plate 8. 10a is a leaf spring 1
Numeral 0 indicates a biasing position provided at the bending root of the mirror holder 7 for biasing the mirror holder 7. The angle of the turning mirror 6 can be adjusted by a mirror angle adjusting screw 11.

In an image forming apparatus equipped with such a laser scanner unit, emitted laser light is scanned in the main scanning direction by a polygon mirror 4 according to image information scanned by an image reading device, and is exposed by a return mirror 6. The light is deflected onto the drum.

As described above, an electrostatic latent image is formed on a pre-charged photosensitive drum by the laser beam emitted from the laser scanner unit, and then the electrostatic latent image is developed into a toner image. The image is transferred to a sheet and an image is formed on the sheet.

[0008]

However, in the case of the above-described prior art, the following problems have occurred.

In the mirror unit, since both ends in the longitudinal direction of the mirror holder 7 are urged against the supporting plate 8 by the leaf spring 10, a moment in the direction A shown in FIG. Vibration from the source caused the turning mirror 6 to rotate in the A direction.

For this reason, the folding mirror 6 generally exhibits a behavior in which the rotational vibration in the direction A and the primary bending vibration about the both ends of the mirror holder 7 are superimposed.

In particular, since the rotational vibration of the folding mirror 6 in the direction A greatly affects the fluctuation of the laser irradiation position on the photosensitive drum surface, it is essential to suppress the rotational vibration in the direction A in order to improve the image quality.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to provide an optical deflecting device and an optical deflecting scanning device for suppressing vibration generated in an optical deflecting member. Is to do.

[0013]

According to the present invention, there is provided a light deflecting device for deflecting light, a holding member for holding the light deflecting member, and a holding member. A supporting member for supporting the light deflecting member via biasing means at both ends in the longitudinal direction, and the holding member on a side opposite to a light deflecting surface of the light deflecting member with respect to a center of gravity of the light deflecting member and the holding member. And a reinforcing member attached along the longitudinal direction of the above.

It is preferable that the reinforcing member is made of metal and has been subjected to at least one bending process along a longitudinal direction.

Preferably, the reinforcing member has a substantially U-shaped cross section.

It is preferable that the reinforcing member is fixed to the holding member with at least one screw.

A light deflecting member for deflecting light, a holding member for holding the light deflecting member, and a supporting member for supporting the holding member via urging means at both ends in the longitudinal direction; The biasing unit biases the holding member toward the support member on a light deflection surface side of the light deflection member with respect to a longitudinal center of gravity of the light deflection member and the holding member.

It is preferable that the urging means is urged toward the support member by substantially the center of gravity of the light deflecting member and the holding member.

In the light deflection scanning device according to the present invention, the laser light emitting means, the rotary reflecting means for scanning the laser light emitted by the laser light emitting means in the main scanning direction, and the main scanning direction by the rotary reflecting means. And the above-described light deflecting device that deflects and emits the laser light deflected to.

[0020]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The materials, shapes, relative arrangements, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

(First Embodiment) A first embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram showing a mirror unit as a light deflecting device according to the present embodiment. Since the mirror unit of the present embodiment is applied to the laser scanner unit as the optical deflection scanning device in FIG. 4 similarly to the related art, the description of the laser scanner unit and the image forming apparatus is omitted here. I do.

In FIG. 1, a folding mirror 6 of the mirror unit deflects a laser beam scanned by the polygon mirror 4 of FIG. 4 to a photosensitive drum (not shown). In the mirror unit, the folding mirror 6 is held by a mirror holder 7 as a holding member, and the mirror holder 7 is fixed on the optical stay 1 in FIG. 4 by a support plate 8 as a support member.

The folding mirror 6 and the mirror holder 7 are fixed by a fixing plate (not shown) and integrated. The mirror holder 7 is urged at both ends in the longitudinal direction by a leaf spring 10 as an urging means against the support plate 8 at an urging position 10a at the bending root of the mirror holder 7. The angle of the folding mirror 6 can be adjusted by a mirror angle adjusting screw (not shown).

In this embodiment, a vibration suppressing plate 12 as a metal reinforcing member having a U-shaped cross section and extending in the main scanning direction, which is a longitudinal direction of the mirror holder 7, is fixed to the mirror holder 7. The vibration suppressing plate 12 is fixed to the mirror holder 7 with screws at a plurality of positions along the main scanning direction.

The vibration suppressing plate 12 is disposed on the right side in the drawing on the opposite side of the reflection mirror which is the light deflecting surface of the folding mirror 6 with respect to the center of gravity of the folding mirror 6 and the mirror holder 7.

For this reason, both ends of the mirror holder 7 in the longitudinal direction are supported on the vibration suppressing plate 12 by the leaf spring 10.
, A moment in the direction B shown in FIG. 1 is constantly generated.

On the other hand, no moment is generated by the supporting plate 8 in the direction B and no rotational vibration is generated in the folding mirror 6 and the mirror holder 7, but only the urging force of the leaf spring 10 acts in the direction A to cause the moment. Is generated constantly and rotational vibration is easily generated.
The moment in the direction A shown in the figure due to the both ends in the longitudinal direction being urged against the support plate 8 by the leaf spring 10 steadily occurs, and the return mirror 6 is rotated in the direction A by the vibration from each drive source. A vibrating vibration is also about to occur.

Therefore, by providing the vibration suppressing plate 12 fixed to the mirror holder 7, a moment in the B direction, which reduces the moment in the A direction conventionally generated, can be generated, and the rotational vibration can be suppressed.

Further, the magnitude of the moment in the direction B can be changed depending on the thickness, material, etc. of the vibration suppressing plate 12, so that by suitably adjusting it, the rotational vibration can be avoided while avoiding resonance with other driving sources. Can be suppressed.

Further, by fixing the vibration suppressing plate 12 to the mirror holder 7 along the main scanning direction, it is possible to suppress the bending vibration which has conventionally occurred at both ends of the mirror holder 7 as a fulcrum.

The vibration suppression plate 12 is formed in a U-shaped cross section, and has a strength sufficient to suppress bending vibration with both ends of the mirror holder 7 as fulcrums. Further, the shape for increasing the strength is not limited to this, and a shape obtained by performing at least one bending process along the longitudinal direction is also suitable.

(Second Embodiment) FIG. 2 is a schematic view showing a mirror unit according to a second embodiment. In the first embodiment, the vibration suppressing plate is provided. In the present embodiment, the first position is changed by changing the biasing position 10a of the leaf spring 10 with respect to the center of gravity of the return mirror 6 and the mirror holder 7. An effect similar to that of the embodiment is obtained. In addition,
The same components as those of the prior art and the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 2, the mirror unit has an urging position 1 for urging the mirror holder 7 against the support plate 8 with a leaf spring 10.
0a is performed not on the bending root of the mirror holder 7 but on the reflection mirror side of the return mirror 6 with respect to the return mirror 6 and the center of gravity of the mirror holder 7 in the figure. Then, the center of gravity of the folding mirror 6 and the mirror holder 7 is
It is located on the right side of the drawing from the biasing position 10a of the leaf spring 10.

For this reason, since both ends in the longitudinal direction of the mirror holder 7 are urged against the supporting plate 8 by the leaf spring 10, the moment in the direction B shown in FIG. As in the embodiment, it is possible to reduce the moment in the direction A, which has conventionally occurred, and to suppress the rotational vibration.

In particular, the biasing of the leaf spring 10 against the supporting plate 8 is performed by the substantially center of gravity axis of the return mirror 6 and the mirror holder 7, so that the moment in the direction A and the moment in the direction B become equal to each other. In addition, rotational vibration can be suppressed.

(Third Embodiment) FIG. 3 is a schematic view showing a mirror unit according to a third embodiment. In the present embodiment, similarly to the second embodiment, the same effect as in the first embodiment is obtained by changing the biasing position 10a of the leaf spring 10. The same components as those of the prior art and the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 3, the mirror unit has a mirror 6 fixed at both ends to a mirror holder 7 by mirror stands 13, and a leaf spring 10 provided by an urging stand 14 provided on the opposite side of the reflection surface of the mirror 6. Urges the mirror holder 7 toward the support plate 8.

More specifically, the leaf spring 10 is inserted between the mirror base 13 and the urging table 14, and the leaf spring 10
Is performed between the center of gravity axis of the mirror holder 7 in the longitudinal direction and the center of gravity of the return mirror 6. The mirror holder 7 is heavier than the return mirror 6, and the biasing position 10 a of the leaf spring 10 is closer to the center of gravity of the return mirror 6 than the center of gravity of the mirror holder 7.

Therefore, the moment in the direction B shown in FIG. 3 is also constantly generated, and the same effect as in the second embodiment can be obtained.

[0040]

As described above, the present invention suppresses the vibration generated in the light deflecting member of the light deflecting scanning device applied to the image forming apparatus such as a copying machine, and reduces the laser irradiation position on the photosensitive drum surface. Can be suppressed, and the image quality can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a mirror unit according to a first embodiment.

FIG. 2 is a schematic diagram illustrating a mirror unit according to a second embodiment.

FIG. 3 is a schematic diagram illustrating a mirror unit according to a third embodiment.

FIG. 4 is a schematic view showing a laser scanner unit.

FIG. 5 is a schematic diagram showing a mirror unit of the related art.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 optical stay 2 laser emitting unit 3 cylindrical lens 4 polygon mirror 5 fθ lens 6 folding mirror 7 mirror holder 8 support plate 9 fixing plate 10 leaf spring 10a biasing position 11 mirror angle adjusting screw 12 vibration suppressing plate 13 mirror stand 14 biasing Table

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/113 H04N 1/04 104A

Claims (7)

[Claims] 1. A light deflecting member for deflecting light, a holding member for holding the light deflecting member, a supporting member for supporting the holding member via urging means at both ends in a longitudinal direction, and the light deflecting. A light-deflecting member provided on a side opposite to a light-deflecting surface of the light-deflecting member with respect to a center of gravity of the member and the holding member, the reinforcing member being attached along a longitudinal direction of the holding member. apparatus. 2. The optical deflecting device according to claim 1, wherein the reinforcing member is made of metal and has been subjected to at least one bending process along a longitudinal direction. 3. The light deflecting device according to claim 1, wherein the reinforcing member has a substantially U-shaped cross section. 4. The optical deflecting device according to claim 1, wherein the reinforcing member is fixed to the holding member with at least one screw. 5. A light deflecting member for deflecting light, a holding member for holding the light deflecting member, and a supporting member for supporting the holding member via urging means at both ends in the longitudinal direction. The light biasing means biases the holding member toward the support member on a light deflection surface side of the light deflection member with respect to a longitudinal center of gravity of the light deflection member and the holding member. apparatus. 6. The light deflecting device according to claim 5, wherein the urging means is urged against the support member by substantially the center of gravity of the light deflecting member and the holding member. 7. A laser light emitting means, a rotary reflecting means for scanning the laser light emitted by the laser light emitting means in the main scanning direction, and a laser beam deflected in the main scanning direction by the rotary reflecting means. An optical deflection scanning device comprising: the optical deflection device according to claim 1.