JP2003121774A - Optical scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical scanner restraining the vibration of a reflection member without making a vibration restraining member intervene in the scanning area of the reflection member. SOLUTION: In this optical scanner 10, the end face of a reflection mirror 20 at the end in a beam scanning direction is made to abut on a regulating member 38. Therefore, the movement of the end face is regulated at flexural oscillation of the mirror 20, and the mirror 20 is not vibrated from the supporting position of a supporting member 28 for the mirror 20 to the end face (the abutting surface of the member 38). As a result, the flexural oscillation of the mirror 20 is restrained. Namely, the vibration is restrained with simple constitution without making the vibration restraining member intervene in a beam scanning area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, by scanning and exposing a light beam on a scanning object based on image information,
The present invention relates to an optical scanning device used in an electrophotographic device such as a laser printer for recording an image or a digital copying machine.

[0002]

2. Description of the Related Art An optical scanning device used in a conventional laser printer or electrophotographic device will be described with reference to FIG.

The optical scanning device 300 includes a light source 302 that emits a light beam L based on image information, and the light source 302.
A polygon mirror 304 for deflecting the light beam L emitted from the light source in a predetermined direction, an imaging lens system 306, and a reflection mirror 310 for guiding the light beam L to the scanned object 308, each cover not shown. It is arranged in the housing 312 that is closed by the. The housing 312 is fixed to the frame 314 with a screw 316 and incorporated in the electrophotographic apparatus.

In the electrophotographic apparatus in which the optical scanning device 300 is arranged, well-known charging means, developing means, and transfer means are arranged on the frame 314 around the scanned object 308, and the scanned object 308. The toner image formed on the recording sheet is transferred to a recording sheet, and the toner image is fixed by a fixing unit to form an image on the recording sheet.

As described above, in the optical scanning device 300 disposed inside the electrophotographic apparatus, the vibrations of the drive motors for the polygon mirror 304 and the scanned object 308 and the sheet conveying means inside the electrophotographic apparatus are transmitted to the housing 312. . As a result, the reflection mirror 310 arranged in the housing 312.
However, as shown in the schematic view of FIG. 22, a flexural vibration that oscillates between the positions of the broken lines with respect to the positions of the regular solid lines is generated, and
Due to the fluctuation of 10 A, the optical path of the light beam L deviates from the normal position, causing a scanning line deviation on the scanned object 308, resulting in poor image quality.

As a means for solving this problem, for example,
In the optical scanning device disclosed in Japanese Patent Laid-Open No. 11-187224 (hereinafter referred to as Conventional Example 1), as shown in FIGS. 23A and 23B, a pair of supports 320 formed in the housing.
The reflection mirror 3 is provided in the holes 322A and 322B of A and 320B.
24 is inserted and the projection 326A is formed so as to project into the hole 322A on the reflection surface 324A side of the reflection mirror 324, and the projections 326B and 326C formed so as to project into the hole 322B.
And a surface 324B of the reflection mirror 324 opposite to the reflection surface 324A (hereinafter referred to as a back surface) 324B inserted into the holes 322A and 322B.
Press with A, 328B. Further, the support 320
Supporting portions 330A and 330B protruding from the reflecting surface 324A at a predetermined clearance X (see FIG. 23B) are provided in the hole 322A of A, and the supporting portions 330A and 330 are provided.
An adhesive 332 is applied between B and the reflecting surface 324A.

Conventionally, as shown in FIG. 24A, since the reflecting surface 324A is supported only by the projections 326A to 326C, the reflection mirror 324 (the reflecting surface 324A) contacts the projection 326A by the transmission of vibration. Although it swings in the direction of arrow B around the contact position (see FIG. 24 (B)),
In this configuration, since the supporting portions 330A and 330B are fixed to each other with the adhesive 332, the swing can be prevented.

Another example disclosed in Japanese Patent Application Laid-Open No. 9-120039 (hereinafter referred to as Conventional Example 2) is shown in FIG.
It shows in (B). In this optical scanning device, the reflection mirror-34
Attach the weight 344 to the back surface 342B side of 2, and set the reflection mirror
The resonance frequency of the 342 is changed to approximately 20 Hz from the input frequency of the drive motor for the electrophotographic apparatus and polygon mirror.
By avoiding this, high image quality is achieved.

Another example disclosed in Japanese Patent Laid-Open No. 2-253274 (hereinafter referred to as Conventional Example 3) will be described with reference to FIG.

In this optical scanning device, a pair of support members 3
A buffer member 358 such as rubber or foamed polyurethane is disposed between the housing 356 and a lower surface 354C of the reflecting mirror 354 which is placed on the plate 50 and fixed by the leaf spring 352 and is orthogonal to the reflecting surface 354A of the reflecting mirror 354. Suppresses flexural vibration.

Next, Japanese Unexamined Patent Publication No. 2000-241735 (hereinafter referred to as Conventional Example 4) will be described with reference to FIGS. 27 (A) to (D). In this optical scanning device, FIG.
As shown in, the reflection surface 362A of the reflection mirror 362 is
A pair of support members 364 that support one end of the reflecting surface 362A outside the light beam scanning region S at one point and the other end at two points.
A, 364B and the reflection mirror 362A further outside thereof
Both ends of are supported by support members 366A and 366B. As shown in FIG. 27B, the back surface 362B of the reflection mirror 362 has both ends supported by leaf springs 368A and 368B. The leaf spring 368A has a contact portion 370 that is branched into two.
372, and support members 364A, 36, respectively.
The reflection mirror 362 is pressed against 4B. The leaf spring 368B is similar.

By adopting such a configuration, conventionally,
The maximum amplitude W1 (see FIG. 27C) of the scanning area S of the reflection mirror, which was supported at two points by the supporting members 364A and 364B and the elastic members corresponding thereto, is the same as the supporting member 364.
A, support members 366A, 36 on the outside of the support member 364B.
6B is arranged, the leaf spring 368A from the back surface 362B side,
It is said that the maximum amplitude W2 is suppressed by being pressed by the contact portion 372 of the 368B (FIG. 27).
(D)). Further, the leaf springs 368A and 368B are provided with the contact portions 370 and 372 integrally with each other, so that the cost is reduced.

Furthermore, another example disclosed in Japanese Patent Laid-Open No. 6-324253 (referred to as Conventional Example 5) is shown in FIG.
This will be described with reference to (C). This mirror support mechanism 38
As shown in FIG. 28B, 0 is for inserting and fixing the V-shaped elastic body 388 when the reflection mirror 382 is inserted and fixed in the hole 386 of the wall surface 384.

As shown in FIG. 28 (A), the V-shaped elastic body 388 is provided with an engaging portion 390, a part of which is bent downward on one surface folded back in a V shape. Two projections 392 and 394 of large and small are provided on the other surface (hereinafter, also referred to as a contact surface). Further, a folded-back portion 396 is provided at the tip of this contact surface.

The mirror support mechanism 38 thus constructed
As shown in FIG. 28C, 0 indicates that the elastic body 388 is inserted into the hole 386 after the reflection mirror 382 is inserted into the hole 386.
By inserting it into (the lower part of the reflection mirror 382) and engaging with the wall surface 384 with the engaging portion 390, the large protrusion 3 of the contact surface is formed.
92 supports the reflection mirror 382 and a wall surface 384.
Press on. In addition, the folded portion 396 of the elastic body 382.
Supports the end surface of the reflection mirror 382. When the reflection mirror 382 vibrates in this state (the end face moves from the position indicated by the chain double-dashed line position to the position indicated by the solid line), the elastic body 388 causes the folded portion 396.
When is pressed and deformed, the large projection 392 is rotated as a fulcrum from the two-dot chain line position to the solid line position. As a result, the small protrusion 394 increases the pressure contact force with respect to the reflection mirror 382 and restrains the displacement of the reflection mirror 382, whereby the vibration (amplitude) of the reflection mirror 382 can be suppressed.

[0016]

The above-mentioned conventional examples have the following disadvantages.

In the embodiment of the first conventional example, the reflection mirror 324 is used.
Since the reflection surface 324A in the vicinity of the scanning area is adhered, it is necessary to prevent the adhesive from being accidentally applied to the scanning area, which makes the application work difficult.

Further, in the optical scanning device of the second conventional example, since the weight 344 is attached to the back surface 342B of the reflection mirror 342, the reflection surface 342A of the reflection mirror 342 is distorted, and the light beam characteristic on the scanned object 308 is changed. It could make it worse.

Further, in the optical scanning device of the fourth conventional example, the reflecting mirror 362 is provided to support the outside of the conventional supporting members 364A, 364B by the supporting members 366A, 366B.
Had to be lengthened, and there was a disadvantage that the housing (optical scanning device) became large.

By the way, in the recent optical scanning device, FIG.
As represented by Japanese Patent Application No. 2000-345698 shown in FIG. 0, an optical scanning device in which the optical path of a light beam is complicated has been proposed. Optical scanning device 402 of this electrophotographic device 400
Is a single polygon mirror 403 for four light beams LY corresponding to yellow, magenta, cyan, and black.
LM, LC, LK (hereinafter, also referred to as LY to LK, other reference numerals are the same) are scanned on the respective scanned objects 404Y to 404K, and the transfer belt 40 is moved from each of the scanned objects 404Y to 404K.
A color image is formed by multiple transfer onto No. 6. The light beams LY to L are arranged below the reflection mirrors 408Y to 408K arranged in the optical scanning device 402.
There is an optical path of K, and a cover 412 that closes the housing 410 is located on the upper side. Even in the optical scanning device having such a configuration, it is necessary to suppress the vibration of the reflection mirrors 408Y to 408K in order to perform favorable color image formation. However, the method of the conventional example is difficult because the optical path of the light beam is complicated.

For example, if the method of Conventional Example 3 (installation of a cushioning member) is to be applied, each light beam LY is provided below the reflection mirrors 408Y to 408K of the optical scanning device 402.
Since there are optical paths of LM, LC, and LK, it is difficult to secure a space for installing the buffer member. In addition, the reflection mirror 40
A cover 412 that closes the housing 410 is provided above 8Y to 408K, but it is difficult to increase the rigidity because it is a member that closes the open surface of the housing. Therefore, the cover 412 and the reflection mirrors 408Y to 408K having low rigidity are difficult to increase. It is difficult to achieve the above-mentioned cushioning action even if a cushioning member is interposed therebetween.

Further, in the mirror support mechanism 380 of the conventional example 5, it is not necessary to dispose members in the vertical direction (direction orthogonal to the scanning direction) of the reflection mirror, so the reflection mirror 408Y.
~ 408K, but as shown in FIG.
With respect to the displacement in the lower (-y) direction, the small protrusion 394 regulates the displacement of the reflection mirror 382 to suppress the vibration of the reflection mirror 382 (see FIGS. 29A to 29B), but the upper (). y)
The small projection 394 and the reflection mirror 38 for the displacement in the direction.
Since the vibration directions of 2 are the same (both are upward), the vibration of the reflection mirror 382 cannot be suppressed (FIG. 29 (A) →
(See (C)).

The method of Conventional Example 2 is as described above.
Since the weight 344 is attached to the back surface 342B of the reflection mirror 342, the thickness of the reflection mirror 342 increases.
If the optical path exists below or above the reflection mirror, there is a risk of interfering with the optical path.

In order to solve the above problems, an object of the present invention is to provide an optical system that suppresses the vibration of a reflecting member without interposing a vibration suppressing member in the scanning area (reflecting surface, back surface, orthogonal surface of the reflecting surface) of the reflecting member. It is to provide a scanning device.

[0025]

In order to achieve the above object, an optical scanning device according to claim 1 deflects a light beam emitted from a light source by a polygon mirror, and a reflecting member through an imaging lens system. In the optical scanning device for scanning the object to be scanned by reflecting the light beam on the object to be scanned, a housing for housing each of the optical components, and a light beam reflecting surface at both end portions outside the light beam scanning region in the light beam scanning direction of the reflecting member. Alternatively, the first and second supporting means provided on the housing for supporting the back surface of the reflecting surface and the reflecting surface of the reflecting member supported by the supporting means or the opposite surface of the back surface are pressed to the supporting means side. Pressing means and displacement regulating means for regulating the displacement of at least the end portion of the reflecting member in the light beam scanning direction on the side of the first supporting means. .

The operation of the optical scanning device according to the first aspect will be described.

In this optical scanning device, each optical component is arranged inside the housing, and a light beam emitted from a light source is deflected by a polygon mirror and reflected by a reflecting member via an imaging lens system, whereby the light beam is emitted. Is scanned on the object to be scanned.

In this apparatus, the reflecting member is supported by the first and second supporting means provided on the housing at both ends (outside the light beam scanning region) of the reflecting surface or the back surface of the reflecting surface in the beam scanning direction, and the opposite surface. It is positioned by being pressed from the side toward the support by the pressing means.

Further, since the displacement regulating member regulates the displacement of at least one of the both ends of the reflecting member in the beam scanning direction, the reflecting member is not thickened and the reflection mirror is scanned. The natural frequency of the reflecting mirror can be moved to a high range without interposing a member near the region.

The reason is that, when focusing on the supporting portion of the conventional reflecting member, when the reflecting member vibrates as shown in FIG. 3A, the end portion in the scanning direction of the reflecting member moves as shown in FIG. 3B. do. The natural frequency (Hz) of the reflecting member at this time is f (Hz) = λ ² / 2πL ² × (EI / ρA) ^1/2, where L is the length of the tension, E is the longitudinal elasticity of the tension material. Coefficients, I: Moment of inertia of area, ρ: Density, A: Area of area, and λ is considered to be the support of both ends, so λ: π for the first order, λ: 2π for the second order, third order Λ: 3π, the configuration of the present invention (see FIG. 3 (C)) makes λ approach one-side supported and one-side fixed state, so one-side supported and one-side fixed λ is the primary λ: 3.927, second order λ: 7.069, and third order λ: 10.210. Therefore, for example, when compared in the first order, the natural frequency of the configuration of the present invention is higher. That is, since the natural frequency of the reflecting member can be increased with a simpler structure than the conventional one,
The cost of the optical scanning device can be reduced.

An optical scanning device according to a second aspect is the optical scanning device according to the first aspect, wherein an optical path of the light beam is formed in at least one of an upper side and a lower side of a light beam scanning region of the reflecting member inside the housing. It is characterized by

The operation of the optical scanning device according to the second aspect will be described.

By adopting a constitution in which the end portion of the reflecting member in the light beam scanning direction is regulated by the displacement regulating means,
Since the vibration of the reflection member can be suppressed without interposing a member in the vicinity of the light beam scanning region of the reflection member, the degree of freedom in designing the light beam optical path in the vertical direction (direction orthogonal to the scanning direction) of the light beam scanning region of the reflection member. Will increase. That is,
Considering the cross section of the optical scanning device, since there is no inclusion in the vertical direction of the reflecting surface, the optical path can be provided in at least one of the reflecting members and can be bent in a complicated manner, and the optical scanning device can be miniaturized.

An optical scanning device according to a third aspect is the optical scanning device according to the first or second aspect, in the light beam scanning direction of the reflecting member, from the end of the first supporting means to the supporting position of the first supporting means. Is defined as β, and β is defined as the distance from the end portion on the second support means side to the support position of the second support means.

The operation of the optical scanning device according to the third aspect will be described.

In the light beam scanning direction of the reflecting member, the distance from the first supporting means (displacement restricting means) side end to the first supporting means is α, and the second supporting means (displacement restricting means) side end is second. When the distance to the supporting means is β, the relation of β <α is established, so that the natural frequency of the reflecting member can be moved to a higher range. The reason is that from the first supporting means to the restricting means (first
The longer the distance to the supporting means side end portion, the smaller the force required for contact between the regulating means and the reflecting member. In other words, when the abutting forces are the same, the longer the distance from the first supporting means to the regulating means, that is, the end portion of the reflecting member on the first supporting means side is, the greater the restraining force of the first supporting means side end portion is. become. Therefore, it becomes closer to the firmness of the firmness,
The natural frequency of the reflecting mirror is further increased, and the vibration can be reliably suppressed.

An optical scanning device according to claim 4 is the optical scanning device according to claim 1.
The optical scanning device according to any one of items 1 to 3, wherein the reflecting member is a final reflecting member that finally reflects the light beam inside the housing and reaches the object to be scanned.

The operation of the optical scanning device according to the fourth aspect will be described.

The reflecting member is a final reflecting member that finally reflects the light beam inside the housing to reach the object to be scanned. Since the optical scanning device has a structure in which a light beam is scanned by a polygon mirror, the scanning width widens as it approaches the object to be scanned. Therefore, the light beam scanning region (member length) of the final reflecting member is the reflecting member in the optical scanning device. The longest of all. That is, since the length of the final reflecting member is the longest, it becomes difficult to suppress the vibration. Therefore,
Conventionally, it was necessary to increase the thickness of the final reflecting member or to attach a metal member to the back side of the final reflecting member in order to increase the mass of the final reflecting member, but with the configuration of claims 1 to 3,
It is not necessary to increase the thickness of the reflecting member, and since the metal member can be deleted, it is possible to reduce the weight of the reflecting member (optical scanning device). The reduction in the weight of the reflecting member leads to a reduction in the pressing force of the pressing means, and the pressing means can be downsized. Therefore, the cost of the optical scanning device can be reduced. Further, as the dimension of the reflecting member in the thickness direction is reduced, it contributes to downsizing of the optical scanning device.

An optical scanning device according to a fifth aspect is the optical scanning device according to the first aspect.
The optical scanning device according to any one of claims 1 to 4, wherein the pressing means is provided at two positions offset by a predetermined distance on both sides with respect to a position where each of the supporting means supports the reflecting member in the longitudinal direction of the reflecting member. It is characterized by pressing at a position.

The operation of the optical scanning device according to the fifth aspect will be described.

In the beam scanning direction of the reflecting member, since the pressing means presses at two positions offset by a predetermined distance on both sides of the position supported by the supporting means,
As shown in FIG. 5D, the supporting position (28 or 30,
The pair of pressing means (46A, 46B) respectively suppress vibrations of the reflecting member in both directions that try to bend about 34) as an axis. As a result, the vibration of the reflecting member can be suppressed and the natural frequency of the reflecting member can be moved to a high range.

The optical scanning device according to claim 6 is the optical scanning device according to claim 5.
In the optical scanning device described above, the pressing means includes a mounting portion that is abutted and fixed to the housing, a pressing portion that presses the reflecting surface or the back surface of the reflecting member with two abutting portions, and An elastic portion that is disposed between the mounting portion and the pressing portion and that displaces the pressing portion integrally in a predetermined direction by elastically deforming, the predetermined direction being orthogonal to the reflecting surface of the reflecting member. It is characterized in that it is arranged in the housing as described above.

The operation of the optical scanning device according to the sixth aspect will be described.

The pressing means can press two positions, which are offset on both sides with respect to the supporting position of the supporting means for the reflecting member in the longitudinal direction of the reflecting member, by the two abutting portions of the pressing portion. Further, when different forces act on the two contact portions due to the vibration of the reflecting member (there is a twisting action between the two contact portions), the displacement direction of the pressing portion due to elastic deformation of the elastic portion is Since the direction is orthogonal to the reflecting surface, the twisting action acting between the two contact portions is restricted by the pressing portion that is integrally displaced, and the flexural vibration of the reflecting member is further suppressed.

An optical scanning device according to a seventh aspect is the optical scanning device according to any one of the first to sixth aspects, wherein the first supporting means has one point on the reflecting surface or the back surface of the reflecting member. The second supporting means supports the reflecting surface or the back surface of the reflecting member at two points.

The operation of the optical scanning device according to the seventh aspect will be described.

In the light beam scanning direction of the reflecting member, since the end portion on the side of the first supporting means for supporting the reflecting surface or the back surface at one point is constrained by the displacement regulating means, it occurs at the one-point supporting side other than the bending vibration of the reflecting member. Rotational vibration can also be suppressed,
Further good image quality can be obtained.

The optical scanning device according to claim 8 is the optical scanning device according to claim 1.
The optical scanning device according to any one of claims 1 to 7, wherein the displacement restricting unit has a restricting portion provided in a housing that abuts an end surface of the reflecting member in the light beam scanning direction,
It is characterized in that a sharp-shaped portion is provided on the reflecting member contact surface of the regulation portion.

The operation of the invention of claim 8 will be described.

The displacement restricting means is a restricting portion provided on the housing in contact with the end surface of the reflecting member in the light beam scanning direction, and a sharp-shaped portion is provided on the reflecting member contacting surface of the restricting portion. Here, the sharp-shaped portion is a portion that is formed so as to project on the contact surface with the reflecting member, and refers to a portion where the corner portion of the reflecting member bites when the reflecting member is pressed against the portion.

Therefore, the movement of the end portion of the reflecting member in the light beam scanning direction is fixed by causing the end portion of the reflecting member in the light beam scanning direction to bite into the regulating portion. As a result, the position of the reflecting member can be stably maintained, not only with respect to vibration of each part of the electrophotographic apparatus but also with respect to an abnormal external impact during transportation.

An optical scanning device according to a ninth aspect is the optical scanning device according to any one of the first to eighth aspects, in which the displacement of the reflecting member from the end portion on the side of the second supporting means in the light beam scanning direction. It is characterized in that it is provided with a pressing member that presses toward the regulating means side.

The operation of the invention according to claim 9 will be described.

In the light beam scanning direction of the reflecting member, the pressing member presses the end portion on the side of the second supporting means toward the end portion on the side of the first supporting means (displacement regulating means), so that the cross section of the reflecting member is delicate. Changes to increase the sectional area, that is, the second moment of area. Therefore, the natural frequency of the reflection member can be moved to a higher range, and the position of the reflection member can be stably maintained even when an abnormal external impact is generated during transportation.

An optical scanning device according to a tenth aspect is the optical scanning device according to the ninth aspect, characterized in that adjustment means for adjusting the pressing amount of the reflecting member by the pressing member is provided.

The operation of the optical scanning device according to the tenth aspect will be described.

Since the amount of pressing of the reflecting member by the pressing member can be adjusted by the adjusting means, the natural frequency of the reflecting member can be finely adjusted.

An optical scanning device according to an eleventh aspect is the optical scanning device according to the tenth aspect, wherein the adjusting means can be operated from outside the housing.

The operation of the optical scanning device according to the eleventh aspect will be described.

Since the pressing amount of the pressing member with respect to the reflecting member can be adjusted from the outside of the housing, the natural frequency of the reflecting member can be finely adjusted without opening the housing, in particular, individual variations of the vibration source of the electrophotographic apparatus. It can be adjusted according to. Therefore, the manufacturing requirement standard of the vibration source of the electrophotographic apparatus can be relaxed, and the manufacturing cost of the vibration source can be reduced.

An optical scanning device according to a twelfth aspect is the optical scanning device according to any one of the first to eleventh aspects,
At least one of the displacement restricting means and the pressing member is bonded to the end portion of the reflecting member in the light beam scanning direction.

The operation of the optical scanning device according to the twelfth aspect will be described.

By bonding at least one of the displacement regulating means or the pressing member to the end portion of the reflecting member in the light beam scanning direction, the end portion of the reflecting member in the light beam scanning direction is fixed. As a result, the natural frequency of the reflecting member can be moved to a higher range, and in particular, the position of the reflecting member can be stably maintained even against an abnormal external impact during transportation.
Further, since the adhesive is applied not at the position of the supporting means but at the end portion of the reflecting member in the light beam scanning direction away from the light beam scanning region, when the adhesive is applied, the adhesive is erroneously applied to the light beam scanning region of the reflecting member. There is no risk of applying it. Therefore, the working time can be shortened and the manufacturing cost of the optical scanning device can be reduced.

[0065]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An optical scanning device according to a first embodiment of the present invention will be described in detail with reference to FIGS. Here, FIG. 1 is an explanatory view of an optical scanning device to which the present invention is applied, and FIG. 2 is an enlarged view of a main part of FIG.

The optical scanning device 10 includes a light source 12 which emits a light beam L based on image information, a polygon mirror 14 which deflects the light beam L emitted from the light source 12 in a predetermined direction, and an imaging lens system 16. And a reflecting mirror 20 for guiding the light beam L to the scanned body 18, and a housing 22 for accommodating and installing these optical components and closed by a cover (not shown). The housing 22 is fixed to a frame 26 of the electrophotographic apparatus with a screw 24. The optical scanning device 10 is incorporated in an electrophotographic apparatus, and the light beam L is caused to scan the scanned object 18 based on image information to form an electrostatic latent image on the scanned object 18.

The electrophotographic apparatus is a known means, namely,
A charging unit that uniformly charges the scanned body 18, a developing unit that forms a toner image on the scanned body 18 on which the electrostatic latent image is formed, and a recording sheet are conveyed at a timing at which the toner image can be transferred. It is composed of a sheet conveying means, a transfer means for transferring the toner image on the scanned body onto the recording paper, and a fixing means for fixing the transferred toner image on the recording paper.

The reflecting surface 20A of the reflecting mirror 20 has a first supporting member 28 at one end (outer end of the scanning region) in the longitudinal (light beam scanning) direction and a second supporting member 30 at the other end in the longitudinal direction and the reflecting mirror angle adjusting mechanism. It is supported by 32 adjusting screws 34.
Here, the first support 28 and the second support 30 are integrally formed with the housing 22. On the other hand, the back surface 20B of the reflection mirror 20 is pressed by the leaf springs 36A and 36B at the positions facing the supports 28 and 30 at both ends in the longitudinal direction. Therefore, by adjusting the screwing amount of the adjusting screw 34, the light beam L is scanned by the leaf springs 36A and 36B to adjust the screwing amount of the adjusting mirror 34, which is pressed by the supporting members 28 and 30 and the adjusting screw 34. It is adjustable as described above.

On the other hand, as shown in FIG. 2, the housing 22 has an end face 20C which is the end face in the longitudinal direction of the reflection mirror 20.
A restricting member 38 that comes into contact with is formed to project from the wall surface. When adjusting the angle of the reflection mirror, the regulation member 38 and the end surface 20C are not in contact with each other as shown in FIG. 4A, and the clearance C is secured. Adjusting screw 3
After adjusting the angle at 4, the reflecting mirror 20 is slid in the longitudinal direction (toward the regulating member 38) as shown in FIG. 4B, and the regulating member 38 and the end surface 20C are brought into contact with each other. As a result, the movement of the end surface 20C of the reflection mirror 20 is restricted by the restriction member 38. When the reflection mirror 20 is slid, the back surface 20B of the reflection mirror 20 is pressed by the leaf springs 36A and 36B, and the reflection surface 20A is moved to the first support 28 and the second support 3.
Since it is supported by three points, 0 and the adjusting screw 34,
The adjustment (reflection) angle of the reflection mirror 20 does not change.
Further, by appropriately setting the pressing force of the leaf springs 36A and 36B, the restriction member 3 is prevented from an unnecessary impact during transportation.
It is also possible to prevent the end face 20C of the reflection mirror from being separated from 8.

The operation (suppression of vibration of the reflection mirror 20) of the optical scanning device 10 thus configured will be described.

First, as in the comparative example shown in FIG.
Both ends of the reflection mirror 20 are supported only by the first support 28, the second support 30 and the adjusting screw 34.
In the case of the comparative example shown in the schematic view of FIG.
4, vibration of the sheet conveying means inside the electrophotographic apparatus or the drive motor for driving the scanned body 18 causes the housing 22 to vibrate.
Is transmitted to the reflection mirror 20, and flexural vibration is generated in the reflection mirror 20. As a result, the optical path of the light beam L reflected by the reflection mirror 20 toward the scanned object 18 is deviated, and the scanning line is deviated on the scanned object 18 to deteriorate the image quality. At this time, the end surface 20C of the reflection mirror 20 freely vibrates due to flexural vibration, as indicated by the chain double-dashed line in FIG.

On the other hand, in the optical scanning device 10 of the present embodiment, as shown in FIG. 3C, the end face 20C of the reflection mirror 20 is brought into contact with the regulating member 38, so that the end face 20
The movement of C is regulated. Therefore, the reflection mirror 20
3 does not vibrate from the end face 20C to the supporting position of the first support 28 as indicated by the chain double-dashed line in FIG. 3D, and only the first support 28 and the second support 30 side vibrate. That is, when the reflection mirror 20 is viewed as a beam, the end surface 20C
The restrained state of the portion in which the regulating member 38 is in contact with the regulating member 38 approaches the fixed state. That is, since the restraint state of the end surface 20C is changed from being supported to being fixed, the natural frequency of the reflection mirror 20 can be moved to a high range, and the flexural vibration of the reflection mirror 20 can be suppressed.

Further, since a good image quality can be obtained with a simpler structure than the conventional flexural vibration preventing method, the cost of the optical scanning device can be reduced.

Further, the reflection mirror 20 and each support 2
8 and 30 support the reflecting surface 20A of the reflecting mirror 20, and the end surface 20C of the reflecting mirror 20 in the light beam scanning direction,
20D (end surface on the side opposite to the end surface 20C in the light beam scanning direction)
The positional relationship between and is set as shown in FIG. That is, when the distance from one end surface 20C (on the side of the regulating member 38) of the reflection mirror 20 to the first support 28 is α and the distance from the other end surface 20D to the second support 30 is β, β <α Therefore, when the distance is longer, the end face 20C can be brought closer to the fixed state when pressed with the same force. In other words, the natural frequency of the reflection mirror 20 can be moved to a higher range as the tension becomes closer to the fixed state.

Thus, the end surface 20C of the reflection mirror 20 is
By restraining the reflection mirror 20 with the regulating member 38.
In order to increase the natural frequency of the reflection mirror 20, the thickness of the reflection mirror 20 is increased in order to suppress the vibration of the reflection mirror 20,
In order to increase the mass of the reflection mirror 20, the reflection mirror 2
There is no need to attach a metal member to the back side of 0. Therefore, it is possible to reduce the weight of the optical scanning device 10. Particularly, in this respect, it is more preferable to apply the present invention to the final reflection mirror that finally reflects the light beam to the scanned body 18 inside the housing. This is because the light beam L is deflected by the polygon mirror 14, so that the light beam scanning area becomes the longest in the final reflection mirror. Therefore, the mirror length of the final reflection mirror is the longest, and it is the most difficult to suppress the vibration. However, by applying this configuration, the vibration can be easily suppressed without making the mirror heavy.

Further, by reducing the weight of the reflection mirror 20, the pressing force of the leaf spring 36 supporting the reflection mirror 20 can be reduced, and the dimensions (width and thickness) of the leaf springs 36A and 36B can be reduced. Therefore, the cost of the optical scanning device 10 can be reduced. Furthermore, the reflection mirror 20
Since it is not necessary to increase the dimension in the plate thickness direction, the optical scanning device 10 can be downsized.

Furthermore, the reflection mirror 20 is supported at two points on one side (second support body 30, adjusting screw 34) and one point on the other side (first support body 28) to support the regulating member 38 at one point (first support). Since it was installed on the body 28) side, the reflection mirror 2
In addition to flexural vibration of 0, rotational vibration (see arrow B in FIG. 24) due to twisting of the reflection mirror 20 can be suppressed, and a better image quality can be obtained. Rotational vibration is particularly effective when the cylindrical reflecting mirror is applied to the present invention. Reflection mirror 2
If the rotational vibration due to the twist of 0 is not particularly noticeable, the two-point support (first support body 30, adjustment screw 34) side may be restricted by the restriction member 38. (Second Embodiment) Next, an optical scanning device according to a second embodiment of the present invention will be described with reference to FIG. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Further, only the parts different from the first embodiment will be described, and the description of the other parts will be omitted.

The leaf spring 36A that presses the back surface 20B of the reflection mirror 20 has a shape in which the plate body is folded back in a V shape as shown in FIGS. Side, a mounting portion 40 for mounting to the housing 22, a support portion 42 that supports the reflection mirror 20 at the other end side, and an elastic portion (folding back) that elastically connects the mounting portion 40 and the supporting portion 42 to each other. Part) 44. The support portion 42 has a projection 46 that comes into contact with the back surface 20B of the reflection mirror 20.
A and 46B are formed along the elastic portion 44 with a predetermined distance therebetween.

The leaf spring 36A is fixed to the housing 22 so that the elastic portion 44 of the leaf spring 36A is parallel to the longitudinal direction of the reflection mirror 20. As a result, FIG.
As shown in FIGS. 5B and 5C, the protrusions 46A and 46B of the leaf spring 36A also have
The back surface 20B of the reflection mirror 20 is pressed at a position separated (offset) by a distance x on both sides in the longitudinal direction from the position where the first support 28 supports the reflection surface 20A.

As shown in FIGS. 5B and 5C, the elastic member 36B has the same structure.

The operation of the optical scanning device configured as described above will be described.

As shown in FIG. 5D, the leaf spring 3 is conventionally used.
6A and 36B pressed the positions facing the supports 28 and 30 at both ends in the longitudinal direction of the reflection mirror 20, so that the amplitude of the reflection mirror 20 was large as indicated by the chain double-dashed line. On the other hand, in the present embodiment, the projection 4 is provided at a position offset by a distance x on both sides in the longitudinal direction with the position where the support bodies 28 and 30 support the reflection surface 20A of the reflection mirror 20.
The back surface 20B of the reflection mirror 20 is pressed by 6A and 46B (see FIGS. 5B and 5C). By pressing the back surface 20B in this way, both directions (± y direction)
Vibration can be reliably suppressed. That is, FIG.
As shown in (D), the displacement of the reflection mirror 20 in the y direction is suppressed by the protrusion 46A, and the displacement in the −y direction is the protrusion 4.
Suppressed by 6B. As a result, the conventional support 28,
It is possible to suppress the flexural vibration, which is caused by pressing at a position (1 point) facing 30 and vibrating like a two-dot chain line, as shown by a broken line. Moreover, the natural frequency of the reflection mirror 20 can be moved to a high range.

In the conventional example shown in FIG. 27B, the leaf springs 368A and 368B are displaced toward the center of the reflecting mirror 362 in the longitudinal direction, and the contact portions 370 and 3 are provided.
If the contact position of 72 with respect to the back surface 362B of the reflection mirror 362 is set to a position sandwiching the support positions of the support members 364A and 364B, the configuration is similar to that of the present embodiment.
Since 0 and 372 move independently with respect to the bending of the reflection mirror 362, the above-described cushioning effect cannot be sufficiently exhibited.

On the other hand, in this embodiment, the protrusion 46
Since A and 46B are formed on one support portion 42, when the reflection mirror 20 tries to bend, the leaf spring 36A,
The supporting portion 42 of 36B tries to twist, but the reflecting surface 20
Since the elastic portion 44 arranged parallel to A prevents twisting, vibration can be effectively suppressed. (Third Embodiment) Next, an optical scanning device according to a third embodiment of the present invention will be described with reference to FIG. In addition,
The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Further, only the parts different from the first embodiment will be described, and the description of the other parts will be omitted.

In this embodiment, the shape of the regulating member 38A is different from that of the first embodiment. That is, as shown in FIG. 6A, projections 50A and 50B having a triangular cross section and extending in the longitudinal direction are formed on the surface of the regulating member 38A that abuts the end surface 20C of the reflection mirror 20. ing.

Therefore, as shown in FIGS. 4A and 4B, when the reflecting mirror 20 is slid in the longitudinal direction and pressed against the regulating member 38A, the end face 20C of the reflecting mirror 20 is pushed.
And the reflecting surface 20A make a corner (ridgeline) 52 and the end surface 2
The corner portion (ridgeline) 54 formed by 0C and the back surface 20B is the regulating member 3
Part of the sharp portions 50A and 50B of 8A is broken and bites (the position where the sharp portions are broken and bited is referred to as the biting portion 56A). The destroyed sharp portions 50A and 50B are removed by cleaning with air.

In the optical scanning device of this embodiment, since one end (end face 20C) in the longitudinal direction of the reflection mirror 20 is fixed to the regulating member 38A in this manner, not only the vibration of each part of the electrophotographic device but also Especially, the position of the reflection mirror 20 can be stably maintained even against an abnormal external impact during transportation.

A modified example is shown in FIG. It is suitable when the depth of the housing 22 is large and a sharp portion needs a draft.

The regulating member 38B has a triangular pyramid shape, and the sharp portion 50B, which is the apex of the triangular cross section, is formed so as to have an upward draft. The regulation member 30C arranged in parallel with the regulation member 38B also has a triangular pyramid shape, but the sharp portion 50C that is the apex of the triangular cross section is formed so as to have a draft toward the lower side. In addition, the lower housing surface of the sharp portion 50C is provided with a die punch hole (not shown).

The regulating members 38B, 3 thus constructed
7B by sliding the reflection mirror 20 in the longitudinal direction with respect to 8C and pressing the end surface 20C.
As shown in (D), the corner portion 52 of the reflection mirror 20 is in the sharp portion 50C of the regulating member 38C, and the corner portion 54 is in the sharp portion 50B.
Pressed against. As a result, as shown in FIG. 7D, the corner portion 52 bites the sharp portion 50C into the sharp portion 56C.
And the corner 54 cuts into the sharp portion 50B.
6B can be done. Also in this case, the end surface 20 of the reflection mirror 20
C, that is, the movement of one end in the longitudinal direction can be fixed. (Fourth Embodiment) Next, an optical scanning device according to a fourth embodiment of the present invention will be described with reference to FIG. In addition,
The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Further, only the parts different from the first embodiment will be described, and the description of the other parts will be omitted.

In the present embodiment, as shown in FIG. 8, a pressing protrusion formed on the upright surface 61 of the pressing member 60 fixed to the housing 22 on the end surface 20D on the side opposite to the regulating member in the longitudinal direction of the reflecting mirror 20. 62 is arranged so as to abut and press the reflection mirror 20 toward the regulating member 38 (other end) side.

Further, as a configuration different from the first embodiment,
The mirror angle adjusting mechanism is omitted, and the support portions 64 and 66 of the first support body 30B are formed at two positions separated by a predetermined distance in the lateral direction of the reflection mirror 20. The support portions 64, 66
Since the reflecting surface 20A is supported on the reflecting mirror 2
The angle of 0 is determined.

The present invention is also effective for the reflection mirror 20 having no angle adjusting mechanism as described above. By pressing the end face 20D of the reflection mirror 20 with the pressing protrusion 62 of the pressing member 60 (applying the pressing force P1), as shown by the change from the solid line to the broken line in FIG. The cross section can be changed (thickness t → t1) although it is subtle. As a result, the cross-sectional area of the reflection mirror 20 increases and the moment of inertia of area increases. Therefore, the natural frequency of the reflection mirror 20 can be moved to a higher range, and the position of the reflection mirror 20 can be stably maintained, especially against an abnormal external impact during transportation.

The pressing member 60 is attached to the reflection mirror 20 when it is attached.
Any material can be used as long as it can absorb the dimensional tolerance in the longitudinal direction and can achieve the above-mentioned action. For example, an elastic body, a bracket made of sheet metal, or the shape of the pressing member 60B shown in FIG. (Fifth Embodiment) Next, an optical scanning device according to a fifth embodiment of the present invention will be described with reference to FIGS. The same components as those in the fourth embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Also, the fourth
Only parts different from the embodiment will be described, and description of other parts will be omitted.

The configuration different from that of the fourth embodiment is shown in FIG.
As described above, the screw hole 68 is formed in the upright surface 61 of the pressing member 60A, and the adjusting screw 70 for pressing the end surface 20D of the reflection mirror 20 is screwed into the screw hole 68.

With this configuration, the pressing force P2 (see FIG. 9B) against the reflection mirror 20 is changed by adjusting the screwing amount of the adjusting screw 70 into the screw hole 68, and the cross-sectional area of the reflection mirror 20 is changed. (Thickness t2), cross section 2
Finely adjust the secondary moment. That is, the reflection mirror 20
The natural frequency of can be finely adjusted. Further, by adjusting the screwing amount of the adjusting screw 70, the longitudinal tolerance of the reflecting mirror 20 can be absorbed.

FIG. 10 shows a modification of FIG. Pressing member 6
The upright surface 61 of 0B is brought into direct contact with the end surface 20D of the reflection mirror 20, and a long hole 74 is formed in the base portion 72 of the pressing member 60B, and the screw 76 inserted in the long hole 74 is attached to the housing. The pressing member 60B can be fixed to the housing 22 by being screwed into a screw hole (not shown) of 22. That is, the pressing member 6 along the long hole 74.
OB is configured to be movable and adjustable.

The shape of the pressing member 60B is not particularly limited, and the pressing member 60B may be made of plastic, and in particular, the contact portion with the end surface 20D of the reflection mirror 20 may be formed as the pressing protrusion 62 shown in FIG. The regulating member 38 (see FIG. 2)
(See FIG. 6), 38A (see FIG. 6), 38B, 38C (see FIG. 7). (Sixth Embodiment) Next, an optical scanning device according to a sixth embodiment of the present invention will be described with reference to FIGS. 11 (A) and 11 (B). The same components as those in the fifth embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Further, only the parts different from the fifth embodiment will be described, and description of the other parts will be omitted.

The configuration different from that of the fifth embodiment is shown in FIG.
As shown in (A) and (B), the pressing member 60C is composed of an adjusting screw 70A screwed into a screw hole 80 formed in the wall surface of the housing 22. Housing 2
At one end of the adjusting screw 70A located outside of 2,
An adjustment dial 82 is formed so that the operator can adjust the pressing force from the outside. Further, on the wall surface of the housing 22, a scale 84 is formed around the adjustment dial 82 as a guide for the adjustment amount.

Therefore, the operator can
Adjust dial 82 without opening the cover (not shown)
By rotating according to the scale 84, the pressing force of the adjusting screw 70A against the reflecting mirror 20 can be easily and accurately adjusted.

By the way, if the adjustment is possible as in the fifth embodiment and this embodiment, the reflection mirror 20 is distorted in the scanning line normal direction, and the light beam on the object to be scanned is curved (B
OW). However, in the case of the fifth embodiment, the adjustment may be performed within the BOW specification range when adjusting the optical scanning device, and in the case of the present embodiment, the adjustment range of the adjustment dial 82 may be determined. For example, the adjustment screw 70A is shipped in contact with the end surface 20D when adjusting the optical scanning device. If you want to move the natural frequency of the reflection mirror 20 by incorporating it in an electrophotographic device,
The adjustment range may be determined by the number of scales 84 on the housing. As described above, since the pressing member 60C is adjustable from the outside of the optical scanning device, the natural frequency of the reflection mirror 20 is finely adjusted, and in particular, it is adjusted according to the individual variations of the vibration source of the electrophotographic device. be able to. Therefore, it is possible to relax the manufacturing requirement standard for the vibration source of the electrophotographic apparatus.
The cost of the vibration source can be reduced. (Seventh Embodiment) Further, an optical scanning device according to a seventh embodiment of the present invention will be described with reference to FIGS. The same components as those in the first to sixth embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

In the electrophotographic apparatus 90, as shown in FIG. 12, the light beams LK, LC, LM, and LY (hereinafter LK to LY. Others) of the recording colors of black, cyan, magenta, and yellow from the optical scanning device 92 are provided. The same applies to the reference number) 96K
It is a configuration for emitting light to ~ 96Y. Scanned object 96K ~
In 96Y, an electrostatic latent image is formed by the light beams LK to LY, and a toner image of a color corresponding to each image signal is formed on a portion exposed by the light beams LK to LY. The toner images formed on the respective scan objects 96K to 96Y are superimposed and transferred on the intermediate transfer belt 98 which is conveyed at a constant speed in the arrow A direction, and then transferred onto the conveyed paper 100. To be done. The sheet 100 onto which the toner image has been transferred has the toner image fixed by a fixing device (not shown) and is discharged to a discharge tray (not shown). An optical scanning device 92 used in the electrophotographic device 90 will be described with reference to FIG. FIG. 13 is a perspective view of the optical scanning device with the cover 102 removed. Optical scanning device 9
2 is a light beam LK to LY for the object to be scanned 96K to 96Y
The optical components are arranged inside the housing 22A that is shielded from the outside by the cover 102 for scanning and exposing. That is, the optical scanning device 92 emits the light beams LK to LY in accordance with the recording information signals of black (K) cyan (C) magenta (M) yellow (Y) output from an image processing unit (not shown). Incident light onto the object to be deflected, and the object to be scanned 96K through an opening (not shown).
The optical components are arranged in the housing 22A so that the 96Y can be exposed. Light beam L for details of configuration
A description will be given along the optical path of M. As shown in FIG. 12, the light beam LM emitted from the light source 104M is transmitted through the collimator lens 106M to be a divergent light beam, is transmitted through the cylinder lens 108M, is reflected by the small mirror 110YM, and is in the sub-scanning direction. Focused and polygon mirror 14
Incident on. The light beam LM reflected by the polygon mirror 14 is transmitted through the fθ lens 112YM, which is an imaging optical system, is reflected by the middle mirror 114M, is passed through the lower side of the large mirror 118M, is reflected by the cylinder mirror 116M, and is then large mirror 118M. The object to be scanned 96M is exposed by being reflected by. The reflecting surface of the cylinder mirror 116M constitutes an R surface in the sub-scanning direction, and even if the polygon mirror 14 is tilted, the scanning line does not shift in the sub-scanning direction. Note that another small mirror 109Y is inserted between the cylinder lens 108Y and the small mirror 110YM on the optical path of the light beam LY. The same arrangement is made on the optical path of the light beam LK.

Further, as shown in FIGS. 14 (A) and 14 (B), the optical scanning device 92 of the tandem structure for forming such a color image by superimposing such toner images is SKEW correction, BOW correction (two-dot chain line). A mechanism for correcting the image position of (1) to the solid line image position) is provided. The SKEW correction is performed by the skew correction mechanism 120K to 120Y shown in FIG.
16Y is performed by a cam mechanism (not shown) in the skew correction mechanisms 120K to 120Y with the end portion on the side opposite to the skew correction mechanism side as a reference. For example, the skew correction mechanism 120Y
Adjustment by the cylinder mirror 116Y of FIG.
Skew correction is performed by moving the position of the chain double-dashed line to the position of the solid line.

Next, a large mirror 11 equipped with a BOW adjusting mechanism.
8K-118Y (large mirror 11 on behalf of four)
8M) will be described with reference to FIGS. Figure 1
5 is a partial cutaway view of arrow A in FIG. 16 is shown in FIG.
It is the figure which deleted the regulation member of the arrow C of FIG.

As shown in FIG. 15, in the large mirror 118M, one end side of the reflecting surface 122M is located at the side of the first support member 124M.
At the support portions 126 and 128 at the points, the other end side is the second support body 1.
It is supported by one support section 132 of 30M,
The back surface 134M is supported by the leaf springs 36A and 36B.
It is pressed to the side of 26, 128, 132. In this way, the three supporting portions 126, 128, 132 are provided with the reflecting surface 122M.
Is supported to define the angle of the large mirror 118M (reflection surface 122M). First support 124
A BOW adjusting mechanism is provided on the M side, and an angle member 136M is arranged substantially parallel to the inclined surface 135M formed on the housing 22A. As shown in FIG.
A hemispherical convex portion 140M is formed on the inclined surface 138M of the angle member 136M, and the convex portion 140M supports the back surface 134M of the large mirror 118M. A threaded portion 142M is formed on the inclined surface 138M of the angle member 136M, and the distance between the inclined surface 138M of the angle member 136M and the inclined surface 135M is adjusted by rotating the adjusting screw 144M, and the first support 124M. The pressing amount of the convex portion 140M against the back surface 134M of the large mirror 118M supported at two points can be increased or decreased. Therefore, the bending amount of the large mirror 118M supported by the first support member 124M at two points is changed to correct the BOW from the two-dot chain line position to the solid line position, as shown in FIG. 14B.

On the other hand, as shown in FIG. 17, the housing 22A is integrally provided with a restricting member 38 which comes into contact with the end face end surface 146M of one end of the large mirror 118M in the longitudinal direction. When performing BOW correction (rotating the adjusting screw 144M), the regulating member 38 and the reflection mirror end surface 146 are separated from each other (clearance C) as shown in FIG. After adjustment with the adjusting screw 144, the large mirror 118M is moved in the longitudinal direction (regulating member 38) as shown in FIG.
Side) to slide the regulating member 38 and the large mirror 118M.
The end surface 146M of the above is abutted. Since the reflecting surface 122M of the large mirror 118M is supported at three points, the scanning position on the scanned object 18 does not deviate from the desired position due to the adjusted slide.

With this structure, the regulating member 38 regulates and fixes the movement of the end surface 146M of the large mirror 118M, as in the first embodiment, so that flexural vibration can be suppressed and the formed image quality can be improved. Can be improved.

Further, similarly to the first embodiment, the large mirror 1
In the longitudinal direction of 18M, the distance from the supporting position of the reflecting surface 122M of the supporting portions 126 and 128 to the end surface 146M is α, and the end surface of the supporting portion 130M opposite to the end surface 146M of the large mirror 118M from the supporting position of the reflecting surface 122M. 14
When the distance to 8M is β, the relationship of β <α is established, and thus the tension becomes closer to the fixed state. As a result, the natural frequency of the large mirror 118M can be moved to a higher range.

Particularly, the large mirror 11 which is the final reflection mirror.
By applying to 8M, it is possible to form an optical path of a light beam in a direction orthogonal to the scanning direction of the scanning area of the large mirror 118M (hereinafter, may be referred to as vertical direction), and the optical path in the optical scanning device can be formed. Can be made compact. Moreover, even when the scanning region (mirror length) is the longest as in the large mirror 118M, vibration can be suppressed without thickening the mirror or increasing the mass.
It is also possible to achieve weight reduction (prevention of weight reduction) of the large mirror 118M.

FIG. 18 shows the measurement result of the natural frequency of the large mirror 118M thus constructed. Large mirror 118
M is 310 mm in length, 16 mm in width, and 8 mm in thickness, and the back surface 1
C3 chamfering is applied to one 34M scanning direction corner portion over a length of 310 mm, and α = 30 mm in FIG.
β = 5 mm. In FIG. 18A, the clearance C is 0.5 mm in the state of FIG. 4A. In the state of FIG. 4A, the natural frequency of the large mirror 118M is 276.9 Hz as shown in FIG. 18A, but in the case of the configuration of this embodiment, it is shown in FIG. 18B. Like, large mirror 11
It was confirmed that the natural frequency of 8M was 315.9 Hz, and that the natural frequency of the large mirror 118M moved to a high range by about 40 Hz by this configuration.

In this example, the support for supporting the large mirror 118M is composed of two points on one side (first support 124M) and one point on the other side (second support 130M). The second support 130M may be reversed. If the one-point support side is the regulating member side, in addition to the bending vibration of the reflecting member,
Since the rotational vibration due to the twist of the reflection mirror is suppressed, it is possible to obtain a better image quality. This rotational vibration is particularly effective when the cylindrical reflecting mirror is applied to the present invention. In addition, the leaf springs 36A and 36B have a second embodiment (see FIG. 5).
One having a pair of protrusions 46A and 46B shown in (A) to (C) may be applied. (Eighth Embodiment) An optical scanning device according to the eighth embodiment of the present invention will be described with reference to FIGS. 18 and 19. The same components as those in the seventh embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In this embodiment, the restricting member 38A described in the third embodiment is used instead of the restricting member 38 of the seventh embodiment. That is, as shown in FIG. 19, the restriction member 3 that restricts the movement of the end surface 146M of the large mirror 118M.
Sharp portions 50A and 50B are provided on 8A. Therefore, when the large mirror 118M is slid in the longitudinal direction according to FIG. 4 (A) → (B), the sharp portions 50A, 50
B, the end surface 146M of the large mirror 118M, and the reflecting surface 122M
And the corner portion (ridge line) 150, the end surface 146M, and the back surface 13
The corner portion (ridgeline) 152 with 4M rushes into the sharp portions 50A and 50B of the regulating member 38A, destroys a part of the sharp portions 50A and 50B to form the biting portions 56B and 56C, and the end surface 146M of the reflection mirror. Is fixed. Therefore,
The position of the large mirror 118M can be stably maintained against not only vibration of each part of the electrophotographic apparatus but also abnormal external shock during transportation.

FIG. 20 shows a modification of FIG. 19, in which the restricting members 38B and 38C shown in FIG. 7 are used instead of the restricting member 38A.
Is applied.

As shown in FIGS. 20B to 20D, the corner 150M between the reflecting surface 122M and the end surface 146M is the sharp portion 5.
At 0C, a corner portion 152M between the back surface 134M and the end surface 146M
Contacts the sharp portion 50B. As a result, a biting portion 56C is formed in the sharp portion 50C with respect to the corner portion 150, and a biting portion 56B is formed in the sharp portion 50B with respect to the corner portion 152.
Therefore, the movement of the end surface 146M of the reflection mirror is fixed.

In the seventh and eighth embodiments, the fourth
It is possible to apply the configuration in which the end surface on the opposite side of the regulating member is pressed by the pressing member shown in the embodiment. By pressing the end surface 148M of the large mirror 118M toward the regulating member by the pressing member, the second moment of area of the large mirror 118M can be increased and the natural frequency can be moved to a higher range. Therefore, even if there is an abnormal external impact during transportation,
The position of the reflecting member can be kept stable. The pressing member may have any structure as long as it has the structure capable of absorbing the dimensional tolerance in the lengthwise direction of the reflecting mirror when mounted, and may be, for example, an elastic body or a bracket made of sheet metal.
The shape shown in FIG. 10 may be made of plastic.

In addition, in the seventh embodiment, the large mirror 1
The large mirror 1 when the end surface 148M of 18 is applied with a pressing force of 2 kgf to the regulating member 38 side by the pressing member 60 shown in FIG.
The measurement result of 18M is shown in FIG. In this case, the natural frequency of the large mirror 118M is 324.4 Hz, and only when the large mirror 118M is brought into contact with the regulating member (see FIG. 18).
From (B)), it was confirmed that the natural frequency can be moved to a higher range.

Further, in the seventh and eighth embodiments, as in the fifth embodiment (see FIG. 9), an adjusting screw may be provided on the pressing member to adjust the pressing force. With this configuration, the natural frequency of the large mirror 118M can be finely adjusted. In addition, the tolerance in the length direction of the reflection mirror can be absorbed. Similarly, as shown in FIG.
The pressing member may be provided with a long hole so that the pressing member itself can be moved and adjusted.

The contact portion of the pressing member with respect to the end surface 148M of the large mirror 118M may be made of plastic, and in particular, the pressing protrusion 62 shown in FIG.
Regulating member 38 (see FIG. 17), 38A (see FIG. 19),
The shape may be 38B, 38C (see FIG. 20).

Further, in the seventh and eighth embodiments, the pressing member may be adjusted from the outside of the housing by an adjusting dial as in the sixth embodiment. As described above, since the pressing member 60d can be adjusted from the outside of the optical scanning device, the natural frequency of the large mirror 118M can be finely adjusted.
In particular, it is possible to adjust for individual variations of the vibration source of the electrophotographic apparatus. Therefore, the manufacturing requirement standard of the vibration source of the electrophotographic apparatus can be relaxed, and the manufacturing cost of the vibration source can be reduced. In addition, the seventh and eighth embodiments are BO
Although it has a W adjustment mechanism, as in the first embodiment,
Even a reflecting mirror having a mirror angle adjusting mechanism or one having no mirror angle adjusting mechanism is effective.

By the way, in addition to the structures of the first to eighth embodiments described above, at least one of the regulating member or the pressing member and at least one of the end faces of the reflection mirror are adhered to each other to bond at least one of the end faces of the reflection mirror. It is also conceivable to fix the movement. For example, as shown in FIG. 4C, when the end surface of the reflection mirror 20 is offset from the regulation member 38, the reflection mirror 20 of the regulation member 38 is formed.
Adhesive 160 is attached to the contact surface with respect to, and after the angle is adjusted, the reflecting mirror 20 is slid in the longitudinal direction (toward the regulating member), so that the reflecting mirror 20 is moved as shown in FIG. The end surface 20C of 20 is the regulating member 3
It is fixed to the contact surface of No. 8 with the adhesive 160. As a result, the end surface 20C of the reflection mirror 20 is fixed,
The natural frequency of the reflection mirror 20 can be moved to a higher range,
In particular, the position of the reflection mirror 20 can be stably maintained even against an abnormal external impact during transportation. Further, the end surface 20D of the reflection mirror 20 which is away from the light beam scanning region of the reflection surface 20A is not at the supporting position of the reflection surface as in the conventional example.
Therefore, there is no risk that the adhesive 160 is accidentally applied to the scanning area of the reflection mirror 20 when the adhesive 160 is applied. Therefore, the working time can be shortened and the cost of the optical scanning device can be reduced.

Although the restricting members in the first to eighth embodiments are integrally formed with the housing, they are made of, for example, an elastic body or sheet metal under the condition that the natural frequency of the reflecting mirror is moved. Bracket, Figure 10
Plastic shape with a shape like
The regulating member 38, the regulating member 38A of FIG. 19, the regulating member 38C of FIG. 20, etc.) or the regulating member may be installed on the cover of the optical scanning device and connected and fixed to the housing.

[0122]

As described above, according to the invention described in claim 1, the reflection member is unique without thickening the reflection member and interposing the vibration suppressing member in the vicinity of the scanning region of the reflection member. The frequency can be moved. Therefore, since the natural frequency of the reflecting member can be moved to a higher frequency range with a simpler structure than the conventional one, the manufacturing cost of the optical scanning device can be reduced.

According to the second aspect of the present invention, the natural frequency of the reflecting member can be moved to a high frequency range with a simpler structure than the conventional one, so that the manufacturing cost of the optical scanning device can be reduced. Further, it is possible to suppress the vibration of the reflecting member without interposing a member near the scanning region of the reflecting member, and it is possible to effectively use the vertical space of the reflecting member. That is, when considering the cross section of the optical scanning device, since there is no inclusion in the vertical and vertical directions of the reflecting surface, the optical scanning device can be downsized by complicatedly bending the optical path.

According to the third aspect of the invention, the natural frequency of the reflecting member can be moved to a higher range.

According to the fourth aspect of the present invention, the plate thickness of the reflecting member can be made thin, and the metal member can be omitted. Therefore, the weight of the optical scanning device can be reduced. The reduction in the weight of the reflecting member leads to a reduction in the pressing force of the pressing means used for supporting, and the pressing means can be downsized. Therefore, the cost of the optical scanning device can be reduced. Further, the optical scanning device can be downsized due to the reduction in the dimension of the reflecting member in the plate thickness direction.

According to the fifth aspect of the present invention, the natural frequency of the reflecting member can be further moved to a high range.

According to the invention described in claim 6, it is possible to more reliably suppress the vibration of the reflecting member.

According to the invention described in claim 7, rotational vibration is suppressed in addition to the bending vibration of the reflecting member, so that a better image quality can be obtained.

According to the eighth aspect of the present invention, the movement of the end portion in the scanning direction of the reflecting member is made more fixed. Therefore, not only the vibration of each portion of the electrophotographic apparatus but also an abnormal external movement at the time of transportation. The position of the reflecting member can be stably maintained even with a shock.

According to the invention described in claim 9, the cross-section area and the cross-section 2 are changed by slightly changing the cross-section of the reflecting member.
Second moment increases. Therefore, the natural frequency of the reflection member can be moved to a higher range, and the position of the reflection member can be stably maintained even when an abnormal external impact is generated during transportation.

According to the tenth aspect of the invention, the natural frequency of the reflecting member can be finely adjusted.

According to the eleventh aspect of the present invention, it is possible to finely adjust the natural frequency of the reflecting member, and in particular, to adjust the individual variations of the vibration source of the electrophotographic apparatus. Therefore, the manufacturing requirement standard of the vibration source of the electrophotographic apparatus can be relaxed, and the manufacturing cost of the vibration source can be reduced.

According to the twelfth aspect of the invention, the movement of the end portion of the reflecting member is fixed. Therefore, the natural frequency of the reflecting member can be further moved to a higher range, and in particular,
The position of the reflecting member can be stably maintained even against an abnormal external impact during transportation. When applying the adhesive, there is no risk of accidentally applying the adhesive to the scanning area of the reflecting member. Therefore, the working time can be shortened and the cost of the optical scanning device can be reduced.

[Brief description of drawings]

FIG. 1 is a partially omitted perspective explanatory view of an optical scanning device according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

3A is an explanatory view showing a supporting state and a vibrating state of a reflecting mirror in a comparative example, and FIG. 3B is an explanatory diagram showing a vibrating state at an end portion of a reflecting mirror in a comparative example;
(C) is an explanatory view showing a supporting state of the reflection mirror according to the first embodiment, and (D) is an explanatory view of a vibration state at an end portion of the reflection mirror according to the present embodiment.

4A and 4B are explanatory views showing a state before and after abutting of the end surface of the reflection mirror and the regulating member, and FIGS. 4A and 4B are end views of the reflection mirror. It is explanatory drawing which shows the state before adhering and the regulation member, and the state after adhering.

5A is an explanatory view of a main part of an optical scanning device according to a second embodiment of the present invention, FIG. 5B is a front view showing a supporting position of a leaf spring in a reflection mirror, and FIG. Is a plan view, and (D) is a schematic view showing a vibrating state.

FIG. 6A is an explanatory diagram of a main part of an optical scanning device according to a third embodiment of the present invention, and FIG. 6B is an explanatory diagram of a state in which an end surface of a reflection mirror bites into a regulating member.

7A and 7B are explanatory views of a main part of the optical scanning device according to the modified example of FIG. 6, and FIGS. 7B to 7D are explanatory views of a state where the end surface of the reflection mirror bites into the regulation member.

FIG. 8A is an explanatory view of a main part of an optical scanning device according to a fourth embodiment of the present invention, and FIG. 8B is an explanatory view of a deformed state of a reflection mirror when an end face is pressed.

9A is an explanatory view of a main part of an optical scanning device according to a fifth embodiment of the present invention, and FIG. 9B is an explanatory view of a deformed state of a reflection mirror when an end face is pressed.

10 is an explanatory view of a main part of an optical scanning device according to a modification of FIG.

FIG. 11A is an explanatory view of a main part of an optical scanning device according to a sixth embodiment of the present invention, and FIG. 11B is a plan view of the main part.

FIG. 12 is a schematic explanatory diagram of an electrophotographic apparatus according to a seventh embodiment of the present invention.

FIG. 13 is a perspective explanatory view of an optical scanning device according to a seventh embodiment of the present invention.

FIG. 14A is an explanatory diagram of SKEW correction,
(B) is an explanatory view of the BOW correction.

FIG. 15 is a partial cutaway view of arrow A in FIG.

16 is a diagram in which a restricting member of arrow C in FIG. 15 is deleted.

FIG. 17 is an enlarged perspective view of essential parts of an optical scanning device according to a seventh embodiment of the present invention.

FIG. 18 (A) is a case where there is a clearance C between the large mirror and the regulating member in the configuration of the seventh embodiment, and (B) is a case of applying the configuration of the seventh embodiment of the present invention (C). FIG. 27 is a diagram showing the measurement results of each natural frequency when the end face of the large mirror on the side opposite to the regulating member side is pressed against the regulating member side in the seventh embodiment of the present invention.

FIG. 19A is an explanatory diagram of a main part of an optical scanning device according to an eighth embodiment of the present invention, and FIG. 19B is an explanatory diagram of a state in which an end surface of a reflection mirror bites into a regulating member.

FIG. 20 is an explanatory view of a main part of the optical scanning device according to the modified example of FIG. 19, and FIGS. 20B to 20D are explanatory views of a state in which the end surface of the reflection mirror bites into the restriction member.

FIG. 21 is an explanatory diagram of an optical scanning device according to a conventional example.

FIG. 22 is an explanatory diagram of a vibration state of a reflection mirror in a conventional example.

FIG. 23 (A) is a perspective view for explaining an essential part of an optical scanning device according to Conventional Example 1, and FIG. 23 (B) is a front view for an essential part.

FIG. 24 (A) is a perspective view for explaining main parts of an optical scanning device according to a comparative example, and FIG. 24 (B) is a front view for main parts.

25A is a schematic view of an optical scanning device according to Conventional Example 2, and FIG. 25B is a perspective view of a reflection mirror.

FIG. 26 is an explanatory diagram of a main part of an optical scanning device according to Conventional Example 3.

FIG. 27 (A) is a perspective view of a reflection surface of a reflection mirror according to Conventional Example 4, and FIG. 27 (B) is a back surface perspective view thereof.
(C) is an explanatory view of a vibration state according to a comparative example, and (D) is an explanatory view of a vibration state according to Conventional Example 4.

28A is a perspective explanatory view of a leaf spring according to Conventional Example 5, FIG. 28B is a principal part explanatory diagram of an optical scanning device according to Conventional Example 5, and FIG. Is.

FIG. 29A is an explanatory view of a supporting state of a reflection mirror to which the conventional example 5 is applied, FIG. 29B is an explanatory view of a supporting state when the reflection mirror is displaced in the −y direction, and FIG. It is a support state explanatory view when a mirror is displaced in the y direction.

FIG. 30 is an explanatory diagram of an electrophotographic apparatus (optical scanning apparatus) according to a conventional example.

[Explanation of symbols]

10 ... Optical scanning device 12 ... Light source 14 ... Polygon mirror 16 ... Imaging lens system 18 ... Object to be scanned 20 ... Reflecting mirror (reflecting member) 22, 22A ... Housing 38, 38A, 38B, 38C ... Regulating member

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C362 BA87 DA17                 2H045 AA01 BA22 BA34 DA02 DA41                 5C072 AA03 BA13 DA04 DA21 HA01                       XA05

Claims (12)

[Claims] 1. An optical scanning device in which a light beam emitted from a light source is deflected by a polygon mirror, is reflected by a reflecting member via an imaging lens system, and is scanned by an object to be scanned. Housing and first and second supporting means provided in the housing for supporting the light beam reflection surface or the back surface of the reflection surface at both ends outside the light beam scanning region in the light beam scanning direction of the reflection member. A pressing means for pressing the reflecting surface or the opposite surface of the back surface of the reflecting member supported by the supporting means toward the supporting means, and at least the first support of both ends of the reflecting member in the light beam scanning direction. An optical scanning device comprising: a displacement restricting device that restricts displacement of an end portion on the device side. 2. The optical scanning device according to claim 1, wherein an optical path of the light beam is formed in at least one of an upper part and a lower part of a light beam scanning region of the reflecting member inside the housing. 3. The distance from the end of the first supporting means to the supporting position of the first supporting means in the light beam scanning direction of the reflecting member is α, and the distance from the end of the second supporting means to the second supporting means. When the distance to the support position of the means is β, β <
3. The optical scanning device according to claim 1, wherein α is α. 4. The optical device according to claim 1, wherein the reflecting member is a final reflecting member that the light beam is finally reflected inside the housing and reaches the object to be scanned. Scanning device. 5. The pressing means presses at two positions offset by a predetermined distance on both sides with respect to the position at which each of the supporting means supports the reflecting member in the longitudinal direction of the reflecting member. The optical scanning device according to claim 1. 6. The mounting means includes a mounting portion that is abutted and fixed to the housing, a pressing portion that presses the reflecting surface or the back surface of the reflecting member with two abutting portions, and the mounting portion. And an elastic portion that is disposed between the pressing portion and the elastic member and integrally displaces the pressing portion in a predetermined direction by elastically deforming the predetermined direction so that the predetermined direction is orthogonal to the reflecting surface of the reflecting member. The optical scanning device according to claim 1, wherein the optical scanning device is arranged in a housing. 7. The first supporting means supports the reflecting surface or the back surface of the reflecting member at one point, and the second supporting means supports the reflecting surface or the back surface of the reflecting member at two points. The optical scanning device according to any one of claims 1 to 6, characterized in that. 8. The displacement restricting means has a restricting portion provided on a housing that abuts an end surface of the reflecting member in the light beam scanning direction, and a sharp-shaped portion is provided on a reflecting member contacting surface of the restricting portion. The optical scanning device according to claim 1, wherein the optical scanning device is provided. 9. A pressing member for pressing from the end of the reflecting member on the side of the second supporting means in the light beam scanning direction toward the side of the displacement regulating means, according to any one of claims 1 to 8. The optical scanning device according to the item 1. 10. The optical scanning device according to claim 9, further comprising adjusting means for adjusting a pressing amount of the reflecting member by the pressing member. 11. The optical scanning device according to claim 10, wherein the adjusting means is operable from the outside of the housing. 12. At least one of the displacement restricting means or the pressing member and an end portion of a reflecting member in a light beam scanning direction are bonded to each other, according to any one of claims 1 to 11.
An optical scanning device according to the item.