JP5510857B2 - Optical scanning apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an optical scanning device and an image forming apparatus.

It is known that a latent image is formed on a photosensitive member by irradiating the photosensitive member, which is a latent image carrier, with writing light according to image information by deflecting and scanning, and developing the latent image to obtain an image. It has been. In an optical scanning apparatus that deflects and scans writing light, light emitted from a light source such as a laser diode (LD) is generally shaped into a predetermined shape by a collimating lens or an aperture and enters a polygon mirror. The light incident on the polygon mirror is deflected and scanned by the polygon mirror and imaged on the surface of the photoreceptor.
In such an optical scanning device, as described in Patent Document 1, the light source is press-fitted and fixed to a light source mounting portion provided in a holder or the like.

  However, when the light source is press-fitted and fixed to the light source mounting part, when the light source is removed from the light source mounting part due to initial failure or the like, the light source is forcibly pulled out from the light source mounting part. If the light source is not pulled out straight, there is a problem that the light source mounting portion is damaged, and it is difficult to replace the light source.

  In addition, a laser diode (LD) as a light source emits elliptical light with different divergence angles in the vertical and horizontal directions. Therefore, in order to shape the light that has passed through the aperture into a target shape, it is necessary to match the major axis portion of the elliptical light with the slit direction of the aperture. However, when the light source is press-fitted and fixed to the light source mounting portion, the light source cannot be rotated after press-fitting and fixing. Therefore, if the major axis part of the elliptical light and the slit direction of the aperture are misaligned, depending on the rotation of the light source, the major axis part of the elliptical light and the slit direction of the aperture cannot be matched and pass through the aperture. There is a risk that the light that has been used cannot be formed into the target shape.

  Furthermore, in the case of an optical scanning device having a plurality of light emitting points as a light source and using a laser diode array (LDA) in which these light emitting points are arranged in an array and using a multi-beam scanning method, the beam pitch is set to a target pitch. Thus, it is necessary to position the light source in the rotational direction and attach it to the light source mounting portion. However, when the light source is press-fitted and fixed to the light source mounting portion, the light source cannot be rotated after press-fitting and fixing. For this reason, if the light source rotates in the rotation direction when the light source is pressed, and the light source is displaced in the rotation direction and press-fitted and fixed, the light source cannot be rotated to adjust the beam pitch to the target pitch after installation. This also causes a problem.

  If the light source is attached to the holder and the holder is rotatably attached to the optical housing as in Patent Document 1, the holder is rotated relative to the optical housing so that the beam pitch becomes the target pitch. Adjustment and adjustment for shaping the light that has passed through the aperture into a target shape are possible, but the number of parts such as a holder increases and the cost increases.

  The present invention has been made in view of the above problems, and its purpose is to easily replace the light source while removing the holder for attaching the light source and reducing the number of parts. It is an object of the present invention to provide an optical scanning device and an image forming apparatus characterized in that the light source can be adjusted in the rotation direction.

In order to achieve the above object, an invention according to claim 1 is an optical scanning device that optically scans an object to be scanned with a light beam emitted from a light source, and optical that shapes the light beam emitted from the light source into a target shape. An optical housing that houses an element and a deflection scanning unit that deflects and scans the light beam, and the optical housing is positioned so that the light source is positioned in the optical axis direction by striking the light source in the optical axis direction. A pressing member that presses the light source positioned by the positioning unit toward the positioning unit, and fixes the light source by sandwiching the light source between the pressing member and the positioning unit , It is possible to adjust the clamping force for the light source by the pressing member, and the rotation of the light source can be adjusted relative to the pressing member by weakening the clamping force for the light source. The positioning unit is a positioning surface perpendicular to the optical axis direction, it is characterized in that chromatic 2 or 3 on the same plane of the positioning surface.
According to a second aspect of the present invention, there is provided an optical scanning device that optically scans an object to be scanned with a light beam emitted from a light source, an optical element that shapes the light beam emitted from the light source into a target shape, and the light beam. An optical housing that houses a deflection scanning unit that deflects and scans the optical housing, and the optical housing includes a positioning unit that positions the light source in the optical axis direction by striking the light source in the optical axis direction. A pressing member that presses the light source positioned by the positioning unit toward the positioning unit is provided, the light source is fixed by sandwiching the light source between the pressing member and the positioning unit, and the light source by the pressing member is The clamping force can be adjusted, and the light source can be rotationally adjusted with respect to the pressing member by weakening the clamping force with respect to the light source. And a plurality of light sources are positioned in the positioning portion, the pressing member is one which is characterized by being configured so as to press the plurality of light sources.
According to a third aspect of the present invention , in the optical scanning device according to the first or second aspect , the pressing member is fastened to the optical housing with a screw, and the clamping force is adjusted by rotating the screw. It is a feature .
Also, the invention of claim 4 is the optical scanning apparatus of any one of claims 1 to 3, wherein the pressing member with respect to the optical axis direction to press the opposite side of the light beam emitting-side surface of the serial light source A pressing surface that is perpendicular to the pressing surface and a mounting surface that is parallel to the pressing surface and that is attached to the optical housing in a position different from the pressing surface in the optical axis direction. Is configured to be elastically deformed .
Also, the invention of claim 5 is the optical scanning apparatus according to claim 4, characterized in that the pressing surface, provided 2 or 3 on the same plane, and the contact area between the pressing surface and the light source in the same It is what .
Also, the invention of claim 6 is the optical scanning apparatus according to claim 5, there are a plurality the pressing surface is on the same plane, and configured such that the positioning surface is equal to the number of the pressing surface on the same plane The pressing surface is configured to face the positioning surface with the light source interposed therebetween .
Also, the invention of claim 7, in any one of the optical scanning apparatus according to claim 1 to 6, wherein the pressing member has a mounting surface attached to said optical housing, the optical housing the end portion of the mounting surface It is characterized by using a curved surface that curves in a direction away from the head .
Also, the invention of claim 8 is for an optical scanning apparatus according to claim 3, characterized in that a pressing member positioning means for positioning the pressing member before being fixed to the optical housing in the rotational direction There is .
Also, the invention of claim 9 is the optical scanning apparatus according to claim 3, provided with a separate member between the pressing member and the screw, between the further member and the screw when the pressing member engagement and the A slip in the rotational direction is generated in at least one of the pressing member and the separate member .
Also, the invention of claim 10 includes a latent image bearing member for bearing a latent image, a scanning means for forming a latent image on the surface of the latent image bearing member by an optical scanning, it is carried on the latent image bearing member in the image forming apparatus and a developing means for developing the latent image was, as the light scanning means, is characterized in that with one of the optical scanning apparatus according to claim 1 to 9.

In this onset bright, since the clamping fixing the light source at the pressing member and the positioning unit, simply by removing the pressing member from the apparatus, clamping force of the light source is lost it can be removed light from readily device. Therefore, it is possible to easily replace the light source as compared with the case where the light source is press-fitted and fixed.
Moreover, since the light source is only clamped by the positioning part and the pressing member, if the pressing force of the pressing member is weakened, the clamping force to the light source is weakened and the light source can be rotated. Therefore, after the light source is attached, the light source can be rotated to adjust the beam pitch and the shape of the light emitted from the light source.
In addition, since the light source directly attached to the optical housing can be rotated, the number of parts can be reduced as compared with the configuration in which the light source is attached to the holder and the holder is rotatably attached to the optical housing.

1 is a schematic configuration diagram illustrating a printer according to an embodiment. FIG. 2 is a configuration diagram illustrating a schematic configuration of an image forming station of the printer. It is a schematic sectional drawing which shows the structure of an optical writing unit. The figure which looked at the 1st case from the top. The perspective view of a 1st housing | casing. The figure explaining a mode that a 1st housing | casing is attached to a 2nd housing | casing. The schematic block diagram around the light source attachment surface of a 1st housing | casing. The perspective view of a pressing member. The figure which shows a mode before attaching LDA to a 1st housing | casing with a screw | thread. The figure which shows a mode that LDA was fixed to the 1st housing | casing with the screw. The figure explaining a mode that the pressing surface of a pressing member presses LDA. The figure explaining a mode that the control board was attached to LDA fixed to the 1st housing | casing. The figure which shows embodiment which provided the positioning reference plane at three places at equal intervals in the circumferential direction. The figure which shows a mode that the positioning reference surface and the press surface were made to oppose on both sides of the base part of LDA. The figure which shows embodiment which provided the insulating member between the pressing surface and the base part, or between the inner periphery of the through-hole, and the electric power feeding part. The figure explaining a mode that the longitudinal direction edge part of a press member is hooked on the light source attachment surface. The figure which shows embodiment which formed the escape part in the location facing the longitudinal direction outer side edge part of the attachment surface of a light source attachment surface. The figure which shows embodiment which made the longitudinal direction edge part of the attachment surface of a press member the curved surface shape. The figure explaining a mode that the force of a rotation direction acts on a pressing member at the time of screw fastening, and rotates LDA. The figure which shows the 1st aspect of a pressing member positioning means. The figure which shows the 2nd aspect of a pressing member positioning means. The figure which shows embodiment which provided another member between the head of a screw, and the press member. The figure which shows embodiment which presses two light sources with one press member. The figure which shows embodiment which fixes a press member with a spring member. 1 is a schematic configuration diagram of a monochrome image forming apparatus.

Hereinafter, an embodiment in which the present invention is applied to a printer as an image forming apparatus will be described. In the present embodiment, a so-called intermediate transfer type tandem image forming apparatus will be described as an example, but the present invention is not limited to this.
FIG. 1 is a schematic configuration diagram illustrating a printer according to the present embodiment.
The printer includes an apparatus main body 1 and a paper feed cassette 2 that can be pulled out from the apparatus main body 1. In the central portion of the apparatus main body 1, image forming stations 3Y, 3C, and 3C for forming toner images (visible images) of respective colors of yellow (Y), cyan (C), magenta (M), and black (K). 3M, 3K. Hereinafter, the subscripts Y, C, M, and K of the respective symbols indicate members for yellow, cyan, magenta, and black, respectively.

FIG. 2 is a configuration diagram showing a schematic configuration of a yellow (Y) imaging station. The other image forming stations have the same configuration.
As shown in FIGS. 1 and 2, the image forming stations 3Y, 3C, 3M, and 3K include drum-shaped photoconductors 10Y, 10C, 10M, and 10K as latent image carriers that rotate in the direction of arrow A in the drawing. ing. Each of the photoreceptors 10Y, 10C, 10M, and 10K includes an aluminum cylindrical substrate having a diameter of 40 mm and an OPC (organic photo semiconductor) photosensitive layer that covers the surface of the photoreceptor. Each of the image forming stations 3Y, 3C, 3M, and 3K has charging devices 11Y, 11C, 11M, and 11K that charge the photoconductor around the photoconductors 10Y, 10C, 10M, and 10K, and a latent image formed on the photoconductor. Developing devices 12Y, 12C, 12M, and 12K as developing means for developing an image, and cleaning devices 13Y, 13C, 13M, and 13K for cleaning residual toner on the photoreceptor are provided. Below each image forming station 3Y, 3C, 3M, 3K, an optical writing unit 4 as an optical writing means, which is an optical scanning device that can irradiate the photoconductors 10Y, 10C, 10M, 10K with the writing light L. It has. Above each of the image forming stations 3Y, 3C, 3M, and 3K, an intermediate transfer unit 5 including an intermediate transfer belt 20 to which a toner image formed by each of the image forming stations 3Y, 3C, 3M, and 3K is transferred is provided. ing. Further, a fixing unit 6 is provided for fixing the toner image transferred to the intermediate transfer belt 20 to the transfer paper P as a recording material. In addition, toner bottles 7Y, 7C, 7M, and 7K that store toners of respective colors of yellow (Y), cyan (C), magenta (M), and black (K) are loaded on the upper portion of the apparatus main body 1. . The toner bottles 7 </ b> Y, 7 </ b> C, 7 </ b> M, and 7 </ b> K are configured to be detachable from the apparatus main body 1 by opening a paper discharge tray 8 formed on the upper part of the apparatus main body 1.

The optical writing unit 4 deflects writing light (laser light) L emitted from a laser diode as a light source by a polygon mirror or the like, and irradiates it while scanning on the photoreceptors 10Y, 10C, 10M, and 10K. Detailed description of the optical writing unit 4 will be described later.
The intermediate transfer belt 20 of the intermediate transfer unit 5 is wound around a driving roller 21, a tension roller 22 and a driven roller 23, and is driven to rotate counterclockwise in the drawing at a predetermined timing. The intermediate transfer unit 5 includes primary transfer rollers 24Y, 24C, 24M, and 24K that transfer the toner images formed on the photoreceptors 10Y, 10C, 10M, and 10K to the intermediate transfer belt 20. The intermediate transfer unit 5 cleans the secondary transfer roller 25 that transfers the toner image transferred onto the intermediate transfer belt 20 onto the transfer paper P, and the transfer residual toner on the intermediate transfer belt 20 that has not been transferred onto the transfer paper P. A belt cleaning device 26 is provided.

Next, a process for obtaining a color image in the printer having the above configuration will be described.
First, in the image forming stations 3Y, 3C, 3M, and 3K, the photoreceptors 10Y, 10C, 10M, and 10K are uniformly charged by the charging devices 11Y, 11C, 11M, and 11K. Thereafter, the optical writing unit 4 scans and exposes the laser light L based on the image information to form latent images on the surfaces of the photoreceptors 10Y, 10C, 10M, and 10K. The latent images on the photoconductors 10Y, 10C, 10M, and 10K are developed with toners of the respective colors carried on the developing rollers 15Y, 15C, 15M, and 15K of the developing devices 12Y, 12C, 12M, and 12K, and can be used as toner images. Visualized. The toner images on the photoreceptors 10Y, 10C, 10M, and 10K are sequentially transferred onto the intermediate transfer belt 20 that is rotated counterclockwise by the action of the primary transfer rollers 24Y, 24C, 24M, and 24K. The image forming operation of each color at this time is shifted in timing from the upstream side in the moving direction of the intermediate transfer belt 20 toward the downstream side so that the toner image is transferred to the same position on the intermediate transfer belt 20. Executed. The surfaces of the photoreceptors 10Y, 10C, 10M, and 10K after the completion of the primary transfer are cleaned by the cleaning blades 13a of the cleaning devices 13Y, 13C, 13M, and 13K, and are prepared for the next image formation. The toner filled in the toner bottles 7Y, 7C, 7M, and 7K is placed in the developing devices 12Y, 12C, 12M, and 12K of the image forming stations 3Y, 3C, 3M, and 3K by a conveyance path (not shown) as necessary. A fixed amount is supplied.

  On the other hand, the transfer paper P in the paper feed cassette 2 is transported into the apparatus main body 1 by a paper feed roller 27 disposed in the vicinity of the paper feed cassette 2 and is secondary by a registration roller pair 28 at a predetermined timing. It is conveyed to the transfer unit. Then, the toner image formed on the intermediate transfer belt 20 is transferred to the transfer paper P in the secondary transfer portion. The transfer paper P onto which the toner image has been transferred passes through the fixing unit 6 to be fixed, and is discharged to the paper discharge tray 8 by the discharge roller 29. Similar to the photoconductor 10, the transfer residual toner remaining on the intermediate transfer belt 20 is cleaned by a belt cleaning device 26 that contacts the intermediate transfer belt 20.

Next, the configuration of the optical writing unit 4 will be described.
FIG. 3 is a schematic cross-sectional view showing the configuration of the optical writing unit 4.
FIG. 4 is a schematic configuration diagram of a main part when the first housing 70 is viewed from above, and FIG. 5 is a perspective view of the first housing 70.
The optical writing unit 4 of the present embodiment includes a first housing 70 that stores optical system components provided on an optical path between a laser diode array (hereinafter referred to as LDA) as a light source and the fθ lenses 43a and 43b. The second housing 60 accommodates optical system components provided on the optical path between the fθ lenses 43a and 43b and the photosensitive member.
The optical writing unit of the present embodiment is a multi-beam scanning system that uses an LDA to scan a plurality of lights simultaneously on the surface of the photosensitive member. As described above, the image forming speed can be increased by adopting the multi-beam scanning method.

  As shown in FIGS. 4 and 5, the first housing 70 that is an optical housing has a collimating lens that is an optical element that shapes a light beam emitted from the LDAs 51 a, 51 b, 51 c, and 51 d that are light sources into a target shape. 52a and 52b, cylindrical lenses 53a and 53b, a polygon scanner 140 serving as a deflection scanning means, and fθ lenses 43a and 43b serving as scanning lenses for changing the equiangular motion of laser scanning into a uniform linear motion are accommodated.

As shown in FIG. 5, the LDAs 51a, 51b, 51c, 51d will be described in detail later, but the light source mounting holes 76a, 76b, 76c (on the light source mounting surfaces 75a, 75b provided at the end of the first housing 70). (Not shown) and 76d.
FIG. 5 shows a state in which only the LDA 51c is attached to the first housing 70.

  The polygon scanner 140 is a circuit on which two polygon mirrors (rotating deflectors) 41a and 41b having a regular polygonal column shape, a polygon motor (driving means) 144, and an electronic component for controlling the driving of the polygon motor 144 are mounted. It is comprised with the board | substrate 141. FIG. The polygon scanner 140 is fastened to the first housing 70 by screws in a polygon scanner housing portion 73 surrounded by the polygon scanner housing wall 74.

  The fθ lenses 43 a and 43 b are attached to the scanning lens housing portion of the first housing 70. Further, the collimating lenses 52a and 52b and the cylindrical lenses 53a and 53b are mounted on the optical paths from the LDAs 51a, 51b, 51c and 51d of the first housing 70 to the polygon mirrors 41a and 41b, respectively. The polygon scanner housing wall 74 of the first housing 70 is provided with soundproof glasses 49a and 49b.

  As shown in FIG. 6, the first housing 70 is attached to the second housing 60. As shown in FIG. 3, in addition to the first housing 70, the second housing 60 has mirrors 44a, 44b, 44c, 44d, 46a, 46b for guiding laser light to the photoreceptors 10Y, 10C, 10M, 10K. , 46c, 46d, 47a, 47b, 47c, 47d, long lenses 50a, 50b, 50c, 50d for correcting surface tilt of the polygon mirrors 41a, 41b, synchronization detection means (not shown), and the like. Note that reference numerals La, Lb, Lc, and Ld in FIG. 3 indicate the optical paths of the writing light applied to the respective photoreceptors 10Y, 10C, 10M, and 10K.

  The light emitted from the LDAs 51a to 51d is transmitted through the collimating lens 52a (52b), and then formed into a fixed shape by an aperture (not shown) provided in the first housing 70, and then the cylindrical lens 53a (53b). Is transmitted in the sub-scanning direction (the direction corresponding to the direction of movement of the photosensitive member surface on the photosensitive member surface). Next, the main scanning direction (the axial direction on the surface of the photosensitive member) is reflected by any one of the mirror surfaces formed on each of the six side surfaces of the polygon mirror 41a (41b) having a regular hexahedron structure rotated at high speed by the polygon motor 144. Direction). Then, an fθ lens 43a (43b) that converts the moving speed in the deflection direction of light deflected in the main scanning direction at a constant angular velocity by the polygon mirror 41a (41b), a mirror, and a length for correcting surface tilt. After sequentially passing through the scale lens and the dust-proof glass that seals the optical scanning device, it reaches the surface of the photoreceptor not shown.

Next, attachment of the LDA to the first housing 70 will be described. In the following description, the attachment of the LDA 51c will be described, but the same applies to the attachment of the LDA 51a, 51b, 51d.
FIG. 7 is a schematic configuration diagram around the light source mounting surface of the first housing 70. FIG. 8 is a perspective view of the pressing member 110. FIG. 9 is a diagram illustrating a state before the LDA 51c is attached to the first housing with a screw.
As shown in FIG. 7, the LDA 51c has a light emitting unit 512, a pedestal unit 513, a power feeding unit 511, and the like. The outer diameter of the pedestal portion 513 is larger than the outer diameter of the light emitting portion 512, and the surface on the light emitting portion side of the pedestal portion 513 serves as a reference surface 513a for positioning in the optical axis direction. The power feeding unit 511 extends from a surface opposite to the light emitting unit side surface of the pedestal unit 513, and is connected to a control board or the like to be described later, and is arranged in an array form in the light emitting unit 512. To supply power.

  The light source mounting surface 75b of the first housing 70 is provided with a light source mounting hole 76c and a screw hole 752. The light source mounting hole 76c is provided with a light emitting portion insertion portion 752 that is slightly larger than the diameter of the light emitting portion 512 of the LDA 51c and a pedestal portion insertion portion 755 that is slightly larger than the diameter of the pedestal portion 513 of the LDA 51c. A surface that connects the pedestal portion insertion portion 755 and the light emitting portion insertion portion 752 and is perpendicular to the optical axis direction is a positioning surface 754 that is a positioning portion that positions the LDA 51c in the optical axis direction. The length in the optical axis direction of the pedestal portion insertion portion 755 is shorter than the length in the optical axis direction of the pedestal portion 513, and when the LDA 51c is positioned by the positioning surface 754, a part of the pedestal portion 513 is a light source mounting surface. It protrudes from 75b.

The pressing member 110 that presses the LDA 51c is a rectangular plate-like member that is formed by bending a sheet metal or formed by injection molding a resin. A through hole 114 through which the power feeding portion 511 of the LDA 51c passes is provided in a substantially central portion of the pressing member 110. The pressing surface 112 that contacts the surface opposite to the reference surface 513a of the pedestal portion of the LDA so as to surround the through hole 114 and presses the LDA 51c toward the positioning surface 754 side is equally spaced in the circumferential direction. Are provided at three locations (see FIG. 8). Each pressing surface 112 is a surface perpendicular to the optical axis direction so that the LDA 51c can be pressed favorably in the optical axis direction, and the shape of each pressing surface is the same.
A mounting surface 111 having a screw through hole 113 through which a screw passes is provided outside the pressing surface 112 in the longitudinal direction.

  The pressing surface 112 is provided at a position farther from the first housing 70 in the optical axis direction than the mounting surface 111, and the positions of the pressing surface 112 and the mounting surface 111 in the optical axis direction are different. The attachment surface 111 is a surface parallel to the pressing surface 112.

FIG. 9 is a diagram illustrating a state before the LDA 51c is fastened to the first housing 70 with screws.
As shown in the drawing, the light emitting portion 512 of the LDA 51c is inserted into the light emitting portion inserting portion 753, the pedestal portion 513 is inserted into the pedestal portion inserting portion 755, and the positioning reference surface 513a is brought into contact with the positioning surface 754. As a result, the LDA 51c is positioned in the optical axis direction. In addition, the diameter of the light emitting portion insertion portion 752 is slightly larger than the diameter of the light emitting portion 512 of the LDA 51c, and the diameter of the pedestal portion inserting portion 755 is slightly larger than the diameter of the pedestal portion 513 of the LDA 51c. The LDA 51c inserted into the can be rotated.

  Next, the feeding portion 511 of the LDA 51c is passed through the through hole 114 of the pressing member 110, and the pressing surface 112 is brought into contact with the surface opposite to the positioning reference surface of the pedestal portion 513. At this time, the pressing surface 112 is provided at a position farther in the optical axis direction from the light source mounting surface 75b than the mounting surface 111, and the pressing surface 112 is recessed, so that the pedestal portion 513 is loosely fitted in this recess. Thus, the pressing surface 112 can be reliably brought into contact with the surface of the pedestal 513 opposite to the positioning reference surface.

When the LDA 51c is positioned by the positioning portion 754, a part of the pedestal portion 513 protrudes from the light source mounting surface 75b, so that the pressing surface 112 of the pressing member 110 is placed on the pedestal portion 513 as shown in FIG. When a contact is made with the surface opposite to the positioning reference surface, there is a gap between the mounting surface 111 of the pressing member 110 and the light source mounting surface 75b.
Then, the screw 120 is inserted into the screw through hole 113 of the pressing member 110 from a state where a gap is formed between the mounting surface 111 of the pressing member 110 and the light source mounting surface 75b of the first housing 70. When the pressing member 110 is fastened to the first housing 70 by screwing the screw 120 into the screw hole 752 of the light source mounting surface 75b until the mounting surface 111 is in close contact with the light source mounting surface 75b, as shown in FIG. The surroundings are elastically deformed. As a result, a restoring force acts on the pressing surface 112, and the pressing surface 112 presses the LDA 51c toward the positioning surface 754. Accordingly, the pedestal portion 513 of the LDA 51 c is sandwiched between the pressing surface 112 and the positioning portion 754, and the LDA 51 c is attached to the first housing 70.

  In this embodiment, since the mounting surface 111 of the pressing member 110 is parallel to the pressing surface 112, when the pressing member 110 is fixed, the LDA 51c is pressed to the pressing member 110 from the fixing member (screw). Power is added. As a result, it is possible to apply a pressing force to the LDA 51c only by fixing the pressing member 110, and it is not necessary to have a complicated structure for applying the pressing force to the LDA 51c. Therefore, it is possible to apply a pressing force to the LDA 51c with an inexpensive configuration.

Furthermore, according to the present embodiment, since the positions of the pressing surface 112 and the mounting surface 111 in the optical axis direction are different, the LDA 51c can be favorably pressed in the optical axis direction, and the optical axis of the LDA 51c The pressing force in the direction can be increased.
This will be specifically described below.
When the pressing surface 112 and the mounting surface 111 are in the same plane, when the pressing member 110 is fixed and the periphery of the pressing surface is elastically deformed, a part of the pressing surface 112 is lifted from the pedestal portion 512. As a result, the direction in which the LDA 51c is pressed is inclined with respect to the optical axis direction, and the force for pressing the LDA 51c in the optical axis direction is weakened.
On the other hand, when the pressing surface 112 and the mounting surface 111 are different in the optical axis direction, when the pressing member 110 is fixed and the periphery of the pressing surface is elastically deformed, the connecting portion between the pressing surface 112 and the mounting surface 111 is elastic. It can deform | transform and can suppress that the press surface 112 floats from the positioning reference plane of a base part. As a result, the LDA 51c can be pressed in the optical axis direction. Further, since the connecting portion is also elastically deformed, the restoring force of the connecting portion is also applied to the pressing surface. As a result, the pressing force of the LDA 51c in the optical axis direction can be increased.

  Further, according to the present embodiment, three pressing surfaces are provided on the same plane, and the LDA 51c is pressed at three places in the circumferential direction. When the pressing surface is provided over the entire circumference and formed into a ring shape, the pressing force to the LDA 51c may be offset depending on the flatness of the pressing surface, and there is a possibility that the LDA 51c cannot be clamped satisfactorily. However, by providing three pressing surfaces at equal intervals in the circumferential direction, the LDA 51c can be pressed at three points as shown in FIG. 11, and the LDA 51c can be pressed evenly in the circumferential direction. In addition, since it is only necessary to increase the flatness accuracy of the three pressing surfaces, it is easier to increase the flatness accuracy than the one that increases the flatness of the entire circumference, such as a ring-shaped pressing surface. Can do. In the above description, three pressing surfaces are provided, but the same effect can be obtained with two pressing surfaces.

  Moreover, since the shape of each pressing surface is made into the same shape, the contact area of each pressing surface and LDA51c can be made the same, and LDA51c can be pressed equally.

In the present embodiment, a multi-beam scanning method is used in which a plurality of light beams are simultaneously scanned on the surface of the photoreceptor using the LDA 51c. However, if the position of each light emitting point of the LDA 51c deviates from the target, the beam pitch is targeted. Unlike the interval of, the image may be shrunk or stretched than the actual image.
When the LDA 51c is configured to be press-fitted and fixed as described in Patent Document 1, the LDA 51c is attached to a light source unit that is a separate member from the first housing in order to make the beam pitch adjustable. Needs to be rotated relative to the first housing. For this reason, the number of parts increases and the cost of the apparatus increases.
On the other hand, in the present embodiment, the light emitting portion insertion portion 752 of the light source attachment hole 76c is slightly larger than the diameter of the light emitting portion 512 of the LDA 51c, and the diameter of the pedestal portion insertion portion of the light source attachment hole 76c is the diameter of the pedestal portion. The LDA 51c can be rotated in the light source mounting hole 76c. The LDA 51c is only fixed by being sandwiched between the positioning surface 754 and the pressing surface 112 of the pressing member 110 in the optical axis direction. Therefore, the LDA 51c can be rotated in the light source mounting hole 76c simply by loosening the screw 120 and weakening the clamping force of the LDA 51c. Therefore, when the position of each light emitting point of the LDA 51c deviates from the target and the beam pitch is different from the target interval, the LDA 51c is rotated in the light source mounting hole 76c with the screw loosened to weaken the clamping force of the LDA 51c. The beam pitch can be adjusted. Therefore, the beam pitch can be easily adjusted. Moreover, since the beam pitch can be adjusted even if the LDA 51c is directly attached to the first housing 70, the number of parts can be reduced and the apparatus can be made inexpensive.

Furthermore, in this embodiment, since the pressing member 110 is configured to press the surface of the light source on the side opposite to the light beam emitting side, the LDA 51c can be easily attached and detached.
This will be specifically described below. The positioning surface 754 provided in the first housing 70 is configured to come into contact with the surface on the power feeding unit 511 side of the pedestal portion 513 of the LDA 51c, and the pressing member 110 is disposed on the surface on the light emitting portion 512 side of the pedestal portion 513 of the LDA 51a. When configured to be pressed, the LDA 51c is inserted into the light source mounting hole 76c from the inside of the first housing. Further, the pressing member 110 is screwed from the inside of the first housing. In this case, when the LDA 51c is inserted into the light source mounting hole 76c, for example, the tip of the power supply unit 511 may come into contact with the lens inside the first housing and damage the lens. Similarly, when the pressing member 110 is attached, the pressing member 110, the screw 120, a driver, or the like may come into contact with the lens and damage the lens. Moreover, since it is necessary to attach LDA51c etc. carefully so that components, such as a lens in a 1st housing | casing, may not be damaged, LDA51c attachment workability | operativity worsens. In addition, when the screwdriver is inserted into the screw 120, the components of the first housing 70 become an obstacle, and the LDA 51c mounting operation and the beam pitch adjusting operation become difficult.
On the other hand, when the positioning surface 754 is configured to contact the surface of the base portion 513 of the LDA 51c on the light emitting portion 512 side, and the pressing member 110 is configured to press the surface of the base portion 513 of the LDA 51c on the power feeding portion 511 side. The LDA 51 c and the pressing member 110 can be attached from the outside of the first housing 70. Thereby, it is possible to prevent parts such as a lens in the first housing from being damaged. Further, when the screwdriver 120 is inserted into the screw 120, the components of the first housing 70 do not get in the way, and the LDA 51c mounting work, beam pitch adjusting work, and the like can be easily performed.
Of course, when the LDA 51c and the pressing member 110 cannot be attached from the outside of the first casing 70 for some reason, the positioning surface 754 provided on the first casing 70 is connected to the power feeding section 511 side of the pedestal 513 of the LDA 51c. The pressing member 110 may be configured to press the surface of the base portion 513 of the LDA 51a on the light emitting portion 512 side.

  Further, since the pressing member 110 is fixed to the first housing 70 with the screw 120, the pressing member 110 can be easily attached and detached as compared with the case where the pressing member 110 is fixed with an adhesive or the like. The LDA 51c can be easily replaced. Further, the beam pitch can be adjusted by simply loosening the screw 120.

When the LDA 51c is fixed to the first housing 70, a control board 130 for controlling the LDA 51c is attached to the power supply unit 511 of the LDA 51c as shown in FIG. The control board 130 is fixed to the first housing 70 by screws (not shown) or the like. By attaching the control board 130 in this way, the pressing member 110 is arranged in a narrow gap between the LDA 51c and the control board 130. As a result, when the first casing 70 is attached to the second casing 60, some member collides with the pressing member 110, so that the holding force of the LDA 51 c is weakened or a pressing force that is offset from the LDA 51 c is generated. Or the rotation of the LDA 51c can be suppressed. As a result, it is possible to suppress such a problem that the position of the light emitting point is shifted from the target position and the beam pitch needs to be adjusted again.
In addition, a through hole for a driver to pass through may be provided at a location facing the screw 120 that fixes the pressing member 110 of the control board 130. As a result, the screwdriver 120 can easily access the screw 120 for fixing the pressing member 110, and the screw 120 can be loosened to easily adjust the beam pitch. Further, the pressing member 110 can be easily removed, and the LDA 51c can be easily replaced.

  Further, as shown in FIG. 13, three positioning surfaces 754 may be provided on the same plane, and the LDA 51c may be positioned at three locations in the circumferential direction. When the positioning surface is provided over the entire circumference and is formed into a ring shape, the LDA 51c may be attached with an inclination with respect to the target posture depending on the flatness of the positioning surface. However, by providing three positioning surfaces at equal intervals in the circumferential direction, the LDA 51c is positioned at three points. Therefore, since it is only necessary to increase the flatness accuracy of the three positioning surfaces, it is easy to increase the flatness accuracy compared to the positioning surface that increases the flatness of the entire circumference like a ring-shaped one. Can do. Therefore, the LDA 51c can be correctly positioned. In FIG. 13, three positioning surfaces 754 are provided, but the same effect can be obtained with two positioning surfaces.

  Further, the number of the positioning surfaces 754 is the same as the number of the pressing surfaces 112 so that the positioning surfaces 754 (dotted lines in the drawing) face the pressing surfaces 112 with the pedestal portion 513 of the LDA 51c interposed therebetween, as shown in FIG. It is preferable to configure. Thereby, the pressing force of the pressing surface 112 in the optical axis direction can be received by the positioning surface 112, and the LDA 51c can be clamped and fixed satisfactorily.

  The pressing member 110 is preferably composed of an insulating member such as resin. This is because the power feeding portion 511 of the LDA 51c penetrates the pressing member 110. For example, when the beam 120 or the light amount of the LDA 51a is adjusted while loosening the screw 120 to emit the LDA 51a, a hand or the like is applied to the pressing member 110. There is a risk that the inner periphery of the through-hole 114 (the surface facing the power feeding portion of the pressing surface 112) and the power feeding portion 511 may come into contact with each other. As a result, when the pressing member 110 is made of a conductive material, current may leak from the power feeding unit 511. In addition, when the pedestal 513 that is not at the ground level is used as the LDA 51c, if the pressing member 110 is made of a conductive material, current leaks to the pressing surface 112. In addition, when the gap between the control board 130 and the control board 130 is narrowed, a portion where the control board 130 and the pressing member 110 come into contact with each other. When the pressing member 110 is made of a conductive material, current leaks to the pressing member 110. There is also. Therefore, the current leakage to the pressing member 110 can be eliminated by configuring the pressing member 110 with an insulating member.

In addition, when it is necessary to use a conductive member such as aluminum or iron in order to obtain a necessary pressing force for holding the LDA 51c, the inner periphery of the pressing surface 112 or the through-hole 114 (the feeding of the pressing surface 112). 15 is applied between the pressing surface 112 and the pedestal portion 513, and the inner periphery of the through-hole 114 (the feeding portion facing surface of the pressing surface 112) and the feeding portion. An insulating material such as rubber may be provided between the LDA 51c and the pressing member, or an insulating material may be provided between the LDA 51c and the pressing member.
When the pedestal portion 513 of the LDA 51c is at the ground level, an insulating material is applied only to the inner periphery of the through hole 114 (the surface facing the power feeding unit of the pressing surface 112), or the inner periphery of the through hole 114 (the pressing surface facing the power feeding unit) Surface) and the power feeding unit 511 may be provided with an insulating member.
Further, when the control board 130 is attached, an insulating material may be applied to a portion of the pressing member 110 that is likely to come into contact with the control board 130, or an insulating member such as rubber may be attached.
By configuring in this way, the pressing member 110 can ensure the necessary pressing force and insulation for holding the LDA 51a.

Further, when the pressing member 110 is screwed, as shown in FIG. 16, the central portion in the longitudinal direction of the pressing member 110 is farthest from the light source mounting surface 75b, and the longitudinal outer end portion of the mounting surface 111 (as indicated by the dotted line in the figure). The enclosed portion A) has a curved shape closest to the light source mounting surface 75b. Accordingly, when the pressing member 110 is further pushed into the light source mounting surface side with the screw 120 in order to bring the mounting surface 111 of the pressing member 110 into close contact with the light source mounting surface 75b, the outer end in the longitudinal direction of the mounting surface 111 becomes the mounting surface. On the other hand, it abuts at an angle. As described above, since the outer end portion in the longitudinal direction of the mounting surface makes contact with the light source mounting surface 75b at an angle, the outer end portion in the longitudinal direction of the mounting surface 111 is caught by the light source mounting surface 75b, and the pressing member 110 is engaged. However, there is a possibility that the LDA 51c cannot be pressed evenly without deforming the target shape, or a desired pressing force cannot be obtained. In particular, when the screw 120 is fastened with a torque-controlled screwdriver, the pressing member 110 does not deform into the target shape, and the LDA 51c cannot be pressed evenly or a desired pressing force cannot be obtained. The fear increases.
Further, the light source mounting surface 75b is scraped by the outer end in the longitudinal direction of the mounting surface 111, and the scraped residue adheres to a mirror, a lens, or the like in the optical writing unit, and an abnormal image is formed, or the power feeding unit 511 of the LDA 51c. There is also a possibility that an electrical failure may occur due to adhesion.

Therefore, as shown in FIG. 17, a relief portion 756 is formed by recessing the portion facing the outer end in the longitudinal direction of the mounting surface 111 of the light source mounting surface 75 b from the other portion, and the outer side in the longitudinal direction of the mounting surface 111. It is preferable that the end and the light source mounting surface 75b are not in contact with each other.
As shown in FIG. 17, by providing a relief 756 on the light source mounting surface 75b, when the pressing member 110 is pushed into the light source mounting surface 75b with the screw 120, the outer end in the longitudinal direction of the mounting surface 111 is the light source. It does not get caught on the mounting surface 75b. As a result, the outer end in the longitudinal direction of the mounting surface 111 moves smoothly in the direction B in the drawing, and the pressing member 110 can be deformed so that the mounting surface 111 is in close contact with the light source mounting surface 75b, and the LDA 51c is evenly distributed. It can be pressed and a desired pressing force can be obtained. Further, since the light source mounting surface 75b is not scraped by the outer end portion in the longitudinal direction of the mounting surface 111, an abnormal image is formed or an electrical failure occurs due to adhesion to the power feeding unit 511 of the LDA 51c. There is no fear.

  Further, as shown in FIG. 18, the outer end portion in the longitudinal direction of the attachment surface 111 may have a curved shape. Thereby, even if the longitudinal direction outer side edge part of the attachment surface 111 contact | abuts to the light source attachment surface 75b, the longitudinal direction outer side edge part of the attachment surface 111 is not caught by the light source attachment surface 75b. Therefore, the pressing member 110 can be smoothly deformed so that the mounting surface 111 is in close contact with the light source mounting surface 75b, the LDA 51c can be pressed evenly, and a desired pressing force can be obtained. Further, since the light source mounting surface 75b is not scraped by the outer end in the longitudinal direction of the mounting surface 111, scraping scrap does not occur, the scraping scrape adheres to a lens or the like and becomes an abnormal image, or power feeding of the LDA 51c. There is no risk of adhesion to the portion 511 and an electrical failure.

  Further, a member having a low friction coefficient is attached to a contact portion of the attachment surface 111 with the outer end in the longitudinal direction of the attachment surface 111 or the outer end of the attachment surface 111 of the light source attachment surface 75b. You may suppress the catch of an edge part.

Further, as shown in FIG. 19, since the pressing member 110 is fastened with the screw 120, a force in the rotational direction is generated in the pressing member 110, and the pressing member 110 may slightly rotate in the rotational direction. When the pressing member 110 rotates, the LDA 51c pressed by the pressing member 110 rotates and the beam pitch may shift.
For this reason, as shown in FIG. 20, it is preferable to provide a pressing member positioning means for positioning the pressing member 110 before being fixed to the first housing 70 in the rotation direction.
The pressing member positioning means shown in FIG. 20 is provided on the first engaging convex portion 757a and the second engaging convex portion 757b, which protrude from the light source mounting surface 75b, and the second engaging convex portion. It is comprised by the engagement long hole 116 engaged with 757b, and the engagement round hole 117 engaged with the 1st engagement convex part 757a.
The engagement elongated hole 116 and the engagement round hole 117 are provided on the outer side in the longitudinal direction than the screw through hole 113. The lengths of the engagement holes 116 and 117 in the short direction are substantially the same as the diameters of the first and second engagement protrusions 757a and 757b. Therefore, when the engagement holes 116 and 117 and the engagement convex portions 757a and 757b are engaged, the engagement holes 116 and 117 and the engagement convex portions 757a and 757b engage with each other in the short direction. . Thereby, even if the pressing member 110 is positioned in the rotation direction and a force in the rotation direction acts on the pressing member 110 when the screw 120 is fastened, the pressing member 110 does not rotate. Therefore, the LDA 51c does not rotate when the screw is fastened, and the beam pitch is prevented from being different from the target after the LDA is attached.
Moreover, since the round hole 117 and the 1st engagement convex part 757a are fitted, it can position not only in a rotation direction but a perpendicular | vertical direction with respect to an optical axis.

Further, since the pressing member 110 rotates around the fastening position with the screw 120, the closer the fastening position is to the pressing position that presses the LDA 51c, the smaller the rotational force that acts on the LDA 51c. Further, the further away the engagement position between the engagement holes 116 and 117 and the engagement protrusions 757a and 757b is from the fastening position of the screw 120, the more the engagement holes 116 and 117 and the engagement protrusions 757a and 757b become. The amount of rotation of the pressing member 110 when there is a gap in the short direction can be reduced.
For this reason, the engagement holes 116 and 117 of the pressing member 110 are arranged on the outer side in the longitudinal direction from the screw through hole 113. Thereby, a fastening position and the press position which presses LDA51c can be closely approached, and the rotational force which acts on LDA51c can be made small as much as possible. Further, the engagement position between the elongated hole 116 and the first engagement convex portion 757 a can be provided apart from the fastening position of the screw 120 adjacent to the round hole 117. Therefore, when the pressing member 110 rotates around the fastening position of the screw 120 adjacent to the round hole 117, the movement of the pressing member 110 in the rotation direction is good due to the engagement between the elongated hole 116 and the first engagement convex portion 757a. Can be suppressed. Further, the engagement position between the round hole 117 and the second engagement protrusion 757 b can be provided away from the fastening position of the screw 120 adjacent to the elongated hole 116, and the fastening position of the screw 120 adjacent to the elongated hole 116. When the pressing member 110 is rotated around the center, the movement of the pressing member 110 in the rotation direction can be satisfactorily suppressed by the engagement between the round hole 117 and the first engagement convex portion 757a.

  Further, as shown in FIG. 21, the positioning means is formed by only the cylindrical first engaging convex portion 757a and second engaging convex portion 757b provided on the light source mounting surface 75b of the first housing 70, The first engaging convex portion 757a is brought into contact with the upper end surface which is one surface extending in the longitudinal direction of the pressing member 110, and the second engaging convex portion 757b is disposed on the other surface extending in the longitudinal direction of the pressing member 110. You may make it contact | abut with a certain lower end surface. Also in this case, the engagement position that engages with each of the engagement protrusions 757a and 757b is provided on the outer side in the longitudinal direction from the fastening position of the screw. Whether the first engagement portion 757a is brought into contact with the upper end surface or the lower end surface is determined based on the rotation direction of the pressing member when the screw is fastened. Further, the length in the vertical direction from the lower end portion of the first engagement convex portion 757 a to the upper end portion of the second engagement convex portion 757 b is substantially the same as the length in the short direction of the pressing member 110. Yes.

  Also in the configuration of FIG. 21, the rotation of the pressing member 110 can be restricted by the two engaging convex portions 757 a and 757 b, and the rotation force acting on the LDA 51 c when the screw 120 is fastened can be suppressed. And the rotation of the LDA 51c can be suppressed. Further, by providing an engagement position that engages with each of the engagement convex portions 757a and 757b in the longitudinal direction outside the fastening position of the screw 120, the fastening position of the screw 120 is brought close to a pressing position that presses the LDA 51c. It is possible to further suppress the rotational force acting on the LDA 51c when the screw 120 is fastened.

  In addition, an engagement groove is provided at a position where the upper end surface of the pressing member 110 is in contact with the first engagement convex portion 757a and at a position where the lower end surface of the pressing member 110 is in contact with the second engagement convex portion 757b. An engagement protrusion may be engaged with the engagement groove.

Further, as shown in FIG. 22, another member 118 may be provided between the head of the screw 120 and the pressing member 110. Thus, by providing the separate member 118 between the head of the screw 120 and the pressing member 110, the separate member 118 may slip between the screw head when the screw is fastened, or the pressing member and the separate member may be provided. It is possible to suppress the transmission of the rotational force of the screw to the pressing member 110 and to apply only the force in the optical axis direction to the pressing member 110.
As the separate member 118, a member having a small friction coefficient with the head of the screw 120 is desirable, and a plain washer or the like can be used. By using a member having a small friction coefficient, it is possible to suppress a rotational force applied to the separate member 118 by causing a good slip between the screw head when the screw is fastened. A minute rotational movement can be prevented.
Further, by reducing the coefficient of friction with the pressing member 110, slippage can occur between the pressing member 110 and the separate member 118, so that the rotational force can be prevented from being transmitted to the pressing member 110 as much as possible. As a result, the LDA 51c fixed by the pressing member 110 can keep the initial set position with high accuracy, and desired optical characteristics can be obtained.

Further, as shown in FIG. 23, the LDA 51c and the LDA 51d inserted into the light source mounting hole 76d immediately below the light source mounting hole 76c into which the LDA 51c is inserted may be sandwiched by one pressing member 110. Similarly, the LDA 51b inserted into the light source mounting hole 76b directly below the light source mounting hole 76a into which the LDA 51a is inserted may be sandwiched by one pressing member.
In this manner, by sandwiching the plurality of LDAs 51c with one pressing member 110, the number of parts can be reduced and the cost can be reduced. Further, the number of assembly steps can be reduced, and the manufacturing cost can be reduced.

In the above description, the pressing member 110 is fixed to the light source mounting surface 75b by fastening the screw 120. However, as shown in FIG. 24, the pressing member 110 may be fixed to the light source mounting surface 75b by the spring member 121. Good. Even with this configuration, the pressing member 110 can be deformed so that the mounting surface 111 is in close contact with the light source mounting surface 75b by the pressing force of the spring member 121, and the periphery of the pressing surface 112 can be elastically deformed. Therefore, also in this configuration, the LDA 51 c can be favorably pressed by the pressing surface 112 of the pressing member 110, and the LDA 51 c can be sandwiched between the positioning surface 754 and the pressing surface 112.
When it is desired to rotate the LDA 51c in order to adjust the beam pitch, the LDA 51c is clamped by reducing the pressing force applied to the pressing member 110 by stuffing between the light source mounting surface 75b and the spring member 121. The force is weakened, the LDA 51c can be easily rotated, and the beam pitch can be easily adjusted.

  In the above description, the example applied to the color image forming apparatus has been described. However, the present invention can also be applied to a monochrome image forming apparatus as shown in FIG.

In the above description, the multi-beam scanning optical writing unit that uses the LDA as the light source and simultaneously scans a plurality of lights on the surface of the photosensitive member has been described. However, a laser diode (LD that has one light emitting point as the light source) The present invention can also be applied to a scanning optical writing unit that simultaneously scans the surface of the photosensitive member with a single light. By sandwiching and fixing the LD between the positioning surface of the first housing and the pressing surface of the pressing member, it is possible to easily replace the LD as compared with a case where the LD is press-fitted and fixed.
In addition, since LD emits elliptical light with different divergence angles in the vertical and horizontal directions, in order for the light passing through the aperture to have a target shape, the long diameter portion of the elliptical light is slit in the aperture. It is necessary to match the direction. For this reason, the LD is attached to the first housing with the rotational direction positioned, but the LD attached to the first housing may be displaced in the rotational direction due to some factor. In such a case, the screw for fixing the pressing member to the first housing is loosened to weaken the clamping force of the LD. As a result, the LD can be rotated with the LD attached to the first housing, and the major axis portion of the elliptical light emitted from the LD can be adjusted to match the slit direction of the aperture.

As described above, the optical writing unit, which is the optical scanning device of the present embodiment that optically scans the photosensitive member, which is the scanning object, with the light beam emitted from the LDA, which is the light source, causes the LDA to abut the optical axis direction. A positioning surface serving as a positioning portion and a pressing member that presses the LDA in the optical axis direction, and the LDA is sandwiched and fixed between the pressing member and the positioning surface. With this configuration, the LDA can be easily removed from the apparatus because the holding force of the LDA is lost simply by removing the pressing member from the apparatus. Therefore, it is possible to easily replace the LDA as compared with the case where the LDA is press-fitted and fixed.
Further, since the LDA is only sandwiched between the positioning surface and the pressing member, if the pressing force of the pressing member is weakened, the clamping force to the LDA is weakened and the LDA can be rotated. Therefore, after the LDA is attached, the LDA can be rotated to adjust the beam pitch and the shape of the light emitted from the LDA.

  Also, a first optical housing that houses a cylindrical lens or a collimating lens that is an optical element that shapes the light beam emitted from the LDA into a target shape, and a polygon scanner that is a deflection scanning unit that deflects and scans the light beam. Position and fix the LDA to the housing. As described above, since the LDA is directly positioned and fixed to the first housing, the LDA is positioned and fixed to another member such as a light source unit, and then the parts are compared with those for fixing the light source unit to the first housing. The number of points can be reduced, and the apparatus can be made inexpensive.

  Further, the pressing member is fastened to the first housing which is a member having a positioning surface with a screw. Thereby, a press member can be easily attached to or detached from the first housing. Therefore, the LDA can be easily replaced as compared with the case where the pressing member is fixed with an adhesive. Further, by loosening the screw, the pressing force of the pressing member to the LDA can be weakened, and the LDA can be rotated. As a result, the LDA can be rotated with the LDA held in the first housing to adjust the beam pitch and the shape of the light emitted from the LDA.

  Moreover, you may fix to a 1st housing | casing by pressing a press member against a 1st housing | casing with a spring member. Accordingly, the pressing member can be removed simply by eliminating the pressing force of the spring member to the pressing member, and the LDA can be easily replaced as compared with the case where the pressing member is fixed with an adhesive. Further, by weakening the pressing force of the spring member to the pressing member, the pressing force of the pressing member to the LDA can be weakened, and the LDA can be rotated. As a result, the LDA can be rotated with the LDA held in the first housing to adjust the beam pitch and the shape of the light emitted from the LDA.

  The pressing member has a pressing surface that contacts the LDA and presses the LDA, and an attachment surface that is attached to the first housing. When the pressing member is fixed, at least the periphery of the pressing surface is elastically deformed. Configured. Thereby, restoring force works on the pressing surface, and the pressing surface can press the LDA in the optical axis direction. As a result, it is possible to obtain a clamping force sufficient to fix the LDA.

  Also, by making the positions of the pressing surface and the mounting surface different in the optical axis direction, when the periphery of the pressing surface is elastically deformed, it is possible to suppress the pressing surface from floating from the LDA, and the LDA can be moved in the optical axis direction. Can be pressed well. In addition, since the portion connecting the pressing surface and the mounting surface is also elastically deformed, the pressing force in the optical axis direction of the LDA can be increased.

  Moreover, when the pressing member is fixed by making the mounting surface of the pressing member parallel to the pressing surface, a force in the direction of pressing the LDA is applied to the pressing member from the fixing member (screw). As a result, it is possible to apply a pressing force to the LDA simply by fixing the pressing member, and it is not necessary to have a complicated structure for applying the pressing force to the LDA. Therefore, it is possible to apply a pressing force to the LDA with an inexpensive configuration.

  Also, by making the pressing surface perpendicular to the optical axis direction, the LDA can be pressed in the optical axis direction, and a sufficient clamping force for fixing the LDA can be obtained.

  In addition, by providing two or three pressing surfaces on the same plane, the surface area for pressing the LDA can be reduced compared to pressing the entire LDA with one pressing surface, and the flatness accuracy can be improved. The area to be increased can be reduced. Therefore, the structure which presses LDA equally can be manufactured at low cost.

  Moreover, by making the contact area of each pressing surface and LDA the same, the LDA can be pressed evenly, and the LDA can be clamped and fixed satisfactorily.

  Further, the pressing member is configured to press the surface opposite to the light beam emitting side surface of the LDA, so that the pressing member and the LDA can be attached and detached from the outside of the first housing, and the LDA can be removed. Can be easily exchanged.

  Moreover, it can prevent that the electric current which flows into LDA leaks to a press member by making a press member into an insulating member.

  Further, by providing an insulating material between the pressing member and the LDA, it is possible to prevent the current flowing through the LDA from leaking to the pressing member.

  In addition, by disposing the pressing member between the LDA and the control board that controls the LDA, when the first casing is attached to the second casing, the control board can prevent other members from striking the pressing member. Can prevent. Thereby, when attaching the 1st case to the 2nd case etc., LDA rotates, and it can control the trouble that adjustment of a beam pitch is needed again.

  Further, by having two or three positioning surfaces on the same plane, the surface area for positioning the LDA can be reduced compared to the case where one positioning surface is positioned in contact with the entire LDA. The area for increasing the accuracy of the degree can be reduced. Therefore, a configuration for positioning the LDA in the optical axis direction can be manufactured at a low cost.

  Further, since the pressing surface is configured to face the positioning surface with the LDA sandwiched therebetween, the pressing surface can receive the pressing force in the optical axis direction of the pressing surface, and has a sufficient clamping force to fix the LDA. Can be obtained.

  In addition, by providing a relief portion in which a portion facing the pressing member end portion of the first housing is recessed in the optical axis direction, the pressing member end portion is secured to the first housing when the pressing member is fixed to the first housing. The pressing member can be smoothly deformed without hitting the body. Also, the first housing is not scraped by the end of the pressing member, causing an abnormal image, for example, by shavings adhering to the lens, or by attaching to the power feeding part of the LDA, causing an electrical failure. There is no risk of stagnation.

  Moreover, even if the end portion of the attachment surface is a curved surface, the end portion of the attachment surface is not caught by the first housing, and the pressing member can be smoothly deformed. In addition, the first housing is no longer scraped by the end of the mounting surface, causing an abnormal image such as by scraping scraps adhering to the lens, or by attaching to the power feeding portion of the LDA and causing electrical problems. There is no risk of stagnation.

  Further, by configuring the pressing member to press a plurality of light sources positioned on the positioning surface, it is possible to reduce the number of components compared to pressing a single light source with a single pressing member. The apparatus can be made inexpensive. Also, the assembly man-hour can be reduced.

  Further, by providing a pressing member positioning means for positioning the pressing member before being fixed to the first casing in the rotation direction, when the pressing member is fixed to the first casing with a screw, the screw rotates on the pressing member. Even if the force is transmitted, the pressing member is not restricted by the pressing member positioning means and is not rotated. As described above, since the rotation of the pressing member at the time of fixing the pressing member can be suppressed, the rotation of the LDA pressed against the pressing member is suppressed, and the beam pitch deviates from the target by fixing the pressing member. Can be suppressed.

  Further, the pressing member positioning means includes a first engaging convex portion that comes into contact with a portion other than the central portion in the longitudinal direction of the upper end surface, which is one end surface extending in the longitudinal direction of the pressing member, and the other end surface extending in the longitudinal direction of the pressing member. It is comprised with the 2nd engagement convex part contact | abutted except the longitudinal direction center part of the lower end surface which is. When the pressing member tries to rotate at the time of fixing, the upper end surface and the lower end surface of the pressing member abut against the first and second engaging convex portions, and the rotation of the pressing member can be suppressed.

  Moreover, you may comprise a press member positioning means with the engagement convex part provided in the 1st housing | casing, and the engagement hole provided in a press member and the engagement convex part engages. Even if it comprises in this way, if a press member tries to rotate at the time of fixation, the engagement hole of a press member will contact | abut an engagement convex part, and it can suppress rotation of a press member.

  Further, the engagement position of the engagement convex portion with the pressing member is set to the end side in the longitudinal direction from the fastening position by the screw of the pressing member, thereby bringing the LDA pressing position at the center in the longitudinal direction and the fastening position close by the screw. The rotational force by the screw applied to the LDA can be reduced, and the rotation of the LDA can be suppressed.

  In addition, another member is provided between the screw and the pressing member, and at the time of fastening the pressing member, the screw is generated by sliding in the rotational direction between at least one of the screw and the other member and between the pressing member and the other member. Can be suppressed from being transmitted to the pressing member, and the rotation of the pressing member can be suppressed. Therefore, the rotation of the LDA being pressed by the pressing member is suppressed, and it is possible to suppress the beam pitch from deviating from the target by fixing the pressing member.

  Further, by using a plain washer as another member, it is possible to generate a slip in the rotational direction between the screw and the separate member and between the press member and the separate member when the pressing member is fastened. It is possible to satisfactorily suppress the force from being transmitted to the pressing member.

  In addition, by using an LDA that is a semiconductor laser as a light source, it is possible to scan light on the photoconductor satisfactorily.

  Further, by using the above-described optical writing unit in the image forming apparatus, it is possible to obtain a good image without image expansion or contraction.

3Y, 3C, 3M, 3K Image forming station 4 Optical writing unit 10Y, 10C, 10M, 10K Photoconductor 11Y, 11C, 11M, 11K Charging device 12Y, 12C, 12M, 12K Developing device 51a, 51b, 51c, 51d LDA
20 intermediate transfer belt 60 second housing 70 first housing 110 pressing member 111 mounting surface 112 pressing surface 115 insulating member 120 screw 121 spring member 130 control board 511 power supply portion 512 light emitting portion 513 pedestal portion 754 positioning surface 756 escape portion 757a 1st engagement convex part 757b 2nd engagement convex part

Japanese Patent No. 3681555

Claims (10)

In an optical scanning device that optically scans a scanning object with a light beam emitted from a light source,
An optical housing that houses an optical element that shapes the light beam emitted from the light source into a target shape and a deflection scanning unit that deflects and scans the light beam;
The optical housing has a positioning portion for positioning the light source in the optical axis direction when the light source hits in the optical axis direction,
A pressing member that presses the light source positioned by the positioning unit toward the positioning unit;
The light source is fixed by clamping the light source between the pressing member and the positioning unit, and the pressing force with respect to the light source by the pressing member is adjustable, and the pressing member is weakened by reducing the clamping force with respect to the light source. The light source can be rotated and adjusted with respect to
The positioning unit is a positioning surface perpendicular to the optical axis direction, and has two or three positioning surfaces on the same plane .   In an optical scanning device that optically scans a scanning object with a light beam emitted from a light source,
An optical housing that houses an optical element that shapes the light beam emitted from the light source into a target shape, and deflection scanning means that deflects and scans the light beam;
The optical housing has a positioning portion for positioning the light source in the optical axis direction when the light source hits in the optical axis direction,
A pressing member that presses the light source positioned by the positioning unit toward the positioning unit;
The light source is fixed by clamping the light source between the pressing member and the positioning unit, and the pressing force with respect to the light source by the pressing member is adjustable, and the pressing member is weakened by reducing the clamping force with respect to the light source. The light source can be rotated and adjusted with respect to
A plurality of positioning parts;
A plurality of light sources positioned at each positioning portion,
The optical scanning device, wherein the pressing member is configured to press a plurality of light sources. The optical scanning device according to claim 1 or 2 ,
The optical scanning device according to claim 1, wherein the pressing member is fastened to the optical housing with a screw, and the clamping force is adjusted by rotating the screw . The optical scanning device according to any one of claims 1 to 3 ,
The pressing member includes a pressing surface that is perpendicular to the optical axis direction that presses the surface opposite to the light beam emission side of the light source, and is parallel to the pressing surface and is positioned in the pressing surface and the optical axis direction. And a mounting surface that is attached to the optical housing, and at least the periphery of the pressing surface is elastically deformed when the pressing member is fixed. The optical scanning device according to claim 4 .
An optical scanning device characterized in that two or three pressing surfaces are provided on the same plane, and the contact area between each pressing surface and the light source is the same . The optical scanning device according to claim 5 .
There are a plurality of the pressing surfaces on the same plane, and the positioning surfaces are configured to have the same number as the number of the pressing surfaces on the same plane,
An optical scanning device characterized in that the pressing surface is configured to face the positioning surface across the light source. In the optical scanning device in any one of Claims 1 thru | or 6 ,
The pressing member has an attachment surface attached to the optical housing,
An optical scanning device characterized in that an end of the mounting surface is a curved surface that bends away from the optical housing . The optical scanning device according to claim 3 .
An optical scanning device comprising: a pressing member positioning means for positioning the pressing member before being fixed to the optical housing in the rotation direction. The optical scanning device according to claim 3 .
A separate member is provided between the screw and the pressing member, and when the pressing member is fastened, a slip in the rotational direction occurs between at least one of the screw and the separate member and between the pressing member and the separate member. An optical scanning device characterized by being made. A latent image carrier that carries a latent image, an optical scanning unit that forms a latent image on the surface of the latent image carrier by optical scanning, and a developing unit that develops the latent image carried on the latent image carrier. In the image forming apparatus provided,
As the light scanning unit, an image forming apparatus characterized by using any of the optical scanning apparatus according to claim 1 to 9.

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