JP2019200374A - Optical scanner and image forming apparatus - Google Patents

Abstract

To provide an optical scanner that can improve dustproof performance.SOLUTION: An optical scanner comprises: a light source that emits a laser beam; a holding member 2M that holds the light source; deflection units that deflect the laser beam emitted from the light source; and a frame body 9 that accommodates the deflection units, the frame body 9 having a positioning part that is engaged with the holding member 2M to determine the position of the holding member 2M with respect to the frame body 9. The holding member 2M has a fixing part 71M for fixing the holding member 2M to the frame body 9, and a cover part 72M that covers a gap between the holding member 2M and the frame body 9 while the position of the holding member is determined by the positioning part. The gap is a gap formed between the holding member 2M and the frame body 9 in a direction orthogonal to the optical axis direction of the laser beam, and the cover part 72M and the fixing part 71M are arranged to put the positioning part therebetween in the optical axis direction of the laser beam.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an optical scanning device suitable for an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer.

  In an electrophotographic image forming apparatus, a plurality of laser beams are used to form an electrostatic latent image on each corresponding photoconductor, visualized with yellow, magenta, cyan, and black toners, and then superimposed. A configuration for forming a color image together is known. As described above, an optical scanning device is used as a device for forming an electrostatic latent image by scanning a laser beam on the surface of a photosensitive member.

  Here, the optical scanning device described in Patent Document 1 describes a configuration for positioning a light source that emits laser light with high accuracy. 10 is an exploded perspective view (FIG. 10A) and a schematic cross-sectional view (FIG. 10B) of the optical scanning device 100 described in Patent Document 1. As shown in FIG. 10, the optical scanning device 100 includes four holding members 102 that hold four semiconductor lasers 101 that are light sources. The optical box 109 which is a frame of the optical scanning device 100 has four positioning portions 131 which are tapered grooves for positioning the four holding members 102 respectively. The four holding members 102 are positioned by engaging the cylindrical portions 102 a formed on the respective holding members 102 with respect to the respective positioning portions 131. Furthermore, the holding member 102 has a fixing portion 171 for fixing the holding member 102 to the optical box 109, and the fixing member 171 is fixed to the optical box 109 with an adhesive or the like. Is fixed to the optical box 109.

JP 2014-134781 A

  However, in the configuration described in Patent Document 1, a gap 177 (177a, 177b, 177c) is generated between the cylindrical portion 102a of the holding member 102 and the positioning portion 131. In addition, in order to prevent the posture of the holding member 102 from changing when a load is applied to the lid (not shown) that covers the upper opening of the optical box 109, the lid (not shown) of the fixing portion 171 and the optical box 109 is not shown. There is a gap (not shown) between the two parts. When there are such gaps, there is a concern that dust may enter the optical box 109 together with outside air from these gaps. In this case, dust adheres to an optical member such as a rotating polygon mirror or lens inside the optical box 109, the amount of laser light irradiated to the photosensitive member is reduced, and the image quality is deteriorated, such as whiteout of an image. Connected.

  Accordingly, the present invention has been made in view of such a current situation, and an object thereof is to provide an optical scanning device capable of improving dustproof performance.

  In order to achieve the above object, a typical configuration of an optical scanning device according to the present invention includes a light source that emits laser light, a holding member that holds the light source, and a deflection that deflects the laser light emitted from the light source. And a frame that houses the deflection unit, the frame having a positioning unit that engages with the holding member and positions the holding member with respect to the frame. The holding member includes a fixing portion for fixing the holding member to the frame body, and a cover portion that covers a gap between the holding member and the frame body in a state of being positioned by the positioning portion. And the gap is a gap formed between the holding member and the frame body in a direction orthogonal to the optical axis direction of the laser beam, and the cover part and the fixing part are The position in the optical axis direction of the laser beam Characterized in that it is arranged so as to sandwich the fit portion.

  According to the present invention, the dustproof performance can be improved in the optical scanning device.

1 is a schematic cross-sectional view of an image forming apparatus. 1 is a schematic perspective view of an optical scanning device. It is a schematic diagram for demonstrating the emission angle of the laser beam by a semiconductor laser. It is an expansion perspective view around a light source unit. It is an expansion perspective view around a light source unit. It is a cross-sectional schematic diagram around the light source unit. It is an expansion perspective view around a light source unit. It is an expansion perspective view around a light source unit. It is a cross-sectional schematic diagram around the light source unit. It is a figure which shows the structure of a prior art.

(First embodiment)
<Image forming apparatus>
Hereinafter, an overall configuration of an image forming apparatus including an optical scanning device according to a first embodiment of the present invention will be described with reference to the drawings together with operations during image formation. It should be noted that the dimensions, materials, shapes, relative arrangements, and the like of the component parts described below are not intended to limit the scope of the present invention only to those unless otherwise specified.

  The image forming apparatus A according to the present embodiment transfers the toner of four colors, yellow Y, magenta M, cyan C, and black K, to an intermediate transfer belt, and then transfers the image to a sheet to form an image. This is an image forming apparatus. In the following description, although the members using the toners of the respective colors are given subscripts Y, M, C, and K, the configuration and operation of each member are different except that the color of the toner used is different. Since they are substantially the same, subscripts are omitted as appropriate unless distinction is required.

  As shown in FIG. 1, the image forming apparatus A includes an image forming unit that transfers a toner image to a sheet, a sheet feeding unit that supplies the sheet toward the image forming unit, and a fixing unit that fixes the toner image on the sheet. With.

  The image forming unit includes a photosensitive drum 51 (51Y, 51M, 51C, 51K), a charging roller 52 (52Y, 52M, 52C, 52K) for charging the photosensitive drum 51, a developing device 54 (54Y, 54M, 54C, 54K), An optical scanning device 10 is provided. Further, an intermediate transfer unit including a primary transfer roller 57 (57Y, 57M, 57C, 57K), a secondary transfer roller 53, a secondary transfer counter roller 56, an intermediate transfer belt 58, a driving roller 50, and the like is provided. The intermediate transfer belt 58 rotates around as the driving roller 50 rotates.

  Next, an image forming operation will be described. First, when a control unit (not shown) receives an image forming job signal, the sheets S stacked and stored in the sheet stacking unit 59 are conveyed to the image forming unit by the feeding roller 61 and the conveying roller 62.

  On the other hand, in the image forming unit, first, the surface of the photosensitive drum 51 as the photosensitive member is charged by the charging roller 52. Thereafter, the optical scanning device 10 irradiates the surface of each photosensitive drum 51 with laser light L (LY, LM, LC, LK) in accordance with image data transmitted from an external device (not shown). An electrostatic latent image is formed.

  Thereafter, toner of each color is attached to the electrostatic latent image formed on the surface of the photosensitive drum 51 as a photosensitive member by the developing device 54 to form a toner image on the surface of the photosensitive drum 51. The toner image formed on the surface of the photosensitive drum 51 as the photosensitive member is primarily transferred to the intermediate transfer belt 58 by applying a primary transfer bias to the primary transfer roller 57. As a result, a full-color toner image is formed on the surface of the intermediate transfer belt 58.

  Next, the intermediate transfer belt 58 rotates and the toner image is sent to the secondary transfer portion formed by the secondary transfer roller 53 and the secondary transfer counter roller 56. Then, a secondary transfer bias is applied to the secondary transfer roller 53 in the secondary transfer portion, whereby the toner image on the intermediate transfer belt 58 is transferred to the sheet S.

  Next, the sheet S to which the toner image has been transferred is subjected to a heating and pressurizing process in the fixing device 65, whereby the toner image on the sheet S is fixed to the sheet S. Thereafter, the sheet S on which the toner image is fixed is discharged to the outside of the image forming apparatus A by the discharge roller 66.

<Optical scanning device>
Next, the configuration of the optical scanning device 10 will be described.

  FIG. 2 is a schematic perspective view of the optical scanning device 10. 2 is a diagram showing a state in which a cover 90 (see FIG. 4) corresponding to the upper surface of the frame of the optical scanning device 10 is removed in order to explain the internal configuration of the optical scanning device 10. The lid 90 is a member that covers an opening formed above the optical box 9. That is, the frame of the optical scanning device 10 includes the optical box 9 and the lid 90.

  As shown in FIG. 2, the optical scanning device 10 includes a semiconductor laser 1 (1Y, 1M, 1C, 1K), a collimator lens 3 (3Y, 3M, 3C, 3K), and a cylindrical lens 4 as light sources. Further, a deflecting unit including a rotating polygon mirror 5 and a driving motor 6 that rotates the rotating polygon mirror 5, a first scanning lens 14 (14a, 14b), a second scanning lens 15 (15a to 15d), and a mirror 8 (8a). To 8f). The collimator lens 3 is a lens for converting the laser light L emitted from the semiconductor laser 1 as a light source into parallel light.

  The semiconductor lasers 1Y and 1M and the semiconductor lasers 1C and 1K are arranged adjacent to each other at different positions in the sub-scanning direction. Each semiconductor laser 1 and collimator lens 3 are held by holding members 2 (2Y, 2M, 2C, 2K). Specifically, the semiconductor laser 1 is fixed to the holding member 2 by press fitting, and the collimator lens 3 is fixed by adhesion. These optical members are accommodated in the optical box 9.

  Next, the basic operation of the optical scanning device 10 will be described. First, the laser light L emitted from the semiconductor laser 1 as the light source passes through the collimator lens 3 and the cylindrical lens 4 and is then focused on the reflection surface 5a of the rotary polygon mirror 5 of the deflection unit.

  Here, in this embodiment, as shown in FIG. 3, the laser beams LY and LM emitted from the semiconductor lasers 1Y and 1M are in the sub-scanning direction with respect to the reference line X orthogonal to the reflecting surface 5a of the rotary polygon mirror 5. Are incident on the same reflecting surface 5a at a predetermined angle θ1. That is, the semiconductor lasers 1Y and 1M emit the laser beams LY and LM in the direction of the angle θ1 that is an angle formed with respect to the reference line X. Thereafter, the laser beams LY and LM are scanned on the surfaces of different photosensitive drums 51Y and 51M, as will be described later. The semiconductor lasers 1C and 1K have the same configuration.

  Next, each laser beam L incident on the reflecting surface 5a of the rotating polygon mirror 5 of the deflecting unit is reflected on the reflecting surface 5a which is a deflecting surface when the rotating polygon mirror 5 is rotationally driven by the drive motor 6. Deflected. Thereafter, the deflected laser light L is condensed and scanned on the surface of each photosensitive drum 51 as follows.

  That is, the laser beam LY passes through the first scanning lens 14a and the second scanning lens 15a, is reflected by the mirror 8a, and is collected on the surface of the photosensitive drum 51Y. The laser beam LM passes through the first scanning lens 14a, is reflected by the mirror 8b, passes through the second scanning lens 15b, is reflected by the mirror 8c, and is then condensed on the surface of the photosensitive drum 51M. The laser beam LC is transmitted through the first scanning lens 14b, reflected by the mirror 8e, transmitted through the second scanning lens 15c, reflected by the mirror 8d, and then condensed on the surface of the photosensitive drum 51C. The laser beam LK passes through the first scanning lens 14b and the second scanning lens 15d, is reflected by the mirror 8f, and is condensed on the surface of the photosensitive drum 51K.

  In this way, the optical scanning device 10 scans the laser light L on the photosensitive drum 51 to form an electrostatic latent image. Specifically, the angle at which the laser beam L is deflected is changed by the rotation of the rotary polygon mirror 5 of the deflecting unit, and the spot image formed by the laser beam L is scanned in the main scanning direction. The spot image formed by the laser beam L is scanned in the sub-scanning direction as the photosensitive drum 51 rotates. The sub-scanning direction is a direction orthogonal to the main scanning direction, and the main scanning direction is the same direction as the rotation axis direction of the photosensitive drum 51.

<Semiconductor laser positioning configuration>
Next, a configuration for positioning the semiconductor laser 1 in the optical box 9 as a frame will be described. In the following description, for convenience of explanation, the holding member 2 holding the semiconductor laser 1 and the collimator lens 3 is referred to as a light source unit 21 (21Y, 21M, 21C, 21K).

  4 and 5 are an enlarged perspective view and a front view around the light source unit 21. FIG. 4 shows a state where the light source unit 21 is attached to the optical box 9 as a frame, and FIG. 5 shows a state where the light source unit 21 is detached from the optical box 9 as a frame. 4A is a view of the state where the lid 90 is removed, and FIG. 4B is a view of the state where the lid 90 is attached.

  As shown in FIGS. 4 and 5, the optical box 9 as a frame is provided with positioning portions 31 (31 Y, 31 M, 31 C, 31 K) and 32 (32 Y, 32 M, 32 C, 32 K) for positioning the light source unit 21. ), Positioning portions 11 (11a, 11b) are formed. The positioning part 31 as the first positioning part and the positioning part 32 as the second positioning part are grooves having a tapered shape, more specifically, a V-shaped apex portion, and are integrally formed in the optical box 9. Formed with. The positioning part 31 as the first positioning part is formed on the outer peripheral part of the optical box 9, and the positioning part 32 as the second positioning part is formed on the rotating polygon mirror 5 side with respect to the positioning part 31.

  In addition, the holding member 2 of the light source unit 21 is formed with an engaging portion, a cylindrical portion 75 as a first engaging portion, and a cylindrical portion 76 as a second engaging portion. The cylindrical portion 76 as the second engaging portion is disposed at a position closer to the rotary polygon mirror 5 than the engaging portion and the cylindrical portion 75 as the first engaging portion. The holding member 2 of the light source unit 21 is formed with a fixing wall 71 (71Y, 71M, 71C, 71K) as a fixing portion for fixing the holding member 2 to the optical box 9. The fixing wall 71 as a fixing portion is a member formed integrally with the holding member 2 and is fixed to the optical box 9 with an adhesive, whereby the holding member 2 is fixed to the optical box 9. . Moreover, the fixed wall 71 as a fixing portion has a function of suppressing dust from the outside from entering the optical box 9 as described later.

  The light source unit 21 has cylindrical portions 75 and 76 engaged (fitted) with the positioning portions 31 and 32 as the first positioning portion and the second positioning portion of the optical box 9, and the positioning portion 31 by a spring (not shown). , 32. As a result, the light source unit 21 is positioned with respect to the optical box 9 in a direction orthogonal to the optical axis direction of the laser light L (the direction of the dashed line R shown in FIGS. 4, 5, and 7). In other words, the positioning portion 31 as the first positioning portion and the positioning portion 32 as the second positioning portion are the surface portions of the groove cut in a tapered shape, and positioning is performed by fitting the cylindrical portions 75 and 76 therein. Done. Further, the light source unit 21 causes the abutment portion 78 (78Y, 78M, 78C, 78K) formed on the fixed wall 71 of the holding member 2 to abut on the positioning portion 11 that is the outer peripheral surface of the optical box 9, thereby making the laser The position of the light L with respect to the optical box 9 in the optical axis direction is positioned. In the case where the semiconductor laser 1 is a multi-laser having a plurality of light sources, the light source unit 21 is rotated around the optical axis of the laser light L to adjust the interval of the laser light L on the photosensitive drum 51 in the sub-scanning direction, and then the optical It is fixed to the bonding part 11a provided in the box 9 with an adhesive.

  In addition, by increasing the distance between the positioning portion 31 and the positioning portion 32 in the optical axis direction of the laser light L, the light source unit 21 is prevented from being displaced relative to the positioning portion 31 by a relative height. The positioning accuracy with respect to the optical box 9 can be improved. As a result, the angle deviation of the angle θ1 shown in FIG. 2 can be reduced. Further, by setting the taper angle θ2 of the positioning portions 31 and 32 to 60 ° to 80 °, the center axis of the light source unit 21 can be easily centered.

  FIG. 6 is a schematic cross-sectional view around the light source unit 21. As shown in FIG. 6, gaps 77 (77 a, 77 b, 77 c) are generated between the cylindrical portion 75 of the light source unit 21 and the positioning portion 31. Further, in order to prevent the posture of the light source unit 21 from changing when a load is applied to the lid 90 of the optical box 9, a gap 79 (see FIG. 5) is formed between the fixed wall 71 and the lid 90 of the optical box 9. 4 (b)). When there are the gap 77 and the gap 79 as described above, dust enters into the optical box 9 from these gaps together with the outside air due to the influence of the air flow E (FIG. 4B) generated by the rotation of the drive motor 6. There is a risk that optical performance and image quality will deteriorate. In particular, most of the dust that has entered the optical box 9 from the gap 79 due to the airflow E passes through the gap 77a between the cylindrical portion 75 and the positioning portion 31 in the direction perpendicular to the optical axis direction and the vertical direction of the laser light L. It penetrates further into the optical box 9.

  Therefore, in order to cover the gap 77, in the present embodiment, as shown in FIGS. 4 and 5, the light source unit 21 is provided with a dustproof wall 72 (72Y, 72M, 72C, 72K) as a cover portion. The dust-proof wall 72 as a cover portion is a member that is positioned inside the optical box 9 relative to the fixed wall 71 and is integrally formed with the holding member 2, and is in the sub-scanning direction, that is, in the optical axis direction of the laser beam L. It has a shape that is elongated in the orthogonal height direction. In addition, the fixed wall 71 has the same rectangular plane as the dust-proof wall 72.

  When the light source unit 21 is positioned with respect to the optical box 9, the dust-proof wall 72 positioned inside the optical box 9 as the cover portion is located inside the optical wall 9 with respect to the optical wall of the laser beam L together with the fixed wall 71 as the fixed portion. It arrange | positions so that the positioning part 31 may be inserted | pinched in a direction. The fixing wall 71 as the fixing portion and the dust-proof wall 72 as the cover portion allow the clearance 77 of the laser light L to be generated when the cylindrical portion 75 as the engaging portion of the light source unit 21 is engaged with the positioning portion 31. Covering from the inside of the optical box 9 in the optical axis direction. Specifically, the fixed wall 71 as the fixed portion is disposed adjacent to the positioning portion 31 outside the optical box 9, and the dust-proof wall 72 as the second cover portion is adjacent to the positioning portion 31 inside the optical box 9. The gap 77 is covered by the both from the optical axis direction of the laser beam L. Further, in order to cover the gap 77 as a whole, the width in the height direction perpendicular to the optical axis direction of the laser light L of the fixed wall 71 and the dustproof wall 72 is configured to be larger than the width of the cylindrical portion 75 in the same direction. Yes.

  Thereby, it is possible to prevent dust from entering the optical box 9 from the gap 77. In particular, since the fixed wall 71 and the dust-proof wall 72 cover the gap 77a in which dust is most likely to enter from the optical axis direction of the laser light L, it is possible to effectively prevent dust from entering the optical box 9 through the gap 77a. can do. Even if the gap 77 cannot be completely blocked by the fixed wall 71 and the dust-proof wall 72, the dust-proof performance is improved by reducing the gap 77. Further, the closer the fixed wall 71 and the dust-proof wall 72 are in the optical axis direction of the laser light L, the more the dust-proof performance is improved. Thus, according to the configuration of the present embodiment, the optical scanning device 10 can position the semiconductor laser 1 with high accuracy and improve the dustproof performance.

(Second Embodiment)
Next, the configuration of the image forming apparatus including the optical scanning device according to the second embodiment of the present invention will be described. The same parts as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

  FIG. 7 is a perspective view of the periphery of the light source unit 21 according to the present embodiment. As shown in FIG. 7, the light source unit 21 according to this embodiment includes two dust-proof walls 73 and 74 as a second cover part and a third cover part in addition to the fixed wall 71 and the dust-proof wall 72. Other configurations are the same as those in the first embodiment.

  The dust-proof wall 73 as the second cover part and the dust-proof wall 74 as the third cover part have the same shape as the dust-proof wall 72. That is, the dust-proof walls 73 and 74 as the second cover part and the third cover part are formed integrally with the holding member 2 and have a shape extending in a direction perpendicular to the optical axis direction of the laser light L. ing.

  When the light source unit 21 is positioned with respect to the optical box 9, the dust-proof walls 73 and 74 as the second cover part and the third cover part are arranged so as to sandwich the positioning part 32 in the optical axis direction of the laser light L. The The dust-proof walls 73 and 74 cover a gap generated when the cylindrical portion 76 of the light source unit 21 is engaged with the positioning portion 32 from the optical axis direction of the laser light L. Specifically, the dust-proof wall 73 as the second cover portion is disposed adjacent to the positioning portion 32 on one side in the optical axis direction, and the dust-proof wall 74 as the third cover portion is adjacent to the other side. It arrange | positions and covers a clearance gap from the optical axis direction of the laser beam L by both. Further, in order to entirely cover this gap, the width of the dust-proof walls 73 and 74 in the direction perpendicular to the optical axis direction of the laser light L is configured to be larger than the width of the cylindrical portion 76 in the same direction.

  With such a configuration, even when dust enters the inside of the optical box 9, it is possible to prevent the dust from entering the rotary polygon mirror 5 by the dustproof walls 73 and 74, and to further improve the dustproof performance. Can be improved.

(Third embodiment)
Next, the configuration of the image forming apparatus including the optical scanning device according to the third embodiment of the present invention will be described. The same parts as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  8 and 9 are a perspective view and a schematic cross-sectional view around the light source unit 21 according to the present embodiment. As shown in FIGS. 8 and 9, the configuration of the present embodiment is a configuration in which an elastic member 80 is added to the configuration of the second embodiment.

  The elastic member 80 is provided between the fixed walls 71M and 71K and the dustproof walls 72M and 72K so as to be in contact with the lid 90, and when the cylindrical portions 75M and 75K are engaged with the positioning portions 31M and 31K. The generated gap 77 is covered from a direction orthogonal to the optical axis direction of the laser light L. As the material of the elastic member 80, a soft material such as urethane foam, hot melt adhesive, or ultraviolet curable adhesive can be used so that the posture of the light source unit 21 can be easily maintained.

  By providing the elastic member 80 in this way, when the cylindrical portions 75M and 75K of the holding members 2M and 2K are engaged with the positioning portions 31M and 31K, a gap 77 generated on the upper side in the vertical direction of the positioning portions 31M and 31K. It can be lost. Accordingly, the dustproof performance can be further improved.

  Even when the lid 90 is pressurized by an impact or the like when dropped, the pressure is absorbed by the compression of the elastic member 80, and the pressure transmitted to the light source units 21M and 21K is reduced. Therefore, it becomes easy to maintain the posture of the light source units 21M and 21K.

  In addition, although this embodiment demonstrated the structure which provides the elastic member 80 between the fixed walls 71M and 71K and the dust-proof walls 72M and 72K, this invention is not limited to this. In other words, the elastic member 80 may be provided between the fixed walls 71Y and 71C and the dustproof walls 72Y and 72C. In this case, the elastic member 80 is pressed against the holding members 2Y and 2C with a leaf spring, for example, so that the elastic member 80 does not fall off. Further, another elastic member may be further provided at a position between the dustproof wall 73 and the dustproof wall 74. Thereby, dustproof performance can further be improved.

  In the first to third embodiments, the configuration in which four light source units 21 are attached to one optical box 9 has been described. However, the present invention is not limited to this, and the number of light source units 21 may be any number. it can.

1. Semiconductor laser (light source)
2 ... Holding member 3 ... Collimator lens (lens)
5 ... Rotating polygon mirror (deflection part)
6 ... Drive motor (deflection part)
9 ... Optical box (frame)
DESCRIPTION OF SYMBOLS 10 ... Optical scanning device 31 ... Positioning part (1st positioning part)
32 ... Positioning part (second positioning part)
51 ... Photosensitive drum (photoconductor)
71 ... Fixed wall (fixed part)
72 ... Dust barrier (cover, first cover)
73 ... Dust barrier (second cover part)
74 ... Dust barrier (third cover)
75. Cylindrical portion (engagement portion, first engagement portion)
76. Cylindrical portion (second engaging portion)
78 ... Abutting portion 80 ... Elastic member 90 ... Lid (frame)
A: Image forming apparatus

Claims (10)

A light source that emits laser light;
A holding member for holding the light source;
A deflecting unit for deflecting the laser light emitted from the light source;
A frame that houses the deflection unit, the frame having a positioning unit that engages with the holding member and positions the holding member with respect to the frame;
An optical scanning device comprising:
The holding member includes a fixing portion for fixing the holding member to the frame body, and a cover portion that covers a gap between the holding member and the frame body in a state of being positioned by the positioning portion, Have
The gap is a gap formed between the holding member and the frame body in a direction orthogonal to the optical axis direction of the laser beam,
The optical scanning device, wherein the cover part and the fixing part are arranged so as to sandwich the positioning part in the optical axis direction of the laser light.   The optical scanning device according to claim 1, wherein the fixing portion includes a flat portion having the same shape as the cover portion. The frame includes an optical box having the positioning portion formed therein and an opening on an upper surface, and a lid that covers the opening of the optical box,
The elastic member which is provided between the said fixing | fixed part and the said cover part so that it may contact with the said cover part, and covers the said clearance gap from the direction orthogonal to the said optical axis direction is provided. 2. The optical scanning device according to 2. When the positioning portion is a first positioning portion, a portion of the holding member that engages with the first positioning portion is a first engaging portion, and the cover portion is a first cover portion,
The frame includes a second positioning unit for positioning the holding member at a position closer to the deflection unit than the first positioning unit in the optical axis direction;
The holding member is disposed adjacent to one side in the optical axis direction with respect to the second positioning portion, a second engaging portion that is positioned by engaging with the second positioning portion, and the second positioning portion. A second cover portion that covers a gap generated when the engaging portion engages with the second positioning portion from one side in the optical axis direction, and adjacent to the other side in the optical axis direction with respect to the second positioning portion And a third cover portion that covers a gap generated when the second engaging portion engages with the second positioning portion from the other side. The optical scanning device according to claim 1.   5. The optical axis of laser light emitted from the light source is tilted in a sub-scanning direction with respect to a direction orthogonal to a deflection surface of the deflection unit. Optical scanning device.   The width of the cover part is larger than the width of the part engaging the positioning part in the holding member with respect to the height direction orthogonal to the optical axis direction. The optical scanning device according to Item.   The optical scanning device according to claim 1, wherein the fixing portion includes a contact portion that contacts the frame body and determines a position of the holding member in the optical axis direction. .   The part of the holding member that engages with the positioning portion is cylindrical, and the positioning portion of the frame is a tapered groove. Optical scanning device.   9. The optical scanning device according to claim 1, wherein the holding member further holds a collimator lens through which the laser light emitted from the light source is transmitted. A photoreceptor,
An image forming apparatus comprising: the optical scanning device according to claim 1, wherein an electrostatic latent image is formed by scanning a laser beam on the surface of the photosensitive member.

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