JP4578214B2 - Optical scanning apparatus and image forming apparatus - Google Patents

Description

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

  An image forming apparatus such as a laser printer includes an optical scanning device that emits a light beam according to image data from a light source and scans the surface of the photosensitive member (for example, see Patent Document 1).

  The optical scanning device described in Patent Document 1 will be described with reference to FIGS. The optical scanning device 100 includes semiconductor lasers (hereinafter referred to as LDs) 101a and 101b that are light sources, cylindrical lenses 102a and 102b that collect light beams La and Lb emitted from the LDs 101a and 101b, and around the center line. The light beams La and Lb that are driven to rotate and pass through the cylindrical lenses 102a and 102b are deflected. The light beams La and Lb deflected by the deflector 103 are scanned at a constant speed on the surface of the photosensitive member (not shown). The scanning optical system 104, the LDs 101a and 101b, the cylindrical lenses 102a and 102b, the deflector 103, the housing (not shown) that holds the scanning optical system 104, and the like are configured.

  The two LDs 101a and 101b are arranged in the vertical direction, and the two cylindrical lenses 102a and 102b are arranged on the optical axis of the light beams La and Lb emitted from the LDs 101a and 101b and arranged in the vertical direction.

  A lens holding portion 105 for holding the two cylindrical lenses 102a and 102b is formed in the housing. The lens holding portion 105 is a stepped recess formed in the wall portion 106 disposed at a position orthogonal to the optical axes of the light beams La and Lb emitted from the LDs 101a and 101b. The upper portion wide portion 107 and the lower step And a narrow portion 108 on the side. One cylindrical lens 102a is held in the upper wide portion 107, and the other cylindrical lens 102b is held in the lower narrow portion 108.

  The cylindrical lens 102b is held with both end surfaces in the width direction being in contact with the wall surfaces 108a on both sides of the narrow portion 108, and the bottom surface being in contact with the bottom surface 108b of the narrow portion 108. Adhesive is injected between both end faces of the cylindrical lens 102b and the wall surface 108a, and between the lower surface and the bottom face 108b of the cylindrical lens 102b, and the cylindrical lens 102b is bonded and fixed.

  The cylindrical lens 102a is held with both end surfaces in the width direction in contact with the wall surfaces 107a on both sides of the wide portion 107, and the bottom surface on both ends is in contact with the step surface 107b between the narrow portions 108. Yes. Adhesive is injected between the both end surfaces of the cylindrical lens 102a and the wall surface 107a, and between the lower surface of both ends of the cylindrical lens 102a and the stepped surface 107b, and the cylindrical lens 102a is bonded and fixed.

  The procedure for holding the cylindrical lenses 102a and 102b with the lens holding unit 105 is to drop the cylindrical lens 102b into the narrow portion 108, align and fix it by injecting an adhesive, and then fix the cylindrical lens 102a to the wide portion 107. After being positioned and aligned, the adhesive is injected and fixed.

  Further, as disclosed in Patent Document 2, as an optical scanning device including four LDs that emit light beams according to different color image data, four LDs and four cylindrical members facing each LD are disclosed. A lens in which lenses are arranged at substantially equal intervals around a deflector is known.

Japanese Patent No. 2691717 JP 2004-280056 A

  However, in the invention disclosed in Patent Document 1, two cylindrical lenses 102a and 102b having different length dimensions in the width direction are used. These cylindrical lenses 102a and 102b have the same required length in the width direction. Therefore, if the length in the width direction of the cylindrical lens 102b is the minimum required length, the width direction of the cylindrical lens 102a. These dimensions are formed larger than necessary.

  For this reason, in the process of manufacturing the cylindrical lenses 102a and 102b, material is wasted, which causes an increase in cost.

  Further, in the structure in which four LDs and cylindrical lenses are arranged around the deflector as in the invention disclosed in Patent Document 2, each LD and the cylindrical lens must be arranged at a certain interval. The width dimension in the direction along the arrangement direction of the cylindrical lenses becomes large, and the optical scanning device becomes large.

  An object of the present invention is to reduce the size of an optical scanning device by installing a light source and a cylindrical lens within a narrow installation width.

  Another object of the present invention is to reduce the cost by making the shape of the cylindrical lens common.

The optical scanning device according to the first aspect of the invention deflects the light beam emitted from the light source with a rotationally driven deflector, and scans the surface of the photosensitive member with the light beam deflected by the deflector. in, disposed in a direction intersecting obliquely with respect to the rotation center of the front Symbol deflector, a plurality of light sources for emitting against the light beam corresponding to image data of different colors the deflector, before Symbol source A plurality of cylindrical lenses for condensing the emitted light beam toward the deflector; a housing for holding the light source, the cylindrical lens, and the deflector ; and a plurality of the cylindrical lenses formed in the housing. A staircase-shaped mounting portion that is mounted, wherein the staircase-shaped mounting portion includes a plurality of cylindrical lenses that are mounted in the scanning direction of the light beam. The plurality of placement units are arranged in different positions, and the plurality of placement units are stepwise arranged at different heights in the vertical direction perpendicular to the scanning direction of the light beam, The cylindrical lenses arranged in each are arranged adjacent to each other in the scanning direction of the light beam and at different heights in the vertical direction, and the interval between the end portions of the adjacent cylindrical lenses is the scanning of the light beam. It is characterized by being arranged at a position where 0 or overlap in the direction .

According to a second aspect of the invention, in the optical scanning apparatus according to claim 1, being pre Machinery stepped mounting portion is formed, placed on said cylindrical lens is adhesively bonded to the stepped mounting portion It is characterized by .

According to a third aspect of the present invention, in the optical scanning device according to the second aspect, at least a pair of protrusions are formed on the stepped mounting portion, and the cylindrical lenses are mounted on the upper end surfaces of these protrusions and are adjacent to each other. adhesive between the projections, characterized in that it is filled.

According to a fourth aspect of the present invention, in the optical scanning device according to the first aspect, a stepped mounting portion on which the plurality of cylindrical lenses are mounted is formed in the housing, and the stepped mounting portion is mounted. has been the cylindrical lens is characterized in that it is pressed and fixed by the pressing fixing member.

According to a fifth aspect of the present invention, in the optical scanning device according to the fourth aspect of the present invention, a plurality of the pressing and fixing members are respectively provided on the plurality of mounting portions, and the plurality of corresponding cylindrical lenses are pressed and fixed, respectively. Among the plurality of pressing fixing members that press and fix the plurality of adjacent cylindrical lenses, the pressing fixing member positioned above is positioned on the other cylindrical lens side where the cylindrical lens positioned above is positioned below. characterized in that it also serves as a member for restricting the move.

According to a sixth aspect of the invention, in the optical scanning apparatus according to claim 4 or 5, wherein said pressing and fixing member may be provided one by one corresponding to each of the cylindrical lenses.

According to a seventh aspect of the present invention, in the optical scanning device according to the fourth or fifth aspect, in the pressing and fixing member, a portion for pressing and fixing the one cylindrical lens and a portion for pressing and fixing the other cylindrical lens are integrated. It is characterized by being formed.

The invention of claim 8, wherein, in the optical scanning apparatus according to any one of claims 1 to 7, a plurality of the light source is characterized by being unitized.

The invention of claim 9, wherein, in the optical scanning apparatus according to any one of claims 1 to 8, a plurality of the cylindrical lenses is characterized in that it is formed in the same size.

According to a tenth aspect of the present invention, there is provided an image forming apparatus comprising: a photosensitive member on which an electrostatic latent image is formed; and a surface of the photosensitive member that is scanned by a light beam emitted from the light source. An optical scanning device according to any one of claims 1 to 9, which writes an electrostatic latent image on the developing device, a developing device that develops the electrostatic latent image formed on the surface of the photoconductor to form a toner image, and the toner image on the surface of the photoreceptor, characterized by comprising a transfer device for transferring the transfer object.

According to the optical scanning device of the first aspect, the cylindrical lenses respectively arranged on the plurality of mounting portions are arranged adjacent to each other in the scanning direction of the light beam and at different heights in the vertical direction. In addition, since the interval between the end portions of the adjacent cylindrical lenses is arranged at a position such that it is 0 or overlaps in the scanning direction of the light beam , a plurality of cylindrical lenses and light sources should be installed within a narrow installation width. Thus, the optical scanning device can be downsized.

  According to the optical scanning device of the second aspect of the present invention, it is possible to reliably fix the position in a state where the plurality of cylindrical lenses are arranged in a step shape.

  According to the optical scanning device of the third aspect of the present invention, it is possible to easily perform an operation of bonding and fixing a plurality of cylindrical lenses arranged in a staircase pattern with an adhesive.

  According to the optical scanning device of the invention described in claim 4, the position of the plurality of cylindrical lenses can be surely fixed in a state of being arranged stepwise, and maintenance and replacement of the cylindrical lenses can be performed as necessary. Can do.

  According to the optical scanning device of the fifth aspect of the invention, the movement of the cylindrical lens toward the other cylindrical lens can be regulated by the pressing and fixing member without providing a new member.

  According to the optical scanning device of the sixth aspect of the present invention, it is possible to form a pressing and fixing member that applies an appropriate pressing force to each cylindrical lens.

  According to the optical scanning device of the seventh aspect of the invention, a plurality of cylindrical lenses can be pressed and fixed by one pressing and fixing member, and the number of parts of the pressing and fixing member can be reduced.

  According to the optical scanning device of the eighth aspect of the invention, since the plurality of light sources are unitized, the structure can be made cheaper than when each light source is provided as an individual unit.

  According to the optical scanning device of the ninth aspect, since the plurality of cylindrical lenses are formed in the same size, it is sufficient to prepare one type of cylindrical lens of the same size, and the cost can be reduced by reducing the number of types of components. Can be achieved.

  According to the image forming apparatus of the tenth aspect, the same effect as that of any one of the first to ninth aspects can be obtained.

  A first embodiment of the present invention will be described with reference to FIGS. The image forming apparatus according to the present embodiment is a so-called tandem color printer, and FIG. 1 is a front view showing a schematic structure inside the color printer 1.

  In the apparatus main body 2 of the color printer 1, an image forming unit 3, an optical scanning device 4, a paper feeding device 5, a fixing device 6 and the like are accommodated.

  The image forming unit 3 includes four image forming units 7Y, 7C, 7M, and 7K that form toner images of different colors (the subscripts of Y, C, M, and K are yellow, cyan, magenta, and black, respectively). It means that these subscripts are omitted if necessary.) The intermediate transfer unit 8 is located above the image forming unit 7, the secondary transfer roller 9 and the like.

  The structure of the four image forming units 7 is the same. A drum-shaped photoconductor 10 that is rotationally driven in the direction of an arrow, a charging roller 11 arranged around the photoconductor 10 in the order of an electrophotographic process, and a developing device 12. And the cleaning device 13 and the like. The four photoconductors 10 are arranged in parallel and at equal intervals. Each photoconductor 10 has a structure in which an organic semiconductor layer, which is a photoconductive substance, is provided on the surface of an aluminum cylinder having a diameter of about 30 to 100 mm, and the uniformly charged surface is emitted from the optical scanning device 4. An electrostatic latent image is formed by scanning with the light beam. By supplying toner from the developing device 12 to the surface of the photoreceptor 10 on which the electrostatic latent image is formed, the electrostatic latent image is developed and a toner image is formed. It should be noted that a belt-shaped photoconductor may be used instead of the drum-shaped photoconductor 10.

  The intermediate transfer unit 8 includes an intermediate transfer belt 14 that is a transfer target, three rollers 15, 16, and 17 that rotatably support the intermediate transfer belt 14, and a toner image formed on the surface of the photoreceptor 10. 14 includes a primary transfer roller 18 that is a transfer device that transfers the toner to a cleaning device 14, a cleaning device 19, and the like. One of the three rollers 15, 16, 17 is used as a driving roller to which a driving force for rotating the intermediate transfer belt 14 is transmitted. The intermediate transfer belt 14 is, for example, a belt based on a resin film or rubber having a base thickness of 50 to 600 μm, and has a resistance value capable of transferring a toner image from the photoreceptor 10.

  The paper feeding device 5 feeds the recording medium S from a paper feeding roller 21 that feeds the recording medium S from a paper feeding cassette 20 accommodated in the main body 2 and a manual feed tray 22 attached to the side surface of the main body 2. A paper feed roller 23 for paper, a registration roller 24 for adjusting timing for feeding the recording medium S to a transfer position between the intermediate transfer belt 14 and the secondary transfer roller 9 are provided.

  The fixing device 6 includes a fixing roller 6a and a pressure roller 6b, and fixes the toner image transferred to the recording medium S by applying heat and pressure to the recording medium S to which the toner image is transferred.

  FIG. 2 is a perspective view showing a part of the optical scanning device 4. The optical scanning device 4 includes four LDs 25Y, 25C, 25M, and 25K, which are light sources that emit laser beams L corresponding to image data of different colors, and parallel laser beams L emitted from the LDs 25. Collimating lenses 26Y, 26C, 26M, and 26K to be converted into cylindrical lenses, and cylindrical lenses 27Y, 27C, 27M, and 27K that condense the laser light L that has passed through the collimating lens 26, and are rotated around the center line and transmitted through the cylindrical lens 27. A deflector 28 that deflects the laser light L, a scanning optical system 29 (see FIG. 1) such as a lens and a mirror that guides the light beam deflected by the deflector 28 so as to scan the surface of the photoreceptor 10, and the like. ing. The LD 25, the collimating lens 26, the cylindrical lens 27, the deflector 28, and the scanning optical system 29 are accommodated in a housing 30 (see FIG. 1).

  Of the four LD 25 and the four collimating lenses 26, two LD 25Y, 25C and two collimating lenses 26Y, 26C are unitized to form a first LD unit 31, and two LD 25M, 25K and two collimating lenses 26M. , 26K are unitized to form a second LD unit 32. The structure of the first LD unit 31 and the second LD unit 32 is the same.

  FIG. 3 is a front view showing the positional relationship between the LD 25M and the LD 25K in the second LD unit 32. As shown in FIG. The two LDs 25M and 25K are arranged so as to face the outer peripheral surface around the rotation center of the deflector 28 and obliquely intersect the rotation center of the deflector 28. Although not shown, the two LDs 25Y and 25C in the first LD unit 31 are similarly opposed to the outer peripheral surface around the rotation center of the deflector 28 with respect to the rotation center of the deflector 28. It is arranged in a direction that crosses diagonally.

  FIG. 4 is a perspective view showing the positional relationship between the cylindrical lenses 27M and 27K that collect the laser light L emitted from the LDs 25M and 25K of the second LD unit 32. FIG. The two cylindrical lenses 27M and 27K are arranged stepwise on the optical path of the laser light L emitted from the LDs 25M and 25K toward the deflector 28, and the ends of the adjacent cylindrical lenses 27M and 27K are “d”. It arrange | positions so that it may overlap with the space | interval of. The interval “d” may be set to “0”. Although not shown, the positional relationship between the cylindrical lenses 27Y and 27C that condense the laser light L emitted from the LDs 25Y and 25C of the first LD unit 31 is set in the same manner. All the cylindrical lenses 27Y, 27C, 27M, and 27K are formed in the same size, and the width dimension L1 of the cylindrical lens 27M shown in FIG. 4 is the same as the width dimension L2 of the cylindrical lens 27K.

  FIG. 5 is a side view showing a mounting state of the cylindrical lenses 27M and 27K in the housing 30, and FIG. 6 is a front view showing a mounting state of the cylindrical lenses 27M and 27K in the housing 30. The housing 30 is formed with a stepped mounting portion 33 having a stepped shape for mounting the cylindrical lenses 27M and 27K. In the two regions where the cylindrical lenses 27M and 27K are placed in the stepped placement portion 33, a pair of protrusions 34 that are in contact with the bottom surfaces of the placed cylindrical lenses 27M and 27K are formed. An adhesive 35 is filled between the pair of protrusions 34, and the cylindrical lenses 27 </ b> M and 27 </ b> K are bonded and fixed to the stepped mounting portion 33 by the adhesive 35.

  In such a configuration, in this color printer 1, the laser light L emitted from the LD 25 of the optical scanning device 4 passes through the collimator lens 26 and the cylindrical lens 27, is deflected by the deflector 28, and is deflected by the deflector 28. The laser beam scans the surface of the photoconductor 10 at a constant speed via the scanning optical system 29, and an electrostatic latent image is written on the surface of the photoconductor 10 that is uniformly charged by the charging roller 11. The electrostatic latent image is developed with the toner supplied from the developing device 12 to form a toner image. The toner image formed on the surface of each photoconductor 10 is formed in a different color corresponding to the color of the toner accommodated in each developing device 12.

  The toner images of different colors formed on the respective photoconductors 10 are transferred onto the intermediate transfer belt 14 that moves in synchronization with the photoconductor 10 by the transfer action of the primary transfer roller 18. Then, the color toner images are formed on the intermediate transfer belt 14 by sequentially transferring the toner images of different colors formed on the respective photoreceptors 10 onto the intermediate transfer belt 14.

  The color toner image on the intermediate transfer belt 14 is fed from the paper feed cassette 20 or the manual feed tray 22 and sent to a transfer position between the intermediate transfer belt 14 and the secondary transfer roller 9 by the registration roller 24 at a timing. Is transferred onto the recording medium S. The recording medium S to which the color toner image has been transferred is subjected to fixing processing by the fixing device 6 and is discharged onto a paper discharge tray 36 formed on the upper surface of the apparatus main body 2 after the fixing processing.

  Here, in the optical scanning device 4 of the present embodiment, the two LDs 25M and 25K (or 25Y and 25C) are opposed to the outer peripheral surface around the rotation center of the deflector 28 with respect to the rotation center of the deflector 28. The cylindrical lenses 27M, 27K (or 27Y, 27C) that are arranged in an obliquely intersecting direction and collect the laser light L emitted from these LD25M, 25K (or 25Y, 25C) are laser light L Are arranged in a step-like manner so that adjacent end portions partially overlap on the optical path toward the deflector 28, the LD 25 and the cylindrical lens 27 can be installed within a narrow installation width, and the optical scanning device 4 can be reduced in size.

  Further, since the LD 25M and 25K (or 25Y and 25C) are unitized to form the first LD unit 31 and the second LD unit 32, as compared with the case where each LD 25 is provided as an independent unit. An inexpensive structure can be obtained.

  Since all the cylindrical lenses 27 are formed to have the same dimensions, it is sufficient to prepare one type of cylindrical lens 27 of the same size, and the cost can be reduced by reducing the number of types of components.

  Since the cylindrical lenses 27M and 27K (or 27Y and 27C) are mounted on the staircase-shaped mounting portion 33 formed in a staircase shape, the cylindrical lenses 27M and 27K (or 27Y and 27C) are reliably stepped. Can be arranged.

  After adjusting the positions of the cylindrical lenses 27M and 27K (or 27Y and 27C) placed on the stepped placement portion 33, the adhesive 35 is filled between the adjacent protrusions 34, whereby the stepped placement portion 33 is filled. The cylindrical lenses 27 </ b> M and 27 </ b> K (or 27 </ b> Y and 27 </ b> C) placed on the substrate can be reliably fixed by the adhesive 35.

  A second embodiment of the present invention will be described with reference to FIGS. The same parts as those of the first embodiment shown in FIGS. 1 to 6 are denoted by the same reference numerals, and the description thereof is omitted (the same applies to the following embodiments). The basic structure of the present embodiment is the same as that of the first embodiment, and the difference between the present embodiment and the first embodiment is that the cylindrical lens 27 placed on the stepped placement portion 33. This is a fixed structure. In the present embodiment, the cylindrical lens 27 placed on the stepped placement portion 33 is pressed and fixed by a pressing and fixing member 40 formed of sheet metal or resin.

  FIG. 9 is a perspective view showing the pressing and fixing member 40. The pressing and fixing member 40 has an opening 40 a that allows the laser light L emitted from the LD 25 to pass through and be incident on the cylindrical lens 27, a first pressing portion 40 b that presses the upper surface of the cylindrical lens 27, and the cylindrical lens 27. A round hole 40d is formed through which a second pressing portion 40c that presses the edge portions on both sides of the front side and a screw 41 (see FIG. 7) that screws the pressing fixing member 40 to the housing 30 are inserted.

  FIG. 7 is a side view showing a mounting state of the cylindrical lenses 27M and 27K in the housing 30, and FIG. 8 is a front view showing a mounting state of the cylindrical lenses 27M and 27K in the housing 30. The housing 30 is provided with restriction bosses 42a, 42b, 43a, 43b as members for positioning the cylindrical lenses 27M, 27K placed on the protrusions 34 of the stepped placement portion 33 and restricting the displacement. Is formed. The restriction boss 42a abuts on one side surface in the width direction of the cylindrical lens 27M, and restricts the movement of the cylindrical lens 27M in a direction away from the cylindrical lens 27K. The restricting boss 42b is in contact with one side surface in the width direction of the cylindrical lens 27K, and restricts the cylindrical lens 27K from moving in a direction away from the cylindrical lens 27M. The restricting boss 43a abuts on the edges on both sides of the rear surface of the cylindrical lens 27M, and restricts the cylindrical lens 27M from moving in a direction away from the LD 25M. The restricting boss 43b is in contact with the edges on both sides of the rear surface of the cylindrical lens 27K, and restricts the cylindrical lens 27K from moving in a direction away from the LD 25K.

  The wall portion 33a of the stepped placement portion 33 faces the other side surface of the cylindrical lens 27M, and when the cylindrical lens 27M moves by a predetermined dimension toward the cylindrical lens 27K, the other side surface of the cylindrical lens 27M becomes the wall portion 33a. Abut. Thereby, the wall 33a restricts the cylindrical lens 27M from moving toward the cylindrical lens 27K side by a predetermined dimension or more. This eliminates the need for a dedicated member for restricting the cylindrical lens 27M from moving toward the cylindrical lens 27K by a predetermined dimension or more.

  Of the two cylindrical lenses 27M and 27K mounted on the stepped mounting portion 33, a part of the pressing fixing member 40 that presses and fixes the cylindrical lens 27M positioned on the lower side is a cylindrical positioned on the upper side. When the cylindrical lens 27K moves to a side of the cylindrical lens 27M by a predetermined dimension, positioned on the side of the other side surface of the lens 27K, the other side surface of the cylindrical lens 27K comes into contact with the pressing fixing member 40 that presses and fixes the cylindrical lens 27M. . As a result, the pressing and fixing member 40 that presses and fixes the cylindrical lens 27M restricts the cylindrical lens 27K from moving toward the cylindrical lens 27M by a predetermined dimension or more. This eliminates the need for a dedicated member for restricting the cylindrical lens 27K from moving to the cylindrical lens 27M side by a predetermined dimension or more.

  Although only the structure for pressing and fixing the two cylindrical lenses 27M and 27K has been described here, the other two cylindrical lenses 27Y and 27C are also pressed and fixed with the same structure.

  According to the present embodiment, since the cylindrical lens 27 is pressed and fixed by the pressing and fixing member 40, maintenance, replacement, etc. of the cylindrical lens 27 can be performed as necessary.

  A third embodiment of the present invention will be described with reference to FIG. FIG. 10 is a perspective view showing the pressing and fixing member. In the present embodiment, it is placed on the projection 34 (see FIG. 8) of the stepped placement portion 33, and is positioned and displaced by the restriction bosses 42a, 42b, 43a, 43b (see FIGS. 7 and 8). The restricted cylindrical lenses 27 </ b> M and 27 </ b> K are pressed and fixed by a single pressing fixing member 50.

  The pressing and fixing member 50 is formed by integrating a portion 50A for pressing and fixing the cylindrical lens 27M and a portion 50B for pressing and fixing the cylindrical lens 27K. An opening 50a that allows the laser light L emitted from the LD 25 (see FIG. 4) to pass through and enter the cylindrical lens 27 is provided in a portion 50A for pressing and fixing the cylindrical lens 27M in the pressing fixing member 50, and the cylindrical lens. The 1st press part 50b which presses the upper surface of 27, and the 2nd press part 50c which presses the edge part of the front both sides of the cylindrical lens 27 are formed. The portion 50B of the pressing and fixing member 50 that presses and fixes the cylindrical lens 27K presses the upper surface of the cylindrical lens 27 and the opening 50a that allows the laser light L emitted from the LD 25 to pass through and enter the cylindrical lens 27. The first pressing portion 50b and the second pressing portion 50c that presses the edge portions on both sides of the front surface of the cylindrical lens 27 are formed. Further, the press fixing member 50 is formed with a round hole 50d through which a screw 41 (see FIG. 7) for screwing the press fixing member 50 to the housing 30 is inserted.

  Of the two cylindrical lenses 27M and 27K placed on the stepped placement portion 33, a part of the portion 50A for pressing and fixing the cylindrical lens 27M located on the lower side is the other side of the cylindrical lens 27K located on the upper side. When the cylindrical lens 27K moves by a predetermined dimension toward the cylindrical lens 27M, the other side surface of the cylindrical lens 27K comes into contact with a part of the portion 50A that presses and fixes the cylindrical lens 27M. This eliminates the need for a dedicated member for restricting the cylindrical lens 27K from moving to the cylindrical lens 27M side by a predetermined dimension or more.

  Although only the structure for pressing and fixing the two cylindrical lenses 27M and 27K has been described here, the other two cylindrical lenses 27Y and 27C are also pressed and fixed with the same structure.

  According to the present embodiment, since the cylindrical lens 27 is pressed and fixed by the pressing and fixing member 50, maintenance, replacement, etc. of the cylindrical lens 27 can be performed as necessary.

  In addition, since the two cylindrical lenses 27M and 27K arranged in a staircase pattern on the staircase-shaped mounting portion 33 are pressed and fixed by one pressing and fixing member 50, the number of parts of the pressing and fixing member 50 to be used is reduced. Can do.

1 is a front view showing a schematic internal structure of a color printer that is an image forming apparatus according to a first embodiment of the present invention; It is a perspective view which shows a part of optical scanning device. It is a front view which shows the positional relationship of two LD in a 2nd LD unit. It is a perspective view which shows the positional relationship of the two cylindrical lenses which condense the laser beam radiate | emitted from two LD of a 2nd LD unit. It is a side view which shows the attachment state of the two cylindrical lenses arrange | positioned in the step shape within a housing. It is a front view which shows the attachment state of the two cylindrical lenses arrange | positioned in the step shape in a housing. It is a side view which shows the attachment state of the two cylindrical lenses arrange | positioned stepwise within the housing of the optical scanning device of the 2nd Embodiment of this invention. It is a front view which shows the attachment state of the two cylindrical lenses arrange | positioned in the step shape in a housing. It is a perspective view which shows a press fixing member. It is a perspective view which shows the press fixing member of the 3rd Embodiment of this invention. It is a perspective view which shows a part of optical scanning device of a prior art example. It is a perspective view which shows the attachment structure of the cylindrical lens in the optical scanning device of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 4 Optical scanning apparatus 10 Photoconductor 12 Developing apparatus 18 Transfer apparatus 25 Light source 27 Cylindrical lens 28 Deflector 30 Housing 33 Stair-shaped mounting part 34 Protrusion 35 Adhesive 40 Press fixing member 50 Press fixing member

Claims (10)

In an optical scanning device that deflects a light beam emitted from a light source by a rotationally driven deflector and scans the surface of the photoreceptor with the light beam deflected by the deflector,
A plurality of light sources are arranged in a direction intersecting obliquely, for emitting a light beam corresponding to image data of different colors to said deflector with respect to the rotation center of the front Symbol deflector,
A plurality of cylindrical lenses for condensing light beams emitted from the front Symbol source toward said deflector,
A housing for holding the light source, the cylindrical lens, and the deflector;
A stepped mounting portion formed on the housing and on which the plurality of cylindrical lenses are mounted;
With
The stepped placement unit is configured such that a plurality of placement units on which the plurality of cylindrical lenses are placed are arranged at different positions in the scanning direction of the light beam, and the plurality of placement units are disposed on the light beam. Steps are arranged at different heights in the vertical direction perpendicular to the scanning direction of the beam,
The cylindrical lenses respectively disposed on the plurality of placement portions are arranged adjacent to each other in the scanning direction of the light beam and at different heights in the vertical direction, and an interval between the end portions of the adjacent cylindrical lenses is The optical scanning device is arranged at a position where 0 or overlaps in the scanning direction of the light beam . Before Machinery stepped mounting portion is formed, the optical scanning apparatus according to claim 1, wherein the mounting stepped mounting portion by said cylindrical lens is characterized in that it is adhesively bonded. At least a pair of protrusions are formed on the stepped mounting portion, wherein said cylindrical lens on the upper end surfaces of the protrusions are placed, the adhesive between the projections adjacent to and characterized in that it is filled Item 3. The optical scanning device according to Item 2. Characterized in that said housing, stepped mounting portion in which a plurality of the cylindrical lens is placed is formed, the mounting stepped mounting portion by said cylindrical lens is pressed and fixed by the pressing fixing member The optical scanning device according to claim 1. A plurality of the pressing and fixing members are provided on the plurality of mounting portions, respectively , press and fix the corresponding cylindrical lenses, and a plurality of the pressing and fixing members that press and fix the adjacent cylindrical lenses. claim out, the pressing fixation member located upwardly, characterized in that also serves as a member for regulating said cylindrical lens positioned above moves in addition to the cylindrical lens which is located below the 4. The optical scanning device according to 4. 6. The optical scanning device according to claim 4, wherein the pressing fixing member is provided one by one corresponding to each of the cylindrical lenses. 6. The optical scanning device according to claim 4, wherein the pressing and fixing member is formed integrally with a portion for pressing and fixing one of the cylindrical lenses and a portion for pressing and fixing the other cylindrical lens. . The optical scanning device according to claim 1, wherein the plurality of light sources are unitized. The optical scanning device according to claim 1, wherein the plurality of cylindrical lenses are formed in the same size. A photoreceptor having an electrostatic latent image formed on the surface;
The optical scanning device according to any one of claims 1 to 9, wherein an electrostatic latent image is written on the surface of the photoconductor by causing the light beam emitted from the light source to scan the surface of the photoconductor.
A developing device that develops an electrostatic latent image formed on the surface of the photoreceptor to form a toner image;
A transfer device for transferring a toner image on the surface of the photoreceptor to a transfer target;
An image forming apparatus comprising:

Images