JP2011051128A - Optical scanning apparatus and color image forming apparatus equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical scanning apparatus which can obtain a color image with a high quality with no color shift by simply performing adjustment of SKEW. <P>SOLUTION: A plurality of optical scanning units 13M, 13C, 13Y and 13K are configured by storing a set of a light source, optical components and a polarizing means into respective independent housings respectively. A first fixing member 25 for fixing one end in the main scanning direction of respective optical scanning units 13M, 13C, 13Y and 13K, and a second fixing member 26 which while the other end in the main scanning direction of one optical scanning unit 13K at the endmost part is fixed, fixes the other ends in the main scanning direction of the other optical scanning units 13M, 13C and 13Y to be adjustable in position in the sub-scanning direction, are provided. A plurality of the optical scanning units 13M, 13C, 13Y and 13K are unified by the first and second fixing members 25 and 26. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a color image forming apparatus such as a color copying machine or a color printer that forms a color image by an electrophotographic method, and an optical scanning device provided in the color image forming apparatus.

  In an image forming apparatus such as a copying machine or a printer that forms an image on a sheet by electrophotography, exposure light is scanned from the optical scanning device onto the image carrier uniformly charged by the charging means. Then, an electrostatic latent image is formed on the image carrier, and the electrostatic latent image is developed with toner by a developing unit to be visualized as a toner image.

  By the way, for example, a laser scanner unit (LSU) is used as an optical scanning device, and this laser scanner unit includes various optical components such as a collimator lens, a cylindrical lens, an fθ lens as a scanning lens, and a reflection mirror inside a housing. In addition, a polygon mirror which is a polarizing means and a polygon motor which rotationally drives the mirror are housed.

  In such a laser scanner unit, laser light emitted from a laser diode as a light source is incident on a polygon mirror via a collimator lens and a cylindrical lens, and the laser light reflected by the polygon mirror is reflected via a scanning lens. The image is reflected by a mirror and imaged on an image carrier such as a photosensitive drum and exposed and scanned, and an electrostatic latent image corresponding to image information is formed on the image carrier.

  By the way, in a color image forming apparatus in which a plurality of image carriers are arranged in tandem, the surface of each image carrier is exposed and scanned by an optical scanning device. The optical path (main scanning line) to each image carrier is A color shift occurs in a color image due to a positional shift in the sub-scanning direction (SKEW) or a curvature of the image plane due to oblique incidence (BOW).

  Therefore, in Patent Document 1, lens means for condensing the light beam in the sub-scanning direction is arranged between the scanning means for exposing and scanning the photosensitive member (image carrier) with the light beam in the main scanning direction. Thus, there has been proposed an optical scanning device in which the scanning position of the light beam is finely adjusted in the sub-scanning direction without using a precise adjustment mechanism.

Japanese Patent Laid-Open No. 10-206764

  By the way, in an optical scanning apparatus provided with one polygon mirror common to all image carriers, a method of adjusting the deviation in the sub-scanning direction of other optical paths with reference to a certain optical path for adjusting the skew, specifically, A method of adjusting SKEW by adjusting the folding mirror left and right with respect to either the front or back is adopted.

  However, in the above adjustment method, a difference in optical path length occurs before and after the optical path other than the reference, and an image defect occurs due to uneven light quantity. In addition, since a plurality of optical paths are condensed on one polygon mirror, there is a concern about a problem of color misregistration due to curvature of image plane (BOW) due to oblique incidence.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical scanning device capable of easily adjusting SKEW and obtaining a high-quality color image without color misregistration. The object is to provide a color image forming apparatus.

In order to achieve the above object, the invention described in claim 1 is directed to a light source, a lens, a mirror, and the like for optically scanning each image carrier of a color image forming apparatus having a plurality of image carriers arranged in tandem. In the optical scanning device provided with a pair of polarizing means including optical parts and polygon mirrors for each image carrier,
A set of the light source, the optical component, and the polarizing means are respectively housed in independent housings to form a plurality of optical scanning units, and the optical scanning units are arranged in the sub-scanning direction,
A first fixing member that fixes one end in the main scanning direction of each optical scanning unit, and the other end in the main scanning direction of one optical scanning unit at the outermost end, and the other end in the main scanning direction of the other optical scanning unit A second fixing member that fixes the position of the optical scanning unit in the sub-scanning direction is provided, and the plurality of optical scanning units are integrated by the first and second fixing members.

  According to a second aspect of the present invention, in the first aspect of the present invention, the other end in the main scanning direction of the optical scanning unit other than the one optical scanning unit at the outermost end is disposed in the sub-scanning direction. A long hole is formed to fix the position so as to be adjustable.

According to a third aspect of the present invention, there is provided a color image forming apparatus comprising the optical scanning device according to the first or second aspect.
One end of the optical scanning device in the sub-scanning direction is fixed to one side plate opposite to the main body of the device, and the other end of the optical scanning device in the sub-scanning direction is fixed to the other side plate so that the position can be adjusted in the main scanning direction. Features.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, a positioning boss is formed at the other end in the sub-scanning direction of the optical scanning device, and a positioning plate to which the positioning boss is fitted to the other side plate. The optical scanning device is mounted so that its position can be adjusted in the main scanning direction, and the positioning boss is operated from the outside of the side plate to adjust the position of the other end of the optical scanning device in the main scanning direction.

  According to the first and second aspects of the invention, one end in the main scanning direction of each optical scanning unit is fixed, the other end in the main scanning direction of one optical scanning unit at the outermost portion is fixed, and the other optical scanning unit. Since the other end of the main scanning direction is fixed so as to be adjustable in the sub-scanning direction, the position of the optical path of the other optical scanning unit is adjusted in the sub-scanning direction with reference to the optical path of one optical scanning unit at the extreme end. SKEW can be easily adjusted, and a high-quality color image without color shift can be obtained. Since each image carrier has one polygon mirror, the influence of the curvature of the image plane (BOW) due to the oblique incidence is small, and the problem of color misregistration of the color image does not occur.

  According to the third and fourth aspects of the present invention, the optical scanning device and the image forming apparatus main body (image carrier) are adjusted by adjusting the position of the other end in the sub-scanning direction in the main scanning direction with one end in the sub-scanning direction of the optical scanning device as a fulcrum. SKEW can be adjusted with respect to the body, and a high-quality color image free from color shift can be obtained.

1 is a cross-sectional view of a color image forming apparatus (color laser printer) according to the present invention. It is a perspective view which fractures | ruptures and shows a part of optical scanning unit of the optical scanning device based on this invention. It is sectional drawing of the optical scanning unit of the optical scanning device concerning this invention. It is a disassembled perspective view which shows the assembly procedure of the optical scanning unit of the optical scanning device which concerns on this invention. 1 is a perspective view of an optical scanning device according to the present invention. FIG. 6 is an enlarged detail view of part A in FIG. 5. It is explanatory drawing which shows SKEW adjustment. FIG. 3 is an exploded perspective view showing a procedure for assembling the optical scanning device according to the present invention into a printer main body. It is a figure of the arrow B direction of FIG. It is a figure of the arrow C direction of FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[Color image forming apparatus]
FIG. 1 is a cross-sectional view of a color laser printer as an embodiment of a color image forming apparatus according to the present invention. The illustrated color laser printer is a tandem type, and a magenta image is formed at the center of the main body 100. The unit 1M, the cyan image forming unit 1C, the yellow image forming unit 1Y, and the black image forming unit 1K are arranged in tandem at regular intervals.

  Each of the image forming units 1M, 1C, 1Y, and 1K is provided with photosensitive drums 2a, 2b, 2c, and 2d, which are image carriers, and a charger 3a is disposed around each of the photosensitive drums 2a to 2d. 3b, 3c, 3d, developing devices 4a, 4b, 4c, 4d, transfer rollers 5a, 5b, 5c, 5d and drum cleaning devices 6a, 6b, 6c, 6d, respectively.

  Here, the photosensitive drums 2a to 2d are drum-shaped photosensitive members, and are driven to rotate at a predetermined process speed in a direction indicated by an arrow (clockwise) by a driving motor (not shown). The chargers 3a to 3d uniformly charge the surfaces of the photosensitive drums 2a to 2d to a predetermined potential by a charging bias applied from a charging bias power source (not shown).

  Further, the developing devices 4a to 4d contain magenta (M) toner, cyan (C) toner, yellow (Y) toner, and black (K) toner, respectively, and are formed on the photosensitive drums 2a to 2d. In addition, the toner of each color is attached to each electrostatic latent image to visualize each electrostatic latent image as a toner image of each color.

  The transfer rollers 5a to 5d are arranged so as to be able to contact the photosensitive drums 2a to 2d via the intermediate transfer belt 7 in the respective primary transfer portions. Here, the intermediate transfer belt 7 is stretched between the secondary transfer counter roller 8 and the tension roller 9 and is disposed on the upper surface side of each of the photosensitive drums 2a to 2d. The roller 8 is disposed so as to be in contact with the secondary transfer roller 10 via the intermediate transfer belt 7 in the secondary transfer portion. A belt cleaning device 11 is provided in the vicinity of the tension roller 9.

  Incidentally, toner containers 12a, 12b, 12c, and 12d for supplying toner to the developing devices 4a to 4d are arranged in a line above the image forming units 1M, 1C, 1Y, and 1K in the printer main body 100. It is installed.

  Also, an optical scanning device (laser scanner unit (LSU)) 13 according to the present invention is disposed below each image forming unit 1M, 1C, 1Y, 1K in the printer main body 100, and the bottom of the printer main body 100 below that is disposed. The paper cassette 14 is detachably installed in the printer. A plurality of sheets of paper (not shown) are stacked and accommodated in the paper feed cassette 14, and a pickup roller 15 for picking up paper from the paper feed cassette 14 and a picked up paper are placed near the paper feed cassette 14. A feed roller 16 and a retard roller 17 that are separated and fed one by one to the transport path S are provided.

  Further, the conveyance path S extending in the vertical direction on the side of the printer main body 100 includes a conveyance roller pair 18 that conveys the sheet, and the secondary transfer counter roller 8 and the second transfer opposing roller 8 at a predetermined timing after the sheet is temporarily held. A registration roller pair 19 is provided to be supplied to a secondary transfer portion which is a contact portion with the next transfer roller 10. Next to the transport path L, another transport path S ′ used when forming images on both sides of the sheet is formed, and a plurality of reversing roller pairs 20 are appropriately used for the transport path S ′. Are provided at regular intervals.

  By the way, the conveyance path S arranged in the vertical direction on one side of the printer main body 100 extends to the paper discharge tray 21 provided on the upper surface of the printer main body 100, and the fixing device 22 and the discharge path are disposed in the middle. Paper roller pairs 23 and 24 are provided.

  Next, an image forming operation by the color laser printer having the above configuration will be described.

  When an image formation start signal is issued, the respective photosensitive drums 2a to 2d are rotationally driven in the image forming units 1M, 1C, 1Y, and 1K in a direction indicated by arrows (clockwise) at a predetermined process speed, and these photosensitive drums 2a. ˜2d are uniformly charged by the chargers 3a to 3d. The optical scanning device 13 emits a laser beam modulated by a color image signal for each color, irradiates the laser beam on the surface of each photosensitive drum 2a to 2d, and each color is applied to each photosensitive drum 2a to 2d. An electrostatic latent image corresponding to the color image signal is formed.

  First, magenta toner is attached to the electrostatic latent image formed on the photosensitive drum 2a of the magenta image forming unit 1M by the developing device 4a to which a developing bias having the same polarity as the charged polarity of the photosensitive drum 2a is applied. The electrostatic latent image is visualized as a magenta toner image. This magenta toner image is moved in the direction of the arrow in the figure by the action of the transfer roller 5a to which a primary transfer bias having a polarity opposite to that of the toner is applied in the primary transfer portion (transfer nip portion) between the photosensitive drum 2a and the transfer roller 5a. Primary transfer is performed on the intermediate transfer belt 7 that is rotationally driven.

  The intermediate transfer belt 7 on which the magenta toner image has been primarily transferred as described above moves to the next cyan image forming unit 1C. In the cyan image forming unit 1C as well, the cyan toner image formed on the photosensitive drum 2b is transferred to the magenta toner image on the intermediate transfer belt 7 in the primary transfer portion in the same manner as described above.

  Similarly, yellow and black toners respectively formed on the photosensitive drums 2c and 2d of the yellow and black image forming units 1Y and 1K on the magenta and cyan toner images superimposed and transferred on the intermediate transfer belt 7, respectively. The images are sequentially superimposed at each primary transfer portion, and a full-color toner image is formed on the intermediate transfer belt 7. The transfer residual toner which is not transferred onto the intermediate transfer belt 7 and remains on the photosensitive drums 2a to 2d is removed by the drum cleaning devices 6a to 6d, and the photosensitive drums 2a to 2d are prepared for the next image formation. It is done.

  The full color toner image on the intermediate transfer belt 7 is picked up from the paper feed cassette 14 in accordance with the timing at which the leading end of the full color toner image reaches the secondary transfer portion (transfer nip portion) between the secondary transfer counter roller 8 and the secondary transfer roller 10. The sheet fed to the transport path S by the roller 15, the feed roller 16 and the retard roller 17 is transported to the secondary transfer unit by the registration roller pair 19. Then, a full-color toner image is collectively transferred from the intermediate transfer belt 7 to the sheet conveyed to the secondary transfer unit by the secondary transfer roller 10 to which a secondary transfer bias having a polarity opposite to that of the toner is applied. .

  Thus, the sheet on which the full-color toner image has been transferred is conveyed to the fixing device 22, and the sheet on which the full-color toner image has been fixed by being heated and pressurized and thermally fixed on the surface of the sheet. Then, the paper is discharged onto the paper discharge tray 21 by the paper discharge roller pair 23 and 24, and a series of image forming operations is completed. The transfer residual toner that is not transferred onto the sheet and remains on the intermediate transfer belt 7 is removed by the belt cleaning device 11, and the intermediate transfer belt 7 is prepared for the next image formation.

[Optical scanning device]
Next, details of the optical scanning device 13 according to the present invention will be described with reference to FIGS.

  2 is a perspective view showing a part of the optical scanning unit of the optical scanning device according to the present invention in a cutaway state, FIG. 3 is a sectional view of the optical scanning unit, and FIG. 4 is an exploded perspective view showing an assembly procedure of the optical scanning unit. 5 is a perspective view of the optical scanning device according to the present invention, FIG. 6 is an enlarged detail view of part A of FIG. 5, FIG. 7 is an explanatory view showing SKEW adjustment, and FIG. 8 is an assembly of the optical scanning device to the printer body. FIG. 9 is an exploded perspective view showing the insertion procedure, FIG. 9 is a view in the direction of arrow B in FIG. 8, and FIG. 10 is a view in the direction of arrow C in FIG.

  As shown in FIG. 5, the optical scanning device 13 according to the present invention includes a total of four optical scanning units 13M, 13C, 13Y, and 13K for the photosensitive drums 2a to 2d of the respective colors. The scanning units 13M, 13C, 13Y, and 13K are assembled and integrated by fixing both ends in the main scanning direction to fixing members 25 and 26 (see FIG. 4).

  Here, since the configurations of the optical scanning units 13M, 13C, 13Y, and 13K are the same, the configuration of one optical scanning unit 13M will be described below with reference to FIGS.

  The optical scanning unit 13M includes a polygon mirror 28 that is a polarizing means, a polygon motor 29 that rotationally drives the polygon mirror 28, a laser diode that is not shown, and a collimator that is not shown. A lens, a cylindrical lens, two scanning lenses 30, 31, and three reflecting mirrors 32, 33, 34 are accommodated. As shown in FIG. 2, two bosses 13a, 13b on the left and right sides project from one end surface of the housing 27 in the main scanning direction, and one boss 13c projects from the other end surface.

  In the optical scanning unit 13M configured as described above, laser light emitted from a laser diode (not shown) is condensed into a linear light beam by a collimator lens and a cylindrical lens, and then rotated by a polygon motor 29. Is incident on the polygon mirror 28.

  As described above, the laser light incident on the polygon mirror 28 is polarized and scanned by the rotating polygon mirror 28, and the reflected light passes through the two scanning lenses 30 and 31 and the three reflection mirrors 32 to 34 onto the photosensitive drum 2 a. The imaged luminous flux is scanned on the photosensitive drum 2a in the main scanning direction by the rotation of the polygon mirror 28, and is scanned in the sub scanning direction by the rotation of the photosensitive drum 2a. Form an image.

  Thus, the optical scanning device 13 according to the present invention is configured by assembling and integrating the optical scanning units 13M, 13C, 13Y, and 13K, as shown in FIGS. The assembly procedure of the optical scanning units 13M, 13C, 13Y, and 13K will be described below with reference to FIG.

  The fixing member 25 on the one side (the rear side of the printer main body 100) has four round-shaped fixing holes 25a in the longitudinal direction (sub-scanning direction) (locations corresponding to the optical scanning units 13M, 13C, 13Y, and 13K). Long hole-shaped detent holes 25b are respectively formed, and the other (front side of the printer main body 100) fixing member 26 has three longitudinal directions corresponding to the optical scanning units 13M, 13C, 13Y in the sub-scanning direction (printer main body 100). In the left and right directions, long fixing holes 26a are formed, and a circular fixing hole 26b is formed at one position corresponding to the optical scanning unit 13K of the fixing member 26.

  In each of the optical scanning units 13M, 13C, 13Y, and 13K, one end (rear end) in the main scanning direction is fixed to one fixing member 25, and the other end (front end) is sub-scanned with respect to the other fixing member 26. The optical scanning device 13 shown in FIG. 5 is configured by being assembled and integrated by being fixed so that the position can be adjusted in the direction.

  Here, one end (rear side) in the main scanning direction of each of the optical scanning units 13M, 13C, 13Y, and 13K is formed with the bosses 13a and 13b (see FIG. 2) formed on the one fixing member 25. The fixing member 25 is fixed to the fixing member 25 in a state in which the rotation is prevented by passing through the fixing hole 25a and the anti-rotation hole 25b. Further, the other end (front end) in the main scanning direction of the optical scanning unit 13K at the end is a circular hole-shaped fixing hole 26b formed on the other fixing member 26 with a boss 13c (see FIG. 2) formed thereon. It fixes to the other fixing member 26 by passing through and fixing. Therefore, both ends of the optical scanning unit 13K in the main scanning direction are fixed to the fixing members 25 and 26 so that the position cannot be adjusted.

  On the other hand, the other end (front end) in the main scanning direction of the optical scanning units 13M, 13C, and 13Y other than the optical scanning unit 13K is formed on the front fixing member 26 with the boss 13c (see FIG. 2) formed thereon. By fixing through the long hole-shaped fixing hole 26a, the fixing member 26 is fixed so as to be position adjustable in the sub-scanning direction. That is, the other end (front end) in the main scanning direction of the optical scanning units 13M, 13C, and 13Y can be moved within the elongated fixing hole 26a of the other fixing member 26 even after the bosses 13c are assembled. In such a range, the front end position can be adjusted in the sub-scanning direction (the arrow direction in FIG. 6).

  As described above, in the present embodiment, one end (rear end) in the main scanning direction of each of the optical scanning units 13M, 13C, 13Y, and 13K is fixed, and the main scanning direction and the like of one optical scanning unit 13K at the extreme end. Since the end (front end) is fixed and the other end (front end) in the main scanning direction of the other optical scanning units 13M, 13C, and 13K is fixed to be adjustable in the sub-scanning direction, as shown in FIG. The positions of the optical paths Lm, Lc, Ly of the other optical scanning units 13M, 13C, 13Y can be adjusted in the sub-scanning direction (arrow direction shown in the drawing) with the optical path Lk of the one optical scanning unit 13K as a reference. For this reason, the shift (SKEW) in the sub-scanning direction with respect to the optical path Lk of the optical scanning unit 13K at the position of each optical path Lm, Lc, Ly of the optical scanning units 13M, 13C, 13K can be easily adjusted. A high-quality color image without deviation can be obtained. In this embodiment, since each photosensitive drum 2a to 2d has one polygon mirror 28, the influence of the curvature of the image plane (BOW) due to the oblique incidence is small, and the problem of color misregistration of the color image is Does not occur.

  Next, a procedure for incorporating the optical scanning device 13 into the printer main body 100 will be described with reference to FIGS.

  In the present embodiment, the optical scanning device 13 is incorporated into the printer main body 100 from the opening (not shown) on the left side to the back side (right direction) as indicated by an arrow in FIG. Two points on the back side (right side) are fixed to the right side plate 35 provided on the printer main body 100 side, and a positioning plate 37 is attached to the left side plate 36 where one point on the near side (left side) faces the side plate 35. Through the main scanning direction (front-rear direction).

  Specifically, a long hole-like fixing hole 35a that is long in the front-rear direction is formed at both longitudinal ends of the right side plate 35, and a long hole-like positioning hole 35b that is long in the vertical direction is formed between these. Yes. As shown in FIG. 9, a cylindrical positioning boss 38 projects from the center of the left end surface of the optical scanning device 13 in the front-rear direction, and the positioning boss 38 is inserted into the positioning plate 37. A circular fitting hole 37a is formed, and two circular screw holes 37b and two positioning projections 37c are formed around the fitting hole 37a. Further, a long hole-like fitting hole 36a that is long in the front-rear direction (main scanning direction) is formed in the middle of the left side plate 36 in the front-rear direction, and two screw holes 36b that are long in the front-rear direction are formed around the fitting hole 36a. And two positioning holes 36c are formed. And the boss | hub 13d protrudes in the front-back direction both ends of the right end surface of the optical scanning device 13, and the boss | hub 13e protrudes in the middle (refer FIG. 8).

  Thus, the optical scanning device 13 has its right end portion fixed by passing the bosses 13d and 13e protruding from the right end surface thereof through the fixing hole 35a and the positioning hole 35b formed in the right side plate 35, respectively. Is fixed to the side plate 35 so that the position cannot be adjusted. On the other hand, the left end portion of the optical scanning device 13 has a positioning boss 38 protruding from the positioning boss 38 inserted and fitted into a fitting hole 37a of the positioning plate 37, and the positioning plate 37 is formed with two screws formed thereon. The two screws 39 inserted into the hole 37b and the two screw holes 36b formed in the side plate 36 are fastened to the side plate 36, and the positioning protrusion 37c protruding from the positioning plate 37 is positioned in the positioning hole 36c formed in the side plate 36. To fit. For this reason, the left end (the other end in the sub-scanning direction) of the optical scanning device 13 is within the main scanning direction (in the range in which the screw 39 and the positioning projection 37c can move within the long hole-shaped screw holes 36b and 37b and the positioning hole 36c) The position can be adjusted in the front-rear direction). That is, the optical scanning device 13 operates the positioning boss 38 from the outside of the side plate 36 with the screw 39 loosened even after the optical scanning device 13 is assembled to the printer main body 100, thereby The position (one end in the sub-scanning direction) can be adjusted in the main scanning direction (the arrow direction in FIG. 10).

  As described above, in the present embodiment, the position of the left end, which is the rear end in the insertion direction, is adjusted in the main scanning direction (front-rear direction) with the right end, which is the front end in the insertion direction, of the optical scanning device 13 as a fulcrum. Therefore, the skew can be adjusted between the optical scanning device 13 and the printer main body 100 (photosensitive drums 2a to 2d), and a high-quality color image without color misregistration can be obtained.

  Although the present invention has been described with respect to a mode in which the present invention is applied to a color laser printer and an optical scanning device provided therein, the present invention is not limited to any other color image forming apparatus such as a color copying machine. Of course, the present invention can be similarly applied to the optical scanning device provided.

1M Magenta image forming unit 1C Cyan image forming unit 1Y Yellow image forming unit 1K Black image forming unit 2a to 2d Photosensitive drum (image carrier)
3a to 3d charger 4a to 4d developing device 5a to 5d transfer roller 6a to 6d drum cleaning device 7 intermediate transfer belt 8 secondary transfer counter roller 9 tension roller 10 secondary transfer roller 11 belt cleaning device 12a to 12d toner container 13 light Scanning device)
13M optical scanning unit (magenta)
13C Optical scanning unit (cyan)
13Y Optical scanning unit (yellow)
13K optical scanning unit (black)
13a-13e Optical Scanning Device Boss 14 Paper Feed Cassette 15 Pickup Roller 16 Feed Roller 17 Retard Roller 18 Transport Roller Pair 19 Registration Roller Pair 20 Transport Roller Pair 21 Discharge Tray 22 Fixing Device 23, 24 Discharge Roller Pair 25 Fixed Member (First fixing member)
26 fixing member (second fixing member)
27 Housing of optical scanning device 28 Polygon mirror 29 Polygon motor 30, 31 Scanning lens 32 to 34 Reflection mirror 35 Side plate 35a Side plate fixing hole 35b Side plate positioning hole 36 Side plate 36a Side plate fitting hole 36b Side plate screw hole 36c Side plate Positioning hole 37 Positioning plate 37a Positioning plate fitting hole 37b Positioning plate screw hole 37c Positioning protrusion 38 Positioning boss 39 Screw 100 Printer main body (image forming apparatus main body)
Lm light path (magenta)
Lc Light path (cyan)
Ly light path (yellow)
Lk light path (black)
S, S 'transport path

Claims (4)

Each color image forming apparatus having a plurality of image carriers arranged in tandem includes a light source that optically scans the image carriers, optical components such as lenses and mirrors, and polarizing means including a polygon mirror. In the optical scanning device provided for each pair,
A set of the light source, the optical component, and the polarizing means are respectively housed in independent housings to form a plurality of optical scanning units, and the optical scanning units are arranged in the sub-scanning direction,
A first fixing member that fixes one end in the main scanning direction of each optical scanning unit, and the other end in the main scanning direction of one optical scanning unit at the outermost end, and the other end in the main scanning direction of the other optical scanning unit And a second fixing member that fixes the position of the optical scanning unit in the sub-scanning direction, and a plurality of the optical scanning units are integrated by the first and second fixing members.   The second fixing member is formed with a long hole for fixing the other end in the main scanning direction of the optical scanning unit other than the one optical scanning unit at the outermost end so that the position can be adjusted in the sub-scanning direction. The optical scanning device according to claim 1. A color image forming apparatus comprising the optical scanning device according to claim 1 or 2 loaded therein.
One end of the optical scanning device in the sub-scanning direction is fixed to one side plate opposite to the main body of the device, and the other end of the optical scanning device in the sub-scanning direction is fixed to the other side plate so that the position can be adjusted in the main scanning direction. A characteristic color image forming apparatus. A positioning boss is formed at the other end in the sub-scanning direction of the optical scanning device, and a positioning plate to which the positioning boss is fitted is attached to the other side plate so that the position can be adjusted in the main scanning direction. 4. The color image forming apparatus according to claim 3, wherein the positioning boss is operated to adjust the position of the other end of the optical scanning device in the main scanning direction.

Images