JP5396408B2 - Optical scanning device and image forming apparatus having the same - Google Patents

Description

  The present invention relates to an optical scanning device for optically scanning a photoreceptor and an image forming apparatus such as a copying machine and a printer provided with the optical scanning device.

  In an image forming apparatus such as a copying machine or a printer, a photosensitive member whose surface is uniformly charged by a charger is optically scanned by an optical scanning device, and an electrostatic latent image corresponding to image information is formed on the surface. . The electrostatic latent image is developed by a developing device using toner as a developer to be visualized as a toner image. The toner image is transferred onto a sheet by a transfer device and then heated and heated by a fixing device. A series of image forming operations is completed by discharging the sheet having the toner image fixed thereon by being pressed and fixed on the sheet.

  By the way, an optical scanning device that optically scans a photoconductor to form an electrostatic latent image on the surface thereof includes a deflector such as a polygon mirror that deflects a light beam emitted from a light source, and light deflected by the deflector. An imaging lens that converts the beam into constant speed scanning light and a plurality of reflection mirrors that fold back the constant speed scanning light and guide it to the photosensitive member are housed in a housing.

  Since the reflection mirror used in such an optical scanning device is generally composed of a long mirror that is long in the main scanning direction, it easily vibrates due to vibrations of the image forming apparatus main body, polygon mirror, and the like. When the reflecting mirror vibrates, the light beam moves up and down on the photosensitive member, and this causes a problem that the image is affected as a jidder.

  As a method for solving the above problem, it is general to deviate the resonance frequency (natural frequency) of the reflection mirror from the driving frequency of the polygon motor by devising the fixing structure of the reflection mirror or attaching a weight. Has been done. For example, Patent Document 1 proposes a configuration in which the resonance frequency of the reflection mirror is changed by changing the pressure contact position of the reflection mirror with a screw member.

JP 2008-242146 A

  By the way, in recent years, models that increase the speed of polygon mirrors and models that can select a plurality of print resolutions by switching the number of rotations of the polygon mirror have become standard. Furthermore, in order to enable the optical scanning device to be developed to other models, there are various rotational speeds in which resonance must be taken into account, which complicates the problem.

  As a matter of fact, it is inevitable to solve the reflection mirror vibration problem in order to achieve high image quality. To improve the jedder level, the resonance point can be moved to a high frequency range or even if it resonates. It is necessary to dampen the vibration to an acceptable level.

  The present invention has been made in view of the above circumstances, and an object thereof is an optical scanning device capable of stably obtaining high optical performance by suppressing the vibration of the reflection mirror to be low over a wide frequency range. An object of the present invention is to provide an image forming apparatus provided with this.

In order to achieve the above object, a first aspect of the present invention includes a deflector that deflects a light beam emitted from a light source, and an imaging lens that converts the light beam deflected by the deflector into constant-speed scanning light. A reflection mirror that folds back the constant-speed scanning light and guides it to the photosensitive member is housed in the housing, and both ends of the reflection mirror in the main scanning direction are elastically supported with respect to the housing via the sheet metal stays. In an optical scanning device provided with scanning line curvature correcting means for correcting the curvature of a scanning line by changing the shape, the optical scanning apparatus is interposed between the reflection mirror and the sheet metal stay and contacts only the side surface of the reflection mirror. An elastic member is provided .

According to a second aspect of the present invention, in the first aspect, wherein the benzalkonium be supported by the convex three positions the rear is formed in the sheet metal stay of the reflecting mirror.

A third aspect of the invention is characterized in that, in the first or second aspect of the invention, the surface of the elastic member that contacts the reflecting mirror is coated with a film that reduces friction .

  An image forming apparatus according to a fourth aspect includes the optical scanning device according to any one of the first to third aspects.

  According to the first aspect of the present invention, the vibration of the reflection mirror is suppressed to be low over a wide frequency range by the damping effect by the elastic member interposed between the reflection mirror and the sheet metal stay, and the optical scanning device has high optical performance. Stable performance is ensured.

  According to the second aspect of the present invention, since the mounting angle of the reflecting mirror is determined by the three convex portions of the sheet metal stay, high flatness is not required for the sheet metal stay, and the manufacture of the sheet metal stay is facilitated. In addition, by providing an elastic member between the side surface independent of the mounting angle of the reflecting mirror and the sheet metal stay, the angle variation of the reflecting mirror due to environmental variation or the like is suppressed, and high optical performance is ensured for the reflecting mirror.

  According to the invention of claim 3, since the film is coated on the surface of the elastic member that contacts the reflection mirror, the friction with the reflection mirror is suppressed by the film during assembly of the elastic member, and the assemblability of the elastic member is improved. It is done.

  According to the fourth aspect of the present invention, since the vibration of the folding mirror is suppressed, the vertical movement of the light beam on the photosensitive member is suppressed, and the occurrence of image defects such as jedder is prevented, and the high quality image is stabilized. Can be obtained.

1 is a side sectional view of an image forming apparatus (color laser printer) according to the present invention. It is a perspective view which removes and shows the cover of the optical scanning device concerning the present invention. It is a top view which removes and shows the cover of the optical scanning device concerning the present invention. FIG. 4 is a sectional view taken along line AA in FIG. 3. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is CC sectional view taken on the line of FIG. It is a perspective view of a reflective mirror and a sheet metal stay. It is a perspective view of a sheet metal stay. It is a front view of the reflective mirror provided with the scanning line curvature correction means. FIG. 10 is a sectional view taken along line D-D in FIG. 9. It is the E section enlarged detail drawing of FIG. It is the FF sectional view taken on the line of FIG. It is a perspective view of the holding | maintenance bracket of a scanning line curvature correction means. It is a figure which shows the vibration characteristic of the reflective mirror of the optical scanner which concerns on this invention compared with the conventional one.

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

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

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

  Here, the photosensitive drums 2a to 2d are drum-shaped photosensitive members, and are rotationally driven 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 in contact with the photosensitive drums 2a to 2d via the intermediate transfer belt 7 at each primary transfer portion. Here, the intermediate transfer belt 7 is stretched between a driving roller 8 and a tension roller 9 and is disposed on the upper surface side of each of the photosensitive drums 2a to 2d. The driving roller 8 is a secondary roller. The transfer unit is disposed so as to be in contact with the secondary transfer roller 10 via the intermediate transfer belt 7. 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.

  Further, below each image forming unit 1M, 1C, 1Y, 1K in the printer main body 100, four optical scanning devices (laser scanner units) 13 are arranged in parallel in the paper transport direction, and these optical scanning devices. A paper feed cassette 14 is detachably installed at the bottom of the printer main body 100 below the printer 13. A plurality of sheets (not shown) are stacked and accommodated in the sheet cassette 14, and in the vicinity of the sheet cassette 14, a pickup roller 15 that extracts sheets from the sheet cassette 14, and the extracted sheets A feed roller 16 and a retard roller 17 are provided for separating the components and feeding them one by one to the conveyance path S.

  In addition, 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 a sheet, and the secondary transfer counter roller 8 and the second roller 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 that is a contact portion with the next transfer roller 10. Next to the transport path S, another transport path S ′ used for forming an image 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 photosensitive drums 2a to 2d are driven to rotate at a predetermined process speed in the direction of the arrow (clockwise) in the image forming units 1M, 1C, 1Y, and 1K, and these photosensitive drums 2a. ˜2d are uniformly charged by the chargers 3a to 3d. Each optical scanning device 13 emits a light beam modulated by a color image signal for each color, irradiates the surface of each photosensitive drum 2a to 2d with each light beam, and each color on each photosensitive drum 2a to 2d. The electrostatic latent images corresponding to the color image signals are respectively 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. The magenta toner image is moved in the direction indicated by the arrow in the primary transfer portion (transfer nip portion) between the photosensitive drum 2a and the transfer roller 5a 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. 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.

  Then, in accordance with the timing at which the leading end of the full-color toner image on the intermediate transfer belt 7 reaches the secondary transfer portion (transfer nip portion) between the drive roller 8 and the secondary transfer roller 10, The sheet fed to the conveyance path S by the feed roller 16 and the retard roller 17 is conveyed 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 onto 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. A pair of paper discharge rollers 23 and 24 are discharged onto the paper discharge tray 21 to complete a series of image forming operations. 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, the optical scanning device 13 according to the present invention will be described with reference to FIGS.

  2 is a perspective view of the optical scanning device according to the present invention with the cover removed, FIG. 3 is a plan view of the same, and FIG. 4 is a sectional view taken along line AA of FIG. The color laser printer shown in FIG. 1 has four optical scanning devices 13 described below arranged in parallel. However, since all of these configurations are the same, only one optical scanning device 13 will be described below. explain.

  The optical scanning device 13 has a housing 25 integrally formed in a rectangular box shape with resin, and a polygon mirror 26 that is a deflector and a polygon mirror 26 are disposed at the bottom of the housing 25 as shown in FIG. A polygon motor 27 is arranged to rotate the motor. Although not shown, a laser diode as a light source is attached to the side wall of the housing 25, and a collimator lens and a cylindrical lens are arranged in the housing 25 along the light beam emitting direction from the laser diode. ing.

  As shown in FIG. 4, the housing 25 includes first and second imaging lenses 28 and 29 for converting the light beam deflected by the polygon mirror 26 into constant speed scanning light, and constant speed scanning light. The first to third reflecting mirrors 30, 31, and 32 that are folded and led to the photosensitive drum 2a (2b to 2d) are accommodated.

  Meanwhile, the illustrated optical scanning device 13 exposes and scans the photosensitive drum 2a of the magenta image forming unit 1M shown in FIG. 1. As shown in FIG. A cover 33 made of resin is attached, and an opening 33a through which scanning light passes is formed in the optical path connecting the third reflecting mirror 32 and the photosensitive drum 2a of the cover 33.

  Thus, a light beam emitted from a laser diode (not shown) that is a light source in the optical scanning device 13 is collimated by a collimator lens (not shown), and then converges in the sub-scanning direction by a cylindrical lens (not shown). The light enters the polygon mirror 26 that is rotationally driven by the polygon motor 27.

  As described above, the light beam incident on the polygon mirror 26 is deflected by the polygon mirror 26, passes horizontally through the first imaging lens 28, and then is folded upward and vertically by the first reflecting mirror 30. The reflection mirror 31 is folded toward the third reflection mirror 32. The light beam folded back by the second reflecting mirror 31 passes through the second imaging lens 29 and then is folded back obliquely upward toward the photosensitive drum 2 a by the third reflecting mirror 32, and is formed in the cover 33. The photosensitive drum 2a is exposed and scanned by forming a spot that passes through the portion 33a toward the photosensitive drum 2a, forms an image on the photosensitive drum 2a, and moves at a constant speed in the main scanning direction.

  The one optical scanning device 13 shown in FIGS. 2 to 4 exposes and scans the photosensitive drum 2a of the magenta image forming unit 1M shown in FIG. 1, but the printer main body of the color laser printer shown in FIG. As described above, four similar optical scanning devices 13 are arranged in parallel in 100, and these four optical scanning devices 13 provide another cyan image forming unit 1C, yellow image forming unit 1Y, and Bralac image forming unit 1K. All of the four photosensitive drums 2a to 2d including the photosensitive drums 2b, 2c and 2d are exposed and scanned by the light beam.

  Here, a mounting structure of the third reflection mirror (hereinafter simply referred to as “reflection mirror”) 32 will be described with reference to FIGS. 2, 3, and 5 to 8.

  5 is a cross-sectional view taken along line BB in FIG. 3, FIG. 6 is a cross-sectional view taken along line CC in FIG. 3, FIG. 7 is a perspective view of a reflecting mirror and a sheet metal stay, and FIG.

  The reflection mirror 32 is a long mirror that is long in the main scanning direction as shown in FIGS. 2, 3, and 7, and both ends in the scanning direction (left and right direction) are elastically supported by the metal plate stays 35 by metal plate springs 34. It is supported. Here, as shown in FIG. 8, the sheet metal stay 35 is a channel-shaped member having an open top surface, and one convex portion 35 a is projected on one bottom surface in the longitudinal direction, and 2 on the other bottom surface. Two projecting portions 35b are projected. The reflecting mirror 32 is placed on the convex portions 35a and 35b projecting from the left and right ends of the sheet metal stay 35 at the main left and right ends of the bottom surface of the reflecting mirror 32, and the both ends in the left and right direction are supported by the plate springs 34. By being pressed, the sheet metal stay 35 is elastically supported.

  Further, one end of the reflecting mirror 32 in the main scanning direction is inserted into the rectangular hole 25A of the housing 25 as shown in FIG. 5, and is pressed by the protrusion 25a formed on the inner surface of the rectangular hole 25A by the plate spring 36. Thus, one end in the longitudinal direction is fixed to the housing 25. As shown in FIG. 6, the other end in the longitudinal direction of the reflection mirror 32 is fixed by pressing the back surface of the reflection mirror 32 against the projection 25 b projecting from the mounting surface 25 </ b> B of the housing 25 by the plate spring 37. The spring 37 is attached to the housing 25 by a screw 38.

  Incidentally, a scanning line curve correcting means 39 is provided in the central part of the reflecting mirror 32 in the main scanning direction (horizontal direction), and the scanning line curve correcting means 39 corrects the curve of the scanning lines on the photosensitive drum 2a.

  Next, details of the configuration of the scanning line curve correcting means 39 will be described with reference to FIGS.

  9 is a front view of a reflecting mirror provided with scanning line curvature correcting means, FIG. 10 is a sectional view taken along the line D-D in FIG. 9, FIG. 11 is an enlarged detail view of a portion E in FIG. FIG. 13 is a perspective view of a holding bracket of the scanning line curvature correcting means.

  The scanning line curvature correcting means 39 includes a holding bracket 40 that engages the central portion in the main scanning direction of the reflection mirror 32, and is retracted between the holding bracket 40 and the sheet metal stay 35 so that the reflection mirror passes through the holding bracket 40. 32, the two compression springs 41 for pulling the center portion in the main scanning direction downward, and the boss portion 35A projecting from the bottom of the sheet metal stay 35 in the center in the main scanning direction so as to be movable back and forth (movable up and down) and reflected. The mirror 32 includes an adjustment screw 42 that presses the center in the longitudinal direction upward in the direction opposite to the pulling direction (downward) by the compression spring 41.

  Here, as shown in FIG. 13, the holding bracket 40 is a channel-shaped member having an open upper surface, and a pair of engaging claws bent inward at the longitudinal center of the left and right upper edges. 40a is integrally formed, and leaf springs 40b bent in an inverted U shape toward the inside are integrally formed on both sides of each engaging claw 40a. A circular hole 40c is formed in the center of the bottom surface of the holding bracket 40 in the width direction, and two crescent-shaped locking holes 40d for locking the lower end of the compression spring 41 are formed on both sides thereof. ing.

  Thus, the holding bracket 40 is fitted with the opening portion up so as to cover the sheet metal stay 35 and the central portion in the main scanning direction of the reflecting mirror 32 held by the holding bracket 40 from below, and the engaging claw 40a is formed by the reflecting mirror 40a. By being engaged with the upper surface of 32, it is held by the reflecting mirror 32. Then, the holding bracket 40 is biased downward by the two compression springs 41 that are compressed between the holding bracket 40 and the sheet metal stay 35, so that the engaging claw 40 a of the holding bracket 40 is applied to the reflection mirror 32. Engage and pull the center in the longitudinal direction of the reflecting mirror 32 downward. As a result, the reflecting mirror 32 is bent and deformed so that the center in the longitudinal direction is convex downward. Note that the center of the reflecting mirror 32 in the width direction is held by the leaf springs 40b of the holding bracket 40 in two directions perpendicular to the longitudinal direction (perpendicular to the plane of FIG. 9 and FIG. 11).

  Further, as shown in FIG. 12, a screw hole 35c is formed in a boss portion 35A projecting at the center in the longitudinal direction of the bottom surface of the sheet metal stay 35, and a screw of the adjusting screw 42 is provided in the screw hole 35c. The portion 42a is screwed from below. The tip of the adjustment screw 42 facing the sheet metal stay 35 is in contact with the center of the bottom surface of the reflecting mirror 32 in the longitudinal direction. Further, a hexagonal columnar portion 42b is formed integrally with a portion adjacent to the screw portion 42a of the outer diameter portion that protrudes downward from the sheet metal stay 35 of the adjustment screw 42, and the tip of the driver is on the lower end surface of the adjustment screw 42. A cross hole 42c for engagement is formed, and the cross hole 42c is exposed downward from the circular hole 40c formed in the bottom surface of the holding bracket 40, as shown in FIG.

  Further, as shown in FIG. 9, a rectangular tool insertion hole 40e is formed in the side portion of the holding bracket 40, and the hexagonal columnar portion 42b of the adjusting screw 42 faces the tool insertion hole 40e. It is out.

  Thus, as described above, the reflecting mirror 32 is bent and deformed so that the central portion in the longitudinal direction thereof is attracted downward by the two compression springs 41 and protrudes downward, but the adjusting screw 42 abuts on the lower surface thereof. It is bent and deformed so as to be convex upward by pressing upward. Therefore, when correcting the curvature of the scanning line (bow correction), the tip of an adjustment tool (not shown) is inserted from the tool insertion hole 40e formed on the side portion of the holding bracket 40, and the tip is a hexagonal columnar portion of the adjustment screw 42. When the adjusting screw 42 is rotated by the adjusting tool after being engaged with 42b, the upward pressing force against the reflecting mirror 32 by the tip of the adjusting screw 42 is adjusted, and on the photosensitive drum 2a in the color laser printer shown in FIG. The curvature of the scanning line is corrected.

  Incidentally, in the optical scanning device 13 according to the present invention, as shown in FIGS. 7, 9, and 10, two reflection mirrors 32 in the longitudinal direction (the scanning line curve correcting means 39 and the leaf spring 34 in the longitudinal direction). The elastic member 43 is interposed between the reflecting mirror 32 and the sheet metal stay 35. As shown in FIG. 10, each elastic member 43 is sandwiched between a part (both ends in the width direction) of the reflecting mirror 32 and the sheet metal stay 35 and contacts only the side surface of the reflecting mirror 32, and the other parts are The outer periphery of the sheet metal stay 35 is covered. And in this Embodiment, the film which is not illustrated is coat | covered on the outer surface which contacts the reflective mirror 32 of the elastic member 43. FIG.

  As described above, in the optical scanning device 13 according to the present invention, the elastic member 43 is interposed between the reflecting mirror 32 and the sheet metal stay 35 at two locations in the longitudinal direction of the reflecting mirror 32. The damping effect (attenuation effect) suppresses the vibration from the sheet metal stay 35 to the reflection mirror 32, the vibration of the reflection mirror 32 is kept low over a wide frequency range, and high optical performance is stably secured in the optical scanning device 13. Is done. Here, FIG. 14 shows the vibration characteristic of the reflection mirror 32 of the optical scanning device 13 according to the present invention in comparison with the conventional one. The conventional vibration characteristic indicated by a broken line shows acceleration (amplitude) in a certain polygon rotation speed range. ) Shows a peak value. It is understood that the peak value is attenuated by the damping effect of the elastic member 43 and shows a low value in the vibration characteristic of the reflection mirror 32 of the optical scanning device 13 according to the present invention indicated by a solid line. .

  Further, in the optical scanning device 13 according to the present invention, since the mounting angle of the reflection mirror 32 is determined by a total of three protrusions 35 a and 35 b formed on the sheet metal stay 35, high flatness is required for the sheet metal stay 35. Therefore, the manufacture of the sheet metal stay 35 is facilitated. Further, by providing the elastic member 43 between the side surface independent of the mounting angle of the reflection mirror 32 and the sheet metal stay 35, the angle variation of the reflection mirror 32 due to environmental variation or the like is suppressed, and the reflection mirror 32 has high optical performance. Is secured.

  Furthermore, in this embodiment, since the film is coated on the surface of the elastic member 43 that contacts the reflection mirror 32, the friction with the reflection mirror 32 is suppressed by the film when the elastic member 43 is assembled, and the elastic member 43 is assembled. Sexuality is enhanced.

  As described above, according to the optical scanning device 13 of the present invention, since the vibration of the reflection mirror 32 is suppressed, the vertical movement of the light beam on each of the photosensitive drums 2a to 2d of the color laser printer shown in FIG. The occurrence of image defects such as jedder is prevented, and high-quality images can be stably obtained.

  Although the above description has been made on the mounting structure of one reflection mirror of the optical scanning device, the vibration of these reflection mirrors can be suppressed by adopting the same mounting structure for the other reflection mirrors. 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 in the color laser printer, the present invention is not limited to a color printer and other arbitrary images including monochrome. Of course, the present invention can be similarly applied to the forming apparatus and the optical scanning device provided therein.

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 (photoconductor)
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 drive roller 9 tension roller 10 secondary transfer roller 11 belt cleaning device 12a to 12d toner container 13 optical scanning device 14 Paper cassette 15 Pickup roller 16 Feed roller 17 Retard roller 18 Transport roller pair 19 Registration roller pair 20 Transport roller pair 21 Paper discharge tray 22 Fixing device 23, 24 Paper discharge roller pair 25 Optical scanning device casing 26 Polygon mirror 27 Polygon Motor 28, 29 Imaging lens 30-32 Reflection mirror 33 Cover 34 Plate spring 35 Sheet metal stay 36, 37 Plate spring 38 Screw 39 Scan line curve correction means 40 Holding bracket 41 Compression bar 42 Adjusting screw 43 Elastic member 100 Printer body S, S 'Transport path

Claims (4)

A deflector that deflects the light beam emitted from the light source, an imaging lens that converts the light beam deflected by the deflector into constant-speed scanning light, and a reflection mirror that folds the constant-speed scanning light and guides it to the photoconductor A scanning line curve that is housed in a housing and elastically supports both ends of the reflecting mirror in the main scanning direction with respect to the housing via a sheet metal stay, and changes the shape of the reflecting mirror to correct the scanning line curvature. In the optical scanning device comprising the correcting means,
The reflecting mirror and interposed between said sheet metal stay, an optical scanning apparatus characterized by comprising an elastic member in contact only on the side surfaces of the reflecting mirror. The optical scanning apparatus according to claim 1, wherein the benzalkonium be supported by the convex three positions the rear is formed in the sheet metal stay of the reflecting mirror. 3. The optical scanning device according to claim 1, wherein a film that reduces friction is coated on a surface of the elastic member that contacts the reflecting mirror. An image forming apparatus comprising the optical scanning device according to claim 1.

Images