JP2012242760A - Optical scanner and image forming apparatus - Google Patents

Abstract

An optical scanning device and an image forming apparatus capable of removing fine deposits attached to the surface of a transparent dustproof member and suppressing the scratch on the surface of the transparent dustproof member.
When opening and closing a shutter member 60, each dust-proof glass 48Y, by a first cleaning member 67Y, C, M, K made of a nonwoven fabric provided at the tip of each shielding member 66Y, C, M, K. Remove deposits on C, M and K surfaces. When the number of write operations exceeds a predetermined number, the shutter member 60 is further moved from the shielding position, the shutter member 60 is brought closer to the dust-proof glass side, and the substantially central portion of each shielding member 66Y, C, M, K Second cleaning members 68Y, 68C, 68M, and 68K made of a blade member provided in the vicinity are brought into contact with each dustproof glass 48Y, 48Y, 48M, 48K. Then, deposits on the dust-proof glass surface are removed by the second cleaning members 68Y, 68C, 68M, and 68K.
[Selection] Figure 3

Description

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

  Some image forming apparatuses such as copiers, printers, facsimiles, and the like form a latent image on a latent image carrier by irradiating the latent image carrier with writing light according to image information by deflecting scanning. It is known that the latent image is developed to obtain an image. In general, an optical scanning apparatus that deflects and scans writing light is a polygon scanner that is a light variable deflection apparatus in which light emitted from a light source such as a laser diode (LD) is shaped into a predetermined shape by an optical element such as a cylindrical lens. Incident on the polygon mirror. The light incident on the polygon mirror is deflected and scanned, passes through optical elements such as a scanning lens and a reflection mirror, and is then applied to the latent image carrier from dust-proof glass, which is a transparent dust-proof member attached to the opening of the optical housing. The

  In recent years, there has been a demand for higher image quality in image forming apparatuses, and in optical scanning apparatuses, the problem that dirt such as dust adheres to dust-proof glass and the image quality is deteriorated by blocking laser light has become serious. It was. Patent Document 1 includes a shutter member that moves between a covering position that covers the dust-proof glass and an open position that opens the dust-proof glass. The shutter member abuts on the dust-proof glass and moves the surface of the dust-proof glass as the shutter member opens and closes. Thus, there is described an optical scanning device in which a cleaning member that removes adhering substances such as dust and dust adhering to dust-proof glass is provided on the shutter member.

  However, in the optical scanning device described in Patent Document 1, a non-woven fabric is used as the cleaning member. However, the non-woven fabric has a problem in that fine dust attached to the dust-proof glass surface cannot be sufficiently removed. Therefore, it is conceivable to use a blade member such as a rubber blade having a higher cleaning ability than the nonwoven fabric as the cleaning member. By using the blade member, it is possible to improve the adhesion to the surface of the dust-proof glass as compared with the case of using a non-woven fabric, and it is possible to scrape and remove fine deposits on the surface of the dust-proof glass. However, when the blade member is used, there is a risk that the dust-proof glass may be damaged when, for example, a relatively hard deposit is caught in the contact portion of the blade member with the dust-proof glass.

  The present invention has been made in view of the above problems, and its purpose is to remove fine deposits adhering to the surface of the permeable dust-proof member and to suppress the surface of the permeable dust-proof member from being damaged. It is an object of the present invention to provide an optical scanning device and an image forming apparatus that can do the same.

In order to achieve the above object, the invention of claim 1 is directed to a light source, deflection means for deflecting and scanning a light beam emitted from the light source in a main scanning direction, and a light beam deflected by the deflection means to be scanned. A plurality of optical elements guided to the light source, the light source, the deflecting means, an optical housing in which the optical elements are mounted, and an opening formed in the housing so that the light flux is incident on a scanned surface. A permeable dust-proof member that covers the permeable dust-proof member, a shutter member that is movably provided between a covering position that covers the permeable dust-proof member, and an open position where the permeable dust-proof member is opened; When scanning the light beam on the scanning surface, the shutter member is moved from the covering position to the open position, and when scanning of the light beam on the surface to be scanned is completed, the shutter member is moved from the open position to the covering position. The shutter member is configured to be movable beyond an opening / closing range between the open position and the covering position, and the opening / closing of the shutter member. A first cleaning member that moves the surface of the permeable dust-proof member at the time of movement of the range to remove deposits attached to the permeable dust-proof member, and when the shutter member moves beyond the opening / closing range, A second cleaning member having a higher cleaning ability than the first cleaning member that moves on the surface of the permeable dustproof member to remove deposits attached to the permeable dustproof member, and the shutter member at a predetermined timing. And a control means for executing control for moving the permeable dustproof member by the second cleaning member so as to move beyond the opening / closing range.
According to a second aspect of the invention, in the optical scanning device of the first aspect, the first cleaning member is a non-woven fabric, and the second cleaning member is a blade member.
According to a third aspect of the present invention, in the optical scanning device according to the first or second aspect, the second cleaning member is separated from the surface on which the opening of the optical housing is formed, rather than the first cleaning member. The contact member is provided at a position where the shutter member is moved closer to the optical housing when the shutter member is moved beyond the opening / closing range.
According to a fourth aspect of the present invention, in the optical scanning device according to the third aspect, the contact / separation means includes a protrusion protruding from the shutter member, and the protrusion when the shutter member moves beyond the opening / closing range. And pressing means for pressing the projecting portion toward the optical housing.
According to a fifth aspect of the present invention, in the optical scanning device according to the fourth aspect, a part of the transmissive dustproof member protrudes from a surface on which the opening of the optical housing is formed, and the contacting / separating means includes: The protrusion has an inclined surface in the moving direction of the shutter member, and when the shutter member is moved beyond the opening / closing range, the pressing portion comes into contact with the inclined surface, and the shutter is moved along with the movement of the shutter member. The member is brought close to the optical housing, and when the shutter member is brought close to the optical housing by the contact / separation means, the first cleaning member rubs the ridge line portion of the permeable dustproof member. It is what.
According to a sixth aspect of the present invention, in the optical scanning device according to any one of the first to fifth aspects, the moving means includes a motor, a worm gear, a biasing means for biasing the shutter member toward the worm gear, and the worm gear. And a protrusion for pressing the shutter member in a direction opposite to the urging direction of the urging means.
According to a seventh aspect of the present invention, in the optical scanning device according to the sixth aspect, the shutter member abuts on the protrusion when the motor is rotated forward to move the shutter member within an opening / closing range. And a second abutting part for abutting the projecting part when the motor is rotated in reverse and moving the shutter member beyond the open range. It is a feature.
According to an eighth aspect of the present invention, in the optical scanning device according to the seventh aspect, the second contact portion is disposed closer to the worm gear than the first contact portion.
According to a ninth aspect of the present invention, in the optical scanning device according to any of the sixth to eighth aspects, the protrusion is covered with a cover member, and the cover member is provided so as to be rotatable with respect to the protrusion. It is characterized by that.
According to a tenth aspect of the present invention, in the optical scanning device according to any one of the first to ninth aspects, the second cleaning member is formed of a highly elastic member.
According to an eleventh aspect of the present invention, there is provided an image forming apparatus comprising: a latent image carrier that carries a latent image; and an optical writing unit that writes the latent image on the surface of the latent image carrier. The optical scanning device according to any one of claims 1 to 10 is used as the insertion means.

  According to the present invention, during the opening / closing operation of the shutter member when performing optical scanning on the surface to be scanned, the first cleaning member moves on the surface of the permeable dustproof member to clean the surface of the permeable dustproof member. In addition, the shutter member is moved beyond the opening / closing range at a predetermined timing, and the surface of the permeable dustproof member is cleaned with the second cleaning member having a higher cleaning ability than the first cleaning member. Thereby, fine deposits that could not be removed by the first cleaning member can be removed by the second cleaning member. Further, during the opening / closing operation of the shutter member when performing optical scanning on the surface to be scanned, the surface of the transparent dustproof member is cleaned by the first cleaning member, so that the shutter member when performing optical scanning on the surface to be scanned is used. Even when the opening / closing operation is performed, the surface of the permeable dustproof member can be prevented from being damaged as compared with the case where the surface of the permeable dustproof member is cleaned by the second cleaning member.

1 is a schematic configuration diagram illustrating a printer according to an embodiment. FIG. 2 is a schematic configuration diagram illustrating an image forming station for Y in the printer. FIG. 2 is a schematic configuration diagram showing an optical writing unit in the printer together with four photosensitive members. The top view of the optical writing unit. The schematic perspective view of a drive mechanism. FIG. 3 is an enlarged configuration diagram illustrating the periphery of a guide hole of a shutter member. The control flow figure of a movement of a shutter member. The figure explaining operation | movement of the drive mechanism at the time of opening / closing operation | movement of a shutter member. The figure explaining operation | movement of the drive mechanism at the time of cleaning operation | movement. The schematic block diagram of the optical writing unit when a shutter member exists in a shielding position. FIG. 3 is a schematic configuration diagram of an optical writing unit during a cleaning operation. The figure explaining a mode that the deposit | attachment adhering to the dust-proof glass surface was removed. The figure which shows the paper dust adhering to the nonwoven fabric of a 1st cleaning member. FIG. The figure explaining cleaning of dustproof glass at the time of cleaning operation. The figure which shows the modification of the contact part of a shutter member.

Hereinafter, an embodiment in which the present invention is applied to an electrophotographic color laser printer (hereinafter simply referred to as a printer) will be described.
FIG. 1 is a schematic configuration diagram illustrating a printer according to the present embodiment. The printer includes a housing 1 and a paper feed cassette 2 that can be pulled out from the housing 1. Image forming stations 3Y, 3C, and 3C for forming toner images (visible images) of each color of yellow (Y), cyan (C), magenta (M), and black (K) are provided at the center of the housing 1. 3M, 3K. Hereinafter, the subscripts Y, C, M, and K of the respective symbols indicate members for yellow, cyan, magenta, and black, respectively.

FIG. 2 is a schematic configuration diagram showing an image forming station for yellow (Y). The other image forming stations have the same configuration.
As shown in FIGS. 1 and 2, the image forming stations 3Y, 3C, 3M, and 3K include drum-shaped photoconductors 10Y, 10C, 10M, and 10K as latent image carriers that rotate in the direction of arrow A in the drawing. ing. Each of the photoreceptors 10Y, 10C, 10M, and 10K includes an aluminum cylindrical substrate having a diameter of 40 [mm] and an OPC (organic photo semiconductor) photosensitive layer that covers the surface of the photoreceptor. Each of the image forming stations 3Y, 3C, 3M, and 3K includes charging devices 11Y, 11C, 11M, and 11K that charge the photoconductors around the photoconductors 10Y, 10C, 10M, and 10K, respectively. Further, developing devices 12Y, 12C, 12M, and 12K as developing means for developing the latent image formed on the photosensitive member, and cleaning devices 13Y, 13C, 13M, and 13K for cleaning residual toner on the photosensitive member are also provided around the photosensitive member. In preparation.

  Below each of the image forming stations 3Y, 3C, 3M, and 3K, there is provided an optical writing unit 4 as an optical scanning device that performs optical scanning with the writing light L on the photoreceptors 10Y, 10C, 10M, and 10K. Yes. Further, an intermediate transfer unit 5 including an intermediate transfer belt 20 to which toner images formed by the image forming stations 3Y, 3C, 3M, and 3K are transferred above the image forming stations 3Y, 3C, 3M, and 3K. It has. Further, a fixing unit 6 is provided for fixing the toner image transferred to the intermediate transfer belt 20 onto a recording paper P as a transfer member. In addition, toner bottles 7Y, 7C, 7M, and 7K that contain toner of each color of yellow (Y), cyan (C), magenta (M), and black (K) are loaded on the top of the casing 1. . The toner bottles 7 </ b> Y, 7 </ b> C, 7 </ b> M, and 7 </ b> K can be detached from the housing 1 by opening a paper discharge tray 8 formed on the top of the housing 1.

  An optical writing unit 4 as an optical scanning device has a semiconductor laser as a light source, and writing light L as a light beam is directed from this semiconductor laser toward a polygon mirror having a regular polygonal column structure that is rotationally driven. Fire. The emitted writing light L is reflected while being deflected in the main scanning direction by the mirror surface of the rotating polygon mirror. Then, after being folded by a plurality of reflecting mirrors, the peripheral surfaces of the photoreceptors 10Y, 10C, 10M, and 10K that are uniformly charged by the charging devices 11Y, 11C, 11M, and 11K are scanned. Thereby, electrostatic latent images for Y, C, M, and K are formed on the peripheral surfaces of the photoreceptors 10Y, 10C, 10M, and 10K as latent image carriers. The detailed description of the optical writing unit 4 will be described later.

  The intermediate transfer belt 20 of the intermediate transfer unit 5 serving as transfer means is driven to rotate counterclockwise in the figure at a predetermined timing while being wound around a drive roller 21, a tension roller 22 and a driven roller 23. In addition, the intermediate transfer unit 5 includes primary transfer rollers 24Y, 24C, 24M, and 24K that primarily transfer the toner images formed on the photoreceptors 10Y, 10C, 10M, and 10K to the intermediate transfer belt 20. Further, a secondary transfer roller 25 that transfers the toner image primarily transferred onto the intermediate transfer belt 20 to the recording paper P, and a belt that cleans residual toner on the intermediate transfer belt 20 that has not been transferred onto the recording paper P. A cleaning device 26 is also provided.

Next, a process for obtaining a color image in this printer will be described.
First, in the image forming stations 3Y, 3C, 3M, and 3K, the photoreceptors 10Y, 10C, 10M, and 10K are uniformly charged by the charging devices 11Y, 11C, 11M, and 11K. Thereafter, scanning exposure is performed with the writing light L generated based on the image information, and electrostatic latent images are formed on the surfaces of the photoreceptors 10Y, 10C, 10M, and 10K. These electrostatic latent images are developed with toners of the respective colors carried on the developing rollers 15Y, 15C, 15M, and 15K of the developing devices 12Y, 12C, 12M, and 12K, and are converted into Y, C, M, and K toner images. Become. The Y, C, M, and K toner images on the photoreceptors 10Y, 10C, 10M, and 10K are formed on the intermediate transfer belt 20 that is rotated counterclockwise by the action of the primary transfer rollers 24Y, 24C, 24M, and 24K. The primary transfer is carried out in order. The image forming operation of each color at this time is shifted in timing from the upstream side in the moving direction of the intermediate transfer belt 20 toward the downstream side so that the toner image is transferred to the same position on the intermediate transfer belt 20. Executed.

  The surfaces of the photoconductors 10Y, 10C, 10M, and 10K after the completion of the primary transfer are cleaned by the cleaning blades 13a of the cleaning devices 13Y, 13C, 13M, and 13K to prepare for the next image formation.

  The toner filled in the toner bottles 7Y, 7C, 7M, and 7K is placed in the developing devices 12Y, 12C, 12M, and 12K of the image forming stations 3Y, 3C, 3M, and 3K by a conveyance path (not shown) as necessary. A fixed amount is supplied.

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

Next, the optical writing unit 4 will be described.
FIG. 3 is a schematic cross-sectional view showing the configuration of the optical writing unit 4.
The optical writing unit 4 includes an optical element such as a light source (not shown), a polygon scanner 50 as a deflecting unit, various reflection mirrors, and various lenses, which are housed in an optical housing 131. The optical housing 131 includes a housing member 131a and an upper cover member 131b, and the upper cover member 131b is attached so as to cover the opening above the housing member 131a. The upper cover member 131b is provided with four openings 132Y, 132C, 132M, and 132K through which writing light passes, corresponding to the photoconductor, and each opening has a dustproof member that is a transparent dustproof member. Glasses 48Y, 48C, 48M, and 48K are provided.

  The polygon scanner 50 serving as a deflecting unit includes a polygon motor 51, and an upper polygon mirror 52b and a lower polygon mirror 52a each having a regular polygonal column shape fixed to a rotation shaft 51a of the polygon motor 51. The polygon scanner 50 is disposed substantially at the center of the optical writing unit 4 and is surrounded by a soundproof glass or a soundproof wall (not shown).

  An M optical system and a K optical system are arranged on the right side of the polygon scanner 50 in the drawing. On the left side of the polygon scanner 50 in the drawing, an optical system for Y and an optical system for C are arranged.

FIG. 4 is a schematic plan view of the optical writing unit 4.
As shown in FIG. 4, the optical writing unit 4 includes a semiconductor laser 53K as a light source that emits writing light Lk, Lm, Lc, and Ly as light beams respectively corresponding to the photoconductors 10K, 10M, 10C, and 10Y. , 53M, 53C, 53Y. The semiconductor laser 53K is arranged directly below the semiconductor laser 53M and is not shown. Further, the semiconductor laser 53Y is disposed directly below the semiconductor laser 53C and is not shown. A collimating lens, an aperture (not shown), and a cylindrical lens are arranged on the optical path from the semiconductor laser to the polygon mirror. The K-color collimating lens is not shown because it is directly below the M-color collimating lens 54M, and the K-color cylindrical lens is directly below the M-color cylindrical lens 55M. Similarly, the Y-color collimating lens is not shown because it is directly under the C-color collimating lens 54C, and the Y-color cylindrical lens is directly under the C-color cylindrical lens 55C.

  As shown in FIG. 3, scanning lenses (fθ lenses) 43a and 43b, first mirrors 44K, 44M, 44C and 44Y, and second mirrors 45M and 45C, which are optical elements, are arranged from the polygon scanner 50 to the photosensitive member 10. It is arranged on the optical path.

  The writing light Lk emitted from a K semiconductor laser (not shown) passes through a K collimator lens (not shown) and is then shaped into a fixed shape by a K aperture (not shown). Next, by passing through a cylindrical lens for K (not shown), the light is condensed in the sub-scanning direction (the direction corresponding to the moving direction of the photosensitive member surface on the photosensitive member surface) and incident on the side surface of the lower polygon mirror 52a. To do. When the writing light Lk is incident on the side surface of the lower polygon mirror 52a, the writing light Lk is deflected and scanned in the main scanning line direction. The writing light Lk deflected and scanned by the lower polygon mirror 52a is collected by the scanning lens 43a (fθ lens). The K writing light Lk collected by the scanning lens 43a is applied to the photoconductor 10K through the first mirror 44K.

  The writing light Lm emitted from the M semiconductor laser 53M, like the K color, passes through the M collimating lens 54M, the M aperture (not shown), the M cylindrical lens 55M, etc., and the upper polygon mirror 52b. Scanned. The M-color writing light Lm scanned by the upper polygon mirror 52b passes through the scanning lens 43a, the first mirror 44M, and the second mirror 45M, and irradiates the photoconductor 10M.

  The writing light Lc emitted from the C semiconductor laser 53C also passes through the C collimating lens 54C, the C aperture (not shown), the C cylindrical lens 55C, etc., and is scanned by the upper polygon mirror 52b. . The C-color writing light Lc scanned by the upper polygon mirror 52b passes through the scanning lens 43b, the first mirror 44C, and the second mirror 45C and is irradiated onto the photoconductor 10C.

  The writing light Ly emitted from the Y semiconductor laser (not shown) also passes through the Y collimating lens (not shown), the Y aperture (not shown), the Y cylindrical lens (not shown), etc. It is scanned by the mirror 52a. The Y-color writing light Ly scanned by the lower polygon mirror 52a passes through the scanning lens 43b and the first mirror 44Y and is irradiated to the photoreceptor 10Y.

  As shown in FIG. 3, the shutter member 60 is slidably and integrally mounted on the upper cover 131b. The shutter member 60 has two guide holes 69 extending in a direction perpendicular to the main scanning direction (longitudinal direction of the optical writing unit 4). The shutter member 60 can reciprocate to the upper cover 131b by inserting a stepped screw 168 into each guide hole 69 and screwing it into a screw hole (not shown) of the mounting base 133 provided on the upper cover member 131b. Supported by The shutter member 60 is urged toward the drive mechanism 200 (right side in FIG. 3) by an urging means (not shown), and is inserted into each guide hole 69 when the shutter member 60 is in the open position. A stepped screw 168 abuts against the end of each guide hole 69 opposite to the drive mechanism 200 side.

FIG. 6 is an enlarged configuration diagram showing the periphery of the guide hole 69 of the shutter member 60.
As shown in the figure, a protrusion 62 protruding from the shutter member 60 is provided around the guide hole 69. An inclined surface 62a is provided on the side opposite to the drive mechanism 200 side of the protrusion 62 (upper side in FIG. 6). Although details will be described later, when the shutter member is further moved from the covering position, the inclined surface 62a abuts against the head of the stepped screw 168, and as the shutter member 60 moves, the inclined surface 62a becomes the stepped screw. The shutter member 60 is pushed by the head of 168 and approaches the upper cover member 131b.

  As shown in FIG. 3, the shutter member 60 is provided with four passage holes 63Y, 63C, 63M, and 63K for allowing the writing light extending parallel to the main scanning direction to pass therethrough. One end of a shielding plate 66Y, 66C, 66M, 66K is attached to the opening end of each through hole 63Y, 63C, 63M, 63K, and the other end is slid with dustproof glass 48Y, 48C, 48M, 48K. First cleaning members 67Y, 67C, 67M, and 67K for rubbing and cleaning the surfaces of the dustproof glasses 48Y, 48C, 48M, and 48K are attached. In addition, second cleaning members 68Y, 68C, 68M, and 68K are attached to substantially the center of the shielding plates 66Y, 66C, 66M, and 66K. The first cleaning members 67Y, 67C, 67M, and 67K are non-woven fabrics, and the second cleaning member is a blade member made of a highly elastic material such as rubber. As shown in FIG. 3, when the shutter member 60 is in the open position, the first cleaning members 67Y, 67C, 67M, and 67K are in contact with the right ends of the dustproof glasses 48Y, 48C, 48M, and 48K in the drawing, The second cleaning members 68Y, 68C, 68M and 68K are separated from the dustproof glasses 48Y, 48C, 48M and 48K.

A driving mechanism 200 as a moving means is provided on one end side (right side in the drawing) of the shutter member 60 in the longitudinal direction.
FIG. 5 is a schematic perspective view of the drive mechanism 200.
The drive mechanism 200 includes a drive motor 201 and a worm gear 202, which are held by a bracket 204 fixed to the side surface of the housing member 131a. The screw gear 202 a of the worm gear 202 is fixed to the motor shaft of the drive motor 201, and the helical gear 202 b of the worm gear 202 is rotatably held by the bracket 204. The helical gear 202b is provided with a projection 203, and the projection 203 is covered with a metallic cylindrical cover member 205. The cover member 205 is held by the helical gear 202b so as to be rotatable with respect to the protrusion 203.

An extension portion 65c extending to the drive mechanism side is provided at the center portion in the main scanning direction of the end portion on the drive mechanism side of the shutter member 60, and one end portion in the main scanning direction of the extension portion 65c is A first abutting portion 65 a that abuts against the protruding portion 203 via the cover member 205 when the helical gear 202 b rotates forward is provided. Further, at the other end in the main scanning direction of the extended portion 65c, the protruding portion 203 is extended through the cover member 205 when the helical gear 202b is rotated in the reverse direction. Is provided with a second contact portion 65b. Each contact part 65a, 65b is a curved surface along the movement accompanying the rotation of the helical gear 202b of the projection part 203.
By covering the protrusion 203 with a cover member 205 that is rotatable with respect to the protrusion 203, when the surfaces of the contact portions 65a and 65b are moved, the metal cover member 205 moves while rotating. As a result, it is possible to suppress wear of the protrusion 203 and the contact portions 65a and 65b.

Next, the opening / closing operation of the shutter member 60 will be described.
FIG. 7 is a control flow chart of the movement of the shutter member 60, FIG. 8 is a diagram illustrating the operation of the drive mechanism 200 when the shutter member 60 is opened and closed, and FIG. 9 is the drive mechanism during the cleaning operation. It is a figure explaining operation | movement of 200. FIG. FIG. 10 is a schematic configuration diagram of the optical writing unit 4 when the shutter member is in the shielding position, and FIG. 11 is a schematic configuration diagram of the optical writing unit 4 during the cleaning operation.
When the optical writing unit 4 is stopped, as shown in FIG. 10, the shutter member 60 is in the shielding position, and the shielding plates 66Y, 66C, 66M, 66K are respectively provided with the corresponding dustproof glasses 48Y, 48C, It faces 48M and 48K and shields the dustproof glass 48Y, 48C, 48M and 48K. As a result, it is possible to suppress the floating matter such as dust or the like floating in the main body of the image forming apparatus from adhering to the dustproof glasses 48Y, 48C, 48M, and 48K.
When the shutter member 60 is in the shielding position, as shown in FIG. 8A, the protrusion 203 provided on the helical gear 202b is in contact with the first contact portion 65a and is located closest to the optical housing. (See FIG. 10). At this time, the first cleaning members 67Y, 67C, 67M, and 67K provided at the tips of the shielding plates 66Y, 66C, 66M, and 66K are opposite to the drive mechanism 200 side of the dust-proof glasses 48Y, 48C, 48M, and 48K. It is in contact with the end of the.

  As shown in FIG. 7, when image information is received (S1), the control means (not shown) moves the shutter member 60 from the shielding position to the open position shown in FIG. 3 (S2). Specifically, as shown in FIG. 8, the drive motor 201 of the drive mechanism 200 is rotated in the reverse direction, and the helical gear 202b is rotated clockwise in FIG. Then, the shutter member 60 moves to the drive mechanism 200 side by the biasing force of the biasing means (not shown). Then, when the protruding portion 203 moves to the position of FIG. 8B, the stepped portion of the stepped screw 168 hits the end of the guide hole 69 opposite to the drive mechanism 200 side, as shown in FIG. The shutter member 60 stops at the open position. When the shutter member 60 stops at the open position, the shielding plates 66Y, 66C, 66M, and 66K that shielded the dust-proof glasses 48Y, 48C, 48M, and 48K are retracted, and the dust-proof glasses 48Y, 48C, 48M, and 48K are opened. . When the shutter member 60 is opened, the first cleaning members 67Y, 67C, 67M, and 67K provided at the tips of the shielding plates 66Y, 66C, 66M, and 66K cover the surfaces of the dust-proof glasses 48Y, 48C, 48M, and 48K. It moves to remove deposits such as paper dust that has adhered to the dustproof glasses 48Y, 48C, 48M, and 48K while the optical writing unit 4 is stopped. The drive mechanism 200 continues to drive even after the shutter member 60 is located at the open position, and stops when the protrusion 203 comes to the position farthest from the optical housing, as shown in FIG. When the drive motor 201 is a pulse motor such as a stepping motor, the protrusion 203 can be stopped so as to be in a predetermined position by counting the number of pulses. Further, when the drive motor 201 is a DC motor or the like, by measuring the drive time of the drive motor 201, the protrusion 203 can be stopped so as to be in a predetermined position.

  Thus, when the shutter member 60 stops at the open position, the optical writing unit 4 starts a writing operation (S3), and writes a latent image based on the image information on each of the photoreceptors 10Y, 10C, 10M, and 10K. Include. Next, when the write operation is completed, it is checked whether the number of write operations is equal to or greater than a predetermined number (S4).

  When the writing operation is less than the predetermined number of times, the control means (not shown) rotates the drive motor 201 in the forward direction. Then, the projection 203 of the helical gear 202b comes into contact with the first contact part 65a and moves the shutter member 60 toward the shielding position. Then, when the protrusion 203 reaches the position of FIG. 8A, the drive of the drive motor 201 is stopped.

  FIG. 12 is a diagram illustrating a state in which deposits attached to the surface of the dust-proof glass 48M are removed. As shown in FIGS. 12A and 12B, when the shutter member 60 is moved from the open position to the shielding position, the first cleaning member 67M moves the surface of the dust-proof glass 48M, and the dust-proof glass during the writing operation. The deposits attached to 48M are removed. The first cleaning members 67Y, 67C, and 67K also move on the surfaces of the other colors of the dust-proof glasses 48Y, 48C, and 48K to remove the deposits attached to the dust-proof glass 48M during the writing operation.

  On the other hand, when the writing operation is performed a predetermined number of times or more (YES in S4), the control unit (not shown) executes a cleaning operation (S5). In this embodiment, whether or not to perform the cleaning operation is determined based on the number of write operations. However, for example, an elapsed time since the previous cleaning operation may be used.

FIG. 13 is a diagram illustrating paper dust adhered to the nonwoven fabric of the first cleaning member 67, and FIG. 14 is a diagram illustrating toner. In addition, the table | surface of the lower right in the figure of FIG. 13 is the data which measured the length of the paper dust adhering to the nonwoven fabric.
As shown in FIG. 13, since the paper dust is relatively large at about 50 μm, the paper dust attached to the dustproof glass 48 is entangled with the first cleaning member 67 made of a nonwoven fabric and can be removed well. However, as shown in FIG. 14, the toner having a size of about 6.8 μm, which is much finer than paper dust, is not easily entangled with the nonwoven fabric and may not be removed well by the first cleaning member 67. Therefore, when the dust-proof glass 48 is cleaned only by the first cleaning member 67, fine deposits such as toner accumulate on the surface of the dust-proof glass 48 over time, affecting the image. Therefore, it is also conceivable that the first cleaning member 67 is a blade member having a higher removal capability than the nonwoven fabric. However, since the blade member does not entangle the adhering matter adhering to the dust-proof glass 48 unlike the nonwoven fabric, it scrapes off the blade member, so that it is necessary to contact with a somewhat higher contact pressure than in the case of the nonwoven fabric. There is. As a result, when the blade member is used, there is a drawback that the surface of the dust-proof glass 48 is likely to be damaged. In view of the above, in the present embodiment, the second cleaning member 68 made of a blade member is provided, and when the shutter member 60 is opened and closed, the dust-proof glass 48 is cleaned by the first cleaning member 67 made of a nonwoven fabric. The cleaning operation is executed at a predetermined timing, and the dust-proof glass is cleaned by the second cleaning member 68. Thereby, it is possible to suppress the dust-proof glass surface from being damaged and to prevent fine deposits such as toner from accumulating on the dust-proof glass surface.

  When the cleaning operation is executed, a control unit (not shown) rotates the drive motor 201 of the drive mechanism 200 in the reverse direction. Then, the protrusion 203 located at the position of FIG. 9A moves clockwise in the figure, and as shown in FIG. 9B, the protrusion 203 comes into contact with the second contact portion 65b. Then, the shutter member 60 is moved from the open position to the shield position side against an urging means (not shown). Since the second abutting portion 65b is on the drive mechanism side by a length L from the first abutting portion 65a, as shown in FIG. 9C, the protruding portion 203 is positioned closest to the optical housing side. At this time, the shutter member 60 is moved further to the side opposite to the drive mechanism 200 side by the length L from the shielding position. The length L is set to be at least the length of the dust-proof glass 48 in the moving direction of the shutter member 60. By setting in this way, as shown in FIG. 11, the second cleaning members 68Y, 68C, 68M, 68K can move the surface of the dust-proof glass 48Y, 48C, 48M, 48K from one end to the other, The entire dust-proof glass 48Y, 48C, 48M, 48K can be cleaned by the second cleaning members 68Y, 68C, 68M, 68K.

FIG. 15 is a diagram for explaining the cleaning of the M-color dust-proof glass 48M during the cleaning operation. The same applies to dust-proof glasses of other colors.
As shown in FIG. 15A, when the shutter member 60 moves further to the side opposite to the drive mechanism 200 side than the shielding position, the inclined surface 62 a hits the head of the stepped screw 168. From this state, when the shutter member 60 further moves to the side opposite to the drive mechanism side, the head of the stepped screw 168 presses the inclined surface 62a toward the upper cover member 131b, and the inclined surface 62a is stepped. The shutter member 60 gradually moves toward the upper cover member 131b as it enters between the head of the screw 168 and the mounting base 133. As the shutter member 60 moves toward the upper cover member 131b, the shielding plate 66M is elastically deformed. Further, when the shutter member 60 is moved, the protrusion 62 of the shutter member 60 enters between the head of the stepped screw 168 and the mounting base 133. As shown in FIG. 15A, the height from the surface of the dust-proof glass 48M to the second cleaning member 68M is lower than the height H from the shutter member 60 of the protrusion 62. Therefore, when the protrusion 62 of the shutter member 60 enters between the head of the stepped screw 168 and the mounting base 133 and the shutter member 60 is close to the upper cover member 131b by the height H of the protrusion 62, As shown in FIG. 15B, the second cleaning member 68M provided at the substantially central portion of the shielding plate 66M contacts the end portion of the dust-proof glass 48M on the drive mechanism 200 side with a predetermined contact pressure. Thus, in the present embodiment, the stepped screw 168 functions as a pressing unit, and the stepped screw 168 and the protruding portion 62 constitute a contact / separation unit. When the shutter member 60 is further moved to the side opposite to the driving mechanism 200 side, the second cleaning member 67M moves on the surface of the dust-proof glass 48M and adheres to the dust-proof glass 48M as shown in FIG. Scrape off and remove deposits.

  Since the second cleaning member 68M is a blade member having a higher cleaning ability than the first cleaning member 67M made of a nonwoven fabric, it cannot be removed by the first cleaning member 67M, and fine deposits such as toner remaining on the dust-proof glass 48M. Can be removed. As a result, it is possible to prevent fine deposits such as toner from accumulating on the surface of the dust-proof glass 48M and hindering the writing light. Further, since the cleaning with the blade member is performed at a predetermined timing, the dust-proof glass 48 can be prevented from being damaged.

  Further, when the shutter member 60 is moved to the opposite side of the drive mechanism 200 from the shielding position and the shutter member 60 is moved to the upper cover member 131b side, the first cleaning member provided at the tip of the shielding plate 66M. 67M slides along the ridgeline of the end of the dust-proof glass 48M opposite to the drive mechanism 200 side. As a result, the adhering matter adhering to the first cleaning member 67M by the ridge line of the dustproof glass 48M is scraped off. Thereby, the cleaning capability of the first cleaning member 67M can be recovered.

  As shown in FIG. 9C, even if the protrusion 203 reaches the optical housing side most, the reverse rotation is performed without stopping the drive of the drive motor 201. As a result, when the shutter member 60 reaches the position of FIG. 15C, it moves to the drive mechanism 200 side. When the protruding portion 62 of the shutter member 60 passes between the head of the stepped screw 168 and the mounting base 133, the shutter member 60 gradually separates from the upper cover member 131b while being guided by the inclined surface 62a. Move in the direction. This is because when the shutter member 60 is brought close to the upper cover member 131b, the shielding plate 66M is elastically deformed, and this shielding plate 66M acts just like a leaf spring, so that the shutter member 60 is covered with the upper cover. This is because the biasing is performed in a direction away from the member 131b. And as shown to Fig.15 (a), when the shutter member 60 returns to a shielding position, the 2nd cleaning member 68M will space apart from the dust-proof glass 48M.

  When the drive motor 201 is further rotated in the reverse direction, the protruding portion 203 moves to the position shown in FIG. 9D, the stepped portion of the stepped screw 168 hits the guide hole 69, and stops at the open position. When the protrusion 203 reaches the position shown in FIG. 9A again, the drive of the drive motor 201 is stopped.

  After performing the cleaning operation as described above, the drive motor 201 is rotated forward, the protrusion 203 of the helical gear 202b is brought into contact with the first contact portion 65a, and the shutter member 60 is moved toward the shielding position. . Then, when the protrusion 203 reaches the position of FIG. 8A, the drive of the drive motor 201 is stopped. As a result, the dust-proof glasses 48Y, 48C, 48M, and 48K are covered with the shielding plates 66Y, 66C, 66M, and 66K, and deposits adhere to the dust-proof glasses 48Y, 48C, 48M, and 48K when the optical writing unit 4 is stopped. Can be suppressed.

  Moreover, in this embodiment, although the 1st contact part 65a and the 2nd contact part 65b are provided, it is sufficient to provide only the 2nd contact part 65b. In this case, when the shutter member 60 is positioned at the shielding position, the driving of the drive motor 201 is controlled so that the protrusion 203 stops at the position shown in FIG. The drive motor 201 is further rotated from the state shown in FIG. 16A, and the protrusion 203 is positioned in FIG. Then, when there is a next writing operation, the driving motor 201 is driven so that the protrusion 203 comes to the position shown in FIG. 16C to position the shutter member 60 in the open position, and the next writing operation is performed. If not, the drive motor 201 is rotated in the reverse direction to stop the protrusion 203 at the position shown in FIG.

  In this embodiment, the shutter member 60 is reciprocated by the worm gear 202 and the protrusion 203, but the shutter member may be reciprocated by a rack and pinion mechanism, for example.

As described above, according to the optical writing unit 4 that is the optical scanning device of the present embodiment, the semiconductor laser 53 that is the light source, the polygon scanner 50 that is the deflection unit that deflects and scans the light beam emitted from the semiconductor laser 53 in the main scanning direction, A plurality of optical elements (collimating lens 54, cylindrical lens 55, scanning lens 43, reflection mirrors 44, 45) for guiding the light beam deflected by the polygon scanner 50 to the surface of the photosensitive member 10 as the surface to be scanned are an optical housing 131 ( It is mounted on a housing 131a and an upper cover member 131b. Further, a dust-proof glass 48 that is a transparent dust-proof member that closes the opening 132 formed so that a light beam is incident on the photoconductor 10 in the optical housing 131 and a covering position that covers the dust-proof glass 48. The shutter member 60 is provided so as to be movable between a barrel shielding position and an open position where the dust-proof glass 48 is opened. Further, when scanning the light beam on the photoconductor 10, the shutter member 60 is moved from the shield position to the open position, and when the light beam scan on the photoconductor is completed, the shutter member 60 is moved from the open position to the shield position. A drive mechanism 200 is provided. The shutter member 60 is configured to be movable beyond the opening / closing range between the open position and the shielding position, and moves on the surface of the dust-proof glass when the shutter member 60 is opened / closed between the shielding position and the opening position. When the first cleaning member 67 and the shutter member 60 are moved over the open / close range, the surface of the dust-proof glass 48 is moved to remove the matter attached to the dust-proof glass 48. And a second cleaning member 68 having a higher cleaning ability than the first cleaning member 67.
By having such a configuration, as described above, it is possible to suppress the dust-proof glass from being damaged, and to prevent fine deposits such as toner from accumulating on the dust-proof glass.

  The first cleaning member 67 is a non-woven fabric, and the second cleaning member 68 is a blade member. Thereby, in cleaning with the first cleaning member 67, since the soft nonwoven fabric moves on the surface of the dust-proof glass, it is possible to prevent the dust-proof glass 48 from being damaged by sliding with the first cleaning member 67. Further, by using the second cleaning member 68 as a blade member, fine deposits such as toner adhering to the dust-proof glass can be removed well.

  Further, the second cleaning member 68 is formed at a position farther from the surface on which the opening 132 of the optical housing 131 is formed than the first cleaning member 67, and has moved the shutter member 60 beyond the opening / closing range. At this time, contact / separation means for bringing the shutter member 60 close to the optical housing 131 is provided. Thus, when the shutter member 60 is moved beyond the opening / closing range, the shutter member is brought close to the optical housing 131 and the second cleaning member 68 located at a position away from the dust-proof glass surface is brought into contact with the dust-proof glass surface. Can do. As a result, the second cleaning member 68 can be slid with the dustproof glass surface only when the shutter member 60 is moved beyond the opening / closing range, and the dustproof glass surface can be prevented from being damaged.

  The contact / separation means is a protrusion 62 protruding from the shutter member 60 and a pressing means that contacts the protrusion 62 and presses the protrusion 62 toward the optical housing when the shutter member 60 moves beyond the opening / closing range. A stepped screw 168 was provided. Thereby, when the shutter member 60 moves beyond the opening / closing range, the protrusion 62 is pushed by the head of the stepped screw 168, and the shutter member 60 is brought close to the optical housing by the height of the protrusion 62 from the shutter member 60. be able to. As a result, the second cleaning member 68 can be brought into contact with the dust-proof glass surface with a predetermined contact pressure, and fine dust on the dust-proof glass surface can be removed well.

  Further, a part of the dustproof glass 48 protrudes from the surface where the opening 132 of the optical housing is formed, and the contacting / separating means has an inclined surface 62a in the moving direction of the shutter member 60 of the protruding portion 62, and the shutter When the member 60 is moved beyond the opening / closing range, the head of the stepped screw comes into contact with the inclined surface 62a, and the shutter member 60 is brought close to the optical housing as the shutter member 60 moves. When the shutter member 60 is brought close to the optical housing by the contact / separation means, the first cleaning member 67 rubs the ridge line portion of the dust-proof glass 48. Thereby, the adhering matter adhering to the 1st cleaning member 67 is scraped off by the ridgeline part of the dust-proof glass 48, and the cleaning capability of the 1st cleaning member 67 can be revived. As a result, the dust-proof glass surface can be favorably cleaned by the first cleaning member 67 over time.

  The drive mechanism 200 includes a drive motor 201, a worm gear 202, and a biasing unit (not shown) that biases the shutter member 60 toward the worm gear 202. Further, it has a projection 203 provided on the helical gear 202b of the worm gear 202, for contacting the shutter member 60 and for pushing the shutter member 60 in the direction opposite to the urging direction of the urging means. Thereby, if the drive amount of a drive motor is controlled and the rotation angle of a helical gear is controlled, the shutter member 60 can be stopped in an open position or a shielding position. Further, the shutter member 60 can be reciprocated by the rotational movement of the helical gear 202b.

  Further, the shutter member 60 is reversely connected to the first contact portion 65a for contacting the projection 203 when the drive motor 201 is rotated forward and moving the shutter member 60 within the open / close range. A second abutting portion 65b is provided for abutting against the protrusion 203 when rotated and moving the shutter member 60 beyond the open range. Thereby, the moving range of the shutter member 60 can be varied only by changing the rotation direction of the drive motor.

  Further, by disposing the second contact portion 65b on the worm gear side with respect to the first contact portion 65a, the movement range of the shutter member 60 when the projection 203 contacts the first contact portion 65a, the second The moving range of the shutter member 60 when contacting the contact portion 65b can be made different.

  Further, the protrusion 203 is covered with the cover member 205, and the cover member 205 is provided so as to be rotatable with respect to the protrusion 203, so that the protrusion 203 is brought into contact with the contact portions 65a and 65b via the rotatable cover member 205. Abut. Accordingly, the protrusion 203 moves along the contact portions 65a and 65b via the cover member 205. At this time, since the cover member 205 rotates, the contact portions 65a and 65b and the protrusion 203 are worn. Can be suppressed.

  Further, by configuring the second cleaning member 68 with a highly elastic member, the second cleaning member 68 can be elastically deformed and brought into contact with the dust-proof glass surface, and the contact with the dust-proof glass becomes good, By the second cleaning member 68, fine deposits on the dust-proof glass surface can be cleaned well.

  Further, in the image forming apparatus of the present embodiment, by providing the optical writing unit 4 described above, a good latent image can be written on the surface of the photoreceptor over time, and a good image can be obtained over time. it can.

4: Optical writing unit 10: Photoconductor 48: Dust-proof glass 50: Polygon scanner 53: Semiconductor laser 60: Shutter member 62: Protruding portion 62a: Inclined surface 63: Passing hole 65a: First contact portion 65b: Second contact Contact portion 65c: Extension portion 66: Shield plate 67: First cleaning member 68: Second cleaning member 69: Guide hole 131: Optical housing 131a: Housing member 131b: Upper cover member 132: Opening portion 168: Stepped screw 200: drive mechanism 201: drive motor 202: worm gear 202a: screw gear 202b: helical gear 203: protrusion 204: bracket 205: cover member

JP 2005-329622 A

Claims (11)

A light source;
Deflection means for deflecting and scanning the light beam emitted from the light source in the main scanning direction;
A plurality of optical elements for guiding the light beam deflected by the deflecting means to the surface to be scanned;
An optical housing in which the light source, the deflection means, and the optical element are mounted;
A permeable dust-proof member that closes the opening formed so that the light beam is incident on the scanned surface in the housing so that the light beam can be transmitted;
A shutter member movably provided between a covering position covering the permeable dustproof member and an open position where the permeable dustproof member is opened;
When scanning the light beam on the surface to be scanned, the shutter member is moved from the covering position to the open position, and when scanning of the light beam on the surface to be scanned is completed, the shutter member is moved from the open position to the covering position. In an optical scanning device comprising a moving means,
The shutter member is configured to be movable beyond an opening / closing range between the open position and the covering position,
A first cleaning member that moves the surface of the permeable dust-proof member when the shutter member moves in the open / close range and removes deposits attached to the permeable dust-proof member;
When the shutter member moves beyond the opening / closing range, the cleaning performance is higher than that of the first cleaning member that moves the surface of the permeable dust-proof member to remove the deposits attached to the permeable dust-proof member. A second cleaning member;
And a control unit that performs control to move the shutter member beyond the open / close range at a predetermined timing and perform cleaning of the permeable dust-proof member by the second cleaning member. Scanning device. The optical scanning device according to claim 1.
The first scanning member is a non-woven fabric, and the second cleaning member is a blade member. The optical scanning device according to claim 1 or 2,
The second cleaning member is formed at a position farther from the surface on which the opening of the optical housing is formed than the first cleaning member,
An optical scanning apparatus comprising: a contact / separation unit that moves the shutter member closer to the optical housing when the shutter member is moved beyond the opening / closing range. The optical scanning device according to claim 3.
The contacting / separating means includes a protruding portion protruding from the shutter member,
An optical scanning device comprising: a pressing unit that contacts the protruding portion and presses the protruding portion toward the optical housing when the shutter member moves beyond the opening / closing range. The optical scanning device according to claim 4.
A part of the permeable dustproof member protrudes from the surface on which the opening of the optical housing is formed,
The contacting / separating means has an inclined surface in the moving direction of the shutter member of the protruding portion, and when the shutter member is moved beyond the opening / closing range, the pressing portion abuts on the inclined surface, Along with the movement, the shutter member is brought close to the optical housing,
The optical scanning device according to claim 1, wherein when the shutter member is brought close to the optical housing by the contact / separation means, the first cleaning member rubs the ridge line portion of the transmissive dustproof member. The optical scanning device according to claim 1,
The moving means includes a motor,
Worm gear,
Biasing means for biasing the shutter member toward the worm gear;
An optical scanning device, comprising: a projection provided on a helical gear of the worm gear, for contacting the shutter member and for pushing the shutter member in a direction opposite to the urging direction of the urging means. . The optical scanning device according to claim 6.
The shutter member includes a first contact portion for contacting the protrusion when the motor is rotated forward to move the shutter member within an opening / closing range, and the motor when the motor is rotated reversely. An optical scanning device comprising: a second abutting portion that abuts against the protrusion and moves the shutter member beyond the open range. The optical scanning device according to claim 7.
The optical scanning device according to claim 1, wherein the second contact portion is disposed closer to the worm gear than the first contact portion. The optical scanning device according to any one of claims 6 to 8,
The protrusion is covered with a cover member,
An optical scanning device, wherein the cover member is provided so as to be rotatable with respect to the protrusion. The optical scanning device according to any one of claims 1 to 9,
An optical scanning device characterized in that the second cleaning member is made of a highly elastic member. A latent image carrier for carrying a latent image;
In an image forming apparatus comprising optical writing means for writing a latent image on the surface of the latent image carrier,
An image forming apparatus using the optical scanning device according to claim 1 as the optical writing unit.