JP2008257040A - Optical scanner and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical scanner where a dust proof means is detachably positioned, wherein the workability of mounting and detaching is improved while preventing the dust proof means from breakage due to the mounting and detaching work. <P>SOLUTION: A guide 31b, for guiding a dust proof unit 40 when the dust proof unit 40 is mounted and detached, is provided on a housing 31 in a direction (short direction C) perpendicular to the longitudinal direction at an open part 31a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical scanning device and an image forming apparatus used for a laser beam printer, a digital copying machine, and the like.

  In an optical scanning device used in a conventional image forming apparatus, dust enters the optical scanning device from an opening provided in the optical scanning device and adheres to optical components. When the laser beam scans the part to which the dust is attached, the exposure light amount on the photoconductor is reduced and the image performance is deteriorated. For this reason, there is an optical scanning device in which dustproof means such as a glass material is formed in the opening.

  However, since dirt also adheres to the surface of the dustproof member over time, it is necessary to clean or replace the dustproof member.

As an example of such a prior art, there is a mechanism that provides a mechanism that rotates around one end in the longitudinal direction of the dust-proof member, and that allows the glass member to be inserted and removed in the longitudinal direction while being rotated, and that is cleaned and replaced. Yes (see Patent Document 1). As another example, there is a configuration in which the dust-proof glass holding portion is configured not in the optical scanning device but in the main body frame so that the dust-proof glass is detachable in the longitudinal direction from the outside of the image forming apparatus (see Patent Document 2).
JP 2000-181201 A JP 2002-127495 A

  However, in the case of the prior art as described above, the following problems are concerned.

  In Patent Document 1, since it is necessary to rotate the dust-proof member about the one end in the longitudinal direction of the dust-proof member to a position where the dust-proof member can be attached and detached, it is necessary to secure a sufficient space for this, and the device configuration is restricted. Furthermore, since the dustproof member is attached and detached in the longitudinal direction of the dustproof member, there is a possibility that the dustproof glass surface may be damaged during the attachment / detachment work due to the longer work stroke. Moreover, in patent document 2, since it becomes the operation | work which attaches or detaches dust-proof glass itself only in the longitudinal direction of dust-proof glass from the state which attached dust-proof glass, possibility of damaging the dust-proof glass surface at the time of attachment / detachment is high.

  The present invention has been made in view of the circumstances as described above, and in an optical scanning device in which dustproof means is detachably provided, the attachment / detachment workability is improved while suppressing damage to the dustproof means due to the attachment / detachment work. With the goal.

In order to achieve the above object, the present invention provides:
Deflection scanning means for deflecting and scanning light emitted from a light source;
An optical member for imaging the light deflected and scanned by the deflection scanning means on an image carrier;
A housing provided with the deflection scanning means and the optical member;
An opening provided in the housing for passing light that passes through the optical member, and is provided in a long hole shape so that the scanning direction of the light deflected and scanned by the deflection scanning means is the longitudinal direction. An opening,
A dust-proof means that is detachably provided on the housing and has a light-transmitting member that transmits light that has passed through the optical member, and closes the opening;
An optical scanning device comprising:
An attachment / detachment portion that allows the dustproof means to be attached / detachable in a direction orthogonal to the longitudinal direction of the opening is provided in the housing.

  According to the present invention, in an optical scanning device in which dustproof means is detachably provided, it is possible to improve attachment / detachment workability while suppressing damage to the dustproof means due to attachment / detachment work.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. It is not intended to limit the scope to the following embodiments.

  FIG. 1 is a cross-sectional view for explaining a schematic configuration of the image forming apparatus according to the first embodiment.

  The basic operation of the image forming apparatus 1 will be described below.

  The recording materials S loaded and stored in the cassette 4 are sequentially conveyed from the upper direction toward the process cartridge 6 which is an image forming unit by a conveying unit 5 constituted by rollers 5a to 5c and the like.

  The surface of the electrophotographic photosensitive member 6a as an image carrier incorporated in the process cartridge 6 is uniformly charged by a charging device (not shown). On the surface of the charged electrophotographic photosensitive member 6a, the laser beam J emitted from the optical scanning device 8 corresponding to the image information is irradiated to form an electrostatic latent image. The electrostatic latent image is developed as a toner image by developing means (not shown), and then transferred onto the recording material S by the transfer means 7.

  Next, the recording material S is conveyed by the fixing unit 10, and the toner image on the recording material S is heated and fixed to the recording material S. Then, the recording material S is discharged to the paper discharge stacking unit 11 by the conveying unit 11a configured by a group of rollers, and the image forming process ends.

  Here, in FIG. 1, 2 is an exterior portion including a door 3 as an opening / closing member that is opened and closed when the process cartridge 6 is attached to and detached from the image forming apparatus 1, and 9 is a frame (not shown) of the image forming apparatus 1. And a support member that positions and supports the optical scanning device 8.

  FIG. 2 is a diagram illustrating an attaching / detaching operation of the process cartridge 6 in the image forming apparatus according to the present exemplary embodiment.

  As shown in FIG. 2, the image forming apparatus 1 includes a door 3 that can be opened and closed with respect to the image forming apparatus main body, and an apparatus main body opening that opens a part of the image forming apparatus main body when the door 3 is opened. As an opening 3a.

  The process cartridge 6 is configured to be detachable in the direction of arrow A shown in FIG. 2 with the door 3 of the image forming apparatus 1 being opened.

  Next, details of the optical scanning device 8 will be described.

FIG. 3 is a plan view illustrating a schematic configuration of the optical scanning device of the present embodiment. FIG. 4 is a perspective view illustrating a schematic configuration of the optical scanning device of the present embodiment. FIG. 5 is a perspective view showing the appearance of the optical scanning device and the electrophotographic photosensitive member of this embodiment. FIG. 6 is a cross-sectional view illustrating a schematic configuration of the optical scanning device 8 in which a dustproof unit 40 described later is assembled.

  Hereinafter, a basic adjustment method and assembly method of the optical scanning device 8 of the present embodiment will be described.

  The light source device 21 is attached to the housing 31 in a state where optical adjustment of a semiconductor laser (not shown) as a light source and the collimator lens 22 is completed in advance, and the cylindrical lens 23 is temporarily disposed on the housing 31. Here, the housing 31 has an opening 31 a for irradiating the process cartridge 6 (electrophotographic photosensitive member 6 a) with the laser beam J from the optical scanning device 8. As shown in FIG. 4, the opening 31 a is provided in the shape of a long hole whose longitudinal direction is the main scanning direction (scanning direction) of the laser beam J by the rotation of the polygon mirror 24.

  A deflection scanning device 25 as a deflection scanning means on which the polygon mirror 24 is mounted, imaging lenses 26 and 27 as imaging means, a reflection mirror 28 as a reflecting member, and a scanning start signal detector 29 are provided on a housing 31 in a predetermined manner. It is positioned at a position and fixed by a screw or a fixture not shown. Here, the imaging lenses 26 and 27 and the reflection mirror 28 constitute an optical member.

  The cylindrical lens 23 is moved and adjusted in the direction of the optical axis of the laser beam 14 that has passed through the collimator lens 22 so that the focal position of the laser beam J is adjusted. Further, the reflection mirror 30 is adjusted and fixed so that the laser beam deflected and scanned by the polygon mirror 24 is incident on the scanning start signal detector 29.

  As described above, the optical adjustment of the optical scanning device 8 is completed, and the housing 31 is sealed with the lid 32 to constitute the optical scanning device 8.

  Next, the basic operation of the optical scanning device 8 will be described.

  The laser beam J generated from the light source device 21 passes through the cylindrical lens 23 and is irradiated to the polygon mirror 24 of the deflection scanning device 25 to be deflected and scanned.

  The laser beam J that has been deflected and scanned is reflected by the reflecting mirror 28 via (imaging) the imaging lenses 26 and 27, passes through the opening 31a provided in the housing 31, and forms an image on the surface of the electrophotographic photosensitive member 6a. Is done.

  The laser beam J imaged on the electrophotographic photosensitive member 6a is scanned in the main scanning direction by the rotation of the polygon mirror 24, and an electrostatic latent image is formed in the sub-scanning direction by the rotation of the electrophotographic photosensitive member 6a.

  Further, a part of the laser beam J deflected and scanned by the deflection scanning device 25 is guided to the scanning start signal detector 29 by the reflection mirror 30 for detecting the scanning start signal, and the light source is generated by the output signal of the scanning start signal detector 29. Write modulation of the device 21 is started. Here, in FIG. 5, 40 is a dustproof unit described later.

  Next, the configuration and assembling method of the dustproof unit 40 as dustproof means provided to prevent dust from entering the optical scanning device 8 from the opening 31a will be described.

FIG. 7 is a diagram for explaining the configuration of the dustproof unit 40. FIGS. 8A and 8B are diagrams for explaining an assembly process when the dustproof unit 40 is assembled to the housing 31, FIG. 8A is a perspective view, and FIG. 8B is a cross-sectional view. FIG. 9 is a cross-sectional view for explaining an assembly process when the dustproof unit 40 is assembled to the housing 31.

  First, the configuration of the dustproof unit 40 will be described.

  As shown in FIG. 7, the glass 43 as the light transmitting member and the elastic member 41 are stored in the storage portion 43 a of the holder 43, so that the holder 43, the glass 42, and the elastic member 41 are integrated to prevent dust. A unit 40 is configured. Here, the elastic member 41 has an opening 41a through which the laser beam J passes. 43b is an opening through which the laser beam J passes, 43c is a shaft as a shaft provided at both ends in the longitudinal direction of the holder 43, and 43d is a hook as a first holding part. Here, the longitudinal direction of the holder 43 is the same direction as the main scanning direction (scanning direction) by the rotation of the polygon mirror 24 in the optical scanning device 8.

  Next, a method for assembling (assembling and mounting) the dustproof unit 40 to the housing 31 will be described.

  As shown in FIG. 8, the dust-proof unit 40 is inserted into a guide 31b as an attaching / detaching portion (guide portion) provided in the casing 31, and the shaft 43c of the holder 43 is guided (guided, guided) to the guide 31b. The shaft 43c is positioned at a position where the shaft 43c contacts the positioning portion 31c of the housing 31.

  Here, the guide 31b provided in the housing 31 guides the shaft 43c of the holder 43 in a direction orthogonal to the longitudinal direction of the opening 31a (short direction C shown in FIG. 8B). Is provided. The dustproof unit 40 is moved from the position shown in FIG. 8B in the direction of arrow D (short direction C), inserted into the guide 31b, and positioned in the guide 31b along the short direction C. It is positioned at a position where it comes into contact with. The positioning unit 31 c positions the shaft 43 c of the holder 43 at a mounting position where the dustproof unit 40 is mounted on the housing 31.

  As shown in FIG. 9, the dust-proof unit 40 is rotated in a direction (arrow E direction) that closes the opening 31a of the housing 31 around the shaft 43c positioned in the positioning portion 31c. As a result, the hook portion 43 d of the holder 43 is fixed in a state of being inserted and locked into the fixing portion 31 d as the second holding portion of the housing 31. The opening 31 a of the housing 31 is closed (shielded, dust-proof) by the dust-proof unit 40 when the elastic member 41 is in close contact with the elastic member 41.

  By such a method, the dust-proof unit 40, in particular the glass 42, can be mounted on the housing 31 without contacting and sliding with other components.

  FIG. 10 is a diagram for explaining a case where the dustproof unit 40 is attached and detached while the optical scanning device 8 is mounted on the image forming apparatus 1.

  The optical scanning device 8 configured as described above is positioned and fixed on the support member 9 of the image forming apparatus 1 as shown in FIG.

  The dust-proof unit 40 in a state where the optical scanning device 8 is mounted on the image forming apparatus 1 is in the direction in which the process cartridge 6 is attached to and detached from the image forming apparatus 1 with the door 3 of the image forming apparatus 1 opened (FIG. 2). , 10 in the same direction as the arrow A). That is, in the image forming apparatus 1, the dustproof unit 40 can be attached / detached from the door 3 (opening 3a) to which the process cartridge 6 can be attached / detached.

  Conventionally, the attachment and detachment direction of the dustproof glass is different from the operation side of the image forming apparatus, so that a new mechanism and configuration for attachment and detachment are required for the image forming apparatus.

  On the other hand, in this embodiment, the dustproof unit 40 can be attached / detached by opening / closing the door 3 for attaching / detaching the process cartridge 6, so that a new part for enabling the dustproof unit 40 to be attached / detached from the image forming apparatus 1. There is no need to adopt a complicated configuration. And since the dustproof unit 40 can be attached or detached in the same direction as the attachment or detachment direction of the process cartridge 6, convenience (usability) can be improved.

  As described above, according to the present embodiment, the dustproof unit 40 is detachably provided by being guided in the short direction C (see FIG. 8B) by the guide 31b. Accordingly, the dustproof unit 40 can be prevented from coming into contact with and sliding with other parts or the like as compared with the case where the dustproof unit is attached and detached along the longitudinal direction of the opening 31a. Can be suppressed. Moreover, since the dustproof unit 40 can be attached and detached in the short direction C, the dustproof unit 40 can be attached and detached more easily than when the dustproof unit is attached and detached in the longitudinal direction of the opening 31a. Work reliability can be improved. For example, in the configuration in which the dustproof unit 40 is attached and detached in the longitudinal direction, the entire dustproof unit 40 may not be visually confirmed. And in order to avoid the contamination and damage of the dustproof unit 40 mentioned above, it is necessary to carefully attach and detach the dustproof unit 40, and the efficiency of workability is reduced.

  Further, the dust-proof unit 40 can be mounted on the optical scanning device 8 by the above-described series of mounting operations without the glass surface being in contact with or sliding with other components. It can be reliably occluded. Thereby, the sealing property of the optical scanning device 8 can be further improved, and the optical performance can be improved.

  Further, since the dustproof unit 40 can be attached / detached by opening / closing the door 3 for attaching / detaching the process cartridge 6, new parts and a complicated configuration for making the dustproof unit 40 removable from the image forming apparatus 1 are adopted. There is no need to do it. This makes it possible to reduce the size of the apparatus, simplify the configuration, and reduce the cost. And since the dustproof unit 40 can be attached or detached in the same direction as the attachment or detachment direction of the process cartridge 6, the convenience can be improved.

  Here, in the present embodiment, the guide 31b is provided as the attaching / detaching portion, but the present invention is not limited to this. That is, as long as the positioning part 31c is provided so as to position the shaft 43c of the dustproof unit 40 that moves along the short direction C, a configuration in which the guide 31b is not provided may be employed.

  In this embodiment, when the dustproof unit 40 is assembled to the housing 31, the dustproof unit 40 closes the opening 31a of the housing 31 around the shaft 43c positioned by the positioning portion 31c (FIG. 9). This is due to rotation in the direction of arrow E). However, the method of assembling the dustproof unit 40 to the housing 31 is not limited to such a configuration. That is, the detachable part is configured so that the surface of the glass 42 moves in parallel in the short direction C in the opening 31a (for example, the holder 43 moves in parallel with the guide provided in the housing 31). 40 may be assembled to the housing 31. In this case, the dustproof unit 40 is assembled to the housing 31 without rotating operation. Even if it is such a structure, it can suppress that the dustproof unit 40 contacts and slides with other components etc. rather than the case where a dustproof unit is attached or detached along the longitudinal direction of the opening part 31a.

  Example 2 will be described below.

FIG. 11 is a perspective view showing a schematic configuration of the dustproof unit of the present embodiment. FIG. 12 is a cross-sectional view showing a schematic configuration of the optical scanning device of the present embodiment. The same configurations as those of the first embodiment described above are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

  In the present embodiment, the dustproof unit 50 is configured to be housed and integrated in the housing portion 43 a of the holder 43 in the order of the glass 42, the leaf spring 51 as a spring member, and the elastic member 41. It is a feature. As shown in FIG. 12, the tip of the leaf spring 51 is provided so as to contact a part of the reflection mirror 28 in a state where the dustproof unit 50 is assembled to the optical scanning device 8.

  According to the present embodiment, the leaf spring 51 is brought into contact with the reflecting mirror 28, whereby the vibration of the reflecting mirror 28 can be attenuated and the curvature of the reflecting mirror 28 can be corrected. Can be improved.

  Here, in the present embodiment, the leaf spring 51 is used as the spring member, but the present invention is not limited to this as long as the vibration of the reflection mirror 28 can be attenuated or the curvature of the reflection mirror 28 can be corrected. is not. In the present embodiment, the leaf spring 51 is brought into contact with the reflection mirror 28, but the present invention is not limited to this, and the leaf spring 51 may be brought into contact with an imaging lens or the like as an optical member.

  In addition, with the optical scanning device 8 attached to the image forming apparatus 1, it is possible to make final adjustments for vibration attenuation and curvature correction of the reflection mirror 28, so that the printing accuracy of the image forming apparatus 1 can be improved. Become.

  Moreover, the material of the leaf | plate spring 51 and the contact position of the reflective mirror 28 can be arbitrarily set according to the specification of a product. As a result, even with image forming apparatuses having different printing speeds, vibration attenuation and curvature correction of the reflecting mirror 28 can be performed, and the versatility of the optical scanning apparatus can be improved.

1 is a cross-sectional view for explaining a schematic configuration of an image forming apparatus according to Embodiment 1. FIG. FIG. 4 is a diagram illustrating an attaching / detaching operation of a process cartridge 6 in the image forming apparatus according to the first exemplary embodiment. It is a top view showing schematic structure of the optical scanning device of a present Example. It is a perspective view showing schematic structure of the optical scanning device of a present Example. It is a perspective view showing the external appearance of the optical scanning device of this example and an electrophotographic photosensitive member. It is sectional drawing showing schematic structure of the optical scanner with which the dustproof unit was assembled | attached. It is a figure for demonstrating the structure of a dustproof unit. It is a figure for demonstrating the assembly | attachment process at the time of attaching a dustproof unit to a housing | casing, (a) is a perspective view, (b) is sectional drawing. It is sectional drawing for demonstrating the assembly | attachment process at the time of attaching a dustproof unit to a housing | casing. FIG. 5 is a diagram for explaining a case where a dustproof unit is attached and detached while the optical scanning device is mounted on the image forming apparatus. It is a perspective view which shows schematic structure of the dustproof unit of Example 2. FIG. FIG. 6 is a cross-sectional view illustrating a schematic configuration of an optical scanning device according to a second embodiment.

Explanation of symbols

6a Electrophotographic photosensitive member 8 Optical scanning device 25 Deflection scanning device 26, 27 Imaging lens 28 Reflecting mirror 31 Housing 31a Opening 31b Guide 40 Dust-proof unit 42 Glass

Claims (5)

Deflection scanning means for deflecting and scanning light emitted from a light source;
An optical member for imaging the light deflected and scanned by the deflection scanning means on an image carrier;
A housing provided with the deflection scanning means and the optical member;
An opening provided in the housing for passing light that passes through the optical member, and is provided in a long hole shape so that the scanning direction of the light deflected and scanned by the deflection scanning means is the longitudinal direction. An opening,
A dust-proof means that is detachably provided on the housing and has a light-transmitting member that transmits light that has passed through the optical member, and closes the opening;
An optical scanning device comprising:
An optical scanning device characterized in that an attachment / detachment portion for attaching / detaching the dustproof means in a direction perpendicular to the longitudinal direction in the opening is provided in the housing.   The optical scanning apparatus according to claim 1, wherein the detachable portion includes a guide portion that guides the dustproof means in a direction orthogonal to the longitudinal direction of the opening. The dust prevention means includes a shaft portion guided by the guide portion and a first holding portion held by the housing.
The housing is provided with a positioning part for positioning the shaft part guided by the guide part at a mounting position, and a second holding part for holding the first holding part,
The dustproof means is rotated by the positioning portion around the shaft portion guided by the guide portion, whereby the first holding portion is held by the second holding portion and attached to the housing. The optical scanning device according to claim 2.   The optical scanning device according to claim 1, wherein the dustproof unit includes a spring member that contacts the optical member. An optical scanning device according to any one of claims 1 to 4,
A process cartridge having an image carrier;
An apparatus main body opening for opening a part of the image forming apparatus main body when the opening and closing member is opened;
An image forming apparatus configured such that the process cartridge is detachable through the apparatus main body opening when the opening / closing member is opened.
The attachment / detachment direction of the dust-proof means with respect to the housing is the same direction as the attachment / detachment direction of the process cartridge with respect to the image forming apparatus main body,
The image forming apparatus, wherein the dust-proof means is detachably attached to the housing through the apparatus main body opening when the opening / closing member is opened.

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