JP2009048004A - Optical scanning device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce angular fluctuation of a light beam in the sub-scanning direction due to influence of an assembly error and a machining error for reducing a bend of a scanning line and deterioration in wave front aberration in an oblique incident optical scanning device suitable for reduction in cost, in power consumption, and in size. <P>SOLUTION: A light source unit member 110 (a support means), a reflecting mirror 107, and an image formation lens 106b are mounted on an installation face 108 (a housing means). The installation face 108 is tilted at a predetermined angle to a polygon installation face 109, on which a polygon mirror 105 and an image formation lens 106a are mounted. An installation face 108a (a first reference face) of the light source unit member 110 and an installation face 108b (a second reference face) of the image formation lens 106b are planes parallel to each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical scanning device used for a laser printer or the like, and an image forming apparatus including the optical scanning device.

[About optical scanning device and image forming apparatus]
In general, an optical scanning device widely known in relation to a laser printer or the like deflects a light beam from a light source side by an optical deflector and condenses it toward a surface to be scanned by a scanning imaging optical system such as an fθ lens. Thus, a light spot is formed on the surface to be scanned, and the surface to be scanned is optically scanned (main scan) with this light spot.
What constitutes the surface to be scanned is a photosensitive surface of a photosensitive medium such as a photoconductive photosensitive member.

  As an example of a full-color image forming apparatus, four photoconductors are arranged in the conveyance direction of the recording paper, and light beams emitted from a plurality of light source devices corresponding to the photoconductors are formed by one deflecting unit. A deflection scan is performed, and a plurality of scanning imaging optical systems corresponding to the respective photosensitive members are simultaneously exposed to the respective photosensitive members to form latent images, and these latent images are developed in different colors such as yellow, magenta, cyan, and black. After being visualized by a developing device using an agent, these visible images are sequentially superimposed and transferred and fixed on the same recording paper so that a color image can be obtained.

  As described above, an image forming apparatus that obtains a two-color image, a multicolor image, a color image, or the like by using two or more combinations of the optical scanning device and the photosensitive member is known as a “tandem image forming apparatus”. ing.

As such a tandem type image forming apparatus, a type in which a plurality of photosensitive media share a single optical deflector is known.
For example, a plurality of light beams that are substantially parallel and separated in the sub-scanning direction are incident on a deflector, and a plurality of scanning optical elements corresponding to the plurality of light beams are arranged in the sub-scanning direction and scanned.
Further, a light beam is incident from one side of the deflector, and a three-element scanning optical system is configured such that a plurality of light beams directed to different scanned surfaces pass through L1 and L2, and L3 is provided for each scanned surface. There is something that was done.

  As described above, when the optical deflectors are shared by a plurality of scanned surfaces, the number of the optical deflectors can be reduced, so that the image forming apparatus can be made compact.

  However, for example, as an optical scanning device of a full-color image forming apparatus having four different scanned surfaces (photosensitive members) of cyan, magenta, yellow, and black, the number of optical deflectors can be reduced. There is a problem that the polygon mirror is increased in size in the sub-scanning direction because light beams directed to a plurality of photoconductors in the scanning direction are arranged substantially in parallel and enter the optical deflector.

  In general, the cost of the polygon mirror portion is high due to the optical elements in the optical scanning device, which is a harmful effect when the cost of the entire device is reduced and the size is reduced.

[About oblique incidence optical system]
More recently, as a means for reducing the cost of a single optical deflector in an optical scanning device of a color image forming apparatus, an optical beam is provided with an angle in the sub-scanning direction on the deflection reflection surface of the optical deflector. An oblique incidence optical system for incidence is known.

In such an oblique incidence optical system, after a plurality of light beams are deflected and reflected by the deflecting / reflecting surfaces, they are separated and guided to corresponding scanning surfaces (photoconductors) by folding mirrors or the like.
At this time, the angle of each light beam in the sub-scanning direction (the angle obliquely incident on the optical deflector) is set to an angle at which each light beam can be separated by the mirror.

  By using this oblique incidence optical system, the distance between adjacent light beams in the sub-scanning direction, where each light beam can be separated by the mirror, can be increased in size, that is, by increasing the number of polygon mirrors in the sub-scanning direction. It becomes easy to realize without thickening.

  However, the oblique incidence method has a problem that “scanning line bending” is large. The amount of bending of the scanning line differs depending on the oblique incident angle of each light beam in the sub-scanning direction, and color misregistration occurs when the latent images drawn by the respective light beams are visualized by overlaying with the respective color toners. Appears.

  In addition, the oblique incident light causes the light beam to be twisted into the scanning lens, thereby increasing the wavefront aberration. Especially, the optical performance is significantly deteriorated at the peripheral image height, the beam spot diameter is increased, and the image quality is improved. It becomes a factor to prevent.

  As a method of correcting the “large scanning line curve” inherent to such an oblique incidence method, the scanning imaging optical system is configured to read “the intrinsic inclination of the lens surface in the sub-scanning section in the main scanning direction so as to correct the scan line curve”. A method of including a “lens having a changed lens surface” has been proposed (see, for example, Patent Document 1).

  Also proposed is a method of including a “corrected reflecting surface having a reflecting surface in which the intrinsic inclination of the reflecting surface in the sub-scan section is changed in the main scanning direction so as to correct the scanning line curvature” in the scanning imaging optical system. (For example, refer to Patent Document 2).

  In addition, a method has been proposed in which the obliquely incident light flux passes through the off-axis of the scanning lens, and the position of the scanning line is aligned using a surface that changes the aspherical amount of the child line of the scanning lens along the main scanning direction. (For example, refer to Patent Document 3).

  In this Patent Document 3, an example is given in which correction is performed with a single scanning lens, and the above-mentioned scanning line bending can be corrected. However, regarding the deterioration of the beam spot diameter due to the increase of wavefront aberration described below. It is not described.

  As an optical scanning device that can satisfactorily correct the above-mentioned “scan line bending and wavefront aberration degradation” which can be said to be a problem with the oblique incidence method, the scanning imaging optical system includes a plurality of rotationally asymmetric lenses, and the lens surfaces of these rotationally asymmetric lenses. There has been proposed one in which the shape of a bus connecting the child line vertices is curved in the sub-scanning direction (see, for example, Patent Document 4).

  However, in these patent documents, although the correction method with the design value is described, the oblique incident angle changes due to the influence of the assembly error of the optical element, the processing error, etc. There is a problem that line bending and wavefront aberration are deteriorated and image quality is lowered.

Another problem is that when the oblique incident angle changes due to the effects of assembly errors and processing errors, the light beam is vignetted by an optical element such as a scanning lens or a folding mirror, and the beam spot diameter is deteriorated. There arises a problem that the light beam does not reach the scanning surface.
Problems can be reduced by processing and assembling each optical element with high accuracy, but the assembly cost increases and the assembly difficulty increases due to a significant increase in the cost of components and the difficulty of assembly.

In an oblique incidence optical system, when the angle of oblique incidence on the deflecting / reflecting surface increases, various aberrations deteriorate and optical performance deteriorates. Specifically, beam spot diameter deterioration due to wavefront aberration deterioration, scanning line bending increase, and the like can be mentioned.
From the viewpoint of optical performance and miniaturization of the optical scanning device, it is desirable to set the oblique incident angle as small as possible.

However, if the oblique incident angle is reduced, it becomes difficult to separate the light beams on the corresponding scanned surfaces.
This makes it possible to separate the light beams directed to different scanning surfaces while setting the oblique incident angle small, so that the interval in the sub-scanning direction of the light beams at the separation position is set as narrow as possible. At this time, when the oblique incident angle changes and the light beam changes in the sub-scanning direction, a part of the light beam is vignetted on the optical element, and the beam spot diameter is thickened. Since the diameter fluctuates, a stable beam spot diameter cannot be obtained.

Further, in the gazette of Patent Document 5, the invention of the light source device of the oblique incidence optical system is disclosed, but the problem with respect to the change in the oblique incidence angle is not solved due to the above-described assembly error and processing error.
It is possible to adjust the coupling lens after all the optical elements have been assembled to adjust the angle in the sub-scanning direction. However, the assembly and adjustment of the light source device is complicated, and problems such as increased adjustment time are required. Is also undesirable.
Japanese Patent Laid-Open No. 11-14932 Japanese Patent Laid-Open No. 11-38348 JP 2004-70109 A Japanese Patent No. 3450653 JP 2004-271906 A

  The present invention has been made to solve the above-described problems. In an oblique incidence type optical scanning apparatus suitable for cost reduction, low power consumption, and downsizing, the present invention is affected by the effects of assembly errors and processing errors. An object of the present invention is to provide an optical scanning device capable of reducing the change in angle of the light beam in the sub-scanning direction and reducing the deterioration of scanning line bending and wavefront aberration, and an image forming apparatus using the optical scanning device. .

  In order to achieve such an object, an optical scanning device according to the present invention includes a light source, an optical deflector that deflects a light beam from the light source, and an imaging lens that collects the light beam deflected by the optical deflector. A first reference surface for attaching a support means for supporting the light source and a second reference surface for attaching at least one of the imaging lenses. And the plane is inclined by a predetermined angle from a main scanning plane orthogonal to the rotation axis of the optical deflector.

  Housing means for integrally supporting the light source, the optical polarizer, and the imaging lens, the housing means being provided at a predetermined angle from a main scanning plane orthogonal to the rotation axis of the optical deflector; The first reference plane and the second reference plane are preferably included.

  A coupling lens corresponding to the light source; and an aperture having an opening for shaping a light beam from the coupling lens; and the support means further supports the coupling lens and the aperture as a single unit. Is preferred.

It is preferable that a cylindrical lens having a refractive power at least in the sub-scanning direction is provided, and the supporting means further supports the cylindrical lens as a single unit.
It is preferable to have a folding mirror between the optical path between the cylindrical lens and the optical deflector.

The support means preferably has a mechanism for performing installation adjustment in a direction orthogonal to the first reference plane.
The support means preferably has a mechanism for performing installation adjustment of an angle between a light beam emitted from the light source and a main scanning plane orthogonal to the rotation axis of the deflector.
The light source is preferably a multi-beam light source device that emits a plurality of light beams.

  An image forming apparatus according to the present invention includes the above-described optical scanning device according to the present invention.

  As described above, according to the present invention, in the oblique incidence type optical scanning device suitable for cost reduction, low power consumption, and downsizing, the angle change in the sub-scanning direction of the light beam due to the effects of assembly errors and processing errors. And the deterioration of scanning line bending and wavefront aberration can be reduced.

  Next, an embodiment to which an optical scanning device and an image forming apparatus according to the present invention are applied will be described in detail with reference to the drawings.

  In each of the embodiments described below, in a tandem type full-color image forming apparatus, a light source and an optical element that are arranged along a light beam incident at a predetermined angle with respect to the rotation axis direction of a rotary polygon mirror that is an optical deflector. It is intended to make layout and adjustment easy.

[First Embodiment]
For this reason, the optical scanning device according to the first embodiment of the present invention includes a light source, an optical deflector that deflects the light beam from the light source in the main scanning direction (the rotation axis direction of the photosensitive member), and the light beam that has passed through the optical deflector. In an optical system comprising an imaging lens for condensing the light beam to a desired light beam diameter and housing means for integrally supporting them, the housing means is at a predetermined angle from a main scanning plane orthogonal to the rotation axis of the optical deflector. It just comes to lean.
A first reference surface for attaching the support means for supporting the light source having a common axis of symmetry and a second reference surface for attaching at least one of the imaging lenses are provided.

  The first reference surface for attaching the support means for supporting the light source and the second reference surface for attaching at least one of the imaging lenses are parallel planes.

  In addition, a coupling lens corresponding to the light source and an aperture having an opening for shaping a light beam from the coupling lens are provided, and are integrally supported by a supporting unit that supports the light source.

Further, a cylindrical lens having a refractive power in at least the sub-scanning direction (the rotating direction of the photosensitive member) is provided, and is integrally supported by a supporting unit that supports the light source.
Furthermore, a folding mirror is provided between the cylindrical lens and the optical deflector.

Next, the configuration of the first embodiment will be described in detail with reference to FIGS. 1 to 3 and FIGS. 7 and 8.
4 to 6 are schematic views of a general optical scanning device, and are shown for comparison with FIGS. 1 to 3.

  As shown in FIGS. 1 to 3, the optical scanning device according to the present embodiment includes a light source unit member 110 (supporting means), a folding mirror 107, and an imaging lens 106 b on an installation surface 108 (housing means). is set up. The ground contact surface 108 is a plane inclined by a predetermined angle with respect to the polygon installation surface 109 on which the polygon mirror 105 and the imaging lens 106a are installed.

Further, as will be described later, the optical axis by the light source unit member 110 and the optical axis incident on the imaging lens 106b are adjusted to be parallel planes.
For this reason, in this embodiment, the installation surface 108a (first reference surface) of the light source unit member 110 and the installation surface 108b (second reference surface) of the imaging lens 106b are parallel planes. . The “parallel plane” includes a case where they are the same plane.

  The semiconductor laser 101 as a light source is press-fitted and held in a fitting hole formed in the light source unit member 110 made of aluminum. Further, the coupling lens 102 is placed on a support portion formed in a pair with the light source holding member at a position where the divergent light beam of the semiconductor laser becomes a desired light beam and in a predetermined beam emission direction by a UV curable adhesive. It is fixed.

  In FIG. 8, the number of bonding points is one point as indicated by 114, but the number of points is not limited to one point depending on the form of the support portion, and may be a plurality of points.

The aperture 103 and the cylindrical lens 104 are installed on the same member as the member that holds the semiconductor laser 101 and the coupling lens 102.
At this time, the cylindrical lens 104 is fixed by being pressed to a place where a predetermined incident position is obtained by a spring material such as 115 and held by 110.

The light source 101, the coupling lens 102, the aperture 103, and the cylindrical lens 104 are collectively formed on the same member and configured as a light source unit.
As a result, the position and angle can be adjusted in a state where the relationship among the light source 101, the coupling lens 102, the aperture 103, and the cylindrical lens 104 is fixed.

  As described above, the light source unit formed on the same member is fastened to the installation plane 1 provided to be inclined at the same angle as the angle of the optical axis incident on the optical deflector and the sub-scanning direction.

  Further, in the configuration in which the cylindrical lens is integrally supported by the light source unit member 110 (support means) and the configuration in which the folding mirror is provided between the cylindrical lens and the optical deflector, the elastic member 117 is a tension spring and 116 is a screw. It is an example using.

Add a description of the fastening part.
As shown in FIGS. 7 and 8, the light source unit is fastened by an elastic member 117 interposed between the light source unit member 110 and the first reference surface 108a, and is also fixed between 110 and 108a. The height position and angle (tilt) of the light source unit are fixed by the member 116.

In the light source unit of the present embodiment, the angle of the light beam in the sub-scanning direction can be adjusted, so that the above-described problem can be solved.
In other words, when the light beam changes the angle in the sub-scanning direction due to an assembly error or the like, it is possible to easily adjust the light source device in the direction to cancel the angle change, thereby easily and stably improving the optical performance without increasing the assembly accuracy, and Image quality can be provided.

  Further, as a problem of a general optical scanning device, when the angle of the light beam incident on the scanning lens in the sub-scanning direction is changed, the wavefront aberration is deteriorated and a stable beam spot diameter cannot be obtained. In addition, the scanning line is similarly bent, and in the tandem type image forming apparatus described later, color misregistration occurs and the image quality is remarkably deteriorated. This is because the oblique incidence optical system has a larger fluctuation than the normal horizontal incidence optical system.

  On the other hand, in the present embodiment, as described above, the reference planes 1 and 2 of the present embodiment are parallel planes, so that the angle variation of the light beam in the sub-scanning direction between the optical elements is generated. Thus, it is possible to suppress deterioration of wavefront aberration and increase in scanning line bending.

  As described above, according to the light source unit of the present embodiment, the angle of the light beam in the sub-scanning direction can be adjusted, so that the oblique-incidence optical scanning suitable for low cost, low power consumption, and miniaturization is possible. It is possible to reduce changes in the angle of the light beam in the sub-scanning direction due to the effects of assembly errors and processing errors in the apparatus, and to reduce scanning line bending and wavefront aberration deterioration.

  In other words, when the light beam changes the angle in the sub-scanning direction due to an assembly error or the like, it is possible to easily adjust the light source device in the direction to cancel the angle change, thereby easily and stably improving the optical performance without increasing the assembly accuracy, and Image quality can be provided.

  In addition, the installation surface 108a (first reference surface) of the light source unit member 110 and the installation surface 108b (second reference surface) of the imaging lens 106b are parallel planes, so that each optical element can be connected. It is possible to eliminate the occurrence of angular fluctuations of the light beam in the sub-scanning direction, and to suppress the deterioration of wavefront aberration and the increase in scanning line bending.

  Therefore, it is possible to realize a small optical scanning device while realizing good and stable optical performance.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
The optical scanning device according to the second embodiment refracts at least in the sub-scanning direction (rotating direction of the photosensitive member), a coupling lens corresponding to the light source, an aperture having an opening for shaping the light beam from the coupling lens. A cylindrical lens having a force is provided and is integrally supported by a supporting means for supporting the light source.
A mechanism that enables adjustment (referred to as Z adjustment) in a direction orthogonal to the first reference plane is provided.

  Further, it has a mechanism that enables adjustment (referred to as β adjustment) of an angle between a light beam emitted from the light source and a main scanning plane orthogonal to the rotation axis of the optical deflector.

The configuration of the second embodiment will be described in detail with reference to FIGS.
As in the first embodiment described above, the light source 101, the coupling lens 102, the aperture 103, and the cylindrical lens 104 are configured on the same member. These light source units are elastic members 117 with respect to the installation plane as described above. And the fixing member 116.
In the second embodiment, the elastic member 117 is a tension spring and the fixing member 116 is a screw.

Add explanation about β adjustment.
Between the light source unit member 110 and the installation surface 108a, β adjustment is performed using an elastic member 117 installed on a line perpendicular to the optical axis and a fixing member 116.
It is possible to adjust the inclination of the sub-scanning direction with respect to the optical axis direction of the light source unit by changing the amount of protrusion of each 116 to the lower surface of the light source unit with the 117 as a fulcrum. Adjustment is possible.

A description of Z adjustment will be added.
Similar to the β adjustment described above, Z adjustment is performed between the light source unit member 110 and the installation surface 108a using the elastic member 117 and the fixing member 116 installed on a line perpendicular to the optical axis.
By using the elastic member 117 as a fulcrum and changing the protruding amount of each of the fixing members 116 to the lower surface of the light source unit, it is possible to adjust in a direction orthogonal to the first reference surface of the light source unit member 110. Z adjustment in the whole light source unit becomes possible.

In the light source unit of the present embodiment, the angle of the light beam in the sub-scanning direction can be adjusted, so that the above-described problem can be solved.
In other words, when the light beam changes the angle in the sub-scanning direction due to an assembly error or the like, it is possible to easily adjust the light source device in the direction to cancel the angle change, thereby easily and stably improving the optical performance without increasing the assembly accuracy, and Image quality can be provided.

  As described above, according to the present embodiment, the angle of the light beam in the sub-scanning direction can be adjusted by the light source unit. Therefore, the light caused by the effects of assembly errors and processing errors in the oblique incidence type optical scanning device. It is possible to reduce the angle change of the beam in the sub-scanning direction, and to reduce the scanning line bending and the wavefront aberration.

  In other words, when the light beam changes the angle in the sub-scanning direction due to an assembly error or the like, it is possible to easily adjust the light source device in the direction to cancel the angle change, thereby easily and stably improving the optical performance without increasing the assembly accuracy, and Image quality can be provided.

[Third Embodiment]
Next, a third embodiment of the present invention will be described.
In the optical scanning device according to the third embodiment, a multi-beam light source device that emits a plurality of light beams is used as a light source.

  As described above, in the optical scanning device of the present embodiment, the light source is, for example, a semiconductor laser array having a plurality of light emitting points, or a multi-beam light source device using a plurality of light sources having a single light emitting point or a plurality of light emitting points. The optical scanning apparatus and the image forming apparatus can be configured to achieve high speed and high density by scanning a plurality of light beams simultaneously on the surface of the photosensitive member. Further, even when such an optical scanning device and an image forming apparatus are configured, the same effects as those obtained by the above-described embodiment can be obtained.

FIG. 9 shows an example of a light source unit constituting the multi-beam light source device according to the present embodiment.
In FIG. 9, the semiconductor lasers 403 and 404 are individually fitted in fitting holes 405-1 and 405-2 (not shown) formed on the back side of the base member 405, respectively. The fitting holes 405-1 and 405-2 are inclined at a predetermined angle in the main scanning direction, in the embodiment, about 1 °, and the semiconductor lasers 403 and 404 fitted in the fitting holes are also in the main scanning direction. Is inclined about 1 °.

  In the semiconductor lasers 403 and 404, notches are formed in the cylindrical heat sink portions 403-1 and 404-1, and the protrusions 406a and 407a formed in the center round holes of the holding members 406 and 407 are formed on the heat sink portions. The alignment direction of the light emitting sources is adjusted by matching the notches.

The holding members 406 and 407 are fixed to the base member 405 with screws 412 from the back side thereof, so that the semiconductor lasers 403 and 404 are fixed to the base member 405.
Further, the collimating lenses 408 and 409 are adjusted in the optical axis direction along the outer circumferences of the semicircular mounting guide surfaces 405d and 405e of the base member 405, and the divergent beams emitted from the light emitting points become parallel light beams. So that it is positioned and glued.

  By arranging and holding a plurality of base members as light sources in the sub-scanning direction on the light source holding member, in the light source device of this embodiment, the light source can be a multi-beam light source device having a plurality of light emitting points. Become.

  At this time, each semiconductor laser of the base member may be formed to have an angle in the sub-scanning direction, or each base member may be held by the light source holding member so as to have an angle in the sub-scanning direction.

Furthermore, the configuration of the present invention may be applied between the base member and the light source holding member, and a mechanism for adjusting the angle in the sub-scanning direction may be provided for the base member in addition to the light source holding member.
Furthermore, a semiconductor laser array having a plurality of light emitting points may be used as the semiconductor laser.
Needless to say, a plurality of semiconductor laser arrays may not be provided and a multi-beam may be formed independently.

  As described above, according to the present embodiment, the light source is, for example, a semiconductor laser array having a plurality of light emission points, a multi-beam light source device using a single light emission point or a plurality of light sources having a plurality of light emission points, By configuring the plurality of light beams to simultaneously scan the surface of the photoreceptor, it is possible to configure an optical scanning device and an image forming apparatus that are increased in speed and density.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described.
In the fourth embodiment, an image forming apparatus using the optical scanning device according to any of the above-described embodiments is configured.

The image forming apparatus as the present embodiment will be described with reference to FIG.
The configuration example shown in FIG. 10 is an example in which the optical scanning device according to each of the above-described embodiments is applied to a tandem type full color laser printer.

In FIG. 10, a transport belt 17 is provided on the lower side of the apparatus to transport transfer paper (not shown) fed from a paper feed cassette 13 disposed in the horizontal direction.
On the transport belt 2, a yellow Y photoconductor 7Y, a magenta M photoconductor 7M, a cyan C photoconductor 7C, and a black K photoconductor 7K are sequentially arranged from the upstream side in the transfer paper transport direction. They are arranged at intervals.
Hereinafter, subscripts Y, M, C, and K are appropriately added to the reference numerals to distinguish them.

These photoreceptors 7Y, 7M, 7C, and 7K are all formed to have the same diameter, and process members that perform each process according to the electrophotographic process are sequentially arranged around the photoreceptors.
Taking the photoconductor 3Y as an example, a charging charger 8Y, an optical scanning optical system 6Y, a developing device 10Y, a transfer charger 11Y, a cleaning device 12Y, and the like are sequentially arranged. The same applies to the other photoconductors 7M, 7C, and 7K.

  In other words, in the present embodiment, the surfaces of the photoconductors 7Y, 7M, 7C, and 7K are set as scan surfaces or irradiated surfaces set for the respective colors, and an optical scanning optical system is applied to each photoconductor. 6Y, 6M, 6C, and 6K are provided in a one-to-one correspondence. However, the scanning lens L1 is commonly used for M and Y, and is commonly used for K and C.

In addition, a registration roller 16 and a belt charging charger 20 are provided around the transport belt 17 on the upstream side of the photoconductor 7Y, and are positioned on the downstream side in the rotation direction of the belt 17 with respect to the photoconductor 7K. A belt separation charger 21, a static elimination charger 22, a cleaning device 23, and the like are provided in this order.
Further, a fixing device 24 is provided downstream of the belt separation charger 11 in the transfer paper conveyance direction, and is connected to a paper discharge tray 25 by a paper discharge roller 26.

  In such a schematic configuration, for example, in the case of the full color mode (multiple color mode), each of the photoconductors 7Y, 7M, 7C, and 7K is based on image signals of colors Y, M, C, and K, respectively. In this optical scanning device 6Y, 6M, 6C, 6K, an electrostatic latent image corresponding to each color signal is formed on the surface of each photoconductor.

These electrostatic latent images are developed with color toners by the corresponding developing devices to become toner images, which are superposed by being sequentially transferred onto transfer paper that is electrostatically attracted onto the transport belt 17 and transported. As a result, a full-color image is formed on the transfer paper.
This full-color image is fixed by the fixing device 24 and then discharged to the discharge tray 25 by the discharge roller 26.

  By using the optical scanning optical systems 6Y, 6M, 6C, and 6K of the above-described image forming apparatus as the optical scanning device according to any one of the above-described embodiments including the light source device according to any of the above-described embodiments. In an oblique-incidence optical scanning device suitable for low cost, low power consumption, and miniaturization, angle changes in the sub-scanning direction of the light beam due to the effects of assembly errors and processing errors are reduced, and scanning line bending and wavefront aberration are reduced. It is possible to realize an image forming apparatus capable of reducing deterioration and realizing good and stable image quality.

As described above, according to the present embodiment, it is possible to provide an image forming apparatus that can obtain the effects of the above-described embodiments.
Therefore, it is possible to provide an image forming apparatus suitable for low power consumption at low cost and capable of realizing good and stable image quality.

Each of the above-described embodiments is a preferred embodiment of the present invention, and the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.
For example, the image forming apparatus according to the present invention may be various types as long as it uses an optical scanning device, and may be a digital copying machine, a laser printer, a laser facsimile, or the like.

It is the schematic which shows the structure of the optical scanning device by embodiment of this invention. It is the schematic which shows the structure of the optical scanning device by embodiment of this invention. It is the schematic which shows the structure of the optical scanning device by embodiment of this invention. It is the schematic which shows the structure of a general optical scanning device. It is the schematic which shows the structure of a general optical scanning device. It is the schematic which shows the structure of a general optical scanning device. It is a figure which shows the structure detail of the optical scanning device by embodiment of this invention. It is a figure which shows the structure detail of the optical scanning device by embodiment of this invention. It is a disassembled perspective view which shows the example of the light source unit which comprises a multi-beam light source device. It is the schematic which shows the structure of the image forming apparatus as 4th Embodiment.

Explanation of symbols

101 Semiconductor laser (an example of a light source)
106 Imaging lens 108a Installation surface (an example of a first reference surface)
108b Installation surface (an example of a second reference surface)
110 Light source unit member (an example of support means)

Claims (9)

An optical scanning device comprising a light source, an optical deflector that deflects a light beam from the light source, and an imaging lens that collects the light beam deflected by the optical deflector,
A first reference surface for attaching support means for supporting the light source;
A second reference plane for mounting at least one of the imaging lenses is a plane parallel to the plane, and the plane is inclined by a predetermined angle from a main scanning plane perpendicular to the rotation axis of the optical deflector. An optical scanning device characterized by the above. Housing means for integrally supporting the light source, the optical polarizer, and the imaging lens;
2. The housing means is provided to be inclined at a predetermined angle from a main scanning plane orthogonal to a rotation axis of the optical deflector, and includes the first reference plane and the second reference plane. The optical scanning device described. A coupling lens corresponding to the light source;
An aperture having an opening for shaping the light beam from the coupling lens,
The optical scanning device according to claim 1, wherein the support unit further supports the coupling lens and the aperture as a single unit. A cylindrical lens having a refractive power in at least the sub-scanning direction;
4. The optical scanning device according to claim 1, wherein the supporting unit further supports the cylindrical lens as a single unit. 5.   5. The optical scanning device according to claim 1, further comprising a folding mirror between optical paths between the cylindrical lens and the optical deflector. 6.   6. The optical scanning device according to claim 1, wherein the support unit includes a mechanism for performing installation adjustment in a direction orthogonal to the first reference plane.   The said support means has a mechanism for performing installation adjustment of the angle between the light beam emitted from the light source and the main scanning plane orthogonal to the rotation axis of the deflector. 2. An optical scanning device according to item 1.   8. The optical scanning device according to claim 1, wherein the light source is a multi-beam light source device that emits a plurality of light beams.   An image forming apparatus comprising the optical scanning device according to claim 1.

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