JP2007206707A - Light source apparatus, optical scanner and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multibeam light source having excellent accuracy of adjustment of the positions of light beams including the gap between the beam spots of the light beams in a subscanning direction, a small variation in the beam spot diameters accompanying the adjustment, a stable beam spot diameters and small light quantity variation. <P>SOLUTION: Two semiconductor lasers 1,001 and 1,002 are fixed on a light source holding member 1,005 along a main scanning direction, and two coupling lenses 1,003 and 1,004 are turnably fitted in front of the lasers on the light source holding member 1,005. A shift quantity continuously varies according to the turning of the coupling lenses 1,003 and 1,004, the turning quantity of the coupling lenses is determined so as to obtain a desired variation. The gap between the beam spots in the subscanning direction is excellently adjustable when it is adjusted without turning the semiconductor lasers 1,001 and 1,002. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical scanning device used for a writing system in a recording apparatus such as a digital copying machine, a laser printer, and a laser facsimile, and in particular, scans and scans a surface to be scanned such as a photoconductor simultaneously with a plurality of light beams. The present invention relates to a light source device, an optical scanning device, and an image forming apparatus suitable as a light source in a multi-beam optical scanning device that remarkably improves speed.

As a technique for improving the recording speed in an optical scanning apparatus used in an optical writing system of a recording apparatus such as a laser printer and a laser facsimile, the rotational speed of a rotating polygon mirror, that is, a polygon mirror, as an optical deflector used as a deflecting means There is a way to raise. However, in this method, the durability, noise, vibration, modulation speed of the semiconductor laser, and the like of the motor used for rotational driving of the polygon mirror become problems, and the recording speed is limited. In view of this, a multi-beam optical scanning device has been proposed that improves the recording speed by simultaneously scanning a plurality of light beams and simultaneously recording a plurality of lines.
For example, the applicant of the present invention previously described in Patent Document 1 (Japanese Patent Laid-Open No. 11-023988), Patent Document 2 (Japanese Patent Laid-Open No. 11-212006), Patent Document 3 (Japanese Patent Laid-Open No. 2000-75227), etc. A multi-beam light source device that solves the problem and emits a plurality of laser light beams was proposed. These multi-beam light source devices of these prior applications are, for example, a plurality of semiconductor lasers, coupling lenses provided corresponding to the respective semiconductor lasers, and these semiconductor lasers and corresponding coupling lenses arranged in the main scanning direction. A first light source unit having a light source holding member for holding it integrally, a second light source unit configured substantially the same as the first light source unit, and the light beams of the first and second light source units are close to each other. And beam combining means for emitting the light.

Also proposed is a multi-beam light source device that does not have the beam combining means and uses only a single light source unit having a configuration corresponding to the first light source unit.
By the way, in these light source devices, the coupling lens is bonded and fixed to the light source holding member with an ultraviolet (UV) curing adhesive or the like from the viewpoint of miniaturization and cost reduction. By directly bonding the coupling lens to the light source holding member, the cell of the coupling lens becomes unnecessary, and the plurality of coupling lenses can be arranged closer to each other.
A configuration of an example of a multi-beam light source device having a single light source unit is shown in FIG. FIG. 24 is an exploded perspective view showing the configuration of the multi-beam light source device. Coupling lenses 1003 and 1004 are provided corresponding to the two semiconductor lasers 1001 and 1002, respectively. These coupling lenses 1003 and 1004 are paired with each other, and couple the emitted light from the semiconductor lasers 1001 and 1002 to the scanning optical system. A light source holding member 1005 that holds these members integrally is provided in the multi-beam light source device.

The light source holding member 1005 is provided with two fitting holes for press-fitting and supporting the semiconductor lasers 1001 and 1002 in parallel in the main scanning direction. The semiconductor lasers 1001 and 1002 are respectively pressed into the fitting holes from the back side of the light source holding member 1005 and attached. Further, a support protrusion 1005a is formed to protrude from the front side of the light source holding member 1005, and coupling lenses 1003 and 1004 are fixed to the support protrusion 1005a using an ultraviolet curing adhesive.
FIG. 25 shows a configuration of an example of a multi-beam light source device that includes the first light source unit, the second light source unit, and the beam combining unit described above. FIG. 25 is an exploded perspective view showing the configuration of the multi-beam light source device. The multi-beam light source device includes semiconductor lasers 1011, 1012, 1021, 1022, coupling lenses 1013, 1014, 1023, 1024, and a light source holding member 1015. 1025 and a prism 1030.

A portion including the semiconductor lasers 1011 and 1012, the coupling lenses 1013 and 1014, and the light source holding member 1015 constitutes a first light source unit, and includes the semiconductor lasers 1021 and 1022, the coupling lenses 1023 and 1024, and the light source holding member 1025. The part constitutes a second light source part. Each of the first light source unit and the second light source unit is configured in the same manner as the portion including the semiconductor lasers 1001 and 10002, the coupling lenses 1003 and 1004, and the light source holding member 1005 in FIG. A support protrusion 1015 a is projected from the member 1015, and a support protrusion 1025 a is projected from the light source holding member 1025.
The prism 1030 includes a parallelogram column portion 1031, a triangular column portion 1032 and a half-wave plate 1033, and a plurality of light beams emitted from the respective light emitting points of the semiconductor lasers 1011, 1012, 1021 and 1022. Beam synthesizing means that emits light in the vicinity of the optical axis of the scanning optical system in the sub-scanning direction is configured. The half-wave plate 1033 is provided in the incident portion of the laser beam from the semiconductor lasers 1021 and 1022 in the parallelogram pillar portion 1031 of the prism 1030.

The light emitted from the semiconductor lasers 1021 and 1022 side is reflected by the oblique side surface of the parallelogram column portion 1031 and then further reflected by the boundary surface with the triangular column portion 1032, thereby passing through this triangular column portion 1032 portion. The light emitted from the semiconductor lasers 1011 and 1012 is emitted from the prism 1030 as being close to the sub-scanning direction.
The semiconductor laser and the coupling lens in the multi-beam light source device described above are positioned and adjusted and held by the light source holding member so as to obtain a desired sub-scanning beam pitch. However, it is difficult to accurately adjust the positioning of the semiconductor laser and the coupling lens. Adjustment errors, mounting errors when mounting the multi-beam light source device to the optical housing, optical element processing variations, and optical element assembly variations Also, the desired sub-scanning beam pitch is not maintained due to variations in processing of the optical housing. Therefore, in Patent Document 2 and Patent Document 3 described above, as shown in FIG. 26, the light source unit is rotated with the axis in the direction substantially coincident with the optical axis of the emitted beam as the rotation axis C (hereinafter, referred to as “the light axis”). Such rotation is referred to as “γ rotation”), and the beam spot interval in the desired sub-scanning direction on the surface to be scanned, that is, the sub-scanning beam pitch, is obtained by changing the emission direction of the emission beam. It is possible to adjust as follows.

  For example, when each pair of the corresponding semiconductor laser and coupling lens has an angle in the main scanning direction so that the respective emitted lights intersect at the reflection surface of the polygon scanner mirror, the light source unit is rotated by γ. Thus, each exit beam has an angle in the sub-scanning direction, and the beam spot position on the image plane changes in the sub-scanning direction. That is, as shown in FIG. 27, when the rotation axis C is at the center of the two light sources in the main scanning direction, the positions of the beam spots S1 and S2 in the sub-scanning direction on the image plane are As shown in FIG. 27, the sub-scanning direction moves upside down and the sub-scanning beam spot interval changes.

Japanese Patent Laid-Open No. 11-023988 Japanese Patent Laid-Open No. 11-212006 JP 2000-75227 A

By the way, in recent digital copying machines and laser printers, in order to obtain higher image quality compared to conventional machines, the writing density has been shifted to a higher density. The demand for positional accuracy is also very high. The positional accuracy of each light beam on the surface to be scanned in the configuration shown in Patent Document 1, Patent Document 2, and Patent Document 3 described above is well adjusted by the initial adjustment when the coupling lens is bonded, There has been a problem in the positional accuracy of the light beam with respect to environmental fluctuations such as temperature and humidity fluctuations.
At the time of bonding of the coupling lens described above, each light beam is positioned so as to be in a desired position on the surface to be scanned, and the coupling lens CL such as the coupling lens 1003 is UV-cured as shown in FIG. It is bonded and fixed to a light source holding member SM (a support projection portion 1005a thereof) such as a light source holding member 1005 via an adhesive layer GL made of an adhesive or the like.

  However, as shown in FIG. 29, the coupling to the light source holding member SM12 is caused by the influence of the component accuracy of each component, such as the variation of the light emitting point position of the semiconductor laser, or the assembly accuracy of the adjuster. The lens CL is decentered and fixed, and the adhesive layer GL between the coupling lens CL and the light source holding member SM12 is biased and non-uniformity associated therewith occurs. As a result, the position accuracy of each light beam is adjusted well at the time of initial adjustment. However, when the adhesive layer GL expands or contracts at the time of environmental change, due to the difference in the thickness of the adhesive layer GL, for example, FIG. As indicated by the arrows, the position of the coupling lens CL also changes in the sub-scanning direction. Thus, since the positional relationship between the light source and the coupling lens CL cannot be maintained at the time of initial adjustment, the positional accuracy of each light beam at the time of initial adjustment, that is, the beam spot interval in the sub-scanning direction on the surface to be scanned, etc. Can not keep good.

  In addition, as shown in FIG. 26, when the light source unit is rotated by γ and adjusted so that a desired sub-scanning beam spot interval is obtained on the surface to be scanned, a semiconductor laser, a semiconductor laser array, etc. The light source also rotates at the same time. In general, in the case of an edge emitting laser such as a semiconductor laser and a semiconductor laser array used as a light source, the oscillation region has a divergence angle different between a direction perpendicular to the direction of the active layer and a direction parallel to the active layer. Therefore, the shape of the emitted laser beam becomes an ellipse that is long in the direction orthogonal to the direction of the active layer. Therefore, when the light source rotates, the elliptical beam rotates. Therefore, the divergence of the light source corresponding to the main scanning direction corresponding to the deflection direction of the polygon mirror and the sub-scanning direction that is orthogonal to the main scanning direction, respectively. The angle changes with rotation. Therefore, such a configuration causes the following problems.

Coupling efficiency (light power immediately after the aperture is emitted / light power immediately after being emitted from the light source) is deteriorated, and it is difficult to secure a light amount necessary for exposing the photosensitive member.
The beam spot diameter varies as the light beam thickness changes (the beam spot diameter decreases as the light beam increases, and the beam spot diameter increases as the light beam decreases).
-Especially when the light beam is thin, it becomes susceptible to variations in the divergence angle, and a stable beam spot diameter cannot be obtained.
The present invention has been made in view of the above-described circumstances, and has good adjustment position accuracy of a light beam including a beam spot interval of the light beam in the sub-scanning direction, and is stable with little fluctuation of the beam spot diameter accompanying the adjustment. An object of the present invention is to provide a light source device suitable as a multi-beam light source device capable of obtaining a beam spot.

  An object of claim 1 of the present invention is to rotate a light source particularly in a multi-beam light source device having a plurality of light sources each having one or more light-emitting portions and a coupling lens individually corresponding to each light source. Therefore, it is possible to satisfactorily adjust the beam spot interval in the sub-scanning direction, to maintain a stable beam spot diameter with little fluctuation of the beam spot diameter due to the adjustment, and to provide a light source device with little light quantity fluctuation. is there.

The object of the second aspect of the present invention is to reduce the sensitivity of the fluctuation of the beam spot position with respect to the rotation of the coupling lens, to enable fine adjustment of the beam spot position in the sub-scanning direction, and to adjust the beam spot interval more precisely. It is in providing the light source device which can implement | achieve.
The object of the third aspect of the present invention is to enable a plurality of adjustments with different sensitivity of the fluctuation of the beam spot position with respect to the rotation of the coupling lens, and to selectively use the coarse adjustment and the fine adjustment. An object of the present invention is to provide a light source device that can be improved.
The purpose of claims 4 and 5 of the present invention is to provide a stable beam spot with a good adjustment position accuracy of the light beam including the beam spot interval of the light beam in the sub-scanning direction and a small fluctuation of the beam spot diameter due to the adjustment. An object of the present invention is to provide an optical scanning device and an image forming apparatus provided with the obtained multi-beam light source device.

In order to achieve the above-described object, the light source device according to the present invention described in claim 1
A plurality of light sources each having one or more light emitting portions;
A multi-beam light source device having a coupling lens individually corresponding to each of the light sources,
Each of the coupling lenses is rotatable with respect to each of the corresponding light sources about an axis substantially parallel to the optical axis of the coupling lens as a rotation axis.
In the light source device according to the second aspect of the present invention, an axis that is a rotation axis of the coupling lens is between an optical axis of the coupling lens and a light emitting unit of a light source corresponding to the coupling lens, and When there are a plurality of light emitting portions in the light source corresponding to the coupling lens, either between the optical axis of the coupling lens and the center point of the light emitting portions of the light source corresponding to the coupling lens It is characterized by setting the position to include.

According to a third aspect of the present invention, the light source device according to the present invention includes a plurality of rotation shafts for rotating the coupling lens.
In addition to the above-described configuration, the present invention can also be configured as follows.
In the above light source device, the light source holding member may be configured to be movable within a plane substantially orthogonal to the optical axis.

The image forming apparatus can also be configured using an optical scanning device including the light source device.
An optical scanning device can be configured using the light source device according to any one of the first to third aspects.
In addition, an image forming apparatus can be configured using an optical scanning device including the light source device according to any one of claims 1 to 3.

[Action]
The light source device according to claim 1 of the present invention includes a plurality of light sources each having one or more light emitting units, and a coupling lens individually corresponding to each of the light sources, and each coupling lens includes: Each of the corresponding light sources can be rotated about an axis substantially parallel to the optical axis of the coupling lens.
With such a configuration, in particular, in a multi-beam light source device having a plurality of light sources each having one or more light emitting units, and a coupling lens individually corresponding to each light source, without rotating the light source, The beam spot interval in the sub-scanning direction can be satisfactorily adjusted, the beam spot diameter variation due to the adjustment is small, a stable beam spot diameter can be maintained, and the light amount fluctuation is small.

In the light source device according to a second aspect of the present invention, the axis that is the rotation axis of the coupling lens is between the optical axis of the coupling lens and the light emitting unit of the light source corresponding to the coupling lens, and the coupling. In a position including any one of the optical axis of the coupling lens and the center point of the plurality of light emitting units of the light source corresponding to the coupling lens when the light source corresponding to the lens has a plurality of light emitting units. Set.
With such a configuration, in particular, the sensitivity of fluctuations in the beam spot position with respect to the rotation of the coupling lens is reduced, and the fine adjustment of the beam spot position in the sub-scanning direction is possible, thereby realizing more precise beam spot interval adjustment. Can do.
A light source device according to a third aspect of the present invention includes a plurality of rotating shafts for rotating the coupling lens.
With such a configuration, in particular, a plurality of adjustments with different sensitivity of fluctuations in the beam spot position with respect to the rotation of the coupling lens can be performed, and coarse adjustment and fine adjustment can be selectively used, which greatly improves work efficiency. It becomes possible.

According to the present invention, it is possible to obtain a stable beam spot with a good adjustment position accuracy of the light beam including the beam spot interval of the light beam in the sub-scanning direction and a small variation in the beam spot diameter due to the adjustment. A light source device, an optical scanning device, and an image forming apparatus suitable as a multi-beam light source device can be provided.
Furthermore, according to the light source device of claim 1 of the present invention, each of the cups has a plurality of light sources each having one or more light emitting portions, and a coupling lens individually corresponding to each of the light sources. The ring lens can be rotated with respect to each of the corresponding light sources about an axis substantially parallel to the optical axis of the coupling lens as a rotation axis. In a multi-beam light source device having individual light sources and coupling lenses individually corresponding to the respective light sources, it is possible to satisfactorily adjust the beam spot interval in the sub-scanning direction without rotating the light sources. A stable beam spot diameter can be maintained with little variation in spot diameter, and the variation in light quantity is small.

According to the light source device of claim 2 of the present invention, the axis that is the rotation axis of the coupling lens is between the optical axis of the coupling lens and the light emitting unit of the light source corresponding to the coupling lens, and the In the case where there are a plurality of light emitting portions in the light source corresponding to the coupling lens, any one of the optical axis of the coupling lens and the center point of the plurality of light emitting portions of the light source corresponding to the coupling lens is included. By setting the position, in particular, the sensitivity of the fluctuation of the beam spot position with respect to the rotation of the coupling lens is reduced, the fine adjustment of the beam spot position in the sub-scanning direction is possible, and more precise beam spot interval adjustment is realized. be able to.
According to the light source device of the third aspect of the present invention, a plurality of rotation shafts for rotating the coupling lens are used, and in particular, a plurality of different sensitivity of beam spot position fluctuations with respect to the rotation of the coupling lens. Thus, it is possible to selectively use coarse adjustment and fine adjustment, and the working efficiency can be greatly improved.
According to the optical scanning device of claim 4 of the present invention, high-quality image reproducibility can be ensured by using the light source device according to any one of claims 1 to 3. Also, as a means to improve the recording speed, by scanning multiple light beams at the same time and recording multiple lines at the same time, the recording speed is improved without increasing the rotational speed of the rotary polygon mirror, and the power is saved. Can be realized.
According to the image forming apparatus of the fifth aspect of the present invention, an image forming apparatus capable of ensuring high-quality image reproducibility is realized by using the optical scanning device according to the fourth aspect. be able to.

Hereinafter, based on an embodiment of the present invention, a light source device of the present invention will be described in detail with reference to the drawings.
<First Embodiment>
FIG. 1 shows a configuration related to adhesion of a coupling lens that is a main part of a light source device according to a first embodiment of the present invention.
FIG. 1 shows a coupling lens CL such as a collimator lens and four lens support portions SM1 to SM4 as a light source holding member for bonding and fixing the coupling lens CL. The four lens support portions SM1 to SM4 are arranged around the coupling lens CL at intervals of 90 °, and the peripheral surface of the coupling lens CL is used at four points at intervals of 90 °, for example, using an ultraviolet curable adhesive or the like. It is bonded and fixed via an adhesive layer GL.

As a conventional adhesion holding method for holding and fixing the coupling lens CL, as shown in FIG. 28, the coupling lens CL is held in a cantilever state in which the coupling lens CL is bonded and held at one place on the peripheral surface. As described above, the position variation of the coupling lens CL due to the environmental variation could not be suppressed. On the other hand, according to the present invention, by providing a plurality of adhesive holding portions of the coupling lens CL on the peripheral surface of the coupling lens CL, the positional fluctuation of the coupling lens CL during the environmental fluctuation is effectively suppressed. It becomes possible to do.
That is, as shown in FIG. 1, it adhere | attaches on the lens support parts SM1-SM4 of a light source holding member via the contact bonding layer GL at 4 points | pieces of the 90 degree space | interval of the surrounding surface of the coupling lens CL. In this case, when the environment changes, stress is generated from each of the four bonded portions. At this time, the position fluctuation of the coupling lens CL is canceled out by the forces from the opposing directions and greatly reduced. Further, even when the coupling lens CL is eccentrically fixed to the light source holding member and the adhesive layer GL between the coupling lens CL and the light source holding member is biased, the force that has been generated only in one direction conventionally. On the other hand, a force in a direction to suppress the force is generated from another holding adhesive portion that holds the coupling lens CL.
For this reason, the positional fluctuation of the coupling lens CL is effectively reduced.

<Second Embodiment>
Furthermore, as a method for suppressing the fluctuation of the position of the coupling lens when the environment fluctuates, a case where bonding is performed at three points as shown in FIG.
FIG. 2 shows a configuration relating to adhesion of a coupling lens, which is a main part of the light source device according to the second embodiment of the present invention.
FIG. 2 shows three lens support portions SM11 to SM13 of the coupling lens CL and a light source holding member for bonding and fixing the coupling lens CL. The three lens support portions SM11 to SM13 are arranged around the coupling lens CL at intervals of 120 °, and the peripheral surface of the coupling lens CL is used at three points at intervals of 120 °, for example, using an ultraviolet curable adhesive. It is bonded and fixed via an adhesive layer GL.
As described in the first embodiment described above, by having three adhesion holding portions for the coupling lens CL, the positional variation of the coupling lens CL during environmental variation can be suppressed.

  According to the configuration of the present invention shown in FIG. 2, the thicknesses of the coupling lens CL and the adhesive layer GL are different in each adhesive holding portion of the coupling lens CL, that is, the lens support portions SM11 to SM13 with the adhesive layer GL interposed. Even in this case, the cross-sectional area of the adhesive layer GL of the adhesive part between the coupling lens CL and the lens support parts SM11 to SM13 of the light source holding member in each adhesive holding part is made equal (see FIG. 3). The stress generated by the expansion or contraction of the adhesive layer GL due to the fluctuation can be made equal in the adhesive portion formed by the adhesive layer GL between the coupling lens CL and the lens support portions SM11 to SM13 of the light source holding member. Further, in the direction in which the force acts as indicated by an arrow in FIG. 4, the position of the center of gravity of the polygon and the cup formed by connecting the bonding portions between the coupling lens CL and the lens support portions SM11 to SM13 of the light source holding member. Since the center positions of the ring lenses CL coincide with each other, the acting forces are balanced and the position of the coupling lens CL does not change.

At this time, the adhesive surfaces of the coupling lens CL and the lens support portions SM11 to SM13 of the light source holding member are flat, and the thickness of the adhesive layer GL is uniform, so that the adhesive layer GL expands or contracts when the environment changes. It is possible to further reduce the influence of.
By using the light source device having the configuration shown in the first and second embodiments described above, it is possible to reduce the positional variation of the coupling lens CL due to the expansion or contraction of the adhesive even when the environment varies. .

<Third Embodiment>
Furthermore, it is desirable that the plurality of holding portions to which the coupling lens is bonded are not positioned in the facing direction in a plane substantially orthogonal to the optical axis.
FIG. 5 shows a configuration related to adhesion of a coupling lens that is a main part of a light source device according to the third embodiment of the present invention.
FIG. 5 shows the three lens support portions SM11 to SM13 of the coupling lens CL and a light source holding member that adheres and fixes the coupling lens CL in substantially the same manner as FIG. The three lens support portions SM11 to SM13 are arranged around the coupling lens CL at intervals of 120 °, and the peripheral surface of the coupling lens CL is used at three points at intervals of 120 °, for example, using an ultraviolet curable adhesive. It is bonded and fixed via an adhesive layer GL.

That is, the coupling lens CL is held by being bonded to the lens support portions SM11 to SM13 of the light source holding member by the adhesive layer GL. As the adhesive forming the adhesive layer GL, an ultraviolet curable adhesive is often used. The ultraviolet curable adhesive is filled between the coupling lens CL and the lens support portions SM11 to SM13 of the light source holding member, and the ultraviolet curable adhesive is cured by irradiating ultraviolet rays (UV), The coupling lens CL is fixed to the light source holding member. This ultraviolet irradiation needs to uniformly irradiate the adhesive in order to suppress fluctuations during curing of the adhesive layer GL. For this reason, as shown in a partial detail view in FIG. 6, it is possible to irradiate ultraviolet rays from the direction facing the adhesive layer GL portion (adhesive portion between the coupling lens CL and the lens support portions SM11 to SM13 of the light source holding member). desirable. According to the light source device having such a configuration, it is possible to uniformly irradiate the adhesive with ultraviolet rays from the facing direction of the adhesive layer GL.
In the light source device according to the third embodiment, an ultraviolet ray irradiation portion is provided, and it is possible to uniformly irradiate the ultraviolet curable adhesive, thereby suppressing the fluctuation of the position of the coupling lens when the adhesive is cured, and the light beam. The initial adjustment accuracy in the injection direction can be improved.

<Fourth embodiment>
It is desirable that all light beams emitted from the semiconductor laser intersect in the main scanning direction in the vicinity of the reflection surface of the polygon mirror.
FIG. 7 schematically shows a configuration related to an optical system which is a main part of a light source device according to the fourth embodiment of the present invention.
FIG. 7 shows semiconductor lasers LD1 and LD2, polygon mirror PM, scanning optical systems SO1 and SO2, and a scanned surface SP.
Reflecting surface D ₁ is light emitted beam represents the reflection surface of the polygon mirror PM when reaching the image height P1 located in the scanning plane SP from the semiconductor laser LD1. The reflecting surface D ₂ is light emitted beam represents the reflection surface of the polygon mirror PM when reaching the same image height P2 in the scanning plane SP from the semiconductor laser LD2. Each light beam is separated by a certain angle Δα when entering the polygon mirror PM. Therefore, the reflecting surface to reach the same image height P1, P2, time delay of the scan corresponding to the angular difference between these reflecting surfaces D ₁ and the reflecting surface D ₂ occurs.

That is, in the state shown in FIG. 8, the two light beams emitted from the semiconductor lasers LD1 and LD2 pass through considerably different optical paths. In the state shown in FIG. 7, the semiconductor lasers LD1 and LD2 The two light beams emitted from the laser beam follow exactly the same optical path. When the light beam passes through different positions in each optical element, it naturally undergoes different optical actions, so the optical characteristics such as aberration in the two light beams that reach the same image heights P1 and P2 in the main scanning direction on the surface to be scanned are In particular, the influence on the fluctuation of the scanning line pitch between the image heights is very large.
Therefore, in this embodiment, as shown in FIG. 7, in the vicinity of the reflection surface of the polygon mirror PM, the two light beams from the semiconductor lasers LD1 and LD2 are made to intersect each other on the surface to be scanned SP. When the same image heights P1 and P2 are reached, they pass through substantially the same optical path in the main scanning direction of the optical element, and scanning line bending and the like can be effectively reduced. In addition, the writing position variation in the main scanning direction between the light beams due to the variation of the optical components on the image plane side from the polygon mirror PM becomes substantially the same for all the light beams, and the main scanning direction between the beams. The writing position deviation about is effectively suppressed.

Further, by passing all light beams formed at the same image heights P1 and P2 through substantially the same position in the main scanning direction of the scanning optical system, the influence of the aberration of the lenses constituting the scanning optical system is reduced. In addition, the image formation position in the main scanning direction can be accurately matched for each beam, and even if a delay time is set for all light beams after synchronization detection, the image height at the beginning of writing can be reduced. The positional deviation in the main scanning direction can be effectively suppressed.
Furthermore, with the configuration as shown in FIG. 7, the inscribed circle radius of the polygon mirror PM can be minimized.
According to the light source device of such an embodiment, the influence of optical sag can be reduced, and even when the environment changes, it is possible to ensure good beam position accuracy on the surface to be scanned. Optical performance can be obtained. In addition, the polygon mirror can be made small, which contributes to noise reduction.

<Fifth embodiment>
Next, for a light source device according to the fifth embodiment, for example, a two-beam light source device in which a pair of semiconductor lasers and corresponding coupling lenses are juxtaposed in the main scanning direction and integrally held is taken as an example. explain.
That is, FIG. 9 schematically shows a configuration that is a main part of a light source device according to the fifth embodiment of the present invention.
The light source device shown in FIG. 9 includes semiconductor lasers 1 and 2, coupling lenses 3 and 4, and a light source holding member 5.
This light source device is configured as a two-beam light source device using two semiconductor lasers 1 and 2 each composed of a single beam semiconductor laser. Coupling lenses 3 and 4 are provided corresponding to the semiconductor lasers 1 and 2, respectively. These coupling lenses 3 and 4 are paired with each other, and couple the light emitted from the semiconductor lasers 1 and 2 to the scanning optical system.

  Further, a light source holding member 5 that holds these members together is provided. The light source holding member 5 is provided with, for example, two fitting holes for press-fitting and supporting the semiconductor lasers 1 and 2 in parallel in the main scanning direction at a required interval. The semiconductor lasers 1 and 2 are each press-fitted and attached to the two fitting holes from the back side of the light source holding member 5. In addition, five lens support portions 5 a, 5 b, 5 c, 5 d, and 5 e protrude from the front side of the light source holding member 5. The lens support portion 5 a is disposed corresponding to the middle portion of the two fitting holes, and both side surfaces are concave curved surfaces corresponding to the outer peripheral surfaces of the coupling lenses 3 and 4. The lens support portions 5b and 5c are disposed so as to surround the fitting hole corresponding to the semiconductor laser 1 with the lens support portion 5a at intervals of 120 °, and are concavely curved surfaces corresponding to the outer peripheral surface of the coupling lens 3, respectively. It is formed as. The lens support portions 5d and 5e are disposed so as to surround the fitting hole corresponding to the semiconductor laser 2 with the lens support portion 5a at intervals of 120 °, and are concave portions corresponding to the outer peripheral surface of the coupling lens 4 respectively. It is formed as a curved surface. The coupling lens 3 is fixed to the light source holding member 5 by filling the lens supporting portions 5a, 5b and 5c with, for example, an ultraviolet curing adhesive and curing them.

The coupling lens 4 is fixed to the light source holding member 5 by filling the lens support portions 5a, 5d, and 5e with, for example, an ultraviolet curing adhesive and curing them.
The semiconductor laser 1 and the corresponding coupling lens 3 have the same optical axis, the semiconductor laser 2 and the corresponding coupling lens 4 have the same optical axis, and these optical axes are polygon mirrors as optical deflectors. The light source is held by the light source holding member 5 with an inclination that forms an angle θ between them so as to intersect in the vicinity.
As described above, the light source unit composed of the semiconductor laser 1 and the corresponding coupling lens 3 and the light source unit composed of the semiconductor laser 2 and the corresponding coupling lens 4 are arranged in the main scanning direction as shown in FIG. The light beams are emitted at an angle θ in the main scanning direction. Further, the light source holding member 5 is supported by an appropriate support member so that it can be rotated about a substantially central position of an angle θ formed by both light beams as a rotation axis.

Since these light beams have an angle θ in the main scanning direction, by turning the light source holding member 5 to adjust the angle to be given in the sub-scanning direction, as shown in FIG. It is possible to adjust the interval between BS1 and BS2 in the sub-scanning direction. Since the beam spot interval in the sub-scanning direction can be adjusted, the alignment adjustment accuracy of the optical axis of each light source unit can be relaxed, and a light source device suitable for mass production can be realized.
According to the light source device according to such an embodiment, since the beam spot interval in the sub-scanning direction can be adjusted, it is possible to relax the alignment adjustment accuracy of the optical axis of the light source unit, which is suitable for mass production. Can be realized.

<Sixth embodiment>
Next, as a sixth embodiment of the light source device, the light source holding member includes two first light source holding members that support a single or a plurality of light emitting units, and these two first light source holding members. A light source device having a second light source holding member that integrally supports two coupling lenses corresponding thereto will be described.
That is, FIG. 11 schematically shows a configuration that is a main part of a light source device according to the sixth embodiment of the present invention. The light source device shown in FIG. 11 includes light sources 11 and 12, coupling lenses 13 and 14, first light source holding members 15A and 15B, and a second light source holding member 15C.
For example, the light sources 11 and 12 such as a semiconductor laser and a semiconductor laser array may be press-fitted into the first light source holding members 15A and 15B as shown in FIG. 12, or may be pressed by the spring 16 as shown in FIG. Or, it is fixed and held by a method such as screwing by screw fastening. The first light source holding members 15A and 15B are integrally held by the second light source holding member 15C together with the corresponding coupling lenses 13 and 14.

When an expensive light source such as a semiconductor laser array is used as the light sources 11 and 12, if such a configuration is used, when one of the light sources is damaged or failed, only the corresponding one can be replaced relatively easily. When a large number of light sources are used, the risk of damage or failure of the light source can be minimized.
Further, when the light beam emission direction is initially adjusted, even if the coupling lenses 13 and 14 are bonded and fixed to the second light source holding member 15C, the first light source holding members 15A and 15B are arranged on the optical axis. Since the light source 11 and 12 can be moved in a substantially orthogonal plane, the light beam emission direction can be adjusted by the movement of the light sources 11 and 12 by the movement of the first light source holding members 15A and 15B.

  In addition, the coupling lenses 13 and 14 are fixedly adhered to the second light source holding member 15C so as to reduce environmental fluctuations, for example, in the same manner as in the first to fifth embodiments by adjusting the focus direction. Thus, the deviation of the light beam emission direction at the time of initial adjustment can be adjusted by the first light source holding members 15A and 15B.

  Furthermore, it is desirable that the materials of the first light source holding members 15A and 15B and the second light source holding member 15C match. This is because the first light source holding members 15A and 15B and the second light source holding member 15C are integrally fixed by screw fastening or the like, so that if the linear expansion coefficients of the two are different, the difference in elongation between the fastening points is different. Due to the above, deformation occurs. Therefore, the first light source holding members 15A and 15B and the second light source holding member 15C are made of the same material so that the linear expansion coefficients are substantially the same, thereby reducing the deformation due to the difference in the linear expansion coefficient when the temperature changes. By maintaining a stable beam spot interval even in a high-density optical scanning device, it is possible to realize an optical scanning device that can ensure high-quality image reproducibility. Further, even when the range of material selection is widened in terms of workability and cost, for the reason described above, at least the material of the fastening portion between the first light source holding members 15A and 15B and the second light source holding member 15C. It is desirable to match.

When an expensive light source such as a semiconductor laser array is used, according to the sixth embodiment, even if a part of the plurality of light sources is damaged, it can be replaced relatively easily. In the case where a large number of are used, the risk of damage to the light source can be minimized. In addition, the direction of the exit beam after the light source replacement can be easily adjusted, and good beam position accuracy can be ensured even after the light source replacement.
As described above, since the light source unit can be replaced for each part, it is possible to easily realize the recycling of parts. In addition, by matching the materials of the first light source holding member and the second light source holding member so that the linear expansion coefficients are substantially the same, deformation due to the difference in the linear expansion coefficient at the time of temperature change is reduced, and high-density light is obtained. Even in the scanning device, by maintaining a stable beam spot interval, an optical scanning device capable of ensuring high-quality image reproducibility can be realized.

<Seventh embodiment>
FIG. 14 is a perspective view showing a configuration of a main part of a multi-beam optical scanning apparatus according to the seventh embodiment of the present invention. The optical scanning device of this embodiment uses a light source device according to FIG. 1, FIG. 2, FIG. 5, FIG. 7, FIG.
14 includes a light source device 21, an aperture (aperture aperture) 22, a cylindrical lens 23, a polygon mirror (rotating polygonal mirror) 24, an fθ lens 25, a toroidal lens 26, a reflection mirror 27, and a photoreceptor 28. It comprises. In this case, the multi-beam light source device 21 is the two-beam light source device shown in FIG. 9 or FIG. 11 and includes a semiconductor laser and a coupling lens. The fθ lens 25 and the toroidal lens 26 constitute a scanning imaging optical system.
When the two laser light beams emitted from the light source device 21 pass through the aperture 22, the peripheral portion of the light beam is blocked and removed to form a beam, and enter the cylindrical lens 23 as a line image imaging optical system. The cylindrical lens 23 is arranged with the refractive power, that is, the direction without power in the main scanning direction, and has a positive power in the sub scanning direction, and focuses the incident light beam in the sub scanning direction.

That is, the light beam emitted from the light source device 21 is formed as a long line image in the main scanning direction in the vicinity of the polygon mirror 24 by the cylindrical lens 23. The cylindrical lens 23 condenses the light beam emitted from the light source device 21 in the vicinity of the deflection reflection surface of the polygon mirror 24 that is an optical deflector. The polygon mirror 24 that reflects the light beam by the deflecting reflecting surface is driven to rotate at a constant speed, so that the light beam is deflected and scanned at a constant angular velocity as the polygon mirror 24 rotates at a constant speed. The light beam deflected along with the constant speed rotation of the polygon mirror 24 passes through the fθ lens 25 and the toroidal lens 26 forming the scanning imaging optical system, and is reflected and deflected by the reflection mirror 27, so that the actual surface to be scanned is obtained. A focused image is formed on the photoconductive photosensitive member 28 forming the following. The fθ lens 25 and the toroidal lens 26 condense these light beams on the surface of the photosensitive member 28 as two light spots separated in the sub-scanning direction, and simultaneously scan as two scanning lines by these two light spots. To do.
By using the light source device described in the first to sixth embodiments as the light source device 21 in such an optical scanning device, the positional accuracy of each light beam is maintained while maintaining good optical performance. An optical scanning device that is stable regardless of environmental fluctuations can be realized.

<Eighth embodiment>
FIG. 15 is a longitudinal sectional view schematically showing a configuration of a main part of a laser printer which is an image forming apparatus according to the eighth embodiment of the present invention. The laser printer of this embodiment uses the light scanning device shown in FIG. 14, that is, the light source device according to FIG. 1, FIG. 2, FIG. 5, FIG. 7, FIG. The optical scanning device used was used.
That is, the laser printer 100 shown in FIG. 15 includes an image carrier 111, a charging roller 112, a developing device 113, a transfer roller 114, a cleaning device 115, a fixing device 116, an optical scanning device 117, a cassette 118, a registration roller pair 119, a supply roller. A paper roller 120, a conveyance path 121, a discharge roller pair 122, and a tray 123 are provided.
The laser printer 100 has a photoconductive photosensitive member formed in a cylindrical shape as the image carrier 111. Around the image carrier 111, a charging roller 112, a developing device 113, a transfer roller 114, and a cleaning device 115 are provided. Here, the charging roller 112 is used as the charging unit, but a corona charger can also be used as the charging unit.

Further, an optical scanning device 117 that performs optical scanning with the laser beams LB1 and LB2 is provided, and the image carrier 111 is exposed by optical writing at an intermediate point between the charging roller 112 and the developing device 113. The cassette 118 stores transfer paper P as a recording medium.
When image formation is performed, the image carrier 111, which is a photoconductive photosensitive member, is rotated at a constant speed in the clockwise direction, and the surface of the image carrier 111 is uniformly charged by the charging roller 112. An electrostatic latent image is formed by exposure by optical writing of 117 laser beams LB1 and LB2. The formed electrostatic latent image is a so-called “negative latent image”, and the image portion is exposed. This electrostatic latent image is reversely developed by the developing device 113, and a toner image is formed on the image carrier 111.
The cassette 118 in which the transfer paper P is stored is detachable from the main body of the image forming apparatus 100. In the state where the cassette 118 is mounted as shown in FIG. 15, the uppermost sheet of the stored transfer paper P is taken out by the paper feed roller 120 and fed to the paper feed conveyance system. In the paper feeding / conveying system, the registration roller pair 119 catches the leading end of the fed transfer paper P. Then, the registration roller pair 119 feeds the transfer paper P to the transfer unit at the timing when the toner image on the image carrier 111 moves to the transfer position.

The transferred transfer paper P is superimposed on the toner image at the transfer portion, and the toner image is electrostatically transferred onto the transfer paper P by the action of the transfer roller 114. The transfer paper P onto which the toner image has been transferred is sent to the fixing device 116, where the toner image is fixed in the fixing device 116, and is further discharged onto the tray 123 by the paper discharge roller pair 122 through the conveyance path 121. . The surface of the image carrier 111 after the toner image is transferred is cleaned by a cleaning device 115, and residual toner, paper dust, and the like are removed.
In this way, in the image forming apparatus that forms a latent image on the image carrier 111 by optical scanning and visualizes the latent image to obtain a desired recorded image, as an optical scanning device that optically scans the image carrier 111, The optical scanning device shown in FIG. 14 is used. The image carrier 111 is a photoconductive photoconductor, and an electrostatic latent image is formed by uniform charging and optical scanning, and the formed electrostatic latent image is visualized as a toner image.

  According to the seventh and eighth embodiments, an optical scanning device that can ensure high-quality image reproducibility by using the light source device described above, and an image forming apparatus using the optical scanning device. Can be realized. The present invention also provides an optical scanning device that improves the recording speed by scanning a plurality of light beams at the same time and simultaneously recording a plurality of lines as means for improving the recording speed, and a polygon mirror (rotating polygon mirror). Since the recording speed is improved without increasing the rotation speed, it is possible to realize power saving.

<Ninth embodiment>
The ninth embodiment of the present invention is a light source device that makes it possible to change the emission angle of the light beam after passing through the coupling lens without rotating the entire light source.
As shown in FIG. 16, the coupling lens CL has a rotation axis B on an axis parallel to the optical axis A thereof. “X” shown in FIG. 16 indicates the position (on the optical axis) of the semiconductor laser as the light source. For example, the coupling lens CL is rotated by 180 ° about the rotation axis B from the state of FIG. 16 to the state of FIG. At this time, the light source is fixed so as not to rotate. In this case, as can be seen from FIGS. 16 and 17, by rotating the coupling lens CL, the angle of the light beam emitted from the coupling lens CL in the sub-scanning direction can be changed. As shown in FIG. 17, when the shift amount in the sub-scanning direction of the coupling lens CL at this time is Z1, the shift amount Z2 of the beam spot position on the surface to be scanned is
Z2 = Z1 × m (m: lateral magnification in the sub-scanning direction of the entire system)
It is expressed.

For example, in a multi-beam light source device in which two pairs of semiconductor lasers and corresponding coupling lenses are arranged in the main scanning direction as shown in FIG. With the configuration according to the form, the shift amounts Z1 and Z2 can be changed by the rotation of the coupling lens CL, and a desired sub-scanning beam spot interval can be obtained on the surface to be scanned.
Here, in order to facilitate understanding, the case where the coupling lens CL is rotated by 180 ° has been described as an example, but the value of the shift amount Z1 continuously changes as the coupling lens CL rotates. Therefore, the rotation amount of the coupling lens CL can be determined so as to obtain a desired change amount.
According to the configuration of the ninth embodiment, when adjusting the beam spot interval in the sub-scanning direction, the beam spot interval in the sub-scanning direction can be satisfactorily adjusted without rotating the light source. Thus, it is possible to realize a multi-beam light source device with little fluctuation in light amount while maintaining a stable beam spot diameter with little fluctuation in beam spot diameter.

<Tenth embodiment>
The light source device according to the tenth embodiment of the present invention is an example of a light source device specifically configured based on the above-described ninth embodiment.
FIG. 18 shows a semiconductor laser LD as a light source, a coupling lens CL, and a first cell SC1 and a second cell SC2 that support these and can rotate relatively, respectively. And in FIG.
As shown in FIGS. 18 and 19, the semiconductor laser LD is fixed and held in the first cell SC1. The coupling lens CL has a position and a direction so that the second lens SC2 provided to be rotatable in the γ rotation direction with respect to the first cell SC1 has a desired light flux state and an emission direction. Adjusted, fixed and held. At this time, the optical axis A1 of the coupling lens CL does not coincide with the rotation axis B1 of the second cell SC2, and the rotation axis B1 of the second cell SC2 is the optical axis of the semiconductor laser LD that is a light source. And the optical axis A1 of the coupling lens CL.

As in this embodiment, the coupling lens CL, that is, the rotation axis B1 of the second cell SC2 is set between the optical axis A1 of the coupling lens CL and the optical axis position of the semiconductor laser as the light source. The sensitivity of the fluctuation of the beam spot position corresponding to the rotation of the coupling lens CL becomes low, fine adjustment is possible, and a better sub-scanning beam spot interval can be obtained. According to this embodiment, when adjusting the beam spot interval in the sub-scanning direction, it is possible to satisfactorily adjust the beam spot interval in the sub-scanning direction without rotating the light source. Therefore, it is possible to realize a multi-beam light source device that has little beam spot diameter variation due to adjustment, stably maintains the beam spot diameter, and little light amount fluctuation.
According to the light source device shown in the tenth embodiment, the sensitivity of the fluctuation of the beam spot position with respect to the rotation of the coupling lens is lowered, and the fine adjustment of the beam spot position in the sub-scanning direction is made possible, so that it is more precise. It is possible to achieve an appropriate beam spot interval adjustment.

<Eleventh embodiment>
Next, as a light source device according to an eleventh embodiment of the present invention, a configuration in which two rotation axes of a coupling lens are provided will be described with reference to FIGS. 20 and 21. FIG.
As shown in FIGS. 20 and 21, the semiconductor laser LD as a light source is fixedly held in the first cell SC11. The coupling lens CL has a position and a direction so as to be in a desired light flux state and an emission direction in the second cell SC12 provided to be rotatable in the γ rotation direction about the rotation axis B11 with respect to the first cell SC11. Adjusted and fixedly held. Further, the second cell SC2 is held in the third cell SC13 provided so as to be rotatable in the γ rotation direction with respect to the rotation axis B12 different from the second cell SC12 with respect to the first cell SC11. Yes.

As described above in connection with the tenth embodiment, the rotation axis B11 of the second cell SC12 is coupled to the coupling lens CL, that is, the rotation axis B11 of the second cell SC12. By setting between the axis A11 and the optical axis position of the light source, the sensitivity of the fluctuation of the beam spot position with respect to the rotation of the coupling lens CL is reduced, and the fine adjustment of the beam spot position in the sub-scanning direction is enabled. In addition, the rotation axis of the third cell SC13 is arranged outside the region sandwiched between the optical axis A11 of the coupling lens CL and the optical axis position of the light source, thereby changing the beam spot position with respect to the rotation of the coupling lens CL. And the coarse adjustment of the beam spot position in the sub-scanning direction is possible. As a result, when adjusting the sub-scanning beam spot interval, coarse adjustment and fine adjustment can be used properly, and the adjustment work efficiency is greatly improved. Also, with such a configuration, when adjusting the beam spot interval in the sub-scanning direction, it is possible to satisfactorily adjust the beam spot interval in the sub-scanning direction without rotating the semiconductor laser LD that is a light source. Therefore, it is possible to realize a multi-beam light source device with less fluctuation in light amount, with less fluctuation in beam spot diameter due to adjustment, and maintaining a stable beam spot diameter.
According to the light source device of the eleventh embodiment, by having a plurality of rotation adjustment axes of the coupling lens, it is possible to set a plurality of beam spot position fluctuation sensitivities with respect to the rotation of the coupling lens. The adjustment can be used properly, and the working efficiency can be greatly improved.

<Twelfth embodiment>
FIG. 22 is a perspective view showing a configuration of a main part of a multi-beam optical scanning apparatus according to the twelfth embodiment of the present invention. The optical scanning device of this embodiment uses a light source device according to FIG. 16, FIG. 17 and FIG. 19, or FIG. 20 and FIG.
That is, the optical scanning device shown in FIG. 22 includes a light source device 31, an aperture (aperture aperture) 32, a cylindrical lens 33, a polygon mirror 34, an fθ lens 35, a toroidal lens 36, a reflection mirror 37, and a photoreceptor 38. In this case, the multi-beam light source device 31 is a two-beam light source device including the light source device shown in FIG. 16, FIG. 17, FIG. 19, or FIG. 20 and FIG. 21, and includes a semiconductor laser and a coupling lens. . The fθ lens 35 and the toroidal lens 36 constitute a scanning imaging optical system.

When the two laser light beams emitted from the light source device 31 pass through the aperture 32, the peripheral portion of the light beam is blocked and removed, and the light is shaped, and enters the cylindrical lens 33 as a line image imaging optical system. The cylindrical lens 33 is arranged with the refractive power, that is, the direction without power in the main scanning direction, has a positive power in the sub scanning direction, and focuses the incident light beam in the sub scanning direction. That is, the light beam emitted from the light source device 31 is formed as a long line image in the main scanning direction in the vicinity of the polygon mirror 34 by the cylindrical lens 33. The cylindrical lens 33 condenses the light beam emitted from the light source device 31 in the vicinity of the deflection reflection surface of the polygon mirror 34 that is an optical deflector. The polygon mirror 34 that reflects the light beam by the deflecting reflection surface is driven to rotate at a constant speed, so that the light beam is deflected and scanned at a constant angular speed as the polygon mirror 34 rotates at a constant speed. The light beam deflected along with the constant speed rotation of the polygon mirror 34 passes through the fθ lens 35 and the toroidal lens 36 forming the scanning imaging optical system, and is reflected and deflected by the reflection mirror 37, so that the actual surface to be scanned is obtained. A focused image is formed on the photoconductive photosensitive member 38 forming the above. The fθ lens 35 and the toroidal lens 36 condense these light beams on the surface of the photoconductor 38 as two light spots separated in the sub-scanning direction, and simultaneously scan these two light spots as two scanning lines. To do.
By using the light source device as described in the ninth to eleventh embodiments as the light source device 31 in such an optical scanning device, the positional accuracy of each light beam is maintained while maintaining good optical performance. An optical scanning device that is stable regardless of environmental fluctuations can be realized.

<Thirteenth embodiment>
FIG. 23 is a longitudinal sectional view schematically showing a configuration of a main part of a laser printer which is an image forming apparatus according to the thirteenth embodiment of the present invention. The laser printer of this embodiment uses the optical scanning device shown in FIG. 22 as the optical scanning device, that is, the optical scanning using the light source device according to FIG. 16, FIG. 17 and FIG. The device is used.
23 includes an image carrier 211, a charging roller 212, a developing device 213, a transfer roller 214, a cleaning device 215, a fixing device 216, an optical scanning device 217, a cassette 218, a registration roller pair 219, and a supply roller. A paper roller 220, a conveyance path 221, a discharge roller pair 222, and a tray 223 are provided.
The laser printer 200 has a photoconductive photoconductor formed in a cylindrical shape as the image carrier 211. Around the image carrier 211, a charging roller 212, a developing device 213, a transfer roller 214, and a cleaning device 215 are provided. Here, the charging roller 212 is used as the charging unit, but a corona charger can also be used as the charging unit.

Further, an optical scanning device 217 that performs optical scanning with the laser beams LB1 and LB2 is provided, and the image carrier 211 is exposed by optical writing at an intermediate point between the charging roller 212 and the developing device 213. The cassette 218 stores a transfer sheet P as a recording medium.
When performing image formation, the image carrier 211, which is a photoconductive photosensitive member, is rotated at a constant speed in the clockwise direction, and the surface of the image carrier 211 is uniformly charged by the charging roller 212. An electrostatic latent image is formed by exposure by optical writing of the laser beam LB 217. The formed electrostatic latent image is a so-called “negative latent image”, and the image portion is exposed. This electrostatic latent image is reversely developed by the developing device 213, and a toner image is formed on the image carrier 211.
The cassette 218 in which the transfer paper P is stored is detachable from the main body of the image forming apparatus 200. In the state where the cassette 218 is mounted as shown in FIG. 23, the uppermost sheet of the stored transfer paper P is taken out by the paper feed roller 220 and fed to the paper feed conveyance system.

In the paper feeding / conveying system, the registration roller pair 219 catches the leading end portion of the fed transfer paper P. Then, the registration roller pair 219 feeds the transfer paper P to the transfer unit at the timing when the toner image on the image carrier 211 moves to the transfer position. The transferred transfer paper P is superimposed on the toner image at the transfer portion, and the toner image is electrostatically transferred onto the transfer paper P by the action of the transfer roller 214. The transfer paper P onto which the toner image has been transferred is sent to the fixing device 216, where the toner image is fixed in the fixing device 216, and is further discharged onto the tray 223 by the paper discharge roller pair 222 through the conveyance path 221. . The surface of the image carrier 211 after the toner image has been transferred is cleaned by a cleaning device 215 to remove residual toner, paper dust, and the like.
In this way, in the image forming apparatus that forms a latent image on the image carrier 211 by optical scanning and visualizes the latent image to obtain a desired recorded image, as an optical scanning device that optically scans the image carrier 211. The optical scanning device shown in FIG. 22 is used. The image carrier 211 is a photoconductive photoconductor, and an electrostatic latent image is formed by uniform charging and optical scanning, and the formed electrostatic latent image is visualized as a toner image.

  According to these twelfth and thirteenth embodiments, by using the light source device described above, an optical scanning device capable of ensuring high-quality image reproducibility and an image forming apparatus using the same are realized. be able to. The present invention also provides an optical scanning device that improves the recording speed by scanning a plurality of light beams at the same time and simultaneously recording a plurality of lines as means for improving the recording speed, and a polygon mirror (rotating polygon mirror). Since the recording speed is improved without increasing the rotation speed, it is possible to realize power saving.

It is a figure which shows typically the structure of the principal part of the light source device which concerns on the 1st Embodiment of this invention. It is a figure which shows typically the structure of the principal part of the light source device which concerns on the 2nd Embodiment of this invention. It is a figure which shows typically the principal part for demonstrating the light source device of FIG. It is a figure which shows typically the principal part for demonstrating the light source device of FIG. It is a figure which shows typically the structure of the principal part of the light source device which concerns on the 3rd Embodiment of this invention. It is a figure which shows typically the principal part for demonstrating the light source device of FIG. It is a figure which expand | deploys and shows typically the structure of the principal part of the optical system of the light source device which concerns on the 4th Embodiment of this invention. It is a figure which expand | deploys and shows typically the structure of the principal part of the optical system for demonstrating the light source device of FIG. It is a disassembled perspective view which shows typically the structure of the principal part of the light source device which concerns on the 5th Embodiment of this invention. It is a figure which shows typically the principal part for demonstrating the light source device of FIG. It is a disassembled perspective view which shows typically the structure of the principal part of the light source device which concerns on the 6th Embodiment of this invention. It is a figure which shows typically the principal part for demonstrating the light source device of FIG. It is a figure shown for demonstrating the other example of the light source device of FIG. It is a perspective view which shows typically the structure of the principal part of the optical scanning device concerning the 7th Embodiment of this invention. It is a longitudinal cross-sectional view which shows typically the structure of the principal part of the laser printer which concerns on the 8th Embodiment of this invention. It is a figure which shows typically the structure of the principal part of the light source device which concerns on the 9th Embodiment of this invention. It is a figure for demonstrating an effect | action of the light source device which concerns on the 9th Embodiment of this invention. It is a disassembled perspective view which shows typically the structure of the principal part of the light source device which concerns on the 10th Embodiment of this invention. It is sectional drawing which shows typically the principal part for demonstrating the light source device of FIG. It is a disassembled perspective view which shows typically the structure of the principal part of the light source device which concerns on the 11th Embodiment of this invention. It is sectional drawing which shows typically the principal part for demonstrating the light source device of FIG. It is a perspective view which shows typically the structure of the principal part of the optical scanning device based on the 12th Embodiment of this invention. It is a longitudinal cross-sectional view which shows typically the structure of the principal part of the laser printer based on the 13th Embodiment of this invention. It is a disassembled perspective view which shows typically the structure of the principal part of an example of the conventional light source device. It is a disassembled perspective view which shows typically the structure of the principal part of another example of the conventional light source device. It is a disassembled perspective view which shows typically the principal part for demonstrating the effect | action in an example of the conventional light source device. It is a schematic diagram of the beam spot arrangement | positioning for demonstrating the effect | action in an example of the conventional light source device. It is a schematic diagram of the adhesion structure of the coupling lens for demonstrating the structure of another example of the conventional light source device. It is a schematic diagram for demonstrating the effect | action in the other example of the conventional light source device.

Explanation of symbols

CL coupling lens SM1 to SM4, SM11 to SM13 Light source holding member GL Adhesive layer LD, LD1, LD2 Semiconductor laser (light source)
PM polygon mirror (rotating polygon mirror)
SO1, SO2 scanning optical system SP scanned surface D _{1, D 2} reflecting surfaces SC1, SC2, SC11, SC12, SC13 cells 1, 2, 11, 12, the semiconductor laser 3,4,13,14 coupling lens 5 and 15 Light source holding members 5a to 5d Support projections 21, 31 Multi-beam light source device 22, 32 Aperture (aperture aperture)
23,33 Cylindrical lens 24,34 Polygon mirror (Rotating polygon mirror)
25, 35 fθ lens 26, 36 Toroidal lens 27, 37 Reflective mirror 28, 38 Photoconductor 100, 200 Laser printer 111, 211 Image carrier 112, 212 Charging roller 113, 213 Developing device 114, 214 Transfer roller 115, 215 Cleaning Devices 116, 216 Fixing device 117, 217 Optical scanning device 118, 218 Cassette 119, 219 Registration roller pair 120, 220 Paper feed roller 121, 221 Conveyance path 122, 222 Paper discharge roller pair 123, 223 Tray

Claims (5)

A plurality of light sources each having one or more light emitting portions;
A multi-beam light source device having a coupling lens individually corresponding to each of the light sources,
Each of the coupling lenses is rotatable with respect to each of the corresponding light sources about an axis substantially parallel to the optical axis of the coupling lens as a rotation axis. The axis of rotation of the coupling lens has a plurality of light emitting units between the optical axis of the coupling lens and the light emitting unit of the light source corresponding to the coupling lens, and the light source corresponding to the coupling lens. 2. The position according to claim 1, wherein the position is set to include any of an optical axis of the coupling lens when present and a center point of a plurality of light emitting portions of the light source corresponding to the coupling lens. The light source device described. The light source device according to claim 1, wherein the light source device has a plurality of rotation shafts for rotating the coupling lens. An optical scanning device comprising the light source device according to claim 1. An image forming apparatus comprising the optical scanning device according to claim 4.

Images