JP4820089B2 - Multi-beam light source device, multi-beam light scanning device, image forming device - Google Patents

Description

  The present invention relates to a multi-beam light source device including a plurality of light sources, a multi-beam light scanning device, and an image forming apparatus.

In an image forming apparatus such as a laser printer, an image is formed by optically scanning a scanned medium (an image forming body such as a photosensitive member) with a plurality of light beams at once in order to improve output speed. A “device” has been developed.
By optically scanning the scanned medium with a plurality of light beams, the rotational speed of the deflector can be reduced compared to the case of optically scanning the scanned medium with a light beam from a single light emitting point. And the calorific value can be lowered.
As a light source of the multi-beam optical scanning device, a plurality of semiconductor lasers (LD) are combined, or a semiconductor laser array (LDA) having a plurality of light emitting points is used.

A plurality of pairs (sets) of semiconductor lasers and coupling lenses are arranged in the main scanning direction, are integrally supported by a support member (holder), the support members are arranged in the sub scanning direction, and emitted from each light source. A multi-beam light source device is disclosed in Japanese Patent Application Laid-Open No. H10-228707.
In addition, a plurality of pairs (sets) composed of a semiconductor laser array (LDA) and a coupling lens are arranged in the main scanning direction, and beam combining means for emitting light beams emitted from the respective light sources close to each other is formed. A multi-beam light source device is disclosed in Patent Document 5.

Further, Patent Document 2, Patent Document 3, and Patent Document 4 disclose configurations in which light beams are incident on beam combining means from different directions to perform beam combining.
Japanese Patent Laid-Open No. 11-23988 JP 2003-121772 A JP 2003-315709 A JP 2002-31771 A JP 2003-255246 A

  However, in the invention disclosed in Patent Document 1, since the synthesizing means is integrally formed, this becomes larger in the sub-scanning direction, resulting in a higher component unit price. In addition, there is a problem in that a separate part is required for adjusting the scanning interval between the emitted light beams between the subunits, and the structure becomes complicated.

  In the invention disclosed in Patent Document 5, the composition means becomes large in the main scanning direction, and the unit cost is high. In addition, there is a problem that a separate component is required for adjusting the scanning interval in the sub-scanning direction between the emitted light beams between the subunits, and the structure becomes complicated.

In the inventions disclosed in Patent Document 2, Patent Document 3, and Patent Document 4, since the LDs that are light sources are arranged apart from each other, the thermal influence from the periphery differs between the LD and the light source module. There is a problem in that there is a difference in the fluctuation of the operation position in the sub-scanning direction of the light beam emitted from the light source module, and as a result, the fluctuation of the sub-scanning beam pitch becomes large.
Furthermore, the invention disclosed in Patent Document 4 has a problem in that a separate part is required to adjust the scanning interval between the emitted light beams between the subunits, and the structure becomes complicated.

  The change in the scanning interval causes unevenness during image formation and causes a reduction in image quality.

  Conventionally, when the light source device has a configuration in which the scanning interval can be adjusted, there has been a problem that the structure of the device becomes complicated and large.

  SUMMARY An advantage of some aspects of the invention is that it provides a multi-beam light source device capable of adjusting a scanning interval with a simple configuration, a multi-beam light scanning device including the same, and an image forming apparatus. To do.

In order to achieve the above object, the present invention provides, as a first aspect, a plurality of light source units each including a light source and a first imaging optical system that condenses and couples a divergent light beam emitted from the light source, A light beam combining unit that emits light beams emitted from each light source unit close to each other, and each light source unit is arranged in a predetermined direction. The optical element includes the same number of optical elements, and each of the optical elements has a right angle portion, and at least one of the optical elements has one side surface of the two side surfaces forming the right angle portion parallel to the arrangement direction of the light source portions. A multi-beam light source device is provided, which is arranged so as to be movable in the arrangement direction, and is capable of changing the beam interval of a plurality of combined beams . By dividing the light beam combining means, the unit cost of the optical elements constituting the light beam combining means can be suppressed even when the interval between the light source portions is widened.
Moreover, it is preferable that the optical element is assembled | attached on the basis of said right angle part .

  In the first aspect of the present invention, the optical elements preferably have the same shape. By making the optical elements have the same shape, the parts can be shared, and the manufacturing cost can be reduced.

In any configuration of the first aspect of the present invention, the optical element is preferably a triangular prism. Moreover, it is preferable that at least one of the optical elements can be tilted with respect to the arrangement direction of the light source units . Also, each light source unit is preferably are integrally held by a common support member. By holding each light source unit integrally with a common support member, it is possible to make the respective temperature change amounts accompanying the surrounding temperature change the same. Each light source is preferably driven by electric power supplied from a common circuit board. By integrating each light source unit with a common circuit board for driving light, it becomes possible to make the respective temperature change amounts accompanying the surrounding temperature change the same.

In order to achieve the above object, the present invention, as a second aspect, optically scans an object to be scanned using the multi-beam light source device according to any one of the first aspect of the present invention. A multi-beam optical scanning device characterized by the above is provided.
In the second aspect of the present invention, it is preferable that the emission optical axes of the light beams emitted from the respective light source units are configured to intersect when projected in the main scanning direction. By configuring each light beam to intersect in the main scanning direction, the separation of each light beam on the deflecting / reflecting surface is reduced, and the deflecting / reflecting surface can be reduced to reduce the size of the deflector.

  In order to achieve the above object, according to a third aspect of the present invention, there is provided an image forming method characterized in that the image carrier is optically scanned by the multi-beam optical scanning device according to the second aspect of the present invention. A device is provided.

  In order to achieve the above object, as a fourth aspect of the present invention, the data input from the information processing apparatus is converted into an image signal, and the image signal is converted into the multi-beam according to the third aspect of the present invention. It is an object of the present invention to provide an image forming apparatus characterized in that an image carrier is optically scanned by inputting to an optical scanning device.

  According to the present invention, it is possible to provide a multi-beam light source device capable of adjusting a scanning interval with a simple configuration, a multi-beam light scanning device including the same, and an image forming apparatus.

[First Embodiment]
A first embodiment in which the present invention is suitably implemented will be described. FIG. 1 shows a configuration of a multi-beam light source device according to the present embodiment. In this multi-beam light source device, the semiconductor lasers (LD) 101-1 and 102-1 are held and fixed by holders (not shown). The holder is formed by aluminum die casting, and is fixed to the support member 103 through a screw from the back side. For the holder, a configuration in which the semiconductor lasers 101-1 and 102-1 are sandwiched and held between the plate-like member through screws from the back side, a configuration in which the semiconductor laser is press-fitted into the fitting hole, and the like can be applied.

The coupling lenses 104 and 105 couple the divergent light beams emitted from the semiconductor lasers 101-1 and 102-1, respectively, so that they are in any state among the parallel light beam, the convergent light beam, and the divergent light beam. Are fixed to the V-shaped support portions 103-1 and 103-2 formed in pairs with the semiconductor lasers 101-1 and 102-1. The coupling lenses 104 and 105 and the support portions 103-1 and 103-2 are fixed by applying a UV curable adhesive to these gaps (gap between the lens and the periphery of the support portion contact surface).
A set consisting of the semiconductor lasers 101-1 and 102-1 and the coupling lenses 104 and 105 is integrally supported via a support member 103 to form a first light source unit (first subunit).

Similarly, in the second light source unit, the semiconductor lasers 106-1 and 107-1 and the coupling lenses 119 and 109 held and fixed to the holder are fixed to the support member 108, and these are integrated with each other via the support member 108. It is configured to support.
Here, the holder and the support member may be integrally configured as one component.

The first and second light source units are arranged symmetrically with respect to the X axis. When the cylindrical portions 103-6 and 108-6 formed on the supporting members 103 and 108 are engaged with the fitting holes 110-1 and 110-2 from the back side of the base member 110, the positioning portions 103- 3, 103-4 and 103-5, and 108-3, 108-4 and 108-5 are in contact with each other as a reference. With these in contact, the positioning members 103-3, 108-3, and 108-4 are each fixed through screws from the front side of the base member 110. Here, the support members 103 and 108 are configured to be rotatable around the centers of the cylindrical portions 103-6 and 108-6 and to be fixed at arbitrary positions.
As a result, the arrangement of the light beams emitted from the support member can be tilted (the line connecting the light emitting points of the LDs can be tilted about the rotation axis).

  The base member 110 includes a plate (aperture) 111 provided with an aperture stop corresponding to each of the semiconductor lasers 101-1, 102-1, 106-1 and 107-1, and the semiconductor lasers 106-1 and 107-1. Beam combining prisms 112-1 and 112-2 constituting beam combining means for emitting the emitted beam close to the optical axis of the semiconductor laser 101-1 or 102-1 are supported.

  The base member 110 having the above configuration is held by the holder member 113. The holder member 113 is attached to an optical housing (not shown) that houses the scanning optical means so that the optical axis of the scanning optical means is aligned with the center of the cylindrical portion 113-1, thereby allowing a plurality of beams to enter the scanning optical means. The holder member 113 may be directly assembled to the optical housing, or may be assembled via an assembly member (such as a bracket).

  The holder member 113 is held rotatably about the cylindrical member by moving the lever 113-3 up and down with the adjusting screw 115. Thereby, the arrangement | sequence of the light beam inject | emitted from the supporting members 103 and 108 can be inclined.

  A substrate 114 on which a drive circuit for each of the semiconductor lasers 101-1, 102-1, 106-1 and 107-1 is formed is fixed to a support column 113-2. Circuit connections are made by soldering the leads of the respective semiconductor lasers 101-1, 102-1, 106-1, and 107-1 to the drive circuit on which the substrate 114 is formed.

  FIG. 2 shows the overall configuration of the multi-beam optical scanning optical apparatus according to the present embodiment. This device uses the multi-beam light source device shown in FIG. 1 as a light source. Note that components for holding each optical element are omitted in the drawing.

  A combination of a coupling lens 2a (first imaging optical system) that collects a divergent light beam from a light source 1a made of a semiconductor laser and a coupling lens 2b that collects a divergent light beam from the light source 1b. The set is integrally supported to form the light source unit 12 (subunit).

  Note that, on the back side of the light source unit 12A, similarly to the light source unit 12A, two sets of a light source and a coupling lens are integrally supported, and a light source (not shown) is slightly overlapped in the sub-scanning direction of the light source unit 12A. The part 12B is arranged.

  Beam combining prisms 4a and 4b (4b not shown) constituting the light beam combining means emit the light beams emitted from the light source unit 12A and the light source unit 12B close to each other in the sub-scanning direction.

  The width of the light beam emitted from the light source 1a is regulated by the aperture stop 3a. Thereafter, the light is incident on a cylindrical lens 5 (second imaging optical system), which is a line imaging optical system, via a beam prism (light beam synthesis means) 4a, and deflected and reflected by a deflector 6 (polygon scanner) by the cylindrical lens 5. The light is condensed as a long line in the main scanning direction in the vicinity of the surface 6A.

  The deflector 6 rotates at a constant angular velocity about the rotation shaft 6B, and deflects the incident light beam at a constant angular velocity. A third imaging optical system 7 is disposed between the deflector 6 and the scanned medium 9, and the light beam 8 a deflected by the deflection reflection surface 6 a forms a light spot 10 a on the scanned medium 9. To do. The light spot 10a optically scans the scanned medium 9 in the direction of the arrow in the figure by the rotation of the deflector 6 (the direction indicated by the arrow in the figure).

  Similarly, the luminous flux emitted from the light source 1b is regulated by the aperture stop 3b, and then the cylindrical lens 5 (second imaging optical system) which is a line image imaging optical system via the beam synthesis prism 4a. Is incident on. The light beam incident on the cylindrical lens 5 is condensed in the vicinity of the deflecting reflection surface 6a of the deflector 6 (polygon scanner) as a long line in the main scanning direction. At this time, the aperture stops 3a and 3b may be separate.

  The light beam 8b deflected by the deflecting / reflecting surface 6A forms a light spot 10b on the scanned medium 9. The light spot 10b optically scans the scanned medium 9 in the direction of the arrow in the figure by the rotation of the deflector 6.

  The light beam emitted from the light source 1a and the light beam emitted from the light source 1b are configured to intersect in the vicinity of the deflecting reflection surface 6A. The light beam emitted from the light source 1b is deflected with respect to the light beam emitted from the light source 1a in a state where the scanning angle of the deflector 6 is shifted by an angle (φ / 2) that is half of the angle φ forming the light beams emitted from the light sources 1a and 1b. It is configured to scan. With this configuration, the light beams emitted from the light sources 1a and 1b and then reflected by the deflecting / reflecting surface 6A have the same optical path in the third imaging optical system 7 that is a scanning optical system. As a result, the tilt of the imaging image plane of the scanning light beam on the scanned surface 9 can be reduced, and deterioration of imaging performance (field curvature, magnification error, etc.) can be prevented.

  In other words, the light beams emitted from the light sources of the light source unit 12A are arranged so as to intersect in the vicinity of the deflecting reflection surface 6A of the deflector 6 when projected onto the main scanning plane.

  Similarly, the light beams emitted from the respective light sources of the light source unit 12B are arranged and configured so as to intersect in the vicinity of the deflecting / reflecting surface 6A of the deflector 6.

  The light source unit 12A is configured to be rotatable about a spatial center line 14a (or an axis substantially parallel to 14a) passing through the vicinity of the intersection of the optical axes (exit axes) of light beams emitted from the light sources 1a and 1b. To do.

  Similarly, the light source unit 12B is also configured to be rotatable about a spatial center line 14B (or an axis substantially parallel to 14B) passing through the vicinity of the intersection of the optical axes (exit axes) of the emitted light beam. The center line 14 is not shown in FIG. 2 because it is a position hidden behind the paper surface in FIG.

  The synchronization detection optical system 11 passes the light beam deflected by the deflector 6 through the mirror 11-3 and the synchronization detection imaging element 11-2, and then includes a synchronization detection sensor 11-1 configured by a photodiode or the like. Lead to. Then, a synchronization signal is generated when the light beam passes over the synchronization detection sensor 11-1, and is processed by a synchronization circuit (not shown) to transmit a write start signal after a certain timing. Here, the “certain timing” is a time until the light beam reaches the writing start position from the detection position of the synchronization detection sensor 11-1. The synchronization detection imaging element 11-2 may be a lens having power (refractive power) only in the sub-scanning direction, a lens having power only in the main scanning direction, or a lens having power in both main and sub-directions. Further, as the synchronization detection imaging element 11-2, a curved mirror having power may be used instead of the lens. In addition, the synchronization detection optical system 11 is configured such that the mirror 11-3 is directly guided to the synchronization detection sensor 11-1 without using the synchronization detection imaging element 11-2. May be.

FIG. 3A shows a detailed configuration of the light source device 13. Here, the vertical direction of the paper is the sub-scanning direction.
A light source and a coupling lens that are hidden behind the light source 1A and the coupling lens 2A and supported on the same supporting member are arranged, and these constitute a light source unit 12A. Similarly, a light source and a coupling lens that are hidden behind the light source 1B and the coupling lens 2B and supported by the same support member are disposed, and these constitute the light source unit 12B.

  The divergent light beams emitted from the light sources 1A and 1B are separately coupled and collected by the corresponding coupling lenses 2A and 2B, and the light beam width is regulated by the corresponding aperture stops 3A and 3B, respectively. The beams are synthesized by the constituting beam synthesis prisms 4A and 4B.

By configuring the light beam combining means with two beam combining prisms, the distance between the light source unit 12A and the light source unit 12B can be freely set.
When the light beam combining means is integrally configured, if the holder or support member that holds the components (light source, coupling lens) constituting the light source section becomes large due to design reasons, the light beam combining means will be located between the light source sections. , And the cost increases.

  Therefore, the present invention aims to improve the degree of freedom in the layout by dividing the light beam combining means by the number of the light source sections. By arranging one light beam combining means (beam combining prism) for each light source unit, the light beams are combined.

  Further, by using the same beam combining prism as the beam combining means, it is possible to share parts and reduce costs. Further, as shown in FIG. 3, by combining triangular prisms, the right angle portion of the triangular prism can be used as a reference, and the optical axes of the light beams emitted from the respective light source units can be easily aligned. As for the shape, if it is a triangular prism shaped prism that is long in the main scanning direction, both ends of the prism can be supported and fixed by the support.

The beam combining prism 4A has a polarization separation film 4-1, and the light beam from the light source 1A is transmitted through the polarization separation film 4-1. The light beam from the light source 1B is rotated 90 degrees from the initial state by the half-wave plate 4-2, reflected by the prism surface 4-3 of the beam combining prism 4B, and then polarized by the beam combining prism 4A. The light is also reflected by the film 4-1, and is emitted in a state close to the light beam from the light source 1A in the sub-scanning direction.
In this manner, by combining the polarization separation film and the half-wave plate, loss in light quantity can be reduced, and light emitted from the light sources 1A and 1B can be used with an efficiency close to 100%.

  Since the polarization direction of the light beam emitted from the light source 1A and the light beam emitted from the light source 1B is shifted by 90 degrees, the transmission and reflection characteristics of each optical element are different, and a difference occurs in the light amount at each scanning position on the surface to be scanned. (Shading characteristics are different), thereby causing unevenness in the amount of light. This unevenness in the amount of light is conspicuous as unevenness in the density of the output image, particularly in a color image output machine, and the image quality deteriorates.

  As a method of reducing this unevenness in the amount of light, for example, as in another arrangement example shown in FIG. 3B, the beam combining prism 4A is rotated 180 degrees from the case of FIG. 3A (from the light source 1A). A state where the light beam is incident on the surface on which the polarization separation film 4-1 is formed), and a quarter wave plate 4-4 is disposed immediately thereafter, and the polarization direction of the transmitted light beam is rotated by 45 degrees. is there.

  The optical axes (indicated by chain lines in the figure) of the coupling lenses 2A and 2B are parallel to each other, and the beam combining prism 4A and the subsequent beams are combined into a single combined optical axis AX as illustrated.

  As shown in the figure, the light beam emitted from the beam synthesis prism 4A exits from the beam synthesis prism 4A close in the sub-scanning direction.

The emission directions of the light beams of the light emitting units 1a-1 and 1b-1 of the light sources 1a and 1b are substantially parallel in the sub-scanning direction, and are in the sub-scanning direction with respect to the optical axes of the corresponding coupling lenses 2A and 2B, respectively. The light beams B1 and B2 combined by the beam combining prisms 4A and 4B constituting the light beam combining means are angled with respect to each other in the sub-scanning direction.
In addition, since each light source unit is held close to a common holder, each light source unit is equally affected by environmental fluctuations (thermal fluctuations, etc.), and the influence on optical characteristics (scanning pitch and imaging position fluctuations) can be reduced. .

  Similarly, by making the light source drive circuit board that supplies power to drive the light sources 1A and 1B common to the light sources 1A and 1B, each light source unit has an environmental variation (such as a thermal variation) as in the case where the holder is shared. ) Can be made uniform, and the influence on the optical characteristics (scanning pitch and imaging position fluctuation) can be reduced. Each light source generates heat when it is driven, and the difference in the amount of heat generated causes a difference in the change in oscillation wavelength and peripheral temperature. By using a common drive substrate in contact with the light source, each light source It is possible to eliminate the difference in thermal fluctuations at and maintain the same state.

  The relative positional relationship between the light emitting points of the semiconductor laser, which is the light source, is the image forming system between the light source and the surface to be scanned (in the configuration shown in FIG. 2, the coupling lens 2, the cylindrical lens 5, and the third connection). According to the sub-scanning direction composite magnification β of the image optical system 7), the scanning interval (scanning pitch) of each scanning line on the scanned medium is determined to be a desired value.

  FIG. 4 shows an arrangement of light spots by light beams emitted from the respective light sources on the surface to be scanned. Each light spot is arranged at a scanning interval Pi in the sub-scanning direction. The scanning interval Pi is a value determined by the writing density, and is 42.3 μm for 600 dpi and 21.2 μm for 1200 dpi.

  The light spots 24A-1 and 24A-2 are light spots generated by light beams emitted from the light source unit on the side that transmits the beam combining prism 4a. In addition, the light spots 24B-1 and 24B-2 are light spots by the light beams emitted from the light source unit on the side reflected and polarized by the beam combining prism 4B. At this time, the center points 24A-3 and 24B-3 indicate the center points of the light spots by the light beams emitted from the light source units 12A and 12B, respectively.

  As shown in FIG. 3C, by adjusting (tilting) the posture of the beam combining prism 4B, the emission direction (emission angle) of the light beam B2 emitted from the light source 1B can be adjusted. When the beam combining prism 4B is tilted with the direction orthogonal to the paper surface (deflection scanning section: direction parallel to the main scanning direction) as the rotation axis (θ in the figure), the light beam reflected by the beam combining prism 4B is before the tilt angle adjustment. The 2θ exit direction changes with respect to the exit direction of the light beam to become a light beam B2 ′. This change in the emission direction also occurs in the same manner with respect to the light beam emitted from the light source arranged behind the light source 1B constituting the light source unit 1B. As described above, when the emission angle changes, the light spots (light spots 24B-1 and 24B-2 on the scanned surface) by the light beam emitted from the light source unit 12B on the scanned surface have the same amount in the sub-scanning direction. Moved. That is, the interval Pi3 between the light beams from each light source unit changes, which means that the scanning interval can be adjusted.

Similarly, as shown in FIG. 3D, the scanning interval can be adjusted also when the beam combining prism 4B is moved in the direction of the arrow (sub scanning direction) in the figure. When the beam combining prism 4B is changed by Δ in the sub-scanning direction, the light beam emitted from the beam combining prism 4B changes by Δ in the sub-scanning direction with respect to the light beam before moving when the beam combining prism 4A is output. To become a light beam B2 ''. Therefore, the irradiation position on the deflecting / reflecting surface also changes by Δ, and on the surface to be scanned, the composite magnification in the sub-scanning direction of the third optical system 7: the amount multiplied by β ₃ , Δ × β ₃ change Will be. That is, the light spots (light spots 24B-1 and 24B-2 on the scanned surface) due to the light beam emitted from the light source unit 12B on the scanned surface move by Δ × β _{3 in the} sub-scanning direction. Therefore, the scanning interval Pi3 can be adjusted as in the case of adjusting (tilting) the attitude of the beam combining prism 4B.

  Although the beam combining prism 4b is used as an adjuster, the same effect can be obtained when the beam combining prism 4a is used as an adjuster. If the adjustment range of each beam combining prism is not sufficient, both of the two beam combining prisms may be used as adjusters.

When the light source unit 12A is rotated about the spatial center line 14A (or a straight line substantially parallel to 14A) passing through the vicinity of the intersection of the optical axes (exit axes) of the emitted light beam of the light source unit 12A shown in FIG. By rotating around the rotation axis 14A, the light emitting point interval between the light sources 1A and 1B in the sub-scanning direction can be changed. As described above, the distance between the light emitting points of the light source and the relative positional relationship on the scanned medium are determined by the composite magnification β in the sub-scanning direction of the imaging system between them, and the light on the scanned medium. The spots 24A-1 and 24A-2 rotate about the center point 24A-3 as a rotation center by an amount obtained by multiplying the change amount of the light emitting point interval by β, and the scanning interval Pi1 changes. Thereby, the scanning interval Pi1 of the light spots (24A-1, 24A-2) by the light beam emitted from the light source unit 12A on the scanned medium can be adjusted.
Further, by using the spatial center line as the rotation axis, the relative position of the light emitting point of each light source can be adjusted with substantially the same amount of change, and the positional relationship can be easily adjusted.

  Further, for the light source unit 12B hidden in the light source unit 12A in FIG. 2, the interval Pi2 between the light spots 24B-1 and 24B-2 on the scanned medium can be adjusted.

  In other words, the interval inside the light source unit (the interval between the light spot of the light beam emitted from one light source unit and the light spot of the light beam emitted from another light source unit) makes it possible to adjust the rotation of the beam combining prism 4B. By making it possible to adjust the movement in the scanning direction, it is possible to adjust all the scanning line intervals on the surface to be scanned.

  Here, a configuration in which the light source units are arranged in the sub-scanning direction is taken as an example. However, when the light source units are arranged in the main scanning direction, the beam combining prism 4b is rotated about an axis orthogonal to the main scanning direction. The same effect can be obtained by adjusting or moving and adjusting in the main scanning direction.

Rotating and adjusting a spatial center line (or a substantially parallel straight line) of light beams emitted from the light source unit as a rotation axis, and adjusting the interval between the light beams emitted from the light source units by the beam combining prism 4b; The following can be listed as effects.
Due to variations in processing accuracy of optical elements, assembly errors, and the like, the scanning interval Pi on the scanned medium is not the intended interval, but is shifted. However, by making the light source unit rotatable about the spatial center line as a rotation axis and adjusting the interval between the light beams emitted from each light source unit by the beam adjusting prism, processing errors and writing of the light source device components When the scanning interval of the light beam on the scanned medium deviates from a desired interval due to processing errors of the components constituting the optical system. It can be adjusted to the correct scanning interval.

In the above explanation, a configuration in which two sets of a semiconductor laser as a light source and a coupling lens (first imaging optical system) are mounted on one light source unit (subunit) is taken as an example. You may combine. Conversely, one light source unit may be configured as a set.
Similarly, although an example in which two light source units (subunits) are combined as a multi-beam light source device has been described, a multi-beam light source device may be configured by combining more light source units.

  By forming a light source unit using a plurality of light sources (LD) and further combining a plurality of light source units, the number of light beams scanned on the scanned medium 9 can be increased. As a result, the output speed of the image forming apparatus equipped with the writing optical system can be improved. On the other hand, when the output speed is not changed, the rotation speed of the deflector can be reduced, and a writing optical system considering the environment such as power consumption and heat generation can be configured.

Further, the light source is not limited to the semiconductor laser, and other known light sources can be applied.
For example, a “semiconductor laser array in which a plurality of light emitting points are monolithically arrayed” may be used, and a plurality of divergent light beams emitted from the light emitting points may be coupled by a common coupling lens.

[Second Embodiment]
A second embodiment in which the present invention is suitably implemented will be described. FIG. 5 shows a configuration of an image forming apparatus equipped with the scanning optical system according to the present embodiment. This image forming apparatus is equipped with the scanning optical system described in the first embodiment.
The document 31 is placed on a contact lens 32 and illuminated by a lamp 33. The image of the irradiated original is guided to the scanner lens block 34 by a mirror. The image light guided to the scanner lens block 34 is converted into image data 35 by the CCD. The image data 35 is transferred to the multi-beam optical scanning device 36. In the multi-beam optical scanning device, the LD is repeatedly turned on and off based on the image signal, and the light spot scans on the photosensitive drum 20. The photosensitive drum 20 charged by the charger 40 is optically scanned to form an electrostatic latent image. The developing unit 37 develops the toner image, and the paper stored in the paper feed tray 38 is guided to the photosensitive drum 20 by the paper feeding roller 39, and the toner image on the photosensitive drum 20 is transferred to the paper by the transfer roller 40. Is done.
The toner image transferred to the paper is fixed on the paper by the fixing device 41. The paper on which the toner image is fixed is discharged to the paper discharge tray 42 by the paper discharge roller 414. After the toner image is transferred, the photoconductor 20 is subjected to charge removal and cleaning by a charge removal / cleaner 43, and the process from charging is repeated.
By incorporating the light source device or optical scanning device described in the first embodiment into the image forming apparatus, an image forming apparatus capable of multi-beam writing can be obtained.

Further, by connecting the image forming apparatus according to the present embodiment to an electronic arithmetic device (such as a computer) or an image information communication system (such as a facsimile) via a network, data is transmitted by a control controller included in the image forming apparatus. It can be converted into an image signal and input to a multi-beam optical scanning device.
Further, by connecting via a network, it is possible to form an image processing system that processes output from a plurality of devices with a single image forming apparatus.
If multiple image forming devices are connected to the network, the status of each image forming device (job congestion, power ON / OFF, presence / absence of failure, etc.) can be known from each output request. The image can be output by selecting an image output apparatus having the best quality (best suited to the user's wishes).

  Each of the above embodiments is an example of a preferred embodiment of the present invention, and the present invention is not limited to these, and various modifications are possible.

It is a figure which shows the structure of the multi-beam light source device concerning 1st Embodiment which implemented this invention suitably. It is a figure which shows the structure of the optical scanning device using the multi-beam light source device concerning 1st Embodiment which implemented this invention suitably. It is a figure which shows the adjustment method of the scanning interval of the subscanning direction of the optical scanning device concerning the 1st Embodiment of this invention. It is a figure which shows the positional relationship of the light spot and rotation center of the optical scanning device concerning 1st Embodiment. It is a figure which shows the structure of the image forming apparatus concerning 2nd Embodiment which implemented this invention suitably.

Explanation of symbols

1A, 1B Light source 2A, 2B Collimating lens 3A, 3B Aperture stop 4A, 4B Synthetic prism 5 Cylindrical lens 6 Rotating polygon mirror 7 Imaging optical system 8a, 8b Light beam 9 Photosensitive body scanning surface 10a, 10b Light spot 11 Detection optical system 11 -1
11-2
11-3 Mirror 12A, 12B Light source unit 13 Light source device 14A Center line 101-1, 102-1, 106-1, 107-1 Semiconductor laser 103, 108 Support member 103-1, 103-2, 108-1, 108 -2 Supporting part 103-3, 103-4, 103-5, 108-3, 108-4, 108-5 Positioning part 103-6, 108-6, 113-1 Cylindrical part 104, 105, 109, 119 Cup Ring lens 110 Base member 110-1, 110-2 Fitting hole 111 Aperture 112-1, 112-2 Beam combining prism 113 Holder member 113-2 Post 113-3 Lever 114 Substrate 115 Adjustment screw

Claims (11)

A plurality of light source units each including a light source and a first imaging optical system that collects and couples a divergent light beam emitted from the light source, and a light beam combining unit that emits light beams emitted from the light source units in close proximity to each other. A multi-beam light source device in which the light source units are arranged in a predetermined direction,
The light beam combining means is composed of the same number of optical elements as the light source unit,
The optical element has a right angle portion;
At least one of the optical elements has a plurality of side surfaces that are parallel to each other in one of the two side surfaces constituting the right-angled portion and the arrangement direction of the light source units, and are arranged to be movable in the arrangement direction of the light source units. A multi-beam light source device characterized in that a beam interval of beams can be changed . The optical element multi-beam light source apparatus according to claim 1, characterized in that is assembled on the basis of the said right-angled portions. Wherein each optical element is a multi-beam light source apparatus according to claim 1 or 2, wherein the identical shape. The optical element, the multi-beam light source apparatus according to any one of claims 1, wherein 3 to be a triangular prism. At least one multi-beam light source apparatus according to any one of claims 1, wherein 4 to be tiltable with respect to the arrangement direction of the light source unit of the optical element. Wherein each light source unit, a multi-beam light source apparatus according to any one of claims 1-5, characterized in that it is integrally held by a common support member. Wherein each light source is multi-beam light source apparatus according to any one of claims 1, characterized in that each driven by electric power supplied from a common circuit board 6. A multi-beam optical scanning device that optically scans an object to be scanned using the multi-beam light source device according to any one of claims 1 to 7 . 9. The multi-beam optical scanning device according to claim 8, wherein the emission optical axes of the light beams emitted from each of the light source units are configured to intersect when projected in the main scanning direction. An image forming apparatus, wherein the image carrier is optically scanned by the multi-beam optical scanning device according to claim 8 . 10. An image forming apparatus comprising: converting data input from an information processing apparatus into an image signal; and inputting the image signal to a multi-beam optical scanning apparatus according to claim 8 or 9 to optically scan an image carrier. .

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