JP5387150B2 - Multi-beam light source device, optical scanning device, and image forming apparatus - Google Patents

Description

  The present invention relates to a digital writing optical system, and more particularly to a multi-beam light source device, an optical scanning device, and an image forming apparatus in a digital output device such as a digital copying machine, a printer, and a facsimile.

  In recent years, image forming apparatuses such as laser printers and digital copiers simultaneously scan the surface to be scanned of a photosensitive member with a plurality of laser beams in response to the demand for higher recording speed and higher recording density. A multi-beam scanning device is employed. Conventionally, various types of multi-beam light source devices used in such a multi-beam scanning device have been used.

  For example, as described in Patent Document 1 or 2, there is a CAN (can) package type semiconductor laser light source. This is a semiconductor laser light source in which a light-emitting chip is mounted on a side surface of a mount portion erected at the center of a cylindrical package body (heat sink) and connected to the tip of a lead protruding on the surface side by bonding.

  In a CAN package type semiconductor laser light source, the attitude of the semiconductor laser is maintained with reference to the outer periphery of a cylindrical heat sink. Therefore, the arrangement of the light sources and the direction of the emission axis can be defined, and even if a plurality of light sources are arranged eccentric from the optical axis of the coupling lens, the imaging state of the light beam from each light source on the scanned surface There is an advantage that can be made uniform.

  Further, as described in Patent Document 3, there is a semiconductor laser light source in which a light emitting chip is mounted on a lead frame. In such a semiconductor laser light source, since the lead terminals extending on the lead frame are arranged on a plane, there is an advantage that even if the number of beams is increased, it is only necessary to expand flatly.

  Further, as described in Patent Documents 4 and 5, there is a semiconductor laser light source in which a semiconductor laser is mounted such that an emission axis is perpendicular to a mounting surface of a drive circuit board.

  In the semiconductor laser light source, as the number of beams increases, the number of lead terminals increases. However, in a CAN package type semiconductor laser light source, for example, when the number of beams is four or more, it is difficult to accommodate the increased lead terminals in the CAN package. . Further, since the wiring length of wire bonding becomes long, there is a risk that short-circuiting or breaking between wires is likely to occur.

  In a semiconductor laser light source in which a light emitting chip is mounted on a lead frame, it is difficult to maintain the placement accuracy of the coupling lens and the plurality of light sources while increasing the number of beams. Also, the sub-scanning pitch must be adjustable so that a plurality of beam spots from each light source have a predetermined sub-scanning pitch corresponding to the recording density on the surface to be scanned. It is difficult to achieve this while increasing the number of beams.

  In a semiconductor laser light source in which the semiconductor laser is mounted so that the emission axis is perpendicular to the mounting surface of the drive circuit board, the substrate becomes larger due to the multi-beam and the space in the thickness direction of the optical scanning device is increased. It becomes necessary and obstructs the thinning of the optical scanning device.

  As described above, in various conventional semiconductor laser light sources, it has been difficult to realize adjustment of the beam spot sub-scanning pitch and reduction in size and weight of the semiconductor laser light source while realizing multi-beam. In a multi-beam light source device, an optical scanning device, and an image forming apparatus that use a conventional semiconductor laser light source, the recording speed can be increased and the recording density can be increased while the size of the apparatus can be reduced. Was difficult.

  The present invention has been made in view of the above-described problems. By using a semiconductor laser unit in which a light emitting chip is mounted on a lead frame, the recording speed is increased and the recording density is increased without increasing the size of the apparatus. An object of the present invention is to provide a light source device corresponding to the densification.

  (1) The present invention provides a lead frame having a plurality of lead terminals, a plurality of semiconductor laser light sources mounted on the lead frame, and the semiconductor provided integrally with the lead frame around the semiconductor laser light sources. A frame package type semiconductor laser array having a resin frame for protecting a laser light source, a drive circuit board on which the semiconductor laser array is mounted and driving the semiconductor laser light source, and light from the semiconductor laser array are coupled In the multi-beam light source device including a coupling lens, the lead frame has a heat radiating portion that extends outside a contact portion with the resin frame, and the heat radiating portion is in close contact with the drive circuit board. The drive circuit board is fixed substantially parallel to the emission axis of the semiconductor laser light source. Has a lens position adjustment fixing portion having at least one mounting surface, the coupling lens on the mounting surface of the lens position adjustment fixing portion is the most important feature that it is in contact with the fixed.

  Although not particularly limited in the present invention, it is preferable that the lens position adjustment fixing portion has two attachment surfaces, and the coupling lens is fixed in a state of being sandwiched between the two attachment surfaces.

  Further, although not particularly limited in the present invention, the lens position adjustment fixing portion is a notch portion provided at an end portion of the drive circuit board, and the two attachment surfaces are the notch portions, The two side surfaces are preferably substantially parallel to the emission axis of the semiconductor laser light source.

  Further, although not particularly limited in the present invention, the lens position adjustment fixing portion is a groove portion provided in the drive circuit board, and two mounting surfaces of the groove portions emit the semiconductor laser light source. Two side surfaces that are substantially parallel to the axis are preferred.

  Although not particularly limited in the present invention, it is preferable that an angle formed between the mounting surface of the semiconductor laser array of the drive circuit board and the mounting surface is an obtuse angle.

  Further, although not particularly limited in the present invention, the lens position adjustment fixing portion has an attachment arm portion protruding from an end portion of the drive circuit board, and the attachment arm portion is in a plane with respect to the plane of the drive circuit board. It is preferable that a rising portion that rises vertically is provided, and the coupling lens is fixed to a side surface of the rising portion that is substantially parallel to the emission axis of the semiconductor laser light source.

  Although not particularly limited in the present invention, the drive circuit board is positioned when the semiconductor laser array is placed on the drive circuit board, and a positioning reference when the multi-beam light source device body is attached. It is preferable that positioning means is provided.

  Although not particularly limited in the present invention, it is preferable that the drive circuit board is made of metal.

  Although not particularly limited in the present invention, the drive circuit board is provided with a step portion having a height different from the mounting surface of the semiconductor laser array, and the lens position adjustment fixing portion is provided on the step portion. It is preferable to be provided.

  Further, although not particularly limited in the present invention, it is preferable that an aperture portion is provided on the drive circuit board.

  Further, although not particularly limited in the present invention, it is preferable that the drive circuit board is provided with an elastically deformable bent portion protruding from a surface opposite to the mounting surface of the semiconductor laser array.

  Although not particularly limited in the present invention, a bearing portion for rotatably supporting the multi-beam light source device is provided on the drive circuit board with the light beam emission axis from the semiconductor laser light source as a rotation axis. It is preferable that

  (2) The present invention also provides a multi-beam light source device, deflecting means for deflecting and scanning a light beam from the multi-beam light source device, and a scanning optical system for imaging the deflected and scanned light beam on a surface to be scanned. The main feature is that the multi-beam light source device is the multi-beam light source device described above.

  (3) The present invention is also an image forming apparatus that forms a latent image by performing optical scanning on a photosensitive surface of a photosensitive medium by an optical scanning device, and obtains an image by visualizing the latent image. Is mainly characterized by the optical scanning device described above.

  According to the present invention, by adopting a frame package type semiconductor laser array in which a semiconductor laser array and a coupling lens are provided on the same drive circuit board, it is possible to reduce the size of the apparatus while reducing the recording speed. It is possible to provide a multi-beam light source device, an optical scanning device, and an image forming apparatus that can realize high speed and high recording density.

It is a perspective view which shows the multi-beam light source device which concerns on Example 1 of this invention. It is an exploded view of the multi-beam light source device of FIG. It is a perspective view which shows the frame package type semiconductor laser array used for the multi-beam light source device of FIG. It is the schematic which shows a mode that the multi-beam light source device of FIG. It is a perspective view which shows the multi-beam light source device which concerns on the modification of Example 1 of this invention. It is a perspective view which shows the multi-beam light source device which concerns on Example 2 of this invention. FIG. 7 is an exploded view of the multi-beam light source device of FIG. 6. It is a perspective view which shows the multi-beam light source device which concerns on Example 3 of this invention. FIG. 9 is an exploded view of the multi-beam light source device of FIG. 8. It is a perspective view which shows the multi-beam light source device which concerns on the modification of Example 3 of this invention. It is a perspective view which shows the multi-beam light source device which concerns on Example 4 of this invention. It is a perspective view which shows the multi-beam light source device which concerns on Example 5 of this invention. It is a schematic perspective view which shows the optical scanning device based on the Example of this invention. It is a principal part front view which shows the optical scanning device based on the Example of this invention. 1 is a schematic front view illustrating an image forming apparatus according to an embodiment of the present invention.

[Multi-beam light source device]
Embodiments of the multi-beam light source device according to the present invention will be described below with reference to the drawings.

<Example 1>
As shown in FIGS. 1 and 2, the multi-beam light source device according to the first embodiment of the present invention is configured by fixing a semiconductor laser array 100 and a coupling lens 300 to a drive circuit board 200.

  As shown in FIG. 3, the semiconductor laser array 100 has a so-called frame package configuration in which a plurality of light emitting chips 101 are mounted on a lead frame 102 with joint surfaces parallel to an active layer and covered with a resin frame 103.

  The light emitting chip 101 is a semiconductor laser light source and is disposed in a plane parallel to the lead frame 102, and a light beam from each light emitting chip 101 is emitted in parallel to the lead frame 102. Even in a multi-beam semiconductor laser of 2ch or more, the number of lead terminals 104 is increased by the amount of the light emitting chip 101, and the other configurations are the same.

  The lead frame 102 has a symmetrical shape with respect to the emission axis 105 passing through the array center of the plurality of light emitting chips 101, and has end sides 102a and 102b parallel to the emission axis 105, and an abutting end 102c in the optical axis direction. . Further, in the lead frame 102, the peripheral portions of the end sides 102 a and 102 b and the peripheral portion of the abutting end 102 c protrude to the outside of the contact surface with the resin frame 103 and serve as a heat radiating plate. A lead terminal 104 extends from the lead frame 102 and is connected to a plurality of light emitting chips 101 and photodiodes (not shown) as light emitting sources by wire bonding, and can be driven independently.

  The resin frame 103 is a substantially U-shaped member made of resin, and covers and protects the periphery of the light-emitting chip 101 so that the light beam from the light-emitting chip 101 can be emitted to the outside from the open part. However, it is provided integrally with the lead frame 102.

  The semiconductor laser array 100 having such a configuration is mounted on a drive circuit board 200 which is a metal-based printed board, soldered at the end sides 102a and 102b of the lead frame 102, and the lead terminals 104, and driven by the drive circuit board 200. It is fixed to.

  On the driving circuit board 200, driving elements, connectors (not shown) and the like of the multi-beam semiconductor laser 100 are mounted, and a circuit pattern for driving the semiconductor laser array 100 is formed. Further, the drive circuit board 200 is formed with a long hole-shaped notch 201 having one end opened as a lens position adjustment fixing part for fixing the coupling lens 300 while adjusting the position in the optical axis direction. Yes.

  The notch 201 is substantially U-shaped, and is formed by two long sides 201a and 201b that are substantially parallel to the injection shaft 105, and a short side 201c that is between them and is substantially perpendicular to the injection shaft. Yes. The groove width W of the notch 201, which is the distance between the two long sides 201a and 201b, is the multi-beam semiconductor laser 100 when a coupling lens 300 described later is placed between the two long sides 201a and 201b. The exit axis 105 of the lens and the optical axis of the coupling lens 300 are designed to be arranged substantially coaxially.

  The coupling lens 300 is a cylindrical lens, and the adhesive 400 has a gap with the edge portion, that is, the outer peripheral surface, in a state where the outer peripheral portion 301 is in contact with the long sides 201a and 201b of the notch 201 described above. The adhesive is fixed by filling. The coupling and fixing of the coupling lens 300 is performed by arranging the coupling lens 300 in a plane orthogonal to the emission axis 105 and the arrangement in the optical axis direction so that the light beam emitted from the coupling lens 300 becomes a parallel light flux. Adjusted and done.

  Further, in order to improve the placement accuracy of each component when assembling the multi-beam light source device mainly including the above-described configuration, the drive circuit board 200 is provided with reference holes 202 and 203. The drive circuit board 200 is fixed on a component mounting apparatus (not shown) with reference to the reference holes 202 and 203. Then, the semiconductor laser array 100 is positioned and mounted with high accuracy on the mounting surface of the drive circuit board 200 using the end sides 102a and 102b, the abutting end 102c, and the like of the lead frame 102. As described above, the reference holes 202 and 203 function as positioning means for defining an inclination in a plane parallel to the mounting surface when the semiconductor laser array 100 is mounted on the drive circuit board 200. Thereby, when assembling the multi-beam light source device, the long sides 201 a and 201 b can be made straight lines that are substantially parallel and symmetrical to the emission axis 105 of the semiconductor laser array 100.

  The reference holes 202 and 203 can also be used as a reference when the multi-beam light source device 1 is assembled to an optical scanning device (described later). The multi-beam light source device is positioned on the housing of the optical scanning device (not shown) using the reference holes 202 and 203, and is fixed with screws (not shown) through the mounting holes 205 and 206, so that the multi-beam light source device is It can be accurately arranged at a predetermined mounting position of the scanning device.

  Here, the scanning pitch adjustment using the multi-beam light source device according to the present embodiment in an optical scanning device in which a polygon mirror, a scanning lens, a folding mirror and the like are accommodated in a housing (not shown) as shown in FIG. Will be described.

As shown in FIG. 4, the overall magnification of the imaging optical system in the sub-scanning direction is m, the sub-scanning direction pitch between adjacent beam spots by light beams from a plurality of light-emitting sources is p, and the adjacent spacing of the light-emitting sources is d and the inclination of the plurality of light emitting chips 101 of the multi-beam light source device 1 fastened to the optical scanning device 1 with respect to the main scanning direction (hereinafter referred to as “array angle”) as γ degrees, the following equation is obtained. It holds.
γ = sin ⁻¹ (p / m / d)

  When m is 1.5 to 2, p is 21.2 μm and d is 50 μm in accordance with a scanning pitch corresponding to 1200 dpi, γ is 12.2 ° to 16.4 °. In other words, in order to adjust the scanning pitch corresponding to 1200 dpi in such an optical scanning device, the multi-beam light source device may be disposed at the optical scanning device tilted by this angle with respect to the main scanning direction.

  By configuring the multi-beam light source device according to the present embodiment, beam shaping and adjustment can be easily performed only by adjusting the mounting angle of the multi-beam light source device in the optical scanning device.

  In addition, since the semiconductor laser array and the coupling lens are provided on the same drive circuit board, fluctuations in the relative fixed position of the semiconductor laser array and the coupling lens with respect to ambient temperature changes are suppressed, and the light beam is stabilized. Can increase the sex.

  In addition, by adopting a frame package type semiconductor laser array having a simple structure compared to a CAN package type semiconductor laser light source, it is possible to easily cope with an increase in the number of beams than the CAN package type without cost, High speed and high density can be achieved with a smaller environmental load.

  Further, by providing the reference hole, the direction of the laser beam emission axis can be reliably defined.

  In addition, since the arrangement angle of the light emitting chips can be easily adjusted in a plane perpendicular to the emission axis, the pitch adjustment on the scanned surface can be easily performed as in the case of using a conventional CAN package type semiconductor laser array. Can be done.

  In addition, the heat generated by the light emission of a plurality of light emitting chips can be released from the metal-based drive circuit board through the heat dissipation plate of the lead frame, so that the heat dissipation effect can be enhanced, and crosstalk and Lifetime deterioration can be reduced and light emission stability can be improved.

  In addition, a part of the light emitted from the frame package type multi-beam light source device is not blocked by the drive circuit board, and is fixed securely after adjusting the position of the coupling lens in the emission axis direction. And can be integrated.

  In the present embodiment, the angle formed between the surface on which the semiconductor laser array is placed in the drive circuit substrate and the surface forming the long sides 211a and 211b of the notch 201 is substantially vertical. The invention is not limited to this, and other modes can be adopted.

  For example, as shown in FIG. 5, the angle formed by the surface on which the semiconductor laser array is placed in the drive circuit substrate and the surface forming the long sides 211a and 211b of the notch 201 is an obtuse angle. It may be configured.

  By receiving the cylindrical coupling lens 300 on the inclined surface, when the coupling lens 300 is bonded and fixed, fillets are surely formed on both sides of the tangent line between the inclined surface and the coupling lens 300, thereby increasing the adhesive strength. The coupling lens 300 can be fixed stably.

In this embodiment, a plurality of reference holes 202 and 203 are provided. However, the present invention is not limited to this, and various modes can be adopted. For example, a part of the long sides 201a and 201b of the notch 201 may be used as positioning means for mounting without providing the reference hole. Further, a long hole-like notch is formed in parallel with the long side 204 of the outer periphery of the drive circuit board 200, and the notch and the long side 204 of the outer periphery of the drive circuit board 200 are connected to each other at the time of mounting. You may utilize as a reference | standard when assembling a light source device to a positioning means and an optical scanning device.
In this embodiment, the notch portion is provided as the lens position adjustment fixing portion. However, the present invention is not limited to this and may be a long hole lens position adjustment fixing portion. Even in such an aspect, the same effect as in the present embodiment can be obtained.

<Example 2>
A multi-beam light source device according to Embodiment 2 of the present invention is shown in FIGS. Since the multi-beam light source device according to the second embodiment is the same as the multi-beam light source device according to the first embodiment except for the configuration of the drive circuit board, the description of the overlapping portions is omitted.

  On the drive circuit board 220, a standing bent portion 221 is formed as a position adjustment fixing portion of the coupling lens 300.

  The rising and bending portion 221 is formed by raising a side portion of the protruding portion 224 protruding from the end portion of the drive circuit board 220 in the direction in which the laser beam is emitted substantially vertically.

  The drive circuit board 220 is fixed on a component mounting apparatus (not shown) with reference to the end sides 222 and 223, and the end sides 102a and 102b of the lead frame 102 of the semiconductor laser array 100, the abutting end 102c, and the like. By utilizing this, it is positioned and mounted on the drive circuit board 220 with high accuracy. Thereby, the mounting surface 221a of the coupling lens of the standing bent portion 221 and the emission shaft 105 of the semiconductor laser array 100 can be made substantially parallel. Further, the end sides 222 and 223 of the outer peripheral portion of the drive circuit board 220 are also used as reference end surfaces when the light source device is assembled to the optical scanning device. As another aspect different from the present embodiment, the mounting surface 221a may be used as a positioning means when the semiconductor laser array 100 is mounted.

  The coupling lens 300 is bonded and fixed by filling the adhesive 400 between the outer peripheral portion 301 and the mounting surface 221a of the standing bent portion 221 and filling the gap between the coupling lens 300 and the coupling lens 300. The fillet of the adhesive 400 is formed so as to sandwich the tangent line.

  The mounting surface 221a of the standing bent portion 221 is arranged so that the emission axis 105 of the semiconductor laser array 100 and the optical axis of the coupling lens 300 are arranged substantially coaxially when the coupling lens 300 is bonded and fixed thereto. Designed. Then, the coupling lens 300 is bonded and fixed by adjusting the arrangement of the coupling lens 300 in the plane orthogonal to the emission axis 105 and the arrangement in the optical axis direction. Thus, the light beam emitted from the coupling lens 300 can be converted into a parallel light beam.

  Similar to the multi-beam light source device according to the first embodiment, the multi-beam light source device according to the present embodiment is fastened and fixed to the optical scanning device by setting the array angle of the plurality of light emitting chips to a predetermined angle.

  By employing the configuration of the multi-beam light source device according to the second embodiment, it is possible to prevent a part of light emitted from the frame package type semiconductor laser from being blocked by the drive circuit board.

  Moreover, after adjusting the position of the coupling lens in the emission axis direction, it can be securely fixed and integrated with the drive circuit board.

  In addition, when the coupling lens is bonded and fixed, fillets are surely formed on both sides of the contact surface and the tangent line of the coupling lens, so that the bonding strength can be increased and the fixing stability of the coupling lens is increased. Can do.

<Example 3>
A multi-beam light source device according to Embodiment 3 of the present invention is shown in FIGS. The multi-beam light source device according to the third embodiment is the same as the configuration of the multi-beam light source device according to the first embodiment except for the configuration of the drive circuit board.

  The drive circuit board 230 is provided with a bent step portion 231 formed as a step having a height different from that of the mounting surface of the semiconductor laser array 100. A long hole 232 that is a position adjustment fixing portion of the coupling lens 300 is provided in the approximate center of the bending step portion 231 in parallel with the long end 233 of the drive circuit board 230. Long sides 232 a and 232 b of the long hole 232 of the bending stepped portion 231 are substantially parallel to an emission axis 105 of the semiconductor laser array 100 described later, and are symmetric with respect to the emission axis 105.

  The drive circuit board 230 is positioned and fixed with high accuracy on a component mounting apparatus (not shown) with reference to the edges 233 and 234 of the outer periphery. The semiconductor laser array 100 is positioned and mounted on the drive circuit board 230 with high accuracy using the ends 102a and 102b and the abutting end 102c of the lead frame 102. Further, the edges 233 and 234 on the outer peripheral portion of the drive circuit board 230 also function as reference end surfaces when the multi-beam light source device is assembled to the optical scanning device.

  The outer periphery of the coupling lens 300 is brought into contact with the long sides 232a and 232b of the long hole, and the adhesive 400 is filled and bonded and fixed between the gaps with the edge.

  The height h of the step of the bending step portion 231 and the distance (groove width) W between the long sides 232a and 232b of the long hole 232 are determined by the emission axis 105 of the semiconductor laser array 100 and the optical axis of the coupling lens 300. It is designed to be arranged substantially coaxially. The coupling lens 300 is bonded and fixed by adjusting the arrangement in the plane orthogonal to the emission axis 105 and the arrangement in the optical axis direction so that the light beam emitted from the coupling lens 300 becomes a parallel light flux. .

  Similar to the multi-beam light source device according to the first embodiment, the multi-beam light source device according to the present embodiment is tilted so that the arrangement angle of the plurality of light emitting chips becomes a predetermined angle, and is fastened and fixed to the optical scanning device. .

  By employing the configuration of the multi-beam light source device according to the third embodiment, it is possible to effectively prevent a part of light emitted from the frame package type semiconductor laser from being blocked by the drive circuit board.

  Moreover, after adjusting the position of the coupling lens in the emission axis direction, it can be securely fixed and integrated with the drive circuit board.

  In addition, compared to the case where one end of the long hole is opened, the strength of the coupling lens mounting portion can be increased, and the fluctuation of the relative fixing position of the semiconductor laser and the coupling lens due to disturbances such as vibration and shock can be reduced. It can be effectively suppressed.

  Unlike the embodiment of the present embodiment, as shown in FIG. 10, a standing bent portion 247 may be provided following the bent stepped portion 241 of the drive circuit board 240, and an aperture 248 for beam shaping may be provided. By integrally configuring the aperture and the substrate, it is possible to increase the mechanical strength of the position adjustment fixing portion of the coupling lens and to reduce the cost by reducing the number of parts.

<Example 4>
FIG. 11 shows a multi-beam light source device according to Embodiment 4 of the present invention. Since the multi-beam light source device according to the fourth embodiment is the same as the multi-beam light source device according to the first embodiment except for the configuration of the drive circuit board, the description of the overlapping portions is omitted.

  The driving circuit board 250 of the multi-beam light source device according to the present embodiment is provided with bending portions 257 and 258 for inclined installation. The bent portions 257 and 258 are members for defining an in-plane angle perpendicular to the emission axis 105 of the semiconductor laser unit 100. When the multi-beam light source device is mounted in the optical scanning device using a screw, the inclination amount of the plurality of light-emitting sources of the multi-beam light source device is finely adjusted by using the elastic deformation of the bent portion accompanying the tightening of the screw. Can do.

  By configuring the multi-beam light source device as in the present embodiment, fine adjustment of the beam pitch can be facilitated. In addition, with the temperature change around the light source device, the relative position of the multi-beam light source device changes due to the thermal expansion of the peripheral members, and the problem that the beam position changes, the elasticity of the bent part The deformation can be effectively prevented and the beam position stability can be enhanced.

<Example 5>
FIG. 12 shows a multi-beam light source device according to Embodiment 5 of the present invention. Since the multi-beam light source device according to the fifth embodiment is the same as the multi-beam light source device according to the first embodiment except for the configuration of the drive circuit board, the description of the overlapping portions is omitted.

  The drive circuit board 260 of the multi-beam light source device according to this embodiment is provided with a rotation support portion 267 for rotatably supporting the multi-beam light source device substantially coaxially with the emission shaft 105 of the semiconductor laser array 100. Yes. The rotation support portion 267 is provided continuously with the protruding portion 267a protruding from the end portion of the drive circuit board 260 opposite to the laser beam emission direction from the semiconductor laser array 100, and is emitted. The bearing portion 267b has a substantially V-shaped cross section in a plane perpendicular to the shaft 105.

  When a support shaft (not shown) provided on the optical scanning device side is inserted into the V-shaped space of the bearing portion 267b, it is pressed with a predetermined pressing force by the bearing portion 267b and the surface of the drive circuit board 260. Is done. Due to this pressing force, the drive circuit board 260 is rotatably supported by the support shaft. The multi-beam light source device according to the present embodiment is rotated around the support shaft, so that the arrangement angle of the plurality of light emitting sources is set to a predetermined angle, and then fastened and fixed to the optical scanning device.

  As described above, since the drive circuit board is rotatable around the support shaft, the beam pitch can be easily adjusted.

  In the present embodiment, a notch portion similar to that in Embodiment 1 is provided as the lens position adjustment fixing portion. However, the present invention is not limited to this, and a long hole lens position adjustment fixing portion may be used. Moreover, it is good also as a structure which provided the bending level | step-difference part like Example 3. FIG.

  In each of the embodiments of the multi-beam light source device described above, a metal-based printed board is used as the drive circuit board. However, in the present invention, the metal-based printed board is not necessarily required. However, a metal-based printed circuit board is preferable because it has a large heat dissipation effect and can accurately form a reference hole, a reference side, and the like when mounting the multi-beam semiconductor laser array.

[Optical scanning device]
An embodiment of the optical scanning device according to the present invention will be described below with reference to FIGS.

  The optical scanning apparatus according to the present embodiment is an optical system before entering a two-stage polygon mirror optical deflector having a phase difference in the rotation direction, and the light beam is directed in the sub-scanning direction (the rotation axis direction of the polygon mirror). This is an optical scanning device that divides into two and scans light beams onto four photoconductive photosensitive members with two light source devices.

  13 and 14, reference numerals 1 and 2 respectively denote light source devices in which a 2ch semiconductor laser array is mounted on a substrate.

  The light beam from the semiconductor laser array is converted into a light beam form (parallel light beam or weakly divergent or weakly convergent light beam) suitable for the subsequent optical system by a coupling lens. Each light beam emitted from the coupling lens and formed into a desired luminous flux shape is shaped through the aperture of the aperture that regulates the light beam width, and then enters the half mirror prism, and the action of the half mirror prism Are divided into two in the sub-scanning direction, and each is divided into two upper and lower optical paths 1a and 1b.

  The light beam divided into the two optical paths 1a and 1b is incident on the cylindrical lens, condensed in the sub-scanning direction by the action of the cylindrical lens, and in the vicinity of the deflecting / reflecting surface of the polygon mirror type optical deflector 3 in the main scanning direction. To form a long line image. In order to avoid the complexity of the drawing, two light beams emitted from a multichannel semiconductor laser of 2ch are shown as one optical path. The aperture, the half mirror prism, and the cylindrical lens are not shown.

  The light beam incident on and deflected to the polygon mirror type optical deflector 3 is emitted to the scanning imaging optical system side. As shown in the figure, the polygon mirror type optical deflector 3 has an upper polygon mirror 3a and a lower polygon mirror 3b stacked and integrated in two stages in the direction of the rotation axis, and is rotated around the rotation axis by a drive motor. ing.

  The upper polygon mirror 3a and the lower polygon mirror 3b have the same shape with four deflection reflection surfaces in this example, but the deflection reflection surface of the lower polygon mirror 3b with respect to the deflection reflection surface of the upper polygon mirror 3a. However, it is shifted by a predetermined angle (45 degrees in this embodiment) in the rotation direction. Reference numerals 4a, 4b, 4c and 4d denote scanning lenses, and reference numerals 5a, 5a ', 5b, 5c, 5c' and 5d denote optical path bending mirrors. Reference numerals 9K, 9M, 9C, and 9Y denote photoconductive photoreceptors.

  The scanning lens 4 a and the optical path bending mirrors 5 a and 5 a ′ are optical scanning positions corresponding to the two light beams from the light source device 1 deflected by the upper polygon mirror 3 a of the polygon mirror optical deflector 3. A set of scanning imaging optical systems is formed which guides light onto the photoconductive photoreceptor 9M and forms two light spots separated in the sub-scanning direction. The scanning lens 4b and the optical path bending mirror 5b are a photoconductive photosensitive member that is a light scanning position corresponding to two light beams from the light source device 1 deflected by the lower polygon mirror 3b of the polygon mirror type optical deflector 3. A set of scanning imaging optical systems is formed which guides light onto the body 9K and forms two light spots separated in the sub-scanning direction. Further, since these light spots are also separated in the main scanning direction, two light beams for optically scanning each photosensitive member can be individually detected to synchronize the start of optical scanning for each light beam. it can.

  In this way, the two light beams deflected by the upper polygon mirror 3a of the polygon mirror optical deflector 3 are subjected to multi-beam scanning on the photoconductive photoreceptor 9M, and the lower polygon of the polygon mirror optical deflector 3 is scanned. The two light beams deflected by the mirror 3b are subjected to multi-beam scanning on the photoconductive photosensitive 9K.

  Since the deflecting and reflecting surfaces of the upper polygon mirror 3a and the lower polygon mirror 3b of the polygon mirror optical deflector 3 are deviated from each other by 45 degrees in the rotational direction, the deflected light beam from the upper polygon mirror 3a is emitted from the photoconductive photoconductor 9M. When scanning, the light beam deflected by the lower polygon mirror 3b is not guided to the photoconductive photoreceptor 9K. Further, when the light beam deflected by the lower polygon mirror 3b scans the photoconductive photoconductor 9K, the light beam deflected by the upper polygon mirror 3a is not guided to the photoconductive photoconductor 9M. That is, the optical scanning of the photoconductive photoreceptors 9M and 9K is performed alternately with a time shift.

  When the optical scanning of the photoconductive photoconductor 9M is performed, the light intensity of the light source is modulated by the image signal of the magenta image, and when the optical scanning of the photoconductive photoconductor 9K is performed, the light intensity of the light source is black. By modulating with the image signal of the image, the electrostatic latent image of the magenta image can be written on the photoconductive photoreceptor 9M, and the electrostatic latent image of the black image can be written on the photoconductive photoreceptor 9K.

  Similarly, the photoconductive photoreceptors 9Y and 9C are subjected to multi-beam scanning by two light beams emitted from the light source device 2 in the right part. The details of the multi-beam scanning are the same as those in which the photoconductive photoreceptors 9K and 9M are subjected to multi-beam scanning, and thus the description thereof is omitted.

Since the optical scanning device according to the present embodiment uses the multi-beam light source device according to each of the embodiments described above, it is possible to increase the stability of the light beam while realizing higher speed and higher density of optical scanning. it can. Further, it is possible to provide an optical scanning device in which the environmental load is reduced by reducing the thickness of the optical scanning device. Furthermore, the manufacturing cost of the optical scanning device can be reduced.
[Image forming apparatus]
An embodiment of the image forming apparatus according to the present invention will be described below with reference to FIG.

  The photoconductor drum 9 (YMCK) is a drum-shaped image carrier provided for each of Y, M, C, and K colors, and each photoconductor drum 9 has the same diameter. In the vicinity of the periphery of the photosensitive drum 9, a charging device 10, a developing device 12, an intermediate transfer belt 13, a drum cleaning device 11, and a charge eliminating device (not shown) are disposed along the drum rotation direction. The photosensitive drum 9 is pressed against the intermediate transfer belt 13 at equal intervals. Laser light for writing from the optical scanning device is irradiated on the photosensitive drum 9 between the charging device 10 and the developing device 12.

  The charging device 10 (YMCK) is a roller-shaped device that is disposed in a non-contact manner for each photosensitive drum 9 and charges the surface of the photosensitive drum 9. When the surface of the photosensitive drum 9 charged by the charging device 10 is irradiated with laser light for writing from the optical scanning device, an electrostatic latent image corresponding to each color is formed on the photosensitive drum 9.

  The developing device 12 (YMCK) is a device that is provided with a developing roller in contact with each photosensitive drum 9 and holds toner (developer) of a color corresponding to the photosensitive drum 9 corresponding to each color. . At the time of image formation, the developing device 12 supplies toner to the photosensitive drum 9 and develops the electrostatic latent image formed on the photosensitive drum 9. The electrostatic latent image becomes a toner image by being developed with toner.

  The drum cleaning device 11 (YMCK) is a device that is provided with a blade (cleaning blade) in contact with each photosensitive drum 9, and remains on the photosensitive drum 9 after the transfer of the toner image to the intermediate transfer belt 13. Residual toner and paper pieces are removed and collected, and the surface of the photosensitive drum 9 is cleaned.

  Further, a neutralization device (not shown) is provided between the drum cleaning device 11 and the charging device 10. With this static eliminator, the surface of the photosensitive drum 9 is neutralized.

  The intermediate transfer belt 13 is an endless belt for transferring each color toner image formed on the surface of each photoconductor drum 9 in a superimposed manner. A full color image is formed on the intermediate transfer belt 9 by sequentially superimposing the respective color toner images.

  The optical sensor 14 is disposed in a non-contact manner on the intermediate transfer belt 13 and detects a toner pattern formed as a test pattern for maintenance of the image forming apparatus.

  The transfer belt cleaning device 15 is a device that is disposed by bringing a blade (cleaning blade) into contact with the intermediate transfer belt 13. The transfer belt cleaning device 15 remains on the intermediate transfer belt 13 after the transfer of the toner image onto the recording paper to be fed. The remaining toner or toner pattern is removed and collected, and the surface of the intermediate transfer belt 13 is cleaned.

  The transfer roller 16 is a roller for transferring the color image formed on the intermediate transfer belt 13 onto the recording paper conveyed from the paper feed tray 19.

  The fixing device 17 is a device for thermally fixing the color image transferred on the recording paper to the recording paper.

  The paper feed roller 18 is a roller for feeding recording paper.

  The paper feed tray 19 is a tray for storing recording paper for each recording paper size.

  The paper discharge roller 20 is a roller for discharging the recording paper on which the color image is thermally fixed to the outside of the image forming apparatus.

  The paper discharge tray 21 is a tray on which the discharged recording paper is placed.

  The photosensitive drums 9 all rotate in the same direction. Further, the intermediate transfer belt 13 rotates in a direction opposite to the rotation direction of the photosensitive drum 9, and the transfer roller 16 rotates in a direction opposite to the intermediate transfer belt 13 (the same rotation direction as that of the photosensitive drum 9). To do.

  Since the image forming apparatus according to the present embodiment uses the multi-beam light source device according to each of the embodiments described above, the stability of the light beam can be improved while realizing high-speed and high-density image formation. it can. In addition, the image forming apparatus can be reduced in size and thickness, and an image forming apparatus with reduced environmental load can be provided. Furthermore, the manufacturing cost of the image forming apparatus can be reduced.

DESCRIPTION OF SYMBOLS 100 Semiconductor laser array 101 Light emitting chip 102 Lead frame 102a Heat sink 102b, 102c Edge 103 Resin frame 200,220 Drive circuit board 201 Notch 202, 203 Reference hole 221 Standing bent part 224 Protruding part 230 Drive circuit board 231 Bending step Part 232 long hole 258 bent part 267 rotation support part 300 coupling lens 400 adhesive

JP 2000-105347 A JP 2003-031905 A JP 2006-222177 A JP 2006-072136 A JP 2003-283031 A JP 2007-324407 A

Claims (14)

A lead frame having a plurality of lead terminals, a plurality of semiconductor laser light sources mounted on the lead frame, and a resin frame that is provided integrally with the lead frame around the semiconductor laser light sources and protects the semiconductor laser light source A frame package type semiconductor laser array comprising:
A drive circuit board on which the semiconductor laser array is mounted and drives the semiconductor laser light source;
A coupling lens for coupling light from the semiconductor laser array;
In a multi-beam light source device comprising
The lead frame has a heat radiating portion that extends outside a contact portion with the resin frame, and the heat radiating portion is fixed to the drive circuit board in a state of being in close contact with the drive circuit board,
The drive circuit board has a lens position adjustment fixing portion having at least one mounting surface substantially parallel to the emission axis of the semiconductor laser light source,
A multi-beam light source device in which the coupling lens is in contact with and fixed to the mounting surface of the lens position adjustment fixing portion.   2. The multi-beam light source device according to claim 1, wherein the lens position adjustment fixing portion has two attachment surfaces, and the coupling lens is fixed in a state of being sandwiched between the two attachment surfaces.   The lens position adjustment fixing portion is a cutout portion provided at an end portion of the drive circuit board, and the two attachment surfaces are substantially parallel to the emission axis of the semiconductor laser light source of the cutout portion. The multi-beam light source device according to claim 2, which is two side surfaces.   The lens position adjustment fixing portion is a groove portion provided in the drive circuit board, and the two attachment surfaces are two side surfaces of the groove portion that are substantially parallel to the emission axis of the semiconductor laser light source. Item 3. The multi-beam light source device according to Item 2.   5. The multi-beam light source device according to claim 2, wherein an angle formed between the mounting surface of the semiconductor laser array of the drive circuit board and the mounting surface is an obtuse angle.   The lens position adjustment fixing part has an attachment arm part protruding from an end part of the drive circuit board, and the attachment arm part is provided with a rising part that rises perpendicularly to the plane of the drive circuit board. The multi-beam light source device according to claim 1, wherein the coupling lens is fixed to a side surface substantially parallel to an emission axis of the semiconductor laser light source of the rising portion.   The driving circuit board is provided with positioning means serving as a reference for positioning when mounting the semiconductor laser array on the driving circuit board and when mounting the multi-beam light source device main body. The multi-beam light source device according to any one of 1 to 6.   The multi-beam light source device according to claim 1, wherein the drive circuit board is made of metal.   9. The drive circuit board is provided with a step portion having a height different from a mounting surface of the semiconductor laser array, and the lens position adjustment fixing portion is provided at the step portion. The multi-beam light source device according to any one of the above.   The multi-beam light source device according to claim 1, wherein an aperture portion is provided on the drive circuit board.   11. The multi-beam light source device according to claim 1, wherein the drive circuit substrate is provided with an elastically deformable bent portion protruding from a surface opposite to the mounting surface of the semiconductor laser array.   12. The drive circuit board according to claim 1, wherein a bearing portion for rotatably supporting the multi-beam light source device is provided on a rotation axis that is substantially coaxial with an emission axis of the light beam from the semiconductor laser light source. The multi-beam light source device described in 1. A multi-beam light source device;
Deflection means for deflecting and scanning a light beam from the multi-beam light source device;
A scanning optical system that forms an image of the deflected and scanned light beam on the surface to be scanned;
An optical scanning device comprising: the multi-beam light source device according to any one of claims 1 to 12.   The optical scanning device according to claim 13, wherein a latent image is formed on a photosensitive surface of a photosensitive medium by performing optical scanning with an optical scanning device, and the latent image is visualized to obtain an image. An image forming apparatus as a device.

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