JPH0687911U - Optical axis adjustment device for laser light source - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a highly accurate optical axis adjusting device for a laser light source by reducing the number of parts and simplifying the adjusting process. [Structure] A cylindrical lens barrel holder 22 integrally formed with a laser light source mounting portion 26 and an optical lens mounting portion 30 on an inner peripheral surface thereof, and a frame 32 rotatably holding the lens barrel holder 22 are provided. If the laser light source mounting portion 26 and the optical lens mounting portion 30 on the inner peripheral surface of the lens barrel holder 22 are precisely processed, the laser light source 24 is press-fitted into the mounting portion 26 and the optical lens 28 is fitted into the mounting portion 30. Just insert it and the optical axis center of the laser light source 24 and the optical lens 2
The optical axis center of 8 can be made to correspond.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical axis adjusting device for a laser light source, and more particularly to a mounting structure for the laser light source and an optical lens.

[0002]

[Prior art]

 In the optical axis adjustment device of the laser light source, the center of the optical axis of the laser light source and the center of the optical axis of the collimating lens that converges or converges the laser light from the laser light source must be aligned, and the scanned The distance between the laser light source and the collimator lens in the direction of the optical axis must be a predetermined distance so that the laser light is focused on the surface. Therefore, as shown in FIG. 5, the position of the collimator lens 54 is adjusted in two directions, X and Y, which are directions orthogonal to the optical axis of the laser light emitted from the laser light source 50 made of a semiconductor laser. Then, the center of the optical axis of the laser light source 50 and the center of the optical axis of the collimator lens 54 are aligned with each other, and the collimator lens 54 is positionally adjusted in the Z direction, which is the optical axis direction, to perform focus adjustment.

FIG. 4 shows an example of a laser light source unit and a collimator lens unit of a conventional optical axis adjusting device for a laser light source, which enables adjustment as described above. In FIG. 4, a laser light source holder 56 is fixed to a flange portion 60 formed at one end of a cylindrical lens barrel holder 58 by screwing or the like. A hole for press-fitting a laser light source is formed in the laser light source holder 56, and the laser light source 50 made of a semiconductor laser or the like is press-fitted into this hole, and the step portion is used as a reference surface in this step portion. The laser light source 50 is positioned with respect to the laser light source holder 56 by abutting the flange portion 52 of the laser light source 50. The outer edge 68 of the hole is caulked to fix the laser light source 50. The laser light source 50 is connected to a predetermined wiring pattern of the flexible wiring board 70 fixed to the laser light source holder 56.

A cylindrical lens barrel 62 is fitted in the lens barrel holder 58 so as to be movable in the central axis direction. A collimator lens 54 is incorporated in the lens barrel 62. A groove 64 is formed on the outer peripheral portion of the lens barrel 62 in the central axis direction, that is, in the optical axis direction of the lens 54. A set screw 66 is screwed in the lens barrel holder 58 in the radial direction, and the tip of the set screw 66 is in contact with the bottom surface of the groove 64 of the lens barrel 62.

The flange portion 60 of the lens barrel holder 58 and the laser light source holder 56 are moved relative to each other in the X direction and the Y direction shown in FIG. It is possible to adjust so that the center of the optical axis and the center of the optical axis of the collimator lens 54 coincide with each other, and after the adjustment, tighten the fixing screw to fix. Further, the focus can be adjusted by moving the lens barrel 62 in the optical axis Z direction along the inner peripheral surface of the lens barrel holder 58, and the adjusted adjustment screw 66 is tightened to fix the lens barrel 62.

[0006]

[Problems to be solved by the device]

 According to the configuration of the light source portion of the conventional optical axis adjusting device for a laser light source, the lens barrel holder 58 and the laser light source holder 56 are used as separate components, and two components in the X direction and the Y direction, which are perpendicular to the optical axis, are used. The center of the laser beam and the center of the collimator lens 54 are adjusted by moving the collimator lens 54 in the optical axis Z direction together with the lens barrel 62 to adjust the focus. Has become. Therefore, the number of parts and the number of adjustment points are increased, and errors between parts are accumulated, so that the accuracy is not always good, so that there is a problem that reliability is low. Further, since the laser light source 50 is fixed to the holder 56 by caulking, there is a problem in that the laser light source 50 cannot be accurately positioned with respect to the holder 56 and the laser light source 50 easily tilts.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and reduces the number of parts and simplifies the adjustment process, and the optical axis adjustment device for a highly accurate laser light source is provided. The purpose is to provide.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides an optical axis adjusting device for a laser light source, which adjusts an optical axis of the laser light source when a laser beam from a laser light source is scanned on a surface to be scanned by a laser scanning system. A cylindrical lens barrel holder integrally formed with a laser light source mounting portion and an optical lens mounting portion for mounting a laser light source and an optical lens on the inner peripheral surface, respectively, and a frame for rotatably holding the lens barrel holder. In addition, the above-mentioned laser light source is attached to the laser light source attachment portion by press fitting.

Another aspect of the present invention is characterized in that the laser light source is attached to the laser light source attachment portion so that the press-fitting depth can be adjusted.

Another aspect of the present invention is characterized in that the lens barrel holder has its rotation center set substantially at the center of the optical lens.

Another aspect of the present invention is characterized in that the lens barrel holder has its rotation center set substantially at the center of the laser light source.

[0012]

[Action]

 According to the configuration of the present invention as set forth in claim 1, a cylindrical lens barrel holder integrally formed with a laser light source mounting portion and an optical lens mounting portion on an inner peripheral surface, and the lens barrel holder is rotatably held. By using the frame, the laser light source can be pressed into the laser light source mounting part and fixed, and the optical axis of the laser light source and the optical lens can be aligned simply by fitting the optical lens into the optical lens mounting part. it can. Further, the focus can be adjusted by adjusting the position of the laser light source in the laser light source mounting portion.

According to the configuration of the present invention as set forth in claim 2, since the press-fitting depth of the laser light source is adjustable, the same operation as in claim 1 can be achieved.

According to the configuration of the present invention as set forth in claim 3, by setting the rotation center of the lens barrel holder at substantially the center position of the optical lens, the same operation as in claim 1 can be performed.

According to the configuration of the present invention as set forth in claim 4, the same operation as in claim 1 can be performed by setting the rotation center of the lens barrel holder at the substantially central position of the laser light source.

[0016]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. First, a configuration example of an optical axis adjusting device for a laser light source will be schematically described. In FIG. 3, a laser light source unit 12 is fixed to one side portion of a frame 11 having a peripheral wall, and a cylindrical lens 13 is arranged in the path of the laser light emitted from the laser light source unit 12, and further, its The laser light from the laser light source unit 12 is deflected within a certain angle range by the rotation of the polygon mirror 15 which is driven to rotate by the motor 14 in the forward direction. The laser light deflected by the polygon mirror 15 passes through the fθ lens 16 arranged in the vicinity of the polygon mirror 15, and is reflected by the first scanning reflection mirror 17 arranged at the upper edge of the frame 11 in FIG. To be done. The reflected light is further reflected toward the outside of the frame 11 by the second scanning reflection mirror 18. The polygon mirror 15, the fθ lens 16, and the mirrors 17 and 18 form a laser scanning system.

A photoconductor (not shown) or the like is located on the path of the light reflected by the second scanning reflection mirror 18. The photosensitive surface of this photosensitive member is a surface to be scanned, and a scanning line is drawn on this photosensitive surface. In FIG. 3, assuming that the scanning direction is from left to right, a reflection mirror 19 for reflecting a part of the light reflected by the second scanning reflection mirror 18 is arranged on the left side which is the scanning start side. A sensor 20 is arranged on the path of the light reflected by the reflection mirror 19. The sensor 20 is fixed to the frame 11 between the fθ lens 16 and the second reflection mirror 18 for scanning so as not to hinder the progress of the laser light passing through the fθ lens 16. The sensor 20 detects the scanning start position of the laser light. A synchronization signal is generated after a fixed time from the time when the detection signal is output from the sensor 20, the laser light is modulated according to the recorded information signal, and a good latent image without jitter is formed on the photosensitive surface of the photoconductor. .

A specific configuration of the laser light source unit 12 is shown in FIGS. 1 and 2. The laser light source unit 12 is integrally provided with a laser light source mounting portion 26 for mounting a laser light source 24 made of a semiconductor laser or the like on the inner peripheral surface by press fitting and an optical lens mounting portion 30 for mounting by mounting an optical lens 28 such as a collimator lens. It has a substantially cylindrical lens barrel holder 22 made of molded resin and the like, and a frame 32 for rotatably holding the lens barrel holder 22. The mounting portions 26 and 30 to which the laser light source 24 and the optical lens 28 are mounted are precision-machined, and there is almost no clearance between the mounted laser light source 24 and optical lens 28 and the inner peripheral surface of the lens barrel holder 22. Will not occur. The press-fitting depth of the laser light source 24 can be adjusted along the optical axis of the inner peripheral surface, whereby focus adjustment is performed.

A pin 34 is provided substantially at the center of the optical lens 28 of the lens barrel holder 22, and the pin 34 is pressed by a leaf spring 36 as shown in FIG. 22 is held by a frame 32. Reference numeral 38 is a fixing screw for fixing the leaf spring 36 to the frame 32. The frame 32 is provided with an adjusting screw 40 for pressing the outer peripheral surface of the lens barrel holder 22, and this adjusting screw 40 is located on the left side of the pin 34 at the center position of the optical lens 28 of the lens barrel holder 22 in FIG. It is arranged to press the outer peripheral surface of. Accordingly, when the outer peripheral surface of the lens barrel holder 22 is pressed by the adjusting screw 40, the lens barrel holder 22 rotates about the pin 34 as a fulcrum, so that the optical axis of the laser light from the laser light source 24 can be adjusted. It is possible. When the optical axis of the laser beam is adjusted by the adjusting screw 40 as described above, the pin 34 at the fulcrum of the rotation is not limited to the substantially central position of the optical lens 28, but the laser light source 24 is operated by the same principle. It may be provided at a substantially central position.

According to the embodiment described above, the cylindrical lens barrel holder 22 integrally formed with the laser light source mounting portion 26 and the optical lens mounting portion 30 on the inner peripheral surface, and the lens barrel holder 22 are rotated. Since the frame 32 that holds freely is provided, if the laser light source mounting portion 26 and the optical lens mounting portion 30 on the inner peripheral surface of the lens barrel holder 22 are precisely processed, the laser light source 24 is press-fitted into the mounting portion 26. In addition, the optical axis 28 of the laser light source 24 and the optical axis 28 of the optical lens 28 can be aligned with each other only by fitting the optical lens 28 into the mounting portion 30. Further, focus adjustment can be performed by adjusting the position of the laser light source 24 in the direction of the optical axis by adjusting the press-fitting depth. On the other hand, the optical axis can be adjusted by rotating the lens barrel holder 22 with the pin 34 as a fulcrum by the adjusting screw 40 provided on the frame 32 as needed.

[0021]

[Effect of device]

 As described above, according to the present invention, the cylindrical lens barrel holder integrally formed with the laser light source mounting portion and the optical lens mounting portion on the inner peripheral surface, and the lens barrel holder is rotatably held. Since the frame is provided, if the laser light source mounting part and the optical lens mounting part on the inner peripheral surface of the lens barrel holder are precision processed, the laser light source is press-fit into the mounting part and the optical lens is mounted on the mounting part. The optical axis center of the laser light source and the optical axis center of the optical lens can be aligned simply by fitting them. In addition, the focus can be adjusted by adjusting the press-fitting depth of the laser light source. Therefore, as compared with the conventional example, the number of parts can be reduced and the adjustment process can be simplified. Since errors between parts are not accumulated, the accuracy is improved and the reliability is increased. Further, since the laser light source and the optical lens are attached by using the lens barrel holder integrally formed, the positional accuracy of the laser light source can be obtained, so that the inclination of the laser light source can be prevented.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of a laser light source part which is a main part of an embodiment of an optical axis adjusting device for a laser light source of the present invention.

FIG. 2 is a schematic diagram showing a configuration of part of FIG.

FIG. 3 is a plan view showing an example of an optical axis adjusting device of a laser light source in which a laser light source unit is incorporated.

FIG. 4 is a vertical cross-sectional view showing an example of a conventional laser light source unit.

FIG. 5 is a perspective view showing an adjustment direction of a laser light source section in a conventional example.

[Explanation of symbols]

 22 Lens barrel holder 24 Laser light source 26 Laser light source mounting part 28 Optical lens 30 Optical lens mounting part 32 Frame 34 Pin 36 Leaf spring 40 Adjustment screw

Claims (4)

[Scope of utility model registration request] 1. An optical axis adjusting device for a laser light source, which adjusts an optical axis of the laser light source when the laser light from the laser light source is scanned on a surface to be scanned by a laser scanning system, wherein A laser light source is provided by press-fitting the laser light source by providing a cylindrical lens barrel holder integrally formed with a laser light source mounting portion for mounting a lens and an optical lens mounting portion, and a frame for rotatably holding the lens barrel holder. An optical axis adjusting device for a laser light source, which is mounted on a mounting portion. 2. The optical axis adjusting device for a laser light source according to claim 1, wherein the laser light source is attached to the laser light source attachment portion so that the press-fitting depth can be adjusted. 3. The optical axis adjusting device for a laser light source according to claim 1, wherein the lens barrel holder has a center of rotation set substantially at the center of the optical lens. 4. The optical axis adjusting device for a laser light source according to claim 1, wherein the lens barrel holder has its center of rotation set substantially at the center position of the laser light source.