JPH0728652U - Optical system light source structure - Google Patents

Abstract

(57) [Abstract] [Purpose] Elasticity of the board between the board and the holder attached to the board without applying a load to the soldering part of the semiconductor laser or other mounted parts mounted on the board. Provided is a light source unit structure capable of positioning and holding a semiconductor laser in the optical axis direction by deformation. [Structure] The screw insertion holes 2 are provided on both sides of the terminal insertion hole 2903 of the substrate 29 through which the terminal 1905 of the semiconductor laser 19 is inserted.
901 are formed respectively, and the holder 25 is attached to the substrate 29 by the mounting screws 33 inserted in the screw insertion holes 2901.
When the flange 1903 of the semiconductor laser 19 is abutted against the recess 2505 of the holder 25 and the flange 1903 is sandwiched between the substrate 29 and the recess 2505, the screw insertion holes 2901 are surrounded. Thus, each groove 2905 is formed, and an elastic piece 2911 that is deformable in the optical axis direction of the semiconductor laser 19 is formed in the portion of the substrate 29 surrounded by the groove 2905.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a light source structure of an optical system.

[0002]

[Prior art]

 For example, in an optical system used in a laser beam printer, a laser beam output from a semiconductor laser is converted into a parallel beam bundle laser beam by a collimator lens, the laser beam is scanned and deflected by a polygon mirror, and the laser beam thus scanned and deflected. The scanning speed on the scanning target is constantly corrected by the fθ lens.

In such an optical system, the semiconductor laser is fixed to the substrate by soldering the terminals of the semiconductor laser to a substrate on which the driver of the semiconductor laser is mounted and the collimator. A holder for holding the lens is mounted and fixed to the substrate by mounting screws with the collimator lens facing the semiconductor laser. In this case, focusing of the laser beam that has passed through the collimator lens is performed by moving the collimator lens in the optical axis direction inside the holder, and the semiconductor laser is moved in the optical axis direction between the substrate and the holder. Positioned. Therefore, conventionally, in order to position the semiconductor laser in the optical axis direction, a recess is formed on the surface of the holder facing the substrate at a depth slightly shorter than the height of the semiconductor laser in the optical axis direction, and the recess is formed in the recess. While inserting the semiconductor laser, the surface of the holder is screwed to the substrate, and the substrate portion around the portion abutted on the semiconductor laser is elastically deformed to urge the semiconductor laser to the recess side. I was guessing.

[0004]

[Problems to be solved by the device]

 However, in the above-described conventional configuration, due to the elastic deformation of the substrate, a load is applied to the soldered portions of the mounted components such as the semiconductor laser and the driver, and cracks are generated in the soldered portions, so that these mounted components are cracked. There was a problem that the electrical continuity might be cut off. The present invention has been made in view of the above circumstances, and an object of the present invention is to apply a load to the base plate and the substrate without applying a load to the soldered portion of the semiconductor laser or other mounted components mounted on the substrate. An object of the present invention is to provide a light source section structure of an optical system capable of positioning and holding a semiconductor laser in the optical axis direction by elastic deformation of a substrate with a holder to be attached.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention has a substrate on which a semiconductor laser is mounted, and a holder attached to the substrate and sandwiching the semiconductor laser between the substrate and the structure of a light source section of an optical system. In the above, the substrate is formed with an elastic piece that is displaceable in the optical axis direction of the semiconductor laser, and the elastic piece includes a base plate portion for sandwiching the semiconductor laser and a substrate portion to which the holder is attached. It is characterized in that either one of the substrate parts is provided.

Further, according to the present invention, substrate portions to which the holder is attached are provided on both sides of a substrate portion for sandwiching the semiconductor laser, and the elastic pieces are provided on both sides of a substrate portion for sandwiching the semiconductor laser. Each elastic piece is provided with a substrate portion to which the holder is attached. Further, in the present invention, the elastic piece is defined by a groove formed in the substrate.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing a schematic configuration of an optical scanning device to which the structure of the light source unit of the optical system of the present invention is applied. In FIG. 1, 1 is an optical scanning device, 3 is a photoconductor that is scanned by a scanning light beam B1 output from the optical scanning device 1, and the optical scanning device 1 outputs a laser beam B0 modulated by print information. The light source unit 11, the polygon mirror 13 for scanning and deflecting the laser beam B0 into the scanning light beam B1, and the scanning speed of the scanning light beam B1 deflected by the polygon mirror 13 on the photoconductor 3 are constantly corrected. The fθ lens 15 and a housing 17 that houses them are provided.

FIG. 2 is a plan view of the light source unit 11, FIG. 3 is a rear view, and FIG. 4 is a transverse sectional view. The light source unit 11 includes a semiconductor laser 19, a collimator lens 21, a lens frame 23 holding the collimator lens 21, a holder 25 holding the lens frame 23, and a slit plate 27 attached to the holder 25. And a substrate 29 on which the semiconductor laser 19 and its driver (not shown) are mounted and which is attached to the holder 25. A laser beam B modulated by print information is output from the semiconductor laser 19, the laser beam B is converted into a laser beam of parallel light flux by the collimator lens 21, and the laser beam is converted into the slit plate 27. By passing through the slit (not shown), a laser beam B0 having a predetermined beam shape corresponding to the slit is emitted to the polygon mirror 13.

The semiconductor laser 19 is composed of, for example, a laser diode, and as shown in FIG. 4, a cylindrical main body 1901, a flange 1903 formed on the bottom of the main body 1901, and the flange 1903. And three terminals 1905 extending from the bottom surface. The terminals 1905 are soldered to the substrate 29. The lens frame 23 is formed in a cylindrical shape, the collimator lens 21 is positioned and fixed in the optical axis direction by a holding ring 2301 inside the lens frame 23, and a male screw 2303 is formed on the outer peripheral surface of the lens frame 23. There is.

As shown in FIG. 2, the holder 25 includes a main body 2501 that is horizontally long in a direction parallel to the bottom surface of the housing 17 and orthogonal to the optical axis direction of the collimator lens 21, and the main body 2501. 2503 bulged at the end of the bulge, a recess 2505 formed at the center of the bulge 2503 for mounting the semiconductor laser 19, and bosses formed on both sides of the bulge 2503. The holder 25 includes a positioning pin insertion hole 2509 on both sides of the main body part 2501 with the positioning pin insertion hole 2509 protruding from the housing 17 being inserted. It is attached to the housing 17 by a mounting screw (not shown) that is inserted into a screw insertion hole 2510 near 2509.

A hole 2511 is formed at a central portion in the longitudinal direction of the main body portion 2501 in a direction orthogonal to the longitudinal direction and parallel to the bottom surface of the housing 17, and the female screw 2513 of the hole 2511 is provided with the hole 2511. The lens frame 23 is held in the hole 2511 by screwing the male screw 2303, and with the lens frame 23 held in the hole 2511, the optical axis of the collimator lens 21 is aligned with the center of the hole 2511. Located concentrically. Further, the lens frame 23 is biased in the optical axis direction within the hole 2511 by a wave washer 31 interposed between the lens frame 23 and the inner surface of the hole 2511.

A screw hole 2515 is formed in each of the bosses 2503, and the recess 2505 and the hole 2511 of the main body 2501 communicate with each other by a hole 2517, and the hole 2517 is the main body of the semiconductor laser 19. The diameter is larger than the portion 1901 and smaller than the flange 1903, and is formed concentrically with the hole 2511. The recess 2505 is formed with a depth smaller than the thickness of the flange 1903 of the semiconductor laser 19.

As shown by an imaginary line in FIG. 3, screw insertion holes 2901 are formed in the substrate 29 so as to face the screw holes 2515, and the terminals 1905 are provided at the centers of the screw insertion holes 2901. Three terminal insertion holes 2903 to be inserted are formed. In the semiconductor laser 19, the bottom surface of the flange 1903 is brought into contact with the terminal insertion hole 2903 portion of the substrate 29, the terminals 1905 are inserted into the terminal insertion holes 2903, and exposed from the terminal insertion holes 2903. The respective terminals 1905 are soldered to a conductive pattern (not shown) formed on the substrate 29.

A groove 2905 is formed on the substrate 29 so as to surround each of the screw insertion holes 2901. As shown in FIG. 3, the groove 2905 includes a circular arc portion 2907 formed around the screw insertion hole 2901 and a straight line extending from both ends of the circular arc portion 2907 toward the terminal insertion hole 2903 in parallel with each other. This groove 2905 defines elastic pieces 2911 extending from the terminal insertion hole 2903 in the direction orthogonal to the optical axis direction on both sides of the terminal insertion hole 2903. In the elastic piece 2911, the screw insertion hole 2901 portion can be deformed in the optical axis direction with the terminal insertion hole 2903 portion as a fulcrum.

As shown in FIG. 4, the substrate 29 is attached to the holder 25 by inserting the body portion 1901 of the semiconductor laser 19 into the hole 2517 and the flange 1903 against the recess 2505. This is performed by tightening the mounting screws 33 inserted into the respective screw insertion holes 2901 into the screw holes 2515 of the boss portion 2507. As shown by an imaginary line in FIG. 3, the shaft portion 3301 of the mounting screw 33 has a diameter smaller than that of the screw insertion hole 2901. Therefore, the semiconductor laser 19 and the collimator lens 21 are connected to each other. The alignment of the optical axes is performed by loosening the fastening of the mounting screws 33 and sliding the substrate 29 in a direction intersecting the optical axis direction.

With the tightening of the mounting screw 33, the depth of the recess 2505 is formed to be smaller than the thickness of the flange 1903 of the semiconductor laser 19, and the bottom surface of the flange 1903 is closer to the substrate 29 side than the boss portion 2507. Because of the protrusion, the screw insertion hole 2901 portion of the elastic piece 2911 is elastically deformed toward the boss portion 2507 side, and the reaction force generated by this elastic deformation causes the flange 1903 to be pushed by the terminal insertion hole 2903 portion of the substrate 29. The concave portion 2505 is pressed and held.

As described above, according to the light source structure of this embodiment, the screw insertion holes 2901 are formed on both sides of the terminal insertion hole 2903 of the substrate 29 through which the terminal 1905 of the semiconductor laser 19 is inserted. The holder 25 is attached to the substrate 29 with the mounting screws 33 inserted in the screw insertion holes 2901, and the flange 1903 of the semiconductor laser 19 is abutted on the recess 2505 of the holder 25, and the flange 1903 is attached to the substrate 1 29 and the concave portion 2505, a groove 2905 is formed so as to surround each of the screw insertion holes 2901, and the optical axis of the semiconductor laser 19 is formed on the substrate 29 portion surrounded by the groove 2905. An elastic piece 2911 that is deformable in the direction is formed.

Therefore, as the mounting screw 33 is tightened, only the elastic pieces 2911 of the substrate 29 are elastically deformed, and the other substrate 29 is not deformed. Therefore, the semiconductor laser 19 and its driver, etc. It is possible to prevent a load from being applied to the soldered portion of the component mounted on the board 29, and to prevent breakage of the soldered portion and disconnection of electrical continuity of the mounted component.

A conductive pattern (not shown) is provided in the above-mentioned terminal insertion hole 2903 portion of the substrate 29 facing the bottom surface of the flange 1903 of the semiconductor laser 19 separately from the conductive pattern for soldering the terminal 1905. The semiconductor laser 19 can be firmly fixed to the substrate 29 by forming and forming the conductive pattern on the flange 1903 by soldering. By doing so, when the substrate 29 is slid in a direction intersecting the optical axis direction for aligning the optical axes of the semiconductor laser 19 and the collimator lens 21, the flange 1903 of the semiconductor laser 19 and the holder are held. The reaction force applied to the semiconductor laser 19 by the rubbing of the concave portion 2505 of the semiconductor laser 25 is less likely to be applied to the terminal 1905 of the semiconductor laser 19. Therefore, it is possible to prevent the semiconductor laser 19 from being damaged by the glass sealing member on the bottom surface of the flange 1903 that seals the terminal 1905 being cracked by the load due to the reaction force.

In the case where an identification member made of a conductive member is formed at the base of the grounding terminal 1905 among the terminals 1905, the identification member is soldered to the conductive pattern, and the conductive pattern is connected to the substrate. If it is configured to be electrically connected to another conductive pattern for grounding on 29, the semiconductor laser 19 can be fixed to the substrate 29 at the same time without increasing the number of soldering steps.

Further, in the present embodiment, the elastic piece 2911 is configured such that the screw insertion hole 2901 portion can be deformed in the optical axis direction with the terminal insertion hole 2903 portion of the substrate 29 as a fulcrum. The terminal insertion hole 2903 may be configured to be deformable in the optical axis direction with the screw insertion hole 2901 portion as a fulcrum. In that case, the elastic piece 2911 may have one screw insertion hole 2901 portion. It may be used as a fulcrum. Further, in the present embodiment, the structure in which the elastic piece 2911 is defined by the groove 2905 has been described, but a structure in which a part of the substrate 29 is formed thin and the elastic piece is defined by the thin substrate part. May be

Furthermore, in the present embodiment, the case where the flange 1903 of the semiconductor laser 19 is sandwiched between the holder 25 for holding the lens frame 23 and the substrate 29 has been described. It is needless to say that the present invention is also applicable to a case where a laser frame for holding a semiconductor laser is provided between a holder for substrate and a substrate, and a flange of the semiconductor laser is sandwiched between the laser frame and the substrate.

[0023]

[Effect of device]

 As described above, according to the present invention, a semiconductor laser, a substrate on which the semiconductor laser is mounted, a screw insertion hole formed in the substrate portion near the substrate portion on which the semiconductor laser is mounted, In a structure of a light source section of an optical system having a holder that is attached to the substrate by a screw inserted into the screw insertion hole and holds the semiconductor laser between the substrate and the substrate, the semiconductor is attached to the substrate. An elastic piece that is displaceable in the optical axis direction of the laser is formed by a groove, and one of the substrate portion holding the semiconductor laser and the substrate portion to which the holder is attached is formed in the elastic piece. It is supposed to be provided. For this reason, the semiconductor laser is mounted between the substrate and the holder attached to the substrate by elastic deformation of the substrate without applying a load to the soldered portion of the semiconductor laser mounted on the substrate or other mounted components. It can be positioned and held in the optical axis direction.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a schematic configuration of an optical scanning device to which a light source structure of an optical system of the present invention is applied.

FIG. 2 is a plan view of the light source unit of FIG. 1 according to an embodiment of the present invention.

FIG. 3 is a rear view of the light source unit of FIG.

FIG. 4 is a cross-sectional view of the light source unit of FIG.

[Explanation of symbols]

 11 light source unit 19 semiconductor laser 25 holder 29 substrate 2901 screw insertion hole 2903 terminal insertion hole 2905 groove 2911 elastic piece (board portion surrounded by groove)

Claims (3)

[Scope of utility model registration request] 1. A structure of an optical system light source section, comprising: a substrate on which a semiconductor laser is mounted; and a holder attached to the substrate and sandwiching the semiconductor laser between the substrate and the substrate. Is formed with an elastic piece that is displaceable in the optical axis direction of the semiconductor laser, and the elastic piece has either one of a substrate portion holding the semiconductor laser and a substrate portion to which the holder is attached. The light source part structure of the optical system is characterized in that a part is provided. 2. A substrate portion to which the holder is attached is provided on both sides of a substrate portion holding the semiconductor laser, and the elastic pieces are formed on both sides of the substrate portion holding the semiconductor laser, respectively. The light source part structure of an optical system according to claim 1, wherein each elastic piece is provided with a substrate portion to which the holder is attached. 3. The light source part structure of an optical system according to claim 1, wherein the elastic piece is defined by a groove formed in the substrate.