JP2007027376A - Laser unit mounting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and surely mount a laser holder to the predetermined position of laser unit by mounting the laser unit on the laser holder by pressing the same to the internal wall of the hole of the laser holder, in almost the vertical and horizontal directions for the surface direction of a lead frame. <P>SOLUTION: The laser unit mounting apparatus comprises a first pressing part 11 for pressing one frame expanding part 4a of the laser unit 1 substantially perpendicularly to the surface direction of the lead frame 4 to a clamping member 10 which is inserted together with a laser unit 1 into a hole 8 of the laser holder 7, and a second pressing part 12 for pressing a corner of the other frame expanding part 4b of the laser unit in the oblique direction. The laser unit 1 is pressed to the internal wall of the hole 8 in a direction substantially perpendicular to the surface direction of the lead frame 4 with the first pressing part 11, and the laser unit 1 is also pressed to the internal wall of the hole 8 in the direction substantially perpendicular and horizontal to the surface direction of the lead frame 4 with the second pressing part 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laser unit mounting apparatus for mounting a frame type laser unit to a laser holder, and more particularly to a laser unit mounting apparatus having a structure in which a laser unit is mounted in a hole formed in the laser holder.

  An optical pickup that optically reads or writes a signal on a signal recording medium such as a disk is configured by installing an objective lens driving mechanism that drives an objective lens in an optical housing in which various optical elements are incorporated. The optical housing has a laser unit serving as a light source, a photodetector serving as a light receiving element, and a laser beam emitted from the laser unit to the objective lens, and a laser beam reflected by the signal recording medium and returned to the objective lens. An optical system leading to the photodetector is formed.

  By the way, a so-called frame laser unit, which is a plastic mold package type semiconductor laser, is known as a laser unit. Although this frame laser unit is inferior in heat dissipation performance compared to the can package type, it is advantageous in terms of cost. Therefore, this frame laser unit is used when a high-power laser beam that is not dedicated to reproduction or does not support high speed is not required.

When using a frame laser unit, the frame laser unit is mounted on the optical housing by mounting the frame laser unit on the laser holder and fixing the laser holder to the optical housing to adjust the position of the laser emission point and to prevent heat dissipation. Often. (See Patent Document 1)
By the way, when the frame laser unit is attached to the laser holder (or optical housing), each lead frame protruding from both sides of the resin-molded main body portion is pressed by a leaf spring to attach the frame laser unit to the laser holder (or optical housing). There is known a structure in which the frame laser unit is attached by being pressed against the inner wall of the hole. (See Patent Document 2)
JP 2004-192755 A JP-A-10-269601

  However, the conventional structure in which the frame laser unit is attached using a leaf spring only presses the lead frame of the frame laser unit substantially perpendicularly to the surface direction. Not done. For this reason, the optical axis of the laser beam emitted from the frame laser unit is shifted from the optical axis of the optical system on the forward path toward the signal recording medium of the optical housing, and optical aberrations occur and optical characteristics are deteriorated.

In particular, in the case of an optical pickup having a configuration in which a plurality of laser units are switched to be used for a plurality of types of signal recording media, the optical magnification differs depending on the type of the signal recording medium, or the laser light utilization efficiency is improved. For this reason, the laser light immediately after being emitted from the predetermined laser unit is narrowed by a divergent lens, and in the case of an optical pickup in which a convex lens for increasing the magnification is inserted immediately after the laser unit, the convex lens Since the optical path magnification is increased by this, the influence of deterioration of the optical characteristics due to the deviation between the optical axis of the laser light emitted from the laser unit and the optical axis of the optical system on the outward path of the optical housing becomes large.

  Further, in the case where the lens is installed coaxially with the frame laser unit in the laser holder, the position of the frame laser unit in the surface direction of the lead frame is not fixed, and the optical axis of the frame laser unit and the optical axis of the lens Since this displacement is not related to the position of the laser holder with respect to the optical housing, it is a problem that cannot be dealt with by adjusting the position of the laser holder.

  The present invention provides a laser holder with a hole into which a laser unit is loaded, and a holding member that is inserted into the hole of the laser holder together with the laser unit and holds the laser unit into the hole, and is mounted on the lead frame on the laser unit. Frame extending portions projecting from both sides of the package surrounding the laser element, and engaging the pressing member with the hole of the laser holder, and placing one frame expanding portion of the laser unit on the pressing member in the surface direction of the lead frame A first pressing portion that presses substantially perpendicular to the second pressing portion and a second pressing portion that presses the corner of the other frame expansion portion of the laser unit in an oblique direction, and the laser unit is moved in the direction of the lead frame by the first pressing portion. The laser unit is pressed against the inner wall of the hole of the laser holder in a substantially vertical direction, and the laser unit is So that pressed against the inner wall of the substantially vertical and substantially horizontal direction into the hole with respect to the plane direction of the lead frame.

  Since the laser unit mounting apparatus according to the present invention presses the laser unit against the inner wall of the hole of the laser holder in a direction substantially vertical and substantially horizontal with respect to the surface direction of the lead frame, the laser unit is attached to the laser holder. The unit can be attached to the laser holder by positioning it in two directions: a direction substantially perpendicular to the surface direction of the lead frame and a direction perpendicular to this direction and perpendicular to the optical axis direction of the laser beam. It can be securely attached to a predetermined position of the laser unit.

  In this case, the pressing member is formed by sheet metal processing, and the first pressing portion and the second pressing portion are integrally formed in a leaf spring shape on the pressing member, and the pressing member is not composed of a plurality of parts. .

  Further, since the pressing member can be positioned and loaded in the hole of the laser holder, the positional deviation of the pressing member is prevented, and the positioning of the laser unit is ensured.

  In addition, since a lens mounting portion for mounting the lens is formed in the front portion of the laser unit of the laser holder, the optical axis alignment between the lens and the laser beam emitted from the laser unit can be performed with high reliability. Can be prevented from deteriorating the optical characteristics due to the optical axis deviation between the lens and the laser light from the laser unit. Is effective in preventing this adverse effect.

  FIG. 1 is an exploded perspective view showing an embodiment of a laser unit mounting apparatus according to the present invention.

A laser unit 1 of a frame type laser diode, a so-called frame laser unit, has a structure in which a laser chip 2 is mounted on a silicon-based submount 3 and the submount 3 is mounted on a lead frame 4 nickel-plated on a copper base. It has become. A package 5 is formed on the lead frame 4 so as to surround the periphery of the laser chip 2 excluding the laser emission direction and the back surface of the lead frame 4 by a plastic mold, and the frame expansion portions 4a of the lead frame 4 are respectively formed from both side surfaces of the package 5. , 4b is overhanging.

  Lead terminals 6a, 6b, and 6c protrude from the rear surface of the package 5, the central lead terminal 6b serves as a ground terminal for a negative electrode of a laser diode formed extending from the lead frame 4, and the lead terminal 6a is bonded. Connected to the laser chip 2 by a wire to become a positive electrode terminal of the laser diode, and the lead terminal 6c is a non-connect lead terminal not involved in electrical connection, or a monitor output terminal when a monitor diode is formed on the submount 3. Become.

  A hole 8 is formed in the laser holder 7 so as to penetrate the laser holder 7 in the optical axis direction of the laser light emitted from the laser unit 1, and the laser unit 1 is loaded on the front side of the hole 8. As shown in the perspective view from the front of the second laser holder 7, a lens mounting portion 7 a to which the divergent lens 9 is mounted is formed in the front portion of the laser unit 1 in the hole 8.

  When the laser unit 1 is loaded into the hole 8, a pressing member 10 that presses the laser unit 1 into the hole 8 is inserted together with the laser unit 1. The pressing member 10 is formed by phosphor bronze sheet metal processing, and the pressing member 10 is integrally formed with a first pressing portion 11 and a second pressing portion 12 in a plate spring shape.

  Further, a groove 13 in the direction of the optical axis of the laser beam is formed substantially in the center on the inner wall of the bottom surface of the hole 8 of the laser holder 7, and the protrusion 14 inserted into the groove 13 is integrally formed with the pressing member 10. The tip of the pressing member 10 is provided with a wide width and is a contact portion 15 that contacts the side wall of the inner wall of the hole 8.

  FIGS. 3 and 4 are a sectional view showing the state in which the pressing member 10 is inserted into the hole 8 of the laser holder 7 from above and a perspective view showing the state from the rear, respectively. Abutting against the side wall of the inner wall of the hole 8, the projecting piece 14 is inserted into the hole 8 in a state of being engaged with the side wall of the groove 13, whereby the pressing member 10 is positioned in the hole 8 while being positioned. Installed. The amount of insertion of the pressing member 10 into the hole 8 is limited by the bent portion 16 at the rear end of the pressing member 10 being in contact with the end surface of the laser holder 7.

  When the pressing member 10 is inserted into the hole 8 of the laser holder 7, the laser unit 1 loaded in the hole 8 of the laser holder 7 has the first pressing portion 11 that causes the frame expansion portion 4 a to be connected to the lead frame as shown in the rear view of FIG. 5. 4 is pressed substantially perpendicularly to the surface direction of 4, and the corner of the frame expansion portion 4b is pressed in an oblique direction by the second pressing portion 12. Therefore, the laser unit 1 is attached to the laser holder 7 by positioning in two directions, a direction substantially perpendicular to the surface direction of the lead frame 4 and a direction perpendicular to this direction and perpendicular to the optical axis direction of the laser beam. Of these, the pressing in the direction substantially perpendicular to the surface direction of the lead frame 4 is performed at two locations of the frame expansion portions 4 a and 4 b on both sides of the laser unit 1, and the laser unit 1 is surely attached to the inner wall of the hole 8. Pressed against the upper surface and attached to the laser holder 7. Here, the laser holder 7 is made of zinc die casting, and the laser unit 1 radiates heat by the frame expansion portions 4 a and 4 b of the laser unit 1 being pressed against the inner wall of the hole 8.

The cross sections along AA ′ and BB ′ shown in FIG. 5 are shown in FIGS. 6 and 7, respectively. 6 shows that the first pressing portion 11 presses the frame expansion portion 4a and the laser unit 1 is pressed against the upper surface of the inner wall of the hole 8. FIG. 7 shows that the second pressing portion 12 presses the frame expansion portion 4b. This indicates that the laser unit 1 is pressed against the side surface of the inner wall of the hole 8 by pressing. Further, as shown in FIG. 7, the laser unit 1 is inserted into the hole 8 by the tips 18a and 18b of the frame expansion portions 4a and 4b coming into contact with the wall surface formed by narrowing the opening of the hole 8. The amount is limited and attached to the laser holder 7.

  The laser holder 7 to which the laser unit 1 is loaded and the divergent lens 9 is attached is attached to an optical housing 17 made of synthetic resin, for example, polyphenylene sulfide (PPS). In this case, the front lens mounting portion 7 a to which the divergent lens 9 of the laser holder 7 is mounted is inserted into the mounting hole 19 formed in the optical housing 17, and the laser holder 7 is irradiated with laser light to the optical housing 17. After the laser unit 1 is positioned by being displaced in a direction orthogonal to the axial direction and the optical axis direction, the laser holder 7 is bonded and fixed to the optical housing 17 with an adhesive at that position.

  The material of the pressing member 10 is phosphor bronze, which is the same type of metal as the lead frame 4 of the laser unit 1, and importance is placed on reliability by avoiding contact with different metals. It is only necessary that the portion 11 and the second pressing portion 12 can be integrally formed in a leaf spring shape, and stainless steel or the like is also suitable.

It is an expansion | deployment perspective view which shows one Example of the laser unit attachment apparatus which concerns on this invention. 3 is a perspective view from the front of the laser holder 7. FIG. FIG. 6 is a cross-sectional view showing a state in which a pressing member 10 is inserted into a hole 8 of the laser holder 7 from above. It is a perspective view which shows the state which inserted the pressing member 10 in the hole 8 of the laser holder 7 from back. 4 is a rear view showing a state in which the laser unit 1 is loaded in the hole 8 of the laser holder 7. FIG. It is sectional drawing which shows the cross section in A-A 'shown in FIG. It is sectional drawing which shows the cross section in B-B 'shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser unit 4 Lead frame 4a, 4b Frame expansion part 7 Laser holder 7a Lens mounting part 8 Hole 9 Divergent lens 10 Holding member 11 1st press part 12 2nd press part 13 Groove 14 Projection piece 15 Contact part 17 Optical housing

Claims (4)

A laser unit mounting apparatus for mounting a frame type laser unit to a laser holder, wherein a hole for loading the laser unit is provided in the laser holder, inserted into the hole of the laser holder together with the laser unit, and the laser unit is pressed into the hole. A pressing member is provided, and the laser unit includes frame expansion portions that respectively extend from both sides of the package surrounding the laser element mounted on the lead frame, and the pressing member is engaged with a hole of the laser holder, A first pressing part that presses the frame extension part substantially perpendicularly to the surface direction of the lead frame; and a second pressing part that presses the corner of the other frame extension part of the laser unit in an oblique direction. The laser unit in a direction substantially perpendicular to the lead frame surface direction. Along with pressed against the inner wall of the hole, the laser unit mounting apparatus characterized by pressing the inner wall of the substantially vertical and substantially horizontal direction into the hole a laser unit with respect to the plane direction of the lead frame by the second pressing part. 2. The laser unit mounting device according to claim 1, wherein the pressing member is formed by sheet metal processing, and the first pressing portion and the second pressing portion are integrally formed in a plate spring shape on the pressing member. A groove in the optical axis direction of the laser beam emitted from the laser unit is provided on the inner wall of the hole of the laser holder, a protruding piece inserted into the groove is provided on the pressing member, and the inner wall of the hole is provided at the tip of the pressing member. 2. The laser unit mounting apparatus according to claim 1, wherein contact portions are provided to be in contact with both side walls to position the pressing member. 2. The laser unit mounting apparatus according to claim 1, wherein a lens mounting portion for mounting a lens is formed in a front portion of the laser unit of the laser holder.

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