JP2005078778A - Optical pickup and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup in which heat generated from a light source is radiated efficiently and which is excellent in easiness of assembling and adjusting because of excellent flexibility. <P>SOLUTION: The optical pickup 100 is provided with a light source 1 emitting a light beam, an objective lens 11 converging the light beam emitted from the light source 1 to a surface of an information recording medium, a light source unit 2 in which the light source 1 is mounted on a surface, a heat radiation plate 4 having a plurality of through holes for radiating heat generated from the light source 1 and provided so as to oppose to the back of a light source unit 2, and an elastic member 5 formed at both planes of the heat radiation plate 4 passing through one part of the plurality of through holes, the elastic member 5 is formed so as to abut to the back of the light source 2 to transmit heat generated from the light source 1 to the heat radiation plate 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical pickup device for optically recording and reproducing information on an information layer of an information medium, and a method for manufacturing the same.

  A conventional optical pickup device includes an elastic member that supports and fixes a light source unit to a base and conducts heat generated from a laser element mounted on the light source unit to the base (for example, , See Patent Document 1).

  FIG. 7 is a diagram schematically showing a conventional optical pickup 90 described in Patent Document 1. In FIG. In FIG. 7, a laser element 101 that emits a light beam 107 is mounted on a heat sink 103 and constitutes a light source unit 104. A light beam 107 emitted from the laser element 101 is irradiated onto an optical disk board (not shown) by the objective lens 102. The light source unit 104 is supported and fixed to the base 105 by the spring property of the elastic member 106. The heat generated when the laser element 101 built in the light source unit 104 emits the light beam 107 has a function of conducting to the base 105 via the heat sink 103 and the elastic member 106.

  FIG. 8 is a diagram showing the configuration of another conventional optical pickup disclosed in Japanese Patent Laid-Open No. 11-25489 (Patent Document 2). This optical pickup includes a flexible substrate 61. The flexible substrate 61 is bent as shown in FIG. A hologram unit 62 is provided on the flexible substrate 61. A holder 64 is provided so as to cover the hologram unit 62. The holder 64 is formed with an opening 64 a through which the emitted light emitted from the hologram unit 62 passes.

  The flexible substrate 61 includes a high frequency superimposing circuit mounting surface 61c on which a high frequency superimposing module for reducing noise due to high frequency driving of the laser element or returning light to the laser element, a surface on which the hologram unit 62 is mounted, and a high frequency superimposing circuit. And a bridge portion 61d formed to connect the mounting surface 61c. A heat radiating member 66 is provided on the bridge portion 61d so as to face the hologram unit 62 with the flexible substrate 61 interposed therebetween.

A shield case is provided so as to cover the heat radiating member 66, the bridge portion 61d, and the high-frequency superimposed circuit mounting surface 61c.
JP 2002-15451 A JP 11-25489 A

  However, in the configuration disclosed in Patent Document 1, the attachment of the light source unit 104 and the base 105 is a spring biasing force between the concave portion 106a of the elastic member 106 and the pair of crotch portions 106b. After adjusting the optical axis of the light beam 107 and the objective lens 102 emitted from the unit 104, if the light source unit 104 is fixed to the base 105 with the elastic member 106, the adjusted optical axis is likely to be displaced, and the recess 106a and the crotch portion 106b is connected by a flat portion 106c, and the back surface of the light source unit 104 and the crotch portion 106b are engaged with each other in a planar shape. Since the movement of only the unit 104 is virtually impossible, there is a problem that the mounting variation is large.

  In addition, since heat is radiated from the back surface of the light source unit 104 to the base 105 via the crotch portion 106b and the concave portion 106a of the elastic member 106, the contact area of the heat conducting portion is reduced and heat cannot be radiated efficiently. It had the problem that.

  As described above, in order to solve the problem of the heat dissipation configuration disclosed in Patent Document 1, it is possible to adjust the optical axes of the light beam 107 emitted from the light source unit 104 and the objective lens 102, and the light source unit. It is necessary to efficiently dissipate the heat generated from 104.

  Incidentally, in order to optically record or reproduce information on the information layer of the information recording medium, it is necessary to reduce the thickness of an optical pickup for recording or reproducing information.

  In the configuration disclosed in Patent Document 2 described above with reference to FIG. 8, since the flexible substrate 61 is provided between the heat radiating member 66 and the hologram unit 62, the heat radiating member is generated from the hologram unit 62. Heat toward 66 is blocked by the flexible substrate 61. For this reason, there is a problem that heat generated from the hologram unit 62 cannot be efficiently radiated by the heat radiating member 66.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical pickup that efficiently dissipates heat generated from a light source and is excellent in flexibility and is excellent in assemblability and adjustability, and a method for manufacturing the same.

  An optical pickup according to the present invention includes a light source unit on which a light source that emits a light beam is mounted, an objective lens that condenses the light beam emitted from the light source on the surface of an information recording medium, and the light source unit. A heat radiating plate having a plurality of through-holes opposed to the back surface, at least a part of the through-holes arranged to face the back portion of the light source unit among the plurality of through-holes, and the heat radiating plate and the light source unit It has the adhesive agent in the interface with the back surface of.

  The method for manufacturing an optical pickup according to the present invention includes a step of attaching an adhesive to at least a part of the plurality of through holes of the heat radiating plate in contact with a back surface portion of the light source unit.

  As described above, according to the present invention, there is provided an optical pickup that efficiently dissipates heat generated from a light source and is excellent in flexibility, and is excellent in assemblability and adjustability, and a method for manufacturing the same. Can do.

  In the optical pickup according to the present embodiment, the elastic members formed on both surfaces of the heat sink through a part of the plurality of through holes formed in the heat sink conduct the heat generated from the light source to the heat sink. Therefore, it is formed so as to contact the back surface of the light source unit. For this reason, the heat generated from the light source can be efficiently radiated through the heat radiating plate.

  In this embodiment, it is preferable that the light source emitted from the light source further includes a light receiving element that receives reflected light reflected by the information layer of the information recording medium on the surface of the light source unit.

  The adhesive preferably has room temperature curability.

  The adhesive preferably has elasticity.

  The adhesive preferably has thermal conductivity.

  It is preferable to further include a fastening means for fastening the base fixed via the holding member holding the light source unit and the heat radiating plate.

  The plurality of through holes are preferably formed on the entire surface of the heat sink.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a configuration diagram of an optical pickup 100 according to the present embodiment, FIG. 2 is an exploded view of the optical pickup 100 according to the present embodiment, and FIGS. 3 and 4 are detailed partial configurations of the optical pickup 100 according to the present embodiment. FIG.

  1 to 4, a light source 1 such as a semiconductor laser and a light receiving element 15 are mounted on a light source unit 2. The light source unit 2 is held by a holding member 13 and soldered to the flexible printed board 3. The flexible printed circuit board 3 is connected to a pickup circuit section (not shown), and is connected to a main circuit (not shown) for controlling the optical pickup 16.

  The plate-like member 4 made of a metal or a material having high thermal conductivity such as carbon has a plurality of through holes 4c formed so as to connect the first surface 4a and the second surface 4b. doing. The member 4 is arranged such that the first surface 4a and the back surface 2a of the light source unit 2 face each other with a space therebetween. For example, the elastic member 5 made of a heat-dissipating material such as silicone, rubber, or high-viscosity grease is filled from the direction of the second surface 4 b of the member 4 and passes through the plurality of through holes 4 c of the member 4. Until the surface 4a of the light source unit 2 is touched over a wide area.

  The member 4 is held on a base 7 by a fixing member 6 such as a screw or an adhesive. When the member 4 is held by the fixing member 6, a pressing force acts on the back surface 2 a of the light source unit 2 through the elastic member 5, and the surface 13 a of the holding member 13 and the surface 7 a of the base 7 are in close contact with each other. ing.

  A deflecting mirror 8 that deflects the light beam 14 from the light source 1, a collimating lens 9 that condenses the diverging light of the light beam 14 into parallel light, and a light beam 14 a that has become parallel light by the collimating lens 9 is applied to a disk (not shown). On the other hand, the rising mirrors 10 that are vertically deflected are mounted on the base 7. The objective lens driving device 12 on which the objective lens 11 is mounted is adjusted and mounted on the base 7. The optical pickup 100 is constituted by these components.

  Here, when the light beam 14 is emitted from the light source 1, heat is generated. Referring to FIG. 3, the heat generated from the light source 1 is conducted to the member 4 through the elastic member 5. The member 4 conducts heat over a wide area by the plurality of through holes 4 c, and further conducts heat to the base 7 through the fixing member 6.

  Next, the operation of the optical pickup 100 will be described. The light beam 14 radiated from the light source 1 is guided to the collimating lens 9 by the deflecting mirror 8 to be condensed to become a light beam 14a which is parallel light, and is vertically deflected by a rising mirror 10 with respect to a disk (not shown). The light is condensed by the objective lens 11 to form a spot on the disk surface. The information signal recorded on the disc passes through the same optical path from the light source 1 to the objective lens 11 and is detected by the light receiving element 15. Based on the detected signal, the main circuit (not shown) controls the optical pickup 100 so that the portion of the objective lens driving device 12 on which the objective lens 11 is mounted follows the surface deviation or eccentricity with respect to the disc, or the recording operation. Or perform playback.

  Here, the light source unit 2 is adjusted so that the intensity distribution of the spots formed by being focused by the objective lens 11 is uniform. The objective lens driving device 12 is also adjusted so that the intensity distribution of the spot is uniform, and is adjusted so as to remove the light distortion called the coma of the spot.

  According to such a configuration, the elastic member 5 is brought into contact with the light source unit 2 to fill the first surface 4 a and the second surface 4 b of the member 4, so that the heat generated from the light source 1 causes the elastic member 5 to flow. It is conducted to the member 4 through, and conducts heat over a wide area by the plurality of through holes 4 c, and further conducts heat to the base 7 through the fixing member 6. For this reason, the heat generated from the light source 1 of the optical pickup can be efficiently radiated.

  Further, according to such a configuration, since the plurality of through holes 4 c are formed in the member 4, for example, even if it is a metal plate shape with high heat dissipation, the member 4 and the elastic member 5 are flexible. Adjustment at the optimum point is possible with the light source unit 2 attached.

  Further, according to such a configuration, the elastic member 5 can fix the member 4 and the light source unit 2 by curing after adjustment as long as the elastic member 5 is a material that cures after application or a material that cures when irradiated with ultraviolet rays. In particular, since the member 4 has a plurality of through holes 4c, the irradiation of ultraviolet rays can be performed stably. For this reason, if the process of irradiating and hardening an ultraviolet-ray is provided in manufacture of an optical pick-up, it can produce efficiently.

  In the present embodiment, the example of the shape shown in FIG. 5A in which the member 4 is provided with a plurality of through holes 4c for filling the elastic member 5 has been described, but the present invention is not limited to this. The plurality of through holes 4c may be formed on the entire surface of the member 4, or a net-like shape as shown in FIG. 5 (b) or a partially enlarged through hole as shown in FIG. 5 (c) may be formed. good.

  Moreover, the structure of the member 4 and the elastic member 5 is good also as a structure which uses the material of the elastic member 5 as resin with heat dissipation, and molds and attaches to the member 4. FIG.

  FIG. 6 is a perspective view showing a configuration of another optical pickup 100A according to the embodiment. As shown in FIG. 6, the member 4 is not directly attached to the base 7 using the fixing member 6, but is attached to the adjustment holding member 17 that is held for adjusting the optical axis of the light source 1. It is good also as composition to do.

  Further, the above-described embodiment is a basic configuration, and can be implemented in addition to a conventionally known technique by changing details within the scope of the right of the present invention.

  Thus, with a simple configuration, heat generated from the laser light source 1 is conducted to the member 4 through the elastic member 5, heat is conducted over a wide area by the plurality of through holes 4 c, and further, the base is made through the fixing member 6. 7 can conduct heat to the optical pickup, efficiently dissipate heat from the optical pickup, prevent deterioration of characteristics such as laser threshold shift due to heat, and extend the life of the laser light source 1.

  As described above, according to the present embodiment, the elastic members 5 formed on both surfaces of the member 4 through a part of the plurality of through holes 4 c formed in the member 4 can generate heat generated from the light source 1. 4 is formed so as to be in contact with the back surface 2a of the light source unit 2 so as to conduct to the light source 4. For this reason, the heat generated from the light source 1 can be efficiently radiated through the member 4.

It is a perspective view which shows the structure of the optical pick-up which concerns on embodiment. It is a disassembled perspective view which shows the structure of the optical pick-up which concerns on embodiment. It is a side view showing composition of an optical unit, a heat sink, an elastic member, etc. which were provided in an optical pickup concerning an embodiment. It is a perspective view showing composition of an optical unit, a heat sink, etc. provided in an optical pickup concerning an embodiment. (A) is a top view which shows the structure of the heat sink provided in the optical pick-up which concerns on embodiment, (b) is the top which shows the structure of the other heat sink provided in the optical pick-up concerning embodiment It is a figure, (c) is a top view which shows the structure of the further another heat sink provided in the optical pick-up which concerns on embodiment. It is a perspective view which shows the structure of the other optical pick-up which concerns on embodiment. The figure which shows the structure of the conventional optical pickup The figure which shows the structure of the other conventional optical pick-up

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 ... Light source 2,104 ... Light source unit 2a ... Light source unit back surface 3 ... Flexible printed circuit board 4 ... Member 4a ... Member's 1st surface 4b ... Member's 2nd surface 4c ... Several through-holes 5 of a member DESCRIPTION OF SYMBOLS 106 ... Elastic member 6 ... Fixed member 7, 105 ... Base 7a ... Base surface 8 ... Deflection mirror 9 ... Collimating lens 10 ... Rising mirror 11 ... Objective lens 12 ... Objective lens drive device 13 ... Holding member 13a ... Holding Surfaces 14 and 107 of the member ... Light beam 14a ... Light beam 15 of parallel light ... Light receiving element 16 ... Optical pickup 17 ... Holding member 103 for adjustment ... Heat sink

Claims (8)

A light source unit having a light source for emitting a light beam placed on the surface;
An objective lens that focuses the light beam emitted from the light source on the surface of an information recording medium;
A heat sink having a plurality of through holes disposed opposite to the back surface of the light source unit;
An optical pickup comprising an adhesive at least at a part of a through hole disposed opposite to a back surface portion of the light source unit among the plurality of through holes, and an interface between the heat radiating plate and the back surface of the light source unit. . The optical pickup according to claim 1, further comprising: a light receiving element that receives reflected light reflected by an information layer of the information recording medium, on the surface of the light source unit. The optical pickup according to claim 1, wherein the adhesive has room temperature curability. The optical pickup according to claim 1, wherein the adhesive has elasticity. The optical pickup according to claim 1, wherein the adhesive has thermal conductivity. The optical pickup according to claim 1, further comprising fastening means for fastening a base fixed via a holding member holding the light source unit and the heat radiating plate. The optical pickup according to claim 1, wherein the plurality of through holes are formed on an entire surface of the heat radiating plate. It is a manufacturing method of the optical pick-up in any one of Claims 1-7,
A method for manufacturing an optical pickup comprising the step of attaching an adhesive to at least a part of a plurality of through holes of the heat radiating plate in contact with a back surface portion of the light source unit.

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