JP2006013286A - Heat-conducting member, optical head using the same, and optical recorder/player using the optical head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-conducting member for conducting heat generated by a semiconductor laser, an optical head with variable characteristics stabilized such as optic characteristics and electric characteristics, capable of lengthening the service life of the semiconductor laser, and to provide an optical recorder/player employing the same. <P>SOLUTION: A heat-conducting member is provided for conducting heat generated by a semiconductor laser, an optical head using it, and an optical recorder/player using it. The semiconductor laser 3 is fixed to a case 31 of the optical head 1 by means of a holder 33. The heat-conducting member 37 is provided between the base 3b of the semiconductor laser 3 and an FPC 35 electrically connected with electrode terminals 3d, 3e and 3f of the semiconductor laser 3. The heat-conducting member 37 serves to conduct the heat (heat-conducting) generated in the light emitter 3c of the semiconductor laser 3, and to discharge the heat to the holder 33 and the case 31 for holding the laser 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat conducting member for guiding heat generated by a semiconductor laser, an optical head using the same, and an optical recording / reproducing apparatus using the same.

  FIG. 7 shows a partial cross section of the conventional optical head 101 near the semiconductor laser (light source) 103 (the semiconductor laser 103 is shown without being cut). In FIG. 7, the entire semiconductor laser 103 is shown without being cut. As shown in FIG. 7, the semiconductor laser 103 includes a light emitting unit 103c that emits a light beam incident on the optical recording medium, and electrode terminals 103d and 103e connected to a power supply terminal and a reference potential terminal to the light emitting unit 103c. 103f. The electrode terminals 103d, 103e, and 103f are formed so as to protrude from the thin plate columnar base portion 103b. The electrode terminals 103d and 103f are disposed opposite to the central axis in a plane including the central axis of the base portion 103b with a predetermined gap, and the electrode terminal 103e is predetermined from the central axis in a plane including the central axis and perpendicular to the plane. The gap is provided. A cap 103a covering the light emitting portion 103c is fixed on the base portion 103b. The cap 103a has an exit (not shown) through which the light beam is emitted.

  In general, the semiconductor laser 103 is attached to the opening provided in the housing 105 from the outside of the housing 105 of the optical head 101, and the light beam exit formed in the cap 103 a is directed to the inside of the housing 105. Has been placed. The electrode terminals 103 d, 103 e, and 103 f are arranged facing the outside of the housing 105.

  The holder 107 for holding the semiconductor laser 103 is made of a conductive metal material and has an opening 109 for avoiding the electrode terminals 103d, 103e, and 103f. If the holder 107 and the electrode terminals 103d, 103e, and 103f are in contact with each other, the optical head 101 may be seriously damaged due to a short circuit. Therefore, the opening 109 is formed to have a sufficient size so that they do not contact each other. ing. The casing 105 side of the opening 109 is formed in a concave shape by the thickness of the base portion 103b. When the holder 107 on which the semiconductor laser 103 is placed is fixed by inserting the cap 103 a into the opening of the housing 105, the base portion 103 b is sandwiched between the housing 105 and the holder 107. Thereby, the semiconductor laser 103 is fixed to the housing 105. The holder 107 is fixed to the housing 105 using screws or an adhesive (both not shown).

  Although not shown, the housing 105 side is formed in a concave shape by the thickness of the base portion 103b, the semiconductor laser 103 is directly fitted into the housing 105, and the side opposite to the light beam emission direction of the semiconductor laser 103 ( An optical head 101 having a structure in which a holder 107 is arranged from the electrode terminals 103 d, 103 e, and 103 f side) and the semiconductor laser 103 is fixed to a housing 105 is also known. The semiconductor laser 103 may be fixed to the housing 105 by deforming (caulking) the housing 105 or using an adhesive.

  The electrode terminals 103 d, 103 e and 103 f protruding from the opening 109 of the holder 107 are soldered to a flexible printed circuit board (hereinafter abbreviated as FPC) 35 with solder 39. Thereby, the semiconductor laser 103 is connected to the power supply circuit (not shown) via the FPC 35.

  The recording / reproducing optical head 101 is required to have a better shape for the recording / reproducing light spot focused on the optical recording medium. Therefore, in order to adjust the position of the light emitting point of the semiconductor laser 103 and the emission direction of the laser light emitted from the semiconductor laser 103, the semiconductor laser 103 is attached to the housing 105 while adjusting the position and inclination through the holder 107. Often attached.

The holder 107 and the housing 105 also serve as a heat sink for releasing heat generated from the semiconductor laser 103. In particular, the recordable optical head 101 generates a high-intensity light beam at the time of recording, and therefore generates a large amount of heat from the semiconductor laser 103. The holder 107 or the housing 105 places importance on thermal conductivity and heat dissipation. Metal materials are used. Also in the semiconductor laser 103, the light emitting portion 103c, which is a heat generating portion, is provided on a pedestal integrated with a base portion 103b made of a metal material, and efficiently transfers heat to the base portion 103b. Since the metal material is a conductive material, the holder 107 and the housing 105 have a shape and a structure such that only the cap 103a and the base portion 103b are brought into contact with the semiconductor laser 103 but not the electrode terminal 103d. In general, the electrode terminals 103 d and the like are formed very close to the light emitting portion 103 c that is the heat generating portion of the semiconductor laser 103.
JP 2003-272208 A JP 2004-111507 A

  Thus, the holder 107 is provided with the opening 109 so as not to contact the electrode terminal 103d and the like. In addition, a predetermined gap is provided between the base portion 103b and the FPC 35 so that the semiconductor laser 103 is not damaged by heat during soldering to the FPC 35. By the way, most of the heat generated in the light emitting portion 103c is released from the base portion 103b. However, the opening 109 is hollow and is filled with air. The thermal conductivity of air is as small as 0.0241 (W / m · K) at 0 ° C. For this reason, as indicated by the dashed arrows in FIG. 7, the heat generated in the light emitting portion 103 c is conducted to the holder 107 and the housing 105 through the base portion 103 b and conducted to the holder 107 through the opening 109. Are very few. As described above, since the heat conduction path is limited, the heat generated in the light emitting unit 103c is not sufficiently released, and various characteristics such as optical characteristics and electrical characteristics of the semiconductor laser 103 change to change the optical head 101. The performance of the camera deteriorates or the service life is shortened.

  Patent Document 1 discloses an optical pickup in which a thermally conductive resin is interposed between a laser diode and an adjacent portion adjacent thereto, and a semiconductor laser is fixed to a pickup base. However, when resin is used for heat release, there is a possibility that a gap is generated between the laser diode and the adjacent portion due to shrinkage during resin curing. In addition, depending on the resin used, a gas is generated during curing, and other parts may be adversely affected by the gas. Furthermore, the resin to be filled needs to have a high viscosity in order to prevent it from dripping or leaking from the gap, and such a liquid agent has a poor workability because it takes time to discharge and fill.

An object of the present invention is to provide a heat conducting member that efficiently guides heat generated by a semiconductor laser.
Another object of the present invention is to provide an optical head in which various characteristics such as optical characteristics and electrical characteristics are stabilized and the life of the semiconductor laser can be extended, and an optical recording / reproducing apparatus using the optical head.

  The object is to form a first contact portion that is made of an insulating material and is in thermal contact with a base portion of a semiconductor laser, a second contact portion that is in thermal contact with a holder that holds the semiconductor laser, and This is achieved by a heat conducting member having a hollow hole formed so as to surround the electrode terminal protruding from the base portion.

  In the heat conducting member of the present invention, the insulating material is a ceramic material.

  In the heat conducting member of the present invention, the ceramic material is aluminum nitride.

  The heat conducting member according to the invention is characterized in that the insulating material is silicon rubber.

  The heat conducting member according to the invention is characterized in that the first contact portion can be in close contact with the base portion.

  In the heat conducting member according to the present invention, the second contact portion can be in close contact with the holder.

  In the heat conducting member of the present invention, the hollow hole portion is formed so as to collectively surround the plurality of electrode terminals protruding from the base portion.

  In the heat conducting member of the present invention, the hollow hole portion is formed so as to surround each of the plurality of electrode terminals protruding from the base portion.

  Another object of the present invention is to make thermal contact with a semiconductor laser that emits laser light to an optical recording medium, a housing that fixes the semiconductor laser, a holder that holds the semiconductor laser, and a base portion of the semiconductor laser. A heat conducting member including a first contact portion, a second contact portion that is in thermal contact with the holder, and a hollow hole portion that is formed so as to surround the electrode terminal protruding from the base portion; This is achieved by an optical head characterized by:

  The optical head of the present invention is characterized in that the heat conducting member is the heat conducting member of the present invention.

  The optical head according to the invention is characterized in that the heat conducting member is held between a printed wiring board electrically connected to the electrode terminal and the base portion.

  The optical head according to the invention is characterized in that the heat conducting member is held between the base portion and the holder.

  In the optical head according to the invention, the heat conducting member is in thermal contact with the vicinity of the heat generating portion of the semiconductor laser.

  The above object is achieved by an optical recording / reproducing apparatus having the above optical head of the present invention.

  According to the present invention, by using a heat conducting member having excellent thermal conductivity, the heat generated by the semiconductor laser is sufficiently released, and various characteristics such as optical characteristics and electrical characteristics of the semiconductor laser are improved and the life is extended. An optical head that can be realized and an optical recording / reproducing apparatus using the same can be realized.

[First Embodiment]
A heat conducting member and an optical head using the same according to the first embodiment of the present invention will be described with reference to FIGS. First, a schematic configuration of the optical head according to the present embodiment will be described with reference to FIG. FIG. 1A shows the optical head 1 according to the present embodiment and a part of the optical recording medium 29, which is orthogonal to the information recording surface of the optical recording medium 29 and is tangent to the track of the optical recording medium 29. In order to facilitate understanding, the cross-section cut along a plane parallel to the direction is shown, and the upright mirror 15 and the quarter-wave plate 17 that are disposed in the housing 31 and cannot be visually recognized are shown transparently. FIG. 1B shows a state in which the optical system arranged in the semiconductor laser 3 and the casing 31 is viewed in a direction perpendicular to the information recording surface of the optical recording medium 29, and the casing is shown in order to facilitate understanding. The quarter-wave plate 17 disposed in 31 is omitted.

  The configuration and operation of the optical element group will be described with reference to FIGS. 1 (a) and 1 (b). The light beam emitted from the semiconductor laser 3 that is a light source passes through the diffraction grating 7 to become three beams for tracking error detection, and enters the beam splitter 9. The beam splitter 9 has a polarization characteristic that transmits 90% or more of P-polarized light and reflects almost 100% of S-polarized light. The forward light beam in the present embodiment is P-polarized light, and most of the light is transmitted through the beam splitter 9, but about several percent of the reflected light is incident on the front monitor photodetector 11, and its output is output. Originally, the output of the semiconductor laser 3 is controlled.

  Most of the light beam that has passed through the beam splitter 9 enters the collimating lens 13. The collimating lens 13 is movable in a direction parallel to the optical axis, and spherical aberration added to the light beam focused on the information recording surface of the optical recording medium 29 due to the thickness of the light transmission layer of the optical recording medium 29. If it is different from the reference value, the corresponding spherical aberration can be canceled by moving the collimating lens 13 in the optical axis direction.

  The light beam after passing through the collimating lens 13 is reflected by the rising mirror 15, the optical path is bent in the direction of the optical recording medium 29, passes through the ¼ wavelength plate 17, and is passed through the optical recording medium 29 by the objective lens 19. It is set as the focused light which injects into. The quarter-wave plate 17 converts the outward light beam into circularly polarized light, and further converts the circularly polarized light beam reflected and returned by the optical recording medium 29 into linearly polarized light in a direction orthogonal to the polarization direction of the outward light beam. It has the function to convert to.

  A spot is formed on the information recording surface in the optical recording medium 29, and the reflected light beam returns along the return path to the beam splitter 9. The light beam returned to the beam splitter 9 is reflected because it is S-polarized light by the action of the quarter-wave plate 17.

  The reflected light beam enters the concave lens 21. When the optical head 1 is assembled and adjusted, the concave lens 21 is moved in the optical axis direction so that the position of the image point in the optical axis direction in the vicinity of the light receiving surface in the photodetector 25 which is a light receiving element can be adjusted. Yes. The light beam that has passed through the concave lens 21 passes through the cylindrical lens 23 to be given astigmatism for focus error detection, and enters the photodetector 25. The concave lens 21 and the cylindrical lens 23 may be replaced with one anamorphic lens having both functions. The light beam incident on the photodetector 25 is converted into an electric signal by the light receiving portion inside the light beam.

  Next, the heat conducting member and the optical head using the same according to the present embodiment will be described with reference to FIG. FIG. 2 is an enlarged view of α in FIG. FIG. 2A shows a partial cross section of the optical head 1 near the semiconductor laser 3 (the semiconductor laser 3 is shown without being cut). In FIG. 2A, the entire semiconductor laser 3 is shown without being cut. FIG. 2B shows an end face cut along the line AA in FIG. As shown in FIG. 2A, the semiconductor laser 3 is fixed to the housing 31 of the optical head 1 using a holder 33. A heat conducting member 37 is disposed between the base portion 3b of the semiconductor laser 3 and the FPC 35 that is electrically connected to the electrode terminals 3d, 3e, and 3f of the semiconductor laser 3. The heat conducting member 37 functions to conduct heat generated in the light emitting portion 3 c of the semiconductor laser 3 (heat conduction) and to release the heat to the holder 33 and the housing 31 that hold the semiconductor laser 3.

  The semiconductor laser 3 includes a light emitting unit 3c that emits a light beam incident on an optical recording medium 29 (not shown in FIG. 2), and electrode terminals 3d and 3e connected to a power supply terminal and a reference potential terminal for the light emitting unit 3c. 3f. The electrode terminals 3d, 3e, and 3f are formed so as to protrude from the thin plate columnar base portion 3b. A cap 3a covering the light emitting portion 3c is fixed on the base portion 3b. The cap 3a has an exit (not shown) through which the light beam is emitted. In the semiconductor laser 3, a cap 3 a is inserted into an opening formed in the housing 31 so that the emitted light is directed toward the inside of the optical head 1. The housing 31 is made of a metal material. The holder 33 disposed from the electrode terminals 3d, 3e, and 3f side is also formed of a metal material, and an opening having a size that does not contact the electrode terminal 3d of the semiconductor laser 3 is formed. The contact surface side of the holder 33 with the housing 31 is formed in a concave shape by the thickness of the base portion 3b. When the holder 33 on which the semiconductor laser 3 is placed is fixed by inserting the cap 3 a into the opening of the housing 31, the base portion 3 b is sandwiched between the housing 31 and the holder 33. Thereby, the semiconductor laser 3 is fixed to the housing 31. The holder 33 is fixed to the housing 31 using screws or an adhesive (both not shown).

  A heat conducting member 37 is disposed so as to be embedded in the opening of the holder 33. The contact surface of the holder 33 with the FPC 35 (the back surface of the holder 33) and the contact surface of the heat conducting member 37 with the FPC 35 are included in the same plane. A hollow hole portion 37 c is formed in the heat conducting member 37, and the electrode terminals 3 d, 3 e, 3 f are inserted into the hollow hole portion 37 c and protrude from the opening of the holder 33. The electrode terminals 3 d, 3 e, 3 f protruding from the opening of the holder 33 are soldered to the FPC 35 with solder 39. Thereby, the semiconductor laser 3 is connected to a power supply circuit (not shown) via the FPC 35. If the soldering iron heat diffuses through the heat conducting member 37 during soldering and the soldering workability is poor, an FPC 35 with a glass epoxy substrate having a high heat insulating effect may be used.

  As shown in FIGS. 2A and 2B, the heat conducting member 37 is made of an insulating material and is formed in a thin plate cylindrical shape. The heat conducting member 37 is made of, for example, a ceramic material such as aluminum nitride (AlN) using an ordinary sintering method as an insulating material. Further, the heat conducting member 37 is in contact with the first contact portion 37 a that is in thermal contact with the flat surface of the base portion 3 b (the back surface of the base portion 3 b) on the FPC 35 side, and the second contact that is in thermal contact with the side wall of the opening of the holder 33. Part 37b.

  The size of the heat conducting member 37 is formed so as to fit in a space surrounded by the back surface of the base portion 3b, the front surface of the FPC 35 facing the back surface of the base portion 3b, and the side wall of the holder 33. In general, the base portion 3b of the semiconductor laser 3 is gold-plated. Since gold is relatively soft, adhesion increases when a certain amount of pressure is applied. For this reason, the adhesion between the back surface of the base portion 3b and the first contact portion 37a can be enhanced by applying pressure to the heat conducting member 37 side of the semiconductor laser 3 with the housing 31 and the holder 33.

  If pressure cannot be applied due to the strength of the casing 31 or the holder 33, a better effect may be obtained by applying a heat conductive resin and filling a minute gap. . Since the amount of resin to be applied is very small, various problems as shown in the conventional example do not occur if a resin that does not generate corrosive gas during curing (for example, heat curing) is used.

  One hollow hole 37c of the heat conducting member 37 is formed so as to surround the electrode terminals 3d, 3e, and 3f. The electrode terminals 3d and 3f are disposed opposite to the central axis in a plane including the central axis of the base portion 3b with a predetermined gap, and the electrode terminal 3e is predetermined from the central axis in a plane including the central axis and perpendicular to the plane. The gap is provided. For this reason, the hollow hole portion 37c is formed in a hollow shape of a triangular prism so as to collectively surround the three electrode terminals 3d, 3e, and 3f.

  Next, heat conduction by the heat conducting member 37 will be described. The thermal conductivity of AlN of the heat conducting member 37 is about 100 to 200 (W / m · K). Therefore, AlN has a thermal conductivity several thousand times that of air. For this reason, when thermal contact with the base 3b and the holder 33 is ensured and the heat conducting member 37 is embedded in the opening of the holder 33, as shown by the broken arrow in FIG. The conducted heat is guided to the holder 33 and the casing 31 through the base portion 3b, flows into the heat conducting member 37 from the first contact portion 37a through the back surface of the base portion 3b, and flows out from the second contact portion 37b. Guided to the holder 33. In this manner, by arranging the heat conducting member 37 on the back surface of the base portion 3b, the path for guiding the heat generated in the light emitting portion 3c to the holder 33 and the housing 31 can be increased as compared with the conventional optical head 101. And can sufficiently release the heat.

Instead of AlN, silicon carbide (SiC) or silicon nitride (Si ₃ N ₄ ) may be used as a material for forming the heat conducting member 37. The thermal conductivity of SiC is about 200 to 260 (W / m · K), and the thermal conductivity of Si ₃ N ₄ is about 25 to 100 (W / m · K). Therefore, the heat conducting member 37 formed of these materials can also sufficiently conduct the heat generated by the semiconductor laser 3 to the holder 33 and the housing 31.

  As described above, according to the present embodiment, the optical head 1 has the heat conducting member 37 that has a higher thermal conductivity than air and is formed of an insulating material. Since the path for guiding the heat generated by the laser 3 to the holder 33 and the housing 31 can be increased, the heat can be sufficiently released. Further, since the heat conducting member 37 can be disposed closer to the heat generating part (light emitting part 3 c) of the semiconductor laser 3 than the housing 31, heat can be efficiently guided to the holder 33 and the housing 31. As a result, the heat dissipation of the optical head 1 can be improved, the temperature rise of the semiconductor laser 3 can be prevented, various characteristics such as the optical characteristics and electrical characteristics of the semiconductor laser 3 can be stabilized, and the life can be extended. .

  Next, a modification of the present embodiment will be described with reference to FIG. FIG. 3 shows a state where the heat conducting member 37 according to the first and second modifications is viewed from the first contact portion 37a side. FIG. 3A shows a heat conducting member 37 of the first modification. FIG. 3B shows a heat conducting member 37 of the second modification. In FIG. 3, the electrode terminals 3d, 3e, and 3f are shown together for easy understanding.

  As shown in FIG. 3A, the heat conducting member 37 according to the first modified example is characterized in that the cross section of the hollow hole portion 37c is formed in an inverted Y shape in the drawing. The hollow hole portion 37c is formed to extend from the substantially central portion of the virtual triangle having the electrode terminals 3d, 3e, and 3f as vertices to the electrode terminals 3d, 3e, and 3f. The cross-sectional area of the hollow hole portion 37c of this modification can be made smaller than the cross-sectional area of the hollow hole portion 37c of the above embodiment. Thereby, the contact area of the 1st contact part 37a and the base part 3b back surface can be enlarged, and the thermal radiation effect can be improved from the said embodiment.

  As shown in FIG. 3B, the heat conducting member 37 of the second modified example is characterized in that it includes three hollow holes 37c formed so as to surround the electrode terminals 3d, 3e, and 3f, respectively. is doing. The inner diameter of the hollow hole portion 37c is slightly larger than the outer diameter of the electrode terminals 3d, 3e, and 3f. For this reason, the cross-sectional area of the hollow hole part 37c of this modification can be made smaller than the cross-sectional area of the hollow hole part 37c of the said embodiment and a 1st modification. Thereby, the contact area of the 1st contact part 37a and the base part 3b back surface can be enlarged. Furthermore, since the hollow hole portion 37c can be brought closer to the electrode terminals 3d, 3e, and 3f, the heat dissipation effect can be improved as compared with the above embodiment and the first modification.

  The heat conducting member 37 of the above embodiment and the first and second modifications has a hollow hole portion 37c so as not to contact the electrode terminals 3d, 3e, and 3f. However, since the heat conducting member 37 is formed of an insulating material, even if the hollow hole portion 37c is formed so that the heat conducting member 37 contacts the electrode terminals 3d, 3e, and 3f, the electrode terminals 3d, 3e, and 3f are connected to each other. Will not short circuit. Moreover, the heat dissipation effect can be further improved by bringing the heat conducting member 37 into contact with the electrode terminals 3d, 3e, and 3f.

[Second Embodiment]
Next, a heat conducting member according to a second embodiment of the present invention and an optical head using the same will be described with reference to FIG. FIG. 4 shows a partial cross section of the optical head 1 according to this embodiment in the vicinity of the semiconductor laser 3 (the semiconductor laser 3 is shown without being cut). The optical head 1 according to the present embodiment is characterized in that the heat conducting member 37 is held between the base portion 3 b and the holder 33. As shown in FIG. 4, when the heat conducting member 37 and the semiconductor laser 3 are inserted into the opening of the holder 33 of the present embodiment, the cap 3 a side plane (the surface of the base 3 b) of the base 3 b is the surface of the holder 33. It is formed in a concave shape by the thickness of the heat conducting member 37 and the base portion 3b so as to be included in the same plane as the contact surface with the housing 31. The contact surface side of the holder 33 with the housing 31 is opened slightly larger than the outer diameter of the base portion 3b, and the back surface side of the holder 33 is opened smaller than the outer diameter of the base portion 3b.

  The outer diameter of the heat conducting member 37 is formed to be approximately the same as the outer diameter of the base portion 3 b so as to be in thermal contact with the side wall of the opening of the holder 33 and to be held on the back side of the holder 33. When the semiconductor laser 3 is held by the holder 33 and the casing 31, the heat conducting member 37 is pressurized by the base portion 3b and the holder 33, and the adhesion between the back surface of the base portion 3b and the first contact portion 37a can be improved. .

[Third Embodiment]
Next, a heat conducting member and an optical head using the same according to a third embodiment of the present invention will be described with reference to FIG. FIG. 5 shows a partial cross section in the vicinity of the semiconductor laser 3 of the optical head 1 according to the present embodiment (the semiconductor laser 3 is shown without being cut). The optical head 1 of the present embodiment is characterized in that the contact surface side of the housing 31 with the holder 33 is formed in a concave shape by the thickness of the base portion 3b. As shown in FIG. 5, the housing 31 of the present embodiment is formed in a concave shape by the thickness of the base portion 3 b on the contact surface side with the holder 33, so that the semiconductor laser 3 is fitted into the housing 31. The contact surface of the housing 31 with the holder 33 and the back surface of the base portion 3b are included in the same plane. For this reason, the semiconductor laser 3 is held by the housing 31 and the holder 33 by disposing the holder 33 having an opening having an inner diameter smaller than the outer diameter of the base portion 3 b. Further, the heat conducting member 37 is held between the base portion 3b and the FPC 35 by embedding the heat conducting member 37 in the opening of the holder 33 and soldering the FPC 35 to the electrode terminals 3d, 3e, and 3f. Since the heat conducting member 37 can ensure thermal contact with the base portion 3b and the holder 33, the same effect as the above embodiment can be obtained.

  Next, a modification according to this embodiment will be described. In the present embodiment, the heat conducting member 37 is made of a ceramic material. On the other hand, this modified example is characterized in that the heat conducting member 37 is formed of silicon rubber. The heat conducting member 37 of this modification is formed in a sheet shape from a low-hardness heat radiating resin, for example, silicon rubber containing an inorganic filler and having increased thermal conductivity, and is formed in substantially the same shape as the heat conducting member 37 of the above embodiment. Has been. The heat conducting member 37 can be attached in contact with the semiconductor laser 3 so as to be pierced by the electrode terminals 3d, 3e, and 3f of the semiconductor laser 3. Further, in this case, since the heat conducting member 37 can be brought into contact with the electrode terminals 3d, 3e, and 3f close to the heat generating portion, the heat radiation effect can be enhanced. Since the hollow hole portion 37 c is formed by inserting the semiconductor laser 3 into the heat conducting member 37, it is not necessary to form the hollow hole portion 37 c in the heat conducting member 37 in advance.

  The thermal conductivity of silicon rubber is about 1 to 6 (W / m · K), which is lower than the thermal conductivity of the ceramic material used in the above embodiment. However, the thermal conductivity of silicon rubber is several tens to several hundred times higher than the thermal conductivity of air. For this reason, the heat conducting member 37 is formed of silicon rubber and secures thermal contact with the back surface of the base portion 3b and the side wall of the opening portion of the holder 33, thereby guiding the heat generated by the semiconductor laser 3 to the holder 33 and the housing. Heat can be released to the body 31. In addition, since silicon rubber is a flexible material, the adhesiveness between the base portion 3b and the holder 33 can be improved as compared with the heat conducting member 37 formed of AlN. Thereby, the heat conducting member 37 of the present modification can obtain the same effects as those of the above embodiment. Note that the heat conducting member 37 of the present modification can also be used for the heat conducting member 37 of the first and second embodiments.

  Next, an optical recording / reproducing apparatus equipped with the optical head 1 according to the first to third embodiments of the present invention will be described with reference to FIG. FIG. 6 shows a schematic configuration of an optical recording / reproducing apparatus 50 equipped with the optical head 1 according to the present embodiment. As shown in FIG. 6, the optical recording / reproducing apparatus 50 includes a spindle motor 52 for rotating the optical recording medium 29, an optical head 1 that irradiates the optical recording medium 29 with a laser beam and receives the reflected light, and a spindle. A controller 54 that controls the operation of the motor 52 and the optical head 1, a laser drive circuit 55 that supplies a laser drive signal to the optical head 1, and a lens drive circuit 56 that supplies a lens drive signal to the optical head 1 are provided. .

  The controller 54 includes a focus servo tracking circuit 57, a tracking servo tracking circuit 58, and a laser control circuit 59. When the focus servo tracking circuit 57 is activated, the information recording surface of the rotating optical recording medium 29 is focused, and when the tracking servo tracking circuit 58 is activated, the eccentric signal track of the optical recording medium 29 is activated. On the other hand, the laser beam spot is in an automatic tracking state. The focus servo tracking circuit 57 and the tracking servo tracking circuit 58 are respectively provided with an auto gain control function for automatically adjusting the focus gain and an auto gain control function for automatically adjusting the tracking gain. The laser control circuit 59 is a circuit that generates a laser drive signal supplied from the laser drive circuit 55, and generates an appropriate laser drive signal based on the recording condition setting information recorded on the optical recording medium 29. I do.

  The focus servo tracking circuit 57, the tracking servo tracking circuit 58, and the laser control circuit 59 do not need to be circuits incorporated in the controller 54, and may be separate components from the controller 54. Furthermore, these need not be physical circuits, and may be software executed in the controller 54.

The present invention is not limited to the above embodiment, and various modifications can be made.
The heat conducting member 37 of the first to third embodiments is formed in a thin cylindrical shape, but the present invention is not limited to this. For example, as long as the heat conducting member 37 can be in thermal contact with the base portion 3b and the holder 33, the same effects as those of the above-described embodiment can be obtained even in a thin prismatic shape having a hollow hole portion 37c.

  Further, the shape of the semiconductor laser 3 as the light source is not limited to the first to third embodiments. For example, even if the semiconductor laser 3 is integrated with a light receiving element or an optical element, the same effect as in the above embodiment can be obtained.

  Moreover, although the heat conducting member 37 of the first to third embodiments is formed of a ceramic material or a silicon rubber material, the present invention is not limited to this. For example, a sheet-like silicon rubber may be sandwiched between the heat conducting member 37 made of a ceramic material and the base portion 3b. In this case, since the adhesiveness between the heat conducting member 37 and the base portion 3b can be enhanced by the flexibility of the silicon rubber, the same effect as in the above embodiment can be obtained.

  Moreover, although the 1st contact part 37a of the said 1st thru | or 3rd embodiment is a plane, and the 2nd contact part 37b is a curved surface, this invention is not limited to this. For example, as long as the 1st contact part 37a can contact the base part 3b back surface, the shape etc. which follow a flat surface, a curved surface, or the base part 3b back surface may be sufficient. Further, the second contact portion 37 b may be flat, curved, or shaped to follow the side wall of the opening of the holder 33 as long as it can contact the side wall of the opening of the holder 33. Also in this case, the same effect as the above embodiment can be obtained.

It is a figure which shows the optical head 1 by the 1st Embodiment of this invention. FIG. 3 is a view showing the vicinity of a semiconductor laser 3 of the optical head 1 according to the first embodiment of the invention. FIG. 6 is a first and second modification of the optical head 1 according to the first embodiment of the present invention, and is a view showing a heat conducting member 37 viewed from the first contact portion 37a side. It is a figure which shows the semiconductor laser 3 vicinity of the optical head 1 by the 2nd Embodiment of this invention. It is a figure which shows the semiconductor laser 3 vicinity of the optical head 1 by the 3rd Embodiment of this invention. It is a figure which shows schematic structure of the optical recording / reproducing apparatus by the 1st thru | or 3rd embodiment of this invention. It is a figure which shows the semiconductor laser 103 vicinity of the conventional optical head 101. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 Optical head 3, 103 Semiconductor laser 3a, 103a Cap 3b, 103b Base part 3c, 103c Light emission part 3d, 3e, 3f, 103d, 103e, 103f Electrode terminal 7 Diffraction grating 9 Beam splitter 11 Front monitor photodetector 13 Collimating lens 15 Rising mirror 17 1/4 wavelength plate 19 Objective lens 21 Concave lens 23 Cylindrical lens 25 Photo detector 29 Optical recording medium 31, 105 Case 33, 107 Holder 35 Flexible printed circuit board 37 Heat conducting member 37a First Contact portion 37b Second contact portion 37c Hollow hole portion 39 Solder 50 Optical recording / reproducing device 52 Spindle motor 54 Controller 55 Laser drive circuit 56 Lens drive circuit 57 Focus servo tracking circuit 58 Tracking servo tracking circuit 59 Laser controller Circuit 109 opening

Claims (14)

Formed of insulating material,
A first contact portion in thermal contact with the base portion of the semiconductor laser;
A second contact portion in thermal contact with a holder holding the semiconductor laser;
And a hollow hole formed to surround the electrode terminal protruding from the base. The heat conducting member according to claim 1,
The heat insulating member, wherein the insulating material is a ceramic material. The heat conducting member according to claim 2,
The heat conducting member, wherein the ceramic material is aluminum nitride. The heat conducting member according to claim 1,
The heat conducting member, wherein the insulating material is silicon rubber. The heat conducting member according to any one of claims 1 to 4,
The first contact portion can be in close contact with the base portion. The heat conducting member according to any one of claims 1 to 5,
The heat conducting member according to claim 2, wherein the second contact portion can be in close contact with the holder. The heat conducting member according to any one of claims 1 to 6,
The hollow hole portion is formed so as to collectively surround the plurality of electrode terminals protruding from the base portion. The heat conducting member according to any one of claims 1 to 6,
The hollow hole portion is formed so as to surround each of the plurality of electrode terminals protruding from the base portion. A semiconductor laser that emits laser light to an optical recording medium;
A housing for fixing the semiconductor laser;
A holder for holding the semiconductor laser;
A hollow formed so as to surround a first contact portion that is in thermal contact with the base portion of the semiconductor laser, a second contact portion that is in thermal contact with the holder, and an electrode terminal protruding from the base portion. An optical head comprising: a heat conducting member provided with a hole. The optical head according to claim 9, wherein
The optical head according to claim 2, wherein the heat conducting member is the heat conducting member according to claim 2. The optical head according to claim 9 or 10, wherein
The optical head is characterized in that the heat conducting member is held between a printed wiring board electrically connected to the electrode terminal and the base portion. The optical head according to claim 9 or 10, wherein
The optical head is characterized in that the heat conducting member is held between the base portion and the holder. The optical head according to any one of claims 9 to 12,
The optical head, wherein the heat conducting member is in thermal contact with the vicinity of the heat generating portion of the semiconductor laser.   An optical recording / reproducing apparatus comprising the optical head according to claim 9.

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