JP4379249B2 - Optical disk device - Google Patents

Description

  The present invention relates to an optical disk device, and more particularly to a structure for radiating heat generated from the semiconductor laser element.

  In an optical disk device such as a DVD player, on / off of the semiconductor laser element is controlled at a very high frequency, so a large amount of heat is generated from the semiconductor laser element. On the other hand, it is known that the power of a laser beam output from a semiconductor laser element suddenly decreases when the temperature of the semiconductor laser element exceeds a certain level. Therefore, various heat dissipation structures have been proposed in the past in order to keep the temperature of the semiconductor laser element below a certain level.

  In Patent Document 1, an elastic member having good thermal conductivity is brought into contact with the semiconductor laser element, and heat generated by the semiconductor laser element is not transmitted to the housing (optical pickup base member) of the optical pickup, but via the elastic member. To the base (main body).

  In Patent Document 2, a U-shaped heat sink is provided on the outer surface side of the semiconductor laser element, and heat generated in the semiconductor laser element is further transmitted to the guide shaft for moving the optical pickup via the heat sink. Yes.

  In Patent Document 3, the optical pickup base member itself is formed of a material having good thermal conductivity, and heat generated in the semiconductor laser element is radiated by a guide shaft for moving the optical pickup base member and the optical pickup.

  In Patent Document 4, in order to dissipate heat generated by the light receiving element instead of the semiconductor laser element, the light receiving element itself is attached to a plate having excellent thermal conductivity and heat dissipation.

In Patent Document 5, a heat radiating plate is further screwed to the holder of the semiconductor laser element to enhance the heat dissipation effect of the heat generated by the semiconductor laser element.
JP-A-5-258334 JP-A-8-335328 JP 2000-242953 A Japanese Patent Laid-Open No. 2002-237072 Utility Model Registration No. 3093294

  In an optical disk device such as a DVD player, various efforts have been made such as using a resin molded product for the optical pickup base member in accordance with the reduction in size and weight of the optical disk device main body. For this reason, in order to dissipate the heat generated in the semiconductor laser element, it is not realistic to form the optical pickup base member with a material having high thermal conductivity or to provide a heat sink having a special shape.

  The present invention has been made to solve the above problems, and provides an optical disc apparatus using an optical pickup having a structure capable of efficiently dissipating heat generated in a semiconductor laser element using existing components. The purpose is to do.

In order to achieve the above object, the invention of claim 1
A semiconductor laser element that outputs a laser beam to an optical disc;
A light receiving element for receiving a reflected beam reflected by the optical disc;
A part of the laser beam output from the semiconductor laser element is transmitted, the rest is reflected in the first predetermined direction, a part of the reflected beam reflected by the optical disk is transmitted, and the rest is reflected in the second predetermined direction. Half mirror to
A laser beam that is transmitted through the half mirror or reflected in the first predetermined direction by the half mirror is converted into a parallel light beam, and the reflected beam reflected by the optical disk is converged on the light receiving surface of the light receiving element. A lens,
An objective lens for converging the laser beam converted into a parallel beam by the collimator lens on the data recording surface of the optical disc and converting the reflected beam reflected by the optical disc into a parallel beam;
A lens holder for holding the objective lens;
A focusing servo mechanism for moving the reflected light reflected by the optical disc in a direction parallel to the optical axis of the lens holder and the objective lens held by the lens holder;
A tracking servo mechanism for swinging the lens holder and the objective lens held by the lens holder around its optical axis;
An optical pickup base member made of resin that holds at least the semiconductor laser element, the light receiving element, the half mirror, and the collimator lens;
In an optical disc apparatus using an optical pickup including a metal actuator base member that holds the lens holder, the focusing servo mechanism, and the tracking servo mechanism,
The actuator base member is provided on the surface side of the optical pickup base member facing the optical disk via an inclination adjustment mechanism,
The surface of the optical pickup base member opposite to the surface facing the optical disk is covered with the semiconductor laser element held by a metal block, the half mirror, the light receiving element, and the semiconductor laser. A heat sink made of metal is provided to dissipate the heat generated by the element,
By fixing the heat radiating plate via an adjusting screw for adjusting the inclination of the actuator base member, heat generated by the semiconductor laser element is radiated by the block, the heat radiating plate and the adjusting screw. The heat is transferred to the actuator base member through the adjusting screw and is radiated by the actuator base member.

  According to the first aspect of the present invention, the actuator base member, which has conventionally been a component of the optical disk apparatus, can be used as a heat radiating member. Therefore, the optical disk apparatus is generated in the semiconductor laser element without increasing the weight and cost. Heat can be effectively dissipated. Further, since the heat dissipation effect is enhanced, the heat dissipation plate and the like can be reduced in size, and the optical disk apparatus can be reduced in size and weight. Furthermore, the heat generated in the semiconductor laser element is transmitted to the actuator base member using an adjusting screw for adjusting the tilt of the actuator base member, so that the overall heat capacity is increased and the temperature of the semiconductor laser element is increased. Therefore, the performance of the optical disc apparatus can be stabilized.

  An optical disc apparatus according to an embodiment of the present invention will be described. FIG. 1 shows the configuration of the optical disc apparatus 1 according to the present embodiment. The optical disk device 1 includes a table 3 on which an optical disk 2 is mounted, a spindle motor 4 that rotationally drives the table 3 and the optical disk 2 mounted thereon, and irradiates a data recording surface of the optical disk 2 with a laser beam. Controls an optical pickup 5 for reading data recorded on the optical disc, an optical pickup driving mechanism 6 for moving the optical pickup 5 in the radial direction of the optical disc 2, and a spindle motor 4, the optical pickup 5 and the optical pickup driving mechanism 6. It is comprised by the control part 7 for performing.

  The optical disk device 1 is, for example, a DVD player, and reads data from a reproduction-only DVD (ROM) and CD (ROM). In this read-only optical disc apparatus 1, the power of the laser beam output from the semiconductor laser element is smaller and the amount of heat generated is smaller than that of an optical disc apparatus capable of recording data on an optical disc such as a DVD recorder. For this reason, a resin molded product is used as the optical pickup base member in consideration of weight reduction and cost reduction of the optical disk device.

  A basic configuration of the optical pickup 5 in the optical disc apparatus 1 is shown in FIG. The optical pickup 5 includes a first laser light source 51 that outputs a first laser beam having a wavelength of 660 nm (first wavelength) suitable for a DVD (first optical disk), and a wavelength 797 nm (second optical signal) that is suitable for a CD (second optical disk). A second laser light source 52 for outputting a second laser beam having a wavelength. The first laser light source 51 and the second laser light source 52 are provided approximately parallel to each other with a distance of about 100 μm, and are formed as a single chip as one semiconductor laser element 50.

  A diffractive optical element 53 is provided to diffract the laser beam so as to face the light emitting surface of the semiconductor laser element 50 and separate it into three beams of a main beam by 0th order diffracted light and a sub beam by ± 1st order diffracted light. Yes. On the extension of the optical axis connecting the semiconductor laser element 50 and the diffractive optical element 53, a half mirror 54 that transmits a part of the laser beam separated by the diffractive optical element 53 and reflects the rest in a substantially perpendicular direction. Is provided. On the optical axis bent at a right angle by the half mirror 54, a collimator lens 55 for converting the laser beam reflected by the half mirror 54 into a parallel beam, and a parallel beam by the collimator lens 55 on the data recording surface of the optical disc 2 An objective lens 56 for convergence is provided. Further, the optical axis bent at right angles by the half mirror 54 is reflected by the optical disc 2 on the extension opposite to the optical disc 2, converged by the objective lens 56 and the collimator lens 55, and further transmitted through the half mirror 54. A light receiving element 57 for receiving the reflected beam is provided.

  A specific configuration of the optical pickup 5 will be described. FIG. 3 is a front view showing the configuration of the optical pickup, FIG. 4 is a sectional view taken along the line AA, and FIG. 5 is a bottom view thereof. 3 to FIG. 5 further includes a total reflection mirror 58 for bending the optical axis of the optical system by 90 degrees, and the semiconductor laser element 50 and the light receiving element 57 are used for data recording on the optical disc 2. They are arranged on the same plane parallel to the surface.

  As described above, in a read-only optical disc apparatus such as a DVD player, the power of the laser beam output from the semiconductor laser element is small and the amount of heat generated is small. Therefore, a resin molded product is used as the optical pickup base member 100 in consideration of weight reduction and cost reduction of the optical disk device. Therefore, since the optical pickup base member 100 itself cannot be used as a heat sink, the semiconductor laser element 50 is conventionally held by a metal block 60, and a heat sink 61 is connected to the metal block 60. The heat generated by the semiconductor laser element 50 is radiated. As shown in FIG. 5, the heat radiating plate 61 also functions as a cover member that covers the semiconductor laser element 50, the diffractive optical element 53, the half mirror 54, the light receiving element 57, the total reflection mirror 58, and the like.

  The optical pickup base member 100 is provided to surround the reference table 101 facing the optical disc 2, the reference table 101, a substrate fixing portion 102 to which the printed circuit board 120 is fixed on the side surface, and the optical pickup driving mechanism 6. The rack portion 103 and the like are screwed into a pinion gear (not shown). On the surface of the reference table 101 facing the optical disk 2, a focusing servo mechanism that moves the objective lens 56 up and down in the direction of the optical axis and a tracking servo mechanism that swings the objective lens 56 around the optical axis are unitized. The actuator unit 110 is mounted. Further, the semiconductor laser element 50, the diffractive optical element 53, the half mirror 54, the light receiving element 57, and the like are arranged on the surface of the reference table 101 opposite to the surface facing the optical disc 2, and the collimator lens 55 is connected to the reference table. It is fixed to the table 101. Each component constituting the optical pickup 5 is positioned with respect to the reference table 101.

  The actuator unit 110 is made of a metal actuator base member 111, a shaft 112 implanted on the actuator base member 111, reciprocates along the shaft 112, swings about the shaft 112, and the objective lens 56. Lens holder 113, two permanent magnets 114, a focusing coil 115 and a tracking coil 116 provided on the lens holder 113, and the like.

  Of the elements constituting the optical system of the optical pickup 5, other elements except the objective lens are fixed to the optical pickup base member 100, and the optical axis is adjusted with reference to the reference table 101. ing. On the other hand, the objective lens 56 is held by the lens holder 113, and the lens holder 113 is held movably with respect to the actuator base member 111. Further, the actuator base member 111 is fixed on the reference table 101 of the optical pickup base member 100. Therefore, in order to adjust the optical axis of the objective lens 56, adjustment screws 117 and 118 for adjusting the inclination of the actuator base member 111 with respect to the reference table 101 of the optical pickup base member 100 are provided. The adjustment screw 117 adjusts the inclination of the actuator base member 111 in the AA cross section shown in FIG. 4, and the adjustment screw 118 adjusts the inclination of the actuator base member 111 in a plane perpendicular to the AA cross section. .

  As shown in FIG. 4, since the heat radiating plate 61 is fixed to the optical pickup base member 100 via adjusting screws 117 and 118 for adjusting the inclination of the actuator base member 111, it is generated by the semiconductor laser element 50. The heat is transmitted in the order of the block 60, the heat radiating plate 61, the adjusting screws 117 and 118, and the actuator base member 111, and is radiated from these members. Therefore, since the actuator base member 111 that has been conventionally a constituent element of the optical disk apparatus 1 can be used as a heat radiating member, the heat generated in the semiconductor laser element 50 can be generated without increasing the weight and cost of the optical disk apparatus 1. Heat can be effectively dissipated. Further, since the heat dissipation effect is enhanced, the heat dissipation plate 61 and the like can be reduced in size, and the optical disc apparatus 1 can be reduced in size and weight. Furthermore, since heat generated in the semiconductor laser element 50 is transmitted to the actuator base member 111 using the adjusting screws 117 and 118 for adjusting the inclination of the actuator base member 111, the overall heat capacity increases, The temperature rise of the semiconductor laser element 50 is suppressed, and the performance of the optical disc apparatus 1 can be stabilized.

  Needless to say, the present invention is not limited to the above-described embodiment, and can be applied to an optical disc apparatus capable of reading and recording data, such as a DVD recorder using an optical pickup base member of a resin molded product. In addition, a heat sink is not necessarily required. In an optical disk apparatus that reads data by irradiating a laser beam to an optical disk, heat generated by a semiconductor laser element that outputs the laser beam is transferred to a metal actuator base member. It is only necessary to be able to dissipate heat. Further, from the viewpoint of reducing the number of parts, for example, a screw hole is provided in a block that holds the semiconductor laser element, and heat generated in the semiconductor laser element is transferred to the actuator via an adjustment screw for adjusting the inclination of the actuator base member. The structure which transmits to a base member may be sufficient.

1 is a block diagram showing a configuration of an optical disc device according to an embodiment of the present invention. The figure which shows the structure of the optical pick-up in the said optical disk apparatus. The front view which shows the structure of the optical pick-up in the said one Embodiment. AA sectional view showing the composition of the above-mentioned optical pickup. The bottom view which shows the structure of the said optical pick-up.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk apparatus 2 Optical disk 5 Optical pick-up 50 Semiconductor laser element 53 Diffraction optical element 54 Half mirror 55 Collimator lens 56 Objective lens 57 Light receiving element 60 Block 61 Heat sink 100 Optical pick-up base member 101 Reference table 110 Actuator unit 111 Actuator base member 112 Axis 113 Lens holder 114 Permanent magnet (Focusing servo mechanism and tracking servo mechanism)
115 Focusing coil (Focusing servo mechanism)
116 Tracking coil (tracking servo mechanism)
117, 118 Adjustment screw (for adjusting the tilt of the actuator base member)

Claims (1)

A semiconductor laser element that outputs a laser beam to an optical disc;
A light receiving element for receiving a reflected beam reflected by the optical disc;
A part of the laser beam output from the semiconductor laser element is transmitted, the rest is reflected in the first predetermined direction, a part of the reflected beam reflected by the optical disk is transmitted, and the rest is reflected in the second predetermined direction. Half mirror to
A laser beam that is transmitted through the half mirror or reflected in the first predetermined direction by the half mirror is converted into a parallel light beam, and the reflected beam reflected by the optical disk is converged on the light receiving surface of the light receiving element. A lens,
An objective lens for converging the laser beam converted into a parallel beam by the collimator lens on the data recording surface of the optical disc and converting the reflected beam reflected by the optical disc into a parallel beam;
A lens holder for holding the objective lens;
A focusing servo mechanism for moving the reflected light reflected by the optical disc in a direction parallel to the optical axis of the lens holder and the objective lens held by the lens holder;
A tracking servo mechanism for swinging the lens holder and the objective lens held by the lens holder around its optical axis;
An optical pickup base member made of resin that holds at least the semiconductor laser element, the light receiving element, the half mirror, and the collimator lens;
In an optical disc apparatus using an optical pickup including a metal actuator base member that holds the lens holder, the focusing servo mechanism, and the tracking servo mechanism,
The actuator base member is provided on the surface side of the optical pickup base member facing the optical disk via an inclination adjustment mechanism,
The surface of the optical pickup base member opposite to the surface facing the optical disk is covered with the semiconductor laser element held by a metal block, the half mirror, the light receiving element, and the semiconductor laser. A heat sink made of metal is provided to dissipate the heat generated by the element,
By fixing the heat radiating plate via an adjusting screw for adjusting the inclination of the actuator base member, heat generated by the semiconductor laser element is radiated by the block, the heat radiating plate and the adjusting screw. An optical disc apparatus characterized in that heat is transferred to the actuator base member via the adjusting screw and is radiated by the actuator base member.

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