JP2007234069A - Optical pickup device and optical disk drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress optical aberration variations for an optical pickup device and an optical disk drive incorporating it. <P>SOLUTION: The optical pickup device has a collimator lens to make the light output from the light source almost parallel, a focusing lens to focus the almost parallel light on an information medium, a drive to change the position of the focusing lens, and a heat conductive material provided for the collimator lens. The drive has a coil and a magnet to change the position of the focusing lens and at least part of the heat conductive material is provided on the collimator lens at the side of the coil. Also part of the heat conduction material is provided on the collimator lens at the side of the light source drive. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical pickup device for optically recording and / or reproducing data, and an optical disk device equipped with the optical pickup device.

  An optical pickup device for optically recording / reproducing data with respect to an optical disc medium as an information medium is mounted on the optical disc apparatus. The optical pickup device includes a light source that outputs laser light and an optical system for irradiating the optical disk medium with the laser light. In such an optical pickup device, the temperature of the optical system rises due to the laser light output from the laser light source, and there is a problem that optical aberrations occur due to thermal expansion or contraction of each optical element included in the optical system. .

  In order to solve such a problem, in the optical pickup device disclosed in Patent Document 1, two types of astigmatism generated in the optical pickup device are equal in magnitude and opposite in polarity. Thus, the optical aberration is corrected.

  FIG. 8 is a diagram schematically showing the optical pickup device 111 disclosed in Patent Document 1. As shown in FIG.

  With reference to FIG. 8, the laser beam 101a output from the light source 101 is condensed by the collimating lens 102 to be substantially parallel light 101b. The laser beam 101a that has passed through the collimator lens 102 enters the beam shaping element 112 and is shaped. The passing light 101c that has passed through the beam shaping element 112 is reflected by the mirror 103 fixed to the support member 109, and the reflected light 101d is collected by the objective lens 104 and irradiated onto the optical disk medium 110.

  At this time, the mirror 103 and the support member 109 are deformed due to the temperature change, and the first astigmatism occurs due to the difference in the linear expansion coefficient between the mirror 103 and the support member 109. The optical path length between the light emitting point 101A of the light source 101 and the principal point 102B of the collimating lens 102 changes due to thermal expansion or contraction due to a temperature change of the optical base 108 including the light source 101 and the collimating lens 102. The focal position of the collimating lens 102 changes. When the substantially parallel light 101b having a phase distribution caused by the difference between the change amount of the optical path length and the change amount of the focal position passes through the beam shaping element 112, second astigmatism occurs.

In the optical pickup device 111 disclosed in Patent Document 1, the optical aberration is corrected by making the first astigmatism and the second astigmatism equal in magnitude and opposite in polarity. ing.
Japanese Patent Laying-Open No. 2004-281033 (paragraph numbers 0052 to 0061, FIG. 1)

  The objective lens 104 is supported by the lens holding unit 105 of the condenser lens driving unit 113, and is driven by the coil unit 106 and the magnet 107. When the optical spot is made to follow a desired track of the optical disk medium 110, the coil unit 106 is energized to change the position of the objective lens 104, and the coil unit 106 generates heat. Heat generated from the coil unit 106 by energization is conducted and reaches the collimating lens 102. Since this heat is conducted from the coil portion 106 side of the collimating lens 102, the heat is transferred to the collimating lens 102 without being uniformly conducted, so that the heat is locally transmitted. For this reason, there is a problem that the collimating lens 102 is locally thermally expanded or contracted and astigmatism due to such local deformation of the collimating lens 102 occurs.

  In general, when astigmatism occurs in the optical system of the optical pickup device, a converging spot formed on the optical disk medium is distorted, and the recording / reproduction quality of data and the reproduction quality of address signals and the like deteriorate. In addition, when defocusing occurs at the condensing point (deviation in the optical axis direction between the condensing point position and the optical disk medium), astigmatism in which the condensing spot shape extends in the track direction and the direction perpendicular thereto occurs. Since these astigmatisms affect adjacent tracks or reduce the signal resolution in the track direction, they greatly affect the performance of the optical pickup device. In particular, in an optical pickup device used for recording / reproducing data on a DVD (Digital Versatile Disc) or the like having a high recording density, an allowable variation in astigmatism due to a temperature change is extremely severe from 0.00λ to ± 0.010λ. ing.

  In the assembly process of the optical pickup device, an optical system is incorporated in the optical pickup device so that the astigmatism of each optical element is suppressed in the initial state at room temperature. However, as described above, when the coil unit 106 (FIG. 8) generates heat and the temperature of the optical system changes, the state of the optical system deviates from the best state in which astigmatism is suppressed.

  FIG. 9 shows astigmatism fluctuations in the focused spot when the amount of current supplied to the coil unit 106 is increased. The horizontal axis is power consumption, and the vertical axis is the amount of variation of third-order astigmatism. When the coil portion 106 is energized, heat is generated, and heat is transmitted to the collimating lens 102 to generate astigmatism. In the example shown in FIG. 7, the astigmatism fluctuation amount is 0.020λ when the coil section 106 is energized with a rated power consumption of 0.3 W, and it is difficult to maintain a stable recording / reproducing operation.

  Further, when the optical pickup device is reduced in size, weight, and thickness, the coil unit 106 must be disposed in the vicinity of the collimating lens 102, and the collimating lens 102 becomes more susceptible to heat, thereby causing fluctuations in astigmatism. There is a problem that becomes larger.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical pickup device in which fluctuations in optical aberration are suppressed, and an optical disk device equipped with the optical pickup device.

  The optical pickup device of the present invention includes a collimating lens that makes light output from a light source substantially parallel light, a condensing lens that condenses the substantially parallel light onto an information medium, and a drive that changes the position of the condensing lens. And a heat conducting member provided on the collimating lens.

  According to an embodiment, the driving unit includes a coil unit and a magnet that change a position of the condenser lens, and at least a part of the heat conducting member is provided on the coil unit side of the collimating lens. Yes.

  According to an embodiment, the heat conducting member is provided on the entire outer periphery of the collimating lens.

  According to an embodiment, the thermal conductivity of the heat conducting member is higher than the thermal conductivity of the collimating lens.

  According to an embodiment, the thermal conductivity of the heat conducting member is about 1 W / (m · K) or more.

  According to an embodiment, the apparatus further includes a sliding portion that slides the collimating lens.

  An optical disc device according to the present invention includes the optical pickup device, a motor that rotates the information medium, and a control unit that controls the driving unit.

  The optical pickup device of the present invention includes a light source that outputs light, a collimator lens that makes the light output from the light source substantially parallel light, a condensing lens that condenses the substantially parallel light onto an information medium, A driving unit that drives a light source and a heat conducting member provided in the collimating lens are provided.

  According to an embodiment, at least a part of the heat conducting member is provided on the drive unit side of the collimating lens.

  According to an embodiment, the heat conducting member is provided on the entire outer periphery of the collimating lens.

  According to an embodiment, the thermal conductivity of the heat conducting member is higher than the thermal conductivity of the collimating lens.

  According to an embodiment, the thermal conductivity of the heat conducting member is about 1 W / (m · K) or more.

  According to an embodiment, the apparatus further includes a sliding portion that slides the collimating lens.

  An optical disc device according to the present invention includes the optical pickup device, a motor that rotates the information medium, and a control unit that controls the driving unit.

  According to the present invention, the collimating lens is provided with the heat conducting member. By conducting the heat generated from the driving unit that changes the position of the condenser lens and / or the driving unit that drives the light source to the collimating lens through the heat conducting member, it is possible to suppress the heat transfer. As a result, local deformation of the collimating lens can be prevented and fluctuations in optical aberration of the optical pickup device can be suppressed, so that stable recording / reproducing operation can be realized. In addition, since the drive unit and the collimator lens can be disposed close to each other, the optical pickup device can be reduced in size, weight, and thickness.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
First, a first embodiment of an optical pickup device according to the present invention will be described with reference to FIG. FIG. 1 is a diagram schematically showing an optical pickup device 100 of the present embodiment. The optical pickup device 100 is mounted on an optical disc device (not shown) for optically recording and / or reproducing data.

  The optical pickup device 100 includes a light source 1 that outputs laser light 1 a, a collimator lens 2 that condenses the laser light 1 a into substantially parallel light 1 b, a mirror 3 that reflects substantially parallel light 1 b, and reflection by the mirror 3. The condensing lens 4 that condenses the substantially parallel light 1b onto the optical disc medium 10, the condensing lens drive unit 11 that changes the position of the condensing lens 4, and the heat conducting member 9 provided in the collimating lens 2. . The optical pickup device 100 further includes an optical base 8 in which the above-described components are accommodated. The optical disk medium 10 is an information medium for recording and / or reproducing desired data.

  The light source 1 is, for example, a semiconductor laser element. The laser beam 1a is, for example, any one of a laser beam having a center wavelength of 660 nm called red, a laser beam having a center wavelength of 790 nm called infrared, and a laser beam having a center wavelength of 405 nm called blue. The condenser lens 4 is an objective lens, for example.

  The condenser lens driving unit 11 changes the position of the condenser lens 4 so that the light spot follows a desired track of the optical disk medium 10. The condensing lens driving unit 11 includes a lens holding unit 5 that holds the condensing lens 4, and a coil unit 6 and a magnet 7 that change the position of the condensing lens 4. Similar to the condenser lens 4, the coil portion 6 is also held by the lens holding portion 5. A magnetic circuit is configured by the coil unit 6 and the magnet 7 disposed to face the coil unit 6. The position of the condensing lens 4 is changed by the force generated between the coil unit 6 and the magnet 7 when the coil unit 6 is energized from a drive circuit (not shown).

  Each of the light source 1, the collimating lens 2, the mirror 3, and the condenser lens driving unit 11 is adjusted to be optically optimal and fixed to the optical base 8.

  The heat conducting member 9 is formed of a resin material such as a silicon-based sheet or a carbon graphite-based sheet, and is attached to a part of the outer peripheral portion of the collimating lens 2. At least a part of the heat conducting member 9 is provided on the coil part 6 side of the collimating lens 2. The thermal conductivity of the heat conducting member 9 is higher than that of the collimating lens 2. The thermal conductivity of the heat conducting member 9 is preferably 1 W / (m · K) or more.

  Examples of the material of the heat conductive member 9 include a room temperature curable silicon-based grease having a thermal conductivity of 1 to 3 W / (m · K) and a heat conductivity of 1 to 5 W / (m · K) 2. Liquid addition reactive silicon-based grease, a photocurable silicon-based adhesive having a thermal conductivity of 1 to 5 W / (m · K), and a silicon-based sheet having a thermal conductivity of 1 to 30 W / (m · K). Can be mentioned. Further, for example, the material of the heat conductive member 9 may be an aluminum-based material having a thermal conductivity of 100 to 300 W / (m · K), and further a thermal conductivity of 300 to 800 W / (m · K). And a very high carbon graphite sheet.

  Although not shown, the heat conducting member 9 is also provided on the optical base 8.

  Next, the operation of the optical pickup device 100 will be described in more detail.

  The laser beam 1a output from the light source 1 is condensed by the collimating lens 2 and made into substantially parallel light 1b. The substantially parallel light 1 b that has passed through the collimating lens 2 is reflected by the mirror 3, collected by the condenser lens 4, and irradiated onto the optical disk medium 10. In order to cause the focused spot formed on the optical disk medium 10 to follow a desired track of the optical disk medium 10, a current is supplied from a drive circuit (not shown) to the coil unit 6, and the lens holding unit 5 and the lens holding unit 5 hold the current. The position of the condenser lens 4 changes. The moving direction of the condensing lens 4 is based on the direction of the optical disc medium 10 (referred to as the focus direction), the eccentric direction of the optical disc medium 10 (referred to as the tracking direction), and the rotational direction (tangential direction) of the optical disc medium 10 as axes. There is an inclined direction (referred to as a tilting direction). The coil winding and coil section 6 and the magnet 7 are designed so that the condenser lens 4 can move in these directions.

  When the coil unit 6 is energized, heat is generated from the coil unit 6. With reference to FIG. 1 and FIG. 2, how the heat generated from the coil portion 6 is conducted to the collimating lens 2 will be described. FIG. 2 is a diagram showing the collimating lens 2 and its peripheral components viewed from the direction of the arrow A shown in FIG.

  In the optical pickup device 100, the heat conducting member 9 is located between the collimating lens 2 and the coil portion 6. For this reason, the heat generated from the coil portion 6 is conducted in the heat conducting member 9 and is not conducted directly to the collimating lens 2. The heat generated from the coil portion 6 is transmitted through the contact portion 9 a to the collimating lens 2 after diffusing in the heat conducting member 9 attached to the outer peripheral portion of the collimating lens 2. Thereby, since heat is uniformly conducted to the outer peripheral portion of the collimating lens 2 to which the heat conducting member 9 is attached, it is possible to suppress the heat conduction to the collimating lens 2. Since local deformation of the collimating lens can be prevented, fluctuations in optical aberration of the optical pickup device 100 can be suppressed, and stable recording / reproducing operation can be realized.

  In addition, by diffusing the heat generated from the coil portion 6 to the optical base 8 via the heat conducting member 9, the proportion of the deviated heat conduction to the collimating lens 2 can be further suppressed.

  Thus, since the heat conducting member 9 is attached to the coil portion 6 side of the collimating lens 2, the influence of heat on the collimating lens 2 can be efficiently reduced.

  FIG. 3 shows astigmatism fluctuations in the focused spot when the amount of current supplied to the coil unit 6 is increased. The horizontal axis is power consumption, and the vertical axis is the amount of variation of third-order astigmatism. When the coil portion 6 is energized, heat is generated. However, since the heat conduction member 9 suppresses the deviated heat conduction to the collimating lens 2, the third-order astigmatism is compared with the conventional example shown in FIG. The amount of fluctuation is also greatly reduced. In the example shown in FIG. 3, the thickness of the heat conducting member 9 is 0.15 mm, and the amount of variation of the third-order astigmatism is −0.003λ when the coil portion 6 is energized with a rated power consumption of 0.3 W. Thus, the fluctuation amount is very small, and stable recording / reproducing operation can be maintained.

  As shown in FIG. 4, the heat conducting member 9 may be provided on the entire outer periphery of the collimating lens 2. FIG. 4 is a diagram showing the collimating lens 2 and its peripheral components viewed from the direction of the arrow A shown in FIG. As shown in FIG. 4, by attaching the heat conducting member 9 over the entire outer periphery of the collimator lens 2, more uniform heat conduction to the collimator lens 2 can be achieved as compared with the case where it is attached only to a part of the outer periphery. Can be realized.

  As described above, in the optical pickup device 100, by using the heat conducting member 9, the heat generated from the coil unit 6 is uniformly conducted to the collimating lens 2 without conducting the heat to the collimating lens 2, so that the collimating lens 2. It is possible to prevent the local deformation of the astigmatism, and to suppress the fluctuation amount of astigmatism. Stable recording / reproducing operation can be realized by suppressing the fluctuation amount of astigmatism. In addition, since the coil unit 6 and the collimating lens 2 can be arranged close to each other, the optical pickup device 100 can be reduced in size, weight, and thickness.

  In addition, by diffusing the heat generated from the coil portion 6 to the optical base 8 via the heat conducting member 9, the proportion of the deviated heat conduction to the collimating lens 2 can be further suppressed.

  In addition, when the light source 1 (FIG. 1) that outputs laser light having a center wavelength of 405 nm, which is called blue, is used, it is necessary to correct the optical aberration (particularly spherical aberration) of the laser light with very high accuracy. Therefore, as shown in FIG. 5, the optical pickup device 100 may be provided with a sliding portion 12 that slides the collimating lens 2, and the collimating lens 2 may be slid in the optical axis direction so that the optical aberration is optimized. . Thus, even when the relative position of the coil unit 6 and the collimating lens 2 changes and the two approach each other, local deformation of the collimating lens 2 can be prevented and the amount of astigmatism variation can be suppressed. .

(Embodiment 2)
A second embodiment of the optical pickup device according to the present invention will be described with reference to FIG. FIG. 6 is a diagram schematically showing the optical pickup device 200 of the present embodiment. In FIG. 6, the same components as those of the optical pickup device 100 shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In addition to the components of the optical pickup device 100, the optical pickup device 200 includes a light source driving unit 13 that drives the light source 1 to emit light, and a circuit unit 14 such as a printed board or a flexible printed board on which the light source driving unit 13 is mounted. Is provided.

  The light source driving unit 13 causes the light source 1 to emit light when receiving a command from a control circuit (not shown). At this time, a current for causing the light source 1 to emit light flows through the light source driving unit 13, and heat is generated from the light source driving unit 13.

  In the optical pickup device 200, at least a part of the heat conducting member 9 is provided on the light source driving unit 13 side of the collimating lens 2 and is positioned between the collimating lens 2 and the light source driving unit 13. For this reason, the heat generated from the light source driving unit 13 is conducted in the heat conducting member 9 and is not conducted directly to the collimating lens 2. The heat generated from the light source driving unit 13 is transmitted to the collimating lens 2 after diffusing in the heat conducting member 9 attached to the outer periphery of the collimating lens 2. Thereby, since heat is uniformly conducted to the outer peripheral portion of the collimating lens 2 to which the heat conducting member 9 is attached, it is possible to suppress the deviated heat conduction to the collimating lens 2. Since local deformation of the collimating lens can be prevented, fluctuations in optical aberration of the optical pickup device 200 can be suppressed, and stable recording / reproducing operation can be realized.

  As described above with reference to FIG. 4, the heat conducting member 9 may be provided on the entire outer peripheral portion of the collimating lens 2. As shown in FIG. 4, by attaching the heat conducting member 9 over the entire outer periphery of the collimator lens 2, more uniform heat conduction to the collimator lens 2 can be achieved as compared with the case where it is attached only to a part of the outer periphery. Can be realized.

  Further, as described above with reference to FIG. 5, even when the sliding portion 12 slides the collimating lens 2 and the relative position between the light source driving portion 13 and the collimating lens 2 changes and both approach, Local deformation of the collimating lens 2 can be prevented, and the amount of astigmatism variation can be suppressed.

  As described above, in the optical pickup device 200, the heat generated from the light source driving unit 13 is uniformly conducted to the collimator lens 2 by using the heat conducting member 9, so that the collimator lens 2 is locally localized. Can be prevented and the amount of astigmatism variation can be suppressed. Stable recording / reproducing operation can be realized by suppressing the fluctuation amount of astigmatism. In addition, since the light source driving unit 13 and the collimating lens 2 can be arranged close to each other, the optical pickup device 200 can be reduced in size and weight and thinned.

(Embodiment 3)
With reference to FIG. 7, an embodiment of an optical disc apparatus according to the present invention will be described. FIG. 7 is a diagram schematically showing the optical disc apparatus 400 of the present embodiment. The optical disc device 400 includes an optical pickup device 300. The optical pickup device 300 includes the components of the optical pickup devices 100 and 200 (FIGS. 1 and 6), and provides the same effects.

  In the optical pickup device 300, the coil unit 6 and the light source driving unit 13 are arranged in substantially the same direction when viewed from the collimating lens 2. For this reason, at least a part of the heat conducting member 9 is provided on the coil unit 6 side and the light source driving unit 13 side of the collimating lens 2. At least a part of the heat conducting member 9 is located between the collimating lens 2 and the coil part 6 and at the same time located between the collimating lens 2 and the light source driving part 13.

  The optical disc device 400 is a device that optically records and / or reproduces data with respect to the optical disc medium 10. The optical disc apparatus 400 includes a motor 50, a drive control circuit 51, a signal processing circuit 52, a power control circuit 53, an optical disc control circuit 54, and a central processing circuit 55.

  The motor 50 rotates the optical disc medium 10. The drive control circuit 51 is a circuit that controls operations of the motor 50, the condenser lens driving unit 11, the light source driving unit 13, and the circuit unit 14. The drive control circuit 51 supplies a driving current to the condensing lens driving unit 11 to cause the condensing spot to follow along the focus direction, tracking direction, and tilting direction of the optical disc medium 10. In addition, the drive control circuit 51 outputs a command to the light source drive unit 13 for causing the light source 1 to emit light.

  The signal processing circuit 52 binarizes the servo signal output from the photodetector (not shown) and performs arithmetic processing. The power control circuit 53 receives a signal output from a power monitor unit (not shown) that monitors the output power of the light source 1 and supplies the light source 1 with a current at which the output power of the light source 1 is an appropriate value. The light source driving unit 13 is controlled. The optical disk control circuit 54 operates so as to perform recording and / or reproduction operations on a desired optical disk medium 10 according to a command from the central processing circuit 55. The optical disc control circuit 54 controls operations of the drive control circuit 51, the signal processing circuit 52, and the power control circuit 53.

  Since the optical disk device 400 includes the optical pickup device 300, the same effects as the effects of the present invention described in the first and second embodiments can be obtained. As described above, according to the present invention, the optical pickup device can be reduced in size, weight, and thickness, and accordingly, the optical disc device can be reduced in size, weight, and thickness. Further, it is possible to realize an optical disc apparatus that performs a stable recording / reproducing operation.

  As mentioned above, although this invention has been illustrated using preferable embodiment of this invention, this invention should not be limited and limited to these embodiment. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge from the description of specific preferred embodiments of the present invention. Patents, patent applications, and documents cited herein should be incorporated by reference in their entirety, as if the contents themselves were specifically described herein. Understood.

  As described above, the optical pickup device and the optical disc device of the present invention are particularly useful in the technical field for optically recording and / or reproducing data on an optical disc medium.

It is a figure which shows the optical pick-up apparatus by Embodiment 1 of this invention. It is a figure which expands and shows a part of optical pick-up apparatus by Embodiment 1 of this invention. It is a figure which shows the relationship between the amount of electricity supply to the coil part by Embodiment 1 of this invention, and the variation | change_quantity of the astigmatism of a condensing spot. It is a figure which expands and shows a part of optical pick-up apparatus by Embodiment 1 of this invention. It is a figure which shows the optical pick-up apparatus by Embodiment 1 of this invention. It is a figure which shows the optical pick-up apparatus by Embodiment 2 of this invention. It is a figure which shows the optical disk apparatus by Embodiment 3 of this invention. It is a figure which shows the conventional optical pick-up apparatus. It is a figure which shows the relationship between the amount of electricity supply to the coil part in a prior art, and the variation | change_quantity of the astigmatism of a condensing spot.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Collimating lens 3 Mirror 4 Condensing lens 5 Lens holding part 6 Coil part 7 Magnet 8 Optical base 9 Thermal conduction member 10 Optical disk medium 11 Condensing lens drive part 12 Sliding part 13 Light source drive part 14 Circuit part 100,200 , 300 Optical pickup device 400 Optical disc device

Claims (14)

A collimating lens that makes light output from the light source substantially parallel;
A condensing lens for condensing the substantially parallel light onto an information medium;
A drive unit for changing the position of the condenser lens;
An optical pickup device comprising: a heat conducting member provided on the collimating lens. The drive unit includes a coil unit and a magnet that change the position of the condenser lens,
The optical pickup device according to claim 1, wherein at least a part of the heat conducting member is provided on the coil portion side of the collimating lens.   The optical pickup device according to claim 1, wherein the heat conducting member is provided on an entire outer peripheral portion of the collimating lens.   4. The optical pickup device according to claim 1, wherein a heat conductivity of the heat conducting member is higher than a heat conductivity of the collimating lens.   5. The optical pickup device according to claim 1, wherein the thermal conductivity of the heat conducting member is about 1 W / (m · K) or more.   The optical pickup device according to claim 1, further comprising a sliding portion that slides the collimating lens. An optical pickup device according to any one of claims 1 to 6,
A motor for rotating the information medium;
An optical disc apparatus comprising: a control unit for controlling the driving unit. A light source that outputs light;
A collimating lens for making the light output from the light source substantially parallel light;
A condensing lens for condensing the substantially parallel light onto an information medium;
A drive unit for driving the light source;
An optical pickup device comprising: a heat conducting member provided on the collimating lens.   The optical pickup device according to claim 8, wherein at least a part of the heat conducting member is provided on the drive unit side of the collimating lens.   The optical pickup device according to claim 8 or 9, wherein the heat conducting member is provided on an entire outer peripheral portion of the collimating lens.   11. The optical pickup device according to claim 8, wherein a thermal conductivity of the thermal conductive member is higher than a thermal conductivity of the collimating lens.   The optical pickup device according to claim 8, wherein the thermal conductivity of the thermal conductive member is about 1 W / (m · K) or more.   The optical pickup device according to claim 8, further comprising a sliding portion that slides the collimating lens. An optical pickup device according to any one of claims 8 to 13,
A motor for rotating the information medium;
An optical disc apparatus comprising: a control unit for controlling the driving unit.

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