JP2002312968A - Optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk device that sufficiently radiates heat generated from a laser light source. SOLUTION: The optical disk device is equipped with an optical head unit having a laser light source that records or reproduces signals on a disk, a heat transmitting member that is in contact with the laser light source, and a heat radiating member that is connected to the heat transmitting member, and the device is also equipped with a spindle motor for rotatably driving the disk. The heat transmitting member and the heat radiating member are composed of a high-heat conductor. The device is so structured that the heat radiating member is provided near the spindle motor if the optical head unit is situated on the inner periphery of the disk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk apparatus for optically recording or reproducing information on an information recording medium using a laser light source.

[0002]

2. Description of the Related Art In recent years, in optical disk devices such as CDs and DVDs, the density has been increasing in order to handle a large amount of information including images. At the same time, an optical disc device for recording or reproducing this information is required to have higher accuracy.

First, FIG. 6 shows a schematic diagram of a conventional optical disk device. Reference numeral 1 denotes a laser light source, a semiconductor laser being typical. Reference numeral 2 denotes a heat transfer member, which is made of a material having high thermal conductivity such as copper or aluminum.
Is in contact with Reference numeral 3 denotes an optical base on which the heat transfer member 2 is fixed. 4 is a collimating lens, 5 is a polarization beam splitter, 6 is a 1/4 wavelength plate, 7 is a reflection mirror, 8
Denotes an objective lens, and both are optical components mounted on the optical base 3. Reference numeral 9 denotes an optical disk, which is an information recording medium for recording or reproducing a signal using a laser. 10
Reference numeral denotes a spindle motor, which rotatably supports the optical disk 9. Reference numeral 11 denotes a condenser lens and reference numeral 12 denotes a photodetector, both of which are optical components mounted on the optical base 3.
Reference numeral 13 denotes a guide shaft, and two substantially parallel axes are the optical base 3.
Is supported so as to be transported in the radial direction (X direction in the figure) of the optical disk 9.

In this optical system, light traveling in the Z direction emitted from the laser light source 1 is converted into parallel light by a collimator lens 4 and enters a polarization beam splitter 5.
Here, the light emitted from the laser light source 1 is linearly polarized light, and the light is transmitted with high efficiency in the polarization direction of the emitted light, and the light has a polarization direction perpendicular to the direction. Since the polarizing film having a characteristic of reflecting light with high efficiency is applied to the beam splitter 5, the parallel light passes through the polarizing beam splitter 5, passes through the 波長 wavelength plate 6, and is converted into circularly polarized light. . The circularly polarized light is bent in the Y direction by the reflection mirror 7, condensed by the objective lens 8, and irradiated on the optical disc 9. The light reflected by the optical disk 9 passes through the objective lens 8, is again bent in the −Z direction by the reflection mirror 7, and is converted from circularly polarized light to linearly polarized light by passing through the 波長 wavelength plate 6. At this time, since the polarization direction is a direction perpendicular to the polarization direction of the linearly polarized light from the laser light source, the reflected light is reflected by the polarizing film of the beam splitter 5, is bent in the X direction, and is condensed by the condenser lens 11. Is done. Then, the position of the light detector 12 is adjusted so that the collected light is incident on the light detector 12.

[0005]

However, in the configuration of the conventional optical disk apparatus as described above, the heat generated by the laser light source 1 is transmitted to the heat transfer member 2 and transmitted to the optical base 3 as it is. For this reason, thermal deformation of the optical base 3 which has received heat is induced, and the positional relationship of various optical components mounted on the optical base 3 changes, so that the center position of the laser beam incident on the photodetector 12 is changed. However, there is a problem that the position is shifted from a desired position and a stable signal cannot be obtained.

The life of a semiconductor laser, which is often used as a laser light source for an optical head device, is generally closely related to the temperature of the junction at the time of use. As the temperature increases, the life exponentially decreases. Are known. In addition, the higher the operating temperature, the lower the light output,
Since the oscillation wavelength changes with temperature, heat radiation of the laser in the optical head device is a very important issue in order to obtain a more stable signal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and efficiently radiates heat even when a large amount of heat is generated from a laser light source, thereby making it possible to extend the life of a laser and achieve stable recording or reproduction. It is an object to provide an optical disk device.

[0008]

An optical disk device according to the present invention comprises a laser light source for recording or reproducing a signal on or from a disk, a heat transfer member in contact with the laser light source, and a heat radiation member coupled to the heat transfer member. An optical head device, and an optical disk device including a spindle motor that drives the disk to rotate, wherein the heat transfer member and the heat radiating member are made of a high thermal conductor, and the optical head device is on the inner peripheral side of the disk. The above object is achieved by providing the heat radiation member near the spindle motor.

The heat transfer member and the heat radiating member may be the same member.

The slit direction of the heat radiating member may be configured to be substantially perpendicular to the disk surface.

Even when the optical head device is located on the outer peripheral side of the disk, the heat radiating member may be arranged near the spindle motor.

The heat dissipating member may be constituted by a heat pipe, with one end near the laser light source and the other end near the spindle motor.

[0013] A temperature detecting means may be provided near the laser light source, and when the temperature becomes higher than a predetermined value, the optical head device is transferred to the inner peripheral portion of the disk to rotate the disk.

A cooling member for contacting the optical head device is provided on the inner or outer peripheral portion of the traverse disk, and a temperature detecting means is provided near the laser light source. The optical head device may be transferred to a part or an outer peripheral part.

The contact portion of the cooling member may be an elastic body.

The contact portion of the cooling member may be made of silicon.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. In the following description, members corresponding to the members described with reference to FIG. 6 are denoted by the same reference numerals, and detailed description is omitted.

(Embodiment 1) FIG. 1 is a plan view showing a configuration of an optical disk device 100 according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 7a denotes a reflection mirror, which is an optical component that totally reflects incident light, and is fixed to the optical base 3. Reference numeral 14 denotes a heat dissipating member, which is a part of the heat transfer member 2 and is fixed below the inner peripheral side of the optical disk 9 and near the side surface of the spindle motor 10. The heat dissipating member 14 is made of a material having a high thermal conductivity such as copper or aluminum, and has a heat dissipating portion 14a made of fins and the like and a slit 14b. The direction of the slit 14 b of the heat radiation member 14 is configured to be the Y direction in the drawing, that is, substantially perpendicular to the surface of the optical disk 9 and substantially perpendicular to the longitudinal direction X of the guide shaft 13. Reference numeral 15 denotes a temperature detecting means, which is composed of, for example, a thermistor, and is fixed to a part of the heat transfer member 2 and in the vicinity of the laser light source 1. Reference numeral 16 denotes a base on which the spindle motor 10 and two guide shafts 13 are mounted. 1
Reference numeral 7 denotes a head transfer means, which is constituted by, for example, a motor having a shaft portion 17 a having a spiral groove, and mounted on the base 16. Reference numeral 18 denotes a nut piece, which is fixed to the optical base 3 and has a shaft portion 17 with a spiral groove of the head transfer means 17.
It is screwed with a.

The operation when the optical disk 9 is rotated by the spindle motor 10 in the optical disk device according to the first embodiment of the present invention configured as described above will be described with reference to FIGS. 1, 2 and 3. FIG. 2 is a plan view for explaining the behavior when the disk is rotated in the first embodiment of the present invention, and FIG. 3 is a side view for explaining the behavior when the disk is rotated in the first embodiment of the present invention.

First, when the optical disk 9 is rotated by the spindle motor 10 to record or reproduce a signal, an outward wind 21 is generated near the surface layer of the optical disk 9 due to friction on the disk surface and centrifugal force accompanying the disk rotation.
Occurs. At this time, since the air pressure decreases in the inner peripheral portion of the disk, air is taken in from the surroundings in order to set the air pressure. Since the upper part is blocked by the disk, air is taken in from the lower part, and a hoisting wind 31 shown in FIG. 3 is generated.

Here, since the slit portion 14b of the heat radiating member 14 is formed in the path of the hoisting wind 31, the heat radiating member 14 heated by the heat generated from the laser light source 1 is radiated and cooled, and the heat transfer member 2 and The temperature of the laser light source 1 can be reduced. In particular, in an optical disk device having a constant linear velocity such as CLV or Z-CLV, the disk rotation speed on the inner peripheral side is higher than the disk rotation speed on the outer peripheral portion, and the hoisting wind 31 generated by the inner peripheral portion is correspondingly large. Great heat dissipation effect.

Next, when the temperature of the laser light source 1 does not fall sufficiently by the heat radiation and the temperature detected by the temperature detecting means 15 becomes higher than a predetermined value, the head moving means 1
7, the optical head device 100 is moved to the inner peripheral side, and the optical disk 9 is rotated at a high speed to generate a wind 31 to perform a heat radiation operation. As described above, since the wind 31 is the strongest at the inner circumference of the disk, by executing this operation mode, the temperatures of the laser light source 1 and the optical base 3 can be sufficiently lowered to perform stable recording or reproduction.

As described above, according to the configuration of the optical disk device of the first embodiment, the temperature around the laser light source can be effectively reduced without using a separately driven component such as a fan. As a result, the output of the laser is stabilized, so that the laser can be maintained at a high output, which can contribute to a longer life of the laser. In addition, since deformation of the base at high temperatures can be prevented, there is a great advantage in that the quality of recording or reproduction signals is improved.

The direction of the slit 14b of the heat radiating member 14 is substantially perpendicular to the longitudinal direction X of the guide shaft 13, and the optical base 3 is used to record or reproduce signals on the outer peripheral side of the optical disk 9. Since the heat radiating member 14 is located in the vicinity of the spindle motor 10 even when the heat radiating member 14 is transferred, the heat radiating member 14 can receive the wind 31 and maintain the heat radiating effect.

Although the first embodiment has been described with the optical disk 9 being exposed, the optical disk 9 may be provided in a cartridge (not shown).
In this case, since a portion where the wind 31 is blocked by the cartridge is generated, the heat radiating portion 14a of the heat radiating member 14 is larger than the opening of the cartridge.
Must be provided in the vicinity of.

Further, in the first embodiment, the heat transfer member 2
Although the heat radiating member 14 and the heat radiating member 14 are separate members, they may be formed of the same member. In this case, in addition to the effect that the number of parts is reduced and the number of assembling steps can be reduced, since heat loss due to unevenness of the joint does not occur, a more efficient heat radiation effect can be obtained.

In the first embodiment, the wind 31
Is simply caused by the rotation of the disk. However, it is possible to develop applications such as forcibly strengthening the hoisting wind by providing blades on a part of the spindle motor 10, and in this case, the hoisting wind Since the wind speed of 31 can be increased, a further heat radiation effect can be obtained.

In the first embodiment, the temperature detecting means is detected by the thermistor. However, the temperature detecting means may be detected by using a signal such as using the amount of light incident on the photodetector 12 without providing any member. good.

(Embodiment 2) FIG. 4 is a plan view showing a configuration of an optical disk device 200 according to Embodiment 2 of the present invention. In FIG. 4, the difference from the optical disc device 100 according to the first embodiment is that the heat radiating member 14 is replaced with a heat pipe 24. In particular, heat pipe 2
4 is set near the laser light source 1 as a heat absorbing side 24a, and the other end is set as a heat radiating side 24b.
In the vicinity.

The heat pipe 24 is a heat transfer element in which the inside of the metal pipe is evacuated and a small amount of water or a substitute for chlorofluorocarbon is sealed as a working fluid. When the heat absorbing portion 24a, which is one end, is heated, the working fluid evaporates and becomes a steam flow with heat absorption by the latent heat of evaporation, and moves at a high speed to the low temperature portion, that is, the heat radiating portion 24b. There, it comes into contact with the tube wall, is cooled and condensed, and releases heat by the latent heat of condensation. The condensate returns to the heating section by utilizing the capillary phenomenon, etc.
Repeat the condensation cycle.

The basic operation of such an optical head device is basically the same as that of the first embodiment. The difference from the operation of the first embodiment is that the heat conduction by the solid is performed by the fluid instead of the heat conduction by the solid. The heat radiation effect can be further enhanced.

In the second embodiment, the heat radiation member 14
Is replaced with the heat pipe 24, but the heat transfer member 2 may be replaced with the heat pipe 24, that is, a heat radiating member such as a fin may be separately provided on the heat radiating side 24b of the heat pipe 24. Therefore, an optical disk device having a high responsiveness and a high heat radiation effect can be provided.

(Embodiment 3) FIG. 5 is a plan view showing a configuration of an optical disk device 300 according to Embodiment 3 of the present invention. In FIG. 5, the difference from the optical disc device 100 according to the first embodiment is that the heat radiating portion 2 a of the heat transfer member 2 is different.
And the cooling member 34 is arranged on the base 16 so as to be in contact with the heat radiating portion 2a when the optical base 3 is at the inner peripheral portion of the disk. The cooling member 34 is made of an elastic member so as to reduce the impact when the heat transfer member 2 comes into contact. In particular, the contact portion 34a is made of silicon, and enhances a heat radiation effect by a high heat transfer coefficient and a high adhesion.

The operation of the optical disk device according to the third embodiment of the present invention configured as described above is similar to that of the first embodiment. The difference from the operation of the first embodiment is that when the temperature is detected by the temperature detecting means 15 and the temperature becomes higher than a predetermined value, the head transferring means 17 is driven to transfer the optical base 3 to the inner peripheral side. Then, the heat radiating portion 2a of the heat transfer means 2 is brought into contact with the cooling member 34 to perform heat transfer and radiate heat. In this case, since the cooling unit is provided on the base 16, that is, the fixed unit, and the heat capacity can be increased, cooling can be performed with a simple configuration. Also, the cooling member 34
A Peltier element or the like can be used to perform forced cooling and maintain an appropriate temperature.

In the third embodiment, the cooling member 34 is provided on the inner peripheral side of the disk. However, it goes without saying that the same effect can be obtained even on the outer peripheral side of the disk.

[0036]

As described above, according to the present invention, an optical head device having a heat transfer member in contact with a laser light source, a heat radiating member coupled to the heat transfer member, and an optical disk device having a spindle motor. In the above, the heat transfer member and the heat radiating member are formed of a high thermal conductor, and when the optical head device is on the inner peripheral side of the disk, by providing the heat radiating member near the spindle motor, air convection accompanying the rotation of the disk is reduced. By effectively utilizing the heat emitted from the laser light source, it is possible to realize a stable optical disk device without excessively increasing the temperature even when a high output is output.

Further, by making the heat transfer member and the heat radiation member the same member, the number of parts can be reduced, and
Loss of heat transfer can be eliminated, and a high heat dissipation effect can be obtained.

Further, since the slit direction of the heat radiation member is configured to be perpendicular to the disk surface, the flow of air can be effectively sent to the heat radiation member, and the heat radiation effect is improved.

Even when the optical head device is located on the outer peripheral side of the disk, by arranging the heat radiation member near the spindle motor, not only the heat radiation effect on the inner peripheral portion but also the recording or reproduction of signals can be obtained. Accordingly, even when the optical base 3 is transferred in the outer peripheral direction of the disk, the heat radiation effect can be maintained.

Further, the heat radiation member is constituted by a heat pipe,
By setting one end near the laser light source and the other end near the spindle motor, the responsiveness of the heat pipe can be utilized, and the heat radiation effect is further enhanced.

A temperature detecting means is provided in the vicinity of the laser light source, and has an operation mode in which the optical head device is moved to the inner peripheral portion of the disk when the temperature becomes higher than a predetermined value to rotate the disk. It is possible to prevent a decrease in the life of the laser due to an excessive rise in the ambient temperature, and to provide a highly reliable optical disk device.

Further, a cooling member for contacting the optical head device is provided on the inner or outer peripheral portion of the traverse disk, and a temperature detecting means is provided in the vicinity of the laser light source. By transferring the optical head device to the inner peripheral portion or the outer peripheral portion, the temperature near the laser light source can be rapidly lowered by the cooling member.

Further, by forming the contact portion of the cooling member with an elastic body, particularly silicon, it is possible to alleviate the shock at the time of contact between the two members while keeping the heat radiation.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of an optical disc device 100 according to a first embodiment of the present invention.

FIG. 2 is a plan view for explaining the behavior when the disk is rotated according to the first embodiment of the present invention.

FIG. 3 is a side view for explaining a behavior when the disk is rotated in the first embodiment of the present invention.

FIG. 4 is a plan view showing a configuration of an optical disc device 200 according to Embodiment 2 of the present invention.

FIG. 5 is a plan view showing a configuration of an optical disc device 300 according to Embodiment 3 of the present invention.

FIG. 6 is a perspective view showing a configuration of a conventional optical disk device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser light source 2 Heat transfer member 3 Optical base 9 Optical disk 10 Spindle motor 13 Guide shaft 14 Heat radiating member 15 Temperature detecting means 24 Heat pipe 34 Cooling member

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Teruyuki Takizawa 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term (reference) in Matsushita Electric Industrial Co., Ltd. 5D117 AA02 EE00 HH00 HH01 5D119 AA33 BA01 FA32

Claims (9)

[Claims] A laser light source for recording or reproducing a signal on or from a disk; a heat transfer member in contact with the laser light source;
An optical head device having a heat dissipating member coupled to the heat transfer member, and an optical disc device including a spindle motor for rotating the disk, wherein the heat transfer member and the heat dissipating member are made of a high thermal conductor, An optical disk device, wherein the heat radiating member is provided near the spindle motor when the optical head device is on the inner peripheral side of the disk. 2. The optical disk device according to claim 1, wherein the heat transfer member and the heat radiation member are made of the same member. 3. The heat radiation member according to claim 1, wherein a slit direction of the heat radiation member is substantially perpendicular to a disk surface.
An optical disk device according to claim 1. 4. The optical disk device according to claim 1, wherein the heat radiating member is located near the spindle motor even when the optical head device is on the outer peripheral side of the disk. 5. The optical disk according to claim 1, wherein the heat radiating member is a heat pipe, and one end is located near the laser light source and the other end is located near the spindle motor. apparatus. 6. A temperature detecting means is provided near a laser light source,
6. The optical disk device according to claim 1, wherein when the temperature exceeds a predetermined value, the optical head device is transferred to an inner peripheral portion of the optical disk to rotate the disk. 7. An optical disk device having a cooling member in contact with an optical head device on an inner or outer peripheral portion of a disk of a base to which a spindle motor is fixed, wherein a temperature detecting means is provided near a laser light source, and a temperature detecting means is provided. An optical disk device for transferring an optical head device to an inner or outer peripheral portion of a disk when a predetermined value is exceeded. 8. The optical disk device according to claim 7, wherein the contact portion of the cooling member is an elastic body. 9. The optical disk device according to claim 8, wherein the contact portion of the cooling member is made of silicon.