JPH05189949A - Optical disk driving device - Google Patents

Abstract

PURPOSE:To provide an optical disk driving device capable of reducing a difference in temperature between the upper and lower surfaces of an information recording medium at the time of both recording and reproduction. CONSTITUTION:A flap 8 constituted of a shape memory alloy is provided between a cooling fan 6 and an optical information recording medium 1, the fixing tip 8a of the flap 8 near the optical information recording medium 1 is fixed to a case 7 and the flap 8 is supported in cantilever. When the temperature of the lower part of the optical information recording medium 1 is changed high by the heat generation of an optical pick-up 4 at the time of recording and reproduction, the flap 8 of the shape memory alloy is also changed high temp, its form is changed so as to lift a free tip 8b and much of the wind of the cooling fan 6 is supplied to the lower part of the optical information recording medium 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk drive device for recording / reproducing information on / from an optical information recording medium by a laser beam emitted from an optical pickup, and more particularly to using a cooling fan for cooling the optical information recording medium. The present invention relates to an optical disk drive device.

[0002]

2. Description of the Related Art FIG. 7 is a side view showing the configuration of a conventional optical disk drive device. The disc-shaped optical information recording medium 1 is rotatably supported by a turntable 3 and is rotationally driven by a spindle motor 2. The optical pickup 4 and the magnetic head 5 are installed opposite to each other via an optical information recording medium. The optical pickup 4 and the magnetic head 5 are moved in the direction of arrow A by an actuator (not shown). On the side of the optical pickup 4 and the magnetic head 5,
A cooling fan 6 for supplying air is installed above and below the optical information recording medium 1, and a case 7 is provided so that the air generated by the cooling fan 6 is discharged from the opposite side surfaces.

Information is recorded on the optical information recording medium 1 by focusing the laser beam L by the optical pickup 4 to form a light spot on the optical information recording medium 1 and applying a magnetic field by the magnetic head 5. Information is recorded on the optical information recording medium 1.

In reproduction, the laser beam L emitted from the optical pickup 4 is reflected by the optical information recording medium 1 and is incident on the optical pickup 4 again. In the optical pickup 4, a reproduction signal is reproduced by a photodetector (not shown). Is detected as.

[0005]

In the optical disk drive device having the above-mentioned structure, the spindle motor 2, the optical pickup 4, and the magnetic head 5 generate heat during their respective operations. Therefore, the cooling fan 6 supplies air above and below the optical information recording medium 1 to cool each member.

However, the amount of heat generated from each member differs depending on the operating state of each member, and especially when recording or reproducing for a long time, the amount of heat generated by the optical pickup 4 is large, so that the lower part of the optical information recording medium 1 is affected. Temperature rises, and the temperature of the surface facing the optical pickup tends to be higher than the other surfaces. The temperature difference between the upper surface and the lower surface of the optical information recording medium 1 causes a difference in thermal expansion amount, which causes deformation or distortion of the optical information recording medium 1.

Deformation or distortion of the optical information recording medium 1 causes an increase in track offset, an increase in focus offset, and an increase in wavefront aberration, and reduces the accuracy of information recording / reproduction.

An object of the present invention is to provide an optical disk drive device capable of reducing the temperature difference between the upper surface and the lower surface of an information recording medium during recording / reproduction.

[0009]

To achieve the above object, the first means of the present invention is a disk-shaped optical information recording medium, an optical pickup for irradiating the optical information recording medium with a laser beam, and an optical pickup. In an optical disk drive device provided with a cooling fan for cooling an information recording medium, a flap is provided in front of the cooling fan, the flap is made of a shape memory alloy, and the flap is deformed by a temperature change, whereby optical information recording is performed. It is characterized in that the air volume flowing above and below the medium is variably controlled.

A second means is an optical disk drive device provided with a disk-shaped optical information recording medium, an optical pickup for irradiating the optical information recording medium with a laser beam, and a cooling fan for cooling the optical information recording medium. A flap is provided in front of the cooling fan, and the flap has a spring made of a shape memory alloy. When the spring is deformed by temperature change, the angle of the flap is changed, and the flap is placed above and below the optical information recording medium. It is characterized in that it is configured to variably control the amount of air flowing through and.

A third means is an optical disc drive apparatus provided with a disc-shaped optical information recording medium, an optical pickup for irradiating the optical information recording medium with a laser beam, and a cooling fan for cooling the optical information recording medium. A flap having a spring made of a shape memory alloy is provided in front of the cooling fan, and sensors for measuring the temperature are provided above and below the optical information recording medium, and these sensors detect the temperature difference by the signal of the sensor. , A voltage generating circuit for generating a voltage corresponding to the temperature difference is connected, and the spring is applied with the voltage generated by the voltage generating circuit to be deformed,
It is characterized in that the flap angle is changed to variably control the air volume flowing above and below the optical information recording medium.

[0012]

According to the above-mentioned first means, the flap for variably controlling the air volume above and below the optical information recording medium is made of a shape memory alloy, so that the flap is deformed by the temperature change and the high temperature side. The amount of air supplied to the optical information recording medium is increased, the temperature on the high temperature side is decreased, and the temperature difference between the upper side and the lower side of the optical information recording medium is reduced.

According to the second means, the flap for variably controlling the air volume above and below the optical information recording medium has a spring made of a shape memory alloy, and the spring deforms due to temperature change. , The flap angle changes,
The same effect as the first means is obtained.

According to the third means, the flap for variably controlling the air volume flowing above and below the optical information recording medium has a spring made of a shape memory alloy, and the flap above and below the optical information recording medium. By the signal of the temperature sensor installed in
When the voltage generating circuit applies a voltage corresponding to the temperature difference to the spring, the spring heats up and is deformed, so that the angle of the flap changes, increasing the amount of air flow to the high temperature side, and increasing the temperature above the optical information recording medium. The temperature is controlled to be equal to the lower temperature.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, members corresponding to the members described in FIG. 7 are designated by the same reference numerals and the description thereof will be omitted.

1 and 2 are side views showing the configuration of the first embodiment of the optical disk drive device of the present invention.

Between the cooling fan 6 and the optical information recording medium 1,
The flap 8 made of a shape memory alloy is installed, and the fixed end 8a of the flap 8 close to the optical information recording medium 1 is fixed to the case 7 to support the flap 8 in a cantilever manner.

FIG. 1 shows a state in which the temperature above and below the optical information recording medium 1 is low. At this time, flap 8
Is parallel to the optical information recording medium 1, and the same amount of air is supplied to the upper side and the lower side.

When recording / reproducing is performed and the spindle motor 2, the optical pickup 4 and the magnetic head 5 generate heat in the state shown in FIG. 1, the amount of heat generated by the optical pickup 4 is particularly large, so the lower side of the optical information recording medium 1 is upward. It gets hotter. When the temperature of the flap 8 becomes equal to or higher than a certain value due to the ambient temperature, the flap 8 is deformed to lift the free end 8b as shown in FIG. 2, and the wind of the cooling fan 6 is supplied downward much. At this time, the higher the temperature of the flap 8, the larger the amount of deformation.

By the operation of the flap 8, as the lower temperature becomes higher, more air is supplied downward and is strongly cooled, so that the temperature difference between the upper side and the lower side of the optical information recording medium 1 is reduced.

3 and 4 are side views showing the configuration of the second embodiment of the optical disk drive device of the present invention.

A flap 18 is installed between the cooling fan 6 and the optical information recording medium 1, and a flap 18 is rotatably supported by a cantilever at the blade end of the flap 18 on the optical information recording medium 1 side. A moving shaft 18a is provided. The upper surface of the flap 18 is locked by the spring 9, and the lower surface thereof is locked by the spring 10 made of a shape memory alloy.

FIG. 3 shows a state where the temperature above and below the optical information recording medium 1 is low. At this time, flap 18
Is parallel to the optical information recording medium 1, the urging forces of the spring 9 on the upper surface and the spring 10 of the shape memory alloy on the lower surface are in equilibrium, and the upper and lower portions of the optical information recording medium 1 have the same amount. Wind is being supplied.

When recording and reproduction are performed and the temperature of the lower side of the optical information recording medium 1 becomes high, as in the first embodiment, the spring
10 is deformed so as to extend and the biasing force decreases. Therefore, as shown in FIG. 4, the flap 18 has its free end lifted by the spring 9 on the upper surface to change the angle. The amount of deformation of the shape memory alloy spring 10 increases as the temperature increases.

By the operation of the flap 18, as the temperature of the lower part becomes higher, more air is supplied to the lower part and is strongly cooled, so that the temperature difference between the upper part and the lower part of the optical information recording medium 1 is reduced.

5 and 6 are side views showing the configuration of the optical disk drive device of the present invention.

A flap 18 is installed between the front of the cooling fan 6 and the optical information recording medium 1, and a flap 18 is rotatably supported by a cantilever at the free end of the flap 18 on the optical information recording medium 1 side. A moving shaft 18a is provided. The upper surface of the flap 18 is locked by a spring 20 made of a shape memory alloy, and a heat insulating cover 20a is provided around the spring 20. The lower surface of the flap 18 is locked by the spring 9. Temperature sensors 21 are installed above and below the optical information recording medium 1, and a voltage generation circuit 22 detects a temperature difference between above and below by a signal from the temperature sensor 21 and outputs a voltage corresponding to the temperature difference. It is generated and a voltage is applied to the shape memory alloy spring 20. Spring depending on the applied voltage
In order to generate heat in 20, the shape memory alloy is made of a material such as Ni-Ti system which is a defective conductor.

FIG. 5 shows a state in which the temperatures above and below the optical information recording medium 1 are not equal. At this time, the voltage generating circuit 22 does not generate a voltage, the flap 18 is parallel to the optical information recording medium 1, and the top surface of the shape memory alloy spring is used.
The urging forces of the spring 20 and the lower spring 9 are balanced, and the same amount of air is supplied to the upper and lower parts of the optical information recording medium 1.

When recording and reproduction are performed, the temperature of the lower side of the optical information recording medium 1 becomes high and the temperature difference between the upper side and the lower side is generated as in the first embodiment. A temperature difference is detected by the signal, and a voltage corresponding to the temperature difference is applied to the shape memory alloy spring 20. The spring 20 to which a voltage is applied deforms so as to contract due to heat generation, and the biasing force increases. Therefore, as shown in FIG. 6, the flap 18 has its free end lifted by the spring 20 on the upper surface to change the angle. The voltage generation circuit 22 applies a higher voltage to the spring 20 as the temperature difference increases, and the spring 20 has a higher temperature and a larger deformation amount as the applied voltage increases. Since the heat generation of the spring 20 is blocked by the heat insulating cover 20a, it does not affect the surroundings. When the lower part of the optical information recording medium 1 becomes hot due to the operation of the flap 18 and a temperature difference is generated between the upper part and the upper part, a large amount of air is supplied to the lower part to strongly cool the upper part and the lower part of the optical information recording medium 1. The temperature is controlled to be equal.

In the optical disk drive devices of the first to third embodiments described above, the flap 8 or shape memory made of a shape memory alloy for variably controlling the amount of airflow flowing above and below the optical information recording medium 1. The flap 18 locked by a spring made of an alloy controls the supply of air volume so as to reduce or equalize the temperature difference between the upper and lower portions of the optical information recording medium 1 during recording and reproduction, and thus the optical information recording medium 1 is controlled. The temperature difference between the upper surface and the lower surface is reduced, and the deformation or distortion of the optical information recording medium 1 caused by the difference in expansion amount can be prevented. Therefore, it is possible to suppress the track offset, focus offset, and wavefront aberration during recording and reproduction.

[0031]

As described above, according to the first means of the present invention, the temperature difference between the upper surface and the lower surface of the optical information recording medium during recording / reproduction is reduced by the flap formed of the shape memory alloy. Since the deformation or distortion of the optical information recording medium 1 can be prevented, it is possible to provide an optical disk drive device capable of suppressing the track offset, the focus offset, and the wavefront aberration.

According to the second means, it is possible to provide the optical disk drive device having the same effect as that of the first means by the flap having the spring made of the shape memory alloy.

According to the third means, the spring composed of the shape memory alloy and the voltage generating circuit for applying the voltage corresponding to the temperature difference between the upper side and the lower side of the optical information recording medium to the shape memory alloy, An optical disk drive device having the same effect as the first means can be provided.

[Brief description of drawings]

FIG. 1 is a first view of an optical disk drive device of the present invention in a state where the temperature above and below the optical information recording medium is equal.
It is a side view which shows the structure of an Example.

FIG. 2 is a side view showing the configuration of the first embodiment of the optical disc drive device of the present invention when the temperature under the optical information recording medium is higher than that under the optical information recording medium.

FIG. 3 is a second view of the optical disk drive device of the present invention in a state where the temperatures above and below the optical information recording medium are equal.
It is a side view which shows the structure of an Example.

FIG. 4 is a side view showing the configuration of the second embodiment of the optical disk drive device of the present invention in a state where the temperature below the optical information recording medium is higher than that above.

FIG. 5 is a third view of the optical disk drive device of the present invention in a state where the temperature above and below the optical information recording medium is equal.
It is a side view which shows the structure of an Example.

FIG. 6 is a side view showing the configuration of the third embodiment of the optical disc drive device of the present invention in a state where the temperature below the optical information recording medium is higher than that above.

FIG. 7 is a side view showing a configuration of an example of a conventional optical disc drive device.

[Explanation of symbols]

1 ... Optical information recording medium, 4 ... Optical pickup, 6 ... Cooling fan, 8,18 ... Flap, 10, 20 ... Spring, 21
… Temperature sensor, 22… Voltage generator.

Claims (3)

[Claims] 1. A disc-shaped optical information recording medium, and an optical pickup for irradiating the optical information recording medium with a laser beam.
In an optical disk drive device provided with a cooling fan for cooling an optical information recording medium, a flap is provided in front of the cooling fan, the flap is made of a shape memory alloy, and the flap is deformed by a temperature change,
An optical disk drive device, which is configured to variably control the amount of airflow flowing above and below an optical information recording medium. 2. A disc-shaped optical information recording medium, and an optical pickup for irradiating the optical information recording medium with a laser beam.
In an optical disk drive device provided with a cooling fan for cooling an optical information recording medium, a flap is provided in front of the cooling fan, and the flap has a spring made of a shape memory alloy, and the spring is deformed by a temperature change. As a result, the angle of the flap is changed, and the air volume flowing above and below the optical information recording medium is variably controlled. 3. A disc-shaped optical information recording medium, and an optical pickup for irradiating the optical information recording medium with a laser beam.
In an optical disk drive device having a cooling fan for cooling an optical information recording medium, a flap having a spring made of a shape memory alloy is provided in front of the cooling fan to measure the temperature above and below the optical information recording medium. A sensor is provided, and a voltage generation circuit that detects a temperature difference from the sensor signal and generates a voltage corresponding to the temperature difference is connected to these sensors, and the spring is applied with the voltage generated by the voltage generation circuit. An optical disk drive device characterized in that the flap angle is changed by the deformation, and the amount of airflow flowing above and below the optical information recording medium is variably controlled.