JPH11306584A - Optical desk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk device with high dustproof performance. SOLUTION: In the optical disk device provided with a support base 4 supporting a rotating optical disk 2, a slit 5 provided on the support base 4 along the radial direction of an optical disk 2 and a pickup unit moving along the slit 5 and reading out the data recorded on the optical disk 2 through the slit 5, the support base 4 is provided with a step on the front side of the slit 5 for the rotational direction of the optical disk 2.

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 reading data written on an optical disk, and more particularly, to a dust-resistant mechanism in the optical disk apparatus.

[0002]

2. Description of the Related Art An optical disk apparatus for reading data written on an optical disk such as a so-called CD-ROM has become widespread. The optical disk device is used, for example, by being built in a home computer game device, or connected to a home computer game device, a personal computer, or the like as a single device. FIG.
FIG. 11 is a schematic perspective view of a conventional optical disc device. According to FIG. 10, the optical disc device 1 includes a support base 4 having a rotating shaft 3.
Having. The optical disk 2 is supported by the support 4 with its center aligned with the rotation axis 3. And the optical disk 2
Is rotated at a predetermined speed by a motor (not shown) connected to the rotating shaft 3.

[0003] The support base 4 is provided with a slit 5 extending radially from the rotation shaft 3. A pickup unit (reading unit) that reads data written on the optical disk 2 through the slit 5 while moving along the slit 5 is provided below the slit 5.

FIG. 11 is a schematic sectional view of the pickup unit 6. According to FIG. 11, the pickup unit 6 includes a light emitting unit 6 such as a laser diode.
1, a half mirror 62, a lens 63, and a light receiving unit 64. The light from the light emitting unit 61 is reflected by the half mirror 62 and further condensed by the lens 63 before irradiating the recording surface of the optical disc 2. Then, of the reflected light, the light transmitted through the half mirror 62 is received by the light receiving section 64, and data is read out based on the level of the reflected light.

The lens 63 is held by a lens holding section 65. A gap D is provided around the lens 63. The gap D is provided for the following reason.

That is, the lens holding section 65 can adjust the position of the lens 63 up and down so that the light from the light emitting section 61 converges on the recording surface of the optical disk 2. Further, the lens holding section 65 is capable of adjusting the inclination of the lens 63 in order to adjust the position of the light irradiated on the recording surface of the optical disc 2. Specifically, since data spirally recorded on the recording surface is read in accordance with the rotation of the optical disk 2, it is necessary to precisely control the light irradiation position on the recording surface of the optical disk 2. For this purpose, first, the lens 6
By changing the inclination of 3, the light traveling direction is changed, and the light irradiation position is adjusted. Then, if the adjustment range by the inclination of the lens 63 is exceeded, the pickup unit 6 itself moves along the slit 5. Then, at the position after the movement, the irradiation position is adjusted by the inclination of the lens 63. The movement of the lens 63 is controlled by a pickup slide motor (not shown) or the like.

As described above, the lens holding portion 65 is
Since the lens 3 is movably held, the lens 63 is not fixedly positioned by the lens holding portion 65. Therefore,
A gap D is required around the lens 63.

[0008]

However, conventionally, with the rotation of the optical disk 2, dust and a part of the dust contained in the air caught in the space V between the optical disk 2 and the support table 4 are generated. There is a problem that the dust invades through the gap D (see the arrow) and gradually accumulates on the half mirror 62 with the passage of time, so that data cannot be read out finally. That is, the accumulation of dust causes scattering and attenuation of light reflected or transmitted on the half mirror 62. If the light receiving unit 64 cannot receive light of a sufficient level, data cannot be read, and the Failure to do so may cause a failure.

Accordingly, the present invention has been made in consideration of the above problems, and has as its object to provide an optical disk device that reduces dust entering through the gap D of the pickup unit 6 and has high dust resistance.

[0010]

To achieve the above object, an optical disk apparatus according to the present invention comprises a support for supporting a rotating optical disk, and a slit provided on the support along the radial direction of the optical disk. And a pickup unit that moves along the slit and reads data recorded on the optical disk through the slit, wherein the support base has a step on the near side of the slit with respect to the rotation direction of the optical disk. I do. This step preferably extends in the radial direction.

Further, in the above configuration, a step is provided so that the gap distance between the support table and the optical disk on the near side of the slit is smaller than the gap distance on the far side of the slit.

[0012] Preferably, the step is configured to be lower toward the outer peripheral side of the optical disk. Further, the step is formed by arranging a rib having a predetermined thickness on the support base in front of the slit.

[0013]

Embodiments of the present invention will be described below. However, the technical scope of the present invention is not limited to this embodiment.

In the embodiment of the present invention, a dust resistance test was performed on an optical disk device having the following three structures. The test contents and test conditions will be described later in detail.

First, three structures of the optical disk device tested in the embodiment of the present invention will be described. FIG. 1 and FIG. 2 are diagrams for explaining an optical disc device 1 having a first structure according to an embodiment of the present invention. Specifically, FIG. 1 is a top view of the optical disc device 1, and FIG. 2 is a partial cross-sectional view taken along line AA 'in FIG. According to the first structure, in the optical disc device 1, the rib 7 along the slit 5 is arranged on the support base 4 on the near side with respect to the rotation direction of the optical disc 2 in the slit 5. That is, a step is provided on the support 4.

FIG. 7A is a schematic perspective view of the rib 7. The rib 7 is made of, for example, a plastic plate member. The thickness Δd1 of the rib 7 was about 0.3 mm, and the width Δl of the rib 7 was about 10 mm. Accordingly, in FIG. 2, when the gap distance Δs between the support 4 at the portion without the rib 7 and the optical disc 2 is about 1.3 mm, the gap distance Δs1 between the portion with the rib 7 and the optical disc 2 is about 1 mm. Become. The rib 7 may be formed integrally with the support 4.

FIGS. 3 and 4 are views for explaining the optical disk device 1 having the second structure according to the embodiment of the present invention. More specifically, FIG.
FIG. 4 is a partial cross-sectional view taken along line BB ′ in FIG. As shown in FIG. 4, in the second structure, the support 4 on the near side with respect to the rotation direction of the optical disc 2 in the slit 5 has an upper portion 4 a and a lower portion 4 b, and the step portion 4 c is It is provided at a position of a width Δl from the slit 5. The thickness Δd2 of the step portion 4c is approximately 0.4 m
m. The distance Δs2a between the upper part 4a and the optical disk 2 is about 1.3 mm, which is the same as the gap distance Δs between the support 4 and the optical disk 2. The gap distance Δs2b between the lower part 4b and the optical disk device 2 is
This is a value obtained by adding the thickness Δd2 (about 0.4 mm) of the step portion 4c to the distance Δs2a (about 1.3 mm) from the distance a, that is, about 1.7 mm.

The support 4 having the upper portion 4a and the lower portion 4b may be formed, for example, by connecting the support 4 to the thickness Δd of the step portion 4c.
It is constituted by cutting by 2 minutes. Alternatively, it may be formed by a mold having the step portion 4c.

FIGS. 5 and 6 are views for explaining an optical disc device having a third structure according to the embodiment of the present invention. Specifically, FIG. 5 is a top view of the optical disk device, and FIG. 6 is a cross-sectional view taken along line CC ′ in FIG. The third structure is a structure combining the first structure and the second structure. That is, the ribs 8 along the slits 5 are arranged on the upper step 4a provided by the second structure. At this time, the rib 8 has a taper (inclined) along the slit 5 unlike the rib 7 in the first structure.

FIG. 7B is a schematic perspective view of the rib 8. The rib 8 is made of, for example, a plastic plate similarly to the rib 7. The thickness Δd3 of the rib 8 is designed to be about 0.3 mm on the center side of the optical disk 2 but gradually thinner in the radial direction and to be 0 mm near the outer peripheral portion of the optical disk 2. . Therefore, the distance Δs between the optical disc 2 and the support 4 at a portion where the rib 8 is located
3 is about 1 mm on the center side of the optical disk 2, but gradually increases in the radial direction.
It is about 1.3 mm on the outer peripheral side.

The reason why the rib 8 is provided with a taper is as follows. That is, if the shape of the optical disk 2 is, for example, warped, the optical disk 2 rotates when the optical disk 2 rotates.
Causes vertical vibrations. Therefore, if the distance between the optical disk 2 and the support 4 is too small, the optical disk 2 and the support 4 come into contact with each other, and the optical disk 2 may be damaged. The width of the swing is larger at the outer periphery of the optical disc 2. Therefore, the outer periphery of the optical disc 2
To increase the gap distance between the support 4 and the
Is provided with a taper. The lower part 4b provided in the third structure is the same as the second structure.
That is, the gap distance between the lower part 4b and the optical disk device 2 is the distance Δs2b, that is, about 1.7 mm.

FIG. 8 is a block diagram of a test device for performing a dust resistance performance test of the optical disk device performed in the embodiment of the present invention. In FIG. 8, the dust tester 10
For 0, DT-1F manufactured by Suga Test Instruments Co., Ltd. was used. The test tank volume of the dust tester 100 is 1.7 cubic meters. The optical disk device 1 (not shown) placed in the dust tester 100 can be monitored by the monitor television 101. Or video recorder 1
02 may be installed and the screen of the monitor television may be recorded. This eliminates the need for a supervisor.

A sub tank 103 for storing dust is connected to the dust tester 100. Then, due to the pressure from the air compressor 104 connected to the sub-tank 103, dust in the sub-tank 103
5 and supplied into the dust tester 100. 20 g of JIS Class 8 Kanto loam powder was used as the dust. In addition, the air compressor 104
It has the ability to maintain 5 kgf / cm ² when discharging 0 liter of air.

A music CD was mounted on the optical disk device 1 placed in the dust tester 100, and the music CD was reproduced in the all-track repeat mode. Then, air was injected into the dust tester 100 in order to wind up the accumulated dust for 5 seconds at the start of the test and every hour from the start of the test.

Then, from the start of the test, the reproduction of the music CD
The time required to stop due to accumulation of dust on the half mirror 62 was measured. However, when the reproduction is stopped in the following cases, it is not determined that the reproduction is stopped due to accumulation of dust on the half mirror 62.

The first case is a case where the reproduction is continued by cleaning (eg, washing with water) the music CD even when the reproduction is stopped. This is because it is considered that the reproduction was stopped because the dust adhered to the surface of the CD, which made reading impossible.

In the second case, even when the reproduction is stopped, the reproduction can be continued by cleaning the lens 63 of the pickup unit 6 with alcohol or the like. This is because the cause of the playback stop is the lens 6
This is because it is considered that dust adhered to the surface of No. 3 and reading became impossible.

The third case is a case where the regeneration is stopped while the dust tester 100 is vibrating, and the regeneration is continued after the end of the vibration. As described above, air is injected into the dust tester 100 every hour. Before this air injection, the dust tester 100 vibrates for 10 seconds. Therefore, reading may not be possible due to this vibration, and such a case is excluded.

As described above, by excluding the reproduction stoppage due to the first to third conditions, the half mirror 62
It is possible to determine whether the reproduction of the music CD is stopped due to the accumulation of dust on the top.

In the test, three optical disk devices each having the above-described first to third structures were prepared (four for the third structure), and a test was performed for each of them. In addition, for comparison with a conventional optical disk device, three conventional optical disk devices were prepared, and the same test was performed.

FIG. 9 shows the test results. FIG. 9A shows a result of a dust resistance performance test of a conventional optical disk device. According to FIG. 9A, the time required for three conventional optical disk devices to stop reproduction is 63 minutes, respectively.
61 minutes and 14 minutes. From these results, the dust resistance of the conventional optical disk device was
It is estimated that about one hour is the limit.

FIG. 9B shows the results of a dust resistance test of the optical disk device having the first structure. FIG. 9B
According to the above, the time required for the three optical disk devices having the first structure to stop reproduction was 125 minutes, 67 minutes, and 192 minutes, respectively. As shown in the results, the dust resistance of the optical disk device having the first structure is greatly improved as compared with the conventional optical disk device. The second unit (NO.2) is 67 minutes, which is almost the same result as the dust resistance performance of the conventional optical disk device, but the shortest time (67 minutes) of the dust resistance performance of the optical disk device 1 having the first structure. But,
The longest time (6
3 minutes), it can be determined that dust resistance has been improved.

FIG. 9C shows the results of a dust resistance test of the optical disk device having the second structure. FIG. 9 (c)
According to the above, the time required for the three optical disc devices having the second structure to stop reproduction is 232 minutes and 17 minutes, respectively.
6 minutes and 240 minutes or more. Note that 240 minutes or more means that the test was not continued any more, but the regeneration was continued up to that time.

From this result, it was found that the second structure has more excellent dust resistance than the first structure.

FIG. 9D shows a result of a dust resistance test of the optical disk device having the third structure. FIG. 9D
According to this, the time required for reproduction by the four optical disk devices having the third structure was 389 minutes, 164 minutes, 420 minutes or more, and 250 minutes.

According to the test results, three out of four optical disk devices have a dust resistance of 4 hours (240 minutes) or more, and in particular, the third device (NO. 3) has a dust resistance of 7 hours or more. It became dust performance. Thus, since the third structure is a combination of the first structure and the second structure, the first structure and the second structure are formed by a synergistic effect of the first structure and the second structure. It has been found that it has better dust resistance performance than the structure.

As described above, the optical disk device according to the embodiment of the present invention having each of the above three structures has significantly improved dust resistance compared with the conventional optical disk device. The following reasons are presumed as the cause.

In the first structure, as shown in FIG.
The rib 7 has a slit 5 in the rotation direction of the optical disc 2.
Is arranged along the slit 5 on the support table 4 on the near side (hereinafter, simply referred to as the near side). That is, the support table 4 on the front side
Is provided with a step.

The distance Δs 1 between the rib 7 and the optical disk 2 is
It is smaller than the conventional distance Δs between the support 4 and the optical disk 2. Therefore, in FIG. 2, a part of the air entrapped between the optical disk 2 and the support 4 due to the rotation of the optical disk 2 collides with the side surface of the rib 7 before passing over the slit 5, Is blocked. As a result, the amount of air passing over the slit 5 is reduced, so that the amount of dust falling while passing over the slit 5 is reduced, and the dust entering the pickup unit 6 from the gap D is reduced by the half mirror 62.
It is estimated that there is a decrease in the accumulation on the surface.

The air that has collided with the side surface of the rib 7 subsequently changes its flowing direction, for example, upward or downward, so that the flow of air that does not collide with the rib 7 on the near side is also disturbed. That is, turbulence occurs on the near side. Due to the occurrence of the turbulence, the dust contained in the air falls on the near side before passing through the slit 5 and the dust passing through the slit 5 decreases, so that it is estimated that the fall of the dust decreases.

Further, the rib 7 is provided only on the near side, and is not provided on the back side of the slit 5 with respect to the rotation direction of the optical disk 2 (hereinafter simply referred to as the back side). Therefore,
The width through which air can flow differs between the near side and the far side. That is, the width is the gap distance Δs1 between the optical disc 2 and the support 4 at the portion where the ribs 7 are located on the near side, and is the gap distance between the optical disc 2 and the support 4 at the portion without the ribs 7 on the far side. Δs. Accordingly, the pressure on the near side is higher than on the far side of the slit 5. Since the air flows from the higher pressure to the lower pressure, the air flowing from the near side to the far side is further accelerated by this pressure difference and flows to the far side. When air flows over the slit 5 at a higher speed than before, dust in the air is of course accelerated. Therefore, it is presumed that the dust reaches the back side before dropping into the slit 5, and the drop of the dust decreases.

In the second structure, the support 4 has an upper portion 4a
And a lower portion 4b. Gap distance Δs of upper part 4a
2a is the same as the gap distance Δs between the support 4 and the optical disc 2, and the gap distance Δs2b of the lower section 4b is
a is larger than the gap distance Δs2a by a thickness Δd2 of the step portion 4c.

Therefore, in FIG. 4, a part of the air entrapped between the optical disk 2 and the support table 4 due to the rotation of the optical disk 2 before the air passes over the slit 5, the upper part 4a and the lower part 4b. Collides with the step portion 4c, and the flow is interrupted. Then, since the air that has collided with the step portion 4c changes its flowing direction, for example, upward or downward, the flow of the air that does not collide with the rib 7 is disturbed on the near side. That is, turbulence occurs on the near side. Due to the occurrence of the turbulence, the dust contained in the air falls on the near side before passing through the slit 5 and the dust passing through the slit 5 decreases, so that it is estimated that the fall of the dust decreases.

The third structure has an upper portion 4a and a lower portion 4b similar to the second structure, and a rib 8 having a taper is provided on the upper portion 4a instead of the rib 7 in the first structure. Be placed.

Therefore, as shown in FIG. 6, a part of the air flowing from the near side is, before the air passes over the slit 5, similar to the reason for the first structure described above, on the side of the rib 8. And the flow is interrupted. Thereby, the slit 5
Since the amount of air passing above is smaller than before, it is estimated that the amount of dust falling is reduced.

Further, similarly to the reason for the first and second structures described above, the side surface of the rib 8 and the upper step 4a and the lower step 4
Turbulence is generated on the near side by the air that has collided with the step portion 4c with the b. As a result, dust contained in the air is
Before passing through the slit 5, it falls on the near side. And
Since the amount of dust passing through the slit 5 decreases, it is estimated that the fall of dust decreases. Further, as compared with the second structure, since the step is increased by the width of the side surface of the rib 8, it is estimated that the occurrence of turbulence increases, and the drop of dust on the near side increases.

Further, similarly to the reason of the first structure described above, the rib 8 is provided only on the near side and not on the back side, so that a pressure difference occurs between the near side and the back side, and The speed of the air passing through is accelerated. This allows
It is estimated that the fall of dust decreases.

As described above, it is presumed that the third structure has an effect obtained by synergistically combining the reasons of the first structure and the second structure.

The reason for the above-mentioned improvement in dust resistance performance is merely an estimation, and is not conclusively determined as described above.

Further, the various dimensions in the above description are illustrative, and are not limited to the above dimensions.

The optical disk is not limited to a CD-ROM, but includes all storage media from which data is read by light, such as music CDs, DVDs, and CD-Rs.

[0052]

As described above, according to the present invention,
In the optical disk device, by providing a step on the support base on which the optical disk is supported, it is possible to reduce dust falling from the slit. As a result, dust enters the pickup unit from the gap between the pickup units, and the amount of dust accumulated on the half mirror inside the pickup unit can be reduced. Therefore, the dust resistance of the optical disk device is improved, and the life of the optical disk device itself is extended.

[Brief description of the drawings]

FIG. 1 is a top view of an optical disk device having a first structure according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view taken along line AA ′ in FIG.

FIG. 3 is a top view of an optical disc device having a second structure according to the embodiment of the present invention.

FIG. 4 is a partial sectional view taken along line BB ′ in FIG. 3;

FIG. 5 is a top view of an optical disc device having a third structure according to the embodiment of the present invention.

FIG. 6 is a partial sectional view taken along line CC ′ in FIG. 5;

FIG. 7 is a schematic view of ribs 7 and 8;

FIG. 8 is a block diagram of a test device for performing a dust resistance performance test of the optical disc device performed in the embodiment of the present invention.

FIG. 9 is a diagram showing test results.

FIG. 10 is a schematic perspective view of a conventional optical disk device.

FIG. 11 is a diagram showing a schematic sectional view of the pickup unit 6;

[Explanation of symbols]

 2 optical disk 4 support base 5 slit 6 pickup unit 7 rib 8 rib 61 light emitting unit 62 half mirror 63 lens 64 light receiving unit 65 lens holding unit

Claims (5)

[Claims] 1. A support base for supporting a rotating optical disk, a slit provided on the support base along a radial direction of the optical disk, and moving along the slit to be recorded on the optical disk through the slit. An optical disc device, comprising: a pickup unit for reading out read data; wherein the support base has a step on the near side of the slit with respect to a rotation direction of the optical disc. 2. The optical disk device according to claim 1, wherein the step extends in the radial direction. 3. The step according to claim 1, wherein a gap distance between the support table and the optical disk on the near side of the slit is smaller than the gap distance on a deep side of the slit. An optical disk device characterized by being able to be used. 4. The optical disk device according to claim 1, wherein the step is reduced toward an outer peripheral portion of the optical disk. 5. The step according to claim 1, wherein the step is formed by disposing a plate-like member having a predetermined thickness on the front side of the slit on the support base. An optical disc device characterized by the above-mentioned.