JPH05325237A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To provide the information recording and reproducing device which resolves warp and surface jiggling of a disk, and is simple and of a low cost. CONSTITUTION:A plate 17 facing a disk 14 is provided, and the plate 17 is moved by the output of a sensor 18, which detects the distance from the disk 14, to fix the distance to the disk 14. Thus, the information reproducing device is obtained which suppresses warp and surface jiggling of the disk and is simple and of a low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing apparatus effective for use in a video disc player, a compact disc player or the like for optically reading an information signal from a disc.

[0002]

2. Description of the Related Art In recent years, a multiplayer capable of reproducing a compact disc recorded digitally and a video disc recorded a long-time video and audio by a single player is becoming popular.

A conventional information recording / reproducing apparatus will be described below. FIG. 4 shows a main part of a conventional information recording / reproducing apparatus. In FIG. 4, reference numeral 1 is a spindle motor for rotating the disk 4. 2 is a turntable on which the disc 4 is placed. 3 disk 4 turntable 2
It is a disk clamper that is fixed to. Reference numeral 4 is a disk having a PMMA resin as a protective layer. Reference numeral 5 is a signal pickup for reading a signal from the disc 4. The player is entirely enclosed by a case 6.

The operation of the information recording / reproducing apparatus having the above structure will be described below.

First, the disk 4 is placed on the turntable 2 and fixed by the disk clamper 3. Next, the disk 4 rotates, and usually 1800 rpm. p. The spindle motor 1 is controlled to operate at m. And signal pickup 5
The information signal from the disk 4 is read and reproduced. The optical axis of the signal pickup 5 is always controlled to be perpendicular to the disc 4.

[0006]

However, in the above-mentioned conventional structure, there is no structure for suppressing warp, deflection and surface wobbling of the disc, and the disc is easily deformed due to the temperature rise of the casing player, and the signal from the disc is accurately generated. The surface run-out of the turntable to read
m or less, or spindle shaft runout of 10 μm
In addition to the above, or because the optical axis of the signal pickup is tilted perpendicularly to the disk surface, there is a problem that the structure is complicated and causes a cost increase.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a simple and low-cost multiplayer that suppresses warpage and surface wobbling of a disc as much as possible.

[0008]

In order to achieve the second object, the multiplayer of the present invention has a structure in which at least one plate facing the disc is arranged and the distance between the plate and the disc is kept constant. There is.

[0009]

With this structure, when the disc is rotated, dynamic pressure is generated between the disc and the plate, and warpage and surface wobbling of the disc can be suppressed.

[0010]

【Example】

(First Embodiment) A first embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 11 is a spindle motor,
12 is a turntable, 13 is a disk clamper, 14
Is a disc, 15 is a signal pickup, 16 is a player case, 17 is a plate facing the disc, 18 is a sensor for detecting the distance between the disc 14 and the plate 17, and 19 is a plate 17
A guide for holding the plate, 20 is a motor for moving the plate 17, 2
Reference numeral 1 is a distance setting circuit between the disk 14 and the sensor 18, 22 is a comparator, and 23 is a motor drive circuit.

The operation of the multiplayer configured as described above will be described. First, turntable 1
The disc 14 is placed on the disc 2 and fixed by the disc clamper 13. Next, the disk 14 rotates at a rotation speed of 1800 r.
p. Rotate at m. A plate 17 provided below the turntable reference surface by about 5 mm ascends, the output of the distance detection sensor 18 and the distance setting circuit 2 in which the distance is set to 1 mm in advance.
The comparison with 1 is performed by the comparator 22, the difference is sent to the motor drive circuit 23, and the operation for keeping the distance between the disk 14 and the plate 17 constant is performed. If the distance between the disk 14 and the plate 17 is reduced, the warp and surface runout suppressing force during the disk rotation increases, but the limit is set to 1 in consideration of the disk surface runout variation.
set to mm. The larger the disc facing area of the plate 17 is, the more effective it is, but there is a limitation of the player.
It was set to 0 mm ² . The surface runout of the turntable 12 is 8
It was set to 0 μm or less.

0.5 mm was obtained as the effect of suppressing the warp surface deflection of the multi-player disc according to this embodiment.

As described above, according to this embodiment, at least one plate facing the disk is provided, and the operation for keeping the distance to the disk constant is performed, so that the warp and surface wobbling during the disk rotation can be easily performed. Can be suppressed.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a diagram showing a structure of a main part of a multiplayer showing a second embodiment of the present invention, and elements common to those in FIG. 1 are designated by the same reference numerals. 11 is a spindle motor,
12 is a turntable, 13 is a disk clamper, 14
Is a disc, 15 is a signal pickup, 16 is a player case, 17 is a plate facing the disc, 18 is a sensor for detecting the distance between the discs, 19 is a guide for holding the plate, 20 is a motor for moving the plate, Reference numeral 21 is a disk-sensor distance setting circuit, 22 is a comparator, and 23 is a motor drive circuit. The above is the same as in FIG. The difference from the configuration of FIG. 1 is that a plate 24 is arranged on the other side facing the disk 14,
The plate 1 on both sides, which is attached to the plate 24 from the motor 20 that moves the plate 17 via the belt 25 and faces the disc 14,
7, 24 interlock in accordance with the distance from the disk 14 to perform control operation.

As described above, by controlling the plates 17 and 24 on both sides facing the disk 14 in accordance with the distance from the disk 14, the warp and surface runout suppressing force of the disk is about 1.5 times, which is easy. Moreover, a stable effect of suppressing warpage and surface wobbling was obtained.

(Embodiment 3) A third embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a block diagram of a main part showing a third embodiment of the present invention. 3, the same elements as those in FIG. 1 are designated by the same reference numerals. 11 is a spindle motor, 12 is a turntable, 13 is a disk clamper, 14 is a disk, 15 is a signal pickup, 16 is a player case,
Reference numeral 17 is a plate facing the disk, 19 is a guide, 20 is a motor, 21 is a distance setting circuit, 22 is a comparator, and 23 is a motor drive circuit. The above is the same as in FIG. The difference from the configuration of FIG. 1 is a sensor 1 for detecting the distance to the disk.
8 outputs the output of the focus drive circuit 26 generated by the signal pickup 15 to the low-pass filter 27, and changes the output of the low-pass filter 27, that is, the DC component of the focus drive circuit 26, so that the disc 14
The distance detection from can be obtained.

As described above, the DC component of the focus drive circuit 26 of the signal pickup 15 is detected, and the disc 1 is detected.
By performing an operation of keeping the distance from the disk 4 constant, it is possible to easily suppress warpage and surface wobbling during rotation of the disk.

[0021]

As described above, according to the present invention, by providing at least one plate facing the disc, it is possible to realize an excellent information recording / reproducing apparatus capable of suppressing warpage and surface wobbling during rotation of the disc. Is.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a main part of an information recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of a main part of an information recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing the configuration of the main part of an information recording / reproducing apparatus in a third embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a configuration of a main part of a conventional information recording / reproducing apparatus.

[Explanation of symbols]

 11 Spindle Motor 12 Turntable 13 Disc Clamper 14 Disc 15 Signal Pickup 16 Player Case 17 Plate 18 Sensor 19 Guide 20 Motor 21 Distance Setting Circuit 22 Comparator 23 Motor Drive Circuit 24 Plate 25 Belt 26 Focus Drive Circuit 27 Low Pass Filter

Claims (3)

[Claims] 1. An information recording / reproducing apparatus comprising: a disc, at least one plate facing the disc, means for moving the plate, and means for detecting a distance from the disc. 2. The information recording / reproducing apparatus according to claim 1, wherein plates facing the disc are arranged on both sides of the disc. 3. The information recording / reproducing apparatus according to claim 1, wherein the means for detecting the distance to the disc is a focus drive signal for the signal pickup.