JPS619802A - Turntable - Google Patents

Abstract

PURPOSE:To enhance the supporting capability of an information recording disc and to improve especially the resistance to external oscillation and shock by providing plural claws on the outside edge part of a turntable base body and pressing and fixing the outside edge part of the disc to that of the turntable base body by these claws. CONSTITUTION:When the turntable is still, claws are opened up, and a disc 27 can be set or detached. When the disc is set and the turntable is rotated, weights 21 are moved outward against springs 22 by the centrifugal force, and claws 24 interlocked with weights 21 are closed, and elastic bodies 28 are brought into contact with the disc 27. When the rotation number is raised to reach a prescribed value, the centrifugal force corresponding to the mass of weights 21 and the rotative speed is generated, and the contacting pressure between claws 24 and the disc 27 is obtained by this force, and the disc 27 is held firmly between claws 24 and the outside edge part of a turntable base body 18, and the reproducing operation is performed. With respect to springs 22, it is sufficient if they display enought force to return weights 21 to original positions when weights 21 moved outward are stopped.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is an information signal reproducing device such as an audio player or a video disc player, in which a disc on which information is recorded (hereinafter referred to as an information recording disc or disc) is mounted. It concerns turntables.

Configuration of conventional examples and their problems Normally, an information signal reproducing device includes a rotation drive unit that supports and rotates an information recording disk, a detection unit that detects a signal from the information recording disk, and a seasoning for the detected signal. It consists of a signal processing section, and a mechanism section that moves the detection section and raises and lowers the information recording disk.

FIGS. 1 and 2 show the overall configuration of an example of an information signal reproducing apparatus, and FIG. 3 shows the configuration of a signal detecting section of the information signal reproducing apparatus. In this example, a needle contact type video disc player is used, and the turntable is constructed using a conventional type. First, in Figures 1 and 2, (1) is a turntable, (2) is a disk, (3) is a center boss, (4) is a cartridge, (5) is a detection circuit, (6) is an arm, and (7) is a cartridge. ) is the clamp, (8) is the roller, (9) is the shaft, (10) is the rail, (11) is the base, (1
2) is a motor, and (13) is a leg. In Fig. 3, (14) is the needle, (15) is the lead, (16) is the cantilever, and (17) is the suspension. Incidentally, an example of a conventional turntable (1) is shown in FIGS. 4 and 5.

Conventional turntables are often die-cast or resin molded products, and their structure includes a flange surface (1a) for attaching to a rotation drive device and a hole (1a) for centering.
b) has.

On the upper surface of the expanded disc-shaped disc, supporting surfaces (1c) having a certain width necessary for supporting the information recording disc are formed concentrically on the outer and inner peripheries.

On the other hand, the information recording disk [disk (2)] has a concentric part formed on the outer and inner sides of the area where the signal is recorded (signal surface) that is higher than the signal surface. It is supported by the support surface of the turntable mentioned above.

The information recording disk is centered by a center boss and placed on the turntable, and the vicinity of the center hole is pressurized to increase the degree of contact with the turntable.

Information recording disks are mainly made of resin materials.
It itself has waviness (surface runout) in the thickness direction, and if there is excessive surface waviness on the signal surface, it will exceed the tracking capability of the signal detector and cause problems in reproduction. Although it depends on the frequency response characteristics of the detector, in general, if the surface runout has the same amplitude, the higher the frequency, the more likely it is to interfere with reproduction. On the other hand, when the entire reproducing apparatus is vibrated or an impact is applied from the outside, these forces or vibrations are propagated to the information recording disk, increasing the amount of surface runout. In the conventional case, the turntable is a rigid body integrally formed of metal or resin, and it easily propagates vibrations and shocks applied from the outside, and the natural frequency of the vibration generated by this is the same as the unique frequency of the information recording disk. higher than the frequency. If the information recording disk is warped and its outer periphery is only partially in contact with the support surface of the turntable, or if the pressing force near the center hole is not sufficient on the outer periphery, apply pressure from the outside. The high-frequency vibrations of the turntable generated by the vibrations and shocks transmitted are transmitted to the information recording disk, and appear as large-amplitude vibrations on the information recording disk. On the other hand, when the information recording disk vibrates due to vibrations or shocks applied from the outside, if the contact with the turntable is partial or if the applied pressure is not sufficient, the reaction from the turntable will cause the disk to vibrate violently. In other words, the information recording disk and the turntable interfere with each other due to vibrations and shocks applied from the outside, especially at the outer periphery, and high-frequency and large-amplitude vibrations are applied to the information recording disk. Combined with the surface wobbling of the information recording disk itself, this exceeds the tracking limit of the detector, causing trouble in reproduction. Further, especially in the case of a needle contact type information signal reproducing device, needle skipping (the needle bouncing on the signal surface) may occur, which may damage the information recording disk. Depending on the extent of this damage, the signal may be completely lost, or new damage may occur when the needle passes through the damaged area again. When an integrally formed rigid turntable is used, as in the conventional example described above, it is vulnerable to vibrations and shocks applied from the outside, which tends to impede good signal reproduction.

Purpose of the Invention The present invention solves the above-mentioned conventional problems.By improving the turntable of an information recording disc playback device, the supporting capacity of the information recording disc is increased, and in particular, the resistance to external vibration and shock is improved. The purpose is to prevent damage to the information recording disk and to stabilize signal reproduction.

Structure of the Invention In order to achieve the above object, the turntable of the present invention has the following features:
A turntable on which an information recording disk is mounted and driven to rotate, and has a plurality of claws on the outer edge of the turntable base, and these claws move the outer edge of the information recording disk against the outer edge of the turntable base. It is configured so that it can be fixed by pressing.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on the drawings (FIGS. 6 to 9).

(18) is a turntable base, and two shafts (20) are passed through each of eight notches (19) provided at appropriate intervals on the outer periphery of the turntable base (18), and a weight ( 21) is attached so as to be movable in a radial manner,
This weight (21) is biased inwardly into the notch (18) by a tension coil spring (22), and has a pin (2) attached to its outer edge.
The claw (24) and pin (24) rotatably supported by
25). (26) is a weight (21
), and a pin (25) is movably engaged in this long hole (26). Further, an elastic body (28) such as rubber is disposed on the inner surface of the claw (24) that comes into contact with the disk (27).

When the turntable configured as described above is at rest, it is in the state shown in Fig. 8, and the claw (24) is in an upwardly open state so that the disc (27) can be attached and removed. It has become. When the disc is attached and the turntable is rotated, the weight (21) moves outward against the spring (22) due to centrifugal force, and the claw (2
4) is closed in the state shown in FIG. 9, and the elastic body (28) comes into contact with the disk (27). When the rotation speed increases and reaches a predetermined rotation speed, a centrifugal force is generated depending on the mass of the weight (21) and the rotation speed, which causes the claw (24) and the disc (27) to
of contact pressure is obtained, and the disk (27) is firmly held between the claw (24) and the outer edge of the turntable base (18). A reproducing operation is performed in this state. Spring (2
Regarding 2), any force that can exert enough force to return the weight (21) that has moved outward to its original position when the rotation stops is sufficient. Moreover, the elastic body (
28) is for increasing the degree of adhesion between the claw (24) and the disk (27) and absorbing vibrations. When the playback operation is completed and the turntable stops rotating, the state returns to the state shown in FIG. 8 again.

Effects of the Invention As described above, according to the present invention, by tightly fixing the outer edge of the disk to the outer edge of the turntable during playback operation, not only the surface runout and warping of the disk can be suppressed, but also the external edge of the playback device can be suppressed. Even with the vibrations and shocks applied from the turntable, the disc is not greatly excited by the vibrations of the turntable, and the vibration of the disc itself is suppressed, making it possible to achieve extremely stable playback conditions. Further, the operation of the detector is stabilized, and damage to the disk due to defective playback operations (stylus skipping) can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view showing an example of an information signal reproducing device, Fig. 2 is a sectional view of the same level, Fig. 3 is a perspective view showing an example of a signal detection section, and Fig. 4 shows a conventional turntable. 5 is a sectional view taken along the line XX in FIG. 4, FIGS. 6 to 9 show an embodiment of the present invention, FIG. 6 is a plan view, and FIG.
The Y-Y sectional view in the figure, and FIGS. 8 and 9 are enlarged sectional views of main parts for explaining the operation. (18)... Turntable base, (19>...
Notch, (20)...shaft, (21)...weight,
(22)...Tension coil spring, (23)...Pin, (24)...Claw, (25)...Pin, (26)...
...long hole, (27>...disc, (28)...
Elastic bodyFigure 1Figure 2Figure SFigure 7Figure 8BFigure q

Claims (1)

[Scope of Claims] 1. A turntable on which an information recording disk is placed and driven to rotate, which has a plurality of claws on the outer edge of the turntable base, and the outer edge of the information recording disk is gripped by the claws. A turntable configured to be press-fixed to the outer edge of a turntable base. 2. The weights provided in notches formed at appropriate intervals on the outer circumference of the disc-shaped turntable base are configured to be movable in a radial manner, and each weight is linked with the claws on the outer edge to open and close the claws. The turn according to claim 1, wherein the turntable has a mechanism for causing the rotation of the turntable, and obtains a force for pressing the outer edge of an information recording disk placed on the turntable by centrifugal force accompanying the rotation of the turntable. table. 3. The turntable according to claim 1, wherein an elastic body such as rubber is arranged on the surface of the claw provided on the outer edge that presses the information recording disk.