JPS6230205Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a drive device for a turntable on which a disc record is removably mounted.

In order to make it easier to attach and detach a disc record that records high-frequency signals such as video signals to and from a turntable, and to make it possible to scan this disc record from the turntable on which it is placed, It has been considered to form the shape into a ring shape. In that case, it is conceivable to connect three or more rollers around the circumference of the turntable and use one of the rollers as a driving means to drive the turntable. In order to ensure power transmission, it is possible to press the drive roller against the turntable or to engage gears between the two, but these methods result in increased rotational resistance and uneven rotation of the turntable. Stable power transmission cannot be ensured.

In order to ensure stable power transmission, the present invention attempts to provide a turntable drive device in which the drive roller is an axially magnetized magnet that supports and drives a turntable made of magnetic material. It is something to do.

Next, the present invention will be explained based on the drawings. FIG. 1 is a plan view of one embodiment of the device of the present invention, and FIG. 2 is a side sectional view thereof. Reference numeral 1 denotes a ring-shaped turntable made of a magnetic material such as iron, and its outer diameter is larger than the outer diameter of a disc record to be set, and its inner diameter is larger than the diameter of the outermost signal groove of the disc record. 2, 3, and 4 are first, second, and third rollers that circumscribe the circumference of this turntable 1, and the first roller 2 is attached to the rotating shaft 7 of a motor 6 fixed to the base 5, and The second roller 3 is attached to a rotating shaft 8 that is mounted on a base 5,
Furthermore, the third roller 4 is attached to an arm 10 that can rotate around a support shaft 9 fixed to the base 5. The position of each roller relative to the base 5 is the first
The mounting position of the roller 2 on the rotating shaft 7, and the adjustment screw 1 of the second and third rollers 3 and 4.
This can be adjusted by adjusting 1 and 12 respectively.

Furthermore, the rotation center of each roller and turntable 1
are designed to be equidistant from the center of rotation 13.

The first roller 2 is a magnet magnetized in the axial direction, and the width 14 of its circumferential surface is larger than the width 15 of the contact surface of the turntable 1 that is in contact with the roller.

Therefore, the turntable 1 is attracted to the first roller 2, and the weight of the turntable 1 and the attractive force of the magnet are balanced and stabilized at a position halfway down the side of the first roller. ing. In addition, each roller 2, 3, 4 has a collar 16,
17 and 18 to prevent the turntable 1 from falling downward when excessive weight is applied to it. Therefore, in a steady state, the turntable 1 is prevented from coming into contact with these collars. If the above-mentioned attraction force is insufficient, the turntable 1 can also be a vertically magnetized magnet and arranged as shown in Figure 3A, for example, so that the attraction and repulsion of both magnets can be utilized, allowing a relatively heavy object to be placed on the turntable. Can be done.

Reference numeral 19 denotes a central shaft provided at the rotation center 12 of the turntable 1, which is attached to the center hole of the disc record 20 to bring out the center of the disc record. As shown, when the disc record can be positioned on its circumferential side and the center of rotation of the turntable is precisely regulated, it is possible to eliminate the need for this central axis. Reference numeral 21 denotes a pick-up that abuts the disc record from below, and this pick-up is moved in the radial direction of the disc record in synchronization with the motor 6. That is, the rotation of the motor 6 is transmitted through the worm 22 to the drive wheels 23,
A pick-up 2 is removably attached to the scanner via the wire 24 and a scanner 28 provided on a sliding rod 27 supported by guides 25 and 26.
1.

In the device of the present invention, a ring-shaped turntable made of a magnetic material is supported by attraction by a first roller magnetized in the axial direction, and rotation by the first roller is transmitted to the turntable. Unlike the conventional power transmission using pressure rollers, there is no need to press the turntable, and even if a ring-shaped turntable is used, there is no risk of deformation. By using such a ring-shaped turntable, the pick-up can be accessed from the turntable to the disc record, and therefore the playback surface of the disc record can be made on the same basis as the rotating surface of the turntable. The influence of surface runout can be reduced. Also, when loading a disc record, the mirror part of the record can be used to lift it up and down from the turntable. Furthermore, when a disc record is not set on the turntable, it is possible to replace the disc record at that position without having to return the pickup to the rest position each time. In other words, since the turntable is ring-shaped and hollow, when a disc record is not set, the hollow part becomes an empty space through which the pick-up needle can be replaced, and there is no need to take the trouble of resting the pick-up. There is no need to return it to its original position.

The device of the present invention may be configured as follows. That is, as shown in FIG. 4A, the first roller 2 that drives the turntable 1 is arranged inside the turntable. In this case, there is an effect that the structure of the turntable driving device can be further miniaturized.

Furthermore, unlike these methods, the vertical position of the turntable is determined by the stable point with the attraction force of the magnet, but the drive roller 2 is arranged perpendicular to the bottom surface of the turntable, as shown in Figure 4 (b) and (c). However, the radial position of the turntable may also be determined by the magnetism of the magnetizing roller. At this time, since there is a difference in circumferential speed between the two contact areas, methods such as creating a tapered shape as shown in Figure 4 (B) or providing a rib in the center to make it almost a point contact as shown in Figure 4 (C) are available. Bye. In each of the embodiments described above, vibrations caused by surface roughness can be absorbed by coating one of the surfaces of the rolling contact portion between the roller and the turntable with something such as resin or rubber. Alternatively, the turntable may be magnetized in the direction of its rotation axis to attract the drive roller, in which case the width of the circumferential side of the turntable is larger than the width of the contact surface of the drive roller that is in contact with it. Just do it like this. As described above, in the present invention, the turntable is supported only by at least three rollers. Since the turntable is ring-shaped (hollow like a donut), the center cannot be supported by a rotation means like a conventional circular plate-shaped one.
This type of turntable can be supported by supporting the circumference of the ring-shaped turntable with at least three rollers. Moreover, the support is not achieved by pressing the ring-shaped turntable with each roller, but by the magnetic force acting between the turntable and the rollers, which reduces rotational resistance and uneven rotation of the turntable. The effect is that it does not occur. At that time, by creating a difference between the axial width of the turntable and the axial width of the roller, stable support is maintained even if the turntable moves vertically due to the load applied to the table (support by magnetic force). is obtained.

In this way, the turntable of the present invention can be realized as a ring-shaped turntable, so that the hollow space can be used effectively. For example, as mentioned above, the needle of the pick-up can be replaced without returning the pick-up to the rest position.

[Brief explanation of the drawing]

FIG. 1 is a plan view of essential parts of the device of the present invention, and FIG. 2 is a side sectional view of the device. Figure 3 A, B and 4
Figures A, B, and C are side views of other embodiments, respectively. 1...Ring-shaped turntable, 2, 3, 4...
...first, second, and third rollers (the first roller 2 is a driving roller), 6...motor (driving means).

Claims (1)

[Claims for Utility Model Registration] (1) A ring-shaped turntable made of a magnetic material for supporting the outer periphery of a disc record;
at least three rollers disposed around the periphery of the turntable to support the turntable, and driving means for driving one of the rollers and thereby driving the turntable; 1. A turntable driving device, wherein the table is magnetized in the direction of its rotation axis, and the turntable is supported by magnetic force between the roller and the turntable. (2) The turntable drive device according to claim 1, wherein a difference is provided between the axial width of the roller and the axial width of the turntable.