JPS59112402A - Turntable driving device - Google Patents

Abstract

PURPOSE:To obtain a driving device which has a high safety and is compact by providing a tapered groove which can install a dynamic balance correcting weight to one surface of a turntable, in the direction where the weight is detained by a rotation of the turntable. CONSTITUTION:A turntable 2 is installed through a bearing 4 to a housing 5 on a base 11, a motor 8 is rotated in a state that a disk 1 is placed on the table 2, and the disk 1 is subjected to a rotation control through a coupling 6. When correcting an unbalance in case the disk 1 is installed, it is corrected by measuring automatically a phase of the unbalance and its vibration amplitude by a detector 9 and a pickup 10, and installing a weight 3 in a designated phase to a tapered groove A, along an angle scale line of the outside circumference of the table 2. In this way, in case of correcting an unbalance, a driving device which has a high safety and is compact is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field to Which the Invention Pertains The present invention relates to a turntable drive device suitable for finely processing a rotating recording medium such as a video disk.

BACKGROUND TECHNOLOGY AND THEIR PROBLEMS] In a turntable drive device incorporated in a microfabrication device for video discs and the like, microfabrication is generally performed by rotating the master disk at a constant speed or keeping the circumferential speed constant. The turntable itself can be dynamically balanced by itself, but the master discs are replaced one by one each time they are processed and placed on the turntable, so there are conditions such as the eccentricity of the master disc itself and the condition of the installation. If dynamic balance is not taken every time, the vibration effects caused by unbalance will be a major hindrance to microfabrication, which requires accuracy of about 0.1 μm. Conventionally, a weight with a right-angled cross section as shown in Figure 3 was used to correct the balance. There were grooves on the turntable surface for attachment.

The balance was corrected by pushing a weight, such as solder or lead, into this groove, but with a right-angled groove, there is a risk of the weight flying out of the groove due to centrifugal force caused by the rotation of the turntable, which is a safety concern. Ta.

OBJECT OF THE INVENTION This invention improves the above-mentioned drawbacks of the conventional device.
To provide a turntable drive device with high safety by tapering the shape of a groove portion into which a weight for balance correction can be attached so that the weight is locked during rotation.

[Summary of the Invention] This invention provides a turntable drive device that is rotatably supported using a ball bearing, a hydrostatic bearing, or the like, in which the shape of a groove in which a balance correction weight is attached to the turntable is changed during rotation. This is a turntable drive device that is tapered in the direction in which the weight is locked.

〔Effect of the invention〕

According to the present invention, by rotating the turntable,
Even if centrifugal force acts on the weight of the balance correction groove,
Since the groove for attaching the weight is tapered, there is no risk of the weight popping out, and the weight can be easily replaced using tweezers or the like.

[Embodiments of the invention]

The present invention will be explained in detail using the following drawings.

As shown in FIG. 1, a turntable 2 is attached to a housing 5 on a base 1 via a bearing 4, and a motor 8 is rotated with a master 1 placed on the turntable 2, and a coupling 6 is connected to the turntable 2. The rotation of the master disk 1 is controlled through the master disk 1.

When the master disc is installed, the unbalance can be corrected by automatically measuring the phase and vibration amplitude of the unbalance using the detector 9 and pickup 10 of the Balancing Machine (excluding the principle). A weight 3 (solder, lead, etc.) is attached to the tapered groove (2) at the specified phase along the angle scale line to correct the imbalance. Master 1
The laser optical system mechanism that directly processes the image is not shown.

By providing a tapered groove having a shape as shown in FIG. 2 on one surface of the turntable 2 in this way, it is possible to achieve a turntable driving device that is highly safe in correcting unbalance and is compact.

That is, the tapered groove A is provided on the top surface of the turntable 2 in a circular ring shape along the periphery, and when viewed in the radial cross section, the groove width is the same and the taper groove A is inclined toward the periphery as the groove becomes deeper. This prevents the weight 3 installed in the groove from flying out due to centrifugal force when the turntable rotates, and the bottom B of the groove A is formed at right angles to the wall surface of the groove A. Therefore, when the turntable rotates, the weight 3 is pressed against the portion formed by the wall surface of the groove A and the bottom B, so that the position of the weight 3 in the thickness direction of the turntable can always be maintained constant. Furthermore, since the two grooves A are formed with the same groove width, the weight 3 can be easily attached and detached using tweezers or the like when replacing the weight 3, since the position of the weight 3 is exactly the same.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a turntable drive device showing an embodiment of the present invention, Fig. 2 is a sectional view of main parts showing details of an embodiment of the groove, and Fig. 3 is a sectional view of a conventional groove shape. It is. l...Original disc 2...Turntable 3.
... Weight 4 ... Bearing 5 ... Housing 6 ... Coupling 7 ... Bracket
8...Motor 9...Detector 10...
Pickup 11... Base (7317) Representative Patent Attorney Kensuke Chika (and 1 other person) Figure 1

Claims (1)

[Claims] In a device equipped with a turntable rotatably supported by a bearing and a turntable drive unit for driving the turntable, the tapered 11 turntable can be equipped with a weight for dynamic balance correction on one side of the turntable. A turntable drive device characterized in that a weight is provided in a locking direction.