JPH0527170B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a disc-shaped record carrier mold clamping device in an apparatus for reproducing and inspecting a disc-shaped record carrier mold.

Conventional Structure and Problems Disc-shaped record carrier molds are mainly made of nickel, but in order to reproduce and inspect them, it is necessary to clamp the disc-shaped record carrier molds to a rotary table. One conventional clamping device for this purpose is one that mechanically clamps using a protrusion on the rotary table that protrudes through the center positioning hole of the disc-shaped record carrier mold. . This clamping device does not cause any problems when the mold is mechanically clamped because it does not distort much when the mold is thick, but when the mold is thinner, on the order of several hundred microns, Clamping causes distortion, which not only impedes reproduction and inspection, but also causes defects in subsequent processes. Furthermore, as shown in Fig. 1, the disc-shaped record carrier mold A is generally warped and distorted (especially in the case of thin molds), so it is necessary to correct the warp when clamping. However, since the conventional clamping device described above mechanically clamps only the central portion of the mold, it has not been possible to correct the warpage as a whole.

OBJECT OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and provides a disc-shaped record carrier mold clamping device that can reliably fix a disc-shaped record carrier mold to a rotary table with good flatness without causing distortion to the disc-shaped record carrier mold. The purpose is to provide.

Structure of the Invention In order to achieve the above object, the disc-shaped record carrier mold clamping device of the present invention includes a rotary table, a magnetic adsorption means provided on the rotary table for magnetically adsorbing the disc-shaped record carrier mold, and a magnetic adsorption means for magnetically adsorbing the disc-shaped record carrier mold. The apparatus further includes a vacuum suction means for vacuum suctioning the disc-shaped record carrier mold provided on the rotary table at the same time as the suction by the means.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, a rubber magnet disk 2 having a center hole 1 is fitted into a recess 4 provided in an upper rotary table 3a and fixed therein. At this time, the thickness of the rubber magnet disk 2 and the depth of the recess 4 are made equal. A protrusion 5 provided at the center of the upper rotary table 3a is inserted into the center hole 1 and protrudes above the surface of the rubber magnet disc 2. A plurality of through holes 6 arranged concentrically are bored in the outer circumference of the upper rotary table 3a, and concentric annular recesses 7a and 7b are provided on both sides in the radial direction. Vacuum seal rings 8a and 8b are fitted into the recesses 7a and 7b, respectively.

The upper rotary table 3a has a recess 9 on the upper surface and a lower rotary table 3b having an exhaust hole 10 in the center.
The upper and lower rotary tables 3a and 3b constitute a rotary table 3. An exhaust path 11 consisting of the through hole 6, the recess 9, and the exhaust hole 10 is formed inside the rotary table 3. The lower rotating table 3b has a hollow interior and is fixed to a rotating shaft 12 communicating with the exhaust hole 10. Reference numeral 13 denotes a disk-shaped record carrier mold. When this mold is mounted on the upper rotary chip 3a with its center hole 13a aligned with the projection 5, the signal recording area is clamped by the magnetic attraction of the rubber magnet disc 2. Next, the exhaust hole 10 is connected to an external vacuum evacuation device (not shown), and when this vacuum evacuation device is operated, the inside of the exhaust path 11 becomes a vacuum state, and due to the pressure difference with the outside, a disk-shaped recorder is created. The outer periphery of the carrier mold 13 is sucked and pressed against the upper rotary table 3a.

As described in the conventional example, the disc-shaped record carrier mold 13 has a signal recording area curved into a bowl shape. When the disc-shaped record carrier mold 13 having such a warp is clamped to the rotary table 3 with a strong force, high-frequency distortion occurs because the wall thickness is extremely thin, which impedes reproduction and inspection. Disc-shaped record carrier mold 1
If the entire surface of 3 is clamped by vacuum suction, the pressing force will be too strong, and the desired flatness will not be obtained for the above-mentioned reasons. Here, the disc-shaped record carrier mold 13
By clamping the signal recording area by magnetic attraction as in the embodiment of the present invention, it is possible to press with an appropriate attraction force and obtain the desired flatness. Incidentally, the peripheral portion of the disc-shaped recording carrier mold 13 often has distortion because it has undergone several peeling steps. Therefore, magnetic attraction cannot uniformly attract the peripheral area. If the rotary table were to be rotated in this state, uncorrected distortions remaining in the peripheral portion would act as a vibration source, which would impede reproduction and inspection. Therefore, it is necessary to press the periphery with strong force. Therefore, by pressing the periphery of the disk-shaped recording carrier mold 13 with a strong force by vacuum suction as in the embodiment of the present invention, it is possible to prevent vibrations that occur during rotation. At this time, by providing the vacuum seal rings 8a and 8b so that the vacuum pressing force does not act on the signal area, only the peripheral area can be vacuum suctioned.

In this embodiment, the vacuum suction means is provided outside the signal recording area, but depending on the disc-shaped record carrier mold 13, the position of the vacuum suction means is not limited to the outside, but may be provided inside the signal recording area. , or may be provided both inside and outside. Moreover, a disc-shaped record carrier mold 13
When it is removed, since it is clamped only by magnetic attraction, the attraction force is relatively weak, and it can be easily removed, without distorting the disc-shaped record carrier mold 13 during removal.

Effects of the Invention As described above, according to the present invention, since magnetic adsorption and vacuum pressing are used together, molds with large warps or distortions can be reliably clamped without distortion, and the desired flatness can be achieved. It has the advantage of being obtainable.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention,
FIG. 1 is a partially cutaway plan view, FIG. 2 is a longitudinal sectional view, and FIG. 3 is a sectional view of a disc-shaped record carrier mold. 2...Rubber magnet disc, 3...Rotary table, 6...
...Through hole, 8a, 8b...Vacuum seal ring,
11...Exhaust path, 13...Disc-shaped record carrier mold.

Claims (1)

[Scope of Claims] 1. A rotary table, a magnetic attraction means provided on the rotary table for magnetically attracting a disc-shaped record carrier mold, and the disc-shaped record carrier provided on the rotary table at the same time as the magnetic attraction means attracts the disc-shaped record carrier mold. A disc-shaped record carrier mold clamping device comprising vacuum suction means for vacuum suctioning the mold. 2. The disc-shaped record carrier mold clamping device according to claim 1, wherein the vacuum suction means is provided at a position outside the signal recording area of the disc-shaped record carrier mold. 3. The disc-shaped record carrier mold clamping device according to claim 1, wherein the magnetic attraction means is provided in the signal recording area of the disc-shaped record carrier mold. 4. The disc-shaped record carrier mold clamping device according to claim 1, wherein the magnetic attraction means is constituted by an elastic permanent magnet disc.