JPH0650579B2 - Optical disk master cutting device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of an optical disk master cutting device, and more particularly to an improvement of an air slider of a spindle moving type master cutting device.

(Prior Art) Optical discs, which are attracting attention as a recording medium for recording a large amount of information and extracting at a high speed, are read-only discs (ex CD, VD) and write-once discs (DRAW).
Also, there are rewritable discs (E-DRAW), but these three types of discs have an advantage that they can be mass-produced by making a die (generally a stamper) from a master and replicating a large number of replicas. That is, C
In D and VD, audio and video signals are cut on the master by laser light, and DRAW and E-DRA
In W disk, pregrooves and preformats are cut on the master by laser light, and a stamper for replica duplication is created from the cut master, and plastic molding (e
A large amount of replicas are made by x, injection molding, 2P method, compression molding, etc.), a reflection film is attached to the replicas in CD and VD, and a recording medium is attached in the DRAW and E-DRAW disks.

The optical disc thus created is read or written using a player or a recording / reproducing device equipped with a relatively simple optical pickup, so the precision of the optical disc, and therefore the precision of the original master from which it is made Extremely high accuracy is required. Especially the track pitch is 1.60
Those with a thickness of about ± 0.05 μm are required.

The principle itself of the master cutting device for producing the above-mentioned master with high precision is well known, and there are some which have already been put to practical use (Nikkei Mechanical, October 7, 1985, pp. 87-95). reference). This master disk cutting device is, in principle, an optical stand composed of a recording laser and its optical system, a focus control laser and its actuator / detection system, a spindle motor for rotating the master disk, and the optical stand as a spindle. And means for moving one of the motors in the radial direction of the master. In addition to this, a laser optical system for length measurement is generally used to perform highly accurate positioning.

There are two types of the master disc cutting device depending on the above-mentioned relative movement method: an optical table moving type (for example, see JP-A-60-236124) and a spindle moving type. In the former method, adjustment of the optical axis is extremely difficult. However, there is a drawback that the optical axis shifts during use. Further, the latter method has a drawback that the cutting is disturbed due to unbalance of the rotary system, insufficient accuracy of the feeding mechanism, or external vibration.

(Object of the Invention) Therefore, an object of the present invention is to solve the above-mentioned drawbacks of a master cutting device of a spindle motor moving type.
In particular, an object of the present invention is to provide a novel structure of an air slider device for moving a spindle motor, which causes the above-mentioned drawbacks to the greatest extent.

(Structure of the Invention) The present invention relates to an optical disk master cutting device of a movable spindle type in which an optical table supporting an optical system is fixed, while a spindle motor for rotating the master is moved to cut the master with a laser beam. A spindle motor fixing plate having a spindle motor fixed thereto is guided by two mutually parallel air slider devices provided on the left and right of the spindle motor, and the center of gravity of the spindle motor is below the spindle motor fixing plate. I am trying.

The present invention is further characterized in that additional damping means is added to the air slider device.

The additional damping means may be constituted by a friction shoe fixed to the slider of the air slider device, or may be constituted by means for generating mechanical friction between the slider of the air slider device and the slider guide. This means for mechanically generating friction may consist of a friction coating formed on the opposing surface of the slider and / or slider guide.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

First, an outline of the master disc cutting device will be described with reference to FIG. 1 which is a conceptual side view of an optical disc master disc cutting device including the present invention and FIG. 2 which is a conceptual plan view thereof.
Most of the items not directly related to the present invention are omitted.

The optical table 1 in the master cutting device with movable spindle
Is fixed to the anti-vibration base 2 via a support column 3, and an optical system 10 including an Ar laser 4 for cutting, a focus laser 5 and an optical head assembly 6 is mounted on the optical base 1.

On the other hand, the spindle assembly 20 is fixed to the air slider 30, it is moved in the direction of arrow A by the linear transfer means through the air slider device 30 (for example, a linear motor 7 or screw feeder). The position of the air slider device 30 is accurately measured by the length measuring laser 8. The optical system 10 further includes an optical modulator, a lens, a mirror, a shutter, and the like, and is further provided with control means for controlling the entire apparatus, but these are not part of the present invention and therefore omitted. I am doing it.

Feature of the present invention there is an air slider device 30, before describing the air slider device 30 of the present invention will be described with reference to FIG. 3 the structure of a conventional spindle assembly and an air slider device.

The conventional spindle assembly 20 'is a spindle motor 21'
A bracket 23 'for supporting an upper flange 22' of the same is fixedly attached to a slider 31 'of an air slider device 30 ', and this slider 31 'is supported on a slider guide or rail 32'.

The slider 31 'is linearly moved by the linear motor 7'. The air slider device 30 'itself has a well-known structure, and is provided with an air pump (not shown) through an air supply hole 33'.
Pressurized air is supplied through an air supply groove (not shown) formed on the inner surface of the slider 31 ', and the slider 31' is sent on the slider guide 32 'in a non-contact manner.

Since this conventional type structure has a high center of gravity, so-called "Abbe's error" occurs, so that accurate feeding cannot be performed and the vibration damping property is poor.

The present invention improves on the drawbacks of the conventional structure. The structure of the present invention will be described below with reference to FIGS.

Referring to FIG. 4 showing a side conceptual cross-section of an air slider portion according to the present invention, the illustrated spindle assembly 20 is fixed to a spindle fixing plate 35 through an upper flange 22 of a spindle motor 21. Both sides of the spindle fixing plate 35 are fixed to air sliders 31R and 31L, and the air sliders 31R and 31L are supported on slider guides, that is, rails 32R and 32L, respectively. The slider guides 32R and 32L are supported on columns 34 at both ends. The above spindle assembly 20
Is linearly driven by the linear motor 7. Since the spindle assembly 20 and the air sliders 31R and 31L are integrated via the upper flange 22 and the spindle fixing plate 35, the air sliders 31R and 31L are also linearly driven.

As described above, the air sliders 31R and 31L pass through the air supply holes (not shown) from the compressed air source (not shown) and the air supply grooves (not shown) formed on the inner surfaces of the sliders 31R and 31L. Pressurized air is supplied to the slider 31
R and 31L are sent on the slider guides 32R and 32L in a non-contact manner.

In the above-mentioned structure according to the present invention, the center of gravity of the spindle motor is lowered by the spindle motor fixing plate, and the center of gravity is lowered, so that the above-mentioned "Abbe error" is reduced.

Still another feature of the present invention is that additional damping means is added to the air slider device. That is, the vibration generated by the spindle motor or the air slider is not attenuated because there is no portion absorbed because the air slider is not in contact. To overcome this drawback, the present invention is provided with the additional damping means. This additional damping means can be provided between the slider and the guide or between the slider and another fixing member. In the former case, a liner material layer such as a fluororesin is formed on the inner surface of the slider and / or the outer surface of the slider guide to achieve a damping effect by balancing the air bearing function and the mechanical friction effect of the lining material layer. it can. In the latter case, a mechanical friction means can be externally attached to the conventional air slider device to easily achieve the damping effect. An example of the latter case will be described below with reference to FIG.

FIG. 5 is a right side partial view of the air slider portion shown in FIG. 4. In this embodiment, a rod 38 having a friction shoe 36 at its tip is held movably up and down on a bracket 38 fixed to the side wall of the air slider 31R. ing. The rod 40 is urged downward by a compression spring 37, and the urging force is adjusted by a nut 41 screwed with a thread portion at the upper end of the rod. The friction shoe 36 frictionally slides on a friction rail 39 parallel to the slider guide 32.

During operation, most of the weight applied to the air slider 31 which moves linearly by the linear motor 7 is supported by the air slider guide 32 in a non-contact manner, but a part of the weight is passed through the friction shoe mounting bracket 38 and the mounting spring 37. It joins the friction shoe 36 and is supported by the sliding plate 39. The load applied from the friction shoe 36 to the rail 39 is the mounting spring 37.
Therefore, the frictional force between the friction shoe 36 and the rail 39 is kept substantially constant, and this frictional force acts as a vibration suppressing force of the air slider 31.

[Brief description of drawings]

FIG. 1 is a conceptual side view of an optical disk master cutting device including the present invention, FIG. 2 is a conceptual plan view thereof, and FIG. 3 is a conceptual side view of a configuration of a conventional spindle assembly and air slider device, FIG. 4 is a sectional view of an air slider and a spindle motor portion according to the present invention.
The conceptual sectional view by the IV-IV line of a figure. FIG. 5 is a partial sectional view of an air slider portion of an embodiment of the present invention. (Symbols in the figure) 1 ... Optical base 2 ... Vibration isolation base 3 ... Support 4 ... Ar laser 5 ... Focus laser 6 ... Optical head assembly 7 ... Linear motor 8 ... Length measurement laser 10 …… Optical system 20 …… Spindle assembly 21 …… Spindle motor 30 …… Air slider device 31 …… Air slider 32 …… Air slider guide 35 …… Spindle fixed body 36 …… Friction shoe 37 …… Mounting spring 38 …… Bracket 39 …… Friction rail

Claims (5)

[Claims] 1. An optical disk master cutting apparatus of a movable spindle type in which an optical table supporting an optical system is fixed, while a spindle motor for rotating a master is moved to cut the master by a laser beam, and a spindle motor is provided at an intermediate portion. A device in which a fixed spindle motor fixing plate is guided by two air slider devices provided on the left and right of the spindle motor and which are parallel to each other, and a center of gravity of the spindle motor is located below the spindle motor fixing plate. 2. The device according to claim 1, wherein additional damping means is added to the air slider device. 3. An apparatus according to claim 2, wherein the additional damping means is a friction shoe fixed to the slider of the air slider apparatus. 4. The method according to claim 2, wherein the additional damping means is a means for generating mechanical friction between the slider and the slider guide of the air slider device. apparatus. 5. The apparatus according to claim 4, wherein the means for causing friction on the material is a friction film formed on the facing surface of the slider and / or the slider guide.