JP2000306324A - Master disc device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make selectively mountable a thick glass master disc or a thin direct reproducing glass master disk of an optical disc substrate size. SOLUTION: For mounting a glass master disc 2, the center hole 2a of this master disk 2 is fitted to a first taper sleeve 17 and centered on a turntable 3. For mounting a direct reproducing glass master disk 4, the center hole 5f of a spacer sub-turn table 5 is fitted to the first taper sleeve 17 and centered on the turntable 3 and also the center hole 4a of the direct reproducing glass master disk 4 is fitted to a second taper sleeve 21 and centered on the spacer sub-turntable 5 thereby, the height position of an objective lens assembly 24 becomes the same on the glass master disk 2 and the direct reproducing glass master disk 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct reproduction apparatus capable of stably and accurately centering a thick master disk glass master on a turntable in a short time, and having a small optical disk substrate size. The disc glass master can be stably and accurately centered on the turntable in a short time via the spacer subtable,
Also, the present invention relates to a disk master device configured such that the height position of the objective lens assembly for recording is the same for both the master disk glass master and the direct reproduction disk glass master.

[0002]

2. Description of the Related Art At the time of mass production of an optical disk such as a CD disk or a DVD disk, an outer diameter is 200 m.
m, a thickness of 10 mm, a photoresist is applied to a thick master disk glass master having a center hole with a diameter of about 15 mm at the center, and a master disk device (for example, LB
R: A laser beam modulated by an information signal using a laser beam recorder is used to expose a photoresist on a master disk glass master to a latent image and record the latent image, and then develop the master disk glass master for recording. Is produced. Thereafter, a stamper is made by plating based on the master disk glass master, and the stamper is attached to a molding machine, and a 1.2 mm thick CD substrate or a 0.1 mm thick CD substrate is mounted.
A 6 mm thick DVD substrate is made. After that, a reflective film and a protective film of aluminum or the like are sequentially formed on the signal surface of the CD substrate or the DVD substrate, so that the CD disk is a finished product. By bonding two DVD substrates, a bonded disk having a thickness of 1.2 mm is completed. For reading, the respective discs are run to a player to reproduce CD and DVD signals.

[0003] On the other hand, the production of a disk glass master for direct reproduction for checking before mass production of optical disks requires an outer diameter of 120 mm and a thickness of 1.2 mm or 0.6 mm.
m, a photoresist is applied to an optical disk substrate having a central hole having a diameter of 15 mm at the center and having a small thickness, and a photoresist is applied to a thin disk master for direct reproduction, and modulated by an information signal using a disk master (LBR) in the same manner as described above. The photoresist on the master disk for direct reproduction is exposed to the laser beam to record a latent image, and then developed to produce a master disk for direct reproduction disk glass. Thereafter, a reflective film such as aluminum and a protective film are sequentially formed on the signal surface of the direct reproduction disk glass master to complete a direct reproduction disk glass master of a CD disk or a DVD disk. For reading, run the original disk glass for direct reproduction corresponding to the CD disk or DVD disk to the player, and read the CD and DVD.
The signal is reproduced.

[0004] In the production of the above-mentioned disk glass master for direct reproduction, there is no plating step / molding step during the process of producing a molded disk made from a normal stamper, so that a disk glass master for direct reproduction can be produced in a short time. Therefore, in the production and development of the optical disk, the evaluation of the recording signal, the evaluation of the recording signal quality, and the like can be performed in a short time. This can produce great effects in terms of development speed, cost, and the like.

[0005] In normal disk reproduction, the eccentricity of the disk is determined by the tracking sensor of the pickup actuator.
A signal defect is prevented by performing a correction by a boring operation. Strictly speaking, however, distortion is added to the reproduced signal by the tracking servo operation. This distortion amount increases as the disk eccentricity increases. Therefore, in order to obtain a high quality evaluation in disc reproduction, the disc eccentricity must be as small as possible.
μm or less is best.

Therefore, in order to manufacture a precise disc glass master for direct reproduction, a rotatable turntable constituting a part of a disc master disc apparatus (LBR) and a disc glass for direct reproduction during reproduction are required. It is necessary to match the center of the center hole with the rotation center of the turntable so that there is no eccentricity of the center hole of 15 mm, which is a reference for mounting the master.

[0007] Normally, the master disc recording (LBR) is used in a master stamper manufacturing operation for producing a molded disc.
A thick master disk glass master coated with a photoresist having an outer diameter of 200 mm, a thickness of 10 mm, and a center hole having a diameter of 15 mm has a turntable structure that can be set with, for example, a vacuum chuck. . In order to manufacture a disc glass master for direct reproduction of CD or DVD on this turntable, an outer diameter of 120 mm, a thickness of 1.2 mm or 0.6 mm, and an optical disk substrate size having a center hole of 15 mm diameter at the center. Directly setting a thin disk disc for direct reproduction directly
Difficult due to differences in outer diameter, differences in plate thickness, differences in weight, etc.

As a method of centering a general disc glass master, there is a method of centering the disc by pressing the outer periphery of the disc with a work or the like and positioning the disc as disclosed in Japanese Patent Publication No. 1-3587. These are methods suitable for a thick disc glass master having an outer diameter of about 200 mm, a thickness of about 10 mm, and a center hole of about 15 mm.

[0009]

In the above method, the outer diameter is 200 mm, the thickness is 10 mm, and the center hole is 15 mm.
An outer diameter of 120 mm and a thickness of 1.2 mm are formed on a turntable on which a master disk glass master having a large diameter is mounted, for example, to produce a disk glass master for direct reproduction of CD or DVD. Or, it is difficult to directly set a thin disk disc master for direct reproduction with a thickness of 0.6 mm and a center hole of 15 mm in diameter at the center of an optical disc substrate due to differences in diameter, plate thickness, weight, etc. In addition, it is necessary to lower the position of the objective lens assembly for recording in the height direction by 8.8 mm or 9.4 mm as compared with the master disk glass master. Therefore, a high-precision, high-rigidity mechanism is required to move the objective lens assembly in the height direction, and an expensive objective lens having a high NA and a narrow working distance of about 0.1 mm due to an operation error or the like is required. There is a risk of damage.

A method of centering by pressing the outer peripheral portion of the disk is a disk glass for direct reproduction having an outer diameter of 120 mm, a thickness of 1.2 mm or 0.6 mm, an optical disk substrate having a center hole having a diameter of 15 mm at the center, and a thin thickness. Pressing the outer periphery of the master involves the risk of breakage.

Therefore, the present invention solves the above disadvantages,
A thick master disk glass master and a direct reproduction disk glass master such as an optical disk substrate such as a CD or DVD having a small thickness can be selectively and stably and precisely settled on a turntable, and There is a demand for a master disc apparatus having a structure that does not damage the objective lens assembly for recording.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and selectively uses a master disk glass master having a large thickness and a disk glass master for direct reproduction having a small optical disk substrate size. A disk master device that can be mounted on a disc, a rotatable turntable having a first tapered sleeve mounted on the center so as to be vertically movable by a spring force, and a second tapered sleeve mounted on the center by a spring force. A spacer which is movably mounted and has a thickness substantially equal to the thickness of the master disk glass master by adding the thickness of the direct reproduction disk glass master, and is attachable to the turntable. For recording information signals on the master disk glass master or the direct reproduction disk glass master. A's assembly, the when mounting the master disk glass master, the said master disc glass master disk center hole of the master disk glass master is fitted on the first tapered sleeve motor -
Centering on the table, while, when the direct-play disc glass master is mounted, the center hole of the spacer sub-table is fitted into the first tapered sleeve to allow the spacer to be mounted. Centering the sub turn table on the turn table, and centering the center hole of the direct reproduction disc glass master disc on the second turn table.
By centering the direct reproduction disc glass master on the spacer sub-turn table by fitting it into a taper sleeve, the height position of the objective lens assembly is changed to the master disc glass master and the master disc glass master. This is a disk master apparatus characterized in that the disk glass master for direct reproduction is the same.

Further, in the disk master apparatus of the present invention, the master disk glass master or the spacer sub turn is provided on the turntable and discharges air from the upper surface of the turntable during centering. Air is lifted from the turntable with respect to the turntable, and the center hole of the master disc glass master or the center hole of the spacer subturn table is fitted to the first tapered sleeve. Aspirate
First air discharge / suction means for adsorbing the master disk glass master or the spacer sub-table on the upper surface of the turntable; and a first air discharge / suction means provided on the spacer sub-table. In addition, at the time of centering, air is discharged from the upper surface of the spacer sub-turn table to float the direct reproduction disk glass master with respect to the spacer sub-turn table, thereby allowing the direct reproduction. After the center hole of the disc glass master is fitted into the second taper sleeve, air is sucked, and the second air discharge for sucking the direct reproduction disc glass master on the upper surface of the spacer sub-turntable. / A master disc device comprising: a suction means.

Further, in the disk master apparatus of the present invention, the first air discharge / suction means provided on the turntable and the second air discharge / suction means provided on the spacer sub-turntable are provided. A master disc device characterized by being connected to communicate with each other.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a disk master apparatus according to the present invention will be described below in detail with reference to FIGS.

FIG. 1 is a longitudinal sectional view for explaining an initial state of a disk master apparatus according to the present invention, and FIG. 2 is an enlarged longitudinal section showing an initial state of a disk centering mechanism in the disk master apparatus according to the present invention. FIG. 3 is an enlarged plan view of the spacer sub-turn table shown in FIG. 1, and FIG. 4 is a longitudinal sectional view for explaining a use state of the disk master apparatus according to the present invention. FIG. 5 is an enlarged longitudinal sectional view showing the use state of the disk centering mechanism in the disk master device according to the present invention.

Incidentally, in FIG. 1, FIG. 2, FIG. 4 and FIG.
The left side from the center line shows a state in which the original disk glass for direct reproduction having a small thickness and the thickness of the optical disk substrate is placed on the turntable via the spacer sub-table, and the right side from the center line is the right side. This shows a state in which a thick master disk glass master is placed on a turntable.

As shown in FIG. 1, in the disk master device 1 according to the present invention, a turntable 3 is used to stably center a master disk glass master 2 using a thick smooth glass master on a turntable 3. After the master disk glass master 2 is placed on the turntable 3, the master disk glass master 2 is floated from the upper surface of the turntable 3 by air discharge. The center hole 2a of the master disk glass master 2 is fitted into a first taper sleeve 17 having a tapered surface 17a provided vertically movably in the center of the turntable 3, and thereafter, the master disk glass master 2 is sucked by air. On the upper surface of the turntable 3 for centering. The direct reproduction disk glass master 4 is formed slightly thinner than the master disk glass master 2 without directly mounting the direct reproduction disk glass master 4 having a small thickness in the size of an optical disk substrate such as a DVD on the turntable 3. And turntable 3
Is placed on the turntable 3 via a spacer subtable 5 through which air can be communicated, and is directly reproduced by discharging air from the spacer subtable 5 The disc glass master 4 is used as a spacer
A tapered surface 21a is provided in which the center hole 4a of the disc glass master disk 4 for direct reproduction is vertically movable at the center of the spacer sub-table 5 while floating from the upper surface of the table 5. Recording is performed by fitting the disk glass master disk 4 for direct reproduction onto the upper surface of the spacer sub-turn table 5 by air suction so that it can be centered. The height position of the objective lens assembly 24 for the master disk glass master 2 and the disk glass master disk 4 for direct reproduction are the same.

That is, the master disc apparatus 1 has a master disc glass master 2 having a large thickness mounted on a turntable 3, or a disc glass master 4 for direct reproduction having a small thickness of an optical disc substrate such as a CD or DVD. Is mounted on the turntable 3 via the spacer subtable 5, and the turntable 3
Since it is a precision mechanical device that records information signals concentrically or spirally at a track pitch of μm or sub μm on the master disk glass master 2 or direct reproduction disk glass master 4 that rotates integrally with the master disk glass, it can be accurately leveled. It is set on an anti-vibration table (not shown) to take anti-vibration measures.

First, since the above-mentioned turntable 3 requires precise high-speed rotation, a non-contact type static pressure air bearing 7 is integrally mounted above a fixedly installed direct drive motor 6. As the static pressure air bearing 7, for example, an air spindle of NTN # AH-ASR130 is often used. A ring-shaped first air discharge / suction hole 7a is formed in the outer peripheral portion of the static pressure air bearing 7, and the first air discharge / suction hole 7a is brought into non-contact with the static pressure air bearing 8 on the fixed side. Since they are connected, the static pressure air bearing 7 can rotate integrally with the direct drive motor 6.

The fixed-side static pressure air bearing 8 is connected to be able to be switched to a disk floating air supply source 13 and a negative pressure supply source 15 to be described later via a pipe 9 and a path switching valve 10.

The hydrostatic air bearing 7 has a horizontal air hole 7b and a vertical air hole 7c formed at a portion where a first air discharge / suction hole 7a formed in a ring shape along the outer peripheral portion is equally divided into three at 120 ° intervals.
Is formed at a right angle in communication with the first air discharge / suction hole 7a, and further formed in a ring shape along the upper surface with the second air discharge / suction hole 7d communicating with the three vertical holes 7c. I have. Note that the static pressure air bearing 7 is actually 3-551.
Since it is described in detail in Japanese Patent Publication No. 65, the detailed description is omitted.

One of the path switching valves 10 is connected by a pipe 11 to a disk floating air supply source 13 that discharges air through a flow rate adjusting valve 12, and the other of the path switching valves 10 sucks air by a pipe 14. Connected to a negative pressure supply source 15. At this time, clean air that has been dry-processed and passed through a filter is used as the quality of the air for floating the disk. Also,
The flow rate adjusting valve 12 for adjusting the flow rate of the air supplied from the air source 13 for floating the disk is provided with the master disk glass master 2 or the spacer sub turn table 5 with respect to the turntable 3. The adjustment is performed so that the master disk 4 for direct reproduction is floated about 0.1 mm with respect to the sub-table 5 for spacer.

Next, the above-mentioned turntable 3 is formed by using an aluminum material so as to be slightly smaller than the outer shape of the master disk glass master 2 or the spacer sub-table 5. Numeral 3 is fixed to the upper surface of the static pressure air bearing 7 by a screw (not shown), and is rotatably mounted integrally with the static pressure air bearing 7 by the driving force of the direct drive motor 6. At this time, the turntable 3 is manufactured by sufficiently controlling the processing accuracy of each part such as the outer periphery in order to rotate at a high speed, and balances the rotation of the entire rotation system.

The turntable 3 is provided with a first air discharge / suction means, that is, connected to a ring-shaped second air discharge / suction hole 7d on the upper surface of the static pressure air bearing 7. The first air discharge / suction hole 3a is formed in a ring shape along the lower surface, and the first air discharge / suction hole 3a is divided into three equal parts at 120 ° intervals. 3c is the first air discharge / suction hole 3a
And is formed at a right angle. The horizontal holes 3c are formed radially from the inner circumference to the outer circumference at intervals of 120 ° in the turntable 3, and communicate with the horizontal holes 3c so that the second and third vertical holes 3d and 3e are formed on the upper surface. The second vertical hole 3d is formed on the inner peripheral side, and the third vertical hole 3e is formed on the outer peripheral side. Furthermore, the second and third vertical holes 3
d, 3e, the second and third air discharge / suction holes 3
f and 3g are formed in a ring shape along the upper surface. At this time, three lateral holes 3 along the outer periphery of the turntable 3
The open part of the outer periphery of c is sealed with a seal member 16.

The ring-shaped second and third air discharge / suction holes 3f, 3g formed on the upper surface of the turntable 3.
When the air supply source 13 for disk floating is operated to discharge air, the master disk glass master 2
Alternatively, while the sub-table 5 for the spacer is slightly floated from above the table 3, the air is sucked by operating the negative pressure supply source 15, and the master disk glass master 2 or the space for the master is used. -Turn the sub turntable 5
It has a function of adsorbing on the table 3. Further, the second air discharge / suction hole 3f is connected to a first air discharge / suction hole 5a formed on the lower surface of the spacer sub-turn table 5 described later.

At this time, the number of vertical holes and horizontal holes provided in the inside of the turntable 3 and the number of air discharge / suction holes provided on the upper surface thereof are set in the turntable 3 so that air discharge / suction is uniform. It suffices to provide a plurality of them in a substantially balanced manner.

Next, as shown in an enlarged manner in FIG. 2, a concave portion 3i is provided concentrically with the guide shaft portion 3h and lower than the upper surface around the guide shaft portion 3h provided at the center of the turntable 3. It is formed in a concave shape. On the guide shaft 3h of the turntable 3, a first taper sleeve 17 having a tapered cylindrical tapered surface 17a formed upward is provided with a compression spring 18 via a compression spring 18 as a sliding gap of several μm with respect to the guide shaft 3h. The first fitting
The upper end of the tapered surface 17a of the tapered sleeve 17 slightly projects from the inside of the concave portion 3i of the turntable 3 toward the upper surface. At this time, the guide shaft 3h and the first tapered sleeve 17
The concentricity is finished within several μm, and the concentricity of the guide shaft portion 3h with respect to the center of the turntable rotation system is manufactured within several μm. The compression spring 18
Is set to a weak urging force enough to support about twice the weight of the first taper sleeve 17 itself. The first taper sleeve 17 is provided on the guide shaft 3h of the turntable 3.
The upper limit at the time of upward movement is restricted by a stopper 19 attached to the upper end of the guide shaft, and the stopper 19 is prevented from coming off from the guide shaft 3h.

Next, the master disk glass master 2 described above is formed so as to be attachable (removable) to the turntable 3 and has an outer diameter of 200 mm, a thickness of 10 mm and a center of 15 mm using a thick smooth glass master. A center hole 2a of about a diameter is formed, and the concentricity of the center hole 2a and the outer diameter part 2b is finished to about 5 μm. At this time, the value of the concentricity of 5 μm of the outer diameter portion 2b of the master disk glass master 2 is a value that can be realized without any problem by using a grinding device using a dedicated jig or a lapping device.
Although the cost is slightly increased for concentricity, the cost increase is not a problem in view of the fact that the glass master for resist coating is re-used tens or hundreds of times.

Then, master disk glass master 2
Is mounted on the turntable 3, the center hole 2 a of the master disc glass master 2 is fitted to the tapered surface 17 a of the first tapered sleeve 17 movably mounted on the guide shaft 3 h of the turntable 3 so as to be vertically movable. As a result, the master disk glass master 2 is accurately centered on the turntable 3.

Next, a spacer sub-table 5 for mounting the disc glass master 4 for direct reproduction is provided.
The master disk glass master 2 is formed so as to be attachable (removable) to the turntable 3 similarly to the master disk glass master 2, and is made of aluminum.
It has the same outer diameter of 200 mm and is slightly thinner than the master disk glass master 2 and is formed to about 9 mm. That is, the thickness of the spacer sub-turn table 5 is 1. 2mm thick CD or 0.6mm thick DV
The thickness is set to be approximately the same as the 10 mm thickness of the master disk glass master 2 by adding the thickness of the disk glass master 4 for direct reproduction of an optical disk substrate size such as D.

The spacer sub turntable 5 is provided with a second air discharge / suction means, that is, a second air discharge / suction means formed on the upper surface of the turntable 3 in a ring shape.
A first air discharge / suction hole 5a connected to the air discharge / suction hole 3f is formed in a ring shape along the lower surface, and the first air discharge / suction holes 5a are formed at intervals of 120 °.
A first vertical hole 5b and a horizontal hole 5c are formed at equal angles in the equally divided portion so as to communicate with the first air discharge / suction hole 5a. As shown in FIG. 3, the horizontal holes 5c are formed radially from the inner circumference to the outer circumference at intervals of 120 DEG in the spacer sub-turn table 5. As shown in FIG. The second vertical hole 5d is formed toward the upper surface so as to communicate with the upper surface.
Further, a second air discharge / suction hole 5e is formed in a ring shape along the upper surface in communication with the second vertical hole 5d. At this time, three points along the outer periphery of the spacer sub-turn table 5
The outer peripheral portion of the lateral hole 5c is sealed with a seal member 20 at the opening.

Then, a sub turn table 5 for the spacer is provided.
Air discharge / suction hole 5 formed in a ring shape on the upper surface of
e, when the air is supplied by operating the air supply source 13 for floating the disk, the master disk 4 for direct reproduction is slightly lifted from the sub turntable 5 for the space, while the negative pressure is supplied. When the air is sucked by operating the source 15, a function is provided for sucking the direct reproduction disk glass master 4 onto the spacer sub-turntable 5.

Further, as shown in an enlarged manner in FIG.
The first, second, and second
The third center holes 5f, 5g, 5h are formed concentrically in order from the bottom to the top. Here, the first center hole 5f
Is formed in a concave shape with a diameter of about 15 mm on the lower surface side, and the second
The center hole 5g is formed to penetrate the middle portion with a diameter smaller than the diameter of the first center hole 5f, and the third center hole 5f is formed in a concave shape with a diameter larger than 15 mm on the upper surface side.

At this time, the sub turn table 5 for the spacer is used.
The number of vertical holes and horizontal holes provided in the inside and the number of air discharge / suction holes provided on the upper surface are well-balanced in the spacer sub-table 5 so that air discharge / suction is uniform. What is necessary is just to provide multiple substantially equally.

The second central hole 5g of the spacer sub-turn table 5 has an upwardly tapered cylindrical tapered surface 2g.
1a, and a second guide shaft 21b formed below.
The tapered sleeve 21 is fitted via a compression spring 22 so as to be able to move up and down smoothly with a sliding gap of several μm with respect to the second center hole 5g. The upper end of the tapered surface 21a of the second tapered sleeve 21 is It protrudes slightly from the inside of the third center hole 5h of the spacer sub-turn table 5 to the upper surface side. Further, the compression spring 22 is set to a weak urging force enough to support about twice the weight of the second taper sleeve 21 itself. Further, the second tapered sleeve 21 is
The upper limit at the time of upward movement is regulated by the stopper 23 attached to the lower end of b, and the spacer sub-table 5 is prevented from falling out of the second center hole 5g.

Further, a sub turn table for spacer 5
In order to make the original glass disk 4 for direct reproduction of the size of an optical disk substrate such as a CD or DVD having a diameter of 120 mm detachable, the upper surface with an outer diameter of 200 mm is cut in steps to directly reproduce the outer shape on the upper surface. It is formed to have a diameter of about 1 to 2 mm smaller than the 120 mm diameter of the master disk glass master 4.

The spacer sub-table 5
Is mounted on the turntable 3, the first center hole 5 f of the spacer sub-table 5 is attached to the guide shaft 3 h of the turntable 3 so as to be vertically movable. By fitting to the surface 17a,
The spacer sub-table 5 is accurately centered on the turntable 3. Also,
When the disc glass master 4 for direct reproduction is placed on the sub-table 5 for spacer, the center hole 4a of the disc glass master 4 for direct reproduction is placed in the second sub-table 5 for spacer. Tapered surface 21 of second tapered sleeve 21 movably mounted up and down along center hole 5g
a, the direct reproduction disc glass master 4 is accurately centered on the spacer sub-table 5 and also accurately centered on the turn table 3. It has become.

Further, above the master disk glass master 2 or the direct reproduction disk glass master 4,
An objective lens assembly 24 for recording is provided movably in the radial direction of both masters 2 and 4. At this time, the master disk glass master 2 is directly mounted on the turntable 3 and the direct reproduction disk glass master 4 is connected to the turntable 3 via the spacer sub-table 5.
Since the heights of the upper surfaces of both masters 2 and 4 are substantially the same as when mounted on top, the height position of objective lens assembly 24 is set to both master disk glass master 2 and direct reproduction disk glass master 4. The same thing.

Here, the operation of the master disc apparatus having the above configuration will be described with reference to FIGS. 1, 2 and 4 and 5.

First, as shown in FIGS. 1 and 2, when the master disk master 2 is placed on the turntable 3, and when the disk glass master 4 for direct reproduction of the optical disk substrate size is used as the spacer sub-writer. The mounting on the turntable 3 via the turntable 5 is performed separately. At this time, the recording objective lens assembly 24 is retracted to a position where it does not hinder the mounting of the master disk master 2 or the direct reproduction disk glass master 4.

Before the master disk master 2 or the spacer subtable 5 is mounted on the turntable 3, the first taper fitted to the guide shaft 3h of the turntable 3 is used. The sleeve 17 has a compression spring 18
Is pushed upward until it comes into contact with the stopper 19.

The second taper sleeve 21 attached to the spacer sub turntable 5 is also pushed upward by the urging force of the compression spring 22.

Then, the center hole 2a of the master disk master 2 or the first center hole 5f of the spacer sub-table 5 is inserted into the first taper sleeve 17 attached to the turntable 3. In addition, the center hole 4a of the disc glass master disk 4 for direct reproduction is inserted into the second taper sleeve 21 attached to the spacer sub-turn table 5.

Thereafter, when the master disc 2 for master or the sub turntable 5 for spacer is centered and mounted on the turntable 3, the air supply source 13 for floating the disc is operated and the flow rate is adjusted. The air flow rate is adjusted by the adjustment valve 12 and the air having the adjusted flow rate is supplied to the pipe 1.
1, through a path switching valve 10, a pipe 9, and a static pressure air bearing 8 on the fixed side, it is supplied to a static pressure air bearing 7 that rotates integrally with the direct drive motor 6. The air supplied to the static pressure air bearing 7 is also supplied to the turntable 3, and the air is supplied to the upper surface of the turntable 3 in the form of second and third air discharge / suction holes 3 f and 3.
g, the master disc 2 for master or the sub-table 5 for spacer placed on the turntable 3 is uniformly about 0.1 mm from the upper surface of the turntable 3 by the discharge force of air. Surface.

Here, when the master disk master 2 or the spacer sub-table 5 reaches an air float state on the turntable 3, the master disk master 2 or the spacer sub-turn is turned on. The first taper sleeve 17 is pushed downward along the guide shaft 3h against the urging force of the compression spring 18 and sinks, leaving the same as the height of the air float of the bull 5 and the master disk master 2 Edge of center hole 2a or sub turntable 5 for spacer
The edge of the first center hole 5f and the tapered surface 17a of the first tapered sleeve 17 come into contact only by line contact, so that the master disk master 2 or the spacer
The centering (centering) of the table 5 is performed and the table 5 is floating on the turntable 3.

Similarly to the above, the air supplied to the turntable 3 is also supplied to the spacer sub-table 5, and this air is formed on the upper surface of the spacer sub-table 5 in a ring shape. Since the air is discharged from the second air discharge / suction hole 5e, the spacer sub-turn table 5 is formed.
The direct reproduction disk glass master 4 placed on the upper surface is made of a spacer sub turntable 5 by an air discharge force.
Floats about 0.1 mm uniformly from the upper surface of.

Here, when the disk glass master 4 for direct reproduction reaches an air float state on the sub-table 5 for spacer, the height of the air float of the disk glass master 4 for direct reproduction is equal to the height of the air float. The second tapered sleeve 21 remains in the second position against the urging force of the compression spring 22.
It is pushed downward along the center hole 5g and sinks, and the edge of the center hole 4a of the direct-reproduction disk glass master 4 and the tapered surface 21a of the second tapered sleeve 21 come into contact only by line contact, and are stable. The direct reproduction disk glass master 4 is centered (centered) with high precision, and floats on the spacer sub-turn table 5.

Next, as shown in FIGS. 4 and 5, the master disk master 2 or the spacer sub-turn table 5 is used.
In a state in which the airplane floats while centering (centering) on the turntable 3, the path switching valve 10 is switched to the negative pressure supply source 15 side to operate the negative pressure supply source 15 to start the air suction operation. Since the air is sucked into the negative pressure supply source 15 through a route reverse to that of the suction, the master disc 2 for master or the spacer for spacer which has floated up.
The table 5 is turned by an air suction operation.
Absorbed on top. Here, the edge of the center hole 2a of the master disk master 2 or the edge of the first center hole 5f of the spacer sub-table 5 is the first tapered sleeve 17.
Guide shaft portion 3h centered on tapered surface 17a of
And the first taper sleeve 1 with the weight of the master disc 2 for master or the sub turntable 5 for spacer.
7 descends downwardly to crush the compression spring 18. At this time,
The air pressure on the lower surface of the master disk master 2 or the spacer sub-table 5 gradually decreases when viewed microscopically, and the master disk master 2 or the spacer sub-turn table 5 is gradually reduced. The table 5 is softly landed on the upper surface of the turntable 3, and the master disk master 2 or the spacer subtable 5 is precisely centered with respect to the rotation center of the turntable 3. Reach.

When the negative pressure supply source 15 is operated, the direct reproduction disk glass master 4 placed on the spacer sub-table 5 is also in the same manner as described above.
The soft landing is performed on the upper surface of the spacer sub-table 5 in a state where the taper sleeve 21 is centered (centered).

When the master disk master 2 is mounted on the turntable 3, the recording objective lens assembly 24 is advanced into the upper surface of the master disk master 2, and the master disk master 2 is mounted. The objective lens assembly 24 is moved in the radial direction of the master disk master 2 while the master disk master 2 is being rotated at a high speed integrally with the turntable 3 while being adsorbed on the turntable 3 by air. An information signal is recorded on the master disk master 2 by the solid 24.

When the direct reproduction disk glass master 4 is mounted on the turntable 3 via the spacer sub-table 5, the direct reproduction disk glass master 4 is attached to the turntable 3. Is approximately the same as the height of the upper surface of the master disk master 2, so that the objective lens assembly 24 can be directly moved without changing the overall height of the objective lens assembly 24 for recording. It can be made to enter the upper surface of the reproduction disk glass master 4.

[0053]

According to the disk master apparatus of the present invention described in detail above, when a master disk glass master having a large thickness and a disk glass master for direct reproduction having a small optical disk substrate size are selectively mounted. In addition, a thick master disk glass master for a master can be stably and accurately centered on a turntable in a short time, and a disk glass master for direct reproduction having a small thickness on an optical disk substrate is used as a spacer for a spacer. -The center of the objective lens assembly can be stably and accurately centered on the turntable in a short time through the table, and the height position of the objective lens assembly is the same for both the master disc glass master and the direct playback disc glass master. This not only simplifies the mechanism for moving the objective lens assembly, but also allows the objective lens to be Effects such as no risk of colliding with the scan master or direct read disc glass master is obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view for explaining an initial state of a disk master device according to the present invention.

FIG. 2 is an enlarged longitudinal sectional view showing an initial state of a disk centering mechanism in the disk master device according to the present invention.

FIG. 3 is an enlarged plan view of the spacer sub-turn table shown in FIG. 1;

FIG. 4 is a longitudinal sectional view for explaining a use state of the master disk device according to the present invention.

FIG. 5 is an enlarged longitudinal sectional view showing a use state of a disk centering mechanism in the disk master device according to the present invention.

[Explanation of symbols]

1: Master disk unit, 2: Master disk master
2a: center hole, 3: turntable, 3h: guide shaft portion, 3a: first air discharge / suction hole, 3b: first vertical hole,
3c: horizontal hole, 3d: second vertical hole, 3e: third vertical hole, 3h:
Guide shaft part, 4 ... disk glass master for direct reproduction, 4a ... center hole, 5 ... sub turntable for spacer, 5a ... first air discharge / suction hole, 5b ... 1st vertical hole,
5c: horizontal hole, 5d: second vertical hole, 5e: second air discharge /
Suction hole, 5f: first center hole, 5g: second center hole, 6: direct drive motor, 7: static pressure air bearing, 10 ...
Path switching valve, 13: air supply source for disk floating, 15: negative pressure supply source, 17: first tapered sleeve, 1
7a: tapered surface, 18: compression spring, 21: second tapered sleeve, 21a: tapered surface. 22: compression spring, 24: objective lens assembly.

Claims (3)

[Claims] 1. A disk master device capable of selectively mounting a master disk glass master having a large thickness and a disk glass master for direct reproduction having a small optical disk substrate size, wherein a first tapered sleeve is provided at a center portion. A rotatable turntable which is vertically movable by a spring force, and a second taper sleeve which is vertically movable by a spring force at a center portion, and has a thickness of the direct reproduction disk glass master. A spacer sub-table, which is formed to have a thickness substantially equal to the thickness of the master disk glass master and is attachable to the turntable; and the master disk glass master or the direct reproduction. An objective lens assembly for recording information signals on a master disk glass master, and mounting the master disk glass master Occasionally, the center hole of the master disk glass master is fitted to the first tapered sleeve to center the master disk glass master on the turntable. At the time of mounting, the center hole of the spacer sub-table is fitted into the first tapered sleeve to center the spacer sub-table on the turn table, The center hole of the direct reproduction disk glass master is fitted to the second taper sleeve, and the direct reproduction disk glass master is centered on the spacer sub-table,
A master disc apparatus, wherein the height position of the objective lens assembly is the same for both the master disc glass master and the direct playback disc glass master. 2. The master disk device according to claim 1, wherein said master disk glass master or said spacer sub-unit is provided on said turntable and discharges air from the upper surface of said turntable during centering. The center table was lifted with respect to the turn table, and the center hole of the master disk glass master or the center hole of the spacer sub-table was fitted to the first tapered sleeve. A first air discharge / suction means for sucking air later to suck the master disk glass master or the spacer sub-table on the upper surface of the turntable; and Provided on the table, and
At the time of centering, air is discharged from the upper surface of the spacer sub-table to float the direct reproduction disk glass master with respect to the spacer sub-table, thereby producing the direct reproduction disk glass. After the center hole of the master is fitted into the second taper sleeve, air is sucked to suck the air from the disc glass master for direct reproduction onto the upper surface of the spacer sub-turntable. Means for a master disc. 3. The disk master device according to claim 2, wherein said first air discharge / suction means provided on said turntable and said second air discharge / suction means provided on said spacer sub-turntable.
A master disc device, characterized in that said disc master device is connected in communication with said air discharge / suction means.