JP2001338453A - Disk centering device, and master original disk manufacturing device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably center a disk on a turntable. SOLUTION: When a master original disk 2 is centered, air is discharged from the upper part of a turntable 3 to the master original disk 2 to float the disk 2. On the other hand, when air is sucked to adsorb the master original disk 2 on the upper surface of the turntable 3 after a tapered sleeve 14 is fitted in the center hole 2a of the master original disk 2, especially air is discharged from a guide shaft part 3b provided in the center of the turntable 3 toward the center hole 14b of the tapered sleeve 14, and the tapered sleeve 14 is held in a floating state with respect to the guide shaft part 3b, and thus a static pressure air bearing structure is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk centering apparatus capable of stably and accurately centering a disk on a turntable in a short time and a master disk master manufacturing apparatus to which the disk centering apparatus is applied.

[0002]

2. Description of the Related Art Conventionally, a master disk master used for molding an optical disk such as a CD or a DVD is:
The coating is made by applying a photoresist on a smooth glass disk having an outer diameter of 200 mm, a thickness of 10 mm, and a center hole having a diameter of about 15 mm at the center. Then, the master disk master is mounted on the turntable of the master disk master manufacturing apparatus, and the photoresist is exposed to the laser beam modulated by the information signal while the master disk master is rotated at a high speed integrally with the turntable. After recording the information signal as a latent image, the master disk master is removed from the turntable and subjected to development processing.

Here, in order to manufacture a master disk for master with high accuracy, the center of the master disk for master and the turntable must be fixed so that there is no rotational vibration due to unbalance between the turntable rotating at high speed and the master for master disk. It is necessary to match with the rotation center of.

Therefore, the present applicant has previously disclosed in Japanese Patent Application Laid-Open No. 2000-2000.
According to Japanese Patent No. 11505, air is discharged from the upper surface of the turntable to the disk side when the disk is centered to cause the disk to float, and after the tapered sleeve is fitted into the center hole of the floating disk, the air is sucked to remove the disk. A disk centering device that can stably and accurately center a disk on the turntable in a short period of time by adsorbing it on the top surface of the turntable, and has the effect that no dust is generated by the centering operation. And a master disk master manufacturing apparatus to which the disk centering apparatus is applied.

FIG. 1 shows the structure of a conventional disk centering apparatus and a master disk master manufacturing apparatus to which the disk centering apparatus is applied, and also shows a state in which the master disk master is centered on a turntable. FIG. 3 is an enlarged top view of the turntable shown in FIG. 1, and FIG. 3 is a master disk centered on a turntable in a conventional disk centering device and a master disk master manufacturing apparatus to which the disk centering device is applied. FIG. 3 is a diagram showing a state in which an information signal is recorded on a master.

The conventional disk centering apparatus shown in FIGS. 1 to 3 and a master disk master manufacturing apparatus to which the disk centering apparatus is applied have been previously proposed by the present applicant in Japanese Patent Application Laid-Open No. 2000-11505. It is.

In FIG. 1, a master disk master manufacturing apparatus (approximately equivalent to a disk centering apparatus) 1 to which a disk centering apparatus is applied has a master disk master (substantially equivalent to a disk) 2 mounted on a 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 2 for master rotating integrally with the turntable 3, leveling is performed accurately.
It is set on an anti-vibration table (not shown) to take anti-vibration measures.

The above master disk 2 for master has a center hole 2a formed at the center thereof using a heavy smooth glass disk, and the concentricity of the center hole 2a and the outer diameter portion 2b is finished to about 5 μm. Use what you have. At this time, the value of the concentricity of 5 μm is a value that can be realized without any problem with a grinding device using a special 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 reused tens or hundreds of times.

Next, since the above-mentioned turntable 3 requires precise high-speed rotation, a non-contact bearing hydrostatic air bearing 5 is built in the direct drive motor 4. For example, NTN Corporation #
An air spindle or the like of the AH-ASR 130 is often used. When the direct drive motor 4 is rotated, the static pressure air bearing 5 shares a disk floating air supply source 12, which will be described later, and supplies air from the disk floating air supply source 12 via a pipe (not shown). The air is supplied to an air connection passage (not shown) in the static pressure air bearing 5.

The static pressure air bearing 5 includes an air bearing portion 5a rotated by the direct drive motor 4,
It is roughly constituted by a pipe mounting part 5b fixedly installed in a ring shape with a slight gap on the outer peripheral part of the air bearing part 5a for mounting a pipe for air.

Further, the air bearing portion 5 of the static pressure air bearing 5
a, a first ring-shaped air connection passage 5a1 is formed along the outer periphery of the first ring-shaped air connection passage 5a1.
And one vertical hole-shaped air connection passage 5a2 is formed in the inside upward, and further connected to one vertical hole-shaped air connection passage 5a2.
a3 is formed concentrically on the upper surface.

On the other hand, the pipe mounting portion 5b of the static pressure air bearing 5
Is provided with a pipe port at one end of a pipe 6 through which air passes. A ring-shaped air connection path 5b1 is formed in the air bearing section 5a on the inner periphery of the pipe mounting section 5b. 5a1 is formed so as to oppose it with a slight gap. Therefore, the air bearing portion 5a of the static pressure air bearing 5 can rotate without any trouble with respect to the fixedly installed pipe mounting portion 5b.

Further, a pipe port on the other end side of the pipe 6 is connected to a path switching valve 7 for selectively switching an air connection passage. One of the path switching valves 7 is connected to a negative pressure supply source 9 that sucks air through a pipe 8,
The other end of the path switching valve 7 is connected by a pipe 10 to a disk floating air supply source 12 for discharging air via a flow rate adjustment valve 11. Thus, by selectively switching the path switching valve 7, the air from the disk floating air supply source 12 is adjusted by the flow rate adjusting valve 11 at the time of centering the master disk 2 for master and discharged to the turntable 3 side. Or a negative pressure source 9 when recording the master disc 2 for mastering.
Thus, a function of sucking air on the turntable 3 side is provided. In addition, about the static pressure air bearing 5, actual fairness 3-
Since it is described in detail in Japanese Patent No. 55165, detailed description thereof is omitted here.

The turntable 3 is fixed to the upper surface of the hydrostatic air bearing 5 by a screw (not shown), and is rotatably mounted integrally with the hydrostatic air bearing 5. 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.
In addition, the rotation balance of the entire rotation system is maintained.

As shown in FIGS. 1 and 2, the turntable 3 has a ring-shaped air connection passage 3a1 formed in the air bearing portion 5a of the hydrostatic air bearing 5 in the second ring-shaped air connection passage 5a3. And is formed on the inner periphery of the lower surface, facing the ring-shaped air connection passage 3a1.
Three vertical air connection passages 3a2 are formed upward at intervals of approximately 120 ° along the circumferential direction, and three horizontal air connection passages are formed from the three vertical air connection passages 3a2. 3a3 are formed radially at approximately 120 ° intervals toward the outer periphery. At this time, the outer peripheral sides of the three laterally-hole-shaped air connection passages 3a3 are sealed with the sealing member 1
3 is sealed.

In the middle part between the inner circumference and the outer circumference of the three laterally-ported air connection passages 3a3 formed in the turntable 3, three laterally-connected air connection passages 3a3 are connected. The vertical air connection passage 3a4 is formed upward, and three vertical air connection passages 3a4 are formed in a ring-shaped air discharge / suction passage 3a5 concentrically formed on the upper surface of the turntable 3. It is facing in communication with. At this time, the number of air connection passages 3a2 to 3a4 provided in the turntable 3 and the number of ring-shaped air discharge / suction passages 3a5 are balanced in the turntable 3 so that air discharge or air suction is uniform. It suffices to provide a plurality of substantially evenly.

The 3 formed in the turntable 3
The ring-shaped air discharge / suction passage 3a5 is provided with a hydrostatic air bearing 5 when the master disk master 2 is centered.
The air from each of the air connection passages 5a1 to 5a3 is discharged to the upper surface side of the turntable 3 to float the master disk 2 or the negative pressure supply source 9 at the time of recording on the master disk 2. It has a function of sucking air between the disc master 2 and the turntable 3 to attract the master disc 2 to the turntable 3 side.

Next, a concave portion 3c is formed concentrically with the guide shaft portion 3b so as to be concave downward from the upper surface around the guide shaft portion 3b provided at the center of the turntable 3. And the guide shaft 3b at the center of the turntable 3
A central hole 14b of a tapered sleeve 14 having a tapered cylindrical tapered surface 14a is fitted therein so as to be movable up and down with a sliding gap of several μm. Biased to the side,
The tip of the tapered sleeve 14 is the concave portion 3 of the turntable 3.
It protrudes from inside c to the upper surface side. At this time, the concentricity between the guide shaft portion 3b and the tapered sleeve 14 is several μm.
The concentricity of the guide shaft portion 3b with the center of the turntable rotation system is adjusted to within several μm. Further, the compression spring 15 is set to a weak urging force enough to support about twice the weight of the tapered sleeve 14 itself.

The tapered sleeve 14 has a tapered cylindrical tip with a center hole 2a of the master disk master 2.
The diameter of the center hole 2a of the master disk master 2 is smaller than the diameter of the master disk 2 by about 0.1 mm.
The diameter is larger than the diameter of The upper end of the tapered sleeve 14 at the time of upward movement is regulated by the stopper 16 attached to the distal end of the guide shaft portion 3b, and the taper sleeve 14 is prevented from coming off from the guide shaft portion 3b.
The diameter of the stopper 16 is slightly smaller than the diameter of the center hole 2 a of the master disk 2 for master and the diameter of the tip of the tapered sleeve 14. The height of the stopper 16 is 0.5 m higher than the height of the upper surface of the master disc 2 for master.
m, and the high-NA objective lens 17 having a narrow working distance at the time of recording is used for the master disk master 2.
Master disk 2 when entering the upper surface of the
An accident in which the object and the objective lens 17 come into contact with each other can be prevented.

Here, the operation of the conventional master disk master manufacturing apparatus having the above configuration will be described with reference to FIGS.

First, as shown in FIG. 1, before the master disk master 2 is mounted on the turntable 3, the tapered sleeve 14 fitted on the guide shaft 3 b of the turntable 3 includes a compression spring 15. Is pushed upward until it comes into contact with the stopper 16.

On the other hand, when the master disk master 2 is centered and mounted on the turntable 3, the air supply source 12 for levitation of the disk is operated, the flow rate of the air is adjusted by the flow rate adjustment valve 11, and the flow rate is adjusted. The adjusted air is supplied to the pipe 10, the path switching valve 7, and the ring-shaped air connection passage 5b in the pipe mounting portion 5b of the static pressure air bearing 5.
1, each air connection passage 5a1-5a in the air bearing portion 5a of the static pressure air bearing 5, each air connection passage 3a1-3a4 in the turntable 3, and three ring-shaped air discharge / suction passages 3a5 are supplied in this order. . The air from the disk floating air supply source 12 is discharged from the ring-shaped air discharge / suction passage 3a5 formed concentrically on the upper surface of the turntable 3, so that the air for the master placed on the turntable 3 The disk master 2 floats uniformly from the upper surface of the turntable 3 by about 0.1 mm by the air discharge force.

Here, when the master disk master 2 reaches an air float state on the turntable 3, the taper sleeve 14 is provided with a compression spring 15 with the height of the air float of the master disk master 2 remaining. It is pushed down along the guide shaft 3b against the force and sinks,
A state in which the edge of the center hole 2a of the master disk master 2 and the tapered surface 14a of the tapered sleeve 14 contact only by line contact, and the master disk master 2 is stably and accurately centered. Is emerging.

Next, as shown in FIG. 3, the master disk master 2 is floated on the turntable 3, and the center hole 2a of the master disk 2 is centered by the tapered sleeve 14. Is performed, the path switching valve 7 is switched to the negative pressure supply source 9 side, and the negative pressure supply source 9 is operated to start the air suction operation. The air between the three ring-shaped air discharge / suction passages 3a5 formed on the upper surface of the air turntable 3
, And is sucked into the negative pressure supply source 9 via a route reverse to the above, so that the master disk 2 for master that has floated is sucked to the turntable 3 side by an air suction operation. Here, the taper sleeve 14 is compressed by the weight of the master disk 2 while the edge of the center hole 2a of the master disk 2 is centered on the tapered surface 14a of the taper sleeve 14 and along the guide shaft 3b. The spring 15 is lowered downward to crush the spring 15. At this time, the air pressure on the lower surface side of the master disk master 2 gradually decreases when viewed microscopically, so that the master disk master 2 softly lands on the upper surface of the turntable 3 and the master disk master 2 A state is reached in which the center of rotation of the turntable 3 is precisely centered.

Thereafter, the recording objective lens 17 is advanced into the upper surface of the master disk master 2, and the master disk master 2 is integrated with the turntable 3 while the master disk master 2 is adsorbed on the turntable 3 by air. While rotating the disk master 2 at a high speed, the objective lens 17 is moved in the radial direction of the master disk master 2 to
7, an information signal is recorded on the master disk master 2.

[0026]

By the way, in the master disk master manufacturing apparatus 1 to which the above-mentioned conventional disk centering device is applied, when the master disk master (or disk) 2 is centered, the upper surface of the turntable 3 is air-driven. After the taper sleeve 14 is fitted into the center hole 2a of the master disk master 2 floating on the master disk 2, the air is sucked and the master disk master 2 is attracted to the upper surface of the turntable 3 to turn the master disk master 2 Although centering can be performed stably and accurately on the table 3 in a short time, and dust is not generated at all by the centering operation, high-density recording on the master master disc (or disc) 2 is possible. As the track pitch narrows as the The accuracy of the centering of the over for the master disc (or disk) 2 must also pursue more stringent, it is carried out improvement activities by extensive research.

In this improvement activity, the tapered sleeve 14 for fitting into the center hole 2a of the master master disc (or disc) 2 for centering is based on the guide shaft 3b provided at the center of the turntable 3. The sliding gap is fitted to the center hole 14b of the tapered sleeve 14 and the guide shaft portion 3b at the time of fitting. If the sliding gap at the time of fitting between them is large, the taper sleeve 14 and the guide shaft portion 3b will be inclined. Therefore, it is required to further improve the fitting accuracy of the two. ing.

[0028]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above problems, and a first invention is to provide a turntable on which a disk is mounted and which is rotatable, and which is provided at the center of the turntable. A taper sleeve having a tapered surface formed by fitting a center hole to the guide shaft portion so as to be vertically movable along the guide shaft portion, and having a tapered surface that enters and fits into the center hole of the disc; Installed inside the turntable,
And, while centering the disk, the air is discharged from the upper surface of the turntable to the disk side to float the disk, while the air is sucked after the tapered sleeve is fitted into the center hole of the floating disk. In a disk centering device having an air discharge / suction passage for adsorbing the disk on the upper surface of the turntable, air is blown out from a guide shaft provided at the center of the turntable toward a center hole of the tapered sleeve. A disk centering device comprising a hydrostatic air bearing structure for holding the tapered sleeve in a floating state with respect to the guide shaft portion.

According to a second aspect of the present invention, in the disk centering apparatus of the first aspect, the bottom surface of the tapered sleeve held in a floating state with respect to the guide shaft portion is blown from the turntable side with air. Although the taper sleeve moves upward toward a stopper provided at the upper end of the guide shaft portion against its own weight, when the center hole of the disc is fitted to the taper sleeve, the taper sleeve is moved by the weight of the disc. It is characterized by moving down to a centering position.

According to a third aspect of the invention, in the disk centering apparatus of the first or second aspect, air for floating the disk from the upper surface of the turntable and a center of the tapered sleeve from the guide shaft portion. The air blown toward the hole and the air blown to the bottom surface of the tapered sleeve are supplied from the same air supply source.

The fourth aspect of the present invention is directed to the first to third aspects.
In the disk centering device of any one of the inventions,
The air for floating the disk from the upper surface of the turntable is characterized in that the air is sucked by switching a path switching valve after the tapered sleeve is fitted into the center hole of the disk that has floated.

Further, the fifth invention is directed to the first to fourth embodiments.
A master disk master using a smooth glass disk as the disk is centered on a turntable.

[0033]

FIG. 4 shows an embodiment of a disk centering apparatus according to the present invention and a master disk master manufacturing apparatus to which the disk centering apparatus is applied.
This will be described in detail with reference to FIGS.

FIG. 4 shows the configuration of a disk centering apparatus according to the present invention and a master disk master manufacturing apparatus to which the disk centering apparatus is applied, and also shows a state in which the master disk master is centered on a turntable. FIG. 5 is an enlarged view showing the vicinity of the tapered sleeve in the state shown in FIG. 4, and FIG. 6 is a diagram showing a disk centering apparatus according to the present invention and a master disk master manufacturing apparatus to which the disk centering apparatus is applied, on a turntable. FIG. 7 is a diagram showing a state in which an information signal is recorded on the master disk master centered in FIG. 7, and FIG. 7 is an enlarged view showing the vicinity of the tapered sleeve in the state shown in FIG.

For convenience of explanation, the same reference numerals are given to the same constituent members as those shown in the conventional example, and the description will be appropriately given, and new reference numerals will be given to the constituent members different from the conventional example. In addition, this embodiment will be described focusing on points different from the conventional example.

In the master disk master manufacturing apparatus 20 to which the disk centering apparatus according to the present invention shown in FIG. 4 is applied, reference numeral 2 denotes a master disk having a center hole 2a formed at the center thereof using a heavy smooth glass disk. The master (or a hard disk using a heavy aluminum material) 3 has air connection passages 3a1 to 3a4 and three air discharge / suction passages 3a5, and the master disk master 2 is sucked and placed by air. The turntable 4 is a direct drive motor serving as a drive source for rotating the turntable at a high speed. The air connection passage 5a is connected to the air connection passage 3a1 of the turntable 3 while rotating by the direct drive motor 4.
An air bearing 5a formed with 1-5a3 and an air connection which is fixedly installed in a ring shape with a slight gap around the outer periphery of the air bearing 5a and communicates with the air connection passage 5a1 of the air bearing 5a in a non-contact manner. A hydrostatic air bearing roughly constituted by a pipe mounting portion 5b forming a passage 5b1,
8, 10 are pipes for passing air, 7 is a path switching valve for switching the discharge / suction of air, 9 is a negative pressure supply source for sucking air, 11 is a flow control valve for adjusting the discharge flow rate of air, and 12 is compressed. An air supply source for discharging air, 13 is a seal member for sealing a portion of the three laterally formed air connection passages 3a3 formed in the turntable 3 on the outer peripheral side, and 14 is the master disk master 2 A tapered sleeve having a tapered surface 14a that fits in the center hole 2a and a center hole 14b that fits in a guide shaft 3b provided in the center of the turntable 3 and that moves up and down with respect to the guide shaft 3b. , 16 are stoppers which are attached to the tip of the guide shaft portion 3b and regulate the upper limit when the tapered sleeve 14 moves upward, and 17 records information signals on the master disc 2 for master. An objective lens, the components described above are the same as the conventional example.

Accordingly, the master disk master manufacturing apparatus 20 to which the disk centering apparatus according to the present invention is applied.
However, the center hole 2a of the master disk master 2 is fitted to the tapered surface 14a of the taper sleeve 14 in a state where the master disk master 2 is lifted from the upper surface of the turntable 3 while air is discharged on the turntable 3. Thereafter, the master disk master 2 is attracted to the upper surface of the turntable 3 by air suction to perform centering.

Here, in the present invention, points different from the conventional example will be described in detail below.

As shown in FIGS. 4 and 5, in the master disk master manufacturing apparatus 20 to which the disk centering apparatus according to the present invention is applied, a bifurcated pipe is provided at an output port of an air supply source 12 for discharging compressed air. 21 is connected, and one pipe 21a is connected to the master disk master 2
Is connected to a flow adjustment valve 11 for adjusting the discharge flow rate of air for floating the air from the turntable 3, while the other pipe 21 b is connected to a newly provided flow adjustment valve 22. This flow control valve 22 is
As will be described later, the flow rate of the air supplied to the tapered sleeve 14 which moves up and down along the guide shaft 3b formed integrally with the center of the turntable 3 is adjusted. Therefore, air for floating the master disk master 2 from above the turntable 3 and air for blowing to the tapered sleeve 14 side are supplied from the same air supply source 12.

Further, a pipe 23 is connected from the flow control valve 22 to the pipe mounting section 5b on the side of the static pressure air bearing 5, and this pipe 23 is connected to the pipe mounting section 5 as described later.
b is connected to an air connection passage 5b2 newly added. At this time, since a path switching valve is not provided between the air supply source 12 and the air connection passage 5b2 of the static pressure air bearing 5, air from the air supply source 12 is always sent to the air connection passage 5b2. ing.

Next, the air connection passages 5a1-5a3 and the air connection passages 5b, which have been described in the prior art, are provided in the air bearing portion 5a and the pipe mounting portion 5b on the static pressure air bearing 5 side.
1. Air connection passages 5a4 to 5a6 and air connection passages 5b2 having the same structure as that of FIG. Then, the air sent from the flow control valve 22 through the pipe 23 is sent to the ring-shaped air connection path 5a4 of the air bearing section 5a in a non-contact manner from the ring-shaped air connection path 5b2 of the pipe mounting section 5b. As will be described later, the air is sent to the circular concave air connection passage 3d1 additionally formed on the lower surface of the center of the turntable 3 through the passages 5a5 and 5a6.

Next, a circular concave air connection passage 3d1 is newly formed on the lower surface side of the center of the turntable 3. Further, the center of the circular concave air connection passage 3d1 extends from the center of the guide shaft portion 3b. A vertical hole-shaped air connection passage 3d2 is formed so as to be connected upward toward the upper part, and the vertical hole-shaped air connection passage 3d2 is formed in a hole shape that stops above the center of the guide shaft portion 3b. In addition, four small-diameter horizontal hole-shaped air discharge passages 3d3 are formed from the vertical hole-shaped air connection passages 3d2 toward the outer periphery of the guide shaft portion 3b at approximately 90 ° intervals. The number of the horizontal hole-shaped air discharge passages 3d3 may be two or more provided along the outer periphery of the guide shaft portion 3b while maintaining a balance, and may be provided in a plurality of stages in the axial direction of the guide shaft portion 3b.

The air sent from the air connection passages 5a4 to 5a6 of the air bearing portion 5a passes through the circular concave air connection passage 3d1 and the vertical hole air connection passage 3d2 of the turntable 3 to form four air passages. Is constantly blown out from the small-diameter horizontal hole-shaped air discharge passage 3d3 toward the center hole 2a of the tapered sleeve 14. At this time, the sliding gap at the time of fitting the guide shaft portion 3b integrally formed at the center portion of the turntable 3 with the center hole 2a of the tapered sleeve 14 is formed very small. Since the compressed air from the four horizontal hole-shaped air discharge passages 3d3 can uniformly flow around the dynamic gap, a static pressure air bearing structure that holds the tapered sleeve 14 in a floating state with respect to the guide shaft portion 3b is provided. ing. With this static pressure air bearing structure, the tapered sleeve 14 can float up and down smoothly without tilting with respect to the guide shaft 3b because it is evenly suspended in the sliding gap with the guide shaft 3b.

Also, four vertical hole-shaped air connection passages 3d4 are formed upward at intervals of approximately 90 ° from the outer peripheral portion of the circular concave air connection passage 3d1 formed on the central lower surface of the turntable 3. . Further, four small-diameter vertical hole-shaped air discharge passages 3d5 are formed in connection with the four vertical hole-shaped air connection passages 3d4 toward the upper concave portion 3c.
The number of the vertical hole-shaped air connection passages 3d4 and the number of the vertical hole-shaped air discharge passages 3d5 may be two or more provided along the outer periphery of the circular concave air connection passage 3d1 while maintaining a balance.

The air sent from the air connection passages 5a4 to 5a6 of the air bearing portion 5a passes through the circular concave air connection passage 3d1 of the turntable 3 and four vertical hole air connection passages 3d4. The air is constantly sprayed from the four small-diameter vertical hole-shaped air discharge passages 3d5 toward the bottom surface of the tapered sleeve 14. As a result, the tapered sleeve 14 moves upward until it is restricted by the stopper 16 provided at the upper end of the guide shaft portion 3b against its own weight. Therefore, it is necessary to provide the compression spring 15 (FIG. 1) as described in the conventional example. There is no. At this time, the amount of air blown toward the bottom surface of the tapered sleeve 14 can be adjusted by adjusting the hole diameter of the vertical hole-shaped air discharge passage 3d5.

In the inside of the tapered sleeve 14, a through hole 14c is formed upward. When the master disk master 2 is floating from the turntable 3 as shown in FIGS. 4 and 5, the through-hole 14c discharges / suctions air from the upper surface formed on the turntable 3. The passage 3a5 has a function of discharging air blown out from the air discharge passage 3d3 formed in the center air discharge passage 3d5 and the guide shaft portion 3b into the atmosphere. The through-holes 14c of the tapered sleeve 14 are used when the master disk master 2 is attracted to the turntable 3 as shown in FIGS.
The air blown out from the central air discharge passage 3d5 formed in the table 3 and the air discharge passage 3d3 formed in the guide shaft portion 3b is allowed to flow into the atmosphere. Further, although not shown, when the master disk master 2 is not placed on the turntable 3, part of the air blown out from the air discharge passage 3d3 formed in the guide shaft portion 3b is removed by the stopper 16 Guide shaft 3b
Through the escape ring groove 16a provided in the inner peripheral portion of the fixed portion (lower portion), the fluid flows out to the atmosphere through the through hole 14c of the tapered sleeve 14.

The operation of the master disk master manufacturing apparatus having the above configuration will be described with reference to FIGS.

First, as shown in FIGS. 4 and 5, the air supply source 12 is always in operation. The path switching valve 7 is switched to the air discharge side.
The four horizontal air discharge passages 3d are formed in a sliding gap when the guide shaft 3b formed integrally with the center of the turntable 3 and the center hole 2a of the tapered sleeve 14 are fitted.
The compressed air from 3 wraps around uniformly to form a static pressure air bearing structure. Before the master disk master 2 is mounted on the turntable 3, the tapered sleeve 14 is moved along the guide shaft 3b by the air blown from the vertical air discharge passage 3d5 of the turntable 3 to the bottom surface. While being pushed upward until it comes into contact with the stopper 16.

On the other hand, when the master disk master 2 is centered and mounted on the turntable 3, the master disk 2 placed on the turntable 3 is pushed from the upper surface of the turntable 3 by the force of air discharge. .1
It floats uniformly about mm.

Here, when the master disk master 2 reaches the air float state on the turntable 3, the tapered sleeve 14 is turned while leaving the height of the air float of the master disk master 2. 3 is pushed downward along the guide shaft portion 3b against the air blown out from the vertical hole-shaped air discharge passage 3d5, and sinks into the edge of the center hole 2a of the master disk 2 for master and the tapered sleeve 14. The tapered surface 14a contacts only by line contact,
The master disk master 2 is stably floated in a state where the master disk master 2 is centered (centered) with high accuracy. At this time, the guide shaft 3b provided at the center of the turntable 3
And the fitting state of the tapered sleeve 14 and the center hole 14b is of a static pressure air bearing structure, so that the tapered sleeve 14 floats uniformly in the sliding gap with the guide shaft part 3b. Because there is no inclination to 3b,
The master disk master 2 floats with more accurate centering than the conventional example.

Next, as shown in FIGS. 6 and 7, while the master disk master 2 is floating above the turntable 3, the center hole 2a of the master disk 2 is centered by the taper sleeve 14 (FIG. 6). When the path switching valve 7 is switched to the negative pressure supply source 9 from the state where the centering is accurately performed, the negative pressure supply source 9 is operated to start the air suction operation. Since the air between the turntable 3 and the master disk 2 is sucked by the negative pressure supply source 9, the master disk master 2 that has floated is sucked toward the turntable 3 by the air suction operation. Here, the center hole 2a of the master disk master 2 is used.
While the edge of the tapered sleeve 14 is centered on the tapered surface 14a of the tapered sleeve 14 and along the guide shaft portion 3b, the tapered sleeve 14 is formed by the weight of the master disk 2 and the vertical hole-shaped air discharge passage of the turntable 3. Against the air blown out from 3d5, the master disk master 2 is further lowered to a position where it is attracted to the turntable 3 side. At this time, the air pressure on the lower surface side of the master disk master 2 gradually decreases when viewed microscopically, and the master disk master 2 softly lands on the upper surface of the turntable 3, and
The master disk master 2 reaches a state where it is precisely centered (centered) with respect to the rotation center of the turntable 3.

Thereafter, the recording objective lens 17 is advanced into the upper surface of the master disk master 2, and the master disk master 2 is integrated with the turntable 3 while the master disk master 2 is adsorbed on the turntable 3 by air. While rotating the disk master 2 at a high speed, the objective lens 17 is moved in the radial direction of the master disk master 2 to
7, an information signal is recorded on the master disk master 2.

[0053]

According to the disk centering apparatus of the present invention described in detail above, air is discharged from the upper surface of the turntable to the disk side when the disk is centered to float the disk, while the center hole of the floating disk is tapered. When sucking air after the sleeve is fitted and sucking the disc on the top of the turntable, especially
Air is blown out from the guide shaft part provided at the center of the turntable toward the center hole of the taper sleeve, and the tapered sleeve has a static pressure air bearing structure that keeps the tapered sleeve floating relative to the guide shaft part. Shaft 3
Since it floats uniformly in the sliding gap with b, it can move up and down smoothly without tilting with respect to the guide shaft,
Centering (centering) of the disk can be performed more accurately than in the conventional example.

According to the master disk master manufacturing apparatus to which the disk centering device according to the present invention is applied, a master disk master using a heavy smooth glass disk as a disk can be stably and stably placed on a turntable in a short time. Centering can be performed more accurately.

[Brief description of the drawings]

FIG. 1 is a diagram showing the configuration of a conventional disk centering device and a master disk master manufacturing apparatus to which the disk centering device is applied, and also shows a state in which the master disk master is centered on a turntable.

FIG. 2 is an enlarged top view of the turntable shown in FIG. 1;

FIG. 3 is a diagram showing a state where an information signal is recorded on a master disk master centered on a turntable in a conventional disk centering apparatus and a master disk master manufacturing apparatus to which the disk centering apparatus is applied.

FIG. 4 is a diagram showing a configuration of a disk centering apparatus according to the present invention and a master disk master manufacturing apparatus to which the disk centering apparatus is applied, and also shows a state in which the master disk master is centered on a turntable.

FIG. 5 is an enlarged view showing the vicinity of the tapered sleeve in the state shown in FIG. 4;

FIG. 6 is a diagram showing a state in which an information signal is recorded on a master disk master centered on a turntable in a disk centering apparatus according to the present invention and a master disk master manufacturing apparatus to which the disk centering apparatus is applied; .

FIG. 7 is an enlarged view showing the vicinity of the tapered sleeve in the state shown in FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Master disk master manufacturing apparatus (disk centering device), 2 ... Master disk master (disk), 2a ... Center hole, 3 ... Turntable, 3b ... Guide shaft part, 3a1-3a4 ... Air connection passage, 3a5 ... Air discharge / suction passage, 3d1, 3d2, 3d4 ... air connection passage, 3d3, 3d5 ... air discharge passage, 5 ... static pressure air bearing, 5a ... air bearing part, 5a1-5a6 ... air connection passage, 5b ... pipe mounting part 5b1, 5b2: air connection passage, 7: path switching valve, 9: negative pressure supply source, 12: air supply source, 14: taper sleeve, 14
a: tapered surface, 14b: center hole.

Claims (5)

[Claims] A rotatable turntable on which a disk is mounted; and a guide shaft provided at the center of the turntable, wherein a center hole is fitted to the turntable so as to be vertically movable along the guide shaft. And a taper sleeve having a tapered surface that fits into the center hole of the disk and is fitted in the turntable, and air is supplied from the upper surface of the turntable to the disk when the disk is centered. And an air discharge / suction passage for sucking air after the tapered sleeve is fitted into the center hole of the floating disk and sucking the disk to the upper surface of the turntable. In the disk centering device provided with: from a guide shaft provided at the center of the turntable to a center hole of the tapered sleeve Only by blown air, a disk centering device being characterized in that comprising a hydrostatic gas bearing structure for holding the floating state the taper sleeve relative to the guide shaft. 2. The tapered sleeve is provided at the upper end of the guide shaft portion against the own weight by blowing air from the turntable side to the bottom surface of the tapered sleeve held in a floating state with respect to the guide shaft portion. 2. The disk according to claim 1, wherein the disk moves up to the stopper side, but when the center hole of the disk is fitted in the taper sleeve, the disk moves down to a position where the taper sleeve is centered by the weight of the disk. Centering device. 3. The same air as the air that causes the disk to float from the top surface of the turntable, the air that blows from the guide shaft toward the center hole of the tapered sleeve, and the air that blows against the bottom surface of the tapered sleeve. 3. The disk centering device according to claim 1, wherein the disk centering device is supplied from a supply source. 4. The air for floating the disk from the upper surface of the turntable, wherein the air is sucked by switching a path switching valve after the tapered sleeve is fitted into the center hole of the disk that has floated. The disk centering device according to claim 1, wherein: 5. A disk centering device according to any one of claims 1 to 4, wherein a master disk master using a smooth glass disk as said disk is centered on a turntable. Master disc production equipment for masters.