JP2000011505A - Disk centering device and master disk manufacturing device applying the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To center a disk on a turntable stably. SOLUTION: This disk centering device where a disk 2 in mounted on a turntable 3 by centering the center hole 2a of the disk 2 in the center of the rotation of the freely rotatable turntable 3, is provided with a tapered sleeve 14 which is provided movably up and down along the guide shaft part 3b provided at the center of the truntable 3 and on which tapered surfaces 14a are formed to be engaged with the center hole 2a while entering the inside of the hole and air discharging/sucking paths 3a4, 3a5 which are provided in the turntable 3 and which makes the disk 2 float by discharging air to the side of the disk 2 from the upper surface of the turntable 3 at the time of centering the disk 3 and, besides, attracts the disk 2 on the upper surface of the turntable 3 by sucking air after the tapered sleeve 14 is engaged with the center hole 2a of the floated disk 2.

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.

On the other hand, in order to make the center of the disk coincide with the center of rotation of the turntable, as an example of a conventional disk centering device, a cylindrical projection slightly smaller than the center hole of the disk is provided at the center of rotation of the turntable. There is a method of positioning the disk by fitting the projection and the center hole.
As disclosed in Japanese Patent Application Laid-Open No. 587, there is a method of positioning the disk by centering by pressing the outer periphery of the disk on a turntable with a work or the like.

[0005]

By the way, when a master disk master using a heavy smooth glass disk is centered on a turntable, an example of a conventional disk centering device provided with a projection at the center of rotation of the turntable. Is applied, the projection must have a fitting gap of about 30 to 50 μm with respect to the center hole of the master disc for the disc centering mounting operation, and this gap becomes a centering error.

When another example of a conventional disk centering device for centering by pushing the outer periphery of a disk on a turntable is applied, a master disk master having a weight of about 1 kg is pushed to produce a master disk master. Among them, there are inconveniences such as the generation of dust which is least desired among them, and the time required for centering the master disk for master.

Therefore, in the present invention, there is a demand for a disk centering apparatus which can solve the above-mentioned inconvenience, stably perform high-precision settling in a short time, and a master disk master manufacturing apparatus to which the disk centering apparatus is applied.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a first invention is to center the center hole of a disk with respect to the rotation center of a rotatable turntable. In a disk centering device for mounting a disk on the turntable, the disk centering device is provided so as to be able to move up and down along a guide shaft provided at the center of the turntable, and enters and fits into a center hole of the disk. A taper sleeve formed with a tapered surface, provided in the turntable, and ejecting air from the upper surface of the turntable to the disk side during centering of the disk to float the disk, while the disk floats After the taper sleeve is fitted into the center hole of the turntable, the air is sucked and the disc is pulled up on the upper surface of the turntable. A disc centering apparatus characterized by comprising an air discharge / suction passage to adsorption.

In the disk centering apparatus according to the first aspect of the invention, the air discharge / suction passage is formed in a ring shape on the upper surface of the turntable concentrically with the rotation center, or It is characterized by being formed on the upper surface by being divided into a plurality in the circumferential direction.

In the disk centering apparatus of the first invention, the air discharge / suction passage includes a disk floating air supply source for floating the disk from the turntable by a path switching valve, and a disk floating air supply source. It is characterized by being switched to a negative pressure supply source adsorbed on the turntable.

Further, a second invention is provided with the disk centering device of the first invention, wherein a master disk master using a smooth glass disk as the disk is centered on a turntable. This is a master disc manufacturing device.

[0012]

FIG. 1 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. 1 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. 2 is an enlarged top view of the turntable shown in FIG. 1, and FIG. 3 is 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. 4 is a diagram showing a state in which an information signal is recorded on a master disk for master centered on a turntable.

In the disk centering apparatus according to the present invention and the master disk master manufacturing apparatus to which the disk centering apparatus is applied, a disk (hard disk) using a heavy aluminum material or a master using a heavy smooth glass disk In order to stably center the disc master on the turntable, keep the air discharge state on the turntable, place the disc or master disc master on the turntable, and then discharge the disc or master disc master by air discharge. In a state of being floated from the upper surface of the turntable, the center hole of the disk or the center hole of the master disk master is fitted into a tapered sleeve having a tapered surface provided vertically movable at the center of the turntable, and thereafter, Turn the disc by air suction Adsorbed on the upper surface of the table is characterized in that the centering.

The structure for stably and accurately centering a disk (hard disk) using a heavy aluminum material or a master disk master using a heavy smooth glass disk on a turntable in a short time is exactly the same. When the information signal recording means is a disk (hard disk), the magnetic head is used. On the other hand, when the master disk master is an optical pickup, an optical pickup is used. The master production apparatus will be described with reference to FIG.

As shown 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 includes a master disk master (substantially equivalent to a disk) 2 on a turntable 3. In a mounted state, since the information device is a precision mechanical device for recording information signals concentrically or spirally at a track pitch of μm or sub μm on the master disk 2 for the master which rotates integrally with the turntable 3, leveling is accurately performed. Are 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 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 turntable 3 needs precise high-speed rotation, a static air bearing 5 of a non-contact bearing 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.

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 for sucking 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 adjusting 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 with 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 static pressure 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 horizontal hole-shaped air connection passages 3a3 formed in the turntable 3, the three horizontal hole-shaped air connection passages 3a3 are connected to each other. The vertical air discharge / suction passage 3a4 is formed upward, and three vertical air discharge / suction passages 3a4 are formed on the upper surface of the turntable 3 concentrically. / Communicates with the suction passage 3a5. At this time, the number of air connection passages 3a1 to 3a3 provided in the turntable 3, the number of vertical hole air discharge / suction passages 3a4, and the number of ring-shaped air discharge / suction passages 3a5 are determined by air discharge or air suction. May be provided in the turntable 3 in a substantially balanced manner so as to be uniform. Alternatively, a plurality of vertical air discharge / suction passages 3a4 may directly face the upper surface along the circumference without providing the ring-shaped air discharge / suction passages 3a5 on the upper surface of the turntable 3.

The 3 formed in the turntable 3
The vertical hole-shaped air discharge / suction passage 3a4 and the ring-shaped air discharge / suction passage 3a5
Air is discharged from the air connection passages 5a1 to 5a3 of the static pressure air bearing 5 to the upper surface side of the turntable 3 at the time of centering to float the master disk 2 for mastering, or when recording on the master disk 2 for mastering. The negative pressure supply source 9 sucks air between the master disk master 2 and the turntable 3 to attract the master disk master 2 to the turntable 3 side.

Next, around the guide shaft 3b provided at the center of the turntable 3, a recess 3c is formed concentrically with the guide shaft 3b so as to be concave downward from the upper surface. And the guide shaft 3b at the center of the turntable 3
The tapered sleeve 14 having a tapered cylindrical tapered surface 14a is fitted via a compression spring 15 so as to be able to move up and down smoothly with a sliding gap of several μm with respect to the guide shaft portion 3b. The tip of the tapered sleeve 14 is provided so as to protrude from the recess 3 c of the turntable 3 toward the upper surface. At this time, the concentricity of the guide shaft portion 3b and the tapered sleeve 14 is finished within several μm, and the concentricity of the guide shaft portion 3b itself with the center of the turntable rotation system is adjusted within several μm. Also, the compression spring 15
The biasing force is set to be weak 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 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 has a compression spring 15. Is pushed upward until it comes into contact with the stopper 16.

On the other hand, when the master disk 2 for master is mounted on the turntable 3 by centering it, the air supply source 12 for floating the disk is actuated, and the flow rate of air is adjusted by the flow rate adjusting valve 11. 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. Air supply passages 5a1 to 5a3 in the air bearing portion 5a of the static pressure air bearing 5, three vertical air discharge / suction passages 3a4, and a ring-shaped air discharge / suction passage 3a5 are supplied in this order. Then, an air supply source 1 for floating the disk
The air from 2 is concentrically formed on the upper surface of the turntable 3 via three vertical hole-shaped air discharge / suction passages 3a4 provided at an intermediate portion in the turntable 3 and a ring-shaped air discharge / suction passage. 3a5, the master disc master 2 placed on the turntable 3
Floats about 0.1 mm uniformly from the upper surface of the turntable 3 by the discharge force of air.

Here, when the master disc 2 for master 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 disc 2 for master 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 in between passes through the ring-shaped air discharge / suction passage 3a5 of the air turntable 3, and the three vertical hole-shaped air discharge / suction passages 3a4, and is sucked into the negative pressure supply source 9 via the reverse route. Therefore, the master disk master 2 that has floated is sucked to the turntable 3 side by the 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.

After that, 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.

[0035]

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. After the sleeve is fitted, the disk is sucked on the top surface of the turntable by sucking air so that the disk can be centered on the turntable stably and accurately in a short time. This has the effect that no dust is generated.

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 accurately.

[Brief description of the drawings]

FIG. 1 shows 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. It is.

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

FIG. 3 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; .

[Description of References] 1. Master disk master production device (disk centering device), 2: Master disk master (disk), 2a: Center hole, 3: Turntable, 3b: Guide shaft portion, 3a4: Vertical hole shape Air discharge / suction passage, 3a5
... Ring-shaped air discharge / suction passage, 7 ... Path switching valve, 9 ... Negative pressure supply source, 10 ... Disk floating air supply source, 14 ... Taper sleeve, 14a ... Taper surface.

Claims (4)

[Claims] 1. A disk centering apparatus for centering a center hole of a disk with respect to a rotation center of a rotatable turntable and mounting the disk on the turntable, wherein a guide shaft provided at the center of the turntable. A taper sleeve formed so as to be able to move up and down along the portion, and having a tapered surface that fits into the center hole of the disc, and is provided in the turntable, and when the disc is centered. While the air is discharged from the upper surface of the turntable to the disk side to float the disk, the air is sucked after the tapered sleeve is fitted in the center hole of the floating disk to draw the disk into the turntable. A disk center provided with an air discharge / suction passage for suction on an upper surface thereof Packaging equipment. 2. The air discharge / suction passage is formed on the upper surface of the turntable in a ring shape concentrically with the rotation center, or is formed on the upper surface of the turntable by dividing it into a plurality of pieces in the circumferential direction. 2. The method according to claim 1, wherein
The disk centering device as described in the above. 3. The air discharge / suction passage includes a disk floating air supply source for floating the disk from the turntable by a path switching valve, and a negative pressure supply source for sucking the floating disk on the turntable. The disk centering device according to claim 1 or 2, wherein the switching is performed. 4. A disk centering device according to claim 1, 2 or 3, wherein a master disk master using a smooth glass disk as said disk is centered on a turntable. Master disc production equipment for masters.