JPH061586B2 - Master recording device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master disk recording apparatus such as a video disk, a compact disk, a data file disk or the like.

Configuration of Conventional Example and Problems Thereof In general, in a master recording apparatus, first, a glass master coated with a recording material is placed on a turntable in the apparatus. Then, the master is driven to rotate, and a laser beam which is modulated into a signal to be recorded and focused on the surface of the board is exposed. At this time, a signal is recorded in a spiral shape by relatively moving the master and the laser beam. The recording agent used in these devices is, for example, a photosensitizer, and a pattern having a geometrical shape can be obtained on the master by the developing process after the signal recording. These patterns are, for example, fine depressions having a size of 1 micron or less and a depth of about 0.1 micron, and the track pitch of the spiral is as small as about 1.6 micron. Therefore, if dust floating in the normal air adheres to the master during these master manufacturing processes, signal dropout will occur. Therefore, the master disk production process is currently performed in a clean room with high cleanliness. Further, when the master is mounted on the turntable, dust or dust may be generated due to a mounting operation of a person and adhere to the master. In order to avoid this, a system is considered in which the master is stored in the cartridge and the master is automatically mounted on the turntable after the cartridge is loaded in the recording device. With this system, it is possible to prevent scratches and fingerprints on the master due to mistakes and accidents when mounting the master.
Further, since the master is always stored in the cartridge and only goes out of the cartridge within the device, there is an advantage that the cleanliness inside the device only needs to be increased. A problem in this system is centering of the master when the master is automatically placed on the turntable. When the rotation axis of the turntable and the center of the master are misaligned, vibration occurs due to dynamic imbalance during rotation, which has a great influence on recording accuracy such as track pitch. Conventionally, the centering of the glass master during mounting has generally been performed by fitting a hole provided at the center of the glass master and a center boss of the turntable. However, there are various adverse effects due to the central hole of the master during the steps before and after recording, for example, during resist coating and development, and for this reason, the master without the central hole tends to be used. In the case of a master without a central hole, it is necessary to align the outer peripheral side surface with the center. Conventionally, a collet chuck type centering mechanism has been used for such centering, but the master disc of a video disc, etc., has a diameter of 350 mm, which is considerably large for accurate centering. A precise mechanism is required, and the cost is inevitably high.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks, and it is an object of the present invention to provide a master recording apparatus having a centering mechanism having a simple structure and performing a reliable operation and satisfying sufficient accuracy as a recording apparatus. .

To achieve the above object, the master recording apparatus of the present invention, a plurality of positioning members abutting on the outer peripheral side surface of the master mounted on the turntable, the movement of the plurality of positioning members at a fixed position. It has a centering mechanism provided with a stopper for regulating.

Description of Embodiments An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a glass master transport mechanism, in which a cartridge 1 is provided with a resist-coated glass master 2. According to this apparatus, the cartridge 1 inserted into the apparatus by the hand of the operator is transported to the position shown in FIG. 1 by the mechanism not shown. For this, a mechanism such as a linear slide is used. The lid of the cartridge 1 which has reached a predetermined position is opened in the direction of arrow 3 by a mechanism (not shown). Next, the transfer arm 4 which rotates about the shaft 14 moves in the direction of the arrow 6 and comes above the glass master 2. The transport arm 4 is driven by a motor 9, a timing pulley 11 mounted on a motor shaft 10, a timing belt 12, and an arm shaft.
This is done by a timing pulley 13 attached to 14. FIG. 2 shows a side view of the transfer arm mounting portion. A glass master holding member 19 that rotates around an axis 18 is provided at the tip of the transfer arm 4, and the holding member 19 is provided with a pair of left and right claws 5, 5. The claws 5 and 5 can be opened and closed left and right by an air cylinder or the like provided in the holding member 19. Timing pulley on shaft 18 and arm shaft 14
15, 17 are provided and are connected by a timing belt 16. Therefore, the glass master 2 clamped regardless of the position of the transfer arm 4 can always maintain a horizontal state. When the transfer arm 4 rotates in the direction of the arrow 6 and reaches the position shown by the chain double-dashed line in FIG. 1, the claws 5 and 5 that have been open up to that point close and hold the glass master 2. The glass master 2 is stored in the cartridge 1 so that it can be taken out freely, so that the glass master 2 is taken out of the cartridge 1 by the rotation of the transport arm 4 in the direction of the arrow 7, and the direction of the turntable 8 is increased. Be transported to. When the transfer arm 4 comes to the position shown by the solid line in FIG. 1, the claws 5 and 5 are opened, and the glass master 2 is placed on the turntable 8. The operation is shown in detail in FIG. FIG. 3A shows a state in which the transfer arm 4 is placed on the turntable 8, and the glass master 2 is in contact with the turntable 8. FIG. 3b shows a state in which the transfer arm 4 is further rotated slightly in the direction of arrow 7 in FIG. Since the glass master 2 is supported with a slight clearance between the pair of claws 5, 5, the glass master 2 remains on the turntable 8 in the state of FIG. There is. FIG. 3c shows a state in which the claws 5, 5 are rotated around the shaft 24 and are in an open state, and in this state, the transfer arm 4 is again shown by an arrow 6 in FIG.
When moved in the direction of, only the glass master 2 is left on the turntable 8. After that, the transport arm 4 is held in a vertical state and stands by. This completes the placing operation of the glass master 2.

In FIG. 1, the turntable 8 is attached to a spindle 20, and the spindle 20 is fixed to a device base 23. In the device in which the turntable 8 moves with respect to the optical system, the device base 23 serves as a substrate for the feed stage. Reference numeral 21 is a turntable drive motor directly connected to the spindle 20. twenty two
Is an air exhaust tube for vacuum adsorbing the glass master onto the turntable 8.

As described above, the glass master 2 is placed on the turntable 8, and when it is confirmed that the transport arm 4 has reached the standby position at the neutral point, the next centering operation is started. Glass master 2
Whether or not is mounted on the turntable 8 can be confirmed by optical detection means or the like.

Next, the centering mechanism will be described. FIG. 4 shows a centering mechanism including the turntable 8 and the glass master 2. FIG. 4 shows a state in which the glass master 2 is placed on the turntable 8, and the centering operation has not been performed yet. twenty five
Is a positioning member that regulates the outer peripheral side surface of the glass master 2, and a plurality of positioning members are provided independently of the rotating portion including the turntable 8. In FIG. 4, three positioning members 25 are shown. Reference numeral 41 denotes a substrate having a centering mechanism attached thereto, which is attached to the device base 23. The positioning member 25 is rotatable around a shaft 26. 29 is a timing belt, which is hung on timing pulleys 27 around the turntable. The timing belt 29 is also engaged with the drive pulley 30 and is moved by the drive motor 31 in the clockwise direction or the counterclockwise direction. In FIG. 4, the locking piece 32 attached to the timing belt 29 pushes the channel portion 33 of the positioning member 25 as the timing belt 29 moves in the direction of the arrow 42, and
25 is rotated clockwise. At this time the positioning member
25 deforms the spring 34 in the compression direction. When the timing belt 29 moves a certain distance in the direction of the arrow 42, the inclined portion 35a of the switch operating member 35 attached to the timing belt 29.
Pushes the micro switch 36 to stop the rotation of the drive motor 31. At this time, the force of the spring 34 causes the timing belt 29 to move in the direction of the arrow 43, but since the load of the drive motor 31 on the speed reducer is large, the timing belt 29 is stopped at this position. FIG. 4 shows this state, and the positioning member 25
The first and second abutting surfaces 38, 39 at the tip of the are separated from the glass master 2 and the stopper 40. The state shown in FIG. 4 is the standby state of the centering mechanism, and the glass master 2 is placed on the turntable 8 in this state.

Next, the centering operation will be described with reference to FIGS.
In FIG. 5, the timing belt is driven by the drive motor 31.
When 29 moves in the direction of arrow 43 by a certain amount until the inclined portion 35b of the switch operating member 35 pushes the switch 37 to the microphone, the locking piece 32
The positioning member 25 is released from the channel portion 33 of the beam positioning member 25. At this time, the positioning member 25 is rotated counterclockwise by the force of the spring 34, and the second contact surface 39 contacts the ring-shaped stopper 40. In this process, the first contact surface 38 forcibly presses the side surface of the glass master 2 to perform the centering. A plurality of positioning members 25 are provided. When the second contact surface 39 is in contact with the stopper 40, the center of the contact circle formed by each first contact surface 38 is the center of the turntable rotation axis. Designed to match 44. The diameter of the tangent circle matches the diameter of the glass master 2. The outer dimensions of the glass master 2 vary slightly within the tolerance range, but the maximum alignment error in that case is 1/2 of the variation, which is almost negligible. Considering the embodiment in which the positioning member 25 is provided at three places, in most cases, the first and second contact surfaces 38, 39 of the two positioning members 25, 25 are the glass master 2 side surface and the stopper 40 side surface, respectively. , And the glass master 2 is moved to the central portion for centering. Regarding the remaining positioning member 25, when the diameter of the glass master 2 is smaller than the contact circle of the first contact surface 38, the second contact surface 39 contacts the stopper 40,
The first contact surface 38 stops without contacting the side surface of the glass master 2. When the diameter of the glass master 2 is slightly larger than the contact circle, the first contact surface 38 contacts the side surface of the glass master 2,
The second contact surface 39 is separated from the stopper 40.
The closer the diameter of the glass master 2 is to the contact circle of the first contact surface 38, the better the accuracy of alignment. If they match, the centering error is zero, and when the glass master 2 is different from the design value, 1 / of the clearance amount between one of the contact surfaces of the positioning member 25 and the glass master 2 or the stopper 40. 2 is the centering error. The precision of the outer shape processing of the glass master 2 is quite good, and the value of the error due to it is practically negligible.

When the centering operation is completed on the turntable as described above, the suction operation is started next. Although not shown, a large number of small holes are provided on the surface of the turntable 8, and the glass master 2 is sucked by the negative pressure generated by the suction of the vacuum pump. Reference numeral 45 in FIG. 6 denotes a rotary joint mounted below the turntable drive motor 21, from which the exhaust tube 22 extends and is connected to the vacuum pump 46. 47 is a pressure detector, and when it is confirmed that a certain vacuum pressure is reached, the next operation is started. If foreign matter is present on the turntable 8 and the glass master 2 is not adsorbed to the turntable 8 with certainty, the vacuum pressure does not decrease and the pressure detector 47 detects it and the system control section detects the abnormal condition. Can inform you. When it is confirmed that the glass master 2 is attracted to the turntable 8, the centering mechanism is released next. In the upper stage, the first contact surface 38 of the positioning member 25 is still in contact with the side surface of the glass master 2, and it is necessary to release it. This operation is achieved by performing the operation opposite to the centering operation.
That is, as shown in FIG.
When it moves in the direction of, the locking piece 32 rotates the positioning member 25 in the clockwise direction and separates the first and second contact surfaces 38, 39 from the contact portions. When the timing belt 29 moves by a certain amount, the micro switch 36 operates and the drive motor 31 stops. The timing belt 29 is fixed in this state by the load of the reduction gear of the drive motor 31, and the glass master 2 is in a free state in which it is not constrained. Only at this time, the turntable drive motor 21 starts rotating, starts moving relatively to the optical system portion, and enters the recording stage. When the recording work is completed, the rotation of the turntable 8 also stops, and the relative position with respect to the optical system part returns to the original state. Then, the vacuum pump 46 also stops and the suction force of the glass master 2 is made zero. And the transport arm 4
Moves from the standby state to the position shown by the solid line in FIG. 1, catches the glass master 2 and stores it in the cartridge 1 again.

In the centering mechanism of the present invention, the movement of the positioning member is restricted only by the stopper 40 irrespective of the movement of the other positioning members, so that the movement does not require precision. On the other hand, in the centering of the collet chuck method, the positioning member must always move so that the contact surfaces are concentric circles and the center thereof coincides with the rotation axis, which requires a highly accurate mechanism. On the other hand, in the device of the present invention, the positioning member 25
When the second contact surface 39 of the
It may be adjusted once so that the center of the tangent circle formed by the contact surface 38 of FIG. It can be easily adjusted by the following procedure. First, a standard glass master is placed on a turntable, and the end faces of the glass master are aligned with each other as much as possible while observing them with a microscope. If possible, it is sufficient to drive it to about 10 μm. Next, the glass master is adsorbed and fixed. Next, the positioning member 25 is rotated so that the second contact surface 39 contacts the stopper 40. First contact surface
38 is movable with respect to the main body of the positioning member 25 by a screw or the like, and is fixed so that it contacts the outer peripheral side surface of the glass master 2. You only have to make this adjustment once at the beginning. The above description is only an example, and other mechanisms based on the same principle may be used.

Advantageous Effects of Invention 1) In the apparatus according to the present invention, the positioning member stops at a constant position in any situation, and the master controlled by the positioning member is positioned within a certain accuracy. Centering can be performed easily and reliably. Moreover, unlike the other collet chuck methods, a complicated and highly accurate mechanism is not required.

2) It can be manufactured at low cost.

3) The time required for centering is short. This is because the positioning member of this device does not require precision in its movement, and can be operated at high speed until it hits the stopper.

4) First, the accuracy of placing on the turntable is not required. It may be placed in an eccentric state as long as it does not hit the contact surface of the positioning member.

5) The position of the positioning member for centering is fixed. Therefore, the position can be set so as not to come into contact with the claws that are carried by grasping the glass master.

6) The turntable may have a simple structure, and it is not necessary to provide an inner wall for centering that surrounds the outer periphery of the glass master. Therefore, the mass of the rotating system can be reduced.

[Brief description of drawings]

The drawings show one embodiment of the present invention, FIG. 1 is an explanatory view showing a glass master transporting mechanism, FIG. 2 is a side view of a main part of FIG. 1, and FIGS. 3a to 3c are mechanisms shown in FIG. FIG. 4 is a plan view of the centering mechanism before centering, FIG. 5 is a plan view of the centering mechanism at the time of centering, and FIG. It is a figure. 1 ... Cartridge, 2 ... Glass master, 4 ... Transport arm,
5 ... claws, 8 ... turntable, 19 ... glass base plate clamping member, 20 ... spindle, 21 ... turntable drive motor,
22 ... Exhaust tube, 25 ... Positioning member, 26 ... Shaft, 29 ... Timing belt, 30 ... Drive pulley, 31 ... Drive motor, 32 ... Locking piece, 33 ... Channel part, 34 ... Spring, 38, 39
… Abutting surface, 40… Stopper, 46… Vacuum pump

Continuation of the front page (56) References Open 48-100114 (JP, U) Open 51-36305 (JP, U) Open 53-66203 (JP, U) Open 54-66512 (JP) , U) Actually open 52-67303 (JP, U) Actually open 54-180704 (JP, U)

Claims (1)

[Claims] 1. A master having a centering mechanism including a plurality of positioning members that come into contact with an outer peripheral side surface of a master mounted on a turntable, and stoppers that restrict movements of the plurality of positioning members at fixed positions. Recording device.