JPH01101123A - Device for production of optical disc - Google Patents

Abstract

PURPOSE:To reduce inclusion of bubbles in photopolymer by a method wherein a gas pressure controller feeds a pressurized air into the center of the annular transfer region of a stamper, a disc is forcibly brought into contact with the photopolymer with a lowering pressure. CONSTITUTION:Contact of a disc 29 and photopolymer 30 is effected in a manner that a contact face 310 is gradually enlarged along a peak from a certain one point of the peak on the annular bank of the photopolymer, feeding of the pressurized gas is stopped when an initial contact thereof is effected. Accordingly, a pass 320 of the annular becomes escape port of the gas. Since the contact is gradually effected at a minute angle, bubble inclusion in the photopolymer can be reduced. In the initial contact step, an initial contact mechanism 120 is freely driven, simultaneously with the feeding of a pressurized fluid around the center boss 20 in the lowering movement. The arm of the initial contact mechanism is axially moved on a disc 29 in the lowering movement, and a pressure 123 of the free end is lowered to press the disc.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention is directed to manufacturing an optical disc having a transfer layer that bears minute irregularities using a liquid radiation-curable resin (hereinafter referred to as photopolymer) that is cured by radiation such as ultraviolet rays. Regarding equipment.

BACKGROUND ART Conventionally, there have been optical discs in which pit rows are formed concentrically or spirally as information signals on a transparent disc, or optical discs in which spiral guide grooves are formed so that additional recording can be performed using a laser spot after the disc is completed. Are known. Methods for manufacturing optical discs in which minute irregularities such as pit rows and guide grooves are formed on the surface of such optical discs are disclosed in, for example, Japanese Patent Laid-Open Nos. 53-116105 and 1983.
There are those described in JP-A-23501, JP-A-58-36417, and the like. In either manufacturing method, a photopolymer is supported on a disk, a transfer area of a stamper having a predetermined minute unevenness (pattern) is brought into contact with the photopolymer, and the photopolymer is cured by ultraviolet irradiation to transfer the transfer layer onto the disk. It is formed on top.

However, in either method, when the photopolymer is spread between the disk and the stamper, there is a drawback that microbubbles are mixed into the photopolymer. Generally, the interval between pit rows in the radial direction of an optical disc is as small as about 1.6 μm. Therefore, the inclusion of air bubbles in the photopolymer during the transfer process is harmful as it may cause bits or guide grooves to be missing.

A technique for preventing air bubbles from entering the photopolymer between the disk and the stamper is disclosed in Japanese Patent Application Laid-Open No. 60-26104 by the present applicant.
There is an optical disc manufacturing method disclosed in Japanese Patent No. 7. This conventional manufacturing method will be explained based on a partial schematic sectional view of an optical disk manufacturing apparatus shown in FIG.

First, as shown in FIG. 16(a), a photopolymer is supplied onto the stamper 1 fixed at a predetermined position on the base 2. After that, PMM is attached to the flange part on the outer periphery of the center boss 3.
A transparent disk 4 made of A is placed.

Next, lower the center boss 3 and place the disc 4 into the stamper 1.
It is brought into contact with the photopolymer 5 above. In this state, bubbles are present in the photopolymer 5.

Next, as shown in FIG. 16(b), the outer periphery of the disc 4 is fixed with an outer periphery pressing member (ring) so that the outer peripheries of the stamper 1 and the disc 4 are brought into close contact with each other via the photopolymer 5.

Next, as shown in FIG. 16(C), pressure is applied near the center boss 3 to raise the center boss and press the inner peripheral portion of the disc 4 upward. Here, since the outer circumferential portion of the disk 4 is fixed by the outer circumferential ring 6, the disk 4 deforms into an umbrella shape or a conied shape as shown in the figure. At this time, a closed space having an oblate circular distortion shape is formed between the disk 4 and the stamper 1 above the central recess of the base 2. As the center boss 3 rises, the photopolymer 5 spreads toward the outer circumference. At this time, large bubbles with a diameter of 0.5 mm or more in the photopolymer 5 disappear as the photopolymer spreads outward, and bubbles with a smaller diameter gather on the inner peripheral side of the annular photopolymer reservoir.

Here, the closed space formed between the center boss 3, the disc 4, and the stamper 1 is communicated with a gas pressure control device that pressurizes or depressurizes the vicinity of the center boss, so that the closed space is kept in a sealed state by the gas pressure control device. When a slight amount of gas is introduced from the central recess of the base 2 and pressurized, the innermost circumference of the photopolymer 5 vibrates, and the bubbles in the photopolymer disappear.

Next, as shown in the transfer process shown in FIG. 16(d), pressurization is stopped while keeping the four central parts in a sealed state, and as the gas is drawn and the pressure is reduced, the stamper 1 and the disc 4, the photopolymer 5 advances from the outer periphery toward the inner periphery. Then, the center boss 3 is lowered. Here, the photopolymer 5 progresses sequentially from the outer circumference toward the inner circumference.
is present between the disc 4 and the stamper 1 and is consumed until it reaches the innermost periphery of the transfer area and is completely consumed and disappears before reaching the innermost periphery of the stamper 1, or is completely consumed and disappears before reaching the innermost periphery of the stamper 1. Discharge into the section.

Next, as shown in FIG. 16(e), the center boss 3 is further lowered until the entire surface of the disk 4 is on the stamper surface and the groove-plane, and then stopped at a predetermined position. .

Next, the outer periphery ring 6 is removed while maintaining the reduced pressure in the closed space near the lower inner periphery of the center boss 3, and the photopolymer 5 is cured by irradiation with ultraviolet rays.

After the photopolymer 5 is cured, the center boss 3 is raised to separate the disc 4 from the stamper 1, thereby obtaining the disc 4 carrying the transfer layer 5 of the cured photopolymer onto which the fine irregularities of the stamper 1 have been transferred. .

However, in such a conventional manufacturing method, as shown in FIG. 16(a), after the photopolymer is supplied onto the stamper 1, the center boss 3 on which the transparent disc 4 is placed is lowered, and the disc 4 is coated with the photopolymer. 5, microbubbles may be drawn in and cannot be removed even in the next defoaming process in which the outer ring and center boss work together.

When manufacturing optical discs, the inclusion of microbubbles in the photopolymer has been a major drawback that reduces the yield of the resulting optical discs.

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and an object thereof is to provide an apparatus for manufacturing an optical disc in which the inner peripheral shape of the annular transfer area is uniformly circular. do.

In the optical disc manufacturing apparatus of the present invention, a liquid radiation-curable resin is filled between a stamper carrying an optical pattern and a disc, and the radiation-curable resin is cured to form a transfer layer corresponding to the optical pattern on the disc. An optical disc manufacturing apparatus for manufacturing an optical disc, comprising: a turntable having a flat part for supporting a stamper and a concave part in the center; a center boss that is rotatable and movable along the axis of rotation; a pressing means that presses the outer circumferential portion of the disc placed on the center boss against a flat portion; and a gas pressure control means for adjusting the center boss and the turntable when the center boss and the turntable are moved relative to each other so that the stamper supporting surface of the flat part and the disk supporting surface of the center boss are brought close to each other by a predetermined distance. , supplying pressurized gas to the recess, and having a tilting means for tilting the disk during relative movement.

EXAMPLE An example of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 are a front view and a plan view schematically showing an optical disc manufacturing apparatus according to this embodiment.

In such an optical disc manufacturing apparatus, a guide groove 11 with a rectangular cross section extending in the longitudinal direction is provided on the upper surface of a device housing 10 having a substantially rectangular parallelepiped shape. A movable base 13 is provided that is movable in the horizontal direction (in the figure).

As shown in the partially cutaway sectional view of FIG. 3, the rectangular parallelepiped base housing 14 of the movable base 13 includes a circular horizontal flat part 16 (stamper base) that supports the stamper 15 and a recess 17 provided in the center thereof. a rotatable turntable 19 having a horizontal flat portion 16 disposed within the central recess 17;
The center boss support 18 is movable perpendicularly to the
A center boss 20 is provided therein, which is rotatably placed integrally with the turntable. Turntable 1
9 is connected to a motor 23 via a bearing 21a and a gear 22 so as to rotate around the longitudinal solid axis of the center boss 20.

The turntable is provided with an eccentricity adjustment mechanism equipped with a micrometer to slightly move the horizontal flat portion 16 horizontally with respect to the turntable 1'9. Therefore, the horizontal flat portion 16 has a horizontal plane x on the turntable.
The y-force direction can be adjusted freely.

A flange 24 is provided around the head of the upper part of the center boss 20 so that the head fits into the inner peripheral part of the center hole of the transparent disc so that the disc can be placed freely. A chuck 26 is provided on the upper part of the flange 24 for opening and fixing the inner circumference of the center hole of the disc from the inside by means of a cylinder mechanism 25. This chuck is a cylinder having the same outer diameter as the inner diameter of the center hole of the disk to be fixed during operation, and the axis of the cylinder coincides with the center axis of the center boss used for centering the center boss and the disk.

Furthermore, a center boss lifting mechanism consisting of a motor 27, a cam 28, etc. is connected to the center boss 20. The center boss raising mechanism is arranged so that the center boss flange plane (
The disk supporting surface) is located at a plane higher than the main surface of the stamper 15 by the thickness of the transfer layer to be formed (lowest position), and the disk is further configured to be able to move to any position higher than that. has been done.

FIG. 4 is an enlarged partial sectional view of the vicinity of the recess 17 when the disk 29 is placed on the flange 24 with a photopolymer 30 interposed between the disk 29 and the stamper 15 and the center boss is placed at the lowest position. . A bearing 21a is provided around the center boss support 18, and a bearing 21b is further provided around the air cylinder 25, so that the turntable 19 and the center boss 20 can rotate.

The bottom wall of the recess 17 is the upper surface of the center boss support 18, and an opening 31a of a gas passage 31 communicating with a gas pressure control device is provided therein in order to increase or decrease the pressure inside the recess. It is being

Furthermore, a suction nozzle 32 is provided at the bottom of the recess 17 to suck out the photopolymer overflowing from between the stamper and the disc. As shown in FIG. 4, this suction nozzle includes a tube member 32b having a suction port 32a that opens near the inner circumference of the central hole of the fixed stamper 15, that is, toward the inner circumference of the central recess, and the tube member 32b. It consists of a pedestal 32C for fixing the member to the bottom wall of the recess. The suction nozzle 32 also communicates with the gas pressure control device via a gas passage 33 in the center boss support 18 .

The gas passages 31 and 33 are connected to a gas pressure control device, and in order to control the gas pressure, the gas passage 31 is provided with a solenoid valve 34 that opens and closes to communicate with the atmosphere. A leak valve 35 is provided to set the amount of gas leakage so that the pressure difference between the pressure inside the recess 17 and the atmospheric pressure becomes constant during suction by the gas leak valve 32 . Further, the gas passage 31 is provided with a pressure pump 36 that supplies pressurized gas into the recess 17 at the time of initial contact and at the time of disc separation, and a solenoid valve 37 that opens and closes the pump. Further, the gas passage 31 is provided with a pressure reducing pump 38 that reduces the pressure inside the recess 17 during defoaming by pressing, a solenoid valve 39 that opens and closes the vacuum pump 38, and a buffer tank 40.

The buffer tank 40 has a space of a predetermined capacity so that the pressure inside the recess is not suddenly reduced but gradually reduced when the pressure is reduced by the pressure reducing pump 38.

When the solenoid valve 39 and the pressure reducing pump are operated, first,
The pressure inside the tank 40 is reduced, and then the pressure inside the recess 17 is reduced.

In order to achieve such gradual pressure reduction in the recess 17,
Instead of the buffer tank 40, for example, six electromagnetic valves 3 are installed in parallel to the gas passage 31 as a piping system shown by broken lines in FIG.
9a to 39f can be provided to communicate with the vacuum pump 38. By sequentially opening the valves in the group of electromagnetic valves 39a to 39f one by one, the pressure inside the recess 17 can be gradually reduced.

Further, the gas passage 33 is provided with a suction pump 42 that sucks the photopolymer through an electromagnetic valve 41 . The solenoid valves 34, 37, 39 (39a to 39f) and 41 and the pumps 36, 38 and 42 constitute a gas pressure control device, and are controlled by the control device 200, respectively.

Further, a metal ring 50 is fitted into the inner peripheral portion of the center hole of the horizontal flat portion 16 above the recess 17 . The metal ring 50 is fixed onto the presser annular member 51 with an O-ring 52 and a screw 53. Since the outer diameter of the metal ring 50 is larger than the inner diameter of the center hole of the stamper so that it can be fitted, variations in the inner circumference of the stamper can be absorbed. The metal ring 50 is inserted from above the recess and adjusted using screws 53 so that the upper end surface of the metal ring and the stamper surface are flush with each other. Also, when removing the metal ring, use the holding screw 5.
4 and remove the metal ring 50 from below. - When the disk 29 and the stamper 15 are separated from the state of close contact between the disk 29 and the stamper 15 via the photopolymer during the pressing defoaming process or during peeling after irradiation with radiation, excessive Although stress will be applied to the stamper and cause fatigue to the part, by inserting the metal ring 50, fatigue of the inner peripheral part of the stamper can be prevented. When the metal ring 50 receives the stress, only the downward stress is applied to the inner peripheral portion of the stamper, so that the life of the stamper 15 can be extended.

As shown in FIG. 4, only one suction nozzle 32 is provided radially around the center boss, but a plurality of suction nozzles 32 may be similarly provided.

By providing a plurality of suction nozzles, overflowing photopolymer 30 can be quickly suctioned.

As shown in FIG. 3, on the external bottom wall of the base housing 14,
A receiving portion 55 is provided to engage with a pair of rails 12 constructed along the guide groove 11 of the housing 10. Further, an electric fan 56 is provided on the internal bottom wall of the base housing 14 to allow a downward gas flow from the gap between the periphery of the turntable 19 and the base housing 14 to pass from the base housing 14 to the device housing 10. and a plurality of through holes 57 are provided. Similarly, as shown in FIG. 5, the bottom wall of the guide groove 11 of the device housing 10 is also provided with a plurality of through holes 57 for downward gas flow. With these configurations, each housing 10.14 of the device becomes a negative pressure chamber and a downward gas flow is generated, so that dust generated from drive members such as gears inside each housing is not blown up onto the turntable. , the presence of dust in the transfer process can be reduced. Note that the device casing 10 may be provided with an exhaust port 58 for discharging gas to the outside, and the device casing 14 may be provided with an electric fan 56 that generates a downward gas flow.

A wire mesh or a punched metal plate can also be used to provide the plurality of through holes 57 in each wall of the casing.

Further, the movable base 13 is configured such that, for example, the rail 12 is used as a worm, the receiving part 55 is used as a rack, and the worm is rotated by a motor 59 provided in the housing 10 to move the guide groove 11.
It can be moved horizontally inside.

Furthermore, as shown in FIG.
, second and third stations (0, 11■ and ■), and the movable base 13 moves in the guide groove 11 on the rail 12 and stops at each station to undergo operation in a predetermined process. It looks like this.

First, at the initial setting station 0 at one end of the guide groove 11 of the housing 10, an eccentric adjustment monitoring device consisting of a display 100 and a microscope 101 is placed in the guide groove 1.
1 on the casing 10. The moving base 13 is stopped under the microscope R101, and the annular transfer area of the stamper, the turntable, and the center boss are adjusted by the eccentric adjustment monitoring device on the housing 10 side and the eccentric adjustment mechanism with a micrometer on the moving base 13 side. can be adjusted so that the annular transfer area rotates concentrically around the center axis of the center boss.

Further, the first
In the station I, as shown in FIG. 5, a photopolymer discharge mechanism 110, an initial contact mechanism 120, and an excess photopolymer suction mechanism 130 are arranged on three sides so as to surround the end of the guide groove 11.

The photopolymer discharge mechanism 110, as shown in FIG.
It is equipped with an arm 112 that is pivotally supported by a rotary shaft rotation mechanism 111 fixed to the casing and is swingable in parallel to the turntable plane, and the free end of the arm has a discharge nozzle 113 for dropping photopolymer. Then, the photopolymer is supplied to the main surface of the stamper.

As shown in FIG. 7(a), the initial contact mechanism 120 includes an arm 122 that is pivotally supported by a rotating shaft rotation mechanism 121 fixed to the housing and is swingable in parallel to the turntable plane.
The free end of the arm has a pressing body 123. By swinging the arm over the disk and lowering the suppressor 123, the suppressor tilts the disk and forcibly brings it into contact with the photopolymer. The initial contact mechanism 120 uses a suppressor 123 to apply an optimal pressing force depending on the type of disc to be pressed, for example, polycarbonate, epoxy, or PMMA.
It is possible to control the lowering speed of the suppressor and to replace it with a suppressor of different material, shape and weight. In addition, as shown in FIG. 7(b), instead of the suppressing body 123, an embezzling body 123a is provided at the free end of the arm to support the descending disc from below, tilting the disc and applying the photopolymer to the disc. It is also possible to force contact.

As shown in FIG. 8, the surplus photopolymer suction mechanism 130 includes an arm 132 that is pivotally supported by a rotating shaft rotation mechanism 131 fixed to the device housing 10 and is swingable in parallel to the turntable plane. Suction nozzle 133 at the end
It has a vacuum cleaner to suck out excess photopolymer overflowing from between the stamper and the disc. The suction nozzle 133 is biased by a spring or the like in the direction shown by the arrow A, so that it can be expanded and contracted in the longitudinal direction of the suction nozzle. With this configuration, even if cracks, distortions, etc. occur at the peripheral edge of the disk, the suction nozzle properly follows the circumference of the disk when the disk rotates, and uneven suction of the photopolymer can be prevented.

As shown in FIG. 5, only one surplus photopolymer suction mechanism 130 having a suction nozzle 133 is provided toward the guide groove 11, but a plurality of surplus photopolymer suction mechanisms 130 may be provided on the housing 10 in the same manner. By using multiple suction nozzles, overflowing photopolymer can be quickly suctioned.

The arms of each mechanism 110, 120, and 130 are located on the casing 10 when not in operation, and when activated, they swing up to the top of the turntable, and the arms of the mechanisms 110, 120, and 130 are located on the casing 10, and when in operation, they swing up to the top of the turntable, and the arms of the mechanisms 110, 120, and 130 are located on the casing 10 when not in operation.
The seizing body 123a) and the suction nozzle 133 perform a predetermined process on the disc.

Furthermore, in each of the mechanisms 110, 120 and 130, an air cylinder mechanism that moves each arm portion in parallel approximately perpendicular to the turntable plane is provided with each rotary shaft rotating mechanism 111.
121 and 131. Furthermore, each mechanism 11
Lifting and lowering by each air cylinder mechanism at 0.120 and 130, rotation by each rotating shaft rotation mechanism, discharge nozzle 1
Photopolymer discharge from 13 and suction nozzle 133
The suction is performed by independent devices such as motors, solenoid valves, etc., and the control device 200 shown in FIG.
controlled by.

At the adjacent second station (2), a stripping static eliminator 140 that sprays ionized gas onto the disk when peeling the disk and hardened photopolymer from the stamper is installed in the guide groove 1.
The guide groove is constructed so as to cross the guide groove. As shown in FIG. 9, the peeling static eliminator 140 has a plurality of gas ejection openings 142 directed toward the turntable plane on the movable base 13 in a tube 141 fixed to the body 10 across the guide groove 11. A gas is introduced from the side of the tube through a gas passage 144 through a gas filter 143, and a voltage is applied to the protection tube through an electric wire 145 to eject ionized gas onto the trajectory of the moving base.

Subsequently, as shown in FIG. 2, at the third station (2), a press defoaming mechanism 151 having an outer circumferential ring 150 that tightly fixes the stamper that holds the photopolymer and the outer circumferential portion of the disk is inserted into the guide groove of the casing. 11 on the housing 10.

As shown in Fig. 10, the pressure defoaming mechanism is
50 and a pair of arms 152 that support the outer ring 150
, a shaft 153 that moves the outer ring 150 and the arm 152 up and down, and a lifting mechanism 154, and moves the outer ring 150 up and down parallel to the turntable plane. This press defoaming mechanism has an inner circumferential ring 155 on the inner circumferential portion of the outer circumferential ring, and the inner circumferential ring 155 is attached with a plurality of bolts 156 so as to be loosely fitted concentrically and suspended from the outer circumferential ring. There is. Outer ring 15
0 is a three-layer annular body consisting of an acrylic ring 159 attached to a pedestal 157 and sandwiching a silicone sponge ring 158, so that it applies pressing force evenly to the disc, and furthermore, when it comes into contact with the disc, soften the impact.

Furthermore, as shown in FIG. 11(a), before the inner ring 155 presses the disc 29, the pressing surface of the inner ring 155 projects downward from the pressing surface of the outer ring 150 against the disc. It is a ring-shaped body made of metal or plastic. The pressing surface of the outer ring has a larger area than that of the inner ring. Therefore, as shown in FIGS. 11(a) and 11(b), when the outer ring 150 degrees descends, the inner ring 155 comes into contact with the disk 29 first, followed by the outer ring 150.

' In this way, the outer ring and the inner ring fix the entire outer circumference on the disc.

As shown in FIG. 2, between the third station (3) and the initial setting station O, the housing 10 is placed in such a way that a radiation irradiator 160 having an ultraviolet lamp crosses the guide groove 11.
is built on top. The ultraviolet lamp is oriented on the trajectory of the moving base 13 so that the disk receives ultraviolet light while moving together with the moving base 13 under the radiation irradiator 160.

In addition, as shown in FIG. 12, the control device 200 that controls each mechanism in the moving base and each station includes at least a motor 59 for moving the moving base, a motor 23 for rotating the turntable, a seventh motor 27 for moving the center boss up and down,
An air cylinder 25 that drives a chuck provided at the head of the center boss, a photopolymer discharge mechanism 110, an initial contact mechanism 120, an excess photopolymer suction mechanism 130,
Peeling static eliminator 140, press defoaming mechanism 151, radiation irradiator 160, atmosphere communication solenoid valve 34 that opens and closes the turntable central recess to communicate with the atmosphere, pressurized gas at initial contact and disk peeling. A pressurizing pump 36 that supplies water into the recess, a solenoid valve 37 for pressurizing pump communication, a pressure reducing pump 38 that reduces the pressure inside the recess when defoaming by pressing, a solenoid valve 39 for communicating the reduced pressure pump, or electromagnetic valves 39a to 39f1 communicate with the suction nozzle. A controller 18 controls the drive of the suction pump 42 that sucks the photopolymer and the solenoid valve 41 for communicating with the suction pump based on commands from the operation unit 180.
1. The control device 200 also controls the gas pressure control device.

(Operation of Embodiment) FIGS. 13(a) to 13(n) are partial schematic cross-sectional views of the optical disc manufacturing apparatus of this embodiment in the transfer process. This transfer process will be explained in order.

(1) Centering process First, the moving base is moved to the initial setting station 0 of the device and stopped there. As shown in FIG. 1(b), a turntable with a stamper 15 mounted on its horizontal flat portion is rotated. The periphery of the annular transfer area of the stamper is enlarged using a microscope 101 and displayed on the display 100. The horizontal flat portion 16 is slightly moved by the eccentric adjustment mechanism so that the periphery of the annular transfer area does not shake due to eccentricity. In this way, the annular transfer area of the stamper and the center boss are aligned, and A alignment is performed so that the annular transfer area rotates concentrically around the central axis of the center boss.

(2) Photopolymer discharging process Next, from initial setting station 0 to first station I
Move the base to and stop there. Figure 13 (
As shown in a), a turntable 1 equipped with a stamper
Rotate 9. The arm of the photopolymer dispensing mechanism is pivoted onto the stamper and the dispensing nozzle 113 at its free end
A predetermined amount of photopolymer 30 is dropped onto the annular transfer area of the rotating stamper. The photopolymer is supplied like an annular embankment on the annular transfer area (Fig. 13(a)).
. The position of the photopolymer on the annular bank is the same as that of the inner ring 15 provided on the outer ring 150 in the subsequent pressing defoaming process.
This is near the position corresponding to the annular pressing surface No. 5. after that,
Pivot the arm to its original position on the housing. Stop the rotation of the turntable so as not to disturb the annular shape of the photopolymer.

After that, the center boss 20 is raised to the uppermost position and the PM
A flat transparent disk 29 made of MA is placed on the horizontal support surface of the flange so that its inner circumference fits into the center boss head.

(3) Initial contact process Next, as shown in Fig. 13(c), while maintaining the movable base at the first station ■, the center boss 20 is lowered to the lowest position (downward arrow) and the two discs are removed. is brought into contact with the photopolymer 30 raised in the shape of an annular embankment on the stamper.

During this downward movement, if the disc and the photopolymer suddenly come into contact with each other, air bubbles will be generated in the photopolymer, so as shown in FIG. Only the electromagnetic valve 37 is opened via the pressurizing pump 36 to supply pressurized gas to the vicinity of the center boss, thereby generating a weak upward gas flow (upward arrow).

This gas flow reduces the descending speed of the disk and avoids sudden contact between the annular bank-shaped photopolymer and the disk.

The contact between the disk 29 and the photopolymer 30 is made from a certain point on the ridge on the annular ring of the photopolymer along the ridge, as shown in the order of FIGS. 14(a), 14(b) and 14(c). Contact surface 3
10 is gradually expanded. At this time, the gas flows from the central recess 17 to the uncontacted annular bank pass 320 (horizontal arrow). At the time when this initial contact (FIG. 14(a)) is made, the supply of pressurized gas to the vicinity of the center boss is stopped.

Therefore, the mountain pass 320 of the annular embankment of the photopolymer becomes an opening for gas release. Normally, the disk and the photopolymer are rapidly attracted to each other by the surface tension of the photopolymer, causing air bubbles to be drawn into the polymer.
Since contact is gradually carried out at a small angle by the outflow of gas from 20, entrainment of air bubbles into the photopolymer can be extremely reduced.

In this initial contact step, as shown in FIGS. 13(d) and (e), the initial contact mechanism 120 is driven at the same time as pressurized fluid is supplied to the vicinity of the center boss 20 during its descent. The arm part of the initial contact mechanism is pivoted onto the descending disk 29, and the suppressor 12 at its free end is
3 and press the disk. Or, the embezzlement object 12
In the case of the initial contact mechanism having 3a (dashed line), the arm part is pivoted below the disk 29 on the way down, and the usurping body 12
3a is stopped or lowered at a low speed to press the disk from below.

In this way, the disk 29 is tilted and a portion of it comes into contact with the ridge of the annular embankment of the photopolymer. From the initial point of contact between the disk and the photopolymer, the contact surface gradually widens along the crest of the annular embankment. After forming the initial contact point (FIG. 14(a)),
The supply of pressurized gas to the vicinity of the center boss is stopped, and the arm portion is pivoted to its original position on the housing to stop driving the initial contact mechanism.

In this way, despite the resistance caused by the pressurized gas from the recess that attempts to raise the disc as it descends,
By forcibly tilting the disc with the pressing body, the time required for the descending disc to first contact the photopolymer can be shortened.

The supply of gas by the gas pressure control device is stopped by closing the electromagnetic valve 37, and the electromagnetic valve 34 communicating with the gas passage 31 is opened to communicate the central recess 17 of the turntable with the outside in preparation for the next process.

(4) Pressing defoaming process Next, the moving base is moved from the first station (2) to the third station (2) and stopped there.

The chuck on the head of the center boss 20 is operated to fix the disc at the lowest position. At this time, the disk 29 is temporarily aligned.

Next, as shown in FIG. 13(f), the outer ring 150 is lowered.

In this case, since the inner ring 155 protrudes and is loosely fitted into the inner circumferential portion of the outer ring 150, the inner ring contacts the disk first, and then the outer ring comes into contact. The outer circumference ring and the inner circumference ring fix the entire outer circumference of the disk so that the stamper and the outer circumference of the disk come into close contact with each other via the photopolymer. And photopolymer 3
0 is filled between the outer peripheries of the disk 29 and the stamper 15 while facing toward the outer periphery, and is discharged from the outermost periphery thereof. At this time, the photopolymer under the disk is moved together with the air bubbles in the order of the inner ring with a smaller contact area and the outer ring with a larger contact area, so there is no possibility that air bubbles will be included in the outer ring and the photopolymer under the disk. becomes extremely small.

Next, loosen the chuck on the head of the center boss 20 to prevent the inner periphery of the disk from being damaged in the next process.

Next, as shown in FIG. 13(g), the center boss 20 is raised (upward arrow). Since the outer circumferential portion of the disk is fixed by the outer circumferential ring, the disk deforms into an umbrella shape or a conied shape as shown in the figure.

At this time, a closed space having an oblate circular distortion shape is formed between the disc and the stamper following the space inside the recess. At the boundary where the disc 29 and the stamper 15 separate, the photopolymer 30
It becomes a ring-shaped photopolymer pool and spreads toward the outer periphery as the center boss rises.

Next, as shown in FIG. 13(h), the center boss is stopped at a predetermined upper position. Here, the solenoid valves 34 and 37 communicating with the central recess 17 shown in FIG. Open it, connect the gas passage 31 to the decompression pump 38, and start depressurizing (downward arrow). Then, the negative pressure gas vibrates the inner periphery of the photopolymer reservoir, reducing air bubbles in the photopolymer.

When performing such a pressure reduction operation, the photopolymer reservoir will entrain air bubbles if the pressure is reduced rapidly, so the pressure is gradually reduced using a pressure reduction characteristic that draws a gentle curve.

As shown in FIG. 4, a plurality of, for example, six solenoid valves 39a to 39f are provided in parallel in the gas passage 31 communicating with the recess 17, so that a predetermined value can be achieved by sequentially opening the valves within a predetermined time from the start of depressurization. A predetermined degree of vacuum is achieved in the depressurization curve.

At this time, for example, in the case of transferring an 8-inch disc, the pressure reduction by opening the solenoid valve group is performed under the conditions shown in Table 1.

Table 1 In this case, the pressure reduction curve will have a slope as shown in FIG. As shown in the figure, six black dots indicate the opening timings of the solenoid valves 39a to 39f, which open in sequence, and the degree of vacuum at that time.

In this way, for an 8-inch disc, it takes 22 seconds to
When the degree of vacuum is 00+amHg, there is almost no entrainment of air bubbles. By slowly reducing the pressure, it is possible to prevent air bubbles from being drawn into the photopolymer.

The conditions for reducing the pressure in this closed space are influenced by the viscosity and amount of the photopolymer, the size of the disk, ie, the volume of the conied closed space, and the like. For example, when a photopolymer with a viscosity of 500 cP or less was used for an 8-inch disk and a 5-inch disk, the following results were obtained. When the predetermined vacuum level is 100 m+sHg and an 8-inch disc is used, if the predetermined time is less than 10 seconds, many air bubbles will be trapped.
In the case of an inch disc, even if the predetermined time was shortened to several seconds, entrainment of air bubbles could be prevented. Although the predetermined time may be set to 22 seconds or more, the processing time of the apparatus becomes longer. A vacuum degree range of 30 to 500 mmHH can be used for any given time. Small bubbles will not disappear below 30mmHg,
If the pressure exceeds 500+amHg, a large amount of photopolymer will be discharged from the inner periphery of the stamper at the lowest position of the center boss, making it impossible to ensure the film thickness of the photopolymer.

In order to perform pressure reduction with such pressure reduction curve characteristics, six electromagnetic valves 39a to 39f are provided in parallel in the gas passage 31 communicating with the recess 17 shown by the broken line in FIG. 100m by opening the valves in sequence.
Although the degree of vacuum of mHH is achieved, 2
The capacity of the buffer tank 40 shown by the solid line in FIG. 4 is initialized in advance using a pressure gauge or the like so as to have a substantially linear decompression curve that achieves a vacuum level of 100 Hg within 2 seconds. This simplifies the gas pressure control device. In this case, by replacing the buffer tank connected in front of the pressure reducing pump with buffer tanks of various capacities, the desired pressure reducing characteristics can be obtained simply by opening the solenoid valve 39.

Next, while maintaining the depressurized state of the central recess 17 and the closed space,
Lower the center boss. The photopolymer pool between the stamper and the disc advances from the outer circumference toward the inner circumference,
The photopolymer 30 is uniformly filled between the disk 29 and the stamper 15.

Next, as shown in FIG. 13(i), the center boss is lowered until the support surface of the flange on which the disc of the center boss 20 is placed is at the lowest position, and then stopped. The photopolymer pool then reaches the innermost periphery of the annular transfer area and is discharged from the innermost periphery into the recess 17 along with the remaining air bubbles.

By fixing the outer periphery of the disk and moving the photopolymer by raising and lowering the inner periphery in this way, uneven filling of photopolymer in the circumferential direction of conventional stampers is avoided, and the stamper is uniformly filled with no air bubbles. Photopolymer can be filled between the disc and the stamper.

Next, the reduced pressure state of the recessed closed space near the center boss 20 is maintained, and the outer ring is raised.

(5) Excess photopolymer suction process Next, as shown in FIGS. 13(i) and (j), the turntable 19 is rotated and at the same time, the internal surplus photopolymer having the suction nozzle 32 fixed in the central recess of the turntable is removed. Activate the polymer suction mechanism. The suction port of the suction nozzle 32 suctions the excess photopolymer discharged along the entire inner circumference of the stamper.

At this time, as shown in FIG. 4, the degree of vacuum in the closed space of the central recess 17 increases due to suction by the suction pump 42, so only the solenoid valve 34 for leakage to prevent this is opened and the recess is closed. Communicate with the outside. Simultaneously with the start of suction, outside air is introduced through the leak valve 35, and the suction amount of the suction nozzle is adjusted by the gas pressure control device.
Maintain a vacuum of amHg. Further, in the leak valve 35, in order to maintain the degree of vacuum by suction from the suction nozzle 32, the amount of gas leaked from the leak valve is initially set in advance while measuring the degree of vacuum during suction using a pressure gauge.

Next, the moving base is moved from the third station (2) to the first station (2) and stopped there.

At this time, as shown in FIG. 13(j), a circular cover mask 169 is placed on the disk 29 so as to cover the entire surface of the disk. And an external surplus photopolymer suction mechanism 130
Activate. The arm pivots onto the outer periphery of the disk, and the suction port of the suction nozzle 133 at its free end sucks in excess photopolymer being discharged along the outer periphery of the rotating disk and stamper. After suctioning the excess photopolymer, the cover mask 169 is removed. By attaching the cover mask 169 before suctioning the excess photopolymer with the suction nozzle,
This prevents photopolymer droplets from adhering to the disc surface during suction.

Next, as shown in FIG. 13(k), an outer peripheral mask 170 is placed on the turntable so as to cover the outer peripheral edge of the disc. The outer peripheral mask 170 is composed of an annular member and a leg portion supporting the annular member, and the leg portion is provided so as to be located around the turntable, and the annular member is spaced apart from the disk. Also,
The outer circumferential mask 170 may be an outer circumferential mask having only an annular member placed directly on the disk without providing legs. Outer mask 1
70 blocks ultraviolet irradiation to the outer peripheral edge of the disk,
Since the photopolymer at the outer periphery is cured later, there is no possibility of occurrence of fringing at the outer periphery of the photopolymer transfer layer. Further, the outer peripheral edge of the disk, which is protected from UV irradiation by the outer peripheral mask 170, serves as a glue margin for attaching the outer peripheral spacer when assembling the optical disk.

Excess photopolymer is removed from the inner and outer peripheries of the disc within a predetermined time, and the operation of the excess photopolymer suction mechanism is stopped.

(6) Radiation irradiation process With the disk 29 covered with the outer peripheral mask 170 and rotating, the chuck at the head of the center boss 20 is operated to align the center of the disk.

Next, the moving base is moved from the first station I to the third station (2) and stopped there.

Stop the operation of the chuck on the center boss head and remove the disk 29.
is suspended above the photopolymer on the stamper. In such a state, since the pressure in the central recess is reduced, displacement of the disk relative to the stamper 15 can be avoided.

Next, the third and initialization station 0. ■Open the shutter of the ultraviolet irradiation lamp 160 provided in between. While rotating the disk 29 under the ultraviolet irradiation lamp,
As shown in FIG. 13(1), the moving base is moved from the third station (2) to the initial setting station 0. Next, the moving base is moved from the initial setting station 0 toward the second station (2) while rotating the disk.

In this way, rotate the disk under the ultraviolet lamp 2 times.
The photopolymer is passed through the photopolymer twice, and the disk 29 is uniformly irradiated with ultraviolet rays to harden the photopolymer.

In this process, the chuck on the head of the center boss 20 is activated to align and fix the disc, and without irradiating it with ultraviolet rays,
The reason why the disk is suspended above the photopolymer and irradiated with ultraviolet light is to maintain the shape of the bit to be transferred while the photopolymer is curing.

When the center boss chuck is activated to fix the disc, the center boss is slightly eccentrically moved during curing of the photopolymer, which creates stress due to misalignment between the disc and the stamper, resulting in accurate pit formation. This is because the shape cannot be formed.

(7) Disk peeling process Next, after UV irradiation, initial setting station 0
The moving base is moved from to the second station (3) and stopped at a position below the stripping static eliminator where the diameter of the disk 29 and the row of ionized gas jetting openings of the stripping static eliminator substantially match. While the rotation of the turntable is stopped and the stripping static eliminator of the second station (■) is activated to eject ionized gas (downward arrow), pressurized gas is supplied from below the disk from the fourth part 17 (upward arrow). , the center boss 20 is raised under the peeling static eliminator (FIG. 13(m)) and the disk is peeled from the stamper (FIG. 13(n)). In this way, a disk 29 is obtained which carries a transfer layer 231 of cured photopolymer onto which the fine irregularities of the stamper have been transferred.

The stripping static eliminator is installed across the guide groove, and is stopped so that the diameter of the disk on the moving base matches the row of gas ejection holes for the ionized gas. Therefore, the ionized gas ejected from the gas ejection holes hits the main surface of the disk. Ionized gas is
Although it does not directly contact the transfer layer, it cancels the static electricity generated on the surface of the disc when it is peeled off from the stamper, thereby preventing dust from adhering to it due to static electricity. Furthermore, the ionized gas from the peeling static eliminator is applied from above, and the pressurized gas from the central recess 17 is applied from below, and the gas is sucked downward from the gap between the outer periphery of the turntable and the housing, so that during the disk peeling process, It is possible to prevent minute pieces of the cured photopolymer from falling onto the stamper 15.

Next, the moving base is moved from the second station (2) to the first station I and stopped there.

Remove the outer mask and remove the completed disk with transfer layer.

By repeating this series of steps at the first station I to the third station (2) in this way, a disk with a transfer layer is sequentially obtained.

According to conventional equipment, a protective film is pasted on the stamper to protect the stamper when the equipment is shut down, but in this case, the glue on the film can trap air bubbles and leave air bubbles between the film and the stamper. These air bubbles could cause bleeding on the stamper. Furthermore, the film was too thin to provide sufficient protection. However, in the apparatus of the present invention, if the manufacturing process is completed after the radiation irradiation process, the disk serves as a protective film and the stamper can be reliably protected.

Effects of the Invention As described above, according to the optical disc manufacturing apparatus of the present invention,
When the photopolymer is discharged in the shape of an annular salt onto the stamper and the disc is brought into contact with the photopolymer, the gas pressure control means is applied to the annular shape of the stamper from the time the disc approaches the stamper until the disc comes into contact with the photopolymer. Pressurized gas is supplied to the center of the transfer area, and a descending presser force is used to force the disc into contact with the photopolymer, so that the circular salt-shaped photopolymer is formed at a small angle by the gas flowing out from the opening. The gradual contact of the discs can greatly reduce entrainment of air bubbles within the photopolymer. Therefore, since the probability of bubbles remaining is greatly reduced, the optical disc obtained by the present invention has almost no dropout during playback due to bubbles in the signal transfer layer.

[Brief explanation of the drawing]

FIG. 1 is a front view schematically showing the manufacturing device of the present invention, FIG. 2 is a plan view schematically showing the manufacturing device of the present invention, and FIG. 3 is a partial cutaway schematically showing the movable base of the manufacturing device of the present invention. 4 is an enlarged sectional view schematically showing the vicinity of the center boss of the moving base of the manufacturing device of the present invention, and FIG. 5 is a schematic side view for explaining the casing and the moving base of the manufacturing device of the present invention. , FIG. 6 is a schematic side view for explaining the photopolymer discharge mechanism of the manufacturing apparatus of the present invention, and FIGS. 7(a) and (b) are schematic side views for explaining the initial contact mechanism of the manufacturing apparatus of the present invention. 8 is a schematic side view for explaining the external surplus photopolymer suction mechanism, FIG. 9 is a schematic partial cross-sectional view of the stripping static eliminator taken along line B-B in FIG. 2, and FIG. 10 is a schematic side view for explaining the external excess photopolymer suction mechanism. A schematic cutaway side view for explaining the pressure defoaming mechanism of the manufacturing apparatus of the present invention, FIGS. 11(a) and (b) are schematic cross-sectional views for explaining the outer ring, and FIG. 12 is an explanation of the control device. Figure, 1st
3(a) to n) are schematic sectional views for explaining the manufacturing method using the manufacturing apparatus of the present invention, FIG. 14 is a plan view of the disk in the initial contact step, and FIG. 15 is a view of the central recess of the turntable. Graph showing the pressure reduction curve and FIG. 16(a)
to e) are schematic cross-sectional views for explaining a conventional manufacturing method. Explanation of symbols of main parts 10... Housing 13... Moving base 15... Stamper 20... Center boss 29... Transparent circle Plate 30... Photopolymer 32... Suction nozzle 110... Photopolymer discharge mechanism 120
...Initial contact mechanism 130... Surplus photopolymer suction mechanism 140.
... Peeling static eliminator 150 ... Outer ring 155 ... Inner ring

Claims (1)

[Claims] Optical disk manufacturing, in which a liquid radiation-curable resin is filled between a stamper carrying an optical pattern and a disk, and the radiation-curable resin is cured to form a transfer layer corresponding to the optical pattern on the disk. The apparatus includes a turntable having a flat part for supporting the stamper and a recess in the center thereof, and a turntable arranged in the recess and integrally connected to the turntable around the same rotation axis as the turntable. a center boss that is rotatable and movable along the rotation axis; a pressing means that presses an outer peripheral portion of a disk placed on the center boss against the flat portion; and gas pressure control means for adjusting the air pressure inside the center boss, and the gas pressure control means moves the stamper supporting surface of the flat part and the disc supporting surface of the center boss so that they are close to each other by a predetermined distance. An optical disc manufacturing apparatus, comprising: supplying pressurized gas to the recess when moving the turntable relative to the turntable; and tilting means for tilting the disc during the relative movement.