JP4835738B2 - Method for removing light transmission film from optical disc master - Google Patents

Description

  The present invention removes a light-transmitting film from an optical disk master that removes a light-transmitting film formed on the surface of the master after the inspection when inspecting a master of an optical disk such as a BD (Blu-ray Disc), DVD, or CD. Regarding the method. Here, in this specification, the optical disc master is a master used until the optical disc is molded, and means all of the data to be recorded on the optical disc. It includes a master (a glass master, a metal master, a metal mother, etc.) manufactured in a mastering process until the manufacture.

  Conventionally, it is known that an optical disc master is inspected in the same manner as an optical disc inspection method using an optical disc inspection apparatus for inspecting an optical disc, for example, as shown in Patent Document 1 below. . However, since the optical disc master does not have a light-transmitting resin layer such as a polycarbonate layer, polymethylmethacrylate layer, or acrylic resin on the surface like the optical disc, the specifications are determined on the premise of refraction by the light-transmitting resin layer of the optical disc. In the optical disc inspection apparatus that has been used, it is not possible to obtain the same reproduction signal as that of the optical disc as it is from the reflected light from the recording surface of the master disc of the optical disc. Therefore, after forming a light transmissive film having a refractive index substantially equal to the light transmissive resin layer on the recording surface of the optical disk master, the laser light is condensed on the recording surface of the optical disk master through the light transmissive film. The optical disk master is inspected by receiving the reflected light from the recording surface of the optical disk master via the light transmission film to obtain a reproduction signal and evaluating the obtained reproduction signal. According to this, the master disc of the optical disc can be handled in the same manner as the optical disc, and the master disc of the optical disc can be inspected in the same manner as the optical disc inspection method using the optical disc inspection apparatus.

Japanese Patent Laid-Open No. 10-21585

  However, it is necessary to remove the light-transmitting film after forming a light-transmitting film on the optical disk master, and the light-transmitting film is firmly fixed to the optical disk master. It takes a lot of effort. Although there is no conventional literature showing the method of this removal work, the operator usually creates a gap by scratching between the optical disk master and the light transmission film, and presses the optical disk master in this gap to transmit light. The light transmission film is peeled off by adsorbing the film to some adsorbate and pulling it. Since this operation takes time, the efficiency of the inspection of the optical disk master is reduced.

  The present invention has been made to solve the above-described problems, and provides a method for removing a light transmitting film from an optical disk master capable of easily removing the light transmitting film fixed to the surface of the optical disk master. The purpose is to do.

  In order to achieve the above object, a feature of the present invention is that a light transmission film formed on the recording surface of the optical disc master is used to inspect the optical disc master by condensing laser light on the recording surface of the optical disc master. A method of removing a light transmissive film from an optical disc master to be removed, which is solidified by light irradiation and drops a liquid substance that is integrated with the light transmissive film onto the light transmissive film on the optical disc master when solidified. A dropping step (SQ22 in FIG. 7, SQ32, SQ35 in FIG. 12, or SQ42, SQ45, SQ46 in FIG. 15), and the master of the optical disk is rotated to allow the liquid material to move onto the light transmissive film. The outer surface of the optical disc master is irradiated with light while being scattered from the outer periphery of the master disc of the optical disc to the outside. A solidification step (SQ24 in FIG. 7, SQ38 in FIG. 12, or SQ49 in FIG. 15) for solidifying the liquid substance so as to have an overhanging portion and forming a release film on the light transmission film, and the overhanging portion And peeling off the release film from the master of the optical disc to peel off the light transmission film from the master of the optical disc together with the release film (ST24 in FIG. 6). The method is for removing a film.

  In this case, the light for solidifying the liquid substance is, for example, ultraviolet (UV). The liquid substance is, for example, a liquid resin that is solidified by irradiation with ultraviolet rays. The light-transmitting film on the master of the optical disc and the release film formed by solidifying the liquid material on the light-transmitting film are preferably flexible. The release film may be the same material as the light transmission film or a different material as long as it is integrated with the light transmission film after solidification. Moreover, in the said peeling process, when picking the overhang | projection part of a peeling film, the operator may pick the overhang part by hand, and may pick the overhang part using a jig | tool.

  According to this, the liquid substance dropped on the light transmission film by the dropping step is solidified while being scattered from the outer periphery of the optical disc master to the outside in the solidification step, and is projected outward from the outer periphery of the master of the optical disc. A release film having an overhanging portion is obtained. In the peeling process, the protruding portion of the peeling film that protrudes from the outer periphery of the master of the optical disc is picked, and the peeling film is peeled off from the master of the optical disc together with the light transmission film, so that the light fixed to the recording surface of the master of the optical disc The permeable membrane can be easily removed.

  Another feature of the present invention is that in the dropping step, the liquid material is dropped onto the light transmission film near the outer periphery of the master of the optical disk while rotating the master of the optical disk (SQ35 in FIG. 12). Or SQ45, SQ46 in FIG. 15), and in the solidification step, the liquid substance is solidified outward from a position near the outer periphery of the master of the optical disc (SQ38 in FIG. 12 or SQ49 in FIG. 15). is there.

  According to this, the release film is formed outward from the position near the outer periphery of the master disc of the optical disc, and a protruding portion that projects outward from the outer periphery of the master disc of the optical disc is also secured. Therefore, in the peeling step, the entire surface of the light transmission film can be removed on the condition that the light transmission film can be peeled off without being broken during the peeling due to the problem of the strength of the light transmission film. The amount of the liquid material can be reduced as compared with the case of covering with a release film.

  Another feature of the present invention is that, in the case of forming a release film on the outer portion from the position near the outer periphery of the master of the optical disc, in the dropping step, on the light transmission film at a position near the outer periphery of the master of the optical disc. When dripping the liquid material, a large amount of liquid material is dripped only in a part of the circumferential direction compared to other parts (SQ45, SQ46 in FIG. 15), and the overhang part formed in the solidification step is This is because the size is increased only in a part in the circumferential direction of the master of the optical disk (SQ49 in FIG. 15).

  According to this, since the overhang portion is formed largely only in a part in the circumferential direction of the master disc of the optical disc, the amount of the liquid material can be further reduced as compared with the above case. Also in this case, since the overhanging portion for gripping the release film is secured, the release film can be peeled off together with the light transmission film without any trouble.

  Another feature of the present invention is that, when a release film is formed on the outer portion from the position near the outer periphery of the master of the optical disk, in the dropping step, the film is added to the light transmission film at the position near the outer periphery of the master of the optical disk. Then, the liquid substance is dropped on the light transmission film in the vicinity of the inner periphery of the master of the optical disc (SQ32 in FIG. 12 or SQ42 in FIG. 15), and in the solidification step, in the vicinity of the outer periphery of the master of the optical disc In addition to solidifying the liquid substance from the position to the outside, the outer portion from the position near the outer periphery is radially separated from the position near the inner periphery of the master of the optical disc and also on the outer light transmission film. This is because the liquid substance is solidified (SQ38 in FIG. 12 or SQ49 in FIG. 15).

  According to this, when the peeling film is peeled off from the optical disk master together with the light transmissive film, the light transmissive film alone is used even if the light transmissive film is broken due to strength problems during the peeling. The release film formed on the outer light transmission film from the position near the inner periphery is integrated with the light transmission film to increase the strength of the light transmission film. Therefore, when the release film is peeled off from the optical disc master together with the light transmissive film, all the light transmissive films can be reliably peeled without being destroyed.

  In the above description, the figure numbers and reference numerals shown in parentheses are for helping the understanding of the invention, and the constituent elements of the invention are not limited to the embodiments defined by the figure numbers and reference numerals.

1 is an overall schematic block diagram of a spin coater used for forming a light transmission film on a recording surface of a master disk of an optical disc and forming a release film in the shape of a light transmission film. FIG. 2 is a plan view showing a part of a spin coater for explaining a positional relationship of nozzles for dropping a resin liquid for a light transmission film and a release film with respect to the master of the optical disk of FIG. 1. FIG. 6 is a process diagram showing a process of inspecting an optical disk master by forming a light transmission film on a recording surface of the optical disk master. It is a flowchart which shows the sequence control program of the test | inspection light permeable film coating of FIG. (A)-(D) are state explanatory drawings which show a state until the test | inspection light transmissive film | membrane is formed on the recording surface of the original disk of an optical disk by the sequence control of FIG. It is process drawing which shows the process of removing the test | inspection light transmission film | membrane on the recording surface of the original disk of an optical disk. It is a flowchart which shows the 1st sequence control program of peeling film coating of FIG. (A)-(C) are state explanatory drawings which show a state until a peeling film is formed on the light transmissive film | membrane for a test | inspection by the sequence control of FIG. FIG. 3 is a plan view of an optical disc master showing a release film formed on an inspection light transmission film by first sequence control. It is a photograph which shows the state of the peeling film formed on the light transmission film for a test | inspection. It is a photograph which shows the state which has peeled the peeling film with the permeation film for a test | inspection. It is a flowchart which shows the 2nd sequence control program of peeling film coating of FIG. (A)-(F) is a state explanatory drawing which shows the state until a peeling film is formed on the light transmissive film | membrane for a test | inspection by the sequence control of FIG. It is a top view of the original disc of an optical disk which shows the peeling film formed on the light transmission film for a test | inspection by 2nd sequence control. It is a flowchart which shows the 3rd sequence control program of peeling film coating of FIG. (A)-(G) are state explanatory drawings which show a state until a peeling film is formed on the light transmissive film | membrane for a test | inspection by the sequence control of FIG. It is a top view of the original disc of an optical disk which shows the peeling film formed on the light transmission film for a test | inspection by 3rd sequence control.

  Hereinafter, embodiments of the present invention will be described. Before describing a method for removing a light transmitting film from an optical disc master according to the present invention, a spin coater used for forming a light transmitting film and a release film will be described. Next, a method for inspecting an optical disc master will be described.

a. As shown in FIG. 1, the spin coater includes a rotating device 10, a dropping device 20, an ultraviolet irradiation device 30, and a computer device 40. The rotating device 10 has a turntable 11 on which a circular ODK master ODK is placed and fixed. The turntable 11 is fixed to the output shaft 12 a of the electric motor 12. The electric motor 12 is driven by the drive circuit 13 to rotate the output shaft 12a around the axis and rotate the turntable 11 around the vertical axis. The electric motor 12 incorporates an encoder 12b for detecting the rotation of the turntable 11 and the output shaft 12a. The encoder 12b includes a reference signal φo generated each time the rotation position of the turntable 11 reaches the reference rotation position, and a rotation signal φ _A consisting of a pulse train signal that repeats a high level and a low level by a predetermined minute rotation angle. φ _B is output to the computer device 40 and the drive circuit 13. Note that the phases of these rotation signals φ _A and φ _B are shifted from each other by π / 2. In the following description, the reference signal φo and the rotation signals φ _A and φ _B are collectively referred to as a rotation detection signal of the electric motor 12.

The dripping device 20 includes a cylinder 21 that contains a resin solution for a light transmission film or a resin solution for a release film. A nozzle 22 for dropping the resin liquid for light transmission film or the resin liquid for release film is assembled to the lower end of the cylinder 21. The cylinder 21 is assembled to the tip of the arm 23 as shown in FIG. FIG. 2 shows a state in which the nozzle 22 is located at the outer position of the master ODK, that is, the origin position by a solid line, and shows a state in which the nozzle 22 has moved on the recording surface of the master ODK by a two-dot chain line. A base end portion of the arm 23 is fixed to an output shaft (not shown) of the electric motor 24. The electric motor 24 is driven by the drive circuit 25 to rotate the output shaft around the axis and rotate the proximal end portion of the arm 23 around the vertical axis. As a result, the tip of the arm 23 can swing horizontally, and the dropping position of the resin solution for the light transmission film or the release film resin by the nozzle 22 assembled to the cylinder 21 is moved in the radial direction of the master ODK. Is possible. The electric motor 24 incorporates an encoder 24 a for detecting the rotation of the output shaft and the arm 23. The encoder 24 a is configured similarly to the encoder 12 b of the electric motor 12 described above, and outputs the reference signal φo and the rotation signals φ _A and φ _B described above to the computer device 40 and the drive circuit 25. Also in this case, in the following description, the reference signal φo and the rotation signals φ _A and φ _B are collectively referred to as a rotation detection signal of the electric motor 24.

  A pump 26 is connected to the cylinder 21. The pump 26 is driven by a drive circuit 27 and supplies high-pressure air to the cylinder 21 through a resin tube 28. When the high pressure air is supplied from the pump 26, the cylinder 21 drops the resin solution for the light transmission film or the resin solution for the release film onto the recording surface of the master ODK via the nozzle 22.

  The ultraviolet irradiation device 30 is positioned above the turntable 11, that is, above the master ODK fixed to the turntable 11. The ultraviolet irradiation device 30 is driven by the drive circuit 31 to irradiate the entire upper surface of the master ODK with ultraviolet (UV).

  The computer device 40 includes a CPU, a ROM, a RAM, and other storage devices. By the program processing, the electric motor 12, the electric motor 24, the pump 26, and the ultraviolet irradiation device 30 are connected via the drive circuits 13, 25, 27, and 31. Control the operation. Although described in detail in the sequence control described later, the computer device 40 controls the presence / absence and rotation speed of the electric motor 12, that is, the master disk ODK. The computer device 40 also controls the rotation angle of the electric motor 24, that is, the radial position of the master disk ODK of the nozzle 22. The computer device 40 also controls the discharge of high-pressure air from the pump 26, that is, the dropping of the resin liquid for the light transmission film or the resin liquid for the release film. The computer device 40 also controls the irradiation of ultraviolet rays by the ultraviolet irradiation device 30.

  Connected to the computer device 40 is an input device 41 composed of a plurality of operators for inputting data relating to the sequence control and instructing an operation start of the spin coater. The computer device 40 is also connected to a display 42 for displaying the data input state, the spin coater operating state, and the like.

b. Master Disc Inspection Step Next, with reference to FIG. 3, an inspection method for the master disc ODK of the optical disc composed of steps ST11 to ST14 will be described.
(Process ST11)
First, the operator sets the master ODK on the turntable 11 of the spin coater.

(Process ST12)
Next, the operator operates the input device 41 to execute the sequence control of the inspection light transmission film coating by the spin coater. This sequence control of the inspection light-transmitting film coating is executed by the computer device 40 in accordance with the sequence control program shown in FIG. This sequence control program is prepared before entering the light transmission film inspection process, and is stored in a RAM or other storage device in the computer device 40. The control time and control contents of each sequence included in this sequence control program are prepared in advance or input by the operator using the input device 41 by executing a program (not shown). Hereinafter, the sequence control of the inspection light transmission film coating by the sequence control program will be described.

<Sequence SQ11>
First, the computer device 40 controls the rotation of the electric motor 24 via the drive circuit 25 to rotate the arm 23 and move the cylinder 21 horizontally, so that the nozzle 22 is shown in FIG. Next, it moves to a predetermined radius position of the master ODK. In this case, the computer apparatus 40 receives the rotation detection signal of the electric motor 24 from the encoder 24a, and detects the rotation angle from the origin rotation position of the electric motor 24 using the input rotation detection signal, while the electric motor 24 is detected. Is rotated from the origin rotation position to a rotation angle corresponding to a predetermined radius position to which the nozzle 22 is moved. The origin rotation position of the electric motor 24 is a rotation position corresponding to the origin position of the nozzle 22 (see the solid line in FIG. 2). The predetermined radial position is a radial position slightly outside the inner diameter of the master ODK. For example, when the inner diameter of the master ODK is 11 mm and the outer diameter is 70 mm, the position is 12 mm from the center of the master ODK. In the master ODK, data is recorded in an annular portion having a radius of 24 mm to a radius of 58 mm.

  Simultaneously with the movement of the nozzle 22 to the predetermined radius position, the computer device 40 controls the rotation of the electric motor 12 via the drive circuit 13, thereby turning the turntable 11 or master as shown in FIG. The ODK is rotated at a predetermined low speed. In this case, the drive circuit 13 receives the rotation detection signal of the electric motor 12 from the encoder 12b, detects the rotation speed of the electric motor 12 based on the input rotation detection signal, and the detected rotation speed is obtained from the computer device 40. The electric motor 12 is rotated so as to achieve the instructed rotation speed. The predetermined low speed is, for example, 20 rpm. The control time of the sequence SQ11 is a sufficient time until the nozzle 22 moves to the predetermined radius position and the rotation speed of the electric motor 12 reaches the predetermined low speed, for example, 3 seconds.

<Sequence SQ12>
Next, the computer apparatus 40 supplies the high pressure air to the cylinder 21 via the tube 28 by operating the pump 26 for a predetermined time via the drive circuit 27 while maintaining the rotation of the master ODK according to the sequence SQ11. Then, as shown in FIG. 5 (A), a light transmitting film resin solution RE1 as a liquid material for the light transmitting film previously stored in the cylinder 21 is dropped from the nozzle 22. As a result, while the master ODK rotates at a predetermined low speed (20 rpm), the light transmitting film resin solution RE1 is dropped onto a predetermined radial position (12 mm) of the recording surface. The control time of the sequence SQ12 is a time during which the resin film RE1 for light transmission film is dropped over at least the entire circumference of the predetermined radius position (12 mm) of the master ODK, and is, for example, 5 seconds.

<Sequence SQ13>
Next, the computer device 40 controls the rotation of the electric motor 24 via the drive circuit 25 while maintaining the rotation of the master ODK according to the sequence SQ12 and maintaining the dripping of the resin liquid RE1 for the light transmission film. Then, by rotating the arm 23 and moving the cylinder 21 horizontally, the nozzle 22 is moved to the outside in the radial direction of the master ODK for a predetermined time at a predetermined low speed as shown in FIG. In this case, the computer device 40 receives the rotation detection signal of the electric motor 24 from the encoder 24a and detects the rotation angle of the electric motor 24 using the input rotation detection signal, while the nozzle 22 is in the predetermined radius position ( 12 mm), the electric motor 24 is rotated while instructing the rotational speed to the drive circuit 25 so as to move at a predetermined low speed for a predetermined time to a predetermined radial position (for example, 22 mm) outside the master disk ODK in the radial direction. The predetermined low speed is, for example, 1 mm / second, and the predetermined time is, for example, 10 seconds. According to this, the resin liquid RE1 for light transmissive film is dropped on the annular portion of the master disk ODK from the radius 12 mm to the radius 22 mm, and the light transmissive film resin is also applied to the outer portion of the radius 22 mm by the rotation of the master disk ODK. The liquid RE1 is spread.

<Sequence SQ14>
Next, the computer apparatus 40 stops the operation of the pump 26 by the sequence SQ13 to stop the dripping of the resin liquid for the light transmissive film, and then keeps the rotation of the master ODK by the sequence SQ13, while keeping the rotation of the master disk ODK. By controlling the rotation of the electric motor 24 via the arm 23, the arm 23 is rotated to move the cylinder 21 horizontally to return the nozzle 22 to the origin position, that is, the position outside the master ODK. In this case, the computer apparatus 40 receives the rotation detection signal of the electric motor 24 from the encoder 24a, and detects the rotation angle from the origin rotation position of the electric motor 24 using the input rotation detection signal, while the electric motor 24 is detected. Is rotated to its origin rotation position and stopped. The control time of the sequence SQ14 is a sufficient time necessary for returning the nozzle 22 to the origin position, and is, for example, 5 seconds.

<Sequence SQ15>
Next, the computer device 40 controls the rotation of the electric motor 12 via the drive circuit 13 to move the turntable 11, that is, the master ODK to a predetermined high speed (for example, 1200 rpm) as shown in FIG. Rotate for a predetermined time (for example, 0.1 second).

<Sequence SQ16>
Thereafter, the computer device 40 gradually reduces and controls the rotation speed of the electric motor 12 via the drive circuit 13, thereby reducing the rotation speed of the turntable 11, that is, the master disk ODK for a predetermined time as shown in FIG. (For example, 5 seconds), it is reduced to a predetermined rotation speed (for example, 1000 rpm).

<Sequence SQ17>
Thereafter, the computer device 40 controls the rotation of the electric motor 12 via the drive circuit 13 to move the turntable 11, that is, the master ODK at a predetermined low speed (for example, 20 rpm) as shown in FIG. Rotate for a predetermined time (for example, 5 seconds).

  Also in these sequences SQ15 to SQ17, as in the case described above, the drive circuit 13 rotates the rotation speed of the electric motor 12 detected based on the rotation detection signal input from the encoder 12b. Thus, the rotational speed of the electric motor 12 is controlled. Through the processing of the sequences SQ15 to SQ17, the master ODK rotates at a high speed (1200 rpm) for a short time, and then the rotation speed decreases to a predetermined speed (100 rpm) in a predetermined time (5 seconds). Rotates at low speed (20 rpm). By such high-speed rotation (1200 rpm to 1000 rpm) of the master ODK, the light-transmitting film resin solution RE1 dropped on the recording surface of the master ODK by the processing of the sequences SQ12 and SQ13 spreads to the outer peripheral end of the master ODK. As shown in FIG. 5C, the thickness of the resin liquid RE1 for light-transmitting film that has spread to the outer peripheral edge of the master ODK is substantially uniform in the radial direction due to the low-speed rotation (20 rpm) of the master ODK. For example, the thickness RE1 of the resin solution for light transmissive film is about 50 μm. The light-transmitting film resin solution RE1 moved from the outer periphery of the master ODK to the outside by the high-speed rotation (1200 rpm to 1000 rpm) is accommodated in a container (not shown) arranged so as to surround the outer side and the lower side of the master ODK. Is done.

<Sequence SQ18>
Next, the computer device 40 operates the ultraviolet irradiation device 30 via the drive circuit 31 while maintaining the rotation of the master ODK according to the sequence SQ17, and as shown in FIG. 40 seconds), the resin film RE1 for light transmission film spread on the recording surface of the master ODK is irradiated with ultraviolet rays (UV) to solidify the resin liquid RE1 for light transmission film. As a result, the light transmission film RE11 is formed almost uniformly on the recording surface of the master ODK from the position near the inner end (radius 11 mm) of the master ODK (radius 12 mm) to the outer end (radius 70 mm). Is done. The light transmissive film RE11 has a refractive index substantially equal to that of the light transmissive resin layer provided on the optical disk. That is, by forming the light transmission film RE11, the reflected light obtained from the master ODK by condensing the laser light on the recording surface of the master ODK through the light transmission film RE11 is used when the laser light is condensed on the optical disk. This is almost the same as the reflected light from the optical disc. However, the light transmission film RE11 has flexibility (that is, elasticity) even after solidification.

<Sequence SQ19>
Next, the computer device 40 stops the rotation of the electric motor 12 to stop the rotation of the master disk ODK, and stops the operation of the ultraviolet irradiation device 30 to stop the irradiation of the ultraviolet rays to the light transmission film RE11. Then, the sequence control of the inspection light transmission film coating is finished.

  In addition, the various numerical values which prescribe | regulate concrete control content and control time, such as the rotational speed of the master ODK used by the sequence control of FIG. 4, an ultraviolet irradiation time, and each sequence control time, are examples, and various numerical values are shown. These changes can be made as appropriate. The various numerical values are also changed in the case of changing various numerical values used for the sequence control of the release film coating in the inspection light transmission film removing step described later.

(Process ST13)
After the end of the sequence control, the operator continues the inspection process of the master ODK in FIG. After the sequence control step ST12 of FIG. 3, the operator removes the master ODK coated with the light transmission film R11 for inspection from the turntable 11 of the spin coater.

(Process ST14)
Next, the operator inspects the removed master ODK using an optical disc inspection apparatus. That is, the removed master ODK is set in an optical disc inspection apparatus (not shown) for inspecting the optical disc, and the laser beam is condensed on the recording surface of the master ODK via the light transmission film RE11 and obtained from the master ODK. The master ODK is inspected using the reflected light in the same manner as the optical disk. The inspection of the master ODK is not directly related to the present invention and is a conventionally known technique, and thus further explanation is omitted.

c. Next, with reference to FIG. 6, the process of removing the inspection light transmission film formed on the master ODK of the optical disk will be described.
(Process ST21)
First, the operator sets the post-inspection master ODK coated with the above-described inspection light transmission film on the turntable 11 of the spin coater.
(Process ST22)
Next, the operator operates the input device 41 to execute sequence control of the release film coating by the spin coater. The sequence control of the release film coating is executed by the computer device 40 in accordance with the sequence control program shown in FIG. This sequence control program is prepared before the inspection light transmission film removal step, and is stored in a RAM or other storage device in the computer device 40. The control time and control contents of each sequence included in this sequence control program are also prepared in advance or input by the operator using the input device 41 by executing a program (not shown). Hereinafter, the sequence control of the release film coating by the sequence control program will be described.

<Sequence SQ21>
First, similarly to the sequence SQ11 of FIG. 4 described above, the computer apparatus 40 controls the rotation of the electric motor 24 to rotate the arm 23 and move the cylinder 21 horizontally to move the nozzle 22 to the position shown in FIG. As shown to A), it moves to the predetermined radius position of the master ODK. In this case, the predetermined radial position is a radial position slightly outside the radial position (12 mm) where the resin liquid RE1 for light transmitting film is dropped for forming the above-described light transmitting film RE1 for inspection. The position is 13 mm from the center of ODK. Similarly to the sequence SQ11 of FIG. 4 described above, the computer apparatus 40 controls the rotation of the electric motor 12 simultaneously with the movement of the nozzle 22 to the predetermined radius position, as shown in FIG. Next, the turntable 11, that is, the master ODK is rotated at a predetermined low speed (20 rpm). Further, the control time of the sequence SQ21 is, for example, 3 seconds, as in the sequence SQ11 of FIG.

<Sequence SQ22>
Next, as shown in FIG. 8A, the computer device 40 operates the pump 26 for a predetermined time while maintaining the rotation of the master ODK according to the sequence SQ21, as in the sequence SQ12 of FIG. 4 described above. As described above, the release film resin solution RE2 as the release film liquid material previously stored in the cylinder 21 is dropped from the nozzle 22. In this embodiment, the release film resin solution RE2 is the same as the light transmission film resin solution RE1. However, the release film resin solution RE2 may be a variety of liquids as long as it is a liquid material having flexibility (elasticity) that can be integrated with the light transmission film RE11 and peeled off when solidified. Substances can be used. By the processing of this sequence SQ21, the master ODK is rotated at a predetermined low speed (20 rpm), and the release film resin solution RE2 is dropped over the entire circumference of the predetermined radial position (13 mm) on the light transmission film RE1. The control time of this sequence SQ22 is a sufficient amount of release film resin solution so that the release film resin solution RE2 dropped on the light transmission film RE1 is scattered from the outer periphery of the master ODK to the outside by high-speed rotation described later. The time (for example, 7.5 seconds) when RE2 is dropped on the light transmission film RE1 is set.

<Sequence SQ23>
Next, similarly to the sequence SQ14 of FIG. 4 described above, the computer device 40 stops the operation of the pump 26 by the sequence SQ22 to stop the dropping of the release film resin solution RE2, and then the master by the sequence SQ22. By controlling the rotation of the electric motor 24 via the drive circuit 25 while maintaining the rotation of the ODK, the arm 23 is rotated and the cylinder 21 is moved horizontally to move the nozzle 22 to the origin position, that is, the position outside the master ODK. Return to. However, the control time of this sequence SQ23 is a sufficient time required to return the nozzle 22 to the origin position, and is, for example, 8 seconds.

<Sequence SQ24>
Next, the computer device 40 instructs the drive circuit 13 to increase the rotational speed of the electric motor 12, that is, the rotational speed of the master ODK, to a high speed (for example, 1000 rpm). At the same time, the ultraviolet irradiation device 30 is operated via the drive circuit 31, and as shown in FIG. 8B, ultraviolet rays (UV) are applied to the release film resin solution RE2 on the light transmission film RE11 of the master ODK. Irradiation causes the release film resin solution RE2 to solidify. The control time of the sequence SQ24 is a time necessary for solidifying the release film resin solution RE2 to some extent, and is, for example, 5 seconds.

  By the processing of this sequence SQ24, the release film resin solution RE2 on the light transmission film RE11 of the master disk ODK moves outward and is scattered over the entire periphery of the master disk ODK, that is, the outer peripheral end of the light transmission film RE11. On the other hand, the resin film RE2 for the release film on the light transmission film RE11 is solidified by being integrated with the light transmission film RE11 by the irradiation of ultraviolet rays, and is solidified by projecting slightly outward from the outer peripheral end of the light transmission film RE11. The overhang portion A11 is formed. Further, the scattered release film resin solution RE2 is also solidified, and a whisker-like overhang portion A12 is formed on the outer side of the light transmission film RE11. An annular release film R21 including an overhang portion A11 and an overhang portion (whisker-like portion) A12 is formed integrally with the light transmission film RE11 on the light transmission film RE11. It should be noted that the release film resin solution RE2 which has been scattered from the outer peripheral end of the light transmission film RE11 on the master ODK to the outside by the high speed rotation (1000 rpm) and has not solidified surrounds the outside and the bottom of the master ODK. It is accommodated in an arranged container (not shown).

<Sequence SQ25>
Next, the computer device 40 instructs the drive circuit 13 to maintain the irradiation of the ultraviolet rays by the sequence SQ24, and lowers the rotation speed of the electric motor 12, that is, the rotation speed of the master disk ODK to a low speed (for example, 20 rpm). . The control time of this sequence SQ25 is a relatively long time (for example, 35 seconds). Thereby, as shown in FIG. 8C, the release film RE21 is integrated with the light transmission film RE11 and is completely solidified. In this state, a peeling film RE21 having a thickness of 100 to 300 μm, for example, is formed on the light transmission film RE11. The release film RE21 is integrated with the light transmission film R11 and has flexibility (that is, elasticity). FIG. 9 is a plan view showing the release film RE21 formed on the light transmission film RE11 of the master ODK. FIG. 10 is a photograph of the master ODK on which the release film RE21 is formed.

<Sequence SQ26>
Next, similarly to the sequence SQ19 in FIG. 4, the computer device 40 stops the rotation of the electric motor 12 to stop the rotation of the master ODK, and stops the operation of the ultraviolet irradiation device 30 to apply to the release film RE21. Stop UV irradiation. Then, the sequence control of the release film coating is finished.

(Process ST23)
After the end of the sequence control, the operator continues the process of removing the inspection light transmission film shown in FIG. After the sequence control step ST22 of FIG. 6, the operator removes the master ODK coated with the release film R21 from the turntable 11 of the spin coater.

(Process ST24)
Next, the operator holds the master ODK coated with the release film R21 with one hand and holds the overhang portions A11 and A12 of the release film R21 with the other hand (particularly the overhang portion A12 overhanging in a beard shape). The release film R21 is peeled off together with the light transmission film R11 by picking with the other hand. FIG. 11 is a photograph showing a state where the peeling film R21 is peeled off together with the light transmission film R11. In this step ST24, the overhang portions A11, A12 of the release film R21 are picked by hand, but the overhang portions A11, A12 may be picked using a jig.

  According to the method for removing a light transmitting film for inspection, the protruding portions A11 and A12 of the peeling film R21 protruding from the outer periphery of the master ODK and the light transmitting film R11, particularly the whisker-like protruding portion A12, are picked and the peeling film R21 is removed. Since it peels from the master ODK together with the light transmissive film R11, the light transmissive film R11 fixed to the recording surface of the master ODK can be easily removed.

d. Second Sequence Control of Release Film Coating Next, a modified example of the sequence control of the release film R21 executed in step ST22 in the method of removing the inspection light transmission film will be described. The second release film coating sequence control according to this modification is executed by the computer device 40 in accordance with a second sequence control program shown in FIG. 12 instead of the first sequence control program of FIG. This second sequence control program is also prepared before entering the inspection light transmission film removal step, and is stored in the RAM or other storage device in the computer device 40. The control time and control contents of each sequence included in the second sequence control program are also prepared in advance or input by the operator using the input device 41 by executing a program (not shown). Hereinafter, the sequence control of the release film coating by the second sequence control program will be described.

<Sequence SQ31>
First, similarly to the sequence SQ21 of FIG. 7 described above, the computer apparatus 40 controls the rotation of the electric motor 24 to rotate the arm 23 and move the cylinder 21 horizontally to move the nozzle 22 into FIG. As shown in A), the master disk ODK moves to a predetermined radial position (for example, a radial position of 13 mm). Similarly to the sequence SQ21 of FIG. 7 described above, the computer apparatus 40 controls the rotation of the electric motor 12 simultaneously with the movement of the nozzle 22 to the predetermined radius position, as shown in FIG. Then, the turntable 11, that is, the master ODK is rotated at a predetermined medium / low speed (80 rpm). Further, the control time of the sequence SQ31 is, for example, 3 seconds, as in the sequence SQ21 of FIG.

<Sequence SQ32>
Next, similarly to the sequence SQ22 of FIG. 7 described above, the computer apparatus 40 operates the pump 26 for a predetermined time while maintaining the rotation of the master disk ODK according to the sequence SQ31, as shown in FIG. As described above, the above-described release film resin solution RE2 as a release film liquid substance previously contained in the cylinder 21 is dropped from the nozzle 22. By the processing of this sequence SQ32, the master ODK is rotated at a predetermined medium / low speed (80 rpm), and the release film resin solution RE2 is dropped over at least the entire circumference of the predetermined radial position (13 mm) on the light transmission film RE1. The The control time of this sequence SQ32 is an amount necessary for improving the strength of the release film R21 and the light transmission film R11 so that the light transmission film R11 is not destroyed when the release film R21 described later is peeled from the master ODK. It is set to a predetermined short time (for example, 1.0 second) in which the release film resin solution RE2 is dropped on the light transmission film RE1.

<Sequence SQ33>
Next, the computer device 40 instructs the drive circuit 13 to increase the rotation speed of the electric motor 12, that is, the rotation speed of the master ODK to a medium speed (for example, 150 rpm), and keep the master ODK for a predetermined time (for example, 5). Rotate only seconds). In this sequence SQ33, the dropping of the release film resin solution RE2 is stopped. As a result, as shown in FIG. 13B, the release film resin solution RE2 dropped in the sequence SQ32 is slightly spread outward in the radial direction.

<Sequence SQ34>
Next, the computer device 40 controls the rotation of the electric motor 24 to rotate the arm 23 and move the cylinder 21 horizontally to move the nozzle 22 to the original disk ODK as shown in FIG. It moves to a predetermined radial position near the outer periphery (for example, a radial position of 62 mm). Simultaneously with the movement of the nozzle 22, the computer device 40 instructs the drive circuit 13 to reduce the rotation speed of the electric motor 12, that is, the rotation speed of the master ODK, as shown in FIG. For example, the pressure is lowered to 20 rpm. Further, the control time of the sequence SQ21 is a predetermined time (for example, 3 seconds) during which the movement of the nozzle 22 is ensured.

<Sequence SQ35>
Next, the computer device 40 is stored in the cylinder 21 in advance as shown in FIG. 13C by operating the pump 26 for a predetermined time while maintaining the rotation of the master ODK according to the sequence SQ34. The release film resin solution RE2 is dropped from the nozzle 22. By the processing of the sequence SQ35, the master film ODK is rotated at a predetermined low speed (20 rpm), and the release film resin solution RE2 is dropped over the entire circumference of the predetermined radial position (62 mm) on the light transmission film RE1. The control time of the sequence SQ35 is such that a sufficient amount of the release film resin solution RE2 is sufficient to form a whisker-like overhang portion A12 similar to the second sequence control outside the light transmission film RE11 on the master ODK. It is set to a relatively long predetermined time (for example, 8.0 seconds) for dropping on the light transmission film RE1.

<Sequence SQ36>
Next, similarly to the sequence SQ23 of FIG. 7 described above, the computer apparatus 40 stops the operation of the pump 26 by the sequence SQ35 to stop the dropping of the release film resin solution RE2, and then the master by the sequence SQ35. By controlling the rotation of the electric motor 24 via the drive circuit 25 while maintaining the rotation of the ODK, the arm 23 is rotated and the cylinder 21 is moved horizontally to move the nozzle 22 to the origin position, that is, the position outside the master ODK. Return to. However, the control time of this sequence SQ36 is also a sufficient time required to return the nozzle 22 to the origin position, and is, for example, 8 seconds.

<Sequence SQ37>
Next, the computer device 40 operates the ultraviolet irradiation device 30 via the drive circuit 31 while maintaining the rotation of the master ODK according to the sequence SQ36, and as shown in FIG. For this reason, the release film resin solution RE2 on the light transmission film RE11 of the master ODK is irradiated with ultraviolet rays (UV). In this case, the predetermined short time is a short time during which the release film resin solution RE2 does not solidify, for example, 1 second. By the processing of this sequence SQ37, solidification of the release film resin solution RE2 on the light transmission film RE11 is started, and the strength of the release film resin solution RE2 is slightly improved.

<Sequence SQ38>
Next, the computer device 40 instructs the drive circuit 13 while maintaining the irradiation of the ultraviolet rays by the sequence SQ37 to increase the rotation speed of the electric motor 12, that is, the rotation speed of the master ODK, to a high speed (for example, 1000 rpm). . The control time of the sequence SQ24 is a time required for solidifying the release film resin solution RE2 and is, for example, 5 seconds.

  As shown in FIG. 13 (E), the process of sequence SQ38 causes the release film resin RE2 dropped near the inner periphery of the light transmission film RE11 by the process of sequence SQ32 and the light transmission by the process of sequence SQ35. Both the release film resin solution RE2 dropped near the outer periphery of the film RE11 is solidified while moving outward, and the release film resin solution RE2 dropped near the outer periphery of the original film ODK, that is, the light transmitting film RE11. It solidifies while scattering over the entire outer periphery. As a result, the release film resin RE2 dripped in the vicinity of the inner periphery is integrated and solidified on the upper surface of the light transmission film RE11 so as to cover the upper surface in the vicinity of the inner periphery of the light transmission film RE11, thereby forming an annular release film RE21. Form. On the other hand, the release film resin solution RE2 dropped in the vicinity of the outer periphery is integrated and solidified on the upper surface of the light transmission film RE11 so as to cover the upper surface in the vicinity of the outer periphery of the light transmission film RE11, thereby forming an annular release film RE21. .

  Then, as in the case of the second release film coating, the release film resin solution RE2 dripped in the vicinity of the outer periphery protrudes from the outer peripheral end of the light transmission film RE11 slightly to the outside and solidifies. Part A11 is formed. Further, the scattered release film resin solution RE2 is also solidified, and a whisker-like overhang portion A12 is formed over the entire outer periphery of the light transmission film RE11. In this case, the outer peripheral end of the inner annular release film RE21 formed by the release film resin solution RE2 dropped near the inner periphery is outside the outer edge formed by the release film resin solution RE2 dropped near the outer periphery. A certain distance from the inner peripheral edge of the annular release film RE21. In this case as well, the release film resin solution RE2 that has not been solidified by scattering from the outer peripheral edge of the light transmission film RE11 on the master ODK due to the high-speed rotation (1000 rpm) is outside and below the master ODK. Is contained in a container (not shown) arranged to surround the container.

<Sequence SQ39>
Next, as in the sequence SQ25 of FIG. 7, the computer apparatus 40 instructs the drive circuit 13 while maintaining the ultraviolet irradiation by the sequence SQ38 to set the rotation speed of the electric motor 12, that is, the rotation speed of the master ODK. The electric motor 12 is kept rotating for a relatively long time (for example, 35 seconds) by lowering to a low speed (for example, 20 rpm). As a result, as shown in FIG. 13F, the release film RE21 is integrated with the light transmission film RE11 and is completely solidified. Also in this case, a peeling film RE21 having a thickness of 100 to 300 μm, for example, is formed on the light transmission film RE11. Also in this case, the release film RE21 is integrated with the light transmission film R11 and has flexibility (that is, elasticity). FIG. 14 is a plan view showing the release film RE21 formed on the light transmission film RE11 of the master ODK.

<Sequence SQ40>
Next, similarly to the sequence SQ26 of FIG. 7, the computer device 40 stops the rotation of the electric motor 12 to stop the rotation of the master ODK, and stops the operation of the ultraviolet irradiation device 30 to apply to the release film RE21. Stop UV irradiation. Then, the sequence control of the second release film coating is finished.

  Also in this case, as described in the inspection light transmission film removing step in FIG. 6 described above, the release film R21 is peeled off together with the light transmission film R11. Also by this, the projecting portions A11, A12 of the peeling film R21 projecting from the outer periphery of the master ODK and the light transmission film R11, in particular, the whisker-like projecting portion A12 are picked, and the peeling film R21 is peeled from the master ODK together with the light transmission film R11. Therefore, the light transmission film R11 fixed to the recording surface of the master ODK can be easily removed.

  When the second sequence control of the release film coating is used, the release film RE21 is not provided over the entire upper surface of the light transmission film RE11, but is separated into an inner annular portion and an outer annular portion. Therefore, the amount of the release film resin solution RE2 can be reduced. Further, the inner annular portion of the release film RE21 is integrated with the light transmission film RE11 to increase the strength of the light transmission film RE11. As a result, when the release film RE21 is peeled off from the master ODK together with the light transmission film RE11, the light transmission film RE11 is destroyed even if the light transmission film RE11 is destroyed due to strength problems if only the light transmission film RE11 is used. Thus, all the light transmission films RE11 can be surely peeled off.

e. Third Sequence Control of Release Film Coating Next, another modified example of the sequence control of the release film R21 executed in step ST22 in the method of removing the inspection light transmission film will be described. The sequence control of the third release film coating according to this modification is executed by the computer device 40 in accordance with the third sequence control program shown in FIG. 15 instead of the first sequence control program of FIG. This third sequence control program is also prepared before entering the inspection light transmission film removal step, and is stored in the RAM or other storage device in the computer device 40. The control time and control contents of each sequence included in the third sequence control program are also prepared in advance or input by the operator using the input device 41 by executing a program (not shown). Hereinafter, the sequence control of the release film coating by the third sequence control program will be described.

<Sequence SQ41 to SQ44>
This is exactly the same as the processing of sequences SQ31 to S34 in FIG. 12 in the second sequence control. Note that FIGS. 16A and 16B for explaining the state of the third sequence control are the same as FIGS. 13A and 13B.

<Sequence SQ45>
The computer device 40 stops the rotation of the master disk ODK as shown in FIG. 16C by stopping the rotation of the electric motor 12 and operating the pump 26 for a predetermined short time (0.1 second). In this state, the above-described release film resin solution RE2 as a release film liquid material previously contained in the cylinder 21 is dropped from the nozzle 22. By the processing of this sequence SQ45, the release film resin solution RE2 is dropped only at a position in the vicinity of the outer periphery (62 mm) of the light transmission film RE1 on the master ODK, and only at a part in the circumferential direction.

<Sequence SQ46>
Similarly to the sequence SQ35 in FIG. 12, the computer apparatus 40 drops the release film resin solution RE2 for a predetermined short time while rotating the master ODK at a predetermined low speed (20 rpm). Note that FIG. 16D for explaining the state of the third sequence control is the same as FIG. 13C. The predetermined short time is a time during which the release film resin solution RE2 is dropped over at least the entire circumference of the master ODK, and is a time (for example, 4 seconds) that is shorter than the control time (8 seconds) of the sequence SQ35. According to the sequence SQ45 and the sequence SQ46, a relatively small amount of the release film resin solution RE2 is dripped over the entire circumference in the vicinity of the outer periphery of the master ODK, and a large amount of the release film resin solution is only in a part of the circumferential direction. RE2 is dropped.

<Sequence SQ47 to SQ51>
This is exactly the same as the processing of the sequences SQ36 to SQ40 in FIG. 12 in the second sequence control. Note that FIGS. 16E to 16G for explaining the state of the third sequence control are the same as FIGS. 13D to 13F.

  Also in the third sequence control, as in the case of the second sequence control, the separation film RE21 is integrated with the light transmission film RE11 as shown in FIG. 16G by the processing of the sequences SQ49 and SQ50. To solidify completely. In this case, however, a relatively small amount of the release film resin solution RE2 is dripped over the entire circumference in the vicinity of the outer periphery of the master ODK by the processing of sequences SQ45 and SQ46, and a large amount only in a part in the circumferential direction. The release film resin solution RE2 is dropped. Therefore, in the solidification processing of the sequences SQ49 and SQ50, the whisker-like overhanging portion A12 that protrudes outside the outer peripheral end of the master ODK is formed only in a part in the circumferential direction. FIG. 17 is a plan view showing the release film RE21 formed on the light transmission film RE11 of the master ODK.

  Also in this case, as described in the inspection light transmission film removing step in FIG. 6 described above, the release film R21 is peeled off together with the light transmission film R11. Also by this, the protruding portions A11, A12 of the peeling film R21 protruding from the outer peripheral ends of the master ODK and the light transmission film R11, particularly the whisker-like protruding portion A12 formed in a part in the circumferential direction, are picked, and the peeling film R21. Is peeled off from the master ODK together with the light transmissive film R11, so that the light transmissive film R11 fixed to the recording surface of the master ODK can be easily removed.

  Further, when the third sequence control of this release film coating was used, the release film RE21 was separated into an inner annular portion and an outer annular portion on the upper surface of the light transmission film RE11 as in the second sequence control. Since the whisker-like overhanging portion A12 is formed only in a part in the circumferential direction of the master ODK, the amount of the release film resin solution RE2 can be further reduced as compared with the case of the second sequence control. Also in this case, the inner annular portion of the release film RE21 is integrated with the light transmission film RE11 to increase the strength of the light transmission film RE11. As a result, when the release film RE21 is peeled off from the master ODK together with the light transmission film RE11, the light transmission film RE11 is destroyed even if the light transmission film RE11 is destroyed due to strength problems if only the light transmission film RE11 is used. Thus, all the light transmission films RE11 can be surely peeled off.

  Furthermore, in carrying out the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention.

  In the second and third sequence control of the release film coating, in order to prevent destruction of the inner portion when the light transmission film R11 is peeled off from the master disk ODK, the inner position of the master disk ODK near the inner periphery of the light transmission film R11. An annular release film RE21 was formed on the substrate. However, even if the release film RE21 at the inner position is not provided, the strength of the light transmission film R11 is kept sufficiently high, and there is no risk of destruction of the inner part when the light transmission film R11 is peeled off from the master ODK. It is not necessary to provide the release film RE21 at the inner position. In this case, the processes of sequences SQ31 to SQ33 in FIG. 12 and sequences SQ41 to SQ43 in FIG. 15 may be omitted.

DESCRIPTION OF SYMBOLS 10 ... Rotating device, 11 ... Turntable, 12 ... Electric motor, 20 ... Dropping device, 21 ... Cylinder, 22 ... Nozzle, 24 ... Electric motor, 26 ... Pump, 30 ... Ultraviolet irradiation device, 40 ... Computer device, ODK ... Master, RE1 ... resin film for light transmission film, RE11 ... light transmission film, RE2 ... resin solution for release film, RE21 ... release film.

Claims (4)

This is a method for removing a light transmission film from an optical disk master to remove the light transmission film formed on the recording surface of the optical disk master in order to focus the laser beam on the recording surface of the optical disk master and inspect the master of the optical disk. And
A dropping step of solidifying by light irradiation, dropping a liquid substance that is integrated with the light transmission film onto the light transmission film on the master of the optical disc;
While rotating the master of the optical disk, the liquid material is moved to the outer peripheral side of the master of the optical disk on the light transmission film and scattered from the outer periphery of the master of the optical disk to the outside. A solidifying step of solidifying the liquid material to form an exfoliation film on the light transmitting film by solidifying the liquid substance so as to have an overhanging portion projecting outward from the outer periphery of the master disc of the optical disc;
A peeling step of peeling the light-transmitting film from the master disk of the optical disk together with the release film by pinching the protruding portion and peeling the release film from the master disk of the optical disk. A method of removing the light transmission film. In the dropping step, the liquid material is dropped on the light transmission film at a position near the outer periphery of the optical disc master while rotating the optical disc master, and in the solidifying step, a position near the outer periphery of the optical disc master. 2. The method for removing a light transmission film from an optical disc master according to claim 1, wherein the liquid substance is solidified to the outside. In the dropping step, when the liquid material is dropped on the light transmission film in the vicinity of the outer periphery of the master of the optical disc, a large amount of liquid material is dropped in only a part of the circumferential direction compared to other parts, and 3. The method for removing a light transmission film from an optical disc master according to claim 2, wherein an overhang portion formed in the solidifying step is enlarged only in a part in a circumferential direction of the master of the optical disc. In the dropping step, in addition to the light transmission film in the vicinity of the outer periphery of the master of the optical disc, the liquid substance is dropped on the light transmission film in the vicinity of the inner periphery of the master of the optical disc, and the solidification step In addition to solidifying the liquid substance from the position near the outer periphery of the master of the optical disk to the outside, the outer portion from the position near the outer periphery is radially separated from the position near the inner periphery of the master of the optical disk. 4. The method for removing a light transmitting film from an optical disc master according to claim 2, wherein the liquid substance is also solidified on an outer light transmitting film.