JP3477284B2 - Optical disc manufacturing method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing an optical disc used for recording media such as music, video and computers.

[0002]

2. Description of the Related Art Among the conventional methods for laminating disks at the time of manufacturing optical disks, one method for spreading the adhesive by rotating the disks at high speed and utilizing the centrifugal force thereof is shown in FIG. It was A conventional example will be described with reference to FIG. 14. First, as shown in FIG. 14A, the first disk 1 is placed on the rotary stage 2 with the adhesive surface facing upward, and the adhesive is applied around the center hole. The liquid film 64 is discharged. After that, as shown in FIG. 3B, the second disc 41 is placed on the adhesive surface downward, and then the rotary stage 2 rotates at high speed as shown in FIG.
The liquid film 64 of the adhesive between the first disk 1 and the second disk 41 is spread by a centrifugal force and shaken off. After the high speed rotation is completed, the adhesive is cured by a curing device (not shown), and
Complete the bonding of the discs.

[0003]

However, such a conventional disc bonding method has the following problems. In FIG. 14, the shape of the adhesive liquid film 64 discharged onto the first disc 1 is easily disturbed when the second disc 41 is stacked, and as shown in FIG.
The contour line of the liquid film 64 on the surface of the disc is easy to draw, that is, contour irregularities are likely to occur.

In the concave portion of the contour of the liquid film, the boundary line between the liquid film 64 and the disk surface becomes long and the interfacial tension between them becomes strong. Therefore, even if centrifugal force acts on the liquid film 64 due to high speed rotation. In the boundary line, only the contour concave portion of the liquid film becomes difficult to move. Therefore, as shown in FIG. 16, the liquid on both sides of the liquid film concave portion first spreads in the outer peripheral direction, and it is easy to wrap the liquid film concave portion with the liquid and leave bubbles.

Although this kind of action occurs even in general spin coating, there is no escape route for bubbles in the region where both sides are sandwiched by disks as shown in FIG. The bubbles remaining in the adhesive layer not only cause a substantial decrease in the adhesion area, but also expand or contract with the change in the ambient temperature to cause stress on the disk. Adversely affect.

[0006]

SUMMARY OF THE INVENTION Therefore, according to the present invention, when an optical disk is bonded by using a liquid adhesive, not only centrifugal force but also mechanical force in the rotating direction is applied between the bonded disks, The purpose is to suppress air bubbles from entering the space or the adhesive layer and perform high-quality bonding.

[0007]

According to a first aspect of the present invention, in order to solve the above-mentioned problems, only the liquid film is contacted above the first disk to which the liquid film of the adhesive is supplied. By holding the second disk and continuously rotating one or both of the first and second disks so that a rotational speed difference is relatively generated between the first and second disks, An optical disc in which a liquid film sandwiched between two discs is spread while forming a clean annular shape, and no excess liquid droplets of the adhesive are scattered and bubbles are not formed between the first and second discs and in the adhesive layer. The present invention provides a method for manufacturing the same.

In order to solve the above-mentioned problems, the second aspect of the present invention is to provide a second disc above the first disc on which the liquid film of the adhesive has been discharged so as to contact only the liquid film. The liquid film sandwiched between the two discs is held by holding and rotating one or both of the first and second discs so that a relative rotational speed difference is generated between the first and second discs. After spreading while forming a clean annular shape, by rotating the first and second disks at high speed, the excess adhesive is spread and shaken off by centrifugal force to form a uniform liquid film on the entire surface between the two disks. The present invention proposes a method for manufacturing an optical disc in which bubbles are not formed between the first and second discs and in the adhesive layer while being formed.

In order to solve the above-mentioned problems, a third aspect of the present invention is the method according to the second aspect, wherein at the time of high speed rotation, the second disk is opened and placed on the first disk for high speed rotation. By doing so, a method for manufacturing an optical disc is proposed in which the thickness of the adhesive layer between the first and second discs can be made uniform. This method can be used unless the viscosity and surface tension of the adhesive are too low, and has the advantage of simplifying the structure of the device.

In order to solve the above-mentioned problems, a fourth aspect of the present invention is the method according to the second aspect, wherein the second disc is held during high-speed rotation and synchronized with the first disc. By rotating, no bubbles are formed between the first and second discs and in the adhesive layer, and the thickness of the adhesive layer between the first and second discs is set to a predetermined value. The present invention proposes a method of manufacturing an optical disc that is advantageous in bringing it closer. This method is also effective when the adhesive used has low viscosity and surface tension.

According to a fifth aspect of the present invention, in order to solve the above problems, after the method according to the first aspect, the first disk and the second disk are rotated at the same speed at different speeds. By doing so, it is a matter of course that air bubbles are not formed between the first and second disks and in the adhesive layer.
The present invention proposes a method for manufacturing an optical disk, which is advantageous for bringing the thickness of the adhesive layer between the disks close to a predetermined value. This method is also effective when forming a relatively thick adhesive layer.

In order to solve the above-mentioned problems, the invention according to claim 6 is the method according to claim 1, wherein when the first and second disks are rotated so that a rotation speed difference is generated between them. , By rotating the first and second discs in opposite directions, no bubbles are formed between the first and second discs and between the first and second discs, and between the first and second discs. The present invention proposes a method for manufacturing an optical disk, which is advantageous for uniformizing the layer of the adhesive in a shorter time.

In order to solve the above-mentioned problems, the invention according to claim 7 is the method according to claim 1, wherein when rotating so that there is a difference in rotational speed between the first and second disks. , A change in the drive torque value due to the spreading of the liquid film of the adhesive between the first and second disks is detected, and the first and second disks are detected according to the change in the drive torque value. The present invention proposes an optical disk laminating method that controls so as to change the rotational speed difference between the two. Air bubbles are not formed between the first and second disks and in the adhesive layer, and the degree of deformation such as warpage of the disk is estimated from the driving torque value, and the disk deformation is corrected. Since it is controlled so that there is a difference in rotation speed,
In addition to shortening the time to reach a state where high-speed rotation is possible,
It is also possible to suppress the deformation of the disc after the attachment.

According to an eighth aspect of the present invention, in order to solve the above problem, in the method according to the second to fourth aspects, a rotational speed difference is generated between the first and second disks. When the drive torque value reaches a predetermined value by detecting a change in the drive torque value due to the spreading of the liquid film of the adhesive between the first and second disks during rotation. The present invention proposes a method for manufacturing an optical disc in which the first and second discs are rotated at high speed. First and second
Air bubbles are not formed between the disks and in the adhesive layer, and the speed at which the liquid film of the adhesive spreads varies depending on the disk due to deformation such as warping of the disks to be bonded, and high-speed rotation. This is effective when the time required to reach a possible state is not constant.

According to a ninth aspect of the present invention, in order to solve the above problems, in the method according to the first to eighth aspects, a liquid film of an adhesive agent between the first and second disks is formed. 9. The optical disc manufacturing method according to claim 1, wherein the rotation of the first and second discs is stopped after the driving torque value which changes with the spread becomes almost constant. The method is proposed, and the rotation of the first and second disks can be automatically stopped when the adhesive layer spreads over the entire surface between the first and second disks.

According to a tenth aspect of the invention, in order to solve the above-mentioned problems, in the method according to the first to ninth aspects, a liquid film of an adhesive agent between the first and second disks is formed. 10. A method of manufacturing an optical disc according to claim 1, wherein a minute gap between the first and second discs is narrowed in accordance with the spread. No air bubbles are formed between the first and second disks and in the adhesive layer, and pressure can be applied to help the liquid film of the adhesive spread.

In order to solve the above-mentioned problems, the invention according to claim 11 is the method according to any one of claims 1 to 9, wherein the first and second discs are in an atmosphere of a low pressure lower than atmospheric pressure. Rotate so that there is a difference in rotation speed between them,
The present invention proposes a method for laminating an optical disk in which a liquid film of an adhesive is spread substantially evenly between a first disk and a second disk, and air for pressing the liquid film of the adhesive between the first and second disks is proposed. The pressure is reduced to facilitate the spreading of the liquid film and prevent more bubbles from forming between the first and second discs and in the adhesive layer.

According to a twelfth aspect of the present invention, in order to solve the above problems, a first disc and a second disc are attached.
In an apparatus for manufacturing an optical disc by laminating the first disc, a rotary stage capable of holding the first disc with its central axis aligned with its own central axis, and a central hole of the first disc held on the rotary stage. An adhesive supply device capable of supplying an adhesive to the periphery of the second disk, the second disk is held and the central axis of the rotary stage is aligned with the central axis of the second disk, and the second disk is the first disk. A disk holding device that does not come into contact with the disk, but can be stopped at a position where it comes into contact with the liquid film of the adhesive supplied on the first disk.
Hold the holding device stationary and rotate the rotary stage
By doing so, between the first and second disks
An optical disk manufacturing apparatus characterized by producing a rotational speed difference .

In order to solve the above-mentioned problems, the invention according to claim 13 proposes an apparatus for manufacturing an optical disk according to claim 12 , wherein the disk holding device can drive the second disk to rotate. To do.

[0020] The invention according to claim 14, in order to solve the above problems, according to claim 12 comprising an envelope capable of retaining the periphery of two disks to be bonded in the atmosphere of subatmospheric pressure or An optical disk manufacturing apparatus according to claim 13 is proposed.

In order to solve the above-mentioned problems, the invention according to claim 15 is based on the driving torque value from one or both of the rotary drive sources for the first and second disks. An optical disk manufacturing apparatus according to any one of claims 12 to 14 , which has a function of changing the rotation state of the second disk.

According to a sixteenth aspect of the present invention, in order to solve the above problems, the disc holding device has a mechanism capable of adjusting a gap between the first and second discs. An optical disk manufacturing apparatus according to any one of claims 12 to 15 is proposed.

[0023]

1 to 5 are views for explaining an embodiment of an optical disk manufacturing apparatus of the present invention. First, the structure will be described, and then a manufacturing method carried out using these apparatuses will be described. .

Of the two disks to be laminated,
The first disk 1 is placed on the rotary stage 2 with the adhesive surface facing upward. The rotary stage 2 is connected to a spindle unit 3 and is rotationally driven by a spin drive motor 4. A collection housing 5 for collecting the droplets of the adhesive that scatters during high-speed rotation is installed around the rotary stage 2. Details of this portion are shown in FIG.

In FIG. 2, the first disk 1 is placed on the rotary stage 2 via the buffer sheet 7. At that time, the positioning protrusion 8 of the rotary stage 2 is inserted into the hole of the first disk 1. The rotary stage 2 is connected to the spin shaft 9. The spin shaft 9 is mounted on the housing 1 via a bearing 10.
1, rotatably supported. The buffer sheet 7 and the rotary stage 2 are provided with vacuum holes 13 and 14 for sucking and holding the first disk 1. The vacuum holes 13 and 14 are connected to the vacuum hole 15 of the spin shaft 9 and to the internal space 16 of the housing 11. From this internal space 16,
It is connected to a vacuum source (not shown) via the pipe joint 17 and the vacuum pipe 18.

The labyrinth seals 1 are provided on both sides of the internal space 16.
9 is provided. The labyrinth seal 19 is provided when a fluid having compressibility such as air passes through the uneven portion of the labyrinth seal 19.
A non-contact type seal that utilizes the phenomenon of high flow resistance,
By setting the gap with the spin shaft 9 to be 0.1 mm or less, the amount of vacuum leakage can be suppressed to a minimum. As a result, it is possible to obtain a seal mechanism that does not cause torque loss or temperature rise of the motor due to friction at a vacuum flow rate that is practically unproblematic. The above-mentioned members constitute the spindle unit 3.

The lower end of the spin shaft 9 is connected to the spin drive motor 4 via a shaft joint 21. A servo motor is often used for the spin drive motor 4 in order to perform rotation control with high accuracy. If a servo motor is used, the drive torque can be easily detected.

The rotation stage 2 is surrounded by a recovery housing 5. At the bottom of the recovery housing 5, the pipe joint 2
A drainage pipe 23 and a drainage tank (not shown) are connected via 2. Excess adhesive that scatters at high speed rotation is discharged through this. Further, an exhaust port 24 is installed in the recovery housing 5. This is to generate an airflow outward in the radial direction inside the recovery housing 5 to efficiently collect the droplets of the surplus adhesive scattered at the time of high-speed rotation and prevent the droplets from adhering to the disc. . A current plate 25 is also installed for the same purpose. For the purpose of preventing droplets from adhering to the disc, a drip-proof plate 26 is also installed on the rotary stage 2 and rotates together with the disc.

Now, returning to FIG. 1 again, the adhesive discharging device 30 is arranged on the left side of the rotary stage 2. The adhesive discharge device 30 is configured such that the discharge nozzle 31, the discharge valve 32, and the discharge pipes 33 and 34 are placed on the horizontal movement mechanism 35 and the vertical movement mechanism 36. The discharge control of the adhesive is performed from the adhesive supply source (not shown) to the discharge pipe 3
The adhesive that is pressure-fed through 4 is sent to the discharge nozzle 31 through the discharge pipe 33 at a desired timing by opening and closing the discharge valve 32.

The horizontal movement mechanism 35 is a linear feed mechanism here, and an air cylinder or a single axis robot is used as a drive source. The vertical movement mechanism 36 is a linear feed mechanism, and an air cylinder is used as a drive source. A swing type feed mechanism may be used as the horizontal movement mechanism.
An example thereof is shown in FIG. Explaining with reference to FIG. 3, an arm 37 supporting the discharge valve 32 is rotatably supported by a bearing case 38 and connected to a servomotor 40 via a shaft coupling 39. A swing type air cylinder may be used instead of the servo motor 40. The horizontal movement mechanism 35 is supported by the vertical movement mechanism 36. Vertical movement mechanism 3
6 is the same as in FIG.

On the right side of the rotary stage 2, a stage 42 on which a second disc 41 is placed and a second disc 41 are mounted.
A disc holding device 43 is installed to stack the disc on the first disc 1. The second disk 41 is placed on the stage 42 with the adhesive surface facing downward. Disk holding device 4
3 has a disk holding head 44 mounted on a horizontal moving mechanism 45 and a vertical moving mechanism 46. The horizontal movement mechanism 45 is a linear feed mechanism here, and an air cylinder is used as a drive source. The vertical movement mechanism 46 is a linear feed mechanism, and an air cylinder is used as a drive source.

A swivel type feed mechanism may be used as the horizontal movement mechanism, and an example thereof is shown in FIG. Referring to FIG. 4, an arm 47 that supports the disk holding head 44 is rotatably supported in the bearing case 38 in the horizontal direction, and is connected to a revolving air cylinder 48 via a shaft coupling 39. This horizontal movement mechanism 45 is a vertical movement mechanism 46.
Supported by. The vertical movement mechanism 46 is the same as in FIG.

The disk holding head 44 is shown in FIG.
To explain. FIG. 5 is a sectional view of the disk holding head 44 portion. The holding head block 49 has a shape in which two cylinders having different diameters are concentrically attached, and a small-diameter portion is inserted into the support block 52 via a slide bearing 51. A key 50 is also inserted in this portion, and the holding head block 49 is movable only in the vertical direction,
It is supported immovably in the direction of rotation. Further, a stopper 53 is screwed into the upper end of the holding head block 49 to prevent it from falling, and the stopper 53 is the coil spring 5.
It is pressed to the lower movable limit position by 4.

At the lower end of the holding head block 49, a suction pin 56 is inserted via a slide bearing 55. The number of suction pins 56 provided is about 4 to 8 depending on the size and shape of the disc. A stopper protrusion 56a is provided in the middle of each suction pin 56, and a stopper 57 is screwed into the upper end of the suction pin 56 to prevent it from falling. Stopper 57
Is pushed upward by the coil spring 58, and the stopper protrusion 56a is pushed to the upper movable limit position. At the lower end of each suction pin 56, the suction pad 5
9 has been inserted. The suction pad 59 is made of a material such as hard silicone rubber which has a lower hardness than the disc but is hard to be deformed, and is firmly press-fitted into the suction pin 56.

The suction pad 59, the suction pin 56, the holding head block 49, and the support block 52 all have holes for vacuum evacuation inside, and they are all connected, and a pipe joint 60 at the upper end of the support block, It is connected to a vacuum source (not shown) via a vacuum pipe 61. Due to the above structure, the disc holding head 44 has the suction pad 59.
Can be held by vacuum suction by contacting with the disk. At this time, even if the disc holding head 44 is strongly pressed against the disc to firmly attract the coil spring 5,
The excessive pressing force does not act on the disk due to the contracting action of Nos. 4 and 58. Further, even if a rotational torque acts on the disc to be held via the liquid film of the adhesive, the rotation preventing action of the key 50 may cause the disc holding head 44 as well as the disc held by the disc to rotate. Absent.

Further, since the spring constant of the coil spring 58 is set to be low and the sum of the initial spring forces of all the coil springs 58 is set to be slightly stronger than the weight of one disk, when the disk is held. When a downward pulling force acts on the coil spring 58 due to the weight of the disc, the coil spring 58 contracts and the suction pin 56 is pulled out even if the pulling force is weak. With this function, when the second disk 41 is brought into contact with the liquid film of the adhesive, the liquid film spreads and becomes thinner, so that the surface tension of the liquid film attracts the second disk 41. Second disc 41 as
Can be prevented from leaving the liquid film.

Next, a first embodiment of a method of manufacturing an optical disc realized by using the above-mentioned device will be described. First, first, the first disk 1 is placed on the rotary stage 2 with the adhesive surface facing upward, and the second disk 41 is placed on the stage 42 with the adhesive surface facing downward, either manually or by a transfer device (not shown). Place it facing.

Next, after the first disc 1 is sucked and held by the rotary stage 2, the rotary stage 2 starts to rotate at a low speed, and the adhesive discharge device 30 is moved to the discharge position, as shown in FIG. The adhesive is discharged onto the first disk 1 as shown by. When the discharging is completed, the adhesive discharging device 30 returns to the original position and the rotary stage 2 is stopped.

Next, the disc holding device 43 is activated, and the disc holding head 44 attracts the second disc 41 and carries it to the upper side of the first disc 1 as shown in FIG. And contact the liquid film of the adhesive,
The first disc 1 is held at a position where it does not come into contact with it. FIG. 6 shows this state. This is easily realized because the sum of the initial spring forces of all the coil springs 58 is set to be slightly stronger than the weight of one disc as described above. Here, 64 is a liquid film of an adhesive.

Next, the rotary stage 2 starts to rotate. At this time, the upper second disk 41 also starts to rotate by the disk holding device 43, but the respective rotation speeds are predetermined so that a difference in rotation speed occurs between these two disks. This is shown in FIG. 7 (c). This difference in rotation speed varies depending on various factors such as the viscosity of the adhesive and cannot be generally stated, but is generally 10 to 100 rpm. In that state, both discs rotate, and after a predetermined period of time during which the adhesive between the discs is spread to approximately the periphery of the discs, the rotation of both discs stops. At this time, the predetermined period of time during which the adhesive between the disks is spread almost to the vicinity of the outer circumference of the disks depends on the rotation speeds of both disks.

Thereafter, the first stage in the rotary stage 2 is
The vacuum suction of the disk 1 is released, and the vacuum suction of the second disk 1 by the disk holding head 44 of the disk holding device 43 is also released. Finally, the two disks are carried to a curing device by hand or by a transport device (not shown) to cure the adhesive and complete the bonding.
In this embodiment, the adhesive between the discs can be spread evenly, and since it is hardly shaken off by the centrifugal force, the amount of the adhesive used can be saved and a mechanism for preventing the scattering of the adhesive can be provided. Can be simplified. Although the disk is rotated under the atmospheric pressure in the above description, it may be performed in an atmosphere having a pressure lower than the atmospheric pressure as described later.

Next, in the second embodiment, in order to make the required time shorter than in the first embodiment, the first and second disks are rotated with a difference in rotational speed, and the adhesive between the disks is rotated. Is almost evenly spread to some extent,
As shown in (d), the disc holding device 43 releases the second disc 41 and places it on the first disc 1, and returns to the original position. Immediately after that, as shown in FIG. 7E, the rotation of the rotary stage 2 is switched from low speed to high speed, and the two disks are rotated at high speed at substantially the same speed. After holding that state for a predetermined time, the rotary stage 2 is stopped and the vacuum suction of the first disk 1 on the rotary stage 2 is also released. By this high speed rotation,
Since the adhesive between the discs is rapidly spread by a strong centrifugal force and shaken off, the time required for bonding the two discs can be shortened in this embodiment, and the entire surface between the two discs can be made uniform. Further, as described later, it is possible to form a bubble-free adhesive layer.

In this embodiment, the two discs are finally rotated at a high speed at substantially the same speed.
In the step of rotating the first and second discs at a rotational speed difference, only one of the first and second discs may be rotated at a low speed, or even if both discs are rotated, it is determined in advance. Both can rotate at a low rotational speed so as to exhibit a rotational speed difference.

FIG. 8 is a view for explaining the effect of the step of rotating the first and second disks with a difference in rotational speed according to the present invention. FIG. 2A is a view of the state immediately after the two discs are overlapped and is viewed from above. Even if the liquid film 64 of the adhesive can be ejected onto the first disc 1 in a clean annular shape, At the stage of stacking the second disks 41, the contour of the liquid film 64, as shown in FIG. 4A, is formed, that is, the contour is uneven. As described above, the unevenness of the contour of the liquid film 64 causes the bubbles to be mixed. The occurrence of the state as shown in FIG.
The same applies to the conventional example as shown in FIG.

On the other hand, in FIG. 2B, the second disk 41 is positioned at a level where it contacts the liquid film 64 of the adhesive but does not contact the first disk 1, FIG. 6 is a view of the state after the rotation speed difference is generated between the second disc and the second disc and the disc is rotated for a predetermined time in that state, as viewed from above.

Due to the relative rotational movement of these two discs, in addition to the centrifugal force, a mechanical action also acts, so that the liquid film 64 is displaced in the circumferential direction, and the contour concave portion of the liquid film 64 is displaced. It is crushed by the contour convex portion to form a clean annular shape, and the contour of the liquid film 64 spreads in the outer peripheral direction with almost the same diameter at any position. Therefore, in the present embodiment, when the second disc 41 is placed on the first disc 1, the second disc 41 does not contact the liquid film 64 until the first disc
Since it is already close to the disk 1 of No. 1, it does not disturb the shape of the liquid film 64 when the disk is placed,
No bubbles are formed between the disks and in the adhesive. Also,
Since the contact area between the liquid film 64 and the surfaces of the disks 1 and 41 and the length of the contour line become sufficiently large, the disks 1 and 4
The adhesion between No. 1 and No. 1 becomes strong, and even if the second disk 41 is placed on the first disk 1, problems such as disk jumping at high speed rotation do not occur.

In the above embodiment, the first and second disks 4
When the first disc 1 and the second disc 41 are rotated at a high speed, the disc holding device 43 releases the second disc 41 and puts the second disc 41 on the first disc 1. Second disc 1 without opening 41
Can be adsorbed and held and rotated at a high speed, and the same effect can be obtained not only by rotating both disks at the same rotation speed, but also by rotating them at different rotation speeds within a narrow rotation speed difference range, for example, 100 rpm or less. be able to. This is effective for preventing the purchase of bubbles when the predetermined film thickness value is large and the action of defining the contour line by the surface tension of the liquid is relatively low.

Next, FIG. 9 is a view showing a mechanism for realizing the embodiment of the present invention, and is a view showing a tip end portion of the disk holding device 43. In this embodiment, the disk holding device 43 allows the second disk 41 to be rotated while being held. Referring to FIG. 9, the upper part of the support block 54 of the disk holding head 44 is connected so as to be concentric with the spin shaft 66, and the spin shaft 66 is rotatably supported by the housing 11 via the bearing 10. A vacuum hole 15 is formed inside the spin shaft 66, which is connected to a vacuum exhaust hole inside the disk holding head 44, is connected to the internal space 16, and is not shown via a pipe joint 17 and a vacuum pipe 18. Connected to a vacuum source. Labyrinth seals 19 are provided on both sides of the internal space 16. The above-mentioned members constitute the spindle unit 67. The structure and function of the spindle unit 67 are the same as those shown in FIG.

The upper end of the spin shaft 66 is connected to the spin drive motor 4 via the shaft joint 21. Spin drive motor 4
In many cases, a servomotor is used for high-precision rotation control. If you use a servo motor,
The drive torque can be easily detected. The spindle unit 67 and the spin drive motor 4 are fixed to the arm 47 via a base block 68. By using the disc holding device 43 having this structure, the second disc 41 can be rotated while being held from above. At this time, as described above, the liquid film 64 of the adhesive spreads, and the second disk 41 does not separate from the liquid film 64 even if it becomes thin.

Therefore, according to the disc holding device 43 having this structure, the second disc 41 is replaced by the first disc 1.
It is possible to rotate both discs at a rotational speed different from the rotational speed of, or in the opposite direction, and both disks can be rotated at substantially the same speed if necessary. This is the same during low speed rotation and high speed rotation, and this mechanism enables various manufacturing methods. Then, this is effective in eliminating the unevenness of the contour of the boundary line between the liquid film 64 and the second disk 41, among the unevenness of the liquid film 64 of the adhesive that tends to occur when two disks are stacked. No bubbles are formed between the two disks or in the adhesive layer.

FIG. 10 is a view showing another structure of the tip end portion of the disk holding device 43 for realizing another embodiment of the present invention. In this embodiment, the height of the stationary position of the second disc 41 can be set arbitrarily.

Referring to FIG. 10, the disk holding head 69 has a simple structure without a cushioning mechanism, has a suction pad 70 at its tip, has a vacuum hole 71 inside, and is illustrated via a pipe joint 60 and a vacuum pipe 61. Not connected to a vacuum source. The disk holding head 69 is fixed to the movable base 72. The movable base 72 is attached to the guide rod 74 via a slide bearing 73 in a vertically movable state. It is also attached to the ball screw 76 via the ball nut 75. As a result, the disk holding head 69 moves up and down according to the rotation of the ball screw 76. The guide rod 74 is rigidly supported, and the ball screw 76 is rotatably supported by the lower base 78 and the upper base 79 via the bearing 10. The upper end of the ball screw 76 is connected to the servomotor 80 via the shaft coupling 21.

By commanding a signal of the stationary height of the second disk 41 to the servomotor 80, the ball screw 76 is rotated and the disk holding head 69 is moved to the set height. In this embodiment, when the two discs rotate with a rotational speed difference, the gap between the two discs is narrowed as the liquid film 64 of the adhesive spreads and becomes thinner. Since the liquid film 64 is pressed by a certain amount, it helps the liquid film 64 to spread in a clean annular shape.

FIG. 11 is a view showing another structure of the tip end portion of the disk holding device 43 for realizing another embodiment of the present invention. This embodiment is a combination of the embodiments shown in FIGS. 9 and 10. In the figure, a spindle unit 67 that rotatably supports a disk holding head 69.
The spin drive motor 4 is fixed to the movable base 72. The movable base 72 is attached to the guide rod 74 via the slide bearing 73 and the ball screw 76 via the ball nut 75.
Are respectively supported, and the ball screw 76 rotates in accordance with the rotation of the servo motor 80 to move up and down, and the height of the disk holding head 69 is set to an arbitrary level. In this embodiment, the combined action and effect of the mechanisms shown in FIGS. 9 and 10 can be exhibited.

FIG. 12 shows a mechanism for realizing another embodiment of the present invention, in which the rotary stage 2 is surrounded by a closed container 84 which can be covered. The lid 85 of the closed container 84 is attached to the tip of the disk holding device 43. Further, by the vertical movement mechanism 46 of the disc holding device 43,
The lid 85 is pressed against the O-ring 86 mounted on the closed container 84 to close the closed container 84. Also a closed container 8
In order to perform the vertical movement of the second disk 41 independently of the sealing of No. 4, the disk holding head lifting device 87 is equipped. The gap between the closed container 66 and the spindle unit 3 is O
It is sealed with a ring 88. Further, the drainage piping system is equipped with a drainage valve 89. The parts other than the above, which are not shown, are the same as those in FIG.

Exhaust port 24 with hermetically sealed container 84 sealed
By sucking the air therein, the inside of the closed container 84 can be made to have an atmosphere at a pressure lower than atmospheric pressure. The collected excess adhesive liquid can be discharged by opening the drain valve 89 at the same time when the lid 85 is opened. After stacking two disks using this mechanism, the inside of the closed container 84 is made to have an atmosphere at a pressure lower than atmospheric pressure, and in that state, the two disks are rotated with a relative rotational speed difference, or they are rotated at the same speed. Rotate at a high speed with a speed or a relative rotational speed difference. According to this method, there is an effect of helping to uniformly spread the liquid film of the adhesive between the two disks.

FIG. 13 shows a mechanism for controlling the rotation of the disk by the drive torque of the spin drive motor which rotationally drives the disk. This example is based on the following findings. When the first and second discs 1 and 41 are rotating with a relative rotational speed difference as described above, as shown in FIG. 7 or FIG. Therefore, the spin drive motor 4 needs an extra drive torque corresponding to the torque for rotating against the shear stress generated in the liquid film 64. Become. Since the torque value for rotating against the shear stress increases as the contact area between the liquid film 64 and the disk increases, if the torque value is known, the contact area between the liquid film 64 and the disk can be obtained. Further, since the amount of the adhesive dropped on the disk 1 is set in advance and is known, the height of the liquid film 64 is also required. Therefore,
The relationship between the torque value and the contact area between the liquid film 64 and the disc, or the liquid film 64 of the adhesive, which is used in advance as parameters such as the viscosity of the liquid film 64, the rotational speed of the disc, and the gap between the discs, By obtaining the relationship with the height of 64, it becomes possible to have versatility. If there is a periodic fluctuation in this drive torque value,
Since it is caused by the deformation of the disc, it is possible to control the rotation state and the pressing amount of the disc so as to eliminate it.

Based on this, in this embodiment, the first
Servo motors are used as the two spin drive motors 4 for rotationally driving the first and second disks 1 and 41, respectively.
First servo driver 93 for the spin drive motor 4 that rotationally drives the disk 1, and the second servo driver 9 for the spin drive motor 4 that rotationally drives the second disk 41.
4, the driving torque value of each spin drive motor 4 is transmitted to the arithmetic processing unit 95.
The torque value consumed by the spindle mechanism is input to the arithmetic processing unit 95 in advance, and the difference torque value obtained by subtracting the torque value from the drive torque value is recognized as the torque value due to the viscous resistance of the liquid.

The arithmetic processing unit 95 has a first servo driver 93 and a second servo driver 93 for rotating the two spin drive motors 4 for rotationally driving the first and second disks 1 and 41, respectively, at a set rotational speed. The signals corresponding to the drive torque values output by the servo driver 94 are respectively received and arithmetic processing is performed to obtain the contact area between the liquid film 64 and the disk, that is, the spread state of the liquid film 64. When the set value of 1 is reached, an operation command is transmitted to the servo drivers 93 and 94 so that the rotational speed difference between the disks 1 and 41 becomes small or zero. By doing so, it is possible to eliminate the possibility that the facing surfaces of the disks 1 and 41 are damaged by friction.

The arithmetic processing unit 95 operates the first servo driver 93 and the second servo driver 93 in order to rotate the two spin drive motors 4 for rotationally driving the first and second disks 1 and 41, respectively, at a set rotational speed. The signals corresponding to the drive torque values output by the servo driver 94 are respectively received and arithmetic processing is performed to obtain the contact area between the liquid film 64 and the disk, that is, the spread state of the liquid film 64. When the set value of 2 is reached, an operation command is transmitted to the servo drivers 93 and 94 to switch the disks 1 and 41 to high speed rotation.

In addition, the arithmetic processing unit 95 rotates the two spin drive motors 4 that rotate and drive the first and second disks 1 and 41, respectively, at the set rotation speed.
First servo driver 93, second servo driver 94
When the height of the liquid film 64 decreases due to the increase of the driving torque value, the height of the liquid film 64 is reduced by receiving the signal corresponding to the driving torque value output by the An operation command is given to the third servo driver 96, which is the drive source of the servo motor 80, so as to narrow the minute gap between the disks.

Furthermore, the arithmetic processing unit 95 receives the signals corresponding to the driving torque values from the first servo driver 93 and the second servo driver 94, respectively, and the liquid film 6
When 4 spreads over the entire surface of the disk, the driving torque value becomes substantially constant. Therefore, when the change of the signal becomes less than a certain set value, the rotation driving of the disk is stopped. 93, an operation stop command is sent to the second servo driver 94.

If the disk holding head 44 does not have the structure shown in FIG. 5, the liquid film 64 becomes thin due to the spread of the liquid film 64 between the disks, so that the first disk 1 is separated from the liquid film 64. In this case, the arithmetic processing unit 95 receives signals corresponding to the torque values from the first servo driver 93 and the second servo driver 94, respectively, and the drive torque value is obtained in advance. An operation command is given to the third servo driver 96 which is the drive source of the servo motor 80 so as to increase according to the characteristic curve, and the minute interval between the disks is gradually narrowed.

[0064]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned characteristics, when liquid disks are used and the optical disks are rotated at a high speed for bonding, bubbles are mixed between the disks and in the adhesive layer. And it is possible to obtain a high-quality optical disc by bonding.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a disk manufacturing apparatus according to the present invention.

FIG. 2 is a diagram showing a detailed structure of the embodiment of FIG.

FIG. 3 is a diagram showing a modification of the partial structure of the embodiment of FIG.

FIG. 4 is a diagram showing a modification of the partial structure of the embodiment of FIG.

5 is a diagram showing a detailed structure of the embodiment of FIG.

FIG. 6 is a diagram for explaining the operation of the embodiment of FIG.

FIG. 7 is a diagram for explaining an example of the present invention.

FIG. 8 is a diagram for explaining the operation and effect of the embodiment of the present invention.

FIG. 9 is a diagram for explaining another embodiment according to the present invention.

FIG. 10 is a diagram for explaining another embodiment according to the present invention.

FIG. 11 is a diagram for explaining another embodiment according to the present invention.

FIG. 12 is a diagram for explaining another embodiment according to the present invention.

FIG. 13 is a diagram for explaining another embodiment according to the present invention.

FIG. 14 is a diagram showing an example of a conventional optical disc bonding method.

FIG. 15 is a diagram for explaining a conventional disc manufacturing method.

FIG. 16 is a diagram for explaining a conventional disc manufacturing method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st disc 2 ... Rotation stage 3 ... Spindle unit 4 ... Spin drive motor 5 ... Recovery housing 7 ... Buffer sheet 8 ... Positioning protrusion 9 ... Spin shaft 10 ... Bearing 11 ... Housing 13 ... Vacuum hole 14 ... Vacuum hole 15 ... Vacuum hole 16 ... Internal space 17 ... Piping joint 18 ... Vacuum pipe 19 ... Labyrinth seal 21 ... Shaft joint 22 ... Piping joint 23 ... Drainage pipe 24 ... Exhaust port 25 ... Rectifier plate 26 ... Dripproof plate 30 ... Adhesive discharge Device 31 ... Discharge nozzle 32 ... Discharge valve 33 ... Discharge pipe 34 ... Discharge pipe 35 ... Horizontal movement device 36 ... Vertical movement device 37 ... Arm 38 ... Bearing case 39 ... Shaft coupling 40 ... Servo motor 41 ... Second disk 42 ... Stage 43 ... Disk holding device 44 ... Disk holding head 45 ... Horizontal moving mechanism 46 ... Vertical moving mechanism 47 ... Arm 48 ... Swivel type Ar cylinder 49 ... Holding head block 50 ... Key 51 ... Sliding bearing 52 ... Support block 53 ... Stopper 54 ... Coil spring 55 ... Sliding bearing 56 ... Adsorption pin 56a ... Stopper protrusion 57 ... Stopper 58 ... Coil spring 59 ... Adsorption pad 60 ... Piping joint 61 ... Vacuum piping 64 ... Adhesive liquid film 66 ... Spin shaft 67 ... Spindle unit 68 ... Base block 69 ... Disk holding head 70 ... Adsorption pad 71 ... Vacuum hole 72 ... Movable base 73 ... Slide bearing 74 ... Guide rod 75 ... Ball nut 76 ... Ball screw 78 ... Lower base 79 ... Upper base 80 ... Servo motor 84 ... Sealed container 85 ... Lid 86 ... O-ring 87 ... Disk holding head lifting device 88 ... O-ring 89 ... Drain valve 93 ... 1st servo driver 94 ... 2nd servo driver 95 ... Processing unit 96 ... third servo driver

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G11B 7/26

Claims (16)

(57) [Claims] 1. A method of manufacturing an optical disk by bonding a first disk and a second disk together, the step of holding the first disk on a rotary stage with the bonding surface facing upward, Supplying a liquid adhesive around the central hole of the first disc, the first and second discs being concentric, and the second disc being the adhesive on the first disc A step of holding the second disk in a position where it contacts the agent but does not contact the first disk; and a difference in rotational speed between the rear first and second disks. And a step of rotating one or both of the first and second discs while holding the optical disc. 2. A method of manufacturing an optical disk by bonding a first disk and a second disk together, the step of holding the first disk on a rotary stage with the adhesive surface facing upward, Supplying a liquid adhesive around the central hole of the first disc, the first and second discs being concentric, and the second disc being the adhesive on the first disc A step of holding the second disk in a position where it contacts the agent but does not contact the first disk; and a difference in rotational speed between the rear first and second disks. Rotating one or both of the first and second disks at a low rotation speed while holding the first disk and the second disk at a low speed, and rotating the first disk and the second disk at a speed higher than the rotation speed of the step. With the process of rotating Optical disk manufacturing method which is characterized in that it comprises. 3. The step of rotating the first disk and the second disk at a high speed, the second disk is placed on the first disk and rotated at a high speed at the same speed. The optical disc manufacturing method according to claim 2. 4. The optical disk according to claim 2, wherein in the step of rotating the first disk and the second disk at a high speed, the second disk is rotated at a high speed while holding the second disk from above. Manufacturing method. 5. In the step of rotating the first disc and the second disc at a high speed, the first and second discs are rotated.
So that a difference in rotational speed occurs between the discs of the second
3. The method for manufacturing an optical disc according to claim 2, wherein the two discs are rotated at high speeds in different directions at the same time while holding the disc. 6. In the step of rotating one or both of the first and second disks so that a rotational speed difference is generated between the first and second disks, the first and second disks are rotated. 6. The method for manufacturing an optical disc according to claim 1, wherein the disc rotates in a relatively opposite direction. 7. In the step of rotating one or both of the first and second disks so that a rotation speed difference is generated between the first and second disks, the first and second disks are rotated. The control is performed so as to change the rotational speed difference between the first and second disks in accordance with a change in a drive torque value accompanying the spread of the liquid film of the adhesive between the disks. Item 7. A method of manufacturing an optical disc according to any one of items 1 to 6. 8. In the step of rotating one or both of the first and second disks so that a rotation speed difference is generated between the first and second disks, the first and second disks are rotated. 5. When the drive torque value reaches a set value as the liquid film of the adhesive agent spreads between the disks, the process is switched to the step of rotating the first and second disks at a high speed. A method for manufacturing an optical disc according to any one of the above. 9. The rotation of the first and second disks after the driving torque value which changes with the spread of the liquid film of the adhesive between the first and second disks becomes a substantially constant value. 9. The method for manufacturing an optical disc according to claim 1, wherein the optical disc is stopped. 10. The minute gap between the first and second disks is narrowed in accordance with the spread of the liquid film of the adhesive between the first and second disks. 10. The method for manufacturing an optical disc according to any one of 1 to 9. 11. A rotating speed difference between the first and second disks in an atmosphere at a pressure lower than atmospheric pressure,
10. The method of manufacturing an optical disc according to claim 1, wherein one or both of the first and second discs are rotated. 12. The method according to claim 12,Attach the first disc and the second disc
In the device for producing optical disks by combining Align the center axis of the first disc with its own center axis.
A rotating stage that can be held together In the first disk held on the rotating stage
An adhesive supply device capable of supplying adhesive around the core hole, The second disc is held and the central axis of the rotary stage is
The central axes of the second disks are aligned and the second disks are
Although the disc does not contact the first disc,
The liquid film of the adhesive supplied on the first disk is not contacted.
Disk holding device that can be stopped at the position to touch
When, Equipped withKeep the disk holding device stationary,
By rotating the rotary stage, the first and front
A difference in rotational speed is generated between the second disks.That
Characteristic optical disc manufacturing equipment. 13. The optical disk manufacturing apparatus according to claim 12 , wherein the disk holding device can drive the second disk to rotate. Optical disk according to claim 12 or claim 13 around the two disks 14. adhered, characterized in that it comprises an envelope which may be held in an atmosphere of subatmospheric pressure Manufacturing equipment. 15. A function of changing the rotational states of the first and second disks based on a drive torque value from one or both of the rotational drive sources of the first and second disks. The optical disk manufacturing apparatus according to any one of claims 12 to 14 . 16. The disk holding device, producing an optical disk according to any one of claims 12 to claim 15, characterized in that it has a mechanism capable of adjusting a gap between the first and second disk apparatus.