JPH1166645A - Optical disk sticking method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sticking method and a device for an optical disk with which an adhesive layer causing no mixing of air bubbles and having a uniform film is produced. SOLUTION: In the sticking method for the optical disk with which 2 pieces of single plate disk are stuck together by using a liq. adhesive to produce one piece of stuck disk, these 2 pieces of single plate disk DL, DU are being brought in proximity to each other while the adhesive 18 annularly is discharged on a surface of an lower side single plate disk DL out of the 2 pieces of the single plate disk and the upper side single plate disk DU is held on a section in the vicinity of the outer periphery thereof. Then, before the upper side single plate disk DU comes into contact with the annular adhesive 18 on the surface of the lower side single plate disk DL, the pressure of an inner space surrounded with the surface of the upper side single plate disk DU, the surface of the lower side single plate disk DL and the annular adhesive 18 is set lower than that of the outer space. In this state, the upper side single plate disk DU is brought into contact with the annular adhesive 18 on the lower side single plate disk DL.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of optical disks, and more particularly to a method and apparatus for bonding two disks to form one disk.

[0002]

2. Description of the Related Art As a conventional optical disk laminating apparatus using a liquid adhesive, for example, Japanese Patent Application No. Hei.
3460. Here, in order to facilitate the explanation, FIG. 6 shows a conventional example in which the description is simplified. Hereinafter, the configuration and operation will be described with reference to FIG.

In the optical disc bonding apparatus 30, a lower single-plate disc DL is placed at a position P1 on the discharge section turntable 31 by a supply device (not shown) with the bonding surface facing upward. Thereafter, the lower single disk DL on the position P1 is sent to the position P3 through the position P2 by the discharge unit turntable 31. At this time, at the position P2, the adhesive is supplied onto the bonding surface of the lower single-plate disk DL by the adhesive discharge nozzle N. Note that the adhesive discharge nozzle N is a rotary nozzle, and when the lower single-plate disk DL is stationary at the position P2, the adhesive is discharged while rotating, and an annular ring is formed on the lower single-plate disk DL. To form a liquid film.

On the other hand, at a position P4 on the transport table 32, an upper single-plate disk DU is placed by a supply device (not shown).
It is placed with the bonding surface facing down. Thereafter, the upper single-plate disk DU at the position P4 is sent to the position P5 by the transport table 32. Here, the transport table 32
The disk is transported by rotating the disk 180 degrees forward and backward, but may be a unidirectional rotating type having a stop point at every 180 degrees.

[0005] Upper single-plate disc D carried to position P5
The lower single disk DL transported to U and the position P3 is sent to the spinner SP1 at the position P6 or the spinner SP2 at the position P7 while being vertically stacked by the transfer mechanism R1. That is, the transfer mechanism R1 holds the upper single-plate disk DU by suction at the position P5, and then mechanically grips the lower single-plate disk DL therebelow at the position P3.
6, or sent to position P7.

In the spinners SP1 and SP2, the upper single-plate disk DU and the lower single-plate disk DL are rotated at a high speed in a state of being overlapped with an adhesive, and the adhesive is spread to a predetermined area. The disk DD, which has been processed by the spinners SP1 and SP2 and adhered while being uncured, is sent by the transfer mechanism R2 to a position P8 which is an entrance of the hardened unit turntable 33.

Then, the contact disk DD on the position P8
Is sent to the position P10 through the position P9 by the curing unit turntable 33. At this time, the contact disk DD is irradiated by the ultraviolet irradiation device 34 at the position P9, the adhesive layer is cured, and the bonding step is completed.
The hardened section turntable 33 is covered with a light shielding cover 35 to prevent ultraviolet rays from leaking.

[0008] The disk at the position P10 is the adhesive disk DB that has been completely cured, and is taken out by a discharge device (not shown).

Next, details when two disks are stacked by the transfer mechanism R1 will be described. FIG. 7 is a sectional view of the disk holding unit 36 attached to the tip of the transfer mechanism R1 in FIG. 6 and the disk receiving table 37 at the position P3 on the ejection table 31.

The disk holding unit 36 has the following mechanism for holding two disks in an overlapping manner. That is, a suction head 38 for sucking and holding the upper single disk DU, a claw 39 for mechanically holding the lower single disk DL, and air for opening and closing the same in the radial direction. It has a cylinder 40. Further, in the disk receiving table 37, a notch 42 into which the claw 39 is inserted is provided in the projection 41 fitted into the disk center hole in order to position the disk.

FIG. 7 shows a state in which the transfer mechanism R 1 has reached the position P 3 in FIG. 6, and thereafter, the disk receiving table 37 of the discharge section turntable 31 is moved to the liquid film 43 of the adhesive. Is lifted in a state where the lower single-plate disk DL on which is mounted is held. Immediately before the liquid film 43 comes into contact with the upper single disk DU, the disk receiving stand 37 reduces the rising speed and makes the liquid contact at a low speed, that is, makes the liquid film 43 contact the lower surface of the upper single disk DU. When the liquid comes into contact, the claws 39 open outward and hold the lower single-plate disk DL, and the disk receiving base 37 stops its suction and starts descending. In this way, the disc stacking operation by the transfer mechanism R1 is completed.

[0012] By performing the above, the upper veneer disk DU can be gently brought into contact with the liquid film 43 on the lower veneer disk DL. In comparison, it is easy to form a high-quality adhesive layer without disturbing the shape of the liquid film 43.

[0013]

However, the above-mentioned prior art has the following problems. That is, the adhesion surface of the upper single-plate disk DU and the top surface of the liquid film 43 have a variation in the height direction when viewed microscopically,
The site to start wet contact occurs randomly. This was the cause of air bubble mixing at the time of liquid contact. This will be described with reference to FIG.

FIG. 8 is a diagram showing, in order, changes in the liquid contact state when looking downward from a viewpoint at the top of the liquid film 43 on the lower single-plate disk DL. FIG. 8 (a)
In the state where liquid contact has been started, liquid contact portions 44 are generated at random positions. FIG. 8B shows a state in which the upper and lower disks are closer to each other than FIG.
Numerals 4 each show an enlarged state. FIG. 8 (c)
Further, the upper and lower disks approach each other, and the heads of the expanded liquid contact portions 44 come into contact with each other. Here, the liquid contact portions 44 surround the air layer, and bubbles 45 are easily generated. FIG. 8D shows a state at the time when the liquid contact is completed, and the air bubbles 45 generated once remain.

In the above-described conventional example, bubbles generated at the time of liquid contact are shaken off together with excess adhesive at the time of high-speed rotation of the spinner. Therefore, there is a problem that extra adhesive is consumed, which is uneconomical.

In applications where the thickness of the adhesive layer needs to be precisely controlled, such as a single-sided dual-layer reading DVD,
Since the spinner rotation condition is restricted by the bubble whirl, there is a problem that it is difficult to set the condition.

An object of the present invention is to prevent generation of bubbles at the time of such liquid contact.

[0018]

Means for Solving the Problems According to the present invention, in order to solve this problem, of two single-plate disks to be bonded,
The adhesive is discharged in an annular shape on the surface of the lower single disk, and the upper single disk is held only in the vicinity of the outer periphery, and the two single disks are moved closer to each other. Before the upper veneer disk comes into contact with the annular adhesive on the lower veneer disk surface, the pressure in the space surrounded by the upper veneer disk surface, the lower veneer disk surface and the annular adhesive is reduced. The present invention proposes an optical disk bonding method and apparatus in which the pressure is lower than the atmospheric pressure and an annular adhesive on the upper single disk and the lower single disk is brought into contact in such a state.

That is, since the center of the upper single disk is pulled downward by utilizing the above-mentioned pressure difference, a slight inclination is generated so that the center of the disk is lower than the outer side in the radial direction over the entire liquid contact surface. At the same time, the top of the annular adhesive liquid film is drawn toward the center of the disk, so that liquid contact of the upper single-plate disk is caused radially outward from the innermost peripheral portion of the annular adhesive liquid film. The present invention proposes an optical disc bonding method and a band apparatus which can advance liquid contact while eliminating an air layer in a radially outward direction, and can form an adhesive layer without bubbles between upper and lower single discs. It is.

[0020]

EXAMPLES Examples according to the present invention will be described below. FIG. 1 is a cross-sectional view of a mechanism of a part for bringing an upper single disk into contact with an adhesive discharged onto a lower single disk in the disk bonding apparatus as shown in FIG. FIG. 2 is a diagram showing the appearance. They are,
This is to be compared with the portion shown in FIG. 7 in the conventional example.

First, the configuration will be described with reference to FIG. The disk holding unit 1 is attached to the tip of a transfer mechanism Q1 that performs a transfer operation corresponding to the transfer mechanism R1 of the conventional example shown in FIG. Further, a vertically movable disk receiving table 2 is disposed below the disk receiving table 2.

An air cylinder 4 that radially opens and closes a plurality of claws 3 for mechanically gripping the lower single-plate disk DL is provided at the distal end of the transfer mechanism Q1 in the disk holding unit 1. A disk-shaped suction head 5 for mounting and holding the upper single-plate disk DU by suction is mounted on the tip of the air cylinder 4. A plurality of suction pads 7 are attached to the suction head 5 via metal fittings 6 on the outer peripheral portion thereof. Further, a first vacuum pipe joint 8 and a first vacuum pipe 9 for disk suction are connected to the suction head 5. Further, a first vacuum hole 10 is formed inside the suction head 5, and a first vacuum pipe joint 8, each metal fitting 6, and a suction pad 7 are formed.
And are connected.

On the other hand, a plurality of claws 3 are also mounted on the tip of the air cylinder 4, and the claws 3 are arranged at positions protruding from the center hole 11 of the suction head 5.

A disk receiving table 2 located below the disk holding section 1 has a lower single-plate disk DL at its center.
Has a projection 12 that fits into the center hole 11 of the first hole. The projection 12 is formed with a notch 13 into which the plurality of claws 3 enter. Also, a lower single-plate disk DL is provided on the disk support 2.
A second vacuum passage 14 for adsorbing
It is connected to a second vacuum system. However, the second vacuum system may branch off from the same vacuum source as the first vacuum system.

Incidentally, the center hole 11 of the suction head 5 of the disk holding unit 1 is also a space into which the projection 12 of the disk receiving table 2 enters when performing an operation of stacking two single-plate disks. A third vacuum pipe joint 16 and a third vacuum pipe 17 are connected to the center hole 11 via a third vacuum passage 15. However, the third vacuum system is different from the first and second vacuum systems, and differs in both pressure and exhaust flow rate.

The annular adhesive liquid film 18 is discharged onto the lower single-plate disk DL placed on the disk receiving table 2 in the same manner as described above.

Now, the details of the above configuration will be described with reference to FIG. As shown in FIG. 2, three nails 3 of the disk holding unit 1 are often arranged. This is three claws 3
This is because, when the inner surface of the lower single-plate disc DL is opened at an angle in the radially outward direction and the inner peripheral portion of the lower single-plate disc DL is held at three points, it can be stably held. Therefore, the notch 13 of the disk receiving table 2 is often formed in three places. However, in FIG. 1, the claws 3 are illustrated as two pieces for easy viewing.

The tip of the claw 3 is partially thickened. When the claw 3 grips the lower single disk DL, the claw 3 pushes the center hole of the upper single disk DU. This is to prevent That is, when the center hole of the upper single disk DU is slightly smaller than the center hole of the lower single disk DL due to the variation in the disk molding, the claw 3 is placed before the center hole of the upper single disk DU. The lower single-plate disc DL
This is to prevent the gripping force from being insufficient.

Further, a plurality of suction pads 7 of the disk holding unit 1 are mounted, but a quantity between 4 and 16 is often selected. This is the upper single disk DU
When the number of suction pads 7 is less than four, it is difficult to form a uniform inclination when a slight inclination is caused on the liquid contact surface.
This is because the effect is not changed in the sense that a uniform inclination is formed even if the number exceeds the number, and it is wasted.

However, depending on the molding conditions of the single-plate disk, the properties of the adhesive, and the like, if a good disk holding is possible even if the number exceeds the above range, a value outside the above range may be selected.

Here, returning to FIG. 1, the details will be described. A second vacuum passage 14 for holding the lower single-plate disk DL by suction in the disk holder 2 is provided with an adhesive liquid film 18.
Are often arranged in the vicinity of the position where is ejected. This is because when the pressure difference causes the upper veneer disk DU to slightly tilt, the pressure difference causes the portion of the lower veneer disk DL on which the liquid film 18 is placed to be lifted upward, causing unintended contact. This is to prevent the liquid from being generated. However, depending on the molding conditions of the lower veneer disk DL, the properties of the adhesive, and the like, the second vacuum passage may be used depending on the situation, such as when the deformation of the lower veneer disk DL can be ignored at the set pressure difference. 14 may be arranged at a position other than the above.

Next, the operation of this embodiment will be described with reference to FIG. FIG. 3A shows the same state as FIG. Here, the first vacuum system is operating, and the upper single-plate disk DU
The outer peripheral portion is sucked by the suction pad 7 and is held by the disk holding portion 1. On the other hand, the second vacuum system is operating in the disk support 2, and the lower single-plate disk DL from which the adhesive liquid film 18 has been discharged is suction-held on the disk support 2.

The claw 3 is closed, and the third vacuum system is stopped, that is, released to the atmospheric pressure. From this state, the disk receiver 2 starts to rise. The disk receiving table 2 first rises at a high speed, and the liquid film 18 is moved to the upper single disk
Immediately before contacting U, the ascending speed is switched to a low speed.

FIG. 3B shows the moment when the liquid film 18 comes into contact with the upper single disk DU. Here, the protrusion 12 of the disk receiving table 2 is fitted in the center hole 11 of the suction head 5. Before this, the third vacuum system operates.

When the third vacuum system is activated, the pressure in the center hole 11 of the suction head 5 is reduced, so that the upper single-plate disk DU and the lower single-plate disk DL pass through the notch 13 of the projection 12 that enters therein. The pressure in the inner space 19 surrounded by the respective adhesive surfaces and the liquid film 18 is also lower than that in the outer space. As a result, the center of the upper single disk DU whose only outer peripheral portion is sucked and held is pulled downward, and a slight inclination occurs.

On the other hand, when the pressure in the inner space 19 decreases,
The liquid film 18 is pulled toward the center of the disk, and the top of the liquid film 18 also moves toward the center.

The upper single-plate disk DU is slightly inclined such that its central portion is lowered, and the liquid film 18
Due to the synergistic effect of the top of the disk moving toward the center of the disk, contact between the upper single disk DU and the liquid film 18 occurs from the innermost periphery. Here, since the disk receiving table 2 continues to rise at a low speed, and the liquid contact occurs sequentially from the innermost peripheral portion, the liquid can be contacted while removing the air outward, and the liquid film 18 The generation of bubbles can be prevented.

The pressure difference between the pressure in the inner space 19 and the pressure in the outer space, which is the atmospheric pressure, only needs to move the top of the liquid film 18. There is. Although this pressure difference is determined by the viscosity of the adhesive used, an adhesive having a viscosity of 500 cP or less is often used. At this time, the pressure difference is set within a range not exceeding 30 kPa. However, when the liquid film 18 is ejected thinly or when the adhesive used has a higher viscosity, the value may be set to a value outside this range.

It is also important here that the upper single-plate disk DU is sucked by the elastic suction pad 7 made of resin. That is, since the pressure difference is a small value, the force for generating the inclination is weak, and in order to preferably generate the inclination, it is important that the upper single-plate disk DU is held by a holding method that is easily bent.

The vacuum operation of the third vacuum system is stopped at the moment when the first liquid contact occurs, or immediately before or immediately after the first liquid contact. That is, the third vacuum system is released to the atmospheric pressure.

FIG. 3C shows a state in which the liquid contact has been completed. Here, the disk receiving stand 2 is stopped and the claws 3
Opens to grip the lower single-plate disk DL, the second vacuum system is stopped, and released to atmospheric pressure.

Thereafter, the disk receiving table 2 is lowered. As a result, the disk holding unit 1 holds the upper single disk DU and the lower single disk DL in an overlapping manner. As described above, at this time, the liquid film 18 without air bubbles is sandwiched between the upper single disk DU and the lower single disk DL.

Thereafter, a transfer mechanism Q1 (not shown)
Is started, the discs are sent to a spinner (not shown), and a process of spreading the adhesive to a predetermined area is performed. At this stage, no air bubbles are contained in the adhesive layer sandwiched between the two single-plate disks, so that the spin condition can be set to an optimum setting for uniform film thickness.

Next, details of the operation of the present embodiment will be described.

FIG. 4 is an enlarged view of the cross section of the liquid contact portion, and the right side of the paper is the center of the disk. FIG.
FIG. 3A corresponds to FIG. 3A, and shows a state in which the lower single-plate disk DL is lifted by the disk receiving table 2 (not shown) and starts to rise. Hereinafter, from FIG. 4 (b) to FIG. 4 (d) through FIG. 4 (c), the lower single-plate disk DL keeps rising.

FIG. 4B shows a state immediately before the liquid film 18 comes into contact with the upper single-plate disk DU. Here, the third vacuum system is operating. However, since there is a gap between the upper single disk DU and the liquid film 18, the inner space 1 is
9, the pressure in the inner space 19 has not decreased so much, and the upper single disk DU has almost no inclination.

FIG. 4C shows the moment when the upper single-plate disk DU comes into contact with the liquid film 18. FIGS. 4B and 4C
Between the upper single disk DU and the liquid film 18
The gap between them gradually narrows. Accordingly, the flow rate of the air flow decreases, and the pressure of the inner space 19 decreases,
The central portion of the upper single disk DU is pulled downward, and an inclination starts. Further, although the flow rate of the airflow decreases, the gap becomes narrower, so that the flow velocity of the airflow increases. This and inside space 19
As a result, the top of the liquid film 18 is pulled toward the center of the disk. Eventually, the top of the liquid film 18 and the upper single disk DU come into contact with each other, and FIG. 4C shows this state.

Since the pressure in the inner space 19 needs to be reduced until the moment of liquid contact, the third vacuum system is often stopped immediately before liquid contact. This is because a time delay that occurs when the third vacuum system returns to the atmospheric pressure is estimated in advance. Therefore, before the upper single disk DU contacts the liquid film 18, the evacuation system can be closed earlier by a time not exceeding 2 seconds. here,
Depending on the properties of the adhesive used, it may be better to keep the inner space 19 at a low pressure for a while after the contact with the liquid, in which case the third vacuum is applied immediately or immediately after the contact with the liquid. The system will be stopped.

Incidentally, the inclination of the upper single-plate disk DL shown in FIG. 4C is as small as about 2 ° or less.
However, the effect of pulling the top of the liquid film 18 toward the center of the disk is sufficiently effective. If the inclination is increased here, distortion remains in the upper single disk DL even after the two single disks are stacked, and the adhesive disk is likely to be defective.

FIG. 4D shows a state in which the liquid contact portion is spreading over the entire liquid film 18. Here, the liquid contact occurs from the radially inner peripheral side to the outer peripheral side of the disc, and the liquid contact proceeds while removing air outward, so that a liquid film without bubbles between the upper and lower two single-plate discs Can be made.

FIG. 5 is a perspective view of a lower portion of the liquid film 18 on the lower single-plate disk DL when viewed downward from a viewpoint.
FIG. 8 is a diagram sequentially showing a change in a liquid contact state, and corresponds to FIG. 8 in a conventional example.

FIG. 5A shows the moment when the liquid film 18 comes into contact with the upper single-plate disk DU, and corresponds to FIG. 4C. Here, the liquid contact part 20 is the innermost peripheral part of the liquid film 18.

FIG. 5B shows a state where the liquid contact is progressing, and corresponds to FIG. 4D. Here, the liquid contact portion 20 spreads in a substantially uniform state in the outward direction.

Hereinafter, the state shown in FIG.
The liquid contact is completed in the state of (d).

5A to 5D, it can be seen that the liquid contact occurs from the innermost peripheral portion of the liquid film 18 and proceeds in the outward radiation direction. Further, since the contact of the liquid is almost uniform, the contact of the liquid proceeds while removing the air outward, so that no bubbles enter the liquid film 18 when the liquid contact is completed.

In the above-described embodiment, the description has been made on the assumption that the processing in each step is performed in the atmosphere. However, the processing need not always be performed in the atmosphere of the atmospheric pressure. Even if the process is performed in an inert atmosphere such as nitrogen gas, the process can be performed in the same manner as described above, and the same effect can be obtained.

[0057]

Since the present invention has the above-described features, it is possible to provide an optical disk bonding method and apparatus capable of forming an adhesive layer having a uniform film thickness without air bubbles.

[Brief description of the drawings]

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

FIG. 2 is a view showing the appearance of the embodiment shown in FIG.

FIG. 3 is a diagram for explaining the operation of the embodiment shown in FIG. 1;

FIG. 4 is a diagram for explaining the operation of the embodiment shown in FIG. 1;

FIG. 5 is a diagram for explaining the operation of the embodiment shown in FIG. 1;

FIG. 6 is a view showing an example of a conventional bonding apparatus.

FIG. 7 is a diagram showing a part of the conventional bonding apparatus shown in FIG.

FIG. 8 is a diagram for explaining a problem of the conventional example shown in FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disk holding part 2 ... Disk receiving stand 3 ... Claw 4 ... Air cylinder 5 ... Suction head 6 ... Metal fittings 7 ... Suction pad 8 ... 1st vacuum piping joint 9 ... 1st vacuum piping 10 ... 1st vacuum hole DESCRIPTION OF SYMBOLS 11 ... Center hole 12 ... Protrusion 13 ... Notch 14 ... 2nd vacuum passage 15 ... 3rd vacuum passage 16 ... 3rd vacuum piping joint 17 ... 3rd vacuum piping 18 ... Adhesive liquid film 19 ... Upper unit A space surrounded by the respective adhesive surfaces of the plate disk and the lower single disk and the liquid film 20: liquid contact part 30: optical disk bonding device 31: discharge unit turntable 32: transport turntable 33: curing unit turntable 34: ultraviolet light Irradiation device 35 ... Light shielding cover 36 ... Disk holding part 37 ... Disk holder 38 ... Suction head 39 ... Claw 40 ... Air cylinder 41 ... Projection 42 ... Notch 43 ... Liquid film of adhesive 44 ... Liquid contact part 45: air bubble DU: upper single disk DL: lower single disk DD: uncured close contact disk DB: adhesive disk N: adhesive discharge nozzle Q1: transfer mechanism R1: transfer mechanism R2: transfer mechanism P1, P2, P3, P4, P5, P6, P7, P8, P
9, P10: code indicating the disk position in the optical disk bonding apparatus

Claims (14)

[Claims] 1. A method for laminating two single-plate disks using a liquid adhesive to form one bonded disk, wherein the lower side of the two single-plate disks is The adhesive is discharged in an annular shape on the surface of the veneer disk, and the two veneer disks are brought close to each other with the upper veneer disk held in the vicinity of its outer periphery. Before the veneer disk contacts the annular adhesive on the lower veneer disk surface, the upper veneer disk surface and the lower veneer disk surface and the inner space surrounded by the annular adhesive An optical disk laminating method, wherein the pressure is made lower than the pressure of the outer space, and in this state, the upper single disk and the annular adhesive on the lower single disk are brought into contact with each other. 2. The optical disk bonding method according to claim 1, wherein the inner space surrounded by the upper single disk surface, the lower single disk surface, and an annular adhesive is vacuum-sucked. 3. When the inside of the inner space surrounded by the upper single disk surface, the lower single disk surface and the annular adhesive is sucked in vacuum, the lower single disk is held at a substantially constant low speed. 3. The method according to claim 2, wherein the optical disk is raised. 4. The optical disk bonding method according to claim 1, wherein the upper single-plate disk is held by vacuum suction using an elastic suction tool. 5. The method according to claim 1, wherein the lower single-plate disk is vacuum-adsorbed from at least the adhesive discharge range or the periphery thereof from below. Optical disc bonding method. 6. The pressure in the inner space surrounded by the upper single disk surface, the lower single disk surface, and the annular adhesive is set to be lower than the pressure of the outer space by 30 kPa or less. The optical disc bonding method according to any one of claims 1 to 5, characterized in that: 7. When lowering the pressure in the inner space surrounded by the upper veneer disk surface, the lower veneer disk surface, and the annular adhesive, as compared with the outer space, the upper veneer disk is driven by the upper veneer disk. 7. The optical disc bonding method according to claim 1, wherein the vacuum exhaust system is closed earlier by a time not exceeding 2 seconds before coming into contact with the annular adhesive. 8. The method according to claim 1, wherein after the upper veneer disk is brought into contact with the annular adhesive, the two veneer disks are rotated to spread the adhesive to a predetermined area. An optical disk bonding method according to claim 7. 9. The method according to claim 1, wherein the adhesive used is an ultraviolet curable adhesive, and the adhesive is cured by irradiating with ultraviolet light after spreading to a predetermined area. 3. The method for bonding optical disks according to 1. 10. An optical disk bonding apparatus for bonding two single-plate disks using a liquid adhesive to form one bonded disk, wherein a lower side of the two single-plate disks is provided. A disk receiving table for receiving a single disk, an adhesive discharging means for discharging an adhesive in a ring shape onto the surface of the lower single disk, and an outer periphery of an upper single disk of the two single disks Holding means for holding the vicinity, and vacuum suction means for suctioning an inner space surrounded by the upper single-plate surface, the lower single-plate surface, and an annular adhesive; and a pressure in the inner space. An optical disk bonding apparatus, wherein the upper single disk and the annular adhesive on the lower single disk are brought into contact with each other in a state where the pressure is lower than the pressure of the outer space. 11. The optical disk bonding apparatus according to claim 10, wherein the upper single-plate disk is suction-held by a vacuum suction tool made of an elastic body. 12. The disk receiving table is provided with a vacuum suction mechanism, and the vacuum suction mechanism vacuum-adsorbs the discharge range of the adhesive on the surface of the lower single-plate disk or its periphery from the lower side. The optical disc bonding apparatus according to claim 10 or 11, wherein 13. A spinner for rotating the two veneer discs to spread the adhesive to a predetermined area after the upper veneer disc is brought into contact with an annular adhesive. An optical disc bonding apparatus according to any one of claims 10 to 12. 14. An adhesive used is an ultraviolet curable adhesive, and an ultraviolet irradiation device for irradiating and curing ultraviolet rays after the adhesive spreads to a predetermined area is provided. An optical disc bonding apparatus according to any one of claims 13 to 13.