JP2002367245A - Method and apparatus for manufacturing optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely hold and bond a recording layer and a transparent layer even if the transparent layer is thin. SOLUTION: When the recording layer 2 is formed atop a base 1, the outer peripheral part of the transparent layer 3 is held to a flat shape by a transparent layer holding mechanism 5 and the held transparent layer 3 is superposed on the recording layer 2, by which the transparent layer 3 is bonded onto the recording layer 2 across an adhesive layer 4. In such a case, the transparent layer 3 is held at over circumferential four points by an outer peripheral holding section 6 of the transparent layer holding mechanism 5, by which the transparent layer 3 is held to a plane shape, by which the transparent layer is bonded onto the recording layer 2 without deformation in spite of the film thickness of about 0.1 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical disk and a manufacturing apparatus for implementing the method, and more particularly, to a method for irradiating a signal recording layer with a laser beam through a light transmitting layer. The present invention relates to a method and apparatus for manufacturing an optical disk suitable for recording or reproducing information.

[0002]

2. Description of the Related Art Various technologies have been proposed for an optical disk for achieving a higher density and a larger capacity, such as the technology described in Japanese Patent Application Laid-Open No. H8-235638. In this prior art, in order to increase the NA (numerical aperture) of the objective lens for the reproduction pickup and to secure a tilt margin that is reduced by increasing the NA, the thickness of the transparent layer (light transmitting layer) is set to 0.5 mm or less. In particular, it is formed to a thickness of about 0.1 mm, whereby the N
It is disclosed that even if A is large, the occurrence of deterioration of a reproduction signal due to coma aberration is suppressed, and high-density reproduction is enabled.

In this case, in the step of forming the transparent layer,
It is formed by applying a UV resin, which is an ultraviolet curable resin, by a spin coat method and curing the resin by UV. Alternatively, it is disclosed that a transparent layer made of a polycarbonate film or a glass plate can be formed by bonding to a reflection film using a UV resin.

[0004]

However, in the prior art described above, an ultraviolet curable resin is applied by spin coating and cured to form a transparent layer (light transmitting layer) having a thickness of about 0.1 mm. In particular, in the case of a donut shape having a hole at the center, such as an optical disc, a large difference is caused by the centrifugal force in the film thickness of the inner and outer peripheries due to the rotation around the central axis, and the ultraviolet light is generated on the outer peripheral side. There is an essential problem that the cured resin rises and it is difficult to obtain a uniform thickness.

In order to solve this problem, in order to form a uniform film thickness, it is easy to attach a light transmitting layer to a film of polycarbonate or the like via an adhesive layer. However, as described above, an extremely thin one having a thickness of about 0.1 mm cannot maintain its own shape, and is therefore difficult to handle. That is, even if the light transmitting layer of about 0.1 mm is to be held by vacuum tweezers or the like generally used, the outer peripheral side of the light transmitting layer is sagged and deformed, so that the light transmitting layer cannot be bonded well. There is.

The present invention has been made in view of the above-mentioned problems of the prior art,
It is an object of the present invention to provide a method of manufacturing an optical disk capable of securely holding and bonding even if the thickness of a transparent layer is extremely thin, and to provide an optical disk manufacturing apparatus capable of appropriately performing the above method. Make it an issue.

[0007]

According to the present invention, a recording layer is formed on the surface of a support having guide grooves or pits, and a transparent layer is laminated on the recording layer. When the recording layer is formed on the surface of the support, the transparent layer made of one film is held in a substantially planar shape, and the held transparent layer is placed on the recording layer by an adhesive layer. After stacking through
The method is characterized in that the transparent layer is bonded to the recording layer via the adhesive layer by curing the adhesive layer. Further, the transparent layer,
At least four peripheral portions of the outer peripheral portion are adsorbed by the outer peripheral holding portion and held in a substantially planar shape. Furthermore, the transparent layer is characterized in that at least four peripheral portions of the outer peripheral portion are mounted by an outer peripheral holding portion and held in a substantially planar shape. The adhesive layer is made of an ultraviolet curable resin applied on the inner peripheral side of the recording layer, and is in a state where a transparent layer is overlaid on the recording layer and the adhesive layer. When the entire support is rotated about an axis, the support extends over the entire surface between the transparent layer and the recording layer. The transparent layer has a thickness of about 0.1 mm. Further, according to the present invention, in an optical disc manufacturing apparatus in which a transparent layer is laminated on a recording layer formed on the surface of a support having guide grooves or pits, the transparent layer is held in a substantially planar shape, and A transparent layer holding mechanism for releasing the holding is provided. The transparent layer holding mechanism has an outer circumferential holding portion that sucks and holds the outer circumferential portion of the transparent layer at at least four places around the transparent layer. In addition, the transparent layer holding mechanism includes a ring-shaped fixing portion in which each of the outer peripheral holding portions is attached at the same radius position on the same plane at predetermined intervals, and a vacuum suction from each of the outer peripheral holding portions through the fixing portion. And a pressure reducing means for reducing the pressure. Further, the transparent layer holding mechanism, at least four actuators arranged at predetermined intervals at the same radial position on the same plane, mounted on each actuator so as to be able to advance and retreat along the radial direction of the transparent layer,
In addition, a pin-shaped outer peripheral holding portion for mounting the outer peripheral portion of the transparent layer at four locations around the transparent layer and holding it in a substantially planar shape is provided. Still further, a bent mounting piece is provided at a tip end of the pin-shaped outer peripheral holding portion.

[0008]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. 1 to 3 show one embodiment of the method of the present invention. According to the method of the present invention, when the recording layer 2 is formed on the upper surface of the support 1 as shown in FIG. 1, the outer peripheral portion of the transparent layer 3 is held in a planar shape by the transparent layer holding mechanism 5 shown in FIG. By holding the transparent layer 3 on the recording layer 2, as shown in FIG.
The transparent layer 3 is bonded to the recording layer 2 via the adhesive layer 4.

In this case, the transparent layer 3 is maintained in a planar shape by the outer peripheral portion being held at four or more peripheral positions by the outer peripheral holding portion 6 of the transparent layer holding mechanism 5, whereby the thickness is about 0.1 mm. Even if the film thickness is large, it is bonded onto the recording layer 2 without deformation. Transparent layer 3 handled in this example
Is a polycarbonate film having a thickness of about 0.1 mm wound, for example, in a roll shape.
And an outer diameter of 118 m to match the size of the support 1
It is cut and formed into a donut shape having a diameter of 18 mm and an inner diameter of 18 mm.

[0010] More specifically, first, the substrate as the support 1 is made of polycarbonate and has a thickness of 1.2 m.
m, an outer diameter of 120 mm, and an inner diameter of 15 mm.
6 μm (0.3 μm in land / group recording pitch)
Guide groove 1a is formed.

On the support 1, as shown in FIG.
Ag alloy reflective film, a protective film made of ZnS-SiO _2, G
recording film made of e ₂ Sb ₂ Te ₅ , ZnS—SiO ₂ /
By dielectric layer composed of three layers of SiO ₂ / ZnS-SiO ₂ is deposited by sequentially sputtering, the recording layer 2 having a desired thickness is formed.

Thus, the recording layer 2 is formed on the upper surface of the support 1.
Is formed, the transparent layer 3 having a thickness of 0.1 mm is provided thereon. That is, an ultraviolet curable resin having a viscosity of 120 mPa · s is applied as an adhesive layer 4 on the inner peripheral side of the recording layer 2 in advance. In this case, the applied ultraviolet curable resin is applied to the recording layer 2 within a range of a radius of about 28 mm.

Next, the transparent layer 3 is sucked by the outer peripheral holding portion 6 of the transparent layer holding mechanism 5 and held as shown in FIG. 1, and when the transparent layer 3 is positioned on the recording layer 2, the transparent layer 3 When the holding mechanism 5 releases the holding of the transparent layer 3, the transparent layer 3 is placed on the recording layer 2 and the ultraviolet curable resin.
Layer.

After that, the support 1 having the recording layer 2 and the ultraviolet curable resin as the transparent layer 3 and the adhesive layer 4 is placed at a rate of 36 / min.
By rotating the shaft around the axis at 00 rotation for 90 seconds, the ultraviolet curable resin is spread between the transparent layer 3 and the recording layer 2 and spread. Thereafter, ultraviolet rays are irradiated (not shown) from the surface side of the transparent layer 3 to cure the ultraviolet curable resin, so that the transparent layer 3 is formed of an adhesive layer 4 made of an ultraviolet curable resin.
2 is attached to the recording layer 2 through
The optical disk 10 is formed as shown in FIG.

As shown in FIG. 3, the transparent layer holding mechanism 5 comprises four outer circumferential holding portions 6 for holding the outer circumferential portion of the transparent layer 3 by sucking the outer circumferential portion at four locations, and each of the outer circumferential holding portions 6. It has a ring-shaped fixing portion 7 to which 6 is attached at 90 ° intervals along the circumferential direction, and decompression means 8 connected to the fixing portion 7 via a communication portion 9.

The outer peripheral holding portion 6 has a cylindrical shape with its lower end opened and its upper end closed. Fixed part 7
The pipe member is formed in a ring shape having an outer diameter slightly smaller than that of the transparent layer 3, and the outer peripheral holding portions 6 are attached to the bottom at intervals of 90 degrees so that the outer peripheral holding portions 6 are flush with each other. At the same radial position. Although not shown in detail, the decompression means 8 is composed of a vacuum pump connected to the fixing part 7 via the communication part 9, and when driven, the communication part 9, the fixing part 7 and each outer peripheral holding part 6 are driven.
By suctioning from the lower end of the outer peripheral holding portion 6 through
The outer peripheral portion of the transparent layer 3 can be adsorbed to the lower end of each outer peripheral holding portion 6.

In other words, the transparent layer holding mechanism 5 holds the transparent layer 3 in a substantially flat state by the decompression means 8 causing each of the outer peripheral holding portions 6 to adsorb the outer peripheral portion of the transparent layer 3 at four locations around the transparent layer 3. The holding of the transparent layer 3 is released by stopping the driving of the pressure reducing means 8. If the suction force by the pressure reducing means 8 is large, the transparent layer 3 is as thin as about 0.1 mm and may be deformed. Therefore, it is needless to say that the magnitude of the suction force is appropriately adjusted. Needless to say, the outer peripheral holding portion 6 is made of a member that is not deformed by the suction force.

Therefore, when the ultraviolet curable resin as the adhesive layer 4 is applied to the recording layer 2 on the support 1, the transparent layer holding mechanism 5 attaches the transparent layer 3 to the lower end of the outer peripheral holding section 6 by suction. By holding it and positioning it on the recording layer 2 and the ultraviolet curable resin and releasing its support, it is bonded to the recording layer 2 via the ultraviolet curable resin. When the transparent layer 3 is overlaid on the recording layer 2, the transparent layer holding mechanism 5 may be entirely moved in the direction of the recording layer 2 by means not shown, but the transparent layer 3 held by the transparent layer holding mechanism 5 may be moved. The recording layer 2 and the support 1 may be entirely moved in the direction.

In the embodiment of the present invention, as described above, the outer periphery holding portion 6 of the transparent layer holding mechanism 5 sucks the outer periphery of the transparent layer 3 to hold the transparent layer 3 in a planar shape. When the ultraviolet curable resin as the adhesive layer 4 is applied on the recording layer 2 formed on the upper surface of the transparent layer 3, the outer peripheral holding portion 6 of the transparent layer holding mechanism 5 releases the holding of the transparent layer 3 so that the transparent layer 3 is released.
Is superimposed on the ultraviolet curable resin and the recording layer 2.

Thereafter, the support 1 having the transparent layer 3, the ultraviolet curable resin, and the recording layer 2 is rotated to spread the ultraviolet curable resin over the entire surface between the recording layer 2 and the transparent layer 3, and then spread the ultraviolet light. When the ultraviolet curable resin is cured by irradiating the recording layer 2, the transparent layer 3 is bonded to the recording layer 2 via the adhesive layer 4 of the cured ultraviolet curable resin, whereby the optical disc 10 is manufactured as shown in FIG. You.

As described above, when the transparent layer 3 is formed on the recording layer 2 provided on the upper surface of the support 1, the outer peripheral portion of the transparent layer 3 is held by the transparent layer holding mechanism 5 at four places around it. Even if the transparent layer 3 is as thin as about 0.1 mm, the transparent layer holding mechanism 5 can hold the transparent layer 3 in a substantially planar shape. Therefore, when the transparent layer 3 is overlaid on the recording layer 2 by releasing the holding of the transparent layer 3 by the transparent layer holding mechanism 5, the transparent layer 3 comes into close contact with the recording layer 2 without air bubbles or the like being mixed therein. Therefore, the thin transparent layer 3 can be properly handled, and can be securely bonded to the recording layer 2.

Even if air bubbles enter between the transparent layer 3 and the recording layer 2, the ultraviolet curable resin extends in the outer peripheral direction by rotation, and the air bubbles can be extruded in the outer peripheral direction. The recording layer 2 and the recording layer 2 can be surely brought into close contact with each other via the adhesive layer 4, and good bonding can be obtained.

Incidentally, in this example, the thickness of the optical disk was measured after curing the ultraviolet curing resin, and as a result, the radius 22
The thickness was 3 μm at a position of mm and 7 μm at a radius of 58 mm, and the difference in film thickness between the inner and outer circumferences of the optical disk was within 4 μm.
Further, in the circumferential direction of the optical disk, the film thickness variation including the transparent layer 3 was a very small value of about ± 1 μm, and it was confirmed that the lamination could be performed well.

Further, the transparent layer holding mechanism 5 includes an outer circumference holding portion 6.
Holds the transparent layer 3 in a substantially planar shape by sucking the outer peripheral portion of the transparent layer 3 by a pressure reducing means.
Even if the transparent layer 3 has a thickness of about a certain level, it can be accurately maintained in a planar shape. In addition, the transparent layer holding mechanism 5 includes a ring-shaped fixing portion 7 in which the outer peripheral holding portions 6 are arranged at equal intervals on the same plane at the same radius, and a decompression connected to the fixing portion 7 via the communication portion 9. Since the optical disk 10 is configured to include the means 8, the optical disk 10 can serve as a component of the manufacturing apparatus.

In order to confirm the effect of the transparent layer holding mechanism 5, as a comparative example 1, vacuum tweezers were used instead of the transparent layer holding mechanism 5, and the vacuum tweezers were used to measure the vicinity of the inner radius of the transparent layer near 12 mm. Was held in an annular shape, and the transparent layer was as thin as 0.1 mm, so that the transparent layer was deformed by vacuum tweezers and could not be held satisfactorily. Moreover, the pressure of the vacuum tweezers was lowered to adjust the transparent layer so that it did not deform.
Although the deformation of the holding portion could be suppressed, the outer peripheral portion of the transparent layer was sagged and deformed by its own weight, and the bonding could not be performed well.

FIGS. 4 and 5 show other embodiments of the transparent layer holding mechanism 5, respectively. The transparent layer holding mechanism 5 shown in FIG. 4 includes actuators 11 disposed at the same radial position on the same plane at an interval of 90 degrees, and mounted on rods of the respective actuators 11. And a pin-shaped outer peripheral holding portion 12 which mounts the portion at four locations around the holding portion and holds the portion in a substantially planar shape. In this case, as shown in FIG. 4B, each actuator 11 is attached to a ring-shaped fixing portion 14 via a support arm 13 so that the same radial position on the same plane in the outer peripheral direction of the transparent layer 3 is obtained. Are located in Therefore,
When the actuator 11 is driven, the pin-shaped outer peripheral holding portion 12 moves forward or backward to the outer peripheral portion along the radial direction of the transparent layer 3.

When the transparent layer 3 is pasted on the recording layer 2, each of the actuators 11 is driven, and the pin-shaped outer peripheral holding portion 12 is moved radially from the outer peripheral side with respect to the transparent layer 3 as the rod advances. The transparent layer 3 can be held in a substantially planar shape by mounting the outer peripheral portion of the transparent layer 3 from below four places around the transparent layer 3 at the distal end of the outer peripheral holding portion 12.

When the transparent layer 3 is held in a substantially planar shape in this way, after the transparent layer 3 is overlaid on the recording layer 2 via an ultraviolet curable resin, each actuator 11 is driven in reverse. The transparent layer 3 can be overlaid on the entire surface of the recording layer 2 by moving the pin-shaped outer peripheral holding portion 12 backward. In this case, in order to overlay the transparent layer 3 on the recording layer 2, the transparent layer holding mechanism 5 may be entirely moved in the direction of the recording layer 2 by means (not shown). 1 may be moved as a whole.

In order to confirm the effect of the transparent layer holding mechanism 5, as Comparative Example 2, the same component as that of the transparent layer holding mechanism 5 shown in FIG. When the bonding was carried out by disposing, the portion not held at the outer peripheral portion of the transparent layer was sagged by its own weight, and good bonding could not be performed. From this result, it is understood that it is desirable to hold the outer peripheral portion of the transparent layer 3 at four or more surrounding locations. However, although the larger the number of holding points, the more the deformation of the transparent layer 3 can be prevented, if the number is too large, the structure of the transparent layer holding mechanism 5 becomes complicated. It does not hinder the alignment.

The transparent layer holding mechanism 5 shown in FIG. 5 is basically the same as the transparent layer holding mechanism 5 shown in FIG. However, the difference from the transparent layer holding mechanism 5 shown in FIG. 4 is that the distal end of the pin-shaped outer periphery holding portion 12 is inclined obliquely downward and has a bent mounting piece 12a bent horizontally from the tip. I have. As described above, when the bent mounting piece 12a is provided at the tip of the pin-shaped outer peripheral holding portion 12, when the transparent layer 3 is held on the bent mounting piece 12a, the transparent layer 3
Can be fixed at that position, so that the transparent layer 3 can be prevented from shifting, not only can the transparent layer 3 be easily handled, but also the ultraviolet curable resin, the recording layer 2, and the like.
The alignment of the transparent layer 3 with respect to the support 1 can be performed even better.

In the illustrated embodiment, the transparent layer 3
Also, an example is shown in which the support 1 is made of polycarbonate. However, the present invention is not limited to this, and the material of the recording layer 2 is not limited to this example. Although the optical disk 10 in which the recording layer 2 and the transparent layer 3 are provided only on one side of the support 1 is shown, the present invention can be applied to a method and an apparatus for manufacturing a double-sided optical disk provided on both sides.

[0032]

As described above, according to the present invention,
When forming a transparent layer on the recording layer provided on the support,
The outer periphery of the transparent layer is held at four places around it, and the transparent layer is configured to be held in a substantially planar shape, so even if the transparent layer is extremely thin, the transparent layer can be properly handled, There is an effect that the recording layer can be securely bonded to the recording layer.

[Brief description of the drawings]

FIG. 1 is an explanatory view at the time of bonding a transparent layer, showing one embodiment of the method of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a transparent layer is laminated on a recording layer via an adhesive layer.

FIG. 3 is a plan view of a transparent layer holding mechanism showing one embodiment of an optical disk manufacturing apparatus for carrying out the method of the present invention (a).
And a side view (b).

FIG. 4 is a plan view (a) and a side view (b) of a transparent layer holding mechanism showing another embodiment of a method of manufacturing an optical disk for carrying out the method of the present invention.

FIG. 5 is a plan view (a) and a side view (b) of a transparent layer holding mechanism showing still another embodiment of the optical disk manufacturing apparatus for carrying out the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support 1a Guide groove 2 Recording layer 3 Transparent layer 4 Adhesive layer (ultraviolet curable resin) 5 Transparent layer holding mechanism 6 Peripheral holding part 7 Fixed part 8 Decompression means 9 Contact part 10 Optical disk 11 Actuator 12 Pin-shaped peripheral holding part 12a Folding mounting piece 13 Support arm 14 Fixed part

Claims (10)

[Claims] 1. A method for manufacturing an optical disk, comprising: forming a recording layer on a surface of a support having guide grooves or pits; and bonding a transparent layer on the recording layer, wherein the recording layer is formed on the surface of the support. When formed, the transparent layer made of a single film is held in a substantially planar shape, and the held transparent layer is overlaid on the recording layer via an adhesive layer. A method for manufacturing an optical disc, comprising: bonding a recording medium to a recording layer via an adhesive layer. 2. The method for manufacturing an optical disk according to claim 1, wherein the transparent layer is held in a substantially planar shape by adsorbing at least four peripheral portions of an outer peripheral portion by an outer peripheral holding portion. 3. The method for manufacturing an optical disk according to claim 1, wherein the transparent layer is held in a substantially planar shape by mounting at least four peripheral portions of an outer peripheral portion by an outer peripheral holding portion. 4. The adhesive layer is made of an ultraviolet curable resin applied on the inner peripheral side of the recording layer, and has a transparent layer on the recording layer and the adhesive layer. ,
4. The method for manufacturing an optical disk according to claim 1, wherein when the entire recording layer and the support are rotated about an axis, the recording layer and the support extend over the entire surface between the transparent layer and the recording layer. 5. The method according to claim 1, wherein the transparent layer has a thickness of about 0.1 mm. 6. An optical disk manufacturing apparatus comprising a transparent layer laminated on a recording layer formed on the surface of a support having guide grooves or pits, wherein the transparent layer is held in a substantially planar shape and held. An optical disc manufacturing apparatus, comprising: a transparent layer holding mechanism for canceling the optical disc. 7. The optical disk manufacturing apparatus according to claim 6, wherein the transparent layer holding mechanism has an outer peripheral holding portion that sucks and holds the outer peripheral portion of the transparent layer at at least four places around the transparent layer. 8. The transparent layer holding mechanism comprises: a ring-shaped fixing portion in which each of the outer peripheral holding portions is mounted at the same radial position on the same plane at predetermined intervals; and each of the outer peripheral holding portions through the fixing portion. 8. The apparatus for manufacturing an optical disk according to claim 7, further comprising a pressure reducing means for performing a vacuum suction. 9. The holding mechanism is provided with at least four actuators arranged at predetermined intervals at the same radial position on the same plane, and mounted on each of the actuators so as to be able to advance and retreat along the radial direction of the transparent layer, 7. The optical disk manufacturing apparatus according to claim 6, further comprising a pin-shaped outer peripheral holding portion that mounts the outer peripheral portion of the transparent layer at four places around the transparent layer and holds the outer surface in a substantially planar shape. 10. The optical disk manufacturing apparatus according to claim 9, wherein a bent mounting piece is provided at a tip end of the pin-shaped outer peripheral holding portion.