JP3338782B2 - Optical disk medium and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk medium and a method of manufacturing the same, and more particularly, to a reflection type optical disk medium in which two optical disk substrates are bonded and a method of manufacturing the same.

[0002]

2. Description of the Related Art Among bonded optical disk media used for DVDs and the like, a single-sided, single-layered type that reads information from only one side is a data recording disk on which information data is recorded and a dummy disk without data. And are bonded together. In such an optical disc,
A label is formed on a dummy disk having no normal data. As a method of forming the label, there is a method of forming a visually recognizable image using the same method as that of exposing a data recording disk to a dummy disk using an optical disk exposure device, in addition to a printing method. .

An example of a method of forming a label on an optical disk medium by such exposure is disclosed in Japanese Patent Laid-Open No. 10-1181.
No. 4 discloses this. According to this method, after converting a character or an image composed of XY information into r-θ information, pits are formed in a portion other than the portion corresponding to the character or figure by using an optical disk exposure apparatus used for exposing an optical disk data signal. By forming them, regions where the intensity or the diffraction angle of the reflected diffracted light is different are formed to form a visually recognizable label.

As another method of forming such a label on an optical disk medium, a method of forming an image pattern to be a label by etching a stamper in which pits or grooves serving as dummy are formed is disclosed in Japanese Patent Application Laid-Open No. Hei 8 (1996) -108.
-287525.

[0005]

However, these label forming methods require a process of converting XY information into r-θ information, which is not included in a normal optical disk manufacturing process, and an etching process. There is a problem that the manufacturing process becomes complicated. In addition, since it is necessary to prepare an information conversion device and an etching device that are specially designed, there is also a problem that the production cost of the optical disk increases.

[0006] In view of such a problem, an object of the present invention is to provide an optical disk medium in which a disk label by exposure is easily formed at low cost and a method for manufacturing the same.

[0007]

[Means for Solving the Problems]

According to the method of manufacturing an optical disk medium of the present invention, a step of exposing a groove or a pit pattern after applying a photoresist to a predetermined area of the optical disk medium, and further applying a label to the area where the groove or the pit pattern is exposed are performed. Exposing an image to be exposed. The image here is a video of a character, a drawing, a pattern pattern, or a photograph that can be visually recognized. In this way, by further exposing a desired image to the area where the groove or pit pattern has been exposed so that the brightness of the groove or pit pattern forming area is different from that of the label image exposure area, it can be visually confirmed. An image (label) can be easily formed.

The step of exposing an image to be a label can be realized by placing a mask on which an image is formed on the optical disk medium and irradiating an exposure light source through the mask. In this case, the mask on which the image is formed includes a light-shielding portion that blocks light emitted from the exposure light source, and a transmissive portion that transmits light emitted from the exposure light source and / or a semi-transmissive portion that partially transmits light. With this arrangement, a relatively complicated drawing or the like can be formed as a label.

The step of exposing the image to be a label can also be obtained by projecting the image formed on a photographic film onto the optical disk medium using a projector.

Also, in the optical disk medium according to the present invention, a groove or pit forming region in which a groove or pit is formed in a region where a photoresist is coated on a label forming surface, and a region where the photoresist is coated are locally formed. A mirror region and / or a semi-mirror region obtained by exposure, wherein the groove or pit forming region and the mirror surface region and / or the semi-mirror region define an image which can be visually recognized as a whole. And

Further, it is preferable that the optical disk medium is formed by laminating a data disk on which data is recorded and a dummy disk having no data, and the image is formed on the dummy disk side. When a label is formed on a dummy disk, the label formation surface can be made larger than when a label is formed on a part of the data disk other than the data recording area, and the label can be designed freely. Can be.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 3 are views showing a first embodiment of a method for manufacturing an optical disk medium according to the present invention. In the first embodiment, in a single-sided, single-layer DVD in which a data disk on which information is recorded and a dummy disk having no information are bonded, a label is formed by exposing the dummy disk using a mask. I am trying to do it.

First, as shown in FIG. 1, a photoresist is uniformly applied to a disk-shaped glass substrate whose surface is polished to be smooth, thereby producing an optical disk master 1. An optical disk exposure device (not shown) is provided in a predetermined area of the optical disk master 1.
Is used to form a groove or pit exposure region 2. The groove or pit exposure region 2 can be formed in an arbitrary region of the optical disk master 1, and its area can be arbitrarily determined.

On the other hand, a mask 3 on which an image serving as a label design of the optical disc master 1 is formed is prepared. FIG. 2 is a view showing a mask 3 used in the present embodiment.
Is formed by forming an image on a colorless and transparent film sheet with a light-shielding ink or a metal thin film. Mask 3
Is composed of a light shielding part 4 and a transmission part 5, and in FIG.
A portion such as a character or drawing serving as a label is defined as a transparent portion 5, and other shaded portions are defined as a light shielding portion 4.

Next, as shown in FIG. 3, a mask 3 is placed on an optical disk master 1 on which a groove or pit exposure area 2 is formed, and a photoresist on the optical disk master 1 is passed through the mask 3 using a light source 6. Is exposed. The light source 6 has a wavelength and intensity capable of exposing the photoresist. Thereby, the photoresist under the transmission part 5 of the mask 3 is newly exposed, and an image corresponding to the transmission part 5 is exposed.

After these steps are completed, the mask 3 is removed, and the photoresist on the optical disk master 1 is developed to form an exposure pattern. As shown in FIG. 2 ′ and a mirror portion (image) 5 ′ are formed. The groove or pit region 2 ′ corresponding to the light-shielding portion 4 of the mask 3 shines rainbow-colored due to the diffraction of light, while the portion 5 ′ corresponding to the transmission portion 5 of the mask 3 is recognized as having a low brightness as a mirror surface. The whole can be visually confirmed as an image.

Next, using a general optical disk manufacturing process, a stamper is created from the optical disk master 1 created as described above, an optical disk medium is created by injection molding, a reflective film is formed, and data prepared separately. By bonding the optical disk medium to the disk, an optical disk medium in which a label is easily formed at low cost on the dummy disk side is completed.

In the mask 3 used in this embodiment, the image portion is formed as the transmissive portion 5 and the remaining portion is formed as the light shielding portion 4. On the other hand, the portion left as the background is formed as the transmissive portion, and the image portion is formed. Only the light shielding portion may be used. When a halftone is required according to the design of the label, a semi-transmissive portion is formed on the mask 3. In this case, when a plurality of types of halftones having different luminances are required, two or more types of semi-transmission portions having different transmittances may be formed on the mask 3. Further, in this embodiment, after the groove or pit exposure area 2 is formed on the optical disk master on which the photoresist is applied, the image is exposed by the mask 3, but the order of these steps may be reversed. .

Next, a method for manufacturing an optical disk medium according to a second embodiment of the present invention will be described with reference to FIGS. 1, 4 and 5. This embodiment will also be described by taking as an example a case where a label is formed on the dummy disk side by exposure in a bonding type single-sided single-layer DVD. First, as shown in FIG. 1, a groove or pit exposure area 2 is formed on an optical disk master 1. That is, a groove or pit exposure region 2 is formed on an optical disk master 1 in which a photoresist is uniformly coated on a disk glass substrate polished smoothly, using an optical disk exposure apparatus (not shown).

Next, as shown in FIG. 5, an image is projected onto the groove or pit exposure area 2 using a projector 7. The projector 7 is loaded with a negative in which a predetermined image (label image) is formed on a photographic film in advance. The projector 7 includes a light source having a wavelength and intensity capable of exposing the photoresist. The projector 7 and the optical disk master 1 are arranged so as to face each other, and the projected image is enlarged or reduced as necessary, and the entire or a part of the groove or pit exposure area 2 formed on the optical disk master is exposed. I do. As a result, a portion corresponding to the photoresist image in the groove or pit formation region 2 is newly exposed, and the negatively formed image is exposed on the optical disk master 1.

After these steps are completed, the photoresist on the optical disk master 1 is developed to form an exposure pattern. As shown in FIG. 4, the groove or pit formation region 2 'and the mirror surface are formed on the optical disk master 1. (image)
5 'is formed. The groove or pit area 2 'shines iridescent due to the diffraction of light, and the part 5' newly exposed as an image becomes almost specular, and the brightness is recognized as being low. Therefore, the entire image must be visually confirmed as an image. Can be. Thereafter, similarly to the first embodiment, an optical disk medium is completed using a conventional optical disk manufacturing process. In this embodiment, as in the case of the first embodiment, the step of forming the groove or pit exposure area 2 on the optical disk master coated with the photoresist, and the step of forming the mask 3
The order of the steps of exposing the image may be reversed.

In each of the embodiments described above, a case is described in which a label is formed on the dummy disk side in a single-sided, single-layer type DVD, but the scope of the present invention is limited to this type of optical disk medium. Not something. For example, in a double-sided data disk type optical disk medium of a single-sided dual-layer type in which reading is performed from only one side, a label may be formed in a range other than the groove or pit exposure area of the information data of one data disk. Thus, a label can be formed easily and cheaply by using the method of the present invention.

[0024]

As described above in detail, in the method of manufacturing an optical disk medium according to the present invention, after forming a groove or pit formation region, a mask or an image is formed on the groove or pit formation region. By exposing the photographic film to a new image using a projector,
A disc label is formed. Therefore,
A label using an exposure pattern can be formed inexpensively and easily without performing a complicated process such as a process of converting XY information into r-θ information or a complicated process such as etching.

[Brief description of the drawings]

FIG. 1 is a diagram showing a master optical disc having grooves or pits exposed to light used in the method for manufacturing an optical disc medium of the present invention.

FIG. 2 is a diagram illustrating an example of a mask used in the present invention.

FIG. 3 is a perspective view showing a state where the mask shown in FIG. 2 is placed on the optical disk master shown in FIG. 1 and exposed.

FIG. 4 is a diagram showing an optical disc master 1 on which an image is exposed after groove or pit exposure.

FIG. 5 is a diagram showing a state where an image is projected on the master optical disc shown in FIG. 1 by a projector.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 optical disk master 2, 2 'groove or pit exposure area 3 mask 4 light-shielding part 5 transmission part 5' mirror surface part 6 exposure light source 7 projector 8 projected image

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazuhiko Asahara 5-7-1 Shiba, Minato-ku, Tokyo NEC Corporation (56) References JP-A-8-287525 (JP, A) JP-A-10 -106052 (JP, A) JP-A-10-251536 (JP, A) Patent 2614140 (JP, B2) JP-A-6-508712 (JP, A)

Claims (7)

(57) [Claims] A step of applying a photoresist to a predetermined area of the master optical disc; a first exposing step of exposing a groove or a pit pattern to the area to which the photoresist has been applied using an optical disc exposure apparatus; A second exposure step of further exposing a region exposed to the pit pattern through a mask on which an image serving as a label has been formed, a method for manufacturing an optical disc master. 2. A mask used in the second exposure step, wherein a mask that blocks light emitted from the exposure light source, a transmission portion that transmits light emitted from the exposure light source, and / or 2. The method of manufacturing an optical disc master according to claim 1, further comprising a semi-transmissive portion that transmits a part thereof. 3. In the second exposure step, an image formed on a photographic film is used as the mask, and light is projected onto the optical disk master using a projector to expose an image to be a label. A method for manufacturing the optical disk master according to claim 1. 4. The image according to claim 1, wherein the image is a visually recognizable character,
4. The method of manufacturing an optical disc master according to claim 1, wherein the method is an image of a drawing, a pattern, or a photograph. 5. An optical disc master having a label surface formed by the method according to any one of claims 1 to 4. 6. were prepared using the master optical disc was prepared by the method described in any one of claims 1 to 4 de
Disc and manufacturing method of the optical disk medium, characterized in that to match Ri stuck a data disk which is prepared separately from the the optical disk medium. 7. Di created using the optical disc master produced by the method according to any one of claims 1 to 4
Disk and optical disk medium characterized in that a laminated Ri adhered and data disks prepared separately from that of the optical disk medium.