KR100200585B1 - Optical recording medium and its manufacturing method of the partial read only memory type - Google Patents

Abstract

The present invention relates to a partial reproduction-only optical recording medium and a method of manufacturing the same. The disk-shaped is formed on a substrate, a boundary region formed in a columnar shape on a predetermined position between the center and the outer periphery of the substrate, and a regeneration-only region formed on the substrate either on the outside or inside of the boundary region. In the partial reproduction-only optical recording medium including the recording / reproducing area formed on the substrate, unlike the conventional optical recording medium in which the recording layer is formed over the entire area of the substrate, the recording layer is not formed in the reproduction-only area. High reflectance, high reliability of playback signal

Description

Partial reproduction-only optical recording medium and method for manufacturing same

1 is a schematic cross-sectional view of a partial reproduction only optical recording medium conventionally used.

2 is a plan view of a partial reproduction-only optical recording medium according to an embodiment of the present invention.

3 is a cross-sectional view of the optical recording medium shown in FIG.

4 is shielding means for shielding the outer area of the substrate.

5 is a shielding means for shielding the inner region of the substrate.

* Explanation of symbols for the main parts of the drawing

1,11: substrate 2,2 ', 12, 12': protective film

3, 13: recording film 4, 14, 22: reflecting film

5, 15: recording / playback area 6, 16: playback-only area

17: boundary area

The present invention relates to a partial reproducing dedicated optical recording medium and a method of manufacturing the same. Specifically, a partial reproducing area is a reproducing only area in which signal reliability is greatly improved. Partial Read Only Memory (P-ROM) fluorescence recording medium and a method of manufacturing the same.

Currently, the most widely used recording medium is a magnetic recording medium, which utilizes the principle that information is recorded according to the magnetization direction of the magnetic material. Examples of such recording media include video tapes, audio tapes, floppy disks, and the like. However, these magnetic recording media have faced limitations in storing various types of information which are exploding with high informatization of society.

Accordingly, researches on recording media using a new recording and reproducing method have been conducted, and as a result, the era of optical recording media has come. Optical recording media are widely used for recording and reproducing sound and image information. The use is expanding rapidly.

In particular, as a large amount of software for controlling hardware as well as a computer operating system becomes large, recording media for storing them have been replaced by optical recording media such as CD-ROMs in polo disks and hard disks.

On the other hand, the optical recording medium is read only memory (ROM) type that reads only depending on whether it can be erased, write once read many (WORM) type, and erase that can be repeatedly erased and rewritten after recording. It is generally classified as (Erasable) type.

Among them, a reproduction-only type is used as a computer-related optical recording medium such as software storage. The use of such a recording medium requires another medium to store additional information generated by software. As a result, a hard disk or a floppy disk is used, and such a magnetic recording medium has a small storage capacity, and thus a need for a large storage medium has emerged. In addition, when the reproduction-only optical recording medium and the magnetic recording medium are used together, the inconvenience of having to replace the reproduction medium or the storage medium may frequently occur.

In order to solve the above disadvantages, there is a need for a partial reproduction-only optical recording medium in which some areas of the recording medium are dedicated to reproduction, and the remaining areas are made of a recordable area.

FIG. 1 is a schematic cross-sectional view of a P-ROM type optical recording medium used in the prior art, and is composed of a substrate 1, a protective film 2, 2 ', a recording film 3, and a reflective film 4. As shown in FIG. In particular, in the P-ROM type optical recording medium, a recording film 3 is formed over the entire surface of the substrate 1, and a part of the recording medium is used as the recording regeneration area 5, and the rest of the reproducing area 6 Is used.

As described above, the P-ROM type optical recording medium used in the prior art is characterized in that a multilayer film including a recording film is formed over all areas of the read-only area and the recording / reproducing area, although somewhat different.

However, such an optical recording medium has a problem in the reliability of the reproduction signal because the reflectance of the reproduction exclusive area is about 30% at maximum. In addition, in the CAV (Constant Angular Velocity) control method employed to increase the recording signal in the recordable area, the pre-pit is small compared to the outside, so that an error may occur during playback.

Accordingly, an object of the present invention is to provide a partial reproduction-only optical recording medium comprising a reproduction-only area and a region capable of reproduction and recording, and having a high reflectance of the reproduction-only area, thereby greatly improving the reliability of the reproduction signal.

In the present invention, to achieve the above object,

Disc-shaped substrates; A boundary region formed in a columnar shape on a predetermined position between the center of the substrate and the outer height; And

A partial reproduction-only optical recording medium is provided that includes a reproduction-only region formed on one of the substrates, either external or internal to the boundary region, and a recording / reproducing region, formed on the other substrate. .

Another object of the present invention is to provide a method for manufacturing a partial reproduction only optical recording medium having a high reflectance of a reproduction only area and greatly improving the reliability of the reproduction signal.

In this description, to achieve the above another object,

Manufacturing a circular substrate having a prepit formed in either an inner or outer region;

Shielding an area where the prepit is not formed, and then forming a reproducing area by forming a reflective film on the substrate on which the prepit is formed; And

Shielding the region where the prepit is formed, and then forming a recording / reproducing region by sequentially forming a protective film, a recording film, a protective film, and a reflective film on the substrate where the prepit is not formed. There is provided a method of manufacturing a partially reproduced optical recording medium.

That is, in the present invention, unlike the conventional optical recording medium in which the recording layer is formed over the entire area of the substrate, the recording layer is not formed in the reproduction-only area, so that a partial reproduction-only recording medium having high reflectance and improved reliability of the reproduction signal is provided. To provide

2 is a plan view of an optical recording medium only for partial reproduction according to an embodiment of the present invention, wherein the recording / reproducing area 15, the reproduction-only area 16, and the boundary area 17 formed between the two areas are shown. ). 3 is a cross-sectional view of the optical recording medium shown in FIG. 2, in which the group / reproducing region 15 includes the substrate 11, the protective film 12, the recording film 13, the protective film 12 ', and the chestnut. It includes a sand 14, and includes a regenerative electrophoretic region 16, a substrate 11 and a reflective film 22, and a boundary region 17 is formed therebetween to distinguish the two regions 15 and 16. .

As described above, the partial reproduction-only optical recording medium of the present invention has a structure in which the reproduction-only area and the recording / reproduction area are different from each other. In particular, since the reproduction-only area 16 has no recording film, the reflectance is very high. Therefore, there is an advantage that the reproduction characteristics of the recording are very excellent.

Hereinafter, the features of the present invention will be described in more detail through the manufacturing process of the optical recording medium.

In the present invention, the reproduction-only area can be formed in either the external area or the internal area of the recording medium, but will be described with reference to the case where the reproduction-only area is formed in the internal area.

First, the board | substrate with which the prepit was formed in the predetermined area inside is prepared. In this case, the organic substrate may be one having excellent thermal and mechanical properties and excellent light transmitting properties. Examples of the organic substrate include polycarbonate, amorphous polyolefin cellulose acetate, polyethylene terephthalate, and the like.

A reflective film is formed on the portion where the prepit is formed on the prepared substrate. In this case, it is preferable that the reflecting film is made of an aluminum layer and formed through the sputtering method.

In particular, according to the present invention, shielding means (FIG. 4) is used to selectively form only a regeneration-only area. That is, a shielding means as shown in FIG. 4 is attached between the sputtering apparatus and the substrate, and then a reproducing exclusive region is formed by forming a reflective film only in the portion where the prepit is formed through the sputtering process.

When the remnant remnant area is formed, a protective film, a recording film, a protective film, and a reflective film are sequentially formed on the outer area of the substrate while shielding the inner area of the substrate using the shielding means as shown in FIG. By forming the optical recording medium of the present invention, the optical recording medium of the present invention is manufactured. The regeneration-only area formed by such a process has good reproducibility with a reflectance of 90% or more.

On the other hand, in the optical recording medium of the present invention manufactured through the above process, the reproduction-only area and the recording / reproduction area are not clearly distinguished from each other, and the boundary area formed therebetween has a reflectance of 50 to 70%. As low as, compared to the play-only area. This border region can be used as a Standard Formatted Part (SFP). Therefore, the boundary region can not only function as a buffer but also have an inner standard format unit (Inner SFP) function of a conventional optical recording medium, so that there is no difference in capacity in comparison with the conventional optical recording medium.

Hereinafter, the features of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not necessarily limited thereto.

Example

A substrate made of a polycarbonate material having a track pitch of 0.85 μm and having prepits formed therein was prepared. A shielding device (FIG. 4) capable of covering the outer region of the prepared substrate was mounted between the substrate and the sputtering apparatus, and then an aluminum reflective film having a thickness of 1500 Å was formed through the sputtering process. Subsequently, the inner region of the substrate is covered by using a shielding device (FIG. 5) that can cover the inner region of the substrate, and then a sputtering method is used to protect the substrate on the substrate with a protective film of 200 Å thick, 200 Å thick and 600 Å on the substrate. The optical recording medium of the present invention was produced by sequentially forming a reflective film having a thickness. At this time, the material of the recording film target was TbFeCo alloy, and the material of the reflection film target was aluminum. In addition, the sputtering conditions were the initial vacuum degree of 3 × 10 ⁷ mbar, argon gas pressure 3mtorr, argon gas flow rate 50SCCM, power 1.0kW (direct voltage), the distance between the target and the substrate 64mm, as a protective film flow rate of argon and nitrogen gas 1 Si ₃ N ₄ film having a refractive index of 2.01 was formed while keeping at: 1.

The reproduction characteristics of the optical recording medium produced using the dynamic characteristics evaluation apparatus were evaluated and the results are shown in the table. Indicated. Measurement conditions are as follows.

Light source: λ = 532 nm

-Number of revolutions: L 1800rm.

Measurement field

1. Bit errer rate: Measured from 30mm radius to 300MByte (1Byte = 8bits)

2, reflectance: reflectance at pre-pit

-Regeneration wave; 1.2 mW

Comparative example

Except for forming a multilayer film over the entire area on the substrate (without a read-only area). An optical recording medium was prepared in the same manner as in Example. The playback characteristics of the produced recording medium were evaluated in the same manner as in Example, and the results are shown in the table. As can be seen from the table, the optical recording medium manufactured according to the conventional method has very low reflectance and low reliability of the regeneration signal, that is, the optical recording medium manufactured according to the present invention with a bit error rate of 2.0 × 10 ⁻⁶ . It was higher than the (Example).

As can be seen from the above, the partial reproduction-only optical recording medium manufactured according to the present invention is different from the conventional optical recording medium in which a recording layer is formed over the entire area of the substrate. Since the recording layer is not formed in the read only area, the reflectance is high and the reliability of the playback signal is high.

Claims (3)

Disc-shaped substrates; A boundary region formed in a columnar shape on a predetermined position between the center and the periphery of the substrate; And a read-only area formed on one of the substrates outside or inside of the boundary area, and a record / reproduced area formed on the other substrate, wherein the read-only area has a reflective film formed thereon. An optical recording medium exclusively for partial reproduction, characterized in that a protective film, a recording film, a protective film and a reflective film are sequentially formed in the recording / reproducing area. 2. The partial reproduction-only optical recording medium according to claim 1, wherein the boundary region is provided with a preliminary preliminary format portion. Manufacturing a circular substrate having a prepit formed in either an inner or outer region; Shielding an area where the prepit is not formed, and then forming a reproducing area by forming a reflective film on the substrate on which the prepit is formed; And shielding a region where the prepit is formed, and then forming a recording / reproducing region by sequentially forming a protective film, a recording film, a protective film, and a reflective film on the substrate on which the prepit is not formed. A method of manufacturing a partially reproduced optical recording medium.