OPTICAL RECORDING MEDIUM AND PRODUCTION METHOD THEREOF

Abstract

A transparent stamper made of a resin has a defect of being not able to be used repeatedly because of stress at the time of peeling off, and hence, improvement is requested. Then, the present invention provides an optical recording medium including a supporting base member, a plurality of recording layers formed on the supporting base member, an interlayer formed between the plurality of recording layers, and a cover layer formed on the recording layer, wherein, in the supporting base member, a concave portion is formed in an inner periphery region thereof than the recording layer, and an inclined portion is formed in an outer periphery region thereof than the recording layer, and wherein the interlayer contacts with the concave portion and the inclined portion of the supporting base member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B, 1C, 1D, 1E and 1F are schematic diagrams of production steps of the present invention.

FIG. 2 is a schematic diagram of a substrate forming mold according to the present invention.

FIGS. 3A, 3B, 3C and 3D are schematic diagrams illustrating an example of injection steps according to the present invention.

FIGS. 4A, 4B and 4C are schematic diagrams illustrating an example of UV resin coating steps according to the present invention.

FIGS. 5A, 5B and 5C are schematic diagrams illustrating an example of bonding steps according to the present invention.

FIG. 6 is a schematic sectional view of a multilayer-structured optical recording medium of the present invention.

FIGS. 7A, 7B, 7C and 7D illustrate inner stamper forms in respective examples.

FIGS. 8A, 8B, 8C, 8D, 8E, 8F and 8G are schematic diagrams of stamper producing steps.

FIGS. 9A, 9B, 9C, 9D, 9E, 9F, 9G and 9H are schematic diagrams of production steps of a multilayer optical recording medium according to a conventional 2P system.

FIG. 10 is a schematic sectional view illustrating a conventional substrate, signal pattern, and recording layer.

Claims

1. An optical recording medium, comprising: a supporting base member;a plurality of recording layers formed on the supporting base member;an interlayer formed between the plurality of recording layers; anda cover layer formed on the recording layer,wherein, in the supporting base member, a concave portion is formed in an inner periphery region thereof than the recording layer, and an inclined portion is formed in an outer periphery region thereof than the recording layer; andwherein the interlayer contacts with the concave portion and the inclined portion of the supporting base member.

2. The optical recording medium according to claim 1, wherein a depth of the concave portion is 0.1 mm or more and 0.8 mm or less.

3. The optical recording medium according to claim 1, wherein a depth of the concave portion is 0.4 mm or more and 0.7 mm or less.

4. A method of producing an optical recording medium, comprising: (a) a step of forming a recording layer in a recording region of a supporting base member which has a concave portion in an inner periphery region thereof than the recording region, and has an inclined portion in an outer periphery region thereof than the recording region;(b) a step of forming an interlayer on the concave portion, the inclined portion, and the recording layer;(c) a step of transferring a pattern of a transparent stamper to the interlayer by radiating the interlayer with ultraviolet ray through the transparent stamper;(d) a step of forming another recording layer in the recording region of the interlayer;(e) a step of repeating steps (b) to (d) n-2 times, wherein n is an integer of two or more; and(f) a step of forming a cover layer on the n-th recording layer.

5. The method of producing an optical recording medium according to claim 4, wherein a material of the transparent stamper is selected from the group consisting of quartz glass, alkali glass, and free-alkali glass.