Mitsui Toatsu Chemicals, Incorporated

Tadahiko Mizukuki

Sumio Hirose

Tomoyoshi Sasakawa

Nobuhisa Kitagawa

Tadashi Koike

Shinichi Murakami

Kouichi Yabuuchi

Kouhei Shizuka

Hitoshi Miura

Yuko Suzuki

Kouichi Shiina

An optical recording medium comprises a substrate, a recording layer overlying the substrate in a manner such that it is not present at the inner and outer peripheral portions of the substrate, a metal reflective layer overlying the recording layer in a manner such that the inner periphery of the metal reflective layer is coterminous with that of the recording layer while the outer peripheral portion of the reflective layer extends over the outer perphery of the recording layer, and a protective layer wholly covering the metal reflective layer extending over the recording layer, both at the inner and outer peripheral portions. The optical recording medium exhibits an excellent adhesion strength of the protective layer even when stood under high humidity and high temperature conditions for a long period of time, and the protective layer is not peeled off when subjected to a tape peeling test.

Optical recording medium and production thereof

The present invention relates to a method and apparatus for manufacturing a disk-type information recording medium such as an optical disk. The method and apparatus of the present invention involves the concept of automatically removing any surplus organic materials deposited on cylindrical outer surfaces of the disk and also provides for a disk-type information recording medium of a high quality finish. In the method and apparatus of the present invention, a cleaning belt is utilized to contact a disk which is positioned on a rotatable cleaning table to remove any organic materials existing on the cylindrical outer surface of the disk.

Method and apparatus for cleaning cylindrical outer surface of a disk

An optical recording medium comprises a substrate, a recording layer overlying the substrate in a manner such that it is not present at the inner and outer peripheral portions of the substrate, a metal reflective layer overlying the recording layer in a manner such that the inner periphery of the metal reflective layer is coterminous with that of the recording layer while the outer peripheral portion of the reflective layer extends over the outer periphery of the recording layer, and a protective layer wholly covering the metal reflective layer extending over the recording layer, both at the inner and outer peripheral portions. The optical recording medium exhibits an excellent adhesion strength of the protective layer even when stood under high humidity and high temperature conditions for a long period of time, and the protective layer is not peeled off when subjected to a tape peeling test.

Apparatus for cleaning cylindrical outer surface of a disk

An optical recording medium of a single plate type capable of recording comprises a transparent resin substrate having a groove of 900-1800 .ANG. in depth and 0.3-0.6 .mu.m in width, a recording layer containing a dye overlying the substrate, a reflective layer overlying the recording layer and a protective layer overlying the reflective layer, the thickness of the recording layer being 800-1250 .ANG. at the groove portion and 500-1100 .ANG. at the land portion.

Optical recording medium

An optical recording medium of a single plate type comprises a substrate having a groove, a recording layer containing a dye overlying the substrate, a reflective layer overlying the recording layer and a protective layer overlying the reflective layer, wherein the recording layer is formed by a spin-coating method and the dimension of the groove varies from the center portion of the substrate toward the outer periphery thereof.

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Tokyo, Japan

Tadahiko Mizukuki