Taiyo Yuden Co., Ltd.

Masashi Satoh

Fumi Hara

Isao Matsuda

Takeshi Otsu

Shingo Katoh

Toru Fujii

Yuji Arai

Atsuo Shimizu

Isao Okitsu

Sachiko Ishibashi

An optical information recording medium has at least an optical reflective layer, an optical recording layer, an protective layer, and an optical transparency layer formed in that order on the main surface of a disc-shaped substrate. An area in which the protective layer is formed is made wider than an area in which the reflective layer is formed, and made narrower than an area in which the optical transparency layer is formed.

Optical information recording medium and manufacturing method thereof

An optical information recording medium has a substrate, and an optical reflection layer, an optical recording layer containing an organic dye, an interlayer, and a cover layer formed in this order on the substrate. The interlayer contains a sputtered NbO&#x2014;AlO-based composite oxide having an NbOcontent of more than 50 mol % and less than 60 mol %.

Optical information recording medium

An optical information recording medium includes a substrate having a through-hole provided at the central portion thereof and a guiding groove provided on a surface at the light-incident side; a reflective layer provided on the surface of the substrate having the guiding groove; a recording layer provided on the reflective layer and made of an organic substance containing a dye; and a light-transmissive cover layer provided on the recording layer, wherein the cover layer is made of a curable resin, and a modulus of elasticity of at least a portion of the cover layer facing the recording layer is in the range of about 34 MPa to about 96 MPa at 25&#xb0; C.

There is provided a new medium structure to record a bar code for copyright protection or the like in an optical information recording medium capable of recording and reproducing information by a laser with respect to a dye. When a laser beamis irradiated and an optical discis rotation in the direction of an arrow F, the dye of a recording layer is decomposed, a mark piece MA of a bar codeis formed, and a substrate is deformed by heat generated by the dye decomposition. Next, the position of the laser beamis shifted to a position where a part overlaps with the mark piece MA, and when the optical disc is similarly rotated in the direction of the arrow F, a mark piece MB is formed to overlap with the mark piece MA. The above processing is repeated, so that the length of a bar is sequentially lengthened, and the bar code with a length along the standard is formed.

Optical information recording medium and manufacturing method of the same

For improving the jitter property and ensuring the high reliability of an optical disk, a metal film containing phosphorus is disposed in a reflective layer. The layer has a hardness of 60 mgf/&#x3bc;mor more as nano indentation hardness, and an adhesive layer used for bonding has a glass transition temperature of 100&#xb0; C. or higher but 200&#xb0; C. or lower, an elastic modulus at 25 to 80&#xb0; C. of 1000 MPa or more, and an adhesion strength of 4N or more. The dye for the dye recording layer has a water solubility of 20% or less as measured as light absorbance of hot water in which the dye recording layer is soaked.

Growing community of inventors

Takasaki, Japan

Masashi Satoh