Pioneer Electronic Corporation

Tsuneki Okazaki

Fumio Matsui

Shuichi Yanagisawa

Tatsuro Sakai

Hitoshi Taniguchi

Masaaki Hayami

Ayashi Noguchi

Akira Shimpo

Fumio Mitsui

A rewritable photochromic optical disk comprises a photochromic recording layer made of a dibenzothienyl ethene derivative, 1,2-di(2-cyano-3-benzothienyl)-1,2-dicyanoethene capable of assuming first and second states, the first state with a first absorption band transforming into the second state with a second absorption band by irradiating a first light beam of a first wavelength, and the second state transforming into the first state by irradiating a second light beam of a second wavelength in the second absorption band. This rewritable photochromic optical disk has a stability in the repeated recording and erasing information and a high thermal stability and capable of storage of information extended over a long period of time, in accordance with its higher quantum yield than that of the conventional dibenzothienyl ethene derivative so that the achromatic reaction takes place by irradiation of a low power laser beam.

Rewritable photochromic optical disk

An optical recording medium having a recording layer containing a particular cyanine dye matter and a particular quencher. The material of the recording medium can be directly applied to the injection-molded substrate without any damage to the substrate. The productivity of this recording medium is therefore high. This medium also has superior recording/reproduction characteristics.

Optical recording medium

An optical recording medium having a recording layer containing a particular cyanin coloring matter and a particular quencher. The material of the recording medium can be directly applied to the substrate without any damage to the substrate. The productivity of this recording medium is therefore high. This medium also has superior recording/reproduction characteristics.

Growing community of inventors

Okayama, Japan

Tsuneki Okazaki