The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 12, 1993
Filed:
Feb. 14, 1992
Junji Tominaga, Nagano, JP;
Hideki Dohi, Nagano, JP;
TDK Corporation, Tokyo, JP;
Abstract
A recording thin film, a dielectric thin film, and a reflective thin film are stacked on a surface of a substrate in the described order. Upon exposure to recording laser light, an inorganic compound in the recording thin film decomposes to release a gas, creating a space in the recording thin film. Since the substrate is also heated and softened, a recess is created in the substrate surface due to the pressure of evolving gas. The space and recess cause a change of optical conditions, resulting in a substantial lowering of reflectivity where the laser light is irradiated. This enables reproduction in accordance with the CD standard. The use of an inorganic compound which decomposes to release a gas upon heating rather than organic dyes ensures better light resistance, leading to highly reliable information storage. Recording sensitivity is high.