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:
Mar. 14, 2000
Filed:
Apr. 30, 1997
Shigeaki Wachi, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A recording medium and technique which reduces problems relating to copyright, reduces the necessity for collecting an optical disk for, e.g., rental use and enables the optical disk itself to be inhibited from rental use. A reflectance of a reproducing film of the optical disk is changed by an irradiating laser beam having a greater strength than the laser beam strength used to form the film. The depth of a pre-pit in a data section is set to less than a quarter of the wavelength of the laser beam and the reproducing film is composed such that its reflectance drops if it is irradiated by the laser beam having the greater strength.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile