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:
Aug. 12, 2003
Filed:
Jan. 06, 2000
NEC Corporation, , JP;
Abstract
There is disclosed an optical information recording medium having phase-change recording films whose the transmittance can be made substantially uniform irrespective of the presence or absence of recording. There are also disclosed methods for recording, reading, and erasing information well at a high density on such a medium. Each of the phase-change recording films other than the top one has a phase-change recording film for recording and erasing information by a phase change caused by illumination of laser light. A transparent upper protective film is formed on the phase-change recording film to protect the phase-change recording film mainly against thermal deformation during recording and erasing of information. A transparent lower protective film is formed under the phase-change recording film to protect the phase-change recording film mainly against thermal deformation during recording and erasing of information. A foundation interference film is formed under the transparent lower protective film to adjust the transmittance of the phase-change recording film for the laser light.