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. 26, 2004
Filed:
Jul. 03, 2001
Hiroyuki Arioka, Tokyo, JP;
Hideki Sunohara, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
An optical recording medium is provided with a recording layer and a reflecting film on an optically transparent substrate. The principal component of the recording layer is a dye. Virtual recording cells are assumed within grooves on the recording layer and recording marks with five different levels or more of increasing size are formed on each of the virtual recording cells by modulating the irradiation time of the laser beam in five levels or more in correspondence to the information to be recorded. The reflectance of the virtual recording cells modulates in many levels and the reflection level of the reading laser beam during regeneration is changed in five levels or more. The optically transparent substrate is made of a plastic with a glass transition point (Tg) of 160° C. or less. The reflecting film is a metal with a coefficient of thermal conductivity of 300 k/W·m ·K or more and a film thickness of 50 nm or more.