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:
Jul. 19, 2011
Filed:
Mar. 19, 2008
Takuo Kodaira, Gunma, JP;
Isao Matsuda, Gunma, JP;
Takeshi Otsu, Gunma, JP;
Fumi Hara, Gunma, JP;
Taiyo Yuden Co., Ltd., Tokyo, JP;
Abstract
In a write-once optical information recording medium including a substrate, a groove-shaped track such as a guiding groove, and an optical recording layer containing an organic dye material and disposed on the guiding groove, wherein information is recorded by irradiating a short-wavelength laser beam from a surface of the optical recording layer opposite the substrate, and the information can be reproduced by reading a change in the reflected light of a short-wavelength laser beam after the information recording, an unrecorded portion of the optical recording layer has a lower reflectance than a pit portion formed after recording to a portion of the optical recording layer, the optical recording layer has a refractive index n in the range of about 1.2 to about 2.1 before recording and an extinction coefficient k in the range of about 0.01 to about 0.7 before recording, and n+k is in the range of about 1.4 to about 2.1.