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:
Dec. 28, 1999
Filed:
Apr. 23, 1997
Takanobu Higuchi, Tsurugashima, JP;
Satoshi Jinno, Tsurugashima, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
A double-layer optical disk having characteristics that are less wavelength dependent, allows the use of a pickup comprising a light beam of a different wavelength to read each layer accurately and stably. In the double layer optical disk which comprises, a first reflection layer carrying first information, a spacer layer, and a second reflection layer carrying second information, each laminated on a transparent substrate having a specific refractive index thereby allowing a pickup to read said first and second information, the first reflection layer is formed by laminating a metal layer made of a metal thin film and a dielectric layer made of a dielectric having a refractive index higher than the refractive index of the transparent substrate.