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:
Jan. 13, 2009
Filed:
Dec. 22, 2004
Ryosuke Yamamoto, Yokohama, JP;
Sumio Ashida, Yokohama, JP;
Ryosuke Yamamoto, Yokohama, JP;
Sumio Ashida, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
The present invention provides an optical disk apparatus in which a first, second, third, and fourth optical disks are selectively installed, the first and second optical disks having different recording film characteristics and both having a single-layer recording layer, the third and fourth optical disks having different recording film characteristics and both having a double-layer recording layer. A control section determines which of the first to fourth optical disks has been installed, on the basis of the level of a reproduction signal from an optical head. Recording media serving as the optical disks are formed so that the light reflectances of a single-layer L-H medium in an initialized state, an L0 layer of a double-layer H-L medium in the initialized state, and an L0 layer of a double-layer L-H medium in an uninitialized state do not overlap the light reflectance of a single-layer H-L medium in the initialized state.