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. 10, 2004
Filed:
May. 20, 2002
Seiichi Ohsawa, Tsurugashima, JP;
Takanori Maeda, Tsurugashima, JP;
Pioneer Corporation, Tokyo, JP;
Abstract
A multi-layer-information-recording medium is applied to an information recording and reproducing apparatus capable of recording or reproducing information on and from either of a single-layer-information-recording medium having a single recording layer on one side, and a multi-layer-information-recording layer having a plurality of recording layers layered on a spacer layer on one side as a change in reflectivity by irradiating a light beam. The multi-layer-information-recording medium is compatible in terms of at least reproducing and recording with a single-layer-information-recording medium having a cover layer having a predetermined refractive index “n” and a thickness “t” disposed on a recording layer on a light incident side surface. The multi-layer-information-recording medium includes a deepest recording layer deepest from the light incident side surface. The deepest recording layer is formed at an optical distance d from the light incident side surface satisfying an equation d =nt. The multi-layer-information-recording medium also includes at least one shallow recording layer formed at an optical distance d satisfying an inequality d <nt from the light incident side surface.