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:
Nov. 15, 2005
Filed:
Aug. 16, 2001
Yasumori Hino, Ikoma, JP;
Masayoshi Shioya, Itami, JP;
Kazumasa Hirano, Tamana, JP;
Shohei Yumita, Kasuga, JP;
Yasumori Hino, Ikoma, JP;
Masayoshi Shioya, Itami, JP;
Kazumasa Hirano, Tamana, JP;
Shohei Yumita, Kasuga, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An information recording medium for reproducing information by irradiation with a laser beam condensed by an objective lens with a numerical aperture NA includes a disk-shaped substrate and a recording layer disposed on the substrate. On the surface of the substrate, a plurality of prepit regions and a plurality of data regions are disposed alternately along spiral or concentric virtual track centers. Each prepit region includes a pair of wobble pits for tracking servo, and a length L (μm) of the wobble pit along the virtual track center, a wavelength λ (μm) of the laser beam, and a numerical aperture NA satisfy a relationship: 0.3≦L. NA/λ≦0.65.