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:
Mar. 28, 2006
Filed:
Jun. 20, 2003
Tetsuya Akiyama, Hirakata, JP;
Kenichi Nishiuchi, Hirakata, JP;
Kenji Narumi, Ibaraki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
The present invention relates to an optical information recording medium including a disk-shaped transparent substrate and a recording layer for recording, reproducing or erasing information by irradiation of laser light, the recording layer being formed over the substrate. The recording layer of the present invention includes information tracks including groove tracks and land tracks that are formed alternately in a radial direction of the disk. The information tracks comprise information recording regions and address regions interposed between the information recording regions, the information recording regions and the address regions being arranged along the tracking direction of the laser light. In the information recording regions, every second step in the radial direction of steps for dividing the groove tracks from the land tracks adjacent to the groove tracks is wobbled in the tracking direction, and in a range whose ends are defined by the address regions the every second step is wobbled at a constant frequency. Prepit addresses for providing information on a position on the recording medium are formed on the address regions. Moreover, the present invention provides an optical information recording medium including n recording layers (where n is an integer of at least 2), and in at least the first recording layer to the (n-1)th recording layer from the transparent substrate side, no pair of adjacent address regions in the radial direction of the disk are arranged so as to be aligned on a straight line passing through the center of the disk.