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. 31, 1999
Filed:
Feb. 28, 1997
Kazuhiko Nakane, Tokyo, JP;
Masato Nagasawa, Tokyo, JP;
Hiroyuki Ohata, Tokyo, JP;
Masayoshi Shimamoto, Tokyo, JP;
Kouichi Komawaki, Tokyo, JP;
Kenji Gotoh, Tokyo, JP;
Yoshinobu Ishida, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
In optical disk having a track formed of groove tracks and land tracks connected every revolution to form a single spiral, each revolution-of the tracks is divided into sectors, each having identification signal region at the head of the sector, and the identification signal regions in tracks adjacent to each other are aligned in the radial direction. Prepits are formed in the identification signal region, on an extension of a boundary between groove and land tracks adjacent to each other. The prepits have a width substantially equal to the width of the grooves. The identification signal including address information of the sector. The polarity of tracking error signal is detected at the identification signal region of the recording sector, and whether the recording sector is in a groove track or land track is determined based on the polarity of tracking error signal. The identification signal may include information concerning the timing for switching tracking polarity in accordance with whether groove or land sector is being scanned.