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, 1999
Filed:
Jun. 06, 1997
Toshihisa Tanaka, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An information recording and reproduction device records, erases or reproduces information by projecting a laser beam to a recording medium that has a first group of information tracks and a second group of information tracks, both of which are in a concentric or spiral state, there being a difference in a height of the information tracks of the first group relative to the second group, the tracks of the first group alternating with the tracks of the second group in a radial direction of the recording medium. The device includes a recording device that records specific information multiple times at different recording conditions on a selected one of the information tracks; a reproduction device that reproduces the specific information from the selected one of the information tracks; and a controller that determines the recording conditions, erasure conditions, or reproduction conditions to be used for the information tracks of the first group and for the information tracks of the second group based on a plurality of reproduction signals reproduced by the reproduction device. The recording condition can include a wave height value and a pulse width of a recorded pulse. The reproduction conditions can include a reproduction power level and a frequency of the high frequency accumulation. The erasure condition can include an erasure power level.