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:
Oct. 26, 1999
Filed:
Jun. 06, 1997
Hitachi, Ltd., Tokyo, JP;
Abstract
The device seeks to improve the reliability of information and to increase recording capacity by controlling the recording mark to be recorded on the recording medium with high preciseness. To improve the conformity of a recording medium with a device that records, retrieves and erases information, a recording pulse train is generated by a test write data generating circuit 18 and a recording pulse forming circuit 15 and a recording mark is recorded on a recording medium 5 by a laser driver 14. Excessive power recording is reduced, an optimum recording power is determined and regular information recording and retrieving is carried out by detecting a test write data from a test write data detecting circuit 12 to which the retrieved signal from the recording medium 5 is input. Based upon analysis of the retrieved signal by a controller 19, and the range of next power scan is changed so as to avoid excessive power recording while making it possible to determine the optimum recording power.