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:
Jul. 02, 2002
Filed:
Sep. 09, 1999
Hitachi, Ltd., Tokyo, JP;
Abstract
An information recording/reproducing apparatus which can record and reproduce information data into and from various kinds of recording mediums has a laser driver which enables recording strategy control for each kind of recording medium. The laser driver receives an NRZ binary signal and a clock signal synchronized with the NRZ binary signal from a modulation circuit, and generates a recording current signal corresponding to the NRZ binary signal. The laser driver includes a PLL circuit disposed in the laser driver which oscillates at a recording frequency, and an unlock detection circuit which detects an oscillating condition of the PLL circuit and outputs a detection signal indicative of the oscillating condition of the PLL. A recording operation of the information recording/reproducing apparatus is controlled based on the detection signal outputted from the unlock detection circuit.