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:
Sep. 29, 1992
Filed:
May. 30, 1990
Yukihiro Yamasaki, Hirakata, JP;
Toshio Suetsugu, Katano, JP;
Tamotsu Matsuo, Osaka, JP;
Hideo Okamura, Hirakata, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In an optical data recording and reproducing apparatus comprising an information signal generator, a sample/hold switching signal generator, a write/read switching signal generator, a laser beam source, a reference voltage generator, a comparator and a photo detector, a dummy signal is added to the information signal modulating the laser beam or generation of the laser beam is forcedly stopped after a data write servo mode so as to prevent generation of the laser beam of an excessively high level at the time of change-over from the data write servo mode to a data write hold mode or from the data write hold mode to a data read mode, or the level of the write/read switching signal is changed before the level of the sample/hold switching signal is changed at the time of change-over from the data write hold mode to the data read mode, or the duration of emission of the laser beam is extended slightly before the level of the sample/hold switching signal is changed.