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:
May. 08, 1990
Filed:
Feb. 06, 1987
Hiroshi Fuji, Tenri, JP;
Shigemi Maeda, Yamatokoriyama, JP;
Noriaki Sakamoto, Kyoto, JP;
Shigeo Terashima, Tenri, JP;
Takeshi Yamaguchi, Tenri, JP;
Kentaro Tsuji, Nara, JP;
Kunio Kojima, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An optical memory device for recording, reproducing or erasing information by applying an optical beam such as a laser beam onto a recording medium in which the optical memory device includes a recorded region detecting circuit for detecting information recorded in a specified region formed in the recording medium. The optical memory device also includes a timing control for recording, reproducing or erasing data with the use of one result obtained through detection of a synchronizing signal such as a sector mark indicative of a starting point of an information block and another result obtained through detection in the recorded region detecting circuit. The recorded region detecting circuit contains either of at least one peak hold circuit for detecting a peak level of the playback signal and a low pass filter for smoothing the playback signal, and a comparator for comparing an output obtained through the peak hold circuit or through the low pass filter with a reference voltage.