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. 16, 1994
Filed:
Jan. 21, 1993
Yuichiro Akatsuka, Tokyo, JP;
Horiguchi Toshio, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
An apparatus performs servo control of a recording light beam by using a reproducing light beam. The reproducing light beam, which does not destroy the recording material of an optical card, is emitted from a reproducing LD to the optical card. The position of the reproducing light beam is controlled by a control unit. A light beam which does not destroy the recording material of the optical card is emitted from a recording LD to the optical card. The position of the light beam from the recording LD is detected by a recording PD and the detected error signal is stored in the control unit. The reproducing light beam is emitted again from the reproducing LD to the optical card together with emitting the recording light beam, which can destroy the recording material of the optical card, from the recording LD. The position of the recording light beam is controlled by the control unit based on the reflected light beam of the reproducing light beam from the optical card and on the stored signal in the control unit.