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:
Dec. 26, 1989
Filed:
May. 20, 1988
Nobuyuki Kaneko, Kokubunji, JP;
Kiichi Kato, Hachioji, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
In an optical information recording and reproducing apparatus for recording and reproducing information by controlling the focus of an optical system for condensing and projecting lights of a light source onto a recording medium, an offset part produced in case the lights are condensed and projected in a focus servo state in data writing regions in the recording medium and prepit regions which are adjacent to the data writing regions and in which discriminating codes are written is detected in the respective format regions by a format detecting means and an offset fluctuation controlling voltage is impressed on the basis of this detecting signal to inhibit the fluctuation of the offset in the respective regions of different formats.