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. 02, 1995
Filed:
Jun. 04, 1993
Keitaro Hashimoto, Tokyo, JP;
Takashi Aoki, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
An apparatus for performing focusing control and tracking control for an objective lens of an optical head of an optical card reader and/or writer including first and second focusing error detecting systems for generating first and second focusing error signals, respectively, first and second tracking error detecting systems for generating first and second tracking error signals, respectively, a circuit for detecting a defect on an optical card to generate a defect signal, a selecting circuit for selecting one of the first and second focusing error signals and one of the first and second tracking error signals in accordance with the defect signal such that the selected error signals are free from the defect, a focusing actuator for moving the objective lens in the focusing direction in accordance with the selected focusing error signal, and a tracking actuator for moving the objective lens in the tracking direction in accordance with the selected tracking error signal.