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:
Oct. 19, 1993
Filed:
Aug. 13, 1991
Hiroshi Katayama, Higashihiroshima, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A light spot position detector, which detects the two-dimensional position of a light spot projected onto a light receiving element with four quadrant light receiving parts, has an amplifier for amplifying detection signals transmitted from the respective light receiving parts individually, an arithmetic circuit for transmitting a first position signal and a second position signal corresponding to the two-dimensional position, and a variable resistor for adjusting the gains of the amplifier and the arithmetic circuit with respect to the detection signals. With this configuration, the amount of crosstalk between the first and second position signals is restrained within a given range, the crosstalk occurring when there are variations in gain of the amplifier and of the arithmetic circuit with respect to the respective detection signals. When the light spot position detector is incorporated into an optical head and the optical head is designed such that the movement of the objective lens causes a shift in the light spot, the displacement of the objective lens can be correctly detected, achieving accurate tracking control and focussing control.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile