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:
Sep. 10, 1985
Filed:
Dec. 02, 1982
Hitachi, Ltd., Tokyo, JP;
Abstract
In a light spot control signal generating device, a light spot is irradiated on a recording medium having tracks on which information is recorded. In order to jump the light spot from a track being scanned thereby to an adjacent track, a signal representative of light quantity of reflection or transmission of the light spot and a track error signal are detected. The two signals are used to judge whether the light spot has passed through an edge of the track. The track error signal is also used to detect a signal representative of an instant at which the light spot is present at the middle point between adjacent tracks, and this signal is used as a timing signal for changing the polarity of a control signal applied to a spot light deflector.