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:
Mar. 28, 1989
Filed:
Jun. 24, 1987
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
In an optical type head device comprising a light source for emitting a light beam, a beam splitter, a condensor lens and a light detector for receiving said light beam for photoelectric conversion wherein a diffraction grating is provided to separate the light beam into a plurality of subbeams consisting of a zero-order subbeam and other subbeams so that a focussing error of the spot of the zero-order subbeam on an optical type data storing medium is detected by the fact that the light spot of the zero-order subbeam is deformed on the light detector, and a positional error of the spot of the zero-order subbeam with respect to a data track on the optical type data storing medium is detected depending on the position of the spots of the other subbeams.