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:
Feb. 21, 1995
Filed:
Dec. 15, 1992
Masaaki Sofue, Hadano, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
In an optical pickup device, signal light is reflected on an optical disk and is converged by a condenser lens. A polarizing plane of the signal light is rotated 45.degree. by a 1/2 wave plate. The signal light is then incident to a polarizing beam splitter at an incident angle .theta.. The polarizing beam splitter is constructed by a plane parallel plate having a polarizing coating film. An s-polarized component of light reflected on the polarizing beam splitter is received by first divisional light-receiving elements and a difference signal between outputs of the first divisional light-receiving elements is set to a tracking control signal. A p-polarized component of light transmitted through the polarizing beam splitter is received by second divisional light-receiving elements and a difference signal between outputs of the second divisional light-receiving elements is set to a focusing control signal. Sum signals of the first and second divisional light-receiving elements are respectively inputted to a reproducing signal detector. The reproducing signal detector obtains a reproducing signal of recorded information by calculating a difference between these sum signals.