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. 17, 1992
Filed:
Sep. 11, 1991
Kazuhiro Fujita, Yokohama, JP;
Toshiyuki Inokuchi, Yokohama, JP;
Nobuyuki Baba, Yokohama, JP;
Hideo Maeda, Yokohama, JP;
Shigeru Ohuchida, Zama, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An optical pick-up device for use in an optical disc information recording/reproducing apparatus is provided. In the present optical pick-up device, the functions of two or more separate optical elements provided in the prior art structure are combined or integrated in a single element to reduce the total number of separate optical elements provided in the device. In particular, use is made of a diffraction grating rather than lenses and/or lenses are formed as holo lenses. A diffraction grating and a holo lens may be formed substantially in the shape of flat plates, so that many optical components can be put together to define an integrated subassembly, which reduces the total number of discrete elements, facilitates manufacturing and eliminates the necessity of adjustments among optical elements once set.