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. 04, 1988
Filed:
Oct. 11, 1985
Applicant:
Inventors:
Satoshi Shimada, Hitachi, JP;
Hiroshi Sasaki, Hitachi, JP;
Nobuyoshi Tsuboi, Tokai, JP;
Hideki Nihei, Hitachi, JP;
Norifumi Miyamoto, Hitachi, JP;
Ito Tetsuo, Mito, JP;
Yoshio Sato, Hitachi, JP;
Atsumi Watanabe, Hitachi, JP;
Ryo Hiraga, Hitachioota, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 45 ; 369112 ; 250201 ;
Abstract
In the present invention, a micro Fresnel lens in the shape of a thin film is used. A lens driving member constructed of piezoelectric transducers or of magnets and coils is disposed around the lens. The focus of the lens is adjusted by controlling applied voltages to the piezoelectric transducers or the coils.