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:
Aug. 18, 1992
Filed:
Nov. 13, 1990
Applicant:
Inventors:
Hiroyuki Iwasaki, Tokyo, JP;
Yasunobu Kayanuma, Tokyo, JP;
Assignee:
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02K / ; H02K / ; B03B / ;
U.S. Cl.
CPC ...
310191 ; 310156 ; 310267 ; 3542711 ; 354274 ;
Abstract
A diaphragm electromagnetic drive device which comprises ring-shaped rotor and stator disposed coaxially about the optical axis of a taking lens and in which the rotor is rotated to thereby rotate diaphragm blades so as to vary successively a diaphragm diameter defined by the diaphragm blades. The mutually opposed surfaces of the rotor and stator are constructed respectively in the shape of a side surface of a truncated cone, so that the areas of the opposed surfaces can be increased without increasing the outside diameter and the length in the optical axis direction of the electromagnetic drive device.