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:
Sep. 27, 1983
Filed:
Apr. 23, 1982
Applicant:
Inventors:
Takanori Hasegawa, Hachioji, JP;
Susumu Oshio, Tokyo, JP;
Assignee:
Riso Kagaku Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
353 66 ; 353 85 ; 353D / ; 250221 ;
Abstract
In a reflecting type overhead projector having a light source lamp and a projection lens above a reflecting table formed of a Fresnel lens and a mirror upon which an original to be projected is laid, there is provided a control circuit which switches over supply of electric power to the light source lamp between full and part power supply according to whether the intensity of the light beams from the light source lamp received by a photosensitive element provided in the vicinity of the reflecting table is higher or lower than a predetermined value.