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:
Jan. 22, 1991
Filed:
Aug. 04, 1989
Applicant:
Inventor:
Dennis F Vanderwerf, St. Paul, MN (US);
Assignee:
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
353 66 ; 353D / ; 353 38 ;
Abstract
A reflective stage overhead projector has a light source, a projection lens and mirror assembly for focusing and reflecting an illuminated image onto a screen, and a stage area for supporting an image to be illuminated and projected. One reflective surface of the stage area is defined by a noncentral portion of a Fresnel lens.