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, 1988
Filed:
Aug. 28, 1987
Applicant:
Inventors:
Jill F Goldenberg, Pelham Manor, NY (US);
Ralph H Bradley, Jr, Kingsport, TN (US);
William F Guerinot, Knoxville, TN (US);
Thomas S McKechnie, Ossining, NY (US);
Assignee:
North American Philips Corp., New York, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
350128 ;
Abstract
A one-piece projection screen with improved overall efficiency and contrast, the elimination of corner illumination deficiencies and undesirable image artifacts. The optical power of the screen is divided between two or more surfaces acting as Fresnel lenses, and the region or medium separating the surfaces has a different index of refraction than that of the mediums upstream or downstream of the surfaces. The preferred embodiment of the projection screen includes a diffuser and a lenticular array downstream of the surfaces.