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:
Mar. 27, 1990
Filed:
Dec. 23, 1988
Johannes C Van De Ven, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A front projection screen comprises a transparent plate, the front and rear sides of which have linear Fresnel structures crossing each other and whose rear side is reflective. The riser facets, termed edges, of at least the rear Fresnel lens structure, are substantially perpendicular to the plane of the plate. Ambient light incident on the screen leaves the screen on the rear side via the edges on the rear side or are absorbed by light absorbing material on the edges. This results in an enhancement of the contrast in the observed picture. Further measures enhancing the contrast are the provision of wedge-shaped indentations in the rear side of the plate.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile