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:
Feb. 03, 2004
Filed:
May. 10, 2001
Applicant:
Inventors:
Duncan J. Anderson, Briarcliff Manor, NY (US);
Khalid Shahzad, Briarcliff Manor, NY (US);
Assignee:
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02F 1/1335 ;
U.S. Cl.
CPC ...
G02F 1/1335 ;
Abstract
An apparatus for improved contrast in projection optical systems consists of a polarizing beam splitter (PBS) in combination with two or more waveplates whose fast exes are aligned perpendicular to each other. The apparatus has an effective broadband frequency response that is better than that of the individual retarders acting alone, and through the selection of a birefringence factor and thickness of the individual retarders, wavelength dependencies are minimized.