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:
Jul. 18, 2000
Filed:
Jun. 11, 1996
Gary D Sharp, Boulder, CO (US);
Kristina M Johnson, Longmont, CO (US);
The Board of Regents of the University of Colorado, Boulder, CO (US);
Abstract
This invention provides split-element liquid crystal polarization interference filters in wide-field, bandpass, cut-on, cut-off and notch filter embodiments. The split-element filters of this invention comprise a polarization interference stage defined by a pair of polarizers. Disposed within the stage are a center retarder, and first and a second split-element retarder, the split-element retarders having equal retardances and positioned in series with and on either side of the center retarder. The retarders can be liquid crystal variable retarders or can be fixed retarders used in combination with liquid crystal retarders. Double split-element filters in passive and tunable embodiments are provided comprising, within a polarization interference stage, a center retarder, an inside pair of split-element retarders and an outside pair of split-element retarders.