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:
May. 21, 1991
Filed:
Jun. 24, 1988
Michael Kalmanash, Los Altos, CA (US);
Arthur L Berman, Milpitas, CA (US);
Kaiser Aerospace & Electronics Corporation, Oakland, CA (US);
Abstract
A high precision optical filter includes a wideband filter element and a cholesteric liquid crystal notch filter element. In one embodiment, a wideband infrared filter blocks infrared wavelengths beginning at a nearly visible corner wavelength and a cholesteric liquid crystal filter blocks transmission of infrared wavelengths in a precise narrow band that includes the corner wavelength and that extends down to visible wavelengths. The liquid crystal filter may include a polymer for maintaining maximum reflectivity of the filter near the corner wavelength over an anticipated operating temperature range. The combined optical filter may be fabricated by depositing a matched pair of liquid crystal cholesteric films on a glass infrared filter element. In another embodiment, an optical filter according to the invention forms an eyepiece in a night vision goggles assembly for blocking visible light. The filter may also be mounted on a display device to block the transmission of undesirable infrared emissions at the source.