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:
Aug. 04, 1992
Filed:
Sep. 23, 1991
Colin G Whitney, Agoura Hills, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A birefringent prism (36) is disposed in front of the entrance aperture (26a) of a Cassegrain-type telescope (26) which constitutes the optical focussing assembly in a tracking system for a guided missile (10) or the like. The prism (36) refracts first radiation (O) having a first polarization in a first direction, and refracts second radiation (E) having a second polarization which is orthogonal to the first polarization in a second direction which is deviated from the first direction by a predetermined angle .DELTA..phi.. The telescope (26) focusses the first and second radiation (O,E) to form separate, laterally displaced first and second optical images (46,50) on first and second respective sections (34a,34b) of a focal plane photodetector array (34). Polarizing filters (56,58) which pass only the first and second polarizations therethrough are disposed in front of the respective sections (34a,34b) of the photodetector array (34) to eliminate optical crosstalk between the two images (46,50). Optical bandpass filters (54,52) having different wavelength passbands may also be provided in front of the two sections (34a,34b) of the photodetector array (34) such that the two images (46,50) constitute different color images of the scene (16).