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:
Sep. 22, 1992
Filed:
Sep. 26, 1991
Colin G Whitney, Agoura Hills, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A 'Venetian-blind' assembly of dichroic plates (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 plates (36) transmit electromagnetic radiation in a first optical wavelength band such as visible light, and reflect radiation in a second wavelength band such as infrared radiation. The plates (36) are inclined at progressively larger angles relative to the optical axis (22) of the telescope (26) such that the infrared radiation is reflected from a front surface (36a) of one plate (36) and subsequently from a rear surface (36a) of an adjacent plate (36) into the telescope (26) at a predetermined angle to the transmitted visible radiation. The predetermined angle is selected such that the telescope (26) forms separate, laterally displaced optical images (46,50) corresponding to the visible and infrared radiation respectively on separate sections (34a,34b) of a focal plane photodetector array (34). Optical filters (54,52) which pass only the visible and infrared radiation therethrough respectively are disposed in front of the respective sections (34a,34b) of the photodetector array (34) to eleiminate optical crosstalk between the two images (46,50).