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:
Apr. 12, 1994
Filed:
Sep. 25, 1992
Lloyd J Lewins, Marina Del Rey, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A heads-up display (50) for an aircraft includes a digital image generator (52), a cathode ray tube (CRT) (54) and an optical system (56) which projects an image (58) formed on the CRT screen (54a) indicating the status of the aircraft operation onto a holographic mirror combiner (60) at a slant angle. The combiner (60) is transparent to the pilot's direct view through the aircraft windshield, but produces a reflected image of the CRT screen (54a) which is superimposed on the direct view. Pincushion distortion in the CRT (54) and geometric distortion caused by the slant projection angle are corrected by a digital look-up table memory (82, 84) which alters the initially orthogonal CRT horizontal and vertical deflection signals (Vh,Vv) in a manner which is the inverse of the distortion such that the image (58) on the combiner (60) as viewed by the pilot appears undistorted. The size of the look-up table memory (82,84) is greatly reduced by making approximations based on analysis of the mathematical functions which define the distortion.