Design of a Catadioptric VCASS Helmet-Mounted Display

Abstract : A new wide-angle, dual-eye, helmet-mounted display has been designed. Two images combine, with a 15 deg. central field overlap, to provide a panoramic display 102 deg. wide by 45 deg. tall, with a resolution to approximately 1000 TV lines per eye. The image-generating device is a miniature 18-mm CRT. The optics, which are symmetrical for both eyes, comprise partially reflective plastic reflectors, five small glass lens elements, and a 2:1 fiber optic magnifier. A 12-mm exit pupil is obtained with enough eye relief to permit the user to wear glasses, with an interpupillary adjustment of 58 to 73 mm. Total weight of the device, not including the Air Force flight helmet type HGU-2A/P upon which it is mounted, is less than 3 pounds. (Author)