Large-field holographic binocular helmet visor

Abstract

The visor makes it possible to obtain in binocular vision a large field of 60.degree. in the vertical plane and 120.degree. in the horizontal plane. In the case of each monocular vision channel, the visor is constituted by: an image generator such as a miniature cathode-ray tube, for example; an optical relay device; a collimation and combination optical system in which are grouped together a holographic mixing plate for transmitting the landscape channel and reflecting the image channel and a biconvex combining device formed by two holographic spherical optical elements employed on the axis for transmitting the two channels with collimation by diffraction of the image channel. A circular axial zone of zero photometric efficiency is produced in the case of each monocular vision channel and compensated by overlapping of the fields in binocular vision and, in a complementary manner, by the construction of mirror holograms providing variable index modulation.

Dependencies are inferred from the claim text.