Hughes Aircraft Company

Brian D Cohn

Lacy G Cook

Gaylord E Moss

Mao-Jin J Chern

John J Ferrer

Brent L Ellerbroek

Gerard M Perron

Brian K Zellers

A helmet mounted display uses a see-through visor holographic combiner to provide, in the normal field of view of a helicopter pilot, a pair of images derived from an image source such as a miniature cathode ray tube. A source of the video display may be an infrared sensor mounted on an external turret underneath the helicopter. The turret rotates in response to helmet movements so that the pilot is continually provided with a dual image from the CRT display which corresponds with the external scene as visible through the visor.

Biocular holographic helmet mounted display

A head-up display for use in a vehicle is provided with a curved combiner which reflects an image from a cathode ray tube (CRT) as collimated rays to a viewing site. A relay lens is positioned between the CRT and the combiner to magnify and transfer the image. The combiner may be a partially-reflecting mirror or holographic optical element or dielectric laminate. Included within the relay lens is a coma-control plate having two-dimensional undulations described mathematically by a two-dimensional power series having odd symmetry in a plane of a tilting of the combiner and even symmetry in the perpendicular dimension. The coma-control plate substantially reduces coma in an image presented for viewing at infinity, the coma being introduced by the curvature and off-axis use of a surface of the combiner.

Display system having coma-control plate in relay lens

A shearing phase difference sensor including a high energy laser source for generating adjacent coherent light beam. Samples of the beams are extracted by an extracter and directed to an optical modifier. The optical modifier, positioned for intercepting the sample beams from the extracter, diffracts the beams and produces output beams which, in turn, are directed through a lens to a detector. The detector, positioned to intercept the output beams, produces electrical signals indicative of the output beams. The electrical signals are processed by a processor which calculates the phase difference between adjacent coherent light beams. Also, disclosed is a method for measuring the phase difference between adjacent coherent light beams.

Shearing phase difference sensor

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El Segundo, CA, United States of America

Brian D Cohn