John F Weaver

US Patent:

47407808, Apr 26, 1988

Filed:

Jun 24, 1985

Appl. No.:

6/747861

Inventors:

Steven E. Brown - Atlanta GA
John Weaver - Chamblee GA
Ronald A. Sargent - Atlanta GA
Scott W. Patterson - Norcross GA
Maurice L. Stephenson - Mableton GA

Assignee:

GEC Avionics, Inc. - Norcross GA

International Classification:

G02B 2710

US Classification:

340705

Abstract:

A head-up display for use in an automotive or other vehicle having limited space. The optical path from display symbol generator to a collimating lens is folded to fit in a relatively compact housing. Also shown is the use of the automobile windshield as a combiner glass for the display. Corrective lenses, and in particular crossed linear fresnel lenses, are used to correct for the astigmatism introduced by the geometry of the windshield. This provides a combination of optical powers for the display lens and the windshield which has the resultant effect of projecting an image from the image source to the driver's eye. The source is a high light output array of light-emitting diodes. A microprocessor based controller for detecting the status of inputs from the automobile is shown. Data is periodically loaded into a random access memory dedicated to controlling the display.