A device for displaying a virtual image with two mirrors for the dashboard of a vehicle

摘要

A virtual image display for vehicles that includesan image source for providing imaging illumination, anegative power aspheric off-axis mirror responsive to theimage source imaging illumination for providing divergingreflected imaging illumination, and a positive poweraspheric off-axis mirror responsive to the divergingimaging illumination for providing converging reflectedimaging illumination that produces a virtual image of theimage source observable by the vehicle operator at aviewing distance that is greater than the optical pathtravelled by the imaging illumination from the imagesource and the eyes of the vehicle operator. The use of anegative power mirror with a positive power mirror pro-vides for a compact display system which can includerelatively large image sources such as electromechanicalgauges, and which provides for a relatively far viewingdistance and a relatively large field of view.