A display device for displaying information is provided with an optical system for guiding the light of the display device to the eye, the optical system having, in the order in the proceeding direction of the light, an entrance face for receiving the light, a curved face for totally reflecting the light...http://www.google.com/patents/US7567385?utm_source=gb-gplus-sharePatent US7567385 - Head-up display device with curved optical surface having total reflection
