Head-up display system.

摘要

A head-up display system comprises apparatus (30) for projecting a virtual image (13) of information to be viewed by a vehicle operator at an image plane (12) forward of the vehicle operator, a sensing device (18) for sensing the background illumination of the image plane, and a controller (30) responsive to the sensing device (18) for actively controlling the brightness of the projected image (13) at the image plane (12) to maintain the projected image (13) at a constant contrast level with the background illumination (12). In case of a multi-coloured display, each colour is controlled separately. <IMAGE>