Head up display system using a diffusing image plane

A head up display system (20) having a diffusing image plane (21) or diffuser (21). The light output of a relatively small image source (13) is imaged on the diffuser by way of imaging optics (22). A mirror (12) is used to image light from the diffuser onto a windshield (11) and correct for distortion caused by the windshield. The diffuser is advantageously used when a large field-of-view is desired, or sun load characteristics need to be addressed. The diffuser may be flat or curved in order to optimize the system for different applications. The magnification of the mirror may be made relatively low, and the solar energy density that is made incident on the image source is reduced, providing for a low cost, high performance, color head up display system.