An optical see-through display for mutual occlusion of real and virtual environments

In a mixed reality system, mutual occlusion of real and virtual environments enhances the user's feeling that virtual objects truly exist in the real world. However, conventional optical see-through displays cannot present mutual occlusion correctly since the synthetic objects always appear as semi-transparent ghosts floating in front of the real scene. In this paper, we propose a novel display design that attacks this well-known unsettled problem. Our optical see-through display with mutual occlusion capability has the following advantages: (1) since the light-blocking mechanism is embedded in the display and no additional setting is needed, it can be used anywhere, e.g. outdoors; (2) since incoming light can easily be cut off in any situation, virtual images keep their original intended colors, e.g. black; (3) since the light-blocking mechanism is separated from the display for color graphics, most existing see-through displays can be employed. We also describe our prototype display, which has confirmed the effectiveness of the approach.