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 semitransparent 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 following three advantages: 1) Since the light-blocking mechanism is embedded inside the display and no additional setting is needed, it can be used anywhere, e.g., outdoor, 2) Since incoming light can surely be cut off in any situation, virtual images keep their original intended colors, e.g, black, 3) Since the light-blocking mechanism is separated with the display for color graphics, most existing see-through displays can be employed. We also describe our prototype display that has confirmed the effectiveness of the approach.