A method of constructing a telexistence visual system using fixed screens

Projection-based visual display systems are expected to be effective platforms for virtual reality (VR) applications in which the displayed images are generated by computer graphics using 3D models of virtual worlds. However, these kinds of visual displays, as well as other kinds of fixed screen-based displays, such as various head-tracked displays (HTDs) and conventional CRT displays, have not been utilized to achieve precise telexistence in a real environment, which requires appropriate stereoscopic video images corresponding to the operator´s head motion. We found that the time-varying off-axis projection required in these systems has prevented fixed screen-based displays from being used for telexistence, as ordinary cameras only have fixed and symmetric fields of view about the optical axis. After evaluating the problem, a method to realize a live video-based telexistence system with a fixed screen is proposed, aiming to provide the operator with a natural 3D sensation of presence. The key component of our method is a feature that keeps the orientation of the cameras fixed, regardless of the operator´s head motion. Such a feature was implemented by designing a constant-orientation link mechanism