The present invention relates to optical pitch yaw and roll tracking, and in particular to a system for tracking the position of a head or hand of a user for cursor control in interactive television and computer systems, and also for visual tracking display in virtual reality systems.
Remote wireless control of a cursor on a television screen or computer screen has become increasingly popular. See, for example, U.S. Pat. No. 5,045,843, incorporated herein by reference. Movements of a photodetector on a movable remote unit are detected with respect to a light beam source on a fixed base unit. Thus, the direction that the remote unit is pointing is determined and this information is used by the base unit to control the position of a cursor on a television screen or computer screen.
The photodetector on the movable remote unit detects the pointing orientation with respect to the light beam. This provides for two-dimensional orientation detection and signals related to the angular rotative and/or translational orientation between the light beam source and the photodetector are generated at the output of the photodetector. That is, the "pitch" and "yaw" of the remote unit are determined with respect to the light beam source of the base unit.
While the photodetector affords adequate pointing position detection of the remote unit relative to the base by determining relative pitch and yaw, it has been found that more accurate pointing orientation detection, and thus more precise cursor control, can be achieved if the "roll" of the movable remote unit is determined, to correct the determined "pitch" and "yaw" components. Moreover, information related to the roll of the remote unit has useful applications alone.