Relative angle detection apparatus utilizing polarization and virtual reality providing system using the apparatus

摘要

A relative angle detection apparatus requiring only a short time to become active and causing only a small detection error, and a virtual reality providing system adopting the relative angle detection apparatus have been disclosed. The relative angle detection apparatus is a relative angle detection apparatus for detecting a revolution on a plane perpendicular to each axis of an orthogonal coordinate system made by a mounted unit, and includes first to third revolution detecting units each for detecting a revolution about each of the first to third axes of the orthogonal coordinate system serving as axes of revolution. At least one of the first to third revolution detecting units is realized with an optical angle detection unit for detecting an angle of revolution by utilizing polarization. The optical angle detection unit consists of a light source unit separated from the mounted unit, a light-receiving unit united with the mounted unit, and an arithmetic unit. The light source unit irradiates polarized light, of which direction of polarization is confined to a given initial direction, in a direction substantially parallel to an associated axis of revolution. The light-receiving unit includes a polarization filter for receiving light emanating from the light source unit, and a light-receiving device for receiving light emanating from the light source unit and passing through the polarization filter. The arithmetic unit calculates a relative angle of the mounted unit with respect to the given initial direction on the basis of the intensity of a signal output from the light-receiving device.