Patent ID: 7820956
Filing Date: 2010-10-26
Classification: G01D

Abstract:
1. A position transducer system for a limited rotation motor comprising an illumination source that directs illumination toward an illumination reflector that rotates with a rotor of the limited rotation motor said illumination reflector including a plurality of pairs of reflective and non-reflective areas, and a plurality of pairs of detector areas adjacent said illumination source for receiving modulated reflected illumination from said illumination reflector, said plurality of pairs of detector areas corresponding to said plurality of pairs of reflective and non-reflective areas such that each of said pairs of detector areas receives reflected illumination substantially from only one of a respective pair of reflective and non-reflective areas, and wherein each of said pairs of detector areas includes a first detector area and a second detector area, and at all times during rotation, each of the first detector areas of the plurality of pairs of detector areas receives substantially the same amount of illumination, and each of the second detector areas of the plurality of pairs of detector areas receives substantially the same amount of illumination, said plurality of pairs of detector areas being formed on a printed circuit board that further includes the illumination source mounted thereon such that the illumination source is substantially aligned with the axis of rotation of the limited rotation motor, wherein the illumination source provides substantially point source illumination to said illumination reflector and is substantially co-planar with the plurality of pairs of detector areas, and wherein the plurality of pairs of detector areas substantially surround the illumination source and receive illumination from said illumination reflector.