Patent ID: 6240652
Filing Date: 2001-06-05
Classification: B62D,G01D

Abstract:
An optoelectronic position detecting device for determining the position of a movable body that is rotatable with respect to a fixed body, the device comprising:a light source for providing light;a light guiding transmitter disc coupled to the movable body to move in correspondence therewith, the transmitter disc disposed laterally with respect to the light source, the transmitter disc having a scanning code trace on one surface and a reference code trace on the opposite surface, the scanning code trace spirally extending around the one surface of the transmitter disc, the reference code trace circularly extending around the opposite surface of the transmitter disc, the transmitter disc having a periphery connecting the opposing surfaces, the periphery laterally receiving light from the light source, the scanning code trace and the reference code trace having respective reflective notches extending into the opposed surfaces for reflecting respective parallel light beams from the light received from the light source, the scanning code trace and the reference code trace reflecting the light beams perpendicular to the light laterally received by the periphery from the light source; anda photosensitive line sensor disposed perpendicular to the light source and disposed beneath the transmitter disc in a plane parallel therewith and fixed with respect to the transmitter disc for receiving the respective reflected light beams from the scanning code trace and the reference code trace, wherein the photosensitive line sensor generates output signals in response to the respective reflected light beams from the scanning code trace and the reference code trace, the output signals being indicative of the position of the movable body with respect to the fixed body as the movable body rotates.