Patent attributes
A system and method for determining the absolute position of a linear or rotary actuator. A code plate having a series of digital words thereon is associated with the linear or rotary actuator. Each of the digital words consists of a plurality of bits, each bit consisting of a series of parallel encoder elements, each in the shape of a wedge. One or two optical sensor heads would be used in conjunction with a signal processor to determine the exact position of the code plate, and, in turn, the linear or rotary actuator. The exact position of each of the sensor heads with respect to the code plate is determined based upon the value of optical signals reflected off of the wedge-shaped elements and detected by each of the optical sensors.