Patent ID: 7982175

Claim:
A reflective optical encoder system, comprising: (a) an encoder, comprising: (i) a surface mount substrate; (ii) a light emitter disposed on the substrate and configured to emit light therefrom; (iii) an array of light detectors disposed on the substrate and arranged along a common axis to form a single track light detector having first and second ends, the single track light detector having disposed along the axis a plurality of alternating sequences of pairs of A and B data channel light detectors and A/ and B/ data channel light detectors, the A and A/ light detectors, and the B and B/ light detectors, respectively, being arranged 90 degrees out of phase with respect to one another, the axis being oriented along and parallel to an azimuth, and (iv) at least a first index channel light detector disposed on the substrate and having a light-detecting portion of about a first width W as measured in the direction of the azimuth, and (b) a code scale comprising data strips and at least a first substantially non-reflective index strip located at a third end of the code scale, the code scale being configured to travel parallel to the axis and above the encoder, the code scale being located and configured operably in respect of the encoder such that at least portions of light emitted from the light emitter are reflected from the code scale towards the single track light detector and the index channel light detector; wherein the light emitter, the single track light detector and the index channel light detector are operably connected to processing circuitry, the index channel light detector is located adjacent to the first end or the second end of the single track light detector, the index channel light detector does not overlap with the single track light detector anywhere along the axis, the first index strip has a second width greater than or equal to about W as measured in the direction of the azimuth, and as the first index strip moves along the azimuth and into alignment with the index channel light detector a first end-of-motion or limit signal is generated by the processing circuitry.