Patent ID: 9354087
Filing Date: 2016-05-31
CPC Classification: G01D

Claim Text:
1. An encoder for use in an optical encoding system, comprising: an emitter configured to emit light; a detector configured to receive at least a portion of the light emitted by the emitter and convert the received light into one or more electrical signals which are used to generate three output signals, wherein the light used to generate the three output signals at least one of passed through and was reflected by a single optical track of a coding element, wherein one of the three output signals comprises a differential index signal, and wherein the single optical track comprises an index bar, an index window, and at least one non-index bar that separates the index bar from the index window, wherein the detector comprises a sensor area that includes an array of incremental photodiodes, a first index photodiode that generates a first index output, and a second index photodiode that generates a second index output, the second index output being subtracted from the first index output to generate the differential index signal.