Optical sensing apparatus for detecting linear displacement of an object and method of operation thereof with detector matrix and centroid detection
 Apparatus for sensing linear displacement of an object between first and second locations along an axis is used to sense conditions that can be made to vary displacement of an object in accordance with the condition, such as temperature, pressure and rotary motion. A light beam projected along an incident light path to the object is reflected along a reflective light path by a reflector affixed to the object. A photo-sensor array in the reflective light path intercepts the reflected light beam and produces samples of the intensity of the reflected image at multiple positions along a line across the array. An imager coupled to the array converts the light samples to representative electrical samples. The resultant light intensity information is provided to an electronic processor which determines a first centroid of the reflected image when the object is at a first location and a second centroid when the object is at a second location, and employs the difference between the first and second centroids to determine the displacement of the object. 
General Electric Company
G
G01D
inventional
Chung-Yih Jerome J. Ertugrul Fathy F.
Ho Tiemann Berkcan Yassa