Patent ID: 7068861

Claim:
An optical mark reader, comprising: a. a plurality of light sources, each configured and arranged to illuminate an area of a surface, the illuminated area having a reflectance; b. a plurality of light detectors, each configured and arranged to receive at least a portion of any light reflected by the surface from a respective one of the plurality of light sources and output a signal indicative of the intensity of the received light; c. a controller operatively connected to the plurality of detectors and configured and arranged to receive the signals output from the plurality of detectors; and d. a plurality of power sources, each power source operatively connected to one of the plurality of light sources and operatively connected to the controller, and configured and arranged to supply power to the light source in response to signals from the controller, wherein the controller is configured and arranged to generate, responsive to the output of each of the plurality of detectors, a signal indicative of the reflectance of the respective illuminated area.