CPC G01J 3/513 (2013.01) [H01L 27/1461 (2013.01); H01L 27/14616 (2013.01); H01L 27/14621 (2013.01); H01L 27/14623 (2013.01); H01L 27/14629 (2013.01); H01L 27/14645 (2013.01)] | 20 Claims |
1. A system for detecting presence or absence of an object, the system comprising:
a sensor unit, which comprises a plurality of optical sensors, wherein each of the optical sensors is positioned to detect light that is directed from an illumination source; and
a circuit that is electrically connected to each of the optical sensors and that is configured to, when the illumination source directs light into the plurality of optical sensors:
receive signals from each of the plurality of optical sensors,
use the received signals from each of the plurality of optical sensors to generate an output that indicates a color, wherein the color correlates to a surface color of an object; and
if the color corresponds to a predetermined surface color, determine that the object is placed over the sensor unit, otherwise not determine that the object is placed over the sensor unit.
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