Patent ID: 7620330

Claim:
An optoelectronic device, comprising: a support surface; at least two bright photodetectors positioned on the support surface; a dark photodetector positioned on the support surface, wherein the dark photodetector is substantially identical to the at least two bright photodetectors and closely adjacent to the at least two bright photodetectors, and wherein: each of the at least two bright photodetectors has a receiver and an output, wherein each bright photodetector receiver is on a side opposite the support surface and is configured to receive light; and the dark photodetector has a receiver and an output, wherein the dark photodetector receiver is on the side opposite the support surface and is configured to not receive light; and a subtraction circuit, wherein the subtraction circuit is configured to be coupled to the output of only one of the at least two bright photodetectors at any given time, wherein the subtraction circuit is also configured to be coupled to the output of the dark photodetector, and wherein the subtraction circuit is configured to provide an electrical data signal that results from a subtraction of an electrical signal output by the dark photodetector from an electrical signal output by the only one of the at least two bright photodetectors.