Patent ID: 7816638
Filing Date: 2010-10-19
Classification: H05B

Abstract:
1. An optical system, comprising: an array light-emitting diodes arranged to perform an operation, the operation having one or more characteristics of the light emitting diodes in association with a particular area of the array; at least one of the light-emitting diodes in the array being configured solely as a detector electrically connected to a circuit different from that of the other light-emitting diodes, the circuit to apply a reverse electrical bias to the detector light-emitting diode, the detector light-emitting diode arranged to operate in a photovoltaic mode and having its output coupled to a trans-impedance amplifier to generate a signal proportional to a photocurrent from the detector, the detector located in a selected position in the array to monitor one or more characteristics of the light emitting diodes of the particular area of the array; and a controller configured to control the particular area of the array responsive, at least in part, to the signal from the at least one detector.