Automatic power control circuit
A control circuit of a light-emitting device comprises a negative-feedback loop including a photodetector and a sample and hold circuit. The photodetector monitors an optical signal emitted by the light-emitting device and the sample and hold circuit generates a control signal supplied to a light-em...
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Main Author | |
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Format | Patent |
Language | English |
Published |
03.03.1998
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Edition | 6 |
Subjects | |
Online Access | Get full text |
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Summary: | A control circuit of a light-emitting device comprises a negative-feedback loop including a photodetector and a sample and hold circuit. The photodetector monitors an optical signal emitted by the light-emitting device and the sample and hold circuit generates a control signal supplied to a light-emitting device driver. The sample and hold circuit performs the sampling of a monitored signal each time the light-emitting device emits light and holds the sampled monitored signal. The voltage held in the sample and hold circuit is output as the control signal the light-emitting device driver. The light-emitting device driver drives the light-emitting device to switch on and off according to the input digital data with the output light intensity of the light-emitting device controlled by the control signal so as to be kept at a constant level. |
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Bibliography: | Application Number: US19950573147 |