LED driving circuitry with light intensity feedback to control output light intensity of an LED
First Claim
1. An LED indicator system, comprising:
- (a) at least one LED;
(b) a power supply to supply current to the at least one LED based on a received synthesized intensity feedback signal;
(c) a photodetector to detect a luminous output of the at least one LED, and to correspondingly output a detection signal;
(d) a compensation circuit to remove components of stray light from at least one source other than said at least one LED from the detection signal to generate the synthesized intensity feedback signal provided to the power supply.
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Accused Products
Abstract
An LED indicator system with at least one LED, and driving circuitry for driving the at least one LED. A power supply supplies a drive current to the at least one LED. A photodetector detects a luminous output of the at least one LED and correspondingly outputs a detection signal. A conditioning circuit removes signal components indicative of stray light from at least one source other than the at least one LED, for example from sunlight reflected off of an LED array including the at least one LED, from the detection signal. As a result, the conditioning circuit generates a synthesized intensity feedback signal to provide to the power supply. The LED indicator system and driving circuitry for the at least one LED may further include a controller which compares the current supplied by the power supply to the at least one LED with the synthesized intensity feedback signal. A transmitter may transmit a signal indicating a result of the comparison executed by the controller.
255 Citations
19 Claims
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1. An LED indicator system, comprising:
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(a) at least one LED; (b) a power supply to supply current to the at least one LED based on a received synthesized intensity feedback signal; (c) a photodetector to detect a luminous output of the at least one LED, and to correspondingly output a detection signal; (d) a compensation circuit to remove components of stray light from at least one source other than said at least one LED from the detection signal to generate the synthesized intensity feedback signal provided to the power supply. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A driving circuit for at least one LED, comprising:
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(a) a power supply to supply current to the at least one LED based on a received synthesized intensity feedback signal; (b) a photodetector to detect a luminous output of the at least one LED, and to correspondingly output a detection signal; (c) a compensation circuit to remove components of stray light from at least one source other than said at least one LED from the detection signal to generate the synthesized intensity feedback signal provided to the power supply. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. An LED indicator system, comprising:
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(a) at least one LED; (b) a power supply to supply current to the at least one LED based on a received synthesized intensity feedback signal; (c) a photodetector to detect a luminous output of the at least one LED, and to correspondingly output a detection signal; (d) means for removing components of stray light from at least one source other than said at least one LED from the detection signal to generate the synthesized intensity feedback signal provided to the power supply.
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Specification