Interference-resistant compensation for illumination devices using multiple series of measurement intervals
First Claim
1. A method for controlling an illumination device comprising multiple emission light emitting diode (LED) elements, the method comprising:
- operating one or more of the multiple emission LED elements to produce illumination substantially continuously by supplying a respective drive current at an operative drive current level to each of the one or more of the multiple emission LED elements;
bringing the respective drive current of all except one of the emission LED elements within the illumination device to a non-operative drive current level, which is insufficient to produce illumination, for the duration of a first measurement interval, wherein the first measurement interval is one of a first series of measurement intervals interspersed with periods of said illumination; and
bringing the respective drive current of all except one of the emission LED elements to a non-operative drive current level, which is insufficient to produce illumination, for the duration of a second measurement interval subsequent to the first measurement interval, wherein the second measurement interval is one of a second series of measurement intervals interspersed with periods of said illumination, and wherein the first series of measurement intervals and second series of measurement intervals are separated by respective first and second offsets from a timing reference.
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Abstract
A method and illumination device are provided for interference-resistant compensation in light emitting diode (LED) illumination devices. In one embodiment, the method includes bringing to a level insufficient to produce illumination the respective drive current of all except one of multiple emission LED elements for the duration of a first measurement interval and a later-occurring second measurement interval. The first and second measurement intervals are within respective first and second series of measurement intervals interspersed with periods of illumination, and the first and second series of measurement intervals are separated by respective first and second offsets from a timing reference. An embodiment of an illumination device includes multiple emission LED elements, one or more photodetectors, and a lamp control circuit, where the lamp control circuit is adapted to perform steps of the method.
264 Citations
21 Claims
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1. A method for controlling an illumination device comprising multiple emission light emitting diode (LED) elements, the method comprising:
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operating one or more of the multiple emission LED elements to produce illumination substantially continuously by supplying a respective drive current at an operative drive current level to each of the one or more of the multiple emission LED elements; bringing the respective drive current of all except one of the emission LED elements within the illumination device to a non-operative drive current level, which is insufficient to produce illumination, for the duration of a first measurement interval, wherein the first measurement interval is one of a first series of measurement intervals interspersed with periods of said illumination; and bringing the respective drive current of all except one of the emission LED elements to a non-operative drive current level, which is insufficient to produce illumination, for the duration of a second measurement interval subsequent to the first measurement interval, wherein the second measurement interval is one of a second series of measurement intervals interspersed with periods of said illumination, and wherein the first series of measurement intervals and second series of measurement intervals are separated by respective first and second offsets from a timing reference. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An illumination device, comprising:
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multiple emission light emitting diode (LED) elements; one or more photodetectors; and a control circuit operably coupled to the multiple emission LED elements and the one or more photodetectors, wherein the control circuit is adapted to; operate one or more of the multiple emission LED elements to produce illumination substantially continuously by supplying a respective drive current at an operative drive current level to each of the one or more of the multiple emission LED elements; bring the respective drive currents of all except one of the emission LED elements within the illumination device to a non-operative drive current level, which is insufficient to produce illumination for the duration of a first measurement interval, wherein the first measurement interval is one of a first series of measurement intervals interspersed with periods of said illumination; and bring the respective drive currents of all except one of the emission LED elements to a non-operative drive current level, which is insufficient to produce illumination, for the duration of a second measurement interval subsequent to the first measurement interval, wherein the second measurement interval is one of a second series of measurement intervals interspersed with periods of said illumination, and wherein the first series of measurement intervals and second series of measurement intervals are separated by respective first and second offsets from a timing reference. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification