VISIBLE LIGHT COMMUNICATION WITH FLICKERING PREVENTION
First Claim
1. A method, comprising:
- selecting a first intensity level of a light source for transmitting a data symbol to a receiver during a data interval;
selecting a second, different intensity level of the light source based upon the first intensity level to achieve a perceived average intensity level; and
emitting the first intensity level from the light source during the data interval and emitting the second intensity level from the light source during an energy interval to achieve the perceived average intensity level, wherein a receiver is configured to ignore the second intensity level emitted during the energy interval,wherein respective time periods of both the data and energy intervals are set to mitigate an ability of a human eye to detect a change from the first intensity level emitted in the data interval to the second intensity level emitted in the energy interval.
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Accused Products
Abstract
LEDs that transmit or receive data in a VLC may create a flickering effect which is observed when the human eye is able to perceive the fluctuations of the light intensity in a LED. To prevent flickering, the LEDs may emit light based on a pattern of data and energy intervals. During the data intervals, a LED transmitting a message sends one or more data symbols to receiving LEDs. The receiving LEDs, however, are reversed bias and do not emit light. During the energy intervals, any LED in the VLC system may emit light. Each LED uses the energy interval to compensate for the light transmitted (or not transmitted) during the data interval. The combination of data and energy levels results in an observer seeing light with a constant intensity rather than changing intensity.
38 Citations
20 Claims
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1. A method, comprising:
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selecting a first intensity level of a light source for transmitting a data symbol to a receiver during a data interval; selecting a second, different intensity level of the light source based upon the first intensity level to achieve a perceived average intensity level; and emitting the first intensity level from the light source during the data interval and emitting the second intensity level from the light source during an energy interval to achieve the perceived average intensity level, wherein a receiver is configured to ignore the second intensity level emitted during the energy interval, wherein respective time periods of both the data and energy intervals are set to mitigate an ability of a human eye to detect a change from the first intensity level emitted in the data interval to the second intensity level emitted in the energy interval. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system, comprising:
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a light source; and a controller coupled to the light source, the controller configured to select a first intensity level of a light source for transmitting a data symbol to a receiver during a data interval, the controller configured to select a second, different intensity level of the light source based upon the first intensity level to achieve a perceived average intensity level, wherein the light source is configured to emit the first intensity level during the data interval and emit the second intensity level during an energy interval to achieve the perceived average intensity level, wherein the receiver ignores the second intensity level emitted during the energy interval, and wherein respective time periods of both the data and energy intervals are set to mitigate an ability of a human eye to detect a change from the first intensity level emitted in the data interval to the second intensity level emitted in the energy interval. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. A method, comprising:
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establishing an optical communication channel between a first semiconductor light source and a second semiconductor light source according to a predetermined interval pattern comprising at least one data interval and at least energy interval; detecting incident light by reverse biasing the first semiconductor light source during the data interval; selecting an intensity level of the first semiconductor light source to achieve a perceived average intensity level, wherein the perceived average intensity level is an average of the light emitted by the first semiconductor light source during the data and energy intervals; and emitting the intensity level by forward biasing the first semiconductor light source during the energy interval to achieve the perceived average intensity level; and repeating the predefined interval pattern to maintain the perceived average intensity level, wherein respective time periods of both the data and energy intervals are set to mitigate an ability of a human eye to detect a change from the first intensity level emitted in the data interval to the second intensity level emitted in the energy interval.
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Specification