Multi-LED Control
First Claim
1. An apparatus for controlling multiple, series coupled light emitting diodes (LEDs), the apparatus comprising:
- a first LED driver to generate;
a first switch control signal to control a duty cycle of a first switch coupled in parallel across at least a first LED; and
a second switch control signal to control a duty cycle of a second switch coupled to at least a second LED to vary a relative intensity of the first and second LEDs, wherein the first LED is coupled in series with the second LED.
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Accused Products
Abstract
A LED driver and controller system utilizes switches to parallel connect to respective sets of one or more LEDs and a current source to provide efficient control of the LEDs. In at least one embodiment, the LEDs are connected in series. An LED controller of the LED driver and controller system 200 controls conductivity of the switches. In at least one embodiment, the LED controller provides control signals to one or more LED drivers. The LED drivers receive the control signals and, in response to the control signals, control the conductivity of each switch. In at least one embodiment, the conductivity of the each switch is controlled using a duty cycle modulated control signal. In at least one embodiment, the duty cycle modulated control signal is a pulse width modulated control signal. In another embodiment, the duty cycle modulated control signal is a pulse density modulated control signal.
129 Citations
31 Claims
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1. An apparatus for controlling multiple, series coupled light emitting diodes (LEDs), the apparatus comprising:
a first LED driver to generate; a first switch control signal to control a duty cycle of a first switch coupled in parallel across at least a first LED; and a second switch control signal to control a duty cycle of a second switch coupled to at least a second LED to vary a relative intensity of the first and second LEDs, wherein the first LED is coupled in series with the second LED. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method for controlling multiple, series coupled light emitting diodes (LEDs), the method comprising:
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generating a first switch control signal to control a duty cycle of a first switch coupled in parallel across at least a first LED; and generating a second switch control signal to control a duty cycle of a second switch coupled to at least a second LED to vary a relative intensity of the first and second LEDs, wherein the first LED is coupled in series with the second LED. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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Specification