Systems and methods for multi-state switch networks
AssigneeApple Inc.
InventorsJeffrey Terlizzi, Nicholas R. Kalayjian
Life of this patent
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Abstract
Systems and methods for multi-state switch networks and multi-state LED networks are provided. Systems and methods for maintaining the brightness of LEDs in multi-state LED networks are also provided. The multi-state networks contain control circuitry that can output a single control signal that is able to drive a pair of diodes in three different states. In a network of 2*N diodes, N wires are sufficient to drive the diodes in 3N different states. The control circuitry may also include a pulse-width modulator that controls the perceived brightness of the LEDs in a multi-state LED network in response to a voltage level of the power source.
Claims24
A multi-state switch network comprising:
- a serially-connected diode pair that receives a single control signal;
- and
- wherein the single control signal is operative to drive the serially-connected diode pair to one of at least three different states.
A multi-state switch network comprising:
- a first diode and a second diode that receive a single control signal, wherein the single control signal is operative to alternatively:
- turn OFF the first diode and turn ON the second diode;
- turn ON the first diode and turn OFF the second diode;
- and
- turn OFF the first diode and turn OFF the second diode.
A multi-state switch network comprising:
- a power source;
- a ground source;
- a first LED electrically coupled to the power source;
- a first resistor electrically coupled to the first LED;
- a second resistor electrically coupled to the first resistor;
- a second LED electrically coupled to the second resistor and the ground source;
- and
- control circuitry electrically coupled to a node existing between the first and second resistors, the control circuitry operative to selectively turn the first and second LEDs ON and OFF by providing a control signal to the node.
A method of controlling a multi-state switch network comprising first and second diodes, the method comprising:
- receiving a single control signal;
- and
- in response to the single control signal, alternatively:
- turning ON the first diode and turning OFF the second diode;
- turning OFF the first diode and turning ON the second diode;
- and
- turning OFF the first diode and turning OFF the second diode.
A system for controlling a multi-state LED network, the system comprising:
- processor circuitry;
- power distribution circuitry;
- a switch network comprising first and second diodes, wherein the switch network is operative to:
- receive a single control signal from the processor circuitry;
- receive voltage level control signal from the power distribution circuitry;
- drive the first and second diodes to one of at least three different states in response to the single control signal;
- and
- adjust a duty cycle of the single control signal based on the voltage level control signal.
Dependencies are inferred from the claim text.