Hybrid driving scheme for RGB color tuning

Patent metadata

Field	Value
Publication number	US-11140758-B2
Application number	US-201916543230-A
Country	US
Kind code	B2
Filing date	Aug 16, 2019
Priority date	Jan 25, 2019
Publication date	Oct 5, 2021
Grant date	Oct 5, 2021

Abstract

A device includes an analog current division circuit configured to divide an input current into a first current and a second current, and a multiplexer array including a plurality of switches to provide the first current to a first of three colors of LEDs and the second current to a second of three colors of LEDs simultaneously during a first portion of a period, the first current to the second of three colors of LEDs and the second current to a third of three colors of LEDs simultaneously during a second portion of the period, and the first current to the first of three colors of LEDs and the second current to the third of three colors of LEDs simultaneously during a third portion of the period.

First claim

What is claimed is:

1. A light-emitting diode (LED) color tuning apparatus, comprising:
a hybrid driving-circuit to be coupled to a multi-colored LED array, the hybrid driving-circuit including:
an analog current-division circuit to produce current for at least two LED current-driving sources; and
a switching array coupled between the analog current-division circuit and the multi-colored LED array, the switching array being configured to provide periodically, for a predetermined amount of time, current from at least one of the at least two LED current-driving sources to at least two colors of the multi-colored LED array substantially simultaneously.

2. The LED color tuning apparatus of claim 1 , further comprising an LED driver electrically coupled to a voltage regulator, the voltage regulator to provide a voltage signal for the multi-colored LED array, a combination of the LED driver and the voltage regulator to provide a stabilized current as an input to the analog current-division circuit.

3. The LED color tuning apparatus of claim 1 , wherein the switching array comprises a multiplexer array.

4. The LED color tuning apparatus of claim 1 , further comprising a voltage-controlled current source configured to supply current to the analog current-division circuit to produce the current for the at least two LED current-driving sources.

5. The LED color tuning apparatus of claim 1 , wherein the switching array is configured to:
provide a first current from a first of the at least two LED current-driving sources to a first of three colors in the multi-colored LED array and a second current from a second of the at least two LED current-driving sources to a second of three colors in the multi-colored LED array substantially simultaneously during a first portion of a time period,
provide the first current to the second of three colors in the multi-colored LED array and the second current to a third of three colors of in the multi-colored LED array substantially simultaneously during a second portion of the time period, and
provide the first current to the first of three colors in the multi-colored LED array and the second current to the third of three colors in the in the multi-colored LED array substantially simultaneously during a third portion of the time period.

6. The LED color tuning apparatus of claim 5 , wherein the first portion, the second portion, and the third portion of the time period are selectable using pulse width modulation (PWM) time slicing.

7. The LED color tuning apparatus of claim 5 , wherein the first current and the second current sum to substantially be equal an input current supplied to the analog current-division circuit from an LED driver.

8. The LED color tuning apparatus of claim 5 , wherein each of the at least two LED current-driving sources are configured to supply substantially equal amounts of current to the multi-colored LED array.

9. The LED color tuning apparatus of claim 5 , wherein each of the at least two LED current-driving sources are configured to supply unequal amounts of current to the multi-colored LED array.

10. The LED color tuning apparatus of claim 1 , wherein the multi-colored LED array comprises at least one red-colored LED, at least one green-colored LED, and at least one blue-colored LED.

11. The LED color tuning apparatus of claim 1 , wherein the multi-colored LED array comprises at least one desaturated red LED, at least one desaturated green LED, and at least one desaturated blue LED.

12. The LED color tuning apparatus of claim 1 , wherein the switching array comprises at least four switching devices.

13. The LED color tuning apparatus of claim 1 , wherein the hybrid driving-circuit is further configured to supply a pulse-width modulation (PWM) time slicing signal to selected ones of the multi-colored LED array.

14. A light-emitting diode (LED) color tuning apparatus, comprising:
a multi-colored LED array comprising at least one desaturated red LED, at least one desaturated green LED, and at least one desaturated blue LED; and
a hybrid driving-circuit coupled to the multi-colored LED array, the hybrid driving-circuit including:
an analog current-division circuit to produce current for at least two LED current-driving sources; and
a switching array coupled between the analog current-division circuit and the multi-colored LED array, the switching array being configured to provide periodically, for a predetermined amount of time, current from at least one of the at least two LED current-driving sources to at least two colors of the multi-colored LED array substantially simultaneously.

15. The LED color tuning apparatus of claim 14 , further comprising a voltage-controlled current source configured to supply current to the analog current-division circuit to produce the current for the at least two LED current-driving sources.

16. The LED color tuning apparatus of claim 15 , further comprising a computational device configured to compare a first sensed-voltage, V SENSE1 , and a second sensed-voltage, V SENSE2 , to determine and supply a set voltage, V SET , the set voltage being an input voltage for the voltage-controlled current source.

17. The LED color tuning apparatus of claim 14 , wherein the hybrid driving-circuit is further configured to supply a pulse-width modulation (PWM) time slicing signal to selected ones of the multi-colored LED array.

18. The LED color tuning apparatus of claim 14 , further comprising an LED driver electrically coupled to a voltage regulator, the voltage regulator to provide a voltage signal for the multi-colored LED array, a combination of the LED driver and the voltage regulator to provide a stabilized current as an input to the analog current-division circuit.

19. A method for tuning a multi-colored, light-emitting diode (LED) array, the method comprising:
determining and supplying a set voltage as an input voltage for a voltage-controlled current source;
dividing an input current into a first current and a second current; and
based on a determination of a color temperature:
providing the first current to a first of three colors of the multi-colored LED array and providing the second current to a second of three colors of the multi-colored LED array substantially simultaneously during a first portion of a time period;
providing the first current to the second of three colors of the multi-colored LED array and providing the second current to a third of three colors of the multi-colored LED array substantially simultaneously during a second portion of the time period; and
providing the first current to the first of three colors of the multi-colored LED array and providing the second current to the third of three colors of the LED multi-colored array substantially simultaneously during a third portion of the period.

20. The method for tuning a multi-colored, LED array of claim 19 , wherein the providing of the first current and the providing of the second current to different duplets of the LED multi-colored array occurs using pulse-width modulation (PWM) time slicing.

Assignees

• Lumileds Llc

Inventors

• Qiu Yifeng
• Grant John

Classifications

• H05B45/37

  Converter circuits · CPC title

• H05B45/28

  using temperature feedback · CPC title

• H05B45/395

  Linear regulators · CPC title

• H05B45/20 Primary

  Controlling the colour of the light · CPC title

• H05B45/325

  Pulse-width modulation [PWM] · CPC title