Led drive current adjustment for irradiance step response output

Patent metadata

Field	Value
Publication number	US-2016143101-A1
Application number	US-201615007084-A
Country	US
Kind code	A1
Filing date	Jan 26, 2016
Priority date	Jun 19, 2014
Publication date	May 19, 2016
Grant date	—

Abstract

A system and method for operating one or more light emitting devices is disclosed. In one example, the intensity of light provided by the one or more light emitting devices is adjusted responsive to a temperature of the one or more light emitting device. The light is adjusted via modifying a current supplied to the one or more light emitting devices.

First claim

1 . A system for operating one or more light emitting devices, comprising:
a controller including non-transitory instructions to provide a linearized correction to current supplied to one or more light emitting devices, where the linearized correction is based on an equation of a straight line that represents normalized light output versus lighting device temperature for the one or more light emitting devices.

2 . The system of claim 1 , further comprising a driver circuit in electrical communication with the controller.

3 . The system of claim 2 , further comprising a variable resistor in electrical communication with the driver circuit.

4 . The system of claim 3 , further comprising a current sense resistor electrically coupled to the variable resistor and electrical ground.

5 . The system of claim 1 , further a voltage regulator electrically coupled to the controller and the one or more light emitting devices.

6 . The system of claim 5 , where the voltage regulator includes an error amplifier and a pulse width modulator.

7 . The system of claim 5 , where the voltage regulator includes a buck stage.

8 . A method for operating one or more light emitting devices, comprising:
providing a current to one or more light emitting devices that corresponds to a desired irradiance; and modifying the desired irradiance via a linear approximation of lighting array irradiance versus lighting array temperature.

9 . The method of claim 8 , where the linear approximation of lighting array irradiance versus lighting array temperature is expressed as a slope and an offset.

10 . The method of claim 8 , where the lighting array temperature is a temperature of a light emitting diode junction temperature.

11 . The method of claim 8 , where the current is provided via a voltage regulator.

12 . The method of claim 11 , where the current is adjusted via a variable resistor.

13 . The method of claim 12 , where resistance of the variable resistor is adjusted via a controller.

14 . The method of claim 8 , further comprising updating the desired irradiance in response to a change in temperature of the one or more light emitting devices greater than a threshold.

15 . The method of claim 8 , further comprising modifying the current in response to modifying the desired irradiance.

16 . A system for operating one or more light emitting devices, comprising:
a lighting array including one or more light emitting devices; a voltage regulator in electrical communication with the lighting array; and a controller including non-transitory instructions to provide a linearized correction to current supplied to the one or more light emitting devices via the voltage regulator, where the linearized correction is based on an equation of a straight line that represents normalized light output versus lighting device temperature for the one or more light emitting devices.

17 . The system of claim 16 , further comprising a variable resistor, the variable resistor in electrical communication with the controller.

18 . The system of claim 17 , further comprising a driver circuit in electrical communication with the variable resistor and the controller.

19 . The system of claim 16 , further comprising additional instructions to measure a temperature of the lighting array.

20 . The system of claim 16 , further comprising additional instructions to activate the lighting array at a desired irradiance output.

Assignees

• Phoseon Technology Inc

Inventors

• Moore Ognyan
• Eddy Paul
• Smith Jeff

Classifications

• H05B45/395 Primary

  Linear regulators · CPC title

• H05B45/44

  with an active control inside an LED matrix · CPC title

• H05B45/10

  Controlling the intensity of the light · CPC title

• H05B33/0812 Primary

  Electricity · mapped topic

• H05B33/0851

  Electricity · mapped topic