LED drive current adjustment for irradiance step response output

Patent metadata

Field	Value
Publication number	US-9313854-B2
Application number	US-201414309772-A
Country	US
Kind code	B2
Filing date	Jun 19, 2014
Priority date	Jun 19, 2014
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

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

The invention claimed is:

1. A system for operating one or more light emitting devices, comprising:
a voltage regulator including a feedback input, the voltage regulator in electrical communication with the one or more light emitting devices; and
a controller including non-transitory instructions to provide a linearized correction to current supplied to the one or more light emitting devices, where the linearized correction is a correction based on normalized light output and lighting device temperature.

2. The system of claim 1 , where the linearized correction is based on a slope and offset.

3. The system of claim 2 , further comprising additional instructions to divide the current supplied to the one or more light emitting devices by the linearized correction.

4. The system of claim 1 , further comprising additional instructions to revise the linearized correction in response to a temperature change of the one or more light emitting devices.

5. The system of claim 1 , further comprising additional instructions to not revise the linearized correction in response to an absence of temperature change of the one or more light emitting devices.

6. The system of claim 1 , further comprising additional instructions to revise the linearized correction at a fixed time interval.

7. A method for operating one or more light emitting devices, comprising:
selecting a current that corresponds to a desired irradiance output of the one or more light emitting devices in response to a change in the desired irradiance output of the one or more light emitting devices; and
outputting the current modified via a linearized current adjustment to the one or more light emitting devices, where the linearized current adjustment is based on a slope and offset.

8. The method of claim 7 , where the linearized current adjustment is based on a temperature of the one or more light emitting devices.

9. The method of claim 7 , where the current is divided by the linearized current adjustment.

10. The method of claim 7 , where the slope and offset are based on normalized irradiance and a temperature of the one or more light emitting devices.

11. The method of claim 7 , where a variable resistor is adjusted to provide the current modified via the linearized current adjustment to the one or more light emitting devices.

12. The method of claim 7 , where the change is a step increase change.

13. The method of claim 7 , where the change is a step decrease change.

14. A method for operating one or more light emitting devices, comprising:
in response to a change in a temperature of the one or more light emitting devices being less than a threshold, continuing to monitor the temperature of the one or more light emitting devices and not revising a current supplied to the one or more light emitting devices; and
in response to a change in a temperature of the one or more light emitting devices being greater than the threshold, revising the current supplied to the one or more light emitting devices in response to a temperature based linearized current adjustment.

15. The method of claim 14 , where the threshold is based on a slope.

16. The method of claim 15 , where the slope is based on a linear relationship between irradiation of the one or more light emitting devices and a temperature of the one or more light emitting devices.

17. The method of claim 16 , where the irradiation is normalized.

18. The method of claim 14 , where the current supplied to the one or more light emitting devices is divided by a current modifier.

Assignees

• Phoseon Technology Inc

Inventors

• Moore Ognyan
• Eddy Paul
• Smith Jeff

Classifications

• H05B45/395 Primary

  Linear regulators · CPC title

• H05B45/10

  Controlling the intensity of the light · CPC title

• H05B45/44

  with an active control inside an LED matrix · CPC title

• H05B33/0851 Primary

  Electricity · mapped topic

• H05B45/375

  using buck topology · CPC title