LED-based luminaire utilizing optical feedback color and intensity control scheme

• US 20060006821A1
• Filed: 04/25/2005
• Published: 01/12/2006
• Est. Priority Date: 07/06/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Singer, Jeffrey M., Mangum, Scott R., Butsch, Steve M., Barnhart, Brian J., Summers, Paul L., Vangeel, Michael T.
• Granted Patent: US 7,333,011 B2
• Time in Patent Office: Days
• US Class Current: 315/312
• CPC Class Codes: F21S 4/20 with light sources held by or within elongate supports
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/22 using optical feedback

Abstract

A system and method for implementing an LED-based luminaire (100) incorporates one or more color channels (32-n). The luminaire includes a controller (50) that uses optical sensing and feedback to control LEDs (30A) in each channel to deliver a consistent intensity and/or color output. The optical feedback loop may provide measured intensity and/or color of the luminaire'"'"'s output to the luminaire controller. The controller may then adjust the current, pulse width modulation (PWM) duty cycle, or both, which are delivered to discrete color channels of the luminaire to obtain the desired intensity and/or color.

Claims

1. A luminaire comprising:

an emitter module including a light-emitting diode (LED)-based light source;

an optical sensor configured to produce a measured output by measuring an intensity output of the emitter module; and

a regulating device configured to regulate current delivered to the emitter module based on a comparison of the measured output of the emitter module to a selectable predetermined light setting.

2. The luminaire of claim 1, wherein the selectable predetermined light setting comprises a predetermined intensity setting, and the luminaire further comprises:

a control device configured to;

compare the measured output to a predetermined intensity setting; and

generate a control signal based on a difference between the measured output and the predetermined intensity setting, the control signal being sent to the regulating device to regulate the delivered current,

wherein the regulating device is configured to adjust the current delivered to the emitter module to reduce the difference between the intensity output and the predetermined intensity setting.

3. The luminaire of claim 1, wherein

the emitter module includes at least one color channel, each color channel including at least one LED, and

the optical sensor is configured to produce the measured output by measuring an intensity output for each of a plurality of colors corresponding to the at least one color channel.

4. The luminaire of claim 3, further comprising a control device that determines a ratio of the color intensity outputs, and controls the regulating device based on the determined ratio.

5. The luminaire of claim 4, wherein the control device is operable to distinguish between changes in color intensity and changes in wavelength corresponding to each color channel based on the determined ratio of the color intensity outputs.

6. The luminaire of claim 4, wherein the selectable predetermined light setting comprises a predetermined color setting, and the control device is configured to:

determine a color output of the emitter module based on the determined ratio of the color intensity outputs;

compare the color output to a predetermined color setting; and

generate a control signal based on a difference between the color output and the predetermined color setting, the control signal being sent to the regulating device to regulate the delivered current, and

the regulating device is configured to adjust the current delivered to the emitter module to reduce the difference between the color output and the predetermined color setting.

7. The luminaire of claim 6, wherein

the optical sensor is configured to produce the measured output by measuring an overall intensity output in addition to the color intensity outputs, and

the control device is configured to:

compare the overall intensity output to a predetermined intensity setting; and

generate the control signal being based on;

a difference between the overall intensity output and the predetermined intensity setting, and a difference between the color output and the predetermined color setting, and

the regulating device is configured to adjust the current delivered to the emitter module to reduce a difference between the overall intensity output and the predetermined intensity setting, and reduce a difference between the color output and the predetermined color setting.

8. The luminaire of claim 6, wherein

the control device being communicatively linked to an input device, the input device being used to select the predetermined color setting,

the optical sensor is configured to measure the intensity for each of the plurality of color channels at predetermined intervals, and

for each of the predetermined intervals, the control device is configured to:

determine the color output based on the color intensity outputs of the predetermined interval,

compare the color output to the predetermined color setting most recently received from the input device, and

generate the control signal, which is sent to the regulating device, based on a difference between the most recently received input color parameter and the color output.

9. The luminaire of claim 8, wherein

the control device is communicatively linked to the input device via a data bus, and

the predetermined color setting is digitally transmitted over the data bus to the control device.

10. The luminaire of claim 6, wherein the optical sensor comprises a multi-color sensing integrated circuit.

11. The luminaire of claim 6, wherein the optical sensor comprises one or more color sensing devices, each capable of sensing the intensity of at least one color.

12. The luminaire of claim 6, wherein the regulating device utilizes at least one of direct current (DC) control and pulse width modulation (PWM) to regulate the current delivered to the emitter module.

13. The luminaire of claim 6, further comprising:

a housing; and

a thermal management component;

wherein the housing secures the thermal management component in a position relative to the emitter module that allows the thermal management component to dissipate heat from the emitter module.

14. The luminaire of claim 13, wherein the thermal management component includes at least one of the following:

a heat sink, a heat pipe, a cooling fan, and a thermoelectric cooling device.

15. The luminaire of claim 13, further comprising:

an optical component configured to collect and distribute light from the emitter module according to a predetermined pattern.

16. A cabin lighting system for an aircraft comprising a plurality of luminaires recited in claim 1, the system further comprising:

an input device through which a selectable predetermined light setting is selected for each of the luminaires; and

a data bus communicatively linking the input device to the control device of each of the luminaires,

wherein the selected predetermined light setting for each of the luminaires is digitally transmitted to the luminaire via the data bus.

17. The lighting system of claim 16, wherein, for each luminaire,

the luminaire includes a control device configured to:

receive the selected predetermined light setting from the data bus, the selected predetermined light setting being an intensity setting

compare the intensity output to the selected intensity setting; and

generate a control signal based on a difference between the intensity output and the selected intensity setting, the control signal being sent to the regulating device to regulate the delivered current, and

the regulating device is configured to adjust the current delivered to the emitter module to reduce the difference between the intensity output and the selected intensity setting.

18. The lighting system of claim 16, wherein, for each luminaire,

the emitter module includes a plurality of color channels, each color channel including at least one LED, and

the optical sensor is configured to produce the measured output by measuring an intensity for each of a plurality of colors corresponding to the plurality of color channels.

19. The lighting system of claim 18, wherein, for each luminaire,

the control device is configured to:

receive the selected predetermined light setting from the data bus, the selected predetermined light setting being a color setting;

determine a color output of the emitter module based on a ratio of the color intensity outputs;

compare the color output to the selected color setting; and

generate a control signal based on a difference between the color output and the selected color setting, the control signal being sent to the regulating device to regulate the delivered current, and

the regulating device is configured to adjust the current delivered to the emitter module to reduce the difference between the color output and the selected color setting.

20. The lighting system of claim 19, wherein, for each of the luminaires,

the luminaire includes a control device configured to:

analyze an address segment in a message packet transmitted on the data bus to determine whether the message packet is pertinent to the luminaire;

if the message packet is pertinent, extract the selected predetermined light setting from a data segment in the message packet; and

generate the control signal sent to the regulating device based on the extracted predetermined light setting.