Color-compensating Fluorescent-LED hybrid lighting

• US 7,498,753 B2
• Filed: 12/30/2006
• Issued: 03/03/2009
• Est. Priority Date: 12/30/2006
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Larsen, Ty A., McAvoy, Michael B., Cote, Richard A.
• Primary Examiner(s): Vu; David Hung
• Assistant Examiner(s): Le; Tung X
• Application Number:
  US11/618,747
• Publication Number:
  US 20080158871A1
• Time in Patent Office: 794 Days
• Field of Search: 315/209.R, 315246-247, 315/291, 315/294, 315307-309, 315/312, 315/DIG.4, 315149-150, 315/156, 315/158, 345 82- 84, 345/102, 345/204, 362/227
• US Class Current: 315/291
• CPC Class Codes: H05B 35/00 Electric light sources using a combination of different types of light generation
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/22 using optical feedback

Abstract

A hybrid fluorescent-LED lighting system comprising a controller, LED elements, fluorescent lamp, and a color/brightness sensor, wherein the color/brightness sensor measures a combined light output of both the fluorescent lamp and the LED elements. A method for controlling the hybrid fluorescent LED lighting system includes receiving a request for brightness/color, setting a fluorescent lamp output to a particular brightness level, setting output of LEDs to a particular brightness level, measuring a combined output of the fluorescent lamp and LEDs; and adjusting the output of LEDs until the total output of the fluorescent lamp and LEDs matches the request for brightness/color. Adjusting the output of LEDs may include the step of driving a specific spectrum range of the LEDs as necessary in order to fill-in variances in a spectrum range of the fluorescent lamp. The method further allows modifying the color of light output. The method also provides a smooth transition from a current state of the lighting system to the received request for brightness/color by over-driving the LEDs beyond a steady state design rating of the LEDs.

Claims

1. A lighting system comprising:

LEDs;

a multi-step dimmable fluorescent lamp;

a color/brightness sensor wherein the color/brightness sensor measures a combined light output of both the fluorescent lamp and the LEDs; and

a controller programmed to;

receive a request for a combined light output level;

gradually adjust the output of the LEDs from an initial LED power fill to a first transient LED power fill;

step the fluorescent lamp from a first fluorescent power level to a second fluorescent power level, while stepping the LEDs from the first transient LED power fill to a second transient LED power fill such that the combined light output of the fluorescent lamp and the LEDs remains the same; and

gradually adjust the output of the LEDs from the second transient LED power fill to a final LED power fill such that the combined light output of the fluorescent lamp and the LEDs reaches the request for the combined light output level.

2. The lighting system of claim 1 further comprising at least one segment control zone.

3. The lighting system of claim 2 wherein said at least one segment control zone comprises at least one color/brightness sensor.

4. The lighting system of claim 1 further comprising a fluorescent ballast.

5. The lighting system of claim 1 wherein the LEDs are disposed to opposite sides of the fluorescent lamp.

6. The lighting system of claim 1 wherein the LEDs are disposed next to each other on the same side of the fluorescent lamp.

7. The lighting system of claim 1 further comprising LED controls.

8. The lighting system of claim 1 wherein the LED controls are high brightness LED drivers with pulse width modulation dimming capabilities.

9. The lighting system of claim 1 further comprising an input for user requirement for brightness level.

10. The lighting system of claim 1 wherein any high efficiency light source is used in place of the fluorescent lamp.

11. The lighting system of claim 1 wherein any multi-color full-gamut capable light source is used in place of LEDs.

12. The lighting system of claim 1 wherein:

the initial LED power fill is higher than the first transient LED power fill;

the first transient LED power fill is lower than the second transient LED power fill; and

the second transient LED power fill is higher than the final LED power fill; and

the first fluorescent power level is lower than the second fluorescent power level.

13. The lighting system of claim 1 wherein:

the initial LED power fill is lower than the first transient LED power fill;

the first transient LED power fill is higher than the second transient LED power fill;

the second transient LED power fill is lower than the final LED power fill; and

the first fluorescent power level is lower than the second fluorescent power level.

14. The lighting system of claim 1, further comprising:

an open-face reflector for integrating the light from the fluorescent lamp and LEDs.

15. A method for controlling a hybrid fluorescent LED lighting system, the method comprising the steps of:

receiving a request for brightness/color;

measuring a combined output of the fluorescent lamp and LEDs;

gradually adjusting the output of the LEDs from an initial LED power fill to a first transient LED power fill;

stepping the fluorescent lamp from a first fluorescent power level to a second fluorescent power level, while stepping the LEDs from the first transient LED power fill to a second transient LED power fill such that the combined light output of the fluorescent lamp and LEDs remains the same; and

gradually adjusting the output of the LEDs from the second transient LED power fill to a final LED power fill such that the combined light output of the fluorescent lamp and the LEDs reaches the received request for brightness/color.

16. The method of claim 15 further comprising the step of driving a specific range of the LEDs as necessary in order to fill-in variances in a spectrum range of the fluorescent lamp.

17. The method of claim 15 further comprising utilizing fluorescent lamp as the primary illumination source if the request for brightness/color is bright.

18. The method of claim 17 further comprising operating the LEDs at low power levels in parallel with the fluorescent lamps.

19. The method of claim 15 further comprising utilizing fluorescent lamp as the primary illumination source if the request for brightness/color is not dim.

20. The method of claim 15 further comprising modifying the color of light output by using a desired LED color.

21. The method of claim 15 further comprising utilizing the LEDs as the only illumination sources if the requested brightness/color is dim.

22. The method of claim 15 wherein:

the initial LED power fill is higher than the first transient LED power fill;

the first transient LED power fill is lower than the second transient LED power fill; and

the second transient LED power fill is higher than the final LED power fill; and

the first fluorescent power level is lower than the second fluorescent power level.

23. The method of claim 15 wherein:

the initial LED power fill is lower than the first transient LED power fill;

the first transient LED power fill is higher than the second transient LED power fill;

the second transient LED power fill is lower than the final LED power fill; and

the first fluorescent power level is lower than the second fluorescent power level.