Auxiliary illuminating device having adjustable color temperature

• US 6,379,022 B1
• Filed: 04/25/2000
• Issued: 04/30/2002
• Est. Priority Date: 04/25/2000
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Hubel, Paul M, Amerson, Frederic C, Motta, Ricardo J
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): WARD, JOHN A
• Application Number:
  US09/557,137
• Time in Patent Office: 735 Days
• Field of Search: 362/1, 362/234, 362/13, 362/184, 362/800, 362/11
• US Class Current: 362/231
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

An auxiliary illuminating device that has an adjustable color temperature. The color temperature is adjusted by varying the light output at least two independently adjustable light sources. The light source is an array of at least 2 colors. The light source typically uses at least one set of LED'"'"'s.

Claims

1. A multi-element light source with an adjustable color temperature, comprising:

a first light source, the first light source producing light over a first wavelength band;

a second light source, the second light source producing light over a second wavelength band;

a control system, the control system able to adjust the ratio of light produced by the two light sources, the control system configured to switch between at least two preset ratios of light where each preset ratio corresponds to a different color temperature, and where both the at least two preset ratios have both light sources producing light.

2. The multi-element light source of claim 1 where at least one of the light sources is an LED.

3. The multi-element light source of claim 1 where at least one of the wavelength bands is narrow.

4. The multi-element light source of claim 1 were the multi-element light source is powered by a battery.

5. The multi-element light source of claim 1 where the multi-element light source is portable.

6. The multi-element light source of claim 1 where the multi-element light source is configured to mount on a camera.

7. A multi-element light source with an adjustable color temperature, comprising:

a first light source, the first light source producing light over a first wavelength band;

a second light source, the second light source producing light over a second wavelength band;

a third light source, the third light source producing light over a third wavelength band;

a control system, the control system able to adjust the ratio of light produced by the three light sources, the control system configured to switch between at least two preset ratios of light where each preset ratio corresponds to a different color temperature, and where both the at least two preset ratios have all three light sources producing light.

8. The multi-element light source of claim 7 where at least one of the wavelength bands of the light sources is narrow.

9. The multi-element light source of claim 7 where the first light source produces red light, the second light source produces green light, and the third light source produces blue light.

10. The multi-element light source of claim 7 where the first light source produces amber light, the second light source produces green light, and the third light source produces blue light.

11. The multi-element light source of claim 7 where at least one of the light sources is an LED.

12. The multi-element light source of claim 7 were the multi-element light source is powered by a battery.

13. The multi-element light source of claim 7 where the multi-element light source is portable.

14. The multi-element light source of claim 7 where the multi-element light source is configured to mount on a camera.

15. The multi-element light source of claim 7 further comprising:

a fourth light source, the fourth light source producing light over a fourth wavelength band.

16. A method of adjusting the color temperature of a multi-element light source, comprising:

determining the color temperature of the ambient light in a scene;

selecting a color temperature for the multi-element light source (602) that most closely matches the color temperature of the ambient light in the scene;

adjusting the ratio of light outputs of a first light source component with respect to the light output of a second light source component such that the ratio of the light outputs of the two light source components generates the color temperature for the multi-element light source, the first light source component producing light over a first wavelength band and the second light source component producing light over a second wavelength band;

repeating the above steps for a different scene.

17. The method of claim 16 where one of the light source components is a light emitting diode (LED).

19. The method of claim 16 where at least one of the light sources is a light emitting diode (LED).

20. The method of claim 16 where one of the LED'"'"'s is a red LED, one of the LED'"'"'s is a green LED, and one of the LED'"'"'s is a blue LED.

21. The method of claim 20 where one of the LED'"'"'s is an amber LED, one of the LED'"'"'s is a green LED, and one of the LED'"'"'s is a blue LED.

23. The method of claim 16 where the ambient light in the scene is measured to determination of the color temperature the ambient light in the scene.

24. The method of claim 16 where selecting a choice from a list of light sources determines the color temperature of the ambient light in the scene.

18. A method of adjusting the color temperature of a multi-element light source, comprising:

determining the color temperature of the ambient light in a scene;

selecting a color temperature for the multi-element light source that most closely matches the color temperature of the ambient light in the scene;

adjusting the light output of a first light source, the first light source producing light over a first wavelength band;

adjusting the light output of a second light source, the second light source producing light over a second wavelength band;

adjusting the light output of a third light source, the third light source producing light over a third wavelength band, such that the ratio of the light output of the three light sources generates the color temperature of the desired multi-element light source.

25. The method of claim 18 where the ambient light in the scene is measured to determination of the color temperature the ambient light in the scene.

26. The method of claim 18 where selecting a choice from a list of light sources determines the color temperature of the ambient light in the scene.

22. A method of adjusting the color temperature of a multi-element light source, comprising:

determining the color temperature of the ambient light in a scene;

selecting a color temperature for the multi-element light source that most closely matches the color temperature of the ambient light in the scene;

adjusting the light output of a first light source, the first light source producing light over a first wavelength band;

adjusting the light output of a second light source, the second light source producing light over a second wavelength band;

adjusting the light output of a third light source, the third light source producing light over a third wavelength band;

adjusting the light output of a fourth light source, the fourth light source producing light over a fourth wavelength band, such that the ratio of the light output of the four light sources generates the color temperature of the desired multi-element light source.

27. The method of claim 22 where the ambient light in the scene is measured to determination of the color temperature the ambient light in the scene.

28. The method of claim 22 where selecting a choice from a list of light sources determines the color temperature of the ambient light in the scene.

29. A multi-element light source with an adjustable color temperature, comprising:

a first light source, the first light source producing light over a first wavelength band;

a second light source, the second light source producing light over a second wavelength band;

a control system, the control system able to adjust the ratio of light produced by the two light sources, the control system configured to switch between at least two preset ratios of light where each preset ratio corresponds to a different color temperature, and where one of the at least two preset ratios corresponds to the color temperature of an incandescent light.

30. The multi-element light source of claim 29 where at least one of the light sources is an LED.

31. A multi-element light source with an adjustable color temperature, comprising:

a first light source, the first light source producing light over a first wavelength band;

a second light source, the second light source producing light over a second wavelength band;

a control system, the control system able to adjust the ratio of light produced by the two light sources, the control system configured to switch between at least two preset ratios of light where each preset ratio corresponds to a different color temperature, and where one of the at least two preset ratios corresponds to the color temperature of a fluorescent light.

32. The multi-element light source of claim 31 where at least one of the light sources is an LED.