Systems and methods for controlling illumination sources

• US 7,135,824 B2
• Filed: 08/11/2004
• Issued: 11/14/2006
• Est. Priority Date: 08/26/1997
• Status: Expired due to Fees

• Current Assignee: Philips Lighting North America Corporation (Signify N.V.)
• Original Assignee: Color Kinetics Incorporated (Signify N.V.)
• Inventors: Lys, Ihor A., Morgan, Frederick M., Ducharme, Alfred D., Blackwell, Michael K.
• Primary Examiner(s): Philogene, Haissa
• Application Number:
  US10/916,018
• Publication Number:
  US 20050062440A1
• Time in Patent Office: 825 Days
• Field of Search: 315/291, 315/292, 315/294, 315/312, 315/362, 315/318, 345/38, 345/39, 345/48, 345/77, 345 82- 84, 345/214, 345/532, 348/671, 348673-675, 348716-721, 348801-803, 341138-140, 341/144, 711/100, 711/115, 711/202, 711/212, 711/221
• US Class Current: 315/292
• CPC Class Codes: G03B 15/05 Combinations of cameras with electronic flash apparatus; Electronic flash units
• CPC Class Codes: G03B 2215/05 Combinations of cameras with electronic flash units

Abstract

Provided are methods and systems for controlling the conversion of data inputs to a computer-based light system into lighting control signals. The methods and systems include facilities for controlling a nonlinear relationship between data inputs and lighting control signal ouputs. The nonlinear relationship may be programmed to account for varying responses of the viewer of a light source to different light source intensities.

Claims

1. A system to control a light, the system comprising:

a user interface to control at least one nonlinear relationship between a data input and an output control signal for the light; and

a conversion module that converts the data input to the output control signal using the at least one nonlinear relationship,

wherein the at least one nonlinear relationship accounts for a response of a viewer to different intensities of the light.

2. The system of claim 1, further comprising a memory where a table is stored, the table comprising the at least one nonlinear relationship.

3. The system of claim 1, wherein the at least one nonlinear relationship comprises a function selected from a group consisting of an exponential function, a squared function, and a cubed function.

4. The system of claim 1, wherein the at least one nonlinear relationship comprises:

a first linear relationship with a first slope; and

a second linear relationship with a second slope that is different than the first slope.

5. The system of claim 4, wherein the first slope of the first linear relationship and the second slope of the second linear relationship are non-zero.

6. The system of claim 1, wherein the at least one nonlinear relationship includes a plurality of selectable nonlinear relationships, wherein the user interface is configured to select one nonlinear relationship of the plurality of selectable nonlinear relationships, and wherein the conversion module converts the data input to the output control signal using the selected one nonlinear relationship.

7. The system of claim 1, wherein the at least one nonlinear relationship accounts for the response of the viewer to reflected illumination.

8. The system of claim 1, wherein the at least one nonlinear relationship is continuously increasing.

9. The system of claim 1, wherein the user interface is adapted to modify the at least one nonlinear relationship, and wherein the conversion module converts the data input to the output control signal using the modified at least one nonlinear relationship.

10. The system of claim 1, wherein the output control signal is a pulse width modulated signal.

11. The system of claim 2, wherein the user interface is adapted to modify the table, and wherein the conversion module converts the data input to the output control signal using the modified table.

12. A method of controlling a light, the method comprising steps of:

determining a response of a viewer to a change in an intensity of the light;

operating the light based on a nonlinear relationship between data input steps and an output control signal that accounts for the response of the viewer; and

adjusting the nonlinear relationship.

13. The method of claim 12, wherein the step of adjusting the nonlinear relationship further comprises a step of employing a user interface.

14. The method of claim 12, wherein the step of adjusting the nonlinear relationship occurs while the light is viewed by the viewer.

15. The method of claim 14, wherein the response of the viewer comprises a response to reflected illumination.

16. The method of claim 14, further comprising a step of storing the nonlinear relationship in a memory.

17. The method of claim 16, wherein the memory is included in a conversion module.

18. A method of controlling a light, the method comprising steps of:

employing a multi-bit system;

operating the light based on a nonlinear relationship between data input steps and an output control signal that accounts for a response of a viewer; and

scaling the nonlinear relationship so as to minimize a change in intensity between adjacent data input steps corresponding to low light intensities and so as to maximize the change in intensity between adjacent data input steps corresponding to high light intensities,

wherein the multi-bit system is a first size having a first quantity of bits, and

wherein a range of adjustment of the light corresponds to a range of adjustment provided by a linear system employing a multi-bit system that has a second size having a second quantity of bits that is greater than the first quantity of bits.

19. The method of claim 18, wherein the second quantity of bits is at least 50% greater than the first quantity of bits.

20. The method of claim 19, wherein the range of adjustment is a range of intensity of the light.

21. An illumination apparatus, comprising:

at least one first LED configured to generate at least first radiation having a first spectrum, wherein the first radiation, when generated, provides illumination in an environment; and

at least one controller coupled to the at least one first LED to control a first intensity of the first radiation, the at least one controller further configured to;

receive a first X-bit lighting command representing a first value within a first control range for the first intensity;

convert the first X-bit lighting command to a first Y-bit lighting command representing a second value within the first control range for the first intensity, wherein X and Y are different integers, and wherein the second value in the first control range is related to the first value in the first control range based on a non-linear relationship; and

control the first intensity of the first radiation based at least in part on the second value in the first control range.

22. The apparatus of claim 21, further comprising:

at least one second LED configured to generate at least second radiation having a second spectrum different than the first spectrum, wherein the first radiation and the second radiation, when generated, provide the illumination in the environment,

and wherein the at least one controller is further configured to control a second intensity of the second radiation.

23. The apparatus of claim 22, wherein X is less than Y.

24. The apparatus of claim 23, wherein X is eight and wherein Y is at least fourteen.

25. The apparatus of claim 22, further comprising a memory to store at least one representation of the non-linear relationship, wherein the at least one representation includes at least one of a function and a table of values, and wherein the at least one controller utilizes the at least one representation to convert the first X-bit lighting command to the first Y-bit lighting command.

26. The apparatus of claim 25, wherein the non-linear relationship is a continuously increasing relationship.

27. The apparatus of claim 25, wherein the non-linear relationship includes at least two linear relationships having respective different slopes.

28. The apparatus of claim 25, wherein the non-linear relationship includes at least one linear portion over a first part of the first control range and at least one nonlinear portion over a second part of the first control range.

29. The apparatus of claim 25, wherein the non-linear relationship includes one of an exponential relationship, a quadratic relationship, and a cubed relationship.

30. The apparatus of claim 25, wherein the non-linear relationship has a relatively smaller slope for relatively smaller first values and a relatively higher slope for relatively higher first values.

31. The apparatus of claim 21, wherein the at least one first LED includes at least one white LED.

32. The apparatus of claim 22, wherein the at least one controller is further configured to:

receive a second X-bit lighting command representing a first value within a second control range for the second intensity;

convert the second X-bit lighting command to a second Y-bit lighting command representing a second value within the second control range for the second intensity, wherein the second value in the second control range is related to the first value in the second control range based on the non-linear relationship; and

control the second intensity of the second radiation based at least in part on the second value in the second control range.

33. The apparatus of claim 32, wherein the at least one first LED includes at least one white LED.

34. The apparatus of claim 33, wherein the illumination is essentially white, and wherein the at least one controller is configured to control a color temperature of the illumination based at least in part on the second value in the first control range and the second value in the second control range.