Set-point validation for color/intensity settings of light fixtures

• US 20080225520A1
• Filed: 03/14/2007
• Published: 09/18/2008
• Est. Priority Date: 03/14/2007
• Status: Active Grant

• Current Assignee: ABL IP Holding LLC (Acuity Brands, Inc.)
• Original Assignee: Renaissance Lighting Incorporated (Acuity Brands, Inc.)
• Inventors: Garbus, Michael E.
• Granted Patent: US 7,478,922 B2
• Time in Patent Office: Days
• US Class Current: 362/231
• CPC Class Codes: G01J 3/46 Measurement of colour; Colour measuring devices, e.g. colorimeters measuring colour temperature G01J5/60
• CPC Class Codes: G01J 3/462 Computing operations in or between colour spaces; Colour management systems
• CPC Class Codes: G01J 3/50 using electric radiation detectors
• CPC Class Codes: G01J 3/505 measuring the colour produced by lighting fixtures other than screens, monitors, displays or CRTs
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/22 using optical feedback
• CPC Class Codes: H05B 45/28 using temperature feedback
• CPC Class Codes: Y10S 362/802 Position or condition responsive switch

Abstract

Disclosed examples of lighting systems having at least three light sources of different colors may be controlled by validating input settings representing chromaticity and/or intensity of desired light to be generated by determining if the respective lighting system is capable of generating the desired light. This may involve comparing the chromaticity and/or intensity to a three-dimensional gamut representing chromaticity and associated intensities that the lighting system is capable of generating. The top contour of the gamut represents the maximum intensities for every chromaticity which the lighting system is capable of generating. Specifically the top contour is defined by points representing the maximum attainable intensities that each light source is capable of generating and the maximum intensity attainable by the lighting system.

Claims

1. A method for setting operational limitations of a lighting system comprising at least first, second and third light sources generating light of respective first, second and third colors wherein the lighting system is configured to output light containing controlled amounts of light generated by at least one of the first, second and third light sources, the method comprising steps of:

(a) determining a first maximum attainable intensity of light by measuring light output from the lighting system where the first light source is turned on and the second and third light sources are turned off;

(b) determining a second maximum attainable intensity of light by measuring light output from the lighting system where the second light source is turned on and the first and third light sources are turned off;

(c) determining a third maximum attainable intensity of light by measuring light output from the lighting system where the third light source is turned on and the first and second light sources are turned off;

(d) determining a maximum intensity of light attainable by the lighting system represented by light generated by the first, second and third light sources; and

(e) setting the lighting system to determine whether or not desired light corresponding to a given input setting to the lighting system is within a three-dimensional gamut representing colors of light and corresponding attainable intensities that the lighting system is capable of generating wherein a top contour of the gamut is defined by points corresponding to the first, second and third maximum attainable intensities and the maximum intensity of light attainable by the lighting system.

2. The method for setting operational limitations of the lighting system according to claim 1, further comprising steps of:

(i) defining the gamut by a 3-dimensional coordinate system which is representative of colors of light of which the lighting system is capable of generating bounded by the first, second and third colors, the determined first, second, and third maximum attainable intensities, and the determined maximum intensity of light attainable by the system; and

(ii) setting the lighting system to determine whether or not the desired light corresponding to the given input setting represents a color defined within the gamut.

3. The method for setting the lighting system according to claim 1, wherein in Steps (a)-(c) the first, second and third light sources are driven to maximize output, respectively.

4. The method for setting the lighting system according to claim 2, wherein the gamut is defined by coordinates (x,y,Y) where (x,y) corresponds to chromaticity and (Y) corresponds to intensity.

5. The method for setting the lighting system according to claim 2, wherein an apex of the gamut corresponds to a summation of at least the first, second and third maximum attainable intensities.

6. The method for setting the lighting system according to claim 2, wherein the apex represents a white color of light generated by the lighting system at a maximum attainable intensity when the first, second and third light sources are turned on.

7. The method for setting the lighting system according to claim 2, wherein the gamut has a polygon footprint representing chromaticity boundaries with vertices at coordinates corresponding to a color of light generated in each of Steps (a), (b) and (c).

8. The method for setting the lighting system according to claim 7, wherein the polygon footprint is triangular.

9. The method for setting the lighting system according to claim 2, wherein,

(i) a plurality of intersecting planes form the gamut;

and

(ii) each of the plurality of planes intersect another of the planes having at least two coordinates selected from a group consisting of coordinates corresponding to the colors of light generated in Steps (a), (b) and (c), coordinates corresponding to the first, second and third maximum attainable intensities, and a coordinate corresponding to a summation of at least the first, second and third maximum attainable intensities.

10. The method for setting the lighting system according to claim 2, wherein the gamut is formed by at least six planes.

11. The method for setting the lighting system according to claim 1, further comprising the steps of:

(i) determining a fourth maximum attainable intensity of light by measuring light output from the lighting system wherein the first and second light sources are turned on and the third light source is turned off;

(ii) determining a fifth maximum attainable intensity of light by measuring light output from the lighting system wherein the first and third light sources are turned on and the second light source is turned off; and

(iii) determining a sixth maximum attainable intensity of light by measuring light output from the lighting system wherein the second and third light sources are turned on and the first light source is turned off.

12. The method for setting the lighting system according to claim 11, further comprising the steps of:

(I) defining the gamut by a 3-dimensional coordinate system which is representative of colors of light of which the lighting system is capable of generating bounded by the first, second and third colors, the first through sixth maximum attainable intensities and the determined maximum intensity of light attainable by the system; and

(II) setting the lighting system to determine whether or not the desired light corresponding to the given input setting represents a color defined by the gamut.

13. The method for setting the lighting system according to claim 12, wherein,

(i) a plurality of intersecting planes form the gamut;

and

(ii) each of the plurality of planes intersect another of the planes having at least two coordinates selected from a group consisting of coordinates corresponding to the colors of light generated in Steps (a), (b), (c), (i), (ii) and (iii), coordinates corresponding to the first, second, third, fourth, fifth and sixth maximum attainable intensities, and a coordinate corresponding to a summation of at least the first, second and third maximum attainable intensities.

14. The method for setting the lighting system according to claim 9, wherein the gamut is formed by at least nine planes.

15. The method for setting the lighting system according to claim 2, wherein the gamut is formed by a plurality of intersecting planes and at least three of the plurality of intersecting planes intersect at a point that represents the maximum intensity of light attainable by the system.

16. The method for setting the lighting system according to claim 2, wherein the gamut is formed by a plurality of intersecting planes and at least three of the plurality of intersecting planes form sides of a polygonal shaped gamut.

17. The method for setting the lighting system according to claim 16, wherein at least three of the plurality of intersecting planes intersect with the at least three of the plurality of intersecting planes that form sides of a polygonal shaped gamut, respectively, and converge at a point representing the maximum intensity of light attainable by the system.

58. The method for calibrating the lighting system according to claim 1, wherein the maximum intensity of light is determined by measuring light output by the optical system when the first, second and third light sources are turned on.

59. The method for calibrating the lighting system according to claim 1, wherein the maximum intensity of light is determined by a calculation based on at least the first, second and third maximum attainable intensities.

18. A method for processing input color parameters of chromaticity and intensity to a lighting system and controlling illumination outputs of a plurality of light sources of the lighting system to generate a desired color of light corresponding to the input color parameters, the method comprising steps of:

(a) determining whether the input color parameters of chromaticity and intensity places the desired color inside or outside of a gamut representing colors of light of which the lighting system is capable of generating, wherein the gamut is defined by a 3-dimensional coordinate system whereby each axis thereof corresponds to chromaticity or intensity values; and

(b) driving the plurality of light sources to emit light having the desired color when the input color parameters of chromaticity and intensity places the desired color within the gamut.

19. The method according to claim 18, wherein the gamut is formed by a plurality of intersecting planes.

20. The method according to claim 19, further comprising steps of:

(i) determining a coordinate of the chromaticity input color parameter in the 3-dimensional coordinate system;

(ii) comparing the coordinate of the chromaticity input color parameter to each of a plurality of lines formed by an intersection of two planes of the plurality of intersecting planes wherein the plurality of lines form a polygon; and

(iii) determining if the coordinate is outside the polygon based on the comparison result of step (ii).

21. The method according to claim 20, wherein three lines each formed by the intersection of two planes form the polygon.

22. The method according to claim 20, further comprising a step of determining whether or not the coordinate of the chromaticity input color parameter is outside of the polygon.

23. The method according to claim 20, wherein Step (ii) comprises steps of:

(I) for each of the plurality of lines, solving an equation representing a respective line according to at most all but one value of the coordinate wherein the coordinate comprises at least two values to define a position in the n-dimensional coordinate system; and

(II) comparing a result of step (I) with the one value of the coordinate.

24. The method according to claim 23, wherein Step (ii) further comprises steps of:

(A) for each of the plurality of lines, when a slope of the respective line is positive, determining if it is true that the one value of the coordinate is greater than or equal than the result of Step (I);

(B) for each of the plurality of lines, when a slope of the respective line is negative, determining if it is true that the one value of the coordinate is less than or equal than the result of Step (I); and

(C) for each of the plurality of lines, when a slope of the respective line is undefined, determining if it is true that the one value of the coordinate is equal to the result of Step (I),

wherein the coordinate is inside the polygon when for each of the plurality of lines the result of Steps (A), (B) or (C) is true and outside the polygon when at least one the respective results is false.

25. The method according to claim 24, further comprising step of determining that the lighting system is capable of generating chromaticity of the input color parameter when for each of the plurality of lines a result of Steps (A), (B) or (C) is true.

26. The method according to claim 19, further comprising steps of:

(i) determining a coordinate of the chromaticity input color parameter in the 3-dimensional coordinate system; and

(ii) comparing the coordinate of the chromaticity input color parameter to each of the plurality of planes for determining whether or not the lighting system is capable of generating light having a chromaticity corresponding to the desired color.

27. The method according to claim 26, wherein at least three planes of the plurality of planes intersect at an apex.

28. The method according to claim 27, further comprising the steps of:

(I) determining a coordinate of the intensity input color parameter associated with the coordinate of the chromaticity input color parameter; and

(II) determining whether or not the coordinate of the intensity input color parameter is within a space formed by the at least three planes of the plurality of planes for determining whether or not the lighting system is capable of generating light having an intensity corresponding to the desired color.

29. The method according to claim 26, further comprising steps of:

(I) solving at least two equations each representing a line in a plane of the plurality of planes according to at most all but one value of the chromaticity coordinate wherein the chromaticity coordinate comprises at least two values to define a position in the 3-dimensional coordinate system; and

(II) comparing results of step (I) with the one value of the chromaticity coordinate.

30. The method according to claim 29, further comprising steps of:

(A) when a slope of the respective line is positive, determining if it is true that the one value of the chromaticity coordinate is greater than or equal than the result of Step (I); and

(B) when a slope of the respective line is negative, determining if it is true that the one value of the chromaticity coordinate is less than or equal than the result of Step (I).

31. The method according to claim 30, further comprising the step of identifying the plane of the plurality of planes for which Steps (A) or (B) is true for each of the at least two equations.

32. The method according to claim 31, further comprising the steps of:

(x) determining the intensity input color parameter associated with the coordinate of the chromaticity input color parameter; and

(y) determining whether or not the intensity input color parameter is less than or equal to a maximum achievable intensity to be generated by the lighting system for the of the chromaticity input color parameter.

33. The method according to claim 18, wherein the gamut is formed by a plurality of intersecting planes and at least three of the plurality of intersecting planes intersect at an apex which represents the maximum intensity of light attainable by the system.

34. The method according to claim 18, wherein the gamut is formed by a plurality of intersecting planes and at least three of the plurality of intersecting planes form sides of a polygonal shaped gamut.

35. The method according to claim 34, wherein at least three of the plurality of intersecting planes intersect with the at least three of the plurality of intersecting planes forming sides of the polygonal shaped gamut, respectively, and converge at a point representing the maximum intensity of light attainable by the system.

36. A method according to claim 18, further comprising the step of driving the plurality of light sources to emit light having a corrected desired color when the chromaticity or intensity color parameter places the desired color outside of the gamut.

37. The method according to claim 36, further comprising a step of determining whether the specific chromaticity value or the specific intensity value places the desired color outside the gamut.

38. The method according to claim 37, further comprising a step of when the specific intensity value places the desired color outside the gamut, changing the specific intensity value to a maximum intensity value for the specific chromaticity value that the lighting system is capable of generating.

39. The method according to claim 37, further comprising a step of, when the specific chromaticity value places the desired color outside the gamut, changing the specific chromaticity value to a new chromaticity value that the lighting system is capable of generating approximating the desired color.

40. The method according to claim 39, wherein the new chromaticity value has a coordinate in the 3-dimensional coordinate system that is not outside of the gamut.

41. The method according to claim 40, wherein the coordinate of new chromaticity value is substantially closest to a coordinate in the 3-dimensional coordinate system representing the desired color as compared to other coordinates in the 3-dimensional coordinate system that are not outside of the gamut.

42. The method according to claim 40, wherein the gamut has a polygon footprint with vertices each having at coordinate in the 3-dimensional coordinate system corresponding to a different color, further comprising a step of determining whether a coordinate of the specific chromaticity value in the 3-dimensional coordinate system is within a region near a vertex of the polygon footprint or a region near an edge of the polygon footprint.

43. The method according to claim 42, wherein when the coordinate of the specific chromaticity value is in the region near the vertex, the new chromaticity value has a coordinate in the 3-dimensional coordinate system corresponding to a coordinate corresponding to the vertex.

44. The method according to claim 42, wherein when the coordinate of the specific chromaticity value is in the region near the edge of the polygon footprint, the new chromaticity value corresponds to a point on the edge or substantially adjacent thereto on an inside of the polygon footprint.

60. A system for emitting light, comprising:

a plurality of light sources for emission of light and for thereby producing visible light to form a light at least of portion of which is output from the system;

a microcontroller for processing newly user inputted color parameters and controlling illumination emissions of the plurality of light sources, wherein;

the microcontroller is configured to evaluate a gamut defined by a 3-dimensional coordinate system of chromaticity and intensity values,

the gamut is representative of colors of light in which the system is capable of generating, and

the microcontroller executes the steps according to claim 18 for determining if the system is capable of generating light of the desired color.

45. The method for correcting a color parameter corresponding to a desired color having specific chromaticity and intensity values that is input to a lighting system comprising a plurality of light sources for generating light, wherein the lighting system is not capable of generating light corresponding to the desired color, the method comprising steps of:

(a) evaluating at least one of specific chromaticity and intensity values with respect to a gamut representing colors of light of which the lighting system is capable of generating, wherein,

the gamut is defined by a 3-dimensional coordinate system whereby each axis thereof corresponds to chromaticity or intensity values, and

the at least one of the specific chromaticity and intensity values is such as to place the desired color outside of the gamut; and

(b) changing the at least one the specific chromaticity and intensity values to select a color within the gamut.

46. The method according to claim 45, further comprising a step of determining whether the specific chromaticity value or the specific intensity value places the desired color outside the gamut.

47. The method according to claim 46, wherein when the specific intensity value places the desired color outside the gamut, the changing step comprises the specific intensity value to a maximum intensity value for the specific chromaticity value that the lighting system is capable of generating.

48. The method according to claim 46, wherein when the specific chromaticity value places the desired color outside the gamut, the changing step comprises changing the specific chromaticity value to a new chromaticity value having substantially the same color as the desired color that the lighting system is capable of generating.

49. The method according to claim 48, wherein the new chromaticity value has a coordinate in the 3-dimensional coordinate system that is not outside of the gamut.

50. The method according to claim 48, wherein the coordinate of new chromaticity value has is substantially closest to a coordinate in the 3-dimensional coordinate system representing the desired color as compared to other coordinates in the 3-dimensional coordinate system that are not outside of the gamut.

51. The method according to claim 48, wherein the gamut has a polygon footprint with vertices each having at coordinate in the 3-dimensional coordinate system corresponding to a different color, further comprising a step of determining whether a coordinate of the specific chromaticity value in the 3-dimensional coordinate system is within a region near a vertex of the polygon footprint or a region near an edge of the polygon footprint.

52. The method according to claim 50, wherein when the coordinate of the specific chromaticity value is in the region near the vertex, the new chromaticity value has a coordinate in the 3-dimensional coordinate system corresponding to a coordinate corresponding to the vertex.

53. The method according to claim 48, wherein the coordinate of new chromaticity value has a coordinate value within the gamut and a chromaticity substantially the same as the chromaticity of the desired color as compared to other coordinates in the 3-dimensional coordinate system that are not outside of the gamut.

54. The method according to claim 53, wherein the chromaticity of the new chromaticity has a higher saturation of white when compared to the chromaticity of the desired color.

55. The method according to claim 53, wherein the coordinate of the new chromaticity value corresponds to a point on a line fm the coordinate and a coordinate inside the gamut.

56. The method according to claim 55, wherein the coordinate inside the gamut corresponds to the color of white.

57. The method according to claim 48, wherein the coordinate of new chromaticity value corresponds to a point on a line formed between adjacent vertices of a footprint of the gamut.

61. A system for emitting light, comprising:

a plurality of light sources for emission of light and for thereby producing visible light to form a light at least of portion of which is output from the system;

a microcontroller for processing newly user inputted color parameters and controlling illumination emissions of the plurality of light sources, wherein;

the microcontroller is configured to evaluate a gamut defined by a 3-dimensional coordinate system of chromaticity and intensity values,

the gamut is representative of colors of light in which the system is capable of generating, and

the microcontroller executes the steps according to claim 45 for adjusting the newly input color parameters.