Planckian and non-planckian dimming of solid state light sources

Abstract

Systems and methods of Planckian and non-Planckian dimming of solid state light sources are disclosed. For a given first range of correlated color temperature values on the 1931 CIE Chromaticity Diagram, the current through a plurality of solid state light sources is adjusted so that the light output thereby follows the correlated color temperature values relating to the black body curve over that given first range. For a given second range of correlated color temperature values, the current through a plurality of solid state light sources is adjusted so that the light output thereby deviates from black body curve and instead relates to a series of coordinates that tracks a line between the curve and a color point for one of the solid state light sources.

What is claimed is: 
     
       1. A lighting device, comprising:
 a plurality of solid state light sources, comprising a first solid state light source having a first color point, a second solid state light source having a second color point, and a third solid state light source having a third color point; 
 a control circuit connected to the plurality of solid state light sources and configured to control an amount of current through each solid state light source in the plurality of solid state light sources to produce a light output for the lighting device; and 
 a memory system connected to the control circuit, wherein the memory system includes, for a range of correlated color temperatures:
 a first set of data comprising a first plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on the 1931 CIE Chromaticity Diagram, wherein each pair in the first plurality of pairs includes a corresponding luminous flux, wherein each corresponding luminous flux relates to a particular correlated color temperature over a first portion of the range; and 
 a second set of data comprising a second plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on the 1931 CIE Chromaticity Diagram, wherein each pair in the second plurality of pairs includes a corresponding luminous flux, wherein each corresponding luminous flux relates to a particular correlated color temperature over a second portion of the range; 
 
 
       wherein the first plurality of pairs for the first portion of the range is determined by taking pairs of x-coordinates and corresponding y-coordinates from a black body curve for a first set of correlated color temperatures within the first portion of the range, and wherein the second plurality of pairs for a second set of correlated color temperatures within the second portion of the range is determined by taking pairs of x-coordinates and corresponding y-coordinates from a line that connects a first end point and a second end point, wherein the first end point is on the black body curve and the second end point is one of the first color point, the second color point, and the third color point. 
     
     
       2. The lighting device of  claim 1 , wherein the control circuit comprises an input circuit configured to receive an input, and wherein the control circuit is configured to, in response to the input being received, access the first set of data and the second set of data in the memory system to adjust the light output for the lighting device to a desired setting corresponding to the input. 
     
     
       3. The lighting device of  claim 2 , wherein the input defines one of a desired correlated color temperature and a desired luminous flux, for the light output. 
     
     
       4. The lighting device of  claim 1 , wherein a subset of pairs in the first plurality of pairs in the first set of data includes a dimming level corresponding to the luminous flux of the pair. 
     
     
       5. The lighting device of  claim 4 , wherein the control circuit comprises an input circuit configured to receive an input, wherein the input includes a desired dimming level, and wherein the control circuit is configured to, in response to the input being received, access the first set of data and the second set of data in the memory system to adjust the light output for the lighting device to the luminous flux corresponding to the desired dimming level. 
     
     
       6. The lighting device of  claim 1 , wherein the line that connects the first end point and the second end point is a line segment. 
     
     
       7. The lighting device of  claim 1 , wherein the line that connects the first end point and the second end point is defined by a plurality of line segments, wherein a first line segment in the plurality of line segments has a first slope, wherein a second line segment in the plurality of line segments has a second slope, and wherein the first slope is different from the second slope. 
     
     
       8. The lighting device of  claim 1 , wherein the line that connects the first end point and the second end point is a curve. 
     
     
       9. The lighting device of  claim 1 , wherein the line that connects the first end point and the second end point is a plurality of curves. 
     
     
       10. A method of dimming a plurality of solid state light sources, comprising:
 creating a first set of data comprising a first plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on the black body curve of the 1931 CIE Chromaticity Diagram for a first set of correlated color temperatures, wherein each pair in the first plurality of pairs corresponds to a correlated color temperature of the first set of correlated color temperatures; 
 associating a luminous flux and corresponding dim level with each pair in the first plurality of pairs; 
 creating a second set of data comprising a second plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on a line between a first end point and a second end point on the 1931 CIE Chromaticity Diagram for a second set of correlated color temperatures, wherein the first end point is on the black body curve and the second end point is a color point of a solid state light source in the plurality of solid state light sources, wherein each pair in the second plurality of pairs corresponds to a correlated color temperature of the second set of correlated color temperatures; 
 associating a luminous flux and corresponding dim level with each pair in the second plurality of pairs; 
 receiving an input, wherein the input identifies a desired dim level; 
 locating, within the first set of data and the second set of data, the pair of x-axis coordinates and corresponding y-axis coordinates, corresponding correlated color temperature, and associated luminous flux for the corresponding dim level that is the same as the desired dim level; and 
 adjusting current to the plurality of solid state light sources to produce light output having a luminous flux that is substantially the luminous flux in the first set of data and the second set of data that is associated with the desired dim level. 
 
     
     
       11. The method of  claim 10 , wherein creating the second set of data comprises:
 creating a second set of data comprising a second plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on a line between a first end point and a second end point on the 1931 CIE Chromaticity Diagram for a second set of correlated color temperatures, wherein the first end point is on the black body curve and the second end point is a color point of a solid state light source in the plurality of solid state light sources, wherein each pair in the second plurality of pairs corresponds to a correlated color temperature of the second set of correlated color temperatures, and wherein the line is a line segment. 
 
     
     
       12. The method of  claim 10 , wherein creating the second set of data comprises:
 creating a second set of data comprising a second plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on a line between a first end point and a second end point on the 1931 CIE Chromaticity Diagram for a second set of correlated color temperatures, wherein the first end point is on the black body curve and the second end point is a color point of a solid state light source in the plurality of solid state light sources, wherein each pair in the second plurality of pairs corresponds to a correlated color temperature of the second set of correlated color temperatures, and wherein the line is a curve. 
 
     
     
       13. A lighting system comprising:
 a plurality of solid state light sources, comprising a first solid state light source having a first color point, a second solid state light source having a second color point, and a third solid state light source having a third color point; 
 a controller connected to the plurality of solid state light sources; and 
 a memory system connected to the controller; 
 wherein the memory system includes a dimming application, a first set of data and a second set of data; 
 wherein the first set of data comprises a first plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on the black body curve of the 1931 CIE Chromaticity Diagram for a first set of correlated color temperatures, wherein each pair in the first plurality of pairs corresponds to a correlated color temperature of the first set of correlated color temperatures and has an associated luminous flux; 
 wherein the second set of data comprises a second plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on a line between a first end point and a second end point on the 1931 CIE Chromaticity Diagram for a second set of correlated color temperatures, wherein the first end point is on the black body curve and the second end point is a color point of a solid state light source in the plurality of solid state light sources, wherein each pair in the second plurality of pairs corresponds to a correlated color temperature of the second set of correlated color temperatures and has an associated luminous flux; and 
 wherein the dimming application, when executed in the controller as a dimming process, performs operations of:
 receiving an input, wherein the input identifies a desired dim level; 
 locating, within the first set of data and the second set of data, the pair of x-axis coordinates and corresponding y-axis coordinates, corresponding correlated color temperature, and associated luminous flux for the corresponding dim level that is the same as the desired dim level; and 
 adjusting current to the plurality of solid state light sources to produce light output having a luminous flux that is substantially the luminous flux in the first set of data and the second set of data that is associated with the desired dim level. 
 
 
     
     
       14. A computer program product, stored on a non-transitory computer readable medium, including instructions that, when executed on a controller in communication with a plurality of solid state light sources, cause the controller to perform operations of:
 storing a first set of data comprising a first plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on the black body curve of the 1931 CIE Chromaticity Diagram for a first set of correlated color temperatures, wherein each pair in the first plurality of pairs corresponds to a correlated color temperature of the first set of correlated color temperatures and includes an associated luminous flux; 
 storing a second set of data comprising a second plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on a line between a first end point and a second end point on the 1931 CIE Chromaticity Diagram for a second set of correlated color temperatures, wherein the first end point is on the black body curve and the second end point is a color point of a solid state light source in the plurality of solid state light sources, wherein each pair in the second plurality of pairs corresponds to a correlated color temperature of the second set of correlated color temperatures and includes an associated luminous flux; 
 receiving an input, wherein the input identifies a desired luminous flux from the plurality of solid state light sources; 
 locating, within the first set of data and the second set of data, the associated luminous flux that is the same as the desired luminous flux; 
 determining the pair of x-axis coordinates and corresponding y-axis coordinates and corresponding correlated color temperature for the associated luminous flux; and 
 using the determined pair of x-axis coordinates and corresponding y-axis coordinates and corresponding correlated color temperature to adjust current to the plurality of solid state light sources to produce light output having a luminous flux that is substantially the associated luminous flux. 
 
     
     
       15. The computer program product of  claim 14 , wherein the controller performs operations of storing a first set of data by:
 storing a first set of data comprising a first plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on the black body curve of the 1931 CIE Chromaticity Diagram for a first set of correlated color temperatures, wherein each pair in the first plurality of pairs corresponds to a correlated color temperature of the first set of correlated color temperatures and includes an associated luminous flux and corresponding dim level; 
 
       and wherein the controller performs operations of storing a second set of data by:
 storing a second set of data comprising a second plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on a line between a first end point and a second end point on the 1931 CIE Chromaticity Diagram for a second set of correlated color temperatures, wherein the first end point is on the black body curve and the second end point is a color point of a solid state light source in the plurality of solid state light sources, wherein each pair in the second plurality of pairs corresponds to a correlated color temperature of the second set of correlated color temperatures and includes an associated luminous flux and corresponding dim level. 
 
     
     
       16. The computer program product of  claim 15 , wherein the controller performs operations of receiving by:
 receiving an input, wherein the input identifies a desired dim level for light output by the plurality of solid state light sources; 
 wherein the controller performs operations of locating by: 
 locating, within the first set of data and the second set of data, the corresponding dim level that is the same as the desired dim level; 
 wherein the controller performs operations of determining by: 
 determining the pair of x-axis coordinates and corresponding y-axis coordinates and corresponding correlated color temperature for the corresponding dim level; and 
 wherein the controller performs operations of using by: 
 using the determined pair of x-axis coordinates and corresponding y-axis coordinates and corresponding correlated color temperature to adjust current to the plurality of solid state light sources to produce light output having a dim level that is substantially the corresponding dim level. 
 
     
     
       17. The computer program product of  claim 15 , wherein the controller performs operations of storing a second set of data by:
 storing a second set of data comprising a second plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on a line between a first end point and a second end point on the 1931 CIE Chromaticity Diagram for a second set of correlated color temperatures, wherein the first end point is on the black body curve and the second end point is a color point of a solid state light source in the plurality of solid state light sources, wherein each pair in the second plurality of pairs corresponds to a correlated color temperature of the second set of correlated color temperatures, and wherein the line is a line segment. 
 
     
     
       18. The computer program product of  claim 15 , wherein the controller performs operations of storing a second set of data by:
 storing a second set of data comprising a second plurality of pairs of x-axis coordinates and corresponding y-axis coordinates on a line between a first end point and a second end point on the 1931 CIE Chromaticity Diagram for a second set of correlated color temperatures, wherein the first end point is on the black body curve and the second end point is a color point of a solid state light source in the plurality of solid state light sources, wherein each pair in the second plurality of pairs corresponds to a correlated color temperature of the second set of correlated color temperatures, and wherein the line is a curve.