Color management methods and apparatus for lighting devices

• US 7,710,369 B2
• Filed: 12/20/2005
• Issued: 05/04/2010
• Est. Priority Date: 12/20/2004
• Status: Active Grant

• Current Assignee: Signify North America Corporation (Signify N.V.)
• Original Assignee: Philips Solid State Lighting Solutions Inc (Signify N.V.)
• Inventors: Dowling, Kevin J.
• Primary Examiner(s): Hjerpe; Richard
• Assistant Examiner(s): Sheng; Tom V
• Application Number:
  US11/313,427
• Publication Number:
  US 20060158881A1
• Time in Patent Office: 1,596 Days
• Field of Search: 345/82, 345/83, 345/690, 345589-591, 362/230, 362/231, 313/112, 313/113, 358/475, 358/518, 358/520, 382/162, 382/167, 315/291, 315/316
• US Class Current: 345/83
• CPC Class Codes: G03G 15/0435 by introducing an optical element in the optical path, e.g. a filter
• CPC Class Codes: H05B 45/22 using optical feedback

Abstract

Color management and color-managed workflow concepts are applied to lighting apparatus configured to generate multi-colored light, including lighting apparatus based on LED sources. In particular, color management principles are employed to facilitate the generation of variable color light from a given lighting apparatus based on any of a number of possible input specifications for a desired color. In one example, a transformation between an arbitrary input specification for a desired color and a lighting command processed by the lighting apparatus is accomplished via the use of a source color management profile for the input specification of the desired color, a target color management profile for the lighting apparatus, and a common working color space. Colors defined in the common working color space may be reproduced or approximated (e.g., according to one or more rendering intents) by one or more lighting apparatus.

Claims

1. A color-managed illumination system, comprising:

at least one lighting unit comprising;

at least one first LED configured to generate first light having a first spectrum;

at least one second LED configured to generate second light having a second spectrum different from the first spectrum; and

at least one controller configured to control the first light and the second light so as to generate from the at least one lighting unit a range of colors or color temperatures of perceived light;

at least one target color management profile associated with the at least one lighting unit, the at least one target color management profile representing a first mapping from a working color space for the color-managed illumination system to a lighting unit color gamut that specifies the range of colors or color temperatures of the perceived light that can generated by the at least one lighting unit;

at least one color engine to provide at least one lighting command to the at least one controller, based on a desired color specified in the working color space and the at least one target color management profile, so as to generate a single color of the perceived light, wherein the at least one lighting unit is configured to provide ambient illumination that includes the single color of the perceived light at a given time, the single color of the perceived light corresponding to the desired color specified in the working color space; and

at least one color library coupled to the at least one color engine to store the desired color specified in the working color space, wherein the at least one color library is configured to store a plurality of color samples each specified in the working color space, and wherein the system further includes at least one user interface configured to facilitate a selection of the desired color from the plurality of color samples.

2. The color-managed illumination system of claim 1, wherein the working color space includes a CIE color space, and wherein the at least one target color management profile is formatted as an ICC profile.

3. The color-managed illumination system of claim 1, wherein the plurality of color samples includes at least one of an ink color sample, a paint color sample, a fabric color sample, and a colored filter color sample.

4. The color-managed illumination system of claim 1, wherein the plurality of color samples includes a plurality of vendor-specified color samples.

5. The color-managed illumination system of claim 1, wherein the at least one color library is configured to store a plurality of illuminant spectrums specified in the working color space.

6. The color-managed illumination system of claim 5, wherein the desired color is based on a combination of a selected illuminant spectrum of the plurality of illuminant spectrums and a selected color sample of the plurality of color samples.

7. The color-managed illumination system of claim 1, wherein the at least one color engine is configured to provide the at least one lighting command such that the single color of the perceived light approximates the desired color if the desired color is not within the lighting unit color gamut.

8. The color-managed illumination system of claim 1, further comprising a source color management profile representing a second mapping from a device gamut that specifies a second range of colors for a source color device to the working color space, wherein the at least one color engine is configured to receive source color data representing the desired color from the source color device and provide the at least one lighting command to the at least one controller of the at least one lighting unit based on the source color data, the source color management profile, and the target color management profile.

9. A color-managed illumination method for providing ambient illumination that includes a single color of a perceived light at a given time, the method comprising acts of:

A) energizing at least one first LED to generate first light having a first spectrum;

B) energizing at least one second LED to generate second light having a second spectrum different from the first spectrum;

C) controlling the first light and the second light so as to generate a range of colors or color temperatures of perceived light based at least in part on at least one target color management profile associated with at least the first spectrum and the second spectrum, the at least one target color management profile representing a first mapping from a working color space for the color-managed illumination method to a lighting color gamut that specifies the range of colors or color temperatures of the perceived light that can be generated,

D) specifying the desired color in the working color space, wherein the single color of the perceived light corresponds to the desired color; and

E) providing at least one lighting command to control the first light and the second light, based on the act D) and the at least one target color management profile, so as to generate the single color of the perceived light; and

F) storing the desired color in at least one color library, wherein the act F) includes acts of;

F1) storing a plurality of color samples, each specified in the working color space, in the at least one color library; and

F2) selecting the desired color from the plurality of color samples.

10. The color-managed illumination method of claim 9 wherein the working color space includes a CIE color space, and wherein the at least one target color management profile is formatted as an ICC profile.

11. The color-managed illumination method of claim 9, wherein the plurality of color samples includes at least one of an ink color sample, a paint color sample, a fabric color sample, and a colored filter color sample.

12. The color-managed illumination method of claim 9, wherein the plurality of color samples includes a plurality of vendor-specified color samples.

13. The color-managed illumination method of claim 9, further comprising an act of storing a plurality of illuminant spectrums, each specified in the working color space, in the at least one color library.

14. The color-managed illumination method of claim 13, further comprising selecting one illuminant spectrum of the plurality of illuminant spectrums and one color sample of the plurality of color samples to specify the desired color.

15. The color-managed illumination method of claim 9 wherein the act E) comprises an act of:

providing the at least one lighting command such that the single color of the perceived light approximates the desired color if the desired color is not within the lighting color gamut.

16. The color-managed illumination method of claim 9, wherein the act E) comprises acts of:

receiving source color data representing the desired color from a source color device; and

providing the at least one lighting command based on the source color data, the target color management profile, and a source color management profile representing a second mapping from a device gamut that specifies a second range of colors for the source color device to the working color space.