Led Based Illumination Module Color Matched To An Arbitrary Light Source

Abstract

LED based illumination modules are realized that are visually color matched to light sources not based on LEDs based on visually matched color spaces. A visually matched color space is employed to both instrumentally and visually match an LED based light source with a light source not based on LEDs. In one aspect, an LED based illumination module is realized to achieve a target color point in a visually matched color space within a predetermined tolerance. In another aspect, an LED based illumination module is realized to visually match a light source not based on LEDs. A target color point in the CIE 1931 XYZ color space is derived based at least in part on the spectrum of the visually matched LED based illumination module. LED based illumination modules visually matched to light sources not based on LEDs are realized based on the derived target color point.

1 . An illumination module comprising:
 at least one light emitting diode operable to produce an amount of light with a spectral power distribution; and   a first selectable component that includes a first type of wavelength converting material having a first wavelength converting characteristic that is a function of the spectral power distribution, the first selectable component is selected prior to final assembly of the illumination module based on the first wavelength converting characteristic, the first selectable component converting a portion of the amount of light from the at least one light emitting diode to produce light emitted from the illumination module, the first wavelength converting characteristic converts the portion of the amount of light from the at least one light emitting diode to produce light emitted from the illumination module at a first color point with less than a just noticeable difference from light emitted from a light source that does not include a light emitting diode at a second color point, wherein the first color point and the second color point are compared in a visually matched color space prior to final assembly, wherein in the visually matched color space light emitted from the illumination module at the first color point visually matches light emitted from a light source that does not include a light emitting diode.   
     
     
         2 . The illumination module of  claim 1 , further comprising:
 a second selectable component that includes a second type of wavelength converting material having a second wavelength converting characteristic that is different from the first wavelength converting characteristic, wherein the first wavelength converting characteristic of the first selectable component and the second wavelength converting characteristic of the second selectable component convert the portion of the amount of light from the at least one light emitting diode to produce the first color point.   
     
     
         3 . The illumination module of  claim 1 , wherein the light source that does not include a light emitting diode is a light source that emulates an illuminant taken from a group consisting of: an A series illuminant, a B series illuminant, a C series illuminant, a D series illuminant, an E series illuminant, a F series illuminant, and a blackbody radiator. 
     
     
         4 . The illumination module of  claim 1 , wherein the light source is taken from a group consisting of: a halogen lamp, a compact metal halide lamp, a high intensity discharge lamp, and a fluorescent lamp. 
     
     
         5 . The illumination module of  claim 2 , wherein the first and second selectable components are configured to convert a portion of the amount of light emitted by the at least one light emitting diode to an amount of converted light, and wherein the light emitted from the illumination module includes the amount of converted light. 
     
     
         6 . The illumination module of  claim 1 , wherein a light emitted from the illumination module at a target color point in CIE 1931 color space does not visually match a light emitted from the light source that does not include a light emitting diode at the same target color point in CIE 1931 color space. 
     
     
         7 . The illumination module of  claim 2 , further comprising:
 a reflective bottom surface that surrounds the at least one light emitting diode;   at least one reflective sidewall that surrounds the bottom surface and the at least one light emitting diode; and   a window coupled to the at least one reflective sidewall.   
     
     
         8 . The illumination module of  claim 7 , wherein each of the first selectable component and second selectable component comprise at least one of the reflective bottom surface, the at least one reflective sidewall, and the window. 
     
     
         9 . The illumination module of  claim 8 , wherein the at least one reflective sidewall is a sidewall insert that is positioned to form the at least one reflective sidewall. 
     
     
         10 . The illumination module of  claim 7 , wherein the first selectable component is the window and the second selectable component is the at least one reflective sidewall. 
     
     
         11 . The illumination module of  claim 2 , wherein the first selectable component and the second selectable component are selectable for their respective wavelength converting characteristics. 
     
     
         12 - 29 . (canceled) 
     
     
         30 . An apparatus comprising:
 at least one light emitting diode operable to produce an amount of light with a spectral power distribution; and   means for converting a portion of the amount of light from the at least one light emitting diode to produce an amount of combined light emitted from the apparatus, wherein the means is selected prior to final assembly of the apparatus based on the spectral power distribution, wherein a color point of the combined light emitted from the apparatus approaches a target color point, and wherein light emitted from the apparatus at the target color point visually matches light emitted from a light source that does not include a light emitting diode at the same target color point.   
     
     
         31 . The apparatus of  claim 30 , wherein the means includes a first selectable component that includes a first type of wavelength converting material having a first wavelength converting characteristic, the first selectable component converting the portion of the amount of light from the at least one light emitting diode to produce light emitted from the apparatus, wherein the first wavelength converting characteristic converts the portion of the amount of light from the at least one light emitting diode. 
     
     
         32 . The apparatus of  claim 31 , wherein the means includes a second selectable component that includes a second type of wavelength converting material having a second wavelength converting characteristic that is different from the first wavelength converting characteristic, wherein the first wavelength converting characteristic of the first selectable component and the second wavelength converting characteristic of the second selectable component convert the portion of the amount of light from the at least one light emitting diode. 
     
     
         33 . The illumination module of  claim 1 , wherein the second color point is within a degree of departure, Δx′y′, of 0.002 of the first color point, wherein x′y′ are color coordinates of the visually matched color space.