提高LED显色指数好方法.pdf

APPLICATION NOTES: Color Rendering Index Introduction: Color Rendering Index (CRI) is a quantitative measure of the ability of a light source to reproduce the colors of various objects faithfully in comparison with an ideal or natural light source. It is defined by the International Commission on Illumination as follows: “Color rendering: Effect of an illuminant on the color appearance of objects by conscious or subconscious comparison with their color appearance under a reference illuminant „ —CIE 17.4, International Lighting Vocabulary, (Schanda 2002) However, CRI does have limitations and should not be used exclusively to evaluate light quality especially in relations to LED lighting. CRI is measured only with respect to a reference source which is either the blackbody curve below 5000K or a CIE Daylight source above 5000K. The reference must be the closest in chromaticity (color) to the source being tested. Otherwise the comparison makes little sense. Comparing the CRI of two very different color temperature sources is meaningless but in general, higher CRI mean less deviation from the reference source. In the Color Rendering Index, a palette of specific colors is used to measure the color difference between a reference source and the source under test. This is termed the General Color Rendering Test and represents a calculation using color sample numbers R1 through R8. The specification for measuring CRI is given in CIE publication 13.3- 1995.1 The calculation is the difference between each color sample illuminated by the light source under test and the reference source. The group of samples is then averaged and a score between 0 and 100 is calculated. 100 is the best match betw