Colour measurement of LEDs, problems and corrections
The general belief is that tristimulus colorimeters are less accurate, because the spectral shaping of the detector has to be done using filters precisely ground and polished to the required thickness. As the number of filter glasses that can be used is finite, the accuracy of the filter adjustment is also limited. Two methods have been developed to decrease the measurement uncertainty of tristimulus colorimeters: Firstly adding a fifth filter to the stack of X<,short,> X<,long,> Y and Z filters and using matrix transformation of the output signals the measuring accuracy could be increased considerably. As a second step-for the Y tristimulus value, i. e. for the Average LED Intensity (ALI) or luminous flux component of the tristimulus values, colour dependent individual correction factors were introduced. By the help of this technique the determination of the Y tristimulus value could be increased by a factor of 2 to 3. In case of spectrometric measurement the wavelength inaccuracy and the stray light of the instrument cause the most important errors. Our investigations have shown that in case of a modern spectrometer with CCD detector the uncertainty of LED measurements is in the same order of magnitude as that of tristimulus colorimeters.
LED colorimetry tristimulus colorimetry spectroradiometery LED standards
J. Schanda C. Sik-Lanyi Zs. Kosztyan P. Csuti Gy. Schanda
University of Pannonia, Egyetem u. 10, Veszprem, Hungary University of Pannonia, Egyetem u. 10, Veszprem,Hungary TENZI Ltd,Nador u. 25, Budapest, Hungary
国际会议
杭州
英文
10-13
2007-07-12（万方平台首次上网日期，不代表论文的发表时间）