Abstract: In order to provide the lighting environment for quantifying the performance of camera-equipped mobile phone, the LED light source with adjustable color temperature and brightness have been developed in this paper. Red LED light source, green LED light source, cool white LED light source and warm white LED light source were selected as the four primary colors, and an experimental device was designed to realize the development of white light source with continuous adjustable color temperature and brightness. The color matching technology studied in this paper took the relative spectral power distribution, chromaticity coordinate, and luminous flux of the four primary as the input parameters. According to Grassmann's law, the color matching algorithm has been developed, the chromaticity coordinate of the Planckian locus are the function values, and the corresponding light flux are variables. In the model solution, the chromatic aberration △UV is the first optimization parameter, which should be less than 0.005. The first optimization has not been completed until the color difference is within the limit. Then the color rendering index(CRI) R_a is more than 90 as optimization target, and the calculation has not been carried out until the relative color temperature error is within 100. The test results of the developed light source showed that the color difference △UV is less than 0.003 and R_a is more than 91, when achieving the target color temperature and target brightness.

Key words: tunable source, chromaticity coordinate, color temperature, color rendering index