Study on Realization of CIE Standard Illuminant by LED Spectrally Tunable Light Source with UV-LED and Visible-LED

Conventional lighting booths with custom standard fluorescent lights are used in industry for testing and quality control of color materials. In this study, we constructed a lighting booth based on an LED spectrally tunable light source (LSTL) that implemented a simple forced air-cooling system. The LSTL was composed of a UV-LED, single color LED, and quasi-yellow LED to cover the wavelength range from 340 to 800 nm. To compensate for the lack of appropriate green LEDs in the wavelength range from 520 to 625 nm, the LSTL used the quasi-yellow LED, which was made by cutting the blue spectrum of a white LED with a long-pass optical filter. The reconstructed spectrum was more approximate CIE standard illuminant than a D65 fluorescent lamp, and the fluctuation of optical intensity was of considerable well property. In addition, we also discussed advantages of and improvements enabled with LSTL through a comparison with D65 standard fluorescent lamps.