Development of a spectrophotometer system based on an LED spectrally tunable light source for quality assessment of illuminant D50 simulator

For many years, conventional lighting booths with custom standard fluorescent lamps have been used in industry for color material testing and quality control. Particularly, lamps that simulate Illuminant D50 are used in imaging and graphics fields. For this study, a spectrophotometer system based on an LED-based spectrally tunable light source (LSTL) was developed to assess Illuminant D50 simulator quality effects on object color evaluation. The LSTL, which was constructed with 23 bands of LEDs in the ultraviolet (UV) – visible range, can simulate any spectrum accurately by control of each LED. Using this system, various grades of Illuminant D50 were simulated and irradiated on test white papers for direct and detailed evaluation of the effects of different grades, which was difficult when using earlier light sources. The relations between the effects of fluorescence generated using UV light and the MI uv grade were carefully investigated. In addition, the quality of practical Illuminant D50 simulators (D50 lamps and D50 LEDs) in manufacturing was discussed based on these study findings and improvements the practical simulators were suggested. These experiments also demonstrated that the developed system incorporating the LSTL has unprecedented power for use in direct evaluation of lighting source effects on the object color.