Jo Jan 17, 2024

Display of works of art such as color photos needs two competing criteria: appearance and color degradation. The more the blue radiant flux of pc-white LED lamps increases, the more color degradation occurs. However, previous studies have focused on the improvement of color rendering property and luminous efficacy, and decreasing the ratio of blue radiant flux while maintaining the needed color rendering property and luminous efficacy has been hardly discussed.

Kim Ju Yong, a researcher at the Faculty of Electronics, has investigated the effect of correlated color temperature (CCT) and spectral power distribution (SPD) of PC-white LED lamps on the color degradation of color samples and the difference between the decolorizing reduction of color samples and that of textiles dyed with natural dyes.

Controlling the SPD by combining the blue LED chip and G-O-R phosphors, he manufactured a test lamp with high color rendering property. The high color rendering property and small blue peak radiant flux of the test lamps lead to the best effect on color appearance and decolorizing reduction.

After color samples for color pictures were decolorized with accelerating degradation method, the color degradation caused by test lamp (TL) was about a half of that of comparison test LED lamp (CL). The test results showed that for the pc-white LED lamps, the decolorizing reduction effect depends on SPD more than CCT.

He also proved that unlike the textiles dyed with natural dyes, green and violet were decolorized most, followed by yellow from samples for color pictures.