The color properties of a reflective CMYK module using polymer-dispersed liquid crystal (PDLC)

A reflective CMYK (cyan, magenta, yellow, and black) module using polymer-dispersed liquid crystal (PDLC) is investigated for multi-color reflective display. Combined with the electro-optical properties and visible spectral reflectivity of PDLC films, the color properties of the reflective CMYK module were evaluated in terms of the Uniform Color Space-CIE 1976 L * a * b *. It is found that the blue light reflectivity of the PDLC films is lower than green light and red light reflectivity. With the increase of the voltage applied on PDLC, the color lightness of the CMYK module generally decreases, while the color saturation increases. When the voltage changed from 0 to 70 V with a 5-V change amplitude, modules C, M, Y, and K severally exhibit at least five, six, three, and seven colors.