The relationship between flicker and a common voltage (Vcom), which directly affects the image sticking problem of liquid crystal displays, is explained. A simple symmetry of flicker with respect to Vcom is introduced. A new circuit utilizing a digital interface to generate Vcom is proposed. The circuit easily controls Vcom through the digital interface, enabling automation of the Vcom optimization. The development of an automatic Vcom-tuning system plus the Vcom optimization algorithms using the symmetry of flicker is presented. The total tuning time was 0.35 seconds regardless of screen size.
"Common voltage control technology for highly reliable active matrix liquid crystal displays," Optical Engineering 47(2), 024001 (1 February 2008). https://doi.org/10.1117/1.2824378