In a color sequential system using LCDs, the LCD must operate faster than the frame rate because red, green, and blue are done sequentially. Ferroelectric LCDs can do this, but they are not analog devices and so cannot provide analog display levels. Instead, a pulse width modulation (PWM) technique is...http://www.google.de/patents/US6535196?utm_source=gb-gplus-sharePatent US6535196 - Multiplexed display element sequential color LCD panel
