METHODS TO REDUCE POWER CONSUMPTION OF LIQUID CRYSTAL DISPLAYS

Liquid crystal displays (LCDs) are extensively used in many consumer and professional products. Low power consumption is essential in portable devices to extend the life of dry cells or to reduce the frequency of recharging the cells that are the main source of power in portable products. Low power consumption demands a multi-pronged approach, beginning with identifying the right choice of an electrooptic effect for the LCD to selecting the appropriate design, materials, processes, and the methods employed to drive the display. Electronic means of achieving low power consumption is the main focus of this chapter. Simple methods to reduce power consumption by reflective-type passive matrix LCDs are reviewed first, followed by a discussion on universal waveforms to reduce power consumption of active matrix LCDs as well. Other methods to reduce power consumption of active-matrix LCDs are reviewed next. Most LCDs come with a backlight and power consumption of backlight is much higher than the LCDs that act as light modulators. The chapter ends with a review of methods to reduce power consumption of light sources in LCD.