Reducing power consumption in liquid-crystal displays

Abstract

Abstract-Power consumption in liquid-crystal displays is analyzed by including frequent polarity reversals and duty-cycle control. A multistep voltage profile is proposed to reduce the power consumption of multiplexed and nonmultiplexed displays. The authors have also shown that the reduction in the power consumption can be achieved with a minimal increase in hardware complexity of the drive electronics.

Integer Wavelets for Displaying Gray Shades in RMS Responding Displays

“…There are ways of selecting a set of four electrodes with the thirty-two select vectors and the sets of scanning electrodes themselves may be selected in ways. The rms voltage across the pixel will not change with the scanning sequence but the frequency spectrum across the pixels and the power consumption of the display will depend on the scanning sequence [5].…”

Low Power Techniques for Gray Shades in Liquid Crystal Displays

“…Here is the number of pixels that are driven to ON state in a selected row, is the number of OFF pixels in the selected row, is the number of ON pixels in non-selected rows, and is the number of OFF pixels in the non-selected rows. Both the select and data waveforms have similar transitions (except for polarity of the data waveforms) in a bilevel display and therefore the reduction or increase in power dissipation is same as in the case of simple RC-circuit [1] as compared in Fig. 5.…”

“…2, is considered as the reference sequence to compare other sequences that are proposed in this paper and it is referred to as 'select sequence-'. Power dissipated in the series resistor of an RC-circuit is proportional to (1) Here, the first term corresponds to 0 to 1 transition, the summation in the second term corresponds to transitions from the select pulse of LSB to the final pulse corresponding to the MSB and the last term corresponds to transition from voltage corresponding to MSB to 0 (non-select voltage). The expression in (1) simplifies to (2) Power dissipated in the series resistance of -circuit, when the capacitor is charged with ' ' select pulses and discharged to zero is obtained by substituting '…”

“…It is a major component of power consumption in these displays. Multi-step waveforms were proposed to reduce power dissipation in LCD [1]. Several waveforms, viz.…”

Trapezoidal and Triangular Waveform Profiles for Reducing Power Dissipation in Liquid Crystal Displays

“…Therefore, avoiding abrupt changes and introducing smooth transitions in the waveforms can reduce power dissipation. An analysis of power dissipation in multiplexed and non-multiplexed liquid crystal displays can be found in [1]- [3]. In a matrix display, each column is independent of other columns and equivalent circuit of a pixel in a column is shown in Fig.…”