49.2: Reduction of LCTV Backlight Power and Enhancement of Gray Scale Capability by Using an Adaptive Dimming Technique

Abstract

An adaptive dimming technique is introduced for reducing the backlight power consumption in LCTVs. With the technique, the backlight luminance is adjusted according to the input TV signal. For example, when the original input signal is small, the backlight luminance is reduced and the signal is increased so that the perceived luminance is equal to that before the signal processing. From a simulation, backlight power reduction to 1/3 can be expected for APL 25% image. The gray scale capability at low luminance levels is also enhanced.

Bit Slice Addressing of Fast Switching Bi-Stable Displays and Multi-Bit Slice Addressing of Active Matrix Liquid Crystal Displays

“…Some of the advantages of bit slice addressing, viz., low hardware complexity of data drivers, reduction of motion blur, low power consumption of backlight can be retained with multi-bit slice addressing. Backlight power can be saved with techniques proposed by Shigara et al [3] and Pierre de Greef [4]. Digital micro mirror device (DMD) can also be driven with bit slice addressing because the pixels can switched in about 20 .…”

44.4: RGB-LED Backlights for LCD-TVs with 0D, 1D, and 2D Adaptive Dimming

“…A principle of the adaptive dimming technique is explained in refs. [1] and [3]. The technique dims luminance of the LED in block (m, n) from the initial value L b (m, n) to L a (m, n) by a factor k(m, n) (<1), namely, L a (m, n) = k(m, n)·L b (m, n).…”

“…A use of the adaptive dimming technique [1,2] for the LED backlight units can solve some of these problems. For reducing the power consumption, backlight luminance is reduced by a dimming factor k, and, at the same time, video signal is enhanced by a factor 1/k, according to the input video signal.…”

A novel adaptive dimming technique with X-Y channels for LED backlight system of LCD TVs

“…In image analysis for adaptive dimming technique, the most frequent value, average value [3], [9], maximum value [6], and other key values [7] are inspected. And then backlight control level is determined based on histogram analysis.…”