Block-based content adaptive backlight controller VLSI design for local dimming LCDs

Abstract

In this paper, a novel hardware-oriented local dimming content adaptive backlight control (CABC) algorithm is proposed for liquid crystal displays (LCDs). It utilizes an efficient backlight dimming algorithm to reduce the power consumption of the backlight module in LCD and uses a contrast compensation algorithm to compensate the brightness distortion. In order to dim the backlight power and compensate the brightness in real time, the proposed algorithm was realized by a VLSI technique. The VLSI architecture of this design includes a grayscale converter, a maximum detector, an average calculator, a clipped point detector, a brightness compensator, a brightness ratio calculator, a ratio table and a pixel compensator. This design was synthesized by a 0.18-μm technology. Its core area and gate counts are 501,782 μm2 and 42.65-K, respectively, when it operates at 100 MHz. Compared with previous backlight control algorithms, this work improved the average PSNR value over 0.26 dB and reduced the average power consumption of LCD backlight module over 8.29%.