High Contrast Ratio and Low Power Consumption LCD using Simultaneous Optimization of Backlight Luminance and Gamma Conversion Function

In recent years, liquid crystal displays (LCDs) are being increasingly used in various display products, such as cellular phones and televisions, leading to demands for higher image quality and lower power consumption. The contrast ratio of LCDs is, however, lower than that of emissive displays such as organic light-emitting diode ones. A novel algorithm for LCD backlight dimming to improve the contrast ratio of LCDs is proposed. Backlight luminance and a gamma conversion function are simultaneously optimized acording to input images by minimizing the sum of squared difference between the ideal gamma characteristic with an infinite contrast ratio and the LCD gamma characteristic with a finite contrast ratio. Furthermore, LCD prototypes that utilized the proposed algorithm were developed, and they had both a high contrast ratio and low power consumption.