Mini-LED Backlighting Technologies for High-Dynamic-Range LCDs: Local Dimming and Performance Optimisation

Abstract

The increasing demand for high-dynamic-range (HDR) displays has driven the development of more precise backlight control technologies for liquid crystal displays (LCDs). The paper discusses the advantages of mini (Mini-LED) backlighting for HDR LCDs and highlights local dimming as an effective approach for improving contrast and display performance. The paper begins with a description of the Mini-LED backlight and its dimming zones, followed by an explanation of local dimming, which reduces luminance in dark areas while enhancing bright regions. It then discusses optical crosstalk and halo effects due to reduced spatial resolution of the light source as compared to the LCD pixel grid and spreading of the light through the optical films. There are also other current solutions, such as higher density of the dimming zones, enhanced containment of light, compensation of pixels, and adaptive local dimming algorithms, which are contrasted. According to the results of the review, the density of the zones can be increased, but the quality of the image will depend on the design of the optics, complexity of driving, power consumption, and performance of the algorithm. It is not only because of the smaller size of LEDs that mini-LED HDR improvement becomes a system-level optimization issue. Further development requires improved optical confinement, more adaptive dimming control, and balanced power and thermal design.