Impacts of Local Dimming Algorithms on the Halo Effect in LCD With Local Dimming Mini-LED Backlight

Abstract

The local dimming mini-LED backlight has become one of the most important technologies for liquid crystal display (LCD), facilitating the improvement on high dynamic range (HDR) and power saving. The halo effect still limits the performance of LCDs employing mini-LED backlight. The impact of the number of local dimming zones on the contrast ratio has been investigated. The halo effect has also been investigated under four typical local dimming algorithms and different local dimming zones. It has been experimentally demonstrated that the halo area gradually shrinks with increasing the number of local dimming zones, contributing to the improvement on the HDR of LCD.

Enhancing a Display’s Sunlight Readability with Tone Mapping

“…At the 2023 SID Automotive Displays conference, BOE demonstrated an 800-nit 42.2″ curved mLCD integrated infotainment display prototype, featuring 1439 local dimming zones. In addition, innovative approaches, such as advanced backlight driving algorithms, tailored mini-LED light spread function (LSF), and liquid crystal layer optimization, are able to further increase the backlight uniformity [15][16][17], reduce the power consumption [18], and mitigate the undesirable halo effect [19]. Despite these advancements, the LCD panel transmittance is often below 10% due to significant losses from polarizers, opaque thin-film transistors, and color filters, which in turn limit the peak brightness.…”