56.4: Invited Paper: Optimized Algorithm and BLU for Local Dimming of Automotive Displays

Abstract

Local dimming LCDs with a matrix backlight unit (BLU) are favored by many car manufacturers for high quality and low power displays. Automotive application sets high requirement like safety standard, whereas the temperature range and lifespan are wide. The contents are mostly HMIs with high contrast and circular structures. Thus, the two key components, BLU and the local dimming algorithm need to be adopted to automotive needs/demands and shall be jointly optimized. In this paper, the BLU design aspects and specification are described. Specific features relevant for automotive, like black corners and containment against LED outage, are introduced. The tradeoff between performance and cost is lifted. With a BLU with 384 LEDs, the contrast ratio may be enhanced by a factor of 20, while an average power saving ratio of 50% can be achieved.

57‐2: Invited Paper: Reproducible Characterization of Automotive Full Area Local Dimming (FALD) LCDs

“…The device under test: is a 12.3-inch FALD LCD with a resolution of 1980 x 720 pixels and LED backlight with a pitch of 9.2 mm resulting in 384 dimming zones. The SSC local dimming algorithm [2] implemented on an FPGA was used to control the LEDs and the LC panel. The algorithm includes parameters which may set priority like power saving versus visual quality and/or may suppress/mitigate artifacts like Halo, false contour etc.…”

“…All this can affect its luminance and also its uniformity as shown in Figure 2 left. Of course, these effects are influenced massively by the FALD algorithm, which determines the backlight behavior [2].…”

57‐4: Advanced Tone Mapping of Mini‐LED Backlit LCDs for Automotive Displays

“…To improve the contrast ratio and power consumption of an LCD, the backlight panel with local dimming zones is adopted [4][5][6]. The simulation platform is built based on an LCD with 1920×1200 resolution divided into 40×25 local dimming zones.…”

53.1: Boosting Power Efficiency and Visual Quality of Automotive LCDs by Proprietary Local Dimming Algorithm, BLU Design and HMI Adaption

“…A straight-forward BLU-design is that the light spread function (LSF) is of Lambertian distribution. An empirical LSF function with three parameters has been published which meets a real LSF much more accurately than the Gaussian distribution (2).…”