IPS-mode dynamic LCD-TV realization with low black luminance and high contrast by adaptive dynamic image control technology

Abstract

Abstract— In this paper, an active backlight control technology and a data‐processing algorithm has been developed to improve the image quality in IPS‐mode LCD TVs. The image‐blinking problem caused by repeatedly abrupt changes in the backlight luminance was solved by using algorithms [Fba (flexible‐boundary algorithm) and Cfa (cumulative feedback algorithm)] and an optimized number of backlight dimming steps based on human perception. In the IPS‐mode 42‐in. TFT‐LCD panel, the dynamic contrast ratio can be more than twice the typical level by means of a lower black luminance and a higher white luminance. Additionally, the power consumption and LCD temperature were lowered.

13.4: An Electro‐Optical Transfer Function with Improved Uniformity of Palette Color Distribution in Absolute Color Space

“…The dynamic range DR ff can be increased to 111.45 for the display with the 10-bit infinitegamma EOTF and with E 1 = 4.1×10 -5 . The dynamic range DR ff can be increased to 1.0×10 6 for the display with the 12-bit infinite-gamma EOTF and with E 1 = 4.3×10 -9 . The…”

“…The dynamic range for flaw-free color appearance can be increased from 21.2 to 111.45 for the display with the 10-bit infinitegamma EOTF and with E 1 = 4.1×10 -5 in comparison with the display with the 10-bit standard EOTF. The dynamic range for flaw-free color appearance can be increased from 85.0 to 1.0×10 6 for the display with the 12-bit infinitegamma EOTF and with E 1 = 4.3×10 -9 in comparison with the display with the 12-bit standard EOTF.…”

“…practical dynamic range is limited by high-dynamic-range (HDR) display technologies such as dynamic backlight liquid crystal displays (LCD) [6] and organic light emitting diode (OLED) displays [7]. Reference [7] reported that the contrast ratio of a 55-inch OLED TV can be larger than 1×10 5 .…”

“…Reference [7] reported that the contrast ratio of a 55-inch OLED TV can be larger than 1×10 5 . If the dynamic range of a HDR display is up to 1×10 6 , the normalized luminance levels L i < 1×10 -6 are not attainable. The unattainable palette color number is only 0.00648% of the total palette color number for the display with the 12-bit infinite-gamma EOTF and with E 1 = 4.3×10 -9 .…”

“…For an example, the dynamic ranges DR ff of the displays with Y W = 100 cd/m 2 are the same as that of the displays with Y W = 500 cd/m 2 shown above except that DR ff = 9.54×10 5 for the display with the 12-bit infinite-gamma EOTF and with E 1 = 4.3×10 -9 . The value of DR ff can be increased to 1.0×10 6 for the 100 cd/m 2 display with the 12-bit infinite-gamma EOTF and with E 1 = 3.4×10 -9 .…”