Tae-Hyeun Ha

Locally pixel-compensated backlight dimming on LED-backlit LCD TV

— The pixel brightness of an LCD panel perceived by a user is the product of the backlight brightness and the panel transmittance. In conventional LCD panels, the backlight brightness is constant and always at peak luminance. This design suffers from light leakage and power waste problems at dark scenes. This paper presents a new LCD system, which uses locally pixel-compensated backlight dimming (PCBD). The proposed method combines backlight control and pixel processing for reducing light leakage and power consumption while keeping the image at the original brightness. Backlight luminance is dimmed locally in the dark-image region, and pixel values are compensated synchronously according to the luminance profile of dimmed backlight. By reducing the light leakage, a static contrast of over 20,000:1 has been achieved on a large-sized LCD panel with the proposed PCBD method. No obvious artifacts have been noticed as well. The power consumption of the panel can also be greatly reduced, depending on various video content. The PCBD method could be widely used for developing state-of-the-art LCD panels with LED backlights.

39.3: Locally Pixel‐Compensated Backlight Dimming for Improving Static Contrast on LED Backlit LCDs

This paper presents a pixel compensated backlight dimming method for improving contrast on LED-LCD. The backlight luminance is dimmed locally along with image contents, and pixel values are compensated synchronously according to the luminance profile of dimmed backlight. Static contrast above 20000:1 has been achieved on a large size LCD with the proposed method and no obvious artifacts are observed.

33.4: Smooth‐Frame‐Insertion Method for Reducing Motion Blur on OLED Panel

As a kind of hold-type display, OLED panel also suffers from motion blur problem. A smooth frame insertion (SFI) method is proposed to reduce the motion blur on OLED panel. SFI method doubles frame rate by decomposing each original frame into a smooth frame and a compensation frame. The smooth frame is calculated by some low-pass filter. By SFI, hold-type display is converted to impulse-like display and motion blur is reduced significantly without luminance lost and obvious flicker.