Hoi-Sik Moon

38.4: Invited Paper: In-Cell Embedded Touch Screen Technology for Large Size LCD Applications

Design guidelines for large size liquid crystal capacitive sensor panels have been studied. Based on a model taking both column spacer and glass deformation into account, reductions of column spacer density or elastic constant are found to be effective for improving cell gap sensitivity to touch force. The structure of a-Si IR sensor incorporating IR light source and IR passing filter has been proposed, and the issues of optical sensor method are confirmed to be solved by simulation and experiment results.

P-88: Active Local Dimming System for Low Power and Motion Blur Enhancement

Recently, as the light-emitting diodes (LEDs) technology has improved, especially LED brightness is remarkable increased, the brightness of LCD panel is enough even if LED sources are located in only short edge sides (left and right) of the LCD module. As a result, the smart local dimming system is needed to use the invented LED back light unit (BLU) efficiently. In this paper, we proposed the new local dimming system to reduce power consumption and enhance motion picture quality for a new edge LED BLU. The proposed system is applied to active 2D local dimming algorithm and scanning technique at the same time. Our local dimming system has 3 advantages, 25% power saving, 1:100,000 contrast ratio and average MPRT 3.9ms with 240Hz panel. We verified performances by measurement. Finally, our 2D dimming technique was developed as AISC IP type which was merged in timing controller (TCON), so we can apply our system for mass product in 2011 year.

16.3: Enhanced Oblique Viewing Angle Color Performance for S‐PVA Panels

Viewing angle performance of LCDs is a key issue which has been approached by both subjective and statistical means. In this paper, we discuss causes of image quality degradation as a function of grayscale at a fixed off-axis viewing angle, examining both luminance and chromaticity distortions. Oblique viewing angle performance of both 1G-2D and 2G-1D S-PVA panel structures have been enhanced by controlling the two independent sub-pixel data for each of red, green and blue.

Gamma curve determination for each individual pixel on high-resolution flat panel display

This paper presents an automated system to determine gamma curves of each individual pixel on a high-resolution flat panel display. The system consists of a panel and its aligned area scan camera located at a fixed position. To localize a panel pixel position in an image captured from the aligned camera, a mapping function estimation scheme is proposed between the panel and the camera coordinates. The mapping function is modeled by combining both 2-D perspective transform and lens distortion and is estimated via feature-based registration. Intensity values of individual panel pixel are then measured for sampled gray-levels. To alleviate intensity interferences from neighboring pixels, we propose to use evenly spaced dot images as panel input. By using the measured intensity values of each panel pixel, gamma curves are determined to examine the characteristics of defects on the panel, if any. Experimental results show the relevance of the proposed method.