Ji-Won Sohn

Recent Trends on Patterned Vertical Alignment (PVA) and Fringe-Field Switching (FFS) Liquid Crystal Displays for Liquid Crystal Television Applications

This paper reviews the recent trends on super-patterned vertical alignment (S-PVA) and fringe-field switching (FFS) technologies for liquid crystal display (LCD)-television (TV) applications. For PVA mode, Samsung originally announced S-PVA technology in 2004 to enhance off-axis viewing quality of conventional PVA mode. S-PVA is a new technology which enables screen quality advantages over super-in plane switching (S-IPS) and multi-domain VA (MVA), including high transmittance, >2300:1 contrast ratio, and wide viewing angle with no off-axis image inversion. This paper explores and updates Samsungs latest developments toward its goal of ultimate LCD-TV performance. For FFS mode, the technology appeared in 1998 by HYDIS and now it has been commercialized in all kinds of display applications, implying its technical importance. This paper reviews recent developments and performance of LCD-TV using the FFS mode based on published papers and our knowledge.

57.3: Cost-Effective Pixel Structures for High Performance Mobile PVA LCDs

Two new pixel structures are proposed for use in high performance mobile PVA LCDs. The new structures enable use of a conventional polarizer for lowest possible cost. A 4.3″ prototype based on these techniques was built, achieving the worlds highest mobile display contrast ratio of 1200:1, while maintaining wide viewing angle with no loss of transmittance.

15.1: A Novel VA Architecture for Improved Response Time

We designed a novel mountain-shaped cell architecture in order to obtain less than 15 ms of tr+tf response time without an overdriving circuit in vertical alignment mode. This structure significantly reduces the tr+tf time of PVA mode by eliminating abnormal motion in the turn-on process, which is detrimental to rapid switching.