Twisted nematic is the classic structure for active-matrix LCDs used in monitors and notebook computers. When those of us who present tutorials on display technology have time for only one LCD cell structure, twisted nematic (TN) is almost invariably the one that’s presented.

Ken Werner
Senior Analyst and Editor
of HDTV Retailer and
Mobile Display Report

But TN-mode is not used for large-screen TV panels because, even with typical film compensation, the colors, contrast, and viewability change at viewing angles that are even moderately large. Instead, companies who make television panels have spent a great deal of time, money and energy developing other cell structures - variations on in-plane switching (IPS) and multi-domain vertical alignment (MVA) LCD - that provide better dark states and color consistency over the full range of viewing angles.

So it may come as a surprise to learn that several Taiwanese panel-makers are planning to take the technologically retrograde step of making TN-based TV panels, as reported today by DigiTimes. Production, which is intended for the entry-level segment, will start in 2H’06 with the goal of boosting demand in developing markets for TV panels of 30 inches or less.

Chunghwa Picture Tubes (CPT) has already begun development of 26-inch TN-mode TV panels, DigiTime’s sources said, and CMO will start developing a 26-inch TN TV panels in 3Q with volume production planned for 4Q, according to the company. AUO will introduce 20- and 22-inch, wide-screen TN panels in 3Q, said company sources.

Why make an inferior panel? Because it’s cheaper. A 26-inch VA-mode panel costs $30 more than a similar TN-mode panel, panel-makers told DigiTimes . That could take nearly $100 off the price of the TV set you see at Best Buy. And, as CRTs continue on their slow journey to extinction, we will need LCD-TVs in nearly every cost and size category.