LCD Facts and Fiction

by Bruce Berkoff

Through investments in research and development and new manufacturing facilities, LCD manufacturers have significantly enhanced LCD-panel technology, posing a significant challenge to its main rival in the large-sized HDTV market, plasma-display panels (PDPs). But many misperceptions about LCD TVs still linger.

In recent months, PDP adherents have forcefully presented their positions. I believe it is appropriate for an LCD representative to now address some of the key advantages of LCDs and set the record straight on why LCDs are the best solution for a variety of flat HDTVs.

Resolution. Almost all LCD TVs on the market today offer at least high-definition (HD) resolution of 1366 x 768 pixels (over one megapixel), and stores are starting to carry LCD TVs with full HD resolution of 1920 x 1080 (over two megapixels). However, the majority of PDP TVs in the market today deliver enhanced definition (ED) resolution of only 850 x 480 (0.4 megapixel), and full HD resolution has proven difficult to implement in 42-in. PDP TVs because of pixel-size limitations. In fact, no 42-, 50-, or even 60-in. PDP sets on the market today are below the one-megapixel threshold we believe is needed for HD.

Thus, as HDTV broadcasting becomes more widespread, and high-definition DVDs and gaming consoles are released in 2006 and beyond, the LCD TV's significant resolution advantage over PDP TVs will become more apparent, as most existing LCD TVs already offer the resolution necessary to properly display full-HD video content.

Viewing Angle. One of the most common misperceptions about LCD TVs is that they suffer from limited viewing angles, which is often considered a dis-advantage vs. PDP TV. While LCD technology had viewing-angle limitations in its infancy, leading manufacturers are now using specially developed technology to deliver viewing angles of up to 178°, so a crisp and clear picture is viewable from any seat in the house.

Real-Life Performance. One of the least understood and overemphasized points of comparison between LCDs and PDPs is contrast ratio. While many PDP TVs claim contrast ratios of 10,000:1 or more, measured in a dark room with a small dot on a dark screen, they often deliver a contrast ratio of 200:1 or less in a regular living room with real content. LCD TVs, on the other hand, that have reported contrast ratios of between 500:1 and 1000:1 usually achieve about 300:1 in real-life settings.

Because the published contrast ratios for both types of display are measured in a dark laboratory, the LCD values deteriorate less in real-world environments because LCDs have significantly less reflection and glare than PDPs. Historically, PDPs have achieved better black levels than LCDs, but now that LCDs are beginning to use dynamic contrast circuitry, even that is no longer necessarily the case. The bottom line is that consumers should judge flat-panel TVs for themselves in real-life viewing conditions, rather than blindly trusting spec sheets. When consumers can personally compare flat-panel TVs, especially with high-definition content and higher resolution, LCD TVs will certainly stand out from the crowd.

Response Times. Having advanced cell structures and overdrive technology, LCD response times can be improved dramatically. Thus, with the best TV sets today, we are at the point where the human eye cannot perceive any significant differences in the vast majority of images that are broadcast. With today's improved effective response times combined with up-and-coming technology such as scanning backlights, high-quality LCD-TV sets will not suffer from any noticeable problems with image trailing and color distortion, as was indeed the case with earlier sets.

Looking Forward. When made in today's Gen 6 fabs, LCD TVs in the 32–37-in. range of LCD TVs are already quite cost effective. Cost effectiveness for 42- and 47-in. models will soon follow as Gen 7 fabs ramp-up in 2006 and 2007.

At the moment, LCD technology is the only technology well suited for HDTVs 37 in. and smaller, and it will soon be the best for all full HDTVs at 42 in. and below.