November 2005 — Industry Perspective

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Display Technology ‘Tradeoffs’

by Todd Moffett

Significant improvements have been made over the last three or four years in CRT TVs that display computer data for group learning. This is a cost effective way to incorporate computer-driven curricula and Internet browsing for group instruction. If you opt for a CRT TV, remember to select a non-scan conversion-type product, because scan-conversion technology actually converts the 800 x 600 resolution down to fewer than 250 lines of resolution. Simple math will tell you that with fewer lines of resolution, the picture will be soft or fuzzy, and only large fonts or power points will look acceptable. A true SVGA monitor/ TV is a good alternative to those more expensive technologies and can operate in all lighting conditions.

LCD panel. LCD (liquid crystal display) technology passes a light source through three electronic panels—one each for red, green, and blue—combined to reproduce a great image, perfect for data. The newest LCDs also employ very fast response times to help eliminate so-called “motion artifacts,” which used to plague these flat screens when displaying fast-paced action like a sporting event or movie. For pure data, the LCD panel provides a very stable image with no image-sticking from a static image on the screen. Large LCD panels represent great display technology with rich colors and fabulous image reproduction for data display or signage content. The large 42- and 55-inch displays will see major improvements in both performance and price points over the next year. Most IT professionals are comfortable with this display technology, but it has been cost-prohibitive in the past; however, all that will change within the next year due to lower manufacturing costs and competition.

Projector. In recent years, we’ve seen drastic price reductions from various projector companies. And, as the technology has fallen below the $1,000 price point, demand has skyrocketed. However, low cost d'esn’t always mean better performance, so consider the tradeoffs. For optimum performance, select a projector that has more than 2,000 ANSI lumens. Projectors with low lumens require a more controlled environment to display a good image. Ambient or direct light will wash out your image. You may save money upfront, but the cost of ownership can be quite large due to the recurring expense of bulbs and maintenance. Without a regular “cleaning” schedule, your projector will degrade at a faster pace than one that has a regular maintenance schedule. Plus, to get the best out of your projector, you must purchase a good quality screen, because a quality projector will look even better with a proper screen.

Plasma display panel. The latest technology to enter the education field is plasma, which is almost like a new version of the old CRT technology. Just like conventional color TVs, flat panel plasma displays use phosphors illuminated by electrical charges; however, the difference is that inside a plasma screen you will find gas sandwiched between two glass plates. As for image quality, plasma ranks among the very best. It is well suited for full-motion video and data content. Best of all, it has grown much more affordable. Today’s best plasma displays offer 60,000-hour panels (now comparable to CRTs and LCDs), technologies to prevent image sticking, and advanced features that provide zoom and pan functions.