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The big screen

In recent years, the humble monitor has gone from desk-hogging, TV-sized box to slimline flat-screen beauty, George Cole looks at where it's all going next...

You can have the fastest, all-singing, all-dancing computer in the world, but it's as about as useful as a chocolate fireguard if you can't see any of the information that's stored on it.

Most of us take computer displays for granted, but when our monitor goes wrong, we suddenly appreciate how much they matter. Over the years, the content displayed by monitors has changed considerably and so has the technology behind them. Whereas years ago, monitors simply displayed text and perhaps the odd black-and-white graphic, today, they also have to cope with high-resolution colour graphics, complex animations and fast-moving DVD-quality video.

Monitor technology has changed, too. The bulky picture tube monitor is being rapidly replaced by flat-screen displays, which use much less desk space. Flat-screen displays have come on in leaps and bounds over the years and prices have fallen to the extent that almost anyone buying a new monitor today will opt for a flat-display version. Most flat screens use liquid-crystal display (LCD) technology which has been around for years (liquid crystals were discovered in the 19th century), but for a long time, they struggled to supplant picture tube technology because they were much more expensive and offered lower performance.

All that changed when a technology known as Thin Film Transistor (TFT) was developed. There's no need to worry about how the technology works, suffice to say that when TFT arrived many of the issues surrounding LCDs were dealt with. Today's LCD screens offer full-colour, high-resolution images and can cope with fast movement. The viewing angle has also improved, so you don't have to sit directly in front of the screen to get a decent image - handy if you've got small groups of pupils working on one computer. LCDs use less power than picture tube monitors, don't suffer from screen burn (images permanently burnt into the screen) and give out much-reduced electromagnetic emissions. They are also small and light, making them ideal for portable computers - imagine trying to lug around a laptop that used a picture tube monitor. That's why if you walk around a major educational technology show like the BETT show, you only see flat displays on the exhibition floor and why more and more classrooms are full of them too.

One of the leading developers of LCD displays is the Japanese company Sharp. It recently launched a 65-inch LCD TV (don't ask how much it costs) and is about to mass-produce two new and intriguing LCD products. The first is a switchable LCD display which lets two people view two different things on a single screen at the same time. For example, one person could be accessing the internet while another is editing some camcorder footage. The system works by using a special optical filter, which enables the monitor to display two different images on each side of the screen, so that a person sitting to the left of the monitor, sees a different image to someone sitting to the right of it. It's certainly clever and I'm sure schools strapped for cash for buying flat-screen displays might be tempted by the idea of being able to use a display for two different tasks, but there are questions, such as can both displays be independently controlled by the two users (Sharp's description suggests it can) and what about the different sounds?

Sharp's second development is an LCD screen with narrow and wide-angle viewing. Here the LCD screen is covered by a special switching coating that makes it possible to adjust the viewing angle so that only the person directly in front of the screen can view the information. Sharp says this would be useful for laptop users who want to view private information in public, but I'm not too convinced about this - would you really want to look at confidential information with other people around you?

However, Sharp has released a laptop LCD display which some schools could find useful because it can display images in both 2D and 3D. The 3D display uses an optical filter that causes the viewer's left and right eyes to see different images - this is how we perceive depth. It sounds a bit gimmicky, but consider students using computer-aided designs or science lessons where you want to display molecules and other atomic structures in 3D. Sadly, Sharp decided not to launch the 3D laptop in the UK, although some independent distributors have done.

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