Features

When you're sitting in front of a screen you want the best, most realistic viewing experience. Whether you're watching a movie or playing a game, you really want to feel as if you're actually right there in the middle of the action. And while you're putting together a presentation or working on a spreadsheet, you want to see the crispest text and the sharpest images. So what visual treats does the future of displays hold?

New display technologies need to increase the resolution they display without resulting in devices that dwarf our desks - or they need to redefine what we think of as a display entirely.

A realistic visual image requires an adequate resolution. This is the number of pixels, measured horizontally and vertically. It also requires fine control over the colours of those pixels. Manufacturers have made substantial improvements recently by bringing new innovations with names such as IPS, S-IPS and AS-IPS to liquid crystal display (LCD) technology. But even with this tweaking, the LCD as we know it is reaching the end of its ability to offer ever increasing levels of resolution and performance.

However, totally new display technologies are on the way. Here we look at some of the technologies that are just starting to appear in our monitors, projectors and TVs.

SED SCREENS

Developed jointly by Canon and Toshiba, the surface-conduction electron-emitter display (SED) is the latest development in large-screen TVs. According to the hype, SEDs will provide the quality of a cathode ray tube (CRT)

This is more than just marketing speak. An SED screen genuinely resembles a CRT in the way it works. Both CRTs and SEDs generate their own light by directing a beam of electrons on to a chemical called a phosphor, making it glow either red, green or blue. But while a CRT has just one electron gun for each of the three primary colours, and that electron beam has to scan across the front surface of the screen line by line, an SED has an electron emitter for each and every pixel, as you can see in the diagram on page 156. By removing the need to scan the electron beam and focus it into a tight spot, an SED can be just a few centimetres deep, irrespective of the screen size. By comparison, a CRT can be as much as 50cm in depth.

TVs based on this technology are not too far off. According to Ian Rea, Toshiba's UK product manager for flat-screen TVs, SED TVs will be available in the second half of 2007 in screen sizes of 36" and either 50" or 55".

SED has advantages over today's LCD and plasma screens. "The contrast ratio will be around 10,000:1 compared with 1,200:1 for most LCD screens and 3,500:1 for the latest LCD TV, due out later this year, which will have a selectively controllable back light," explained Rea. "Plasma screens also have a contrast ratio of about 3,000:1. It will provide much better movement because of its fast response time, which will be as good as that of a CRT. Scrolling text will be crisp and you won't have blurred movement in the background of a scene."

This technology won't appear in our living rooms to start with. Initial products will be expensive. And while it sounds like the perfect screen technology for PC monitors, don't hold your breath. According to Rea, "you won't see SEDs in PC monitors for a few years yet. This is just a business case. It's not that they're unsuitable; it's to do with economies of scale. Initially we'll be producing large screens for entertainment. It'll be a while before they're scaled down for use in 17" or 20" displays."