Televisions are getting bigger. This week at CeBIT, Samsung will announce what it claims is the world’s first 82-inch LCD TV – there is already a 106-inch plasma screen one.
That might be a little large for your living room but widescreen flat panel TVs give you a larger screen without taking up more room than a traditional cathode ray tube television and more people are buying 36-inch and 42-inch screens.
This year, size will become important for those wishing to enjoy High Definition TV fully.
In the past TV screens have had far lower resolutions than PCs: the 625 lines of a standard TV screen are less than even the most basic PC resolution of 640 by 480 and the US has been even worse with just 480 lines.
The higher the resolution, the more detail can be seen in the picture.
The new HD TV standards take that up to 780 or 1,080 lines; still low compared with PC screen resolutions but offering a significantly better picture quality for HD pictures.
And resolutions are going to keep going up: Taiwanese manufacturer Chi Mei will be showing a 56-inch LCD TV at CeBIT with a resolution of 3,840 by 2,160: four times that of HD 1080.
Sky, the BBC and Telewest are all testing HD services for this year and the Word Cup is going to give HD a big boost, but we will not see a free HDTV service until about 2010. Whichever standard wins, HD-quality DVDs are on their way.
And if you want to experience HD content at home today, try plugging in an Xbox 360. Do not assume that all flat-panel screens are HD quality though, especially cheaper models.
Currently there are three flat screen technologies: plasma, liquid crystal display (LCD) and digital light projection (DLP).
On plasma screens, the pixels are lit by tiny amounts of plasma (charged gas), rather like miniature neon lights. They are thin, you can watch them from different angles and they are often the cheaper option for large screens.
But LCD screens have higher resolution. Even a 32-inch LCD TV will usually be at least 780, but a 40-inch plasma screen that costs less than £1,000 might only have 480 lines, fewer than standard TV.
Less than one-third of the plasma TVs sold in December 2005 were HD ready and only 55-inch and 71-inch models support HD 1080.
Plasma screens can have problems with burn-in if there is a channel logo in the same place all the time.
Newer plasmas last 60,000 hours before screen brightness starts to fade but Gartner analyst Paul O’Donovan warns that “many cheaper models haven’t got the features that extend the lifetime of the screen”.
You will not get a plasma screen smaller than 37 inches. LCD screens go from 3-inch to 82-inch, so there is much more choice. The backlight and screen coating on an LCD TV makes it easier to view in brighter light, but picture quality does not always match the very best of plasma.
DLP is the technology used for digital cinema; it uses a chip with millions of tiny tilting mirrors to reflect light on to the screen and gives excellent picture quality. Samsung is showing a 67-inch DLP set at CeBIT that uses LEDs rather than a projection lamp, producing more colours and a picture that updates 1,000 times faster than LCD.
Most attempts to produce a thin, flat cathode ray tube have also been abandoned – Philips has switched over to working on 3D TV – but Toshiba and Canon have persisted with SED (Surface-conduction Electron-emitter Display).
This uses the same phosphors as a CRT but instead of a bulky electron gun there is a slim, low-power electron emitter for every pixel on screen.
Expect to see 55-inch SED screens later this year but also expect them to be expensive.
You will still need a separate HD set-top box for many new TVs. Sky’s HD service will need a TV with the copy-protected version of the standard HD interface, HDCP.
Do not settle for a bargain without the features you need; Mr O’Donovan predicts prices could drop by another 50 per cent by the end of this year.