By Oo Gin Lee

FLAT panel TVs are getting even slimmer.

Standard LCD and plasma TVs trimmed the thickness of the TV set to about a third of the old CRTs, making them slim enough to be mounted on the wall. When it comes to good looks though, you can never be too trim.

All major TV makers are now launching slimmer models which cost more but make your living room look so much more enchanting. For instance, Samsung's svelte rose-red 46-inch 850 series is just 4.4cm thick, which is 55 per cent thinner than the 9.8cm thick 750 series of the same screen size.

Hitachi has also just launched its Ultra-thin series which boasts a depth of just 3.9cm. There is a catch, however. Hitachi removed some of the electronic innards and placed them in a separate media box, which makes it a little inconvenient.

For me, substance is more important than form. If money were no object, I would go for the display with the best image quality. And that is where LED-backlit LCD TVs are making their mark - by offering sharper images and more vibrant colours through higher contrast ratios. They are also more energy-efficient.

LCD, which stands for liquid crystal display, works this way: liquid crystals are sandwiched between two transparent panels and light is shone from the back (therefore called the backlight) to create the images we see on screen. Traditional LCDs make use of several mini fluorescent tubes (called cold cathode fluorescent lamps or CCFL) as the source of the backlight but their limitation is that all the tubes must be dimmed to the same brightness. An LED backlight, on the other hand, is made up of hundreds to thousands of tiny LEDs (light-emitting diodes), each of which can have its own level of brightness. Therefore, LED-backlit LCDs are able to have higher contrast ratios.

Many manufacturers have just started launching their LED-backlit LCD TVs recently. Generally, they cost about 30 to 40 per cent more than a similar model using CCFL. Some models in the market include the Sony X4 series, Samsung's 950 series and the just-launched Philips 42-inch 42PFL9803 which has an astonishing two million to one dynamic contrast ratio.

LED-backlit LCDs have also found their way into monitors and laptops. Apple's current Cinema Display and HP's HP DreamColor LP2480zx are two premium 24-inch LCD monitors which are LED-backlit. All major laptop brands have launched LED-backlit laptops last year too. For laptops, this means longer battery life as the LED backlight is more energy-efficient.

Another key feature in LCD displays which affects image quality is the type of liquid crystals used. Standard technology makes use of twisted nematics liquid crystals but the ones to look out for are those using in-plane switching (IPS) crystals which offer sharper images and a wider viewing angle.

The problem with IPS panels, however, was that they suffered from slower pixel refresh. This affected the smoothness of fast-moving images in games and video.

The one monitor I am really impressed with is the 24-inch Philips 240PW9EB, which costs $739. It makes use of the new H-IPS technology which has a faster pixel refresh rate and better image quality.