With the home, corporate and education markets all driving growth in the demand for projectors, ARN looks at a long-held rivalry between two technologies competing for dominance.
There was a time when only the most advanced and cashed up boardrooms would have a CRT video projector bolted to the ceiling. Consisting of three separate cathode ray tubes, the projector would simultaneously project the red, blue and green elements of the image onto a wall or screen, where the colours would blend to create the image.
They were expensive, heavy and power hungry, and outside of the corporate market largely unheard of. Then in the 1990s LCD projectors emerged. Rather than mix colours, which make up the image directly on the screen, the LCD projectors combine the red, blue and green elements of the picture within the projector unit.
Each panel consists of thousands of tiny cells, which open or close depending on the image, while light from powerful but expensive halogen lamps are used to push the combined result onto the display.
Cheaper, more efficient to run and considerably lighter than their CRT cousins, LCD technology quickly became dominant in the projector space, and by the end of the 1990s even midsized companies could boast a projector in the meeting room.
At the same time as LCD was storming through the CRT market, a researcher called Larry Hornbeck at Texas Instruments was working on an alternative. Digital Light Processing (DLP) projectors use light beamed through a tiny colour wheel to create the image on display.
As the colour wheel spins the red, green, blue and white components of the image are flashed onto the screen at such speeds that the colours are combined in our mind to create the whole image.
Although they emerged at about the same time, DLP projectors were initially more expensive than LCD and some more light-sensitive individuals complained of being able to perceive the flicker as the image chopped and changed between colours. Also an issue was what's come to be known as the Rainbow Effect, where individuals with low flicker fusion thresholds see the red, green and blue trails or shadows follow moving figures on a DLP display.
However, Hornbeck's longer term vision was to create a projector that ran cooler so it could run for longer periods without the need for lamp replacement. As the CRT technology all but disappeared from view, DLP projectors gradually began gaining ground on the LCD technology, although they rarely crossed paths. Until now ...
So what's the score?
According to the latest figures from researchers at IDC, DLP sales surpassed LCD for the first quarter of 2007. In 2006, LCD projectors still held 50.3 per cent of the market, compared to DLP's 49.4 per cent. However, in Q1 2007, DLP sales jumped to 52.1 per cent of the market, with LCD projectors slipping back to 47.6 per cent.