First unveiled by Texas Instruments in 1996, Digital Light Processing is the only video technology that truly delivers a digital connection between devices like a DVD player and TV or projector – the digital video signal turns to analogue only at the point that it hits your eyes.

At the heart of any DLP projector or TV lies a trio of components: a light source with condensing lens, which focuses the emitted light to a point, a Digital Micromirror Device (DMD) and a projection lens. The most interesting, and complicated, part of the whole setup is the DMD. Effectively an optical switch, a typical XGA DMD contains over 750,000 mirrors measuring 13.8 microns square and spaced just 0.8 microns apart, with each mirror representing a single pixel in a display, although higher-spec DMD's boast even more mirrors in an array. (A micron is a thousandth of a millimetre or, if you prefer, a millionth of a metre.)

To switch a single pixel on or off, each mirror is fed by two address electrodes which tilt each mirror by 12-degrees – either towards the light source, turning the pixel on, or away from it again, making the pixel go dark. This switching occurs several thousand times per second, with each pixel capable of producing up to 1.024 shades of grey according to how long its corresponding mirror is left on or off.

Grey obviously isn't much use in a home cinema system, so a rotating red, green and blue colour wheel is added between the light source and the DMD. Again, by deciding when each mirror is tilted on or off and how long it stays in that state, any one of up to 16 million colours can be illuminated on each pixel in the display. The only thing to determine then is how each mirror's electrode triggers are fired in the first place.

The answer is simple. The incoming video or graphics signal is decoded in such a way that the electrodes which control each micromirror are activated at the appropriate time. The reflected light from each micromirror is then amplified by the projection lens and splashed onto the back of the screen in a rear-projection set, or on to the front of a screen some distance away with a front projector.

The result is a bright, detailed, high-fidelity image that proves why digital cinemas and home cinema fans are rapidly adopting the technology as the new gold standard for big-screen movie viewing.