DLP TV – Beginner’s Guide
DLP (Digital Light Processing) technology is a relatively new system that is providing serious competition for plasma and LCD sets in the home cinema market.
DLP TVs are ‘rear-projection’ types. They generate an image that is projected on to the back of a screen, all of this taking place inside a TV case that is slimmer than a conventional set, but deeper than a plasma or LCD model.
Basic DLP technology
The DLP chip was invented by Dr Larry Hornbeck of Texas Instruments in 1987. It is an array of tiny mirrors that is small enough to fit in the palm of your hand.
Though tiny, it is home to as many as two million tiny mirrors, each capable of tilting to a specified angle. A light source shines light on to the mirrors, and depending on which way they are tilted, they either reflect light on to the screen or they do not.
The result is that a pixel has been created on the screen – it will be light or dark depending on the angle of the mirror.
The addition of a ‘colour wheel’ in between the light source and the mirrors means that each mirror can reflect coloured light, rather than merely white light. This allows a DLP display to generate a full-colour image.
DLP technology can be used in rear-projection TVs, or in front-projection systems for the home or full-scale cinemas.
Pros of DLP TV
- DLP TVs tend to be cheaper than their flat-panel rivals, LCD and plasma sets
- The mirrors on the DLP chip are very closely packed, meaning that the resultant image does not suffer from the cross-hatch ‘chicken wire’ effect that can be visible on LCD displays
- DLP projectors for the home can be very small and light thanks to the compact nature of the DLP chip
- DLP rear-projection TVs are immune to screen burn
- DLP sets deliver sharpness and colour fidelity that is a match for plasma and LCD sets
- Screen sizes can be bigger than plasma and LCD sets while remaining affordable
Cons of DLP TV
- Rear-projection TVs do not produce as bright an image as plasma and LCD sets, so you may need to watch in a darkened room for optimum performance
- Some people can detect a ‘rainbow effect’ caused by the colour wheel. This can be distracting, but most people are totally unaware of it
- The viewing angle can be restrictive on some rear-projection models, although this tends to be less of a problem with bigger screen sizes of 50 inches or more
- DLP rear-projection sets are bigger than plasma and LCD models and cannot be wall-mounted, so they will take up floor space
Top tips for buying a DLP TV
- Make sure you cannot detect a rainbow effect on the TV you are considering buying
- Check that the viewing angle will not be a problem in your media room
- Decide if the brightness of the display is suitable for the room you will be using the TV in
- Remember a DLP rear-projection set will take up floor space – can you realistically fit a big screen into you room?
DLP TV Beginners Glossary
DLP chip – An array of microscopic mirrors that is used to generate a TV picture in a DLP projector or rear-projection TV
Front-projector – A projector that works just like one in a cinema, throwing a potentially huge image on to a screen at the other end of a room
Pixel – A ‘picture element’, the little dots that make up an image on a screen
Rainbow effect – An optical illusion caused by the colour wheel inside a DLP projector or rear-projection TV. Only visible to some
Rear-projection TV – A TV that uses a projector inside a case to deliver an image on to a screen
Screen Burn – A ghost-like image that is permanently displayed on a screen, usually due to a logo that has been left onscreen for hours at a time
Viewing angle – The range within which a watchable image is retained. Stray outside the viewing angle and the picture begins to fade
Article from HomeCinemaUK.com