HD Projector Types

The two most common types of projector are LCD and DLP types. We shall also have a look at two other types of projector, D-ILA and SXRD. They are relatively new to the home cinema projector market, but growing in popularity.

It is important to remember that projectors are at their best when the room is as blacked out as possible. Daylight conditions have an adverse effect on performance, and low contrast models will need a totally blacked out room.

You may also come across references to CRT projectors. Although they provide unbeatable picture quality, they are enormous pieces of kit, and as far as the consumer is concerned, too expensive to buy and run.

Note: Some of the terms we use to describe the different projector types may be unfamiliar;

The 'Chicken-Wire' effect: A phenomenon by which the grid-like structure of the panel on LCD projectors is visible on the projected image.

The 'Rainbow' effect: Whereby DLP projectors can produce bands of red blue or green colour on the projected image.

Screenburn: Whereby a strong picture component such as a TV channel logo leaves a permanent mark or echo on a projector's mechanism.

LCD Projectors

LCD projectors use a miniature optical system to divide concentrated lamplight into primary Reds, Greens and Blues for delivery through three LCD panels. A sophisticated image processing system then analyses the beams on a pixel-by-pixel basis and merges them into the final projected image.

	Most models are small, portable and easy to set up; Do not suffer from screenburn or picture processing noise.
	Fans to keep them cool are often noisy; Contrast ratio can be poor and pictures can suffer from the 'chicken wire' effect.

DLP Projectors

Originally developed by Texas instruments DLP (Digital Light Processing) projectors create an image through a series of many thousands of tiny vibrating mirrors governed by a microchip.

The image is projected onto a screen by a lamp inside the mechanism which shines through a colour wheel.

	Like LCD they are small portable and easy to set up; They offer superior contrast ratios and do not suffer from screenburn; Black levels superior to LCD.
	Spinning colour wheel can add to the noise of the fan; Can suffer 'dead pixels' if a mirror fails.

D-ILA Projectors

A development of LCD technology, D-ILA (digital direct drive image light amplifier) projectors were originally developed by JVC as a means of delivering more light within a projected image.

	Incredibly smooth detailed pictures; Does not suffer from screenburn, rainbow effect or 'chicken wire' effect.
	Expensive; Contrast is not the best.

SXRD Projectors

SXRD (Silicon X-tal Reflective Display) is a technology pioneered by Sony. Light is passed through liquid crystal wedged between two layers of polarized glass rebounding of aluminium electrodes to create the projected image.

	Delivers twice the pixel density of LCD for supremly sharp and detailed pictures; Superior response time offers unrivalled fast motion action.
	Expensive.