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The most typical question customers ask when looking for a new projector for the home, office, or classroom is: will I take an LCD projector or a DLP projector? LCD, standing for ‘liquid crystal device’ and DLP, short for ‘digital light processing’ are the two top projector imaging technologies. With so many different brands and different models available, it can be overwhelming for clients to make a decision between those technologies. The fact is that LCD projectors give better image quality and colour accuracy. The article below will tell you why DLP projectors struggle with bringing up an equal level of image quality.

Think of a set of blinds in your room over your bedroom window. By pulling on a rod you can turn the shutters open or closed, according to whether you want to let light in or not. And this is exactly how an LCD projector operates. Each pixel functions like a single shutter on a set of blinds to either pass light through or to block it. DLP on the other hand is constructed of millions of microscopic mirrors or ‘pixel elements’ as experts like to call them. Each pixel element works to either reflect light or block it.

How the light source is processed from the point at which the projector switches on to when the content reaches your screen is absolutely significant for image quality, brightness and colour accuracy. LCD projectors direct white light from the lamp by dividing it into red, blue and green components, by three mirrors which transfer the coloured light to 3 different LCD panels. The 3 LCD panels form the elements of the image by shining each pixel on and off. The pixels are then simultaneously processed in a glass prism to create the projector image. An important point to realise about LCD projectors is that all three colours are sent onto your wall all at once. The way a DLP projector works is totally different and even how an image comes out is not the same. With DLP, white light from the lamp is directed through a rotating colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This method of forming an image casts a sequence of red, blue and green light. The millions of micro mirrors described above reflect the coloured light on the pixels to produce the image elements. The elements of the image are displayed in sequence on the screen, one colour at a time. The viewer’s vision will then draw each coloured element of the image into a complete image. In LCD projectors, all colours are available all the time to offer the top level of brightness and fantastic colour accuracy. In DLP, only one colour is available at once, resulting in lower colour brightness and accuracy. Some DLP developers have added a white segment for the colour wheel to improve brightness generally, but this further detracts from colour accuracy.

I see in forums all the time that DLP provides a higher contrast ratio and as such must be superior. For those uncertain, the contrast ratio is a measure of a display system defined as the ratio of the luminance of the brightest white to that of the darkest black that the machine is capable of producing. DLP projectors do provide high contrast specifications compared to most LCD projectors. At one glance, this appears to be a plus, however, in real life, the true black level is determined by the ambient light in the room when the projector is being utilised. Do not be fooled by contrast specifications on websites and in brochures.

When the content you plan to bring to life includes moving images, DLP projection technology also creates image marks, or ‘artifacts’. The most often seen artifact that a DLP projector displays with moving images is colour break up. Colour break up is inherent in DLP systems because moving images change up between the time red, blue and green colours are projected. LCD projectors do not have this downside because the colours are processed at the same time. DLP manufacturers have created 3DLP solutions using 3 chips to fix the colour break up artifacts, but the cost of these projectors make them almost impossible for the large part of businesses and consumers.

Another point of difference between LCD and DLP is how they balance for the refractive qualities of light. Think back to high school science, and remember when they taught you how the different colours of light refract different amounts when directed through the same lens. The problem with DLP projectors is that they have the one same panel for the same lens to project Red, Blue and Green. All 3 colours are obviously not the same and refract light in a different way. Often with a DLP projector, some yellow colour will come up above and a superfluous blue will show below an image of something as simple as a straight black line. In manufacturing LCD projectors can be fixed to minimize these effects on the projected image, as each colour is projected on its own LCD panels.

The isolated real buy point (excluding price) with choosing a DLP projector is its overall smaller size and weight. However, this is only relevant for mobility and has to be traded off against the image advantages of LCD projectors. If overall picture quality is vital to you, then the solution is a no-brainer. Take an LCD projector! LCD projectors will definitely create bright, colourful images with fewer image blips. If you wish to ask more about LCD technology in more detail, have a look at this tremendous resource website: Explore 3LCD. If you have any more questions, jump onto Projector Central and send me an email.

Jonathan King is the sales and marketing manager with Projector Central, Australia’s number one online retailer for projectors. Brisbane based, Projector Central has serviced Australia for 15 years. For data projectors in Brisbane and Interactive Whiteboards, contact Projector Central today.