The common question heard when buying a new projector for the home, office, or classroom is: should I buy an LCD projector or a DLP projector? LCD, an acronym for ‘liquid crystal device’ and DLP, which stands for ‘digital light processing’ are the two commonplace projector imaging technologies. With so many brands and types available, it can be overwhelming for clients to make a choice between the two technologies. The fact is that LCD projectors offer better image quality and colour accuracy. The article below will tell you why DLP projectors struggle with projecting a comparable rate of image quality.

Think of a set of blinds in your house on your bedroom window. By pulling a rod you can make the shutters open or closed, according to whether you want to let light in or not. This is exactly how an LCD projector works. Each pixel operates like its own shutter on a set of blinds to either allow 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 functions to either reflect light or block it.

How the light source is processed from the point when the projector turns on to when the content reaches your screen is ultimately significant with regard to image quality, brightness and colour accuracy. LCD projectors project white light from the lamp by cutting it into red, blue and green components, by three mirrors which transfer the coloured light to 3 stand alone LCD panels. The 3 LCD panels make the elements of the image by processing each pixel on and off. The pixels are then projected in a glass prism to form the projector image. Something important to remember about LCD projectors is that all three colours are sent onto your projector screen all at once. The way a DLP projector works is vastly different and even the final product of how an image comes out is not the same. With DLP, white light from the lamp is processed through a rotating colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This way of making an image forms a sequence of red, blue and green light. The millions of micro mirrors as mentioned above reflect the coloured light on the pixels to form the image elements. The elements of the image are cast 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 single whole image. With LCD projectors, all colours are available all the time to form the highest brightness and spectacular colour accuracy. In DLP, just one colour is available at any given time, and so resulting in lower colour brightness and accuracy. Some DLP developers have included a white segment in the colour wheel to improve brightness overall, but this goes and detracts from colour accuracy.

I see in forums all the time that DLP offers a higher contrast ratio and thus must be superior. For those who are unsure, 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 projector is capable of producing. DLP projectors do offer high contrast specifications in comparison to most LCD projectors. At first glance, this must be a benefit, however, in real life, the true black level is determined by the ambient light in the room when the projector is being used. Do not be duped by contrast specifications on websites and in brochures.

When the content you want to project includes moving images, DLP projection technology can also create image errors, or ‘artifacts’. The most commonplace artifact that a DLP projector displays with moving images is colour break up. Colour break up is unavoidable in DLP systems because moving images change between the time red, blue and green colours are pulled up. LCD projectors do not have this problem because the colours are projected simultaneously. DLP developers have developed 3DLP solutions using 3 chips to fix the colour break up artifacts, but the price tag of these projectors make them hardly practical for most businesses and consumers.

Another difference between LCD and DLP is how they make up for the refractive qualities of light. Remember back to high school science, and recall how the different colours of light refract various amounts when projected through the same lens. The downside with DLP projectors is that they have the one same panel with the same lens to project Red, Blue and Green. All 3 colours are obviously not the same and refract light in a different way. Generally with a DLP projector, some yellow colour will appear above and some extra blue will be projected below an image containing something as simple as a lone black line. While being built LCD projectors can be adapted to minimize these effects on the projected image, because each colour is projected on a separate LCD panels.

The one actual buy point (excluding price) with picking a DLP projector is its overall smaller size and weight. However, this is only relevant to mobility and needs to be traded off against the image superiority of LCD projectors. If the result of the picture quality is vital to you, then the decision is easy. Take an LCD projector! LCD projectors will definitely produce bright, colourful images with fewer image mistakes. If you desire to know more about LCD technology in more detail, see this fabulous resource website: Explore 3LCD. If you have any more questions, visit Projector Central and send me an email.

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