The typical question customers ask when acquiring a new projector for the home, office, or classroom is: do I purchase an LCD projector or a DLP projector? LCD, an acronym for ‘liquid crystal device’ and DLP, standing for ‘digital light processing’ are the two top projector imaging technologies. With so many different brands and models available, it can be confusing for the buyer to make a decision between these technologies. Ultimately LCD projectors offer far better image quality and colour accuracy. The next paragraph explains why DLP projectors struggle with creating a similar level of image quality.

Imagine a set of blinds in your room on your bedroom window. With the twist of a rod you can have the shutters open or closed, depending on whether you want to let light in or not. And such is exactly how an LCD projector works. Each pixel operates like its own shutter on a set of blinds to either shine light through or to block it. DLP on the other hand is created of millions of microscopic mirrors or ‘pixel elements’ as the pros like to call them. Each pixel element operates to either reflect light or block it.

How the light source is processed from when the projector switches on to when the picture reaches your screen is absolutely significant in regard to image quality, brightness and colour accuracy. LCD projectors process white light from the lamp by separating it into red, blue and green components, by three mirrors which project the coloured light to 3 individual LCD panels. The 3 LCD panels cast the elements of the image by switching each pixel on and off. The pixels are then projected in a glass prism to deliver the projector image. Something to understad about LCD projectors is that all three colours are projected onto your projector screen at the same time. The way a DLP projector operates is totally different and even the produced image appears is not the same. With DLP, white light from the lamp is sent through a turning colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This way of forming an image requires a sequence of red, blue and green light. The millions of micro mirrors mentioned above reflect the coloured light on the pixels to construct the image elements. The elements of the image are displayed in sequence on the screen, one colour at a time. The viewer’s eye will then pull together each coloured element of the image into the single complete image. Using LCD projectors, all colours are available all the time to create the top level of brightness and great colour accuracy. In DLP, only one colour is available at a time, resulting in lower colour brightness and accuracy. Some DLP manufacturers have put a white segment for the colour wheel to improve brightness overall, but this also degrades colour accuracy.

I find in forums all the time that DLP gives a higher contrast ratio and ergo must be better quality. For those who are unaware, 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 system is capable of. DLP projectors do have high contrast specifications compared to most LCD projectors. At a glance, this can seem to be an advantage, however, in reality, the true black level is determined by the ambient light in the room when the projector is being used. Do not be fooled by contrast specifications on websites and in brochures.

When the content you want to view needs moving images, DLP projection technology also creates image marks, or ‘artifacts’. The most often seen artifact that a DLP projector creates with moving images is colour break up. Colour break up is inherent in DLP systems because moving images change between the time red, blue and green colours are shone. LCD projectors do not have this characteristic because all the colours are processed simultaneously. DLP builders have developed 3DLP solutions using 3 chips to fix the colour break up error, but the expense of these projectors make them hardly practical for many businesses and consumers.

Another variance between LCD and DLP is how they match the balance for the refractive qualities of light. Take yourself back to high school science, and recall how different colours of light refract different amounts when directed through the same lens. The disadvantage 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 not the same and refract light differently. Usually with a DLP projector, some yellow colour will come up above and some blue will come up below an image of something as simple as a lone black line. During manufacturing LCD projectors can be fixed to take away these effects on the projected image, because each colour is projected on isolated LCD panels.

The one actual benefit (excluding price) with picking a DLP projector is its smaller overall size and weight. However, this is only relevant with regard to portability and must be traded off against the image superiority of LCD projectors. If overall picture quality is important to you, then the decision is easy. Go with an LCD projector! LCD projectors will definitely show bright, colourful images with fewer image blips. If you need to find out more about LCD technology in more detail, check out this spectacular resource website: Explore 3LCD. If you have any further questions, visit Projector Central and send me an email.

Jonathan King is the sales and marketing manager with Projector Central, Australia’s top 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.