The most common question asked when acquiring 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 most popular projector imaging technologies. With so many different brands and types available, it can be overwhelming for customers to decide between the two technologies. The simple fact of the matter is that LCD projectors have far superior image quality and colour accuracy. The following article tells you why DLP projectors struggle with creating a comparable standard of image quality.

Imagine a set of blinds in your home on your bedroom window. By pulling on a rod you can make the shutters open or closed, depending on whether you want to let light in or not. That is exactly how an LCD projector functions. 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 formed of millions of microscopic mirrors or ‘pixel elements’ as the experts like to call them. Each pixel element functions to either reflect light or block it.

How the light source is processed from when the projector turns on to when the picture reaches your screen is ultimately important with regard to image quality, brightness and colour accuracy. LCD projectors shine white light from the lamp by dividing it into red, blue and green components, by three mirrors which send the coloured light to 3 individual LCD panels. The 3 LCD panels cast the elements of the image by shining each pixel on and off. The pixels are then combined in a glass prism to send the projector image. Something important to know about LCD projectors is that all three colours are directed onto your projector screen at the same time. The way a DLP projector functions is very different and even the produced image shows up is not the same. With DLP, white light from the lamp is projected through a rotating colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This method of making an image forms a sequence of red, blue and green light. The millions of micro mirrors described above reflect the coloured light on the pixels to construct 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 put together each coloured element of the image into a single whole image. With LCD projectors, all colours are available all the time to create the top level of brightness and superb colour accuracy. In DLP, just one colour is available at once, causing lower colour brightness and accuracy. Some DLP developers have placed a white segment in the colour wheel to improve brightness generally, but this also lessens colour accuracy.

I hear in forums all the time that DLP has a higher contrast ratio and therefore must be superior quality. For those 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 projector is able to produce. DLP projectors do possess high contrast specifications in comparison to many LCD projectors. Initially, this must be a plus, however, in reality, the true black level is determined by the ambient light in the room while the projector is being used. Do not be tricked by contrast specifications on websites and in brochures.

When the content you want to see includes moving images, DLP projection technology also has image marks, or ‘artifacts’. The most common artifact that a DLP projector shows with moving images is colour break up. Colour break up is unavoidable in DLP systems because moving images change up between the time red, blue and green colours are shone. LCD projectors do not have this characteristic because all colours are projected at once. DLP manufacturers have come up with 3DLP solutions using 3 chips to answer the colour break up issue, but the cost of these projectors make them impractical 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. Remember back to high school science, and recall when they taught you how various colours of light refract varied amounts when passing 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 not the same and refract light at different levels. Generally with a DLP projector, some extra yellow colour will come up above and a superfluous blue will appear below an image containing something as simple as a straight black line. During manufacturing LCD projectors can be set to take away these effects on the projected image, as each colour is directed on separate LCD panels.

The sole actual advantage (excluding price) with buying a DLP projector is its smaller overall size and weight. However, this is only relevant in regard to transporting the device and needs to be traded off against the image plusses of LCD projectors. If resulting picture quality is vital to you, then the answer is a no-brainer. Take an LCD projector! LCD projectors will definitely produce bright, colourful images with fewer image mistakes. If you desire to find out more about LCD technology in more detail, have a gander at this fantastic resource website: Explore 3LCD. If you have any other questions, visit Projector Central and send me an email.

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