Business Podcasting Blog

The common question that is asked when looking for a new projector for the home, office, or classroom is: do I take an LCD projector or a DLP projector? LCD, short for ‘liquid crystal device’ and DLP, standing for ‘digital light processing’ are the two commonplace projector imaging technologies. With so many brands and models available, it can be confusing for customers to choose between those technologies. The simple fact of the matter is that LCD projectors provide far better image quality and colour accuracy. The article below tells you why DLP projectors struggle with creating a comparable rate of image quality.

It’s like a set of blinds in your house on your bedroom window. By twisting a rod you can make the shutters open or closed, depending on if you want to let light in or not. Such is exactly how an LCD projector operates. Each pixel works like a unique 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 the time the projector is turned on to when the image reaches your screen is absolutely significant to image quality, brightness and colour accuracy. LCD projectors shine white light from the lamp by splitting it into red, blue and green components, by three mirrors which transfer the coloured light to 3 separate LCD panels. The 3 LCD panels cast the elements of the image by shining 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 projected onto your projected surface all at the same time. The way a DLP projector operates is very different and even the final product of how an image comes out is not the same. With DLP, white light from the lamp is sent 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 described above reflect the coloured light on the pixels to create the image elements. The elements of the image are displayed in sequence on the screen, one colour at a time. The viewer’s eyes will then draw each coloured element of the image into the complete image. In LCD projectors, all colours are available all the time to offer the top level of brightness and great colour accuracy. In DLP, just one colour is available at a time, causing lower colour brightness and accuracy. Some developers have placed a white segment into the colour wheel to improve brightness overall, but this further damages colour accuracy.

I read in forums all the time that DLP offers a higher contrast ratio and thus must be better quality. 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 technology is able to produce. DLP projectors do offer high contrast specifications as compared to the majority of LCD projectors. Initially, this can seem to be a benefit, however, in reality, the true black level is determined by the ambient light in the room where the projector is being utilised. Do not be fooled by contrast specifications on websites and in brochures.

When the content you are trying to project includes moving images, DLP projection technology can also have image errors, or ‘artifacts’. The most commonplace artifact that a DLP projector shows 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 shone. LCD projectors do not have this disadvantage because every colour is projected simultaneously. DLP builders have come up with 3DLP solutions using 3 chips to resolve the colour break up problem, but the price tag of these projectors make them not practical for the majority of businesses and consumers.

Another point of difference between LCD and DLP is how they make up for the refractive qualities of light. Remember back to high school science, and recall when they taught you how the various colours of light refract varied amounts when shone through the same lens. The disadvantage 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 different and refract light differently. Generally with a DLP projector, a spill of yellow colour will come up above and an extra blue will appear below an image as simple as a straight black line. In building LCD projectors can be set to remove these effects on the projected image, because each colour is projected on its own LCD panels.

The only actual benefit (excluding price) with buying a DLP projector is its smaller size and weight. However, this is only relevant in regard to transport and needs to be traded off against the image plusses of LCD projectors. If the result of the picture quality is important to you, then the decision is simple. Go for an LCD projector! LCD projectors will definitely make bright, colourful images with fewer image errors. If you need to learn more about LCD technology in more detail, have a gander at this spectacular resource website: Explore 3LCD. If you have any further questions, go to Projector Central and send me an email.

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