The typical question heard when looking for a new projector for the home, office, or classroom is: would I get an LCD projector or a DLP projector? LCD, which stands for ‘liquid crystal device’ and DLP, which stands for ‘digital light processing’ are the two most popular projector imaging technologies. With so many business brands and types available, it can be challenging for the buyer to make a decision between the two technologies. The simple fact of the matter is that LCD projectors provide superior image quality and colour accuracy. The following article will explain why DLP projectors struggle with creating an equal rate of image quality.
It’s like a set of blinds in your household covering your bedroom window. By twisting a rod you can turn the shutters open or closed, according to if you want to let light in or not. That is exactly how an LCD projector behaves. Each pixel works like a single shutter on a set of blinds to either send light through or to block it. DLP on the other hand is constructed of millions of microscopic mirrors or ‘pixel elements’ as the professionals like to call them. Each pixel element works to either reflect light or block it.
How the light source is processed from the time the projector is turned on to when the picture reaches your screen is extremely significant in regard to image quality, brightness and colour accuracy. LCD projectors direct white light from the lamp by splitting it into red, blue and green components, by three mirrors which direct 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 simultaneously processed in a glass prism to form the projector image. Something important to understad about LCD projectors is that all three colours are delivered onto your wall at the same time. The way a DLP projector runs is totally different and even the produced image looks is not the same. With DLP, white light from the lamp is processed through a spinning colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This approach to creating 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 produce the image elements. The elements of the image are sent in sequence on the screen, one colour at a time. The viewer’s eye will then put together each coloured element of the image into the single total image. With LCD projectors, all colours are available all the time to create the top level of brightness and spectacular colour accuracy. In DLP, just one colour is available at once, and so resulting in lower colour brightness and accuracy. Some manufacturers have added a white segment for the colour wheel to improve overall brightness, but this further detracts from colour accuracy.
I see in forums all the time that DLP has a higher contrast ratio and ergo must be superior quality. For those who do not know, 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 able to produce. DLP projectors do offer high contrast specifications in comparison to a majority of LCD projectors. At one glance, this appears to be a benefit, however, in the real world, the true black level is determined by the ambient light in the room while the projector is being utilised. Do not be fooled by contrast specifications on websites and in brochures.
When the content you want to bring to life requires 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 to be expected in DLP systems because moving images change up between the time red, blue and green colours are projected. LCD projectors do not have this problem because every colour is delivered with the others. DLP builders have formed 3DLP solutions using 3 chips to resolve the colour break up error, but the expense of these projectors make them not practical for most businesses and consumers.
Another difference between LCD and DLP is how they make up for the refractive qualities of light. Take yourself back to high school science, and recall when they taught you how different colours of light refract various amounts when passing through the same lens. The problem with DLP projectors is that they use the one same panel with the same lens to project Red, Blue and Green. All 3 colours are not the same and refract light in different ways. Generally with a DLP projector, an extra yellow colour will be projected above and an extra blue will come through below an image as simple as a single black line. In manufacturing LCD projectors can be fixed to reduce these effects on the projected image, because each colour is refracted on separate LCD panels.
The only real benefit (excluding price) with deciding on a DLP projector is its smaller overall size and weight. However, this is only relevant with regard to mobility and cannot be traded off against the image plusses of LCD projectors. If the result of the picture quality is crucial to you, then the solution is no-brainer. Go for an LCD projector! LCD projectors will constantly produce bright, colourful images with fewer image imperfections. If you need to know more about LCD technology in more detail, have a gander at this tremendous 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 shop for projectors. Based in Brisbane, Projector Central has been serving Australia for 15 years. For data projectors in Brisbane and Interactive Whiteboards, contact Projector Central today.