Projectors: LCD Verses DLP (The downfall of DLP technology)
The common question asked when buying 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, standing for ‘digital light processing’ are the two commonplace projector imaging technologies. With so many business brands and types available, it can be overwhelming for customers to decide between these technologies. Ultimately LCD projectors offer superior image quality and colour accuracy. The next part of this article tells you why DLP projectors struggle with projecting a similar grade of image quality.
It’s like a set of blinds in your house covering your bedroom window. By a twist of a rod you can have the shutters open or closed, according to whether you want to let light in or not. And that is exactly how an LCD projector operates. Each pixel operates 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 professionals like to call them. Each pixel element operates to either reflect light or block it.
How the light source is processed from the time the projector switches on to when the image reaches your screen is absolutely significant in regard to image quality, brightness and colour accuracy. LCD projectors direct white light from the lamp by separating it into red, blue and green components, by three mirrors which direct the coloured light to 3 separate LCD panels. The 3 LCD panels cast the elements of the image by turning 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 wall at the same time. The way a DLP projector works is vastly different and even the produced image looks is not the same. With DLP, white light from the lamp is directed through a turning colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This method of making an image creates a sequence of red, blue and green light. The millions of micro mirrors as described above reflect the coloured light on the pixels to form 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. From LCD projectors, all colours are available all the time to offer the best brightness and spectacular colour accuracy. In DLP, only one colour is available at any given time, causing lower colour brightness and accuracy. Some manufacturers have put a white segment for the colour wheel to improve brightness generally, but this goes and damages colour accuracy.
I see in forums all the time that DLP has a higher contrast ratio and as such must be superior quality. For those 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 technology is capable of. DLP projectors do offer high contrast specifications when compared to a majority of LCD projectors. At a glance, this can seem to be a plus, however, in real life, the true black level is determined by the ambient light in the room where the projector is being used. Do not be tricked by contrast specifications on websites and in brochures.
When the content you are trying to see includes moving images, DLP projection technology also has image errors, or ‘artifacts’. The most common artifact that a DLP projector forms with moving images is colour break up. Colour break up is unavoidable in DLP systems because moving images keep changing between the time red, blue and green colours are pulled up. LCD projectors do not have this characteristic because every colour is projected with the others. DLP manufacturers have formed 3DLP solutions using 3 chips to fix the colour break up issue, but the cost of these projectors make them impractical for most businesses and consumers.
Another difference between LCD and DLP is how they match the balance for the refractive qualities of light. Think back to high school science, and recall how the different colours of light refract various amounts when shone through the same lens. The downside with DLP projectors is that they utilise the one same panel for the same lens to project Red, Blue and Green. All 3 colours are not the same and refract light in different ways. Most of the time with a DLP projector, some extra yellow colour will be projected above and an extra blue will come through below something as simple as a single black line. In building LCD projectors can be set to minimize these effects on the projected image, as each colour is processed on a separate LCD panels.
The sole actual buy point (excluding price) with deciding on a DLP projector is its smaller total size and weight. However, this is only relevant for mobility and has to be traded off against the image superiority of LCD projectors. If the result of the picture quality is important to you, then the answer is no-brainer. Choose an LCD projector! LCD projectors will always create bright, colourful images with fewer image errors. If you want to learn more about LCD technology in more detail, have a look at this fantastic resource website: Explore 3LCD. If you have any other questions, get onto Projector Central and send me an email.
Jonathan King is the sales and marketing manager of Projector Central, Australia’s number one online store for projectors. Brisbane based, Projector Central has been servicing Australia for 15 years. For data projectors in Brisbane and Interactive Whiteboards, contact Projector Central today.
Posted by: Crane Data Logger 
Category: Uncategorized 
Comments (0)Tags: data projectors brisbane, data projectors gold coast —