Projectors: LCD Verses DLP (The downfall of DLP technology)
The most common question asked when purchasing a new projector for the home, office, or classroom is: will I get an LCD projector or a DLP projector? LCD, standing for ‘liquid crystal device’ and DLP, an acronym for ‘digital light processing’ are the two most common projector imaging technologies. With so many business brands and types available, it can be difficult for consumers to decide between both technologies. The fact is that LCD projectors give far superior image quality and colour accuracy. The following article explains why DLP projectors struggle with reproducing the same level of image quality.
It’s like a set of blinds in your home covering your bedroom window. By pulling a rod you can make the shutters open or closed, depending on whether you want to let light in or not. And such is exactly how an LCD projector operates. Each pixel functions like a single shutter on a set of blinds to either allow light through or to block it. DLP on the other hand is formed of millions of microscopic mirrors or ‘pixel elements’ as pros like to call them. Each pixel element operates to either reflect light or block it.
How the light source is processed from the point at which the projector turns on to when the picture reaches your screen is absolutely significant with 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 transfer the coloured light to 3 stand alone LCD panels. The 3 LCD panels create the elements of the image by turning each pixel on and off. The pixels are then projected in a glass prism to deliver the projector image. Something important to realise about LCD projectors is that all three colours are delivered onto your projected surface at the same time. The way a DLP projector runs is very different and even how an image appears is not the same. With DLP, white light from the lamp is directed through a rotating colour wheel with transparent red, blue and green segments, at speeds up to 11,000 rpm/s. This method of creating an image forms a sequence of red, blue and green light. The millions of micro mirrors mentioned above reflect the coloured light on the pixels to form the image elements. The elements of the image are projected 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 the full image. In LCD projectors, all colours are available all the time to form the best brightness and great colour accuracy. In DLP, only one colour is available at any given time, and so causing lower colour brightness and accuracy. Some designers have added a white segment into the colour wheel to improve all over brightness, but this further degrades colour accuracy.
I find in forums all the time that DLP provides a higher contrast ratio and therefore must be better. For those who don’t 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 machine is capable of producing. DLP projectors do have high contrast specifications when compared to the majority of LCD projectors. At first glance, this seems to be a benefit, however, in truth, the true black level is determined by the ambient light in the room while the projector is utilised. Do not be tricked by contrast specifications on websites and in brochures.
When the content you wish to project requires moving images, DLP projection technology can also have image marks, or ‘artifacts’. The most common artifact that a DLP projector displays 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 downside because all colours are sent with the others. DLP designers have created 3DLP solutions using 3 chips to fix the colour break up artifacts, but the price tag of these projectors make them hardly practical for the large part of businesses and consumers.
Another differentiation between LCD and DLP is how they match the balance for the refractive qualities of light. Think back to high school science, and remember how the various colours of light refract different amounts when directed through the same lens. The problem with DLP projectors is that they have the one same panel and the same lens to project Red, Blue and Green. All 3 colours are different and refract light in different ways. Usually with a DLP projector, a superfluous yellow colour will come through above and a superfluous blue will be projected below an image as simple as a straight black line. In building LCD projectors can be adapted to minimize these effects on the projected image, as each colour is projected on a separate LCD panels.
The only actual plus (excluding price) with picking a DLP projector is its smaller overall size and weight. However, this is only relevant to portability and needs to be traded off against the image advantages of LCD projectors. If overall picture quality is important to you, then the choice is no-brainer. Take an LCD projector! LCD projectors will always create bright, colourful images with fewer image blips. If you want to ask more about LCD technology in more detail, see this fabulous resource website: Explore 3LCD. If you have any more questions, go to Projector Central and send me an email.
Jonathan King is the sales and marketing manager with Projector Central, Australia’s top online retailer 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.
Sphere: Related ContentComments
One Comment on Projectors: LCD Verses DLP (The downfall of DLP technology)
-
hvac service in verona on
Thu, 5th Jan 2012 8:25 am
How many followers can be of your blog at blogspot?
Tell me what you're thinking...
and oh, if you want a pic to show with your comment, go get a gravatar!