We look at the what, the where and the WOW of the revolutionary display solution – digital light processing – that makes rear-projection TVs bigger, sharper and surprisingly lighter.
With all of the initials floating around the TV world today, there’s one that may be able to get you lots of video bang for the buck – DLP or Digital Light Processing.
If you’ve looked at big-screen TVs recently, you’ve probably noticed that most rear-projection sets are much lighter and have lower profiles than their predecessors of even just a few years ago. It’s now possible to design a rear-projection TV that weighs less than 100 pounds with a 60-inch screen, and a chassis that only adds an additional foot to its height. This would have been unheard of five or six years ago.
You can thank DLP, a display solution that uses an optical semiconductor to manipulate light digitally. Invented in 1987 by Dr Larry Hornbeck, an engineer at Texas Instruments, it was originally called the Digital Micromirror Device (DMD) – an optical semiconductor capable of steering photons with remarkable precision. By 1993 the technology had a new name, and Texas Instruments created the DLP Products Division. They remain the sole manufacturer of the DLP chipsets, which are licensed to manufacturers.
HOW IT WORKS
Texas Instruments calls DLP “probably the world’s most sophisticated light switch”. A DLP chip contains a rectangular array of up to two million hinge-mounted microscopic mirrors; each of those measures less than one-fifth the width of a human hair. When a DLP chip is coordinated with a digital video or graphic signal, a light source and a projection lens, its mirrors reflect an all-digital image onto a TV’s screen.
As impressive as this chip is, it only creates black, white and shades of grey. DLP technology combines this chip with a colour wheel rotating 120 times per second, to add colour to the equation.
THE RAINBOW CONNECTION
That colour wheel didn’t always rotate so quickly. Originally, it rotated at half its current speed, or 60 times per second. This was known to cause a few problems.
The first generation DLP colour wheel produced a picture containing numerous shimmering rainbow-like images to a significant minority of its viewers. It was most visible when bright objects were visible on a mostly dark background – especially the credits of many movies.
Of course, any new technology has its teething issues. And in an effort to reduce this effect, second-generation DLP products doubled the speed of the colour wheel to 120 times per second, which greatly reduced the visibility of the rainbow effect for the vast majority of viewers.
View a set in person before making your decision. While the internet has created some fantastic opportunities for mail-order bargains, this is one time where sight-unseen might not be a good thing. Issues aside, rear-projection sets have come a long way from the clunky models that sat in sports bars producing dreadful pictures. The combination of HDTV, DBS or digital cable in a rear-projection TV can produce an absolutely first-class picture – and DLP is a big part of that equation.
It took some time for DLP technology to reach critical mass. Today the sales total over two million units produced by over 50 manufacturers.
The reason for DLP’s popularity is obvious: the chip allows rear and front-projection sets to produce smooth, jitter-free images with good colour depth and contrast and no burn-in. DLP rear-projection TVs are smaller, thinner and lighter than both their CRT-based competitors and previous rear-projection technologies. And they are still much less expensive than comparably sized flat-panel LCDs.
While a few people still claim to see the rainbow effect, most folks no longer have problems. Instead, they’re more than a little impressed by DLP’s picture, size to weight ratio and affordable price.
|Samsung HLR6168W DLP TV|