Digital Light Processing was invented in 1987 by Texas Instruments.
It is named for its ability to process light digitally with the aid of
an optical semiconductor called a Digital Micromirror Device or DMD
chip. The DMD chip is comprised of over one million mirrors. The size
of each mirror is less than 1/5” the width of a human hair. Currently,
over fifty manufacturers produce at least one model of a DLP television.
This article is an introduction to DLP. It is not intended to be the
official word. To learn from the source, please visit Texas
Instruments’ official Digital Light Processing website.
What is DLP technology?
Like digital video camcorders, DLP devices come in either one or three-chip models.
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One-chip DLP systems use a projection lamp to pass white light
through a color wheel that sends red-green-blue colors to the DMD chip
in a sequential order to create an image on-screen. Only one DMD chip
is used to process the primary RGB colors.
Three-chip DLP systems use a projection lamp to send white light
through a prism, which creates separate red, green, and blue light
beams. Each beam is sent to their respective red, green, and blue DMD
chip to process the image for display on-screen.
One-chip models are said to produce a display of over 16-million
colors. Three-chip models can produce a display of over 35-trillion
colors.
Should I buy a one or three-chip model?
Most consumers will only be able to purchase a one-chip DLP system, but
that isn’t a bad since DLP technology is recognized for its ability to
display images in great detail. Three-chip DLP systems are for high end
users who need to display images onto a larger screen, like in a movie
theatre or for a business seminar setting.
How much does a DLP television or home theatre system cost?
Price varies by model and manufacturer, but generally DLP televisions
cost 1,500 dollars and up. They’re usually priced less than LCD or
Plasma screens of the same size. DLP projectors cost anywhere from
1,000 to 10,000 dollars and up.
How big is a DLP television?
DLP televisions vary in size with screen sizes ranging from 44-65″, and
weights between 63 and 215-lbs. Most units weigh between 75 and
150-lbs. Width for DLPs range between 7 and 22″, however most models
can be found with a thickness of 15-20″.
What features are important?
Good features to have are HD-compatibility, a DVI or HDMI connection,
HDCP, and a good warranty. Features like parental controls,
user-friendly menu systems, and audio quality are also good to own.
Many DLP televisions are made with a digital cable card slot, which
eliminates the need for a set-top box to receive cable if your provider
offers that service. Most or all DLP televisions with cable card slots
feature a built-in HD-tuner that decodes HD signals without the need of
an additional receiver or set-top box. Regardless, a built-in tuner is
a nice option to have whether or not the TV has a cable card slot.
Does DLP have burn in?
DLP doesn’t have burn in - the sensation plaguing CRT-rear projection
and Plasma televisions. Burn in is a stain on the screen by leaving a
static or still image on the screen for a long period of time. You can
see an example of burn-in by clicking the link to go to Texas
Instruments’ DLP website.
What is Rainbow Effect? How does it apply to DLP?
Rainbow Effect is to DLP what screen door effect is to LCD. It is a
side effect of the refracted light, but is only seen by some of the
people who watch DLP televisions. Online encyclopedia Wikipedia
describes Rainbow Effect “as brief flashes of perceived red/blue/green
‘shadows’ observed most often when the projected content features
bright/white objects on a mostly dark/black background (an example
would be the scrolling end credits of a movie).” It is important to
note that only one-chip DLP televisions are susceptible to Rainbow
Effect.
How does DLP compare LCD, LCOS, and Plasma?
It is safe to argue that DLP offers the best picture of the four
‘high-end’ television types. Of all the technologies, LCOS is probably
the closest to DLP, but the future for LCOS is shaky so the comparison
is somewhat moot at this time. Many people feel LCD has a brighter
picture, and Plasma has a reputation as being the Rolls Royce of
televisions. Aside from walking into an electronics store and comparing
the pictures of various models side-by-side, how do you know what
picture is best for you? The bottom line is you don’t.
Where do I go from here?
If you’re in the market for a new television, it’s important to know
your options. Research is vital in purchasing something as expensive as
a DLP television. You can learn about various types of televisions by
visiting consumer electronics stores, consumer resource websites like
tv.about.com, or going to a manufacturer’s website. The important thing
to understand is the choice is yours. When it comes to TV and video
equipment - nobody can force you to buy any thing any time at any price.
From Matthew Torres,
Your Guide to TV / Video
