The
Science Behind DLP Television by:
Mitchell Medford DLP
televisions are based on a technology invented
by Texas Instruments back in 1987 called
Digital Light Processing. The technology
is based on an optical semiconductor called
DMD (Digital Micromirror Device) chip. It
is a highly reliable, all-digital display
chip that delivers the best picture across
a broad range of products, including large
screen digital TVs, and projectors for business,
home, professional venue and digital cinema.
The chip consists of over one million mirrors
to process light. They come in either single
chip or 3 chip configurations. 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. The
result is maximum fidelity: a picture whose
clarity, brilliance and color must be seen
to be believed.
When a DLP chip is coordinated with a digital
video or graphic signal, a light source,
and a projection lens, its mirrors can reflect
an all-digital image onto a screen or other
surface. The DLP chip and the sophisticated
electronics that surround it are what we
call Digital Light ProcessingT technology.
Benefits of Single chip DLP:
1. Fantastic color accuracy.
2. The best contrast ratios and shadow
detail.
3. Generally very quiet.
4. Very little space between each pixel
creates a very smooth image, even when using
lower resolution projectors.
5. Light engine failures are very rare
so repairs are less costly than other technologies.
6. Technology doesn't degrade over time.
With proper routine maintenance, DLPT projectors
consistently provide just-out-of-the-box
performance. (DLPT is the only technology
that makes this claim).
Benefits of Three chip DLP:
1. Good contrast; much greater than film
theaters.
2. Good shadow detail.
3. Can provide high brightness compared
to the limited brightness of single chip
versions.
4. Overall image quality deemed as the
best of any type of micro display technology.
5. Same technology as projectors installed
in digital theaters.
6. Pure digital technology.
The bit-streamed image code entering the
semiconductor directs each mirror to switch
on and off up to several thousand times
per second. When a mirror is switched on
more frequently than off, it reflects a
light gray pixel; a mirror that's switched
off more frequently reflects a darker gray
pixel. In this way, the mirrors in a DLP
projection system can reflect pixels in
up to 1,024 shades of gray to convert the
video or graphic signal entering the DLP
chip into a highly detailed grayscale image.
The white light generated by the lamp in
a DLP projection system passes through a
color wheel as it travels to the surface
of the DLP chip. The color wheel filters
the light into red, green, and blue, from
which a single-chip DLP projection system
can create at least 16.7 million colors.
And the 3-chip system found in DLP CinemaT
projection systems is capable of producing
no fewer than 35 trillion colors. The on
and off states of each micromirror are coordinated
with these three basic building blocks of
color. For example, a mirror responsible
for projecting a purple pixel will only
reflect red and blue light to the projection
surface; our eyes then blend these rapidly
alternating flashes to see the intended
hue in a projected image.
About The Author
Mitchell Medford is an author and
product consultant for several consumer
electronics manufacturers. Visit his
website for more information on home
theater, LCD TVs, and plasma televisions:
http://www.newtechnologytv.com
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