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 Micro mirror 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
Processing™ 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, DLP™
projectors consistently provide just-out-of-the-box
performance. (DLP™ 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 Cinema™
projection systems is capable of producing no fewer than
35 trillion colors. The on and off states of each micro
mirror 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.
