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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.
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