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Rear Projection: Digital
Rear Projection & CRT Projection
OVERVIEW
Although initially the most popular type of digital television, the low prices of flat screen TV's has made rear projection relatively uncommon.
That said, they are still available (mostly online) and offer a high quality, lost cost digital television alternative.
Essentially, the picture you view is produced
by a smaller image projected on to the back
of the screen from the inside of the TV. While
older rear projection TV's used traditional
glass TV tubes (CRT's) to project the image
on to the TV, most of the new rear projection
televisions employ a variety of competing
digital projection technologies. These televisions
are widely available in sizes ranging from
about 42 inches to 90 inches diagonal.
COMPARISON OF REAR
PROJECTION TV TECHNOLOGY OPTIONS
This is perhaps the most confusing
part of the selection process. There are four
major types of rear projection TV. Nearly
all new rear projection TV's are sold in the
16:9 widescreen format and are HDTV ready.
- CRT Rear Projection
The oldest type of rear projection TV.
You likely won't find one of these except used or in an old sports bar.
- LCD Rear Projection
The oldest and most popular of the digital
technologies. LCD (Liquid Crystal Display)
Rear Projection TV's use small LCD flat
panels and high intensity lamps to create
the picture. The result a large crisp picture
in a light weight set that is typically
about 12 inches deep. LCD's tend to have
a harder time displaying black and grays,
resulting in lower contrast ratios than
some of the other technologies, but this
has improved dramatically in the last few
years. LCD projection televisions are not
susceptible to burn-in, but they do gradually
lose brightness. Most manufacturers call
for periodic bulb replacement and bulb lives
are estimated at about 5 years with normal
use. Bulbs are currently about $200.00-$300.00,
but since many of these TV's are only a
few years old, it is expected that prices
will drop once replacements become more
common. Prices range from $1,500 to $5,000.
- DLP Rear Projection
Digital Light Processing, or DLP technology was developed
by Texas Instruments and is used in Mitsubishi rear projection digital televisions and several brands of projectors. DLP uses thousands of micro mirrors on a tiny
chip to project an image onto the screen.
The result is a large crisp picture on a
slim lightweight set. DLP televisions are not subject
to burn-in, but do need periodic bulb replacement.
DLP Rear Projection televisions
depend on the DLP chip and it's thousands
of tiny moving mirrors. While the technology
has thus far proven itself reliable, it
is still relatively new. With manufacturer warranties
typically only one year, costly repairs
are possible.
- LCOS, or D-ILA Rear Projection
Liquid Crystal On Silicon, or LCOS
is the least popular of the technologies.
JVC's LCOS implementation is known as D-ILA,
or Direct Drive Image Light Amplifier. LCOS
TV's use a technology similar
to the LCD's but instead of passing light
through the LCD projection panels it is
reflected off of them. Like the LCD and
DLP televisions, the result is a high quality
picture even on large screens and a slim
lightweight set. Also like LCD and DLP projection
televisions, LCOS televisions are not subject
to burn-in, but do need periodic bulb replacement.
JVC seems to have abandoned this technology in its consumer TV's in favour of the more popular LCD technology, but a few D-ILA televisions can still be found online and in the wild. This technology is primarily used in home theater projectors.
IMPORTANT CONSIDERATIONS
Knowing what technologies are available helps
us get an idea of what to expect from the
rear-projection television, but there are
other considerations.
Size
It would seem that bigger is better especially,
when viewing the wall of televisions at
some of the large electronic's stores, but
this is not the case. Consider the size
of the room that your widescreen TV will
live in and how far away from the television
you will sit. A 60" television, for
example, would be completely overwhelming
in a smaller living room from 10 feet away.
Style and Color
This is largely personal preference.
Many of the newer models are black which
may be more likely to match your decor than
a silver or gray model. Stands are also
an important element of style. You'll have
to live with your home theater set up.
Real World Use
Do you mostly watch DVD movies?
TV Sports? Play Video Games? HDTV? While
all of the available TVs can accommodate
these uses, some are better at certain activities
than others. Check for the options that
you need. You may want split screen and
picture in picture options for checking
on the game, or an integrated HDTV tuner
if you don't already have one.
You may also want to consider the brightness
and traffic in the room where your TV will
be located. Some big screens are highly
reflective and may be unwatchable in a sunny
room.
GETTING YOUR BIG SCREEN
HOME
A few things you might not have thought
of.
Delivery
While not necessarily heavy, your television
will likely not fit in your car. Be sure
to inquire about delivery options and costs.
Stands
Most of the rear-projection televisions
require a TV stand but they are rarely included
in the price. Be sure that the stand suits
your needs and can accommodate all of the
equipment you will be attaching to it. Many
home theater receivers, for example will
not fit in the smaller stands.
Cables
If you're buying your first HDTV
you will likely need specialized cables
to accommodate the higher quality video
connections to your new television. These
will not be included with your new high
definition television. Be sure to ask about
what you'll need to hook up your equipment.
TIPS
With all this new technology, it
may be a good idea to maximize your warranty
coverage. Some credit cards will automatically
double the length of any factory warranty
for any item purchased using that credit card.
A separate extended warranty might also be
useful.
Make sure you have the right
equipment to complete your home theater. While
most of the widescreen TV's are HD ready -
meaning they can accommodate a Hi-Definition
signal - you still have to send a HD signal
from your equipment. You may want to think
about a new DVD player or HDTV tuner if available.
On the subject of High Definition, you'll
want to make sure your TV can accomodate a
variety of input connectors including the
newer DVI and HDMI connections. This will
ensure compatibility with the latest high
definition equipment.
Be sure to evaluate all options
and comparison shop before choosing a rear-projection
television for your home theater.
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