HDTV - High Resolution Television
High-definition television [HDTV] means television signals broadcast
with a higher resolution than traditional formats like NTSC, S CAM,
PAL. HDTV is broadcasted digitally, except for early analog formats
in Europe and Japan.
History of HDTV
Historically, the term high-definition television was also used
to refer to television standards developed in the 1930s to replace
the early experimental systems.
Shortly afterwards, Philo T. Farnsworth, John Logie Baird and Vladimir
Zworkin had each developed competing TV systems but resolution was
not the issue that separated their substantially different technologies.
It was patent interference lawsuits and deployment issues given
the tumultuous financial climate of the late 20's and 30's. Most
patents were expiring by the end of WW2 leaving the market wide
open and no worldwide standard for television agreed upon. The world
used analog PAL, NTSC, SECAM and other standards for over half a
HD Ready and HD Compatible
The terms HD ready and HD compatible are being used around the
industrial world for marketing purposes. They indicate that a TV
or display is able to accept video over an HDMI connection, using
a new connector design, the main purpose of which seems to be to
ensure that digital video is only passed over an interface which,
by agreement, incorporates copyright protection. Even HD-ready sets
do not necessarily have enough pixels to display video to the 1080-line
(1920x1080) or 720-line (1280x720) HD standards in full resolution
without interpolation, and HD-compatible sets are often just standard-definition
sets with an HDMI input. This is a confusing use of the terms HD
MPEG-2 is most commonly used as the compression codec for digital
HDTV broadcasts. HDTV is capable of "theater quality" audio
because it uses the Dolby Digital (AC-3) format to support "5.1"
Japan has the earliest working HDTV system still in use, with design
efforts going back to 1979. Japan began broadcasting analog HDTV
signals in the early 1990s using an interlaced resolution of 1035
lines (1035i). The Japanese MUSE (Multiple sub-nyquist sampling
Encoding) system, developed by NHK Science and Technical Research
Laboratories (STRL) in the 1980s, employed filtering tricks to reduce
the original source signal to decrease bandwidth utilization.
Japan is forerunner of HDTV in the world. Japan terrestrial broadcast
of HD via ISDB-T started in December 2003.
HDTV transmission in Europe started in 2004. Euro1080 is the
pioneer in HDTV transmission in Europe. Australia started HD broadcasting
in January 2001.
CHUM Limited's Citytv in Toronto was the first HDTV broadcaster
in Canada and CBC (Canadian Broadcasting Corporation) officially
launched HDTV programming on March 5, 2005.
Mexican television company Televisa experimented HDTV broadcasts
in the early 1990s, in collaboration with Japan's NHK.
HDTV specifications are defined by the ATSC in the United States.
An HDTV-compatible TV usually uses a 16:9 aspect ratio display with
an integrated ATSC tuner. Lower resolution sources like regular
DVDs may be upscaled to the native resolution of the TV.
HDTV services were made available in the Republic of Korea
in 2005 and Brazil is expected to go for it in 2006.
There are numerous online sources carrying volumes of info on plasma
HDTV, LCD HDTV, HDTV antenna, HDTV receiver, dlp HDTV, HDTV cables,
HDTV tuner etc. Scores of sites are offering HDTV reviews, HDTV
articles and HDTV news that are very helpful for the potential customers
to buy HDTV.
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