HDTV is the popular acronym for High Definition Television, which is a way of broadcasting video in digital format, whereby the signal is sent in the form of zeros and ones instead of the waves used in analog broadcasting. The term is also used to refer to the television sets that receive these digital signals. Such TVs were introduced into the market in 1998 and have grown in popularity since then, especially with the switch to digital television (DTV).
Previously, television signals were transmitted in analog format. Consumers could receive the analog signals in a variety of ways, including over the air, via satellite or through cable television. However, the analog system has several limitations, which include number of channels that can be accommodated and quality of broadcast.
HDTV is not the only means of transmitting video digitally. The Advanced Television Standards Committee has set up 18 primary DTV standards, with HDTV being the highest standard. Of course, all the digital standards are of better quality than analog broadcasts.
It is important to note that while the Federal Communications Commission (FCC) has set a shut-off date for analog television, this does not mean America is switching to HDTV.
The DTV standards are voluntary for all groups of people involved. Broadcasters decide the standard of digital television to use and many have already opted for HDTV. Television manufacturers decide the resolutions and aspect ratios that their sets use. The consumers also make their purchases based on the resolutions they consider to be most important for them.
The length-to-height ratio of high definition television screen is 16:9. HDTV also has 1080 active pixel lines, which is about two times higher than conventional CRT sets that have only 480 active pixel lines. High definition television provides a better widescreen movie experience without the annoying letterbox ‘black bars.’
One of the major advantages of HDTV is that so long as the signal can be received, the images will be sharp irrespective of the size of the screen. Digital broadcasts use progressive technology where the whole picture is shown continuously as opposed to the interlaced method used in analog broadcast where the images alternate between partial picture displays.
Although some high definition television sets require HDTV tuners, many of the new models have built-in tuners and are ready to receive high definition programming. Integrated HDTVs are relatively costly. However, people who are not yet ready for the financial commitment can opt for the HDTV-ready sets (HDTV monitors) that they can still use to watch analog TV without HDTV tuners.