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Sunday, November 28, 2010

Analog and Digital TVs

For years, we have been watching CRT television that involved cathode ray tube or CRT sets and analog signals. In these kinds of TVs, the signals constitutes of varying radio waves that are translated by the TV into picture and sound. Analog signals can be transmitted to a television set over the air through satellite or a cable. But CRT TVs based on the system of analog signals have certain limitations such as the conventional CRT television sets can display only around 480 visible lines of pixels and with the advancement in technology broadcasters find it difficult to fill a large television into the analog signal. Also the analog pictures are interlaced due to which on some TVs, the picture or the images flicker. One has to compromise with the video quality also as converting video to analog format lowers its quality.

Like all other fields, the gadgets and electronics sector has also witnessed a lot of innovation and advancement in technology to make the things better. Digital TV or DTV is the answer to above mentioned limitations. Rear projection, LCD TV and plasma TVs are based on the system of digital signals. A liquid crystal display popularly known as LCD is a thin, flat panel that is used to display information such as text, images, and moving pictures electronically. Digital televisions are based on the principle of digital signals where the signals are transmitted in the form of binary format or 0s and 1s. The information for video and sound are transmitted as ones and zeros instead of as a wave in the case of DTVs.

Due to this format, these televisions have several advantages over the CRT TVs such as the picture quality is much more improved in case of DTVs. The video is also progressive instead of being interlaced and the TV stations and broadcasters can broadcast using multicasting which includes sending several signals using the same bandwidth. Digital TV can also support high-definition or HDTV broadcasts. HDTV or High Definition TeleVisions are the digital TVs with highest of the DTV technological standards. Three major parameters define the broadcast system of HDTV including frame size in pixels which is the number of horizontal pixels x number of vertical pixels, scanning system and the third parameter is the frame rate which is identified as number of video frames per second. Currently there are two types of HDTV available in the market that includes an integrated HDTV and an HDTV ready set.

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