In the past seven decades functionality of the television is not changed much. It just pushes the video content from the studio to the viewers. Viewers are expected to be passive recipient of video content and be content with 'surfing the channels'.
In 1950s television set had 12" to 14" size Cathode Ray Tube (CRT) screen, Radio Frequency (RF) tuner, RF-to-Baseband converter, Video processing electronics, display electronics and loudspeaker. Television signals are composite in nature and made up of video, audio and synchronization signals. Video and synchronization signals are AM modulated and audio signals are FM modulated. Both signals are multiplexed and transmitted in the Very High Frequency (VHF) and Ultra High Frequency (UHF) range. The TV receives the signals via antenna and feed it to RF tuner. The RF tuner selects one television channel out of 12 (up to 1980s 12 channels only available). They are amplified, demodulated and results in baseband signal (composite signal). From composite signal audio and video signals are extracted or demultiplexed. The video signal will be in YCrCb format. It has to be converted into Red, Green and Blue signals (primary colours). This is done by Video processing electronics. The CRT screen operates at very high voltage and video signals has to be projected on the screen in a proper order (technical term is scanning). The ordering information is present in the synchronization signals. Projecting the signals on to the screen is the task of display electronics.
The article in review [1], i.e. "Kiss your TV goodbye" deals with the transformation occurred in the television in a span of 70 years. It tells the screen size has increased from 12" to 80". Thickness of the television has come down heavily and nowadays TV looks like a wall mounted painting. The pressure to reduce the thickness of the TV has forced the manufacturers to take out lot of components that were inside the TV. First RF tuner, loud speaker and at last video processing board are taken out. Thus in today's TV display electronics and TV screen (made up of either LCD or LED) are the components which reside inside the TV.
In 1950s television set had 12" to 14" size Cathode Ray Tube (CRT) screen, Radio Frequency (RF) tuner, RF-to-Baseband converter, Video processing electronics, display electronics and loudspeaker. Television signals are composite in nature and made up of video, audio and synchronization signals. Video and synchronization signals are AM modulated and audio signals are FM modulated. Both signals are multiplexed and transmitted in the Very High Frequency (VHF) and Ultra High Frequency (UHF) range. The TV receives the signals via antenna and feed it to RF tuner. The RF tuner selects one television channel out of 12 (up to 1980s 12 channels only available). They are amplified, demodulated and results in baseband signal (composite signal). From composite signal audio and video signals are extracted or demultiplexed. The video signal will be in YCrCb format. It has to be converted into Red, Green and Blue signals (primary colours). This is done by Video processing electronics. The CRT screen operates at very high voltage and video signals has to be projected on the screen in a proper order (technical term is scanning). The ordering information is present in the synchronization signals. Projecting the signals on to the screen is the task of display electronics.
The article in review [1], i.e. "Kiss your TV goodbye" deals with the transformation occurred in the television in a span of 70 years. It tells the screen size has increased from 12" to 80". Thickness of the television has come down heavily and nowadays TV looks like a wall mounted painting. The pressure to reduce the thickness of the TV has forced the manufacturers to take out lot of components that were inside the TV. First RF tuner, loud speaker and at last video processing board are taken out. Thus in today's TV display electronics and TV screen (made up of either LCD or LED) are the components which reside inside the TV.
