The Evolution and Impact of Television: From its Origins to Modern Applications

The name 'Television' comes from the Greek word 'tele' (= far) and the Latin word 'visionis' (from videre = to see) which means 'to see from a distance'. The fundamental aim of a television system is to extend the sense of sight beyond its natural limits, along with the sound associated with the scene being televised. Essentially, then, a TV system is an extension of the science of radio communication with the additional complexity that besides sound, the picture details are also to be transmitted.

The first demonstration of actual television was given by J.L. Baird in the UK and C.F. Jenkins in the USA around 1927. However, the real breakthrough occurred with the invention of the cathode ray tube and the success of V.K. Zworykin of the USA in perfecting the first camera tube

In the absence of any international standards, three monochrome ( black and white) systems grew independently. These are the 525 line American, the 625 line European and the 819 line French systems. When both the quality of reproduction and the cost of equipment are taken into account, it is difficult to definitely establish the superiority of any one of these systems over the other two. This naturally prevents direct exchange of programme between countries using different television standards. Committee on radio and television (CCIR) efforts for changing to a common 625 line system by all concerned proved ineffective and thus all the three systems have apparently come to stay. The inability to change over to a common system is mainly due to the high cost of replacing both the transmitting equipment and the millions of receivers already in use. The three different standards of black and white television have resulted in the development of three different systems of color television such as - SECAM, PAL and NTSC.

Each television broadcast station is assigned a channel bandwidth of 7 MHz (6 MHz in the American, 8 MHz in the British and 14 MHz in the French systems).In the earlier days TV broadcast was confined to assigned VHF bands of 41 to 68 MHz and 174 to 230 MHz. Later additional channel allocations have been made in the UHF band between 470 and 890 MHz. 

Applications of Television:

Impact of television is far and wide and has opened new avenues in diverse fields like public entertainment, social education, mass communication, newscasts, weather reports, political organization and campaigns, security(CCTV), live streaming, announcements and guidance at public places like airport terminals, sales promotion and many others.