Historical Review, Invention of Colour Television

Earlier television were in monochrome, but with advancements in technology, they also started coming in colored versions.

Colour Television in 19th  century 

Colour television was by no means a new idea.  In the late 19th century a Russian scientist by the name of A.A.  Polumordvinov devised a system of spinning Nipkow disks and concentric cylinders with slits covered by red, green, and blue filters.  But he was far ahead of the technology of the day;  even the most basic black-and-white television was decades away.  In 1928, Baird gave demonstrations in London of a color system using a Nipkow disk with three spirals of 30 apertures, one spiral for each primary color in sequence.  The light source at the receiver was composed of two Cathode ray tubes or gas-discharge tubes, one of mercury vapor and helium for the green and blue colors and a neon tube for red.  The quality, however, was quite poor.

Colour Television in 20th century 

In the early 20th century, many inventors designed color systems and their basic concept was later called the "sequential" system, different terminologies used as more and more new functions introduced. They introduce three successive coloured filter red, blue, and green to scane the picture. Idea was that in the result out put human eye would see original multicoloured.

Unfortunately, this system required too fast a rate of scanning which were not possible in black-and-white receivers would not be able to reproduce the pictures.  Sequential systems therefore came to be described as "noncompatible."

An alternative approach which is compatible with existing black and white recovers known as “simultaneous” system, which would transmit the three primary-colour signals together.

In 1924, Harold McCreary designed a system using cathode-ray tubes as camera speratly to scane each of three primary colour components of picture at receiving end. In each tube,  elecron struck the phosphors coated screen In the result glow of appropriate three primary Colour produced, series of mirrors would then combine these images into one picture.

At that time this was a new idea but not working properly .

In 1929 Herbert Ives and colleagues at Bell Laboratories transmitted 50-line colour television images between New York City and Washington, D.C.; this was a mechanical method, using spinning disks, but one that sent the three primary colour signals simultaneously over three separate circuits.

After World War II, the Columbia Broadcasting System (CBS) began demonstrating its own sequential color system, designed by Peter Goldmark.  Combining cathode-ray tubes with spinning wheels of red, blue, and green filters, it was impressive enough that's why Federal Communications Commission (FCC) to authorize the Goldmark system for commercial television, but Sarnoff warned against using a "horse-and-buggy" system that was incompatible with monochrome TV.  At the same time, Sarnoff whipped his troops at RCA into developing the first all-electronic compatible color system in 1950.

In this every 1/60 of a second the receiver’s three electron guns painted the entire picture simultaneously with red, green, and blue, left to right, line by line.

And the RCA colour system was compatible with existing black-and-white sets.

In 1952, the National Television Systems Committee (NTSC) was reformed, this time with the purpose of creating an "Industry Color System." Which adopted most of Europe and Japan as well. And after this varity of different colours and system like PAL (phase alternation line) introduce in Germany the United Kingdom, and the rest of Europe had adopted PAL. In France Henri de France developed SECAM Soviet Union adopted SECAM, both these system are based on NTSC system with slitly modifications, These are still the standards of colour television today, despite the arrival of digital television.

With the passage of time different name were given according to modifications of system three colour system then multi coloured and digital television now a days smart television like LCD and LED with high resolution advance futures and systems.

Digital television 

Digital television technology emerged to public view in the 1990s.  In the United States professional action was spurred by a demonstration in 1987 of a new analog high-definition television (HDTV) system by NHK, Japan's public television network.  This incited the FCC to declare an open competition to create American HDTV, and in June 1990 the General Instrument Corporation (GI) surprised the industry by announcing the world's first all-digital television system.  Designed by the Korean-born engineer Woo Paik, the GI system displayed a 1,080-line color picture on a wide-screen receiver and managed to transmit the necessary information for this picture over a conventional television channel.  Heretofore, the main obstacle to producing digital TV had been the problem of bandwidth. 

Within a few months of GI's announcement, both the Zenith Electronics Corporation and the David Sarnoff Research Center (formerly RCA Laboratories) announced their own digital HDTV systems.

In 1993 these and four other TV laboratories formed a "Grand Alliance" to develop marketable HDTV.  In the meantime, an entire range of new possibilities aside from HDTV emerged.  Digital broadcasters could certainly show a high-definition picture over a regular six-megahertz channel, but they might "multicast" instead, transmitting five or six digital standard-definition programs over that same channel.

Indeed, digital transmission made “smart TV” a real possibility, where the home receiver might become a computer in its own right. 

There are varity of smart television like LCD and LED available in market with high resolution advance futures and systems.

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