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Invention of Television

Abhijit Naik
While John Logie Baird is accredited with the invention of television, Philo Farnsworth is accredited with the invention of first fully electronic television system.
Television is a medium of telecommunication which is primarily used for transmitting and receiving moving images accompanied by sound.
The word television is derived from a mixture of Latin and Greek words meaning 'far sight', i.e., tele, meaning 'far' in Greek, and visio, meaning 'sight' in Latin. Today, the television has become a common source of entertainment in all the households and commercial establishments.

Timeline of Television

In the early stages of development, a combination of optical, mechanical, and electronic technologies were used to capture, transmit, and display images on the television. In 1800s, pantelegraph, a mechanical fax machine was developed that facilitated transmission of images electrically.
The invention of telephone was followed by the concept of electronic transmission of television images in motion by a telephonoscope in 1878.
In 1881, the concept of using scanning to facilitate transmission of images was put into practice in the pantelegraph, wherein a pendulum-based scanning mechanism was used in the process of transmitting images. This period marked the beginning of the use of scanning in one form or other in image transmission technology.
The process of converting visual images into stream of electrical pulses was known as 'rasterization'.
In 1884, a 20-year old university student from Germany, Paul Gottlieb Nipkow acquired the patent for the first electromechanical television system. This system utilized a scanning disk with a series of holes spiraling towards the center to facilitate rasterization.
Nipkow's design of the first electromechanical system didn't materialize until amplifier tube technology was upgraded in 1907. Even after the system materialized in 1907, it could only transmit still halftone images, which were represented by equally spaced dots of various sizes, over telephone lines.
By the second half of 1920s, only optical and electronic technologies were utilized to capture, transmit, and display images. Eventually, designs which used a rotating mirror drum scanner to capture the image and a cathode ray tube to display it, were developed.
The poor sensitivity of selenium sensors was still a big hindrance in the transmission of moving images. This problem was solved by the introduction of a scanning disk which produced an image of 30 lines resolution by the Scottish inventor, J. L. Baird.
In 1925, Baird gave a demonstration of moving silhouette images in London, which was followed by the demonstration of moving monochromatic images in 1926. In 1926, Hungarian engineer, Kalman Tihanyi designed a television system featuring fully electronic scanning and display elements, which employed the principle of charge storage within the scanning tube.
The principle of charge storage within the scanning tube was followed by the introduction of a mirror-drum based television system by Leon Theremin, a Russian inventor, in 1927. The mirror-drum based system utilized the process of interlacing to achieve an image resolution of 100 lines.
In the same year, Philo Farnsworth, an American inventor, developed a television system featuring electronic scanning of pickup and display devices. Farnsworth televised a motion picture film to demonstrate this system to media on September 1, 1928. Eventually in 1939, the development of color receiver paved the way for introduction of color television.
With the introduction of regular television broadcasts in 1929, Germany witnessed the first use of television within two years of its invention. The Berlin Olympic Games were broadcast live on television in 1936.
Over the last few decades, television has become one of the major components of mass communication and entertainment. This invention is considered as one of the most important milestones of the last century.