Continue from Part I -
In 1927, Baird transmitted a long-distance television signal over 438 miles (705 km) of telephone line between London and Glasgow; Baird transmitted the world's first long-distance television pictures to the Central Hotel at Glasgow Central Station. This transmission was Baird's response to a 225-mile, long-distance telecast between stations of AT&T Bell Labs. The Bell stations were in New York and Washington, DC. The earlier telecast took place in April 1927, a month before Baird's demonstration. Baird then set up the Baird Television Development Company Ltd, which in 1928 made the first transatlantic television transmission, from London to Hartsdale, New York, and the first television programme for the BBC. In November 1929, Baird and Bernard Natan established France's first television company, Télévision-Baird-Natan. He televised the first live transmission of the Epsom Derby in 1931. He demonstrated a theatre television system, with a screen two feet by five feet (60 cm by 150 cm), in 1930 at the London Coliseum, Berlin, Paris, and Stockholm. By 1939 he had improved his theatre projection system to televise a boxing match on a screen 15 ft (4.6 m) by 12 ft (3.7 m).
Baird demonstrating his mechanical television system in New York, 1931 |
From 1929 to 1932, the BBC transmitters were used to broadcast television programmes using the 30-line Baird system, and from 1932 to 1935, the BBC also produced the programmes in their own studio at 16 Portland Place. On 3 November 1936, from Alexandra Palace located on the high ground of the north London ridge, the BBC began alternating Baird 240-line transmissions with EMI's electronic scanning system, which had recently been improved to 405 lines after a merger with Marconi. The Baird system at the time involved an intermediate film process, where footage was shot on cinefilm, which was rapidly developed and scanned. The trial was due to last 6 months but the BBC ceased broadcasts with the Baird system in February 1937, due in part to a disastrous fire in the Baird facilities at Crystal Palace. It was becoming apparent to the BBC that the Baird system would ultimately fail due in large part to the lack of mobility of the Baird system's cameras, with their developer tanks, hoses, and cables.
Baird's television systems were replaced by the electronic television system developed by the newly formed company EMI-Marconi under Isaac Shoenberg, which had access to patents developed by Vladimir Zworykin and RCA. Similarly, Philo T. Farnsworth's electronic "Image Dissector" camera was available to Baird's company via a patent-sharing agreement. However, the Image Dissector camera was found to be lacking in light sensitivity, requiring excessive levels of illumination. Baird used the Farnsworth tubes instead to scan cinefilm, in which capacity they proved serviceable though prone to drop-outs and other problems. Farnsworth himself came to London to Baird's Crystal Palace laboratories in 1936, but was unable to fully solve the problem; the fire that burned Crystal Palace to the ground later that year further hampered the Baird company's ability to compete.
Baird made many contributions to the field of electronic television after mechanical systems had taken a back seat. In 1939, he showed a system know today as hybrid colour using a cathode ray tube in front of which revolved a disc fitted with colour filters, a method taken up by CBS and RCA in the United States. As early as 1940, Baird had started work on a fully electronic system he called the "Telechrome". Early Telechrome devices used two electron guns aimed at either side of a phosphor plate. The phosphor was patterned so the electrons from the guns only fell on one side of the patterning or the other. Using cyan and magenta phosphors, a reasonable limited-colour image could be obtained. He also demonstrated the same system using monochrome signals to produce a 3D image (called "stereoscopic" at the time). In 1941, he patented and demonstrated this system of three-dimensional television at a definition of 500 lines. On 16 August 1944, he gave the world's first demonstration of a practical fully electronic colour television display. His 600-line colour system used triple interlacing, using six scans to build each picture. Similar concepts were common through the 1940s and 50s, differing primarily in the way they re-combined the colors generated by the three guns. One of them, the Geer tube, was similar to Baird's concept, but used small pyramids with the phosphors deposited on their outside faces, instead of Baird's 3D patterning on a flat surface.
In 1943, the Hankey Committee was appointed to oversee the resumption of television broadcasts after the war. Baird persuaded them to make plans to adopt his proposed 1000-line Telechrome electronic colour system as the new post-war broadcast standard. The picture resolution on this system would have been comparable to today's HDTV (High Definition Television). The Hankey Committee's plan lost all momentum partly due to the challenges of postwar reconstruction. The monochrome 405-line standard remained in place until 1985 in some areas, and the 625-line system was introduced in 1964 and (PAL) colour in 1967. A demonstration of large screen three-dimensional television by the BBC was reported in March 2008, over 60 years after Baird's demonstration.
Some of Baird's early inventions were not fully successful. In his twenties he tried to create diamonds by heating graphite and shorted out Glasgow's electricity supply. Later Baird invented a glass razor, which was rust-resistant, but shattered. Inspired by pneumatic tyres he attempted to make pneumatic shoes, but his prototype contained semi-inflated balloons, which burst. He also invented a thermal undersock (the Baird undersock), which was moderately successful. Baird suffered from cold feet, and after a number of trials, he found that an extra layer of cotton inside the sock provided warmth. Baird's numerous other developments demonstrated his particular talent at invention. He was a visionary and began to dabble with electricity. In 1928, he developed an early video recording device, which he dubbed Phonovision. The system consisted of a large Nipkow disk attached by a mechanical linkage to a conventional 78-rpm record-cutting lathe. The result was a disc that could record and play back a 30-line video signal. Technical difficulties with the system prevented its further development, but some of the original phonodiscs have been preserved, and have since been restored by Donald McLean, a Scottish electrical engineer.
Baird's other developments were in fibre-optics, radio direction finding, infrared night viewing and radar. There is discussion about his exact contribution to the development of radar, for his wartime defence projects have never been officially acknowledged by the UK government. According to Malcolm Baird, his son, what is known is that in 1926 Baird filed a patent for a device that formed images from reflected radio waves, a device remarkably similar to radar, and that he was in correspondence with the British government at the time. The radar contribution is in dispute. According to some experts, Baird's "noctovision" is not radar. Unlike radar (except Doppler radar), Noctovision is incapable of determining the distance to the scanned subject. Noctovision also cannot determine the coordinates of the subject in three-dimensional space.
Blue plaque erected by Greater London Council at 3 Crescent Wood Road, Sydenham, London |
From December 1944, Logie Baird lived at 1 Station Road, Bexhill-on-Sea, East Sussex, immediately north of the station and subsequently died there on 14 June 1946 after suffering a stroke in February. The house was demolished in 2007 and the site is now apartments named Baird Court. Logie Baird is buried with his mother, father and wife in Helensburgh Cemetery.
Australian television's Logie Awards were named in honour of John Logie Baird's contribution to the invention of the television. He became the only deceased subject of This Is Your Life when he was honoured by Eamonn Andrews at the BBC Television Theatre in 1957. He was played by Michael Gwynn (and also by Andrew Irvine, who played him as a boy) in the 1957 TV film A Voice in Vision and by Robert McIntosh in the 1986 TV drama The Fools on the Hill. In 2014, the Society of Motion Picture and Television Engineers (SMPTE) inducted Logie Baird into The Honor Roll, which "posthumously recognizes individuals who were not awarded Honorary Membership during their lifetimes but whose contributions would have been sufficient to warrant such an honor". On 26 January 2016, the search engine Google released a Google Doodle to mark the 90th anniversary of Logie Baird's first public demonstration of live television.
PB Parivar pays tribute to this great scientist on his 127th Birth Anniversary.
Source :- https://en.wikipedia.org/wiki/John_Logie_Baird