John Logie Baird
John Logie Baird (13 August 1888 – 14 June 1946) was a Scottish engineer and inventor of the world's first working television system, also the world's first fully electronic colour television tube.
Baird was born in Helensburgh, Dunbartonshire and educated at Larchfield Academy (now part of Lomond School), Helensburgh; the Glasgow and West of Scotland Technical College (which later became the University of Strathclyde); and the University of Glasgow. His degree course was interrupted by World War I and he never returned to graduate.
In early 1923, and in poor health, Baird moved to 21 Linton Crescent, Hastings on the south coast of England and rented a workshop in Queen's Arcade in the town. In February 1924, he demonstrated to the Radio Times that a semi-mechanical analogue television system was possible by transmitting moving silhouette images. In July of the same year, he received a 1000-volt electric shock but fortunately survived with only a burnt hand. His landlord, a Mr Tree, asked him to quit his Hastings workshop and he moved to upstairs rooms in Soho, London where he made a technical breakthrough. Baird gave the first public demonstration of moving silhouette images by television at Selfridges department store in London in a three-week series of demonstrations beginning on 25 March 1925.
1924 GB Patent 236978, Priority Date: 1924-03-17, Assignees: John Logie Baird and Wilfred Ernest Lytton Day: A System of Transmitting Views Portraits and Scenes by Telegraphy or Wireless Telegraphy.
In his laboratory on 2 October 1925, Baird successfully transmitted the first television picture with a greyscale image: the head of a ventriloquist's dummy nicknamed "Stooky Bill" in a 30-line vertically scanned image, at five pictures per second. Baird went downstairs and fetched an office worker, 20-year-old William Edward Taynton, to see what a human face would look like, and Taynton became the first person to be televised in a full tonal range.
On 26 January 1926, Baird repeated the transmission for members of the Royal Institution and a reporter from The Times in his laboratory at 22 Frith Street in the Soho district of London. The location of his laboratory is now marked by a blue plaque above Bar Italia. By this time, he had improved the scan rate to 12.5 pictures per second. It was the first demonstration of a television system that could broadcast live moving images with tone graduation.
During 1926 continual effort was made to reduce the intense illumination that occurred at the transmitting end of television. Attention was directed at the possibility of using infrared rays which have no deleterious action on the human body, unlike the previously considered ultra-violet rays, and which moreover, transcend in penetrative power the rays of the visible spectrum. The use of these rays in conjunction with the "televisor" enabled Mr. Baird to transmit living scenes without subjecting the sitter to discomfort. The person whose image was to be transmitted would sit in a totally dark room and facial movements, such as smiling etc. were reproduced at the receiving end just as well as they were when the powerful lights were used. Mr. Baird believed that his new system would eventually lead to important developments in connection with warfare, for a beam of infra-red rays used in conjunction with the latest televisor would render "surprise night attacks" impossible.[1]
In 1927, Baird transmitted a long-distance television signal over 438 miles 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 Co, which in 1928 made the first transatlantic television transmission, from London to Hartsdale, New York, and the first television programme for the BBC.
He demonstrated the world's first colour transmission on 3 July 1928, using scanning discs at the transmitting and receiving ends with three spirals of apertures, each spiral with a filter of a different primary colour; and three light sources at the receiving end, with a commutator to alternate their illumination. That same year he also demonstrated stereoscopic television.
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, in 1930 at the London Coliseum, Berlin, Paris, and Stockholm.
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.
In 1932, Baird was the first person in England to demonstrate ultra-short wave transmission.
In November 1936, the BBC began alternating Baird 240-line transmissions with the Marconi-EMI Television Co's electronic scanning system which had recently been improved to 405 lines[2]. The Baird system at the time involved an intermediate film process, where footage was shot on cine film which was rapidly developed and scanned.
The BBC ceased broadcasts with the Baird system in February 1937, 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 superseded by the electronic television system developed by the newly-formed Marconi-EMI Television Co 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's used the Farnsworth tubes instead to scan cine film, in which capacity they proved serviceable through prone to dropouts 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 the 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 colour television 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.
In 1941, he patented and demonstrated a system of three-dimensional television at a definition of 500 lines.
On 16 August 1944, he gave the world's first demonstration of a fully electronic colour television display. His 600-line colour system used triple interlacing, using six scans to build each picture.
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 quality on this system would have been comparable to today's HDTV. 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 it was three decades until the introduction of the 625-line system 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 perfected 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.
Baird built what was to become the world's first working television set by purchasing an old hatbox and a pair of scissors, some darning needles, a few bicycle light lenses, a used tea chest, and sealing wax and glue.
There is a working model of the Baird televisor at the London Science Museum.
From December 1944 until his death two years later, Baird lived at a house in Station Road, Bexhill-on-Sea, immediately north of the station itself.
Baird died in Bexhill-on-Sea, Sussex, England on 14 June 1946 after a stroke in February of that year. The old house was demolished in 2007. The Sea Road-Station Road skyline now features a new block of 51 flats on the site, renamed "Baird Court".
John Logie Baird is buried with his mother, father and wife in Helensburgh Cemetery, Dunbartonshire.
Baird's memoirs have been published in several forms, most recently as edited by his son, Malcolm, in a fascinating book called 'Television and Me' [3]. An earlier version was 'Sermons, Soap and Television'.
The Televisor
The original Baird ‘Televisor’ receivers had mahogany cabinets and were very expensive. A cheaper ‘tin box’ model was designed for Baird by 'Percy Packman' of Plessey. Only about a thousand of these sets were sold, as cheaper kits based on the same 30-line system proved more popular.[4]
Plessey received an order for televisors in late 1929. In addition to complete receivers, Plessey made kits for sale in shops. The Baird 'Junior' kit cost £7 12s 6d including the motor and synchronizing gear and the Baird 'Senior' kit at £12 12s which included a lens and electrical controls.[5]
Servicing manual for the Baird Disc Model Televisor here.
Good zoomable photographs showing details of a televisor made by Plessey for Baird International Television Ltd., 133 Long Acre, London here[6]. This source provides a good description of the Televisor, from which the following information is translated and condensed:-
The Televisor has a 30-hole Nipkow disc of approximately 50 cm (20") diameter, driven by a 750 rpm motor,to provide 12 1/2 images per second. The very thin aluminum disc depends on centrifugal force for its rigidity. Six of the holes in the disc (the innermost and outermost holes, Nos. 1, 2, 3, 28, 29, 30) are rectangular (0.8 x 1 mm), while the other 24 holes are 0.8mm square. The scanning is done in a vertical direction, but the image must be recomposed on the right lateral side of the disc, the aim being to analyze the image in thinner bands in the middle where the attention is mostly focused. There are two control knobs, the left knob adjusting the motor speed, while the central knob determines the framing of the image. The system of automatic synchronization uses special pulses of synchronism sent at the same time and in the same way as the currents which provide the image. These pulses travel through coils which actuate two electromagnets placed on either side of a toothed tone wheel mounted on the motor shaft. The wheel has 30 teeth, corresponding to the 30 holes in the disc. The received current passing through the coils of the magnets creates a magnetic pull on the tooth passing the magnet face and so holds or checks the motor speed. Once the disc has been adjusted to synchronism with the transmitting disc, this system maintains synchronism automatically. The 'Osglim' neon light is the flat electrode type constructed for the Baird TV, providing uniform brightness over its whole surface. When the motor has reached its normal speed, the image may be distorted, with a slightly reddish background, so the speed is adjusted using the left hand knob. Dark lines, framing the top and bottom of the image, will be seen to scroll quickly, so the speed is adjusted to get these lines horizontal and stationary. In this condition the speed of the receiving disk will be the same as the transmitting disk. With the motor speed correctly set, a double or split image may be seen. Then, depending on how the image is split, correction involves either turning the central knob until a single still image is visible, or slowly increasing the motor speed.
The first photo above shows how the central control knob is connecting to a gear on the synchroniser unit. The tiny holes in the aluminium disc can just be seen.
Photos of an 'Osglim' lamp here.
1946 Obituary [7]
1946 Obituary [8]
See Also
Sources of Information
- ↑ The Engineer 1926/12/31
- ↑ The Times, 24 May 1934
- ↑ 'Television and Me: The Memoirs of John Logie Baird' edited and introduced by Malcom Baird, revised and expanded edition published by Mercat Press Ltd. 2004
- ↑ [1] Science Museum: Detail of a 'tin box' televisor, c 1930
- ↑ [2] Ilford Historical Society Newsletter, No.115, August 2014: John Logie Baird and Ilford, by Roger Backhouse
- ↑ [3] Catalogue des appareils cinématographiques de la Cinémathèque française et du CNC - Récepteur de télévision
- ↑ The Engineer 1946 Jan-Jun: Index
- ↑ Engineering 1946 Jan-Jun: Index: General Index
- [4] Wikipedia