Baird JL
ACHIEVEMENT(S): TV
DATE/PLACE OF BIRTH: 13 August 1888, at Helensburgh, Dunbarton, Scotland.
DATE/PLACE/AGE AT DEATH: 14 June 1946, in Bexhill-on-Sea, Sussex, England. Aged 57
DISCIPLINE: Electrical engineer
FIELD: Television
LANGUAGE: English
EDUCATION: Larchfield Academy; Royal Technical College, Glasgow, 1908-11;
University of Glasgow, 1911-14
ASSESSMENT: The first person to assemble a television that actually worked.
MAJOR WORK: Television
LIFE AND TIMES: In 1922, after a nervous breakdown, Baird retired from business to Hastings on the Sussex coast, where he spent the next two years working on the problem of transmitting visual signals. In 1894, the German inventor Nipkow* had patented what became known as the Nipkow disc, a means by which both the scanning of the transmitter and the reassembling of the picture by the receiver could be accomplished by a powerful beam of light passing through small holes arranged in a spiral on two rapidly rotating and properly synchronized discs. Nipkow theorized that the spiral holes in the transmitter disc would form the necessary lines of light to scan the object, and the light signals could then be collected by a light-sensitive photoelectric cell that would create the electrical impulses for transmission, and the disc in the receiver would reverse the process, the resulting lines of light appearing on a small screen.
Boris Rosing's proposition that, in a television system which used mirror-scanning in the camera, a cathode-ray tube with a fluorescent screen should be fitted into the receiver, while in 1911 Swinton* had suggested that magnetically deflected cathode-rays should be used both in the camera and in the receiver.
Baird's great achievement was to take the Nipkow disc and other components of the system and combine them in such a way that a picture could actually be transmitted and received.
Having little money, his first apparatus was crude and makeshift, set up on a washstand in an attic room, with a tea-chest as the base of his motor, a biscuit tin housing the projection lamp, his discs cut out from cardboard, the lenses taken from cheap cycle-lamps, and the whole thing held together by sealing wax, sewing needles, and pieces of string.
With this apparatus he succeeded early in 1923 in transmitting over a distance of a few feet the first very blurred and flickering television picture of the outline of a cross and a moving human hand. A patent was granted in May 1924.
At around the same time, Baird moved to Soho, London, and in 1925 he achieved the transmission of an image of a recognizable human face, and on 26 January 1926 he gave the first formal demonstration of television - the pictures being formed of only 30 lines, repeated approximately 10 times per second - to an audience of about 50 scientists at the Royal Institution, London.
Later in 1926, Baird's Television Development Company built the first television transmission station. By this time he had serious rivals in the United States, who in early 1927 successfully transmitted pictures of Herbert Hoover by radio and telephone line 200 miles from Washington D.C. to New York. In May 1927 Baird transmitted a visual picture across 438 miles of telephone line between London and Glasgow, and in February 1928 he made the first TV* broadcast using radio, between London and the S.S. 'Berengaria', halfway across the Atlantic Ocean.
A few weeks later he also made the first transatlantic television broadcast between Britain and the United States, when signals transmitted from the Baird station in Coulson, Kent were picked up by a receiver in Hartsdale, New York. In June 1928 he broadcasted the first television pictures taken outside in daylight, and in early July he sent out the first colour television image.
Baird's colour television was based on the simplest method of reproducing a colour image, which was to produce the red, blue and green primary images separately and then to superimpose them so that the eye merged the three images into one full-colour picture. Baird used three projection tubes arranged so that each one projected a picture on to the same screen, and used only one amplifier chain and one cathode-ray tube which sequentially amplified the red, blue and green signals and matched the three channels. He again used two rotating discs, but now each contained segments of red, green and blue light filters, rotating in synchronism, one in front of the camera tube and the other in front of the receiver tube, and each primary-coloured filter remained over the tube face for the period of one field.
In September 1929 the BBC allowed Baird to use its facilities for a series of experimental television broadcasts to the very few people who had television sets. At first, the sound and vision were transmitted alternately, but by 1930 it was possible to broadcast them simultaneously. Half-hour programmes were then shown regularly on five mornings a week, during which Baird gave the first live broadcast of the Derby horserace on 3 June 1931.
Meanwhile, since its invention by Braun* in 1897, several scientists had proposed that the cathode-ray tube could be used as a scanner in an all-electronic television system, and in the early 1930s an entirely electronic, high definition system was being developed both by Zworykin* for the Radio Corporation of America (RCA) in the United States and by a team working for the Marconi-EMI Company in Great Britain.
In early 1935, the BBC agreed to a test period in which Baird's system and that developed by Marconi-EMI would broadcast alternately to determine which performed better, and for three months from November 1936, when the BBC started the world's first public high-definition service from Alexandra Palace, London, the two systems were broadcast on alternate weeks. However, by this stage the Marconi-EMI team had devised a completely mobile system with improved a picture quality to 405 horizontal lines with 25 pictures per second, and in February 1937 the BBC announced that it was dropping the Baird mechanical apparatus and would continue its television broadcasting with the Marconi-EMI system only. Baird continued his experimental work in color television, which in 1939 he demonstrated using a cathode-ray tube.
EXTRA-CONNECTIONS: His work related to that of Farnsworth*
1936 Crystal Palace fire, he suspected sabotage.
ONELINER: JL Baird, one inventor of TV
BIBLIOGRAPHY:
EB Collier's
Biographical Dictionary of Engineers and Inventors
Little, John E., "John Logie Baird", inNotable 20th CenturyScientists
McArthur, Tom, The Secret Life of John Logie Baird, London: Hutchinson, 1986
PARENTS: Reverend John Baird and Jessie Morrison Inglis
SIBLINGS: Three elder siblings
SPOUSE: Margaret Albu, married 1931
CHILDREN: One son and one daughter