Alan Archibald Campbell-Swinton

Alan Archibald Campbell-Swinton, FRS (1863–1930) was a Scottish consulting electrical engineer born in Edinburgh. He described an electronic basis of producing television in a 1908 letter to Nature.

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Biography

Campbell-Swinton was educated at Fettes College.

He was one of the first to explore the medical applications of radiography, opening the first radiographic laboratory in the United Kingdom in 1896. He was elected a Fellow of the Royal Society in 1915.

Campbell-Swinton wrote a letter in response to an article in the June 4, 1908 issue of Nature by Shelford Bidwell entitled "Telegraphic Photography and Electric Vision". Even as early as 1908, it was recognized that "The final, insurmountable problems with any form of mechanical scanning were the limited number of scans per second, which produced a flickering image, and the relatively large size of each hole in the disk, which resulted in poor resolution".

Campbell-Swinton's letter was published in the June 18, 1908 issue of Nature. The name of the article is "Distant Electric Vision". He wrote: "This part of the problem of obtaining distant electric vision can probably be solved by the employment of two beams of cathode rays (one at the transmitting and one at the receiving station) synchronously deflected by the varying fields of two electromagnets placed at right angles to one another and energised by two alternating electric currents of widely different frequencies, so that the moving extremities of the two beams are caused to sweep simultaneously over the whole of the required surface within the one-tenth of a second necessary to take advantage of visual persistence. Indeed, so far as the receiving apparatus is concerned, the moving cathode beam has only to be arranged to impinge on a suitably sensitive fluorescent screen, and given suitable variations in its intensity, to obtain the desired result."

A decade later, he repeated his advice in the June 1928 issue of Modern Wireless, "Television by Cathode Rays". "Surely it would be better policy if those who can afford the time and money would abandon mechanical devices and expend their labours in what appears likely to prove the ultimately more promising method in which the only moving parts are imponderable electrons."