Page "Video camera tube" Paragraph 5

In a letter to Nature published in October 1926, Campbell-Swinton also announced the results of some " not very successful experiments " he had conducted with G. M. Minchin and J. C. M. Stanton.

They had attempted to generate an electrical signal by projecting an image onto a selenium-coated metal plate that was simultaneously scanned by a cathode ray beam.

These experiments were conducted before March 1914, when Minchin died, but they were later repeated by two different teams in 1937, by H. Miller and J. W. Strange from EMI, and by H. Iams and A.

Rose from RCA.

Both teams succeeded in transmitting " very faint " images with the original Campbell-Swinton's selenium-coated plate, but much better images were obtained when the metal plate was covered with zinc sulphide or selenide, or with aluminum or zirconium oxide treated with caesium.

These experiments are the base of the future vidicon.

A description of a CRT imaging device also appeared in a patent application filed by Edvard-Gustav Schoultz in France in August 1921, and published in 1922, although a working device was not demonstrated until some years later.