The famous 4.5 inch Image Orthicon monochrome camera tube was devised originally (1947) in the USA by RCA. The prototype was perfected by EEV and Marconi in the UK and the first production models went into service in the mid-1950s. Later versions used the 'ELCON' target glass, making the EEV 4.5 inch I.O. the tube of choice for tv stations throughout the world. EEV I.O. tube manufacture closed in 1982 after sales of over 250,000 units.
The CPS (Cathode Potential Stabilised) EMITRON 10764 was an Orthicon-type monochrome low velocity imaging tube devised originally by RCA in the mid 1930s. A forerunner of the Image Orthicon, the Orthicon design first saw US tv service in 1941. The UK-built EMI CPS 10764 was installed at the BBC's Lime Grove studios in 1956.(Earlier CPS Emitron Orthicon types had been used by the BBC since 1948). The CPS 10764 image quality was much admired in the production gallery although on the home receiver the picture always looked 'soft'.
1850A Iconoscope camera tube. This tube is from the late 1940's but the design is late 1930's. The difference in the period of manufacture is denoted by the internal white flashing. The tube is not gassed and the getter is still good.
The 3 inch Image Orthicon tube was produced first in the USA by RCA initially for WW2 military use and then in 1945 for broadcast use. Termed a 'low velocity' photo emmisive tube, the 3 inch IO revolutionised tv camera design and tv production because of its high sensitivity. This enabled outside broadcasting to be undertaken in very poor light and also implimented the use of camera lens turrets and electronic viewfinders. One 'trick' of the 3 inch IO was that it could photograph the human face by the light of a single small candle. The black 'halo' reproduced around the candle flame was another matter.
Image Iconoscope class of imaging tube. This type was made by Cathodeon (a Pye company). Similar types were made by Marconi-EMI, Philips, RCA etc. pre-war. The idea is to separate the imaging function from that of the storage function. The image section is where the light from the scene is converted into an electron image. This is then transferred to the storage target for reading by the electron gun. Later versions used a number of small lamps around the periphery to help control the 'tilt and bend' problems associated with iconoscope cameras.