Quote:
Originally Posted by dtvmcdonald
Not really. That was Vladimir Zworkin. There really was one absolutely key invention, which was the iconoscope camera. This was the first device that stored up information from photons no matter when they arrived, at every spot on the picture. Even today they make really good pictures in bright sunlight, for example, in a camera made by a guy in Japan using a solid state preamp.
In broad daylight even my WWII bomber camera make quite OK pictures.
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This is a somewhat condensed version of the technical issues of sensitivity. The iconoscope was only 5 or 10 percent as sensitive as a tube should be that stored charge for a full field. This was because of the large secondary emission of charge due to the high-velocity scanning beam. The sensitivity could be increased about 10 times by adding an electron image section in front of the scanned plate. This was done successfully in the "Super Emitron" (image iconoscope) used in Europe. RCA was well aware if this, but didn't use it due to interference of Farnsworth's patents for an image section. It is a blatant example of how RCA's business policies sometimes held back technology instead of advancing it. RCA eventually did use an image section and combined it with low-velocity scanning in the even more sensitive image orthicon, which achieved 100% storage efficiency.