Video camera tube
The video camera tube was a type of vacuum tube used to capture television images between the 1930s and 1980s.[1]
A video camera tube uses a lens to focus the image on a photoelectric material (a material which emits electrons when light hits it) housed at the front of a glass tube.
An electron gun at the back of the tube, like those used in a cathode ray tube,[2] fires electrons at the material. When the photoelectric material is hit with brighter light, it produces more electrons, which cause more of the electrons fired by the electron gun to bounce back.
By measuring the number of electrons which bounced back, the video camera tube is able to tell how bright each part of the image is, and create a signal suitable for display on a cathode ray tube.[3]
Video Camera Tube Media
A display of numerous video camera tubes from the 1930s and 1940s, photographed in 1954, with iconoscope inventor Vladimir K. Zworykin.
Farnsworth image dissector tube from 1931
A graphic from Kálmán Tihanyi's "Radioskop" patent from 1926 (part of the UNESCO's Memory of the World Programme)
Zworykin holding an iconoscope tube
Diagram of the iconoscope, from Zworykin's 1931 patent
CPS Emitron television camera
Schematic of image orthicon tube
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Related pages
References
- ↑ "RCA TV Equipment Archive". www.oldradio.com.
- ↑ "Cathode-ray tube." McGraw-Hill Concise Encyclopedia of Science & Technology. Third Ed., Sybil P. Parker, ed., McGraw-Hill, Inc., 1992, pp. 332-333.
- ↑ fazano.pro.br The Image Converter