Nipkow 1860 - 1940
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German engineering student, Paul
Nipkow proposed and patented the world's first electromechanical television
system in 1884. Paul Nipkow devised the notion of dissecting the image
and transmitting it sequentially. To do this he designed the first television
Paul Nipkow was the first person
to discover television's scanning principle, in which the light intensities
of small portions of an image are successively analyzed and transmitted.
In 1873 the photoconductive properties of the element selenium were discovered,
the fact that selenium's electrical conduction varied with the amount of
illumination it received. Paul Nipkow created a rotating scanning disk
camera called the Nipkow disk, a device for picture analyzation that consisted
of a rapidly rotating disk placed between a scene and a light sensitive
selenium element. The image had only 18 lines of resoution.
How It Worked
"The Nipkow disk was a rotating disk
with holes arranged in a spiral around its edge. Light passing through
the holes as the disk rotated produced a rectangular scanning pattern or
raster which could be used to either generate an electrical signal from
the scene for transmitting or to produce an image from the signal at the
receiver. As the disk rotated, the image was scanned by the perforations
in the disk, and light from different portions of it passed to a selenium
photocell. The number of scanned lines was equal to the number of perforations
and each rotation of the disk produced a television frame. In the receiver,
the brightness of the light source would be varied by the signal voltage.
Again, the light passed through a synchronously rotating perforated disk
and formed a raster on the projection screen. Mechanical viewers had the
serious limitation of resolution and brightness." - source "Who Invented
Television" by R. J. Reiman, Historian
No one is sure if Paul Nipkow actually
built a working prototype of his television system. It would take the development
of the amplification tube in 1907 before the Nipkow Disc would become practical.
All electromechanical television systems were outmoded in 1934 by electronic
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