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Saturday, August 3, 2019

television :: essays research papers

Television was not invented by a single inventor, instead many people working together and alone, contributed to the evolution of TV. 1831: Joseph Henry's and Michael Faraday's work with electromagnetism makes possible the era of electronic communication to begin. 1862: Abbe Giovanna Caselli invents his "pantelegraph" and becomes the first person to transmit a still image over wires. 1873: Scientists May and Smith experiment with selenium and light, this opens the door for inventors to transform images into electronic signals. 1876: Boston civil servant George Carey was thinking about complete television systems and in 1877 he put forward drawings for what he called a "selenium camera" that would allow people to "see by electricity." Eugen Goldstein coins the term "cathode rays" to describe the light emitted when an electric current was forced through a vacuum tube. Late 1870's: Scientists and engineers like Paiva, Figuier, and Senlecq were suggesting alternative designs for "telectroscopes." 1880: Inventors like Bell and Edison theorize about telephone devices that transmit image as well as sound. Bell's photophone used light to transmit sound and he wanted to advance his device for image sending. George Carey builds a rudimentary system with light-sensitive cells. 1881: Sheldon Bidwell experiments with telephotography, another photophone. 1884: Paul Nipkow sends images over wires using a rotating metal disk technology calling it the "electric telescope" with 18 lines of resolution. 1900: At the World's Fair in Paris, the 1st International Congress of Electricity was held, where Russian, Constantin Perskyi made the first known use of the word "television." Soon after, the momentum shifted from ideas and discussions to physical development of TV systems. Two paths were followed: Mechanical television - based on Nipkow's rotating disks, and Electronic television - based on the cathode ray tube work done independently in 1907 by English inventor A.A. Campbell-Swinton and Russian scientist Boris Rosing. 1906: Lee de Forest invents the "Audion" vacuum tube that proved essential to electronics. The Audion was the first tube with the ablity to amplify signals. Boris Rosing combines Nipkow's disk and a cathode ray tube and builds the first working mechanical TV system. 1907: Campbell Swinton and Boris Rosing suggest using cathode ray tubes to transmit images - independent of each other, they both develop electronic scanning methods of reproducing images. American Charles Jenkins and Scotsman John Baird followed the mechanical model while Philo Farnsworth, working independently in San Francisco, and Russian à ©migrà © Vladimir Zworkin, working for Westinghouse and later RCA, advanced the electronic model.

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