• Sujet du message: The Invention of Television by Philo T. Farnsworth
Publié: Mer Juin 16, 2010 6:12 pm
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In 1921 the 14-year-old Mormon had an idea while working on his father's Idaho farm. Mowing hay in rows, Philo realized an electron beam could scan a picture in horizontal lines, reproducing the image almost instantaneously. This would prove to be a critical breakthrough in Philo Farnsworth's invention of the television in 1927. Earlier TV devices had been based on an 1884 invention called the scanning disk, patented by Paul Nipkow. Riddled with holes, the large disk spun in front of an object while a photoelectric cell recorded changes in light. Depending on the electricity transmitted by the photoelectric cell, an array of light bulbs would glow or remain dark. Though Nipkow's mechanical system could not scan and deliver a clear, live-action image, most would-be TV inventors still hoped to perfect it. Not Philo Farnsworth. In 1921 the 14-year-old Mormon had an idea while working on his father's Idaho farm. Mowing hay in rows, Philo realized an electron beam could scan a picture in horizontal lines, reproducing the image almost instantaneously. It would prove to be a critical breakthrough. But young Philo was not alone. At the same time, Russian immigrant Vladimir Zworykin had also designed a camera that focused an image through a lens onto an array of photoelectric cells coating the end of a tube. The electrical image formed by the cells would be scanned line-by-line by an electron beam and transmitted to a cathode-ray tube. Rather than an electron beam, Farnsworth's image dissector device used an "anode finger" -- a pencil-sized tube with a small aperture at the top -- to scan the picture. Magnetic coils sprayed the electrons emitted from the electrical image left to right and line by line onto the aperture, where they became electric current. Both Zworykin's and Philo's devices then transmitted the current to a cathode-ray tube, which recreated the image by scanning it onto a fluorescent surface. Farnsworth applied for a patent for his image dissector in 1927. The development of the television system was plagued by lack of money and by challenges to Farnsworth's patent from the giant Radio Corporation of America (RCA). In 1934, the British communications company British Gaumont bought a license from Farnsworth to make systems based on his designs. In 1939, the American company RCA did the same. Both companies had been developing television systems of their own and recognized Farnsworth as a competitor. World War II interrupted the development of television. When television broadcasts became a regular occurrence after the war, Farnsworth was not involved. Instead, he devoted his time to trying to perfect the devices he had designed.
David Sarnoff, vice president of the powerful Radio Corporation of America, later hired Zworykin to ensure that RCA would control television technology. Zworykin and Sarnoff visited Farnsworth's cluttered laboratory, but the Mormon inventor's business manager scoffed at selling the company -- and Farnsworth's services -- to RCA for a piddling $100,000. So Sarnoff haughtily downplayed the importance of Philo's innovations, saying, "There's nothing here we'll need." In 1934 RCA demonstrated its "iconoscope," a camera tube very similar to Farnsworth's image dissector. RCA claimed it was based on a device Zworykin tried to patent in 1923 -- even though the Russian had used Nipkow's old spinning disk design up until the time he visited Philo's lab. The patent wars had truly begun -- and Phil, as the grown-up Farnsworth preferred to be called, was in a bind. He could not license his inventions while the matter was in court, and he wrestled with his backers over control and direction of his own company. The men in Farnsworth's loyal "lab gang" were fired and rehired several times during his financial ups and downs, but retained confidence in Phil. When Farnsworth's financiers refused his request for a broadcasting studio, the inventor and a partner built a studio on their own. Meanwhile back at RCA, Sarnoff had spent more than $10 million on a major TV R & D effort. At the 1939 New York World's Fair, Sarnoff announced the launch of commercial television -- though RCA's camera was inadequate, and the corporation didn't own a single TV patent. Later that same year, the company was compelled to pay patent royalties to Farnsworth Radio and Television. By the time World War II began, Farnsworth realized that commercial television's future was in the hands of businessmen -- not a lone inventor toiling in his lab. With his patents about to expire, Phil grew depressed, drunk and addicted to painkillers. In 1949 he reluctantly agreed to sell off Farnsworth Radio and Television. Philo T. Farnsworth was always an outsider, a bright star blazing in the dawn of a new electronic age. His romance with the electron was a private affair, a celebration of the spirit of the lone inventor.
• Sujet du message: The Invention of Television by Philo T. Farnsworth
Publié: Jeu Juin 17, 2010 1:33 am
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Really informative! The history of science tickles my fancy.I have read a book titled Inventions and Inventors. It's so handy and puts other books on the same topic in the shade.
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