Electrical engineer and inventor, born in Council Bluffs, Iowa, USA. He studied theoretical mathematical physics and electricity at Yale (1899 PhD), and while working for Western Electric Co he made the first of his inventions. He started a radio broadcasting company (1902) and made the first broadcast of live opera, Enrico Caruso singing at the Metropolitan Opera (1910). Although he invented a number of devices crucial to radio, including a microphone and a three-element vacuum tube (or triode), his corporate enterprises failed and he worked briefly with the Federal Telegraph Co (1912). In 1913 he sold his triode invention to the American Telephone and Telegraph Co; the triode made transcontinental telegraphy possible and revolutionized military communications during World War 1 and would eventually become the basis of modern electronics. He used his profits from the triode to establish a firm in New York City which he then sold in 1923. He went on to work in telephony and sound motion-pictures but, due partly to his prickly personality, he continued to experience financial and legal complications in each field. Although he eventually held more than 300 patents and was called the Father of Radio, he died with an estate of only $1200.
Lee De Forest|
De Forest patented the Audion, a three-electrode tube. |
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| Born: |
August 26, 1873 |
|---|---|
| Died: |
June 30, 1961 Hollywood, California |
| Occupation: | inventor |
Lee De Forest, (August 26, 1873 – June 30, 1961) was an American inventor with over 300 patents to his credit. De Forest invented the Audion, a vacuum tube that takes relatively weak electrical signals and amplifies them. De Forest is one of the fathers of the "electronic age", as the Audion helped to usher in the widespread use of electronics.
He was involved in several patent lawsuits and he spent a fortune from his inventions on the legal bills.
Early years
Lee De Forest was born in Council Bluffs, Iowa to a Congregational minister who hoped that his son would become a minister like himself. Nevertheless, Lee De Forest had several friends among the African American children of the town.
De Forest went to Mount Hermon School, and then he enrolled at the Sheffield Scientific School at Yale University in 1893.
De Forest's interest in wireless telegraphy led to his invention of the Audion tube in 1906, and he developed an improved wireless telegraph receiver. De Forest said that he didn't know why it worked;
He was a charter member of the Institute of Radio Engineers, one of the two predecessors of the IEEE (the other was the American Institute of Electrical Engineers).
Marriages
Lee de Forest had four wives:
Lucille Sheardown in 1906.Middle years
De Forest invented the Audion in 1906, an improved version of John Fleming's recently invented diode vacuum tube detector. In January 1907, he filed a patent for a three-electrode version of the Audion, which was granted US Patent 879,532 in February 1908. De Forest's innovation was the insertion of a third electrode, the grid, in between the cathode (filament) and the anode (plate) of the previously invented diode.
The United States District Attorney sued De Forest for fraud (in 1913) on behalf of his shareholders, stating that his claim of regeneration was an "absurd" promise (he was later acquitted). De Forest filed a patent in 1916 that became the cause of a contentious lawsuit with the prolific inventor Edwin Armstrong, whose patent for the regenerative circuit had been issued in 1914. The Supreme Court ruled in favor of De Forest, although the view of many historians is that the judgement was incorrect.
In 1916, De Forest, from his own news radio station, broadcast the first radio advertisements (for his own products) and the first Presidential election report by radio.
In 1919, De Forest filed his first patent on a sound-on-film process, which improved on the work of German inventors and called it the De Forest Phonofilm process. De Forest established his De Forest Phonofilm Corporation, but he could interest no one in Hollywood in his invention at that time. De Forest premiered 18 short films made in Phonofilm on 15 April 1923 at the Rivoli Theater in New York City. De Forest chose to film primarily vaudeville acts, not features, limiting the appeal of his process. De Forest also worked with Theodore Case (1888-1944), using Case's patents to perfect the Phonofilm system. Eventually Hollywood came back to the sound-on-film methods De Forest had originally proposed, such as Fox Movietone and RCA Photophone. Today, many sources such as the Encyclopaedia Britannica list Lee De Forest as one of the inventors of sound film.
Later years
De Forest sold one of his radio manufacturing firms to RCA in 1931. In 1934, the courts sided with De Forest against Edwin Armstrong (although the technical community did not agree with the courts). De Forest won the court battle, but he lost the battle for public opinion. For De Forest's initially rejected, but later adopted, movie soundtrack method, he was given an Academy Award (Oscar) in 1959/1960 for "his pioneering inventions which brought sound to the motion picture", and a star on the Hollywood Walk of Fame.
De Forest received the IRE Medal of Honor in 1922, as "recognition for his invention of the three-electrode amplifier and his other contributions to radio".
An important annual medal awarded to engineers by the Institute of Electrical and Electronic Engineers is named the Lee De Forest Medal.
De Forest was the guest celebrity on the May 22, 1957 episode of the television show This Is Your Life, where he was introduced as the "Father Of Radio and the Grandfather of Television".
Quotes
De Forest was given to expansive predictions, many of which were not borne out, but he also made many correct predictions, including microwave communication and cooking. – 1952
Trivia
Lee De Forest's great nephew, actor Calvert DeForest, became well known in another broadcasting venue some 75 years following his uncle's Audion invention.
Patents
Patent images in TIFF format
U.S. Patent 1214283 "Wireless Signaling Device" (directional antenna), filed December 1902, issued January 1904 U.S. Patent 0824637 "Oscillation Responsive Device" (vacuum tube detector diode), filed January 1906, issued June 1906 U.S. Patent 0827523 "Wireless Telegraph System" (separate transmitting and receiving antennas), filed December 1905, issued July 1906 U.S. Patent 0827524 "Wireless Telegraph System", filed January 1906 issued July 1906 U.S. Patent 0836070 "Oscillation Responsive Device" (vacuum tube detector - no grid), filed May 1906, issued November 1906 U.S. Patent 0841386 "Wireless Telegraphy" (tunable vacuum tube detector - no grid), filed August 1906, issued January 1907 U.S. Patent 0876165 "Wireless Telegraph Transmitting System" (antenna coupler), filed May 1904, issued January 1908 U.S. Patent 0879532 "Space Telegraphy" (increased sensitivity detector - clearly shows grid), filed January 1907, issued February 18, 1908 U.S. Patent 0926933 "Wireless Telegraphy" U.S. Patent 0926934 "Wireless Telegraph Tuning Device" U.S. Patent 0926935 "Wireless Telegraph Transmitter", filed February 1906, issued July 1909 U.S. Patent 0926936 "Space Telegraphy" U.S. Patent 0926937 "Space Telephony" U.S. Patent 0979275 "Oscillation Responsive Device" (parallel plates in Bunsen flame) filed February 1905, issued December 1910 U.S. Patent 1101533 "Wireless Telegraphy" (directional antenna/direction finder), filed June 1906, issued June 1914 U.S. Patent 1214283 "Wireless Telegraphy"
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