Lee De Forest

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Lee De Forest

De Forest patented the Audion,
a three-electrode tube.
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. He had four marriages and several failed companies, he was defrauded by business partners, and he was once indicted for mail fraud, but was later acquitted.

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[edit] 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. Both his parents were born in France and his mother's maiden name was Robbins. His father accepted the position of President of Talladega College (a traditionally Black school) in Talladega, Alabama where Lee spent most of his youth. Most citizens of the white community resented his father's efforts to educate Black students. 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. As an inquisitive inventor, he tapped into the electrical system at Yale one evening and completely blacked out the campus, leading to his suspension. However, he was eventually allowed to complete his studies. He paid some of his tuition with income from mechanical and gaming inventions, and he received his Bachelor's degree in 1896. He remained at Yale for graduate studies, and earned his Ph.D. in 1899 with a doctoral dissertation on radio waves.

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. At that time, he was a member of the faculty at the Armour Institute of Technology, now part of the Illinois Institute of Technology. He filed a patent for a two-electrode device for detecting electromagnetic waves. His Audion tube, a three-electrode device (plate, cathode, control grid), was a vacuum tube which allowed for amplification for radio reception. De Forest said that he didn't know why it worked; it just did.

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).

[edit] Marriages

Lee de Forest had four wives:

  • Lucille Sheardown in 1906. They divorced the same year they were married.
  • Nora Blatch in 1907, they had a child, but by 1911 they divorced.
  • Mary Mayo (1892-?) in 1912. In 1920 they were living with their child Deena DeForest (1919-?).
  • Marie Mosquini in 1930, the silent film actress.

[edit] Middle years

De Forest Audion from 1906.
Enlarge
De Forest Audion from 1906.

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. It was also called the De Forest valve, and since 1919 has been known as the triode. 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 resulting triode or three-electrode vacuum tube could be used as an amplifier for electrical signals, and, equally important, as a fast (for its time) electronic switching element, later applicable in digital electronics (such as computers). The triode was vital in the development of long-distance (e.g. transcontinental) telephone communications, radio, and radars. The triode was an important innovation in electronics in the first half of the 20th century, between Nikola Tesla's and Guglielmo Marconi's progress in radio in the 1890s, and the 1948 invention of the transistor.

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 lawsuit lasted twelve years, winding its way through the appeals process and ending up before the Supreme Court. 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. He went on to lead radio broadcasts of music (featuring opera star Enrico Caruso) and many other events, but he received little financial backing.

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. It recorded sound directly onto film as parallel lines. These lines photographically recorded electrical waveforms from a microphone, which were translated back into sound waves when the movie was projected. This system, which synchronized sound directly onto film, was used to record stage performances (such as in vaudeville), speeches, and musical acts. 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. He was forced to show his films in independent theaters such as the Rivoli, since the movie studios controlled all major theater chains. De Forest chose to film primarily vaudeville acts, not features, limiting the appeal of his process. Max Fleischer and Dave Fleischer used the Phonofilm process for their Sound Car-Tune series of cartoons -- featuring the "Follow the Bouncing Ball" gimmick -- starting in May 1924. De Forest also worked with Theodore Case (1888-1944), using Case's patents to perfect the Phonofilm system. However, the two men had a falling out, and Case took his patents to studio head William Fox, who then perfected the Fox Movietone process. Shortly before the Phonofilm Company folded in September 1926, Hollywood introduced a different method for the "talkies", the sound-on-disc process used by Warner Brothers as Vitaphone. Eventually Hollywood came back to the sound-on-film methods De Forest had originally proposed, such as Fox Movietone and RCA Photophone. A theater chain owner, M. A. Schlesinger, acquired the UK rights to Phonofilm and released short films of British music hall performers from September 1926 to May 1928. Almost 200 short films were made in the Phonofilm process, and many are preserved in the collections of the Library of Congress and the British Film Institute. Today, many sources such as the Encyclopaedia Britannica list Lee De Forest as one of the inventors of sound film.

[edit] 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. His peers would not take him seriously as an inventor or trust him as a colleague. 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". In 1946, he received the Edison Medal of the American Institute of Electrical Engineers 'For the profound technical and social consequences of the grid-controlled vacuum tube which he had introduced'.

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".

He died in Hollywood in 1961 and was interred in San Fernando Mission Cemetery in Los Angeles, California.

[edit] 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.

  • "I foresee great refinements in the field of short-pulse microwave signaling, whereby several simultaneous programs may occupy the same channel, in sequence, with incredibly swift electronic communication. Short waves will be generally used in the kitchen for roasting and baking, almost instantaneously" – 1952 [1]
  • "While theoretically and technically television may be feasible, commercially and financially it is an impossibility." – 1926[2]
  • "To place a man in a multi-stage rocket and project him into the controlling gravitational field of the moon where the passengers can make scientific observations, perhaps land alive, and then return to earth—all that constitutes a wild dream worthy of Jules Verne. I am bold enough to say that such a man-made voyage will never occur regardless of all future advances." – 1926[3]
  • "I do not foresee 'spaceships' to the moon or Mars. Mortals must live and die on Earth or within its atmosphere!" – 1952[1]
  • "The transistor will more and more supplement, but never supplant, the Audion. Its frequency limitations, a few hundred kilocycles [kilohertz], and its strict power limitations will never permit its general replacement of the Audion amplifier." – 1952[1]

[edit] 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. Calvert DeForest portrayed the comic "Larry 'Bud' Melman" character on David Letterman's late night television programs for two decades.

[edit] See also

[edit] Notes

  1. ^ a b c "Dawn of the Electronic Age", Popular Mechanics, January, 1952 (linked below)
  2. ^ Wikiquote: Incorrect predictions (television)
  3. ^ Wikiquote: Incorrect predictions (space travel)

[edit] External links

[edit] Patents

Patent images in TIFF format

[edit] Other sites

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