Lee De Forest

Lee De Forest ( born August 26, 1873 in Council Bluffs, Iowa, † June 30, 1961 in Hollywood, California ) was an American inventor. It issued more than 300 patents to his name.

De Forest invented the Audion gas-filled tube, the precursor of the high-vacuum triode, a three -electrode tube, could be amplified by the weak electrical signals and reported it on October 25, 1906 for a patent. It is known as one of the fathers of the electronic age, as the Audion contributed significantly to the spread of electronic devices.

De Forest was involved in a number of patent disputes and used the fortune he had made with his inventions, for the court costs. He was married four times, failed with several companies, was betrayed by some of his business partners and was once accused of mail fraud. From this charge he was later acquitted.

Early years

De Forest was born in Iowa, the son of pastor Henry Swift De Forest; his mother was Anna Margaret De Forest, nee Robbins. Lee had an older sister and a younger brother.

His father hoped Lee would even continue the priesthood. 1879 his father took the post of college presidents at Talladega College, a school for blacks, in Talladega (Alabama ) to. There, Lee spent most of his young life. Most members of the white community met at his father's work to teach blacks. Lee had some friends among black boy in town.

De Forest signed up in 1893 at the Sheffield School of Science at Yale University. As a curious student, he caused one evening to a complete power failure on the school grounds, as he wanted to tap into the electrical system of the university. He was then suspended from school. Some time later, he was allowed to finish his studies. A part of his school fees he earned with inventions, he received his bachelor's degree in 1896. He received his Ph.D. in 1899 at Yale, his doctoral thesis dealt with the radio waves.

De Forest was interested in wireless telegraphy, which led to the invention of the Audion tube in 1906, and he developed a wireless telegraph receiver. He filed a patent for a " two-electrode component " for the detection of electromagnetic waves. With the Audion tube, a gas-filled tube, it was possible to reinforce language to radio communications. De Forest said he did not know why it worked, they would do it easy. Robert von Lieben writes about the Audion tube: " ... has the obvious disadvantage that can only go half-waves between the cathode and the other electrode due to the valve effect of the glowing cathode".

He was a founding member of the Institute of Radio Engineers, one of the two predecessors of the IEEE.

Mean annual

1906 De Forest invented the Audion as an improvement of the thermionic diode used at that time, and announced his invention of a patent. Later this tube was also called De Forest valve, and is now known as the triode. De Forest's innovation was the insertion of a third electrode, the grid between the cathode and the anode in the process invented by John Ambrose Fleming diode. He was then accused of Fleming of imitation.

The resulting three-electrode or triode tube could as an amplifier for audio signals, and - to be used as a fast ( for this time ) switching element - as important. 1907 De Forest went on air for the first time as a test, with a discussion on women's rights movement that he led with his mother Harriot Stanton Blatch, a famous suffragette.

At the instigation of its shareholders, the district attorney of the United States 1913 De Forest sued for securities fraud on the grounds that regeneration would be an absurd promise. He was later acquitted of this charge.

1916 De Forest filed a patent, the trigger for a controversial process with the prolific inventor Edwin Armstrong, who had received a patent for the regenerative circuit in 1914. The process took twelve years, and went through appeals to the Supreme Court. There was ruled in favor of De Forest; However, most historians hold that judgment is wrong.

In 1916, De Forest beamed from his news channel, the first radio advertising ( for its own products ), and he first reported on the radio of a presidential election. Although he ( with recordings of Enrico Caruso, 1910) aired the first music program and many other events brought on the radio, he received little support.

It is reported that he his classmate Theodore Willard Case at Yale stole the idea in the early twenties to talkies. 1922 De Forest improved the work of German inventors and developed the Phonofilm. When Phonofilm the sound with parallel lines was taken directly to the film. The sound was converted by a microphone into electrical impulses and then photographically recorded as lines. When playing these lines were then converted back into sound. With the Phonofilm system that the sound synchronously recorded to the image, stage performances, speeches and musical performances could be recorded.

De Forest founded the De Forest Phono Film Corporation, but was interested at that time no one in Hollywood for his invention. Some years later, Hollywood opted for another acquisition system, but later returned to the developed by De Forest technology.

De Forest married shortly after patenting the Audion, 1907, his assistant, Nora Stanton Blatch Barney, the civil engineer, with whom he had a daughter.

Later years

1931 Lee De Forest sold one of his companies to RCA. In 1934 the Supreme Court ruled in patent dispute with Armstrong in favor of De Forest's. Although he won the case but lost to public reputation. In public opinion, he was not regarded as a serious inventor, and as a colleague he no longer trust was met with. In 1942 he received the IEEE Edison Medal for his pioneering work for the radio technology and the invention of the triode.

His Tonaufzeichnungsverfahren, first rejected, was introduced later in the film. 1959/1960 he was awarded an Oscar for " his pioneering invention that brought the sound in the moving pictures ," and a star on the Hollywood Walk of Fame.

Lee De Forest died in 1961 in Hollywood and has been on the San Fernando Mission Cemetery in Los Angeles, California, buried.

Important patents

• Patent US841387: Device For Amplifying Feeble Electrical Currents. Remember on October 25, 1906 Inventor: Lee De Forest ( The De Forest triode ).
• Patent US879532: Space Telegraphy. Registered on January 29, 1907, Inventor: Lee De Forest ( Audion with triode).