Happy birthday Lee de Forest



Lee de Forest (August 26, 1873 – June 30, 1961) was an American inventor. He is most remembered for his contributions to radio broadcast and the wireless telegraph, but also held the patent for the first sound-on-film recording.


De Forest was born in Council Bluffs, Iowa to Anna Margaret and Henry Swift de Forest. His father was a minister. He later became president of Talladega College. The school was attended predominantly by African American students, and many white members of the community disapproved of the senior de Forest's efforts to educate African Americans. De Forest spent a lot of time at the school during his childhood.

De Forest attended Mount Hermon School in Massachusetts. Despite being very concerned about his popularity and attaining little among his peers, he began inventing things and became confident enough to attempt to sell them and enter them into contests. After graduating, he attended Yale's Sheffield Scientific School. While he was there, he caused a blackout on the campus when he was fiddling with some of the school's electrical system. He was suspended, but was able to return to obtain his Bachelor's degree in 1896. He went on to get a Ph.D. in 1899, doing his dissertation on radio waves.


De Forest modified the work of many inventors who had preceded him, especially in regard to the wireless telegraph. In 1906, he invented the Audion. The crux of the invention was a vacuum tube filled with gas, which served to strengthen weak telegraph and radio signals. Following that invention, he developed an improved wireless telegraph receiver. It wasn't until later that others experimented with his invention and discovered that a vacuum without gas would function even better.

In 1910, De Forest moved to San Francisco to work for the Federal Telegraph Company. In July 1913, he sold his patent for the telegraph vacuum-tube AT&T and the Bell Company for $50,000. He later relinquished all rights to wireless telegraphy to AT&T. (Image source)

In 1912, he invented a feedback circuit, which increased the output of a radio transmitter. Unfortunately, he did not patent it quickly enough and another inventor, Edwin Howard Armstrong, beat him to it. He filed a lawsuit, and the case went all the way to the Supreme Court in 1926. Ultimately, the Court sided with De Forest.



De Forest is also credited with discovering how to record sound on film, leading directly to sound motion pictures. He received the patent for sound on film in 1921, calling it the Phonofilm, though Hollywood didn't take to using his method until years later. De Forest produced his own "talkies," sticking primarily to vaudeville themes. He first premiered 18 of his short films in an independent theater in New York in 1923.

In 1950, De Forest wrote an autobiography titled Father of Radio. Though he contributed greatly to the broadcast industry, many see him as just one of many contributors.


Additional Info

  • Birthday Date: Tuesday, 26 August 2014
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