kids encyclopedia robot

Lee de Forest facts for kids

Kids Encyclopedia Facts
Quick facts for kids
Lee de Forest
Lee De Forest.jpg
Lee de Forest circa 1900–1910
Lee DeForest

(1873-08-26)August 26, 1873
Died June 30, 1961(1961-06-30) (aged 87)
Nationality American
Alma mater Yale College (Sheffield Scientific School)
Occupation Inventor
Known for Three-electrode vacuum-tube (Audion), sound-on-film recording (Phonofilm)
Lucille Sheardown
(m. 1906; div. 1906)

Nora Stanton Blatch Barney
(m. 1908; div. 1911)

Mary Mayo
(m. 1912; div. 1923)

Marie Mosquini
(m. 1930)
Parent(s) Henry Swift DeForest
Anna Robbins
Relatives Calvert DeForest (grandnephew)
Awards IEEE Medal of Honor (1922)
Elliott Cresson Medal (1923)

Lee de Forest (August 26, 1873 – June 30, 1961) was an American inventor, self-described "Father of Radio", and a pioneer in the development of sound-on-film recording used for motion pictures. He had over 180 patents, but also a tumultuous career—he boasted that he made, then lost, four fortunes. He was also involved in several major patent lawsuits, spent a substantial part of his income on legal bills, and was even tried (and acquitted) for mail fraud. His most famous invention, in 1906, was the three-element "Audion" (triode) vacuum tube, the first practical amplification device. Although De Forest had only a limited understanding of how it worked, it was the foundation of the field of electronics, making possible radio broadcasting, long distance telephone lines, and talking motion pictures, among countless other applications.


DeForest building San Jose
The DeForest Lofts at Santana Row, San Jose, California, are in this building named for Lee de Forest.

The grid Audion, which de Forest called "my greatest invention", and the vacuum tubes developed from it, dominated the field of electronics for forty years, making possible long-distance telephone service, radio broadcasting, television, and many other applications. It could also be used as an electronic switching element, and was later used in early digital electronics, including the first electronic computers, although the 1948 invention of the transistor would lead to microchips that eventually supplanted vacuum-tube technology. For this reason de Forest has been called one of the founders of the "electronic age".

De Forest's archives were donated by his widow to the Perham Electronic Foundation, which in 1973 opened the Foothills Electronics Museum at Foothill College in Los Altos, California. In 1991 the college closed the museum, breaking its contract. The foundation won a lawsuit and was awarded $775,000. The holdings were placed in storage for twelve years, before being acquired in 2003 by History San José and put on display as The Perham Collection of Early Electronics.

Awards and recognition

  • Charter member, in 1912, of the Institute of Radio Engineers (IRE).
  • Received the 1922 IRE Medal of Honor, in "recognition for his invention of the three-electrode amplifier and his other contributions to radio".
  • Awarded the 1923 Franklin Institute Elliott Cresson Medal for "inventions embodied in the Audion".
  • Received the 1946 American Institute of Electrical Engineers Edison Medal, "For the profound technical and social consequences of the grid-controlled vacuum tube which he had introduced".
  • Honorary Academy Award Oscar presented by the Academy of Motion Picture Arts and Sciences in 1960, in recognition of "his pioneering inventions which brought sound to the motion picture".
  • Honored February 8, 1960 with a star on the Hollywood Walk of Fame.
  • DeVry University was originally named the De Forest Training School by its founder Dr. Herman A. De Vry, who was a friend and colleague of de Forest.

Personal life


Mary Mayo (1892-1957) who married Lee DeForest
Mary Mayo, his third wife

De Forest was married four times, with the first three marriages ending in divorce:

  • Lucille Sheardown in February 1906. Divorced before the end of the year.
  • Nora Stanton Blatch Barney (1883–1971) on February 14, 1908. They had a daughter, Harriet, but were divorced by 1911.
  • Mary Mayo (1892–1957) in December 1912. According to census records, in 1920 they were living with their infant daughter, Deena (born ca. 1919); divorced October 5, 1930 (per Los Angeles Times). Mayo died December 30, 1957 in a fire in Los Angeles.
  • Marie Mosquini (1899–1983) on October 10, 1930; Mosquini was a silent film actress, and they remained married until his death in 1961.


  • "Wireless Signaling Device" (directional antenna), filed December 1902, issued January 1904;
  • "Oscillation Responsive Device" (vacuum tube detector diode), filed January 1906, issued June 1906;
  • "Wireless Telegraph System" (separate transmitting and receiving antennas), filed December 1905, issued July 1906;
  • "Wireless Telegraph System," filed January 1906 issued July 1906;
  • "Oscillation Responsive Device" (vacuum tube detector – no grid), filed May 1906, issued November 1906;
  • "Wireless Telegraphy" (tunable vacuum tube detector – no grid), filed August 1906, issued January 1907;
  • "Device for Amplifying Feeble Electrical Currents" (...), filed August 1906, issued January 1907;
  • "Wireless Telegraph Transmitting System" (antenna coupler), filed May 1904, issued January 1908;
  • "Space Telegraphy" (increased sensitivity detector – clearly shows grid), filed January 1907, issued February 18, 1908;
  • "Wireless Telegraphy";
  • "Wireless Telegraph Tuning Device";
  • "Wireless Telegraph Transmitter," filed February 1906, issued July 1909;
  • "Space Telegraphy";
  • "Space Telephony";
  • "Oscillation Responsive Device" (parallel plates in Bunsen flame) filed February 1905, issued December 1910;
  • "Transmission of Music by Electromagnetic Waves";
  • "Wireless Telegraphy" (directional antenna/direction finder), filed June 1906, issued June 1914;
  • "Wireless Telegraphy."

Images for kids

kids search engine
Lee de Forest Facts for Kids. Kiddle Encyclopedia.