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| Lee De Forest |
The American inventor and electrical engineer, Lee De Forest is credited
for inventing the Audion, a vacuum tube that takes moderately weak
electrical signals and amplifies them. The device helped AT&T
establish coast-to-coast phone service, and it was also used in
everything from radios to televisions to the first computers.
Early Life, Education and Career:
Lee De Forest was born on August 26, 1873 in Council Bluffs, IA, the
son of Henry Swift DeForest and Anna Robbins. His father was a
Congregational Church minister and the President of Talladega College,
an all-black school in Alabama. He had always hoped that his son would
choose the same career path but De Forest had other plans. De Forest
completed his schooling from the Mount Hermon School, and then enrolled
at the Sheffield Scientific School at Yale University in Connecticut in
1893. Here he completed his graduation and earned his Ph.D. degree in
1899 with a dissertation on radio waves.
After completing his graduation he got employed at Western Electric,
where he devised dynamos, telephone equipment, and early radio gear. In
1902 he started his own business, the De Forest Wireless Telegraph
Company, selling radio equipment and demonstrating the new technology by
broadcasting Morse code signals. Within a span of four years De Forest
had been squeezed out of the management of his own company.
De Forest was highly creative and active, but many a times did not
see the potential of his inventions or grasp their theoretical
implications. While working on improving wireless telegraph equipment,
he modified the vacuum tube invented by John Ambrose Fleming and
designed the Audion (a vacuum tube containing some gas) in 1906. It was a
triode, including a filament and a plate, like regular vacuum tubes,
but also a grid between the filament and plate. This reinforced the
current through the tube, amplifying weak telegraph and even radio
signals. De Forest thought the gas was an essential part of the system;
however in 1912 others showed that a triode in a complete vacuum would
function much better.
In 1913 the United States Attorney General sued De Forest for deceit
on behalf of his shareholders, stating that his declaration of rebirth
was an “absurd” promise (he was later acquitted).In 1916 the American
inventor made two triumphs: the first radio advertisement (for his own
products) and the first presidential election reported by radio.
In 1919, De Forest filed the first patent on his sound-on-film
process, which enhanced the work of Finnish inventor Eric Tigerstedt and
the German partnership Tri-Ergon, and named it the De Forest Phonofilm
process. This process involved recording sound directly onto film as
parallel lines of variable shades of gray, and later became known as a
“variable density” system as opposed to “variable area” systems such as
RCA Photophone.
Death:
Lee De Forest died in Hollywood on July 1, 1961, and was interred in
San Fernando Mission Cemetery in Los Angeles, California. He died as a
poor man with just $1,250 in his bank account at the time of his death.
