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60-المجهر الالكتروني فلاديمير زفوركن أمريكي 1939م
- نادرا ما مان يلتقي مع والده
- لا نعرف متى ماتت والدته
- هو اقرب الى اليتم الاجتماعي
==
Vladimir Kosmich Zworykin
(
Russian
: Влади́мир Козьми́ч Зворы́кин -
Vladimir Koz'mich Zvorykin
) (July 29 [
O.S.
July 17] 1888 – July 29, 1982) was a
Russian-American
inventor, engineer, and pioneer of
television
technology. Zworykin invented a television transmitting and receiving system employing
cathode ray tubes
. He played a role in the practical development of television from the early thirties, including charge storage-type tubes,
infrared
image tubes and the
electron microscope
.
[3]
Biography]
Vladimir Kosmich Zworykin was born in
Murom
,
Russia
, in 1888, on July 29 (old style July 17), to the family of a prosperous
merchant
.
He had a relatively calm upbringing, and he rarely saw his father except on religious holidays
.
He studied at the
St. Petersburg Institute of Technology
, under
Boris Rosing
. He helped Boris Rosing with experimental work on television in the basement of Rosing's private lab at the School of Artillery of
Saint Petersburg
. Rosing had filed his first patent on a television system in 1907, featuring a very early cathode ray tube as a receiver, and a mechanical device as a transmitter. Its demonstration in 1911, based on an improved design, was among the first demonstrations of TV of any kind.
[4]
Drawing from V. Zworykin's 1923 patent application
Television System
.
[5]
[6]
Vladimir Zworykin's patent diagram of an iconoscope, 1931,
[7]
with an apparatus similar to the camera part.
[5]
[6]
V. Zworykin graduated in 1912 and, thereafter, studied X-rays under professor
Paul Langevin
in Paris.
[4]
During
World War I
, Zworykin was enlisted and served in the Russian Signal Corps, then succeeded in getting a job working for
Russian Marconi
, testing radio equipment that was being produced for the Russian Army.
Zworykin decided to leave Russia for the
United States
in 1918, during the
Russian Civil War
. He left through
Siberia
, travelling north on the
River Ob
to the
Arctic Ocean
as part of an expedition led by Russian scientist
Innokenty P. Tolmachev
, eventually arriving in the US at the end of 1918. He returned to
Omsk
, then capital of
Admiral Kolchak
's government in 1919, via
Vladivostok
, then to the United States again on official duties from the
Omsk government
. These duties ended with the collapse of the
White movement
in Siberia at the death of Kolchak. V. Zworykin decided, this time, to remain permanently in the US.
Once in the U.S., V. Zworykin found work at the
Westinghouse
laboratories in
Pittsburgh
, where he eventually had an opportunity to engage in television experiments. He summarized the resulting invention in two patent applications. The first, entitled "Television Systems", was filed on December 29, 1923, and was followed by a second application in 1925 of essentially the same content, but with minor changes and the addition of a Paget-type screen for color transmission and reception.
[8]
He was awarded a patent for the 1925 application in 1928,
[8]
and two patents for the 1923 application that was divided in 1931,
[5]
[6]
although the equipment described was never successfully demonstrated.
[9]
[10]
[11]
Vladimir Zworykin demonstrates electronic television (1929).
Vladimir Zworykin described cathode ray tubes as both transmitter and receiver. The operation, whose basic thrust was to
prevent
the emission of electrons between scansion cycles, was reminiscent of
A. A. Campbell Swinton
's proposal published in
Nature
in June 1908.
[12]
[13]
This would result in the television signal being derived from the modest number of electrons released at the instant the cathode ray swept over an image point.[
citation needed
]
The demonstration given by V. Zworykin sometime in late 1925 or early 1926, was far from a success with the Westinghouse management, even though it showed the possibilities inherent in a system based on the Braun tube. Although he was told by management to "devote his time to more practical endeavours", Zworykin continued his efforts to perfect his system. As attested to by his own writing, including his doctoral dissertation of 1926, earning him a
PhD
from the
University of Pittsburgh
, his experiments were directed at improving the output of photoelectric cells.
There were, however, limits to how far one could go along these lines, and so, in 1929, V. Zworykin returned to vibrating mirrors and facsimile transmission, filing patents describing these. At this time, however, he was also experimenting with an improved cathode ray receiving tube, filing a patent application for this in November 1929, and introducing the new receiver that he named "Kinescope", reading a paper two days later at a convention of the
Institute of Radio Engineers
.
Having developed the prototype of the receiver by December, Zworykin met
David Sarnoff
,
[14]
who eventually hired him and put him in charge of television development for
RCA
at their newly established laboratories in
Camden, New Jersey
.
The move to the laboratories occurred in the spring of 1930 and the difficult task of developing a transmitter could begin. There was an in-house evaluation in mid-1930, where the kinescope performed well (but with only 60 lines definition
[15]
), and the transmitter was still of a mechanical type. A "breakthrough" would come when the Zworykin team decided to develop a new type of cathode ray transmitter, one described in the French and British patents of 1928 priority by the Hungarian inventor
Kalman Tihanyi
whom the company had approached in July 1930, after the publication of his patents in England and France. This was a curious design, one where the scanning electron beam would strike the photoelectric cell from the same side where the optical image was cast. Even more importantly, it was a system characterized by an operation based on an entirely new principle, the principle of the accumulation and storage of charges during the entire time between two scansions by the cathode-ray beam.
According to Albert Abramson, Zworykin's experiments started in April 1931, and after the achievement of the first promising experimental transmitters, on October 23, 1931, it was decided that the new camera tube would be named
Iconoscope
. The system was ready to be launched at the end of 1934, a contract had of course been signed with the Hungarian inventor for the purchase of his patents. In early 1935, the new tube was introduced in Germany. It was soon developed there, with some improvements, and was successfully used at the 1936
Berlin Olympic Games
as one of several cameras, including
Philo Farnsworth
's
Image Dissector
, for film transmission only, broadcasting the games to some two-hundred public theaters. Although the tube went through a number of adjustments and improvements, it continued to be called by the generic name of Iconoscope.
The developments in England, by the British firm
Marconi
/
EMI
, followed the original charge storage design under a patent exchange. This electronic system was officially adopted by the
BBC
whose experimental public broadcasts began in England in November 1936 and initially included the
Baird
-system. The British electronic system featured
405 scanning lines
, while German television adopted
441 line
scanning and so did RCA following the initial (1934) 375 line definition.
Second marriage and calling[
edit
]
Vladimir Zworykin married for a second time in 1951. His wife was Katherine Polevitzky (1888-1985), a Russian-born professor of bacteriology at the
University of Pennsylvania
. It was the second marriage for both. The ceremony was in
Burlington, New Jersey
.
[16]
He retired in 1954.
But new frontiers in
medical engineering
and
biological engineering
appealed to him, and he became a founder and first President of the
International Federation for Medical and Biological Engineering
. The Federation continues to honor outstanding research engineering with a
Zworykin Award
, the prize being travelling funds to the Award's presentation at a World Congress.
[17]
Death
He died on July 29, 1982 in
Princeton, New Jersey
.
[2]
His wife Katherine died on February 18,1985.
==
Father: (merchant)
Wife:
Tatiana Vasilieff (m. 1916)
Wife:
Katherine Polevitsky (m. 1951)
---
VLADIMIR ZVORYKIN - A RUSSIAN AMERICAN WHO INVENTED TELEVISION
*
**** The year 1931 marked an event that from time to time occurs in the world of invention. Two engineers living in different parts of the world – Semyon Kataev in Russia and Vladimir Zvorykin in the USA - applied for a patent on a transmitting television tube – “iconoscope”. With only one month and a half’s difference in time* between their applications the two Russian inventors did not start a dispute over who should be considered the first but made friends instead and often saw one another when Zvorykin visited Russia.**
Born into a wealthy family of a merchant in the city of Murom on July 30th, 1889 Vladimir Zvorykin used to spent his summer holidays on board his father’s ship sailing along the Oka River. Out of pleasure he helped repair and maintain the ship’s electrical equipment and since then took an interest in electrical engineering. After becoming an engineer Zvorykin underwent training in France. In August 1917 he and a group of other engineers who were to buy arms for Russia went on a business trip to Europe. Soon afterwards the Bolshevik Revolution shook Russia and Zvorykin never came back.*
===
http://www.davidsarnoff.org/vkz.html
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