|
Kenjiro Takayanagi among Worlds Premier Innovators
In Japan, Hamamatsu Industrial High School, Waseda University, and other
institutions began studies on television at the end of the Taisho era.
It is said that Kenjiro Takayanagi became determined to work on television
when he saw a picture in a French magazine illustrating a future television.
Kenjiro Takayanagi (1899-1990) had already begun studies on a television
set using an electric device for both imaging and image reception by
1925. Later, due to the technical and experimental conditions, Takayanagi
constructed a system that utilized a mechanical Nipkow disk and a photoelectric
tube in the transmitting device, and an electric Braun tube in the receiving
device. He succeeded in displaying a clear image of the character
on a Braun tube on December 25, 1926 (on a mechanical and electrical
system with 40 scanning lines). His research progressed
to the successful experimental TV transmission of an image of a person
in 1928 (40 scanning lines, 14 frames/second)
In 1930, at the 5th anniversary exhibition of radio broadcasting, two
TV systems, one from Hamamatsu Industrial High School and one from Waseda
University, were demonstrated and experiments conducted. The experiment
by Professors Tadaoki Yamamoto and Masataro Kawarada of Waseda University
gained favorable comments with its 60 scanning line, 125 frames per
second resolution image projected on a five-foot square display.
All-electric TV System Completed
The NHK Science & Technical Research Laboratories, which was established
in 1930, also initiated research on television around this time. Takayanagi
successfully conducted a TV experiment with a 100 scanning line, 20
frames per second system, and Tokyo Denki K.K. conducted an experiment
using a 120 scanning line system employing a Farnsworth tube.
This was followed by the invention of an image pickup tube iconoscope
by Zworykin of the United States in 1931, a development which shocked
the world. Immediately afterwards, Takayanagis team test manufactured
an iconoscope by themselves (220 scanning lines, 20 frames/second), and
completed an all-electric TV system with 245 scanning lines, interlaced
scanning, and 30 frames per second transmission. Further improvements
were made by Takayanagis team, and in 1937, they fabricated
TV set with 441 scanning lines at 30
frames per second, which at the time was the worlds best and
is almost equivalent to the present TV system.
In 1939, NEC and Toshiba developed the first domestic TV set.
Resolution Focus of Global Competition in the 1930s
The 1930s saw preparations for implementing TV broadcasting in Europe.
This was especially true in Germany, where preparations for broadcast
of the 1936 Berlin Olympics had been mandated with a government initiative
and the claim that the countrys prestige was at stake. Experimental
TV broadcasting first started in March 1935 in Germany, with a 180 scanning
line system (increased to 441 scanning lines in 1937). France also launched
a test broadcast using the same 180 scanning line system in April of
the same year. The first regular TV broadcasting in the world originated
in Britain and employed the epoch-making 405 scanning line system. In
Japan, the Television Research Committee adopted a provisional standard
of a 441 scanning line, 25 frames per second, interlaced scanning system
in 1938.
1. Milestones
of great Japanese
|

Reproduction of character
(NHK Broadcasting Museum)

Takayanagi lectures on TV at the National Science Museum
(The National Science Museum)
Takayanagi (second from left) with an image-transmitting device at
an exhibition in 1930 (Hamamatsu Electronics Promotion Association)
Waseda University TV system experiment (1933)

Image from an early Waseda University TV system (Wyler mirror is used
in the receiving set)
|