26 August 2014
Miniature portable radio that used transistors and
created a new mass market for electronic products.
The people behind the invention:
John Bardeen (1908-1991), an American physicist
Walter H. Brattain (1902-1987), an American physicist
William Shockley (1910-1989), an American physicist
Akio Morita (1921-1999), a Japanese physicist and engineer
Masaru Ibuka (1907-1997), a Japanese electrical engineer and
A Replacement for Vacuum Tubes
The invention of the first transistor by William Shockley, John
Bardeen, andWalter H. Brattain of Bell Labs in 1947 was a scientific
event of great importance. Its commercial importance at the time,
however, was negligible. The commercial potential of the transistor
lay in the possibility of using semiconductor materials to carry out
the functions performed by vacuum tubes, the fragile and expensive
tubes that were the electronic hearts of radios, sound amplifiers,
and telephone systems. Transistors were smaller, more rugged,
and less power-hungry than vacuum tubes. They did not suffer
from overheating. They offered an alternative to the unreliability
and short life of vacuum tubes.
Bell Labs had begun the semiconductor research project in an effort
to find a better means of electronic amplification. This was
needed to increase the strength of telephone signals over long distances.
Therefore, the first commercial use of the transistor was
sought in speech amplification, and the small size of the device
made it a perfect component for hearing aids. Engineers from the
Raytheon Company, the leading manufacturer of hearing aids, were
invited to Bell Labs to view the new transistor and to help assess the
commercial potential of the technology. The first transistorized consumer
product, the hearing aid, was soon on the market. The early
models built by Raytheon used three junction-type transistors and
cost more than two hundred dollars. They were small enough to go
directly into the ear or to be incorporated into eyeglasses.
The commercial application of semiconductors was aimed largely
at replacing the control and amplification functions carried out by
vacuum tubes. The perfect vehicle for this substitution was the radio
set. Vacuum tubes were the most expensive part of a radio set
and the most prone to break down. The early junction transistors
operated best at low frequencies, and subsequently more research
was needed to produce a commercial high-frequency transistor.
Several of the licensees embarked on this quest, including the Radio
Corporation of America (RCA), Texas Instruments, and the Tokyo
Telecommunications Engineering Company of Japan.
Perfecting the Transistor
The Tokyo Telecommunications Engineering Company of Japan,
formed in 1946, had produced a line of instruments and consumer
products based on vacuum-tube technology. Its most successful
product was a magnetic tape recorder. In 1952, one of the founders
of the company, Masaru Ibuka, visited the United States to learn
more about the use of tape recorders in schools and found out that
Western Electric was preparing to license the transistor patent.With
only the slightest understanding of the workings of semiconductors,
Tokyo Telecommunications purchased a license in 1954 with
the intention of using transistors in a radio set.
The first task facing the Japanese was to increase the frequency
response of the transistor to make it suitable for radio use. Then a
method of manufacturing transistors cheaply had to be found. At
the time, junction transistors were made from slices of germanium
crystal. Growing the crystal was not an exact science, nor was the
process of “doping” it with impurities to form the different layers of
conductivity that made semiconductors useful. The Japanese engineers
found that the failure rate for high-frequency transistors was
extremely high. The yield of good transistors from one batch ran as
low as 5 percent, which made them extremely expensive and put the
whole project in doubt. The effort to replace vacuum tubes with
components made of semiconductors was motivated by cost rather
than performance; if transistors proved to be more expensive, then
it was not worth using them.
Engineers from Tokyo Telecommunications again came to the
United States to search for information about the production of
transistors. In 1954, the first high-frequency transistor was produced
in Japan. The success of Texas Instruments in producing the
components for the first transistorized radio (introduced by the Regency
Company in 1954) spurred the Japanese to greater efforts.
Much of their engineering and research work was directed at the
manufacture and quality control of transistors. In 1955, they introduced
their transistor radio, the TR-55, which carried the brand
name “Sony.” The name was chosen because the executives of the
company believed that the product would have an international appeal
and therefore needed a brand name that could be recognized
easily and remembered in many languages. In 1957, the name of the
entire company was changed to Sony.
Although Sony’s transistor radios were successful in the marketplace,
they were still relatively large and cumbersome. Ibuka saw a
consumer market for a miniature radio and gave his engineers the
task of designing a radio small enough to fit into a shirt pocket. The
realization of this design—“Transistor Six”—was introduced in 1957.
It was an immediate success. Sony sold the radios by the millions,
and numerous imitations were also marketed under brand names
such as “Somy” and “Sonny.” The product became an indispensable
part of popular culture of the late 1950’s and 1960’s; its low cost enabled
the masses to enjoy radio wherever there were broadcasts.
The pocket-sized radio was the first of a line of electronic consumer
products that brought technology into personal contact with
the user. Sony was convinced that miniaturization did more than
make products more portable; it established a one-on-one relationship
between people and machines. Sony produced the first alltransistor
television in 1960. Two years later, it began to market a
miniature television in the United States. The continual reduction in
the size of Sony’s tape recorders reached a climax with the portable
tape player introduced in the 1980’s. The SonyWalkman was a marketing
triumph and a further reminder that Japanese companies led
the way in the design and marketing of electronic products.
The transistor reduced the size of electronic circuits and at
the same time the amount of energy lost from them as heat.
Superconduction gave rise to electronic circuits with practically
no loss of energy at all. John Bardeen helped unlock the secrets
Bardeen was born in 1908 in Madison,Wisconsin, where his
mother was an artist and his father was a professor of anatomy
at the University ofWisconsin. Bardeen attended the university,
earning a bachelor’s degree in electrical engineering in 1928
and a master’s degree in geophysics in 1929. After working as a
geophysicist, he entered Princeton University, studying with
Eugene Wigner, the leading authority on solid-state physics,
and received a doctorate in mathematics and physics in 1936.
Bardeen taught at Harvard University and the University of
Minnesota until World War II, when he moved to the Naval
Ordnance Laboratory. Finding academic salaries too low to
support his family after the war, he accepted a position at Bell
Telephone Laboratories. There, with Walter Brattain, he turned
William Shockley’s theory of semiconductors into a practical
device—the transfer resistor, or transistor.
He returned to academia as a professor at the University of
Illinois and began to investigate a long-standing mystery in
physics, superconductivity, with a postdoctoral associate, Leon
Cooper, and a graduate student, J. Robert Schrieffer. In 1956
Cooper made a key discovery—superconducting electrons
travel in pairs. And while Bardeen was in Stockholm, Sweden,
collecting a share of the 1956 Nobel Prize in Physics for his work
on transistors, Schrieffer worked out a mathematical analysis of
the phenomenon. The theory that the three men published since
became known as BCS theory from the first letters of their last
names, and as well as explain superconductors, it pointed toward
a great deal of technology and additional basic research.
The team won the 1972 Nobel Prize in Physics for BCS theory,
making Bardeen the only person to ever win two Nobel Prizes
for physics. He retired in 1975 and died sixteen years later.
See also : Compact disc; FM radio; Radio; Radio crystal sets; Television;
Handy, Roger, Maureen Erbe, and Aileen Antonier. Made in Japan:
Transistor Radios of the 1950s and 1960s. San Francisco: Chronicle
Marshall, David V. Akio Morita and Sony. Watford: Exley, 1995.
Morita, Akio, with Edwin M. Reingold, and Mitsuko Shimomura.
Made in Japan: Akio Morita and Sony. London: HarperCollins, 1994.
Nathan, John. Sony: The Private Life. London: HarperCollins-