By Mary Bellis
Return to The History of Television
CRT and Television
Electronic television is based on the development of the cathode ray tube - CRT - which is the picture tube found in modern television sets. A cathode ray tube or CRT is a specialized vacuum tube in which images are produced when an electron beam strikes a phosphorescent surface. Television sets, computers, automated teller machines, video game machines, video cameras, monitors, oscilloscopes and radar displays all contain cathode-ray tubes. Phosphor screens using multiple beams of electrons have allowed CRTs to display millions of colors.
The first cathode ray tube scanning
device was invented by the German scientist Karl
Ferdinand Braun in 1897. Braun introduced a CRT with a fluorescent
screen, known as the cathode ray oscilloscope. The screen would emit a
visible light when struck by a beam of electrons. In 1907, the Russian
scientist Boris Rosing (see Zworykin)
used a CRT in the receiver of a television system that, at the camera end,
made use of mirror-drum scanning. Rosing transmitted crude geometrical
patterns onto the television screen and was the first inventor to do so
using a CRT. The first practical signal generating
tubes were invented by Vladimir K. Zworykin and Philo
T. Farnsworth. Zworykin invented the iconoscope, which became the
imaging iconoscope. Farnsworth invented the image dissector.
Highlights of CRT History
1855 - German, Heinrich Geissler invents the Geissler tube, created using his mercury pump this was the first good evacuated (of air) vacuum tube later modified by Sir William Crookes.
1859 - German mathematician and physicist, Julius Plucker experiments with invisible cathode rays. Cathode rays were first identified by Julius Plucker.
1878 - Englishmen, Sir William Crookes was the first person to confirm the existence of cathode rays by displaying them, with his invention of the Crookes tube, a crude prototype for all future cathode ray tubes.
1897 - German, Karl Ferdinand Braun invents the CRT oscilloscope - the Braun Tube was the forerunner of today's television and radar tubes.
1929 - Vladimir Kosma Zworykin invented a cathode ray tube called the kinescope - for use with a primitive television system.
1931 - Allen B. Du Mont made the first commercially practical and durable CRT for television.
The
Cathode Ray Tube - 1855 to 1896
Timeline of the development of the
CRT prior to the invention of the Braun tube.
Cathode
Rays and the Discovery of the Electron
Several inventors including Karl
Braun who created innovations based on the science of the cathode ray and
the electron.
How
A CRT Works
How
A CRT Works in a Television
Oscilloscopes
The oscilloscope is an electronic display device containing a cathode ray tube (CRT), used to produce visible patterns that are the graphical representations of electrical signals.
Karl
Ferdinand Braun
Karl Ferdinand Braun was the German
physicist who shared the Nobel Prize for Physics in 1909 with Guglielmo
Marconi for the development of wireless telegraphy.
Braun is also known as the developer of the CRT oscilloscope. He demonstrated
the first oscilloscope in 1897, after work on high frequency alternating
currents.
Vladimir
Kosma Zworykin 1889-1982
Vladimir Kosma Zworykin invented
the kinescope in 1929 for television transmission. Zworykin also invented
the iconoscope, an early television camera. See the personal photographs
of television pioneer, Dr. Vladimir Kosma Zworykin and read about Vladimir
Zworykin and television history.
William
Coolidge
William Coolidge obtained a patent
for an improved cathode ray tube in 1935, a critical ingredient of TV.
and other electronic applications.
Definitions: Source Encyclopedia Britannica
- A cathode is a terminal or electrode at which electrons enter a system, such as an electrolytic cell or an electron tube.
- A cathode ray is a stream of electrons leaving the negative electrode, or cathode, in a discharge tube (an electron tube that contains gas or vapor at low pressure), or emitted by a heated filament in certain electron tubes.
- A cathode ray tube is a vacuum tube that produces images when its phosphorescent surface is struck by electron beams.
- A vacuum tube is an electron tube consisting of a sealed glass or metal enclosure from which the air has been withdrawn.
Vacuum Tubes
Television
Telegraphy
sources IEEE & USPTO
photo FCC
