Charactron
Encyclopedia
Charactron was U. S. registered trademark (number 0585950, 23 February 1954) by Consolidated Vultee Aircraft Corporation (Convair
) for its shaped electron beam cathode ray tube
. Charactron CRTs performed functions of both a display device and a read-only memory
storing multiple characters and fonts. Typotron was U. S. registered trademark (23 November 1953) of Hughes Aircraft Corporation for its type of shaped electron beam storage tube
with a direct-view bistable storage screen.
The Charactron CRT used an electron beam to flood a specially patterned perforated anode that contained the stencil patterns for each of the characters that it could form. The first deflection positioning of the electron beam steered the beam to pass through one of the (typically 64 or 116) characters and symbols that could be formed. The beam, which then had the cross-section of the desired character, was re-centered along the axis of the tube and deflected to the desired position of the screen for display. Alternately, as in the accompanying image, the entire matrix was filled with the electron beam then deflected through a selection aperture to isolate one character.
The term Charactron is sometimes mistakenly applied to another type of CRT properly called a monoscope
which generates an electrical signal by scanning an electron beam of uniform cross section across a printed pattern on an internal target electrode.
The technical expertise -- and trademarks -- for the Charactron ultimately passed to Stromberg-Carlson, General Dynamics, Stromberg DatagraphiX, Anacomp, and finally Lexel Imaging Systems.
Convair
Convair was an American aircraft manufacturing company which later expanded into rockets and spacecraft. The company was formed in 1943 by the merger of Vultee Aircraft and Consolidated Aircraft, and went on to produce a number of pioneering aircraft, such as the Convair B-36 bomber, and the F-102...
) for its shaped electron beam cathode ray tube
Cathode ray tube
The cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
. Charactron CRTs performed functions of both a display device and a read-only memory
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
storing multiple characters and fonts. Typotron was U. S. registered trademark (23 November 1953) of Hughes Aircraft Corporation for its type of shaped electron beam storage tube
Storage tube
Mostly obsolete, a storage tube is a special monochromatic CRT whose screen has a kind of 'memory' : when a portion of the screen is illuminated by the CRT's electron gun, it stays lit until a screen erase command is given...
with a direct-view bistable storage screen.
The term Charactron is sometimes mistakenly applied to another type of CRT properly called a monoscope
Monoscope
A monoscope was a special form of cathode ray tube that was used to generate, rather than display, a video signal. Each tube was only capable of generating a single video signal, hence the name...
which generates an electrical signal by scanning an electron beam of uniform cross section across a printed pattern on an internal target electrode.
Applications
There were two basic types/uses of Charactrons:- Direct view -- where the intended user watched the face of the tube. An example was the 19 inches (482.6 mm) tube of the AN/FSQ-7 SAGE Semi Automatic Ground EnvironmentSemi Automatic Ground EnvironmentThe Semi-Automatic Ground Environment was an automated control system for tracking and intercepting enemy bomber aircraft used by NORAD from the late 1950s into the 1980s...
computer console. - Photographic output where the display screen was photographed by a microfilm camera for recording of computer generated data. The Stromberg-Carlson SC-4000 series system was a typical use of the 5 inches (127 mm) tube
The technical expertise -- and trademarks -- for the Charactron ultimately passed to Stromberg-Carlson, General Dynamics, Stromberg DatagraphiX, Anacomp, and finally Lexel Imaging Systems.