Charactron was a
U.S. registered trademark
The registered trademark symbol, , is a typographic symbol that provides notice that the preceding word or symbol is a trademark or service mark that has been registered with a national trademark office. A trademark is a symbol, word, or wo ...
(number 0585950, 23 February 1954) of Consolidated Vultee Aircraft Corporation (
Convair
Convair, previously Consolidated Vultee, was an American aircraft manufacturing company that later expanded into rockets and spacecraft. The company was formed in 1943 by the merger of Consolidated Aircraft and Vultee Aircraft. In 1953, ...
) for its shaped electron beam
cathode ray tube. Charactron CRTs performed functions of both a display device and a
read-only memory
Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing s ...
storing multiple characters and fonts. The similar Typotron was a 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.
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 tube of the AN/FSQ-7 SAGE
Semi Automatic Ground Environment
The Semi-Automatic Ground Environment (SAGE) was a system of large computers and associated networking equipment that coordinated data from many radar sites and processed it to produce a single unified image of the airspace over a wide area. SA ...
computer console.
# Photographic output — where the display screen was photographed by a
microfilm
Microforms are scaled-down reproductions of documents, typically either films or paper, made for the purposes of transmission, storage, reading, and printing. Microform images are commonly reduced to about 4% or of the original document size. F ...
camera for recording of computer generated data. The Stromberg-Carlson SC-4000 series system was a typical use of the tube
The technical expertise, and trademarks, for the Charactron ultimately passed to
Stromberg-Carlson
Stromberg-Carlson was a telecommunications equipment and electronics manufacturing company in the United States. It was formed in 1894 as a partnership by Swedish immigrants Alfred Stromberg (1861 Varnhem, Sweden - 1913 Chicago) and Androv Car ...
,
General Dynamics
General Dynamics Corporation (GD) is an American publicly traded, aerospace and defense corporation headquartered in Reston, Virginia. As of 2020, it was the fifth-largest defense contractor in the world by arms sales, and 5th largest in the Un ...
, Stromberg DatagraphiX,
Anacomp
Anacomp, Inc., is an American company that specializes in computer services and document management. It was founded in Indianapolis, Indiana, in 1968 by Ronald D. Palamara, Robert R. Sadaka, and J. Melvin Ebbert, three professors at Purdue Univ ...
, and finally Lexel Imaging Systems.
Patents
*
*
See also
*
Nimo tube
References
External links
Description of a Direct view Charactron used on a UNIVAC 1107 computer in the late 1960s*
* ttp://bitsavers.org/pdf/ibm/sage/3-62-0_Display_System_Vol1_Aug58.pdf Theory of Operation for the SAGE display system. Detailed description of Charactrons Page 37 ff.
Vacuum tube displays
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