Nimo was the trademark of a family of small

cathode-ray tube A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms (oscilloscope), pictur ...

(CRTs) used for numerical displays. They were manufactured by

Industrial Electronic Engineers Industrial Electronic Engineers, Inc. (IEE; sometimes spelled Industrial Electronics Engineers), is an American electronics company based in Van Nuys, California. Founded by Donald Gumpertz in 1946, the company is best known for its electronic di ...

(IEE) around the mid-1960s. The tube had ten

electron gun An electron gun (also called electron emitter) is an electrical component in some vacuum tubes that produces a narrow, collimated electron beam that has a precise kinetic energy. The largest use is in cathode-ray tubes (CRTs), used in nearly ...

s with

stencil Stencilling produces an image or pattern on a surface, by applying pigment to a surface through an intermediate object, with designed holes in the intermediate object, to create a pattern or image on a surface, by allowing the pigment to reach ...

s that shaped the

electron beam Cathode rays or electron beam (e-beam) are streams of electrons observed in discharge tubes. If an evacuated glass tube is equipped with two electrodes and a voltage is applied, glass behind the positive electrode is observed to glow, due to ele ...

as digits.

Details

The Nimo tube operated on a similar principle as the

charactron Charactron was a U.S. registered trademark (number 0585950, 23 February 1954) of Consolidated Vultee Aircraft Corporation (Convair) for its shaped electron beam cathode ray tube. Charactron CRTs performed functions of both a display device and a r ...

, but used a much simpler design. They were intended as single digit, simple displays, or as four or six digits by means of a special horizontal magnetic deflection system. Having only three electrode types (a

filament The word filament, which is descended from Latin ''filum'' meaning " thread", is used in English for a variety of thread-like structures, including: Astronomy * Galaxy filament, the largest known cosmic structures in the universe * Solar filament ...

, an

anode An anode is an electrode of a polarized electrical device through which conventional current enters the device. This contrasts with a cathode, an electrode of the device through which conventional current leaves the device. A common mnemonic is ...

and ten different grids), the driving circuit for this tube was very simple, and as the image was projected on the glass face, it allowed a much wider viewing angle than, for example,

Nixie tube A Nixie tube ( ), or cold cathode display, is an electronic device used for displaying numerals or other information using glow discharge. The glass tube contains a wire-mesh anode and multiple cathodes, shaped like numerals or other symbols ...

s, which Nimo tried to replace. The tube required 1750 volts

direct current Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or even ...

(DC) for the anode and also required 1.1 volts for the filaments, as well as a cathode bias for the filaments that enables or disables the display of a character on a specific tube. This allows the display tubes to be multiplexed, simplifying the interface circuitry. The German tube manufacturer

Telefunken Telefunken was a German radio and television apparatus company, founded in Berlin in 1903, as a joint venture of Siemens & Halske and the ''Allgemeine Elektrizitäts-Gesellschaft'' (AEG) ('General electricity company'). The name "Telefunken" app ...

tried to sell an unlicensed copy of the design under the type number XM1000, but was sued by IEE in 1969 and lost, having to destroy all tubes already produced. Only a few survived, most of them not yet labeled.

References

External links

* by

Fran Blanche Frantone Electronics is an American Philadelphia-based hand-made effects pedal manufacturer founded and run by Fran Blanche. Blanche operates a YouTube channel where she discusses the company's history and showcases various electronics projects. ...

* {{YouTube, xmWg7CtN0Ac, title="Developing the Nimo Display Tube – The Untold Story!" with original documents from the original engineers, link=no by Fran Blanche Cathode ray tube Television technology Vacuum tube displays

Details

See also

References

External links