Nimo tube


Nimo was the trademark of a family of very small non-standard cathode ray tube manufactured by Industrial Electronics Engineers around mid-1960s, with ten electron guns with stencils which shaped the electron beam as digits.

Details

The Nimo tube operated on a similar principle as the charactron, but used a much simpler design. They were intended as single digit, simple displays, or as 4 or 6 digits by means of a special horizontal magnetic deflection system. Having only 3 electrode types, 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 tubes which Nimo tried to replace.
The tube required 1750 volts direct current for the anode and also required 1.1 volts AC for the filaments as well as a cathode bias for the filaments.
The German tube manufacturer Telefunken 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.