Single connection gas discharge display and driver
US4742278A · kind A · utility
Inventor
Key dates
| Filing date | Jun 3, 1987 |
| Grant date | May 3, 1988 |
| Priority date | — |
| Expiry date | Jun 3, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J17/38
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A new method and apparatus for driving a neon display tube or the like. The tube, containing an ionizable gas, has only a single cathode element at one end in contact with the gas. A power source connected to ionize the gas and cause illumination thereof wherein the power source is connected to the single cathode element and produces alternating voltage referenced to ground potential and of sufficient frequency to cause the gas to ionize through the natural surrounding capacitance between the ionized gas and ground potential. In the preferred embodiment, the power source produces an increasing voltage ramp output whereby the ionization of the gas in the tube moves as a localized ionization along the tube in a direction away from the single cathode element. The voltage ramp may start at a level to cause initial ionization of the gas adjacent the single cathode element, rise to a level to cause final ionization of the gas adjacent the end of the tube oppose the single cathode element, and rise at a rate to produce a visible progression of illumination from one end of the tube to the other whereby an illuminated handwriting effect is created by the progressive illumination of the tube…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.