Method and apparatus for detecting the location of a light detecting pen on a gas discharge display panel
US4139803A · kind A · utility
5Cited by
8References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1976 |
| Grant date | Feb 13, 1979 |
| Priority date | — |
| Expiry date | Nov 12, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0386
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In conjunction with an AC plasma display panel a light detecting pen is employed to designate coordinate points on the panel. Circuitry is employed to scan the electrodes of the panel with sustain voltage pulses at predetermined intervals and determine the coincidence of a selectively applied sustain voltage pulse with light detected by the light pen to indicate the location of the light pen with respect to the panel. A negative scanning method is also disclosed wherein coincidence between a sustain voltage pulse which is selectively not applied and the non-detection of light indicates the location.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.