Coordinate input apparatus including a detection circuit to determine proper stylus position
US4818826A · kind A · utility
60Cited by
1References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 25, 1987 |
| Grant date | Apr 4, 1989 |
| Priority date | — |
| Expiry date | Aug 25, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/046
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A coordinate input apparatus includes proximity detecting means for a coordinate pointing tool on an input plane, wherein detection of the coordinates indicated by the pointing tool is performed when the absolute value of the signal level detected by the coordinate pointing tool twice exceeds a predetermined output level during a single scanning operation. When the coordinate pointing tool is dropped or laid on the input plane, the output signal level does not twice exceed the predetermined level within one scanning operation, and consequently, no coordinate detecting operation will be performed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.