Coordinate input apparatus with pen and finger input detection
US5790106A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1995 |
| Grant date | Aug 4, 1998 |
| Priority date | — |
| Expiry date | Nov 14, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0446
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A coordinate input apparatus which performs an input operation with high precision by use of either an operator's finger or an input pen. The input apparatus includes a tablet having a plurality of X electrodes and Y electrodes arranged in the form of a matrix on the respective top and bottom surfaces of a glass substrate. The input apparatus also has a first oscillation circuit connected to the X electrodes through an analog switch. It is further provided with an input pen containing a second oscillation circuit. When the pen is used to perform the input operation through use of coordinates, the following method of determining the coordinates designated by the pen is employed. A voltage oscillating from the pen is applied to each electrode through capacitance, and the resulting output voltage varies depending on the distance from each electrode to the pen. Based on the varied output voltages, a predetermined computation process is executed to determine the coordinates designated by the pen. On the other hand, when the operator's finger is used to perform the input operation, the analog switch is switched to the first oscillation circuit. Then, a voltage at a predetermined frequenc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.