Coordinate input apparatus and method
US5539678A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 4, 1994 |
| Grant date | Jul 23, 1996 |
| Priority date | — |
| Expiry date | May 4, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0433
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
When vibration is entered on a vibration transmitting tablet, the vibration is sensed by vibration sensors attached at four corners of the tablet. When this is done, a time delay from entry of the vibration to detection thereof is measured, and the distance between each sensor and the source of the vibration is calculated in dependence upon the time delay. At this time the vibration sensors also sense reflected waves resulting from reflection of the vibration at the end face of the tablet. The larger the angle of reflection, the greater the magnitude of the reflected waves sensed. Accordingly, sensors most likely to sense reflected waves are excluded from calculation, and coordinates are calculated based upon vibration sensed by the remaining sensors only. As a consequence, a discontinuity in coordinates occurs at the boundary of a region decided by whichever of the sensors are excluded. For this reason, a weighted mean is computed of a set of coordinates calculated based upon data obtained from a set of a plurality of sensors, and the value of the weighted mean is adopted as the coordinates sought.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.