Input/output apparatus and method therefor
US5059749A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 1990 |
| Grant date | Oct 22, 1991 |
| Priority date | — |
| Expiry date | Mar 22, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/046
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An input/output apparatus includes a coordinate input device and a display device which are stacked on each other. The coordinate input device detects position coordinates of an input designating device by (a) intermittently transmitting radio waves from a tablet to excite a tuned circuit incorporated in the input designating device and (b) receiving radio waves generated by the tuned circuit while transmission of radio waves by the tablet is suspended. The times while the display data latch pulses are generated in the display device is synchronized with the transmission of radio waves from the tablet in the coordinate input device. In consequence, noise is not generated in synchronism with the generation of the display data latch pulses while the tablet receives the radio waves, so noise is not imposed on a signal received by the tablet. As a result, there is no reduction in the accuracy with which position is detected on the basis of the received radio waves and malfunction of the apparatus is substantially eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.