Electronic watch with touch-sensitive keys
US4257117A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 4, 1979 |
| Grant date | Mar 17, 1981 |
| Priority date | — |
| Expiry date | Apr 4, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/962
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Touch sensitive key switches of an electronic watch which control functions of the watch such as time setting, are gated to reduce the power consumption of the watch. The key switches are capacitive and are fed signals derived from the time standard oscillator of the watch. A change in the key switch signals when the switches are touched by the user activate the time setting functions. Gates are provided coupling the signals derived from the oscillator to the key switches so that the signals are applied to the key switches either under control of the user or during repetitive time periods, reducing the time the signals are applied to the key switches and the power necessary to continuously supply such signals to the key switches.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.