Electronic timepiece
US4443116A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 1982 |
| Grant date | Apr 17, 1984 |
| Priority date | — |
| Expiry date | Jan 6, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L1/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electronic timepiece is provided with a timebase signal source comprising a relatively low frequency quartz crystal oscillator circuit and with means for compensating the timebase signal frequency for the effects of temperature changes on the low frequency oscillator circuit, and further with means for comparing the timebase signal frequency with the frequency of a relatively high frequency quartz crystal oscillator circuit having high stability against aging changes, to thereby compensate for changes in the timebase frequency caused by aging of the low frequency quartz crystal vibrator, this comparison being carried out only within a specific narrow range of operating temperatures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.