Electronic timepiece having an adjustable rate of division and method for its manufacture
US4154053A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 1977 |
| Grant date | May 15, 1979 |
| Priority date | — |
| Expiry date | Apr 20, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04G5/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An internal correction circuit is provided to correct the timepiece error caused by the crystal oscillator frequency changes. The timepiece operates by frequency dividing the oscillator frequency to obtain a predetermined operating frequency. The correction circuit is operated by the user on any initialization point, such as the start of any minute from a reference time source to generate a first input signal. The user at any following minute of the reference time source generates a second input signal. The correction circuit counts a first and second number of time units of different lengths between the first and second input signals. The circuit then forms a division ratio from the first and second numbers. That ratio is used to change the frequency divider division ratio to adjust the watch for the crystal frequency error just calculated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.