| 摘要 |
PURPOSE:To easily secure a high accuracy, by providing an emergency mechanism which is capable of controlling for a gain/losing with an external operation plus another emergency mechanism which is capable of controlling the same in a circuit block state or in a movement state and incapable of controlling with an external operation. CONSTITUTION:An electronic wristwatch is provided with not only a logical emergency mechanism A which emerges by an external operation but another emergency mechanism B which is incapable of operation from outside and has no change even with an exchange of battery. With said mechanism B, a nominal accuracy of about + or -15 seconds per month can be secured. In other words, the mechanism B is provided with a quartz oscillator 31 and a trimmer capacitor 32, and the oscillation frequency of the oscillator 31 is controlled by varying the capacity of the capacitor 32. Thus an emergency is given to the time rate. In such way, the mechanism B adapts such system in which the degree of emergency has no change although the primary power source is removed when exchanging the battery. Thus the nominal accuracy of the wristwatch is ensured by the mechanism B only to secure the nominal accuracy at all times. |
