腕時計における音叉の高速爪送り機構について

抄録

An electronic wrist watch vith a tuning fork oscillating at h igh frequency, for example 1,000 Hz is studied. The quality factor Q of the tuning fork is measured and, distribution of energy losses is calculated. The amplitude of the tuning fork as a function of Q and the driving current is calculated and the results are compared with the experimental values. The force factor of the transducer is calculated. Then, the characteristics of magnetic circuit of the cup composed of 78 permalloy and alnico magnet is analized and the results are veryfied by experiments. Furthermore, the motion of the indexing wheel was observed using a high speed camera, and even at l,000 Hz, it was observed that the tuning fork advanced the index wheel exactly one tooth for each cycle of vibration.