衝撃スイッチシステムの開発と腕時計への応用 (1988年秋季講演会発表) Development of System with a Built-In Shock Sensor and Application to a Watch
We have developed a watch with a shock-sensor for sports-men. This shock sensor is a piezo-electric element which is set up on a back cover of the watch. In this report, the systems are described which eliminate noise from the watch on wearing and operate correctly when the watch is tapped. Since it uses the shock sensor for the start-stop operation of the stopwatch time measuring system, this watch is useful for the sportsman who will measure his training time by himself.
日本時計学会誌 (128), 17-26, 1989-03-20