A wristwatch is essentially a high density micro mechanism that includes a power supply, oscillator, control and drive circuits, micromotor, micro transfer mechanism, micro sensor and display elements.
The key technology behind this micro mechanism is the micro motor. SII successfully launched mass production of the world's smallest ultrasonic motor (4.5mm diameter by 2.5mm thick), and incorporated it in wristwatches as the actuator for the fully-automatic calendar. Highly evaluated for its small size, low voltage operation using a simple drive circuit, and application in wristwatches, the ultrasonic micromotor received the Aoki Award from the Horological Institute of Japan, the Technology Award from the Japan Society for Precision Engineering, and the Japan Society for the Promotion of Machine Industry Prize.
We have also developed many types of ultrasonic micro-motors, with a focus on downsizing.