Touch-control setting button for water-tight electronic watch - has seal preventing ingress of moisture or dust, and fixed operating button insulated from watch case

摘要

The setting button for an electronic watch has an operating element fitting into an opening in the conductive watch case and insulated from the latter via a surrounding seal, the operating element lying at a different potential to the watch case. The operating element fits securely into the opening in the watch case with further movement after its initial insertion being prevented. Its outer surface is curved and projects from the outside surface of the watch case by about 0.5mm. The inside end surface of the operating element has a similar curvature and lies in permanent contact with a contact spring of the electronic timepiece module. The timepiece module has an input circuit for the setting button with a pull-up resistance of between 50 and 100 M0 and only activated when the button is contacted for at least 200 mseconds.