Touch sensitive key switch device

摘要

The switch has emitters and receivers (14) arranged along a control panel to emit and receive electromagnetic rays, respectively. A control and evaluating unit (18) is connected with the emitters and receivers to control the emitters in a temporarily offset manner and compare temporarily offset reception signals of the receivers to find the position of operating units of the panel. The emitters are connected with the unit in groups. An independent claim is also included for an operating system for an electronic household appliance with a touch sensitive key switch.