Switch operating device, mobile device and method for operating a switch by a presence of a part emitting heat

A switch operating device comprising:

• a presence sensor adapted to operate a switch in response to presence on the presence sensor of a heat emitting part, wherein the presence includes an approach phase during which the part approaches the presence sensor, a remaining phase during which the part remains in proximity of the presence sensor, and a withdrawal phase during which the part is moved away from the presence sensor, wherein the presence sensor is adapted to detect heat emitted by the part with at least one pixel comprising a thin film that comprises pyroelectric material and to output per pixel a signal with signal deflections indicative of a temporal intensity curve of the heat detected by the pixel,
• a signal processing unit with which the approach phase and the withdrawal phase are determined from the temporal succession and a shape of the signal deflections, and
• an actuator controlled by the signal processing unit and adapted to operate the switch when the approach phase, the remaining phase and/or the withdrawal phase (41) is determined.