In a typical implementation of the operating unit, said operating unit is a touchpad or a touchscreen with a touch-sensitive surface.

Typically, it is provided that the operating unit is configured to detect a valid actuation as a function of the actuation pressure or actuation force or the course of the actuation pressure or actuation force.

In a further expedient embodiment of the invention, the actuator can be designed as a tension rod magnet, as a plunger coil drive or as a piezo drive.

In the following the invention is further described with reference to the drawings. The drawings show different diagrams which were already discussed above and will be discussed below.

As described above, the mass-spring system has resonance frequencies with which it oscillates, provided that it is excited accordingly. The receptors for haptic sensation in the finger predominantly respond to frequencies below a cut-off frequency of e.g. 200 Hz. If the mechanical system can be designed such that its resonance frequencies are all above this threshold, e.g. 200 Hz, then a haptically well perceptible pulse can be generated which cannot post-oscillate at all.

The first resonance frequency of a mass-spring system follows the equation