Abstract: A capacitive sensor for detecting the movement of an object, such as actuation of a key of an operating unit, includes first and second electrodes that are provided for connection or mechanical coupling to or arrangement on the object, the distance of which second electrode from the first electrode changes when the object moves. The electrodes form a first capacitor with a volume between the electrodes, the size of which changes when the object moves. An evaluation unit determines a change of capacitance between the two electrodes resulting from a change of their spacing and volume. A deformable, non-gaseous first dielectric is arranged between the electrodes and defines at least one gas volume that is filled by a gaseous second dielectric that can escape from the gas volume when the two electrodes approach one another.

Abstract: The capacitive sensor for detecting the movement of an object, particularly for detecting the actuation of a key of an operating unit, is furnished with a first electrode (30; 32) and a second electrode (34; 36) which is provided for connection or mechanical coupling to or arrangement on the object, the distance of which second electrode from the first electrode changes (30; 32) when the object moves. The two electrodes (30, 34; 32, 36) form a first capacitor (26; 28) with a volume (40) between the electrodes (30, 34; 32, 36), the size of which changes when the object moves. An evaluation unit (38), which is connected to the two electrodes (30, 34; 32, 36) and determines a change of capacitance between the two electrodes (30, 34; 32, 36) resulting from a change of their spacing and volume, is further provided. A deformable, non-gaseous first dielectric (42) is arranged between the two electrodes (30, 34; 32, 36).