Head-rest for motor vehicle seat, has electronic switch setting resonance variation with respect to reference resonant circuit, and information about relative position of head relative to head-rest is obtained from in-reference-position

摘要

The head-rest has a detection device for detecting a position of a head (17) of a passenger (14) relative to the head-rest by setting alternating voltage between electrodes (25c) of an electrode arrangement (21). The device is attached to an electronic switch. A measurement resonant circuit experiences a resonance variation due to a presence of the head opposite to an unloaded condition. The switch sets the variation with respect to a reference resonant circuit, and information about the relative position of the head relative to the head-rest is obtained from an in-reference-position.