摘要 |
A device to illuminate a display window (18) is fastened to a carrier (24) separated from the outside by a transparent pane (12). Inside is a sensor which determines movement or the presence of a person outside the pane and it is a radar sensor using microwaves. The sensor signals emitted are suitable for penetrating the pane. As a reaction to the signals, a control unit activates the display lighting. The sensor is a broad-band impulse radar sensor and transmits signals with a frequency lying between one and twenty gigahertz. The control unit has a delay to deactivate the illumination after a certain period. The activation or deactivation is also dependent upon the ambient lighting outside. |