| 摘要 |
A system (20) for the detection of an obstruction in the path of a closing window (14) which is movable by an electric motor (16) and which has an edge (18) receivable in a portion (10) of a window frame (12) on closing of the window, the system comprising a dielectric waveguide (22) mountable on the portion of the window frame; a high frequency transmitter (24) connected to one end (30) of the waveguide for transmitting a high frequency signal into the waveguide to produce an evanescent field; a high frequency receiver (26) connected to the other end (32) of the waveguide for receiving the evanescent field; and a control unit (28) for monitoring the evanescent field received by the receiver, the control unit being connectable to the electric motor to control the operation of the motor dependent on the signal received by the receiver. <IMAGE> |
