Automatically controlled cleaning arrangement in particular for a vehicle windshield
AssigneeSMH Management Services AG
InventorsBenjamin Ittah, Louis Bechet, Marcel Arditi
Life of this patent
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Abstract
An automatically controlled cleaning device (14) for removing visibility-impairing foreign matter, e.g. rain, snow or mud, from the surface of a window such as a motor vehicle windscreen (8). The device uses a sensor such as an ultrasonic transducer (12a, 12b) in which the frequency (f) and the spacing (d) between the transmitter (12a) and the receiver (12b) enable the presence of foreign matter to be detected simply by measuring the phase difference between the transmitted signal and the received signal. This device may be used in automatic wiper systems or the like.
Claims8
Automatically controlled cleaning arrangement intended for the elimination of moist foreign bodies from a glass surface and comprising cleaning means for said surface, activating means for said cleaning means, means for detecting the presence of foreign bodies with the help of an ultrasonic transmitter and receiver arranged on the glass in order to furnish a detection signal representing such presence and control means for operating said activating means in response to the detection signal, characterized in that the frequency (f) of the signal emitted by the transmitter and the distance (d) existing between the transmitter and the receiver are selected in a manner such that the phase difference between said emitted signal and the signal received by the receiver is a maximum in the presence of foreign bodies and in that said control means includes a circuit for measuring said phase difference.
Dependencies are inferred from the claim text.