| 摘要 |
A device for detecting the environmental change of a windshield comprises a plane capacitor which is disposed on the inner surface of the windshield, two electrodes of said plane capacitor are disposed on the same surface, the area of the two electrodes is less than 100 sq.centimetres, said plane capacitor is a sense element which detects the environmental change of windshield and the envirom-nental change after operating, said plane capacitor is electrically connected to a sensor detection circuit, the change signal in capacitance which is affected by the environment is transmitted to said sensor detection circuit, said sensor detection circuit is responsive to the change of capacitance to produce a control signal which controls the device. The structure of this device is simple, the known photoelectric capacitor and a plan capacitor detection device have disadvantages that the measure area is small and the installation is difficult, they can not measure the thickness of rain and be easy to be affected by dirt, they have poor adaptability and the cost is high, said device can solve above-described problems.
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