Embedded self-test for rain sensors
First Claim
Patent Images
1. A sensor for detecting moisture on an outside surface of a windshield, said sensor comprising:
- an emitter circuit for emitting light energy;
a detector circuit for receiving light energy;
a processor for controlling the emitter circuit and processing signals received from the detector circuit; and
a self test circuit connected between the processor and the emitter circuit, the self test circuit being operably associated with the emitter circuit for generating a test signal for simulating the presence of moisture on the outside surface of the windshield.
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Abstract
A sensor for detecting moisture on an outside surface of a windshield is disclosed. The sensor includes an emitter circuit for emitting light energy, and a detector circuit for receiving light energy. A processor controls the emitter circuit and processes signals received from the detector circuit. A self test circuit is connected between the processor and the emitter circuit, the self test circuit is operably associated with the emitter circuit for generating a test signal for simulating the presence of moisture on the outside surface of the windshield.
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Citations
20 Claims
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1. A sensor for detecting moisture on an outside surface of a windshield, said sensor comprising:
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an emitter circuit for emitting light energy; a detector circuit for receiving light energy; a processor for controlling the emitter circuit and processing signals received from the detector circuit; and a self test circuit connected between the processor and the emitter circuit, the self test circuit being operably associated with the emitter circuit for generating a test signal for simulating the presence of moisture on the outside surface of the windshield. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A rain sensor for detecting moisture on an outside surface of a windshield, said rain sensor comprising:
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a photoemitter circuit for transmitting infrared light energy into the windshield; a photodetector circuit for receiving light energy which is internally reflected from the outside surface of the windshield; a processor for controlling the photoemitter circuit and processing signals received from the photodetector circuit; a windshield wiper circuit connected to the processor for receiving control signals from the processor; and a self test circuit connected between the processor and the photoemitter circuit, the self test circuit including a resistor connected to ground via a transistor, the processor being connected to the transistor for biasing the transistor between an on state and an off state for generating a test signal for simulating the presence of moisture on the outside surface of the windshield. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A method for testing a rain sensor circuit for detecting moisture on the outside surface of a windshield comprising:
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providing an emitter circuit for transmitting light energy, said emitter circuit including a photoemitter in series with a first resistor for conducting current through the photoemitter; providing a detector circuit for receiving light energy; providing a processor for controlling the emitter circuit and processing signals received from the detector circuit; providing a self test circuit connected between the processor and the emitter circuit, the self test circuit including a second resistor in parallel with the first resistor, the second resistor being connected to ground via a transistor; generating a pulse signal for biasing the transistor; and switching the transistor between an on state and an off state, the transistor changing the current through the photoemitter. - View Dependent Claims (18, 19, 20)
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Specification