Lighting and/or indicating apparatus for use in foggy conditions
First Claim
1. A fog lamp unit in a vehicle, comprising a combining circuit having a first input and a second input, a relative humidity detecting device having an output connected to said first input of the combining circuit, and a visibility detecting device having an output connected to said second input of the combining circuit, said combining circuit having an output for connection to at least one fog lamp unit of the vehicle, whereby the combining circuit combines signals received from said detecting devices so as to produce command signals for illumination and extinction of said at least one fog lamp unit of the vehicle.
1 Assignment
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Accused Products
Abstract
A lighting and indicating apparatus for a motor vehicle, for use in poor visibility. The unit includes a fog lamp and apparatus for automatically detecting the presence of poor visibility. The control system for automatic control of the lighting and indicating apparatus includes a humidity detecting circuit and an optical visibility detecting circuit, the outputs from which are combined by a combining circuit, the combined signal then being processed so as to control lighting or extinction of the fog lamp.
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Citations
9 Claims
- 1. A fog lamp unit in a vehicle, comprising a combining circuit having a first input and a second input, a relative humidity detecting device having an output connected to said first input of the combining circuit, and a visibility detecting device having an output connected to said second input of the combining circuit, said combining circuit having an output for connection to at least one fog lamp unit of the vehicle, whereby the combining circuit combines signals received from said detecting devices so as to produce command signals for illumination and extinction of said at least one fog lamp unit of the vehicle.
- 4. A fog lamp unit in a vehicle comprising, a combining circuit having a first input and a second input, a relative humidity detecting device having an output connected to said first input of the combining circuit, and a visibility detecting device having an output connected to said second input of the combining circuit, said combining circuit having an output for connection to at least one fog lamp unit of the vehicle, whereby the combining circuit combines signals received from the said detecting devices so as to produce command signals for illumination and extinction of said at least one fog lamp unit of the vehicle, wherein the visibility detecting device comprises an emitter connected to the terminals of an infra-red emitting diode, said diode emitting a beam of infra-red radiation, and further comprising infra-red radiation receiving means for receiving said infra-red radiation as said radiation is retrodiffused towards said receiving means, said receiving means comprising an infra-red receiving diode.
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7. A fog lamp unit in a vehicle comprising, a combining circuit having a first input and a second input, a relative humidity detecting device having an output connected to said first input of the combining circuit, and a visibility detecting device having an output connected to said second input of the combining circuit, said combining circuit having an output for connection to at least one fog lamp unit of the vehicle, whereby the combining circuit combines signals received from the said detecting devices so as to produce command signals for illumination and extinction of said at least one fog lamp unit of the vehicle, wherein the humidity detecting device comprises a sensor consisting of a first capacitor having a dielectric constant dependent upon the relative humidity, and an oscillator for generating oscillations of predetermined period, the sensor being connected to said oscillator for receiving said oscillations, and further comprising first datum value setting means connected to a first comparator which is also connected to the sensor for comparing the output signals from the sensor with a first datum value predetermined by the first setting means.
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8. A fog lamp unit in a vehicle comprising, a combining circuit having a first input and a second input, a relative humidity detecting device having an output connected to said first input of the combining circuit, and a visibility detecting device having an output connected to said second input of the combining circuit, said combining circuit having an output for connection to at least one fog lamp unit of the vehicle, whereby the combining circuit combines signals received from the said detecting devices so as to produce command signals for illumination and extinction of said at least one fog lamp unit of the vehicle, wherein the humidity detecting device comprises a sensor consisting of a first capacitor having a dielectric constant which depends on the relative humidity, and an oscillator for generating oscillations of predetermined period, the sensor being connected to said oscillator for receiving said oscillations, and further comprising first datum value setting means connected to a first comparator which is also connected to the sensor for comparing the output signals from the sensor with a first datum value predetermined by the first setting means, wherein the visibility detecting device comprises an emitter connected to the terminals of an infra-red emitting diode, whereby said diode causes a beam of infra-red radiation to be emitted, and further comprising infra-red radiation receiving means for receiving said infra-red radiation when said radiation is retrodiffused towards said receiving means, said receiving means comprising an infra-red receiving diode, and further including:
- a synchronous detection module having an input connected to the infra-red receiving diode, for receiving therefrom the retrodiffused radiation detection signal, said module having an output; and
oscillator for generating oscillations of predetermined period, connected to the synchronous detection module;
an amplifier connecting the infra-red emitting diode to said oscillator;
second datum value setting means connected to a second comparator which is also connected to the output of the synchronous detection module for comparing output signals from the synchronous detection module with a second datum value set by the second setting means, the unit further including;
a first diode connected to said first and second comparators for combining the comparison signals therefrom;
power transistor having a grid connected to said first diode or receiving signals representing the combination of said comparison signals as control signals;
a power supply terminal for a fog lamp connected to the drain of said power transistor; and
a first resistor connecting the source of said power transistor to ground. - View Dependent Claims (9)
- a synchronous detection module having an input connected to the infra-red receiving diode, for receiving therefrom the retrodiffused radiation detection signal, said module having an output; and
Specification