Abstract: A method and an assembly for sensing moisture (20) on the exterior surface (22) of a sheet of glass (14) by positioning an imaging lens (16) adjacent to the interior surface (18) of the sheet of glass (14), passing light rays from moisture (20) on the exterior surface (22) of the sheet of glass (14) through the imaging lens (16) and producing first and second successive images of the moisture (20) on the glass (14), and successively directing the first and second images from the lens (16) onto a focal plane detector (12). The focal plane detector (12) is divided into rows of pixels (24) which are ligned into columns. The assembly and method are characterized by scanning the pixels (24) of each row in a first scan (FIG. 4) and producing a reference value X for each pixel (24) in response to an initial image in that pixel (24), scanning the pixels (24) of each row in a second scan (FIG.

Abstract: A system for detecting the presence of rain droplets on a windshield employs a source of radiant energy, such as an LED, and a photodetector installed on the instrument panel of a vehicle. The LED and the photodiode are arranged with respect to one another such that light from the LED cannot reflect directly off the windshield onto the photodiode. Only when the light from the LED is back scattered by an environmental condition, such as the raindrops on the exterior of the windshield, the condensation of moisture on the interior of the windshield, or the presence of smoke in the cabin, will the photodiode receive the light from the LED. Each of these environmental conditions has a predeterminable characteristic signature that permits the processing of data to detect same.

Abstract: An apparatus and method for controlling the operation of the windshield wipers of a vehicle in response to the deposition of water on the exterior of the windshield; the operation of the air conditioning system in response to the formation of water condensation on the interior of the windshield of the vehicle; and the operation of the ventilation system in response to the presence of smoke in the cabin of the vehicle.

Abstract: An automatic windshield wiper system connected to a source of power and windshield wipers of a vehicle for automatically controlling operation of the windshield wipers based upon an intensity of falling precipitation. The automatic windshield wiper system includes a transducer for sensing precipitation and generating a signal indicative of the sensed precipitation and a comparator connected to receive the control signal. The comparator analyzes the control signal to determine whether precipitation is falling. A relay is connected between the comparator and the windshield wipers. The relay is toggled by the comparator to supply power from the power source to activate the windshield wipers upon a determination by the comparator that the transducer sensed falling precipitation, the transducer continually senses the state of falling precipitation and continually transmits signals to the comparator.

Abstract: A control system for automatically detecting moisture on the windshield of a vehicle. The automatic moisture detecting system includes an optical system for imaging a portion of the windshield on to an image array sensor, such as a CMOS active pixel sensor. The voltages of each of the pixels which represents the illumination level is converted to a corresponding gray scale value by an analog digital converter. The gray scale values corresponding to the image are stored in memory. The spatial frequency composition of the gray scale values are analyzed to determine the amount of rain present. In order to provide a control signal to control the operation of the windshield wipers of the vehicle as a function of the amount of moisture present. The system is also adapted to detect the level of fog both on the interior of the windshield as well as the exterior of the windshield.

Abstract: A detector for detecting the presence of ice, water, mist, frost or other solids or liquids on a sensing surface is provided. The sensing surface is provided by a medium substantially transparent to electromagnetic radiation and solids or liquids are deposited on the surface. A transmitter directs radiation onto the surface and a receiver is responsive to radiation reflected from the surface. A discriminator circuit receivers an output from the receiver and provides an output indicative of whether a solid or a liquid is present on the surface.

Abstract: The invention relates to a device for the automatic control of a windscreen wiper motor. The device has a moisture sensor which emits a signal depending on the moisture on the windscreen or another point on a motor vehicle so that this signal to some extent produces an analog reflection of the moisture varying in time. The output signal of the sensor is evaluated in such a way that it is continuously compared with a threshold value which can be altered. Every time this threshold value is reached or exceeded by a pulse-like change in the sensor output signal, this event is counted. After a given number Z of such events the windscreen wiper motor is switched on.

Abstract: An optoelectronic sensor 1 for detecting foreign bodies, especially raindrops on a windshield, includes an outer housing part 2 and an inner housing part as well as a fastening device 4, which is glued to a pane 5. A fastening means, for instance comprising two slides 6, is provided, guided in the outer housing part 2, and can be made to engage the fastening device 4 for securing the sensor 1 to the pane 5. In the interior of the sensor 1, the inner housing part, which carries the optoelectronic elements of the sensor 1, is pressed toward the pane 5 with a spring force braced against the outer housing part 2, in order to accomplish the optical coupling with the pane.

Abstract: A system for detecting the presence of rain droplets on a windshield employs a source of light, such as an LED, and a photodetector installed on the instrument panel of a vehicle. The LED and the photodiode are arranged with respect to one another such that light from the LED cannot reflect directly off the windshield into the photodiode. Only when the light from the LED is backscattered by an environmental condition, such as the raindrops on the exterior of the windshield, the condensation of moisture on the interior of the windshield, or the presence of smoke in the cabin, will the photodiode receive the light from the LED. Each of these environmental conditions has a predeterminable characteristic signature which permits the processing of data to detect same.

Abstract: A method for controlling a windshield wiper, particularly on a motor vehicle, in which a rain sensor is located on the windshield to be wiped in the region of the windshield wiper and gives off a sensor signal as a function of the amount of wetness. The rate of change of the sensor signal after the windshield wiper has passed the sensor is determined and used in order to control the frequency of wiping.

Abstract: A method and a system for controlling a windshield wiper, particularly on a motor vehicle, provides that the windshield wiper is automatically activated as a function of the intensity of rain. A frequency-limited variation of the signal of a sensor serves as a measure of the intensity of the rain.