Abstract: An apparatus for operating a windshield wiper having a sensor device for determining the state of wetness of a windshield, an evaluation device which receives the sensor signal, a dirt-recognition stage and an adjusting device for updating a reference value when dirt is present on the windshield, and an actuating unit for the windshield wiper which can be actuated by the evaluation device in order to initiate a wiping process if the difference between the reference value and a current measured value of the sensor signal exceeds a predetermined threshold value. The measured values can be evaluated by the dirt-recognition stage with respect to signal breaks of the sensor signal caused by the wiping action of the wiper across the sensor surface.

Abstract: A dryness control circuit for a household clothes dryer including a power supply circuit and a moisture sensing circuit. The power supply circuit converts high voltage AC power into low voltage, DC power. The low voltage, DC power is supplied to the moisture sensing circuit. The moisture sensing circuit includes a moisture sensor having a pair of spaced-apart electrodes, a time delay circuit, an electrostatic discharge attenuation circuit, and a motor controller circuit. The motor controller circuit includes a control hysteresis or dead-band in which operation of a timer motor is unaffected. The time delay circuit includes an RC network which slowly charges and discharges to prevent erroneous dryness or moisture readings, which are sensed by the moisture sensor, from causing the motor controller circuit to improperly actuate or deactuate the timer motor. The electrostatic discharge attenuation circuit negates the deleterious effects of static build up.

Abstract: A device for operating a windshield wiper, with the device including a sensor for detecting the degree of moistness of a windshield, an evaluator for receiving a signal from the sensor, and a control unit which receives a control signal from the evaluator for operating the windshield wiper if a difference between a reference value and values derived from the sensor signal exceeds a predetermined threshold value. The evaluator includes a detector stage for determining whether the sensor signal or the values derived therefrom lie within a normal range (UGR, OGR), and a selector stage for switching to a predetermined base interval mode of operating of the wipes when the detector stage determines that the sensor signal or the values derived therefrom lie outside of the normal range.

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: A windshield wiper arrangement which includes a windshield having a wiping area and a sensor-active surface on its wiping area. A wiper sweeps over the wiping area during a wiper operation. A wiper control system includes: a drive motor for driving the wiper; and a sensor system including a sensor disposed in the wiping area such that the wiper passes over the sensor n times during each wiper operation, n being equal to at least one, the sensor system further being configured for generating a sensor signal in response to an element coming into contact with the sensor-active surface on the windshield. The wiper control system further includes a signal processing device for generating the motor signal in response to the sensor signal which includes a counter arrangement having a counter for counting sensor signals generated by the sensor system thereby resulting in a counter state of the counter, the counter state of the counter further being equal to a predetermined starting value before each wiper operation.

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: Proposed is a device for operating a windshield wiper in the intermittent and continuous modes. To do this, at least one sensor (12) is provided, which emits signals in dependence on the coat of moisture or the amount of rain on a windshield to be cleaned, as well as an electronic control (16) for operating the windshield wiper (11) in dependence of the signal from sensor (12). The number for the sensor signals (E) per wiping interval (WP) is recorded as control signal (n) in one evaluating mechanism (14). Furthermore and depending on whether at least one threshold value (S1, S2) is exceeded or not reached by the control signal (n) or a signal (M1, M2), derived from control signals, there is a changeover between intermittent and continuous modes by means of a changeover device (21, 22).

Abstract: A windshield wiper control detects a stall condition of the windshield wiper motor such as may be caused by a freezing of wiper blades to the windshield by monitoring the commutating switch normally used to park the windshield wiper blades when the wipers are turned off. Failure of the signal from the switch to change indicates the motor has stalled and causes a timer holding a value greater than a wiper cycle to time out and de-energize the wiper motor. The wiper motor is re-energized by turning off then on again the wiper control. A method of setting the interval between intermittent operation of the wiper with a single switch, times from previous wiper cycles to the switch activation to set a longer or shorter wiper cycle interval.

Abstract: A process and a system for controlling a windshield wiper, in particular on a motor vehicle, employs a sensor which recognizes the intensity of the rain. The sensor gives off a signal whereby the windshield wiper is automatically controlled as a function of the intensity of the rain. A variation in the signal of the sensor is effected by random signals produced by the continuous movements of drops of water, and serves as measure for the intensity of the rain. In order to assure an optimal and reliable control of the windshield wiper as a function of the intensity of the rain, there is a monitoring of the time between a first sudden change of the signal and a second sudden change. When the time exceeds a given value, the windshield wiper is controlled as a function of at least an earlier one of the sudden changes in the sensor signal which precedes the aforementioned first sudden change.

Abstract: This invention relates to a control system and method for a vehicle speed-response type intermittent wiper. An operation time interval for the wiper, which serves to wipe a window of a vehicle, is set in accordance with a speed of the vehicle to drive the wiper at the operation time interval. Upon detection of a start of the vehicle from a stopped state, the wiper is driven in temporary precedence of the wiper operation time interval so that driving of the wiper can be adequately controlled to ensure the provision of a sufficient area of vision without driving the wiper beyond necessity.

Abstract: The invention concerns rainwater sensors for windshields. In one embodiment, a first, inner, conductive film is applied to the inner surface of the windshield, and a second film, of same size and shape as the first, is applied to the outer surface. However, a narrow strip is removed from the second film, forming a gap which divides the second film into parts 1 and 2. The resulting structure forms two capacitors, namely: (1) inner film plus part 1, and (2) inner film plus part 2. The impedance of one capacitor is monitored. When rain occurs, it falls into the gap between parts 1 and 2, and acts as a resistor, bridging part 1 to part 2. This bridging adds a new impedance in parallel with the first capacitor, thereby changing the effective impedance. This change indicates the presence of rain.

Abstract: An arrangement for indicating a change in a reflective element of a radiation-permeable medium having a detection side disposed opposite the reflective element. The arrangement includes two measured sections each having a radiation source for generating radiation for transmission through the radiation-permeable medium; a sensor-active surface on the reflective element for reflecting at least a portion of the generated radiation through the detection side; and a radiation receiver for receiving the reflected radiation which has an output for producing a detection signal representing received radiation.

Abstract: A wiper system for a motor vehicle window includes a wiper arm, a permanent magnet motor, a linkage connecting the motor with the wiper arm, and a switching mechanism. The wider arm is adapted to be rotatably mounted on a vehicle body for operable movement between first and second end wipe positions. The motor is of the three brush permanent magnet type, the brushes being a high speed brush, a low speed brush and a common brush. The switching mechanism is responsive to wider blade position and is closed, electrically connecting the high speed brush with the low speed brush, thereby achieving an intermediate speed, in at least one end wipe position.

Abstract: A windshield wiper controller 10 is provided for automatically regulating the operating speed of a motor powering a windshield wiper. An automatically set or manually set wiper speed selector 36, 48 is provided for selecting a wiper speed setting to initially control the operating speed of the windshield wiper motor. A sensor 22 senses the actual speed of the windshield wiper movement relative to the windshield. Controller 32 is responsive to the sensor 22 and automatically generates a wiper speed increase signal to the selector when the sensed wiper speed is less than a selected value, and similarly generates a wiper speed reduce signal when the sensed wiper speed is greater than a selected value. The wiper speed sensor 22 may include a magnet 20 which acts as a triggering mechanism outputting a signal from the wiper sensor. A timer 44 measures the time interval between at least a substantial portion of the forward wiping motion and the return wiping motion.

Abstract: An intermittent windshield wiper system includes a wiper control module and a wiper switch which allows an operator to set a time delay between consecutive wipes of a windshield wiper. The wiper switch includes an input setting that allows an operator to set the time delay according to the operator's needs and weather conditions. The wiper control module records the time delay and controls a wiper motor to repeatedly actuate a windshield wiper with the operator-set time delay between consecutive actuations of the windshield wiper. In one embodiment, the control module includes a timer for measuring the time delay, a memory for recording the time delay and a motor control for controlling the wiper motor. A method of controlling a windshield wiper for a vehicle is also disclosed.

Abstract: An optoelectronic sensor device which has a beam transmitter/beam receiver arrangement associated with a beam guide element. The arrangement is disposed together with a heating device in a common housing. In order to install the heating device in a convenient manner in the surrounding area of the sensor device, the heating device consists of at least one heat conducting plate fixed to a support part, which is allocated with its substantial main areas to the beam guide element and is connected by at least one connection arm to the electrical printed circuit board. The heating device includes at least one heating element, which is disposed in the proximity of a connection arm directly on the electrical printed circuit board. For communicating the necessary heat into the heat conducting plate, the printed circuit board is connected at least in a material-locking manner to an associated connection arm.

Abstract: The composite wall comprises a first sheet and second sheet separated by an intermediate layer as well as an ultrasonic detection device placed on a face of said second sheet and comprising a transducer element able to emit an incidental ultrasonic signal of frequence f, and able to receive an ultrasonic signal reflected on a face of said first sheet. The intermediate layer comprises at least facing the transducer element, an inserted element whose two faces are respectively in close contact with the first and second sheets. Further, the frequence f of the transducer element satisfies the following relationships:f.apprxeq.K.sub.1. V.sub.1 /2e.sub.1 .apprxeq.K.sub.2.V.sub.2 /2e.sub.2 .apprxeq.K.sub.3.V.sub.3 /2e.sub.3where K.sub.1, K.sub.2 and K.sub.3 are defined integers, e.sub.1, e.sub.2 and e.sub.3 are respectively the thickness of the first sheet, the second sheet and the inserted element, and V.sub.1, V.sub.2 and V.sub.

Abstract: A process and a system for controlling a windshield wiper, in particular on a motor vehicle, in which a rain sensor is located on the glass to be wiped and within the region of the windshield wiper. The sensor outputs a sensor signal as a function of the amount of moisture. The signal is detected periodically and, when a reference degree of moisture is reached during a measurement cycle, the system produces a triggering signal and the windshield wiper is activated. The wiping process takes place even when the windshield wiper is wetted with moisture only to a slight but nevertheless disturbing extent. In the process, when a degree of moisture below a reference degree of moisture is present at the end of the measurement cycle, this degree of moisture is included additively to the degree of moisture of a further measurement cycle. Thereupon, the degree of moisture of the further measurement cycle is compared with the reference degree of moisture.

Abstract: An optoelectronic sensor device includes a waveguide element for affixing to a transparent pane on one surface and connected to a housing by way of latching barbs provided on U-shaped arms which engage corresponding recesses in the waveguide element. Slide-like locking elements are guided by the housing, parallel to the waveguide element and the pane, into the spaces defined by the U-shaped arms to prevent the arms from disengaging their respective recesses. The locking elements are adjustable by way of a handle which is flush with the housing when the latching elements are in their locked position. The locking elements include dome-shaped protrusions which cooperate with an edge of the housing to secure the locking elements within the housing.

Abstract: Disclosed is an automatic windshield wiper control system which responds to sensed moisture in a manner which is responsive to changes in conditions, yet subjectively smooth. Moisture and noise sensitive signals from a sensor are digitized, and a functional block detects the reversals of the moisture sensing signal towards a quiescent level. These reversals are considered rain events and a method is disclosed for producing an ongoing measure of the frequency of these events. The resulting signal is representative of the flow rate of the raindrops impinging upon the moisture sensor. Another functional block with a logarithmic characteristic converts this quantity into an intensity value, in a manner which mimics human perception. A multiple time-constant averaging means maintains a value representative of the long-range prevailing conditions under which the device is operating.

Abstract: An ultrasonic detection device having a transducer (10) for emitting and receiving ultrasonic pulses through a windshield, and producing an echo signal (40,50) representative of the reflected pulses. The detection device also includes an amplifier (23) for amplifying the echo signals (40,50) by a selectable gain, an integrating circuit (26) for integrating each of the echo signals (40,50) during a selected time period (62,63) so as to produce an integral value, amplifier control circuitry (27,28) measuring the integral value and selecting the gain of the amplifier so as to maintain the integral value at a steady-state value, and the temporal deviation of the integral value from the steady-state value is measured to determine if it is greater than a predetermined threshold value. The invention may be used to detect water on a windscreen and to control the operation of a windscreen cleaning system.

Abstract: A sensor device for detecting the degree of wetting of a multi-layer transparent pane, made in particular of glass, by an, in particular, drop-shaped precipitation. The sensor device is provided with a beam guide element which comprises two beam windows and cooperates with a beam transmitter and a beam receiver. In order to prevent spurious beams caused by an extremely thin intermediate layer located in the pane from having a noticeable influence on the signal used to control the windscreen wiper system, the beam guide element comprises a further beam exit window in the central region of its rear surface facing away from the pane. The region is located between the two beam windows. The further beam exit window is allocated to the measuring path and cooperates with an additional beam detector. Only those irrelevant beams reflected at the extremely thin metallic intermediate layer located in the pane exit therefrom.

Abstract: A vehicle window wiper interfacing arrangement for interconnecting a window wiper function switch, a wiper motor controller, and an auto-delay controller to permit a water drop sensor to control a window wiper delay time when a window wiper system is operated in an AUTO-DELAY mode. The auto-delay controller outputs three wiper function signals, namely OFF, LOW speed and WASH to the wiper motor controller via a single bi-directional multiplexed line. The wiper motor controller outputs a wiper position signal to the auto-delay controller via the same bi-directional multiplexed line for use by a control program to determine a proper wiper delay time period.

Abstract: A polarization based optical sensor for detecting the presence, composition, or both of substances (26) on a transparent material's (12) surface (14). A polarized-light source (18) introduces light (22) into the material (12). Within the material (12), the light (22) undergoes one or more total internal reflections (18, 20) whether or not the substance to be detected or analyzed (26) is present. The presence of the substance causes a shift in the polarization of the light (22). This shift is detected by a polarized-light detector (20) when the light (22) exits the material (14).

Abstract: A moisture-responsive system for closing the windows or sunroof of a vehicle having one or more openings each closed by a power driven closure; the system having a moisture sensor for providing a moisture signal in response to the sensing of moisture; a circuit coupled to the closure and the moisture sensor for providing a signal to actuate the closure in response to the receipt of a moisture signal, the circuit including disabling features for safety purposes.

Abstract: A neural network provides automatic control of a windshield wiper. A rain sensor generates sensing signals indicating a rain pattern, and the neural network generates wiping demand signals indicating a wiping action desired by the driver. A training unit uses manually generated wiping supervision signals to create weight factors for the neural network.

Abstract: The outside mirror of a motor vehicle is provided with a wiper blade reciprocating on the mirror surface, as well as a liquid spraying means. An LED/photocell unit automatically senses the degree of soiling of the mirror and initiates a wiping cycle when a predetermined light limit is not reached. Irrespective of the degree of soiling, a cleaning operation is initiated after the engine has been started or stopped. The outside mirror is always in a perfect condition in which it offers good visibility to a driver. This considerably increases the road safety of an automotive vehicle.

Abstract: A rain detector in which the level of a sensor signal (15) which is emitted by a sensor (14) or the level of a sensor signal (17) which is processed by a signal processing unit (16) is set at a predetermined resting level (44) by a control unit (19, 30). This use of a predetermined reference level makes possible an automatic calibration of the rain detector which takes into consideration all tolerances for electrical and optical components, their age-related drift, and tolerances during the installation of the rain detector.

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.

Abstract: A system for automatically controlling the wiping of automotive windscreens is disclosed. The wiping is conducted at a rate corresponding to the amount of water determined to be on the windscreen at each wiping cycle.

Abstract: An apparatus and method for controlling a windshield wiping system, including a motor and windshield wipers, by detecting when a wiper passes over the portion of the windshield monitored by an optoelectronic sensor for the last time during a complete wipe cycle. In addition to the sensor, the apparatus includes a switch arrangement for activating the windshield wiping system and a circuit for processing the sensor output. The apparatus also includes a switching contact device associated with the motor for detecting the resting position of the windshield wipers.

Abstract: A moisture sensor which registers the amount of moisture from tear-shaped precipitation, particularly on a windshield. The device includes a beam director which is mounted on the windshield by an optical adhesive. The beam director has a beam transmitter on one side and a beam receptor on the other. To ensure an optically perfect attachment of the beam director as an integrated unit to the windshield, there is a parallel relationship between the windshield and the facing surface of the beam director. An optical adhesive is applied to the gap between the windshield and the beam director, and is confined to a particular area.

Abstract: A moisture-sensing device for automatically closing motor vehicle external openings such as convertible tops, sun or moon roofs, or windows; a moisture sensor for providing a signal by as little as a single drop of water; a device providing for closing any combination of external openings simultaneously (or sequentially); a device providing for the closing of a sun or moon roof that possesses a safety feature requiring two separate closure steps; a device providing for a signal to a hand-held beeper to alert a person to close a manually operated vehicle opening.

Abstract: An apparatus and method for use with a vehicular windshield wiping system, the apparatus recognizing various rain patterns and accordingly controlling the wiping system. The wiping system includes at least one windshield wiper, and the apparatus includes a sensor mounted to the windshield for monitoring a portion of the windshield wiped by the wiper during each wipe cycle. The sensor generates a signal having a value which varies as a coating collects on the monitored portion.

Abstract: The invention concerns a device for controlling a drive mechanism (70), e.g. for windshield wipers (5, 6), wiping/washing systems, sliding roofs and tops of motor vehicles dependent on how moist or dirty the windshield is on the outside. With help of a sensor (3) and a special computation circuit, the degree and type of moisture or dirt can be ascertained. Depending on whether or not there is only a fine mist or a heavy thundershower, the appropriate circuits on the windshield wipers (5, 6), sliding roofs or tops are automatically actuated. If dirt is detected on the windshield (2), then a wiping/washing system is switched on. Sudden splashes on the windshield, which appear just before the last wiping action of a wiper (5, 6) is completed, are definitely detected and lead to a new wiping action.

Abstract: A water drop sensor comprises a pair of electrodes disposed in association with a portion of a surface of a vehicle window within a wipe pattern and having edges defining an extended insulating gap between the electrodes. The electrodes define a gap which varies in width over the range of diameters of drops to be sensed. The result is that the sensor shows more sensitivity to larger drops than to smaller drops as compared with a similar sensor having a constant gap width. The variation in gap width may be continuous or stepwise over the total range of drop diameters.

Abstract: With an automobile having electric power windows a power drive control circuit includes a solid state on-off power solid state device such as a PNP transistor with a moisture content sensor element interconnecting two electrodes of the solid state device (the emitter and base of the PNP transistor). When the moisture content sensor element becomes moistened as by rain falling thereon its electric through path resistance lessens to thereby achieve bias to conductive state for the PNP transistor through conductive state to activate the window motor drive and close any vehicle windows from the open state.

Abstract: A skylight operator includes a chain drive driven by a motor. Polarity of power applied to the motor is controlled to selectively open or close the window. Polarity is controlled by an H-bridge switching circuit driven by a microcontroller. The microcontroller receives commands from any one of a plurality of control devices The operator includes a feedback circuit using a hall effect sensor in connection with a ring magnet on the motor shaft for sensing incremental movement of the motor, representing movement of the window. A potentiometer control device allows unattended full or partial opening of the window. A user need only turn the potentiometer knob to a desired amount of opening. The microcontroller in response to such a command compares the command to the feedback signal and controls the motor to minimize the difference between the two.

Abstract: An automatically controlled cleaning device is adapted to remove foreign bodies such as water from the surface of a window, such as a car window, which has an inside surface and an outside surface. This device has cleaning element which define at least one predetermined area on the outside surface of this window, driving circuit for the cleaning element which operate in response to a control signal, detection element capable of supplying a detection signal representative of the presence of foreign bodies on the outside surface of the window and control device capable of supplying a control signal in response to the detection signal wherein the detection element comprise a transducer able to emit at least one incident ultrasonic signal propagating within the thickness of the window and able to receive a reflected ultrasonic signal representative of the presence of the foreign bodies to analyse the detection signal and where the transducer is fixed by a first face against the inside surface of the window.

Abstract: Mounting of a sensing unit upon the interior surface of a vehicle windshield for detecting the presence of moisture upon the exterior surface and controlling operation of windshield wipers in response thereto is disclosed. The sensing unit comprises a block in which angularly oriented bores are disposed. Light pipes in a first set of the bores communicate with light sources for transmitting light to the outer surface of the windshield, and light pipes in a second set of the bores transmit light reflected from the outer surface to photo-detectors. The lower ends of the light pipes are coplaner with or raised slightly above the surface of the block which is to be secured to the windshield. The block is affixed to the interior surface of the windshield by a double faced adhesive interlayer which both securely adheres the block to the windshield surface and optically couples the light pipes to the windshield.

Abstract: A combination manual and automatic vehicle windshield wiper control system is provided which integrates a windshield moisture-sensing based wiper control system into an existing design of original equipment wiper system with minimum impact on manufacture and retrofit by using the existing vehicle wiring harness and existing connectors. The invention provides easy integration of a moisture-sensitive wiper control system into a class of vehicles in a manner which does not interfere with the operation of the standard or pulse-wipe systems already existing in the manual mode even if the moisture-sensitive system should fail for any reason. The moisture-sensing mode of operation replaces the delay or pulse mode.

Abstract: A device is provided for controlling a windscreen wiping system, which mainly comprises a control stage, a clock generator unit comprising a switch and a clock-pulse generator, an I/V converter, a phase-selective rectifier and an amplifier with a low-pass filter as well as an optoelectronic apparatus having a plurality of beam transmitters, a beam guide element and a plurality of beam receivers. Such a device is intended to solve the technical problem of effecting automatic adjustment of the control system even under very widely varying measuring conditions determined in particular by the various damping factors of different types of windscreen.

Abstract: A rain-actuated control for covering systems makes it possible to obtain a device capable of automatically closing open coverings in the event of rain. The device must be simple and easy to mount in existing installations. The rain-actuated control comprises a sensor consisting of two electrodes (1,15) with an intermediate layer of glass (13) and air (29) which functions as a capacitor. When rain is deposited (30) on the glass, the dielectric constant of the glass is changed, and signals are generated, which cause the control system to close the covering system. Automobile windows and automobile bodies can be used advantageously as elements of the capacitor.

Abstract: In a device for controlling a windshield wiper, in particular on a motor vehicle, the windshield wiper is switched on when a sensor indicates wetness above a preset threshold value. The windshield wiper can furthermore be turned on by a manually actuatable switch. The threshold value is reduced upon actuation of the switch.

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.

Abstract: A raindrop detector comprises a vibration detection unit, a signal converter unit for converting the electrical signal output from the vibration detection unit into a data signal, a memory for storing data of the data signal converted by the signal converter unit and for outputting a signal to a wiper motor, and a cancel circuit for cancelling the data. According to this invention, it is possible to improve the control accuracy of the wiper motor because the distance to send the data signals to the memory from the signal converter unit shortens and the data signal is independent of radio interference.

Abstract: A wiper apparatus comprises a wiper motor, a wiper switch, a moisture sensor for sensing presence of moisture, a vibration sensor for sensing a vibration caused by raindrops and a controller for actuating the wiper motor in accordance with output signals from the moisture sensor and the vibration sensor. The apparatus is free from the malfunction and works automatically by sensing even a drizzling rain.

Abstract: An apparatus and method for controlling a windshield wiping system, including a motor and windshield wipers, by detecting when a wiper passes over the portion of the windshield monitored by an optoelectronic sensor for the last time during a complete wipe cycle. In addition to the sensor, the apparatus includes a switch arrangement for activating the windshield wiping system and a circuit for processing the sensor output. The apparatus also includes a switching contact device associated with the motor for detecting the resting position of the windshield wipers.

Abstract: An optical detection system for detecting rain or other water droplets on the outer surface of a window and fog on the inner surface with a single photo-detector. The invention measures the accumulation of water droplets on the window by light refraction of a first light beam with droplets to redirect a first light beam to the photo-detector. A masking device prevents light from reaching the photo-detector directly without refraction. As a result the rain measurement output signal of the photo-detector increases with an increasing accumulation of water droplets on the window. The fog accumulation is measured by a second light beam reflected off the inner surface of the window to the photo-detector so that the output signal of the photo-detector decreases with increasing amounts of fog since fog scatters the light to reduce the amount of light reflected to the photo-detector.