Abstract: A rain detection system generates an operation signal for operating a wiper system on a window based on a detected window condition. The rain detection system includes a detection mechanism for intermittently detecting an amount of liquid on the window, a calculation mechanism for calculating an increase rate of the amount of the liquid detected in a detection operation by the detection mechanism and a determination mechanism for determining the window condition based on the increase rate calculated by the calculation mechanism. The determination mechanism distinguishes difference between condensation on the window and rain based on the detected liquid on the window.

Abstract: A sensor device for detecting wetting on a windshield includes a light emission element for emitting a light, a first light reception element for receiving the light in a first light path that includes reflective redirection by the windshield, and a second light reception element for receiving the light in a second light path that does not include reflective redirection by the windshield. The sensor device uses a ratio of the amount of the received light by the first light reception element and the amount of the received light by the second light reception element to determine wetting on the windshield.

Abstract: An inter-device communication system for a wiper control apparatus that includes a rain detection device and a wiper driving device includes communication circuits having a transmission line for unidirectionally sending a rain detection signal to the wiper driving device, a transmission circuit arranged in the wiper driving device for short-circuiting a potential of the signal unidirectionally sent through the transmission line, and a recognition circuit arranged in the rain detection device for recognizing transmitting information sent in an opposite direction to a direction of the unidirectional transmission, i.e., from the wiper driving device to the rain detection device based on the short-circuited signal.

Abstract: A wiper control system for detecting an amount of raindrops landed on a windshield of a vehicle and driving a wipe operation of a wiper to wipe the landed raindrops. The wiper control system includes raindrop sensing means, average landed raindrop amount calculation means, vehicle acceleration sensing means, and wipe operation mode selection means. The raindrop sensing means is capable of detecting the amount of landed raindrops for each of a plurality of wipe cycles of the wiper. The average landed raindrop amount calculation means calculates an average value of the amount of landed raindrops for the plurality of wipe cycles. The vehicle acceleration sensing means detects an acceleration of the vehicle. The wipe operation mode selection means selects a wipe operation mode based on the acceleration of the vehicle and any one of the amount of landed raindrops and the average amount of landed raindrops.

Abstract: A rain detection system generates an operation signal for operating a wiper system on a window based on a detected window condition. The rain detection system includes a detection means for intermittently detecting an amount of liquid on the window, a calculation means for calculating an increase rate of the amount of the liquid detected in a detection operation by the detection means and a determination means for determining the window condition based on the increase rate calculated by the calculation means. The determination means distinguishes difference between condensation on the window and rain based on the detected liquid on the window.

Abstract: A raindrop sensor detects an amount of raindrops landed on a window glass and outputs a measurement signal to a microcomputer. The microcomputer calculates an average amount of raindrops by averaging a predetermined number of the latest measurements. The microcomputer calculates an interval time for the wiper based on the calculated average amount of raindrops. At this time, when the calculated average amount of raindrops deviates from a predetermined reference value, the microcomputer calculates the average amount of raindrops using a smaller number of the latest measurements.

Abstract: A raindrop sensor detects an amount of raindrops landed on a window glass and outputs a measurement signal to a microcomputer. The microcomputer calculates an average amount of raindrops by averaging a predetermined number of the latest measurements. The microcomputer calculates an interval time for the wiper based on the calculated average amount of raindrops. At this time, when the calculated average amount of raindrops deviates from a predetermined reference value, the microcomputer calculates the average amount of raindrops using a smaller number of the latest measurements.