Device for preventing air moisture condensing on the inside of a vehicle windscreen utilizes a dew point detecting device to detect dew point temperature using test signals from a temperature sensor and a moisture sensor

摘要

A dew point detecting device (72) detects dew point temperature using test signals from a temperature sensor (52) and a moisture sensor (66). Factors calculated include windscreen temperature, external temperature, vehicle speed and temperature, and flow temperature of air coming from defrost air escape openings (48) and spreading inside on the windscreen. A controller (58) connected to the dew point detecting device and an inner surface temperature sensor transmits a triggering signal to an air distribution device, an air current generator (14), a fresh air circulator (16) and an air dehumidifier, whenever the temperature of the inner surface (64) is less than a temperature threshold at a preset difference above the dew point temperature.