Fog detecting apparatus for use in vehicle

摘要

In a fog detecting apparatus with optoelectronic system, comprising infrared-emitting means and infrared-receiving means, is provided means for adjusting a reference which is compared with a voltage value of a detecting signal generated according to an electrical signal produced by the infrared-receiving means in order to distinguish whether a windshield of a vehicle is in the fogging condition or not. The reference is changed according to the detecting signal which is produced when the windshield is in good condition against the fogging after a fog removing apparatus has been actuated to remove the fog attached on the windshield, so that the fogging condition is detected in accuracy independently of the contamination of the optoelectronic system or the like.