Apparatus for detecting fogged window of vehicle

A fog sensing apparatus for a vehicle window, comprising:

• an adhesive layer having a top adhesive surface and a bottom adhesive surface, the bottom adhesive surface being capable of adhering to a glass surface of the vehicle window;
• a flexible printed circuit board attached directly on the top adhesive surface of the adhesive layer, the flexible printed circuit having a conductive pattern;
• a temperature and humidity sensor module mounted directly on the conductive pattern of the flexible printed circuit board, the temperature and humidity sensor module including a glass surface temperature sensor for measuring a temperature of the glass surface of the vehicle window, and a humidity sensor for measuring relative humidity around the glass surface of the vehicle window;
• a substrate assembly having a through hole for the temperature and humidity sensor module to pass through, and connection terminals connected to the conductive pattern;
• and
• a case covering the substrate assembly, the substrate assembly interposed between the case and the flexible printed circuit board,
• wherein the adhesive layer has heat conductivity to facilitate heat transfer from the glass surface of the vehicle window to the glass surface temperature sensor of the temperature and humidity sensor module.