Unauthorised photographing prevention method for vehicle in road traffic

摘要

A motor vehicle is equipped with a photo-sensitive unit (1), a photo-diode, fitted in the region of the windscreen. As the car approaches an intersection, there is often a video recording procedure or some photographing of vehicles with the camera (3), using a flash (4). The light sent out to the vehicle is received by a photo-diode, amplified (V) and converted into an electrical signal, its level depending on the amount of light. The level is compared with a reference signal or threshold, and, if this is exceeded, a thyristor is triggered and a flash (2) is sent out against the flash from the traffic monitoring equipment, thus spoiling the picture.