Method and sensor unit for detecting a degree of wetting of a glass pane

摘要

A method for detecting a degree of wetting of a glass pane, in particular a windscreen of a motor vehicle, is provided. A transmitter is arranged on the inside relative to a glass pane and emits electromagnetic waves, which are reflected according to the total reflection principle on the outer, from the transmitter's point of view the opposite surface of the glass pane, and which are received by a receiver arranged on the inside relative to the glass pane. Electromagnetic waves are emitted further from a transmitter. Waves pass through the glass pane and are scattered on particles or droplets in front of the glass pane and are received by a receiver arranged on the inside relative to the glass pane.

主权项

1. A method for detecting a degree of wetting of a glass pane, with a first transmitter that is arranged on the inside relative to the glass pane and that emits first electromagnetic waves from the first transmitter's point of view to the opposite surface of the glass pane, the first electromagnetic waves emitted from the first transmitter being reflected at an outer surface of the glass pane according to the total reflection principle, and received by a receiver which is arranged on the inside relative to the glass pane, wherein:
second electromagnetic waves are emitted from a second transmitter, which pass through the glass pane and are scattered on particles or droplets in front of the glass pane and are received by the same receiver which is arranged on the inside relative to the glass pane, the receiver is arranged between the first transmitter working according to the total reflection principle and the second transmitter for scattered light measuring, and there receives the reflected electromagnetic wave and scattered electromagnetic wave, and a first distance between the first transmitter and the receiver is at least twice longer than a second distance between the second transmitter and the receiver.