Device for detecting surface wetness

US6369378B1 · kind B1 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Hubert Lamm · Kappelrodeck, DE
• Hans Meier · Ottersweier, DE
• Wolfgang Hermann · Lechenich, DE
• Henry Blitzke · Laufenburg (Baden), DE
• Guenter Haderer · Laufenburg (Baden), DE

Key dates

• Filing date: Dec 1, 1999
• Grant date: Apr 9, 2002
• Expiry date: Dec 1, 2019

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60S1/0833
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

The device for the detection of a wetting of a pane of glass, has an optical rain sensor which detects extraneous light and evaluates it for purposes of day-night detection. The amount of light striking the receiver (14) is integrated in an integration stage (16) and supplied to a comparator stage (20). The total light quantity formed by the light of a transmitter (12) and extraneous light and the extraneous light quantity detected when the transmitter (12) is switched off are measured in separate time intervals (Tg, Tf, Tf′). The time interval (Tf, Tf′) utilized for measurement of the extraneous light quantity is to be extended after a predeterminable number of measurement cycles (M) or after a predeterminable time period and/or the threshold (S2) is to be lowered for day-night detection.