Ultrasonic detection device, notably for an automatically controlled windscreen cleaning system
US5539289A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 24, 1994 |
| Grant date | Jul 23, 1996 |
| Priority date | — |
| Expiry date | May 24, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S318/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ultrasonic detection device having a transducer (10) for emitting and receiving ultrasonic pulses through a windshield, and producing an echo signal (40,50) representative of the reflected pulses. The detection device also includes an amplifier (23) for amplifying the echo signals (40,50) by a selectable gain, an integrating circuit (26) for integrating each of the echo signals (40,50) during a selected time period (62,63) so as to produce an integral value, amplifier control circuitry (27,28) measuring the integral value and selecting the gain of the amplifier so as to maintain the integral value at a steady-state value, and the temporal deviation of the integral value from the steady-state value is measured to determine if it is greater than a predetermined threshold value. The invention may be used to detect water on a windscreen and to control the operation of a windscreen cleaning system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.