Water drop detector on transparent substrate
US5998782A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1998 |
| Grant date | Dec 7, 1999 |
| Priority date | — |
| Expiry date | Nov 13, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60S1/0888
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A windshield (transparent substrate) 1 having the function of detecting the presence of water drops W upon one side surface of the windshield depending upon variations in an amount of reflected light, comprising a rain sensor provided on the other side surface of the windshield, which further comprises: light emitting means 6 for guiding light into the windshield 1; light receiving means 7 for detecting the light which is reflected within the windshield 1; and, light shielding members 10 and 11 provided on the other side surface of the windshield 1 opposing the light emitting means 6 and the light receiving means 7, respectively; wherein the light shielding member 10 shields the light emitted from the light emitting means 6 at an incident angle less than a critical angle at which total internal reflection occurs at a boundary surface between air and the windshield 1, while the other shielding member 11 shields outside ambient light incident upon the light receiving means 7.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.