Rain sensor using statistical analysis
US6144022A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 1999 |
| Grant date | Nov 7, 2000 |
| Priority date | — |
| Expiry date | Mar 15, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S318/02
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A method and an assembly for sensing moisture (20) on the exterior surface (22) of a sheet of glass (14) by positioning an imaging lens (16) adjacent to the interior surface (18) of the sheet of glass (14), passing light rays from moisture (20) on the exterior surface (22) of the sheet of glass (14) through the imaging lens (16) and producing first and second successive images of the moisture (20) on the glass (14), and successively directing the first and second images from the lens (16) onto a focal plane detector (12). The focal plane detector (12) is divided into rows of pixels (24) which are ligned into columns. The assembly and method are characterized by scanning the pixels (24) of each row in a first scan (FIG. 4) and producing a reference value X for each pixel (24) in response to an initial image in that pixel (24), scanning the pixels (24) of each row in a second scan (FIG. 5) and producing a subsequent value Y different from the reference value in response to an subsequent image in that pixel (24). A correlation coefficient value r is developed for each row with a statistical formula from the reference and subsequent values to produce a wiper signal in response to the c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.