http://rdf.ncbi.nlm.nih.gov/pubchem/patent/EP-0647551-A1
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_7fe442a39c142943c9fb47ea76d1410f |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/G01N21-43 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/B60S1-0837 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/B60S1-0822 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/G01N21-41 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G01N21-17 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/B60S1-08 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G01N21-43 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G01N21-47 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G01N21-41 |
| filingDate | 1994-09-26-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_414f0727d740b8982d21639782415557 |
| publicationDate | 1995-04-12-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | EP-0647551-A1 |
| titleOfInvention | Optical detection of water droplets using light refraction |
| abstract | An optical detection system for detecting rain or other water droplets (30) on the outer surface of a window (12) and for detecting fog on the inner surface of such window with a single photo-detector (14) is disclosed. The optical detection method and apparatus of the invention measures the accumulation of water droplets on the window (12) by light refraction of a first light beam (20,22) with such droplets to redirect a first light beam (20,22) to the photo-detector (14). A masking device (26) prevents such first light beam from reaching the photo-detector directly without refraction (18). As a result the rain measurement output signal of the photo-detector (14) increases with an increasing accumulation of water droplets on the window (12). The fog accumulation is measured by a second light beam (36) reflected off the inner surface of the window to the photo-detector (14) so that the fog measurement output signal of the photo-detector (14) decreases with increasing amounts of fog since such fog scatters and diffuses the light to reduce the amount of light reflected to the photo-detector. A third light source (40) is focused directly on the photo-detector (14) to bias it into an operating point of high sensitivity to infrared light and is connected in a negative feedback circuit from the output of the photo-detector amplifier. The photo-detector output is connected to a narrowband amplifier that is tuned to the frequency of an oscillator which pulses the first and second light sources at different times. As a result of this negative feedback, changes in the output signal of the photo-detector (14) due to external factors such as temperature changes or aging of the light sources (10,34,40) and photo-detector (14), as well as changes in the supply voltage and ambient light are cancelled so they do not produce errors in the measurement signals. |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/DE-10256429-A1 |
| priorityDate | 1993-10-08-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 22.