Red/near-infrared filtering for CCD cameras
US5555464A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 28, 1995 |
| Grant date | Sep 10, 1996 |
| Priority date | — |
| Expiry date | Jul 28, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/131
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A CCD camera is adapted for detecting red and near-infrared wavelengths by employing filters that are constructed to allow for the passage of only red light in certain areas and near-infrared light in other areas of the filter. The areas are designed to match the pixel geometry of the lens of a primary color CCD camera that has a predefined pattern of red, blue and green pixels. The match is such that the red bandpass filter areas overlay the red pixels, and the near-infrared bandpass filter areas match the blue and green pixel areas. The red, green and blue output lines of the CCD camera are supplied to a signal processor which uses the signals on these lines to provide combinations of red and near-infrared magnitude that are capable of detecting vegetation from a background. The camera is suitable for full color use again merely by removing the filter that provides R and NIR sensing without otherwise disabling or modifying the camera.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.