Range finder for still or moving picture cameras
US4304487A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1979 |
| Grant date | Dec 8, 1981 |
| Priority date | — |
| Expiry date | Nov 29, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/46
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
To measure the distance to a selected object, the range finder transmits infrared light in a beam having a straight limiting edge on one side. The object reflects light back from the illuminated region and a lens receives part of the light and creates an image of the illuminated region including the straight limiting edge on a plane inclined at an angle to the optical axis of the lens. A detector, including a photoelectric transducer part of which is masked by a mask having a straight edge, is moved along the plane until the edge of the mask and the edge of the image are aligned as closely as possible. The position of the detector when this alignment takes place is indicative of the distance of the object from the range finder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.