Apparatus for range finding equipment
US4250376A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1979 |
| Grant date | Feb 10, 1981 |
| Priority date | — |
| Expiry date | Jul 20, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/30
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Apparatus for determining the direction a lens should be moved in order to provide a proper focus of a remote object on a predetermined plane. A plurality of radiation detectors are positioned to receive radiation in first and second patterns from the object and to produce signals in accordance therewith. A first group of radiation detectors, produces signals indicative of the radiation received on the first pattern while a second group of radiation detectors produces signals indicative of the radiation received, in the second pattern. The two patterns coincide at the proper focus but at other than the proper focus position, the two patterns are spaced from one another in a direction which depends upon the direction the lens should be moved to achieve proper focus. The absolute value of the difference between the signal from a first detector in the first pattern and the signal from a first detector in the second pattern is compared with the absolute value of the difference between the signal from a second detector in the first pattern and the signal from a second detector in the second pattern. The result is summed over a predetermined range and a characteristic of the summed value…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.