Method and apparatus for focusing an objective
US3953863A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 27, 1973 |
| Grant date | Apr 27, 1976 |
| Priority date | — |
| Expiry date | Nov 27, 1993 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/40
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a method for focusing a reproducing objective, such as may be used for measuring distances, wherein multiplication of the image of the entrance pupil is achieved by image-splitting optical elements mounted in the plane of the object image, the improvement comprising: Projecting the light fluxes from different parts of the pupil image plane on separate sets or groups of photoelectric receivers, deriving a signal from the comparison of the output signals from these receiver groups and using this signal as a criterion for focusing as a function of magnitude and sign. Apparatus for performing the method includes a grid of prisms or pyramids, and a beam splitter for directing light through two separate photoelectric receiver masks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.