Apparatus and method for detecting focus condition of imaging optical system employing both sharpness detection and lateral shift detection
US4562346A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 1983 |
| Grant date | Dec 31, 1985 |
| Priority date | — |
| Expiry date | May 13, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2217/005
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a camera, a focus condition of an objective lens system is automatically detected in accordance with a combination of two different type detection methods. A light flux emanating from the objective lens system is divided into two light fluxes by means of a prism having a half mirror and a reflecting mirror and a first light flux transmitted through the half mirror is received by a first light receiving element array via a lenticular lens array and a second light flux reflected by the half mirror and reflecting mirror successively is directly received by a second light receiving element array. The lenticular lens array is so arranged that an exit pupil of the objective lens and the first light receiving element array are conjugated with each other and thus divided images of the exit pupil are projected upon respective elements of each pair of adjacent light receiving elements. At first, illumination signals supplied from the first image receiving element array are processed to derive a first evaluation value on the basis of an image lateral shift detection to indicate roughly a focal condition of the objective lens system. After the objective lens system has driven near the best …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.