Automatic focus control device
US3970842A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 8, 1975 |
| Grant date | Jul 20, 1976 |
| Priority date | — |
| Expiry date | Jul 8, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/36
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An automatic focus control device has an optical system including an image scanner. The image scanner is disposed between a range-finding lens and at least one light receptor element and on the path of travel of the incoming light towards the light receptor element through the range-finding lens. A mechanism is also disclosed for simultaneously measuring the object-to-lens distance and detecting the contrast of an image of the object projected on the scanner merely by moving the scanner in a direction diverging from the optical axis while a parallel relation between the plane of the scanner and the plane perpendicular to the optical axis is retained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.