Automatic focus detection system
US5023646A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 1989 |
| Grant date | Jun 11, 1991 |
| Priority date | — |
| Expiry date | May 12, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/36
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A camera with an automatic focusing device has an objective lens mounted on a camera. An image formed by the objective lens is divided into a plurality of zones. In each zone, a brightness distribution is obtained so as to detect a rough focusing condition in each zone, thereby producing a plurality of rough focusing condition data. Based on the result of the rough focusing condition data, one zone is selected. Furthermore, a precise focusing condition is detected in the selected zone based on the light contained in the selected zone, so as produce a precise focusing condition data. Based on the precise focusing condition data obtained from the selected zone, the objective lens is driven to an infocus condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.