Automatic focusing device utilizing a trend of variation and degree of reliability of a focusing evaluation value signal to improve image focusing
US5337084A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 2, 1992 |
| Grant date | Aug 9, 1994 |
| Priority date | — |
| Expiry date | Apr 2, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/365
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An automatic focusing device including a lens group by which movement of a focused field of an object changes, a drive motor for moving the lens group, a luminance processing circuit for image-sensing the object through the lens group to extract a luminance signal, an accumulating circuit for outputting a focusing evaluation value signal for evaluating a focal condition of the object on the basis of the extracted luminance signal, a least squares circuit for determining reliability of the output focusing evaluation value signal, and a control circuit for controlling the drive motor to improve the focal condition of the object on the basis of the determined reliability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.