Automatic focus detecting device
US5905919A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 21, 1996 |
| Grant date | May 18, 1999 |
| Priority date | — |
| Expiry date | Jun 21, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/346
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An automatic focus adjusting device is adapted to detect focus information of an objective lens on the basis of two images of a subject. The device includes a photosensor having a number of pixels on which the two images are formed, a focus detecting area setup device for selectively setting up either of first and second focus detecting areas on the photosensor, the first focus detecting areas being initially set up and the second focus detecting areas being less in the number of pixels than the first focus detecting areas, an operation device for performing predetermined operations on outputs of the first focus detecting areas set up on the photosensor to provide focus information of the objective lens, an evaluator for evaluating whether the results of operations are proper or not, and a controller responsive to the evaluator for, when the results of operations are improper, causing the focus detecting area setup device to set up the second focus detecting areas on the photosensor and then causing the operation device to perform the operations on outputs of the second focus detecting areas. This device permits the time taken to detect the focus to be reduced without the need of m…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.