Apparatus for detecting the focus adjusting state of an objective lens by performing filter processing
US5367153A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1992 |
| Grant date | Nov 22, 1994 |
| Priority date | — |
| Expiry date | Oct 30, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/28
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A focus detection apparatus includes an optical system for forming first and second optical distributions associated with object images whose relative positional relationship is changed in accordance with an imaging state of an imaging optical system subjected to focus detection, a photoelectric conversion element, having a plurality of picture elements, for outputting first and second signals respectively corresponding to the first and second optical distributions, and a calculating unit for performing filter processing of the first and second signals, sequentially displacing the first and second signals relative to each other on the calculation basis, calculating an evaluation amount representing a coincidence between the first and second signals at the relatively displaced positions, obtaining positional deviations between the first and second object images on the basis of a change in evaluation amount, and detecting the imaging state of the imaging optical system on the basis of the deviations. The filter processing is performed using a filter determined by the relatively displaced positions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.