Device for detecting the focus adjusted state of an objecting lens
US4959677A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1989 |
| Grant date | Sep 25, 1990 |
| Priority date | — |
| Expiry date | Jun 30, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/346
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a focus detecting device has a plurality of optical systems each forming a pair of light distributions whose relative position varies in conformity with the focus adjusted state of an objective lens. The optical systems are disposed so that the direction in which the relative position of the light distributions is varied differs. Focus detecting sensors are provided for receiving the relative position of the light distributions, an the optical systems are constructed so that the optical spacing between the centers of gravity of the areas in which light beams passed through one of the optical systems differs from the optical spacing between the centers of gravity of the areas on another of the optical systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.