Focus detection device
US4561748A · kind A · utility
7Cited by
5References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 16, 1984 |
| Grant date | Dec 31, 1985 |
| Priority date | — |
| Expiry date | May 16, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/32
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An active focus detecting device for use in a camera is provided and includes emitting light that is polarized, and collimated so that the light forms a light bundle which will pass near the optical axis of the objective lens, and then will be projected in a diverging light path after having been focused by the objective lens towards the object. A polarization component is provided for receiving the returning light and directing a component of that light towards a detector for determining a focusing condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.