Focus detecting device for an optical apparatus
US6649893B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 2001 |
| Grant date | Nov 18, 2003 |
| Priority date | — |
| Expiry date | Apr 12, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/40
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A focus detecting device includes a multi-beam producing member for emitting a plurality of light beams; a light-blocking member for blocking a part of the plurality of light beams; a beam splitting member having a surface for reflecting or transmitting an incident light beam; a light-condensing optical system for condensing the incident light beam; and a photodetector having at least two light-receiving sections. The multi-beam producing member and the light-blocking member are placed on a first optical path, and the light-condensing optical system and the photodetector are placed on a second optical path. The beam splitting member is located at the intersection of the optical axis of the first optical path with the optical axis of the second optical path, and the photodetector is located at a position where the light beam is condensed by the light-condensing optical system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.