Apparatus for dark field illumination
US4291938A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 30, 1979 |
| Grant date | Sep 29, 1981 |
| Priority date | — |
| Expiry date | Nov 30, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B21/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Apparatus for dark field illumination consisting of light conducting fibers having end faces arranged within an annular region which is coaxial with the optical axis of an optical assembly, such as a microscope objective. The annular region is within the numerical aperture of the optical assembly and is positioned in the rear focal plane thereof so that light emitted by the fibers becomes dark field illumination for the object plane of the optical assembly when viewed through the central aperture of the annular region. Illumination of the object plane through the central aperture also dark field illuminates the object plane when viewed through the fibers. This is true even when the object plane is illuminated in only a small area by forcussing an illumination source through the central aperture and onto the object plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.