Dark field illuminator ringlight adaptor
US5820250A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1995 |
| Grant date | Oct 13, 1998 |
| Priority date | — |
| Expiry date | Oct 24, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B21/084
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A system enabling conversion of a conventional ringlight for differential illumination such as dark field or Rheinberg illumination is disclosed. The system comprises a ringlight having an annular light emitting portion and a hood that fits over the ringlight. The hood has an aperture and an annular reflective surface, disposed opposite the light emitting portion, that reflects the light from the ringlight through the aperture. An angle of the annular reflective surface is selected relative to a direction of light from the ringlight to form a cone of light exiting the aperture. To ensure good contrast, a light baffle in the form of a sleeve, inserted into the ringlight, may be incorporated to prevent stray light from the ringlight from directly exiting through the aperture. The differential illumination produced by the invention is applicable to machine vision applications, but also microscopy, gemology, and serology, for example.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.