Patent · US Expired

Epidark illumination system

US4186993A · kind A · utility

7Cited by
2References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 22, 1977
Grant dateFeb 5, 1980
Priority date
Expiry dateSep 22, 1997

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B21/10
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An epidark illumination system for use with a microscope in which a sample is illuminated from around an objective by a ring-shaped light flux having its center coincident with the optic axis of the objective to enable the sample to be observed in a dark field of view comprises a ring-shaped condenser lens member disposed adjacent to the forward end of the objective with the center of the lens member being coincident with the optic axis of the objective to condense the light flux upon the sample, and a scattering member for scattering the ring-shaped light flux disposed in the light path before the ring-shaped light flux reaches the ring-shaped condenser lens member.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.