Patent · US Expired

Wide field eyepiece lens system

US5227918A · kind A · utility

4Cited by
1References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 3, 1992
Grant dateJul 13, 1993
Priority date
Expiry dateApr 3, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B25/001
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An eyepiece lens system comprising, in the order from the side of incidence of rays, a first lens unit having positive or negative refractive power as a whole and a second lens unit having positive refractive power as a whole, said eyepiece lens system having little aberrations, image surface flatness excellent to the marginal portions of visual field, a high eye point and a wide visual field.

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