Patent · US Expired

Refractor optical system

US4413891A · kind A · utility

10Cited by
2References
3Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 27, 1980
Grant dateNov 8, 1983
Priority date
Expiry dateMar 27, 2000

Classification

  • Technology area (CPC A)Human Necessities
  • CPC primaryA61B3/12
  • WIPO fieldMedical technology
  • WIPO sectorInstruments

Abstract

A refractor optical system having a new series of spherical and cylinder lenses substantially eliminates the irregular occurrence of additive errors when lenses spaced from the reference plane are used or more than two lenses are combined and permits correction for the significant additive errors by non-additive lens selection is disclosed.

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