Patent · US Expired

Zoom lens

US5267082A · kind A · utility

6Cited by
6References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 17, 1992
Grant dateNov 30, 1993
Priority date
Expiry dateSep 17, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B15/144113
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A zoom lens includes sequentially from an object side toward an image surface side a fixed first lens group, a movable second lens group, a fixed third lens group, and a movable fourth lens group. The fixed first lens group is constituted by a first concave lens, a first convexo-convex lens, a second concave lens, a second convexo-convex lens and a meniscus convex lens. The movable second lens group is constituted by a meniscus concave lens, a concavo-concave lens and a convex lens. The fixed third lens group is constituted by a single lens having at least one aspherical surface. The movable fourth lens group is constituted by a concave lens and a convex lens, at least one of which has at least one aspherical surface.

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