Patent · US Expired

Zoom lens system

US6229655A · kind A · utility

25Cited by
1References
57Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 21, 1999
Grant dateMay 8, 2001
Priority date
Expiry dateDec 21, 2019

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B15/143507
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A zoom lens system has, from the object side, a first lens unit, a second lens unit and a third lens unit. The first lens unit has a negative optical power as a whole. The second and third lens units have a positive optical power as a whole. In the zoom lens system, zooming is achieved by varying the distance between the first and second lens units, and at least one of the lens elements is a plastic lens element.

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