Patent · US Expired

Gas zoom lens

US4331388A · kind A · utility

16Cited by
4References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 25, 1980
Grant dateMay 25, 1982
Priority date
Expiry dateFeb 25, 2000

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02B3/12
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A multi-element lens is provided having a central cavity containing a heavy, high index gas. The central cavity is defined by a pair of meniscus elements and acts as a thick positive lens. The pressure of the gas in the cavity is varied in response to magnification changes desired, the pressure change causing a change in the refractive index of the gas thereby altering the focal length of the lens.

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