Patent · US Expired

High resolution objective for large-format photography

US6028720A · kind A · utility

23Cited by

4References

6Claims

0Family size

Assignee

Jos. Schneider Optische Werke Kreuznach GmbH & Co. KG · DE

Inventors

Rolf Wartmann · Bösinghausen, DE
Udo Schauss · Bad Sobernheim, DE

Key dates

Filing date	Dec 7, 1998
Grant date	Feb 22, 2000
Priority date	—
Expiry date	Dec 7, 2018

Classification

Technology area (CPC G)Physics
CPC primaryG02B13/06
WIPO fieldOptics
WIPO sectorInstruments

Abstract

A high-resolution objective for large-format photography has a pair of positive meniscuses flanking a stop area forming a lens aperture; and a respective negative cemented doublet on a side of each meniscus turned away from the stop area, the positive meniscuses being composed of glass having anomalous partial dispersion, a refractive index n.sub.e <1.63 and a dispersion or Abbe number .nu..sub.e >63, the cemented doublets each having a negative lens element and a positive lens element, the negative lens element being composed of a lead-free, arsenic-free and antimony-free glass with an anomalous dispersion, a refractive index n.sub.e >1.63 and an Abbe number .nu..sub.e <50.

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