High aperture objective lens

US6504653B2 · kind B2 · utility

Assignee

• Carl Zeiss Jena GmbH · DE

Inventors

• Manfred Matthae · Jena, DE
• Lothar Schreiber · Jena, DE
• Andreas Faulstich · Aalen, DE
• Werner Kleinschmidt · Dransfeld, DE

Key dates

• Filing date: Aug 15, 2001
• Grant date: Jan 7, 2003
• Expiry date: Aug 15, 2021

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B21/02
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A high-aperture objective comprising a first lens L1 with positive refractive power f1 and a second lens L2 with negative refractive power f2, wherein the focal length ratio between the two lenses is in the range of &#8722;0.4<(f1/f2)<&#8722;0.1 and the total refractive power 1/f1+1/f2 is greater than zero, two positive lenses L3, L4 whose ratio diameter d3, d4 to focal length f3, f4 satisfies the condition greater than 0.3 and less than 0.6:0.3<d3/f3<0.6, 0.3<d4/f4<0.6, a negative lens L5 and a collective lens L6, wherein the negative lens faces the front group and the focal length ratio of L5 and L6 f5/f6 is between &#8722;0.5 and &#8722;2:&#8722;0.5<f5/f6<&#8722;2.