Light trap for surgical operation microscopes

US4715704A · kind A · utility

Assignee

• Carl Zeiss Stiftung · DE

Inventors

• Klaus Biber · Aalen, DE
• Gerhard Unold · Oberkochen, DE

Key dates

• Filing date: Oct 21, 1986
• Grant date: Dec 29, 1987
• Expiry date: Oct 21, 2006

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61F2009/0087
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A microscope for examinations and surgical operations on the eye, having provision for projecting onto the eye a hollow beam of illuminating light, the beam having a dark center portion of the same diameter as the pupil of the eye. Thus the surgeon may have adequate illumination of the external surface of the eye around the pupil, without projecting light which might be disturbing or damaging to the patient, onto the retina or fundus of the eye. The light blocking structure, in the form of an annular diaphragm with a light-impervious central portion, is located in the illuminating light beam at a point which is conjugated with respect to the object plane, i.e., the plane of the pupil of the eye being examined. The diaphragm may be moved aside to an ineffective position when required.