Autofocus method for microscope and microscope with autofocus device

US9389405B2 · kind B2 · utility

Assignee

• Carl Zeiss Microscopy GmbH · DE

Inventors

• Peter Westphal · Jena, DE
• Reiner Mitzkus · Oettingen, DE

Key dates

• Filing date: Dec 13, 2013
• Grant date: Jul 12, 2016
• Expiry date: Jan 9, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B21/245
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An autofocus method for a microscope with an objective which images a sample lying in an object plane, including the steps: projecting a longitudinally extended grating slit which lies in a grating slit plane onto the sample, and imaging the projection of the grating slit onto an autofocus camera; determining an intensity distribution of the grating slit image and from this, deducing a preset for a relative adjustment of sample and object plane; projecting a likewise longitudinally extended comparison slit onto the sample, and imaging the projection of the comparison slit onto the autofocus camera; evaluating the width of the comparison slit image at right angles to the longitudinal extension at at least two sites which are spaced apart along the longitudinal extension, and determining a width variation of the comparison slit image, a gradient of the width variation and a direction of the relative adjustment.