Method and arrangement for focusing in an optical measurement
US7205518B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 6, 2004 |
| Grant date | Apr 17, 2007 |
| Priority date | — |
| Expiry date | Feb 23, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B21/241
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method and arrangement for focus detection in an optical measuring apparatus. The invention is applicable to focus detection for measuring biological or chemical samples or for compiling an image. The position of a focus for an objective lens in a microscope can be measured more precisely than before. Another aim is to decrease scatter-inflicted interferences in the focusing of samples with a microscope and to reduce reflected light which disturbs focus detection. The aims are accomplished with an inventive solution, in which light reflecting from a measured object is occluded with a mask, positioned essentially in an image plane, and in which, at a suitable distance downstream of the mask, is a detector detecting the space distribution of light. According to a second aspect of the invention, the aims are achieved by a method and arrangement, wherein disturbing reflected light is eliminated by utilizing the polarization of light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.