Method and apparatus for estimating an in-focus position
US9835837B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 15, 2014 |
| Grant date | Dec 5, 2017 |
| Priority date | — |
| Expiry date | Dec 31, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B21/367
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for estimating an in-focus position of a target using an image scanning apparatus is provided. The in-focus position is monitored at a seed location and an end location on the target and a pre-scan path is calculated between these locations. A pre-scan is then performed and a focus parameter is monitored for a plurality of locations along the pre-scan path. An imaging scan is next performed wherein the target is imaged along an image scan path and a focus parameter is monitored for a plurality of locations along said path. The focal height of the apparatus is adjusted during the imaging scan by comparing the focal parameter monitored for a current location on the image scan path with the focal parameter monitored for a similar location on the pre-scan path. The focal parameter monitored for different locations on the image scan path may also be compared.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.