Method for detecting lens cleanliness using spectral differential flat field correction
US11300527B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 2021 |
| Grant date | Apr 12, 2022 |
| Priority date | — |
| Expiry date | Sep 24, 2041 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30108
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for detecting lens cleanliness of a lens disposed in a flat-field optical path, the flat-field optical path including a light source, the lens, a camera, the light source is a narrow-band multispectral uniform surface light source, the camera's light-sensitive surface is disposed perpendicular to an optical axis of the lens and in the light position of the lens, the method including collecting the bright-field image data and dark-field image data in a plurality of spectra through the lens; for each pixel, performing a spectral differential flat-field correction operation to yield a plurality of spectral differentials; and displaying the spectral differentials in the form of a plurality of images to show a uniformity of each of the plurality of images, wherein a non-uniform area on each of the plurality of images is determined to have been caused by an impurity of the lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.