Contrast improvement optical apparatus and method
US6657787B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 26, 1999 |
| Grant date | Dec 2, 2003 |
| Priority date | — |
| Expiry date | Jan 26, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/46
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical apparatus (10) and method for improving the contrast in an image-forming optical apparatus. The optical apparatus of the invention comprises an illumination optical system (26) for illuminating an object (O). An objective optical system (42) is located adjacent the object and has a transform plane (28). A pupil modulation filter F is arranged at the transform plane and has a transmittance distribution which can be varied from a first transmission distribution (T1) to a second transmission distribution (T2) so that first and second images (I1, I2) can be formed at an image plane (14). A detector (54) is located at the image plane and detects the first and second images. An image synthesizer (58) electrically connected to the detector synthesizes a contrast-improved image from the first and second images.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.