Adjustable fourier mask
US5742422A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 1995 |
| Grant date | Apr 21, 1998 |
| Priority date | — |
| Expiry date | Sep 19, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/95623
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A Fourier mask includes a base plate, an aperture plate having a pair of cross hairs fixedly mounded on the base plate and a pair of four bar linkages, each four bar linkage being made up of a pair of parallel cross bars and a pair of parallel mask bars pivotally interconnected end-to-end in a closed loop configuration. Each cross bar in each four bar linkage is pivotally mounted on the base plate, the four bar linkages being arranged on the base plate such that the mask bars in one four bar linkage are at right angles to the mask bar in the other four bar linkage and each pair of parallel mask bars is symmetrically disposed about one of the cross hairs. By pivotally moving either or both sets of cross bars on the base plate, the spacing between the parallel mask bars in either a both sets of mask bars can be changed as desired.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.