Method for quantitatively determining petal piston in a segmented imaging assembly
US5124542A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 30, 1990 |
| Grant date | Jun 23, 1992 |
| Priority date | — |
| Expiry date | Nov 30, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method suitable for determining piston in a segmented imaging assembly. The assembly preferably comprises a source of radiation that outputs a radiation beam; and, a segmented imaging system comprising a reference component and a test component, which components can be used to form an imaged radiation beam. The method comprises the steps of intercepting preselected portions of the imaged radiation beam with a mask, for masking at least one portion of at least one of the reference component and the test component, so that a portion of the imaged radiation beam incurs a predetermined and differential phase retardation, relative to another portion of the beam passing through the mask. These actions create a real time masked image. A step of comparing the real time masked image against a family of off-line images generated for a sequence of known petal position errors, can provide a determination of the magnitude of the real time test component piston.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.