Optical deformation measuring apparatus by double-writing speckle images into a spatial light modulator
US5166742A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 1991 |
| Grant date | Nov 24, 1992 |
| Priority date | — |
| Expiry date | Aug 23, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/162
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An object is typically illuminated by laser light, and reflected light carrying a speckle pattern is amplified by an image intensifier. First and second speckle patterns representing the object before and after its deformation, respectively are written by double writing into a ferroelectric liquid crystal spatial light modulator (FLC-SLM). The double-written image is read out from the FLC-SLM, and converted by a Fourier transform optical system into an output optical image, i.e., Young's fringe. The output optical image is detected by a photoelectric converter, and analyzed by an image processing device to determine a deformation of the object.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.