Compact fiber optic electronic laser speckle pattern interferometer
US6043870A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 1, 1997 |
| Grant date | Mar 28, 2000 |
| Priority date | — |
| Expiry date | Jul 1, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/162
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Material defects and damage are detected and evaluated by stressing the material and looking for flaw-induced anomalies in a fringe pattern generated by the interference between two coherent laser beams and electronic image processing. In terms of apparatus, the system includes a sensor head and a head-mounted display (HMD) interfaced to a computer, power supply, and control electronics. In one embodiment, the sensor head contains a thermal stressing unit and an in-plane displacement sensitive ESPI arrangement which measures the in-plane displacement of the deformation induced by applying thermal stressing. In operation, a thermal stressing unit is integrated with the sensor head to provide a slight temperature difference between a localized region and surrounding areas, with the change in temperature being used to reveal the defects and damage through the interference between the two laser beams and electronic image processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.