Method and apparatus for speckle-shearing interferometric deformation analysis
US4682892A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 30, 1985 |
| Grant date | Jul 28, 1987 |
| Priority date | — |
| Expiry date | Aug 30, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/162
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A nondestructive means of testing tires for subsurface defects by speckle-shearing interferometry. The tire is illuminated with a beam of coherent light. The light reflected from a surface of the tire is directed through a converging lens having one-half of one of its surfaces covered by a transparent plate having flat parallel sides such that a photographic media is exposed to a first pair of focused images of the tire displaced with respect to one another. The tire is then subjected to a stress, and a second pair of slightly displaced images is recorded on the same photographic media. The photographic media is developed to form a transparency, and then a first surface of the developed photographic media is illuminated with a collimated white light source. Interference fringes that are observed by viewing the opposite surface of the photographic media may then be analyzed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.