Non-contact perforation/pinhole detection system for opaque vessels
US5451773A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 1994 |
| Grant date | Sep 19, 1995 |
| Priority date | — |
| Expiry date | Sep 1, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9036
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for detecting a side wall perforation in containers operates non-invasively and at line speeds. A stream of similar containers are communicated to an inspection area. An exterior of each container is illuminated while the container is in the inspection area. Light from an interior of the container is focused, via a lens, to a video camera. Any perforate flaw in the container walls results in a point source of light in the container interior. Since the perforations are relatively small, the point source is created due to diffractive properties of the slit perforation. These diffractive properties facilitate obtaining an image of the flaw from the camera disposed to the interior of the container when the camera is mounted orthogonally to the perforation or parallel to the wall being inspected. In an other embodiment, the relative positions of the light source and camera are interchanged. A method for container inspection is also provided in connection with the afore-noted structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.