Device for detecting incipient tears on a sheet during manufacture
US4788442A · kind A · utility
4Cited by
5References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1987 |
| Grant date | Nov 29, 1988 |
| Priority date | — |
| Expiry date | Jun 30, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/8901
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Device for detecting insipient cracks or tears on the edges (4) of a moving heet (5), of the type comprising: PA1 a light source (6), PA1 and a receiving cell for picking up the light transmitted by the source (6) through the sheet (5) moving between the source (6) and the cell, characterized in that: PA1 on the one hand, the light source (6) is a laser source; PA1 and on the other hand, the receiving cell (17) is an optoelectronic cell placed in such a way that the solid angle under which the serviceable surface of said cell (17) or of its image by an optical system, can be seen from the sheet, is less than 0.01 steradian.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.