Device for detecting incipient tears on a sheet during manufacture
AssigneeCentre Technique De L'industrie Des Papiers, Cartons Et Celluloses
InventorsJacques Sabater, Serge Bauduin
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Abstract
Device for detecting insipient cracks or tears on the edges (4) of a moving heet (5), of the type comprising: a light source (6), 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: on the one hand, the light source (6) is a laser source; 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.
Claims10
A device for detecting insipient cracks or tears on the edges of a moving sheet comprising:
- a laser light source, and
- an opto-electronic receiving cell for receiving the light transmitted by the laser light source through the sheet moving continuously between the laser light source and the receiving cell, wherein the receiving cell is placed whereby a solid angle under which the serviceable surface of said cell, or of an image of the serviceable surface of said cell produced by an optical system, can be seen from said moving sheet of paper is less than 0.01 steradian.
A device for detecting insipient cracks or tears on the edges of a moving sheet consisting of a U-shaped assembly, comprising two branches which are joined to a casing said branches encasing opposingly disposed a laser source and a receiving cell for receiving the light transmitted by the laser source through the sheet moving continuously between the branches of the U-shaped assembly, wherein said receiving cell is an optoelectronic cell comprising a diaphragm inserted between the moving sheet and the cell, or the image thereof via an optical system, and
- said receiving cell being placed whereby the solid angle under which the serviceable surface of said cell, or of an image of the serviceable surface of said cell produced by an optical system, can be seen from the moving sheet is less than 0.01 steradian.
Dependencies are inferred from the claim text.