Patent ID: 7333202
Filing Date: 2008-02-19
Classification: G01N

Abstract:
1. A yarn sensor for optically scanning a yarn traveling in its lengthwise direction through a measurement gap, comprising: a light source for projecting a beam of light across the measurement gap, the light source comprising an emitter having an emission characteristic approaching a characteristic of a Lambert emitter, at least one receiver for directly transmitted light, elements for transmitting the light between the light source, measurement gap and the at least one receiver, comprising: a first light transmitting element disposed between the light source and the measurement gap and including a diaphragm and a lens, downstream of the light source in the direction of light projection, and arranged such that the diaphragm is projected at least approximately into infinity, and a diffusor disposed between the light source and the diaphragm, the diffusor being adapted to shape the light beam passing through the diaphragm symmetrically to the optical axis of the lens.