US 4,057,351 A · Coherent scanning system for fabric inspection

Abstract

A system is provided for scanning a laser beam across the width of fabric material to be inspected. A scanning mirror receives coherent light from the beam and is mounted to repeatedly swing through a given scan angle. An optical arrangement of mirrors in side-by-side relationship receives the light beam from the scanning mirror and directs it in successive side-by-side parallel directions or channels towards the fabric to irradiate successive areas of the fabric across its width. A de-scanning mirror is mounted to repeatedly swing through the same given scan angle in synchronism with the scanning mirror and a second optical arrangement of mirrors in alignment with the first mentioned mirrors receives the beam after passing through successive areas of the fabric and directs it to the de-scanning mirror. The beam reflected from the de-scanning mirror in turn can then be analyzed.

Claims10

Dependent claims

A coherent scanning system for inspecting a given area of fabric by analysis of the diffraction pattern developed by a single coherent light beam passed through said fabric wherein the cross-sectional area of the light beam is substantially less than said given area including:

a. a scanning mirror receiving said coherent light beam and mounted for repeated swinging movement through a given scan angle;
b. a plurality of first optical means in side-by-side relationship successively receiving said light beam from said scanning mirror and directing it in successive side-by-side parallel directions towards said fabric to irradiate successive areas of said fabric covering said given area;
c. a de-scanning mirror adapted to swing through said given scan angle;
and
d. a plurality of second optical means in side-by-side relationship in alignment with said first optical means respectively for successively receiving said beam after passing through said successive areas of fabric and successively directing the beam to said de-scanning mirror as it swings through said scan angle so that the beam reflected from said de-scanning mirror can be analyzed.

2 more elements

A coherent scanning system for inspecting fabric of a given horizontal width while supported in a vertical plane including, in combination:

a. a coherent light beam source;
b. a left housing positioned on the left side of said vertical plane including a left scanning mirror receiving said light beam, means for oscillating said mirror about a vertical axis through a given scan angle, a plurality of individual left upper plane mirrors positioned on a horizontal row and oriented to successively receive said light beam reflected from said scanning mirror as it swings through said given scan angle and direct said beam in successive parallel directions generally normal to said vertical plane, and a plurality of individual left concave mirrors positioned on a horizontal row in alignment with said parallel directions to successively receive said light beams reflected from said plurality of upper plane mirrors respectively and direct said beam towards said vertical plane such that successive areas in a horizontal row across the width of the fabric in said plane are exposed to said light beam;
c. a right housing positioned on the right side of said vertical plane including a de-scanning mirror, means for oscillating said de-scanning mirror about a vertical axis through said given scan angle in synchronism with said left scanning mirror, and a plurality of lower plane mirrors positioned in a horizontal row and oriented to successively receive said light beam from said left concave mirrors after passing through said vertical plane and reflecting said light beam to said de-scanning mirror as it swings through said given scan angle;
and
d. detector means receiving said light beam from said de-scanning mirror for analyzing time sequential diffraction patterns developed by said beam in passing through fabric in said vertical plane for discerning defects in the fabric material.

2 more elements

Dependencies are inferred from the claim text.

Coherent scanning system for fabric inspection

Life of this patent

Coherent scanning system for fabric inspection

Life of this patent

Abstract

Claims10