US4116566A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Line scanning device for detecting defects in webs of material
Assignee: Erwin Sick GmbH Optik Elektronik
•
Filing: 1976-11-03
•
Granted: 1978-09-26
•
Expires: 1996-11-03
Abstract
Abstract A line scanning device for detecting defects in webs of material, wherein a laser light source throws a light spot by way of an objective, a light deflector device, and a cylindrical lens onto a web of material moving parallel to its surface, the light spot periodically scanning the web at right angles to the direction of its movement and parallel to its surface, and wherein a light receiving arrangement comprising a rod light guide and at least one photoreceiver is disposed parallel to the web of material and to the direction of scanning. The rod light guide carries a step mirror arrangement on that side of its periphery lying opposite the light inlet, and a light-scattering cylindrical lens grid, the axes of whose lenses extend in the scanning direction, is disposed between the light source and the objective.
Inventors
- 👤 Erwin Sick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:59
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/89; G01N21/8901
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
217 words
In a line scanning device for detecting defects in webs of material, wherein a laser light source throws a light spot by way of an objective, a light deflector device, and a cylindrical lens onto a web of material moving parallel to its surface, said light spot periodically scanning the web at right angles to the direction of its movement and parallel to its surface, and wherein a light receiving arrangement comprising a rod light guide having a first surface, a second surface opposite said first surface and having a longitudinal axis and at least one photoreceiver is disposed parallel to the web of material and to the direction of scanning; the improvement comprising a step mirror arrangement carried by said rod light guide along said first surface and parallel to said axis, on that side of its periphery lying opposite the light inlet to said guide, and comprising a plurality of mirrors inclined with respect to said longitudinal axis, and arranged substantially exactly one behind the other when looking in the direction of said axis such that light reflected by said mirrors impinges on said second surface at angles of total reflection, and a light-scattering cylindrical lens grid, the axes of whose lenses extend in the scanning direction, disposed between the light source and said objective.
Claim 2
Dependent Claim
217 words
In a line scanning device for detecting defects in webs of material, wherein a laser light source throws a light spot by way of an objective, a light deflector device, and a cylindrical lens onto a web of material moving parallel to its surface, said light spot periodically scanning the web at right angles to the direction of its movement and parallel to its surface, and wherein a light receiving arrangement comprising a rod light guide having a first surface, a second surface opposite said first surface and having a longitudinal axis and at least one photoreceiver is disposed parallel to the web of material and to the direction of scanning; the improvement comprising a step mirror arrangement carried by said rod light guide along said first surface and parallel to said axis, on that side of its periphery lying opposite the light inlet to said guide, and comprising a plurality of mirrors inclined with respect to said longitudinal axis, and arranged substantially exactly one behind the other when looking in the direction of said axis such that light reflected by said mirrors impinges on said second surface at angles of total reflection, and a light-scattering cylindrical lens grid, the axes of whose lenses extend in the scanning direction, disposed between the light source and said objective.
Claim 3
Dependent Claim
20 words
A device according to claim 1, wherein the cylindrical lens grid is situated at the focal point of the objective.
Claim 4
Dependent Claim
22 words
A device according to claim 1, wherein the cylindrical lens grid is axially displaced slightly from the focal point of the objective.
Claim 5
Dependent Claim
27 words
A device according to claim 3, wherein the distance from the focal point amounts to from 5 to 20 percent, of the focal length of the objective.
Claim 6
Dependent Claim
20 words
A device according to claim 1, wherein the cylindrical lens grid is displaceable in the direction of the optical axis.
Claim 7
Dependent Claim
31 words
A device according to claim 1, wherein the cross-section of the light beam falling on the cylindrical lens grid covers at least five juxtaposed negative lenses of the cylindrical lens grid.
Claim 8
Dependent Claim
13 words
A device according to claim 1, wherein the rod light guide is circular.
Claim 9
Dependent Claim
29 words
A device according to claim 1, wherein the diameter of the rod light guide is at least five times as great as the width of the step mirror arrangement.
Claim 10
Dependent Claim
15 words
A device according to claim 8, wherein said diameter is about twenty times said width.
Claim 11
Dependent Claim
23 words
A device according to claim 1, wherein the light beam passes through a beam widening optical system before it impinges on the objective.
Claim 12
Dependent Claim
18 words
A device according to claim 10, wherein the widening optical system comprises first and second crossed cylindrical lenses.
Claim 13
Dependent Claim
25 words
A device according to claim 11, wherein the axis of the first cylindrical lens extends at right angles to the axis of the mirror wheel.
Claim 14
Dependent Claim
24 words
A device according to claim 11, wherein the focal length of the first and second cylindrical lenses are in the ratio of approximately 10:1.
Claim 15
Dependent Claim
23 words
A device according to claim 11, wherein the focal line of the second cylindrical lens coincides with the focal point of the objective.
Claim 16
Dependent Claim
40 words
A device according to claim 1, wherein a light-scattering cylindrical lens grid comprising negative cylindrical lenses extending at right angles to the axis of the rod light guide is provided between the web of material and the light receiving arrangement.
Claim 17
Dependent Claim
22 words
A device according to claim 11, wherein the first cylindrical lens is adapted to be displaceable in the axial direction or exchangeable.
Claim 18
Dependent Claim
31 words
A device according to claim 1, wherein between the web of material and the rod light guide a cylindrical lens is disposed which concentrates the light on the step mirror arrangement.
Claim 19
Dependent Claim
35 words
A device according to claim 1, wherein the light inlet of an Ulbricht sphere, at whose light outlet the photoreceiver is disposed, is provided at at least one end face of the rod light guide.
Claim 20
Dependent Claim
28 words
A device according to claim 18 wherein the direct light path from the light inlet to the light outlet of the Ulbricht sphere is interrupted by a diaphragm.
Claim 21
Dependent Claim
22 words
A device according to claim 18, wherein at the other end of the rod light guide an Ulbricht sphere is likewise provided.
Claim 22
Dependent Claim
25 words
A device according to claim 18, wherein the light inlet and light outlet openings of the Ulbricht sphere are at right angles to one another.
Claim 23
Dependent Claim
21 words
A device according to claim 16, wherein at the other end of the rod light guide a mirror coating is provided.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-25 | 1982-03-27 | 1982-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-25 | 1986-03-27 | 1986-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-25 | 1990-03-27 | 1990-09-26 | $7700.00 | Window Closed / Lapsed |