US4866288A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for optically scanning a web of material
Assignee: Erwin Sick GmbH Optik Elektronik
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Filing: 1986-08-15
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Granted: 1989-09-12
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Expires: 2006-08-15
Abstract
Abstract The sharply bounded entry pupil (13) of an optical web monitoring apparatus is imaged by the system after passage through or reflection at the material web onto a dark field stop (16). This stop is provided at its periphery with light receiving surfaces having a relatively small area relative to the extent of the dark field stop (16). These light receiving surfaces conduct the received light to a photoconverter arrangement which is connected to an electronic processing circuit. In this way material faults are detected which bring about only small angular deviations of the scanning beam. In order to detect faults with greater light scattering a multiplier (23) is additionally mounted behind this receiver arrangement and receives light deflected beyond the light receiving surfaces.
Inventors
- 👤 Klaus Weber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:56
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/89; G01N21/8901
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
146 words
Optical web monitoring apparatus which, by means of a deflecting device and image forming optical elements, generates a point of light which cyclically scans the material web transverse to its longitudinal direction and concentrates light deflected or scattered on passage through the material, or on reflection at the material, onto a photoreceiver device, characterized in that a sharply bounded bead of light is generated on the deflecting device (12) which is imaged, through the optical scanning and receiving system (14, 15), onto a complementary dark field stop (16), which is preferably slightly larger than the image of the light bead (13) and which is provided along its periphery with light receiving surfaces (17), which are of small area relative to the extent of the dark field stop (16) and which conduct the received light to the photo-receiver device, which is connected to an electronic processing circuit.
Claim 2
Dependent Claim
146 words
Optical web monitoring apparatus which, by means of a deflecting device and image forming optical elements, generates a point of light which cyclically scans the material web transverse to its longitudinal direction and concentrates light deflected or scattered on passage through the material, or on reflection at the material, onto a photoreceiver device, characterized in that a sharply bounded bead of light is generated on the deflecting device (12) which is imaged, through the optical scanning and receiving system (14, 15), onto a complementary dark field stop (16), which is preferably slightly larger than the image of the light bead (13) and which is provided along its periphery with light receiving surfaces (17), which are of small area relative to the extent of the dark field stop (16) and which conduct the received light to the photo-receiver device, which is connected to an electronic processing circuit.
Claim 3
Dependent Claim
31 words
Apparatus in accordance with claim 1, characterized in that the light receiving surfaces (17) are provided closely adjacent one another distributed over the entire periphery of the dark field stop (16).
Claim 4
Dependent Claim
22 words
Apparatus in accordance with claim 1, characterized in that the light receiving surfaces (17) are connected together to a common photoreceiver (21).
Claim 5
Dependent Claim
35 words
Apparatus in accordance with claim 3, characterized in that respective diametrically oppositely disposed groups of light receiving surfaces (17) are connected together to form pairs of photoelectric signals which are applied to difference amplifiers (29).
Claim 6
Dependent Claim
25 words
Apparatus in accordance with claim 4, characterized in that each group extends over a quadrant (1, 2, 3, 4) of the dark field stop (16).
Claim 7
Dependent Claim
30 words
Apparatus in accordance with claim 1, characterized in that the light receiving surfaces are the end faces of thin circular light conductors (20) which are led individually to photoreceivers (21).
Claim 8
Dependent Claim
43 words
Apparatus in accordance with claim 1, characterized in that the light receiving surfaces (17) are the rectangular end faces of light conductors (20) which each take in one side of a rectangular dark field stop (16) and each lead to a photoreceiver (21).
Claim 9
Dependent Claim
43 words
Apparatus in accordance with claim 1, characterized in that the dark field stop (16) is surrounded radially outside of the light receiving surfaces by a ring-like light entry surface (22) which is connected to a further photoreceiver, in particular to a photomultiplier (23).
Claim 10
Dependent Claim
33 words
Apparatus in accordance with claim 8, characterized in that a reflecting light funnel (24) follows the light entry surface (22) and tapers towards the photoreceiver (23) down to the diameter of the photoreceiver.
Claim 11
Dependent Claim
15 words
The apparatus of claim 1 wherein the bead of light has a circular cross-sectional shape.
Claim 12
Dependent Claim
15 words
The apparatus of claim 1 wherein the bead of light has a rectangular cross-sectional shape.
Claim 13
Dependent Claim
27 words
The apparatus of claim 1 wherein the light receiving surfaces are the end faces of thin circular light conductors (20) which are led to one photoreceiver (21).
Claim 14
Dependent Claim
148 words
Optical web monitoring apparatus which, by means of a deflecting device and image forming optical elements, generates a point of light which cyclically scans the material web transverse to its longitudinal direction and concentrates light deflected or scattered on passage through the material, or on reflection at the material, onto a photoreceiver device, characterized in that a sharply bounded bead of light is generated on a correspondingly shaped physical diaphragm (28), which is imaged, through the optical scanning and receiving system (14, 15), onto a complementary dark field stop (16), which is preferably slightly larger than the image of the light bead (13) and which is provided along its periphery with light receiving surfaces (17), which are of small area relative to the extent of the dark field stop (16) and which conduct the received light to the photo-receiver device, which is connected to an electronic processing circuit.
Claim 15
Dependent Claim
148 words
Optical web monitoring apparatus which, by means of a deflecting device and image forming optical elements, generates a point of light which cyclically scans the material web transverse to its longitudinal direction and concentrates light deflected or scattered on passage through the material, or on reflection at the material, onto a photoreceiver device, characterized in that a sharply bounded bead of light is generated on a correspondingly shaped physical diaphragm (28), which is imaged, through the optical scanning and receiving system (14, 15), onto a complementary dark field stop (16), which is preferably slightly larger than the image of the light bead (13) and which is provided along its periphery with light receiving surfaces (17), which are of small area relative to the extent of the dark field stop (16) and which conduct the received light to the photo-receiver device, which is connected to an electronic processing circuit.
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) | 1992-09-11 | 1993-03-13 | 1993-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-11 | 1997-03-13 | 1997-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-11 | 2001-03-13 | 2001-09-12 | $7700.00 | Window Closed / Lapsed |