Patent US4168907A successfully refreshed from Google Patents.
US4168907A
Expired / Lapsed
US
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Method for inspecting transparent rods
Assignee: AT&T Inc
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Filing: 1977-12-30
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Granted: 1979-09-25
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Expires: 1997-12-30
Abstract
Abstract A sensitive, nondestructive method of viewing the internal structure of multilayered optical fiber preforms is described. The method comprises the steps of transversely illuminating the preform, and intercepting the light that traverses the preform on a viewing screen. To obtain a complete picture, the preform is rotated 360 degrees about its axis. The technique provides a detailed view of the core size and eccentricity, and of the structure of the multilayered core.
Inventors
- 👤 Herman M. Presby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:50
CPC Classifications
G; G01; G01M; G01M11/00; G01M11/30; G01M11/37; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/8803; G01N21/95; G01N21/958
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
55 words
A method of viewing the internal structure of transparent rods, comprising at least two layers of different refractive index material, including the steps of: transversely illuminating the length of rod to be viewed; intercepting the light that traverses said rod on a viewing screen for displaying a picture of the internal structure of said rod.
Claim 2
Independent Claim
55 words
A method of viewing the internal structure of transparent rods, comprising at least two layers of different refractive index material, including the steps of: transversely illuminating the length of rod to be viewed; intercepting the light that traverses said rod on a viewing screen for displaying a picture of the internal structure of said rod.
Claim 3
Dependent Claim
19 words
The method according to claim 1 wherein said rod is an optical fiber preform having a multilayered core region.
Claim 4
Dependent Claim
13 words
The method according to claim 2 wherein said layers have different refractive indices.
Claim 5
Dependent Claim
17 words
The method according to claim 1 including the step of rotating said rod about its longitudinal axis.
Claim 6
Dependent Claim
16 words
The method according to claim 1 wherein the illuminating light is derived from a coherent source.
Claim 7
Dependent Claim
17 words
The method according to claim 1 wherein said illuminating light is derived from an incoherent light source.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-09-24 | 1983-03-26 | 1983-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-24 | 1987-03-26 | 1987-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-24 | 1991-03-26 | 1991-09-25 | $7700.00 | Window Closed / Lapsed |