US4726677A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Autofocused lightguide preform profiler
Assignee: Furukawa Electric North America Inc
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Filing: 1986-12-22
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Granted: 1988-02-23
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Expires: 2006-12-22
Abstract
Abstract A method for automatically determining the refractive index profile of a lightguide preform.
Inventors
- 👤 Werner J. Glantschnig
- 👤 Albert Holliday
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:25
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/41; G01N21/412
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
202 words
A method of determining the refractive index profile of a lightguide preform by directing a beam of light through a focusing lens to cause said beam to converge towards the focal plane of the lens and then diverge and impinge upon an apparatus which detects deflection angles of the beam to determine the refractive index profile of the preform, comprising the steps of: imparting relative motion between the beam and the preform, the longitudinal axis of the preform being substantially perpendicular to the axis of the beam, until the edge of said preform is detected; imparting relative motion between the beam and the preform until the beam no longer contacts the preform; moving the preform parallel to the axis of the beam until said preform contacts the beam; moving the preform parallel to the axis of the beam in the opposite direction until said preform contacts the beam on the opposite side of the focal plane while periodically monitoring the deflection angle of the beam; determining the position of the focal plane based upon the deflection angle information; moving the preform axis into the focal plane; and scanning the preform with the beam of light to determine the refractive index profile thereof.
Claim 2
Independent Claim
202 words
A method of determining the refractive index profile of a lightguide preform by directing a beam of light through a focusing lens to cause said beam to converge towards the focal plane of the lens and then diverge and impinge upon an apparatus which detects deflection angles of the beam to determine the refractive index profile of the preform, comprising the steps of: imparting relative motion between the beam and the preform, the longitudinal axis of the preform being substantially perpendicular to the axis of the beam, until the edge of said preform is detected; imparting relative motion between the beam and the preform until the beam no longer contacts the preform; moving the preform parallel to the axis of the beam until said preform contacts the beam; moving the preform parallel to the axis of the beam in the opposite direction until said preform contacts the beam on the opposite side of the focal plane while periodically monitoring the deflection angle of the beam; determining the position of the focal plane based upon the deflection angle information; moving the preform axis into the focal plane; and scanning the preform with the beam of light to determine the refractive index profile thereof.
Claim 3
Dependent Claim
212 words
Apparatus for automatically determining the refractie index profile of a lightguide preform by directing a beam of light through a focusing lens to cause said beam to converge towards the focal plane of the lens and then diverge and impinge upon an apparatus which detects deflection angles of the beam to determine the refractive index of the preform, comprising: means for imparting relative motion between the beam and the preform, the longitudinal axis of the preform being substantially perpendicular to the axis of the beam, until the edge of the preform is detected; means for imparting relative motion between the beam and the preform until the beam no longer contacts the preform; means for moving the preform parallel to the axis of the beam until said preform contacts the beam; means for moving the preform parallel to the axis of the beam, in the opposite direction, until said preform contacts the beam, on the opposite side of the focal plane, while periodically monitoring the deflection angle of the beam; means for determining the position of the focal plane based upon the deflection angle information; means for moving the preform axis into the focal plane; and means for scanning the preform with the beam of light to determine the refractive index profile thereof.
Claim 4
Dependent Claim
212 words
Apparatus for automatically determining the refractie index profile of a lightguide preform by directing a beam of light through a focusing lens to cause said beam to converge towards the focal plane of the lens and then diverge and impinge upon an apparatus which detects deflection angles of the beam to determine the refractive index of the preform, comprising: means for imparting relative motion between the beam and the preform, the longitudinal axis of the preform being substantially perpendicular to the axis of the beam, until the edge of the preform is detected; means for imparting relative motion between the beam and the preform until the beam no longer contacts the preform; means for moving the preform parallel to the axis of the beam until said preform contacts the beam; means for moving the preform parallel to the axis of the beam, in the opposite direction, until said preform contacts the beam, on the opposite side of the focal plane, while periodically monitoring the deflection angle of the beam; means for determining the position of the focal plane based upon the deflection angle information; means for moving the preform axis into the focal plane; and means for scanning the preform with the beam of light to determine the refractive index profile thereof.
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) | 1991-02-22 | 1991-08-24 | 1992-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-22 | 1995-08-24 | 1996-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-22 | 1999-08-24 | 2000-02-23 | $7700.00 | Window Closed / Lapsed |