US4952226A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lightguide coating control
Assignee: Furukawa Electric North America Inc
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Filing: 1989-02-27
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Granted: 1990-08-28
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Expires: 2009-02-27
Abstract
Abstract A laser (20) directs a laser beam at an optical fiber (12) and the resulting forward-scattered light is detected by a detector (21). The energy of the foward-scattered laser light is monotonically inversely proportional to the thickness of a carbon coating on the optical fiber. A computer (22) generates an electrical signal for controlling carbon coating thickness by driving a valve (24) to control the flow of acetylene from a source (14) used to coat the optical fiber in a coating chamber (13).
Inventors
- 👤 Ralph E. Frazee, Jr.
- 👤 David H. Smithgall, Sr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:18
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/07; C03C; C03C25/00; C03C25/10; C03C25/104; C03C25/12; C03C25/22; C03C25/223; G; G05; G05D; G05D5/00; G05D5/02; G05D5/03
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
134 words
A method for making optical fibers comprising the steps of drawing a glass fiber from a heated glass body, directing the fiber through a coating chamber, exposing the fiber in the coating chamber to a carbon-containing gas compound, thereby to coat the glass fiber with a carbonaceous coating to a thickness of 1000 angstroms or less, and thereafter coating the glass fiber with a polymer coating, characterized by: directing a laser beam at the fiber after it has been coated with polymer, the impingement of the beam on the optical fiber resulting in a forward-scattered light pattern; using the intensity of said pattern to generate a signal which is a function of the thickness of the carbonaceous coating; and using the signal to control the thickness of the carbonaceous coating in the coating chamber.
Claim 2
Independent Claim
134 words
A method for making optical fibers comprising the steps of drawing a glass fiber from a heated glass body, directing the fiber through a coating chamber, exposing the fiber in the coating chamber to a carbon-containing gas compound, thereby to coat the glass fiber with a carbonaceous coating to a thickness of 1000 angstroms or less, and thereafter coating the glass fiber with a polymer coating, characterized by: directing a laser beam at the fiber after it has been coated with polymer, the impingement of the beam on the optical fiber resulting in a forward-scattered light pattern; using the intensity of said pattern to generate a signal which is a function of the thickness of the carbonaceous coating; and using the signal to control the thickness of the carbonaceous coating in the coating chamber.
Claim 3
Dependent Claim
41 words
The method of claim 1, further characterized in that: as the fiber is directed through the coating chamber, the coating is made by contacting the fiber with a gas containing carbon so as to form a carbonaceous coating on the fiber.
Claim 4
Dependent Claim
24 words
The method of claim 2, further characterized in that: the signal is used to control the flow of the gas to the coating chamber.
Claim 5
Dependent Claim
13 words
The method of claim 3, further characterized in that: the gas includes acetylene.
Claim 6
Dependent Claim
32 words
The method of claim 3 further characterized in that: the uncoated glass fiber has a diameter of approximately 125 microns and the outer diameter of the polymer coating is approximately 250 microns.
Claim 7
Dependent Claim
71 words
The method of claim 3 further characterized in that: the intensity of the forward-scattered light is detected by inserting a screen in the path of the forward-scattered light and directing a television camera at the screen, and the signal is a first electrical output signal of the television camera which is a function of the forward-scattered light intensity, such intensity being monotonically inversely proportional to the thickness of the carbonaceous coating.
Claim 8
Dependent Claim
48 words
The method of claim 6 further characterized in that: the first electrical output signal of the television camera is directed to a computer which generates a second electrical signal and the second electrical signal controls a valve that controls the flow of carbon-containing gas into the coating chamber.
Claim 9
Dependent Claim
99 words
The method of claim 3 further characterized in that: the laser beam is split into two components which are directed at the optical fiber at right angles to each other; the forward-scattered light from each of the laser beams is detected by locating two screens such that each screen intercepts forward-scattered light from one of the two laser beam components; and two television cameras are used to generate third electrical signals indicative of the intensity on the two screens; the third electrical signals being combined to form said signal which is a function of the thickness of the coating.
References Cited (Backward Citations)
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Cited
US4210431A
Cited
FR2493302A1
Cited
SU1006402A1
Cited
JPS58140605A
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US4450333A
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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) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |