US4176961A
Expired / Lapsed
US
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Methods and apparatus for improving the resolution of measured parameters
Assignee: AT&T Inc
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Filing: 1977-09-26
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Granted: 1979-12-04
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Expires: 1997-09-26
Abstract
Abstract The diameter of an optical fiber is continuously measured by directing a laser beam at the fiber to form a light intensity fringe pattern. The pattern is converted to a substantially sinusoidal electrical signal having a period proportional to the fiber diameter. The sinusoidal signal is forwarded to a tapped delay line to form a plurality of delayed replicas thereof having a predetermined delay therebetween. A pulse is generated for each zero crossing of all the sinusoidal signals and the pulses interleaved to form an output train having an interpulse interval proportional to a fraction of the fiber diameter.
Inventors
- 👤 Ralph E. Frazee, Jr.
- 👤 David H. Smithgall, Sr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:48
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/08; H; H03; H03K; H03K5/00; H03K5/00006
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
99 words
A method of improving the resolution of a measuring system in which the period, T, of a substantially periodic electrical signal is proportional to a measured parameter, the method comprising the steps of: (a) forming more than two replicas of the periodic electrical signal having a predetermined delay therebetween; (b) generating a pulse at selected corresponding points of all the replicas of the periodic electrical signal to form a pulse train for each replica; and (c) interleaving the pulse trains to form a single output pulse train having an interpulse interval that is a fraction of the period T.
Claim 2
Independent Claim
99 words
A method of improving the resolution of a measuring system in which the period, T, of a substantially periodic electrical signal is proportional to a measured parameter, the method comprising the steps of: (a) forming more than two replicas of the periodic electrical signal having a predetermined delay therebetween; (b) generating a pulse at selected corresponding points of all the replicas of the periodic electrical signal to form a pulse train for each replica; and (c) interleaving the pulse trains to form a single output pulse train having an interpulse interval that is a fraction of the period T.
Claim 3
Dependent Claim
18 words
The method as set forth in claim 1 which is further characterized by accurately maintaining the predetermined delay.
Claim 4
Dependent Claim
89 words
The method as set forth in claim 2 wherein the predetermined delay is accurately maintained by: generating a pulse train having the same frequency as the substantially periodic electrical signal; converting the frequency of the pulse train into a d.c. voltage; filtering the d.c. voltage; converting the filtered d.c. voltage into a timing pulse train having a frequency which is an integral multiple of the substantially periodic electrical signal; and accurately maintaining the delay between the substantially periodic electrical signal replicas under the control of the timing pulse train.
Claim 5
Dependent Claim
61 words
The method as set forth in claim 3 wherein the measured parameter is the diameter of an optical fiber and the method is further characterized by, prior to step (a): directing a monochromatic, coherent beam of light at the optical fiber to form a scattered light intensity fringe pattern; and converting the light intensity fringe pattern into the periodic electrical signal.
Claim 6
Independent Claim
150 words
A method of measuring the diameter of an optical fiber comprising the steps of: directing a laser beam at the optical fiber to form a scattered light intensity fringe pattern; converting the light intensity fringe pattern into an electrical signal; filtering the electrical signal to produce a substantially sinusoidal signal having a period, T, which is proportional to the diameter of the fiber; forming more than two replicas of the sinusoidal signal having a predetermined delay therebetween; accurately maintaining the predetermined delay; passing each replica of the sinusoidal signal to a zero-crossing detector, each detector producing a pulse train representing the zero crossings of the sinusoidal signals; interleaving the pulse trains to form a single output pulse train having an interpulse interval that is a fraction of the period T; and counting the pulses in the single pulse train over a predetermined period of time to determine the fiber diameter.
Claim 7
Independent Claim
150 words
A method of measuring the diameter of an optical fiber comprising the steps of: directing a laser beam at the optical fiber to form a scattered light intensity fringe pattern; converting the light intensity fringe pattern into an electrical signal; filtering the electrical signal to produce a substantially sinusoidal signal having a period, T, which is proportional to the diameter of the fiber; forming more than two replicas of the sinusoidal signal having a predetermined delay therebetween; accurately maintaining the predetermined delay; passing each replica of the sinusoidal signal to a zero-crossing detector, each detector producing a pulse train representing the zero crossings of the sinusoidal signals; interleaving the pulse trains to form a single output pulse train having an interpulse interval that is a fraction of the period T; and counting the pulses in the single pulse train over a predetermined period of time to determine the fiber diameter.
Claim 8
Dependent Claim
92 words
A measuring system, having improved resolution, in which the period, T, of a substantially periodic electrical signal is proportional to a measured parameter, the system comprising: means for forming more than two replicas of the periodic signal having a predetermined delay therebetween; means for generating a pulse at selected corresponding points of all versions of the periodic signals to form a pulse train for each replica; and means for interleaving said pulse trains to form a single output pulse train having an interpulse interval that is a fraction of the period T.
Claim 9
Dependent Claim
92 words
A measuring system, having improved resolution, in which the period, T, of a substantially periodic electrical signal is proportional to a measured parameter, the system comprising: means for forming more than two replicas of the periodic signal having a predetermined delay therebetween; means for generating a pulse at selected corresponding points of all versions of the periodic signals to form a pulse train for each replica; and means for interleaving said pulse trains to form a single output pulse train having an interpulse interval that is a fraction of the period T.
Claim 10
Dependent Claim
23 words
The measuring system as set forth in claim 6, which comprises: means for accurately maintaining the delay between the substantially periodic signal replicas.
Claim 11
Dependent Claim
104 words
The measuring system as set forth in claim 7 wherein the means for accurately maintaining the delay between the substantially periodic signal replicas comprises: a comparator circuit to receive the substantially periodic signal and generate a pulse train having the same frequency; a frequency-to-voltage converter to convert the pulse train output from the comparator circuit to a d.c. voltage; a signal conditioner circuit to filter the d.c. output from the frequency-to-voltage converter; and a voltage controlled oscillator which converts the filtered d.c. voltage to a timing pulse train having a frequency which is an integral multiple of the frequency of the substantially periodic signal.
Claim 12
Dependent Claim
59 words
The measuring system as set forth in claim 7 wherein the measured parameter is the diameter of an optical fiber and the substantially periodic electrical signal is formed by: means for directing a laser beam at the optical fiber to form a scattered light intensity fringe pattern; and means for converting the light intensity pattern into an electrical signal.
Claim 13
Dependent Claim
140 words
A measuring system for measuring the diameter of an optical fiber, comprising: means for directing a laser beam at the optical fiber to form a scattered light intensity fringe pattern; means for converting the light intensity fringe pattern into an electrical signal; means for filtering the electrical signal to produce a substantially sinusoidal signal having a period, T, which is proportional to the diameter of the fiber; means for forming more than replicas of the sinusoidal signal having a predetermined delay therebetween; means for accurately maintaining the predetermined delay; means for producing an output pulse train for each replica of the sinusoidal signal, each pulse train representing the zero crossings of the sinusoidal signals; and means for interleaving the pulse trains to form a single output pulse train having an interpulse interval that is a fraction of the period T.
Claim 14
Dependent Claim
140 words
A measuring system for measuring the diameter of an optical fiber, comprising: means for directing a laser beam at the optical fiber to form a scattered light intensity fringe pattern; means for converting the light intensity fringe pattern into an electrical signal; means for filtering the electrical signal to produce a substantially sinusoidal signal having a period, T, which is proportional to the diameter of the fiber; means for forming more than replicas of the sinusoidal signal having a predetermined delay therebetween; means for accurately maintaining the predetermined delay; means for producing an output pulse train for each replica of the sinusoidal signal, each pulse train representing the zero crossings of the sinusoidal signals; and means for interleaving the pulse trains to form a single output pulse train having an interpulse interval that is a fraction of the period T.
Claim 15
Independent Claim
86 words
A method of measuring the period of a substantially periodic electrical signal, which comprises the steps of: (a) forming at least two delayed replicas of the signal; (b) generating a pulse at selected corresponding points of the periodic electrical signal and each delayed replica thereof to form a series of markers; (c) interleaving the markers to form a single pulse train; and (d) determining, from the number of markers appearing in said single pulse train during a predetermined period of time, the period of the signal.
Claim 16
Independent Claim
86 words
A method of measuring the period of a substantially periodic electrical signal, which comprises the steps of: (a) forming at least two delayed replicas of the signal; (b) generating a pulse at selected corresponding points of the periodic electrical signal and each delayed replica thereof to form a series of markers; (c) interleaving the markers to form a single pulse train; and (d) determining, from the number of markers appearing in said single pulse train during a predetermined period of time, the period of the signal.
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) | 1982-12-03 | 1983-06-04 | 1983-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-03 | 1987-06-04 | 1987-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-03 | 1991-06-04 | 1991-12-04 | $7700.00 | Window Closed / Lapsed |