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US4320974A Expired / Lapsed US ⏱️ 0.0 years remaining

Pathlength controller for a ring laser cyroscope

Assignee: Kearfott Guidance and Navigation Corp
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Filing: 1980-06-30
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Granted: 1982-03-23
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Expires: 2000-06-30
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Abstract

Abstract Separate photodetectors and preamplifiers of prior art path controllers are replaced with an electronic circuit using the outputs of gyro fringe detectors. A ring laser gyro ordinarily includes fringe detectors for producing a data signal. Thus, the same detectors are used to serve two purposes. Pathlength controller simplification and cost reduction is thus realized since it is unnecessary to mount and align separate photodetectors to a gyro and to connect these photodetectors via flexible connections to a vibrating gyro.

Inventors

  • 👤 Bo H. G. Ljung

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 16:12
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/58; G01C19/64; G01C19/66; G01C19/661; G01C19/665

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 89 words
In a ring laser gyroscope having a pathlength controlling movable mirror assembly and a fringe detector with dual output signals produced therefrom, the improvement comprising: means connected at the input thereof to the detector output signals for squaring each signal separately; summing means connected at the input thereof to each squared signal for producing a new signal including the summation of squared output signals from the detector; and means connected between the output of the summing means and the movable mirror assembly for maximizing laser intensity in the gyroscope.
Claim 2
Dependent Claim 89 words
In a ring laser gyroscope having a pathlength controlling movable mirror assembly and a fringe detector with dual output signals produced therefrom, the improvement comprising: means connected at the input thereof to the detector output signals for squaring each signal separately; summing means connected at the input thereof to each squared signal for producing a new signal including the summation of squared output signals from the detector; and means connected between the output of the summing means and the movable mirror assembly for maximizing laser intensity in the gyroscope.
Claim 3
Dependent Claim 36 words
The subject matter set forth in claim 1 together with means connected between the summing means and intensity maximizing means for demodulating a modulation component superimposed on the signal from the output of the summing means.
Claim 4
Dependent Claim 32 words
The subject matter set forth in claim 1 together with preamplifier means connected between the outputs of the detector and the inputs of the squaring means for amplifying the detector output signals.
Claim 5
Dependent Claim 34 words
The subject matter set forth in claim 1 wherein the means connected between the output of the summing means and the movable mirror assembly include means for integrating the signal from said summing means.
Claim 6
Dependent Claim 28 words
The subject matter of claim 4 together with second summing means connected to the output of the integrating means for adding a jitter signal to the integrated signal.
Claim 7
Dependent Claim 38 words
The subject matter set forth in claim 5 together with a high voltage amplifier connected in circuit between the output of the second summing means and the movable mirror assembly for increasing the voltage for operating the mirror.
Claim 8
Dependent Claim 208 words
A ring laser gyroscope pathlength control system comprising: a fringe detector with at least dual output signals produced therefrom for detecting the intensity of lasing in a gyroscope; a pathlength controlling movable mirror assembly for reflecting laser light from the surface thereof; means connected at the input thereof to the detector output for squaring each detector output signal separately; preamplifier means connected between the outputs of the detector and the inputs of the squaring means for amplifying the detector output signals; summing means connected at the input thereof to each squared signal for producing a new signal including the summation of squared output signals from the detector; means connected at its input to the output of the summing means for demodulating a modulation component superimposed on the signal from the output of the summing means; means connected between the output of the demodulating means and the movable mirror assembly for integrating the signal from the demodulating means; second summing means connected in series with the output of the integrating means for adding a jitter signal to the integrated signal; and a high voltage amplifier connected in series with the output of the second summing means and the movable mirror assembly for increasing the voltage for operating the mirror.
Claim 9
Dependent Claim 208 words
A ring laser gyroscope pathlength control system comprising: a fringe detector with at least dual output signals produced therefrom for detecting the intensity of lasing in a gyroscope; a pathlength controlling movable mirror assembly for reflecting laser light from the surface thereof; means connected at the input thereof to the detector output for squaring each detector output signal separately; preamplifier means connected between the outputs of the detector and the inputs of the squaring means for amplifying the detector output signals; summing means connected at the input thereof to each squared signal for producing a new signal including the summation of squared output signals from the detector; means connected at its input to the output of the summing means for demodulating a modulation component superimposed on the signal from the output of the summing means; means connected between the output of the demodulating means and the movable mirror assembly for integrating the signal from the demodulating means; second summing means connected in series with the output of the integrating means for adding a jitter signal to the integrated signal; and a high voltage amplifier connected in series with the output of the second summing means and the movable mirror assembly for increasing the voltage for operating the mirror.
Claim 10
Independent Claim 65 words
A method for controlling the pathlength of a laser beam in a ring laser gyroscope equipped with a fringe detector with at least dual output signals produced therefrom and a pathlength controlling movable mirror, the method comprising the steps of: squaring each detector output signal; summing the squared output signals; connecting the summed signals to the movable mirror for maximizing laser intensity in the gyroscope.
Claim 11
Independent Claim 65 words
A method for controlling the pathlength of a laser beam in a ring laser gyroscope equipped with a fringe detector with at least dual output signals produced therefrom and a pathlength controlling movable mirror, the method comprising the steps of: squaring each detector output signal; summing the squared output signals; connecting the summed signals to the movable mirror for maximizing laser intensity in the gyroscope.
Claim 12
Dependent Claim 26 words
The subject matter of claim 8 together with the steps of: demodulating a modulation component superimposed on the summed signal; and integrating the signal after demodulation.
Claim 13
Dependent Claim 22 words
The subject matter set forth in claim 9 together with the step of superimposing a reference jitter signal on the integrated signal.

References Cited (Backward Citations)

US4219276A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-03-22 1985-09-21 1986-03-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-03-22 1989-09-21 1990-03-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-03-22 1993-09-21 1994-03-23 $7700.00 Window Closed / Lapsed

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