US3752586A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Minimizing frequency locking in ring laser gyroscopes
Assignee: Boeing North American Inc
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Filing: 1969-08-04
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Granted: 1973-08-14
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Expires: 1989-08-04
Abstract
Abstract A ring laser gyroscope utilizes a pair of oppositely rotating beams which are given a difference frequency in accordance with the rotation rate of their optical paths. A plurality of frequency modulated bias signals are imposed upon the beams, the modulation indices of these frequency modulation signals being chosen to minimize the effects of frequency locking at low rotation rates.
Inventors
- 👤 T Hutchings
- 👤 J Winocur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:01
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/58; G01C19/64; G01C19/66; G01C19/68
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
87 words
A method for minimizing the frequency locking of a ring laser gyroscope comprising the steps of: generating first and second laser beams; causing said beams to rotate in a ring path in opposite directions around said path, said beams thus being caused to oscillate; freqUency modulating said beams in phase opposition to each other with a plurality of signals of mutually different frequencies, each of said signals having a predetermined modulation index; and adjusting the modulation indices of said signals to minimize frequency locking of said beams.
Claim 2
Independent Claim
87 words
A method for minimizing the frequency locking of a ring laser gyroscope comprising the steps of: generating first and second laser beams; causing said beams to rotate in a ring path in opposite directions around said path, said beams thus being caused to oscillate; freqUency modulating said beams in phase opposition to each other with a plurality of signals of mutually different frequencies, each of said signals having a predetermined modulation index; and adjusting the modulation indices of said signals to minimize frequency locking of said beams.
Claim 3
Dependent Claim
33 words
The method of claim 1 wherein said beams are frequency modulated by applying magnetic fields which vary in accordance with said signals to an optical material in the optical path of said beams.
Claim 4
Dependent Claim
32 words
The method of claim 1 wherein said modulation indices are adjusted so as to cause the carrier of the beat signal generated between the frequency modulated signals to go substantially to zero.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein the modulation indices are each adjusted to one of the following: (1.2, 2.75, 4.3).
Claim 6
Dependent Claim
33 words
The method of claim 1 wherein in adjusting said modulation indices, the modulation frequencies are set so they are beyond the frequency corresponding to highest rotation rate to be measured by said gyroscope.
Claim 7
Dependent Claim
20 words
The method of claim 5 wherein the frequencies of said plurality of signals are substantially different, one from the other.
Claim 8
Independent Claim
63 words
A method for minimizing the frequency locking of a ring laser gyroscope comprising: frequency modulating the beams of said laser with a first signal, frequency modulating the beams of said laser with a second signal, and adjusting said first and second modulation indices to values at which the amplitude of the carrier of the beat difference signal developed between said beams is minimized.
Claim 9
Independent Claim
63 words
A method for minimizing the frequency locking of a ring laser gyroscope comprising: frequency modulating the beams of said laser with a first signal, frequency modulating the beams of said laser with a second signal, and adjusting said first and second modulation indices to values at which the amplitude of the carrier of the beat difference signal developed between said beams is minimized.
Claim 10
Dependent Claim
88 words
In a ring laser gyro including means for generating a pair of oppositely rotating beams, means for minimizing frequency locking of said beams comprising: an optical member interposed in the path of said beams, at least two A-C modulation means for imposing a plurality of magnetic fields on said optical member so as to frequency modulate said beams, and means for adjusting the frequency and amplitude of said modulation means to set the modulation indices of the modulation of said beams so as to minimize frequency locking thereof.
Claim 11
Dependent Claim
88 words
In a ring laser gyro including means for generating a pair of oppositely rotating beams, means for minimizing frequency locking of said beams comprising: an optical member interposed in the path of said beams, at least two A-C modulation means for imposing a plurality of magnetic fields on said optical member so as to frequency modulate said beams, and means for adjusting the frequency and amplitude of said modulation means to set the modulation indices of the modulation of said beams so as to minimize frequency locking thereof.
Claim 12
Dependent Claim
23 words
The device of claim 8 wherein said optical member has electrical windings thereon, said modulation means including A-C sources connected to said windings.
Claim 13
Dependent Claim
19 words
The device of claim 9 wherein said plurality of magnetic fields frequency modulate said beams at mutually different frequencies.
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) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |