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US 6,639,680 B1Granted
Ring laser gyro and driving method therefor with improved driving current
AssigneeCanon Kabushiki Kaisha
InventorTakahiro Numai
Life of this patent
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Abstract
To make a time averaged value of a driving current small. After a current I1 of a first current value not less than an oscillation threshold is injected to a semiconductor laser gyro, a current I2 of a second current value smaller than the first current value is injected.
Claims24
A ring laser gyro comprising:
- first means for injecting a first current having a first current value not less than an oscillation threshold value to said ring laser gyro;
- second means for injecting a second current having a second current value smaller than the first current value to said ring laser gyro;
- and
- an optical waveguide for propagating a first laser beam and a second laser beam,
- wherein the first laser beam and the second laser beam are circularly counterpropagated, and the first laser beam and the second laser beam have different oscillation frequencies when said ring laser gyro is stationary.
2 more elements
A method for driving a ring laser gyro, comprising the steps of:
- injecting a first current having a first current value not less than an oscillation threshold value to the ring laser gyro, and
- injecting, after the first current is injected, a second current having a second current value, smaller than the first current value, to the ring laser gyro,
- wherein, with either of the first and second currents, a first laser beam and a second laser beam are circularly counterpropagated in the ring laser gyro, and the first laser beam and the second laser beam have different oscillation frequencies when the ring laser gyro is stationary.
A method for driving a ring laser gyro comprising the steps of:
- injecting a first current having a first current value not less than an oscillation threshold value to the ring laser gyro;
- injecting, after the first current is injected, a second current having a second current value smaller than the first current value to the ring laser gyro;
- and
- repeating both the injection of the first current and the injection of the second current at least once,
- wherein, with either of the first and second currents, a first laser beam and a second laser beam are circularly counterpropagated in the ring laser gyro, and the first laser beam and the second laser beam have different oscillation frequencies when the ring laser gyro is stationary.
2 more elements
Dependencies are inferred from the claim text.