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US 7,397,211 B2Granted
Motor control apparatus
AssigneeCanon Kabushiki Kaisha
InventorSatoru Ishikawa
Life of this patent
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Abstract
A motor control apparatus includes a first FG pattern for generating a first induced voltage attendant upon rotation of the rotor of a motor; a second FG pattern for generating a second induced voltage due to noise; a differential amplifier for differentially amplifying the first and second induced voltages, which are input thereto; and a motor speed control unit for controlling rotation of the motor so as to achieve synchronization between the output of the differential amplifier and a prescribed frequency signal.
Claims11
A motor control apparatus comprising:
- a rotation signal generator configured to generate a first induced voltage attendant upon rotation of a rotor of a motor;
- a noise signal generator arranged adjacent to said rotational signal generator and configured to generate a second induced voltage due to noise independent from the rotation of the rotor;
- a differential amplifier configured to differentially amplify the first and second induced voltages, which are input thereto;
- and
- a motor rotation control unit configured to control rotation of the motor so as to achieve synchronization between the output of the differential amplifier and a prescribed frequency signal,
- wherein said differential amplifier subtracts the second induced voltage from the first induced voltage to output a signal in which the noise has been removed.
3 more elements
Dependencies are inferred from the claim text.