Double servo type magnetic disc apparatus
AssigneesNHK Spring Co., Ltd., Aruga Research LLC
InventorsMasao Hanya, Keiji Aruga
Life of this patent
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Abstract
According to one embodiment, a magnetic disc apparatus includes a magnetic head which reads information stored in a magnetic disc, an arm which supports the magnetic head, and a feedback controller which controls a coarse actuator to move the magnetic head above the magnetic disc by driving the arm, a fine actuator to hold a position of the magnetic head, and a feedback path which feeds back a displacement of the actuator to a target value of the coarse actuator. The feedback controller controls decoupling of a double actuator system which adds up the coarse actuator and the fine actuator.
Claims6
A magnetic disc apparatus comprising:
- a magnetic head which reads information stored in a magnetic disc;
- an arm which supports the magnetic head;
- and
- a feedback controller which comprises:
- a coarse controller configured to control a coarse actuator to move the magnetic head above the magnetic disc by driving the arm,
- a fine controller configured to hold a position of the magnetic head, and
- a feedback path which feeds back a displacement of a fine actuator to a target value of the coarse actuator,
- wherein the feedback controller controls decoupling due to the feedback path of a double actuator system which adds up the coarse actuator and the fine actuator,
- wherein the coarse controller comprises a first amplifier which amplifies a signal input to the coarse controller and a first notch filter which notches an output of the first amplifier, and wherein the coarse controller does not comprise a phase compensator, and
- wherein the fine controller comprises a second amplifier which amplifies a signal input to the fine controller, an integrator which integrates an output of the second amplifier, and a second notch filter which notches an output of the integrator.
A magnetic disc apparatus comprising:
- a magnetic head which reads information stored in a magnetic disc;
- an arm which supports the magnetic head;
- and
- a feedback controller which controls a coarse actuator to move the magnetic head above the magnetic disc by driving the arm, and a fine actuator to hold a position of the magnetic head,
- wherein the feedback controller controls coupling of a double actuator system which adds up the coarse actuator and the fine actuator, and
- wherein the feedback controller comprises, as components thereof:
- a coarse controller which controls the coarse actuator, and which comprises a first amplifier that amplifies an input signal and a first notch filter that notches an output of the first amplifier, wherein the coarse controller does not comprise a phase compensator, and
- a fine controller which controls the fine actuator, and which comprises a second amplifier that amplifies an input signal, an integrator that integrates an output of the second amplifier, and a second notch filter that notches an output of the integrator.
Dependencies are inferred from the claim text.