Actuator velocity control system for moving a magnetic head in a magnetic disk unit and a magnetic disk unit with said system

Claim 2

An actuator velocity control system of actuator driving mechanism for a magnetic head of magnetic disk unit, comprising outputting the desired velocity of an actuator from a desired velocity output means to an actuator driving mechanism for moving the magnetic head under the actuator velocity control in compliance with the desired velocity so that the values of changes in acceleration in acceleration process of the actuator driving mechanism and at a transition of from the acceleration process to the constant-velocity process thereof are not more than the maximum of changes in negative acceleration in deceleration of the actuator mechanism.

Claim 3

An actuator control system as claimed in claim 1, wherein the desired velocity is outputted from the desired velocity output means to the actuator driving mechanism in such a manner that velocity versus time curve in acceleration process of the actuator driving mechanism approximates sine curve.

Claim 4

A magnetic disk unit with a closed loop of actuator velocity control in compliance with the desired velocity of actuator in driving actuator driving mechanism for moving a magnetic head, comprising a desired velocity output means for outputting the desired velocity to the actuator driving mechanism so that the values of changes in acceleration in acceleration process of the actuator driving mechanism and at a transition of from the acceleration process to the constant velocity process thereof are not more than the maximum of changes in negative acceleration in deceleration of the actuator driving mechanism.

Claim 5

A magnetic disk unit with a closed loop of actuator velocity control in compliance with the desired velocity of actuator in driving actuator driving mechanism for moving a magnetic head, comprising a desired velocity output means for outputting the desired velocity to the actuator driving mechanism so that the values of changes in acceleration in acceleration process of the actuator driving mechanism and at a transition of from the acceleration process to the constant velocity process thereof are not more than the maximum of changes in negative acceleration in deceleration of the actuator driving mechanism.

Claim 6

A magnetic disk unit as claimed in claim 3, wherein the desired velocity output means is a means for outputting the desired velocity to the actuator driving mechanism so that the velocity versus time curve in acceleration process of the actuator driving mechanism approximates a sine curve.

Claim 7

A magnetic disk unit as claimed in claim 3, wherein the desired velocity output means is a means for outputting the desired velocity of one selected from output forms in compliance with a seek length to the actuator driving mechanism.

Claim 8

A magnetic disk unit as claimed in claim 3 or 4, wherein the desired velocity output means is a means for outputting the desired velocity not depending on a distance between the current cylinder and the target cylinder but every constant period in the acceleration process and at the transition of from the acceleration process to the constant velocity process.

Claim 9

A magnetic disk unit comprising a magnetic disk turned on a spindle, a magnetic head for writing/reading which approaches a surface of the magnetic disk in writing/reading, an actuator driving mechanism for moving the magnetic head to the target cylinder position, a position control circuit for driving the actuator driving mechanism, a read/write circuit, an interface circuit through which said magnetic disk unit is interfaced with a host control unit, wherein said magnetic disk unit comprises a target cylinder position register means for storing seek command information from the host control unit as target cylinder position, a cylinder counter means for storing the current position of the magnetic head, a computing means for computing successively remaining seek lengths from values outputted from the target cylinder position register means and values outputted from the current cylinder counter means, a desired velocity output means for outputting the desired velocity in compliance with remaining seek length, a velocity servo circuit means for making an actuator velocity follow-up the desired velocity, and a microprocessor means for controlling the above-mentioned member.

Claim 10

A magnetic disk unit comprising a magnetic disk turned on a spindle, a magnetic head for writing/reading which approaches a surface of the magnetic disk in writing/reading, an actuator driving mechanism for moving the magnetic head to the target cylinder position, a position control circuit for driving the actuator driving mechanism, a read/write circuit, an interface circuit through which said magnetic disk unit is interfaced with a host control unit, wherein said magnetic disk unit comprises a target cylinder position register means for storing seek command information from the host control unit as target cylinder position, a cylinder counter means for storing the current position of the magnetic head, a computing means for computing successively remaining seek lengths from values outputted from the target cylinder position register means and values outputted from the current cylinder counter means, a desired velocity output means for outputting the desired velocity in compliance with remaining seek length, a velocity servo circuit means for making an actuator velocity follow-up the desired velocity, and a microprocessor means for controlling the above-mentioned member.