Stepping motor control method and disk drive apparatus

A disk apparatus comprising:

• a disk having helically or concentric circle-like formed tracks;
• a pick-up for recording on or playing back information from said disk;
• a stepping motor for moving said pick-up in a radial direction of said disk;
• and
• a stepping motor driving means for driving said stepping motor by changing a driving current pattern for driving said stepping motor by 1/4 cycle or more when said stepping motor is initialized after its power supply is turned on so that the state of excitation is synchronized between said stepping motor driving means and said stepping motor.

A disk apparatus comprising:

• a disk having helically or concentric circle-like formed tracks;
• a pick-up for recording on or playing back information from said disk;
• a stepping motor for moving said pick-up in a radial direction of said disk;
• a stepping motor driving means for driving said stepping motor;
• and
• a focus servo or tracking servo means for starting a servo operation after the state of excitation is synchronized between said stepping motor driving means and said stepping motor to make said pick-up follow said tracks on said disk.

A disk apparatus comprising

• a disk having helically or concentric circle-like formed tracks;
• a pick-up for recording on or playing back information from said disk;
• a stepping motor for moving said pick-up in a radial direction of said disk;
• a step-out detecting means for detecting step-out which occurs in said stepping motor;
• and
• a stepping motor driving means for driving said stepping motor by changing a stepping motor driving current pattern by 1/4 cycle or more when said step- out detecting means detects the step-out in said stepping motor so that the state of excitation is synchronized between said stepping motor driving means and said stepping motor.

A disk apparatus comprising:

• a disk having helically or concentric circle-like formed tracks;
• a pick-up for recording on or playing back information from said disk;
• a focus servo means or tracking servo means for making said pick-up follow said tracks on said disk;
• a stepping motor for moving said pick-up in the radial direction of said disk;
• a stepping motor driving means for driving said stepping motor;
• and
• a step-out detecting means for detecting a step-out of said stepping motor, wherein when said step-out detecting means detects the step-out in said stepping motor and servo operation of said focus servo means, or said tracking servo means is turned off, said stepping motor driving means synchronizes a state of excitation between said stepping motor driving means and said stepping motor, and thereafter, said focus servo means or said tracking servo means restarts said servo operation.

A disk apparatus comprising:

• a disk having helically-formed tracks and storing information on said tracks;
• a motor for rotating said disk;
• a pick-up means having a focus servo means and a tracking servo means for reading the information recorded on said disk by following the information stored on said tracks;
• a traverse means having a stepping motor for moving said pick-up by a specified distance;
• and
• a stepping motor driving means for driving said stepping motor at a pulse proportion change rate according to a pulse rate for driving said stepping motor.

A disk apparatus comprising:

• a disk having helically-formed tracks and storing information on said tracks;
• a motor for rotating said disk;
• a pick-up means having a focus servo means and a tracking servo means for reading said information recorded on said disk by following said tracks;
• a traverse means having a stepping motor for moving said pick-up by a specified distance;
• and
• a stepping motor driving means for applying a driving voltage to said stepping motor at an amplitude determined by both a pulse rate for driving said stepping motor and a pulse rate change proportion.

A disk apparatus comprising:

• a disk having helically-formed tracks and storing information on said tracks;
• a motor for rotating said disk;
• a pick-up means having a focus servo means and a tracking servo means for reading said information recorded on said disk by following the information stored on said tracks;
• a traverse means having a stepping motor for moving said pick-up by a specified distance;
• and
• a stepping motor driving means for supplying said stepping motor with a driving voltage that is increased or reduced at an inclination determined by both a pulse rate for driving said stepping motor and a pulse rate change proportion.

A disk apparatus comprising:

• a disk having helically-formed tracks and storing information on said tracks;
• a motor for rotating said disk;
• a pick-up means having a focus servo means and tracking servo means for reading said information recorded on said disk by following the information stored on said tracks;
• a traverse means having a stepping motor for moving said pick-up by a specified distance;
• a pulse rate measuring means for measuring a pulse rate for driving said stepping motor;
• a tracking speed detecting means for detecting a moving speed of a lens from a tracking error signal;
• a pick-up vibration value detecting means for detecting a vibration value of said pick-up by comparing the measured value of said pulse rate measuring means with the measured value of said track speed detecting means;
• and
• a stepping motor driving means for supplying said stepping motor with a driving voltage according to said detected vibration value of said pick-up vibration detecting means.

A disk apparatus comprising:

• a disk having helically-formed tracks and storing information on said tracks;
• a motor for rotating said disk;
• a pick-up means having a focus servo means and a tracking servo means for reading said information recorded on said disk by following the information stored on said tracks;
• a traverse means having a stepping motor for moving said pick-up by a specified distance;
• a pulse rate measuring means for measuring a pulse rate for driving said stepping means;
• a tracking speed detecting means for detecting a tracking speed of said lens from a tracking error signal;
• a pick-up vibration value detecting means for detecting a vibration value of said pick-up by comparing the measured value of said pulse rate measuring means with the measured value of said tracking speed detecting means;
• a tracking actuator driving means for driving a tracking actuator for moving a lens incorporated in a tracking servo means in the tracking direction;
• and
• a switching means for switching an input to said tracking actuator to an output of said tracking servo means or to an output of said pick-up vibration value detecting means.

A disk apparatus comprising:

• a pick-up for reading/writing signals from/on a disk;
• a pick-up base provided with said pick-up;
• a traverse motor for moving said pick-up in a radial direction of said disk;
• a feed screw rotated by said traverse motor and provided with a thread groove on its periphery;
• a rack having a fixing portion fixed to said pick-up base and a nut portion engaged with said thread groove;
• a guiding mechanism for guiding said pick-up movably in a radial direction of said disk;
• and
• a cantilever parallel spring for connecting said fixing portion to said nut portion of said rack, said spring being displaceable in a radial direction of said feed screw.

A disk apparatus comprising:

• a pick-up for reading/writing signals from/on a disk;
• a pick-up base provided with said pick-up;
• a first guide shaft fit in a guide hole provided in said pick-up base and used for guiding said pick-up base slidably in a radial direction of said disk;
• a second guide shaft fit in a guide groove provided on said pick-up base and used for limiting the rotation of said pick-up base around said first guide shaft;
• a shaft holder fixed to said pick-up base at one end and pressed against said second guide shaft at the other end at a position where said other end is separated from said guide groove on one side in an axial direction of said second guide shaft and presses said pick-up base in an direction where the inside face of said guide groove is in contact with said second guide shaft.

A disk apparatus comprising:

• a pick-up for reading/writing signals from/on a disk;
• a pick-up base provided with said pick-up;
• a traverse motor for moving said pick-up in a radial direction of said disk;
• a feed screw rotated by said traverse motor and provided with a thread groove on its periphery;
• a rack having a fixing portion fixed to said pick-up base, a nut portion engaged with said thread groove, and a cantilever parallel spring for connecting said fixing portion to said nut portion;
• a first guide shaft fit in a guide hole provided in said pick-up base and used for guiding said pick-up base slidably in a radial direction of said disk;
• a second guide shaft fit in a guide groove provided on said pick-up base and used for limiting the rotation of said pick-up base around said first guide shaft;
• and
• a shaft holder fixed to said pick-up base at one end and pressed against said second guide shaft at a position where the other end is separated from said guide groove on one side in an axial direction of said second guide shaft and presses said pick-up base in a direction where the inside face of said guide groove is in contact with said second guide shaft, wherein a direction in which said cantilever parallel spring is displaced and a direction in which said shaft holder is pressed against said second guide shaft are orthogonal to each other.

A method for controlling a stepping motor comprising:

• a first driving signal generating means for generating a first driving signal for slowly rotating said stepping motor;
• a second driving signal generating means for generating second driving signal for rapidly rotating said stepping motor;
• and
• a control means for switching a signal generating means between said first driving signal generating means and said second signal generating means, wherein said controlling means, when switching the rotation of said stepping motor from slow to rapid, decides whether or not a rotator of said stepping motor exists near a mechanical stability point of said stepping motor according to a voltage value of a driving signal output from said first driving signal generating means, and wherein when the rotator of said stepping motor exists near a mechanical stability position, said controlling means outputs a command to said second driving signal generating means, and when said second driving signal generating means receives said command, said second driving signal generating means outputs a driving signal for rotating said stepping motor to the next mechanical stability position of said above mechanical stability position, in a rotating direction of said stepping motor.

A method for controlling stepping motors comprising:

• a first driving signal generating means for generating a first driving signal, for slowly rotating said stepping motor;
• a second driving signal generating means for generating second driving signal for rapidly rotating said stepping motor;
• and
• control means for switching a signal generating means between said first driving signal generating means and said second signal generating means, wherein said controlling means, when switching the rotation of said stepping motor from slow to rapid, decides whether or not a rotator of said stepping motor exists near a mechanical stability point of said stepping motor according to a state number owned by said first driving signal generating means, and wherein when the rotator of said stepping motor exists near a mechanical stability position, said controlling means outputs a command to said second driving signal generating means, and when said second driving signal generating means receives said command, said second driving signal generating means outputs a driving signal for rotating said stepping motor to the next mechanical stability position of said above mechanical stability position, in a rotating direction of said stepping motor.

A disk apparatus comprising:

• a disk having helically-formed tracks and storing information on said tracks;
• a motor for rotating said disk;
• a pick-up means having a focus servo means and a tracking servo means for reading information recorded on said disk by following the information stored on said tracks;
• traverse means having a stepping motor for moving said pick-up means by a specified distance;
• pulse generating means for generating pulse signals for controlling said stepping motor;
• stepping motor driving means for driving said stepping motor according to said pulse signals received from said pulse generating means;
• a step-out detecting means for detecting a step-out of said stepping motor;
• and
• a driving voltage changing means for changing a driving voltage of said stepping motor when said step-out detecting means detects the step-out in said stepping motor driving means.

A disk apparatus comprising:

• a having helically-formed tracks and storing information on said tracks;
• a motor for rotating said disk;
• a pick-up means having a focus servo means and a tracking servo means for reading the information recorded on said disk by following the information stored on said tracks;
• a traverse means having a stepping motor for moving said pick-up means by a specified distance;
• a means of generating pulse signals for controlling said stepping motor;
• a means of driving said stepping motor according to said pulse signals received from said pulse signal generating means;
• a means of detecting step-up errors of said stepping motor;
• and
• a means for changing the pulse rate output from said pulse generating means to a specified pulse rate when said step-out detecting means detects a step-out in said stepping motor driving means.

A disk apparatus comprising:

• a disk having helically-formed tracks and storing information on said tracks;
• a motor for rotating said disk;
• a pick-up means having a focus servo means and a tracking servo means for reading the information recorded on said disk by following the information stored on said tracks;
• a traverse means having a stepping motor for moving said pick-up means by a specified distance;
• a pulse generating means for generating pulse signals for controlling said stepping motor;
• a stepping motor driving means of driving said stepping motor according to said pulse signals received;
• a step-out detecting means for detecting a step-out of said stepping motor;
• a step-out count storing means of storing the number of step-out times detected by said step-out detecting means;
• a driving voltage changing means for changing a driving voltage of said stepping motor according to a value stored in said step-out count storing means, said driving voltage changing means being connected to said stepping motor driving means, and pulse rate changing means for changing a frequency of pulses (pulse rate) output from said pulse generating means according to a value stored in said step-out count storing means.