Method and apparatus for controlling disc drive using counter-electromotive force

A method of controlling a disc drive using a counter-electromotive force, the method comprising:

• detecting a voltage applied to a voice coil during a predetermined mode;
• performing an operation of the value of the counter-electromotive force using the voice coil voltage;
• comparing the value of the counter-electromotive force operated with a predetermined threshold;
• and
• when the value of the counter-electromotive force is equal to or larger than the predetermined threshold, controlling a voice coil motor and a spindle motor so that a current mode is stopped and a parking or unloading mode is executed,
• wherein the predetermined threshold is calculated from a regression function corresponding to a statistical correlation between the magnitude of an external shock and the counter-electromotive force.

A method of controlling a disc drive using a counter-electromotive force, the method comprising:

• detecting a moving distance variation ΔLh/Δt of a transducer with respect to a variation in time during a predetermined mode;
• performing an operation of a value of the counter-electromotive force by applying the detected moving distance variation ΔLh/Δt of the transducer with respect to the variation in time to a predetermined counter-electromotive force calculation Equation;
• comparing the value of the counter-electromotive force with a predetermined threshold;
• and
• when the value of the counter-electromotive force is equal to or larger than the predetermined threshold, controlling a voice coil motor and a spindle motor so that a current mode is stopped and a parking or unloading mode is executed.

A disc drive, comprising:

• a disc having a surface;
• a spindle motor to rotate the disc;
• a transducer to write and read information in and from the disc;
• a voice coil motor to move the transducer;
• and
• a controller to control the spindle motor and the voice coil motor according to a set mode, and to perform a shock damage prevention process of controlling the voice coil motor and the spindle motor, so that a current mode is stopped and a parking or unloading mode is executed if a counter-electromotive force operation process of performing an operation of a value of a counter-electromotive force using a voltage detected from the voice coil and the value of the counter-electromotive force are equal to or larger than a predetermined threshold value,
• the voltage detected from the voice coil being determined according to a position error of the transducer.

A disc drive, comprising:

• a disc having a surface;
• a spindle motor to rotate the disc;
• a transducer to write and read information in and from the disc;
• a voice coil motor to move the transducer;
• and
• a controller to control the spindle motor and the voice coil motor according to a set mode, and to perform a shock damage prevention process of controlling the voice coil motor and the spindle motor, so that a current mode is stopped and a parking or unloading mode is executed if a counter-electromotive force operation process of performing an operation of a value of a counter-electromotive force using a voltage detected from the voice coil and the value of the counter-electromotive force are equal to or larger than a predetermined threshold value,
• wherein the predetermined threshold is calculated from a regression function corresponding to a statistical correlation between the magnitude of an external shock and the counter-electromotive force.

A disc drive, comprising:

• a disc having a surface;
• a spindle motor to rotate the disc;
• a transducer to write and read information in and from the disc;
• a voice coil motor to move the transducer;
• and
• a controller to control the spindle motor and the voice coil motor according to a set mode, and to perform a shock damage prevention process of controlling the voice coil motor and the spindle motor, so that a current mode is stopped and a parking or unloading mode is executed if a counter-electromotive force operation process of performing an operation of a value of a counter-electromotive force using a voltage detected from the voice coil and the value of the counter-electromotive force are equal to or larger than a predetermined threshold value,
• wherein the controller further comprises:
• a circuit to compensate signal delay between a driving signal to drive the voice coil motor and a voltage detection signal from the voice coil.

A disc drive, comprising:

• a disc having a surface;
• a spindle motor to rotate the disc;
• a transducer to write and read information in and from the disc;
• a voice coil motor to move the transducer;
• and
• a controller to control the spindle motor and the voice coil motor according to a set mode, and using a moving distance variation ΔLh/Δt of the transducer with respect to a variation in time detected during the set mode Δt, to perform a shock damage prevention process of controlling the voice coil motor and the spindle motor, so that a current mode is stopped and a parking or unloading mode is executed if a counter-electromotive force operation process of performing an operation of the value of a counter-electromotive force using a predetermined counter-electromotive force calculation Equation and the value of the counter-electromotive force of which operation is performed in the counter-electromotive force operation process are equal to or larger than a predetermined threshold value.

A computer readable storage storing at least one program to control a disc drive using a counter-electromotive force according to a process comprising:

• detecting a voltage applied to a voice coil during a predetermined mode;
• performing an operation of the value of the counter-electromotive force using the voice coil voltage;
• comparing the value of the counter-electromotive force operated with a predetermined threshold;
• and
• when the value of the counter-electromotive force is equal to or larger than the predetermined threshold, controlling a voice coil motor and a spindle motor so that a current mode is stopped and a parking or unloading mode is executed,
• wherein the predetermined mode is selected among a seek mode, a track following mode, a read mode, and a write mode.

A computer readable storage storing at least one program to control a disc drive using a counter-electromotive force according to a process comprising:

• detecting a voltage applied to a voice coil during a predetermined mode;
• performing an operation of the value of the counter-electromotive force using the voice coil voltage;
• comparing the value of the counter-electromotive force operated with a predetermined threshold;
• and
• when the value of the counter-electromotive force is equal to or larger than the predetermined threshold, controlling a voice coil motor and a spindle motor so that a current mode is stopped and a parking or unloading mode is executed,
• wherein the predetermined threshold is calculated from a regression function corresponding to a statistical correlation between the magnitude of an external shock and the counter-electromotive force.

A computer readable storage storing at least one program to control a disc drive using a counter-electromotive force according to a process comprising:

• detecting a moving distance variation ΔLh/Δt of a transducer with respect to a variation in time during a predetermined mode;
• performing an operation of a value of the counter-electromotive force by applying the detected moving distance variation ΔLh/Δt of the transducer with respect to the variation in time to a predetermined counter-electromotive force calculation Equation;
• comparing the value of the counter-electromotive force with a predetermined threshold;
• and
• when the value of the counter-electromotive force is equal to or larger than the predetermined threshold, controlling a voice coil motor and a spindle motor so that a current mode is stopped and a parking or unloading mode is executed.

A method of controlling a disc drive having a transducer and a disc by using a counter-electromotive force, the method comprising:

• calculating the counter-electromotive force using a voice coil voltage or a position error signal without installing an additional shock sensor to sense disturbance in the disc drive;
• determining a magnitude of an external shock or a magnitude of vibration by the calculated counter-electromotive force;
• and
• when the magnitude of an external shock or the magnitude of vibration determined by the counter-electromotive force exceeds a tolerance range of the disc drive, controlling the disc drive so that a current mode is automatically converted into a parking or unloading mode, preventing
• malfunctions of the disc drive due to collisions between the transducer and the disc.