Magnetic head positioning device and method

A magnetic head positioning apparatus for adjusting the position of a magnetic head along a widthwise direction of magnetic tape, the magnetic head having first and second servo heads for respectively reproducing first and second servo signals from first and second servo tracks of the magnetic tape and a data head for reproducing a data signal from a data track of the magnetic tape, the magnetic head positioning apparatus comprising:

• magnetic head moving means for moving the magnetic head along the widthwise direction of the magnetic tape;
• subtraction means, coupled to the first and second servo heads, for determining a difference between the first and second servo signals;
• and
• driving means, coupled to said subtraction means, for generating a pulse signal for driving said magnetic head moving means in accordance with the determined difference to position the data head along the data track, said driving means having
• polarity detecting means, coupled to said subtraction means, for obtaining the polarity of the determined difference,
• determination means, coupled to said subtraction means, for determining if an absolute value of the determined difference is not less than a predetermined reference level, and
• motor rotating means, responsive to outputs of said polarity detecting means and said determination means, for outputting the pulse signal.

A method of positioning a magnetic head along a widthwise direction of a magnetic tape, the magnetic head having first and second servo heads for respectively reproducing first and second servo signals from first and second servo tracks of the magnetic tape and a data head for reproducing a data signal from a data track of the magnetic tape, the method comprising the steps of:

• a) determining a difference between the first and second servo signals;
• b) determining the polarity of the determined difference;
• c) determining if an absolute value of the determined difference is greater than a predetermined reference level;
• and
• d) moving the magnetic head along the widthwise direction of the magnetic tape in accordance with the determinations of said steps b) and c) to position the data head along the data track.

A magnetic head positioning device for adjusting the position of a magnetic head with respect to a magnetic tape according to a servo signal reproduced from a servo track recorded on said magnetic tape, comprising:

• a pair of servo track reproduce heads for reproducing a signal from said servo track, said pair of servo track reproduce heads being arranged to trace different portions widthwise of said magnetic tape;
• magnetic head moving means for moving said magnetic head along said widthwise direction of said magnetic tape, said magnetic head moving means including a stepping motor responsive to an input pulse signal for providing rotation, the rotation amount of said stepping motor determining the moving distance of said magnetic head;
• subtracting means for obtaining the difference between output signals of said pair of servo track reproduce heads;
• determination means for determining if an output signal of said subtracting means is greater in magnitude than a predetermined reference value;
• and
• motor rotation control means, responsive to said determination means, for applying the input pulse signal to said stepping motor to drive said stepping motor for rotation.