Method and apparatus for measuring magnetic head
AssigneeKabushiki Kaisha Toshiba
InventorMasayuki Abe
Life of this patent
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Abstract
In a magnetic head measuring apparatus for measuring a magnetic head, an amplitude-modulated electric current whose amplitude is modulated by a specified carrier wave frequency and modulation frequency is applied to a magnetic head. A calibrating magnetic field generating source causes the magnetic head to generate a magnetic field having a specified strength and frequency, thereby calibrating measurement variations of the magnetic head. A magnetic head measuring device measures a high-frequency magnetic field generated from the magnetic head. If necessary, an interchangeable magnetic material probe is used to replace a probe of the magnetic head measuring device.
Claims27
A magnetic head measuring apparatus for measuring a magnetic head, comprising:
- a calibrating magnetic field generating source which causes the magnetic head to generate a magnetic field having a constant strength and frequency;
- an electric current applying device which applies an amplitude-modulated electric current whose amplitude is modulated by a specified carrier wave frequency and modulation frequency, to the magnetic head from which the magnetic field is generated by the calibrating magnetic field generating source;
- and
- a magnetic head measuring device which measures a high-frequency magnetic field generated from the magnetic head by application of the amplitude-modulated electric current from the electric current applying device.
A method of inspecting a magnetic head, comprising:
- setting the magnetic head;
- selecting an analysis item for which the magnetic head is to be inspected;
- applying to the magnetic head an amplitude-modulated electric current whose amplitude is modulated by a specified carrier wave frequency and modulation frequency;
- measuring, in accordance with the selected analysis item, the magnetic head to which the amplitude-modulated electric current is applied, by using a high-frequency magnetic force microscope;
- analyzing and evaluating data, obtained by the measurement, of the magnetic head;
- and
- determining success or failure of the magnetic head on the basis of the evaluation result.
A magnetic recording-head measuring apparatus for measuring a magnetic recording-head, comprising:
- an electric current applying device which applies to the magnetic recording-head an amplitude-modulated electric current whose amplitude is modulated by a specified carrier wave frequency and modulation frequency;
- a cantilever to which a probe having a magnetic material is attached;
- a vibrator which applies a vibration with specified vibration amplitude to the cantilever;
- and
- a measuring device which measures a dynamic interaction which a magnetic field generated in the magnetic recording-head by application of the amplitude-modulated electric current from the electric current applying means exerts on the probe vibrating,
- wherein while the probe is scanned to measure the dynamic interaction by the magnetic field, a vibration range of the probe falls within a range from a surface of the magnetic recording-head to a point at which the probe does not interact with the magnetic field any longer.
A method of measuring a magnetic recording-head, comprising:
- applying to the magnetic recording-head an amplitude-modulated electric current whose amplitude is modulated by a specified carrier wave frequency and modulation frequency;
- applying a vibration with specified vibration amplitude to a cantilever to which a probe having a magnetic material is attached;
- and
- measuring a dynamic interaction which a magnetic field generated in the magnetic recording-head by application of the amplitude-modulated electric current exerts on the probe which vibrates together with the cantilever,
- wherein while the probe is scanned to measure the dynamic interaction by the magnetic field, a vibration range of the probe falls within a range from a surface of the magnetic recording-head to a point at which the probe does not interact with the magnetic field any longer.
Dependencies are inferred from the claim text.