Method and apparatus for detecting touch-down and contact between a head and a storage medium using a sensor, and a drive disk and storage medium using the method

An apparatus for detecting a touch-down and contact between a head and a storage medium in a storage device, the apparatus comprising:

• a sensor installed in a slider and having a resistance value that changes according to a temperature;
• a constant current source for supplying a constant current to the sensor;
• a direct current (DC) component extractor for separating and outputting a DC component from a voltage signal across two terminals of the sensor;
• an alternating current (AC) component extractor for separating and outputting an AC component from the voltage signal across the two terminals of the sensor;
• a subtractor for outputting an offset compensated DC component by subtracting an initially set offset voltage from the DC component output from the DC component extractor;
• and
• a determiner for determining a touch-down state of the head during a touchdown test to determine a value of a control signal for adjusting a flying height of the head corresponding to a target flying height of the head by using the offset compensated DC component, and for determining a contacting state between the head and the storage medium in an operating state of the data storage device by using the AC component output from the AC component extractor.

An apparatus for detecting a touch-down and contact between a head and a storage medium in a storage device, the apparatus comprising:

• a constant voltage source for generating a constant voltage, the constant voltage source having first and second terminals;
• a sensor installed in a slider and having a resistance value that changes according to a temperature, the sensor having first and second terminals where the second terminal is connected to the second terminal of the constant voltage source;
• a resistor having a fixed resistance value and being connected between the first terminal of the constant voltage source and the first terminal of the sensor;
• a direct current (DC) component extractor for separating and outputting a DC component from a voltage signal across the first and second terminals of the sensor;
• an alternating current (AC) component extractor for separating and outputting an AC component from the voltage signal across the first and second terminals of the sensor;
• a subtractor for outputting an offset compensated DC component by subtracting an initially set offset voltage from the DC component output from the DC component extractor;
• and
• a determiner for determining a touch-down state of the head in a touch-down test to determine a value of a control signal for adjusting a flying height of the head corresponding to a target flying height of the head by using the offset compensated DC component, and for determining a contacting state between the head and the storage medium in an operating state of the storage device by using the AC component output from the AC component extractor.

A disk drive, comprising:

• a disk for storing information;
• a slider in which are installed a heater, a sensor having a resistance value that changes according to a temperature, and a head for recording information on the disk or reading information from the disk;
• a sensor signal processor for:
• separating a voltage signal across two terminals of the sensor or a current signal flowing in the sensor into a direct current (DC) component and an alternating current (AC) component that correspond to a resistance value of the sensor while a current or a voltage, respectively, generated by a constant current source or a constant voltage source is applied to the sensor;
• detecting a touch-down state of a head in a touch-down test to determine a value of a first signal corresponding to a target flying height of the head by using the separated DC current component, and detecting a contacting state between the head and the disk in an operating state of the disk drive by using the separated AC component;
• and
• a controller for generating the first signal for adjusting power supplied to the heater, and for adjusting the value of the first signal based on the result of determining the touch-down state of the head in the touch-down test, and the contacting state between the head and the disk in the operating state of the disk drive.