Magnetic recording device capable of stabilizing oscillations of high frequency assisted element
AssigneesKabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
InventorsGaku Koizumi, Masaya Ohtake
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Abstract
According to one embodiment, a magnetic disk device applies a bias voltage for measurement to a high frequency assist element according to a setting instruction of the bias voltage to measure a conduction current by in a recording head, calculates the resistance value in the supply path of the bias voltage from a relationship between the measured current and the bias voltage for measurement, and changes the bias voltage applied at the time of data recording based on the calculated resistance value.
Claims16
A magnetic disk device comprising:
- a magnetic disk having a recording layer;
- a recording head that applies a perpendicular recording magnetic field to the recording layer;
- and
- a controller that controls the recording head, wherein
- the recording head includes:
- a main pole that generates the perpendicular recording magnetic field at a distal end portion;
- a return pole having a distal end portion facing the distal end portion of the main pole via a write gap;
- a coil that excites a magnetic flux in a magnetic circuit formed by the main pole and the return pole;
- a high frequency assist element that is disposed in the write gap, oscillates a high frequency wave by an application of a bias voltage, and assists magnetization of the magnetic disk using the high frequency wave;
- and
- a bias voltage supply source that supplies the bias voltage to be applied to the high frequency assist element through the main pole and the return pole,
- the controller applies a bias voltage for measurement to the high frequency assist element according to a setting instruction of the bias voltage to measure a conduction current, calculates a resistance value in a supply path of the bias voltage from a relationship between the measured current and the bias voltage for measurement, and changes the bias voltage applied at the time of data recording based on the calculated resistance value.
A recording head controlling method for a magnetic disk device, when
- a recording head that applies a perpendicular recording magnetic field to a recording layer of a magnetic disk comprises:
- a main pole that generates the perpendicular recording magnetic field at a distal end portion;
- a return pole having a distal end portion facing the distal end portion of the main pole via a write gap;
- a coil that excites a magnetic flux in a magnetic circuit formed by the main pole and the return pole;
- a high frequency assist element that is disposed in the write cap, oscillates a high frequency wave by an application of a bias voltage, and assists magnetization of the magnetic disk using the high frequency wave;
- and
- a bias voltage supply source that supplies the bias voltage to be applied to the high frequency assist element through the main pole and the return pole,
- the method comprising:
- applying a bias voltage for measurement to the high frequency assist element according to a setting instruction of the bias voltage to measure a conduction current,
- calculating a resistance value in a supply path of the bias voltage from a relationship between the measured current and the bias voltage for measurement, and
- changing the bias voltage applied at the time of data recording based on the calculated resistance value.
Dependencies are inferred from the claim text.