In one embodiment, an apparatus includes a module having an array of transducers, and a heating element having multiple parts positioned proximate to the array of transducers. The multiple parts of the heating element are distinct from each other, where the multiple parts include a first part, a second part, and a third part. In addition, the first part includes a center portion and the second and third parts include a second portion and a third portion, respectively, and are positioned on opposite ends and a center portion positioned therebetween. The heating element is configured to produce more heat per unit length along the second and third portions at the opposite ends than in the center portion.

In one embodiment, an apparatus includes a module having an array of transducers, and a heating element having multiple parts positioned proximate to the array of transducers. The multiple parts of the heating element are distinct from each other, where the multiple parts include a first part, a second part, and a third part. In addition, the first part includes a center portion and the second and third parts include a second portion and a third portion, respectively, and are positioned on opposite ends and a center portion positioned therebetween. The heating element is configured to produce more heat per unit length along the second and third portions at the opposite ends than in the center portion.

In one embodiment, an apparatus includes a module having an array of transducers, and a heating element having multiple parts positioned proximate to the array of transducers. The multiple parts of the heating element are distinct from each other, where the multiple parts include a first part, a second part, and a third part. In addition, the first part includes a center portion and the second and third parts include a second portion and a third portion, respectively, and are positioned on opposite ends and a center portion positioned therebetween. The heating element is configured to produce more heat per unit length along the second and third portions at the opposite ends than in the center portion.

In one embodiment, an apparatus includes a module having an array of transducers and a heating element positioned proximate to the array of transducers. The heating element has opposite ends and a center portion therebetween, where the heating element is configured to produce more heat per unit length along the opposite ends than in the center portion.

Systems and methods are disclosed for magnetoresistive asymmetry compensation using a hybrid analog and digital compensation scheme. In certain embodiments, a method may comprise receiving an analog signal at a continuous-time front end (CTFE) circuit, and performing, via the CTFE circuit, first magnetoresistive asymmetry (MRA) compensation on the analog signal to adjust the dynamic range of the analog signal based on an input range of an analog-to-digital converter (ADC). The method may further comprise converting the analog signal to a digital sample sequence via the ADC, and performing, via a digital MRA compensation circuit, second MRA compensation to correct residual MRA in the digital sample sequence. Offset compensation may also be performed in both the analog and digital domains.

Systems and methods are disclosed for magnetoresistive asymmetry (MRA) compensation using a digital compensation scheme. In certain embodiments, a method may comprise receiving an analog signal at a continuous-time front end circuit, and performing analog offset compensation to constrain the extrema of the analog signal to adjust a dynamic range based on an input range of an analog-to-digital converter (ADC), rather than to modify the analog signal to have a zero mean. The method may further comprise converting the analog signal to a digital sample sequence via the ADC; performing, via a digital MRA compensation circuit, digital MRA compensation on the digital sample sequence; receiving, via a digital backend (DBE) subsystem, the digital sample sequence prior to digital MRA compensation; and generating, via a DBE, a bit sequence corresponding to the analog signal based on an output of the DBE subsystem and an output of the digital MRA compensation circuit.

A pattern is pre-written using a pre-erase or pre-conditioning magnetic field applied within at least part of a target track of a hard disk via a first write transducer prior to the target track being written. Subsequent to the pre-writing, target user data is written to the part of the target track.

An apparatus may include a circuit configured to generate a set of first ADC samples based on a first signal associated with a first read head position and a failed segment and to generate a set of second ADC samples based on a second signal associated with a second read head position and the failed segment. The circuit may then generate, by a MISO equalizer, a set of equalized ADC samples based on the set of first ADC samples and the set of second ADC samples.

A magnetic recording and reproducing device includes a magnetic recording medium having a lubricant on a surface of the magnetic recording medium, a heat-assisted magnetic recording head configured to perform magnetic recording on the magnetic recording medium, a humidity sensor, and a write procedure control circuit configured to control a write procedure of the heat-assisted magnetic recording head in accordance with a measurement result of the humidity sensor.

According to one embodiment, a magnetic disk device includes a disk, a head configured to write data to the disk, and an integrated circuit configured to acquire a detection signal indicative of a first pattern of a first frequency of write data, change a first current of a second pattern of a write current corresponding to the first pattern on the basis of the detection signal, detect a third pattern of a second frequency which is greater than the first frequency from the write data, change a second current of a fourth pattern of the write current corresponding to the third pattern, and output the write current with the changed first current and the changed second current to the head.