Abstract: A hard disk drive that includes a disk and a head that is separated from the disk by a flying height. The disk drive also includes a circuit that determines the flying height from an equation that uses a third harmonic of a read signal. The read signal includes a data pattern that is a product of a first data pattern and a second data pattern. The resultant data pattern provides a third harmonic with a relatively high magnitude and improved signal to noise ratio.

Abstract: The method and system provide a perpendicular magnetic recording (PMR) head having an air bearing surface (ABS). The PMR head includes first and second poles each having front and back gap regions, a first nonmagnetic insertion layer between the back gap regions, a magnetic pole layer with a front terminating at the ABS, a write gap, shield(s), a second nonmagnetic insertion layer between the second pole back gap region and the shield(s), and coil(s) between the shield(s) and the first pole. The magnetic pole layer terminates between the ABS and the second pole back gap region and has pole angle(s) of at least thirty and not more than fifty degrees. At least part of the magnetic pole layer resides on the second pole. Part of the shield(s) are adjacent to the write gap. Another part of the shield(s) is coupled with the second pole back gap region.

Abstract: A hard disk drive that includes a disk and a head that is separated from the disk by a flying height. The disk drive also includes a circuit that determines the flying height from an equation that uses a third harmonic of a read signal. The read signal includes a data pattern that is a product of a first data pattern and a second data pattern. The resultant data pattern provides a third harmonic with a relatively high magnitude and improved signal to noise ratio.

Abstract: A recording head comprises a write element, including a coil and a dynamic fly-height heater, and two electrical lapping guides. The head also comprises a number of bonding pads including a DFH bonding pad and a shared bonding pad both electrically connected to the dynamic fly-height heater. Each lapping guide defines a circuit between the shared bonding pad and a dedicated bonding pad and each includes a resistive element. The resistive elements of the two lapping guides can be vertically aligned to be used to control a lapping tilt angle when a bar of unfinished heads is lapped. After lapping, a channel is defined into the transducer of the recording head. Forming the channel can remove at least a portion of each lapping guide in order to break the electrical circuit of that guide.

Abstract: A hard disk drive with a disk that has a servo field with an A servo burst and a B servo burst. The A servo burst has a trimmed erase band. The trimmed erase band can be created by offsetting the write head relative to a burst centerline to reduce the width of the erase band. For example, the write head can be moved toward a centerline of the A servo burst. The offset can be a function of write current and cylinder location of the disk. The offsets are selected so that the resultant burst profiles do not contain a flat minimum portion.

Abstract: A method for implementing a power saving mode in a hard disk drive. The method includes the steps of flying a head over a data track of a disk that is covered with a lubricant. The speed of the disk is reduced. A voltage is applied to a heating element of the head to move the head closer to the disk. The fly height of the head is then determined. The voltage can be incrementally varied until the head makes contact with the disk. The voltage is terminated and the head is allowed to fly over the data track. The head is also moved to adjacent tracks on either side of the data track. A pressure gradient of the flying head moves the lubricant about the disk to mitigate a modulated wear pattern caused by the reduction in disk speed. The disk speed is then increased in a normal operating mode.

Abstract: A perpendicular recording head for a hard disk drive. The head includes a non-magnetic backside shield that minimizes or eliminates the flow of backside flux through the head. The head can be fabricated by forming a non-magnetic backside shield layer on a main pole. Portions of the backside shield and main pole can be removed to form a tapered pole portion. A non-magnetic write-gap layer and write shield are then formed onto the backside shield and main pole.

Abstract: A hard disk drive with a disk that has a servo field with an A servo burst and a B servo burst. The A servo burst has a trimmed erase band. The trimmed erase band can be created by offsetting the write head relative to a burst centerline to reduce the width of the erase band. For example, the write head can be moved toward a centerline of the A servo burst. The offset can be a function of write current and cylinder location of the disk. The offsets are selected so that the resultant burst profiles do not contain a flat minimum portion.

Abstract: Disclosed is a perpendicular recording head for a hard disk drive. The perpendicular recording head includes a yoke that has a plurality of grooves essentially perpendicular to a magnetic flux that flows in a vertical direction relative to the yoke.