Abstract: A Load-UnLoad (LUL) hard disk drive rotating its disks with ramp speeds when loading and/or unloading its sliders from its ramp based upon at least one atmospheric condition (AC) within the hard disk drive. Embodiments include load and unload ramp speeds that differ for a single AC, load ramp speeds that differ for differing AC, and/or unload ramp speeds that differ for differing AC. Also a method of operating such hard disk drive and its implementation within an embedded circuit.

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: The present invention provides a tunable terahertz (THz) wavelength selector device, which includes a fixed phase retarder, a tunable phase retarder and a pair of linear polarizers to form a unit. The fixed phase retarder and tunable phase retarder basically utilizes liquid crystals to provide phase retardation, moreover, utilizing birefringence phenomenon possessed by liquid crystals can provide adequate phase retardation. The fixed phase retarder utilizes horizontal orientation of liquid crystal cell to provide fixed phase retardation, while the tunable phase retarder however utilizes homeotropic liquid crystal cell and a rotatable magnet to provide a tunable phase retardation, wherein the tunable phase retarder can provide the positive or negative phase retardation relative to the fixed phase retarder, based on the direction of the magnet's rotating axes and totally use the entire tunable range into adjusting frequencies which can pass through.

Abstract: A head that flies relative to a disk of a hard disk drive. The head includes a substrate that has a pole tip, and an air bearing surface that has at least one rail and a central pad. The air bearing surface also has a plurality of contact dot that each makes contact with the disk at different skew angles. Providing contact at different skew angles insures that multiple dots do not make contact with the same track of the disk. This is particularly advantageous when the head is landed on the disk at the same skew angle.

Abstract: A method for measuring the mobility of a lubricant located on the top surface of a disk used in hard disk drives. The method includes forming one or more scribe lines in a lubricant layer of the disk. The disk is then spun by a spin stand where lubricant moves in response to the centrifugal forces of the spinning disk. The disk is removed from the spin stand and the height of lubricant that moved into the scribe line is measured to determine lubricant mobility.

Abstract: A method for measuring the mobility of a lubricant located on the top surface of a disk used in hard disk drives. The method includes forming one or more scribe lines in a lubricant layer of the disk. The disk is then spun by a spin stand where lubricant moves in response to the centrifugal forces of the spinning disk. The disk is removed from the spin stand and the height of lubricant that moved into the scribe line is measured to determine lubricant mobility.

Abstract: A disk for a hard disk drive. The disk includes a protective layer of shape memory alloy material over a magnetic layer. Contact between a head of the drive and the shape memory alloy material will cause frictional heat. The heat will cause a solid-solid phase transformation of the shape memory alloy material that will absorb energy and reduce wear. After head-disk contact terminates the shape memory alloy material will resume its initial solid phase. The shape memory alloy material may be relatively thin thereby improving the magnetic characteristics of the disks while providing a protective coating.

Abstract: A calibration method for a fly on demand head of a hard disk drive. The method includes the steps of flying a head over a test track of a disk that is covered with a lubricant. 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. This sequence can cause a modulated wear pattern in the lubricant of the disk. The voltage is terminated and the head is allowed to fly over the test track. The head is also moved to adjacent tracks on either side of the test track. A pressure gradient of the flying head moves the lubricant about the disk to mitigate the modulated wear pattern.

Abstract: The present invention enables a means of continuously shifting the phase of electromagnetic waves in the THz (0.1 to 10 THz, 1 THz=10?12 Hz) or sub-millimeter wave range. It is based on magnetically controlled birefringence of liquid crystals. The device consists of an assembly of a liquid crystal cell and rotatable magnets. By varying the angle of the magnet with respect to the incident THz wave, desired phase shift or delay can be achieved. To increase the amount of phase shift, the device employs multiple liquid crystal cells in a compact sandwich structure.

Abstract: The present invention enables a means of continuously shifting the phase of electromagnetic waves in the THz (0.1 to 10 THz, 1 THz=10?12 Hz) or sub-millimeter wave range. It is based on magnetically controlled birefringence of liquid crystals. The device consists of an assembly of a liquid crystal cell and rotatable magnets. By varying the angle of the magnet with respect to the incident THz wave, desired phase shift or delay can be achieved. To increase the amount of phase shift, the device employs multiple liquid crystal cells in a compact sandwich structure.