Abstract: Provided is an actuator of a disk drive to move a read/write head, for recording and reproducing data, to a predetermined position on a disk. The actuator includes an actuator pivot installed on a base member of the disk drive, a swing arm that is rotatably coupled to the actuator pivot and has a suspension supporting the head at a leading end portion of the swing arm, a coil support portion provided at a rear end portion of the swing arm, a VCM coil coupled to the coil support portion and having four sections having respective particular directions, and magnets arranged to face the VCM coil and having four poles respectively corresponding to the four sections of the VCM coil.

Abstract: The invention includes sliders provided with indented surfaces, reducing the roll center for head gimbal assemblies below the effective thickness of the slider. Head gimbal assemblies built with these sliders may reduce off-track displacements induced by disk vibration. The load beam gimbal may contact the indented surface, creating a slider roll center less than the slider thickness. Alternatively, the sliders may include a slider contact cover interfacing to the load beam forming the gimbal. The slider contact covers may couple with the slider through an indented surface located closer than the slider thickness. These may have a negative slider roll center. The invention includes actuator arms, actuator assemblies, and hard disk drives including these head gimbal assemblies. The invention includes making the invention's sliders, head gimbal assemblies, actuator arms, actuator assemblies, and hard disk drives. The invention includes the products of these processes.

Abstract: Improved head gimbal assemblies reducing TMR (Track Mis-Registration) in a hard disk drive are provided. These head gimbal assemblies are as mechanically simple as contemporary head gimbal assemblies, support parallel flying sliders over flat disk surfaces, and reduce TMR induced by disk vibration. They are easier to build, more reliable, and cost less to make, than other known approaches at comparable track densities and rotational rates. The improved head gimbal assemblies include three sets of mechanisms for moving the slider parallel the disk surface, when the disk surface is flat, and radially moving the slider toward the track, when the disk surface is bent. The first and third mechanisms as well as the second and third mechanisms can be used together in a head gimbal assembly. An improved and distinctive servo-controller scheme resulting in an overall improvement in PES performance, particularly when applied to hard disk drives employing the invention's TMR reduction mechanisms.

Abstract: Improved head gimbal assemblies reducing TMR (Track Mis-Registration) in a hard disk drive are provided. These head gimbal assemblies are as mechanically simple as contemporary head gimbal assemblies, support parallel flying sliders over flat disk surfaces, and reduce TMR induced by disk vibration. They are easier to build, more reliable, and cost less to make, than other known approaches at comparable track densities and rotational rates. The improved head gimbal assemblies include three sets of mechanisms for moving the slider parallel the disk surface, when the disk surface is flat, and radially moving the slider toward the track, when the disk surface is bent. The first and third mechanisms as well as the second and third mechanisms can be used together in a head gimbal assembly. An improved and distinctive servo-controller scheme resulting in an overall improvement in PES performance, particularly when applied to hard disk drives employing the invention's TMR reduction mechanisms.

Abstract: The invention applies to servo controllers for at least the voice coil motor of a hard disk drive. Today, many control algorithms require 80 to 90 percent of the sampling period to complete their calculation of the next control, making computation time delay no longer negligible. The invention accommodates the transport delay, such as computation time delay, into the state estimator and into the whole control system. Experimental results using a commercial hard drive, as well as simulation results, show that the invention's method effectively improves the hard disk drive control system stability by increasing the phase margin and gain margin. The invention includes the method of operating the servo-controller, as well as the apparatus implementing that method. The invention also includes hard disk drives containing servo-controllers implementing the method, and program systems residing in accessibly coupled memory to a computer within the servo controller implementing the method.

Abstract: The invention applies to servo controllers for at least the voice coil motor of a hard disk drive. Today, many control algorithms require 80 to 90 percent of the sampling period to complete their calculation of the next control, making computation time delay no longer negligible. The invention accommodates the transport delay, such as computation time delay, into the state estimator and into the whole control system. Experimental results using a commercial hard drive, as well as simulation results, show that the invention's method effectively improves the hard disk drive control system stability by increasing the phase margin and gain margin. The invention includes the method of operating the servo-controller, as well as the apparatus implementing that method. The invention also includes hard disk drives containing servo-controllers implementing the method, and program systems residing in accessibly coupled memory to a computer within the servo controller implementing the method.

Abstract: Aerodynamic forces contribute to disk and actuator vibration leading to track positioning errors in storage devices such as hard disk drives. The invention provides a variety of dampening mechanisms and a method of dampening to alleviate these problems in single disk storage devices. This includes disk drives of at most 13 millimeters in height.

Abstract: A servo writer that writes servo information onto a disk of a hard disk drive. The servo writer can write servo information onto a disk of a hard disk drive while the disk is within an inner chamber of a housing. The rotating disk creates a flow of fluid within the inner chamber. The disk is rotated during the servo writing process. The density of a fluid medium within the inner chamber is controlled by a medium control system so that the density of the medium is less than the density of air at one atmosphere. Lowering the density decreases the amplitude of vibrational forces created by the flow of fluid. Decreasing the amplitude reduces errors in the servo writing process. The density can be reduced by pulling a vacuum within the inner chamber. The density can also be reduced by filling the inner chamber with a gas such as helium that has a lower density than air.

Abstract: The invention applies to servo controllers for at least the voice coil motor of a hard disk drive. Today, many control algorithms require 80 to 90 percent of the sampling period to complete their calculation of the next control, making computation time delay no longer negligible. The invention accommodates the transport delay, such as computation time delay, into the state estimator and into the whole control system. Experimental results using a commercial hard drive, as well as simulation results, show that the invention's method effectively improves the hard disk drive control system stability by increasing the phase margin and gain margin. The invention includes the method of operating the servo-controller, as well as the apparatus implementing that method. The invention also includes hard disk drives containing servo-controllers implementing the method, and program systems residing in accessibly coupled memory to a computer within the servo controller implementing the method.

Abstract: The invention includes sliders provided with indented surfaces, reducing the roll center for head gimbal assemblies below the effective thickness of the slider. Head gimbal assemblies built with these sliders may reduce off-track displacements induced by disk vibration. The load beam gimbal may contact the indented surface, creating a slider roll center less than the slider thickness. Alternatively, the sliders may include a slider contact cover interfacing to the load beam forming the gimbal. The slider contact covers may couple with the slider through an indented surface located closer than the slider thickness. These may have a negative slider roll center. The invention includes actuator arms, actuator assemblies, and hard disk drives including these head gimbal assemblies. The invention includes making the invention's sliders, head gimbal assemblies, actuator arms, actuator assemblies, and hard disk drives. The invention includes the products of these processes.

Abstract: A hard disk drive that includes an optical pick-up coupled to a head of a hard disk assembly (“HDA”). The head is located adjacent to a disk. The optical pick-up can sense the surface of the disk by detecting light reflected from the surface. The optical pick-up is coupled to a particle circuit that can distinguish between an embedded particle and a floating particle from the reflected light.

Abstract: Aerodynamic forces contribute to disk and actuator vibration leading to track positioning errors in storage devices such as hard disk drives. The invention provides a variety of dampening mechanisms and a method of dampening to alleviate these problems.

Abstract: An improved and distinctive servo-controller scheme resulting in an overall improvement in PES performance, particularly when applied to hard disk drives employing the invention's TMR reduction mechanisms. The servo-controllers trade off gain in the disk vibration frequency range, in favor of, increased rejection of low frequency disturbances. This leads to the lowest PES statistics, when applied to hard disk drives with the TMR reduction mechanisms of the invention. Improved head gimbal assemblies reducing TMR (Track Mis-Registration) in a hard disk drive are provided. These head gimbal assemblies are as mechanically simple as contemporary head gimbal assemblies, support parallel flying sliders over flat disk surfaces, and reduce TMR induced by disk vibration. They are easier to build, more reliable, and cost less to make, than other known approaches at comparable track densities and rotational rates.

Abstract: An improved and distinctive servo-controller scheme resulting in an overall improvement in PES performance, particularly when applied to hard disk drives employing the invention's TMR reduction mechanisms. The servo-controllers trade off gain in the disk vibration frequency range, in favor of, increased rejection of low frequency disturbances. This leads to the lowest PES statistics, when applied to hard disk drives with the TMR reduction mechanisms of the invention. Improved head gimbal assemblies reducing TMR (Track Mis-Registration) in a hard disk drive are provided. These head gimbal assemblies are as mechanically simple as contemporary head gimbal assemblies, support parallel flying sliders over flat disk surfaces, and reduce TMR induced by disk vibration. They are easier to build, more reliable, and cost less to make, than other known approaches at comparable track densities and rotational rates.

Abstract: A hard disk drive that includes a wave stringer. The wave stringer can attenuate energy which propagates through a base plate of the disk drive. The wave stringer may be designed by initially analyzing propagation patterns of both acoustic and shock waves applied to the drive. The wave stringer is then designed, constructed and assembled to the disk drive to attenuate critical frequencies at weak points of the disk drive. The wave stringer may have a plurality of ribs designed to vary the mechanical impedance of the drive to attenuate the propagated energy.

Abstract: A hard disk drive that has a reaction mass and a transducer that can be used to move and/or sense the acceleration of an actuator arm of the drive. The transducer is coupled to a disk controller that can provide output signals which induce a movement of the reaction mass. Movement of the reaction mass will cause a responsive movement of a head(s) coupled to the actuator arm. The transducer can also provide input signals to the controller that correspond to an acceleration of the actuator arm. The acceleration signal can provide force feedback for a servo system of the drive.

Abstract: Improved head gimbal assemblies reducing TMR (Track Mis-Registration) in a hard disk drive are provided. These head gimbal assemblies are as mechanically simple as contemporary head gimbal assemblies, support parallel flying sliders over flat disk surfaces, and reduce TMR' induced by disk vibration. They are easier to build, more reliable, and cost less to make, than other known approaches at comparable track densities and rotational rates. The improved head gimbal assemblies include three sets of mechanisms moving the slider parallel the disk surface, when the disk surface is flat, and radially moving the slider toward the track, when the disk surface is bent. The first and third mechanisms as well as the second and third mechanisms can be used together in a head gimbal assembly. An improved and distinctive servo-controller scheme resulting in an overall improvement in PES performance, particularly when applied to hard disk drives employing the invention's TMR reduction mechanisms.

Abstract: A servo writer that writes servo information onto a disk of a hard disk drive. The servo writer can write servo information onto a disk of a hard disk drive while the disk is within an inner chamber of a housing. The rotating disk creates a flow of fluid within the inner chamber. The disk is rotated during the servo writing process. The density of a fluid medium within the inner chamber is controlled by a medium control system so that the density of the medium is less than the density of air at one atmosphere. Lowering the density decreases the amplitude of vibrational forces created by the flow of fluid. Decreasing the amplitude reduces errors in the servo writing process. The density can be reduced by pulling a vacuum within the inner chamber. The density can also be reduced by filling the inner chamber with a gas such as helium that has a lower density than air.

Abstract: Provided is an actuator of a disk drive to move a read/write head, for recording and reproducing data, to a predetermined position on a disk. The actuator includes an actuator pivot installed on a base member of the disk drive, a swing arm that is rotatably coupled to the actuator pivot and has a suspension supporting the head at a leading end portion of the swing arm, a coil support portion provided at a rear end portion of the swing arm, a VCM coil coupled to the coil support portion and having four sections having respective particular directions, and magnets arranged to face the VCM coil and having four poles respectively corresponding to the four sections of the VCM coil.

Abstract: Improved head gimbal assemblies reducing TMR (Track Mis-Registration) in a hard disk drive are provided. These head gimbal assemblies are as mechanically simple as contemporary head gimbal assemblies, support parallel flying sliders over flat disk surfaces, and reduce TMR induced by disk vibration. They are easier to build, more reliable, and cost less to make, than other known approaches at comparable track densities and rotational rates. The improved head gimbal assemblies include three sets of mechanisms moving the slider parallel the disk surface, when the disk surface is flat, and radially moving the slider toward the track, when the disk surface is bent. The first and third mechanisms as well as the second and third mechanisms can be used together in a head gimbal assembly. An improved and distinctive servo-controller scheme resulting in an overall improvement in PES performance, particularly when applied to hard disk drives employing the invention's TMR reduction mechanisms.