Patent application number | Description | Published |
20120019955 | HARD DISK DRIVE, METHOD FOR ESTIMATING BACK ELECTROMOTIVE FORCE, AND METHOD FOR CONTROLLING VELOCITY OF HEAD - According to one embodiment, a hard disk drive includes a head, a voice coil motor, a driving circuit, an identification unit, a storage unit, and an estimation unit. The head is configured to perform write/read of information to a storage medium. The voice coil motor is configured to move the head. The driving circuit is configured to drive the voice coil motor, based on a command signal. The identification unit is configured to identify at least one parameter of a discrete-time model. The discrete-time model represents a transfer function from the command signal to a voltage drop quantity by an inductance of a coil of the voice coil motor. The storage unit is configured to store the parameter. The estimation unit is configured to estimate a back electromotive force of the coil, based on the discrete-time model including the parameter. | 01-26-2012 |
20120075742 | MAGNETIC DISK DEVICE, ELECTRONIC APPARATUS AND, HEAD CONTROL METHOD - A magnetic disk device includes a head, a coil motor, a drive circuit, a voltage detector, a head position calculation unit, a velocity calculation unit, a counter electromotive voltage calculation unit, a coil resistance estimation unit, and a control unit. The head position calculation unit calculates a position of the head for each sampling cycle on the basis of servo information. The velocity calculation unit calculates a velocity of the head for each sampling cycle. The counter electromotive voltage calculation unit calculates a counter electromotive voltage of the coil for each sampling cycle. The coil resistance estimation unit successively estimates a coil resistance value of the coil. The control unit calculates a drive instruction for controlling the velocity and outputs the drive instruction to the drive circuit. In addition, the counter electromotive voltage calculation unit subtracts a voltage drop from the inter-terminal voltage to calculate the counter electromotive voltage. | 03-29-2012 |
20120281311 | RAMP-UNLOADING SEEK CONTROL DEVICE FOR MAGNETIC DISK DRIVE - A ramp-unloading seek control device includes a voice coil motor, a detector, an instruction-current detector, a head-speed computing unit, and an identification structure. The identification structure estimates an error between a true resistance value and an estimated resistance value of the voice coil motor. The identification structure can minimize an estimated error defined as a difference between an estimated value ลท(k) of the head speed and the head speed y(k), and employs {circumflex over (b)} | 11-08-2012 |
20130070368 | MAGNETIC DISK DEVICE AND CONTROLLING METHOD OF HEAD - A magnetic disk device includes a head, a coil, a drive circuit, a detector, a first calculation unit, a generation unit, a first estimation unit, and a control unit. The detector detects an inter-terminal voltage across the coil. The first calculation unit calculates a back electromotive force across the coil by the use of the inter-terminal voltage. The generation unit generates a target velocity as a reference value of a velocity of the head. The first estimation unit estimates a first velocity of the head and an error of the first velocity by the use of the back electromotive force. The first estimation unit estimates a second velocity for decreasing the error. The control unit calculates a control instruction to bring the second velocity close to the target velocity. | 03-21-2013 |
Patent application number | Description | Published |
20130319754 | TERMINAL PROTECTION COVER AND ELECTRICAL JUNCTION BOX - A terminal holding part of a terminal protection cover includes a pair of lateral shaking-preventing wall parts which stands from a terminal-attachment surface of the terminal protection cover, and has surfaces facing lateral end edge surfaces, respectively, of the bent plate-type terminal which is held therein. The terminal holding part further includes a first vertical shaking-preventing wall part and a second vertical shaking-preventing wall part provided at a position upwards from the first vertical shaking-preventing wall part. The second vertical shaking-preventing wall part has a surface which is on the same side as the tip end edge surface of the lateral shaking-preventing wall part, and which is formed to be recessed relative to the tip end edge surface at a certain position at least upwards from an end edge surface of the second vertical shaking-preventing wall part. | 12-05-2013 |
20130327566 | ELECTRICAL JUNCTION BOX - An electrical junction box includes an upper box section having an opened lower part, and a lower box section whose upper part is open and is mounted to the lower part of the upper box section, wherein the lower box section includes an abutment protrusion part which protrudes from an outer surface of the lower box section and has an abutment surface that abuts against an edge surface of the lower part of the upper box section when the lower box section is mounted to the upper box section. The abutment protrusion part includes an inclined surface at a place where the abutment protrusion part further extends outwards at least than an outer surface of the upper box section in a direction parallel with the abutment surface, the inclined surface connecting to the abutment surface and being inclined downwards from the abutment surface. | 12-12-2013 |
20130335889 | ELECTRICAL JUNCTION BOX - An electrical junction box includes a box body in which electrical parts are mounted and that has a water draining hole provided at a bottom wall part of the box body and a waterproof wall that is provided inside the box body along a periphery of an opening of the water draining hole. The waterproof wall includes a spherical cover wall part standing from the periphery of the water draining hole to cover the water draining hole with an inner spherical surface, and a draining opening part formed at a portion of the spherical cover wall part to allow water exist in the box body to drain to the outside of the box body through the water draining hole. | 12-19-2013 |
20150047870 | ELECTRICAL JUNCTION BOX - An electrical junction box for connecting a power supply and a load, includes a terminal block that holds a conductor to which a first electric wire and a second electric wire are commonly connected, wherein first electric wire is connected to the power supply and the second electric wire is connected to the load, a conductive case that accommodates the terminal block, and a resin insulative member that is attached along an inner wall surface of the case. Crimped terminals which are connected respectively to ends of the first and second electric wires are fastened to the conductor with fastening members. | 02-19-2015 |
20150050831 | ELECTRIC WIRE CONNECTING STRUCTURE AND ELECTRICAL JUNCTION BOX - An electric wire connecting structure includes a connector, a pair of electrical wires, a pair of crimped terminals, and a resin block to which the pair of crimped terminals are attached in a state that the pair of electric wires are curved. Each of the pair of crimped terminals includes a terminal part, a crimped part, and a conductor that connects the terminal part and the crimped part, the conductor is located between the terminal part and the crimped part. The crimped part crimps the core wire of the electric wire and the electric wire is extended toward the conductor. The pair of electric wires are wired in a crossed state between the connector and the pair of crimped terminals. | 02-19-2015 |