Abstract: In seek control for a head of a rotary recorder/reproducer, the seek time is reduced with noise reduced while utilizing a driving force of an actuator effectively. In one embodiment, when a microprocessor generates a control signal for a drive current given to an actuator for head seek, a signal generator generates a prespecified acceleration allowing for the allowable maximum acceleration when the actuator is accelerated, a prespecified deceleration signal allowing for the allowable maximum deceleration when the actuator is decelerated, and a zero level signal when the actuator is settled. Switching from deceleration to settling is performed at a point of time computed by the microprocessor as a time point when settling is to be started so that the head may reach a target position within the shortest period of time.

Abstract: Embodiments of the present invention provide a magnetic disk drive, in which a disturbance component contained in an output signal from a rotational vibration detector, can be appropriately suppressed irrespective of frequency of the component, and a method of controlling the drive. According to one embodiment, in a magnetic disk drive having a rotational vibration detector for detecting rotational vibration of a drive housing, a main control circuit performs a head moving step of driving a voice coil motor to move a magnetic head on a magnetic disk, a frequency estimation step of estimating a frequency of each disturbance component contained in an output signal from the rotational vibration detector after moving the magnetic head, and a suppressor setting step of setting a notch filter for suppressing the disturbance component based on the estimated frequency.

Abstract: Embodiments of the invention provide a data storage device and its control method that are capable of minimizing the possibility of head deterioration while maintaining the minimum required sustained data rate. In one embodiment, each track is divided into three areas (A, B, and C). When a ? track is accessed, the head is changed to access a ? track on the next recording surface. In this instance, LBAs are assigned to disks so that heads Hd0 through Hd4, which access both surfaces of disks 0 and 1, are selected for accessing purposes in the Hd0, Hd1, Hd2, Hd3, Hd0, and Hd1 order while an area selection is made in the area A, area B, and area C order.

Abstract: The invention relates to a thermosetting composition comprising (A) a compound having at least one oxetanyl group in the molecule, (B) a compound having at least two carboxyl groups in the molecule, and (C) an imidazolium salt, curing method thereof and products cured thereby. Cured products prepared from the composition of the invention is excellent in electrical isolation, flexibility, adhesiveness and mechanical strength.

Abstract: Embodiments of the present invention help to achieve a read error recovery, and suppress decreases in the capacity of the disk drive device and degradation in performance. In one embodiment, a hard disk drive (HDD) performs following control without use of repeatable run-out (RRO) compensation information on a magnetic disk in a normal reading process. When an error occurs in a normal reading process, the HDD moves a read element to a position different from a target position of the normal reading process. At the position where the read element has been moved, the read element reads out the RRO compensation information. In a recovery procedure for the reading process where the error has occurred, the HDD performs following control with compensation by the servo compensation information read out by the read element.

Abstract: The invention relates to a carboxyl group-containing polyurethane, which is obtained by reacting (a) a polyisocyanate compound, (b) a polycarbonate diol having a molecular weight of 300 to 50,000, (c) a dihydroxy compound having a carboxyl group and when necessary (d) a monohydroxy compound, a thermosetting composition using the carboxyl group-containing polyurethane and a paste for forming a film using thermosetting composition. The thermosetting composition of the invention is excellent in adhesion to a substrate, low warpage, flexibility, plating resistance and soldering heat resistance.

Abstract: An asymmetric hollow-fiber gas separation membrane is made of a soluble aromatic polyimide that is composed of a specific repeating unit. The tetracarboxylic acid component of the unit has a diphenylhexafluoropropane structure and a biphenyl structure. The diamine component of the unit essentially contains diaminobenzoic acids and any of diaminodibenzothiophenes, diaminodibenzothiophene=5,5-dioxides, diaminothioxanthene-10,10-diones, and diaminothioxanthene-9,10,10-triones.

Abstract: The invention provides a heat-curable resin composition comprising (A) a polyurethane having two or more carboxyl groups in one molecule, in particular a polyurethane having one or more carboxyl groups at a molecular terminal and (B) a heat-curable component, a cured product thereof, a solder resist and a protective film consisting of the cured product and a printed wiring board coated with the cured product. The polyurethane(A), preferably has a number average molecular weight of 500 to 100,000 and an acid value of 5 to 150 mgKOH/g. The heat-curable component (B) is preferably an epoxy resin. The heat-curable resin composition of the invention is excellent in adhesion with a substrate, low-warpage property, flexibility, resistance to moisture and heat, soldering heat resistance and resistance to tin plating.

Abstract: Embodiments in accordance with the present invention provide a magnetic disk drive with sufficiently low noise. A digital/analog converter supplies to a voice coil motor (VCM) driver a control voltage comprising a first preset voltage value, a second preset voltage value, and a transition voltage value of a substantially cosine wave that interconnects the first preset voltage value and the second preset voltage value. A driving current is supplied from the VCM driver to a voice coil of an actuator assembly. Since a current not containing higher-harmonic components in a transition period flows as a VCM current that flows into the voice coil, vibromotive force can be easily suppressed by shifting a structural resonance point of the entire disk drive including the actuator assembly.

Abstract: Embodiments in accordance with the present invention provide a magnetic disk drive with reduced noise during seek operation without causing any delay in control response. According to one embodiment of the present invention, a control circuit of a magnetic disk drive controls the drive power supplied to a voice coil motor during a seek operation adapted to move a magnetic head over a target track formed on a magnetic disk so as to bring the travel speed of the magnetic head close to a predetermined target speed. The control circuit determines a provisional current according to the difference between the predetermined target speed and an actual travel speed in an acceleration zone adapted to accelerate the magnetic head to the predetermined target speed. If the provisional current exceeds a limit specified in relation to an elapsed time from the start of acceleration, the control circuit sets the limit as the current of the drive power supplied to the voice coil motor to control the motor.

Abstract: Embodiments of the present invention provide a magnetic recording apparatus capable of generating RRO compensation information that can expand the disturbance frequency range in which to compensate for RRO. Embodiments of the present invention describe a magnetic recording apparatus that uses a plurality of repetitive control systems to detect repeatable runout during the rotation of a magnetic recording medium for a frequency characteristic of each of the repetitive control systems. The magnetic recording apparatus further generates compensation information to compensate for each of the detected repeatable runout. The magnetic recording apparatus still further writes the compensation information generated for each of the repetitive control systems to a servo signal, thus suppressing and controlling the repeatable runout.

Abstract: There are provided a novel photosensitive resin composition, a cured film of which has ample flexibility, and which yields an insulating protective coating having superior soldering heat resistance, thermal degradation resistance and electroless gold plating resistance. The photosensitive resin composition as claimed in the present invention comprises: a photopolymerizeable component containing a urethane acrylate compound (A) and a compound (B) having an ethylenic unsaturated group other than said urethane acrylate compound (A), a thermosetting resin (C), a photopolymerization initiator (D) and a thermal polymerization catalyst (E); wherein, said urethane acrylate compound (A) is the reaction product of an isocyanate compound (a-1) of the following general formula (1): CH2?CH—COO—R—NCO??(1) (wherein, R represents a hydrocarbon group having 1 to 30 carbon atoms) with a polyhydroxy compound (a-2).

Abstract: The analytical pretreatment column of the present invention is filled with at least the inorganic type filler having a number average diameter consisting of double pore structure having both a through pore with a number average diameter of the range of 0.5 to 25 micrometers, and meso pore with number average diameter of the range of 2 to 50 nm.

Abstract: This invention relates to an injection molding method using an injection mold. The method comprises (1) a molten resin injection step for injecting the molten resin from a gate into a cavity, (2) a pressure-keeping step for continuously applying pressure from the gate after the molten resin injection step, and (3) a fluid injection step for injecting a fluid toward the back surface of the molded product. The pressure-keeping step and the fluid injection step are simultaneously executed. Simultaneously executing these two steps can lower the pressure that is to be continuously applied from the gate. The present injection molding method can reduce the pressure of the fluid to be injected toward the back surface of the molded product in order to cause the back surface of the molded product to separate from the cavity surface.

Abstract: There are provided a novel curable polyester, a cured product thereof, and a process for preparing the same, as well as a resist composition and a jet Printing ink composition comprising the curable polyester, curing methods and uses thereof. The curable polyester of the present invention has a polyester skeleton as a main chain and also has an oxetanyl group at the molecular end. The curable polyester of the present invention is excellent in curability and has excellent flexibility, adhesion and mechanical strength, and also exhibits high safety to the human.

Abstract: A process for producing a both end-hydroxyl group-terminated diol, wherein an epoxy alcohol represented by the general formula (1) is subjected to a hydrogenolysis reaction in the presence of a catalyst for producing both end-hydroxyl group terminated diols, which catalyst contains at least one element selected from the group consisting of Group V elements, Group VI elements, Group VII elements, Group VIII elements, Group IX elements, Group X elements, and Group XI elements in the periodic table, in the presence of at least one solvent selected from the group consisting of ethers, esters, aromatic hydrocarbon compounds, alicyclic hydrocarbon compounds and aliphatic hydrocarbon compounds, to thereby obtain a both end-hydroxyl group-terminated diol represented by general formula (2). General formula (1) and (2) are as described in the specification.

Abstract: Disclosed is a product designing system for designing a given product while setting a design parameter value for each of a plurality of design parameters of the product each contributing to noise and vibration characteristics of an installation base for the product.

Abstract: The present invention relates to an epoxy resin composition comprising a polyphenylene ether having a number average molecular weight of 1,000, to 4,000 and containing components having a molecular weight of 20,000 or more in an amount of substantially 20% or less, and an epoxy resin. The present invention further relates to an epoxylated polyphenylene ether resin obtained by reacting a phenolic hydroxyl group of a polyphenylene ether having a number average molecular weight of 1,000 to 4,000 with an epoxy group of an epoxy compound or an epoxy resin.

Abstract: Embodiments of the present invention provide a method and a system for generating optimal feedforward signal for the seek control to suppress the RTV (Random Transient Vibrations) and the seek acoustic noise. One aspect is directed to a method of providing a revised feedforward signal using an adaptive filter in a feedforward control system for controlling an actuator to move a head to seek a track and settle on the track of a disk in a disk drive apparatus. The method comprises performing a seek operation of the head using an initial feedforward signal; obtaining an error signal at settling after performing the seek operation; determining filter characteristics of the adaptive filter to minimize the error signal; and implementing the adaptive filter having the determined filter characteristics in the feedforward control system to produce a revised feedforward signal for controlling the actuator for moving the head in the disk drive apparatus.