Abstract: A multistage high frequency power amplifier circuit device has a plurality of semiconductor amplification elements connected in a cascade. The circuit device is provided with a bias control circuit used to control the bias voltage or bias current of the output semiconductor amplification element in each stage so as to reduce the variation of the output power with respect to the power control signal voltage in an area around the threshold voltage of the semiconductor amplification elements. This realizes a high frequency power amplifier circuit device provided with excellent controllability of the output power and high efficiency at the time of low power output realized with use of such a control voltage as a power control signal.

Abstract: A magnetic disk device having a head integrated circuit mounted on a magnetic head supporting mechanism. In order to secure the reliability by controlling the integrated circuit temperature below a predetermined level, the difference in the integrated circuit cooling ability which varies with the radial position on the disk is quantified, so that power (signal) sufficient to maintain a constant temperature according to the integrated circuit temperature is supplied to the integrated circuit. Since the cooling ability at a given radial position of the integrated circuit is not exceeded by the power consumption, the integrated circuit temperature can be maintained below a predetermined level.

Abstract: A head support mechanism includes a slider equipped with a magnetic head to read/write information from/to a magnetic disk, a load beam to provide the slider with an appropriate load, the load beam being flexible in a direction substantially perpendicular to the disk, and a microactuator mounting portion equipped with a microactuator. A first actuator fixing portion, which connects the microactuator mounting portion to a carriage, and a second actuator fixing portion on the magnetic head side of the microactuator mounting portion, which connects the microactuator mounting portion to the load beam, are coupled by two arm portions of the microactuator mounting portion. The microactuator is mounted on the microactuator mounting portion so that the microactuator does not come into contact with the microactuator mounting portion between the first actuator fixing portion and the second actuator fixing portion.

Abstract: It is to be made possible to eliminate unevenness of the inductances of bonding wires and to reduce the size of semiconductor devices. Over the surface of a semiconductor device in whose MISFET formation area a MISFET comprising a plurality of unit MISFETs connected in parallel, gate electrode pads electrically connected to the gate electrode of the MISFET and drain electrode pads electrically connected to the drain electrode of the same are arranged in a row each. The intervals of the gate electrode pads become gradually shorter from the end areas towards the central area of the electrode array of the gate electrode pads. The intervals of the drain electrode pads also become gradually shorter from the end areas towards the central area of the electrode array of the drain electrode pads.

Abstract: A magnetic disk drive having a high recording density and enabling high speed transfer is achieved by reducing vibration of a carriage arm assembly to reduce a positioning error. The disk drive is configured so that a carriage arm is configured by two arm portions, the arm portions being coupled to each other by a restraint member through a viscoelastic material, the restraint member being supported on a carriage body or an area of the carriage arm in the vicinity of the body by means of adhesion or a viscoelastic material. By providing a high damping effect against various vibration modes in which in-plane bending and out-plane bending of the carriage arm are generated, vibration of the carriage arm assembly is suppressed, so that the positioning error is reduced, thereby the magnetic disk drive having a high recording density can be achieved.

Abstract: In a magnetic recording apparatus including a support arm movable with respect to a magnetic recording disk, a first actuator for moving the support arm with respect to the magnetic recording disk, a pair of support members at least one of which holds a magnetic head thereon and each of which is connected to the first actuator through the support arm to be driven by the first actuator through the support arm, and a pair of second actuators for moving respectively the support members with respect to the support arm so that the support members are respectively moved with respect to the magnetic recording disk by the first actuator and the second actuators, the second actuators move simultaneously the support members respectively with respect to the support arm in respective directions opposite to each other.

Abstract: A magnetic head supporting apparatus having a magnetic head for reading and writing information on a magnetic disc, a slider for mounting the magnetic head, and a suspension for supporting the slider. An IC chip for controlling a signal of the magnetic head is mounted on a heat insulating substrate which substantially prevents conduction of heat therethough, and the heat insulating substrate is mounted to the suspension.

Abstract: A magnetic disk apparatus of the present invention is equipped with a microactuator for micro motion using piezoelectric elements in addition to a coarse adjustment actuator such as a voice coil motor or the like, eliminates parts that slide between the microactuator and surrounding members, and alleviates stress on the piezoelectric elements even if an impact is given to the magnetic disk apparatus. Thus, a first actuator fixing portion on a carriage side and a second actuator fixing portion on a magnetic head side of a microactuator mounting portion are coupled with a plurality of flexible coupling portions and coupling portions are placed outside the microactuator in substantially symmetric with respect to a centerline in a longitudinal direction of a suspension.

Abstract: To restrain temperature rise by controlling heat radiation from an IC. More specifically, an area of junctioning pads which are in contact with an IC is enlarged to substantially overlap the whole or at least half or more of the area of the IC. Further, the IC is covered with an overcoat which protrudes to other parts of a head supporting mechanism.

Abstract: A kernel (40) operating on a Java virtual machine (33) is provided. When executing a Java application, a single Java virtual machine (33) is activated. On this Java virtual machine 33 that is activated, the kernel (40) obtains information for identifying a Java application (35 or 36), generates an internal process for the application identified by this obtained information, and starts this generated internal process. Then, the kernel (40) serially generates and starts an internal process for each of the plurality of Java applications (35 or 36) to be executed. Thus, the plurality of Java applications are executed on the single Java virtual machine. This reduces the memory amount required for execution of a plurality of Java applications and reduces the processing time before execution starts.

Abstract: In the magnetic disk unit comprising suspensions in each of which an IC is mounted on a load beam, a magnetic head displacement caused by the warp of the load beam occurring due to heat generated from the IC is compensated, whereby the shortening of an access speed and high reliability of reading/writing are realized. The thermal displacement of the magnetic head is compensated by operating micro actuators on the load beam in accordance with the temperature rise of the IC which is measured by a temperature sensor. Namely, by driving the micro actuators so that the magnetic head may move in a direction reverse to the direction of the magnetic head movement caused by the thermal displacement, the thermal displacement of the magnetic head is made to be substantially zero.

Abstract: A magnetic disk drive comprises at least one magnetic head for reading and writing information on at least one magnetic disk, a carriage supporting the magnetic head over the magnetic disk for movement of the magnetic head about a predetermined shaft, an annular coil supported by a bobbin provided on the carriage and subjected to an electromagnetic force for driving the carriage. The drive further comprises a first connection member for joining the annular coil and the bobbin, an in-coil member arranged inside the annular coil, and a second connection member for joining the in-coil member and the annular coil. A modulus of longitudinal elasticity of the in-coil member is larger than that of the first or second connection member. The drive thus formed has the increased carriage rigidity, the improved positioning accuracy of a magnetic head and the increased recording capacity of the disk.

Abstract: According to the invention, there is provided a carriage arm assembly including a carriage arm having two arm members. The arm member is constructed in such a way that the width of its coil side end and the width of its suspension side end are narrower than that of its intermediate area. This construction widens a servo band width, improves positioning accuracy, and reduces positioning errors of a magnetic disk apparatus, so that recording density is improved and storage capacity is increased. Further, by coupling two arm members using a restriction member via a visco-elastic member, it is possible to achieve a high damping effect on various vibration modes including in-plane bending of the arms, and suppress vibration of the carriage so as to reduce the positioning errors.

Abstract: A magnetic head supporting apparatus having a magnetic head for reading and writing information on a magnetic disc, a slider for mounting said magnetic head, and a suspension for supporting the slider. An IC chip for controlling a signal of the magnetic head is mounted on a heat insulating substrate, and the heat insulating substrate is mounted to the suspension.

Abstract: A magnetic disk unit includes a magnetic disk attached to a spindle so as to be rotatable, a slider having a magnetic head for reading/writing data onto/from the magnetic disk, a suspension for providing the slider with a predetermined load, and an actuator arm for positioning the slider attached to the suspension on the magnetic disk. A first pad including the magnetic head and second pads including no magnetic heads are disposed on an air bearing surface of.the slider. During rotation of said magnetic disk, a part of the first pad keeps in contact with the magnetic disk. A load point of the suspension with respect to the slider is positioned between a leading edge of the slider and a position located at a distance equivalent to substantially 0.42 times a whole length of the slider from the leading edge of the slider.

Abstract: A multistage high frequency power amplifier circuit device has a plurality of semiconductor amplification elements connected in a cascade. The circuit device is provided with a bias control circuit used to control the bias voltage or bias current of the output semiconductor amplification element in each stage so as to reduce the variation of the output power with respect to the power control signal voltage in an area around the threshold voltage of the semiconductor amplification elements. This realizes a high frequency power amplifier circuit device provided with excellent controllability of the output power and high efficiency at the time of low power output realized with use of such a control voltage as a power control signal.

Abstract: A magnetic head supporting apparatus includes a magnetic head for reading and writing information on a magnetic disc, a slider having the magnetic head, and a suspension for supporting the slider. An IC chip for controlling a signal of the magnetic head is mounted on a first surface of a heat insulating substrate, and a second surface of the heat insulating substrate opposite to the first surface thereof is mounted to the suspension.

Abstract: A magnetic disk unit includes a magnetic disk, a slider having a magnetic head, a suspension for providing the slider, and an actuator arm for positioning the slider on the magnetic disk a first pad including the magnetic head and second pads including no magnetic heads are disposed on an air bearing surface of the slider. A load point of the suspension with respect to the slider is positioned between a leading edge of the slider and a position located at a distance equivalent to substantially 0.42 times a whole length of the slider from the leading edge of the slider. When the slider is seek-positioned on a certain track on the magnetic disk, a frictional force exerted between the first pad of the slider and the magnetic disk is smaller than a product of lateral stiffness of the suspension in a seeking direction and a track width.

Abstract: In magnetic disk structures having a high density, positioning errors (generally referred to as “flutter error”) occur due to a fluctuation of a magnetic disk. As a result, reading precision deteriorates. This is a significant problem in realizing a large capacity for a magnetic disk apparatus. This can be resolved by providing a magnetic apparatus such that a suspension which holds a slider having a magnetic head at one end and which is attached to a supporting arm at the other end is inclined so that an interval between the suspension and the magnetic disk is small on the inner rim side and is large on the outer rim side with this arrangement, the occurrence of the positioning error due to the fluctuation of a deformation of the magnetic disk is reduced, thereby enabling a high density recording of the magnetic disk.

Abstract: A magnetic disk unit includes a magnetic disk attached to a spindle so as to be rotatable, a slider having a magnetic head for reading/writing data onto/from the magnetic disk, a suspension for providing the slider with a predetermined load, and an actuator arm for positioning the slider attached to the suspension on the magnetic disk. A first pad including the magnetic head and second pads including no magnetic heads are disposed on an air bearing surface of the slider. During rotation of said magnetic disk, a part of the first pad keeps in contact with the magnetic disk. A load point of the suspension with respect to the slider is positioned between a leading edge of the slider and a position located at a distance equivalent to substantially 0.42 times a whole length of the slider from the leading edge of the slider.