Abstract: A magnetic disk device comprises a magnetic disk in which a data zone is formed. An actuator has a voice coil and a head slider carrying a magnetic head, the actuator being swung to move the magnetic head over the disk between an innermost position of the data zone and an outermost position of the data zone. A magnet has a magnetization center and is opposed to the voice coil so that a voice coil motor which swings the actuator is formed, the magnet having a north pole and a south pole confronting each other via the magnetization center. The magnetic disk device is provided so that a deviation of a center of the voice coil from the magnetization center when the magnetic head is in the innermost position of the data zone is substantially equal to a deviation of the center of the voice coil from the magnetization center when the magnetic head is in the outermost position of the data zone.

Abstract: A guide pin is set in common in first and second voids defined in the peripheries of first and second flexible printed wiring boards. The second void has the shape identical to the shape of the first void. When the guide pin rotates around a rotation axis so as to bring the guide pin in contact with the peripheries of the first and second flexible printed wiring boards inside the first and second voids, the first and second flexible printed wiring boards can be arranged. This leads to arrangement of the first and second flexible printed wiring boards at a time in a facilitated manner.

Abstract: A magnetic disk device comprises a magnetic disk in which a data zone is formed. An actuator has a voice coil and a head slider carrying a magnetic head, the actuator being swung to move the magnetic head over the disk between an innermost position of the data zone and an outermost position of the data zone. A magnet has a magnetization center and is opposed to the voice coil so that a voice coil motor which swings the actuator is formed, the magnet having a north pole and a south pole confronting each other via the magnetization center. The magnetic disk device is provided so that a deviation of a center of the voice coil from the magnetization center when the magnetic head is in the innermost position of the data zone is substantially equal to a deviation of the center of the voice coil from the magnetization center when the magnetic head is in the outermost position of the data zone.

Abstract: An ion current detecting apparatus includes a capacitor C that is charged as a spark plug 3 discharges, a Zener diode ZD that limits a maximum voltage of the capacitor C while charging, a detection resistor R2 through which a discharge current of the capacitor C flows, and a comparator circuit 5 that compares a current value of the detection resistor R2 with a predetermined value. A charge quantity Q of the capacitor C at discharge start is set so that, as a consequence of a discharging operation of the capacitor C, discharge duration required until the current value of the detection resistor R2 falls below the predetermined value becomes longer than time duration in which the ion current generated by fuel combustion in the engine combustion chamber lasts. The ion current detecting apparatus according to the present invention quickly and automatically detects degradation in an insulation resistor in the spark plug to ensure a normal operation in engine control.

Abstract: The present invention is a combustion state determination method of an internal combustion engine for detecting an ion current which is generated in a combustion chamber at combustion of the internal combustion engine in a detection period to determine a combustion state, comprising steps of detecting a primary combustion period on the basis of a first ion current which forms the detected ion current and occurs immediately after ignition, detecting a secondary combustion period on the basis of the ion current which occurs after disappearance of the first ion current when at least the detected primary combustion period is normal, determining the combustion state on the basis of the detected primary combustion period when the secondary combustion period is smaller than a predetermined value, and determining the combustion state on the basis of a whole combustion period from start of the detection period of the ion current to end of the last secondary combustion period in the detection period when the secondary

Abstract: A guide pin is set in common in first and second voids defined in the peripheries of first and second flexible printed wiring boards. The second void has the shape identical to the shape of the first void. When the guide pin rotates around a rotation axis so as to bring the guide pin in contact with the peripheries of the first and second flexible printed wiring boards inside the first and second voids, the first and second flexible printed wiring boards can be arranged. This leads to arrangement of the first and second flexible printed wiring boards at a time in a facilitated manner.

Abstract: A magnetic disk device comprises a magnetic disk in which a data zone is formed. An actuator has a voice coil and a head slider carrying a magnetic head, the actuator being swung to move the magnetic head over the disk between an innermost position of the data zone and an outermost position of the data zone. A magnet has a magnetization center and is opposed to the voice coil so that a voice coil motor which swings the actuator is formed, the magnet having a north pole and a south pole confronting each other via the magnetization center. The magnetic disk device is provided so that a deviation of a center of the voice coil from the magnetization center when the magnetic head is in the innermost position of the data zone is substantially equal to a deviation of the center of the voice coil from the magnetization center when the magnetic head is in the outermost position of the data zone.

Abstract: According to the present invention, in a spark ignition-type internal combustion engine which has a spark plug and mounted in a vehicle, an ion current generated in a combustion chamber through the spark plug after ignition is detected and smoldering of the spark plug is determined on the basis of the detected ion current. An operation state of the internal combustion engine is detected and smoldering of the spark plug is determined based on that the detected ion current satisfies a predetermined condition when the detected operation state falls within an operation determination range set corresponding to an operation range in which an intake port pressure close to an atmospheric pressure is achieved using predetermined engine speed as an upper limit and a predetermined intake port pressure as a lower limit.

Abstract: A fixing member is spaced from a head actuator by a predetermined distance. A flexible printed circuit board extends at least from the head actuator to the fixing member. The flexible printed circuit board is superposed on the surface of the fixing member. A viscoelastic layer and a protecting layer are overlaid on the surface of the flexible printed circuit board. A clip clips all the fixing member, the flexible printed circuit board, the viscoelastic layer and the protecting layer together. When a head slider is positioned, the head actuator changes its attitude relative to a recording disk. The inertial force based on the rotation causes the first flexible printed circuit board to vibrate when the actuator block stops rotating. The viscoelastic layer serves to absorb this residual vibration of the first flexible printed circuit board. Vibration of the flexible printed circuit board can be suppressed.

Abstract: A fixing member is spaced from a head actuator by a predetermined distance. A flexible printed circuit board extends at least from the head actuator to the fixing member. The flexible printed circuit board is superposed on the surface of the fixing member. A viscoelastic layer and a protecting layer are over laid on the surface of the flexible printed circuit board. A clip clips all the fixing member, the flexible printed circuit board, the viscoelastic layer and the protecting layer together. When a head slider is positioned, the head actuator changes its attitude relative to a recording disk. The inertial force based on the rotation causes the first flexible printed circuit board to vibrate when the actuator block stops rotating. The viscoelastic layer serves to absorb this residual vibration of the first flexible printed circuit board. Vibration of the flexible printed circuit board can be suppressed.

Abstract: A magnetic disk apparatus for reading and writing information to a magnetic disk including a motor for rotating the magnetic disk mounted thereon; a disk-shaped clamp for mounting the magnetic disk on the motor by screw fastening; and a C-shaped balancer for adjusting the rotary balance of the magnetic disk and mounted on the outer surrounding portion of the clamp, wherein the C-shaped balancer has a generally rectangular cross-section.

Abstract: A disc unit includes a head that records information onto and/or reproduces information from a disc, a suspension that includes a top surface and a side surface, and supports the head on the top surface, a flexible printed circuit board attached to the side surface of the suspension through an air gap, the flexible printed circuit board transmitting a signal indicative of the information to and from the head, and a damper that damps oscillation of the flexible printed circuit board.

Abstract: A head actuator that positions a head to perform information recording or playback on a computer readable storage medium, has a voice coil flanked by magnets. Through the voice coil a drive current flows and a damper to fit in a space between the voice coil and one of the magnets is formed on at least a portion of the voice coil. The head actuator vibration is controlled to achieve a more compact information storage apparatus and high-density recording. For example, on a voice coil (51) of a head actuator (20), a damping material (71) consisting of single layer viscoelasticity is formed along one lap of the voice coil (51). The damping material (71) is a single layer to not take up dimensions in the thickness direction, and, while pursuing making the apparatus more compact, it is possible to hold down vibration generated by the actuator (20).

Abstract: A thermal component is mounted on the front surface of an isolator sheet within a first specific area. A thermally-conductive material is located on the back surface of the isolator sheet on the back of the first specific area. An electrically-conductive material is located on the front surface of the isolator sheet within a second specific area. A thermally-insulating material is located on the back surface of the isolator sheet on the back of the second specific area. The flexible printed circuit board unit of this type allows heat of the thermal component to efficiently radiate from the thermally-conductive material. An increase in temperature can be suppressed in the thermal component. Heat can reliably stay in the electrically-conductive material when a solder material is applied to the surface of the electrically-conductive material. The solder material is allowed to reliably fuse.

Abstract: A magnetic disk apparatus includes an actuator including a magnetic head, a coil which forms a voice coil motor, and a coil arm which supports the coil, wherein the magnetic head can be rotated or swung by the voice coil motor so as to be positioned at any position on a magnetic disk, a magnet which forms the voice coil motor with the coil, and a latch mechanism for controlling the actuator so that the actuator is situated at a designated latch position in a non-operation condition. The latch mechanism is formed by the magnet and a magnetic metal piece provided to the coil arm, an extended part is formed at the magnetic metal piece, and the extended part is formed and positioned at a strong magnetic force generation part of the magnet when the actuator is positioned at the latch position.

Abstract: A fixing member is spaced from a head actuator by a predetermined distance. A flexible printed circuit board extends at least from the head actuator to the fixing member. The flexible printed circuit board is superposed on the surface of the fixing member. A viscoelastic layer and a protecting layer are overlaid on the surface of the flexible printed circuit board. A clip clips all the fixing member, the flexible printed circuit board, the viscoelastic layer and the protecting layer together. When a head slider is positioned, the head actuator changes its attitude relative to a recording disk. The inertial force based on the rotation causes the first flexible printed circuit board to vibrate when the actuator block stops rotating. The viscoelastic layer serves to absorb this residual vibration of the first flexible printed circuit board. Vibration of the flexible printed circuit board can be suppressed.

Abstract: A magnetic disk device comprises a magnetic disk in which a data zone is formed. An actuator has a voice coil and a head slider carrying a magnetic head, the actuator being swung to move the magnetic head over the disk between an innermost position of the data zone and an outermost position of the data zone. A magnet has a magnetization center and is opposed to the voice coil so that a voice coil motor which swings the actuator is formed, the magnet having a north pole and a south pole confronting each other via the magnetization center. The magnetic disk device is provided so that a deviation of a center of the voice coil from the magnetization center when the magnetic head is in the innermost position of the data zone is substantially equal to a deviation of the center of the voice coil from the magnetization center when the magnetic head is in the outermost position of the data zone.

Abstract: For a magnetic disk apparatus for reading and writing information to a magnetic disk in the present invention, the recessed portion of the cover of the magnetic disk apparatus has a two-level structure; the space between the inner surface of the recessed portion, corresponding to the region of the magnetic disk surface which the actuator arm does not traverse, and the surface of the magnetic disk is made as narrow as possible. The air flow generated in that space by the rotation of the magnetic disk is thereby suppressed and as a result, magnetic disk resonance is suppressed. Also, the noise level is further suppressed by having two layers of damping plates attached to the outer surface of the cover.

Abstract: A disc unit includes a head that records information from and/or reproduces information onto a disc, a suspension that includes a top surface and a side surface, and supports the head on the top surface, a flexible printed circuit board attached to the side surface of the suspension through an air gap, the flexible printed circuit board transmitting a signal indicative of the information to and from the head, and a damper that damps oscillation of the flexible printed circuit board.

Abstract: A thermal component is mounted on the front surface of an isolator sheet within a first specific area. A thermally-conductive material is located on the back surface of the isolator sheet on the back of the first specific area. An electrically-conductive material is located on the front surface of the isolator sheet within a second specific area. A thermally-insulating material is located on the back surface of the isolator sheet on the back of the second specific area. The flexible printed circuit board unit of this type allows heat of the thermal component to efficiently radiate from the thermally-conductive material. An increase in temperature can be suppressed in the thermal component. Heat can reliably stay in the electrically-conductive material when a solder material is applied to the surface of the electrically-conductive material. The solder material is allowed to reliably fuse.