Nsk Corporation

Teac Corporation

Kabushiki Kaisha Toshiba

Shigeru Fukinuki

Shin Kumagai

Sari Maekawa

Minoru Minase

Junichi Kanenaga

Naoto Shinkawa

Naoki Kimura

Noriyuki Kato

Kyosho Uryu

Minoru Awazu

Shigeru Shimakawa

Yo Kamei

Teruyoshi Kogure

Manabu Murakami

Noriyuki Katou

An electric power steering apparatus that drive-controls a motor by an inverter, and a motor release-switch is connected between the inverter and the motor, comprising: a control section to detect an assist state on a driving control system and to ON/OFF-switch a control of the inverter based on a detection result; a motor rotational number detecting section to detect a rotational number of the motor; an energy calculating section to calculate an energy of a motor back-EMF and a regenerative current based on the rotational number; and a judging section to compare the energy with an area of safety operation of the motor release-switch and to OFF-switch the d motor release-switch when the energy becomes within the area of safety operation. As occasion demands, the area of safety operation is calculated with the temperature.

Motor control apparatus and electric power steering apparatus provided the same

A motor control unit which drives a motor through an inverter based on a calculated command value of a control section to which a power supply voltage is supplied, including: a charging/discharging mechanism for charging and discharging electric charges of an inverter voltage supplied to the inverter; and a separation means for separating the charging/discharging mechanism from the power supply voltage, wherein when a warning signal informing of a drop in the power supply voltage is inputted, the charging/discharging mechanism is separated from the power supply voltage by the separation means as well as a voltage is applied to the control section from the charging/discharging mechanism to avoid power supply reset of the control section. The motor may be a motor with multi-system windings.

Motor control unit and electric power steering apparatus using the same and vehicle

An inverter device includes a switch circuit configured by series-connecting two N-channel semiconductor switching elements in opposite directions so that the switch circuit makes or breaks electrical connection between a DC power supply and an inverter circuit, and a control circuit carrying out a protecting operation in which when the control circuit outputs a control signal to control switching of the inverter circuit and an operating condition is met, the control circuit stops output of the control signal to turn off all switching elements configuring the inverter circuit and the switch circuit. In the protecting operation, the switch circuit is turned off after output of the control signal has been stopped so that changes in drain-source voltages and drain currents of the N-channel semiconductor switching elements are rendered slower.

Inverter device and power steering device

A switch driving circuit electrically opens and closes a switch circuit including two N-channel type semiconductor switching elements series connected in a reverse direction, thereby electrically opening and closing a path between a DC power supply and an inverter circuit. The switch driving circuit has a reference potential point in common with the inverter circuit and supplies an opening/closing control signal to the switch circuit. The switch driving circuit includes a half bridge circuit including two semiconductor switching elements series connected between a driving power supply and the reference potential point. Two protection diodes are connected in parallel to the semiconductor switching elements respectively. At least one current blocking diode is configured to block current from flowing from the reference potential point through the diode to the switch circuit side when the DC power supply is connected to the inverter circuit in reverse polarity.

Switch driving circuit, inverter apparatus and power steering apparatus

There is provided a printed circuit substrate and a noise suppression structure capable of minimizing constraint on a component layout on a substrate and suppressing noise. The printed circuit substrate includes conductive patterns of odd numbered layers and conductive patterns of even numbered layers which are alternately arranged in a vertical direction and hold an insulating layer between each layer. Portions excepting predetermined areas for connecting a first through-hole and predetermined areas for insulating from a second through-hole in the conductive patterns of the odd numbered layers have a same shape as portions excepting predetermined areas for connecting the second through-hole and predetermined areas for insulating the first through-hole in the conductive patterns of the even numbered layers, and the portions are laminated on one another at the same position in the vertical direction.

Controlling apparatus for electric power steering apparatus

An electric power steering apparatus includes a shunt resistor connected to an inverter, a controlling motor current detection circuit connected to two terminals of the shunt resistor in a positive direction, which detects phase currents of a motor and uses the detected phase current as a controlling motor current detection value of assist control, and a diagnostic motor current detection circuit that is connected to two terminals of the shunt resistor in an opposite direction and detects a failure of the controlling motor current detection circuit. Each phase current of the motor is detected by one-shunt type and the assist control is performed, and two systems of a circuit for amplifying a voltage between two terminals of the shunt resistor are provided.

Electric power steering apparatus

According to one embodiment, an optical disk device includes types of semiconductor laser diodes configured to emit laser light of different wavelengths, an output control circuit configured to control light output of each semiconductor laser diode, and a composite power source configured to generate voltages required for driving the types of semiconductor laser diodes and operating the output control circuit from a single power source voltage and to selectively output the generated voltages. The composite power source includes an input port to input an external control signal at a time of voltage selection and is configured to change the output voltage stepwise in response to the control signal.

Optical disk device and power supply method

A disk device for improving a S/N ratio is provided with a spindle motor control substratearranged below a trayvia a buffer material and a medium substratearranged at a position different from the spindle motor control substratebelow the tray. The spindle motor control substrate, the medium substrateand the main control substrateof the device body are connected each other with a flexible print circuit (FPC). The medium substrateand a pickup headare connected with other FPC. The head detection signal is provided to the main control substratethrough the medium substrate. A driver IC for motor drive system is carried on the spindle motor control substrate. The motor drive signal is apart from the head detection signal and is provided to a spindle motoror a head transferring motor.

Disk device

A CD-ROM drive has a disk tray ejectable from a data transfer position within a casing, where the disk is read, to a load/unload position outside the casing where the disk is loaded on and unloaded from the tray. Being locked in the data transfer position against the bias of an ejector spring, the tray is ejected by being unlocked by brief energization of a solenoid under the direction of a controller. The solenoid might overheat to self-destruction if, upon malfunctioning of the controller, it were left energized after tray ejection. A protection circuit is therefore provided for permitting a solenoid driver circuit to energize the solenoid in response to an ejection command from the controller only when the tray is in the data transfer position.

Overheat prevention of a solenoid or the like in a CD-ROM drive or the like

A disk apparatus in which a control unit performs a seek control includes a disk motor which rotates a disk placed at a loaded position in the disk apparatus. A motor driver controls the disk motor such that the disk is rotated by the disk motor at a controlled speed. A read/write head reads information from or writes information to the disk when the disk is rotated by the disk motor at the controlled speed. A head shifting unit shifts the head in a radial direction of the disk to a target location thereof when a seek is performed. A current supply control unit controls current supplied to the disk motor during the seek. In the disk apparatus, the current supply control unit cuts off the current supply to the disk motor for a predetermined period after a start of the seek.

Disk apparatus in which an improved current supply control is performed to effectively reduce a current consumption

A CD-ROM drive is disclosed which is for use with disks having various degrees of spindle hole eccentricity and data track eccentricity. The hole eccentricity of each disk manifests itself during disk rotation as periodic vibration of the disk and, in consequence, periodic departures of the light beam spot from the track to an extent proportional to the speed of disk rotation, whereas the track eccentricity manifests itself during disk rotation as periodic departures of the beam spot from the track to a constant extent regardless of the speed of disk rotation. Therefore, on being loaded into the disk drive, each disk has its hole eccentricity and track eccentricity measured at two different disk eccentricity check speeds in terms of, for example, the amplitude of an eccentricity-caused periodic component of a tracking error signal. The hole eccentricity of the disk is ascertainable by subtracting the eccentricity measurement at the lower check speed from that at the higher check speed. A speed suitable for reading the disk, at which speed the disk will cause no inconvenient vibration, is determined on the basis of the thus ascertained hole eccentricity thereof.

Growing community of inventors

Tokyo, Japan

Shigeru Fukinuki