Denso Corporation

Nippon Soken, Inc.

Other

Nippondenso Co., Ltd.

Shizuoka University

So-ken Corporation

Showa Shell Sekiyu K.k.

Masao Tokunaga

Kenji Takeda

Naoki Nakane

Kiyoshi Sugimura

Koji Ito

Shigetoshi Fukaya

Masanori Yasuda

Yoshihiko Aihara

Kunio Iritani

Akitoshi Mizutani

Takashi Hagiwara

Yoshiichi Suzuki

Norio Yamamoto

Tsutomu Nakamura

Jun Yamaoka

Junichi Ishikawa

Tetsuo Hariu

Noriko Yamakawa

Shinji Makita

Ichiro Kawamura

Kimio Uchida

Nobuaki Koshobu

Shigenori Sakuma

Hiroyasu Baba

Yuichiro Yamada

Hiroshi Takeyama

Etsuro Yoshino

Junichi Asama

Keiichi Yasuda

Nobuaki Koshoubu

Tomomitsu Kamiya

Shiget Shi Fukaya

Hirotsugu Ishino

Taiji Morishita

Kahoru Mori

An electric motor system includes a rotary shaft having an axis line displaceable relative to a rotation center, a magnetic bearing for supporting the rotary shaft, a permanent magnet mounted on the rotary shaft and having a plurality of magnetic poles arranged in a circumferential direction around the axis line of the rotary shaft, three detection elements arranged in the circumferential direction around the rotation center for detecting a magnetic flux generated from the permanent magnet, and a coordinate detection section for determining coordinates of the axis line of the rotary shaft based on output values of two detection elements selected out of the three detection elements in accordance with a rotation angle of the rotary shaft.

Electric motor system

In an electric motor, a magnetic bearing generates an electromagnetic force between multiple permanent magnets and a coil and rotatably supports an other side of a rotation shaft in an axis line direction. The rotation shaft is configured to be capable of being inclined with a rotation center line using a bearing side of the rotation shaft as a fulcrum. An electronic control device controls a current that flows to the coil such that an axis line of the rotation shaft approaches the rotation center line due to a supporting force which is the electromagnetic force between the multiple permanent magnets and the coil. Accordingly, the rotation shaft is rotatably supported to be freely rotatable by a magnetic bearing and the bearing.

Electric motor, control device, and motor control system

A battery temperature rise causing system has a converting unit for converting voltage of electric power held in one of a rechargeable battery and an accumulator and applies the converted voltage to the other one, and a control unit controlling the converting unit to alternately perform first transfer of electric power from the battery to the accumulator and second transfer of electric power from the accumulator to the battery while changing the first transfer for the second transfer each time the battery voltage reaches a lower limit and changing the second transfer for the first transfer each time the battery voltage reaches an upper limit, and to increase temperature of the battery due to heat generated by electric current flowing through the battery during the electric power transfer.

System for causing temperature rise in battery

A torque sensor has a torsion bar coaxially in alignment with input and output shafts, a ring shaped magnet fixed to an axial end of the input shaft, a pair of magnetic yokes fixed to an axial end of the output shaft, and a magnetic sensor for detecting magnetic flux density generated between the pair of magnetic yokes. Each of the magnetic yokes is provided with claws, which are circumferentially spaced at constant intervals, and whose number is equal to that of each of N and S poles alternately arranged circumferentially in the magnet. Each, center of the claws coincides with a boundary between immediately adjacent N and S poles of the magnet, when the torsion bar is not twisted. The magnetic sensor is inserted into an axial gap between the pair of magnetic yokes without contacting the magnetic yokes.

Torque sensor and electric power steering system having same

A torque sensor has a torsion bar coaxially in alignment with input and output shafts, a ring shaped magnet fixed to an axial end of the input shaft, a pair of magnetic yokes fixed to an axial end of the output shaft, and a magnetic sensor for detecting magnetic flux density generated between the pair of magnetic yokes. Each of the magnetic yokes is provided with claws, which are circumferentially spaced at constant intervals, and whose number is equal to that of each of N and S poles alternately arranged circumferentially in the magnet. Each center of the claws coincides with a boundary between immediately adjacent N and S poles of the magnet, when the torsion bar is not twisted. The magnetic sensor is inserted into an axial gap between the pair of magnetic yokes without contacting the magnetic yokes.

Electric power steering system having a torque sensor

A magnetic sensor unit includes an actuator motor and a magnetic position sensor. The actuator motor has a magnetic circuit including motor magnets. The magnetic position sensor includes a sensor magnet and a hall element for detecting magnetic flux. Magnet clearances are formed between the motor magnets. The hall element is disposed outside of the motor to detect the magnetic flux in a direction penetrating through the magnet clearances, and which is perpendicular to a direction from one of the motor magnets to the other. In this disposition of the hall element, it is restricted that the hall element detects leaking magnetic flux from the motor magnets.

Magnetic sensor unit less responsive to leaking magnetic flux

A displacement sensor precisely detects displacement of a moving body in a rectilinear movement direction even if the moving body rotates. The sensor includes a detector and a magnet. The cross sectional area of the permanent magnet in a plane perpendicular to an axis, which extends in the rectilinear movement direction, varies in the direction of movement. The permanent magnet is magnetized in the rectilinear movement direction. The detector is located so that magnetic flux passes through a detection face of the detector substantially perpendicularly.

Displacement sensor

A rain sensor includes an amplifier circuit that amplifies an output voltage from a photodiode and then provides this voltage signal to a CPU. The amplifier circuit conducts an offset amplification. The output voltage from the amplifier circuit is controlled to be at a predetermined level, for example, 3.0V, and the CPU detects rainfall based on the drop in the output voltage from the predetermined level, 3.0V. Then it becomes possible to improve sensor sensitivity, maintain a small sensor size, and a low manufacturing cost.

Vehicle windshield rain sensor

A precipitation sensor has a prism bonded to a front windshield, a beam transmitter, and a beam receiver. The prism has an entry-side prism wall, a connection wall, and an exit-side prism wall. The entry-side prism wall of the prism parallelizes light transmitted from the beam transmitter by refracting them on a convex lens face. The parallelized light is reflected from a parabolic outer face of the prism wall toward the inner face of the windshield. The parallel beams reflected from the inner face of the front windshield are reflected from a parabolic outer face of the exit-side prism wall and then focused on the beam receiver through a convex lens face of the prism wall. The convex shapes of the lens faces form arcs, the centers of which are aligned with the beam transmitter and the beam receiver, respectively.

Precipitation sensor

A raindrop sensor detects an amount of raindrops landed on a window glass and outputs a measurement signal to a microcomputer. The microcomputer calculates an average amount of raindrops by averaging a predetermined number of the latest measurements. The microcomputer calculates an interval time for the wiper based on the calculated average amount of raindrops. At this time, when the calculated average amount of raindrops deviates from a predetermined reference value, the microcomputer calculates the average amount of raindrops using a smaller number of the latest measurements.

Wiper control system and method for controlling wiper

Burning and flickering effects of a display screen in a matrix-type liquid crystal display device using an anti-ferroelectric liquid crystal medium are avoided by controlling the duration of the holding period to a certain length. A control circuit measures the cycle of the input of the picture signals to one picture frame, and the duration of the blanking period is controlled according to the result of the measurement in order to keep the duration of the holding period constant.

Matrix type liquid crystal display device

A matrix liquid crystal display using an antiferroelectric liquid crystal prevents the displayed image from tailing off. The liquid crystal display includes a liquid crystal panel, a temperature sensor, a control unit, a scanning electrode driver circuit, and a signal electrode driver circuit. When the temperature of the liquid crystal panel is detected by the temperature sensor, the control unit increases or reduces the de-select period according to the detected temperature. The scanning electrode driver circuit and the signal electrode driver circuit serve to drive scanning electrodes and signal electrodes, respectively included in the liquid crystal panel according to control signals from the control unit and from a level converter. These control signals include a signal indicating the controlled de-select period. Thus, the controlled de-selected period is secured.

Matrix liquid crystal display having temperature-dependent element drive

There is disclosed herein a ferroelectric liquid crystal electro-optical apparatus of the maxtrix type comprising a liquid crystal cell having first and second electrode substrates which include n striped line electrodes and m striped column electrodes, respectively, facing at right angles each other. A ferroelectric liquid crystal is put in therebetween so as to form n by m indication picture elements. Also included in the apparatus a scanning drive device adapted to supply a scanning signal and a data signal to the n striped line electrodes and the m striped column electrodes, respectively. The ferroelectric liquid crystal shows three stable states in accordance with an application voltage and has a light transmittance with a hysteresis sufficient to a dynamic drive in accordance with increase or decrease in the application voltage in a predetermined voltage range. The scanning drive device produces a first combination signal as a signal running to variation from a voltage below a refernece voltage in a predetermined one polarity voltage range to a voltage above the reference voltage and produces a second combination signal as a signal which does not exceed the reference voltage in the range, and supplies a direct-current combination signal between the electrodes after the supply of the first and second combination signal thereto.

Ferroelectric liquid crystal electro-optic apparatus and manufacturing

Growing community of inventors

Gamagori, Japan

Masao Tokunaga