Seiko Epson Corporation

Tokyo R & D Co., Ltd.

Zexel Gmbh

Epson Corporation

Seikon Epson Corporation

Akihito Uetake

Osamu Shinkawa

Takeshi Seto

Yoshihiko Yamagishi

Tatsuya Shimoda

Kunio Tabata

Shinichi Miyazaki

Yoshiki Fukui

Takashi Nagate

Nobukazu Takagi

Satoshi Yamazaki

Masao Ono

Masatoshi Fukuda

Teruhiko Fujisawa

Kunihiko Takagi

Hiroshi Miyazawa

Osamu Takahashi

Kinya Matsuzawa

Yoshikazu Koike

Hiroshi Nakazato

Takeshi Ishikawa

Yutaka Takada

Kuniaki Tanaka

Issei Yamakoshi

Katsumi Shinkai

Akihiko Ikegami

Shigeo Kanna

Tamotsu Fukazawa

Kiyohiro Harada

Haruki Torizuka

Shinji Okayama

Mitsugu Igura

Haruhiko Baba

Takeshi Fujihisa

Sakae Mashio

A superdirectional acoustic system for reproducing a sound signal supplied from a real sound source by using a superdirectional speaker and producing a virtual sound source in a vicinity of a sound wave reflection surface. The system includes an ultrasonic speaker, which includes an ultrasonic transducer for oscillating a sound wave in an ultrasonic frequency band, for reproducing an audio signal in a relatively medium to high frequency sound range, which is included in the sound signal supplied from the real sound source; and a low frequency sound reproducing speaker for reproducing an audio signal in a relatively low frequency sound range, which is included in the sound signal supplied from the real sound source. Sound in the medium-high frequency range is reproduced in a manner such that the sound is produced from a virtual sound source which is formed in the vicinity of the sound signal reflection surface such as a screen.

Superdirectional acoustic system and projector

A projector includes an ultrasonic speaker, a visual information generation unit that generates visual information relating to a sound reproduction range of the ultrasonic speaker, and an image projection unit that displays the visual information generated by the visual information generation unit on a screen.

Project equipped with ultrasonic speaker, and method for displaying sound reproduction range in projector

An electrostatic ultrasonic transducer includes a diaphragm having a conducting layer and a pair of first and second fixed electrodes opposed to the corresponding surfaces of the diaphragm, the pair of fixed electrodes having a plurality of through holes in corresponding positions, wherein a DC bias voltage is applied to the conducting layer of the diaphragm and an alternating current signal is applied between the first and second fixed electrodes to generate an ultrasonic wave. Part of the pair of fixed electrodes includes s driving fixed electrode for driving the ultrasonic transducer, and the other part includes a detecting fixed electrode for detecting the amplitude of the diaphragm. The ultrasonic transducer includes a control unit that controls the vibration of the diaphragm so that the amplitude is proportional to the input signal based on the amplitude of the diaphragm detected by the detecting fixed electrode.

Ultrasonic transducer, ultrasonic speaker, and method of controlling the driving of ultrasonic transducer

A recycling job supporting system is provided which is capable of efficiently carrying out a disassembly job. Information management center equipmenthas an object disassembly information register DBin which the object disassembly information is registered by associating the object disassembly information with object identification information, retrieves the object disassembly information from the object disassembly information register DBbased on the received object identification information when receiving the object identification information, and transmits the object disassembly information found through the retrieval to recycling center equipment. The recycling center equipmentreads out the object identification information from the recycling object, transmits the read-out object identification information to the information management center equipment, constructs any one of a plurality of disassembly diagrams capable of being constructed through the received object disassembly information depending on a progress condition of the disassembly job of the recycling objectwhen receiving the object disassembly information through the transmission, and then displays the constructed disassembly diagram in a display unit

Recycling job supporting system, recycling center equipment, information management center equipment, equipment program, and recycling job supporting method

The present invention relates to a control method and a control device for a position sensorless motor which has position sensorless operation and synchronized operation, wherein a rotation position of a rotor is detected on the basis of counter electromotive forces generated in stator coils in the position sensorless operation, the stator coils are excited in synchronization with the detected rotation position of the rotor to rotate the rotor and a deviation between a target position and the present position is determined from a target rotation position according to the position command signal and the detected rotation position, position sensorless close loop drive is made on the basis of the determined deviation, and when the synchronized operation is made, the stator coils of the motor are excited in synchronization with the position command signal to rotate the rotor.

Method and device for controlling position sensorless motor

Sensor, drive force auxiliary device using the sensor, and torque sensor

A power-generating device can include a dynamo for converting kinetic energy into electrical energy, a switch capable of short-circuiting output terminals of the dynamo, a controller capable of controlling the switch, a rectifier for rectifying an output of the dynamo, and a charging portion capable of storing the output of the dynamo. The controller can perform chopper control for cyclically turning on and off the switch in accordance with a PWM signal. Where an electromotive voltage of the dynamo is lower than a charged voltage, a boosted voltage can be produced by chopper amplification. If the electromotive voltage is low, it can be charged in the charging portion if the boosted voltage is increased to a sufficient level prior to charging.

Power-generating device, charging method and clocking device

A drive for an electric vehicle includes by forming a drive unit 8 having a transmission by combining a single propelling motor 7 with the transmission, respectively interconnecting the drive unit 8 with propelling wheels to be a drive wheel, and separately controlling the drive units 8. Besides, traveling speed detecting means are provided on the respective drive units 8, 8, and the respective drive units are simultaneously controlled according to a revolution signal from one of the traveling speed detecting means. A method for controlling an electric vehicle by separately controlling the drive units 8, 8, making the output torque of the motor zero or minimum during the gear change, and producing again the output torque of the motor after completing the gear change.

Drive for electric vehicle and control method of the same

A method of manufacturing a permanent magnet rotor comprising a rotor yoke (2) of a rotor (1) which is formed by laminating a large number of steel sheets (4), (14), (24), (34) and (44), has 2n times (n is a positive integer) of magnetic poles (5) on the outer periphery, has slots (6) at the bases of all or every other magnetic poles at a substantially equal distance from a rotatable shaft hole (7), and has permanent magnets (3) for a field inserted into the slots, and a method for producing it. It has a structure that the permanent magnets for the field are prevented from coming out, or the permanent magnets for the field have their faces treated in order to improve the safety and reliability of the permanent magnet rotor.

Method of producing a permanent magnet rotor

A DC brushless motor 3 is provided which comprises armature 31 and rotor 32. Rotor 32 is provided with a rotor yoke that has four main poles 321 on its periphery. Slots with a radial-direction size of L.sub.m are formed on main poles 321 of the rotor yoke. Magnetic-field permanent magnet 323 with an approximate thickness of L.sub.m is embedded in each slot 322, such that the radial-direction size L.sub.m of slot 322 and the air gap length L.sub.g of the air gap formed between rotor 32 and armature 31 satisfy the relationship 0&lt;L.sub.m +L.sub.g .ltoreq.2 mm.

DC brushless motor having an interior permanent magnet rotor with

Battery control system for electric vehicle

DC brushless motor having auxiliary salient poles

In an electric vehicle provided with an electric motor (M), a motor drive circuit (17) and a control circuit section (15) for outputting an operation command to the motor drive circuit, a variable speed drive unit for electric vehicles has a transmission apparatus (20) which engages or disengages a drive shaft (7a) which receives the drive force from a propelling motor and a driven shaft (5a) which is interconnected with propelling wheels by an electromagnetic engagement clutch (30), the transmission apparatus has the electromagnetic clutch comprised of a first clutch (22) interconnected with the drive shaft, a second clutch (25) having a rotational speed different from the first clutch, and an output side clutch (21) interconnected with the driven shaft; and the output side clutch and the first clutch or the second clutch are alternatively connected to selectively change the motor output. And, to connect the clutches mutually, the rotational speed of the clutch on the drive side is synchronized with the rotational speed of the clutch on the driven side.

Variable speed drive unit for electric vehicle and variable speed

A brushless DC motor drive apparatus according to the invention comprises a stator and a rotor, the stator including multi-phase armature windings which are connected in a star formation and generate a plurality of terminal voltages at respective terminals of the armature windings, and the rotor including a plurality of permanent magnets which form pairs of magnetic poles. The motor drive apparatus also includes an inverter coupled to the rotor for adjusting the speed of the rotor, a rotor position detection means for detecting the terminal voltages generated in the armature windings and for generating a position signal indicative of a magnetic pole position of the rotor. The rotor position detection means includes a line voltage generation means for generating line voltages corresponding to the terminal voltages of the armature windings and comparison means for comparing signals derived from the line voltages in predetermined combinations and outputting comparison signals as the positional signal. The motor drive apparatus also includes a drive control means for controlling and driving the inverter according to the position signal generated by the rotor position detection means, the drive control means including PWM (Pulse Width Modulation) chopper control means for generating a PWM chopper control signal to control the inverter. The motor drive apparatus according to the present invention can always detect accurate rotor position without being affected by the rotational frequency or load of the brushless DC motor. Furthermore, the motor drive apparatus can easily expand the operational range of a brushless DC motor, particularly that of a brushless DC motor possessing an embedded magnet-type rotor structure. Additionally, the motor drive apparatus can easily and accurately operate a brushless DC motor according to its motor characteristics and control method.

Brushless DC motor drive apparatus

A controller according to one embodiment restarts the motor when a commutation timing signal is mismatched with an output pattern mode. A controller according to another embodiment compares the motor speed with the reference signal to change the chopper frequency in accordance with the compared value. A controller according to still another embodiment continuously changes the chopper frequency in accordance with the motor speed. A controller according to yet another embodiment inhibits the position detection immediately after commutation in accordance with the current flowing through the motor. A controller according to another embodiment detects the position of the rotor in accordance with the waveform of the current flowing through the motor.

Controller for brushless DC motor without position sensor

Growing community of inventors

Suwa, Japan

Akihito Uetake