An electric power tool includes: a brushless motor having a plurality of stator windings and configured to rotate in accordance with voltages applied to the plurality of stator windings, an induced voltage being generated in accordance with a rotation of the brushless motor; a rectifier circuit configured to rectify an AC voltage; a smoothing capacitor configured to smooth the AC voltage rectified by the rectifier circuit to a pulsation voltage having a maximum value larger than the induced voltage and a minimum value smaller than the induced voltage; and an inverter circuit configured to perform switching operations to output the pulsation voltage to the plurality of stator windings by rotation.

Electric power tool

An object is to provide a method for manufacturing a semiconductor device, in which the number of photolithography steps can be reduced, the manufacturing process can be simplified, and manufacturing can be performed with high yield at low cost A method for manufacturing a semiconductor device includes the following steps: forming a semiconductor film; irradiating a laser beam by passing the laser beam through a photomask including a shield for shielding the laser beam; subliming a region which has been irradiated with the laser beam through a region in which the shield is not formed in the photomask in the semiconductor film; forming an island-shaped semiconductor film in such a way that a region which is not irradiated with the laser beam is not sublimed because it is a region in which the shield is formed in the photomask; forming a first electrode which is one of a source electrode and a drain electrode and a second electrode which is the other one of the source electrode and the drain electrode; forming a gate insulating film; and forming a gate electrode over the gate insulating film

Method for Manufacturing Semiconductor Device

A power conversion device includes a power switching circuit that supplies AC voltages generated between switching elements operating as upper arms and switching elements operating as lower arms, and a control circuit that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements by a PWM method in a first operational region in which frequency of an AC power to be outputted is low, and that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements at timings based upon the phase of the AC power to be outputted in an operational region in which the frequency of the AC power to be outputted is higher than in the first operational region.

Power Conversion Device

A control computing unit blends a feedforward axial force and a feedback axial force at an allocation ratio, based on an axial force difference, a lateral acceleration, a vehicle velocity, a steering angle, and a steering angular velocity so as to set a final axial force. Then, the control computing unit applies a steering reaction force based on the final axial force that has been set.

Steering control device

An illumination device is provided and includes: a light guide member; a light source provided on one or more side faces of the light guide member; and a light modulating element including a pair of transparent substrates disposed to oppose each other with a gap therebetween, a first electrode provided on a surface of one of the transparent substrates, a second electrode provided on a surface of the other of the transparent substrates, and a light modulation layer provided in the gap and expressing a scattering property or a transparency to light from the light source in accordance with a magnitude of an electric field. The first electrode, the second electrode, or both thereof is patterned, and a density of pattern of the first electrode, the second electrode, or both thereof to which the patterning is applied is varied depending on a distance from the light source.

Illumination device and display device

PROBLEM TO BE SOLVED: To provide a freezing-refrigerating unit and a refrigerator using the freezing-refrigerating unit capable of ensuring high safety while using an inflammable refrigerant with a low global warming potential and avoiding to the utmost such a failure as to cause a sudden stop of cooling by detecting a leakage of the refrigerant to cope with the prevention of the leakage before air flows in to increase the load of a compressor even when piping is damaged on the low pressure side of a connection part or the like of an evaporator. SOLUTION: The refrigerant whose pressure becomes negative in cooling is used, and a condensation temperature sensor 31 disposed in the condensation starting position of a condenser 20, and an evaporation temperature sensor, are provided. When the condensation temperature is not lower than a predetermined temperature in the evaporation temperature, the leakage of the refrigerant is determined, and control is performed to maintain a state of preventing the leakage of the refrigerant and the inflow of air by suppressing the rotating speed of the compressor 19. COPYRIGHT: (C)2005,JPO&NCIPI

Freezing-refrigerating unit and refrigerator

PROBLEM TO BE SOLVED: To provide a driving method and a driver of a DC brushless motor in which a conventional r.p.m. of the DC brushless motor is attained during high speed operation while keeping a high motor efficiency at low speeds by winding the stator winding greatly thereby lowering the torque (r.p.m.). SOLUTION: A rectangular wave having a conduction angle of 120-150° or an equivalent waveform is outputted at low speeds, a rectangular wave or a sine wave having a conduction angle of 130-180° or an equivalent waveform is outputted with a specified frequency at high speeds and only the specified frequency is varied while sustaining a constant duty. High efficiency low noise operation is realized at low speeds and a peak current for the effective current can be suppressed because a high speed can be ensured stably and the current waveform approaches a sine wave. COPYRIGHT: (C)2005,JPO&NCIPI

Driving method and driver of dc brushless motor

PROBLEM TO BE SOLVED: To provide an optical element with enhanced efficiency of light utilization and the contrast of output light, and to provide a display device using this optical element. SOLUTION: The main body of the optical element 100 consists of a light guide plate, a light-controlling layer 1 whose diffraction or scattering performance for light is changed under an electric field or magnetic field and a reflection plane 6. The body changes the direction of the light propagating in the light guide plate 3 by using the light-controlling layer 1 and the reflection plane 6 to emit the light. The optical element body 100 is provided with a noise preventing means 101 comprising a polarizing plate 7 as a principal element so as to prevent production of noise light which enters the optical element main body from the exit side of the main body and is then reflected by the aforementioned reflection plane and emitted through the exit face.

Optical element and display device using that optical element

PROBLEM TO BE SOLVED: To provide a motor drive improving efficiency, speed and torque. SOLUTION: The motor drive is provided with a brushless DC motor 5 composed of a rotor having a permanent magnet and a stator having three phase winding, an inverter 3 supplying power to three phase winding, a first waveform generating part 15 outputting a rectangular wave whose conduction angle is 120 to 150 degrees or a waveform conforming thereto, a second waveform generating part 17 outputting the rectangular wave whose conduction angle is 130 to 180 degrees or a waveform conforming thereto, and a switching determination part 18 selecting output of the first waveform generating part 15 at a prescribed speed or lower and output of the second waveform generating part 17 at a speed higher than the prescribed speed. When a drive mode transition from the second waveform generating part 17 to the first waveform generating part 15, the conduction angle is set to be not more than 150 degrees. Thus, stable mode transition is achieved. COPYRIGHT: (C)2009,JPO&INPIT

Motor drive and refrigerator using the same

PROBLEM TO BE SOLVED: To expand a drive region by improving stability in high load and high-speed drive of a brushless DC motor. SOLUTION: A motor drive device includes: a brushless DC motor 4 comprising a rotor having a permanent magnet and a stator having a three-phase winding; and an inverter 3 for supplying power to the three-phase winding. In the motor drive device, the phase of a current flowing through the winding of the brushless DC motor is unfailingly acquired by selecting either a winding current or an output terminal voltage of the inverter 3 depending on the drive state of the brushless DC motor 4, the winding for energizing the brushless DC motor 4 is switched so that the current phase and voltage phase of the brushless DC motor 4 can keep a predetermined phase relation, and the predetermined phase relation kept between the current phase and voltage phase is changed depending on the amount of change of the peak of current flowing through the brushless DC motor 4 to expand the load region which can be driven by the brushless DC motor 4. Thus, even if any component is out of order, the motor can be driven while preventing step-out or overcurrent, thereby stably driving high load at a high speed. COPYRIGHT: (C)2011,JPO&INPIT

秀尚田中

Papers

Freezing-refrigerating unit and refrigerator

Driving method and driver of dc brushless motor

Optical element and display device using that optical element

Motor drive and refrigerator using the same

Motor drive device, compressor and refrigerator

秀尚 田中

Papers

Freezing-refrigerating unit and refrigerator

Driving method and driver of dc brushless motor

Optical element and display device using that optical element

Motor drive and refrigerator using the same

Motor drive device, compressor and refrigerator

秀尚田中