Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Nihon Yamamura Glass Co., Ltd.

Mitsuo Ueda

Hideki Nakata

Makoto Yoshida

Takahiko Origuchi

Masanori Ogawa

Kaneharu Yoshioka

Hidehiko Shoji

Hideo Matsushiro

Mitsuo Kawaji

Tomohiro Sugimoto

Hiroshi Hasegawa

Yuuichi Yakumaru

Yoshiaki Doyama

Yasuhiro Arai

Satoshi Sugimoto

Sugimatsu Hasegawa

Melvin Lim Si

Kenichi Gomyo

Hiroyuki Nagai

Katsumi Hashimoto

Yutaka Myoujin

Display luminance is uniformized and the brightness is enhanced. A plasma display device has image signal processing circuit including loading correction part. The loading correction part has: number of lit cells calculator for calculating the number of discharge cells to be lit in each display electrode pair, in each subfield; load value calculator for calculating a load value of each discharge cell, according to the calculation result in number of lit cells calculator; correction gain calculator for calculating a correction gain of each discharge cell, according to the position of the discharge cell and the calculation result in load value calculator, such that the correction gain is smaller in the central portion than in the peripheral portion on the plasma display panel's image display surface; and corrector for subtracting the multiplication result of the output from correction gain calculator and an input image signal, from the input image signal.

Plasma display device and plasma display panel driving method

In a plasma-display-panel driving method, a field period is divided into a plurality of sub fields, each of which has an address period for allowing discharge cells to selectively generate an address discharge and a sustain period for allowing the discharge cells having generated the address discharge to generate a sustain discharge by a number of times corresponding to a brightness weight. In the sustain period, a period for setting display electrode pairs to the base potential is disposed between the sustain pulse for causing the final sustain discharge in the sustain period and the previous sustain pulse. In a time interval corresponding to the lighting ratio of the discharge cells in the sub field after applying to the display electrode pairs a voltage for generating the final sustain discharge, a voltage for reducing the potential difference between electrodes of the display electrode pairs is applied to the display electrode pairs. Accordingly, it is possible to generate a stable address discharge and thus to reduce a crosstalk without increasing the voltage for generating the address discharge.

Plasma display device and plasma-display-panel driving method

A plasma display panel is driven by providing a plurality of subfields within one field period, the subfield having an initializing period in which the initializing discharge is generated in a discharge cell by applying a ramp-waveform voltage that is gradually descending to a scan electrode, an address period in which an address discharge is generated in the discharge cell by applying a scan pulse voltage to the scan electrode, and a sustain period in which sustain discharges by the number of times corresponding to the luminance weight are generated in the selected discharge cell. The lowest voltage is set of the descending ramp-waveform voltage in the subfield where the luminance weight is the smallest lower than the same voltage in the subfield where the luminance weight is the largest, and a voltage is kept for a prescribed period after the descending ramp-waveform voltage reaches the lowest voltage in the subfield where the luminance weight is the smallest.

Plasma display panel drive method and plasma display device

Plural subfields are provided in one single field period, where each subfield has an initialization period during which a gradient waveform voltage gently falling is applied to a scan electrode to generate initializing discharge in a discharge cell; a writing period during which a scan pulse voltage is applied to a scan electrode to generate writing discharge in a discharge cell; and a sustain period during which sustain discharge is generated in a discharge cell selected, by the number of times corresponding to a luminance weight. The lowest voltage of a falling gradient waveform voltage in a subfield with the smallest luminance weight is set so as to be lower than that with the largest luminance weight. A method of driving a plasma display panel is provided that generates stable writing discharge without increasing voltage required for generating writing discharge even for a large-screen, high-luminance panel.

Method of driving plasma display panel and plasma display apparatus

A motor controller () according to the invention comprises an inverter circuit () for driving a brushless motor () and a control unit for controlling the rotational speed of the brushless motor () by controlling the phase of the motor current of the brushless motor () through the inverter circuit ().

Motor controlling device, compressor, air conditioner and refrigerator

A converter circuit for converting an output voltage from an AC power supply includes a rectifier circuit for rectifying the output voltage of the AC power supply; first and second capacitors connected in series, for smoothing the output of the rectifier circuit; and a switch circuit for switching the connections between the respective capacitors and the AC power supply so that the output voltage of the AC power supply is applied to each of the respective capacitors at a cycle that is shorter than the cycle of the AC power supply.

Converter circuit and motor driving apparatus

The present invention provides a quality control method and a quality control apparatus for use in the formation of a glass product. A feeder mechanism cuts a column-like molten glass pushed out through an orifice thereof into a glass gob and allows each glass gob to fall with gravity from the orifice. A predetermined glass product is formed from the glass gob after delivering the fallen glass gob to a predetermined position. According to the present invention, the glass gob produced by the feeder mechanism is observed by a plurality of optical observing means spaced apart from each other during a falling process of the glass gob, and three-dimensional coordinates data of the entire surface of the glass gob is generated. Measurement data relating to at least one of a volume, a weight, a surface shape, a length, a thickness, an angle in a falling direction, and a cut surface shape of the glass gob is produced based on the three-dimensional coordinates data. The presence or absence of a defect in the quality of the glass gob is detected by comparing the measurement data with quality standard data of a normal glass gob. A causal relationship between at least one of the operational factors of the feeder mechanism and the quality defect is determined depending on the type of quality defect identified.

Quality control method and quality control apparatus for glass gob in the formation of a glass product

A motor driving apparatus includes an inverter circuit for converting an output of a rectifier circuit connected to a single-phase AC power supply into a driving voltage, and outputting the driving voltage to a brushless motor, and an inverter control unit for controlling the amplitude value of the voltage outputted from the inverter to the brushless motor so as to minimize a difference between a command rpm indicated by an external command signal and an actual rpm derived from an estimated phase of the rotor, wherein the command rpm is set to an rpm outside a predetermined range of rpms.

Motor driving apparatus

A motor driving apparatus for driving a motor includes a single-phase rectifier circuit having an input connected to a single-phase AC power supply, an inverter circuit that is connected to the single-phase rectifier circuit and applies a current and a voltage to the motor, and an inverter control unit for controlling the inverter circuit. The inverter control unit controls the current applied to the motor, i.e., the output of the inverter circuit, so that the inverter input voltage becomes equal to the absolute value of the voltage of the single-phase AC power supply.

A motor driving apparatus includes an inverter circuit for converting an output voltage of a power supply into a three-phase AC and outputting the same to the brushless motor, a rotor position estimation unit for estimating a rotor position of the brushless motor, and an inverter control unit for controlling the inverter circuit so that the brushless motor is driven by a current based on the estimated rotor position. The inverter control unit determines an advance angle of the current supplied to the brushless motor with respect to the estimated rotor position so as to minimize a deviation between a command rpm and an actual rpm. Therefore, it is possible to perform stable weak field control for the brushless motor, independently from the input voltage of the inverter circuit, without using predetermined control variables such as table values.

A motor driving apparatus for driving a linear vibration motor having a spring member that supports a mover so as to form a spring vibration system including the mover. The motor driving apparatus employs an accurate spring constant of the spring member corresponding to an individual linear vibration motor at a position calculation for obtaining the position of the mover during the operation, thereby increasing the accuracy of the position calculation. The motor driving apparatus includes a mover force vibration unit for making the mover of the linear vibration motor freely vibrate, a relative position detection unit for detecting a timing when the freely vibrating mover passes through a fixed point (relative position), and a natural frequency detection unit for detecting a natural frequency of the mover based on output information from the relative position detection unit, thereby calculating the spring constant based on the detected natural frequency.

A motor drive control apparatus for driving and controlling a linear vibration motor having a mover supported by a spring, with an AC current. The motor drive control apparatus includes a waveform creation unit for creating a comparative current waveform to be a reference of a driving current for the linear vibration motor based on the operating condition of the linear vibration motor, a current detector for detecting the driving current, and a controller for controlling a driving voltage of the linear vibration motor so that a difference between the comparative current waveform and a waveform of the current detected by the current detector becomes zero. The frequency of the driving current is controlled to be close to the resonance frequency of the linear vibration motor, based on the comparative current waveform. Accordingly, the driving frequency of the linear vibration motor can always be brought to the resonance frequency without using a sensor for detecting a displacement, speed, or acceleration of the mover, for example.

Motor drive control apparatus

An inverter control device for driving a motor with small size, light weight and low cost is provided. The inverter control device includes a first motor voltage command corrector that corrects a voltage command of each phase by multiplying the each phase voltage command by a PN voltage correction coefficient, and a second motor voltage command corrector that corrects again the each phase voltage command once corrected by the first motor voltage command corrector, only when any one of the phase voltage commands corrected by the first motor voltage command corrector is larger than the inverter DC voltage, by multiplying the voltage command of each phase corrected by the first motor voltage command corrector by the inverter DC voltage value, and dividing the product of the multiplication by the maximum value of the phase voltage commands corrected by the first motor voltage command corrector.

Inverter control device for driving a motor and an air conditioner

An apparatus for driving a linear vibration motor that employs a proper motor thrust constant value corresponding to each linear vibration motor at position calculation for obtaining the position of the mover of the linear vibration motor, thereby increasing the accuracy of the position calculation. This motor driving apparatus includes a motor driver for applying a DC voltage to the linear vibration motor, and a thrust detection unit for detecting a thrust of the mover, which is generated by the application of the DC voltage to the linear vibration motor, and calculates the thrust constant of the linear vibration motor according to an arithmetic operation of dividing the mover thrust detected by the thrust detection unit, by a value of a DC current that is supplied to the linear vibration motor due to the application of the DC voltage to the linear vibration motor.

Growing community of inventors

Nishinomiya, Japan

Mitsuo Ueda