Hitachi, Ltd.

Other

Hitachi Media Electronics Co., Ltd.

Tkr Corporation

Minoru Moteki

Kenji Tamaru

Daini Okajima

Kazuhide Tamizu

Akihiko Kanouda

Takeshi Saitoh

Takayuki Ouchi

Takashi Shiba

Akitsuna Yuhara

Shigeo Matsuura

Yoshihiro Yamada

Hiroshi Hatashita

A switching power supply has a function of improving a power factor, and outputs insulated DC. The switching power supply performs two kinds of controls for switching devices exclusive to each other: controlling of a switching device provided in a direction in which the discharging of a primary-side smoothing capacitor is prohibited at the time of suspension of commercially available AC power and near the zero cross of an input voltage; and causing a switching device provided between the output side of a third winding and the primary-side smoothing capacitor to control a charging current, thereby charging a capacitor in a boosted manner.

Switching power supply and display device provided the same

A radio receiver apparatus for receiving a spread spectrum signal in which a signal derived through a level detection of a signal demodulated by a correlative demodulator and a signal obtained by extracting a signal component of a synchronous frequency from a reception synchronizing clock are combined to thereby generate a reference signal having a level which changes in accordance with change of the detected signal, and by comparing the detected signal with the reference signal, the received signal is discriminated.

Radio receiver using level-variable reference signal for discriminative detection of data signal and signal discrimination method

Radio receiver using level-variable reference, signal for discriminative

A surface acoustic wave device makes it possible to increase the electrode width without generating mass-electrical-loading and is capable of operating in a high-frequency band higher than or equal to the UHF band, and this surface acoustic way device may be used in a communication device to eliminate need for any down-converter which is indispensable to the conventional high-frequency communication device, and which is therefore capable of being manufactured at a reduced cost. The surface acoustic wave device is provided with an electrode structure meeting conditions represented by: s+m=(2n+1)L/(4k), where L is electrode period, not taking into consideration the polarity of an interdigital transducer, m is electrode line width, s is minimum electrode gap width, and n and k are natural numbers. The surface acoustic wave device is used as the demodulator of the communication device.

Surface acoustic wave device and communication device employing the

A double-superheterodyne tuner for a television receiver comprises a tunable oscillator, a fixed oscillator, two mixer stages and a band-pass filter between the mixer stages, and operates at a GHz intermediate frequency between the mixer stages. The two oscillators and the bandpass filter each includes a microstrip line resonator formed in a dielectric body having substantially the same dielectric constant and dielectric constant temperature coefficient to each other, thereby compensating the variation of the resonant frequency in the resonator due to an ambient temperature variation.

Wide-band tuner having a temperature-compensated microstrip resonator

Growing community of inventors

Chigasaki, Japan

Minoru Moteki