Kureha Kagaku Kogyo Kabushiki Kaisha

Pioneer Electronic Corporation

Kureha Kagku Kagyo Kabushiki Kaisha

Yasushi Nishimura

Yasuo Uehara

Hirosi Nagai

Kazuhiro Watanabe

Yoshio Okada

Kohji Ishida

Kuniaki Hino

Shigeru Yamaguchi

Kazuaki Sugawara

Tamio Haga

Kazuhiko Kanishi

Stereo audio signals of right and left channels are inputted to a stereo surround system. The stereo surround system is provided with: a right side speaker group including at least two speakers arranged vertically; and a left side speaker group arranged at a left side of the right side speaker group, and including at least two speakers arranged vertically. The stereo surround system is further provided with a process device, coupled to the right side speaker group and the left side speaker group, for processing the inputted stereo audio signal of the right channel to generate at least two kinds of the surround signals to the right side speaker group, and for processing the inputted stereo audio signal of the left channel to generate at least two kinds of the surround signals to the left side speaker group.

Stereo surround system

A power amplifier is provided, wherein the output of a first transistor supplied with an input signal at the base thereof is supplied to the base of a second transistor, a current proportional to a collector current of the second transistor is supplied to the emitter of the first transistor by a current mirror circuit, a third transistor is provided for outputting an emitter current in accordance with a base-to-emitter voltage of the second transistor, and emitter currents of the second and third transistors, in accordance with an emitter potential level of the first transistor, is used as an output current. This configuration allows non-linear portions in the transistor characteristics to be cancelled by each other, thereby providing a power amplifier which presents a good linearity.

Power amplifier

A noise reduction apparatus in an FM stereo tuner including a circuit for generating a stereo sum signal and a stereo differential signal; a noise eliminating circuit for dividing, in accordance with several frequency bands, the stereo differential signal into several divisional signals and for outputting, in accordance with signals levels corresponding to the frequency bands, a composite signal of divisional stereo differential signals respectively corresponding to the signal levels; and a circuit for reproducing a stereo signal from the composite signal and the stereo sum signal. In another embodiment, the noise reduction apparatus includes a circuit for generating a stereo sum signal and a first stereo differential signal; a noise eliminating circuit for dividing the stereo sum signal and the first stereo differential signal into several divisional differential signals and several divisional sum signals, for eliminating a low-level divisional stereo differential signal in each of the frequency bands to generate a second stereo differential signal, and for outputting a composite signal representing the second stereo differential signal and those divisional stereo sum signals in the same divisional band as the eliminated divisional stereo differential signals; and a circuit for reproducing a stereo signal from the composite signal and the stereo sum signal.

Noise reduction apparatus in an FM stereo tuner

A VCA circuit is used at an input stage of communication device, an OA device or the like. The VCA circuit includes an output varying circuit which distributes a current supplied from a power supply side in accordance with a predetermined coefficient. The VCA circuit also includes an operational amplifier provided on an input side of the output varying circuit, and a feedback resistor connected between one of two input terminals and an output terminal of the operational amplifier. An input signal is applied to one of the two input terminals of the operational amplifier, a signal output from the output varying circuit is applied to the other input terminal. An output signal of the VCA circuit is drawn from the output terminal of the operational amplifier. An offset current generated in the output varying circuit can be reduced by varying the predetermined coefficient since the operational amplifier and the feedback resistor are provided on the input side of the output varying circuit and the output signal of the output varying circuit is applied to one of the two input terminals of the operational amplifier.

VCA circuit

A voltage-current conversion circuit comprises a transistor (Q1) on the input side whose emitter is employed as the input terminal (IN), and a transistor (Q2) on the output side whose base is connected to the base of the transistor (Q1), and the collector current and the emitter current of the transistor (Q1) on the input side are made equal to the collector current of the transistor (Q2) on the output side with the aid of current mirrors circuits (1 and 2). Hence, the transistors on the input and output sides are equal in base-emitter voltage to each other, and the non-linear distortion is therefore eliminated. In addition, the inflow or outflow of current from the input voltage source is zeroed, so that a high input impedance is obtained.

Voltage-current conversion circuit

A noise reduction apparatus in an FM stereo tuner including a circuit for generating a stereo sum signal and a stereo differential signal; a noise eliminating circuit for dividing, in accordance with several frequency bands, the stereo differential signal into several divisional signals and for outputting, in accordance with signals levels corresponding to the frequency bands, a composite signal of divisional stereo differential signals respectively corresponding to the signal levels; and a circuit for reproducing a stereo signal from the composite signal and the stereo sum signal. In another embodiment, the noise reduction apparatus includes a circuit for generating a stereo sum signal and a first stereo differential signal; a noise eliminating circuit for dividing the stereo sum signal and the first stereo differential signal into several division differential signals and several divisional sum signals, for eliminating a low-level divisional stereo differential signal in each of the frequency bands to generate a second stereo differential signal, and for outputting a composite signal representing the second stereo differential signal and those divisional stereo sum signals in the same divisional band as the eliminated divisional stereo differential signals; and a circuit for reproducing a stereo signal from the composite signal and the stereo sum signal.

Activated carbon, useful in a pharmaceutical composition for adsorbing exogenous or endogenous toxins from the gastrointestinal tract of a patient can be prepared by a process including a step of treating activated carbon with an aqueous ammonia solution to provide a resultant activated carbon having a pH of 6 to 8.

Process for treating activated carbon with aqueous ammonia

Disclosed is a pharmaceutical composition having an antidotal activity, which in dosage unit form is capable of adsorbing exogenous or endogenous toxins in the gastrointestinal tract of a patient without disintegration of said pharmaceutical composition and without causing the patient to become constipated. The active ingredient comprises spherical particles of an activated carbon wherein at least 85% in number of said spherical particles of activated carbon are microscopically spherical particles which have smooth and convex-curved surfaces without sharp edges. Specific physical parameters of the carbon particles include, maximum to minimum diameter ratios of 1.0 to 1.3, diameters of 0.05 to 2.0 mm and pore cavity volume of not more than 0.5 cc/g determined in the range of pore-radius of 5000 to 75,000 .ANG.. Dosage unit forms included, capsules, tablets, and aqueous slurries.

Antidote including activated carbon particles

This invention relates to hydroxyapatite, ceramic material, implant material and a process for preparing thereof. The ceramic material is hydroxyapatite ceramic having an excellent thermal stability.

Hydroxyapatite, ceramic material and process for preparing thereof

A novel adsorbent for ethylene prepared by contacting an active carbon with at least one metal substance selected from the group consisting of copper, iron, cobalt, nickel, and their salts in the presence of nitric acid; heating the same at a temperature of 150.degree. to 900.degree. C. in an atmosphere of inert gas and thereby to obtain the adsorbent containing 0.01 to 20% by weight of said metal(s) therein.

Adsorbent for ethylene and process for preparation thereof

A process for producing spherical particles of activated carbon having a low susceptibility to dusting.

Spherical activated carbon having low dusting property and high physical

An absorbant for use in artificial organs which is obtained by mixing and dissolving pitch with an aromatic compound and a polymer or copolymer of a chain hydrocarbon, dispersing the resultant mixture in water giving rise to beads and subjecting these beads to a series of treatments of removing of the aromatic hydrocarbon, infusibilizing, carbonizing and activating.

Growing community of inventors

Tokyo, Japan

Yasushi Nishimura