Kabushiki Kaisha Audio Technica

Audio-technica Corporation

Hiroaki Furuya

Hiroshi Akino

Satoshi Yoshino

Haruhito Shimura

A microphone includes a tubular microphone case having conductivity, a circuit board on which a circuit is configured, the circuit being used for an operation of a microphone unit that converts an audio signal into an electrical signal, a light source that is accommodated in a position close to a first end of the microphone case and emits light, a light source mounting board on which the light source is placed, a holding member that has conductivity, holds the light source mounting board and the circuit board, and is fixed to the microphone case, and a light guide member including a protrusion. The holding member includes a light source mounting board accommodating portion that accommodates the light source mounting board, a circuit board accommodating portion that accommodates the circuit board, and a hole that can accept the protrusion.

Microphone

To enable light to be easily visually recognized, the light indicating an operation state. A tubular microphone case, a light source that is accommodated in a position close to a first end of the microphone case and emits light in a direction of the first end, a light source mounting board on which the light source is placed, a light guide member including a protrusion and having an optically transmissive property, and a holding member that maintains a position of the light source and a position of the light guide member, and is fixed to the microphone case together with the light source mounting board are included, and the holding member includes a hole capable of accepting the protrusion.

A condenser microphone is provided that can ensure the fixation of an electroacoustic transducer inside a unit case and the grounding of the electroacoustic transducer, regardless of variations in manufacture of the unit case and a circuit board. A condenser microphone unit includes an electroacoustic transducer and a unit case accommodating the electroacoustic transducer. The unit case includes at least one protrusion that is disposed on the inner circumferential surface of the unit case. The electroacoustic transducer is fixed inside the unit case with the protrusion.

Condenser microphone unit, condenser microphone, and method of manufacturing condenser microphone

An audio output circuit of a condenser microphone includes a condenser microphone unit, first and second impedance conversion circuits that receive a positive phase output signal and a reverse phase output signal from the condenser microphone unit, first and second output circuits that output an audio signal from the condenser microphone unit in a balanced line to a balanced output terminals upon receipt of outputs of the first and second impedance conversion circuits. First and second impedance conversion circuits respectively use FETs as source follower circuits and supply first and second impedance conversion outputs generated across source resistors to the first and second output circuits. A voltage regulating device that generates a constant voltage is connected in series to the source resistors. With this configuration, an audio output circuit of a condenser microphone is provided, which solves a problem of operation instability caused by variation of Idss's of the FETs.

Audio output circuit of condenser microphone

A back air room of a microphone unit can be enlarged and a model with a sound signal output switch can easily be diverted to a switchless model. A reed switchis used as the sound signal output switch which turns on or off the sound signal from a microphone unit. This reed switch is disposed at an output connectorportion at an rear end of a microphone case. It is arranged that a magnetis disposed at a connector coverwhich surrounds an output connector and relative movement of the connector cover with respect to the output connector allows on/off operation. Thus, by removing the connector cover, it is possible to provide the microphone as a switchless model which always outputs the sound signal from the microphone unit

A capacitor microphone includes: a capacitor microphone unit including a diaphragm that vibrates upon receiving sound waves and a fixed electrode arranged opposite to the diaphragm with a space therebetween; and a polarization voltage generating circuit that generates polarization voltage to be applied across the diaphragm and the fixed electrode. The polarization voltage generating circuit includes an oscillating circuit that alternately turns on and off DC power, coils to boost the voltage of the power alternately turned on and off, and a DC boosting circuit including a rectifying circuit that rectifies the boosted voltage. The coils are formed of two inductors that are electromagnetically coupled and are provided with an electromagnetic coupling adjusting unit with which the level of electromagnetic coupling between the two inductors is adjusted to adjust the polarization voltage.

Capacitor microphone

A dynamic microphone includes a vibration pickup that detects vibration of a dynamic microphone unit, and outputs a signal for cancelling vibration noise; and a microphone case that supports the microphone unit and the vibration pickup, wherein the vibration pickup includes a laminated ceramic piezoelectric element that detects vibration of a microphone unit case and outputs a signal corresponding to the detected vibration, the laminated ceramic piezoelectric element has a capacitance that defines a resonance circuit in conjunction with an inductance of an inductor, the resonance circuit producing a response signal to acceleration corresponding to that of the vibration noise, and the resonance circuit is connected such that the response signal is output in an opposite direction to the vibration noise signal.

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Tokyo, Japan

Hiroaki Furuya