Abstract: A stereo ribbon microphone includes four ribbon microphone units disposed in a circle on a single horizontal plane. The ribbon microphone units are alternately assigned to a right channel and a left channel along the circumferential of the circle.

Abstract: An output circuit of a bidirectional side microphone element includes an inverting amplifier inverting a phase and outputting an inverted signal, adds a non-inverted output signal of the side microphone element to an output signal of a middle microphone element having unidirectivity to produce a signal for one channel of the left and right channels; and adds an inverted output signal of the side microphone element being the output signal from the inverting amplifier to the output signal of the middle microphone element to produce another signal for the other channel. An input resistor and a feedback resistor to the inverting amplifier are dividable. The division ratio of the input resistor to the feedback resistor is varied to change the levels of the non-inverted output signal and the inverted output signal of the side microphone element, and to change the angle between the left and right directional axes.

Abstract: A condenser microphone includes a plurality of condenser microphone units, each unit including a diaphragm and a fixed electrode one of which has an electret layer thereon. The condenser microphone units include respective sensitivity controllers changing sensitivities of the units. The sensitivity controllers include respective variable resistors connected between a power source and a ground. Each of the variable resistors has a slidable terminal connected to one, opposed to the electret layer, of the diaphragm and the fixed electrode, of the corresponding condenser microphone unit.

Abstract: Diaphragms of a plurality of capacitor microphone units are arranged in the same plane and the capacitor microphone units are connected in series to make an output from an impedance converter connected to one capacitor microphone unit drives a ground side of another capacitor microphone unit connected to the impedance converter.

Abstract: 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.

Abstract: A stereo ribbon microphone includes four ribbon microphone units disposed in a circle on a single horizontal plane. The ribbon microphone units are alternately assigned to a right channel and a left channel along the circumferential of the circle.

Abstract: 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.

Abstract: A condenser microphone includes a plurality of condenser microphone units, each unit including a diaphragm and a fixed electrode one of which has an electret layer thereon. The condenser microphone units include respective sensitivity controllers changing sensitivities of the units. The sensitivity controllers include respective variable resistors connected between a power source and a ground. Each of the variable resistors has a slidable terminal connected to one, opposed to the electret layer, of the diaphragm and the fixed electrode, of the corresponding condenser microphone unit.

Abstract: A variable directional microphone unit includes, a pair of microphone elements disposed back to back, output signal systems of the microphone elements connected to a hot-side terminal and a cold-side terminal of a balanced output respectively, an inverting amplifier connected to one output signal system of the microphone elements, an input resistance and a feedback resistance of the inverting amplifier at least any one of which is divided, and a switching device switching a signal retrieving point by arbitrarily selecting each divide of at least one of the input resistance or the feedback resistance. The switching device switches one output of the balanced output to enable directivity of the balanced output signal to vary. A circuit for switching the directivity does not become a load or a noise source.

Abstract: A variable directional microphone unit includes two capacitor elements. Each of the two capacitor elements has: a back plate formed on one side of an insulating plate to be insulated from a back plate of the other capacitor element; and a vibrating plate disposed to face the back plate with a certain amount of space therebetween, in which a polarization voltage is applied between each of the back plates and the vibrating plates so that an electroacoustically transduced signal is obtainable from each of the back plates. The variable directional microphone unit is characterized in that the two vibrating plates of the two capacitor elements are acoustically connected in series as a plurality of holes are formed on both of the back plates.

Abstract: An output circuit of a bidirectional side microphone element includes an inverting amplifier inverting a phase and outputting an inverted signal, adds a non-inverted output signal of the side microphone element to an output signal of a middle microphone element having unidirectivity to produce a signal for one channel of the left and right channels; and adds an inverted output signal of the side microphone element being the output signal from the inverting amplifier to the output signal of the middle microphone element to produce another signal for the other channel. An input resistor and a feedback resistor to the inverting amplifier are dividable. The division ratio of the input resistor to the feedback resistor is varied to change the levels of the non-inverted output signal and the inverted output signal of the side microphone element, and to change the angle between the left and right directional axes.

Abstract: Diaphragms of a plurality of capacitor microphone units are arranged in the same plane and the capacitor microphone units are connected in series to make an output from an impedance converter connected to one capacitor microphone unit drives a ground side of another capacitor microphone unit connected to the impedance converter.

Abstract: A variable directional microphone unit includes two capacitor elements. Each of the two capacitor elements has: a back plate formed on one side of an insulating plate to be insulated from a back plate of the other capacitor element; and a vibrating plate disposed to face the back plate with a certain amount of space therebetween, in which a polarization voltage is applied between each of the back plates and the vibrating plates so that an electroacoustically transduced signal is obtainable from each of the back plates. The variable directional microphone unit is characterized in that the two vibrating plates of the two capacitor elements are acoustically connected in series as a plurality of holes are formed on both of the back plates.