JP2004072559A - Microphone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a microphone output only when a sound source (person) exists in front of the microphone. <P>SOLUTION: A pyroelectricity sensor 30 for detecting a human body existing within the sound acquisition range of a microphone unit 20 is provided with in addition to the microphone unit 20. A switch 23 is controlled by its human body detection signal, and the output state of a microphone outputting part 22 is switched to either output on or output off. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a microphone used solely for collecting voices emitted by a person, and more particularly, to a microphone provided with a pyroelectric sensor for detecting the presence of a person.
[0002]
[Prior art]
Microphones are roughly classified into condenser microphones and dynamic microphones. In any case, when there is no sound source (in this case, a person) in front of the microphone, microphone output is not necessary.
[0003]
However, as long as the microphone switch (power switch) is turned on, the microphone unit is in the operating state, so that even if there is no sound source in front of the microphone, the microphone output always remains on. I have. Therefore, for example, even when there is no sound source (speaker) in front of the microphone in a conference hall or the like, ambient noise (unwanted sound) may be picked up and output.
[0004]
To prevent this, it is only necessary to turn on the microphone switch when the sound source is in front of the microphone, and turn off the microphone switch when the sound source leaves the microphone, but as a practical problem, It is difficult to do this reliably.
[0005]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide a microphone that can automatically determine whether or not a sound source (person) exists in front of the microphone and control on / off of the microphone output.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a microphone including a microphone unit that converts a sound wave into an electric signal, and a microphone output unit that outputs the electric signal converted by the microphone unit to an external device. A switch for switching the output state of the microphone output unit to one of an output on state and an output off state, a pyroelectric sensor for detecting a human body present within a sound collection range of the microphone unit, and an output from the pyroelectric sensor. Switch control means for switching the switch based on the detection signal.
[0007]
According to this, when there is no sound source (person) in front of the microphone, the switch is turned off because no detection signal is output from the pyroelectric sensor. Therefore, the microphone output is turned off. When there is a sound source (person) in front of the microphone, a detection signal is output from the pyroelectric sensor, the switch is turned on, and the microphone output is turned on.
[0008]
The switch may be connected between the microphone unit and the microphone output unit, or may be provided on the signal output terminal side of the microphone output unit. The microphone of the present invention includes a wireless microphone, and in that case, a radio wave transmitting unit or an infrared transmitting unit is used as the microphone output unit. As the switch, an electronic switch can be used in addition to a mechanical switch such as a relay switch.
[0009]
In a preferred embodiment, the microphone of the present invention further includes a sensor output unit that outputs a detection signal of the pyroelectric sensor to a predetermined external device, in addition to the microphone output unit. According to this, a video camera or a recorder can be operated by the sensor output.
[0010]
Further, the present invention is applicable to a hand microphone, a stand microphone, a hanging microphone, a line microphone having an acoustic tube, and the like. Is done.
[0011]
In this case, by making the position of the pyroelectric sensor in the acoustic tube adjustable in the front-rear direction, the viewing angle of the pyroelectric sensor can be arbitrarily set according to the position of the pyroelectric sensor.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows a main part of a microphone according to the present invention.
[0013]
The microphone 10 includes a microphone unit 20 that converts an incoming sound wave into an electric sound signal, and a pyroelectric sensor 30 for detecting a sound source (in this case, a person). The type of the microphone unit 20 is not particularly limited, and for example, a condenser type or an electrodynamic type microphone unit can be used.
[0014]
The output side of the microphone unit 20 is connected to an output terminal (microphone output unit) 22 via an amplifier circuit 21. In this example, a switch 23 is connected between the amplifier circuit 21 and the output terminal 22. .
[0015]
In the case of a cable microphone, a connector is used for the output terminal 22, whereas in the case of a wireless microphone, a radio wave transmitting unit or an infrared transmitting unit is used as the output terminal 22.
[0016]
The switch 23 may be either a mechanical switch such as a relay switch or an electronic switch. The switch 23 may be connected between the microphone unit 20 and the amplifier circuit 21. When the output terminal 22 includes a radio wave transmitting unit or an infrared transmitting unit, the driving circuit of the transmitting unit may be turned on and off.
[0017]
The directional axis of the pyroelectric sensor 30 is directed within the sound collection range of the microphone unit 20. A comparator 32 is connected to the pyroelectric sensor 30 via an amplifier 31. The comparator 32 is a switch control means, and controls on / off of the switch 23 by the output thereof.
[0018]
The microphone 10 has a sensor output terminal (sensor output unit) 33 connected to the output side of the comparator 32. In the case of a wireless microphone, a radio wave transmitting unit or an infrared transmitting unit is used as the sensor output terminal 33.
[0019]
When detecting a sound source (person), the pyroelectric sensor 30 outputs a detection signal voltage of a predetermined level. The comparator 32 compares the detection signal voltage SV amplified by the amplifier circuit 31 with a predetermined threshold voltage Vref. For example, when SV> Vref, the output is set to “Hi”, and SV ≦ Vref In this case, the output is inverted to “Lo”.
[0020]
When the output of the comparator 32 is “Hi”, that is, when the sound source (person) is in front of the microphone 10, the switch 23 is turned on. In contrast, when the output of the comparator 32 is “Lo”, that is, when the microphone 10 is When there is no sound source (person) before the switch 23, the switch 23 is turned off. The “Hi” and “Lo” outputs are also provided to the sensor output terminal 33.
[0021]
Here, an example in which the present invention is applied to the hand microphone 10A will be described with reference to FIG. In the hand microphone 10 </ b> A, the microphone unit 20 is supported on one end side of the cylindrical grip portion 11, and the entire microphone unit 20 is covered by the wind screen 12.
[0022]
The pyroelectric sensor 30 is attached to the microphone so that its directional axis faces the sound pickup range of the microphone unit 20. However, the directional axis of the pyroelectric sensor 30 is set to the sound pickup axis of the microphone unit 20 as shown in FIG. Is preferably provided at the vertex position of the wind screen 12 so as to coincide with
[0023]
Next, an example in which the present invention is applied to the line microphone 10B will be described with reference to FIG. FIG. 3 includes (a) to (d), but each of these figures is for explaining the relationship between the position of the pyroelectric sensor 30 and the viewing angle α.
[0024]
The line microphone 10 </ b> B includes an elongated acoustic tube 13 having a predetermined length. Assuming that the left side of the acoustic tube 13 in FIG. 3 is the front facing the sound source, the microphone unit 20 is disposed on the rear end side in the acoustic tube 13.
[0025]
In the case of the line microphone 10 </ b> B, an electret condenser type microphone unit is generally used as the microphone unit 20, which is mounted in the acoustic tube 13 via the rubber damper 25.
[0026]
The pyroelectric sensor 30 may be provided outside the acoustic tube 13 via a suitable support or the like, but the directional axis of the pyroelectric sensor 30 in the acoustic tube 13 coincides with the axis of the acoustic tube 13 as shown in FIG. It is preferable to arrange them. However, the position is a position in front of the microphone unit 20.
[0027]
When arranging the pyroelectric sensor 30 inside the acoustic tube 13, the viewing angle α of the pyroelectric sensor 30 can be adjusted by changing its position. As an example, as shown in FIGS. 3A to 3D, by gradually shifting the position of the pyroelectric sensor 30 from the front to the back of the acoustic tube 13, the viewing angle α is set to 90 ° to 10 °. It can be adjusted stepwise or continuously.
[0028]
Although not shown, in order to continuously shift the position of the pyroelectric sensor 30, for example, a guide slit is formed in the tube wall of the acoustic tube 13 along the axial direction, and the support plate moving in the guide slit is focused. The electric sensor 30 may be attached.
[0029]
As another method, in order to shift the position of the pyroelectric sensor 30 stepwise, a plurality of female screw holes are formed in the tube wall of the acoustic tube 13 at predetermined intervals along the axial direction thereof, and One of the screw holes may be selected and the pyroelectric sensor 30 may be supported by a male screw screwed into the selected screw hole.
[0030]
In any of the above embodiments, only when the pyroelectric sensor 30 detects a sound source (person) in front of the microphone 10 (10A, 10B), the switch 23 is turned on and the microphone output is turned on. In other cases, the switch 23 is turned off and the microphone output is turned off.
[0031]
Therefore, for example, when a plurality of microphones are used simultaneously in a state adjacent to each other in a conference facility or the like, microphone outputs are obtained only from the microphones whose speakers have been detected by the pyroelectric sensor 30, and other microphones collect unnecessary sound. Is gone.
[0032]
Further, when the microphone 10 (10A, 10B) of the present invention is applied to, for example, a security system, the microphone automatically enters an operating state upon detecting an intruder, and a video camera or the like is output by a sensor output obtained from the sensor output terminal 33. The recorder can be operated.
[0033]
As another application example, in drive-through, a visitor can be known from a sensor output obtained from the sensor output terminal 33, and a customer's order can be heard from an output of the microphone activated at this time.
[0034]
【The invention's effect】
As described above, according to the present invention, in addition to the microphone unit, the microphone unit includes a pyroelectric sensor that detects a human body existing within the sound pickup range of the microphone unit, and the output of the microphone output unit is output by the human body detection signal. By switching the state between the output on state and the output off state, a microphone output can be obtained only when there is a sound source (person) in front of the microphone.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a main part of a microphone according to the present invention.
FIG. 2 is a side view schematically showing a hand microphone to which the present invention is applied.
FIG. 3 is a sectional view schematically showing a line microphone to which the present invention is applied.
[Explanation of symbols]
10 (10A, 10B) Microphone 11 Grip unit 12 Windscreen 13 Acoustic tube 20 Microphone unit 22 Microphone output unit 23 Switch 30 Pyroelectric sensor 32 Comparator 33 Sensor output unit

Claims (4)

In a microphone including a microphone unit that converts sound waves into an electric signal, and a microphone output unit that outputs the electric signal converted by the microphone unit to an external device,
A switch for switching the output state of the microphone output unit to one of an output on state and an output off state, a pyroelectric sensor for detecting a human body present within a sound collection range of the microphone unit, and an output from the pyroelectric sensor. And a switch control means for switching the switch based on the detection signal. The microphone according to claim 1, further comprising a sensor output unit that outputs a detection signal of the pyroelectric sensor to a predetermined external device. 2. The microphone according to claim 1, wherein the microphone is a line microphone having an acoustic tube in which the microphone unit is housed, and the pyroelectric sensor is disposed in the acoustic tube at a position in front of the microphone unit. 3. The microphone according to 2. The position of the pyroelectric sensor in the acoustic tube is adjustable in the front-back direction, and a viewing angle of the pyroelectric sensor is selected according to the position of the pyroelectric sensor. Microphone.

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