JP3796470B2 - Microphone - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a microphone that is used exclusively for the purpose of collecting sound emitted by a person, and more particularly to a microphone that includes a pyroelectric sensor that detects the presence of a person.
[0002]
[Prior art]
Microphones can be broadly 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 microphones, no microphone output is required.
[0003]
However, in the conventional microphone, as long as the microphone switch (power switch) is turned on, the microphone unit is in an operating state. Therefore, even when there is no sound source in front of the microphone, the microphone output is always kept on. Yes. Therefore, even when there is no sound source (speaker) in front of the microphone in a conference hall or the like, ambient noise (unnecessary sound) may be picked up and output.
[0004]
In order to prevent this, the microphone switch should be turned on when a sound source exists in front of the microphone, and the microphone switch should be turned off when the sound source leaves from the microphone. It is difficult to do this reliably.
[0005]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a microphone capable of automatically determining whether or not a sound source (person) is present in front of the microphone and controlling the microphone output on and off.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a microphone including a microphone unit that converts sound waves into an electrical signal, and a microphone output unit that outputs the electrical signal converted by the microphone unit to an external device. The microphone is a line microphone having an acoustic tube in which the microphone unit is housed, a switch for switching the output state of the microphone output unit between output on and output off, and the sound collection range of the microphone unit A pyroelectric sensor for detecting a human body existing in the inside, and switch control means for switching the switch based on a detection signal output from the pyroelectric sensor , wherein the pyroelectric sensor is connected to the microphone unit in the acoustic tube. The position of the pyroelectric sensor is Adjustable in the longitudinal direction along the axis of the sound tubes, according to the position of the pyroelectric sensor, it is characterized in that the viewing angle of the pyroelectric sensor is selected.
[0007]
According to this, when there is no sound source (person) in front of the microphone, the detection signal is not output from the pyroelectric sensor, so the switch is turned off. 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 this case, a radio wave transmission unit or an infrared transmission unit is used as the microphone output unit. The switch may be an electronic switch in addition to a mechanical switch such as a relay switch.
[0009]
As a preferred embodiment, the microphone of the present invention is further provided with 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, a recording machine, etc. can be operated by the sensor output.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a basic configuration of a microphone according to the present invention .
[0011]
The microphone 10 includes a microphone unit 20 that converts an incoming sound wave into an electrical 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 capacitor type or an electrodynamic type microphone unit can be used.
[0012]
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. .
[0013]
In the case of a cable type microphone, a connector is used as the output terminal 22, but in the case of a wireless type microphone, a radio wave transmission unit or an infrared transmission unit is used as the output terminal 22.
[0014]
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 transmission unit or an infrared transmission unit, the drive circuit of the transmission unit may be turned on / off.
[0015]
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 the switch 23 is controlled to be turned on / off by its output.
[0016]
The microphone 10 includes 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 transmission unit or an infrared transmission unit is used as the sensor output terminal 33.
[0017]
The pyroelectric sensor 30 outputs a detection signal voltage of a predetermined level when detecting a sound source (person). The comparator 32 compares the detection signal voltage SV amplified by the amplifier circuit 31 with a preset threshold voltage Vref. For example, when SV> Vref, the output is “Hi” and SV ≦ Vref. In this case, the output is inverted to “Lo”.
[0018]
When the output of the comparator 32 is “Hi”, that is, when there is a sound source (person) in front of the microphone 10, the switch 23 is turned on, whereas when the output of the comparator 32 is “Lo”, that is, the microphone 10. When there is no sound source (person) in front of the switch 23, the switch 23 is turned off. The “Hi” and “Lo” outputs are also given to the sensor output terminal 33.
[0019]
Next, FIG. 2, describes the line microphone 10B Nitsu according to the present invention. FIG. 2 includes (a) to (d), but these figures are for explaining the relationship between the position of the pyroelectric sensor 30 and the viewing angle α.
[0020]
The line microphone 10 </ b > B includes a long and narrow acoustic tube 13, and the microphone unit 20 is disposed on the rear end side in the acoustic tube 13, assuming that the left side of the acoustic tube 13 is directed to the sound source in FIG. 2 .
[0021]
In the case of the line microphone 10 </ b> B, an electret condenser type microphone unit is generally used as the microphone unit 20 and is mounted in the acoustic tube 13 via a rubber damper 25.
[0022]
In the present invention, the pyroelectric sensor 30, as shown in FIG. 2, it is arranged the directional axes within the acoustic tube 13 to coincide with the axis of the acoustic tube 13. However, the position is the front position of the microphone unit 20.
[0023]
When the pyroelectric sensor 30 is disposed 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 FIG. 2 (a) ~ FIG 2 (d), by shifting gradually the position of the pyroelectric sensor 30 to the rear from the front of the acoustic tube 13, the viewing angle α of 90 ° to 10 DEG, It can be adjusted stepwise or continuously.
[0024]
Although not shown, in order to continuously shift the position of the pyroelectric sensor 30, for example, a guide slit is formed along the axial direction on the tube wall of the acoustic tube 13, and the pyroelectric sensor 30 is focused on a support plate that moves in the guide slit. The electric sensor 30 may be attached.
[0025]
As another method, in order to shift the position of the pyroelectric sensor 30 step by step, 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. One of the screw holes may be selected and the pyroelectric sensor 30 may be supported by a male screw screwed into the screw hole.
[0026]
In any of the above-described aspects, the switch 23 is turned on and the microphone output is turned on only when the pyroelectric sensor 30 detects a sound source (person) in front of the microphone 10 B. Otherwise, the microphone output is turned on. The switch 23 is turned off and the microphone output is turned off.
[0027]
Therefore, for example, when a plurality of microphones are used simultaneously in a conference facility or the like, the microphone output can be obtained only from the microphone in which the speaker is detected by the pyroelectric sensor 30, and the other microphones pick up unnecessary sounds. Nothing will happen.
[0028]
Moreover, applying the microphone 10 B of the present invention, for example, in a security system, with a microphone is automatically operating state by detecting an intruder, and video cameras and recorders by the sensor output obtained from the sensor output terminal 33 It can be operated.
[0029]
As another application example, in the drive-through, the customer can be known from the sensor output obtained from the sensor output terminal 33, and the order of the customer can be heard from the output of the microphone that is in the operating state at this time.
[0030]
【The invention's effect】
As described above, according to the present invention, in addition to the microphone unit, a pyroelectric sensor that detects a human body existing in the sound collection range of the microphone unit is provided, 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, the 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 basic configuration of a microphone according to the present invention.
FIG. 2 is a side view schematically showing a line microphone according to the present invention.
[Explanation of symbols]
10 ( 10B) Microphone 13 Acoustic tube 20 Microphone unit 22 Microphone output unit 23 Switch 30 Pyroelectric sensor 32 Comparator 33 Sensor output unit

Claims (1)

In a microphone including a microphone unit that converts a sound wave into an electrical signal, and a microphone output unit that outputs the electrical signal converted by the microphone unit to an external device,
The microphone is a line microphone having an acoustic tube in which the microphone unit is housed, a switch for switching the output state of the microphone output unit between output on and output off, and the sound collection range of the microphone unit A pyroelectric sensor for detecting a human body existing in the inside, and a switch control means for switching the switch based on a detection signal output from the pyroelectric sensor ,
The pyroelectric sensor is disposed at a front position of the microphone unit in the acoustic tube, and the position of the pyroelectric sensor is adjustable in the front-rear direction along the axis of the acoustic tube. A microphone, wherein a viewing angle of the pyroelectric sensor is selected according to a position .

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