JPH06233366A - Microphone device - Google Patents

Abstract

PURPOSE:To simply discriminate a fact that the sounds are properly absorbed by checking the display state of a display device provided on a microphone device in accordance with the detection level of a detector device. CONSTITUTION:The input signal rectified by a rectifier diode 13 is supplied to a level discriminator circuit 19 via a variable resistor 15. At the same time, the output of the resistor 15 is divided by a series circuit of resistors 16, 17 and 18. Then the signalsreceived from the joint between resistors 16 and 17 and the joint between resistors 17 and 18 are supplied to the circuit 19. The circuit 19 consisting of a microcomputer discriminates the levels of the signal received from the resistor 15 and two types of divided signals based on the output received from microunits 11, 2a1 and 2b. When these discriminated levels are higher than each set threshold level, the control signal is supplied to a display panel 30 via a drive circuit 20. Thus the panel 30 consisting of a liquid crystal display shows those level states in a bar graph using three bars.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microphone device connected to a tape recorder or the like for recording.

[0002]

2. Description of the Related Art When recording a conversation such as a meeting using a recorder such as a tape recorder, the microphone device connected to the recorder via a cable is brought close to the person who is talking, and the microphone device is I try to pick up the voice of conversation. Alternatively, when using a microphone device having a relatively high directivity, even if the microphone device is installed in a place away from the person in conversation, by pointing the microphone device in the direction of the person in conversation, Good recording is possible.

[0003]

By the way, when recording is performed in such a form, it is difficult to easily determine whether the microphone device is installed at the correct position. That is, in the case of full-scale recording in a studio or the like, a test may be conducted in advance to find the most suitable position for picking up a conversation, and the microphone device may be installed at the searched position. It is troublesome to conduct such a test in advance at each meeting. Therefore, the installation position of the microphone device is determined by empirically determining the position that is most likely to be recorded.

However, in such a case, it is not possible to judge from the microphone whether or not the data is properly recorded, and the data is not correctly recorded due to being placed at the wrong position or being used incorrectly. Even if this is not known until later the recorded tape is replayed.

In order to prevent such a recording error,
It is conceivable that an earphone or the like is connected to the monitor terminal of the recorder to simultaneously monitor the sound being recorded by the recorder, but such monitoring by the earphone or the like is troublesome.

In view of these points, the present invention has an object to provide a microphone device capable of reliably and easily recording a targeted voice.

[0007]

According to the present invention, as shown in FIG. 1, for example, microphone units 1, 2a and 2b for converting changes in sound pressure into electrical voice signals, and the microphone units 1, 2a, and Amplifier circuit 12 for amplifying the audio signal output by 2b, and rectifying means 1 for rectifying the output of this amplifier circuit 12.
3, the detection means 15 to 19 for detecting the output level of the rectifying means 13, and the display means 30 for displaying the level according to the detection level of the detection means 15 to 19 are integrally housed. is there.

Further, in this case, a plurality of microphone units having different directivities are provided, and the output levels of the plurality of microphone units are selectively displayed on the display means 30.

Further, in this case, as the level display on the display means 30, as shown in FIG. 3, a bar graph is displayed in at least three stages.

[0010]

According to the present invention, the sound pickup state can be easily determined by observing the display state on the display means installed in the microphone device.

In this case, by selectively displaying the sound collecting states of a plurality of microphone units having different directivities, it is possible to easily determine which directivity microphone unit to use.

Further, by displaying at least three levels in a bar graph as the level display on the display means, for example, there are three levels of a proper output level, an excessive output level, and an excessive output level. Easy to judge.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a diagram showing the structure of a microphone device of this example. In this example, an omnidirectional microphone and a sharply directional microphone are integrally housed. In FIG. 1, 1 is an omnidirectional microphone. Microphone units 2a and 2b are sharp directivity microphone units, and
A process of converting a change in sound pressure received by 2a and 2b into an electrical audio signal is performed. The two directivity microphone units 2a and 2b are used in combination to adjust the directivity. As each of these microphone units, an electret condenser type unit or the like is used, and they are integrally housed as shown in FIG. 2, for example. That is, the omnidirectional microphone unit 1 is arranged at the end of the box-shaped first casing 41, and at the end of the second casing 42 rotatable with respect to the first casing 41. When two microphone units 2a and 2b are arranged and sound is picked up by the microphone units 2a and 2b having sharp directivity, the second microphone unit
By properly rotating the housing 42, the sound collecting range can be oriented in the direction of sound.

Further, a display panel 30, which will be described later, a microphone selection switch 9, and an operation changeover switch 43 are arranged on the upper surface of the first casing 41. Further, the signal line 44 is drawn out from the rear end of the first housing 41, and the plug 45 at the tip of the signal line 44 is inserted into the microphone terminal of the recorder (not shown), so that the recorder side is closed. A picked-up audio signal is supplied.

Now, returning to FIG. 1, the circuit configuration in the microphone device will be described. In order to combine the outputs of the two microphone units 2a and 2b, the output of one microphone unit 2a and the other microphone unit 2a are combined. The output of 2b is the inverting amplifier 3
The one inverted at step (4) is supplied to one end and the other end of the variable resistor (4) and is taken out from the movable terminal of the variable resistor (4). At this time, the directivity is adjusted by adjusting the position of the movable terminal of the variable resistor 4. Then, the audio signal taken out from the movable terminal of the variable resistor 4 is supplied to the equalizer 5 to correct the frequency characteristic. And
The output of the equalizer 5 is supplied to the high pass filter 6 to cut the low frequency component. This low-frequency component cut is performed to remove low-frequency noise such as the vibration noise of a desk. Then, the output of the high pass filter 6 is supplied to the microphone selection switch 9 side. In addition, the omnidirectional microphone unit 1
Is also supplied to the microphone selection switch 9 side.

In this case, in the vicinity of the microphone selection switch 9, a circuit for switching the sensitivity of the microphone having a sharp directivity is formed. That is, the output of the omnidirectional microphone unit 1 is supplied to the first fixed contact 9a of the switch 9, and the combined output of the acute directional microphone units 2a and 2b (that is, the output of the high-pass filter 6) is directly switched. 9 to the second fixed contact 9b. Furthermore, a circuit grounded via resistors 7 and 8 is connected to the output part of the high-pass filter 6, and the midpoint of connection between this resistor 7 and the resistor 8 is set to the switch 9
Connected to the third fixed contact 9c.

By constructing the periphery of the microphone selection switch 9 in this manner, the movable contact 9m of this switch 9 is set to the first position.
Of the omnidirectional microphone unit 1 is output from the microphone selection switch 9, and the movable contact 9m is connected to the second fixed contact 9b. The outputs of 2a and 2b are output from the microphone selection switch 9 with high sensitivity, and by connecting the movable contact 9m to the third fixed contact 9c, the outputs of the sharply directional microphone units 2a and 2b are output from the microphone selection switch 9. Output with low sensitivity.

The audio signal obtained at the movable contact 9m of the microphone selection switch 9 is supplied to the output terminal 11 via the buffer amplifier 10, and the plug 45 (at the tip of the signal line 44 connected to the output terminal 11 The audio signal is supplied to the recorder in which (see FIG. 2) is inserted.

In this example, the audio signal obtained at the movable contact 9m of the microphone selection switch 9 is converted into the amplification circuit 1
The signal is supplied to the second side, and the amplification circuit 12 performs amplification for level detection. Then, the audio signal amplified by the amplifier circuit 12 is supplied to the rectifying diode 13 to be rectified. In this case, the cathode side of the diode 13 is connected to the capacitor 14
To ground. Then, the signal rectified by the rectifying diode 13 is supplied to the level determination circuit 19 via the variable resistor 15. Further, the output of the variable resistor 15 is divided by the series circuit of the resistors 16, 17 and 18, and the signal obtained at the connection midpoint of the resistors 16 and 17 and the resistor 17,
The signal obtained at the connection midpoint of 18 is compared with the level determination circuit 1
Supply to 9.

The level discriminating circuit 19 is composed of a microcomputer and discriminates the levels of the signal directly supplied from the variable resistor 15 side and the divided two types of signals. Then, when the determined level is equal to or higher than the threshold value set for each, a control signal for display is supplied to the display panel 30 via the drive circuit 20. Here, the display panel 30 includes a liquid crystal display,
The display is performed as shown in FIG. The display state of FIG. 3 shows a state in which all the displayable items are displayed, and three bars 31, 32, 33 having different heights are displayed together with the operating state display such as the ON and battery dead marks. The three levels 31, 32, 33 of bar graphs are used to display the sound pickup levels (output audio signal levels) in three stages. For example, the sound pickup levels of the three discriminated points are V ₁ , V ₂ , and V ₃ (where V ₁ <V ₂ <V ₃ )
Then, when the lowest level V ₁ is exceeded, only the bar 31 having the lowest height is displayed, and when the next level V ₂ is exceeded, the second height bar 32 and the bar 31 are displayed. Then, when the maximum level V ₃ is exceeded, all the bars 31, 32, 33
Is controlled to be displayed.

Here, the output sound level V ₁ for displaying only the lowest bar 31 is set to an excessively small sound collecting level at which it is difficult to judge the conversation content, and the bar 3 of the second height is set.
The output sound level V ₂ displayed up to ₂ is set to an appropriate sound collection level, and the output sound level V ₃ displayed for all the bars 31, 32, 33 is close to the maximum output level of this microphone device. Set to an excessive sound collection level. These settings are performed by adjusting the variable resistor 15.

Although not shown, this microphone device has a built-in battery, and power is supplied to each circuit from the battery.

According to the microphone device of this example having the above-described configuration, the output level of the sound picked up by the microphone unit in use is displayed on the display panel 30 and serves as a guide for the sound pickup state. That is, for example, when the sharp directivity microphone units 2a and 2b are used with high sensitivity by the microphone selection switch 9 (that is, when the movable contact 9m is connected to the second fixed contact 9b), the level determination circuit When it is detected at 19 that the output level is excessive, all the bars 31, 32, 33 are continuously displayed on the display panel 30. At this time, the user of the microphone may change the installation position of the microphone device or operate the microphone selection switch 9 to switch the microphone units 2a and 2b having sharp directivity so as to be used with low sensitivity. . Alternatively, it may be switched to the omnidirectional microphone unit 1.

On the contrary, when the level discriminating circuit 19 detects that the output level is too low and only the bar 31 is occasionally displayed on the display panel 30, the installation position of the microphone device is in conversation. It can be considered to bring the microphone closer to a person or to switch the usage state of the microphone to one having higher sensitivity and directivity.

As described above, just by confirming that the sound pickup level of the sound is the proper level on the display panel 30, the proper sound pickup is performed and the recording error due to the cause on the microphone side can be prevented. In the case of this example, since the level is displayed directly on the microphone device, when deciding the microphone installation position and usage condition (selection of sensitivity and directivity, etc.), it is only the microphone that is suitable for the position and state. It is not necessary to check the display etc. on the recorder side connected via the signal line 44 and it is possible to judge whether or not the recorder is in a place away from the microphone device, or the recording monitor on the recorder side. It is convenient when it is difficult to do.

Although two sets of microphone units having different directivities are switched in the above embodiment, the present invention can be applied to a microphone device having only a single microphone unit. Alternatively, the present invention can be applied to a microphone device that includes two sets of microphone units having the same directivity and performs stereo sound collection by changing the sound collection direction of each microphone unit. In the case of a microphone device that performs stereo sound collection, there are a case where the sound collection levels of the respective channels are individually displayed and a case where the sound collection levels of the respective channels are mixed and displayed.

In the above embodiment, the liquid crystal display panel is used to display the levels on the three bar graphs, but other display forms may be used. However, there is no need to display the level in detail because it only needs to be a guide for the sound pickup state.

[0029]

According to the present invention, the sound pickup state can be easily judged by observing the display state on the display means installed in the microphone device, and it is not necessary to connect an earphone to the recorder and monitor the recording. Also, it is possible to easily determine that proper sound pickup is being performed, and it is possible to prevent a recording error due to the cause on the microphone side.

In this case, by selectively displaying the sound collecting states of a plurality of microphone units having different directivities, it is possible to easily determine which directivity microphone unit should be used, and to select an appropriate microphone. Easy to select.

Further, as the level display on the display means, at least three stages are displayed by a bar graph, so that, for example, an appropriate output level, an excessive output level, or an insufficient output level is displayed. Judgment can be made easily with the minimum display.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view showing an example of an external appearance of a microphone device according to an embodiment.

FIG. 3 is a plan view showing a display example on the display panel of the embodiment.

[Explanation of symbols]

 1 Microphone unit (omnidirectional microphone) 2a, 2b Microphone unit (sharp directional microphone) 9 Microphone selection switch 11 Audio signal output terminal 12 Amplifying circuit 13 Rectifying diode 19 Level discriminating circuit 20 Drive circuit 30 Display panel

Claims (3)

[Claims] 1. A microphone unit for converting a change in sound pressure into an electric audio signal, an amplifier circuit for amplifying an audio signal output by the microphone unit, and a rectifying means for rectifying an output of the amplifier circuit, A microphone device in which a detection unit that detects the output level of the rectification unit and a display unit that displays a level according to the detection level of the detection unit are integrally housed. 2. The microphone device according to claim 1, wherein a plurality of microphone units having different directivities are provided, and the output levels of the plurality of microphone units are selectively displayed by the display means. 3. The microphone device according to claim 1, wherein at least three stages of bar graphs are displayed as the level display on the display means.