JPS5941995A - Directional microphone device - Google Patents

Abstract

PURPOSE:To obtain an excellent directivity, by switching an element constitution in accordance with a direction of a main lobe of an array consisting of a pair of microphone elements whose main shaft is inclined, respectively, by an angle in less than a specified angle, in a clockwise direction and in a counterclockwise direction. CONSTITUTION:When varying the direction of a main lobe (front lobe) of a microphone array MA to an angle by less than 90 deg. counterclockwise from the front direction, microphone elements A1l-Anl are used, and when varying said direction to an angle by less than 90 deg. clockwise, microphone elements A1gamma- Angamma are used. The element A1l and A1gamma constitute a pair of elements, and each element pair is placed at prescribed intervals on the same plane. The element A1l-Anl are provided by inclining them by an angle theta in the clockwise direction, and also the elements A1gamma-Angamma are provided by inclining them by an angle theta in the counterclockwise direction. A controller CR is adjusted, and a control signal generating circuit CSG executes control of a delay quantity of delaying circuits D1-Dn-1 and switching of changeover switches SW1-SWn, by which the excellent directivity is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a 1/'l 7C directional microphone device using a microphone array.

(Prior Art) In order to configure a microphone having a sharp V directivity characteristic, a microphone in a microphone array format in which a plurality of microphone elements are arranged in a desired arrangement, or individual microphones in a microphone array are used. By giving a predetermined amount of time delay to each output signal from the element, the direction of the main a-b can be freely changed. Recently, attempts have been made to put these devices into practical use1.

Figure 1 shows a microbon device in which the direction of the main lobe can be freely changed by giving a predetermined amount of time delay to each output signal from each microbon element in seven microphone arrays. 1 is a block diagram showing an example of the configuration of A, , A2...M in FIG.
Hasonezone Microphone Element (Microphone Unit)
The first microphone elements A1 to An are as follows:
By arranging the microphones approximately in a straight line at a predetermined distance d from each other, a 7-ray kite is constructed.

The output signals from each microphone-phone element A, , A2...An are controlled by individual changeover switches sw, , s.
W2...SWn's movable contact a and fixed contact t or fixed contact r, each microphone element A, , A2
. . . An to f) are applied to circuits that respectively apply a predetermined amount of time delay to the output signal.

Each of the above-mentioned 1 changeover switches SW, , SW2...S
Wn is an interlocking changeover switch, and the changeover control signal σ
] Switching control 15 applied to input terminal 1 via line t1
According to the numbers, the movable contacts a in all changeover switches SW, to SWn are replaced by the fixed contacts 1. to 1 with the same reference numbers. M1 and R are designed to switch all at once to R.

By means of a switching control signal applied via input terminal 1,
The movable contact a in each changeover switch SW, ~SWn is
When the fixed contacts of the changeover switches SW, ~SWn are switched to the V side, the output signal of the microphone element A1 is sent to the output terminal 2 without any delay, and , the output signal of the microphone element A2 is given a delay of time τi by the delay circuit and is sent to the output terminal 2 in this state, and the output signal of the microphone element A3 is further delayed by the delay circuit D2.
The signal is sent to the output terminal 2 with a delay of 2τ1 by the delay circuit and the delay circuit. Similarly, the output signal from microphone element An-2 is (n-
3) delay circuits give a time delay of (n-, 3)τi and send it to output terminal 2.
The output signal from the microphone element An-1 is given a time delay of (n-2)τi by (n-2) delay circuits and sent to the output terminal 2, and then output from the five microphone elements An. The signal is processed by ('n - 1) delay circuits.
-1) τ! is sent to output terminal 2 after a time delay of .

As mentioned above, each delay circuit M D, , D2 is used to delay the output signal from each microphone element arranged approximately on a straight line at predetermined equal intervals d.
...D(n'-1) The delay times for each individual house are all set to the same value τi, but if the delay time τi described above is
The direction of the main low of the microphone 7 ray MA is changed so as to gradually increase from t, - The lobe gradually changes along the arrow in the diagram showing the movement mode until it faces 90 degrees to the left.

Next, each changeover switch SW1 to S is controlled by a changeover control signal.
When the movable contact a of Wn is switched to the fixed contact r side, the microphone elements A, ~M until the output signals of the microphone elements A, ~M are not sent to the output terminal 2, The amount of time delay given to the output signal of An is determined by the amount of time delay given to the output signal of the plurality of microphone elements A1 to F of the microphone 7-ray MA when the movable contacts a of the changeover switches SW1 to SWn are switched to the fixed contacts to the V side.
The amount of time delay given to each output signal of An is different. That is, in this case, the output signal from the microphone ρ phone element An is sent to the output terminal 2 without delay, and the output signal from the microphone element An-1 is delayed due to the delay (b) path. Also, given a time delay of τl, the signal is sent to the output terminal 2 in the tt, y=state, and in the same manner, each microbon element An-2...+A3
+ A2 + A.

The amount of time delay given to the output signal is 2τl・
−+ (n-3)ri+ (n-2)ri+ (n-1
)ri.

Then, in the state where the movable contact a of each changeover switch SW1 to SWn is switched to the fixed contact r side and V is set, the above-mentioned delay circuit 1 gradually increases the delay time τi of the n-1 side from 0. When I change it to ℃, the direction of the main rope of microphone 7 ray MA is my direction ψ Oo
The main rope gradually changes from the state shown in FIG. 1 to the state facing 90 degrees to the right along the arrow R in the diagram showing the movement mode of the main rope, which is shown for reference in FIG.

Therefore, the movable contact a of each changeover switch SW1 to SWn is controlled by the changeover control signal supplied via the 5 input terminal.
means for selectively switching the fixed contact t+r to either one of the fixed contacts t+r, and each delay circuit, ~D(n-IX) delay time τ
By applying means for varying i, the direction of the main rope of the microphone array MA can be changed as required within a range of 180° in front of the microphone array MA.

FIG. 2 shows a configuration gtt in which the delay time is variably controlled.
2 is a boot diagram showing an example of the configuration of a delay circuit, in which l) a to Dd have delay times of τ12τ and 4τ, respectively, as shown in the diagram.

8τ is a delay circuit element configured in 5,
Separate switches 81 + 82 + 83 + are provided between the input and output terminals of each of the delay circuit elements Da=Dd.
84 is connected.

The delay circuit shown in FIG. 2 includes switches 81-S connected between the input and output terminals of each delay circuit element Da-S.

1 by 16 combinations of on and off states of
The first is a delay circuit that shows six different delay times. That is, when all the switches S and s4 are in the on state, the delay time of the delay circuit is set to 0, and
Roughly speaking, when only the switch S1 is off, the delay circuit has a delay time of τ, and when only the switch S2 is off, the delay circuit has a delay time of 2τ. and I/-5 yo'5vc.

Depending on the combination of on and off of switches S and ~S4,
The delay time of the delay circuit is 0. τ12τ, 3τ14τ...
・It can be changed in 51C16 steps such as 15τ.

Then, the four switches 81 to S4 mentioned above are turned on.

The off control is controlled by a 4-bit digital signal that is applied to the delay path via line t2. This can be easily done depending on the number. If the delay circuit is constructed using a larger number of delay circuit elements than the delay circuit shown in FIG. 2, it is natural that the number of switchable delay times in the delay circuit will not be large.

Assuming that the delay time τ1 at =D(n-1) in each delay circuit is changed in 16 steps as described above, the first line and the line 1. In combination with the left and right switching operations by the switching control signal applied to input terminal 1 via It will be changed.

That is, the changeover switches SW1 to SWn are connected via the line t1.
The 1-bit switching control signal applied to the line t2 and the 4-bit delay amount control signal applied to =D(n-1) through the delay circuit through the line t2 are the The control signal generating circuit C8G determines the angular position within the range of 180 degrees in front of the control signal generating circuit C8G.
If the 8G is configured to include, for example, a microcomputer, it can easily generate the required control signals.

In the example shown in No. 11, the controller CR is composed of a variable resistor ■ and a 7-stage digital converter 1v'D, and the operator adjusts the slider of the variable resistor ■ to Set the direction of the main loaf of the kite.

A voltage between the 10B voltage and the ground voltage appears on the slider of the variable resistor (2) by adjusting the slider (1).
The voltage obtained at the slider is converted to an analog-to-digital converter N.
By converting the 511C analog to digital so that the entire range of voltage change in the slider corresponds to a suitable value, for example 256, the 7p dental converter M[
An 8-bit main lobe direction indicating signal corresponding to the position of the slider of the variable resistor (2) is generated from the main lobe (F), and this signal is applied to the aforementioned control signal generator MC8G.

Now, adjust the entire adjustment range of the slider of variable resistor
It corresponds to the change range of the direction of the main lobe of the microbon array MA over the range of 1, and also corresponds to the displacement of the slider of the variable resistor In response, the voltage value appearing on the slider is given to the control signal generation circuit C8G as an 8-bit main lobe direction indication signal by the analog-to-digital converter N width, and roughly speaking, the voltage value appearing on the slider is applied to the control signal generation circuit C8G as an 8-bit main lobe direction indicating signal. The delay circuits D1 to D(n-1) which provide time delays to the respective output signals A, to An are configured to have their delay times τi switched in 16 stages by a 4-bit switching control signal. Taking a case as an example, an example configuration of the control signal generation circuit C8G described above will be explained.

By adjusting the slider of the variable resistor ■ of the controller α, the operator can set the direction of the main roof of the microphone array MA to the front center of the microphone array MA (the straight line - A state in which the main lobe is orthogonal to The position of the slider of resistor (2) is in the middle range of the change range of the slider of variable resistor (2), and the numerical value indicated by the output digital signal from the analog-to-digital converter at this time is 128.

By the way, the direction of the main lobe of the Mikelhonfrey kite is 0.
To set the direction of the main lobe of the microphone array MA to 0°, it is necessary to set the delay signal τi at ~D(n-1) to 0 for each delay circuit.
7-step digital converter A/
]) In the control signal generator C8G, each delay circuit corresponds to the numerical value 128 indicated by the output digital signal, =D(
4 such that the delay time τi of n-1) can be brought to a state of 0.
A bit delay amount control signal, that is, a delay amount control signal that turns on all four switches S, .about.S shown in FIG. 2, is generated. Microphone array M
If the direction of the main lobe of A is 00, the switch S
Since the movable contacts a of W1 to SWn may be connected to any of the fixed contacts 1 + r, the switching control signal in this case is such that the movable contact a is connected to the predetermined one of the fixed contacts t + r. All you have to do is set it to one that can be switched to either one.

By adjusting the slider of the variable resistor ■ of the controller α, the direction of the main lobe of the microphone array MA is set within the range of 900 degrees to the right from the 0 degree direction and 90 degrees to the left from the − direction. . Then, the numerical value indicated by the first 8-bit main lobe direction indicating signal generated in the analog-to-digital converter is 1 to 128, corresponding to the adjustment position of the slider of the variable resistor (2) of the controller (α). In the case of , for example, it corresponds to the range from 90 degrees to the left to 0 degrees, and if the numerical value indicated by the 8-pips main loop direction indication signal is 128 to 256, , for example Oo
For example, the direction of the main p-no expressed by the numerical value of the 8-bit output digital signal from the analog-digital converter is If the left p, the control signal generation circuit C8G:
Create a switching control signal that allows the movable contacts a of the changeover switches SW and SWn to switch the fixed contacts to the side, and apply it to the changeover switches SW1.1 to SWn via the line t1. A delay amount control signal whose direction is set to 00 is generated, and it is applied to the delay circuits D1 to D(n-1) via the line t2, and the 8-bit output digital signal from the analog-to-digital converter is If the direction of the main lobe represented by the signal value f is, for example, right t, the control signal generation circuit C8G switches the changeover switch S.
When the movable contacts a of W1 to SWn are switched to the fixed contact r side, 1
Create a switching control signal like this and give it to the changeover switches SW1 to SWn via the line t1. Also, create a delay amount control signal such that the main direction is t and the direction of the main direction is t. ,
Then j'l is connected to a delay circuit via line t2, =D(n-1)
The control signal generation circuit C8G
, a required switching control signal and a required delay amount control signal are created based on the main lobe direction indication signal sent from the controller, and are sent to the line tl14! It is clear that the orientation of the microphone array MA should be made as the operator sets it by adjusting the slider of the variable resistor ■ of the controller α. be.

(Problems to be Solved by the Invention) Now, in the above-mentioned microphone device configured in I', 5, its main lobe is a variable resistor with an input α. By adjusting the mic-pong/
The ray kite can be set to point in a desired angular direction within a range of 180° in front of the ray MA, but if it is constructed using multiple microphone elements, the directional characteristics of the ray kite will vary. So, the ten ropes are in the direction of 00,
That is, the directional characteristics of the microphone array MA in the case where the microphone 1 is oriented to face the front of the microphone array MA are as follows: Depending on the case of so-called cardioite as shown in a of Fig. 3 and the case of so-called hypercardioid A as shown in a of Fig. 4, respectively, and bK in FIG. 4.

As is clear from the Jl ψ shown in a and b of FIG. 3 and a and b of FIG. (front lobe) becomes sharper than V
': 7. ) However, the front a-b of the microphone array becomes increasingly sharp as the number of micropon elements used to construct the microphone array increases.

However, when we look at the front-back ratio of the sensitivity of the entire microphone 7-ray, we find that it is the same as the front-back ratio of the sensitivity of the micro-bon element used to construct the Microphone 7-ray. Karu.

Further, the direction of the front o-:j is shown by b in FIG. 3 and bK in FIG. 4. 0 direction, i.e., microphone array M
Within the range from the front of A to the right (or left) 90' (0
90° clockwise (or counterclockwise) from the direction of
3), the directional characteristics of the microphone play kite change to states such as C1d, e in FIG. 3 and e + d + e in FIG. 4.

That is, when the direction of the main lobe of the microphone array MA is tilted in the direction oo, that is, by an angle β clockwise (or counterclockwise) from the front of the microphone-pond 7-ray MA, the line 90'-270o A rear a-b is created at a mirror-symmetrical position.

The above-mentioned main rope (front lobe) and rear rope are defined by the directional characteristic curve (dotted line in b = e in Figure 3 and b - e in Figure 4) of the microphone element constituting the microphone 7-ray kite. Since the size is determined by the main lobe (
When the direction of the front rope (p-branch) is changed from the direction of 00 clockwise (some f is counterclockwise) within the range of 900, the size of the front rope and the rear lobe increases as the angle β increases. Sano ratio frE J\G < becomes. Therefore, the microphone array 0 front lobe (
When the direction of the main lobe (main lobe) is gradually tilted from the 0° direction, a problem arises in that the directivity of the microphone array kite becomes substantially obtuse.

(Means for Solving the Problems) The present invention uses a microphone element having unidirectionality as a microphone element constituting the microphone 7 array, and directs the microphone element toward the front of the microphone array within a plane including the main axis of the microphone element. When a straight line is used as a reference line, an angle θ within 90% L in the clockwise direction with respect to the reference line
a microphone element whose principal axis is inclined by an angle θ of 90 mm in a counterclockwise direction with respect to the reference line; A microphone array is formed by a pair of microphone elements, and when the direction of the main rope (front lobe) of the microphone array is oriented in a clockwise direction within 90 degrees with respect to the above-mentioned reference line, the microphone array is formed. For each pair of microphone elements f, the main axis is tilted by an angle θ in the counterclockwise direction with respect to the reference line, and the microphone C-phone 7 ray is composed of only mitalopon elements f. is useful. J: 5, and - when the direction of the main rope of the microbo/array is oriented in a counterclockwise direction within 90 degrees with respect to the above-mentioned reference line, each microphone element making up the microphone array By using a microphone array consisting only of microphone elements whose principal axes are inclined by an angle θ in a clockwise direction with respect to the reference line described above, The rope is
By causing the rear lobe to occur near the insensitive portion of the directivity characteristic of the microphone element, the rear lobe in the microphone array can be eliminated or greatly reduced.

(Example) FIG. 5 is a block diagram of an embodiment of the directional microphone device of the present invention, and in this FIG. 5, the configuration corresponds to the component in the microphone device shown in FIG. The same drawing numerals used in FIG. 1 are used for parts.

In FIG. 5, A, t l A, 7 + A, t-
AnA is when the microphone array MA attempts to change the direction of its main rope (front rope) within an angular range of 90° counterclockwise from the direction of Ou, that is, the direction in front of the microphone array. n microphone elements with unidirectionality used as a microphone array, and AHr + A2 r +
A3r...Anr is the direction of the main rope (front a-) of the microphone array kite, which is clockwise I
c. n microphone elements having unidirectionality that can be used as microphone 7 ray when changing the angle within 90%, and the above 20 microphone elements are microphone elements Alt and A, r
constitutes a pair of microphone elements, and microphone elements A2t and A2r constitute a pair of microphone elements. This constitutes a pair of micropon elements.

A total of 2n microphone elements constitute n microphone element pairs.The first microphone C-phone 7-ray MA
20 microphone elements A, t.

A. Each pair of microphones may be arranged at a predetermined interval. Alternatively, each pair of microphones may be arranged at a predetermined interval on a polygonal line on the same plane as shown in Figure 7. It is done like this. The mode of arrangement as shown in FIGS. 6 and 7 is as follows:
This is effective in preventing the directivity characteristics at high V frequencies from becoming too sharp even when the direction of the main rope is not set at a large angle from the - direction.

The n microphone element pairs constituting the microphone array MAk need to be spaced apart by a distance d that is shorter than a half wavelength of the sound at the upper limit frequency in the frequency range that is the target of sound collection in the microphone array MA. However, depending on the size of the microphone elements used, there may be cases where it is not possible to arrange the microphone element pairs at the distance d as described above.

In such a case, as shown in the plan view of FIG. 8, microphone elements A, t, A2t...AnA and microphone elements A1 r + A2 r...Anr
The microphone elements may be arranged in separate rows and arranged in a direction perpendicular to the direction in which the microphone elements are lined up. , a pair of flea microbon elements An r +A
nt, A(n 1 ) r 1A(n 1 )t,...
・If Al r, A, and z are stacked vertically, 1tl/!
I) The arrangement is as follows: 4 L/'6 In the microphone array MA, each microphone element A having unidirectionality, t + k2t-AntIA,...
In r + A2r...Anr, microphone elements A, t, A2t...Ant are arranged in a straight line M toward the front of the microphone array (a straight line indicating the direction of 0°) in a plane including the principal axis of each microphone element. ) is used as a reference line, the main axis is inclined by an angle θ within a clock-shaped direction [90'%L, and each microphone element A+ r lA2 r... Anr is within 90 degrees in the counterclockwise direction when the reference line is the 5 straight line facing the front of the microphone array (the straight line indicating the 0° direction) in the plane that includes the principal axis of each microphone element. The main axis is inclined by an angle θ of 4.

The angle θ at which the main axis of the microphone element is tilted clockwise with respect to the reference line V is the angle θ at which the main axis of the microphone element is tilted counterclockwise with respect to the reference line. It should be determined depending on the angle range in which the direction of the main rope should be changed in the microphone array MA. Next, we will explain how to determine the above-mentioned angle 0, and the directivity characteristics ψ of the microphone array MA configured gti using microphone elements whose principal axes are inclined by the angle θ as described above.

FIG. 10 shows the microphone device of the present invention, taking as an example the case where the microphone elements used in the configuration of the microphone-phone array MA have cardioid directivity characteristics as shown in FIG. 3a. FIG. 2 is a reference diagram for explaining points such as what inclination angle θ should be used to incline the main axis of the microphone element with respect to the front of the microphone array to obtain Kv when configuring the microphone array in FIG.

A, r (~Anr
) is a microphone element shown for reference, and A and t (~Ant) in the diagram bK of FIG. 10 are also microphone elements shown for reference, and the 10th
The dotted lines Kr -Kr and -KA in a of the figure and b of Fig. 10 respectively indicate the microphone elements A, r(
~Anr) and A, t (~Ant), which is the main axis of the microphone element A, r (~Anr), which has unidirectional characteristics.
has a more cardioid directivity characteristic as shown by the imaginary line Ra in a of FIG.
It has a cardioid directivity characteristic as shown by the imaginary line Lb in the middle.

In FIG. 10a and FIG. 10b, #MX-X is the direction in which the microphone elements are arranged in the microphone array MA, and the 0° direction in the figure is the direction in front of the microphone array MA. show.

Microphone elements A, r (~A
nr), the direction of the main axis Kr - Kr is inclined by an angle θ 6tt in the counterclockwise direction with respect to the direction in front of the microphone array MA, that is, the direction of 05°. Microphone element Alt shown by bK
(~AnA) is tilted at an angle of 0 in the clockwise direction with respect to its main axis in the 7-to-4 direction with respect to the front direction of the microphone array kite, that is, the 0° direction, so for example, the 10th Like the microphone element A, r (~Anr) shown in figure a, the main axis Kr −
Using a microphone array constituted by an arrangement of microphone elements A and r-Anr in which the direction of Kr is inclined by 0 degrees counterclockwise with respect to the direction in front of the microphone 7 ray, its main rope is The direction of
When varied over a range of 180° in front of the microphone array, the main rope of the microphone array is
The size changes along the part above the line, and as in the microphone element A, t (~Ant) shown in FIG.
Using a microphone array constituted by an array of microphone elements A, A-AnA, whose direction is tilted by 0 degrees clockwise with respect to the front direction of the microphone array, its main o-j When the direction of the main O-beam of the microphone array is changed over a range of 180° in front of the microphone 7 ray, the main O-beam of the microphone array is
The size changes along the portion above the line XX in the curve Lb indicated by bK in the figure.

By the way, in the microphone 7 ray, the rear rope is formed in a position that is mirror symmetrical to the main rope (front rope) with the X-X line as the axis of symmetry, as already mentioned in the explanation of Figures 3 and 4. However, with the X-X line as the axis of symmetry, it occurs in a mirror-symmetrical position with respect to the front O-b)
If 5g':l is located in the insensitive region of the microphone element, then the force ρ actually appears and the first effect is V-8. Therefore, the directional microphone device of the present invention So, X-X
With the line of symmetry as the axis of symmetry, the microphone array is arranged so that the rear a-no, which occurs in a mirror-symmetrical position with respect to the front rope within the movement range of the front rope, is located near the insensitive area of the microphone element. By making the plurality of constituent microphone elements whose main axes are tilted by a required angle θ from the direction in front of the microphone array (0° direction), the rear rope can change the direction of the front rope. The microphone array used for changing the clockwise direction [9 (+') from the front direction (0° direction) of the microphone array, that is, the main axis Kr as shown in a in FIG. - A microphone array configured by V using microphone elements A, r to Anr whose direction of Kr is tilted counterclockwise from the direction in front of the microphone array (0° direction) by the angle θ of term 4; A microphone array used to change the direction of the front rope in a counterclockwise direction from the direction in front of the microphone array (the θ° direction) over an angle range of within 90 degrees, i.e., as shown in FIG. 10b. Indicates L',
+ Microphone element A, 1-Anl with the direction of the VC5 principal axis U-■ tilted clockwise from the front direction of the microphone array (Oo direction) by a certain angle θ.
A microphone A and a microphone configured using a microphone are prepared, and the two microphones 7 and 7 are switched and used in accordance with the above-mentioned range of change in the direction of the front IJ-b of the microphone 1 and ray. 7. By setting r to 5, it is possible to eliminate or significantly reduce the backward 1'J-no, and to realize V
Ru.

To change the direction of the front p-node of the microphone array within an angular range of 90 degrees clockwise from the reference foot indicating the front direction of the microphone IJ phone array (0 degree direction). Microphone 1 phono elements A and r Anr constituting the micro ray/7 ray used in the microphone array are such that the direction of their principal axes Kr-Kr is in front of the microphone array, as shown by avc in Fig. 10. direction (0° direction)
By tilting Jl by a required angle θ in the counterclockwise direction with respect to a reference line indicating :The size of the front rope of the microphone array when the direction of the front rope is changed clockwise from the reference line within an angle range of 90° is shown by the imaginary line a in Figure 10. The curve RaO shown by
In addition, the direction of the front rope b of the microphone array is changed in the direction of the front of the microphone array (0° direction). Construct a microphone array used to change the angle within 90 degrees in the counterclockwise direction from a reference line indicating As shown in b, ψ
As shown in FIG. , the above l, microbo/element A, t-
The front side of the microphone array when the direction of the front side is changed in the counterclockwise direction from the reference line within an angle range of 9 (J') is -1) The size of ゛ is determined by the straight line 0-00 within the curve Lb shown as an imaginary line in b of Figure 1O.
and the straight line 0-270°.

Then, the front ρ-no changes in size 3f1 according to the curve between the straight line 0-0° and the straight line 0-90' in the curve Ral1'I: shown in a of Figure 1O. When the direction is changing gtt, the rear rope that should be generated in a mirror symmetrical position with the front Q-beam with the X-X line as the axis of symmetry is the microphone element between the straight line 0-90° and the straight line 0-180°. A, r = Anr It does not occur in the insensitive part of vc, and follows the curve Ra only when the direction of the front a-b is made at an angle of 90° VC near f in a clockwise direction from the reference line. This will occur due to large differences.

In addition, the front lobe is shown in b and f in Figure 1O, which is the curve L
When the size changes according to the curve between the straight line 0-0° and the straight line 0-270' in b, the direction of the fidget changes while the size changes. The rear rope that should be generated at a mirror-symmetrical position is the straight line 0-
This does not occur in the insensitive part of the microphone element A, t-Ant between 270° and the straight line 0-180', and the direction of the front a-b is in the counterclockwise direction fc90' from the reference line. Only when the angle is close to ψ, the magnitude according to the curve Lb will occur.

In the examples shown in Figures 10a and 10b, the rear lobe is generated when the front lobe is oriented at an angle near V to 90° from the reference line. However, in order to be able to vary the direction of the front rope in the microphone 7 lay up to an angle of 90° from the front of the microphone array, the inclination angle θ of the microphone element is determined even on the X-X line. This is because the inclination angle θ of the VC and microphone element is set so that no rear rope occurs at all, corresponding to a predetermined movement range of the direction of the front rope. Of course, there is no need to worry.

In the directional microphone device of the present invention shown in the fifth factor, microphone elements A in a microphone array style,
The t-Ant is used when the direction of the front a-no of the microphone array is to be changed counterclockwise from the front direction of the microphone array within an angular range of 90 degrees. Also, microphone elements A and r in the microphone array MAvc
-Anr is the direction of the front rope of the microphone array clockwise from the front direction of the microphone array.
Used when trying to change the angle within a range of 0.
To change the direction of the microphone array wind (main 0) within a range of 180 degrees in front of the microphone array, selector switch SW, = SWn movable contact a
It is necessary to switch the fixed contact to the fixed contact R side and the fixed contact R side, but this is done by the above-mentioned first
The procedure is carried out in the same manner as in the case shown in the figure.

In addition, the above-mentioned switching control signal and the delay circuit ~D(n
-1) Configuration of a control signal generation circuit C8G for generating a delay amount control signal to be applied via the VC waxed wire 4, a variable resistor ■, a 7sag digital converter, a Φ and a naro controller α, etc. The operation is also as explained with reference to FIG.

(Effects) As is clear from the detailed explanation above, the directional microphone device of the present invention is a microphone device in which a plurality of microphone elements having unidirectionality are arranged in a desired arrangement manner. By varying the output from each microphone element in the array (for each number 8), the spatial position of the micropon itself is kept constant by varying the predetermined amount of delay given to each of the 4 powers. The direction of the main rope (front (J-brake)) can be changed freely while the
In a directional microphone device, the angle required in the clockwise direction from the front of the microphone array is to eliminate or significantly reduce the rear ap that occurs at a position mirror-symmetrical to the front lobe. A microphone composed of a microphone element whose principal axis is tilted by 0. A phon array and a microphone ρ pon array constituted by microphone elements whose principal axes are tilted by a predetermined angle θ in a counterclockwise direction from the front direction of the microphone array are provided. - When the direction of the ray is 90 degrees from the front of the microphone array, the required angle is set in the direction of time Kt 1 from the front direction of the microphone 0 phon/ray. icL so that a microphone-phone gray configured by a microphone element whose main axis direction is inclined by θ is used.

Also, when the direction of the front [J-] of the microphone-phone array is oriented clockwise within 90 degrees from the front direction of the microphone-phone array, the counter-clockwise direction from the front direction of the microphone-phone array is This was achieved by applying an extremely simple method of using a micropon array composed of microbon elements whose main axis is tilted by the required angle θ in the surrounding direction. According to the invention, it is possible to easily provide a directional microbond device with excellent directional characteristics.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a microphone device, Fig. 2 is a block diagram of an example configuration of a delay circuit, Figs. 3 and 4 are directional characteristic curve diagrams, and Fig. 5 is a directional microphone device of the present invention. 122, FIGS. 6 to 9
The figure is a diagram for explaining the arrangement of the microphone elements, and Figure 1O is a diagram for explaining the state of inclination of the microphone elements constituting the microphone array in the apparatus of the present invention. MA...Microphone 7 Ray +A, ~An r A,
r++−Anr+A, /1. ~Ant...Microphone element, SW1~SWn...Selector switch, D+-D
(n l)...Delay circuit, C8G...Control signal generation circuit, α...Controller, Patent applicant: Victor Japan Co., Ltd.

Claims (1)

[Claims] In a microphone array formed by arranging a plurality of unidirectional microbon elements in a predetermined arrangement manner, each of the predetermined signals to be given to each output signal from each microphone element First, since the amount of delay is variable, the direction of the main rope can be freely changed while keeping the spatial position of the microphone itself constant. V, when the reference line is a straight line facing the front of the microphone array in a plane including the main axis of each microphone element having unidirectionality in the microphone array, the hour hand rotates relative to the reference line. A microphone element whose principal axis is inclined by an angle θ within VC90% in the direction of A plurality of microphone element pairs constitute a microphone element pair, and the direction of the main rope of the microphone array is within 90 degrees of the reference line mentioned above. G' when it is directed in the opposite direction! , for each microphone element pair ψ constituting the microphone array, only the microphone elements whose principal axes are inclined by an angle θ in a direction counterclockwise with respect to the reference line mentioned above are used. A micro, t-, and n-array is used, and the direction of the main rope of the microphone array is 90°
Even in the middle of the day, I turned counterclockwise. When the microphone array is configured, each pair of microphone elements is set at an angle θ in the direction of the hour wheel with respect to the reference line mentioned above.
fi: A microphone element that is tilted (direction microphone device)