Patent Translate Powered by EPO and Google Notice This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate, complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or financial decisions, should not be based on machine-translation output. DESCRIPTION JP2008118260 PROBLEM TO BE SOLVED: To provide a variable directional electret condenser microphone unit capable of continuously changing directivity from omnidirectional to bidirectional, and a microphone using the same. SOLUTION: A single plate comprising a diaphragm, a diaphragm holder to which the diaphragm is fixed, and a fixed electrode which is disposed opposite to the diaphragm with a gap therebetween and constitutes the capacitor. A bi-directional condenser microphone unit in which fixed electrodes of the directional electret condenser microphone unit are opposed to each other, and an acoustic resistance material fixed by an insulating seat is disposed between the fixed poles and integrally coupled; The variable directional electret condenser microphone unit has a variable capacitance capacitor that connects the fixed pole of the unidirectional electret condenser microphone unit to the diaphragm of the other unidirectional electret condenser microphone unit. [Selected figure] Figure 1 Variable directivity electret condenser microphone unit and condenser microphone [0001] The present invention relates to a variable directional electret condenser microphone unit capable of continuously changing directivity from nondirectionality to bidirectionality and a microphone using the same. [0002] Several inventions are known for variable directional condenser microphones that can vary the directivity of the condenser microphone. 03-05-2019 1 For example, the invention of a microphone of variable directivity is known that includes phase shift means for phase shifting the output from each condenser microphone, and addition means for adding the output and the output of the phase shift means. Reference 1). [0003] There is also known an invention of changing the characteristics of the microphone units disposed on the front and the left and right to change the directivity of the entire microphone (see, for example, Patent Document 2). [0004] There is also known an invention of changing directivity by changing a ratio of mixing a plurality of microphone outputs (see, for example, Patent Document 3). [0005] Patent Document 1: Japanese Unexamined Patent Publication No. 11-069481 Japanese Utility Model Application Publication No. 02-075895 Patent Document 1: Japanese Patent Publication No. 61-055838 [0006] In addition, a bidirectional directivity condenser microphone unit (hereinafter referred to as bidirectional directivity microphone unit can be obtained by arranging fixed poles of two pairs of unidirectional directivity condenser microphone units (hereinafter referred to as unidirectional unit ) facing each other. In the bi-directional unit , the directivity from the bi-directional unit as a whole can be changed by changing the polarity of the diaphragm and the fixed pole of the single-directional unit on the back side. [0007] FIG. 3 is a cross-sectional view showing an example of a bi-directional unit in which two single directional units are disposed to face each other. In FIG. 3, the bi-directional unit 1 is formed by the diaphragm holder 11a, the diaphragm 12a 03-05-2019 2 and the fixed pole 13a, and is disposed on the front side of the bi-directional unit 1; A single directional unit B formed by the diaphragm 11 b and the fixed pole 13 b and disposed on the back side of the bidirectional unit 1 is disposed opposite to each other with the insulating seat 14 interposed. A damper 15, which is an acoustic resistance, is provided near the center of the insulating seat 14, and thereby, a back air chamber 16 is formed between the fixed pole 13a and the fixed pole 13b. These members are fixed to the insulating seat 14 by pressing rings 19 fitted to the front and rear end outer peripheral portions of the insulating seat 14 to constitute the bi-directional unit 1. [0008] Diaphragm electrodes 17a and 17b, which are outputs from the diaphragm 12 and the fixed pole 13 of the single pointing unit A and the single pointing unit B, and fixed pole electrodes 18a and 18b are provided. The diaphragm electrodes 17a and 17b are electrically connected to the diaphragms 12a and 12b via the diaphragm holders 11a and 11b for fixing the diaphragms 12a and 12b. The fixed electrode 18a and 18b are connected to the fixed electrode 13a and 13b and electrically connected via a wire extending from the slit provided in the insulating seat 14 to the outside of the unit 1. [0009] When the capacitor portion formed by the diaphragm 12 and the fixed electrode 13 of the unit A and the unit B requires application of a polarization voltage, the polarity and the magnitude of the polarization voltage are changed. The directivity of the pointing unit 1 can be changed. FIG. 4A is an explanatory view showing necessary configurations and respective connections in order to explain an example of changing the polarity of the polarization voltage. FIG. 4B is an explanatory view showing necessary configurations and respective connections in order to explain an example in which the magnitude of the polarization voltage is changed. 03-05-2019 3 [0010] In FIG. 4A, a DC voltage of a constant voltage is used as the polarization voltage of the unit A. As the polarization voltage source of the unit B, a DC-DC converter 3 capable of changing the polarity of the output voltage is used. The output terminal of the converter 3 is provided with a variable resistor, and the output voltage can be continuously changed from −100 V to +100 V by changing the variable resistance value. The polarity can be changed. An impedance converter P is connected to the fixed pole electrode 18 for extracting the output of the bi-directional unit 1. [0011] If the polarity of the output voltage of the DC-DC converter 3 is made positive, the polarities of the polarization voltages of the unit A and the unit B become the same, so the directivity of the unit A and the unit B becomes the same. Therefore, the bi-directional unit 1 as a whole becomes omnidirectional. If the polarity of the output voltage of the DC-DC converter 3 is negative, the directivity of the bi-directional unit 1 is bi-directional. Also, when the polarization voltage is not polarized, ie, when the polarization voltage is zero, only unit A will function as a microphone unit, and unit 1 will be unidirectional. [0012] Further, in FIG. 4B, the DC-DC converter 3a can change the output voltage from 0 V to 120 V by providing a switch at the output terminal on one side. The diaphragm electrode 17a of the unit A is directly connected to the impedance converter P, and the fixed electrode 18a and 18b are connected to the fixed output terminal of the DC-DC converter 3a. The diaphragm electrode 17b is connected to an output terminal which is a changeover switch of the DC-DC converter 3a. By changing the magnitude of the polarization voltage applied to the diaphragm electrode 17b in the bi-directional unit 1 connected in this manner, it is possible to relatively change the polarities of the diaphragm 12b and the fixed electrode 13b, By changing the magnitude of the polarization voltage, it is possible to switch between bi-directionality, non-directionality and unidirectionality. [0013] 03-05-2019 4 Figure 5 shows an example of the configuration of a variable directional microphone unit using a bi-directional electret condenser microphone in which polarization voltage is eliminated by using electrets for the diaphragm 12a and the diaphragm 12b of the bi-directional unit 1 shown in FIG. It demonstrates using. The diaphragm 12 of the bi-directional unit 1 in FIG. 5 is configured of an electret, but the other configuration is the same as that of the bi-directional unit 1 described above. [0014] In FIG. 5A, the output taken from the fixed pole 13a and the fixed pole 13b is connected to the impedance converter P via the fixed pole electrode 18. Here, the impedance converter P needs to be connected to each fixed electrode 18 one by one. [0015] Further, as shown in FIG. 5B, instead of connecting the impedance converter P to each of the fixed electrode 18a and the fixed electrode 18b, the impedance converter P is connected only to the fixed electrode 18a, The directivity can be varied by connecting the fixed electrode 18b to the changeover switch. According to the bi-directional unit 1 in the above configuration, the bidirectional unit 1 becomes nondirectional when the impedance converter P is connected to the diaphragm electrode 17 b by switching the above-mentioned changeover switch. When the impedance converter P is connected to the diaphragm electrode 18b, the bi-directional unit 1 is bi-directional. When the switch is placed at the neutral point and neither the diaphragm electrode 17b nor the fixed electrode 18b of the unit B is connected to the impedance converter P and the output of the unit B is not taken out, the bi-directional unit 1 is uni-directional It becomes sex. [0016] In the prior art shown above, when a power supply (DC-DC converter in FIG. 4) is used to apply a polarization voltage, the noise generated from the power supply will adversely affect the characteristics of the microphone unit itself. . Also, in the case of a condenser microphone using an electret for the diaphragm, when an impedance converter is connected to the output of each 03-05-2019 5 single-directional unit, the S / N ratio is degraded when the outputs are mixed. Also, if an attenuator (PAD) is used to prevent deterioration of the S / N ratio, miniaturization of the microphone unit becomes difficult. In addition, in the configuration in which the connection to the impedance converter by the switch is switched back, the directivity can not be continuously changed. [0017] The present invention has been made in view of the above problems, and outputs of bidirectional electret condenser microphones configured by combining unidirective electret condenser microphone units are combined by a variable capacitance condenser, and directivity is continuously varied. It is an object of the present invention to provide a variable directivity electret condenser microphone unit and a microphone using the same. [0018] According to the present invention, there is provided a single diaphragm comprising: a diaphragm; a diaphragm holder to which the diaphragm is fixed; and a fixed electrode disposed opposite to the diaphragm with a gap therebetween and constituting a capacitor. Two directional electret condenser microphone units are provided, the fixed poles of the two microphone units are made to face each other, and an acoustic resistance material fixed by an insulating seat is disposed between the fixed poles and integrally coupled. A variable capacitance capacitor for connecting the bi-directional condenser microphone unit, the fixed pole of the uni-directional electret condenser microphone unit of the above 1, and the diaphragm of the other unidirectional electret condenser microphone unit Main feature [0019] Further, according to the present invention, the fixed pole of the unidirectional electret capacitor microphone unit of the above 1 is connected to the impedance converter, and the diaphragm of the unidirectional electret capacitor microphone unit of the above 1 is grounded. The unipolar electret capacitor microphone unit fixed pole is connected to the movable pole of the variable capacitor, and the other unipolar electret capacitor microphone unit diaphragm is connected to the fixed pole of the variable capacitor. It is characterized by [0020] According to the present invention, by combining the outputs of two unidirectional electret condenser microphone units by a variable capacitance condenser, a microphone unit capable of continuously changing directivity from omnidirectionality to bidirectionality. You can get 03-05-2019 6 [0021] Hereinafter, an embodiment of a variable directivity electret condenser microphone unit according to the present invention will be described using the drawings. FIG. 1 is an explanatory view of a variable directional electret condenser microphone unit configured by using a bidirectional electret condenser microphone. The bi-directional unit 1 is shown in cross section in FIG. A variable capacitance capacitor (varicon) 2 is connected to the bi-directional unit 1 to variably invert the polarity of the unit B. The variable capacitance capacitor 2 schematically shows the electrical structure. [0022] The physical configuration of the bi-directional unit that can be used in the embodiment of the present invention is the same as the example of the conventional bi-directional unit described above. Therefore, the same components as in the conventional bi-directional unit example are denoted by the same reference numerals and detailed description of the configuration will be omitted. In FIG. 1, reference numeral 1 is a bi-directional unit, 11a and 11b are diaphragm supports, 12a and 12b are diaphragms, 13a and 13b are fixed poles, 14 is an insulating seat, 15 is a damper which is an acoustic resistance material, 16 Denotes an air chamber, 17a and 17b denote diaphragm electrodes, 18a and 18b denote fixed electrodes, and 19 denotes a pressing ring. [0023] The variable capacitor 2 is a two-piece variable capacitor having two variable capacity parts, and includes two movable poles 21a and 21b interlocking with each other, and fixed poles 22a, 23a, 03-05-2019 7 22b and 23b cooperating with the movable poles 21a and 21b. Is equipped. The movable poles 21a and 21b have a common rotation axis, and integrally rotate by rotation of the rotation axis. The movable pole 21a cooperates with the fixed poles 22a and 23a, and when the movable pole 21a rotates, the overlapping areas with the fixed poles 22a and 23a are opposite to each other, that is, the area with one fixed pole is As it becomes larger, the area with the other fixed pole is configured to be smaller. Therefore, when the capacitance of the capacitor formed by the movable pole 21a and the fixed pole 22a increases, the capacitance of the capacitor formed by the movable pole 21a and the other fixed pole 23a decreases. The movable pole 21b cooperates with the fixed poles 22b and 23b, and when the movable pole 21b rotates, the overlapping areas with the fixed poles 22b and 23b are opposite to each other, that is, the area with one fixed pole is As it becomes larger, the area with the other fixed pole is configured to be smaller. Therefore, when the capacitance of the capacitor formed by the movable pole 21b and the fixed pole 22b increases, the capacitance of the capacitor formed by the movable pole 21b and the other fixed pole 23b decreases. The movable poles 21a and 21b constituting one variable capacitance portion and the other variable capacitance portion are set to have the same phase relationship, and one fixed pole 22a and the other fixed pole 23a, and one fixed pole 22b and the other fixed pole 23b. Are also set to the same phase relationship. [0024] In FIG. 1, the diaphragm electrode 17a is grounded, and the other diaphragm electrode 17b is connected to the fixed pole 23a constituting one variable capacitance portion of the variable capacitor 2 and the fixed pole 22b constituting the other variable capacitance portion . Further, the fixed electrode 18a and the movable electrode 21a constituting one variable capacitance portion of the variable capacitor 2 are connected to the impedance converter P, and the other fixed electrode 18b is a fixed electrode constituting one variable capacitance portion of the variable capacitor 2. It is connected to the fixed electrode 23b which comprises 22a and the other variable capacity part. The movable pole 21b constituting the other variable capacitance portion of the variable capacitor 2 is grounded. [0025] The change in directivity of the bi-directional unit 1 due to the facing pattern of the movable pole 21 of the variable capacitor 2 and the fixed poles 22 and 23 will be described with reference to FIG. FIG. 2A shows a state in which the movable pole 21a is opposed to the fixed pole 22a, and the movable pole 21b is opposed to the fixed pole 22b. Thus, when the variable capacitor 2 is adjusted, the diaphragm 12b connected to the electrode 17b of the unit A is grounded via the 03-05-2019 8 variable capacitor 2, and the fixed electrode 13b connected to the electrode 18b is connected via the variable capacitor 2 It will be connected to the impedance converter P. That is, since each polarity of the unit A and the unit B is the same, the bi-directional unit 1 as a whole becomes omnidirectional. [0026] Moving the movable poles 21a and 21b gradually narrows the area facing the fixed poles 22a and 22b, and gradually increases the area facing the fixed poles 23a and 23b, the directivity of the bi-directional unit 1 gradually In the changing state, i.e. in the state of FIG. 2 (b), the bidirectional unit 1 is somewhat uni-directional. Further, in the state of FIG. 2C, since the polarities of the diaphragm 12b and the fixed pole 13b of the unit B are the same and opposite in polarity, the electrical output from the unit B is offset and the impedance converter P is canceled. Since it is not input, only the output of the unit A is input to the impedance converter P, which is unidirectional. [0027] Furthermore, when the movable pole 21a and the movable pole 21b are moved to make the facing area of the fixed pole 22b and the fixed pole 23b larger than the facing area of the fixed pole 22a and the fixed pole 23a, the bi-directional unit 1 Through directivity (the state of FIG. 2 (d)), bi-directional (FIG. 2 (e)) is obtained. [0028] As described above, the output level of the rear side unit is changed by connecting a variable capacity capacitor to the output terminal of the rear side unit of the bi-directional electret condenser microphone constituted by the unidirectional electret condenser microphone and changing the capacitance. Since the polarity can be changed, a variable directional condenser microphone unit can be obtained. [0029] The variable directional capacitor microphone unit according to the embodiment described above can constitute a variable directional capacitor microphone by incorporating it into a microphone case. [0030] 03-05-2019 9 It is an explanatory view showing an example of a variable directivity electret condenser microphone unit concerning the present invention. It is explanatory drawing which showed the directivity according to the state of a variable capacity capacitor in the variable directivity electret capacitor microphone unit which concerns on this invention. FIG. 6 is a longitudinal sectional view showing an embodiment of a conventional bi-directional condenser microphone unit. It is explanatory drawing which shows the example of the structure which can vary directivity using the conventional bi-directional capacitor ¦ condenser microphone unit which applies a polarization ¦ polarized-light voltage. It is explanatory drawing which shows the example of the conventional structure which can change directivity using the bi-directional capacitor ¦ condenser microphone unit which used the electret for the diaphragm. Explanation of sign [0031] DESCRIPTION OF SYMBOLS 1 Bi-directional capacitor microphone unit 2 Variable capacity capacitor 3 DC-DC converter 10 Presser ring 11 Diaphragm support 12 Diaphragm 13 Fixed pole 14 Insulating seat 15 Damper 16 Back air chamber 17 Diaphragm electrode 18 Fixed pole electrode 21 Variable capacity Movable pole of capacitor 22 Fixed pole of variable capacitor 23 Fixed pole of variable capacitor 03-05-2019 10
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