JP4117096B2 - Microphone with induction loop - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a microphone with an induction loop. In particular, the present invention is particularly beneficial when used in combination with a hearing aid in that the clarity of the hearing aid can be increased.
[0002]
[Prior art]
Hearing aids are widely used to supplement the hearing of people with inadequate hearing. However, normal hearing aids do not have reception directivity or frequency selectivity, so if there is a lot of ambient noise or if the conversation partner is some distance away, unnecessary sounds will be amplified and conversation will not be possible. It can be difficult.
[0003]
Various methods for solving this have been proposed. One of them is a method of making a conversation easy to hear by connecting a directional microphone to the external input terminal of the hearing aid with a cable and directing the microphone toward the conversation partner. However, this method does not look good because the hearing aid and the directional microphone are connected by a cable. And the like.
[0004]
The second method is to transmit the other party's conversation sound via a wireless microphone, receive it with a receiver and listen to the demodulated sound with an earphone, or connect a magnetic induction device to the earphone terminal of this receiver In this method, the magnetic guidance device and the hearing aid are inductively coupled to listen to sound. According to this method, there is an advantage that it is not necessary to use a cable connecting the microphone and the hearing aid. On the other hand, since many devices such as a wireless microphone, a magnetic induction device, and an earphone are required, management is troublesome and inconvenient to carry. In addition, there is a drawback that preparation work at the time of use is troublesome.
[0005]
Furthermore, the third method is a method in which an FM receiver is incorporated in the hearing aid and an audio signal is sent from the dedicated wireless microphone. According to this method, it is necessary to purchase a dedicated hearing aid with a built-in FM receiver and a wireless microphone, which is costly and has a drawback that only a person wearing the dedicated hearing aid can receive.
[0006]
The disadvantage of this method is that only cables are considered for the wired one and only radio waves for the wireless one as the interface between the microphone that receives the voice of the speaker and the hearing aid.
[0007]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above problems, and an object of the present invention is to provide a microphone with an induction loop for transmitting an audio signal to a receiving device such as a hearing aid by magnetic field coupling.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention
A microphone element for receiving sound;
An induction loop that is driven by a signal corresponding to the output from the microphone element to generate a magnetic field;
A microphone with an inductive loop, comprising:
I will provide a.
[0009]
In one embodiment of the present invention, the microphone element, an amplifier circuit that amplifies the output of the microphone element, an output coil coupled to the output of the amplifier circuit, and the induction loop magnetically connected to the output coil. Means for coupling to the housing is provided in the housing, and the induction loop is attached to the housing.
[0010]
The output coil and the induction loop can be coupled by, for example, a magnetic core. Moreover, it is desirable that the microphone element and the induction loop are configured to be detachable from the housing.
[0011]
The microphone element preferably has a narrow directivity, for example, a secondary pressure gradient microphone so that only desired sound can be heard.
[0012]
[Action]
The sound received by the microphone element is converted into a corresponding current and then flows through the induction loop. As a result, a magnetic field corresponding to the received voice is generated from the induction loop.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram schematically showing one embodiment of a microphone according to the present invention. In the figure, a microphone 10 includes a housing forming a main body 1 and an induction loop 2 provided at one end of the main body 1. A microphone element 3 that receives sound from a sound source such as a speaker is attached to the other end of the main body 1. A through hole 4 is formed at one end of the main body 10, and the induction loop 3 is attached so as to pass through the through hole 4. The induction loop 2 generates a magnetic field corresponding to sound from a sound source such as a speaker. It is desirable that the induction loop 2 also serves as a hand strap or a neck strap. Moreover, you may comprise the induction loop 2 so that extension is possible.
[0014]
Specifically, as shown in FIG. 2A, the sound input to the microphone element 3 is converted into an electric signal corresponding to the sound by the microphone element 3, and the electric signal is amplified by the amplifier circuit 5. Applied to the output coil 6. As a result, a current corresponding to the sound input to the microphone element 3 flows through the output coil 6. Since the induction loop 2 is magnetically coupled to the output coil 6, a current corresponding to the current flowing through the output coil 6, that is, the current corresponding to the sound input to the microphone element 3 flows through the induction loop 2. As a result, a magnetic field corresponding to the sound input to the microphone element 3 is generated around the induction loop 2.
[0015]
In order to magnetically couple the output coil 6 and the induction loop 2, for example, as shown in FIG. 2B, the output coil 6 is wound around a ring-shaped magnetic core 7 having a through hole at the center. The guide loop 2 may be passed through the through hole of the magnetic core 7 while turning.
[0016]
The magnetic field generated by the induction loop 2 can be received by a receiver including a magnetic field receiving element such as an induction coil. An example of a receiver is a hearing aid carried by a person with insufficient hearing such as an elderly person or a hearing impaired person. In this case, the microphone 10 shown in FIG. 1 is desirably designed to have high sensitivity in a certain direction, such as a unidirectional microphone. In particular, a narrow directional microphone is used as the microphone of the present invention. Is preferred. By designing in this way, the microphone 10 can collect sound with some emphasis on the sound from the sound collection target even if it is separated from the sound collection target that is the sound source or there is a lot of ambient noise. Because.
[0017]
FIG. 2C schematically shows a situation where the microphone 10 of the present invention is used with the hearing aid 20, and the ear-hung type hearing aid 20 includes an induction coil inductively coupled to the induction loop 2. Yes. Thereby, the magnetic field generated by the induction loop 2 is received by the induction coil inside the hearing aid 20 and generates an electromotive force in the induction coil. By amplifying this and converting it into air vibration, the sound from the hearing aid 20 is heard. Played.
[0018]
An example of the narrow directional microphone is a secondary pressure gradient microphone configured as shown in FIG. In this microphone, two unidirectional microphone elements are arranged so as to be separated by a distance d and the front axes of these microphone elements coincide with each other, and the difference between the outputs of the respective microphone elements is used as an output. . The interval d is 40 mm, for example. The secondary pressure gradient microphone has a characteristic that the sensitivity in the lateral direction becomes almost zero, and exhibits a sharp single directivity in the front direction compared to a normal unidirectional microphone.
[0019]
FIG. 4 is a diagram schematically showing another embodiment of the microphone with an induction loop according to the present invention. In this embodiment, the induction loop 2 is separate from the main body 1 and is detachable from the main body 1. In order to realize this, the output coil 6 includes a primary coil 61 connected to the output of the amplifier circuit 5 and a secondary coil 62 that is magnetically coupled to the primary coil. 1 are respectively connected to output terminals 81 and 82 provided at one end. Correspondingly, terminals 21 and 22 that can be attached to and detached from these output terminals 81 and 82 are provided at both ends of the induction loop 2. Specifically, the output terminals 81 and 82 are jacks, and the terminals 21 and 22 of the induction loop 2 are plugs. Thus, by inserting the terminals 21 and 22 of the induction loop 2 into the output terminals 81 and 82, an electrical connection is made between the induction loop 2 and the output coil 6, and the induction loop 2 is connected to the main body 1. It is held mechanically.
[0020]
The primary coil 61 and the secondary coil 62 are not always necessary, and the output of the low frequency amplifier may be directly connected to the output terminals 81 and 82 without using these coils. As described above, the configuration in which the primary coil 61 and the secondary coil 62 are not used has a problem that it is difficult to achieve impedance matching with the induction loop 2 as compared with the case where these coils are used. It is advantageous.
[0021]
Although one embodiment of the microphone with an induction loop according to the present invention has been described above, the present invention is not limited to this, and various modifications can be made. For example,
(1) A variable resistor can be combined with the amplifier circuit 5 so that the output of the microphone 10 can be adjusted.
(2) A switch can be provided so that the directivity of the microphone 10 can be changed in a direction that is easy to hear.
(3) The main body 1 is divided into a first part having the microphone element 3 and a second part having the amplifier circuit 5, the output coil 6 and the induction loop 2, and these parts are used by appropriate means. Thus, the microphone element 3 can be exchanged by allowing it to be detachably connected electrically and mechanically.
[0022]
【The invention's effect】
As described above, the present invention can be received by a receiver having a built-in induction coil that can be magnetically coupled to the induction loop by simply taking it out and directing it toward the sound source when necessary. It is simple and can be used easily even by a person who is unfamiliar or unfamiliar with the use of the device. For example, the location of the pronunciation source, such as when speakers in different places speak one after another There is an extraordinary effect of being able to respond quickly to changes.
[0023]
In particular, when the microphone according to the present invention is used in combination with a hearing aid, it is possible to increase the clarity of the output sound of the hearing aid, so that it becomes possible to hear the necessary sound without being bothered by ambient noise and the like. There is an effect. This effect is particularly noticeable when a microphone element with a narrow directivity is used. For example, when the microphone element is configured as a secondary pressure gradient microphone, the lateral sensitivity is substantially zero and the front direction A microphone having sharp directivity can be provided.
[0024]
In addition, by making the induction loop detachable from the housing, it is only necessary to store the housing and the induction loop separately when not in use, making it easy to carry around, and replacing the microphone element with the microphone housing By making it possible, it is possible to produce an effect that the characteristics of the microphone can be easily changed.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing an embodiment of a microphone according to the present invention.
2A is a diagram for explaining the configuration of the microphone of FIG. 1 using an electric circuit, and FIG. 2B is a configuration example for coupling the output unit of the microphone of FIG. 1 and an induction loop; (C) is a figure which shows the use condition of the microphone of FIG.
FIG. 3 is a diagram for explaining a secondary pressure gradient microphone suitable for the microphone according to the present invention;
FIG. 4 is a diagram schematically showing another embodiment of a microphone according to the present invention.
[Explanation of symbols]
10: microphone, 20: hearing aid, 1: body, 2: induction loop,
3: microphone element, 4: through hole, 5: amplifier circuit, 6: output coil,
7: Magnetic core

Claims (6)

A microphone with an induction loop comprising: a microphone element that receives sound; and an induction loop that is driven by a signal corresponding to an output from the microphone element to generate a magnetic field,
An output coil for receiving the signal;
A magnetic core around which the output coil is wound;
And the induction loop penetrates the magnetic core.   The microphone according to claim 1, wherein the magnetic core has a through hole, and the induction loop passes through the through hole. An amplifier that amplifies the output of the microphone element;
The output coil is coupled to the output of the amplifier;
The microphone according to claim 1 or 2, wherein the induction loop is attached so as to pass through a housing containing the microphone element, the output coil, the amplifier, and the magnetic core.   The microphone according to claim 3, wherein the induction loop is detachable from the housing.   The microphone according to claim 1, wherein the microphone element has a narrow directivity.   The microphone according to claim 5, wherein the microphone element is a secondary pressure gradient microphone.

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