JP2000312253A - Earphone cord device with microphone, audible noise suppressing method and phs terminal or cellular telephone terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress audible and continuous noise to be characteristically generated to the other side of communication by attaching a noise filter with an attenuation effect in carrier frequency to an earphone cord device to be utilized as an exterior device. SOLUTION: The earphone cord device 7 with microphone to be used as the exterior device via a connection plug 2 in an earphone cord connection terminal 9 with microphone of a PHS or a cellular telephone terminal 1 is electrically connected with a microphone 5. The device 7 is provided with an earphone 4, a cord 3, the connection plug 2 and the noise filter 6 attached in the vicinity or the inside of the connection plug 2. Cut off frequencies, for example, 100 Hz, 20 kHz, 10 MHz, 100 MHz are created for the cases that all are LC filters and attached as the noise filter 6. The noise is not heard in all cases when the similar confirmation is performed by attaching various noise filters 6 to the earphone cord device 7 with microphone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hands-free device for a PHS or a portable telephone, and more particularly to a device and a method for suppressing audible noise of a communication partner.

[0002]

2. Description of the Related Art Hand-free devices are sometimes used in PHS and mobile phones for the purpose of ensuring safety during telephone calls during driving or walking. This hands-free device usually includes a connector jack, which is a connection plug with a terminal, a cord electrically connected thereto, and a microphone and earphone electrically connected to the cord.
Needless to say, the electric signals handled by the earphone cord device with a microphone are signals in the audible frequency band, and usually do not superimpose other signals.

[0005] However, a new problem has been pointed out that when this device is connected to a terminal and a call is made, the other party of the call becomes audible and continuous noise is mixed.
Explaining this noise anew, it is not transient noise such as electromagnetic noise, lightning noise or illegal radio waves generated by the motor. Moreover, this noise is characteristic when this device is mounted on a terminal.

[0004] This phenomenon is considered to be inherently deeply involved in the form of signal processing and radio wave transmission / reception characteristic of mobile phones and PHSs, and it is considered that countermeasures are not easy. Therefore, the invention of an effective countermeasure device has been awaited. Furthermore, from the viewpoint of portable equipment, it is desirable that this device is lightweight, inexpensive and easy to handle.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a PHS or portable telephone terminal or an earphone cord device with a microphone used externally to the terminal, which is characteristically generated by a communication partner. It is an object of the present invention to provide a method for suppressing continuity noise by making it audible or a device having the function.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have conceived of an earphone cord device with a microphone whose configuration has been significantly improved.
That is, the first invention of the present application is an earphone cord device with a microphone, which is configured by attaching a noise filter having an attenuation effect at a carrier frequency to an earphone cord device with a microphone used as an external device of a PHS terminal or a mobile phone terminal. It is.

The most characteristic feature of the present invention resides in that a device for exclusively handling an audio signal is provided with a noise filter having a carrier frequency of 100,000 times or more of the signal. Moreover, this noise is characteristically generated when the earphone cord device with a microphone is attached to a PHS or a mobile phone terminal.
Noise perceived by the other party of the call.

Further, the second invention of the present application has a microphone, an earphone, a cord, and a connection plug, and is used as an external device for a PHS terminal or a portable telephone terminal. An earphone cord device with a microphone for the purpose of having a means for suppressing continuity noise by making the other party audible, the means having an electric frequency of a frequency much higher than the audible frequency. An earphone cord device with a microphone configured to be equipped with a noise filter that attenuates a target signal or electrical noise.

The gist of the present invention is an unprecedented idea of suppressing the audible noise of a caller and the other party by installing a high-frequency filter having an unnecessary frequency which is irrelevant to a device which exclusively handles audio signals. Device.

In the present invention, the frequency extremely higher than the audible frequency is at least 20 KHz or more, or may be 10 MHz or more, or may be 100 MHz or more to make the features of the invention clearer. In order to obtain the clearest, the carrier frequency of the PHS or the mobile phone, for example, about 800 for a mobile phone,
It is about 1.8 GHz in the case of MHz or PHS.

As a result, it cannot be said that there is no case where general external noise is also removed, but the characteristic of the present invention is that the effect of the present invention is exerted on general external noise. It occurs only when using a PHS or mobile phone terminal with the earphone cord with microphone attached, and the noise is mainly detected only by the other party, in which case the other party's phone It can be used for any kind of noise.

One of the beneficial and important features of the present invention is that this noise countermeasure can be made only by changing the structure of a part of the earphone cord device with a microphone, not of the other party, but of the other party.

The third invention of the present application specifies the noise filter according to the first or second invention as a low-pass filter substantially comprising an inductance element and a capacitance element. This low-pass filter is, for example, π
Type, T type, constant K type, distributed constant type and self-resonant type filters.

In a fourth aspect of the present invention, the noise filter according to the first or second aspect is specified as an impedance element substantially using soft ferrite. Needless to say, this impedance element may be a single-layer type or a chip bead array. In this case, a compact earphone cord device with a microphone is provided.

The fifth invention of the present application shows the most desirable mounting position of the noise filter according to any one of the first to fourth inventions, that is, a PHS terminal or a portable telephone terminal and an external earphone with a microphone. The earphone cord device with a microphone is provided with a connection plug (connector jack) for connecting to the cord device or a noise filter attached near the connection plug.

Further, the sixth invention of the present application provides a PHS terminal by attaching a noise filter having an attenuation effect at a carrier frequency to an earphone cord device with a microphone used as an external device of a PHS terminal or a portable telephone terminal. Alternatively, it is a method of suppressing audible noise in the other party of the call using the mobile phone terminal.

The most novel and characteristic features of the present invention are:
The point that the noise countermeasure side and the victim side are different and the countermeasure method is that the carrier frequency noise filter is installed not in the transmission system but in the earphone cord device with microphone that handles audio frequency exclusively. At one point. It goes without saying that the other party of the call, that is, the communication means on the victim side does not matter whether it is a PHS, a mobile phone, a general wired phone, or the like.

According to a seventh aspect of the present invention, an upstream audio signal and a downstream audio signal are transmitted from a connection terminal for connecting a PHS terminal or a portable telephone terminal and an earphone cord device with a microphone used as an external device to the terminal. A noise filter that is substantially ineffective at the audio frequency and has an impedance | Z | of 5Ω or more at the carrier frequency of the terminal is inserted at any position of the electric circuit portion up to the branch point of the terminal. A PHS terminal or a mobile phone terminal that suppresses voice noise of the other party of the call.

The present invention is an application of the principles of the first to sixth aspects to an internal circuit of a terminal of a PHS or a mobile phone. It is no different from attaching a filter. Further, it goes without saying that the effect of the present invention can be achieved only when the terminal is equipped with an earphone cord device with a microphone.

In the present invention, the noise filter substantially ineffective at the audio frequency refers to, for example, an LPF whose pass band is the audio frequency, or an impedance element whose impedance at the audio frequency is 1Ω or less, for example. The carrier frequency is, for example, about 1.9 G in PHS.
Hz, and the impedance at this frequency is 5Ω.
Above, obviously, the effect of suppressing noise at the other party of the call is exhibited.

In a PHS terminal or a portable telephone terminal, a carrier of a transmission signal and a carrier of a reception signal are temporally separated in communication. The separation period of a so-called burst signal is 400 Hz, 200 Hz, or the like. Each of these burst signals does not become an audible sound because each has a carrier frequency. As a result, it is guided to an external earphone cord device with a microphone, and is mixed with the original audio signal. However, it will not be audible at this stage.

However, once the burst signal mixed with the audio signal passes through the semiconductor, it is detected and becomes an audible frequency component in burst units, so that it is no longer possible to discriminate and separate the audio signal from the audio signal. The voice signal including the noise thus generated is perceived as audible noise when demodulated by the other party of the call.

As a method for suppressing such noise, it is impossible to sacrifice the communication itself, so that no countermeasures can be taken for the transmission / reception system, and it is difficult to separate the noise components after they have been mixed. It is impossible to take countermeasures. Also, it is not realistic to prevent a voice-to-electric converter such as an earphone device with a microphone from receiving the induction of a burst signal.

Therefore, even if a burst signal is induced, if this signal is removed by a noise filter before being detected, it will not be converted into audible noise, so that the method of the present invention is most effective. It is. Therefore, this noise filter may be a noise filter having any frequency characteristics as long as it is effective at the carrier frequency, as long as the signal at the audio frequency is not adversely affected.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments The details of the present invention will be described below based on embodiments. FIG. 1 is an explanatory diagram relating to an earphone cord device with a microphone according to the present invention. However, since they are not drawn realistically, the size and shape of each part may be different. PHS or mobile phone terminal (1)
The earphone cord device with microphone (7) used externally via the connection plug (2) at the earphone cord connection terminal (9) with microphone is composed of an electrically connected microphone (5), earphone (4) and cord. (3), a connection plug (2), and a noise filter (6) mounted near or inside the connection plug (2).

This earphone cord device with microphone (7)
The cord (3) is composed of a pair of two wires leading to the microphone (5) via the connection plug (2) and a pair of two wires leading to the earphone (4) via the connection plug (2). Become.

The noise filter (6) has a cutoff frequency of 100 Hz, 20 KHz, 10 MHz, 100 MH
Each of z was prepared and attached when it was an LC filter. Separately, a filter using various impedance elements was prepared as the noise filter (6). These impedance elements have a maximum impedance frequency of about 10 MHz, 40 MHz, and 100 MHz.
z, 1 GHz and 2 GHz, all using soft ferrite. As a comparative example, a conventional earphone cord device with a microphone (7) not equipped with only the noise filter (6) was prepared.

(Embodiment 1) An earphone cord device with a microphone (7) without a noise filter (6) is mounted on a PHS.
When connected to the terminal (1) and talking with the other PHS terminal (10), the other PHS terminal (10) has a continuity noise of a constant pitch (hereinafter referred to as noise A) independently of conversation. ) Was heard. Call the other party to the mobile phone terminal (1
0) and the other party of the call is a general telephone (10)
Also, the situation of the noise A was exactly the same as that of the PHS terminal (10).

When various noise filters (6) were attached to the above-described earphone cord device with microphone (7) and the same confirmation was performed, the cutoff frequency was 100H.
Conversations were difficult to hear about the one using the LC filter of z and there was no practicality. Cutoff frequency is 2
When the LC filter of 0 KHz or more was attached, the noise A was attenuated to an inaudible level in all cases.

(Embodiment 2) Only the LC filter part is changed to an impedance element, and the others are described in Embodiment 1.
As a result, the noise A was attenuated to an inaudible level in all cases where the earphone cord device with microphone (7) equipped with an impedance element was used. However, when the level of the noise A is electrically measured, the higher the frequency at which the impedance of the used impedance element is maximized, the more the level of the noise A is attenuated. It was approximately proportional to the magnitude of the impedance at 8 GHz.

(Embodiment 3) The PHS terminal (1) of the transmitting method in Embodiments 1 and 2 is replaced by a portable telephone terminal (1).
As a result, almost the same results as in Examples 1 and 2 were obtained. Results in Examples 1 and 2 and Example 3
The differences from the results of the above are as follows. The noise of a continuity of a constant pitch, which was heard by the other party of the call, irrespective of the conversation, was noise of a lower pitch than noise A (hereinafter referred to as noise B). The noise B is smaller than the noise A. The effect of mounting the noise filter (6) showed a different tendency from that of Example 2 when the noise filter (6) was an impedance element. That is, although the noise B is attenuated so as to be inaudible, the level of the noise B is measured electrically, and when the frequency at which the impedance of the used impedance element becomes maximum is about 1 GHz, the noise B is reduced. Was the most attenuated, and the amount of attenuation was approximately proportional to the magnitude of the impedance value of the used impedance element at 0.8 GHz.

(Embodiment 4) The impedance element in the embodiment 2 is an impedance element having a maximum impedance of about 2 GHz, the transmitting method is a PHS terminal (1), and the mounting position of the impedance element is as follows. When various changes were confirmed, the closer the impedance element was to the microphone-equipped earphone cord connection terminal (9), the more the noise A of the reception method (10) by a general telephone was.
Had a great damping effect.

(Embodiment 5) It was also confirmed that the same effect as in Embodiment 4 had the maximum effect even when an impedance element was mounted inside the PHS terminal (1). Here, the inside of the PHS terminal (1) refers to any position of a circuit portion from the earphone cord connection terminal with microphone (9) to a branch point between the upstream audio signal and the downstream audio signal. The same effect was confirmed even at the position. When the impedance at 1.9 GHz of the impedance element was 5Ω or more, the effect of attenuating the noise A could be confirmed in a practical sense.

[0034]

As described above in detail, according to the present invention, there is provided a PHS or a portable telephone terminal or an earphone cord device with a microphone used externally to the terminal, wherein an audible characteristic characteristically generated at the other party of the call is provided. Thus, it has become possible to provide a method for suppressing continuity noise or a device having the function.

[Brief description of the drawings]

FIG. 1 is a perspective view according to an embodiment of the present invention.

[Explanation of symbols]

1 PHS or mobile phone terminal, 2 connection plug, 3 cord, 4 earphone, 5 microphone, 6 noise filter, 7 earphone cord device with microphone, 9 earphone cord connection terminal with microphone, 10 receiving terminal (PHS, mobile phone) Phone or landline phone)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Katsuhiro Okada, Inventor Katsuhiro Okada 2-1-2, Marunouchi, Chiyoda-ku, Tokyo Within Hitachi Metals Co., Ltd. (72) Inventor Yasuo Tani 70-2, Minamisakaemachi, Tottori-shi F-term (reference) in the Tottori Plant of the formula company 5D005 BB16 5K027 AA11 BB07 DD18 HH03 KK07

Claims (7)

[Claims] An earphone cord device with a microphone, wherein a noise filter having an attenuation effect at a carrier frequency is attached to an earphone cord device with a microphone used as an external device of a PHS terminal or a mobile phone terminal. 2. A microphone which has a microphone, an earphone, a cord, and a connection plug, is used as an external device for a PHS terminal or a mobile phone terminal, and substantially only for transmitting and receiving an audible frequency electric signal. An earphone cord device, wherein the microphone-equipped earphone cord device has means for suppressing the continuity noise by making the other party audible, and the means comprises an electric signal or an electric noise having a frequency much higher than an audible frequency. An earphone cord device with a microphone, which is equipped with a noise filter that attenuates noise. 3. The earphone cord device with a microphone according to claim 1, wherein the noise filter is a low-pass filter substantially including an inductance element and a capacitance element. 4. The earphone cord device with a microphone according to claim 1, wherein the noise filter is an impedance element substantially using soft ferrite. 5. A connection plug for connecting a PHS terminal or a mobile phone terminal to an external earphone cord device with a microphone, or a noise filter mounted near the connection plug. Item 5. An earphone cord device with a microphone according to any one of Items 4. 6. A PHS terminal or a mobile phone terminal by attaching a noise filter having an attenuating effect at a carrier frequency to an earphone cord device with a microphone used as an external device of the PHS terminal or the mobile phone terminal. A method for suppressing audible noise, which comprises suppressing audible noise at the other end of a call using a telephone. 7. A connection terminal for connecting a PHS terminal or a mobile phone terminal and an earphone cord device with a microphone used as an external device to the terminal, to a branch point between an upstream audio signal and a downstream audio signal. A noise counterpart which is substantially ineffective at the voice frequency and has an impedance | Z | A PHS terminal or a mobile phone terminal characterized by suppressing voice noise.