JP2000354284A - Transmitter-receiver using transmission/reception integrated electro-acoustic transducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably switch transmission and reception even if noise is large by turning a transmission amplifier circuit to an operation mode when the output level of a bone conduction microphone exceeds the output level of an air conduction microphone. SOLUTION: A bone/air output synthesis amplifier 35 synthesizes the amplified output of a bone conduction microphone amplifier 33 and the amplified output of an air conduction microphone amplifier 34. A bone/air output comparison decision amplifier 36 outputs judgment output when the output level of the bone conduction microphone amplifier 33 exceeds the output level of the air conduction microphone amplifier 34, and the decision output is outputted as a transmission control output by a control circuit 38. The amplified output of the air conduction microphone amplifier 34 is made a reference (threshold level) and the difference output of the amplified output of the bone conduction microphone amplifier 33 relative to the reference is taken out. By setting the threshold level, the threshold level corresponding to the output of the air conduction microphone 32 is controlled regardless of the level of the noise and the transmission operation mode of this transmitter-receiver is stably and accurately controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission / reception apparatus, and more particularly to a transmission / reception apparatus using a transmission / reception integrated electro-acoustic transducer in which a microphone and an earphone are integrated.

[0002]

2. Description of the Related Art Conventionally, in a transmission and reception switching circuit (VOX: Voice Operating Xchange) in a transmission and reception apparatus,
In order to automatically control the transmitter / receiver to the transmission operation mode,
When the output level of the air-conducting microphone exceeds a certain level (threshold level), a control signal for setting the transmission / reception device to the transmission operation mode is issued, and the transmission / reception device is set to the transmission operation mode by this control signal.

FIG. 5 is a block diagram for explaining creation of a transmission / reception switching control signal in a conventional transmission / reception device. Reference numeral 21 denotes an air-conducting microphone, and 22 denotes a microphone for amplifying an output from the air-conducting microphone 21. An amplifier 23 is a threshold determination amplifier that outputs a determination output when the output level from the microphone amplifier 22 exceeds a certain threshold level, and 24 is a transmission output amplifier that amplifies the output from the microphone amplifier 22 and outputs it as a transmission output. , 25 are transmission control circuits for outputting the judgment output from the threshold judgment amplifier 23 as a transmission control output.

FIG. 6 is a block diagram showing an example of a transmission / reception switching circuit in a conventional transmission / reception apparatus.
Reference numeral 26 denotes a transmission amplifier which amplifies a transmission output as obtained from the transmission output amplifier 24 of FIG. 5 and sends the amplified output to a transmission line 29 via a hybrid circuit 28;
8 is a receiving amplifier for amplifying a reception input from the transmission path 29 input via the transmission line 8 and transmitting the amplified input to a receiver such as an earphone.

[0005]

In a transmission / reception apparatus using such an integrated transmission / reception electro-acoustic transducer, when the noise level is low, as shown in FIG. Although a sufficiently stable determination level (threshold level) can be secured for the output, the period during which the voice is present can be correctly determined. However, as shown in FIG. When the level is exceeded or the level is almost the same as the audio level, FIG.
If the fixed threshold level is the same as the threshold level specified when the noise level is low as shown in (a), the noise level will exceed this fixed threshold level, and the sound will not Cannot be detected correctly. Therefore, when the noise level is high, the conventional VOX cannot be used.

On the other hand, as an integrated transmission and reception electro-acoustic transducer,
In recent years, a transmission / reception integrated electroacoustic transducer of a bone conduction / air conduction composite type having a function of combining and outputting both detection outputs of bone conduction voice and air conduction voice has been used. Generally, when a person speaks,
Since vocal cord vibrations and air vibrations in the oral cavity and nasal cavity are transmitted as bone-conducted sound to the external auditory canal wall, if a vibration pickup is pressed against the external auditory canal wall, vibrations associated with utterance can be detected as audio signals. This is a bone conduction microphone. In addition, since the acoustic wave accompanying the utterance is emitted from the mouth into the air, the air-conducted sound can be detected as an audio signal by placing a microphone near the ear.
This is called an air conduction microphone.

FIG. 8 shows a specific structure of a transmission / reception integrated electroacoustic transducer using a bone conduction ear microphone as an example of a bone transmission / reception integrated electroacoustic transducer proposed by the present inventors. FIG. 1 is a side view including a cross section showing an example [refer to Japanese Patent Application No. 9-366260 “Transmission / reception integrated electro-acoustic transducer using a bone conduction ear microphone”). In FIG. 8, 1 is a receiver used as an earphone, 2 is an air-conducting microphone for converting audio frequency vibration in the air into an electric signal, 3 is a bone conduction vibration pickup sensor that operates as a bone conduction ear microphone, and 4, 5 are Housing A (outer body) of ABS resin or the like, housings B and 6 are receiver-side damper holders (second damper holder) of ABS resin or the like, 7 is a bone-side damper holder (first damper holder) of ABS resin or the like, and 8 is ABS Mount holder for resin, 9
Is a mount (insert), 10 is an elastic member such as rubber having a function as an acoustic damper, 11 is a filter such as acetate fiber, 12 is a sound conduit made of silicon rubber or the like acoustically coupled to the receiver 1, and 13 is a wiring Substrate, 14 is a receiver spacer made of silicon rubber or the like, 15 is microphone packing made of silicon rubber or the like, 16 is a filter protector made of stainless steel or the like, 17 is a code sleeve made of PVC or the like,
Reference numeral 8 denotes a 6-core shielded cord. 19 is a stopper. With such a configuration, it has a function as an integrated transmission / reception electro-acoustic transducer including the earphone receiver 1, the air conduction microphone 2, and the bone conduction ear microphone 3.

[0008] A transmission / reception device using such a bone-conducted air-conducting combined transmission / reception integrated electro-acoustic transducer has not been widely used yet. In a transmission / reception device using an acoustic transducer, a technical configuration for stably performing transmission / reception switching even when noise is large has not been proposed yet.

[0009] The present invention relates to an integrated transmission / reception electroacoustic transducer of a bone conduction / conduction combined type which uses an integrated transmission / reception electroacoustic transducer so that transmission / reception switching can be performed stably even when noise is large. The present invention provides a transmission / reception device using a telephone.

[0010]

In order to solve this problem, a transmitting and receiving apparatus using the integrated transmitting and receiving electro-acoustic transducer according to the present invention comprises a bone-conducting microphone for picking up vibration transmitted through the wall of the external auditory canal, and an air-permeable microphone. An integrated transmission / reception electro-acoustic transducer in which an earphone is added to a composite microphone including an air conduction microphone that picks up transmitted vibration, and an amplifying signal of the output of the air conduction microphone and the output of the bone conduction microphone A transmission amplification circuit for transmitting the transmission signal to the transmission line, a reception amplification circuit for amplifying the reception signal from the transmission line and transmitting the signal to the earphone, and operating the transmission amplification circuit or the reception amplification circuit. A transmission / reception switching control circuit for outputting a transmission / reception switching control signal for causing the bone conduction microphone to output a signal during the utterance. The output level of the bone conduction microphone is set to be lower than the output level of the air conduction microphone when the output level is higher than the output level of the microphone and the loud noise is not occurring. The circuit includes a comparison circuit that outputs the transmission / reception switching control signal that causes the transmission amplification circuit to enter an operation mode when the output level of the bone conduction microphone exceeds the output level of the air conduction microphone. Have. A reception signal detection circuit that outputs a reception signal detection signal when a reception signal transmitted from the transmission path to the earphone is detected; and the transmission / reception switching control circuit from the transmission / reception switching control circuit based on the reception signal detection signal. And a signal blocking circuit for blocking transmission of the talk-receive switch control signal.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A transmission / reception apparatus using an integrated transmission / reception electro-acoustic transducer according to the present invention uses an output signal of a bone-conducting microphone which detects and outputs only vibration of the ear canal wall, which is less affected by noise. It has a configuration characterized by controlling transmission / reception switching of the communication device. Further, in the present invention, the levels of the output of the bone conduction microphone amplifier and the output of the air conduction microphone amplifier are set as shown in Table 1. In such a setting, when there is high-level noise similar to that of a normal utterance, and when there is no utterance and there is only noise, the noise output of the air-conducting microphone is the same as the voice output for a normal utterance (−10 to -20) The output is about dBm, while the noise output of the bone conduction microphone is (-20 to -40) d when the sound output for normal utterance is about (0) dBm.
Bm. That is, when uttered, the output of the bone conduction microphone (about (0) dBm) is greater than the output of the air conduction microphone (about (−10 to −20) dBm), while the noise output is the output of the bone conduction microphone [(−−). 20-
40) dBm] is the output of the air conducting microphone [(-1
0 to -20) dBm], so that the output of the bone conduction microphone and the output of the air conduction microphone can be effectively compared. Also, when uttered, the sound output of the air-conducting microphone is (-1) of the same level as the noise output when there is no utterance.
The sound output of the bone-conducting microphone is set to be higher than the noise output of the air-conducting microphone by about (20 to 40) dB when no speech is made.

[0012]

[Table 1]

Next, according to the present invention, if the output level of the bone conduction microphone exceeds the output level of the air conduction microphone,
The operation level of the comparator is set as shown in the following Table 2 so that a comparison judgment output is output.

[0014]

[Table 2]

According to the present invention, the output level of the bone-conducting microphone is compared with the output level of the air-conducting microphone by comparing the output level of the bone-conducting microphone with the output level of the air-conducting microphone, as shown in Table 2. The threshold level for detecting the output level of the bone-conducting microphone is actively changed by making the comparison judgment output appear if the output level of the air-conducting microphone is exceeded, and there is a loud noise or wind noise. Even in the case of performing, it is possible to stably and correctly determine whether or not there is a voice as in the states (3), (4), (5), and (6).

[0016]

(Embodiment 1) FIG. 1 is a block diagram for explaining an example of generation of a transmission / reception switching control signal in a transmission / reception apparatus using a transmission / reception integrated electro-acoustic transducer according to the present invention. Is a bone conduction microphone, 32 is an air conduction microphone, 33 is a bone conduction microphone amplifier that amplifies the output from the bone conduction microphone, 34 is an air conduction microphone amplifier that amplifies the output from the air conduction microphone 32, and 35 is a bone conduction microphone amplifier A bone air output synthesizing amplifier for synthesizing the amplified output from the air conduction microphone amplifier and the amplified output from the air conduction microphone amplifier, the output level of the bone conduction microphone amplifier exceeds the output level of the air conduction microphone amplifier. And a transmission output amplifier 37 for amplifying the output from the bone energy output synthesizing amplifier 35 and outputting the amplified output as a transmission output. Is a transmission control circuit for outputting a determination output from the bone air output comparison judgment amplifier as a transmission control output. Further, 39 is a receiving amplifier for amplifying the receiving input, 4
Reference numeral 0 denotes an earphone connected to the output side of the receiving amplifier 39.

The input level from the bone conduction microphone amplifier 33 to the bone air output comparison / determination amplifier 36 and the air conduction microphone amplifier 34
And the input level to the bone energy output comparison determination amplifier 36 is
The levels are set as shown in Table 1 above. The transmission output from the transmission output amplifier 37, the transmission control output from the transmission control circuit 38, and the reception input to the reception amplifier 39 correspond to the transmission output and transmission in the transmission / reception device as described with reference to FIG. They correspond to a control output and a reception input, respectively, and are controlled by the transmission control output so that the transmission amplifier or the reception amplifier is set to the operation mode.

FIG. 2 is a block diagram showing an example of the bone air output comparing / determining amplifier 36. Reference numeral 36-1 denotes an input terminal for receiving an amplified output from the bone conduction microphone amplifier 33, and reference numeral 36-2 denotes an air conduction microphone amplifier 34. An input terminal for receiving an amplified output from the bone amplifier 36-3 is an amplified output I from the bone conduction microphone amplifier 33.
And a rectifier 36-4 for rectifying the amplified output I from the air-conducting microphone amplifier 33 and rectifying the amplified output II from the air-conducting microphone amplifier 33 to obtain a DC voltage corresponding to the amplitude of the amplified output I. Commutator to take out, 36-5 is commutator 36-
3, an integration circuit of a charging / discharging time constant that is relatively short (for example, 10 to 100 msec) enough to extract the envelope of the audio wave component from the bone conduction microphone amplifier 33, and 36-6 is a rectifier. A relatively long (for example, 100 msec-1 sec) charge / discharge time constant integrating circuit arranged on the output side of the sub-unit 36-4 for smoothing the noise component from the air-conducting microphone amplifier 34. A differential amplifier having each output of the circuit 36-5 and the integrating circuit 36-6 as a differential input;
Reference numeral 6-8 denotes a charging time constant that is relatively short (for example, 100) so that the voice output from the bone-conducting microphone amplifier 33 is not interrupted by the voice judgment from the differential amplifier 36-7 when the instantaneous level is reduced during vocalization. An integration circuit having a relatively long discharge time constant (for example, about 1 to 3 seconds);
-9 is an output terminal of the differential amplifier 36-7. The differential output of the amplified output from the bone conduction microphone amplifier 33 with respect to the threshold level is taken out from the output terminal 36-8 with reference to the amplified output from the air conduction microphone amplifier 34 (threshold level).

The circuit configuration is as shown in FIGS. 1 and 2,
By setting the threshold level of the bone energy output comparison / decision amplifier as shown in Table 2, the transmission / reception apparatus using the integrated transmission / reception electro-acoustic transducer according to the present invention has the following advantages.
The threshold level corresponding to the output from the air-conducting micron 32 when there is no utterance is adaptively adjusted in both the case of the low noise shown in (a) and the case of the high noise shown in FIG. 3 (b). By being controlled, stable and correct voice determination is always performed, and the transmission operation mode of the transmission / reception device can be controlled stably and accurately.

(Embodiment 2) The bone conduction microphone 31 and the air conduction microphone 32 are integrated with the earphone 40. In particular, the bone conduction microphone 31 easily picks up the sound emitted from the earphone 40 as a mechanical drive. When a signal is input to the earphone 40, the vibration of the earphone 40 is coupled to the bone-conducting microphone 31, and is output as a signal output to the output side of the bone-conducting microphone 31. When there is an output from the bone conduction microphone 31, the bone energy output comparison determination amplifier 36 determines that there is voice, and switches the transmission / reception switching circuit of the communication device to the transmission operation mode. In other words, the transmission / reception switching circuit may switch to the transmission operation mode even during the reception, and the reception may not be heard.
In order to eliminate this drawback, it is desirable that the transmission / reception switching circuit does not perform control to switch to the transmission operation mode when a reception signal is detected so that the transmission operation mode is not set during reception.

FIG. 4 is a block diagram for explaining another example of generation of a transmission / reception switching control signal in a transmission / reception apparatus using the integrated transmission / reception electro-acoustic transducer according to the present invention. This is the same as the corresponding circuit of the same reference numeral in the first embodiment shown in FIG. In the second embodiment, a reception signal detection circuit 41 that outputs a reception signal detection signal when a reception signal from a transmission path transmitted to the earphone 40 is detected, in addition to the individual circuits 31 to 40 of the first embodiment, A signal blocking circuit 42 for blocking transmission of the transmission / reception switching control signal from the transmission / reception switching control circuit 38 based on the reception signal detection signal is further provided. When there is a reception input, a reception sound is output from the earphone 40 through the reception amplifier 39, the reception input is input to the reception signal detection circuit 41, and a signal indicating the reception signal is output from the reception signal detection circuit 41. The signal with the reception signal of the reception signal detection circuit 41 is sent to the bone air output comparison / determination amplifier 36 and the transmission control circuit 38.
During this period, the output of the bone air output comparison / judgment amplifier 36 which is input to the signal blocking circuit 42 is blocked so that the output of the bone air output comparison / determination amplifier 36 is not input to the transmission control circuit 38. The output of the bone energy output comparison / judgment amplifier is a signal blocking circuit 4
2, the transmission control circuit 38 cannot transmit the transmission control output for controlling the transmission / reception device to the transmission operation mode. When the reception signal detection circuit 41 detects the presence of the reception, the transmission control circuit 38 does not operate, and the transmission / reception device is not controlled to the transmission operation mode.

[0022]

As described above in detail, according to the present invention, transmission / reception switching can be performed stably even when noise is large, using the integrated transmission / reception electro-acoustic transducer.
When the transmission / reception device receives a reception input, the transmission / reception device is set to the transmission operation mode, and a malfunction in which reception cannot be performed can be effectively prevented. Therefore, for example, when the present invention is applied to a transmission / reception device used in an environment with a high noise level such as a mobile phone, its use effect is extremely large.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining an example of generating a transmission / reception switching control signal in a transmission / reception device using an integrated transmission / reception electro-acoustic transducer according to the present invention.

FIG. 2 is a circuit diagram showing an example of a configuration of a bone energy output comparison / determination amplifier in FIG. 1;

FIG. 3 is a characteristic diagram for explaining the operation of the bone air output comparison / judgment amplifier used in FIG. 2 when the noise is low (a) and when the noise is high (b).

FIG. 4 is a block diagram for explaining another example of generation of the transmission / reception switching control signal in the transmission / reception device using the integrated transmission / reception electro-acoustic transducer according to the present invention.

FIG. 5 is a block diagram for explaining an example of generating a transmission / reception switching control signal in a conventional transmission / reception device.

FIG. 6 is a block diagram for describing transmission / reception switching control in the transmission / reception device.

FIG. 7 is a characteristic diagram for explaining the operation of the threshold determination amplifier used in FIG. 5 when the noise is low (a) and when the noise is high (b).

FIG. 8 is a side view including a cross section showing an example of an integrated transmission / reception electro-acoustic transducer used in the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 receiver 2 air conduction microphone 3 bone conduction microphone 4 housing A 5 housing B 6,7 damper holder 8 mount holder 9 mount 10 elastic member 11 filter 12 sound conduit 13 wiring board 14 receiver spacer 15 microphone packing 16 filter protector 17 cord Sleeve 18 6-core cord 19 Stopper 21 Air conduction microphone 22 Microphone amplifier 23 Threshold judgment amplifier 24 Transmission output amplifier 25 Transmission control circuit 26 Transmission amplifier 27 Receiver amplifier 28 Hybrid circuit 29 Transmission path 31 Bone conduction microphone 32 Air conduction microphone 33 Bone conduction Microphone amplifier 34 Air conduction microphone amplifier 35 Bone air output synthesis amplifier 36 Bone air output comparison / determination amplifier 36-1, 36-2 Input terminal of bone air output comparison / determination amplifier 36 3, 36-4 Commutator 36-5, 36-6 Integrating circuit 36-7 Differential amplifier 36-8 Integrating circuit 36-9 Output terminal of bone energy output comparison / determination amplifier 37 Transmission output amplifier 38 Transmission control circuit 39 Receiver amplifier 40 earphone 41 reception detection circuit 42 signal rejection circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshimasa Kamoto, Inventor Iwasaki Communication Equipment Co., Ltd., 1-7-141 Kugayama, Suginami-ku, Tokyo (72) Inventor Shigeaki Aoki 192-1 Nishishinjuku, Shinjuku-ku, Tokyo No. Nippon Telegraph and Telephone Corporation (72) Inventor Naoki Ishii 1-3-1 Gotenyama, Musashino City, Tokyo NTT Advanced Technology Corporation F-term (reference) 5D017 BA02 BA03 5D020 BB03 BB08 5K027 BB07 DD08 DD11 DD14 DD18

Claims (2)

[Claims] 1. An integrated transmission / reception electro-acoustic transducer in which an earphone is added to a composite microphone including a bone conduction microphone that picks up vibration transmitted through an ear canal wall and an air conductive microphone that picks up vibration transmitted through air. A transmission amplifier circuit for amplifying a composite signal of an output of the air conduction microphone and an output of the bone conduction microphone and transmitting the signal to a transmission line; and amplifying a reception signal from the transmission line to the earphone. A transmission amplification circuit for transmitting; and a transmission / reception switching control circuit for outputting a transmission / reception switching control signal for setting the transmission amplification circuit or the reception amplifying circuit to an operation mode. The output level of the microphone is higher than the output level of the air-conducting microphone, and the output of the bone-conducting microphone when the speaker is not vocal due to loud noise. The level is set so that the bell is smaller than the output level of the air-conducting microphone, and the transmission / reception switching control circuit is configured to output the signal when the output level of the bone-conducting microphone exceeds the output level of the air-conducting microphone. A transmission / reception device using a transmission / reception integrated electro-acoustic transducer including a comparison circuit for outputting the transmission / reception switching control signal for setting the transmission amplification circuit to the operation mode. A reception signal detection circuit that outputs a reception signal detection signal when a reception signal transmitted from the transmission line to the earphone is detected; and a transmission / reception switch control circuit based on the reception signal detection signal. A transmission / reception apparatus using the integrated transmission / reception electro-acoustic transducer according to claim 1, further comprising a signal blocking circuit for blocking transmission of the transmission / reception switching control signal.