JP2002330226A - Hands-free intercom system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hands-free intercom system by which speaking can be smoothly performed between a visitor and an indoor side user even when there are a lot of noises around a front door handset. SOLUTION: A level detecting circuit detects the level of an audio signal from the front door handset and the level of an audio signal from the indoor side user, and the amplification factor of an amplifier circuit in a base unit is changed so that the audio signals of two systems can be practically equally balanced. When there are a lot of surrounding noises and the level of the audio signal outputted from the front door handset is high, the amplification factor of the amplifier circuit is increased and the speech control switching operation of a hands-free IC 21 is surely performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intercom apparatus capable of communicating with a visitor without the need for an indoor user to pick up a handset of an intercom indoor unit (for example, a base unit). The present invention relates to an improved hands-free intercom system.

[0002]

2. Description of the Related Art For a long time, intercom devices that allow an indoor user to be in a room and communicate with a visitor have been widely used. This is equipped with a microphone and a speaker in the entrance cordless handset,
The base unit is provided with a handset and is connected to the entrance terminal via a transmission line, and in response to a call from the entrance terminal, uses the handset to talk with a visitor existing near the entrance terminal. However, for example, in the case of a house where the entrance slave faces a road with a large amount of traffic and a large amount of noise, or in the case where the noise around the entrance slave is large due to work being performed nearby, etc. There is a problem that both the visitor and the indoor user are difficult to hear the voice.

[0003] In order to solve this problem, there is an intercom apparatus having an entrance unit disclosed in, for example, Japanese Patent No. 2980963. This conventional intercom apparatus will be described with reference to FIG. FIG. 2 showing the preceding example
, The entrance slave unit 100 and the master unit 200 are connected to each other by a transmission line 3 for transmitting a signal therebetween.

The entrance cordless handset 100 picks up a visitor's voice and surrounding noise and converts it into an audio signal. The microphone 4 amplifies the audio signal output from the microphone 4, and the microphone 4 outputs the signal. A noise level detection circuit 6 that detects a volume ratio between a signal component of a visitor's voice and other noise from the voice signal and controls the amplification degree of the amplification circuit 5 based on the volume ratio, and an output of the amplification circuit 5 A modulation circuit 7 modulates the signal at the frequency f1. Further, the entrance cordless handset 100 includes a BPF (bandpass filter) 8 for detecting an audio signal modulated at the frequency f2 input from the master unit 200, a demodulation circuit 9 for extracting an audio signal from an output signal of the BPF 8, and further there. 1 that converts the audio signal output from the device into audio and sends it out to the visitor
0, and a call button 11 for a visitor to call a resident.

[0005] In addition, base unit 200 includes handset 12,
A BPF 13 for detecting an audio signal modulated at the frequency f1 input from the entrance device 100, and a handset 12 for demodulating the audio signal from the modulated signal output therefrom.
A demodulation circuit 14 for outputting a voice signal to the handset 12, and a modulation circuit 15 for modulating a voice signal input by a voice of a speaker speaking to the handset 12 at a frequency f2. Further, base unit 200 outputs a chime generating circuit 16 for notifying the indoor user of the presence of a visitor and a chime sound based on a call signal generated when call button 11 of entrance cordless handset 100 is operated. The speaker 17 is provided.

The operation of the conventional intercom apparatus configured as described above will be described with reference to FIG. First, when a visitor operates the call button 11 of the entrance cordless handset 100, a call signal is generated. Master device 200 detects the calling signal sent from entrance cordless handset 100 via transmission line 3 to operate chime generating circuit 16, and outputs a chime sound through speaker 17 to the room. When the indoor user turns off the handset, the chime generating circuit 16 stops its operation. At the same time, the audio signal input from the microphone 4 of the entrance cordless handset 100 is input to the BPF 13 of the parent device 200 through the amplification circuit 5 and the modulation circuit 7, and the demodulation circuit 14
An audio signal is input to the handset 12 through the speaker, and a voice of the visitor is output from the speaker 17 of the handset 12.

At this time, the noise level detection circuit 6 of the entrance device 100 determines the amplification degree of the amplification circuit 5 according to the level of the surrounding noise as follows. That is, when the sound volume ratio (S / N ratio) between the visitor's voice signal S and the noise N is small,
That is, when the noise is relatively large, the amplification factor of the amplifier circuit 5 is increased, and when the S / N ratio is large and the noise is relatively small, the amplification factor of the amplification circuit 5 is decreased. Thus, even when the noise level around the entrance cordless handset 100 is high, the indoor user has a large S / N ratio of the audio signal from the entrance cordless handset 100 through the handset 12 of the parent device 200 (the noise is small). ) Listening to the visitor's voice at a higher volume than in the case. As a result, the entrance slave 10
The call between the visitor and the indoor user was performed when the noise around the area 0 was loud.

[0008]

On the other hand, there is an intercom apparatus without a handset, called a hands-free intercom apparatus, which has recently become popular. In that device, the indoor user responds to the call of the visitor by operating the call button provided on the base unit or recognizing the response voice of the indoor user such as "Yes". The voice signal is transmitted to the cordless handset to start a call. That is, this is an intercom apparatus that allows the indoor user to talk with the visitor without holding the handset. The hands-free intercom apparatus is provided with a call control IC generally called a known hands-free IC. This hands-free IC controls a telephone call by comparing the levels of two input audio signals and transmitting only the audio signal of the higher audio level to the other party. Of course, in the above conventional example, of the above two systems,
One of the systems is an audio signal from the entrance slave, and the other is an audio signal from the master.

When a visitor utters a sound and a sound signal is input from the entrance slave, the sound is output to the master, but the audio signal from the master is not output to the entrance slave. When the resident emits a sound and a sound signal is input from the master unit, the sound is output to the entrance slave unit, but the sound signal from the entrance slave unit is not output to the master unit.
Since the indoor user and the visitor talk alternately through the intercom, the indoor user and the visitor can smoothly communicate with each other by controlling the hands-free IC.

[0010] However, when the noise around the entrance cordless handset is loud, the sound signal from the entrance cordless handset is amplified according to the level of the noise even if the visitor does not emit a sound, and the level of the sound signal is reduced. Get higher. As a result, if the level of the audio signal is lower than the level of the audio signal from the entrance cordless handset even if the indoor user emits a voice, the voice of the indoor user does not reach the visitor and the response There was a problem that calls could not be made.

In the conventional intercom apparatus, when the noise near the entrance is loud, the audio signal input from the entrance terminal is amplified, and a considerably loud sound is output to the room. Therefore, if there is an infant or sleeping person in the room, there is also a problem that a loud sound is output to the room and the person in the room is annoying.

It is an object of the present invention to provide an improved hands-free intercom apparatus so that a call between a visitor and an indoor user can be smoothly performed even when the noise around the entrance cordless handset is loud. is there. Another object of the present invention is to provide a hands-free intercom apparatus in which a loud voice of a visitor is not output indoors even when the noise around the entrance cordless handset is loud.

[0013]

To solve the above-mentioned conventional problems, a hands-free intercom apparatus according to the present invention comprises:
A front-end handset including at least a microphone for picking up the voice of the visitor and the noise around the visitor, and a speaker for transmitting the sound of the indoor user to the visitor; a microphone for picking up the voice of the indoor user; An amplifying circuit that amplifies an audio signal picked up and input by the microphone, and a master unit including at least a speaker that sends out amplified and reproduced audio of a visitor, and a master unit and the entrance slave unit. A hands-free intercom apparatus having a transmission line for mutually transmitting signals between the main unit and a level measuring circuit for measuring a level of an audio signal input from the entrance terminal, and an output of the level measuring circuit. An amplification degree changing means for changing an amplification degree of the amplification circuit according to a signal is provided.

According to this configuration, the base unit measures the level of the audio signal input from the entrance terminal by the level measurement circuit, and the amplification degree changing means according to the measured level of the audio signal from the entrance terminal. Thereby, the amplification degree of the amplification circuit in the master unit can be changed. As a result, hands-free IC
Thus, the balance between the levels of the audio signals of the two systems to be input to the system can be maintained, and the audio signals can be reliably switched. Further, the level of the audio signal of the master unit output to the entrance slave unit can be changed in accordance with the noise, so that even if the noise is loud, the call with the visitor can be reliably performed.

In the above-described hands-free intercom apparatus, when the input level of the audio signal from the entrance cordless handset is continuously equal to or higher than a predetermined value for a predetermined time, the amplification degree changing means may adjust the amplification degree of the amplification circuit. It is desirable to raise. Since the voice of the visitor does not exceed the specified value continuously for a certain period of time or more, discriminate it from noise, and only when the noise is loud, increase the amplification and talk between the indoor user and the visitor. Can be. Further, after the amplification degree changing means increases the amplification degree of the amplification circuit, the amplification degree is preferably fixed until the communication between the master unit and the entrance slave unit ends. Thereby, since the voice signal of the indoor user during conversation, which is output to the entrance cordless handset, does not change, it is possible to transmit a voice that does not make the visitor feel uncomfortable.

[0016] In a hands-free intercom apparatus according to another aspect of the present invention, the hands-free intercom apparatus having the above-described configuration has display means on the master unit. Then, when the level of the audio signal input from the entrance terminal measured by the level measurement circuit exceeds a predetermined value, the content is displayed on the display means. Accordingly, it is possible to inform the indoor user that the noise around the entrance is too loud, so that the voice of the indoor user will not easily reach the visitor in front of the entrance child device. In the hands-free intercom apparatus having the above configuration, when the master unit has volume control means, and the level of the audio signal input from the entrance slave unit measured by the level measurement circuit exceeds a predetermined value, The sound volume control means controls the level of the audio signal to be low and outputs the audio signal indoors. Thus, when the noise is too loud, the output of the sound from the entrance slave unit can be reduced so that it does not bother the person indoors.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a hands-free intercom apparatus according to the present invention will be described below with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a block diagram showing a configuration of a hands-free intercom apparatus according to Embodiment 1 of the present invention. In FIG. 1, an entrance slave unit 1 and a master unit 2 are electrically connected to each other by a transmission line 3 for mutually transmitting signals therebetween.

The entrance cordless handset 1 includes a microphone 4 that picks up a visitor's voice and surrounding noise and converts it into a voice signal, an amplification circuit 5 that amplifies a voice signal output from the microphone 4,
And a modulation circuit 7 for modulating the output signal of the amplification circuit 5 at the frequency f1. Further, the entrance slave unit 1 includes a BPF (band pass filter) 8 that detects an audio signal modulated at the frequency f2, which is input from the base unit 2, a demodulation circuit 9 that extracts an audio signal from an output signal of the BPF 8, and a demodulation circuit. 9
And a call button 11 for the visitor to call the indoor-side user.

The base unit 2 is a BPF for detecting an audio signal modulated at the frequency f1 input from the entrance unit 2.
13, a demodulation circuit 14 for demodulating an audio signal from an output signal of the BPF 13, and a chime sound for informing the indoor user of the presence of a visitor by a call signal generated when the call button 11 of the entrance cordless handset 2 is operated. Chime generator 1
And a speaker 17 for converting the chime sound generated by the chime generating circuit 16 and the audio signal demodulated by the demodulation circuit 14 into an audio output and outputting the audio output. Further master unit 2
Is a microphone 1 that picks up the voice of the indoor user
8. Amplifying circuit 19a for amplifying the audio signal output from master unit microphone 18, amplifying circuit 19b for amplifying the audio signal output from amplifying circuit 19a, and measuring the level of the audio signal output from demodulation circuit 14, A hands-free IC that switches the communication direction according to the level of a voice signal input from both the level measurement circuit 20 and the demodulation circuit 14 and the microphone 18 for changing the amplification degree of the amplifier circuits 19a and 19b according to the output level. 21. Further, base unit 2 modulates an audio signal output from amplifying circuit 19b at frequency f2 and outputs the modulated signal.
It has a call button 22 for the user on the indoor side to operate and start talking with the visitor when there is a call from the visitor.

The operation of the hands-free intercom apparatus according to the first embodiment configured as described above will be described with reference to FIG. First, when the visitor operates the call button 11,
A calling signal is sent to master device 2 via transmission line 3. The chime generating circuit 16 of the base unit 2 operates according to the calling signal, and a chime sound is output from the speaker 17 to the room.
When the indoor user operates the talk button 22 of the base unit 2, the chime generating circuit 16 stops. At the same time, the entrance cordless handset 2
The audio signal input from the microphone 4 is amplified by the amplifier circuit 5, modulated by the modulation circuit 7 at the frequency f 1,
Is input to the BPF 13 of the base unit 2 through And
The modulated signal is detected by the BPF 13 and the demodulation circuit 1
At 4, the signal is demodulated into an audio signal and input to the hands-free IC 21. The audio signal of the indoor user picked up by the microphone 18 of the base unit 2 is also amplified by the amplifier circuit 19a and input to the hands-free IC 21.

In the hands-free IC 21, the demodulation circuit 14
And compares the levels of the two audio signals input from the amplifier circuit 19a, and transmits the higher audio signal to the other party. That is, when the visitor utters a voice, the hands-free IC 21 detects the utterance and outputs a voice signal input from the demodulation circuit 14 to the speaker 17. When the indoor user speaks, the hands-free IC 21 is used.
Detects this, and further amplifies the audio signal input from the amplifier circuit 19a by the amplifier circuit 19b and outputs it to the modulation circuit 15. The modulation circuit 15 of the base unit 2 modulates the input audio signal at the frequency f2, and transmits the modulated audio signal to the entrance device 1 through the transmission line 3. Entrance cordless handset 1
Then, the audio signal modulated at the frequency f2 by the BPF 8 is detected, demodulated into an audio signal by the demodulation circuit 9, and output from the speaker 10 to the visitor as the voice of the indoor user.

At this time, the audio signal output from the demodulation circuit 14 and transmitted from the entrance device 1 is input to the level measurement circuit 20 in order to detect the noise around the entrance device 1. From the level measurement circuit 20, if the level of the audio signal sent from the entrance terminal 1 continuously for a predetermined period of time (for example, set to 2 seconds in advance) is equal to or higher than a predetermined value, The amplifier circuit 19a determines that the noise is loud.
Alternatively, a control output for changing the amplification degree for increasing the amplification degree of the amplifier circuit 19b is output. In normal conversation, the level of the audio signal always fluctuates, so if it exceeds the specified value continuously for 2 seconds or more, it is determined that the noise is loud. That is, the level measurement circuit (20) functions as amplification degree changing means.

As described above, when the level of the audio signal sent from the entrance device 1 is high due to the loud surrounding noise, the amplification degree of the amplifier circuit 19a is increased and the level of the audio signal emitted by the occupant is increased. Will be higher. As a result, the balance between the two audio signals input to the hands-free IC 21 is maintained evenly, so that when the indoor user utters a voice, the hands-free IC 21 detects the utterance and outputs the audio signal from the resident. To the amplifier circuit 19b. Further, the amplified audio signal from the indoor user is output from the amplifier circuit 19b through the entrance device 1. As a result, the voice of the indoor user can be transmitted to the visitor without being masked by the ambient noise.

In the hands-free IC 21,
If the balance of the audio signal of the system is adjusted in advance by taking into account the noise near the entrance, the amplifier circuit 19a
Increasing the amplification degree causes the balance of the hands-free IC 21 to be lost. In this case, even if the indoor user does not speak, the same operation as when speaking is performed by the hands-free IC 21.
Could do it. Therefore, in this case, the amplification degree of the amplifier circuit 19a is maintained without increasing, and the output of the level measurement circuit 20 is input to the amplifier circuit 19b to be amplified.
Increase the degree of amplification. In other words, hands-free IC 2
When the indoor user 1 utters a voice, the voice signal is amplified more than usual by the amplifier circuit 19b and the modulation circuit 15
Is input to Since the audio signal modulated by the modulation circuit 15 is demodulated in the entrance slave unit 1, the sound of the indoor user is not erased by the ambient noise, and the visitor can hear the sound.

The level measuring circuit 2 which is a characteristic part of the present invention
0 will be described in more detail. The level measuring circuit 20 of the present embodiment is configured to measure the levels of two systems of audio signals using a so-called A / D converter, and determine the levels of the two systems of audio signals by a CPU having a timer. ing. Then, when a sound level equal to or higher than a preset specified value is input from the demodulation circuit 14, the CPU operates a timer. When a sound level higher than the specified value is continuously input while the timer is running, CP
U determines that the noise is loud and increases the amplification degree of the amplifier circuits 19a and 19b.

If the noise is reduced after the amplification of the amplification circuits 19a and 19b is increased, the amplification is increased again when the amplification of the amplification circuits 19a and 19b is reduced. There is a need. If the amplification degree of the amplifier circuits 19a and 19b changes during the conversation in this way, the loudness of the indoor user may change for the visitor, and the user may feel uncomfortable. Therefore, once the amplification degree of the amplifier circuits 19a and 19b is increased, the amplification degree is maintained for a certain time thereafter. As a result, the audio signal output to the entrance cordless handset 1 is not changed, and a sound having a volume that does not give a strange feeling to the visitor is transmitted.

Embodiment 2 A hands-free intercom apparatus according to Embodiment 2 of the present invention is provided by adding a part shown by a dotted line to the base unit 2 of Embodiment 1 shown in FIG. Therefore, the same parts as those in the first embodiment are denoted by the same reference numerals, and duplicate description will be omitted. In FIG. 1, Example 2
The base unit 2 in the hands-free intercom apparatus according to the first embodiment uses the signal from the level measurement circuit 20 to display the level of the audio signal from the entrance slave unit 1 and the content of the audio signal, and to perform forced transmission. And a forced transmission button 31. Further, base unit 2 includes a volume control unit 33 that reduces the level of the sound output from speaker 17 when the level of the audio signal from entrance cordless handset 1 exceeds a predetermined level.

In the level measuring circuit 20 of the main unit 2 in the hands-free intercom apparatus of the second embodiment, the level of the voice signal of the visitor from the sub-terminal 1 exceeds the predetermined level due to the loud noise around the entrance. In this case, a screen indicating that fact is displayed on the display unit 32. In this way, even if the noise is too loud, if it is necessary to transmit the voice of the indoor user to the visitor, the indoor user is urged to transmit the forced expanded voice. As a result, the indoor user presses the forced transmission button 31
Is operated to limit the call only from the master unit to the slave unit, and the sound can be reliably transmitted to the visitor by increasing the volume.

When the noise around the entrance is loud, the audio signal input from the entrance device 1 is large, but the volume of the audio signal can be reduced by the volume control unit 33 and output to the room. As a result, if there is a sleeping person such as an infant or a sick person in the room, no loud sound is output to the room, and the person in the room is not bothered.

[0031]

As described above in detail, the hands-free intercom apparatus of the present invention has the following effects. That is, by detecting the level of the audio signal input from the entrance slave unit to the master unit by the level detection circuit, the amplification degree of the amplifier circuit in the master unit can be changed. As a result, the level of the audio signal levels of the two systems input to the hands-free IC can be maintained, and the audio signal can be switched reliably.

Also, the level of the audio signal output to the entrance terminal can be changed in accordance with the noise, and even if the noise is loud, the call with the visitor can be reliably performed. further,
The display unit displays the noise level of the entrance cordless handset and that fact, prompts the user to forcibly transmit the expanded voice, reliably sends the indoor user's voice to the visitor, and controls the voice level of the visitor to the volume control unit. To control the sound to be small, thereby preventing a loud sound from being output indoors.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a hands-free intercom apparatus according to a first embodiment of the present invention (parts indicated by dotted lines indicate parts added in the hands-free intercom apparatus according to the second embodiment);

FIG. 2 is a block diagram showing a configuration of a conventional intercom apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Entrance child unit 2 Base unit 3 Transmission line 4 Microphone (Entrance child unit) 7 Modulation circuit (Entrance child unit) 8 BPF (Band pass filter) (Entrance child unit) 9 Demodulation circuit (Entrance child unit) 10 Speaker (Entrance child) 11) Call button 13 BPF (master) 14 Demodulation circuit (master) 15 Modulation circuit (master) 16 Chime generator 17 Speaker (master) 18 Microphone (master) 19a, 19b Amplification circuit (master) Reference Signs List 20 Level measurement circuit 21 Hands-free IC 22 Talk button 31 Forced transmission button 32 Display unit 33 Volume control unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K027 AA09 BB03 BB07 FF01 FF22 HH01 5K038 AA05 CC02 DD14 FF01 FF06 FF10

Claims (5)

[Claims] 1. An entrance cordless handset provided with at least a microphone for picking up a visitor's voice and noise around the visitor, and a speaker for transmitting an indoor user's voice to the visitor, an indoor user's voice A master unit that includes at least a microphone that picks up an audio signal that is picked up by the microphone, amplifies an input audio signal, and a speaker that sends out amplified and reproduced audio of a visitor; and A hands-free intercom apparatus having a transmission line for mutually transmitting a signal to and from an entrance terminal, wherein the master unit measures a level of an audio signal input from the entrance terminal, and a level measurement circuit, A hands-free intercom apparatus comprising amplification degree changing means for changing the amplification degree of the amplification circuit according to an output signal of a level measurement circuit. 2. The amplification degree changing means increases the amplification degree of the amplification circuit when the level of the audio signal input from the entrance terminal is equal to or higher than a predetermined value for a predetermined time continuously. The hands-free intercom apparatus according to claim 1, wherein 3. The method according to claim 1, wherein the amplification degree changing unit increases the amplification degree of the amplification circuit and then maintains the amplification degree fixedly until a call between the master unit and the entrance slave unit ends. The hands-free intercom device according to claim 1 or 2, wherein: 4. The apparatus according to claim 1, wherein the master unit has display means, and when the level of the audio signal input from the entrance slave unit measured by the level measurement circuit exceeds a predetermined value, the content is displayed. 4. The hands-free intercom apparatus according to claim 1, wherein said means is displayed on a means. 5. When the master unit has a volume control means, and the level of the audio signal input from the entrance slave unit measured by the level measurement circuit exceeds a predetermined value, 5. The hands-free intercom apparatus according to claim 1, wherein the level is controlled to be low and output to a room.