JP4365414B2 - Window communication device - Google Patents

Description

【Technical field】
[0001]
The present invention is provided through a board or wall that partitions the outside and inside of a room such as those found in amusement parks, movie theaters, theaters, railway ticket offices and information centers, financial institution consultations or loan counters, or interview systems. The present invention relates to a call device that can smoothly perform a call between an outside person and an inside person.
[Background]
[0002]
A conventional general communication device will be described with reference to an example of an amusement park ticket office in FIG. In general, the ticket office is where the ticket seller inside the room (indoor) and the ticket purchaser outside the room (outside the room) and the "purchase ticket", "notify the ticket price", " For the purpose of “provide and receive money”, the conversation is smoothly exchanged and an error-free ticket is sold.
[0003]
In such a communication device, as shown in FIGS. 1 and 2, a receiving microphone that picks up the voice of the person outside the room to convey the voice of the purchaser to the seller, and a receiving voice that amplifies the voice input from the receiving microphone. An amplifier and an indoor speaker that outputs the voice amplified by the receiver amplifier are provided, and a microphone that picks up the voice of the person in the room to convey the voice of the seller to the purchaser, and the voice that is input from the microphone A transmission amplifier to be amplified and an outdoor speaker for outputting the sound amplified by the transmission amplifier are provided (see Patent Document 1).
[0004]
However, in the communication apparatus having the receiving side and transmitting side voice amplification systems as shown in FIG. 2, it is difficult to hear each other when the receiving side (purchaser) and transmitting side (seller) voices are simultaneously amplified. And the sound of the indoor (outdoor) speaker is likely to circulate acoustically toward the transmitting (receiving) microphone, so that a howling phenomenon often occurs, making it difficult to hear each other clearly. May be.
[0005]
Therefore, in order to avoid such a problem, as shown in FIG. 3, a voice detection circuit for detecting a transmitted (received) voice at the time of transmission (received) to each of the voice amplification systems on the transmission side and the reception side. There has been proposed a method of detecting the transmitted voice and turning off the output of the reception amplifier during transmission, and detecting the received voice and turning off the output of the transmission amplifier during reception. This method has a priority control function based on the sound from either the sending side or the receiving side, and is excellent in that no acoustic I / O wraparound occurs. If the voice or voice continues to enter, the output of the amplifier on the other side is continuously turned off, making it impossible to respond and making a call impossible. In particular, since the ticket purchaser does not recognize the priority control function of this device, it often causes such a call impossible state to occur unintentionally, and the problem still remains.
[0006]
As a countermeasure against this problem, as shown in FIG. 4, a voice detection circuit for detecting a voice to be transmitted at the time of transmission is provided only on the transmission side (seller side), and continuous reception is performed at the time of non-transmission There is a method of detecting the transmission voice only during transmission and turning off the output of the reception amplifier. Since this method has a priority control function only on the sending side, it is considered that it can be used smoothly by a seller who recognizes the priority function, but when the sender (seller) is not sending a voice. In addition to the voice of the speaker, the receiver amplifier detects the reception sound (buyer's voice and the surrounding outdoor noise) output from the indoor speaker as the transmitter voice, and turns off the receiver amplifier output even when the receiver is receiving the voice. The problem still remains that it may become impossible to talk.
[0007]
As a countermeasure against this problem, in order to prevent the transmission amplifier from detecting the reception sound output from the indoor speaker, which is the main cause of the inability to talk, the voice that enters the transmission amplifier and the reception amplifier as shown in FIG. There is a method of providing filters having pass frequency bands in different ranges with respect to the input. For example, when it is said that it is good to pass a frequency in the range of 300 Hz to 3000 Hz when passing a human voice through an amplifier or the like, it passes a low frequency in the range of 300 Hz to 1500 Hz with respect to the transmission amplifier. If a low-pass filter (LPF) is provided and a high-pass filter (HPF) that passes a high frequency in the range of 1500 Hz to 3000 Hz is provided for the receiver amplifier, the sound of the indoor (outdoor) speaker is transmitted (received) ) Even if you go around the microphone, you can talk without interfering with each other.
[0008]
However, as is well known, it is difficult to completely distinguish the characteristics of two adjacent passing frequencies electrically and acoustically. In addition, this method only shows a slight improvement in sound interference even when using an amplifier that passes the entire audio frequency band, and the received sound output from the indoor speaker is still transmitted on the transmitting side. The possibility to detect remains. Furthermore, the biggest weakness of this method is that the voice quality of the other party's voice output from each speaker that the seller and the purchaser hear will be lower than that in the case where the entire voice frequency band is passed. The sound quality on the side to be used is poorly clear, while the sound quality on the side to which the high frequency band is used is uncomfortable. Such sound quality is not a problem for calls between people who are fully aware of the existence of the device, but the sound output to the purchaser who is a customer who does not recognize the existence of the device is of good quality. The problem still remains because it is required.
[Patent Document 1]
JP 2001-24803 A DISCLOSURE OF THE INVENTION
[Problems to be solved by the invention]
[0009]
The present invention was devised in order to solve the problems of the prior art, and the purpose thereof is an amusement park, a movie theater, a theater, a ticket office such as a railway, an information center, a financial institution consultation or a loan window, or It is an object of the present invention to provide a communication device capable of smoothly performing a call between a person outside and inside a room through a plate or wall that partitions the outside and inside of the room as seen in an interview system or the like.
[Means for Solving the Problems]
[0010]
In order to achieve the above object, the present inventor performs control so as to prevent unnecessary input of sound into the transmission microphone while keeping the sound quality of the sound output to the person outside the room clear. As a result of earnestly examining a communication device that can be used, a band pass filter (BPF) that passes through a frequency that recognizes a band occupied by a fundamental frequency of a voice uttered by a person separated from a line connecting a transmission microphone and a transmission amplifier, and An object of the present invention is to provide a voice detection circuit for detecting the voice that has passed through, and to attenuate or turn off the output of the voice amplification system on the receiver side, for example, the receiver amplifier when this circuit detects the voice. The inventors have found that this can be achieved, and have completed the present invention.
[0011]
That is, the present invention is a communication device that allows a person outside and inside a room to talk via a partition plate or a wall, and picks up the voice of the person outside the room as a voice amplification system on the receiving side. A speech microphone, a reception amplifier that amplifies the voice input from the reception microphone, and an indoor speaker that outputs the voice amplified by the reception amplifier, and the voice of a person inside the room as a voice amplification system on the transmission side A microphone for transmitting a voice, a transmitter amplifier for amplifying the voice input from the microphone, and an outdoor speaker for outputting the voice amplified by the transmitter amplifier. A band-pass filter (BPF) that passes a frequency that recognizes a band occupied by a fundamental frequency of a voice uttered by a person, and a voice detection circuit that detects a voice that has passed through the line are provided. When the path detects voice, the output of the voice amplification system on the receiving side is attenuated or turned off, and the frequency higher than the frequency passing through the band pass filter (BPF) on the line connecting the receiving microphone and the receiving amplifier A high-pass filter (HPF) that passes is provided.
[0012]
In a preferred aspect of the speech device of the present invention, for example, the frequency passing through the band pass filter (BPF) is 90 Hz to 400 Hz, and the frequency passing through the high pass filter (HPF) is higher than 400 Hz. Moreover, in the preferable aspect of the communication device of the present invention, the transmission microphone is a pressure gradient microphone, and is arranged so as not to be substantially sensitive to the output direction of the sound from the indoor speaker.
[Brief description of the drawings]
[0013]
[FIG. 1] A schematic view of an amusement park ticket office where a communication device is installed is shown.
FIG. 2 shows a main configuration diagram of a basic communication device.
[FIG. 3] A main configuration diagram of a communication apparatus in which priority control is mutually applied during transmission and reception.
[FIG. 4] The main block diagram of the telephone apparatus with which priority control works only at the time of transmission is shown.
[FIG. 5] A main configuration diagram of a call device that uses different frequency bands on the transmission side and the reception side.
[Fig. 6] Fig. 6 shows a main configuration diagram of a communication device according to the present invention.
FIG. 7 shows an example of a spherical wave effect of a pressure gradient microphone.
FIG. 8 shows an example of the arrangement of a pressure gradient microphone and an indoor speaker.
[Best Mode for Carrying Out the Invention]
[0014]
Embodiments of the communication device of the present invention will be specifically described below, but the present invention is not limited to these descriptions unless departing from the object.
[0015]
The communication device of the present invention firstly separates from the line connecting the transmission microphone and the transmission amplifier as shown in FIG. 6 and passes the frequency for recognizing the band occupied by the fundamental frequency of the voice uttered by a person. A band filter (BPF) and a sound detection circuit that detects sound that has passed through the filter are provided. This voice detection circuit functions to attenuate or turn off the output of the voice amplification system on the receiving side, for example, the receiving amplifier, when the voice of the sender is detected.
[0016]
This transmission amplifier amplifies the voice signal as it is without passing through the band pass filter (BPF) separately from the voice detection system in which the voice signal is input to the voice detection circuit after passing through the band pass filter (BPF). Therefore, the voice on the transmission side (sales side) can be clearly transmitted to the reception side (purchaser) without being deteriorated by any filter. Therefore, there is no shortcoming as in the conventional apparatus of FIG. 5, and the receiver (purchaser) can clearly hear the voice of the transmitter without having to recognize the control method of this apparatus at all. There will be no inconvenience when talking to the other party.
[0017]
In addition, this voice detection system is a band that passes only a specific frequency so as not to detect other surrounding noise as a filter of the voice before being input to the voice detection circuit, only detecting a person's transmitted voice. Since the pass filter (BPF) is provided, it responds accurately only to the transmission voice of the seller, and the output of the reception amplifier is not unnecessarily attenuated or turned off by a sound other than the transmission voice. This filter uses the fundamental frequency of human voices (similar repetition of waves is observed in the continuous part of voiced sounds generated from vocal cord vibrations as a sound source, and the repetition frequency is generally called the fundamental frequency), especially men Focusing on the frequency of 90 to about 400 Hz of female and child voices, the band occupied by the fundamental frequency of the voice and other frequency bands (such as physical sounds) are identified. The pass frequency is selected so that the function of identifying surrounding object sounds is remarkably enhanced. The frequency passing through the band pass filter (BPF) used here is preferably in the range of 90 Hz to 400 Hz.
[0018]
As described above, the device of the present invention effectively prevents unnecessary control by the voice detection circuit and deterioration of the quality of the voice transmitted from the transmitting side (seller) to the receiving side (purchaser) by the first feature. can do.
[0019]
In addition, the communication device of the present invention has a line connecting the receiving microphone and the receiving amplifier as the second feature in order to effectively function the first feature and eliminate the influence of the wraparound of sound from the indoor speaker to the transmitting microphone. The high pass filter (HPF) which passes a frequency higher than the pass frequency of the band pass filter (BPF) provided in the first feature can be provided. This high-pass filter (HPF) avoids the passing frequency (for example, 90 to 400 Hz) of the voice detection circuit on the transmitting side of the receiving amplifier in order to discriminate the transmitted voice and the surrounding sound (especially the voice coming from the indoor speaker). It is necessary to have a passing frequency characteristic (for example, more than 400 Hz). For example, by providing the receiving amplifier with a high-pass filter (HPF) that passes a frequency higher than the band-pass filter (BPF) on the transmission side, that is, a frequency higher than 400 Hz, which is higher than the band occupied by the fundamental frequency of human voice. The received voice output from the indoor speaker can be prevented from reaching the detection level of the voice detection circuit on the transmission side.
[0020]
In this method, there is a potential problem as pointed out in the conventional apparatus of FIG. 5, that is, there is a problem that the sound quality on the side using the high frequency band becomes uncomfortable. Assuming that the listener on the talk side is the seller who can recognize and overcome the problem, this method of outputting the entire voice frequency band over the frequency range of 400 Hz is “generally in the frequency range of 1000 Hz to 3000 Hz. Considering that it is said that the speech has a clarity of about 90% if there is a passage, it is fully put into practical use.
[0021]
Further, in order to make the first and second features function more effectively and complement the third aspect of the communication device of the present invention, as a third feature, the transmission microphone is a pressure gradient microphone, and this microphone is used for the sound from the indoor speaker. It can arrange | position so that there may be substantially no sensitivity with respect to an output direction.
[0022]
A microphone is an acoustic-electric converter that changes sound pressure changes into electrical changes, but roughly speaking, a pressure microphone that generates an electromotive force proportional to the sound pressure and an electromotive force proportional to the slope of the sound pressure are generated. It can be divided into pressure gradient microphones (also called speed microphones). Among these, the pressure gradient microphone has a characteristic (spherical wave effect) that sensitivity increases at a low frequency at a short distance such that the distance to the sound source is less than or equal to the wavelength because of its operation principle. FIG. 7 shows an example of frequency characteristics showing the spherical wave effect of the pressure gradient microphone. In addition, the directivity characteristic of the sensitivity of the pressure gradient microphone is bi-directional with little sensitivity in the lateral direction of the structure. By using the two characteristics of this pressure gradient microphone for the transmitting microphone, the transmitting microphone becomes difficult to pick up the sound from the indoor speaker, so the voice detection circuit on the transmitting side may detect the received voice by mistake. Almost nothing.
[0023]
The spherical wave effect of the pressure gradient microphone is used to complement the first feature of the communication device of the present invention. When a pressure gradient microphone is used as a microphone, the speaker is used with the mouth close to the microphone, so the distance is sufficiently below the wavelength of the voice, and it is used in the voice detection circuit system. The sensitivity of the low frequency band of the voice to be input is increased to enhance the effect of the filter that passes the basic frequency band of the voice (for example, about 90 Hz to about 400 Hz), and as a result, the voice detection function of the transmitted sound is enhanced. Can do. On the other hand, other voices and sounds coming from the surroundings are far away from the microphone, so the sensitivity of those low frequency bands is not increased. Therefore, the possibility of detecting it as a transmitted sound is also reduced. Thereby, the discrimination capability between the transmitted voice and other voices and sounds coming from the surroundings can be further improved.
[0024]
Moreover, the bidirectionality of the pressure gradient microphone is used to supplement the second feature of the communication device of the present invention. In this case, when using a pressure gradient microphone as a transmission microphone, the pressure gradient microphone has almost no sensitivity in order to prevent unnecessary voice detection from incoming voices coming from indoor speakers, which are most likely to be affected by the surrounding voice. The indoor speaker is arranged at a position at an angle (a lateral direction in the structure) that is not shown. FIG. 8 shows an arrangement example of the pressure gradient microphone and the indoor speaker in the communication device. By arranging the pressure gradient microphone in this manner, the voice detection circuit on the transmission side further prevents detection of the received voice from the indoor speaker.
[0025]
The communication device of the present invention is configured so that the outside and inside of the room can be separated from each other via a plate or wall (transparent or opaque or completely separated from the outside). Used by people who are making calls, especially those who are outside the room are buyers or consultants who are not aware of the control of this device, while those inside the room may be aware of the control of this device It is particularly effective if it is installed in a situation where it is a seller or a responder. For example, it can be preferably used in amusement parks, movie theaters, theaters, railway ticket offices and information centers, places where banks and financial companies provide consultation or financing, or interview systems.
[0026]
Since the communication device of the present invention is configured as described above, the following effects can be obtained.
(1) The audio signal output from the transmission microphone is not used as a control signal as it is, but the signal after passing through a filter that passes through a frequency band that mainly constitutes human voice is used as a control signal. Therefore, there are few malfunctions due to the influence of sound other than the voice of the sender (seller). In addition, since the control signal and the loudspeaker signal are provided in different systems, the loudspeaker sound signal can be amplified normally without passing through the filter.
[0027]
(2) The voice spoken by the receiver (purchaser) is amplified by the receiver amplifier and amplified by the indoor speaker. At that time, when the amplified sound circulates to the transmitter microphone, the voice is received by the control function of the transmitter amplifier. The occurrence of the problem of attenuating or turning off the output of the amplifier is effective to suppress by the above-described method. In order to more reliably suppress the occurrence of this problem, the bandpass filter (BPF) on the transmission amplifier side is used. ), A high-pass filter (HPF) in a band that is excluded from the band is inserted into the receiver amplifier, and the received voice is amplified after passing through the high-pass filter (HPF). Since the audio signal after passing through the band pass filter (HPF) is difficult to react to the control circuit designed to react to the frequency band of the band pass filter (BPF), malfunction due to wraparound occurs. It can be more effectively suppressed.
[0028]
(3) Since the pressure gradient microphone is used as the transmission microphone, the spherical wave effect and the bi-directionality by this microphone can be obtained. That is, first, the voice spoken by the sender (seller) near the microphone reacts characteristically to the frequency band of the band pass filter (BPF) due to the spherical wave effect that increases sensitivity at a low frequency at a short distance. It becomes easy to do. In addition, the directivity characteristic of the sensitivity of the microphone is bi-directional with little sensitivity in the lateral direction of the structure, so that the influence of the reception voice output from the reception speaker on the transmission microphone is reduced. . As a result, when the seller's voice should be controlled, the response is improved. Can be further enhanced.

Claims (4)

  A communication device that enables a person outside and inside the room to talk via a partition plate or wall, and a receiving microphone that picks up the voice of the person outside the room as a receiving side audio amplification system, and receiving A microphone that picks up the voice of a person inside the room as a voice amplification system on the transmission side, including a reception amplifier that amplifies the voice input from the microphone and an indoor speaker that outputs the voice amplified by the reception amplifier And a speaker amplifier that amplifies the voice input from the microphone, and an outdoor speaker that outputs the voice amplified by the microphone, separated from the line connecting the microphone and the voice amplifier Then, a band pass filter (BPF) that passes the frequency that recognizes the band occupied by the fundamental frequency of the voice uttered by a person and a voice detection circuit that detects the voice that has passed through it are provided, and this circuit detects the voice. The frequency of recognizing the band occupied by the fundamental frequency of the voice uttered by the person passes through the line connecting the transmission microphone and the transmission amplifier to attenuate or turn off the output of the voice amplification system on the receiving side. A band pass filter (BPF) is not provided, and a high pass filter (HPF) that passes a frequency higher than a frequency passing through the band pass filter (BPF) is provided on a line connecting the receiving microphone and the receiving amplifier. A call device characterized by that.   The communication device according to claim 1, wherein a frequency passing through the band pass filter (BPF) is 90 Hz to 400 Hz.   The communication device according to claim 1 or 2, wherein a frequency passing through the high-pass filter (HPF) is higher than 400 Hz.   The telephone call according to any one of claims 1 to 3, wherein the transmission microphone is a pressure gradient microphone and is arranged so as to be substantially insensitive to the output direction of the sound from the indoor speaker. apparatus.

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