JP3702507B2 - Hands-free call system for apartment houses - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a hands-free call system for collective housing, and more particularly to prevention of howling in a call between a lobby intercom, a dwelling unit, and an alarm monitoring panel and between a dwelling unit and a doorphone.
[0002]
[Prior art]
  In a call device including a speaker and a microphone, when the call volume is increased, a part of an audio signal emitted from the speaker is fed back to the microphone, and an oscillation phenomenon called howling occurs. In particular, hands-free communication devices such as intercoms have a short distance between the receiving speaker and the transmitting microphone of several centimeters to several tens of centimeters compared to the distance to the caller. There is a problem that howling is likely to occur.
[0003]
  In addition, when a 2/4 conversion circuit is used and a two-way communication line is used for two-way communication, a transmission signal wraps around the reception line side and causes howling in the 2/4 conversion circuit. There is. In order to prevent the occurrence of such howling, the hands-free communication device needs to perform processing to suppress acoustic coupling and the like from the speaker to the microphone. Main wraparound suppression processing used in conventional hands-free communication devices As a method, there are a method using a voice switch and a method using an echo canceller.
[0004]
  However, since a phenomenon called so-called reception blocking occurs in the method using the voice switch, it becomes an alternate call that can transmit only the voice of one of the speakers to the other party, and bi-directional simultaneous call cannot be realized. . For this reason, in order to realize a two-way simultaneous call, it has been necessary to perform wraparound suppression processing by a method using an echo canceller.
[0005]
[Problems to be solved by the invention]
  The above echo canceller method identifies the transfer function until the received signal wraps around the transmitted signal due to acoustic coupling, and performs a convolution operation on the received signal and this transfer function, thereby performing the wraparound included in the transmitted signal. By obtaining a component and removing this component, howling is prevented. Usually, an echo canceller circuit is realized by using a digital signal processing device (DSP).
[0006]
  Therefore, when this echo canceller circuit is provided in the lobby interphone, alarm monitoring panel, each dwelling unit, and each intercom unit, a digital signal processing device (DSP) for performing transfer function identification and convolution calculation on these devices. ) Is required, and each device is expensive, resulting in an expensive call system. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a housing-free hands-free call system that prevents occurrence of howling and ensures practical call quality at low cost.
[0007]
[Means for Solving the Problems]
  The hands-free call system for an apartment house according to the present invention as set forth in claim 1 is configured such that the lobby interphone installed at the common entrance of the apartment house and the master unit installed in each unit of the apartment house have an alarm monitoring panel. Via a two-wire communication line, and the alarm monitoring panel is configured to receive a reception signal component included in the transmission signal due to the wraparound of the reception signal. A simultaneous call circuit to be suppressed, and a two-party selection switching means for selecting any two parties from a dwelling unit, alarm monitoring panel, and lobby intercom and connecting them via a call line. It is characterized in that it is shared for calls between any two parties of the monitoring panel and lobby intercom.
[0008]
  A hands-free call system for an apartment house according to the present invention as set forth in claim 2 is a two-line call between a lobby interphone installed at a common entrance of an apartment house and a base unit installed in each unit of the apartment house. Hands-free for multi-dwelling houses, which are connected by wires, and are connected to the doorphone slave unit installed at the entrance of the unit. The lobby intercom includes a simultaneous call circuit that suppresses a reception signal component included in a transmission signal due to a wraparound of the reception signal, and the dwelling unit has a transmission signal level, a reception signal The loss level of the signal level, whichever is smaller among the signal levels, is greatly controlled, and the loss level of the signal level whose loss level is largely controlled isWith lobby intercomWhen calling, the alternate call circuit that controls smaller than when calling with the door phone slave unit,With lobby intercomIt is characterized by comprising doorphone switching means for switching between a call and a call with a doorphone cordless handset.
[0009]
  A hands-free call system for an apartment house according to the present invention as set forth in claim 3 is the hands-free call system for an apartment house according to claim 1, wherein the dwelling unit has a transmission signal level and a reception signal level. When one of the smaller signal level loss amount is controlled largely and the loss amount of the signal level with the larger loss amount control is communicated with the lobby intercom or the alarm monitoring panel, The present invention is characterized by comprising an alternating call circuit that is controlled to be smaller than the time, and a doorphone switching means for switching between a call with a lobby intercom or an alarm monitoring panel and a call with a doorphone slave unit.
[0010]
  The hands-free call system for collective housing according to the present invention described in claim 4 is the hands-free call system for collective housing according to claim 2 or 3, wherein the simultaneous call circuit is output from the simultaneous call circuit. An adaptive filter that identifies a transfer function until the received signal wraps around the transmission line and is input again to the simultaneous communication circuit as the transmitted signal, and performs a convolution operation on the received signal using the identified transfer function, and the transmission An echo canceller circuit comprising a subtracting circuit for subtracting the output signal of the adaptive filter from the signal is provided.
[0011]
  A hands-free call system for an apartment house according to the present invention as set forth in claim 5 is the hands-free call system for an apartment house according to claim 4, wherein the simultaneous call circuit is a transmission signal from one speaker. And an echo canceller circuit that suppresses the received signal component included in the transmission signal from the other speaker.
[0012]
  A hands-free call system for an apartment house according to the present invention as set forth in claim 6 is the hands-free call system for an apartment house according to claim 5, wherein the simultaneous call circuit is a transmission between two echo canceller circuits. An amplifier circuit is provided in the line or the receiving line.
[0013]
  A hands-free call system for collective housing according to the present invention as set forth in claim 7,2 to 6In the above-described hands-free communication system for collective housing, the above alternating communication circuit is provided in the transmission line, and is provided in the transmission loss variable circuit for changing the gain or loss amount of the transmission signal, and in the reception line. Monitor the received signal loss amount variable circuit that changes the gain or loss amount of the signal, the signal level of the transmission line and the reception line,The transmission loss variable circuit and the reception lossA loss amount control circuit for controlling the gain or loss amount of the variable circuit, and the loss amount control circuit is further configured to change the received loss amount variable circuit or the transmission loss amount based on the connection state of the doorphone switching means. It is characterized by changing the loss amount of the circuit.
[0014]
  The hands-free call system for an apartment house according to the present invention as set forth in claim 8 is the hands-free call system for an apartment house according to claim 1, wherein a dwelling unit is further installed at the entrance of the dwelling unit. In the system configured to be connected to each of the doorphone slave units, while the above-mentioned unit is transmitting the voice signal of one speaker, the voice signal of the other speaker is attenuated and either one of the voices is transmitted. An alternate call circuit for transmitting only a signal to the other side, and a doorphone switching means for switching between a call with the lobby intercom or the alarm monitoring panel and a call with the doorphone slave unit. It is characterized in that it is configured as means for preventing the voice signal of the other speaker from being attenuated during a call with the board.
[0015]
  The hands-free call system for an apartment house according to the present invention as set forth in claim 9 is the hands-free call system for an apartment house according to claim 1, wherein the dwelling unit is further installed at the entrance of the dwelling unit. In the system configured to be connected to each intercom unit, the above-mentioned dwelling unit master attenuates the received signal during transmission, while attenuating the transmitted signal during reception An alternating call circuit for transmitting only to the other side, doorphone switching means for switching between a call with the lobby intercom or alarm monitoring panel and a call with the doorphone slave unit, a call signal from the alternating call circuit, and the alternating call circuit A circuit for adding a call signal from a bypass line that does not pass through, an adder circuit provided in a transmission line or a reception line, and provided in the bypass line And a Na log switch, the analog switch, while being closed during a call with the lobby intercom or alarm monitoring panel, characterized in that during call with the intercom slave unit is opened.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
  An example of the system configuration of the hands-free call system for an apartment house according to the present invention is shown in FIG. In this system, one lobby intercom LP installed at the common entrance of a housing complex is connected to a plurality of dwelling unit master units HP installed in each housing unit in the housing complex through an alarm monitoring panel XP. Furthermore, each dwelling unit main unit HP is configured to be connected to a door phone slave unit DP installed at the entrance of the dwelling unit. These devices are all connected by two-wire communication lines L0 to L2, and are used for two-way communication.
[0017]
  FIG. 1 shows an example of the configuration of a collective housing hands-free call system according to the present invention applied to such a system. The lobby interphone LP includes a reception line constituted by a speaker LSK and a reception signal amplifier circuit LRA, a transmission line constituted by a microphone LMC and a transmission signal amplifier circuit LSA, a reception line and a transmission line. And a 2/4 conversion circuit LCV that mutually converts the audio signal of the 4-wire communication line and the audio signal of the 2-wire signal line L0.
[0018]
  The alarm monitoring board XP includes a reception line composed of a speaker XSK and a reception signal amplifier circuit XRA, a transmission line composed of a microphone XMC and a transmission signal amplifier circuit XSA, and two-person selection switching means XJ1. , XJ2, echo canceller circuits EC1 and EC2, and 2/4 conversion circuits XCV1 and XCV2.
[0019]
  The dwelling unit main unit HP includes a reception line composed of a speaker HSK and a reception signal amplifier circuit HRA, a transmission line composed of a microphone HMC and a transmission signal amplifier circuit HSA, door phone switching means HJ, The voice switch BSW, a 2/4 conversion circuit HCV, and an amplifier circuit are included.
[0020]
  The intercom unit DP includes a reception line constituted by a speaker DSK and a reception signal amplifier circuit DRA, a transmission line constituted by a microphone DMC and a transmission signal amplifier circuit DSA, and a 2/4 conversion circuit DCV. It consists of. The door phone switching means HJ of the dwelling unit main unit HP is a switching unit that switches the connection destination of the transmission / reception line of the dwelling unit main unit HP to the alarm monitoring panel XP or the door phone sub unit DP. If the HP transmission / reception line is connected to the alarm monitoring panel XP via the communication line L1, and connected to the contact b side, the transmission / reception line of the dwelling unit main unit HP is connected to the doorphone slave unit DP via the communication line L2. The
[0021]
  The two-way selection switching means XJ1 and XJ2 of the alarm monitoring panel XP are switching means for selecting two of the three members of the lobby intercom LP, the dwelling unit main unit HP, and the alarm monitoring panel XP so as to make a call. If the two-person selection switching means XJ1, XJ2 are connected to the contact a side, the transmission / reception line of the lobby interphone LP is connected to the dwelling unit main unit HP via the call line L0, the alarm monitoring panel XP, and the call line L1, If the two-person selection switching means XJ1, XJ2 are both connected to the contact b side, the transmission / reception line of the lobby intercom LP is connected to the transmission / reception line of the alarm monitoring panel XP via the communication line L1. Further, if the two-party selection switching means XJ1 is connected to the contact a side and the two-person selection switching means XJ2 is connected to the contact b side, the transmission / reception line of the alarm monitoring panel XP is connected to the dwelling unit base unit via the communication line L1. Connected to HP.
[0022]
  That is, if the door phone switching means HJ is connected to the contact b side, a call can be made between the dwelling unit main unit HP and the door phone slave DP, and when the door phone switching means HJ is connected to the contact a side, the two-person selection switching means. If both XJ1 and XJ2 are connected to the contact a side, a call can be made between the dwelling unit main unit HP and the lobby intercom LP, and if both the two-way selection switching means XJ1 and XJ2 are connected to the contact b side, the dwelling unit main unit HP is connected. And a call with the alarm monitoring board XP. Furthermore, if the two-party selection switching means XJ1 is connected to the contact a side and the two-person selection switching means XJ2 is connected to the contact b side, a call can be made between the lobby intercom LP and the alarm monitoring panel XP.
[0023]
  Note that these calls are two-way calls via a two-wire communication line, and in any case except for a call between the dwelling unit main unit HP and the door phone slave unit, an echo canceller circuit EC1 in the alarm monitoring panel XP. , Via EC2. FIG. 3 shows only the configuration at the time of a call between the alarm monitoring panel XP and the lobby intercom HP regarding the hands-free call system for the apartment house shown in FIG.
[0024]
  The uttered voice collected by the microphone XMC of the alarm monitoring board XP and converted into an electric signal is output to the two-wire communication line L0 via the echo canceller circuits EC1 and EC2 and the 2/4 conversion circuit XCV2. This audio signal is transmitted to the reception line in the 2/4 conversion circuit LCV of the lobby intercom LP, and is reproduced and output as a sound wave from the speaker LSK.
[0025]
  Similarly, the uttered voice picked up by the microphone LMC of the lobby intercom LP is alerted via the 2/4 conversion circuit LCV, the 2-wire communication line L0, the 2/4 conversion circuit XCV2, and the echo canceller circuits EC1, EC2. It is transmitted to the speaker XSK of the monitoring board XP and output as a sound wave. The echo canceller circuits EC1 and EC2 are for preventing the occurrence of howling by suppressing the received signal component included in the transmitted signal when the received signal wraps around.
[0026]
  Since a lobby interphone or the like is generally configured as a hands-free communication device, an acoustic coupling occurs in which a part of a received voice emitted from a speaker LSK is picked up by a microphone LMC. Similarly, acoustic coupling occurs between the speaker LSK and the microphone LMC of the alarm monitoring board XP, and the reception signal wraps around due to such acoustic coupling. Further, in the 2/4 conversion circuit XCV2, since the transmission signal leaks to the reception circuit side, the reception signal wraps around to the transmission side when viewed from the lobby intercom LP.
[0027]
  The echo canceler circuit EC1 suppresses the sneak around the alarm monitoring panel XP, that is, the sneak between the speaker XSK and the microphone XMC of the alarm monitoring panel, and the echo canceler circuit EC2 wraps around the lobby interphone LP, that is, the lobby interphone LP. Sneaking between the speaker LSK and the microphone LMC and the sneak in the 2/4 conversion circuit XCV2. That is, the echo canceller circuits EC1 and EC2 are simultaneous call circuits for enabling simultaneous calls from both the alarm monitoring panel XP and the lobby intercom LP.
[0028]
  An example of the configuration of these echo canceller circuits is shown in FIG. This echo canceller circuit includes an adaptive filter Wa and a subtraction circuit SB provided in the transmission line. The adaptive filter Wa identifies the transfer function W1 until the reception signal output from the echo canceller circuit to the reception line wraps around the transmission line and is input again to the echo canceller circuit as a transmission signal. Then, the reception signal component included in the transmission signal is obtained by performing a convolution operation on the reception signal with the identified transfer function. The subtraction circuit SB can eliminate the influence of the wraparound by subtracting the reception signal component obtained by the adaptive filter Wa from the transmission signal.
[0029]
  Further, FIG. 5 shows a simultaneous call circuit used in the alarm monitoring board XP. This simultaneous call circuit is formed by connecting echo canceller circuits EC1 and EC2 in series as shown in FIG. The adaptive filter Wa of the echo canceller circuit EC1 identifies the transfer function W1 related to the sneak on the side of the alarm monitoring board XP and removes the sneak component from the transmission signal of the alarm monitoring board XP, while the adaptive filter Wa of the echo canceller circuit EC2. Identifies the transfer function W2 related to the wraparound on the lobby interphone LP side, and removes the wraparound component from the transmission signal of the lobby interphone LP.
[0030]
  For the collective housing hands-free call system shown in FIG. 1, only the configuration at the time of a call between the dwelling unit main unit HP and the door phone sub unit DP is shown in FIG. Only the configuration is shown in FIG. In FIG. 6, the transmission / reception line of the dwelling unit main unit HP is connected to the transmission / reception line of the door phone slave unit DP via the voice switch BSW, and the voice switch BSW is always the voice of one of the speakers. Since an alternate call is performed in which only the signal is transmitted to the other side, howling can be prevented even when the same wraparound occurs as described above.
[0031]
  An example of the configuration of this voice switch is shown in FIG. The voice switch BSW includes a reception loss variable circuit RVA provided in the reception line, a transmission loss variable circuit SVA provided in the transmission line, and a loss control circuit VAC for controlling these loss amounts. Composed. Both the reception loss variable circuit RVA and the transmission loss variable circuit SVA can amplify or attenuate an audio signal, and can change the amplification factor or attenuation factor (collectively referred to as loss amount). It is.
[0032]
  The loss amount control circuit VAC monitors the voice signals of the reception line and the transmission line, and inserts a large loss into the lower voice signal level so that the received loss amount variable circuit RVA and the transmission loss amount variable circuit. A control signal is output to SVA.
[0033]
  For example, in FIG. 6, when the level of the reception signal of the dwelling unit main unit HP is higher than the level of the transmission signal, the loss amount of the reception loss variable circuit RVA is 6 dB under the control of the loss amount control circuit VAC. The loss of the loss amount variable circuit SVA is 46 dB, and only a call from the doorphone slave unit DP to the dwelling unit base unit HP is possible. On the other hand, when the level of the transmission signal is higher than the level of the reception signal, the loss of the reception loss variable circuit RVA is 46 dB and the loss of the transmission loss variable circuit SVA is 6 dB. Only a call to the device DP is possible.
[0034]
  In a call between the door phone DP and the dwelling unit main unit HP, by carrying out such an alternate call using the voice switch BSW, the loop gain is prevented from becoming 1 or more, and the howling is caused by the wraparound of the received signal. Can be prevented. In FIG. 7, the transmission / reception line of the dwelling unit main unit HP is connected to the transmission / reception line of the alarm monitoring panel XP via the echo cancellers EC1, EC2 and the voice switch BSW.
[0035]
  The echo cancelers EC1 and EC2 reduce the influence of the sneaking from the speaker XSK of the alarm monitoring board XP to the microphone XMC and the sneaking in the 2/4 conversion circuit XCV2, and the sneaking from the speaker HSK of the dwelling unit main unit HP to the microphone HMC. For this reason, the voice switch BSW can reduce the amount of loss compared with the time of the telephone call of the door phone slave unit DP and the dwelling unit master unit HP. In other words, connection information indicating the communication partner is input to the loss amount control circuit VAC, and if the loss amounts of the reception loss variable circuit RVA and the transmission loss variable circuit SVA are reduced based on the connection information, the transmission information is transmitted. The signal and the reception signal can be set to a level that does not cause a feeling of disconnection as in an alternate call.
[0036]
  For example, when the level of the received signal is higher than the level of the transmitted signal, the loss of the received loss variable circuit RVA is 6 dB and the loss of the transmitted loss variable circuit SVA is 0 dB, while the transmitted signal level is 0 dB. Is higher than the level of the received signal, the loss of the reception loss variable circuit RVA is 0 dB and the loss of the transmission loss variable circuit SVA is 6 dB. In either case, the alarm monitoring panel XP and the dwelling unit HP Since the amount of loss is small enough not to give a sense of disconnection in the inter-calls, simultaneous calls are possible.
[0037]
  That is, the voice switch BSW increases the loss amount during a call with the door phone slave unit DP and functions as an original voice switch for performing an alternate call, while reducing the loss amount during a call with the alarm monitoring panel XP. Smaller, allowing simultaneous calls without a sense of disconnection. FIG. 9 shows only the configuration at the time of a call between the dwelling unit main unit HP and the lobby intercom LP regarding the collective housing hands-free call system shown in FIG. In this figure, the transmission / reception line of the dwelling unit main unit HP is connected to the transmission / reception line of the lobby intercom LP via the echo canceller circuits EC1 and EC2 of the alarm monitoring panel XP and the voice switch BSW of the dwelling unit main unit HP. .
[0038]
  Also in this case, the echo cancelers EC1 and EC2 wrap around from the speaker LSK of the lobby interphone LP to the microphone LMC as in the case of the call between the dwelling unit main unit HP and the alarm monitoring panel XP shown in FIG. In order to reduce the influence of the sneaking in the four conversion circuits XCV1 and XCV2 and the sneaking from the speaker HSK of the dwelling unit main unit HP to the microphone HMC, simultaneous conversation can be performed by reducing the loss amount of the voice switch BSW.
[0039]
  As understood from the above description, all calls between the lobby intercom LP, the alarm monitoring panel XP, and the dwelling unit main unit HP are via the echo canceller circuits EC1 and EC2 of the alarm monitoring panel XP. Thus, it is possible to make a simultaneous call while preventing howling.
[0040]
  Here, the telephone call between the dwelling unit main unit HP and the lobby intercom LP or the alarm monitoring panel XP is further performed via a voice switch. However, simultaneous calls can be made by reducing the loss amount of the voice switch. it can.
[0041]
  On the other hand, since the communication between the dwelling unit main unit HP and the door phone sub unit DP does not go through the echo canceller circuit, howling is prevented by increasing the loss amount of the voice switch BSW. Here, since a visitor to each dwelling unit generally calls a resident in the dwelling unit using the lobby interphone LP and then reaches the entrance of each dwelling unit, the call using the doorphone slave unit DP is short and simple. In many cases, the need for simultaneous calls is relatively low. For this reason, even if the call between the dwelling unit main unit HP and the door phone slave unit DP is an alternating call, the influence on convenience is small.
[0042]
  Next, FIG. 10 shows an example of the system configuration of a collective housing hands-free call system according to another embodiment of the present invention. In this system, one lobby intercom LP installed at a common entrance of an apartment house and a plurality of dwelling unit masters HP installed at each residence unit in the apartment house are connected by a two-wire communication line L1. In addition, each dwelling unit main unit HP is connected to the door phone slave unit DP installed at the entrance of the dwelling unit by a two-wire communication line L2, and is configured without including an alarm monitoring panel. As with the housing-free hands-free call system shown in FIG. 2, the lobby intercom LP and the dwelling unit master HP, or the doorphone slave unit DP and the dwelling unit base unit HP are connected via the two-wire communication line L1 or L2. You can talk in both directions.
[0043]
  FIG. 11 shows an example of the configuration of this collective housing hands-free call system. The dwelling unit main unit HP and the door phone sub unit DP in the figure have the same configuration as that shown in FIG. The lobby intercom LP includes a reception line composed of a speaker LSK and a reception signal amplifier circuit LRA, a transmission line composed of a microphone LMC and a transmission signal amplifier circuit LSA, and echo canceller circuits EC1 and EC2. 2/4 conversion circuit LCV. In other words, the echo canceller circuits EC1 and EC2 as simultaneous call circuits are provided between the transmission / reception circuit of the lobby intercom LP and the 2/4 conversion circuit LCV.
[0044]
  By adopting such a configuration, the echo canceller circuits EC1 and EC2 wrap around from the speaker LSK of the lobby intercom LP to the microphone LMC during a call between the lobby intercom LP and the dwelling unit main unit HP, in the 2/4 conversion circuit LCV1. Since the influence of the wraparound and the wraparound from the speaker HSK of the dwelling unit base unit HP to the microphone HMC is reduced, simultaneous calls can be made by reducing the loss amount of the voice switch BSW of the dwelling unit base unit HP. On the other hand, at the time of a call between the doorphone slave unit DP and the dwelling unit main unit HP, howling is prevented by increasing the loss amount of the voice switch BSW and performing a call alternately.
[0045]
  Next, FIG. 12 shows a configuration example of the main part of another example of the hands-free call system for an apartment house according to the present invention. This figure shows an alarm monitoring panel XP ′ applied to a hands-free call system for an apartment house. This alarm monitoring panel XP ′ is the same as the echo canceller EC1 in the alarm monitoring panel XP shown in FIG. Amplifier circuits AP1 and AP2 are provided between the echo canceller EC2.
[0046]
  The operation of the alarm monitoring board XP 'will be described below. 13A shows the main part of the alarm monitoring panel XP shown in FIG. 1, and FIG. 13B shows the main part of the alarm monitoring board XP ′ shown in FIG. It is a thing. Note that the gain described in the figure is an example of gain related to each amplifier circuit, the speaker XSK, and the reception signal and transmission signal.
[0047]
  In order for the echo canceller circuit EC1 to prevent howling due to sneaking from the speaker XSK to the microphone XMC, it is necessary that the sneaking gain from point A to point B in the figure is 0 dB or less. In other words, the echo canceller circuit EC1 has to have a gain until the reception signal output from the echo canceller circuit EC1 to the reception line wraps around the transmission line and is input again to the echo canceller circuit EC1 as a transmission signal is 0 dB or less. Therefore, the received reception signal component cannot be sufficiently removed.
[0048]
  However, in order to make a comfortable call, it is necessary to secure a predetermined gain for the received signal and the transmitted signal, and thus the gain of each amplifier circuit must be increased. Therefore, if the loss amount from the speaker XSK to the microphone and the phone XMC cannot be increased, the wraparound gain cannot be reduced to 0 dB or less. (A) in the figure shows this state. When the transmission gain from the speaker XSK to the microphone XMC is −20 dB, 30 dB is obtained as the gain for the received signal and 30 dB is obtained as the gain for the transmitted signal. If it is desired to ensure, the gain of each amplifier circuit needs to be 10 dB. In this case, the wraparound gain from point A to point B is 20 dB, and the received signal component that wraps around the transmitted signal is reduced. It cannot be removed sufficiently.
[0049]
  However, the circuit shown in (b) in the figure is provided with amplifier circuits AP1 and AP2 having a gain of 10 dB between the echo canceller circuits EC1 and EC2, so that the transfer gain from the speaker XSK to the microphone XMC is −20 dB. In this case, even if the gain of each amplifier circuit from point A to point B is 5 dB, 30 dB can be secured as the gain for the received signal and the received signal. For this reason, the wraparound gain from point A to point B can be set to 0 dB.
[0050]
  That is, by providing an amplifier circuit between the two echo cancellers, the wraparound gain can be suppressed to 0 dB or less while securing the gain of the received signal and the transmitted signal, so that the echo canceller circuit EC1 has wrapped around. The received signal component can be sufficiently removed. Next, FIG. 14 shows a configuration example of a main part of the hands-free call system for an apartment house according to the present invention as set forth in claim 8. This figure shows a voice switch that is applied to the dwelling unit main unit HP of the housing-free hands-free communication system shown in FIG. 1, and this voice switch BSW1 includes a reception loss variable circuit RVA and a transmission line. An analog switch RJ1, SJ1 is provided in a voice switch constituted by the loss amount variable circuit SVA and the loss amount control circuit VAC.
[0051]
  If this analog switch RJ1 is provided on the reception line and is connected to the contact a side, the reception signal is attenuated by a predetermined loss amount by the reception loss variable circuit RVA and output. When connected to the contact b side, the reception signal is output as it is without passing through the reception loss variable circuit RVA. The analog switch SJ1 is provided on the transmission line, and if it is connected to the contact a side, the transmission signal is attenuated and output, but if it is connected to the contact b side, it is output without being attenuated. .
[0052]
  These analog switches RJ1 and SJ1 are controlled so as to be connected to the contact a side during a call with the lobby interphone LP or the alarm monitoring panel XP, and to be connected to the contact b side during a call with the door phone slave unit DP. . Therefore, the voice switch BSW1 is inserted into the transmission / reception line and functions effectively when talking with the doorphone slave unit DP, while preventing howling due to the alternate call, while talking with the lobby interphone LP or the alarm monitoring panel XP. Since the voice switch BSW1 is separated from the transmission / reception line, the voice switch BSW1 does not function as a voice switch, and simultaneous calls are possible.
[0053]
  FIG. 15 shows a configuration example of a main part of still another hands-free call system for an apartment house according to the present invention. This figure shows a voice switch that is applied to the dwelling unit main unit HP of the housing-free hands-free call system shown in FIG. 1, and this voice switch BSW2 includes a reception loss variable circuit RVA and a transmission line. A voice switch constituted by the loss variable circuit SVA and the loss control circuit VAC is provided with analog switches RJ2 and SJ2 and addition circuits RAD and SAD.
[0054]
  The voice switch BSW2 includes a reception bypass line RBP that bypasses the reception loss variable circuit RVA and a transmission bypass line SBP that bypasses the transmission loss variable circuit SVA, and the analog switch RJ2 receives the reception bypass line. Provided in the RBP, the analog switch SJ2 is provided in the transmission bypass line SBP. The addition circuit RAD is a circuit that adds and outputs the reception signal from the reception loss variable circuit RVA and the reception signal from the reception bypass line RBP. The addition circuit SAD outputs the transmission loss variable circuit SVA. This is a circuit that adds the transmission signal and the transmission signal from the transmission bypass line SBP and outputs the result.
[0055]
  The analog switches RJ2 and SJ2 are both closed during a call with the lobby interphone LP or the alarm monitoring panel XP, and are both opened during a call with the doorphone slave unit DP. Therefore, at the time of a call with the intercom unit DP, only the signal from the reception loss variable circuit RVA is input to the addition circuit RAD, and the signal from the transmission loss variable circuit SVA is input to the addition circuit SAD. Therefore, the voice switch BSW2 functions as a normal voice switch and prevents howling due to the alternate call.
[0056]
  On the other hand, during a call with the lobby intercom LP or the alarm monitoring board XP, in addition to the signal from the reception loss variable circuit RVA, an unattenuated signal from the reception bypass line RBP is also input to the addition circuit RAD. In addition to the signal from the transmission loss variable circuit SVA, an unattenuated signal from the transmission bypass line SBP is also input to the circuit SAD.
[0057]
  At this time, if the loss amount in the reception loss variable circuit RVA and the transmission loss variable circuit SVA is large, the signal from the reception bypass line RBP or the transmission bypass line SBP becomes dominant, and approximately the voice switch BSW2 Becomes the same state as when the telephone is separated from the transmission / reception line, and simultaneous calls are possible.
[0058]
【The invention's effect】
  A hands-free call system for collective housing according to the present invention as set forth in claim 1 is provided with a two-person selection switching circuit and a simultaneous call circuit in an alarm monitoring panel, and this simultaneous call circuit is used as a dwelling unit, alarm monitoring panel and lobby intercom. Therefore, it is possible to make a simultaneous call between any two of the three parties without providing a simultaneous call circuit for the dwelling unit and the lobby intercom.
[0059]
  Therefore, it is possible to provide a housing-free hands-free call system for an apartment house that allows simultaneous calls between any two of the dwelling unit, the alarm monitoring panel, and the lobby intercom.
[0060]
  The hands-free call system for collective housing according to the present invention described in claim 2 is a system that is not provided with an alarm monitoring panel, and is provided with a simultaneous call circuit in a lobby intercom. The loss level of the signal level that is controlled to be larger, and the loss level of the signal level whose loss level is largely controlled isWith lobby intercomDuring a call, an alternate call circuit that is controlled to be smaller than when calling with a door phone slave unit,With lobby intercomBecause it is equipped with doorphone switching means for switching between calls and calls with doorphone slave units, the lobby interphone and each dwelling unit parent unit are installed in each dwelling unit without having a simultaneous call circuit. Simultaneous calls are possible.
[0061]
  Therefore, it is possible to provide a housing-free hands-free calling system that enables simultaneous calls between the dwelling unit master and the lobby intercom at a low cost.
[0062]
  In addition, an alternate call circuit is connected to the dwelling unit.With lobby intercomCompared to when talking between the DOU base unit and the door phone slave unit, the amount of attenuation in the direction of the call to be blocked is reduced to reduce the feeling of disconnection due to alternate calls. In addition to preventing howling by calling,With lobby intercomIt is possible to provide a hands-free calling system for collective housing that allows simultaneous calls with little sense of disconnection during calls.
[0063]
  The hands-free call system for collective housing according to the present invention as set forth in claim 3, when the alternate call circuit is a call between the dwelling unit base unit and the alarm monitoring panel or the lobby intercom, as compared with the time during a call between the dwelling unit base unit and the door phone sub unit, Decreasing the amount of attenuation in the direction of the call to be blocked reduces the feeling of disconnection due to alternate calls.
[0064]
  Therefore, providing a hands-free call system for collective housing that prevents simultaneous howling from occurring during alternate phone calls and enables simultaneous calls with little sense of disconnection when calling with alarm monitoring panels or lobby intercoms. can do.
[0065]
  In the hands-free call system for collective housing according to the present invention as set forth in claim 4, the simultaneous call circuit is configured as an echo canceller circuit comprising an adaptive filter and a subtractor circuit, and removes the received signal component that wraps around the transmission line.
[0066]
  In other words, the wraparound component is removed by an echo canceller circuit, and the dwelling unit main unit, alarm monitoring panel or Can provide a hands-free call system for multi-dwelling houses that allows simultaneous calls between lobby intercoms.
[0067]
  In the hands-free call system for collective housing according to the present invention as set forth in claim 5, the simultaneous call circuit is constituted by two echo canceller circuits, and each echo canceller circuit removes the sneak components of both speakers.
[0068]
  Therefore, by providing a simultaneous call circuit only on the alarm monitoring panel or lobby intercom, it is possible to remove the wraparound component on each speaker side and perform simultaneous calls between the dwelling unit master unit, alarm monitoring panel or lobby intercom. It is possible to provide a hands-free call system for collective housing.
[0069]
  The hands-free call system for an apartment house according to the present invention as set forth in claim 6 is provided with an amplifier circuit between two echo canceller circuits constituting the simultaneous call circuit, while ensuring the gain of the received signal and the transmitted signal. By suppressing the wraparound gain to a low level, the echo canceller circuit can sufficiently remove the wraparound received signal component.
[0070]
  Accordingly, it is possible to provide a hands-free call system for collective housing that can effectively suppress howling while ensuring a comfortable call.
[0071]
  In the hands-free call system for collective housing according to the present invention as set forth in claim 7, the alternate call circuit is composed of a variable reception loss amount circuit, a variable transmission loss amount circuit, and a loss amount control circuit. The circuit changes the loss amount of these variable loss amount circuits based not only on the direction of the call but also on the connection state of the door phone switching means.
[0072]
  Therefore, with a simple configuration, it is possible to realize a system in which alternate calls are made when calling with a doorphone slave unit, and simultaneous calls are made when calling with an alarm monitoring panel or lobby intercom. The system can be provided at low cost.
[0073]
  In the hands-free call system for an apartment house according to the present invention as set forth in claim 8, when the alternate call circuit makes a call with the alarm monitoring panel or the lobby intercom, neither the transmission signal nor the reception signal is attenuated.
[0074]
  Therefore, providing a hands-free call system for multi-dwelling houses that can prevent simultaneous howling from occurring during alternate phone calls when talking to doorphone handsets, and allows simultaneous calls without a sense of disconnection when talking to alarm monitoring panels or lobby intercoms. can do.
[0075]
  According to the ninth aspect of the present invention, there is provided a housing-free hands-free call system according to the present invention. The sum of the received signal and the received signal is used as the transmitted / received signal.
Therefore, providing a hands-free call system for multi-dwelling houses that can prevent simultaneous howling from occurring during alternate phone calls when talking to doorphone handsets, and allows simultaneous calls without a sense of disconnection when talking to alarm monitoring panels or lobby intercoms. can do.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration example of a hands-free call system for an apartment house according to the present invention.
FIG. 2 is a diagram showing an example of a system configuration of a hands-free call system for an apartment house.
FIG. 3 is a diagram showing only the configuration at the time of a call between an alarm monitoring panel and a lobby intercom, with respect to the collective housing hands-free call system shown in FIG. 1;
FIG. 4 is a diagram illustrating a configuration example of an echo canceller circuit.
5 is a diagram showing a configuration example of a simultaneous call circuit used in the alarm monitoring panel shown in FIG. 1. FIG.
FIG. 6 is a diagram showing only the configuration at the time of a call between a dwelling unit and a door phone cordless handset, with respect to the collective housing hands-free call system shown in FIG. 1;
FIG. 7 is a diagram showing only the configuration at the time of a call between the dwelling unit and the alarm monitoring panel, with respect to the collective housing hands-free call system shown in FIG. 1;
FIG. 8 is a diagram showing a configuration example of a voice switch used in the dwelling unit master shown in FIG. 1;
9 is a diagram showing only the configuration at the time of a call between the dwelling unit main unit HP and the lobby intercom LP with respect to the hands-free call system for an apartment house shown in FIG. 1;
FIG. 10 is a view showing an example of another system configuration of the hands-free call system for an apartment house according to the present invention.
FIG. 11 is a diagram showing a configuration example of a hands-free call system for an apartment house.
FIG. 12 is a diagram showing a configuration example of a main part of still another example of the hands-free call system for an apartment house according to the present invention.
FIG. 13 is a diagram showing an example of the gain of the amplification circuit of the hands-free call system for an apartment house.
FIG. 14 is a view showing a configuration example of a main part of still another example of the hands-free call system for an apartment house according to the present invention.
FIG. 15 is a diagram showing a configuration example of a main part of still another example of the hands-free call system for an apartment house according to the present invention.
[Explanation of symbols]
LP ・ ・ ・ Lobby Intercom
XP: Alarm monitoring panel
HP ... Dwelling unit
L0 to L2 ... 2-wire communication line
EC1, EC2 ... Simultaneous call circuit, echo canceller circuit
XJ1, XJ2 ... Two-way selection switching circuit
Wa, Wb ... Adaptive filter
SBa, SBb ... subtracting circuit
AP1, AP2 ... Amplifier circuit
BSW ・ ・ ・ alternate call circuit
SVA: Transmission loss variable circuit
RVA: Receive loss variable circuit
VAC ... Loss amount control circuit
RBP, SBP ... Bypass circuit
RJ2, SJ2 ... Analog switches

Claims (9)

Hands for collective housing, consisting of a lobby intercom installed at the common entrance of the apartment building and a dwelling unit base unit installed in each unit of the apartment building connected via a two-line telephone line via an alarm monitoring panel A free call system,
The alarm monitoring panel selects any two of the simultaneous communication circuit that suppresses the reception signal component included in the transmission signal, the dwelling unit, the alarm monitoring panel, and the lobby intercom due to the reception signal wraparound. Two-way selection switching means connected by a telephone line, wherein the simultaneous call circuit is shared for calls between any two of the dwelling unit, alarm monitoring panel and lobby intercom Free call system. The lobby intercom installed at the common entrance of the apartment house and the dwelling unit base unit installed in each dwelling unit of the apartment house are connected by a two-wire telephone line, and the dwelling unit base unit is further installed at the entrance of the dwelling unit A hands-free calling system for collective housing, which is configured to be connected to each of the doorphone slave units, and enables simultaneous calling between the lobby intercom and the dwelling unit,
The lobby intercom includes a simultaneous call circuit that suppresses a received signal component included in a transmitted signal due to a wraparound of the received signal,
The above dwelling unit is
The loss level of the signal level of the smaller one of the transmission signal level and the reception signal level is largely controlled, and the loss amount of the signal level of which the loss amount is largely controlled is determined when talking with the lobby intercom . An alternate call circuit that is controlled to be smaller than when talking with a doorphone handset,
A hands-free call system for collective housing, comprising door phone switching means for switching between a call with a lobby intercom and a call with a door phone slave. A hands-free call system for an apartment house according to claim 1,
The above dwelling unit is
The loss level of the signal level of the smaller one of the transmission signal level and the reception signal level is largely controlled, and the loss level of the signal level of which the loss level is largely controlled is determined by the lobby intercom or the alarm monitoring panel. During the call, the alternate call circuit that controls smaller than the call with the door phone handset,
A hands-free call system for collective housing, comprising door phone switching means for switching a call with a lobby intercom or an alarm monitoring panel and a call with a door phone slave unit. A hands-free call system for collective housing according to claim 2 or 3 ,
The simultaneous call circuit is
The transfer function until the received signal output from the simultaneous call circuit wraps around the transmission line and is input again to the simultaneous call circuit as the transmit signal is identified, and the received signal is convolved with the identified transfer function. An adaptive filter;
A hands-free call system for an apartment house comprising an echo canceller circuit including a subtracting circuit for subtracting the output signal of the adaptive filter from the transmission signal. A hands-free call system for collective housing according to claim 4 ,
The simultaneous call circuit is
An echo canceller circuit for suppressing a received signal component included in a transmission signal from one speaker;
A hands-free call system for an apartment house comprising an echo canceller circuit for suppressing a received signal component contained in a transmitted signal from the other speaker. A hands-free call system for an apartment house according to claim 5 ,
The simultaneous call circuit is
A hands-free call system for an apartment house, characterized in that an amplifier circuit is provided in a transmission line or a reception line between two echo canceller circuits. A hands-free call system for collective housing according to any one of claims 2 to 6 ,
The alternating call circuit
A transmission loss variable circuit that is provided in the transmission line and changes the gain or loss of the transmission signal;
A reception loss variable circuit that is provided in the reception line and changes the gain or loss of the reception signal;
It is composed of a loss amount control circuit that monitors the signal level of the transmission line and the reception line, and controls the gain or loss amount of the transmission loss amount variable circuit and the reception loss amount variable circuit,
The collective housing hands-free call system, wherein the loss amount control circuit further changes the loss amount of the reception loss variable circuit or the transmission loss variable circuit based on the connection state of the doorphone switching means. . It is a collective housing hands-free call system according to claim 1, wherein the dwelling unit is further connected to a door phone sub unit installed at the entrance of the dwelling unit.
The above-mentioned dwelling unit is
During the transmission of the voice signal of one speaker, an alternating call circuit that attenuates the voice signal of the other speaker and transmits only one of the voice signals to the other;
Door phone switching means for switching between a call with the lobby intercom or the alarm monitoring panel and a call with the door phone slave unit,
A collective housing hands-free call system, wherein the alternate call circuit is configured as means for preventing the voice signal of the other speaker from being attenuated during a call with a lobby intercom or an alarm monitoring panel. It is a collective housing hands-free call system according to claim 1, wherein the dwelling unit is further connected to a door phone sub unit installed at the entrance of the dwelling unit.
The above-mentioned dwelling unit is
An alternating communication circuit that transmits only one of the voice signals to the other by attenuating the received signal while transmitting and attenuating the transmitted signal during receiving;
Door phone switching means for switching between a call with a lobby intercom or an alarm monitoring panel and a call with a door phone slave unit;
A circuit for adding a call signal from the alternate call circuit and a call signal from a bypass line not passing through the alternate call circuit, an adder circuit provided in a transmission line or a reception line;
An analog switch provided in the bypass line,
A hands-free call system for collective housing, wherein the analog switch is closed when a call is made with a lobby intercom or an alarm monitoring panel, and is opened when a call is made with a door phone slave unit.

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