JP2009303134A - Public-address system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a public-address system for reducing power consumption when a public-address area is not congested. <P>SOLUTION: The public-address system 1 includes: a plurality of speakers 3 installed in a public-address area; a congestion level detecting unit 21 for detecting a congestion level parameter representing the degree of congestion in the public-address area; a congestion level determining unit 23 for determining whether or not the public-address area is in a non-congested state on the basis of the congestion level parameter; and a speaker power supply control unit 25 for controlling supply of power to the plurality of speakers 3 so as to turn off a part of the plurality of speakers 2 when the public-address area is in the non-congested state. As the congestion level parameter, sound pressure in the public-address area is detected. The sound pressure in the public-address area may be determined from input audio signals acquired by using the speakers 3 as microphones. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a loudspeaker system that outputs sound from a plurality of speakers installed in a loudspeaker area.

  Conventionally, as a loudspeaker system, for example, a business broadcast system that performs local broadcasting in a department store, a factory, a company, or the like is known. In a conventional general loudspeaker system, power to system components including an amplifier and a speaker is turned on all at once before the start of work, the energized state is maintained during working hours, and the power is turned off all at once after working.

  In the conventional loudspeaker system, the volume is adjusted according to the degree of congestion in the loudspeaker area. In the volume adjustment, the playback volume level of the sound source device is set to be high or the reception volume level on the speaker side is set to be high in a time zone where congestion is expected.

Patent Document 1 and Patent Document 2 disclose a loudspeaker system having an automatic power on / off function. Patent Document 1 discloses a nurse call device, which supplies power to a speaker amplifier with a call from a patient as a trigger, and normally turns off the power. Patent Document 2 discloses a gas leak alarm. In this document, power is supplied to the speaker amplifier when an abnormality occurs, and the power is normally turned off.
JP 2001-268251 A JP-A-62-24399

  However, the conventional general loudspeaker system has a problem that the power of the speaker remains on even when the loudspeaker area is quiet, and power is wasted. This is the same in a loudspeaker system that adjusts the volume during quiet periods and when it is congested. That is, even if the volume is adjusted, the power of the speaker is always on, and power is wasted.

  In the volume adjustment in the conventional loudspeaker system, a time zone in which congestion occurs is predicted in advance, a schedule is created so that the volume is increased during the predicted time zone, and the volume is automatically adjusted using a timer according to the schedule. In this case, there is a problem that the predicted time zone and the actual congestion time zone are deviated. In addition, the operator can manually adjust the volume according to the degree of congestion. It is also possible to adjust the volume for each broadcasting location using a dedicated volume control device. However, manual adjustment requires personnel for monitoring and operation, and there is a problem that proper volume adjustment cannot be performed when the degree of congestion varies.

  The conventional loudspeaker system described above turns off the amplifier power when there is no patient call. In another conventional loudspeaker system, the amplifier power is turned off when there is no abnormality. However, these conventional loudspeaker systems are not effective in reducing power consumption when the loudspeaker area is quiet. That is, in the loudspeaker area, it is necessary to secure a volume that allows people in the area to listen to the broadcast even when it is quiet, but the conventional system cannot secure the necessary volume because the amplifier power is turned off.

  The present invention was made in order to solve the conventional problem, and its purpose is to secure a volume necessary for a person in the loudspeaking area to listen to the broadcast when the loudspeaking area is not congested. An object of the present invention is to provide a loudspeaker system that can reduce power consumption.

  The loudspeaker system of the present invention includes a plurality of speakers installed in a loudspeaker area, a congestion degree detection unit that detects a congestion degree parameter that indicates the degree of congestion in the loudspeaker area, and the congestion detected by the congestion degree detection unit. Based on the degree parameter, the loudness area determination unit that determines whether or not the loudness area is in a non-congested state, and the loudness area is in the non-congested state based on the determination result of the congestion degree determination unit A speaker power supply control unit configured to control power supply to the plurality of speakers so as to turn off some of the plurality of speakers.

  With this configuration, the congestion level parameter of the loudspeaker area is detected, and when some loudspeaker areas are not congested, some speakers are turned off. Since some of the speakers are turned off, broadcasting can be continued. Therefore, when the loudspeaker area is not congested, it is possible to reduce power consumption while securing a volume necessary for a person in the loudspeaker area to listen to the broadcast.

  In the loudspeaker system of the present invention, the congestion level detection unit detects a sound pressure in the loudspeaker area as the congestion level parameter. With this configuration, sound pressure is used as a congestion degree parameter, and power consumption can be suitably reduced according to the congestion degree.

  In the loudspeaker system according to the present invention, the congestion degree detection unit obtains an average value of the sound pressures during a predetermined sound pressure measurement time. With this configuration, since the average value of sound pressure is used, it is possible to avoid erroneously determining that congestion has occurred when sudden sound occurs. Therefore, power control according to the degree of congestion can be performed accurately.

  In the loudspeaker system of the present invention, the congestion degree detection unit obtains the sound pressure of the loudspeaker area from an input voice signal acquired by causing at least one of the plurality of speakers to function as a microphone. With this configuration, since the speaker functions as a microphone, the degree of congestion can be suitably detected without providing a separate microphone.

  In the loudspeaker system according to the present invention, the congestion degree determination unit compares the sound pressure with a predetermined threshold sound pressure, and the speaker power supply control unit determines whether the plurality of speakers have a sound pressure that is equal to or lower than the threshold sound pressure. Turn off the power supply to some parts. With this configuration, power control according to the degree of congestion can be performed by comparing the sound pressure with a predetermined threshold sound pressure. Power consumption can be reduced by a relatively simple process.

  In the loudspeaker system of the present invention, the threshold sound pressure is set differently for the plurality of speakers, and the congestion degree determination unit compares the sound pressure with the threshold sound pressure corresponding to each speaker, The speaker power control unit turns off the power of the corresponding speaker when the sound pressure is equal to or lower than the threshold sound pressure. With this configuration, a different number of speakers are turned off according to the detected sound pressure. Therefore, with a simple configuration in which the threshold sound pressure is set for each speaker, the number of power-off speakers can be controlled to further reduce power consumption.

  Further, in the loudspeaker system according to the present invention, the congestion degree determination unit analyzes a tendency of a sound pressure change to determine whether or not there is a sound pressure change tendency corresponding to the non-congested state, and the speaker power control The unit turns off power supply to a part of the plurality of speakers when there is a tendency to change sound pressure corresponding to the non-congested state.

  With this configuration, it is possible to analyze the tendency of the sound pressure change and perform power control of the speaker according to the degree of congestion, thereby reducing power consumption. This configuration is advantageous in the following points. It may not be easy to appropriately set the threshold sound pressure as an absolute reference for determining the degree of congestion. For example, it is assumed that the sound transmission state differs depending on the place and the appropriate threshold sound pressure is different. In this case, it is required to set the threshold sound pressure by actually measuring the sound pressure at various places. However, such work is not easy. Further, unlike the case of using a dedicated microphone, when a speaker is used as a microphone, the sound pressure measurement location is limited to the speaker installation location, and therefore, it is not easy to appropriately set the threshold sound pressure. On the other hand, the present invention focuses on the fact that the characteristics of the sound pressure change differ depending on the degree of congestion. Since the degree of congestion is determined based on such a sound pressure change characteristic, the degree of congestion can be detected easily and appropriately.

  In the loudspeaker system according to the present invention, the congestion degree determination unit may determine whether the sound pressure tends to decrease continuously over a predetermined non-congestion reference time as the sound pressure change tendency corresponding to the non-congested state. Determine. With this configuration, the degree of congestion can be suitably determined by analyzing the sound pressure change tendency. Since it is not necessary to use an absolute standard such as a threshold sound pressure, the degree of congestion can be detected easily and appropriately.

  In the loudspeaker system according to the present invention, the congestion degree determination unit may determine whether the sound pressure tends to decrease continuously over a predetermined non-congestion reference time as the sound pressure change tendency corresponding to the non-congested state. Determine. With this configuration, the degree of congestion can be suitably determined by analyzing the sound pressure change tendency. Since it is not necessary to use an absolute standard such as a threshold sound pressure, the degree of congestion can be detected easily and appropriately.

  Further, in the loudspeaker system according to the present invention, a determination criterion for a sound pressure change tendency corresponding to the non-congested state is set differently for the plurality of speakers, and the congestion degree determination unit includes the determination corresponding to each speaker. The tendency of the sound pressure change is analyzed using the reference, and the speaker power supply control unit turns off the power of the speaker corresponding to the determination result that there is a tendency to change the sound pressure corresponding to the non-congested state. With this configuration, a different number of speakers are turned off depending on the degree of congestion. With a simple configuration in which a criterion for determining a sound pressure change tendency is set for each speaker, the number of power-off speakers can be controlled to further reduce power consumption.

  In the loudspeaker system of the present invention, the speaker power supply control unit changes the number of speakers to be turned off in a stepwise manner according to the degree of congestion of the loudspeaker area. With this configuration, it is possible to supply power to an appropriate number of speakers according to the degree of congestion, and to turn off the remaining speakers. Therefore, it is possible to control the number of power-off speakers and further reduce power consumption.

  Further, the loudspeaker system control method of the present invention detects a congestion degree parameter indicating the degree of congestion in a loudspeaker area where a plurality of speakers are installed, and based on the congestion degree parameter, is the loudness area in an uncongested state? The power supply to the plurality of speakers is controlled so as to turn off the power of some of the plurality of speakers when the loudspeaker area is in the non-congested state. Also by this method, the above-mentioned advantages of the present invention can be obtained. Of course, the various configurations described with respect to the loudspeaker system aspects may also be applied to this method aspect.

  Another aspect of the present invention is a loudspeaker control program executed by a system control unit of a loudspeaker system including a plurality of speakers installed in the loudspeaker area, the congestion representing the degree of congestion in the loudspeaker area A loudness parameter is detected, and based on the congestion degree parameter, it is determined whether or not the loudspeaking area is in a non-congested state. The system control unit is caused to execute processing for controlling power supply to the plurality of speakers so as to turn off. Also with this configuration, the above-described advantages of the present invention can be obtained. Of course, the various configurations described with respect to the loudspeaker system aspect may also be applied to this aspect.

  The present invention detects the congestion level of the loudspeaker area, and when the loudspeaker area is not crowded by providing a configuration to turn off at least some of the speakers when the loudspeaker area is not crowded, It is possible to provide a loudspeaking system having an effect of reducing wasteful power consumption while ensuring a volume necessary for a person in the loudspeaking area to listen to the broadcast.

  Hereinafter, a loudspeaker system according to an embodiment of the present invention will be described with reference to the drawings.

  A loudspeaker system according to the first embodiment of the present invention is shown in FIG. In the example of the present embodiment, the loudspeaker system 1 is a department store premises business broadcasting system. However, it goes without saying that the loudspeaker system 1 is not limited to the on-site business broadcasting system.

  In FIG. 1, the loudspeaker system 1 includes a plurality of speakers 3, a plurality of amplifiers 5, a power supply unit 7, and a system control unit 9. The plurality of speakers 3 are connected to the power supply unit 7 via a plurality of amplifiers 5. Each speaker 3 is supplied with power from a power supply unit 7 via an amplifier 5.

  As shown in FIG. 1, in the present embodiment, a speaker line 11 extends from each amplifier 5, and a plurality of speakers 3 are connected to each speaker line 11. The speaker line 11 is not only a power supply line but also an audio line for broadcasting, and supplies an audio signal to be broadcast to each speaker 3. For example, a plurality of loudspeaker areas are set on each of a plurality of floors. Each loudspeaker area is provided with one or a plurality of speaker lines 11, and a plurality of speakers 3 are connected to each speaker line 11.

  Each speaker 3 is further connected to the system control unit 9 via a control line 13 indicated by a wavy line and a sound collecting line 15 indicated by a double line. The control line 13 is provided for the system control unit 9 to control each speaker 3 individually. In the present embodiment, the control line 13 is used for power control of the speaker 3. Specifically, the power switch provided in each speaker 3 is controlled to be turned on and off, and the connection to the speaker line 13 is disconnected by the switch off. . In FIG. 1, for the sake of simplification, one control line 13 is shown to extend corresponding to each speaker line 11, and then branched to be connected to a plurality of speakers 3. In an actual configuration, a control line 13 may be provided for each speaker 3. Further, the sound collecting voice line 15 is used to collect the sound in the loudspeaker area by causing the speaker 3 to function as a microphone, as will be described below.

  The system control unit 9 is configured by a computer and controls the entire loudspeaker system 1. The system control unit 9 detects a congestion degree parameter indicating the degree of congestion in the loudness area, and the loudness area is in a non-congested state based on the congestion degree parameter detected by the congestion degree detection unit 21. A congestion degree determination unit 23 for determining whether or not the speaker power supply control unit 25 controls power supply to the plurality of speakers 3 based on the determination result of the congestion degree determination unit 23. The speaker power supply control unit 25 includes: The power on / off of each speaker 3 is controlled.

  In the present embodiment, the sound pressure is obtained as the congestion degree parameter. In order to detect sound pressure, the system control unit 9 controls the plurality of speakers 3 to function as microphones. As is well known, the speaker and the microphone have the same structure, and the speaker can function as a microphone in principle. Using this function, the system control unit 9 controls the speaker 3 to function as a microphone, and acquires the sound signal of the loudspeaker area via the sound collecting sound line 15. The system control unit 9 stops the sound output from the speaker 3 when the speaker 3 functions as a microphone.

  The speaker 3 may be a microphone speaker in which a microphone and a speaker are integrated. In this case, the microphone function of the microphone speaker may be controlled by the system control unit 9.

  FIG. 2 shows the configuration of the system control unit 9. As described above, the system control unit 9 includes the congestion level detection unit 21, the congestion level determination unit 23, and the speaker power source control unit 25. The congestion level detection unit 21 includes an A / D conversion unit 31, a sound pressure calculation processing unit 33, and an averaging processing unit 35. The system control unit 9 further includes a calculation result storage unit 41 and a threshold sound pressure storage unit 43.

  An audio signal is input to the system control unit 9. As described above, the audio signal is collected by the speaker 3 functioning as a microphone and input to the system control unit 9. The A / D conversion unit 31 of the congestion degree detection unit 21 converts the input analog audio signal into a digital audio signal.

  The sound pressure calculation processing unit 33 processes the sound signal converted into the digital format to calculate the sound pressure, stores the sound pressure data in the calculation result accumulation unit 41, and averages the sound pressure data to the averaging processing unit 35. To supply.

  The averaging processing unit 35 calculates an average value of sound pressures during a predetermined sound pressure measurement time. Here, the latest sound pressure data is acquired from the sound pressure calculation processing unit 33, the sound pressure data of the past predetermined time is acquired from the calculation result storage unit 41, and the average value is calculated.

  The processing of the congestion level detection unit 21 is performed for each speaker line 11, for example. When a plurality of speakers 3 are used as microphones in one speaker line 11, a plurality of sound pressure average values are calculated from the sound inputs of the plurality of speakers 3. In this case, the plurality of sound pressure average values may be further averaged. Note that the processing of the congestion degree determination unit 23 and the speaker power supply control unit 25 described below is also performed for each speaker line 11.

  The congestion level determination unit 23 processes the sound pressure average value as the congestion level parameter supplied from the averaging processing unit 35 to determine whether the loudness area is in a non-congested state. In the present embodiment, the congestion level determination unit 23 determines the congestion level using the threshold sound pressure. The threshold sound pressure is set in advance and stored in the threshold sound pressure storage unit 43. The congestion degree determination unit 23 compares the average value of the sound pressure acquired from the averaging processing unit 35 with the threshold sound pressure, and determines whether or not the average value of the sound pressure is equal to or lower than the threshold sound pressure. If the average value of the sound pressure is equal to or lower than the threshold sound pressure, the degree of congestion is low and the loudspeaking area is in a non-congested state.

  Here, the setting of the threshold sound pressure will be further described. As described above, the threshold sound pressure is used to determine the presence or absence of congestion. The threshold sound pressure may be set according to the predicted maximum sound pressure in the non-congested state. The threshold sound pressure may be equal to the predicted maximum sound pressure. The threshold sound pressure may be set to a value obtained by adding an appropriate value to the predicted maximum sound pressure. In this case, the power saving effect of the present invention can be increased. The threshold sound pressure may be set to a value obtained by subtracting an appropriate value from the predicted maximum sound pressure. In this case, the control according to the present invention is performed when the loudspeaking area is surely in a non-congested state.

  The predicted maximum sound pressure in the non-congested state may be obtained by actual measurement. For example, the sound pressure is measured when the loudspeaker area is relatively quiet just after the start of work. A plurality of measurement results may be statistically processed to determine the expected maximum sound pressure. The threshold sound pressure is suitably set using the predicted maximum sound pressure obtained in this way. In the example of the present embodiment, the loudspeaker system 1 is installed in a department store. In this case, it is desirable to set the threshold sound pressure for each floor and each loudspeaker area. The threshold sound pressure is stored in the threshold sound pressure storage unit 43, is referred to by the congestion level determination unit 23, and is used for determination of the congestion level.

  The speaker power supply control unit 25 is configured to control power supply to each of the plurality of speakers 3. The speaker power supply control unit 25 performs a process of turning off at least some of the power supplies of the plurality of speakers 3 when the congestion degree determination unit 23 determines that the loudspeaker area is in a non-congested state. Specifically, when the sound pressure is equal to or lower than the threshold sound pressure as determined by the congestion degree determination unit 23, the power-off control is performed. The speaker power control unit 25 turns off the power of a predetermined number, for example, half the number of speakers 3. The power-off control is preferably executed when the non-congested state continues for a predetermined time.

  As described above, the processing of the congestion level detection unit 21, the congestion level determination unit 23, and the speaker power source control unit 25 is performed for each speaker line 11. Therefore, when the sound pressure in a certain speaker line 11 becomes equal to or lower than the threshold sound pressure, the speaker power control unit 25 turns off the power of a predetermined number of speakers 3 connected to the corresponding speaker line 11.

  In addition, the number of speakers that turn off the power in the above control is set as follows. Even if the loudspeaker area is not congested, it is necessary to secure the volume necessary for listening to people in the area. The number of speakers that can ensure this required volume should be maintained in a power-on state. Therefore, the number of power-off speakers is set to a value obtained by subtracting the number of speakers necessary for the above listening from the total number of speakers in each loudspeaker area. The number of power-off speakers may be set differently for each loudspeaker area.

  In the above control, which speaker is turned off may be set in advance. It is desirable that the power-off speakers are properly distributed. For example, when turning off half of the speakers, every other speaker is turned off.

  The configuration of the loudspeaker system 1 has been described above. Next, the operation of the loudspeaker system 1 will be described with reference to FIG.

  As shown in FIG. 3, the system control unit 9 acquires an audio signal from the loudspeaker area by causing the speaker 3 to function as a microphone (S1). The A / D conversion unit 31 converts the input audio signal in the analog format into the audio signal in the digital format (S3), the sound pressure calculation processing unit 33 calculates the sound pressure (S5), and the averaging processing unit 35 performs the predetermined processing. The average value of sound pressure over time is calculated (S7).

  The congestion degree determination unit 23 compares the sound pressure (average value) obtained from the averaging processing unit 35 with the threshold sound pressure stored in the threshold sound pressure storage unit 43 (S9). As a result of the comparison, if the sound pressure is greater than the threshold sound pressure (S11, Yes), the degree of congestion is “high” and the loudspeaker area is not in a non-congested state, that is, not in a quiet state. Therefore, the speaker power supply control unit 25 supplies power to the plurality of speakers 3 (S13).

  When the measured sound pressure is equal to or lower than the threshold sound pressure (S11, No), the degree of congestion is “low” and the loudspeaking area is in a non-congested state. Therefore, the speaker power control unit 25 turns off the power of the predetermined number of speakers 3 (S15).

  The above processing is performed individually for each of the plurality of speaker lines 11. The speaker line 11 is provided for each floor and each loudspeaker area. Therefore, the power supply to the speaker 3 can be controlled in each loudspeaker area according to the degree of congestion.

  Moreover, said process may be performed in real time and may be performed regularly. However, in this embodiment, if the speaker is frequently turned on and off, the power consumption may increase. Considering this point, it is desirable to perform the above processing periodically. The processing cycle is preferably set sufficiently long, for example, 30 minutes.

  In the above embodiment, the plurality of speakers 3 are connected to one speaker line 11 (broadcast audio line). However, in another configuration example, each speaker 3 is connected to one speaker line 11. May be connected. Even in this case, the power supply is suitably controlled for each speaker 3. A plurality of speakers 3 installed in one loudspeaker area may be controlled as one group, and some of the speakers 3 in the group may be turned off according to the degree of congestion. Furthermore, the loudspeaker system may be a combination of a configuration in which a plurality of speakers 3 are connected to a single speaker line 11 and a configuration in which a single speaker 3 is connected to a single speaker line 11.

  The first embodiment of the present invention has been described above. In the first embodiment, the loudspeaker system 1 detects the congestion degree parameter of the loudspeaker area, and turns off some of the speakers when the loudspeaker area is not congested. Since some of the speakers 3 are powered off, broadcasting can be continued. Therefore, when the loudspeaker area is not congested, it is possible to reduce power consumption while securing a volume necessary for a person in the loudspeaker area to listen to the broadcast.

  In addition, this embodiment can achieve power saving with a relatively simple configuration in which a configuration for determining the degree of congestion is added to an existing loudspeaker system such as a business broadcast system.

  In the present embodiment, the sound pressure in the loudness area may be detected as the congestion degree parameter. Therefore, the sound pressure is used as the congestion degree parameter, and the power consumption can be suitably reduced according to the congestion degree.

  Moreover, in this Embodiment, the congestion degree detection part 21 may obtain | require the average value of the sound pressure in predetermined | prescribed sound pressure measurement time. Since the average value of the sound pressure is used, it is possible to avoid erroneously determining that congestion has occurred when sudden sound occurs. For example, it is possible to avoid erroneously determining that an impact sound due to the fall of an object, a door opening / closing sound, or the like is caused by congestion. Therefore, power control according to the degree of congestion can be performed accurately.

  Moreover, in this Embodiment, the congestion degree detection part 21 may obtain | require the sound pressure of a loud sound area from the input audio | voice signal acquired by functioning at least one of the several speakers 3 as a microphone. Therefore, since the speaker functions as a microphone, it is possible to detect the degree of congestion suitably without providing a separate microphone.

  Further, in the present embodiment, the congestion degree determination unit 23 may compare the sound pressure with a predetermined threshold sound pressure, and the speaker power supply control unit 25 determines whether the plurality of speakers 3 have a sound pressure equal to or lower than the threshold sound pressure. The power supply to a part may be turned off. Therefore, the power control according to the degree of congestion can be performed by comparing the sound pressure with a predetermined threshold sound pressure. Power consumption can be reduced by a relatively simple process.

  Next, a second embodiment of the present invention will be described. In the second embodiment, the overall configuration of the loudspeaker system is the same as that of the first embodiment of FIG. In the second embodiment and the first embodiment, the configuration for determining the degree of congestion of the system control unit 9 is different. In the following description, descriptions of items that are the same as those in the first embodiment are omitted.

  FIG. 4 shows the configuration of the system control unit 9 in the present embodiment. The congestion degree detection unit 21 and the calculation result accumulation unit 41 are the same as the configuration of the first embodiment shown in FIG.

  The congestion level determination unit 51 determines the congestion level by processing the average value of the sound pressures provided from the averaging processing unit 35 of the congestion level detection unit 21. In the first embodiment, the sound pressure is compared with the threshold sound pressure. On the other hand, the second embodiment pays attention to the fact that the sound pressure change tendency changes according to the degree of congestion, and determines the degree of congestion based on the sound pressure change.

  The congestion degree determination unit 51 accumulates the sound pressure supplied from the averaging processing unit 35 in the sound pressure accumulation unit 53. The congestion level determination unit 51 processes the accumulated sound pressure and the sound pressure supplied from the averaging processing unit 35, analyzes the sound pressure change tendency, and determines the congestion level.

  Specifically, when the degree of congestion is “low” and the loudness area is in a non-congested state, the sound pressure change characteristic tends to continuously decrease. Therefore, the congestion degree determination unit 51 determines whether or not the sound pressure tends to decrease continuously over a predetermined non-congestion reference time (hereinafter, this tendency is referred to as a sound pressure decrease tendency). Further, when the congestion level is “high” and the loudspeaker area is not in a non-congested state, the sound pressure change characteristic tends to increase continuously. Therefore, the congestion degree determination unit 51 determines whether or not the sound pressure tends to continuously increase over a predetermined congestion reference time (hereinafter, this tendency is referred to as a sound pressure increase tendency). The non-congestion reference time and the congestion reference time are stored in advance, and are referred to by the congestion degree determination unit 51.

  The speaker power supply control unit 25 functions in the same manner as in the first embodiment. That is, when the congestion degree determination unit 51 detects a tendency to decrease the sound pressure, the speaker power source control unit 25 performs a process of turning off at least some of the power sources of the plurality of speakers 3. Further, it is assumed that a tendency of increasing sound pressure is detected by the congestion degree determination unit 51 when some of the speakers 3 are powered off. In this case, the speaker power supply control unit 25 performs control to supply power to all the speakers 3. These processes are performed for each speaker line 11 as described above.

  FIG. 5 shows the operation of the loudspeaker system in the present embodiment. Steps S1 to S7 are the same as the corresponding processes in the first embodiment. The congestion degree determination unit 51 analyzes the tendency of changes in the sound pressure (average value) obtained from the averaging processing unit 35, and determines the congestion degree (S21). As described above, since there is a relationship between the degree of congestion and the change in sound pressure, the degree of congestion can be determined based on the sound pressure change characteristic corresponding to the degree of congestion. As a result of the trend analysis, if a sound pressure increasing tendency is detected (S21, Yes), the loudspeaker area is not in a non-congested state, that is, not in a quiet state. Therefore, the control processing unit 33 supplies power to all the speakers 3 connected to the speaker line 11 to be processed (S13). Therefore, if the determination in step S21 is Yes when some of the speakers are turned off, all the speakers are turned on.

  Moreover, when the tendency of a sound pressure fall is detected as a result of a tendency analysis (S23, Yes), a congestion degree is "low" and the loudness area is in a non-congested state. In this case, the speaker power supply control unit 25 turns off the power of the predetermined number of speakers 3 connected to the speaker line 11 to be processed (S15). If neither an increase in sound pressure nor a decrease in sound pressure is detected (S23, No), the process ends without changing the on / off state of the speaker.

  Here, the second embodiment is compared with the first embodiment. In the first embodiment, the threshold sound pressure is set in advance for determining the degree of congestion. The threshold sound pressure can be said to be an absolute reference value. In contrast, the second embodiment uses a relative change in sound pressure. Therefore, the threshold value need not be set in advance. This is advantageous for the following reasons.

  The threshold sound pressure may not be easily set appropriately in advance. For example, it is assumed that the sound transmission state differs depending on the place and the appropriate threshold sound pressure is different. In this case, it is required to set the threshold sound pressure by actually measuring the degree of congestion and the sound pressure at various places. However, such work is not easy.

  Furthermore, since the speaker 3 is used as a microphone in the present embodiment, setting of the threshold sound pressure may not be easy. That is, when a dedicated microphone is used, the sound pressure can be measured at an arbitrary location, whereas when the speaker 3 is used as a microphone, the sound pressure measurement location must be the speaker installation location. It may not be easy to appropriately set the threshold sound pressure, which is an absolute reference, in the measurement result of such a restricted place.

  On the other hand, the present embodiment focuses on the fact that the sound pressure change characteristics differ depending on the degree of congestion. Since the degree of congestion is detected based on such a sound pressure change characteristic, it is not necessary to use a threshold sound pressure. Therefore, the degree of congestion can be detected easily and appropriately.

  Next, a modified example of the trend analysis process will be described. In the above example, the congestion degree determination unit 51 determines whether or not there is a tendency for the sound pressure to decrease over a predetermined non-congestion reference time. In the modification, the congestion degree determination unit 51 may determine whether or not the sound pressure tends to decrease more than a predetermined decrease width in a predetermined non-congestion reference time in the determination of the sound pressure decrease tendency. Similarly, the congestion degree determination unit 51 may determine whether or not the sound pressure tends to increase beyond a predetermined increase width in a predetermined congestion reference time in the determination of the sound pressure increase tendency. By using the sound pressure change width, the degree of congestion can be determined more accurately.

  In another example, the congestion degree determination unit 51 monitors a change in sound pressure, and determines whether or not the minimum level of sound pressure after the start of monitoring tends to continue over a predetermined non-congestion reference time. Good. Such a tendency to maintain sound pressure also appears when the degree of congestion is low and the loudspeaking area is in a non-congested state. The non-congestion reference time may be the same as or different from the determination reference time for the tendency to decrease the sound pressure. For example, monitoring starts when a department store opens. There is often no congestion immediately after the start. Therefore, immediately after the start of monitoring, the sound pressure at the minimum level corresponding to the non-congested state is measured. Then, assume that the non-congested state appears again. When the sound pressure equivalent to the minimum level immediately after opening the store continues for the non-congested reference time, the congestion level determination unit 51 determines that the loudness area is in a non-congested state. In this way, the degree of congestion can be suitably determined also by trend analysis using the minimum level of sound pressure.

  The second embodiment of the present invention has been described above. In the present embodiment, the congestion degree determination unit 23 analyzes the tendency of the sound pressure change to determine whether or not there is a tendency to change the sound pressure corresponding to the non-congested state. When there is a tendency to change the sound pressure corresponding to the congested state, power supply to a part of the plurality of speakers is turned off. Therefore, by analyzing the tendency of the sound pressure change, the power supply of the speaker can be controlled according to the degree of congestion, and the power consumption can be reduced. As described above, this configuration uses a relative change in sound pressure, and therefore there is no need to set a threshold sound pressure that is an absolute reference value, which is advantageous in this respect.

  In the loudspeaker system according to the present embodiment, the congestion degree determination unit 23 determines whether the sound pressure tends to decrease continuously over a predetermined non-congestion reference time as the sound pressure change tendency corresponding to the non-congested state. It may be determined. With this configuration, the degree of congestion can be suitably determined by analyzing the sound pressure change tendency. Since it is not necessary to use an absolute standard such as a threshold sound pressure, the degree of congestion can be detected easily and appropriately.

  In the loudspeaker system according to the present embodiment, the congestion degree determination unit 23 determines whether the sound pressure tends to increase continuously over a predetermined congestion reference time as the sound pressure change tendency corresponding to the congestion state. You may judge. When the speaker power supply control unit 25 detects an increase in sound pressure, the speaker power supply control unit 25 performs control to turn on all the speakers 3. Therefore, the power can be turned on again.

  In the loudspeaker system according to the present embodiment, the congestion degree determination unit 23 monitors the change in the sound pressure, and the sound pressure at the minimum level after the start of monitoring is a predetermined non-presence as the sound pressure change tendency corresponding to the non-congested state. It may be determined whether there is a tendency to continue over the congestion reference time. Therefore, the degree of congestion can be suitably determined by analyzing the sound pressure change tendency. Since it is not necessary to use an absolute standard such as a threshold sound pressure, the degree of congestion can be detected easily and appropriately.

  FIG. 6 shows a third embodiment of the present invention. The third embodiment is a modification of the first embodiment. Below, the description of the matter which overlaps with 1st Embodiment is abbreviate | omitted.

  In the first embodiment, the speaker 3 functions as a microphone, and the sound pressure in the loudspeaking area is measured. In the third embodiment, microphones 61 are installed in each of the loudspeaker areas. The microphone 61 is connected to the system control unit 9 via the sound collecting voice line 15. The microphone 61 generates an audio signal in the loudspeaker area and supplies it to the system control unit 9. The system control unit 9 processes the audio signal as in the first embodiment, detects the degree of congestion, and controls the power supply to the speaker 3.

  The third embodiment may be combined with the second embodiment. Also in this case, the input audio signal from the microphone 61 is processed by the system control unit 9. Then, the degree of congestion is determined by sound pressure change trend analysis, and power supply to the speaker 3 is controlled.

  The third embodiment of the present invention has been described above. In the present embodiment, since the dedicated microphone 61 is provided, sound pressure measurement can be performed more accurately.

  Next, a fourth embodiment of the present invention will be described. The fourth embodiment is a modification of the first embodiment, and differences from the first embodiment will be described.

  In the first embodiment, one fixed threshold sound pressure is used. When the measured sound pressure became equal to or lower than the threshold sound pressure, the predetermined number of speakers 3 were turned off. In the fourth embodiment, the threshold sound pressure is set differently for the plurality of speakers 3 in each loudspeaker area. More specifically, the threshold sound pressure is set so that the threshold sound pressure changes in a plurality of steps in a plurality of speakers 3. As a result, the number of power-off speakers can be changed step by step in accordance with the degree of congestion in each loudspeaker area.

  The configuration of the loudspeaker system according to the present embodiment may be the same as the configuration of the first embodiment shown in FIGS. In the system control unit 9, the threshold sound pressure storage unit 43 stores the threshold sound pressure of each speaker.

  The system control unit 9 causes all the speakers in the loudspeaker area to function as a microphone and acquires an audio signal. Then, the congestion level detection unit 21 of the system control unit 9 calculates the sound pressure for each speaker, and further calculates the sound pressure average value for each speaker. The congestion degree determination unit 23 compares the sound pressure obtained from each speaker with the threshold sound pressure of the speaker. If the sound pressure is equal to or lower than the threshold sound pressure, the speaker power control unit 25 turns off the power of the corresponding speaker.

  The power supply control according to this embodiment will be described using a specific example. FIG. 7 shows an example of a facility where the loudspeaker system 1 of the present embodiment is installed. In the example of FIG. 7, for simplification, two floors are shown, each floor has two loudspeaker areas, and a total of four loudspeaker areas (first floor A, first floor B, second floor A, Second floor B) is shown.

  In each loudspeaker area, four speakers are connected to the speaker line. As illustrated, speakers 1A-1, 1A-2, 1A-3, and 1A-4 are installed on the first floor A of the area. Similarly, speakers 1B-1, 1B-2, 1B-3, 1B-4 are installed on the first floor B of the area, and speakers 2A-1, 2A-2, 2A-3, 2A-4 is installed, and speakers 2B-1, 2B-2, 2B-3, and 2B-4 are installed on the second floor B of the area.

  The threshold sound pressure is set differently step by step according to the branch number (the number after the hyphen). That is, the threshold sound pressure of branch number 1 is −10 dB, the threshold sound pressure of branch number 2 is 0 dB, the threshold sound pressure of branch number 3 is 6 dB, and the threshold sound pressure of branch number 4 is 12 dB. . The four areas have the same threshold sound pressure (if the branch numbers are the same, the threshold sound pressure is also common).

In a certain time zone, as shown in the figure, area 1st floor A is congested, area 1st floor B is empty (no sound), area 2nd floor A is quite congested, and area 2nd floor B Is quiet and the congestion level is very low. As a result of analyzing the sound collection data of each area, it is assumed that the sound pressure has the following values. Here, for simplicity, it is assumed that the measured sound pressures of all the speakers in the same area are the same.
Area 1st floor A: 7 dB
Area 1st floor B: -10 dB
Area 2nd floor A: 13 dB
Area 2nd floor B: -1 dB

  FIG. 8 shows the control status of each speaker corresponding to the measurement result. In the first floor area A, the sound pressure is 7 dB. Therefore, the sound pressure is equal to or lower than the threshold sound pressure of the speaker 1A-4, and the sound pressure is the threshold sound pressure of the speakers 1A-1, 1A-2, 1A-3. Greater than. Therefore, only the speaker 1A-4 is turned off, and the remaining speakers 1A-1, 1A-2, 1A-3 are turned on.

  In area 1st floor B, the sound pressure is −10 dB, which is below the threshold sound pressure of all speakers. Therefore, all the speakers are turned off.

  In the second floor area A, the sound pressure is 13 dB, and therefore the sound pressure is higher than the threshold sound pressure of all speakers. Therefore, all the speakers are turned on.

  In the second floor area B, the sound pressure is -1 dB. Therefore, the sound pressure is larger than the threshold sound of the speaker 2B-1, and the sound pressure is the threshold sound of the remaining speakers 2B-2, 2B-3, 2B-4. Below the pressure. Accordingly, only the speaker 2B-1 is powered on, and the remaining three speakers 2B-2, 2B-3, 2B-4 are powered off.

  Also, in the loudspeaker system of this embodiment, at the start of broadcasting with high importance such as on-site announcements and emergency broadcasts, the area where all the speakers are turned off by always turning on the power of each speaker. Broadcasting is also performed on the first floor B.

  FIG. 9 is a diagram conceptually showing the power saving effect according to the present embodiment. The line in the figure shows a typical change in the degree of congestion during the business hours of a department store in one day. According to the present embodiment, the number of powered-on speakers increases or decreases according to the degree of congestion. The shaded portion in the figure is the number of speakers that are turned off in each time zone. The shaded area corresponds to the amount of power consumption reduction.

  Next, a modification of the fourth embodiment will be described. In the example of FIG. 7, four loudspeak areas are shown, and each loudspeaker area has four speakers. However, the number of areas and the number of speakers are not limited to the example of FIG.

  Further, in the fourth embodiment, the threshold sound pressures of all the speakers in one area are different from each other. However, within the scope of the present invention, the threshold sound pressure need not be different for all speakers. The threshold sound pressure may be the same for a predetermined number of speakers. For example, in FIG. 7, the threshold sound pressures of branch numbers 1 and 3 may be the same, and the threshold sound pressures of branch numbers 2 and 4 may be the same. Such a configuration also corresponds to the configuration of the present invention in which the threshold sound pressure is different among a plurality of speakers.

  The fourth embodiment is a modification of the first embodiment, and the congestion degree determination process uses a threshold sound pressure. On the other hand, the fourth embodiment may be applied to the second embodiment as follows.

  In the second embodiment, the congestion degree determination process analyzes the sound pressure change tendency and determines the congestion degree. When the fourth embodiment is applied, the sound pressure change tendency determination criterion is set differently for each speaker. The congestion degree determination unit 51 analyzes the sound pressure change tendency using the determination criterion corresponding to each speaker, and the speaker power supply control unit 25 corresponds to the determination result that there is a sound pressure change tendency corresponding to the non-congested state. Turn off the speaker. Even in such a configuration, the number of speakers can be changed in stages according to the degree of congestion, and the power consumption can be further reduced by finer control.

  More specifically, in the second embodiment, the congestion degree determination unit 51 detects a tendency that the sound pressure decreases continuously over a predetermined non-congestion reference time, and continues over a predetermined congestion reference time. The tendency of increasing sound pressure was detected. These non-congestion reference time and congestion reference time may be set differently for each speaker. Then, the degree of congestion may be determined for each speaker, and the power source of the corresponding speaker may be controlled according to the determination result.

  In another example of the second embodiment, the congestion degree determination unit 51 detects a tendency for the sound pressure to decrease more than a predetermined decrease width during a predetermined non-congestion reference time as a sound pressure decrease tendency. Similarly, the congestion degree determination unit 51 detects a tendency for the sound pressure to increase more than a predetermined increase width during a predetermined congestion reference time as a sound pressure increase tendency. The decrease width and the increase width may be different for a plurality of speakers.

  In still another example of the second embodiment, the congestion degree determination unit 51 monitors a change in sound pressure, and detects a tendency that the sound pressure at the minimum level after the start of monitoring continues for a predetermined non-congestion reference time. . This non-congestion reference time may be set differently for a plurality of speakers.

  The fourth embodiment has been described above. In the present embodiment, the speaker power control unit 25 changes the number of speakers 3 whose power is turned off in a stepwise manner in accordance with the degree of congestion in the loudspeaker area. With this configuration, power can be supplied to an appropriate number of speakers 3 according to the degree of congestion, and the remaining speakers 3 can be powered off. Therefore, it is possible to finely variably control the number of speakers that are turned off, and to further reduce power consumption.

  In this embodiment, the threshold sound pressure may be set differently for a plurality of speakers, the sound pressure may be compared with the threshold sound pressure corresponding to each speaker, and the sound pressure is equal to or lower than the threshold sound pressure. In this case, the power source of the corresponding speaker may be turned off. Thereby, the power of different numbers of speakers is turned off according to the detected sound pressure. Therefore, with a simple configuration in which the threshold sound pressure is set for each speaker, the number of power-off speakers can be finely variably controlled to further reduce power consumption.

  Further, in the present embodiment, in the analysis of the sound pressure change tendency, the determination criterion for the sound pressure change tendency corresponding to the non-congested state may be set differently for a plurality of speakers. The sound pressure change tendency may be analyzed using a criterion corresponding to each speaker. And the power supply of the speaker corresponding to the determination result that there is a tendency to change the sound pressure corresponding to the non-congested state may be turned off. With this configuration, a different number of speakers 3 are turned off depending on the degree of congestion. With a simple configuration in which the determination criterion for the sound pressure change tendency is set for each speaker 3, the number of power-off speakers can be finely variably controlled to further reduce power consumption.

  Next, a further modification of the above-described embodiment will be described. In the embodiment described above, the speaker 3 is connected to an analog line. In a variant, a network speaker may be used. The network speaker is connected to the system control unit via a network such as a LAN. Audio is transmitted in the form of digital signals. Voice and control signals are transmitted over the network, which can save wires.

  In the above-described embodiment, the sound pressure in the loudspeaking area is used as a congestion degree parameter, and the congestion degree is determined. However, the present invention is not limited to such a configuration. Parameters other than sound pressure may be used.

  For example, a surveillance camera is installed in each loudspeaker area. Video data of the loudspeaker area is collected using a surveillance camera. The video data is input to the system control unit 9 and processed. The degree of congestion is obtained by analyzing the video data. For example, a person in the video data is detected. Then, the number of persons or the density is detected as a congestion degree parameter and used for determination of the congestion degree. The number or density of people may be compared to a predetermined threshold. If the number of persons or the density is equal to or less than the threshold value, the congestion degree determination unit may determine that the loudness area is in a non-congested state.

  Further, for example, a temperature sensor may be provided, and the measured temperature may be input to the system control unit 9 and used as a congestion degree parameter. The congestion degree determination unit may compare the measured temperature with a predetermined threshold temperature, and may determine that the loudspeaker area is not congested when the measured temperature is equal to or lower than the threshold temperature. The threshold temperature may be set differently for each floor and each loudspeaker area. A pressure sensor may be used instead of the temperature sensor. The collected pressure data may be analyzed as a congestion level parameter and compared to a threshold value to determine the congestion level. Furthermore, the plurality of types of parameters described above may be used in combination to determine the degree of congestion.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and it goes without saying that those skilled in the art can modify the above-described embodiments within the scope of the present invention.

  As described above, the loudspeaker system according to the present invention has an effect that power consumption can be reduced when the loudspeaker area is not congested, and is useful as business broadcasting equipment.

The figure which shows the structure of the loudspeaker system which concerns on the 1st Embodiment of this invention. Diagram showing the configuration of the system controller The figure which shows operation | movement of the loudspeaker system which concerns on the 1st Embodiment of this invention. The figure which shows the structure of the system control part in the 2nd Embodiment of this invention. The figure which shows operation | movement of the loudspeaker system in 2nd Embodiment. The figure which shows the structure of the loudspeaker system which concerns on the 3rd Embodiment of this invention. The figure which shows the example of the plant | facility where the loudspeaker system of this Embodiment is installed The figure which shows the control condition of each speaker when threshold sound pressure differs in several speakers The figure which shows notionally the power saving effect by embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Loudspeaker system 3 Speaker 9 System control part 11 Speaker line 13 Control line 15 Sound collecting voice line 21 Congestion degree detection part 23 Congestion degree judgment part 25 Speaker power supply control part 33 Sound pressure calculation process part 35 Averaging process part 41 Calculation result Storage unit 43 Threshold sound pressure storage unit

Claims (13)

A plurality of speakers installed in the loudspeaker area;
A congestion degree detection unit for detecting a congestion degree parameter indicating the degree of congestion in the loudspeaker area;
Based on the congestion parameter detected by the congestion detection unit, a congestion degree determination unit that determines whether or not the loudness area is in a non-congested state;
A speaker that controls power supply to the plurality of speakers based on the determination result of the congestion degree determination unit so as to turn off some of the plurality of speakers when the loudspeaking area is in the non-congested state. A power control unit;
A loudspeaker system characterized by comprising   The loudspeaker system according to claim 1, wherein the congestion degree detection unit detects a sound pressure in the loudspeaker area as the congestion degree parameter.   The loudspeaker system according to claim 2, wherein the congestion degree detection unit obtains an average value of the sound pressures during a predetermined sound pressure measurement time.   The said congestion degree detection part calculates | requires the said sound pressure of the said loudness area from the input audio | voice signal acquired by making at least one of these several speakers function as a microphone. Loudspeaker system.   The congestion degree determination unit compares the sound pressure with a predetermined threshold sound pressure, and the speaker power supply control unit supplies power to a part of the plurality of speakers when the sound pressure is equal to or lower than the threshold sound pressure. The loudspeaker system according to any one of claims 2 to 4, wherein the loudspeaker system is turned off.   The threshold sound pressure is set differently for the plurality of speakers, the congestion degree determination unit compares the sound pressure with the threshold sound pressure corresponding to each speaker, and the speaker power supply control unit 6. The loudspeaker system according to claim 5, wherein when the pressure is equal to or lower than the threshold sound pressure, the corresponding speaker is turned off.   The congestion degree determination unit analyzes a tendency of the sound pressure change to determine whether there is a sound pressure change tendency corresponding to the non-congested state, and the speaker power supply control unit corresponds to the non-congested state. 5. The loudspeaker system according to claim 2, wherein power supply to a part of the plurality of speakers is turned off when there is a tendency to change sound pressure.   The congestion degree determination unit determines whether or not the sound pressure tends to decrease continuously over a predetermined non-congestion reference time as the sound pressure change tendency corresponding to the non-congested state. Item 8. The loudspeaker system according to Item 7.   The congestion degree determination unit monitors a change in sound pressure, and as a sound pressure change tendency corresponding to the non-congested state, whether or not the minimum level of sound pressure after the start of monitoring tends to continue for a predetermined non-congestion reference time. The loudspeaker system according to claim 7, wherein:   The determination criterion of the sound pressure change tendency corresponding to the non-congested state is set differently for the plurality of speakers, and the congestion degree determination unit uses the determination criterion corresponding to each speaker to indicate the sound pressure change tendency. 10. The analysis according to claim 7, wherein the speaker power supply control unit turns off the power supply of the speaker corresponding to the determination result that there is a tendency to change the sound pressure corresponding to the non-congested state. Crab loudspeaker system.   2. The loudspeaker system according to claim 1, wherein the speaker power control unit changes the number of speakers to be turned off in a stepwise manner in accordance with the degree of congestion of the loudspeaker area. Detect a congestion parameter that represents the degree of congestion in a loudspeaker area where multiple speakers are installed,
Based on the congestion degree parameter, it is determined whether the loudspeaking area is in a non-congested state,
A loudspeaker system control method, comprising: controlling power supply to the plurality of speakers so that a part of the plurality of speakers is powered off when the loudspeaker area is in the non-congested state. A loudspeaker control program executed by a system controller of a loudspeaker system having a plurality of speakers installed in a loudspeaker area,
Detecting a congestion degree parameter representing the degree of congestion in the loudspeaker area;
Based on the congestion degree parameter, it is determined whether the loudspeaking area is in a non-congested state,
When the loudspeaker area is in the non-congested state, the system control unit is caused to execute processing for controlling power supply to the plurality of speakers so as to turn off power to some of the plurality of speakers. A loudspeaker control program.

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