JP2018170695A - Sound reproduction system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To output sound from a speaker device suitable to the position of a listener, when the speaker device and a control terminal are independent, and there are also multiple speaker devices in a different room.SOLUTION: After transmitting supersonic waves of ultrasonic frequency to a control terminal, each speaker device stores distance average value calculated by measuring the distance between each speaker device and the control terminal multiple times based on the delay time of reflection wave, and after transmitting a first supersonic wave of ultrasonic frequency to the control terminal in response to a sound emission instruction signal from the control terminal, measures the distance between each speaker device and the control terminal based on the delay time of reflection wave, determines that there is a listener when the absolute value of the difference between the measured distance and the distance average value is larger than a threshold level, and transmits a listener detection signal including the measured distance to the control terminal, which transmits the sound emission instruction signal upon receiving the listener detection signal from the speaker device, and the speaker device receives an audio-signal based on the sound emission instruction signal and emits sound.SELECTED DRAWING: Figure 4D

Description

  The present disclosure relates to a sound reproduction system that detects a listener and outputs sound from a speaker device.

  Patent Document 1 can selectively form a sound field at the position of the listener by accurately obtaining the direction and distance from the portable terminal device to the listener.

JP 2012-29093 A

Takehiko Tsukiji, “Introduction to Radio and Antenna Engineering”, General Electronic Publishing Company, March 2002

  The present disclosure provides an audio reproduction system capable of outputting sound from a speaker device suitable for the position of a listener when the speaker device and the mobile terminal device are separate.

An audio reproduction system according to an aspect of the present disclosure is provided.
An audio reproduction system comprising a plurality of speaker devices and a control terminal device that controls the speaker devices by wirelessly transmitting and receiving control signals to and from the speaker devices and wirelessly transmits audio signals to the speaker devices. And
Each of the speaker devices transmits the ultrasonic wave having the first ultrasonic frequency to the control terminal device, and then the speaker device and the control terminal device based on a delay time of a reflected wave that is reflected and returned. The distance average value calculated by measuring the distance between and a plurality of times is stored in advance, and in response to the sound output instruction signal from the control terminal device, the ultrasonic wave of the first ultrasonic frequency is After transmitting to the control terminal device, the distance between each speaker device and the control terminal device is measured based on the delay time of the reflected wave reflected and returned, and the measured distance and the distance When the absolute value of the difference from the average value is larger than a predetermined first threshold, it is determined that there is a listener, and a listener detection signal including the measured distance is transmitted to the control terminal device,
When the control terminal device receives a listener detection signal from one of the plurality of speaker devices, the control terminal device transmits a sound output instruction signal to the one speaker device,
The one speaker device receives the sound signal from the control terminal device and outputs the sound based on the sound output instruction signal.

In the audio reproduction system,
When the control terminal device receives a listener detection signal from a plurality of speaker devices of the plurality of speaker devices, the control terminal device outputs a sound to one speaker device having the shortest distance from the control terminal device. Send an instruction signal,
The one speaker device receives the sound signal from the control terminal device and outputs the sound based on the sound output instruction signal.

In the audio reproduction system,
The control terminal device transmits radio waves of a first radio frequency to the speaker devices,
Each of the speaker devices has an absolute value of a difference between the distance measured using the ultrasonic wave having the first ultrasonic frequency and the average distance value greater than a predetermined first threshold value, and the first Based on the received power when a radio wave having a radio frequency of 1 is received, the difference between the distance when the distance from the control terminal device to each speaker device is calculated and the distance measured using the ultrasonic wave When the absolute value is less than a predetermined second threshold value, it is determined that there is a listener, and a listener detection signal including the measured distance is transmitted to the control terminal device.

Furthermore, in the audio reproduction system,
In response to the sound output instruction signal from the control terminal device, each speaker device transmits an ultrasonic wave having a second ultrasonic frequency different from that of the other speaker devices to the control terminal device, and then reflects In the reflected wave that is returned, only the reflected wave of the second ultrasonic frequency is extracted by the filter, and then between each of the speaker devices and the control terminal device based on the delay time of the reflected wave A distance is measured, and when the absolute value of the difference between the measured distance and the average distance is greater than a predetermined first threshold, it is determined that there is a listener, and the measured distance is A listener detection signal is transmitted to the control terminal device.

Still further, in the audio reproduction system,
The control terminal device sequentially transmits a radio wave of a first radio frequency and a radio wave of a second radio frequency to each speaker device,
Each of the speaker devices has an absolute value of a difference between the distance measured using the ultrasonic wave having the first ultrasonic frequency and the average distance value greater than a predetermined first threshold value, and the first The absolute value of the difference between the two distances when the two distances from the control terminal device to the speaker devices are calculated based on the received power when the radio waves having the first and second radio frequencies are received, respectively. A distance that is less than a predetermined third threshold and that is measured using the ultrasonic wave of the first ultrasonic frequency and a radio wave having a lower radio frequency out of the first and second radio frequencies. When the absolute value of the difference from the measured distance is less than a predetermined third threshold, it is determined that there is a listener, and a listener detection signal including the measured distance is controlled. It transmits to an apparatus, It is characterized by the above-mentioned.

Still further, in the audio reproduction system,
Each of the speaker devices transmits an ultrasonic wave having the first ultrasonic frequency to the control terminal device, and then is directed from the control terminal device to the speaker device based on a reflected wave that is reflected and returned. An angle is calculated, and equalizing processing is performed based on the azimuth so that the frequency characteristic of the audio signal is substantially flat at the position of the listener.

  Therefore, the sound reproduction system according to the present disclosure can output sound from the speaker device suitable for the position of the listener when the speaker device and the mobile terminal device are separate and there are a plurality of speaker devices in different rooms. It is.

FIG. 3 is a schematic plan view illustrating a method in which speaker devices 103 and 104 installed in different rooms 101 and 102 measure distances using ultrasonic waves in the audio reproduction system according to the first embodiment. FIG. 3 is a schematic plan view illustrating a method in which the speaker devices 103 and 104 installed in the same room 101 measure distances using ultrasonic waves in the audio reproduction system according to the first embodiment. 1 is a block diagram illustrating a configuration example of an audio reproduction system according to Embodiment 1. FIG. It is a flowchart which shows the audio | voice reproduction | regeneration system control processing performed by the audio | voice reproduction | regeneration system of FIG. 4B is a flowchart illustrating a speaker device control process (S419) executed by the speaker devices 103 and 104 in the subroutine of FIG. 4A. 4B is a flowchart illustrating a mobile terminal device control process (S433) executed by the mobile terminal device 106, which is the subroutine of FIG. 4A. It is a timing chart of the audio | voice reproduction | regeneration system control processing performed with the audio | voice reproduction | regeneration system of FIG. In the audio reproduction system according to the second embodiment, the speaker devices 103 and 104 are schematic plan views illustrating a method for measuring a distance using ultrasonic waves and radio waves. It is a block diagram which shows the structural example of the audio | voice reproduction | regeneration system concerning Embodiment 2. FIG. It is a flowchart which shows the audio | voice reproduction | regeneration system control processing performed with the audio | voice reproduction | regeneration system of FIG. 7B is a flowchart showing a speaker device control process (S711) executed by the speaker devices 103 and 104 in the subroutine of FIG. 7A. FIG. 7B is a flowchart showing a mobile terminal device control process (S721) executed by the mobile terminal device 106 in the subroutine of FIG. 7A. 10 is a timing chart showing signals transmitted and received by speaker devices 103 and 104 in the audio reproduction system according to the third embodiment. It is a block diagram which shows the structural example of the distance measurement part 901 in the control part 309 of the speaker apparatuses 103 and 104 of the audio | voice reproduction system of FIG. It is a flowchart which shows the audio | voice reproduction system control process performed by the audio | voice reproduction | regeneration system concerning Embodiment 4. 10B is a flowchart showing a speaker device control process (S1011) executed by the speaker devices 103 and 104 in the subroutine of FIG. 10A. FIG. 10B is a flowchart illustrating a mobile terminal device control process (S1021) executed by the mobile terminal device 106 in the subroutine of FIG. 10A. 10 is a flowchart illustrating speaker device control processing executed by the speaker devices 103 and 104 of the sound reproduction system according to the fifth embodiment. 12 is a graph showing directivity characteristics of audio signals of respective frequencies output from the speaker devices 103 and 104 in FIG. 11. 12 is a graph showing amplitude frequency characteristics of an audio signal output from the speaker devices 103 and 104 in FIG. 11 in a direction with an azimuth angle of 40 degrees.

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

  The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims. The same or similar components are denoted by the same reference numerals, and detailed description thereof is omitted.

(Background of the embodiment)
Due to the interior and mobile use of AV equipment, it has become an era where speaker devices can be placed anywhere. In order to construct an appropriate listening environment such as sound output from a speaker device close to the listener, it is necessary to detect the position of the listener, in particular, the sensor for measuring the distance to the listener is optical or There is an ultrasonic type, etc., and the ultrasonic type is suitable for measuring the position of a person because it has a longer detection distance (about 10 m) than an optical type and is not affected by the material or color. Yes.

(Definition of terms)
(1) The mobile terminal device refers to a terminal device that is a mobile phone such as a smart phone and stores voice data in a memory and can perform wireless communication.
(2) A listener refers to a person who carries a mobile terminal device and instructs the speaker device to output sound.
(3) The wireless communication system refers to a wireless communication system such as Wi-Fi, Bluetooth (registered trademark).
(4) The speaker unit refers to a device that converts an electric signal into a sound wave.
(5) Pairing means that in a predetermined wireless communication, the mobile terminal device and the speaker device authenticate each other and register connection.
(6) An appropriate speaker device refers to a speaker device in which an obstacle such as a wall is not sandwiched between the speaker device and the listener, and the distance from the listener is the shortest among the plurality of speaker devices. .

(Embodiment 1)
FIG. 1 is a schematic plan view illustrating a method in which speaker devices 103 and 104 installed in different rooms 101 and 102 measure distances using ultrasonic waves in the audio reproduction system according to the first embodiment.

  In FIG. 1, a first speaker device 103 is installed in a first room 101, and a second speaker device 104 is installed in a second room 102 across a wall 107. The listener 105 has a portable terminal device 106 and operates the portable terminal device 106 to instruct the first speaker device 103 or the second speaker device 104 to output sound using a wireless communication method. Here, the first speaker apparatus 103 measures the distance D10 to the wall 107 and the distance D11 to the listener 105 by transmitting and receiving ultrasonic waves. Similarly, the second speaker device 104 measures the distance D20 to the wall 107.

  FIG. 2 is a schematic plan view illustrating a method in which the speaker devices 103 and 104 installed in the same room 101 measure distances using ultrasonic waves in the sound reproduction system according to the first embodiment.

  In FIG. 2, the first speaker device 103 and the second speaker device 104 are both installed in the first room 101. Here, the first speaker apparatus 103 measures the distance D10 to the wall 107 and the distance D11 to the listener 105 by transmitting and receiving ultrasonic waves. Similarly, the second speaker device 104 measures the distance D20 to the wall 107 and the distance D21 to the listener 105.

  FIG. 3 is a block diagram illustrating a configuration example of the audio reproduction system according to the first embodiment. In FIG. 3, the audio reproduction system according to the first embodiment includes a mobile terminal device 106 and, for example, two speaker devices 103 and 104.

  In FIG. 3, each of the speaker devices 103 and 104 includes an ultrasonic transmission unit 303, an ultrasonic reception unit 304, a wireless communication module 305 having an antenna 305A, a speaker unit 306, and a memory 307 having an audio data buffer 308. And a control unit 309. The portable terminal device 106 includes a wireless communication module 312 having an antenna 312A, a memory 313 having an audio data memory 311, a control unit 310, an operation unit 314, and a display unit 315.

  The control unit 309 controls the operation of each unit of the speaker devices 103 and 104. The wireless communication module 305 is wirelessly connected to the wireless communication module 312 of the mobile terminal device 106 by a predetermined wireless communication method. The wireless communication module 305 wirelessly receives a control signal and sound data such as a sound output start instruction signal, a sound output instruction signal, and a sound output stop signal from the mobile terminal device 106, and outputs the control signal to the control unit 309. The audio data is output to the speaker unit 306 via the control unit 309 and the audio data buffer 308 of the memory 307 and output. In addition, the wireless communication module 305 transmits a control signal such as a listener detection signal including a measurement distance from the control unit 309 to the portable terminal device 106 via the wireless communication module 312.

  The ultrasonic transmission unit 303 transmits the ultrasonic signal Su, and the ultrasonic reception unit 302 receives the reflected wave signal Sur reflected by the ultrasonic signal Su hitting the listener 105 or the wall 107. Here, the ultrasonic transmission unit 303 includes a plurality of ultrasonic transmitters, a plurality of phase shifters, and a distributor, and transmits ultrasonic waves that are transmitted using a known phased array technique (for example, see Non-Patent Document 1). The transmission direction can be changed. The ultrasonic receiving unit 304 includes a plurality of ultrasonic receivers, a plurality of phase shifters, and an adder, and receives ultrasonic waves received using a known phased array technique (for example, see Non-Patent Document 1). The direction can be changed. Instead of the phased array technology, the ultrasonic transmission direction or reception direction may be changed by selectively switching a plurality of ultrasonic transmitters or a plurality of ultrasonic receivers.

  The operation unit 314 of the portable terminal device 106 is configured by, for example, a touch panel of a display, and is provided for a listener to input instructions such as a sound data output instruction and sound output stop instruction, and the display unit 315 is configured by a display, for example. The contents of the voice data, the contents waiting for instructions, the contents of instructions, etc. are displayed. The control unit 310 of the mobile terminal device 106 wirelessly communicates control signals such as a sound output start instruction signal, a sound output instruction signal, and a sound output stop signal and sound data (stored in the sound data memory 311 in the memory 313). Via the module 312, wireless transmission is performed to the wireless communication module 305 of the speaker devices 103 and 104 using a predetermined wireless communication method.

  Next, a distance measurement method using ultrasonic waves by the speaker devices 103 and 104 will be described below.

  From the time when the ultrasonic wave Su is transmitted from the ultrasonic wave transmission unit 303 to the time when the ultrasonic wave reception unit 304 receives the reflected wave Sur reflected by the listener 105 or the wall 107, the difference is propagated. Assuming time, the distance D (m) from the speaker devices 103 and 104 to the listener 105 or the wall 107 can be calculated using the following equation.

D = c × T / 2 (1)

  Here, c is the speed of sound and is 340 (m / sec), and T is the round-trip propagation time (sec).

  Each operation of the speaker devices 103 and 104 and the portable terminal device 106 of the sound reproduction system configured as described above will be described below. The speaker devices 103 and 104 and the mobile terminal device 106 perform sound output processing based on the distance measurement result using ultrasonic waves.

  FIG. 4A is a flowchart showing an audio reproduction system control process executed by the audio reproduction system of FIG.

  4A, pairing is performed between the mobile terminal device 106, the first speaker device 103, and the second speaker device 104 by a predetermined wireless communication method (S434). This means that the mobile terminal device 106 registers the first speaker device 103 and the second speaker device 104 as devices that can output sound, as devices that can receive sound data wirelessly and output sound. Next, the control processing in the first speaker device 103 (S419 in FIG. 4B), the control processing in the second speaker device 104 (S419 in FIG. 4B), and the control processing in the portable terminal device 106 (S433 in FIG. 4C) are performed in parallel. And executed.

  4B is a flowchart showing the speaker device control process (S419) executed by the speaker devices 103 and 104 in the subroutine of FIG. 4A. Here, the speaker device control process (S419) includes an average distance calculation process (S451), a distance measurement process (S452), a listener detection signal transmission process (S414) including the measurement distance D (n), and a sound output. And stop processing (S451).

  In the average distance calculation process (S451) of FIG. 4B, the distance measurement calculation count i with one scan of 360 degrees is reset to 0 (S401), and the ultrasonic wave transmission / reception azimuth is set to 0 ° (S402). The transmission / reception azimuth angle of the ultrasonic wave is increased by + 10 °. Next, for example, a waiting time is inserted so that the measurement time is about 1 second, and the distance using ultrasonic waves is measured and temporarily stored in the memory 307 (S404), and the ultrasonic transmission / reception azimuth is set to 360 °. It is determined whether or not (S405). When YES, the process proceeds to step S406, and when NO, the process returns to step S403. Next, the distance measurement calculation count i is incremented by 1 (S406), and it is determined whether or not the distance measurement calculation count i is 1000 (S407). If YES, the process proceeds to step S408. Return to S402. Further, the distance average value Dw (n) = [Dw (10 °),..., Dw (360 °)] of each azimuth is calculated (S408) and stored in the memory 307 (S409). Next, in the sound output start signal reception determination process (S420), it is determined whether or not a sound output start signal has been received from the mobile terminal device 106 (S420). If YES, the process proceeds to step S410 in step S452. If NO, the process returns to step S420.

  Next, in the distance measurement process (S452), the ultrasonic transmission / reception azimuth is set to 0 ° (S410), the ultrasonic transmission / reception azimuth is increased by + 10 ° (S413), and the ultrasonic distance D ( n) is measured (S411). Next, it is determined whether or not | D (n) −Dw (n) |> predetermined threshold value Dth (S412). If YES, the process proceeds to step S414. If NO, the process proceeds to step S413. . Next, a listener detection signal including the measurement distance D (n) is transmitted to the mobile terminal device 106 (S414), and the process proceeds to S415 in step S453.

  Next, in the sound output and stop process (S453), it is first determined whether or not a sound output instruction signal has been received from the mobile terminal device 106 (S415). If YES, the process proceeds to step S416. If NO, The process returns to step S413. In step S416, it is determined whether or not sound data is received from the mobile terminal device 106 and output, a sound output stop instruction signal is received from the mobile terminal device 106, or whether or not the sound data has ended (S417). If NO, the process proceeds to step S418. If NO, the process returns to step S417. In step S418, the sound output is stopped and the process returns to the original main routine.

  In the speaker device control processing of FIG. 4B, the speaker devices 103 and 104 repeat distance measurement (S411) using ultrasonic waves, and the absolute value of the difference between the distance D (n) and the distance average value Dw (n) The predetermined threshold value Dth is compared (S412). As this threshold value Dth, for example, a value in consideration of the distance resolution of the ultrasonic wave and the thickness of the person is used. In order to determine that the listener has been detected when the threshold value Dth is greater than the threshold value Dth, there is a difference between this value and the case where a person such as a listener enters between the wall 107 and the speaker devices 103 and 104. It is necessary to indicate the minimum value (for example, 20 cm) generated under general normal use conditions. This value can be detected sufficiently larger than the resolution of distance measurement using ultrasonic waves. Here, when the difference between the measured distance D (n) and the average value distance Dw (n) is larger than the threshold value Dth, it is determined that a listener has been detected, and a listener detection signal is transmitted to the portable terminal device 106. (S414).

  In step S411 in FIG. 4B, the distance average value Dw (n) may be calculated and updated in consideration of D (n) after measuring the distance every time.

  FIG. 4C is a flowchart of the mobile terminal device control process (S433) executed by the mobile terminal device 106, which is the subroutine of FIG. 4A.

  4C, first, the listener inputs a sound output instruction using the operation unit 314 (S424), and whether or not a listener detection signal including the measurement distance D (n) is received from the speaker devices 103 and 104 is checked. The determination is made (S426). If YES, the process proceeds to step S427. If NO, the process returns to step S426. In step S427, it is determined whether there are a plurality of speaker devices 103, 104 that have detected the listener. If YES, the process proceeds to step S428, and if NO, the process proceeds to step S429. In step S428, the sound output instruction signal is transmitted to the speaker device 103 or 104 having a short distance, and the process proceeds to step S430. On the other hand, in step S429, the sound output instruction signal is transmitted to the speaker devices 103 and 104 that have detected the listener, and the process proceeds to step S430. In step S430, the voice data is wirelessly transmitted to the designated speaker device 103 or 104, and it is determined whether the listener inputs a sound output stop instruction or the voice data is finished (S432). Returns to the original main routine, while if NO, the process returns to step S432.

  FIG. 4D is a timing chart of the audio reproduction system control process executed by the audio reproduction system of FIG. FIG. 4D is a timing chart summarizing FIGS. 4B and 4C.

  In the audio reproduction system configured as described above, when there is one speaker device 103 that transmits a person detection signal as shown in FIG. 1, the mobile terminal device 106 instructs the speaker device 103 to output a sound. Is transmitted (S429). On the other hand, as shown in FIG. 2, when there are a plurality of speaker devices 103 and 104 that transmit person detection signals, the mobile terminal device 106 determines the measurement distance at the time of listener detection transmitted from each of the speaker devices 103 and 104. In comparison, a sound output instruction is transmitted to the speaker device 103 or 104 having a short distance (S428). The speaker device 103 or 104 that has received the sound output instruction signal from the mobile terminal device 106 enters the sound output preparation state (YES in S415), and wirelessly receives the sound data from the mobile terminal device 106 and outputs the sound (S416).

  As described above, in the present embodiment, the speaker devices 103 and 104 measure the distance to the listener 105 or the wall 107 using the ultrasonic transmission unit 303 and the ultrasonic reception unit 304. An average value of the measured distances is set as a distance to the wall 107 and the like, and when a distance having a difference larger than a certain threshold is measured, the listener 105 is detected and transmitted to the portable terminal device 106. The mobile terminal device 106 that has received the person detection signal checks whether or not there are a plurality of speaker devices 103 and 104 that have transmitted the person detection signal, and if there is one, the speaker device 103 or 104 has detected a person. Sound output is instructed to the speaker device 103 or 104 having a short measurement distance. As a result, the audio data is output from the speaker device 103 or 104 having the shortest distance from the listener 105 without interposing the wall 107 with the listener 105. Therefore, it is possible to prevent a decrease in sound pressure and a change in frequency characteristics that occur when sound is output from the speaker device 103 or 104 with the wall 107 interposed therebetween.

  In addition, since the distance between the speaker devices 103 and 104 and the listener 105 can be known relatively accurately, the sound volume output from the speaker devices 103 and 104 may be set based on the information based on the sound volume.

(Embodiment 2)
FIG. 5 is a schematic plan view illustrating a method in which the speaker devices 103 and 104 measure distances using ultrasonic waves and radio waves in the sound reproduction system according to the second embodiment. In FIG. 5, there is a listener 105 having a portable terminal device 106 in a first room 101 having a first speaker device 103, while a portable terminal device 106 is held in a second room 102 having a second speaker device 104. Assume that there is no non-listener 501.

  When the speaker devices 103 and 104 installed in two different rooms 101 and 102 detect humans 105 and 501 who are listeners or non-listeners, respectively, by distance measurement using ultrasonic waves, up to the respective humans 105 and 106. However, the mobile terminal device 106 cannot issue a sound output instruction to an appropriate speaker device 103 because the listener cannot be identified.

  Therefore, in the second embodiment, in addition to the distance measurement using ultrasonic waves, for example, the speaker devices 103 and 104 are connected to the listener 105 by performing distance measurement using a wireless communication method using a 2.4 GHz band radio signal S2.4. Is described below, and a method by which the mobile terminal device 106 can correctly issue a sound output instruction to the speaker device 103 is described below.

  The distance measurement by the wireless communication method is performed using, for example, Wi-Fi radio wave intensity. Here, the received signal power PR [dBm] at the speaker devices 103 and 104 is expressed by the following equation.

PR [dBm] = PT [dBm] + (GTA [dBi] + GRA [dBi]) − LB [dB]
(2)

  Here, PT [dBm] is the known transmission signal power from the mobile terminal device, GTA [dBi] is the absolute gain of the transmission antenna, and GRA [dBi] is the absolute gain of the reception antenna. The free space propagation loss LB [dB] is expressed by the following equation.

LB [dB] = 32.44 + 20 logd [km] +20 logf [MHz]
(3)

  Here, f [MHz] is a frequency used in Wi-Fi, for example. From the equations (2) and (3), the distance d [km] from the portable terminal device 106 to the speaker devices 103 and 104 is expressed by the following equation.

d [km] = 10 ^ ((PT [dBm] + GTA [dBi] + GRA [dBi]
-PR [dBm]-32.44-20 log (f) [MHz]) / 20) (4)

  Here, ^ represents a power.

  Further, the distance D between the person measured by the ultrasonic wave and the speaker devices 103 and 104 and the distance d between the portable terminal device 106 and the speaker devices 103 and 104 measured by the radio wave are measured, and if D ≠ d. It is determined that the person does not have the portable terminal device 106, and control is performed so that no sound is output from the speaker devices 103 and 104. On the other hand, D = d (D≈d: substantially equal; specifically, | D−d | <DDth, where DDth is a threshold value that is a predetermined minute value near 0) If so, it is determined that the person has the portable terminal device 106, and control is performed so as to output sound from the speaker devices 103 and 104. The above determination is made by using the radio wave propagation characteristics in which the radio wave transmitted from the mobile terminal device 106 does not pass through an obstacle such as the wall 107, and the speaker device 103, 104 is installed by the listener who holds the mobile terminal device 106. It is characterized by determining whether or not the user is in a room.

FIG. 6 is a block diagram illustrating a configuration example of an audio reproduction system according to the second embodiment. 6, the speaker devices 103 and 104 and the mobile terminal device 106 according to the second embodiment are different from the first embodiment in the following points.
(1) The wireless communication module 312 transmits, to the wireless communication module 305, a wireless signal that is a radio wave having a frequency of 2.4 GHz, for example, for distance measurement. Note that transmission / reception of control signals between the wireless communication module 312 and the wireless communication module 305 is performed in the same manner as in the first embodiment.
(2) The audio reproduction system according to the second exemplary embodiment executes the audio reproduction system control process of FIG. 7A instead of the audio reproduction system control process of FIG. 4A.
(3) The speaker devices 103 and 104 execute the speaker device control process (S711) of FIG. 7B instead of the speaker device control process (S419) of FIG. 4B.
(4) The mobile terminal device 106 executes the mobile terminal device control process (S721) of FIG. 7C instead of the mobile terminal device control process (S433) of FIG. 4C.
Hereinafter, the difference will be described in detail.

  FIG. 7A is a flowchart showing an audio reproduction system control process executed by the audio reproduction system of FIG. In FIG. 7A, pairing is performed between the mobile terminal device 106, the first speaker device 103, and the second speaker device 104 by a predetermined wireless communication method (S434). This means that the mobile terminal device 106 registers the first speaker device 103 and the second speaker device 104 as devices that can output sound, as devices that can receive sound data wirelessly and output sound. Next, the control processing in the first speaker device 103 (S711 in FIG. 7B), the control processing in the second speaker device 104 (S711 in FIG. 7B), and the control processing in the portable terminal device 106 (S721 in FIG. 7C) are performed in parallel. And executed.

  FIG. 7B is a flowchart showing a speaker device control process (S711) executed by the speaker devices 103 and 104 in the subroutine of FIG. 7A.

  7B, first, the distance D (n) is measured by executing the distance average value calculation process in the same manner as in the first embodiment of FIG. 4B (S451), and ultrasonic waves are used in the same manner as in the first embodiment of FIG. 4B. The measured distance measurement process is executed (S452). Next, a radio signal with a predetermined frequency of, for example, 2.4 GHz band transmitted from the mobile terminal device 106 is received (S702), and the radio signal is based on the received signal power based on the received strength (RSSI) of the received radio signal. The amount of power attenuation is calculated, and based on this, the distance d between the mobile terminal device 106 and the speaker device 103 or 104 is calculated (S703). Next, it is determined whether or not | D (n) −d | <DDth (where DDth is a threshold value that is a minute value in the vicinity of 0) (S704). While the process proceeds to S414, the process returns to Step S452 if NO. Further, a listener detection signal including a measurement distance D (n) using ultrasonic waves is transmitted to the mobile terminal device 106 (S414), and sound output and stop processing is executed as in the first embodiment of FIG. 4B ( S453) Return to the original main routine.

  FIG. 7C is a flowchart of the mobile terminal device control process (S721) executed by the mobile terminal device 106 in the subroutine of FIG. 7A. 7C, the portable terminal device control process (S721) is compared with the portable terminal device control process (S433) of FIG. 4C, for example, in the 2.4 GHz band for calculating the distance between step S424 and step S426. This is the same except that a radio signal having a predetermined frequency is transmitted (S722).

  According to the second embodiment configured as described above, as in the first embodiment, the distance average value D (n) between the mobile terminal device 106 and the speaker device 103 or 104 is measured using ultrasonic waves. In addition, a radio wave having a predetermined frequency of, for example, 2.4 GHz band transmitted from the mobile terminal device 106 is received, the distance d to the speaker device 103 or 104 is measured, and the distance average value D (n) is set to the distance d. If substantially equal, it is determined that the listener carrying the portable terminal device 106 is in the vicinity of the speaker device 103 or 104 (in a room where radio waves can reach), and the distance average value D (n) may be different from the distance d. It is determined that there is no listener. Based on this determination, the audio data is wirelessly transmitted to the speaker device 103 or 104 (103 in FIG. 5).

  In the second embodiment, in addition to the distance measurement using ultrasonic waves, the distance measurement using radio waves can be performed, and the accuracy of the distance measurement can be improved as compared with the first embodiment. As a result, sound can be output only by the speaker device 103 or 104 in the room where the listener exists. Moreover, in Embodiment 2, there exists an effect similar to Embodiment 1.

(Embodiment 3)
In the first embodiment, the distance between the mobile terminal device 106 and the speaker device 103 or 104 is measured using ultrasonic waves of one frequency, but the operations of the ultrasonic transmission unit 303 and the ultrasonic reception unit 304 are performed. When the measurement becomes unstable (for example, the frequency becomes unstable and a deviation occurs), an error occurs in the distance measurement. In this case, in particular, there is a plurality of speaker devices 103 and 104 in one room, and the probability that an error will occur due to the influence of reflected ultrasonic interference by an obstacle such as the wall 107 is increased. In order to solve this problem, the distance between the portable terminal device 106 and the speaker device 103 or 104 is measured using ultrasonic waves of two different frequencies to determine the presence or absence of a listener. It is said.

  FIG. 8 is a timing chart showing signals transmitted and received by the speaker devices 103 and 104 in the sound reproduction system according to the third embodiment. FIG. 9 is a block diagram showing a configuration example of the distance measuring unit 901 in the control unit 309 of the speaker devices 103 and 104 of the sound reproduction system of FIG.

  In FIG. 9, a distance measurement unit 901 includes a high-pass filter 902, an ultrasonic reception unit 304, a reflected wave detection circuit 903, a counter 904, a clock generator 906, a timing signal generator 905, and an ultrasonic transmission unit. 303. Here, the clock generator 906 generates a clock CK having a sufficiently high frequency compared to the frequency of the ultrasonic wave. The timing signal generator 905 generates a timing signal St at which the second speaker device 104 as its own speaker device transmits the ultrasonic wave Su2. At this time, the reflected wave detection circuit 903 changes the output signal Srd from the L level to the H level. At this time, the counter 904 resets the count value, counts the clock CK, and outputs an output signal Scc indicating the count value. The high-pass filter 902 passes, for example, 60 kHz ultrasonic waves, but blocks, for example, 40 kHz ultrasonic waves.

  In FIG. 8, the ultrasonic transmission unit 303 of the second speaker device 104 transmits, for example, an ultrasonic wave Su2 of 60 kHz at the timing of the timing signal St, and the ultrasonic transmission unit 303 of the first speaker device 103 determines from the timing of the timing signal St. Before that, for example, an ultrasonic wave Su1 of 40 kHz is transmitted. As shown in FIG. 8, it is assumed that the ultrasonic reflected waves Sur1 and Sur2 reflected by an obstacle such as the wall 107 reach the ultrasonic receiving unit 304 of the second speaker device 104. Here, the reflected wave Sur1 is a reflected wave of the ultrasonic wave Su1, and the reflected wave Sur2 is a reflected wave of the ultrasonic wave Su2. Here, the high-pass filter 902 of the distance measuring unit 901 passes the reflected wave Sur2, but blocks the reflected wave Sur1. Therefore, the ultrasonic wave reception unit 304 receives only the reflected wave Sur2, converts it to an electrical signal, and outputs it to the reflected wave detection circuit 903. When the reflected wave detection circuit 903 detects a reflected wave Su2 having a predetermined threshold value or more, it changes the output signal Srd from the L level to the H level indicating signal detection. On the other hand, the counter 904 starts counting the clock CK from the timing signal St, and continues counting when the output signal Srd of the reflected wave detection circuit 903 is at the L level. Here, the counter 904 counts the clock CK from the generation timing t1 of the timing signal St to the reception start timing t2 of the reflected wave Sur2, so that the ultrasonic wave Su2 is transmitted and then reflected by an obstacle such as the wall 107. Since the count value from the reflection until reception is proportional to the delay time T2, the delay time T2 is expressed by the following equation.

T2 = (count value of clock CK) × (one cycle of clock CK) (5)

  As described above, the delay time T2 with respect to the ultrasonic wave Su2 transmitted by the ultrasonic transmission unit 303 of the second speaker apparatus 104 can be measured, and even when the ultrasonic wave Su1 from the first speaker apparatus 103 exists. It is possible to measure the correct distance.

  In place of the high-pass filter 902, the ultrasonic distance may be measured using an ultrasonic receiving unit 304 having characteristics of non-detection for 40 kHz and detection for 60 kHz. For the first speaker device 103, a correct distance can be measured by connecting a low-pass filter instead of the high-pass filter 902. When there are three or more speaker devices, a band pass filter that can pass only the corresponding ultrasonic wave may be used.

  As described above, according to the third embodiment, the distance between the mobile terminal device 106 and the speaker devices 103 and 104 is measured by using ultrasonic waves having different frequencies depending on the speaker devices 103 and 104, and thus the first embodiment. Compared to the above, it is possible to measure the distance with high accuracy by removing the influence of ultrasonic interference, thereby accurately determining the presence or absence of the listener, and the speaker in the room where the listener is present Sound can be output only by the device 103 or 104. Other functions and effects are the same as those of the first embodiment.

(Embodiment 4)
In the fourth embodiment, as in the second embodiment, in order to solve the problem when a non-listener who does not have the mobile terminal device 106 is present in another room, the distance measurement using ultrasonic waves according to the second embodiment is performed. In addition to distance measurement using the 2.4 GHz band radio signal S2.4, for example, by performing distance measurement using the 5 GHz band radio signal S5, the speaker devices 103 and 104 correctly identify the listener 105. A method by which the mobile terminal device 106 can correctly issue a sound output instruction to the speaker device 103 will be described below.

The speaker devices 103 and 104 and the mobile terminal device 106 according to the fourth embodiment are different from the second embodiment in the following points.
(1) The wireless communication module 312 transmits, to the wireless communication module 305, a wireless signal that is, for example, a radio wave having a frequency of 2.4 GHz, in addition to a radio signal that is a radio wave having a frequency of 2.4 GHz, for example. To do. Note that transmission / reception of control signals between the wireless communication module 312 and the wireless communication module 305 is performed in the same manner as in the first embodiment.
(2) The audio reproduction system according to the fourth exemplary embodiment executes the audio reproduction system control process of FIG. 10A instead of the audio reproduction system control process of FIG. 7A.
(3) The speaker devices 103 and 104 execute the speaker device control process (S1011) in FIG. 10B instead of the speaker device control process (S711) in FIG. 7B.
(4) The mobile terminal device 106 executes the mobile terminal device control process (S1021) in FIG. 10C instead of the mobile terminal device control process (S721) in FIG. 7C.
Hereinafter, the difference will be described in detail.

  FIG. 10A is a flowchart illustrating an audio reproduction system control process executed by the audio reproduction system according to the fourth embodiment. 10A, pairing is performed between the mobile terminal device 106, the first speaker device 103, and the second speaker device 104 by a predetermined wireless communication method (S434). This means that the mobile terminal device 106 registers the first speaker device 103 and the second speaker device 104 as devices that can output sound, as devices that can receive sound data wirelessly and output sound. Next, the control processing in the first speaker device 103 (S1011 in FIG. 10B), the control processing in the second speaker device 104 (S1011 in FIG. 10B), and the control processing in the portable terminal device 106 (S1021 in FIG. 10C) are performed in parallel. And executed.

  FIG. 10B is a flowchart showing a speaker device control process (S1011) executed by the speaker devices 103 and 104 in the subroutine of FIG. 10A. FIG. 10B is characterized in that steps S1001 to S1004 are added between step S703, step S704, and step S704 as compared to FIG. 7B according to the second embodiment. Hereinafter, the difference will be described in detail. Note that the distance measured in step S703 is d2.4.

  After step S703 in FIG. 10B, a radio signal having a predetermined frequency of, for example, 5 GHz band is received from the mobile terminal device 106 (S1001), and received signal power is calculated based on the received signal strength (RSSI) of the received radio signal. Based on this, as in the second embodiment, the distance d5 between the mobile terminal device 106 and the speaker devices 103 and 104 is calculated (S1002). In step S1003, | d2.4-d5 | <D1th (here Thus, it is determined whether or not D1th is a threshold value that is a predetermined minute value near 0, for example. If YES, the process proceeds to step S1004, and if NO, the process returns to step S452. Next, the distance d2.4 at a predetermined frequency in the 2.4 GHz band calculated in step S702 is set as a measurement distance d using a radio signal, and the process proceeds to step S704.

  FIG. 10C is a flowchart of the mobile terminal device control process (S1021) executed by the mobile terminal device 106 in the subroutine of FIG. 10A. FIG. 10C is characterized in that the process of step S1022 is added between step S722 and step S426, as compared with FIG. 7C according to the second embodiment. Hereinafter, the difference will be described in detail.

  After step S722 in FIG. 10C, for example, a radio signal having a predetermined frequency in the 5 GHz band is transmitted for distance calculation, and then the process proceeds to step S426.

  As described above, according to the fourth embodiment, in addition to the distance measurement using ultrasonic waves and the distance measurement using the 2.4 GHz band radio signal S2.4, for example, the distance measurement using the 5 GHz band radio signal S5. Thus, the speaker devices 103 and 104 can correctly identify the listener 105, and the mobile terminal device 106 can correctly issue a sound output instruction to the speaker device 103, for example. Other functions and effects are the same as those of the second embodiment.

(Embodiment 5)
FIG. 11 is a flowchart showing speaker device control processing executed by the speaker devices 103 and 104 of the sound reproduction system according to the fifth embodiment. In the speaker device control process of the sound reproduction system according to the fifth embodiment, steps S1114 and S1115 are inserted instead of step S414 between step S452 and step S453 as compared to FIG. It is characterized by executing.

  FIG. 12 is a graph showing the directivity characteristics of audio signals of respective frequencies output from the speaker devices 103 and 104 of FIG. FIG. 13 is a graph showing the amplitude frequency characteristics of the audio signal output from the speaker devices 103 and 104 of FIG. 11 in the direction of the azimuth angle of 40 degrees.

  When performing distance measurement using ultrasonic waves, the ultrasonic wave is emitted in the directions of the respective azimuth angles, so that the relationship of the direction with respect to the listener 105 viewed from the speaker devices 103 and 104 can also be measured. On the other hand, as shown in FIGS. 12 and 13, the general speaker unit 306 is known to have a wider directivity as the sound frequency is lower and narrower as the sound frequency is higher. When the deviation from the listener 105 is large, the bass is relatively lowered. In other words, in FIG. 13, frequency characteristics such as making the treble relatively high so as to correct the characteristic 1301 to the flat characteristic 1302 are corrected. By performing the equalizing process, the frequency characteristic deterioration due to the position dependency of the listener 105 can be improved.

  After the process of step S452 in FIG. 11, a listener detection signal including the azimuth angle n and the measurement distance D (n) with respect to the listener 105 is transmitted from the speaker devices 103 and 104 to the portable terminal device 106 (S1114), and the azimuth angle Depending on n, for example, as shown in FIG. 13, the frequency characteristic of the speaker unit 306 is corrected.

  As described above, according to the fifth embodiment, the frequency characteristic is substantially flat at the position of the listener 105 according to the azimuth angle from the portable terminal device 106 to the speaker devices 103 and 104 by ultrasonic waves. By performing equalizing correction, it is possible to improve the deterioration of frequency characteristics due to the position dependency of the listener 105.

(Other embodiments)
As described above, Embodiments 1 to 5 have been described as examples of the technology disclosed in the present application. However, the technology according to the present disclosure is not limited to this, and can be applied to embodiments in which changes, replacements, additions, omissions, and the like are performed. Moreover, it is also possible to combine each component demonstrated in the said Embodiments 1-5 and set it as a new embodiment. That is, not only the combination of Embodiment 1 and Embodiments 2 to 5, but also the combinations of Embodiments 2 to 5 are possible.

  The mobile terminal device control process according to each of the above embodiments can be implemented as an application applicable to a control terminal device such as a smart phone, a mobile phone, a tablet terminal device, or an electronic device.

  As described above in detail, according to the sound reproduction system according to the present disclosure, the speaker device and the mobile terminal device are separate and the speaker device suitable for the position of the listener when there are a plurality of speaker devices in different rooms. It is possible to make sound from.

101 First Room 102 Second Room 103 First Speaker Device 104 Second Speaker Device 105 Listener 106 Mobile Terminal Device 107 Wall 303 Ultrasonic Transmitter 304 Ultrasonic Receiver 305 Wireless Communication Module 305A Antenna 306 Speaker Unit 307 Memory 308 Audio data buffer 309 Control unit 310 Control unit 311 Audio data memory 312 Wireless communication module 312A Antenna 313 Memory 314 Operation unit 315 Display unit 501 Non-listener 901 Distance measurement unit 902 High-pass filter 903 Reflected wave detection circuit 904 Counter 905 Timing signal generation 906 Clock generator

Claims (6)

An audio reproduction system comprising a plurality of speaker devices and a control terminal device that controls the speaker devices by wirelessly transmitting and receiving control signals to and from the speaker devices and wirelessly transmits audio signals to the speaker devices. And
Each of the speaker devices transmits the ultrasonic wave having the first ultrasonic frequency to the control terminal device, and then the speaker device and the control terminal device based on a delay time of a reflected wave that is reflected and returned. The distance average value calculated by measuring the distance between and a plurality of times is stored in advance, and in response to the sound output instruction signal from the control terminal device, the ultrasonic wave of the first ultrasonic frequency is After transmitting to the control terminal device, the distance between each speaker device and the control terminal device is measured based on the delay time of the reflected wave reflected and returned, and the measured distance and the distance When the absolute value of the difference from the average value is larger than a predetermined first threshold, it is determined that there is a listener, and a listener detection signal including the measured distance is transmitted to the control terminal device,
When the control terminal device receives a listener detection signal from one of the plurality of speaker devices, the control terminal device transmits a sound output instruction signal to the one speaker device,
The one speaker device receives and outputs a sound signal from the control terminal device based on the sound output instruction signal. When the control terminal device receives a listener detection signal from a plurality of speaker devices of the plurality of speaker devices, the control terminal device outputs a sound to one speaker device having the shortest distance from the control terminal device. Send an instruction signal,
The sound reproduction system according to claim 1, wherein the one speaker device receives and outputs a sound signal from the control terminal device based on the sound output instruction signal. The control terminal device transmits radio waves of a first radio frequency to the speaker devices,
Each of the speaker devices has an absolute value of a difference between the distance measured using the ultrasonic wave having the first ultrasonic frequency and the average distance value greater than a predetermined first threshold value, and the first Based on the received power when a radio wave having a radio frequency of 1 is received, the difference between the distance when the distance from the control terminal device to each speaker device is calculated and the distance measured using the ultrasonic wave When the absolute value is less than a predetermined second threshold, it is determined that there is a listener, and a listener detection signal including the measured distance is transmitted to the control terminal device. Item 3. A sound reproduction system according to item 1 or 2.   In response to the sound output instruction signal from the control terminal device, each speaker device transmits an ultrasonic wave having a second ultrasonic frequency different from that of the other speaker devices to the control terminal device, and then reflects In the reflected wave that is returned, only the reflected wave of the second ultrasonic frequency is extracted by the filter, and then between each of the speaker devices and the control terminal device based on the delay time of the reflected wave A distance is measured, and when the absolute value of the difference between the measured distance and the average distance is greater than a predetermined first threshold, it is determined that there is a listener, and the measured distance is The sound reproduction system according to claim 1, wherein a listener detection signal including the signal is transmitted to the control terminal device. The control terminal device sequentially transmits a radio wave of a first radio frequency and a radio wave of a second radio frequency to each speaker device,
Each of the speaker devices has an absolute value of a difference between the distance measured using the ultrasonic wave having the first ultrasonic frequency and the average distance value greater than a predetermined first threshold value, and the first The absolute value of the difference between the two distances when the two distances from the control terminal device to the speaker devices are calculated based on the received power when the radio waves having the first and second radio frequencies are received, respectively. A distance that is less than a predetermined third threshold and that is measured using the ultrasonic wave of the first ultrasonic frequency and a radio wave having a lower radio frequency out of the first and second radio frequencies. When the absolute value of the difference from the measured distance is less than a predetermined third threshold, it is determined that there is a listener, and a listener detection signal including the measured distance is controlled. Transmission to a device Sound reproduction system according to one or Re.   Each of the speaker devices transmits an ultrasonic wave having the first ultrasonic frequency to the control terminal device, and then is directed from the control terminal device to the speaker device based on a reflected wave that is reflected and returned. 6. An equalizing process is performed such that an angle is calculated and an audio signal has a substantially flat frequency characteristic at a position of the listener based on the azimuth angle. The audio reproduction system according to one.

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