Patent Publication Number: US-9418525-B2

Title: Monitoring system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a monitoring system which performs data input and output to and from a camera. 
     2. Description of the Related Art 
     In the related art, as an example of a communication system which performs data input and output to and from a camera, there is a monitoring camera system which monitors an intruder who enters a house lot. A monitoring camera system disclosed in Japanese Patent Unexamined Publication No. 2000-99862 includes a home server which can record video and sound, an infrared sensor, a video camera, and a microphone. In a case where the infrared sensor detects an intruder, the home server records a video of the intruder and also records sound of the intruder by using the video camera and the microphone. 
     However, in the above-described patent document, in a case where the sensor detects the intruder, image data indicating a video captured by the video camera and audio data of sound collected by the microphone are just recorded by the home server. 
     A home dweller may recognize the presence of an intruder in circumstances in which the dweller observes the home server at all times, but the dweller is not continuously able to recognize the intruder if the dweller is away from a location (for example, a home study) where image data or audio data stored in the home server can be checked. The dweller reproduces the recorded image data or audio data and thus recognizes the presence of the intruder for the first time. For this reason, the dweller cannot converse with the intruder, such as directly listening to what is wanted from the intruder. In a case where the dweller is out, it is difficult to directly converse with the intruder from a place being visited. 
     SUMMARY OF THE INVENTION 
     In order to solve the problems of the related art, an object of the present invention is to provide a portable terminal and a communication system capable of improving a user&#39;s convenience by performing a call between a camera and a portable terminal in a case where a target is detected by a sensor. 
     According to the present invention, there is provided a monitoring system including a sensor; a monitoring camera that includes an image capturing unit, and has a call function; a master device that communicates with the monitoring camera, and is connected to a fixed telephone network so as to perform calls to other fixed telephones; and a mobile phone terminal that includes a display/input unit, performs wireless communication with the master device, and is connected to other mobile phones via a mobile phone network, in which, when the sensor detects a target, a detection signal is sent to the master device, in which the master device sends a signal for instructing the monitoring camera registered in correlation with the sensor to transmit image data, in which, when an operation of giving an instruction for displaying an image is received, the mobile phone terminal sends information regarding the operation to the master device, in which the master device sends the image data which is transmitted from the monitoring camera, to the mobile phone terminal according to the information regarding the operation, in which the mobile phone terminal sends a request signal for starting a call to the monitoring camera when receiving an operation on a predetermined icon displayed on the display/input unit in a state in which the image data sent from the monitoring camera is displayed on the display/input unit, and in which the master device transmits the request signal for starting a call from the mobile phone terminal, to the monitoring camera. 
     According to the present invention, it is possible to improve a user&#39;s convenience by performing a call between a camera and a portable terminal in a case where a target is detected by a sensor. Consequently, in a case where the present invention is applied to a monitoring camera system, a dweller can converse with an intruder, such as directly listening to what is wanted from the intruder. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram illustrating a system configuration of a monitoring camera system of the present embodiment; 
         FIG. 2  is a block diagram illustrating an internal configuration of a master device; 
         FIG. 3  is a block diagram illustrating an internal configuration of a slave device; 
         FIG. 4  is a block diagram illustrating an internal configuration of a camera; 
         FIG. 5  is a block diagram illustrating an internal configuration of a sensor; 
         FIG. 6  is a block diagram illustrating an internal configuration of a smartphone; 
         FIG. 7  is a diagram illustrating an initial screen of the smartphone during activation; 
         FIG. 8A  is a diagram illustrating transition of a screen of the smartphone when a volume of a microphone and a speaker is set; 
         FIG. 8B  is a diagram illustrating transition of the screen of the smartphone when the volume of a microphone and a speaker is set; 
         FIG. 8C  is a diagram illustrating transition of the screen of the smartphone when the volume of a microphone and a speaker is set; 
         FIG. 9A  is a diagram illustrating transition of the screen of the smartphone when a hands-free call is performed; 
         FIG. 9B  is a diagram illustrating transition of the screen of the smartphone when a hands-free call is performed; 
         FIG. 9C  is a diagram illustrating transition of the screen of the smartphone when a hands-free call is performed; 
         FIG. 10A  is a diagram illustrating transition of the screen of the smartphone when a handset call is performed; 
         FIG. 10B  is a diagram illustrating transition of the screen of the smartphone when a handset call is performed; 
         FIG. 10C  is a diagram illustrating transition of the screen of the smartphone when a handset call is performed; 
         FIG. 11A  is a diagram illustrating transition of the screen of the smartphone when telephone monitoring is performed; 
         FIG. 11B  is a diagram illustrating transition of the screen of the smartphone when telephone monitoring is performed; 
         FIG. 11C  is a diagram illustrating transition of the screen of the smartphone when telephone monitoring is performed; 
         FIG. 12  is a sequence diagram illustrating a flow of an operation of the monitoring camera system; and 
         FIG. 13  is a flowchart illustrating an operation procedure of the master device. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the drawings, a description will be made of an embodiment (hereinafter, referred to as “the present embodiment”) of a monitoring camera system related to the present invention. 
       FIG. 1  is a diagram illustrating a system configuration of monitoring camera system  5  of the present embodiment. Monitoring camera system  5  is mainly provided in house  8 , and includes master device  10 , two slave devices  20 A and  20 B, two cameras  30  (specifically, indoor camera  30 A and monitoring camera  30 B), various sensors  40  (specifically, human sensors  40 A and  40 B, smoke sensor  40 C, and opening/closing sensor  40 D), smartphone  50 , and wireless router  60 . A configuration of monitoring camera system  5  is only an example and may be modified in various aspects. 
     Master device (gateway)  10  is a control device which controls the entire operation of monitoring camera system  5 , and is connected to the slave devices, the cameras, the sensors, and the like in a communicable manner by using a communication method such as digital enhanced cordless telecommunications (DECT). Master device  10  is connected to the Internet  65  (network) via wireless router  60  using a wireless LAN. Master device  10  is connected to fixed telephone network  85  in a wired manner and can perform a call to fixed telephone  80 . Master device  10  has a function of charging slave device  20 A which is inserted into insertion port  10   a.    
     Slave devices  20 A and  20 B are connected to master device  10  in the DECT communication method and can perform a call to master device  10 . Particularly, in a case where two slave devices  20 A and  20 B are not required to be differentiated from each other, the slave devices are collectively referred to as slave device  20 . 
     Various sensors  40  (specifically, human sensors  40 A and  40 B, smoke sensor  40 C, and opening/closing sensor  40 D) are connected to master device  10  in the DECT communication method. Herein, as sensors, opening/closing sensor  40 D which detects opening and closing of a window, smoke sensor  40 C which detects smoke, and human sensors  40 A and  40 B which detect a person with infrared rays are used. Particularly, in a case where the sensors are not required to be differentiated from each other, the sensors are collectively referred to as sensor  40 . As will be described later, infrared sensor  313  (refer to  FIG. 4 ) built into camera  30  is also used as a human sensor. 
     The two cameras (specifically, indoor camera  30 A and monitoring camera  30 B) have a call function and are connected to master device  10  in the DECT communication method. Herein, as cameras, monitoring camera  30 B which captures an image of an outdoor environment, and indoor camera  30 A which captures an image of house  8 , are used. Particularly, in a case where the cameras are not required to be differentiated from each other, the cameras are collectively referred to as camera  30 . 
     Smartphone  50  is connected to master device  10  via wireless router  60  using a wireless LAN, and is connected to mobile phone  70  or other smartphones via mobile phone network  75  using a communication method such as the third generation (3G) method. 
       FIG. 2  is a block diagram illustrating an internal configuration of master device  10 . Master device  10  includes control unit  109 , storage unit  103 , operation unit  105 , and display unit  106 . Master device  10  receives various input operations and displays information such as an image on display unit  106 . Control unit  109  has a call control portion  110  and an audio stream processing portion  112  built thereinto, and performs call control during calling, processing of audio data, and the like. 
     Master device  10  includes an image memory control unit  115  and image memory  116 , and stores image data or the like captured by camera  30  in image memory  116 . 
     Master device  10  includes wireless LAN control unit  121  and wireless LAN communication I/F unit  122 , and transmits and receives image data and audio data to and from smartphone  50 , camera  30 , and the like via wireless router  60  connected over a wireless LAN. 
     Master device  10  includes DECT protocol control unit  108  and DECT wireless I/F unit  107 , and performs wireless connection to slave device  20 , sensor  40 , and camera  30  by using a wireless method such as digital enhanced cordless telecommunications (DECT). 
     Master device  10  includes audio bus  117 , sound input/output control unit  104 , speaker  129 , and microphone  128 , and performs input and output of sound to and from an external device. 
     Master device  10  includes fixed telephone line I/F unit  101 , and can perform a call to external fixed telephone  80  connected to fixed telephone network  85 . 
     Master device  10  includes slave device/portable terminal charging unit  126  and charges slave device  20  or smartphone  50  inserted into insertion port  10   a.    
     Master device  10  includes USB communication I/F unit  127 , and transmits and receives data to and from an apparatus, a memory, or the like having an interface of a universal serial bus (USB) standard. 
     Master device  10  registers various sensors  40  (specifically, human sensors  40 A and  40 B, smoke sensor  40 C, and opening/closing sensor  40 D) and the plurality of cameras  30  in storage unit  103  in correlation with each other. For example, human sensor  40 B and monitoring camera  30 B are installed at close locations outdoors and are thus registered in correlation with each other. Monitoring camera  30 B, as will be described later, integrally has infrared sensor  313  (refer to  FIG. 4 ) which is a human sensor and is built thereinto, and is thus also registered in correlation with infrared sensor  313 . Human sensor  40 A, smoke sensor  40 C, and opening/closing sensor  40 D are all installed inside house  8  and are thus registered in correlation with indoor camera  30 A. 
       FIG. 3  is a block diagram illustrating an internal configuration of slave device  20 . Slave device  20  includes control unit  247 , storage unit  242 , operation unit  244 , and display unit  245 . Slave device  20  receives various input operations and displays information such as an image on display unit  245 . 
     Slave device  20  includes DECT protocol control unit  249  and DECT wireless I/F unit  248 , and performs wireless connection to master device  10 , sensor  40 , and camera  30  by using a wireless method such as DECT. 
     Slave device  20  includes audio bus  255 , sound input/output control unit  243 , speaker  252 , and microphone  251 , and performs input and output of sound to and from an external device. 
       FIG. 4  is a block diagram illustrating an internal configuration of camera  30 . Indoor camera  30 A and monitoring camera  30 B as examples of cameras  30  have substantially the same specification as each other. Camera  30  includes control unit  309 , storage unit  303 , and operation unit  305 . Camera  30  performs an operation related to image capturing and also receives input operations. 
     Camera  30  includes DECT protocol control unit  317  and DECT wireless I/F unit  318 , and performs wireless connection to master device  10  by using a wireless method such as DECT. 
     Camera  30  includes wireless LAN control unit  321  and wireless LAN communication I/F unit  322 , and transmits and receives image data and audio data to and from master device  10 , smartphone  50 , and the like via wireless router  60  connected over the wireless LAN. 
     Camera  30  includes audio bus  307 , sound input/output control unit  304 , speaker  329 , and microphone  328 , and performs input and output of sound to and from an external device. 
     Camera  30  includes image capturing unit  312 , image memory control unit  316 , and image memory  315 , and stores image data captured by image capturing unit  312  in image memory  315 . Image capturing unit  312  has a lens and an imaging element (for example, an image sensor such as a charged coupled device (CCD) or a complementary metal oxide semiconductor (CMOS)). 
     Camera  30  integrally has infrared sensor  313  which is a passive infrared (PIR) sensor as a human sensor built thereinto. Infrared sensor  313  detects the presence of a person by detecting a change in heat (infrared rays) generated by the person. Camera  30  includes power source unit  314  which is constituted by a commercial AC power source. 
       FIG. 5  is a block diagram illustrating an internal configuration of sensor  40 . Sensor  40  includes control unit  447 , storage unit  442 , and display lamp  445 . Sensor  40  performs a predetermined detection operation, such as turning on display lamp  445 , in a case of detecting a target (for example, an intruder which is also the same for the following description). 
     Sensor  40  includes DECT protocol control unit  449  and DECT wireless I/F unit  448 , and performs wireless connection to master device  10  by using a wireless method such as DECT, and sends sensor detection information to master device  10  when a target is detected. 
     Sensor unit  453  differs depending on the kind of sensor  40 . For example, in a case of human sensors  40 A and  40 B, sensor unit  453  is a PIR sensor which detects a person through a change in infrared rays. In a case of opening/closing sensor  40 D which detects opening and closing of a window or the like, sensor unit  453  is a reed switch which switches between turned-on and turned-off states due to opening and closing. In a case of smoke sensor  40 C, sensor unit  453  is a light emitting/receiving unit which detects smoke when emitted light is blocked by the smoke. 
     Rechargeable battery  450  is a battery which can be charged and supplies power to each unit. 
       FIG. 6  is a block diagram illustrating an internal configuration of smartphone  50 . Smartphone  50  includes control unit  506 , storage unit  504 , and display/operation unit (touch panel)  503 . Smartphone  50  receives various input operations and displays information such as an image on touch panel  503 . Monitoring function control portion  514  which can set a function of camera  30  is built into control unit  506  as will be described later. Touch panel  503 , which is a display/input unit in which a display unit and an operation unit are integrally formed, displays information such as an image or an icon on a screen and receives a tap operation (or a touch operation) which is performed on the screen by a user. 
     Smartphone  50  includes 3G protocol control unit  502  and 3G wireless I/F unit  501 , and performs wireless connection to mobile phone  70  or other smartphones connected to mobile phone network  75 , by using a third generation (3G) wireless communication method. 
     Smartphone  50  includes audio bus  515 , sound input/output control unit  505 , speaker  513 , and microphone  512 , and performs input and output of sound to and from an external device. 
     Smartphone  50  includes wireless LAN control unit  507  and wireless LAN communication I/F unit  508 , and transmits and receives image data and audio data to and from master device  10 , camera  30 , and the like via wireless router  60  connected over the wireless LAN. 
     Smartphone  50  includes USB communication I/F unit  511 , and transmits and receives data to and from an apparatus, memory, or the like having an interface of a universal serial bus (USB) standard. 
     A description will be made of an operation of monitoring camera system  5  having the above-described configuration. 
     First, an operation of smartphone  50  will be described. When a user activates an application of the monitoring camera installed in smartphone  50 , smartphone  50  displays an initial screen. 
       FIG. 7  is a diagram illustrating the initial screen of smartphone  50  during activation. When the application of the monitoring camera is activated, image (moving image)  55  captured by camera  30  is displayed at a center of the initial screen of touch panel  503 . Camera icon  51 , speaker icon  52 , mute icon  53 , and disconnect icon  54  are displayed on the screen of touch panel  503  so that a tap operation can be performed thereon. 
     Camera icon  51  is an icon used to instruct camera  30  to start video recording and to set a function of camera  30 . 
     Speaker icon  52  as mode switching means is an icon used to switch a volume of speaker  513  mounted in smartphone  50  and is in a turned-on state during the activation. When a tap operation is performed on speaker icon  52 , speaker icon  52  can switch between a turned-on state and a turned-off state. Herein, speaker icon  52  is displayed green in a turned-on state and is displayed white in a turned-off state. 
     The turned-on state of speaker icon  52  is a state in which the volume of speaker  513  is set to be high and is suitable for typical monitoring or a hands-free call (a speaker phone call). In other words, in a case where speaker icon  52  is in the turned-on state, a volume suitable for a hands-free call (speaker phone call) is set in smartphone  50 . On the other hand, the turned-off state of speaker icon  52  is a state in which the volume of speaker  513  is set to be low as if whispered in a user&#39;s ear, and is suitable for sound monitoring or a handset call. In other words, in a case where speaker icon  52  is in the turned-off state, the volume suitable for a handset call is set in smartphone  50 . 
     Mute icon  53  is an icon used to switch turning-on and turning-off of microphone  512  mounted in smartphone  50 , and is in a turned-on state during activation, that is, in an invalid (silent) state of microphone  512 . When a tap operation is performed on mute icon  53 , mute icon  53  can switch between a turned-on state and a turned-off state. Herein, in the same manner as speaker icon  52 , mute icon  53  is displayed green in a turned-on state and is displayed white in a turned-off state. 
     Disconnect icon  54  in which characters “disconnect” are written, is an icon used to disconnect camera  30  and is in a turned-off state during activation, that is, in a connection state. 
       FIGS. 8A to 8C  are diagrams illustrating transition of a screen of smartphone  50  when the volumes of microphone  328  and speaker  329  of camera  30  are set. When a predetermined operation is performed on the screen of touch panel  503 , selection menus for setting the volume of microphone  328  and speaker  329  of camera  30  are displayed on the screen of touch panel  503 . 
     As illustrated in  FIG. 8A , “Camera Mic Volume” key  56  displayed as a selection menu is a key for setting the volume of microphone  328 . “Camera Speaker Volume” key  57  is a key for setting the volume of speaker  329 . 
     When a tap operation is performed on “Camera Mic Volume” key  56 , as illustrated in  FIG. 8B , the selection menu disappears, and then seek bar  58  is displayed on the screen of touch panel  503 . When the user moves slider  58   a  of seek bar  58  in horizontal directions in the figure, the volume (microphone sensitivity) of microphone  328  of camera  30  is changed. If the volume of microphone  328  is determined, and OK button  58   b  is pressed, the determined volume of microphone  328  is set in camera  30 . 
     Similarly, when a tap operation is performed on “Camera Speaker Volume” key  57 , as illustrated in  FIG. 8C , the selection menu disappears, and then seek bar  59  is displayed on the screen of touch panel  503 . When the user moves slider  59   a  of seek bar  59  in horizontal directions in the figure, the volume of speaker  329  of camera  30  is changed. If the volume of speaker  329  is determined, and OK button  59   b  is pressed, the determined volume of speaker  329  is set in camera  30 . 
     Next, a description will be made of various operation modes using smartphone  50 . 
     In the present embodiment, smartphone  50  can be switched to four operation modes including a typical monitoring mode, a hands-free call mode, a handset call mode, and a sound monitoring mode. As described above, right after the application of the monitoring camera is activated, smartphone  50  displays the initial screen (refer to  FIG. 7 ) and is in the typical monitoring mode. An operation of activating the application corresponds to a monitoring instruction as an operation of giving an instruction for image display. In the typical monitoring mode, sound collected by microphone  328  of camera  30  is output from speaker  513  of smartphone  50  at a high volume, and microphone  512  of smartphone  50  is in an invalid state. In other words, sound of the user is not collected by microphone  512  of smartphone  50 . 
       FIGS. 9A to 9C  are diagrams illustrating transition of a screen of smartphone  50  when a hands-free call is performed. When a tap operation is performed on mute icon  53  in the initial screen of  FIG. 7 , as illustrated in  FIG. 9A , mute icon  53  is turned off, and guidance  61  of “Mute OFF” is displayed on the screen of touch panel  503 . Then, if the switching time (here, 0.2 seconds) has elapsed, as illustrated in  FIG. 9B , microphone  512  of smartphone  50  becomes valid, and the smartphone is switched to the hands-free call mode. In this hands-free call mode, sound collected by microphone  328  of monitoring camera  30 B is output from speaker  513  of smartphone  50  at a high volume, and microphone  512  of smartphone  50  becomes valid so that a hands-free call can be performed to monitoring camera  30 B. 
     In the hands-free call mode, when a tap operation is performed on mute icon  53  again, as illustrated in  FIG. 9C , mute icon  53  is turned on, and guidance  62  of “Mute ON” is displayed on the screen of touch panel  503 . Then, if the switching time (here, 0.2 seconds) has elapsed, the screen returns to the initial screen of  FIG. 7 , microphone  512  of smartphone  50  is invalidated, and the smartphone returns to the typical monitoring mode. 
       FIGS. 10A to 10C  are diagrams illustrating transition of a screen of smartphone  50  when a handset call is performed. When a tap operation is performed on speaker icon  52  in the hands-free call mode illustrated in  FIG. 9B , speaker icon  52  is turned off, and guidance  63  of “Speaker OFF” is displayed on the screen of touch panel  503 , as illustrated in  FIG. 10A . Then, if the switching time (here, 0.2 seconds) has elapsed, as illustrated in  FIG. 10B , the smartphone is switched to the handset call mode. In the handset call mode, sound collected by microphone  328  of monitoring camera  30 B is output from speaker  513  of smartphone  50  at a low volume (a volume at which the sound can be heard when speaker  513  is close to a user&#39;s ear), and microphone  512  of smartphone  50  is still valid. Smartphone  50  can perform a handset call to monitoring camera  30 B. 
     When a tap operation is performed on speaker icon  52  in the handset call mode, as illustrated in  FIG. 10C , speaker icon  52  is turned on, and guidance  64  of “Speaker ON” is displayed on the screen of touch panel  503 . Then, if the switching time (here, 0.2 seconds) has elapsed, the screen returns to the screen illustrated in  FIG. 9B , smartphone  50  increases the volume of speaker  513  and is switched to the hands-free call mode. 
     On the other hand, when a tap operation is performed on mute icon  53  in the handset call mode illustrated in  FIG. 10B , mute icon  53  and speaker icon  52  are turned on, and, as illustrated in  FIG. 9C , guidance  62  of “Mute ON” is displayed on the screen of touch panel  503 . Then, if the switching time (here, 0.2 seconds) has elapsed, the screen returns to the initial screen of  FIG. 7 , microphone  512  of smartphone  50  is invalidated, and smartphone  50  returns to the typical monitoring mode. 
       FIGS. 11A to 11C  are diagrams illustrating transition of a screen of smartphone  50  when telephone monitoring is performed. When a tap operation is performed on speaker icon  52  in the initial screen of  FIG. 7 , as illustrated in  FIG. 11A , speaker icon  52  is turned off, and guidance  63  of “Speaker OFF” is displayed on the screen of touch panel  503 . Then, if the switching time (here, 0.2 seconds) has elapsed, as illustrated in  FIG. 11B , smartphone  50  reduces the volume of speaker  513  of smartphone  50  and is switched to the telephone monitoring mode. In the telephone monitoring mode, sound collected by microphone  328  of monitoring camera  30 B is output from speaker  513  of smartphone  50  at a low volume (a volume at which the sound can be heard when speaker  513  is close to a user&#39;s ear), and microphone  512  of smartphone  50  is still invalid. 
     When a tap operation is performed on speaker icon  52  in the telephone monitoring mode, as illustrated in  FIG. 11C , speaker icon  52  is turned on, and guidance  64  of “Speaker ON” is displayed on the screen of touch panel  503 . Then, if the switching time (here, 0.2 seconds) has elapsed, the screen returns to the initial screen of  FIG. 7 , microphone  512  of smartphone  50  is invalidated, and smartphone  50  returns to the typical monitoring mode. 
     On the other hand, when a tap operation is performed on mute icon  53  in the telephone monitoring mode illustrated in  FIG. 11B , mute icon  53  is turned off, and guidance  61  of “Mute OFF” is displayed on the screen of touch panel  503 . Then, if the switching time (here, 0.2 seconds) has elapsed, as illustrated in  FIG. 10B , microphone  512  of smartphone  50  becomes valid, and the smartphone is switched to the handset call mode. 
     Next, a description will be made of a flow of an operation of monitoring camera system  5 . 
       FIG. 12  is a sequence diagram illustrating a flow of an operation of monitoring camera system  5 . Herein, a description will be made of an operation of monitoring an intruder or the like by using human sensor  40 B and monitoring camera  30 B provided outdoors. 
     First, if human sensor  40 B detects a person present outdoors, a detection signal and sensor detection information are transmitted to master device  10  (step S 101 ). If the sensor detection information is received from human sensor  40 B, master device  10  is wirelessly connected to smartphone  50  by using the wireless LAN (step S 102 ), and transmits the sensor detection information to smartphone  50  when the connection has been completed (step S 103 A). 
     Master device  10  requests monitoring camera  30 B to transmit image/audio data (step S 103 B). If the request for transmission of image/audio data is received, monitoring camera  30 B is connected to master device  10  by using the wireless LAN, and transmits image data captured by image capturing unit  312  and audio data collected by microphone  328  to master device  10  (step S 104 ). 
     If a monitoring instruction is received from the user (step S 105 - 1 ), smartphone  50  requests master device  10  to transmit the image/audio data (step S 105 - 2 ). In response to the request for transmission of the image/audio data from smartphone  50 , master device  10  transmits the image data and the audio data which have been transmitted from monitoring camera  30 B, to smartphone  50  (step S 106 ). 
     Consequently, smartphone  50  displays the initial screen (refer to  FIG. 7 ) and enters the typical monitoring mode. If a tap operation is performed on speaker icon  52  in the typical monitoring mode in which the initial screen is displayed (step S 107 A), smartphone  50  is switched to the sound monitoring mode (step S 108 ). 
     On the other hand, if a tap operation is performed on mute icon  53  in the typical monitoring mode in which the initial screen is displayed (step S 107 B- 1 ), smartphone  50  transmits the operation information to master device  10  (step S 107 B- 2 ). 
     If the operation information is received, master device  10  requests monitoring camera  30 B to perform a hands-free call (step S 109 ). If the hands-free call request is received, monitoring camera  30 B turns on speaker  329  and transmits an acknowledgement (ACK) signal to smartphone  50  via master device  10  (step S 110 ). 
     If the ACK signal is received from monitoring camera  30 B, smartphone  50  is switched to the hands-free call mode and starts performing a call. In other words, smartphone  50  transmits the audio data for conversation, collected by microphone  512 , to master device  10  (step S 111 ). Master device  10  transmits the received audio data for conversation to monitoring camera  30 B (step S 112 ). Monitoring camera  30 B outputs the audio data for conversation received from master device  10 , from speaker  329  (step S 113 ). 
     Transmission of audio data for conversation from monitoring camera  30 B to smartphone  50  is performed in a reverse order. In other words, monitoring camera  30 B transmits audio data for conversation collected by microphone  328  to master device  10  (step S 114 ). Master device  10  transmits the received audio data for conversation to smartphone  50  (step S 115 ). Smartphone  50  outputs the audio data for conversation received from master device  10 , from speaker  513  (step S 116 ). 
     In a case where the smartphone is switched to the sound monitoring mode in step S 108  and then a tap operation is performed on mute icon  53 , smartphone  50  is switched to the handset call mode. 
       FIG. 13  is a flowchart illustrating an operation procedure of master device  10 . Master device  10  starts the present operation with a detection signal from human sensor  40 B as a trigger. First, master device  10  acquires sensor detection information from human sensor  40 B (step S 1 ). Master device  10  determines whether or not a request for transmission of image/audio data has been received from smartphone  50  (step S 2 ). If the request has not been received, master device  10  finishes the present operation. 
     On the other hand, if the request for transmission of image/audio data has been received from smartphone  50 , master device  10  transmits image data and audio data transmitted from monitoring camera  30 B, to smartphone  50  (step S 3 ). 
     Master device  10  determines whether or not a request for a hands-free call or a handset call is made from smartphone  50  (step S 4 ). This call request is made by performing a tap operation on mute icon  53  as described above. If there is no request for a call from smartphone  50 , master device  10  finishes the present operation. 
     On the other hand, if there is a call request from smartphone  50 , master device  10  relays a call between smartphone  50  and monitoring camera  30 B (step S 5 ). 
     Subsequently, master device  10  determines whether or not an instruction for ending of the call is given from smartphone  50  (step S 6 ). The instruction for ending of the call is given by performing a tap operation on mute icon  53  or a tap operation on disconnect icon  54  as described above. If the instruction for ending of the call is not given, master device  10  returns to the process in step S 5 . On the other hand, if the instruction for ending of the call is given, master device  10  finishes the present operation. Master device  10  enters a standby state until being activated with a detection signal from sensor  40  as a trigger again. 
     As mentioned above, in monitoring camera system  5  of the present embodiment, if human sensor  40 B detects an intruder (target), sensor detection information is sent to master device  10 . Master device  10  transmits the sensor detection information sent from human sensor  40 B, to smartphone  50 , and also sends a request for transmission of image/audio data to monitoring camera  30 B which is registered in correlation with human sensor  40 B. If an operation of a monitoring instruction is received, smartphone  50  sends the operation information to master device  10 . Master device  10  sends the image data transmitted from monitoring camera  30 B, to smartphone  50 , according to the operation information. Smartphone  50  displays the image data sent from monitoring camera  30 B on touch panel  503 , and sends a request signal for starting a call to monitoring camera  30 B when receiving a tap operation on mute icon  53 . Master device  10  transmits the request signal for starting a call from smartphone  50 , to monitoring camera  30 B. A call between smartphone  50  and monitoring camera  30 B is started. 
     According to monitoring camera system  5 , in a case where an intruder is detected by human sensor  40 B, a call between monitoring camera  30 B and smartphone  50  can be performed, and thus it is possible to improve convenience. Consequently, a home dweller can converse with the intruder, such as directly listening to what is wanted from the intruder. 
     In a case where speaker icon  52  is turned on, and a high volume suitable for a hands-free call is set, smartphone  50  is switched to a hands-free call mode when receiving a tap operation on mute icon  53 . Smartphone  50  and monitoring camera  30 B enter a voice call state. Consequently, switching to a hands-free call can be easily performed. 
     In a case where speaker icon  52  is turned off and a low volume (a volume at which sound can be heard when speaker  513  is close to a user&#39;s ear) suitable for a handset call is set, smartphone  50  is switched to a handset call mode when receiving a tap operation on mute icon  53 . Smartphone  50  and monitoring camera  30 B enter a voice call state. Consequently, switching to a handset call can be easily performed. 
     As sensor  40 , human sensor  40 B may be built into a single casing integrally with monitoring camera  30 B. Infrared sensor  313  which is integrally built into monitoring camera  30 B may be used as a human sensor. Consequently, a camera and a sensor are easily correlated with each other. 
     Although the various embodiments have been described with reference to the drawings, needless to say, the present invention is not limited to such embodiments. It is obvious that a person skilled in the art can conceive of various modifications or alterations within the scope recited in the claims, and thus it is understood that they naturally fall within the technical scope of the present invention. 
     For example, in the above-described present embodiment, a description has been made of a case where the present invention is applied to a monitoring camera system, but the present invention is not limited thereto and is applicable to, for example, a communication system in which a traveler who possesses a camera converses with a friend or the like who possesses a portable terminal while viewing an image captured on a journey or the like.