Patent Publication Number: US-2022222645-A1

Title: Sales support device and sales support method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-004307, filed on Jan. 14, 2021, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a sales support device and a sales support method thereof. 
     BACKGROUND 
     In recent years, various store systems have been proposed that automatically register products purchased by a consumer based on the behavior of the consumer in the store, thereby eliminating the need for product registration at the time of payment. One example is a store system that specifies that a purchaser of a product is a consumer near a shelf who motions to take out the product, if the product is taken out from the shelf. It is possible to achieve an unmanned store by introducing this type of store system in convenience stores, small shops, and the like, for example. 
     With this type of store system, it is possible to specify who purchases which product. However, it is not possible to specify an amount of the product purchased. For this reason, it is not applied to the sale of product-sold-by-weight, for which the unit price per unit weight was set. For example, it is desired to develop a technology for supporting the sale of product-sold-by-weight for unmanned stores. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view schematically illustrating an appearance of a display fixture according to an embodiment; 
         FIG. 2  is a block diagram illustrating a circuit configuration of a main part of the display fixture and a schematic configuration of a store system; 
         FIG. 3  is a block diagram illustrating a circuit configuration of a main part of a user interface unit; 
         FIG. 4  is a block diagram illustrating a circuit configuration of a main part of a product monitoring unit; 
         FIG. 5  is a diagram schematically illustrating a configuration of a data record included in a product management database; 
         FIG. 6  is a block diagram illustrating a circuit configuration of a main part of a main processing unit; 
         FIG. 7  is a diagram schematically illustrating a configuration of a data record included in a tracking database; 
         FIG. 8  is a diagram schematically illustrating a configuration of a data record included in a membership management database; 
         FIG. 9  is a plan view illustrating a state of areas set in a tracking area; 
         FIG. 10  is a flowchart of a tracking process; 
         FIG. 11  is a flowchart of the tracking process; 
         FIG. 12  is a flowchart of a monitoring process; 
         FIG. 13  is a flowchart of a customer response process; and 
         FIG. 14  is a flowchart of the customer response process. 
     
    
    
     DETAILED DESCRIPTION 
     An exemplary embodiment of a sales support device capable of supporting the sale of a product-sold-by-weight and a sales support method thereof is provided herein. 
     In general, according to at least one embodiment, a sales support device includes a measuring means, a decrease amount acquisition means, a specifying means, and an output means. The measuring means measures a weight of a product displayed in a display section. The decrease amount acquisition means acquires a decrease amount if the weight of the product measured by the measuring means is changed in a decrease direction. The specifying means specifies a customer who takes out the product for which the weight is changed in the decrease direction from the display section. The output means outputs identification information of the customer specified by the specifying means and the information related to a sale of the product based on the decrease amount acquired by the decrease amount acquisition means. The output means outputs the identification information and the information related to the sale to the sales management device that manages the information related to the sale in association with the identification information of the customer. 
     Hereinafter, embodiments will be described with reference to the drawings. In at least one embodiment, a store system using a shelf-type display fixture will be described as an example. Further, an example will be described, in which the store system processes a transaction in which a customer purchases a product-sold-by-weight displayed in a store. 
       FIG. 1  is a perspective view schematically illustrating an appearance of a display fixture  110  according to at least one embodiment. 
     The display fixture  110  is an example of a sales support device that supports the sale of a product-sold-by-weight. The display fixture  110  is mainly formed of a shelf  1 . The shelf  1  is a shelf specialized for a product-sold-by-weight. The shelf  1  is formed as a hollow rectangular parallelepiped with one side open. The shelf  1  includes a plurality of shelf boards  11 , a plurality of casters  12 , a plurality of handles  13 , and a support member  14 . 
     The shelf boards  11  are installed in an internal space. While any number and position of the shelf boards  11  are possible,  FIG. 1  illustrates an example where there are three. As illustrated in the drawing, containers containing the products-sold-by-weight therein are displayed on the shelf boards  11 . Thus, the shelf  1  serves as a display section for displaying the products-sold-by-weight. 
     The casters  12  are attached to a bottom of the shelf  1 . The casters  12  allow the display fixture  110  to be easily moved on the floor. 
     The handles  13  are attached to outer surfaces of each of two sidewalls orthogonal to an open surface of the shelf  1 . An operator holds the handles  13  when moving the display fixture  110 . Any number and position of the handles  13  are possible. It should be noted that the handles  13  may be omitted. 
     The support member  14  is attached to an outer surface of a top plate of the shelf  1 , while protruding upward. The support member  14  supports two tracking cameras  2 , a surveillance camera  3 , and a projector  4 . 
     The two tracking cameras  2  capture an image of a person present in a capturing area that includes a purchase area, a detection area, a preparatory area, and a confirm area, which will be described below. The two tracking cameras  2  may each capture images inside the capturing area, or images of a portion of the capturing area may be captured by only one tracking camera  2 . Only one of the tracking camera  2  may be provided, or another one or a plurality of tracking cameras  2  may be additionally provided. Any position of the tracking camera  2  is also possible. The images captured by the tracking camera  2  are used for tracking a person. This tracking will be described below. For the tracking camera  2 , a well-known camera device such as an optical camera, an infrared camera, a time of flight (TOF) camera, and a stereo camera can be used. For the tracking camera  2 , a camera device suitable for measuring a distance to a subject, such as a TOF camera and a stereo camera is suitable. 
     The surveillance camera  3  captures images of the open surface of the shelf  1  and the space outside the shelf  1  from the open surface. The images captured by the surveillance camera  3  are used to monitor the behavior of a person reaching out to the shelf  1 . This monitoring will be described below. For the surveillance camera  3 , a well-known camera device such as an optical camera, an infrared camera, a TOF camera, and a stereo camera can be used. For the surveillance camera  3 , a camera device suitable for measuring a distance to a subject, such as a TOF camera and a stereo camera, is suitable. 
     The projector  4  projects any image on the floor surface. Lines PL and letters PC illustrated in  FIG. 1  are included in the image projected by the projector  4 . The projector  4  may be omitted, provided that measures such as laying a mat having a size corresponding to the range represented by the lines PL are taken. 
     User interface units (hereinafter referred to as UI units)  5  (e.g., a user interface, a user interface device) are attached to both ends of the open surface of the shelf  1 . The UI unit  5  includes a touch panel  51  and a reader  52 , and performs a user interface operation. The touch panel  51  and the reader  52  will be described below. If it is necessary to distinguish between the two UI units  5  in the following description, the UI unit  5  illustrated on the left side in  FIG. 1  is referred to as a “first UI unit  5 ”, and the other UI unit  5  is referred to as a “second UI unit  5 ”. 
       FIG. 2  is a block diagram illustrating a circuit configuration of a main part of the display fixture  110  and a schematic configuration of the store system  100 . In  FIG. 2 , elements identical to those illustrated in  FIG. 1  are designated by the same reference numerals. 
     The store system  100  is configured by the display fixture  110 , a sales management device  120 , and a payment device  130  which are capable of communicating with each other via a communication network  140 . 
     The sales management device  120  is a device that manages the sale of the product-sold-by-weight displayed on the display fixture  110 . The sales management device  120  has a function of an instruction unit (e.g., an instruction device, an instructor). The instruction unit is a function for instructing the payment device  130  to pay the price of the product-sold-by-weight. The payment device  130  is a payment device that processes a payment for the sale of the product-sold-by-weight displayed on the display fixture  110 . The payment device  130  has a function of a payment unit (e.g., a payment device). The payment unit is a function for paying the price of the product-sold-by-weight. 
     For the communication network  140 , for example, the Internet, virtual private network (VPN), local area network (LAN), public communication network, mobile communication network and the like may be used alone or in combination as appropriate. The display fixture  110 , the sales management device  120 , and the payment device  130  are provided in one store, for example. In this case, in-store LAN is typically used as the communication network  140 . 
     In addition to the tracking cameras  2 , the surveillance camera  3 , the projector  4 , and the UI units  5  illustrated in  FIG. 1 , the display fixture  110  includes a plurality of weighing scales  6  (e.g., a plurality of weight measurement devices), a communication unit  7  (e.g., a communication device), a communication path  8  in the fixture, a product monitoring unit  9  (e.g., a product monitoring device), and a main processing unit  10  (e.g., a main processor). 
     The tracking cameras  2 , the surveillance camera  3 , and the projector  4  are connected to the main processing unit  10 . Further, the UI units  5  are connected to the communication path  8  in the fixture. 
     The plurality of weighing scales  6  are provided on the shelf boards  11  and measure the weights of the products-sold-by-weight that are contained in the container and displayed on the shelf board  11 . The weighing scales  6  output measurement data indicating the measured weights to the product monitoring unit  9 . The weighing scales  6  are prepared for each product-sold-by-weight. The weighing scales  6  are an example of a measuring portion. 
     The communication unit  7  performs wireless communication for data exchange via the communication network  140 . For the communication unit  7 , if the communication network  140  is a LAN, for example, a well-known communication device compliant with the IEEE802.11 standard can be used. However, for the communication unit  7 , a communication device that performs wired communication may be used. 
     The communication path  8  in the fixture enables the UI units  5 , the communication unit  7 , the product monitoring unit  9 , and the main processing unit  10  to exchange data with each other. For example, a LAN is used for the communication path  8  in the fixture. 
     The product monitoring unit  9  is an information processing unit (e.g., an information processor) that performs information processing for monitoring the display status of product-sold-by-weight on the shelf  1  based on the measurement data given from the weighing scale  6 . 
     The main processing unit  10  is an information processing unit (e.g., an information processor) that specifies a person who takes out a product-sold-by-weight from the shelf  1 , based on the images captured by the tracking camera  2  and the surveillance camera  3 , and performs information processing for causing the person to pay the price of the product-sold-by-weight. 
       FIG. 3  is a block diagram illustrating a circuit configuration of a main part of the UI unit  5 . In  FIG. 3 , elements identical to those illustrated in  FIGS. 1 and 2  are designated by the same reference numerals. 
     The UI unit  5  includes a processor  53 , a main memory  54 , an auxiliary storage unit  55  (e.g., an auxiliary storage device, an auxiliary memory), a sound unit  56  (e.g., a sound device), a communication unit  57  (e.g., a communication device), and a transmission line  58 , in addition to the touch panel  51  and the reader  52  illustrated in  FIG. 1 . 
     The processor  53 , the touch panel  51 , the reader  52 , the main memory  54 , the auxiliary storage unit  55 , the sound unit  56 , and the communication unit  57  are capable of communicating with each other via the transmission line  58 . 
     The touch panel  51  is a display device that displays various screens such as an operation screen. The touch panel  51  is an operation device that receives operations in response to the operation screen. 
     The reader  52  reads a member ID (identifier) from a medium carried by the customer. For the reader  52 , a well-known data reading device that reads a visible code such as a barcode or a two-dimensional code displayed on card surface or display device can be used. For the reader  52 , it is also possible to use another type of well-known data reading device such as a well-known magnetic card reader, an integrated circuit (IC) card reader, a non-contact card reader, or the like. The reader  52  may include a plurality of types of reading devices. 
     A computer for controlling the UI unit  5  is configured by connecting the processor  53 , the main memory  54 , and the auxiliary storage unit  55  with the transmission line  58 . 
     The processor  53  corresponds to the central part of the computer. The processor  53  executes information processing for realizing various functions of the UI unit  5  according to an operating system and an information processing program such as an application program. The processor  53  is a central processing unit (CPU) (e.g., a central processor), for example. 
     The main memory  54  corresponds to a main memory portion of the computer. The main memory  54  includes a non-volatile memory area and a volatile memory area. The main memory  54  stores the information processing program described above in the non-volatile memory area. The main memory  54  may store data necessary for the processor  53  to execute information processing in a non-volatile or volatile memory area. The main memory  54  uses the volatile memory area as a work area in which data is appropriately rewritten by the processor  53 . The non-volatile memory area is a read only memory (ROM), for example. The volatile memory area is a random access memory (RAM), for example. 
     The auxiliary storage unit  55  corresponds to an auxiliary storage portion of the computer. The auxiliary storage unit  55  may include a storage unit (e.g., a memory) using a well-known storage device such as electric erasable programmable read-only memory (EEPROM) (registered trademark), hard disk drive (HDD), solid state drive (SSD), and the like. The auxiliary storage unit  55  stores data used by the processor  53  to perform various processes, data generated by the processes of the processor  53 , and the like. The auxiliary storage unit  55  may store the information processing program described above. 
     The sound unit  56  outputs various sounds such as voice and melody. 
     The communication unit  57  is an interface for data communication via the communication path  8  in the fixture. For the communication unit  57 , for example, a well-known communication device for performing data communication via a LAN can be used. 
     The transmission line  58  includes an address bus, a data bus, a control signal line, and the like, and transmits data and control signals exchanged between the connected units. 
     The auxiliary storage unit  55  stores a UI program  551  which is one of the information processing programs. The UI program  551  is an application program, and describes information processing for causing the UI unit  5  to function as a user interface of the display fixture  110 . 
       FIG. 4  is a block diagram illustrating a circuit configuration of a main part of the product monitoring unit  9 . In  FIG. 4 , elements identical to those illustrated in  FIGS. 1 and 2  are designated by the same reference numerals. 
     The product monitoring unit  9  includes a processor  91 , a main memory  92 , an auxiliary storage unit  93  (e.g., an auxiliary storage device, an auxiliary memory), a communication unit  94  (e.g., a communication device), an interface unit  95  (e.g., an interface device, a user interface), and a transmission line  96 . 
     The processor  91 , the main memory  92 , the auxiliary storage unit  93 , the communication unit  94 , and the interface unit  95  can communicate with each other via the transmission line  96 . A computer for controlling the product monitoring unit  9  is configured by connecting the processor  91 , the main memory  92 , and the auxiliary storage unit  93  with the transmission line  96 . 
     The processor  91  corresponds to the central part of the computer. The processor  91  executes information processing for realizing various functions of the product monitoring unit  9  according to an operating system and an information processing program such as an application program. The processor  91  is a CPU, for example. 
     The main memory  92  corresponds to a main memory portion of the computer. The main memory  92  includes a non-volatile memory area and a volatile memory area. The main memory  92  stores the information processing program described above in the non-volatile memory area. The main memory  92  may store data necessary for the processor  91  to execute information processing in a non-volatile or volatile memory area. The main memory  92  uses the volatile memory area as a work area in which data is appropriately rewritten by the processor  91 . The non-volatile memory area is a ROM, for example. The volatile memory area is a RAM, for example. 
     The auxiliary storage unit  93  corresponds to an auxiliary storage portion of the computer. For the auxiliary storage unit  93 , a storage unit (e.g., a memory) using a well-known storage device such as EEPROM, HDD, SSD, and the like can be used. The auxiliary storage unit  93  stores data used by the processor  91  to perform various processes, data generated by the processes of the processor  91 , and the like. The auxiliary storage unit  93  may store the information processing program described above. 
     The communication unit  94  is an interface for data communication via the communication path  8  in the fixture. For the communication unit  94 , for example, a well-known communication device for performing data communication via a LAN can be used. 
     A plurality of weighing scales  6  are connected to the interface unit  95 , respectively. The interface unit  95  interfaces the exchange of data between the processor  91  and the weighing scale  6 . As the interface unit  95 , a well-known device such as various interface boards such as a universal serial bus (USB) board can be used. A plurality of interface units  95  may be provided. 
     The transmission line  96  includes an address bus, a data bus, a control signal line, and the like, and transmits data and control signals exchanged between the connected units. 
     The auxiliary storage unit  93  stores a product monitoring program  931  which is one of the information processing programs. The product monitoring program  931  is an application program, and describes information processing described below for realizing the function of the product monitoring unit  9 . A portion of the storage area of the auxiliary storage unit  93  is used as a storage area of a product management database  932 . The product management database  932  is a database for managing the product-sold-by-weight displayed on the display fixture  110 . 
       FIG. 5  is a diagram schematically illustrating a configuration of a data record DRA included in the product management database  932 . 
     The product management database  932  is a set of a plurality of data records DRA associated with the plurality of weighing scales  6 , respectively. The data record DRA includes fields FA, FB, FC, and FD. In the field FA, a weighing scale ID for distinguishing the associated weighing scale  6  from the other weighing scales is set. In the field FB, a product code for distinguishing the product-sold-by-weight placed on the associated weighing scale  6  from the other products-sold-by-weight is set. The product code is an identification code defined for identifying a product-sold-by-weight for each stock keeping unit (SKU), and for example, a Japanese article number (JAN) code is used. In the field FC, the unit price per unit weight of the product-sold-by-weight identified by the product code set in the field FB is set. In the field FD, the previous measurement value by the associated weighing scale  6  is set. The data record DRA may include a field in which any data other than those described above is set. 
       FIG. 6  is a block diagram illustrating a circuit configuration of a main part of the main processing unit  10 . In  FIG. 6 , elements identical to those illustrated in  FIGS. 1 and 2  are designated by the same reference numerals. 
     The main processing unit  10  includes a processor  101 , a main memory  102 , an auxiliary storage unit  103  (e.g., an auxiliary storage device, an auxiliary memory), a communication unit  104  (e.g., a communication device), an interface unit  105  (e.g., an interface device, a user interface), and a transmission line  106 . 
     The processor  101 , the main memory  102 , the auxiliary storage unit  103 , the communication unit  104 , and the interface unit  105  can communicate with each other via the transmission line  106 . A computer for controlling the main processing unit  10  is configured by connecting the processor  101 , the main memory  102 , and the auxiliary storage unit  103  with the transmission line  106 . 
     The processor  101  corresponds to the central part of the computer. The processor  101  executes information processing for realizing various functions of the main processing unit  10  according to an operating system and an information processing program such as an application program. The processor  101  is a CPU, for example. 
     The main memory  102  corresponds to a main memory portion of the computer. The main memory  102  includes a non-volatile memory area and a volatile memory area. The main memory  102  stores the information processing program described above in the non-volatile memory area. The main memory  102  may store data necessary for the processor  101  to execute information processing in a non-volatile or volatile memory area. The main memory  102  uses the volatile memory area as a work area in which data is appropriately rewritten by the processor  101 . The non-volatile memory area is a ROM, for example. The volatile memory area is a RAM, for example. 
     The auxiliary storage unit  103  corresponds to an auxiliary storage portion of the computer. For the auxiliary storage unit  103 , a storage unit (e.g. a memory) using a well-known storage device such as EEPROM, HDD, SSD, and the like can be used. The auxiliary storage unit  103  stores data used by the processor  101  to perform various processes, data generated by the processes of the processor  101 , and the like. The auxiliary storage unit  103  may store the information processing program described above. 
     The communication unit  104  is an interface for data communication via the communication path  8  in the fixture. For the communication unit  104 , for example, a well-known communication device for performing data communication via a LAN can be used. 
     The two tracking cameras  2 , the surveillance cameras  3 , and the projector  4  are connected to the interface unit  105 , respectively. The interface unit  105  interfaces the exchange of data between the processor  101 , the tracking camera  2 , the surveillance camera  3 , and the projector  4 . For the interface unit  105 , a well-known device such as various interface boards such as a USB board can be used. A plurality of interface units  105  may be provided. 
     The transmission line  106  includes an address bus, a data bus, a control signal line, and the like, and transmits data and control signals exchanged between the connected units. 
     The auxiliary storage unit  103  stores a tracking program  1031  and a customer response program  1032 , each of which is one of the information processing programs. The tracking program  1031  is an application program and describes information processing for tracking a person, which will be described below. The customer response program  1032  is an application program, and describes information processing for customer response, which will be described below. A portion of the storage area of the auxiliary storage unit  103  is used as a storage area of a tracking database  1033  and a membership management database  1034 . The tracking database  1033  is a database for managing data for tracking a person to be tracked. The membership management database  1034  is a database for managing members being tracked. 
       FIG. 7  is a diagram schematically illustrating a configuration of a data record DRB included in the tracking database  1033 . 
     The tracking database  1033  is a set of data records DRB associated with each person as a target of tracking. The data record DRB includes fields FE, FF, FG, FH, FI, FJ, and FK. The data record DRB may include a field FL and following fields. In the field FE, a tracking ID is set, which is assigned to identify an associated person from the other people. The tracking ID is temporarily assigned to the person to be tracked, and is not the data for specifying an individual. In the field FF, a monitoring flag is set, which indicates whether or not the associated person is targeted for behavior monitoring. In at least one embodiment, when in ON state, the monitoring flag indicates that the behavior is to be monitored. In the field FG, a first authentication flag is set, which indicates whether or not an associated person is located in an authentication area corresponding to the first UI unit  5 . In the field FH, a second authentication flag is set, which indicates whether or not an associated person is located in an authentication area corresponding to the second UI unit  5 . In at least one embodiment, when in ON state, the first authentication flag and the second authentication flag indicate that a person is located in the authentication area. In the field FI, a preparatory flag is set, which indicates whether or not an associated person is located in the preparatory area which will be described below. In at least one embodiment, when in ON state, the preparatory flag indicates that a person is located in the preparatory area. In the field FJ, an exit flag is set, which indicates whether or not an associated person exits the tracking area which will be described below. In at least one embodiment, when in the ON state, the exit flag indicates exit of a person. In the field FK, detection data is set, which indicates a result of one position detection for an associated person. As the associated person moves along, the field FL and the following fields are sequentially added, in which detection data is set, indicating the result of position detections after the movement. The data record DRB may include a field in which any data other than those described above is set. 
       FIG. 8  is a diagram schematically illustrating a configuration of a data record DRC included in the membership management database  1034 . 
     The membership management database  1034  is a set of data records DRC associated with each person who is a target of tracking and who is completed with member authentication. Therefore, the number of data records DRC included in the membership management database  1034  varies in response to the number of applicable people. In certain situations, the membership management database  1034  may not contain any data record DRC. The data record DRC includes fields FM and FN. In the field FM, a member ID is set, which is given in advance to the associated person. In the field FN, a tracking ID for tracking the associated person is set. The data record DRC may include a field in which any data other than those described above is set. 
     For the hardware of the product monitoring unit  9  or the main processing unit  10 , for example, a general-purpose information processing device can be used. Then, the product monitoring unit  9  or the main processing unit  10  is generally transferred with the product monitoring program  931  or the tracking program  1031  and the customer response program  1032  stored in the auxiliary storage unit  93  or the auxiliary storage unit  103  respectively, and without the product management database  932  or the tracking database  1033  and the membership management database  1034  stored therein. However, hardware without the product monitoring program  931  or the tracking program  1031  and the customer response program  1032  stored in the auxiliary storage unit  93  or the auxiliary storage unit  103 , or hardware having another version of application program of the same type stored in the auxiliary storage unit  93  or the auxiliary storage unit  103 , may be transferred separately from the product monitoring program  931  or the tracking program  1031  and the customer response program  1032 . Then, in response to an operation by any worker, the product monitoring program  931  or the tracking program  1031  and the customer response program  1032  may be written to the auxiliary storage unit  93  or the auxiliary storage unit  103  to configure the product monitoring unit  9  or the main processing unit  10 . The transfer of the product monitoring program  931  or the tracking program  1031  and the customer response program  1032  to the auxiliary storage unit  93  or the auxiliary storage unit  103  can be performed by recording on a removable recording medium such as a magnetic disk, a magneto-optical disk, an optical disk, and a semiconductor memory, or by communication via a network. The product management database  932  or the tracking database  1033  and the membership management database  1034  are configured in the auxiliary storage unit  93  or the auxiliary storage unit  103  by the processor  91  or  101  executing information processing based on the product monitoring program  931  or the tracking program  1031  and the customer response program  1032 . At least one of the product monitoring program  931  and the product management database  932  may be stored in the main memory  92 . At least a portion of the tracking program  1031 , customer response program  1032 , tracking database  1033 , and membership management database  1034  may be stored in the main memory  102 . 
     Next, the operation of the store system  100  configured as described above will be described. The description of the processes provided below are examples, and it is possible to change the order of some processes, omit some processes, add another process, and the like as appropriate. 
     It is assumed that the display fixture  110  is used for unmanned sales by temporarily installing the product-sold-by-weight on display at a storefront or the like in a normal retail store. Therefore, the display fixture  110  is included the casters  12  and the handles  13  so as to be easily moved by a clerk or the like. However, the display fixture  110  may be installed at any place such as inside a company or the like, or may be permanently installed, and its use is not limited to the examples described above. If it is permanently installed, the casters  12  and the handles  13  may be omitted. Electrical elements included in the display fixture  110  may be operated by power supply from a commercial power source or the like using a power cable, or may be operated by power supply from a battery mounted on the display fixture  110 . 
     In at least one embodiment, one product-sold-by-weight is to be displayed in the measurement area of one weighing scale  6  on the shelf board  11 . Then, an administrator such as a clerk designates a product-sold-by-weight and a measurement area in which the product is to be displayed, by a predetermined operation on the UI unit  5 . For example, the processor  53  displays a graphical user interface (GUI) screen for selecting a measurement area on the touch panel  51 , and receives a designation of the measurement area by a touch on the GUI screen. Further, the processor  53  causes the reader  52  to read a product barcode illuminated by the administrator. Then, it is assumed that the processor  53  designates that the product-sold-by-weight identified by the product code represented by the product barcode read by the reader  52 , is displayed in the designated measurement area. In response to this designation, the processor  53  in the UI unit  5  finds the data record DRA in which the weighing scale ID of the weighing scale  6  corresponding to the designated measurement area is set in the field FA, from the product management database  932 , and sets a product code of the designated product-sold-by-weight in the field FB of the corresponding data record DRA. The processor  53  sets the unit price per unit weight designated in advance by the administrator in the field FC of the data record DRA in which the product code described above is set. At this time, the processor  53  acquires a measurement value of the weighing scale  6  corresponding to the corresponding measurement area, for example. The processor  53  may set the acquired measurement value described above in the field FD of the data record DRA, or may provisionally set a predetermined value such as 0. 
     It should be noted that the product management database  932  may be updated so as to match the display status of the product-sold-by-weight on the shelf board  11 , and the update thereof may use any method. For example, in response to an instruction from any external sales support device, the processor  53  may update the product management database  932 . Further, the processor  53  may access the sales management device  120  or any other server device via the communication unit  57 , the communication path  8  in the fixture, and the communication network  140 , and acquire the unit price per unit weight associated with the product code. 
     If the display fixture  110  is in an operating state for customer response, the processor  101  in the main processing unit  10  executes information processing according to the tracking program  1031  (hereinafter, referred to as tracking process). 
     Meanwhile, the tracking process is mainly a process of specifying a current position of a person as a target of tracking (hereinafter referred to as a person-to-track) in the tracking area, and confirming whether or not the corresponding position is located in an area of some areas within the tracking area that are defined relative to the display fixture  110 . Therefore, prior to describing the tracking process, the area defined in the tracking area will be described. 
       FIG. 9  is a plan view illustrating a state of areas set in the tracking area. 
     As illustrated in  FIG. 9 , the purchase area ARA, the detection area ARB, the preparatory area ARC, the confirm area ARD, and the two authentication areas ARE are logically defined with reference to the position of the display fixture  110 , respectively. The rectangular area that includes the entire area of the confirm area ARD is the tracking area. The specific area type of each area may be freely determined by the developer of the tracking program  1031 , for example. That is, the individual size of each area, the ratio of the sizes between the plurality of areas, and the like may be changed from the state illustrated in  FIG. 9 . Further, the size of each area and the like may be changed in response to an instruction from any operator such as a maintenance worker, a store manager, and the like. In this way, it is possible to adjust each area in consideration of the structure of the installation location of the display fixture  110  and the like. 
     The purchase area ARA is an area where a customer who wants to take out a product-sold-by-weight from the display fixture  110  should be located. The projector  4  projects an image such that the lines PL illustrated in  FIG. 1  substantially coincide with the outer edges of the purchase area ARA. If the size of the purchase area ARA can be changed as described above, the projector  4  makes it possible to change the projection magnification of the image. Then, the projector  4  changes the projection magnification by an operation from the maintenance worker, the store manager, or the like described above, or in response to an instruction from the processor  101  of the main processing unit  10 , for example. For example, a rule for using the service provided by the store system  100  may be such that the customer stays in the purchase area ARA while all the product-sold-by-weight to be purchased are took out from the shelf  1 . 
     The detection area ARB is an area for newly detecting a person-to-track. The detection area ARB is defined as an area through which a person entering the purchase area ARA passes, for example. That is, the detection area ARB is a strip-shaped area around the purchase area ARA, for example. The detection area ARB may partially overlap with the purchase area ARA. 
     The preparatory area ARC and the confirm area ARD are areas for determining an exit of the person-to-track from the tracking area. Both the preparatory area ARC and the confirm area ARD are defined as areas through which a person exiting the purchase area ARA passes. In addition, the preparatory area ARC is closer to the purchase area ARA than the confirm area ARD. In the example of  FIG. 9 , a portion of the preparatory area ARC and a portion of the confirm area ARD overlap with each other. The overlapping area ARF is an area where the preparatory area ARC and the confirm area ARD overlap with each other. The preparatory area ARC and the confirm area ARD may be adjacent to each other without overlapping. Further, the preparatory area ARC may be separated from the confirm area ARD. However, a portion of the confirm area ARD and a portion of the preparatory area ARC may overlap with each other. Further, the confirm area ARD and the preparatory area ARC may be adjacent to each other without overlapping. 
     The two authentication areas ARE correspond to the two UI units  5 , respectively, as described above. Hereinbelow, if it is necessary to distinguish between the two authentication areas ARE, the authentication area ARE corresponding to the first UI unit  5  is referred to as a first authentication area ARE, and the authentication area ARE corresponding to the second UI unit  5  is referred to as a second authentication area ARE. In the example of  FIG. 9 , the circular areas centered on the corresponding UI units  5  are designated as the authentication areas ARE. 
     A direction of image capturing and a size of the field of view of the two tracking cameras  2  are set so as to capture images of the capturing area including at least the tracking area either respectively or for their divided shares. Then, the processor  101  executes information processing (hereinafter, referred to as detection process) for determining the current position of the person based on the image captured by the tracking camera  2 , separately from the tracking process described below. The processor  101  attempts to detect the person reflected in the image based on the image captured by the tracking camera  2 , for example. Then, if the processor  101  can detect the person, the processor determines the position of the person. As a process of determining the position of the person reflected in the image from the image, various well-known processes can be appropriately used. If a camera device having a distance measurement function such as a TOF camera and a stereo camera is used as the tracking camera  2 , the processor  101  may determine the current position of the person in consideration of the measurement result of this function. The processor  101  periodically executes the detection process at predetermined intervals. 
       FIGS. 10 and 11  are flowcharts of the tracking process. 
     In ACT 11  in  FIG. 10 , the processor  101  stands by for the detection of a new person as a target of tracking. For example, if a person who is not a target of tracking is detected as being located in the detection area by the detection process described above, the processor  101  determines YES and proceeds to ACT 12 . In addition, if the processor  101  proceeds to ACT 12  as described above, the tracking process is continued and the tracking process is started in another thread. That is, in a situation where there are a plurality of people to be tracked, the tracking process is executed in parallel for each of those people. Then, if the person detected by the detection process as being located in the detection area is not the person-to-track in the other tracking process, the processor  101  determines that the person is not the target of tracking. 
     In ACT 12 , the processor  101  determines a tracking ID of the newly detected person so as not to overlap with a tracking ID of another person-to-track. 
     In ACT 13 , the processor  101  updates the tracking database  1033  to manage the newly detected person as the person-to-track. For example, the processor  101  adds a new data record DRB to the tracking database  1033 . The processor  101  sets the tracking ID determined by ACT 12  in the field FE of the corresponding new data record DRB. The processor  101  turns off all the flags of the fields FF through FJ of the corresponding new data record DRB. The processor  101  sets the detection data indicating the current position and current date and time as determined by the detection process for the newly detected person in the field FK of the corresponding new data record DRB. The processor  101  does not include the field FL and the following fields in the corresponding new data record DRB. 
     As a result, the newly detected person is set as a person-to-track. As described above, a plurality of tracking processes may be executed in parallel and there may be a plurality of people-to-track for the display fixture  110  at the same time, but if the term “person-to-track” is simply used in the following description, it refers to a person or people-to-track who is or are the target of the tracking process in the description. 
     In ACT 14 , the processor  101  confirms whether or not the person-to-track has moved. Then, if the movement of the person-to-track cannot be confirmed, the processor  101  determines NO and proceeds to ACT 15 . 
     In ACT 15 , the processor  101  confirms whether or not the person-to-track is lost. Then, when tracking of the person-to-track is continued, then the processor  101  determines NO and returns to ACT 14 . 
     Thus, in ACT 14  and ACT 15 , the processor  101  stands by for the person-to-track to move or be lost. 
     For example, each time the result of the detection process is newly obtained, the processor  101  specifies a person-to-track from among the newly detected people based on the current position of the newly detected person and the position indicated in the detection data that is set in the data record DRB associated with the person-to-track. Then, the processor  101  determines whether or not the person-to-track has moved based on the relationship between the current position of the person-to-track and the position indicated by the detection data that is set at the end of the data record DRB associated with the person-to-track. For example, if a distance between the two positions described above is equal to or greater than a predetermined threshold value, the processor  101  determines that the person-to-track has moved. Then, if the person-to-track has moved, the processor  101  determines YES at ACT 14  and proceeds to ACT 16 . 
     In ACT 16 , the processor  101  confirms whether or not the current position of the person-to-track is inside the purchase area ARA. Then, if the current position of the person-to-track is outside the purchase area ARA, the processor  101  determines NO and proceeds to ACT 17 . 
     In ACT 17 , the processor  101  confirms whether or not the current position of the person-to-track is outside the detection area ARB. Then, if the current position of the person-to-track is inside the detection area ARB, the processor  101  determines NO and returns to ACT 14 . 
     Thus, in ACT 14  through ACT 17 , the processor  101  stands by for the person-to-track to move into the purchase area ARA or to move in a direction opposite to the purchase area ARA and exit the detection area ARB. 
     If the person-to-track exits the detection area ARB without entering the purchase area ARA, the processor  101  determines YES at ACT 17  and proceeds to ACT 18 . 
     Meanwhile, the processor  101  deems it lost in a case if the data record DRB associated with the person-to-track in the tracking database  1033  is not updated over a predetermined period of time, for example. Then, if the person is lost during the standby state of ACT 14  and ACT 15 , the processor  101  determines YES at ACT 15  and accordingly proceeds to ACT 18 . 
     In ACT 18 , the processor  101  updates the tracking database  1033  to exclude this person-to-track from the person-to-track. For example, the processor  101  deletes the data record DRB in which the tracking ID of the person-to-track is set in the field FE, from the tracking database  1033 . Then, the processor  101  ends the tracking process with this. 
     A person who intends to purchase the product-sold-by-weight displayed on the display fixture  110  will pass through the detection area ARB and proceed to the purchase area ARA. If the person-to-track moves in that way, the processor  101  determines YES at ACT 16  and proceeds to ACT 19 . 
     In ACT 19 , the processor  101  turns on the monitoring flag set in the field FF of the data record DRB in which the tracking ID of the person-to-track is set in the field FE. 
     In ACT 20 , the processor  101  adds a field in which new detection data is set to the end of the data record DRB in which the tracking ID of the person-to-track is set in the field FE. The processor  101  uses the new detection data as data indicating the current position and current time of the person-to-track as determined by the latest detection process. In this way, by adding the detection data according to the movement of the person-to-track, the movement trajectory of the person-to-track is recorded. 
     In ACT 21 , the processor  101  confirms whether or not the person-to-track has moved. Then, if the movement of the person-to-track cannot be confirmed, the processor  101  determines NO and proceeds to ACT 22 . 
     In ACT 22 , the processor  101  confirms whether or not the person-to-track is lost. Then, when tracking of the person-to-track is continued, then the processor  101  determines NO and returns to ACT 21 . 
     Thus, in ACT 21  and ACT 22 , the processor  101  stands by for the person-to-track to move or be lost. Then, if the processor  101  confirms that the person-to-track has moved in the same manner as in ACT 14 , the processor determines YES at ACT 21  and proceeds to ACT 23 . 
     In ACT 23 , the processor  101  confirms whether or not the current position of the person-to-track is inside the purchase area ARA. Then, if the current position of the person-to-track is inside the purchase area ARA, the processor  101  determines YES and proceeds to ACT 24 . 
     In ACT 24 , the processor  101  confirms whether or not the current position of the person-to-track is inside the first or second authentication area ARE. Then, if the current position of the person-to-track is inside the first or second authentication area ARE, the processor  101  determines YES and proceeds to ACT 25 . That is, if the person-to-track is located in the area where the purchase area ARA and the first or second authentication area ARE overlap with each other, the processor  101  proceeds to ACT 25 . 
     In ACT 25 , if the person-to-track is located in the first authentication area, the processor  101  turns on the first authentication flag, and if the person-to-track is located in the second authentication area, the processor  101  turns on the second authentication flag. Then, the processor  101  returns to ACT 20 , adds the detection data regarding the position of the person-to-track after the movement, and then returns to the standby state of ACT 21 . 
     If the current position of the person-to-track is inside the purchase area ARA, but outside the first or second authentication area ARE, the processor  101  determines NO at ACT 24  and proceeds to ACT 26 . 
     In ACT 26 , the processor  101  turns off both the first authentication flag and the second authentication flag. Then, the processor  101  returns to ACT 20 , adds the detection data regarding the position of the person-to-track after the movement, and then returns to the standby state of ACT 21 . 
     If the person-to-track exits the purchase area ARA, the processor  101  determines NO at ACT 23  and proceeds to ACT 27  in  FIG. 11 . 
     In ACT 27 , the processor  101  adds a field in which the detection data is set, as in ACT 20 . That is, the processor  101  adds new detection data to the data record DRB associated with the person-to-track in order to record the movement of the person-to-track. 
     In ACT 28 , the processor  101  confirms whether or not the person-to-track has moved. Then, if the movement of the person-to-track cannot be confirmed, the processor  101  determines NO and proceeds to ACT 29 . 
     In ACT 29 , the processor  101  confirms whether or not the person-to-track is lost. Then, when tracking of the person-to-track is continued, then the processor  101  determines NO and returns to ACT 28 . 
     Thus, in ACT 28  and ACT 29 , the processor  101  stands by for the person-to-track to move or be lost. Then, if the processor  101  confirms that the person-to-track has moved in the same manner as in ACT 14 , it determines YES at ACT 28  and proceeds to ACT 30 . 
     In ACT 30 , the processor  101  confirms whether or not the current position of the person-to-track is inside the purchase area ARA. Then, if the current position of the person-to-track is inside the purchase area ARA, the processor  101  determines YES and returns to ACT 20  in  FIG. 10 . That is, if the person-to-track returns to the purchase area ARA, the processor  101  adds new detection data in order to record the above movement of the person-to-track and shifts to the standby state of ACT 21  and ACT 22 . 
     If the person-to-track does not return to the purchase area ARA, the processor  101  determines NO at ACT 30  in  FIG. 11  and proceeds to ACT 31 . 
     In ACT 31 , the processor  101  confirms whether or not the current position of the person-to-track is inside the preparatory area ARC. Then, if the current position of the person-to-track is outside the preparatory area ARC, the processor  101  determines NO and proceeds to ACT 27 . That is, the processor  101  adds new detection data in order to record the movement of the person-to-track and returns to the standby state of ACT 28  and ACT 29 . 
     If the person-to-track exits the purchase area ARA and moves into the preparatory area ARC without returning to the purchase area ARA, the processor  101  determines YES at ACT 31  and proceeds to ACT 32 . 
     In ACT 32 , the processor  101  turns on the preparatory flag set in the field FI of the data record DRB in which the tracking ID of the person-to-track is set in the field FE. 
     In ACT 33 , the processor  101  confirms whether or not the person-to-track has moved. Then, if the movement of the person-to-track cannot be confirmed, the processor  101  determines NO and proceeds to ACT 34 . 
     In ACT 34 , the processor  101  confirms whether or not the person-to-track is lost. Then, when tracking of the person-to-track is continued, then the processor  101  determines NO and returns to ACT 33 . 
     Thus, in ACT 33  and ACT 34 , the processor  101  stands by for the person-to-track to move or be lost. Then, if the processor  101  confirms that the person-to-track has moved in the same manner as in ACT 14 , the processor determines YES at ACT 33  and proceeds to ACT 35 . 
     In ACT 35 , the processor  101  confirms whether or not the current position of the person-to-track is inside the confirm area ARD. Then, if the current position of the person-to-track is outside the confirm area ARD, the processor  101  determines NO and proceeds to the ACT 36 . 
     In ACT 36 , the processor  101  confirms whether or not the current position of the person-to-track is inside the preparatory area ARC. Then, if the current position of the person-to-track is inside the preparatory area ARC, the processor  101  determines YES and returns to ACT 33 . 
     Thus, in ACT 33  to ACT 36 , the processor  101  stands by for the person-to-track to move into the confirm area ARD, move in the direction opposite to the confirm area ARD and exit the preparatory area ARC or be lost. 
     If the person-to-track exits the preparatory area ARC without entering the confirm area ARD, the processor  101  determines NO at ACT 36  and proceeds to ACT 37 . 
     In ACT 37 , the processor  101  turns off the preparatory flag set in the field FI of the data record DRB in which the tracking ID of the person-to-track is set in the field FE. Then, the processor  101  returns to ACT 27 , that is, the processor  101  adds new detection data in order to record the movement of the person-to-track and then shifts to the standby state of ACT 28  and ACT 29 . 
     If the person-to-track passes through the preparatory area ARC and proceeds to the confirm area ARD in order to move away from the display fixture  110 , the processor  101  determines YES at ACT 35  and proceeds to ACT 38 . 
     In ACT 38 , the processor  101  adds a field in which the detection data is set, as in ACT 20 . That is, the processor  101  adds new detection data to the data record DRB associated with the person-to-track in order to record the movement of the person-to-track. Then, the processor  101  proceeds to ACT 39 . 
     If the processor  101  confirms that the tracking of the person-to-track is lost in any of the standby states of ACT 21  and ACT 22  in  FIG. 10 , the standby states of ACT 28  and ACT 29  in  FIG. 11 , and the standby states of ACT 33  and ACT 34  in  FIG. 11 , the processor determines YES in ACT 22 , ACT 29  or ACT 34 , and proceeds to ACT 39  in  FIG. 11 . 
     In ACT 39 , the processor  101  turns off the monitoring flag set in the field FF of the data record DRB in which the tracking ID of the person-to-track is set in the field FE. 
     In ACT 40 , the processor  101  turns on the exit flag set in the field FJ of the data record DRB in which the tracking ID of the person-to-track is set in the field FE. Then, the processor  101  ends the tracking process with this. 
     If the processor  101  executes the tracking process as described above, it is possible to confirm the area in which each of the people-to-track is located and also the movement trajectory, based on the tracking database  1033 . The processor  101  also detects that the person-to-track has left the shelf  1  based on the results of such tracking. 
     Meanwhile, if the display fixture  110  is in an operating state for customer response, the processor  91  in the product monitoring unit  9  executes information processing according to the product monitoring program  931  (hereinafter, referred to as monitoring process). The monitoring process is information processing for monitoring the take-out of the product-sold-by-weight displayed on the display fixture  110 . 
       FIG. 12  is a flowchart of the monitoring process. 
     In ACT 41 , the processor  91  confirms whether or not the weight of the product-sold-by-weight displayed on the display fixture  110  is decreased. Then, if the corresponding event cannot be confirmed, the processor  91  determines NO and proceeds to ACT 42 . 
     In ACT 42 , the processor  91  confirms whether or not the weight of the product-sold-by-weight displayed on the display fixture  110  is increased. Then, if the corresponding event cannot be confirmed, the processor  91  determines NO and returns to ACT 41 . 
     Thus, in ACT 41  and ACT 42 , the processor  91  stands by for the weight of the product-sold-by-weight to decrease or increase. 
     If a customer takes out the product-sold-by-weight displayed on the display fixture  110  from the display fixture  110  with a take-out tool such as tongs or a ladle, the weight of the product-sold-by-weight displayed on the display fixture  110  is decreased. Then, in this case, the measurement value obtained by the weighing scale  6  in the measurement area where the corresponding product-sold-by-weight is placed decreases. Further, if the product-sold-by-weight once taken out from the display fixture  110  is returned to the display fixture  110 , the weight of the product-sold-by-weight displayed on the display fixture  110  increases. Then, in this case, the measurement value obtained by the weighing scale  6  in the measurement area where the corresponding product-sold-by-weight is placed increases. 
     If the measurement value of any of the weighing scales  6  decreases, the processor  91  determines YES at ACT 41  and proceeds to ACT 43 . For example, if the measurement value acquired from the weighing scale  6  is smaller than the previous measurement value set in the field FD of the data record DRA associated with the same weighing scale  6  in the product management database  932 , and a difference value is equal to or greater than a specified value, the processor  91  determines a decrease in the measurement value of the weight scale  6 . 
     In ACT 43 , the processor  91  determines the product-sold-by-weight for which weight has decreased. For example, the processor  91  finds the data record DRA in which the weighing scale ID of the weighing scale  6  measuring the decrease in the measurement value as described above is set in the field FA, from the product management database  932 . Then, the processor  91  determines the product-sold-by-weight for which weight has decreased with a product-sold-by-weight identified by the product code set in the field FB of the corresponding data record DRA. 
     In ACT 44 , the processor  91  notifies the main processing unit  10  of a decrease in the product-sold-by-weight. For example, the processor  91  transmits notification data for notifying the decrease in the product-sold-by-weight from the communication unit  94  to the communication path  8  in the fixture toward the main processing unit  10 . The processor  91  includes identification data for identifying the notification of the decrease, the product code of the product-sold-by-weight for which weight has decreased, and the decreased measurement value (decrease amount) in the notification data described above. 
     On the other hand, if the measurement value of any of the weighing scales  6  increases, the processor  91  determines YES at ACT 42  and proceeds to ACT 45 . For example, if the measurement value acquired from the weighing scale  6  is greater than the previous measurement value set in the field FD of the data record DRA associated with the same weighing scale  6  in the product management database  932 , and the difference value is equal to or greater than the specified value, the processor  91  determines that the measurement value of the weight scale  6  has increased. 
     In ACT 45 , the processor  91  determines a product-sold-by-weight for which weight has increased. For example, the processor  91  finds out the data record DRA in which the weighing scale ID of the weighing scale  6  measuring the increased measurement value as described above is set in the field FA, from the product management database  932 . Then, the processor  91  determines the product-sold-by-weight for which weight has increased with a product-sold-by-weight identified by the product code set in the field FB of the corresponding data record DRA. 
     In ACT 46 , the processor  91  notifies the main processing unit  10  of the increase in the product-sold-by-weight. For example, the processor  91  transmits notification data for notifying the increase of product-sold-by-weight from the communication unit  94  to the communication path  8  in the fixture toward the main processing unit  10 . The processor  91  includes identification data for identifying the notification of the increase, the product code of the product-sold-by-weight for which weight has increased, and the increased measurement value (increase amount) in the notification data described above. 
     If the processor  91  finishes the notification at ACT 44  or ACT 46 , the processor proceeds to ACT 47  in either case. 
     In ACT 47 , the processor  91  updates the previous measurement value set in the field FD of the data record DRA associated with the weighing scale  6  of which measurement value has changed in the product management database  932  as the measurement value after change. Then, the processor  91  returns to the standby state of ACT 41  and ACT 42 . 
     If the display fixture  110  is in an operating state for customer response, the processor  101  in the main processing unit  10  executes information processing according to the customer response program  1032  (hereinafter, referred to as customer response process), in addition to the detection process and the tracking process described above. 
       FIGS. 13 and 14  are flowcharts of the customer response process. 
     In ACT 51  in  FIG. 13 , the processor  101  confirms whether or not the member ID is notified. Then, if the corresponding notification cannot be confirmed, the processor  101  determines NO and proceeds to ACT 52 . 
     In ACT 52 , the processor  101  confirms whether or not the decrease notification is performed. Then, if the corresponding notification cannot be confirmed, the processor  101  determines NO and proceeds to ACT 53 . 
     In ACT 53 , the processor  101  confirms whether or not the increase notification is performed. Then, if the corresponding notification cannot be confirmed, the processor  101  determines NO and proceeds to ACT 54 . 
     In ACT 54 , the processor  101  confirms whether or not the exit flag is turned on. Then, if the corresponding event cannot be confirmed, the processor  101  determines NO and returns to ACT 51 . 
     Thus, in ACT 51  to ACT 54 , the processor  101  stands by for the member ID, decrease or increase to be notified, or for the exit flag to be turned on. 
     Meanwhile, a member ID for distinguishing from the other customers is given to the customer who is completed with the member registration. In addition, a customer who is registered as a member can register payment information for payment with a payment method that does not involve the exchange of cash. In addition, various personal information, member ID and payment information about the customer registered as a member are managed by the sales management device  120  or the payment device  130 , or managed by another member server. 
     If a customer who is registered as a member wants to make a payment for the purchase of the product-sold-by-weight displayed on the display fixture  110  using the registered payment information, the customer reads the member ID to the UI unit  5 . For example, the customer makes a display device of a mobile information terminal carried by the customer display a barcode indicating the member ID, and reads the barcode to the reader  52  of the UI unit  5 . Any other method of reading the member ID to the UI unit  5  may be used. 
     If the member ID is read by the reader  52 , the processor  53  in the UI unit  5  notifies the main processing unit  10  of the member ID by information processing based on the UI program  551 . For example, the processor  53  transmits notification data including the identification data for identifying the notification of the member ID and the member ID from the communication unit  57  to the communication path  8  in the fixture toward the main processing unit  10 . 
     For example, if the customer is required to have the member ID face straight the UI unit  5  so as to read it to the UI unit  5 , by appropriately sizing the authentication area ARE, it is prevented that the same authentication flag is turned on for a plurality of people-to-track if the member ID is read by the UI unit  5 . However, the processor  53  may specify a person-to-track who motions to get his or her member ID read, based on an image captured by the surveillance camera  3  or an image captured by another TOF camera or the like, for example, and notify the tracking ID of the person-to-track. 
     If the notification data for notification of the member ID is received by the communication unit  104 , the processor  101  in the main processing unit  10  determines YES at ACT 51  and proceeds to ACT 55 . 
     In ACT 55 , the processor  101  acquires the tracking ID of the person-to-track which corresponds to the customer who read the notified member ID to the UI unit  5 . For example, if the member ID is notified from the first UI unit  5 , the processor  101  finds the data record DRB in which the first authentication flag is turned on, from the tracking database  1033 . Further, if the member ID is notified from the second UI unit  5 , the processor  101  finds the data record DRB in which the second authentication flag is turned on, from the tracking database  1033 . Then, the processor  101  acquires the tracking ID set in the field FE of the corresponding data record DRB. When finding a plurality of data records DRB in which the authentication flag are turned on corresponding to the UI unit  5  that notified the member ID, the processor  101  selects one data record DRB according to a predetermined rule. For example, the processor  101  selects the data record DRB of which position indicated by the detection data set in the field at the end is closer to the center of the authentication area. 
     In ACT 56 , the processor  101  executes authentication process for the notified member ID. For example, the processor  101  inquires of a device that monitors various personal information, member ID, and payment information about a customer registered as a member, and confirms that the notified member ID is a legitimate member ID given to the member. 
     In ACT 57 , the processor  101  confirms whether or not the authentication described above is successful. Then, if the authentication is successful, the processor  101  determines YES and proceeds to ACT 58 . 
     In ACT 58 , the processor  101  updates the membership management database  1034  so as to include data record DRC for managing the member whose member ID is read by the UI unit  5 . That is, for example, the processor  101  sets the notified member ID in the field FM, and adds a new data record DRC in which the tracking ID acquired by ACT 55  is set in the field FN, to the membership management database  1034 . Then, the processor  101  returns to the standby state of ACT 51  through ACT 54 . 
     Thus, the processor  101  identifies the person-to-track as a member identified by the notified member ID. The member is an individual specified by the membership registration. That is, the processor  101  identifies an individual as a person-to-track. 
     At ACT 56 , if authentication fails, the processor  101  determines NO in the ACT 57  and proceeds to the ACT 59 . 
     In ACT 59 , the processor  101  executes error process. The error process is a process for notifying the customer of a failed authentication. For example, the processor  101  instructs the UI unit  5  that read the member ID to display a predetermined error screen for notifying the customer of the failed authentication. Alternatively, the processor  101  instructs the mobile information terminal displaying the barcode indicating the member ID to display the above error screen, for example. Then, the processor  101  returns to the standby state of ACT 51  to ACT 54 . 
     If the notification data for the decrease notification described above is received by the communication unit  104 , the processor  101  determines YES at ACT 52  and proceeds to ACT 60  in  FIG. 14 . 
     In ACT 60 , the processor  101  determines a taker who took out the product-sold-by-weight for which weight has decreased from the display fixture  110  with the take-out tool. For example, the processor  101  extracts all the data records DRB in which the monitoring flag set in the field FF is turned on from the tracking database  1033 , and selects, as the candidates for the taker, the people-to-track as identified by the tracking IDs set in the field FE of the corresponding data records DRB. If a customer takes out a product-sold-by-weight from the display fixture  110  with a take-out tool, the customer extends his or her arm to the take-out tool for taking the corresponding product-sold-by-weight, picks up the product-sold-by-weight using the take-out tool, and then pulls his or her arm to put the product-sold-by-weight in a take-out container. Therefore, for example, the processor  101  specifies the person-to-track who performed the actions described above from among the people-to-track who are the candidates for the taker, based on the image captured by the surveillance camera  3 , and determines the corresponding person-to-track as the taker. 
     More specifically, for example, the processor  101  analyzes changes in a plurality of images captured by the surveillance camera  3  during a monitoring period predetermined in consideration of the period during which the actions described above for taking the product-sold-by-weight are performed, to specify the person who performed the actions described above, and further determine the position of the person. The processor  101  selects, from the extracted data records DRB described above, a data record DRB in which the detection data set in the field at the end shows the closest position to the specified position described above. Then, if a distance between the position shown in the detection data set in the field at the end of the corresponding data record DRB and the specified position described above is shorter than a specified distance, the processor  101  determines that a person-to-track identified by the tracking ID set in the field FE of the corresponding data record DRB is the taker. If the corresponding person-to-track is not found, the processor  101  determines that the taker is unknown. The processor  101  may measure the length of the arm of the taker, based on the relationship between the position shown in the detection data set in the field at the end in the selected data record DRB described above and the displaying position of the product-sold-by-weight for which weight has decreased, and the image captured by the surveillance camera  3 , and determine that the taker is unknown if the length is longer than a specified length. 
     In many cases, if the arm is pulled, the product-sold-by-weight is taken out, and the measurement value of the weighing scale  6  is changed. However, since it takes some time for the measurement value of the weighing scale  6  to stabilize because of the vibration of the shelf board  11 , and the like, there is a time lag before the weighing scale  6  outputs a new measurement value. That is, by the time if the processor  101  receives the decrease notification, the action of the taker to take out the product-sold-by-weight is almost finished. That is, the monitoring period described above starts before the processor  101  receives the decrease notification. Therefore, for example, the processor  101  buffers the images captured by the surveillance camera  3  in the auxiliary storage unit  103  or the like for a certain period of time. Then, after receiving the decrease notification, the processor  101  analyzes the image related to the monitoring period among the buffered images. Alternatively, the process in ACT 60  may be executed by the processor  101  as a process of a thread different from the customer response process. 
     In ACT 61 , the processor  101  confirms whether or not the determination of the taker is successful. Then, if the taker can be determined, the processor  101  determines YES and proceeds to ACT 62 . 
     In ACT 62 , the processor  101  confirms whether or not the person-to-track determined as the taker is an authenticated member. The processor  101  searches the membership management database  1034  for data record DRC in which the same tracking ID as that set in the field FE of the data record DRB selected at ACT 60  is set in the field FN. Then, if the corresponding data record DRC is found, the processor  101  determines YES and proceeds to ACT 63 . 
     In ACT 63 , the processor  101  requests the sales management device  120  to register for the sale of the product-sold-by-weight for which weight has decreased. For example, the processor  101  transmits the request data for the corresponding request from the communication unit  104  to the communication path  8  in the fixture toward the sales management device  120 . Then, the corresponding request data is relayed by the communication unit  7  and transmitted to the sales management device  120  via the communication network  140 . The processor  101  includes the identification data for identifying the registration request, the product code of the product-sold-by-weight for which weight has decreased, the decreased measurement value, and the member ID in the request data described above. The processor  101  includes the product code included in the received notification data described above as it is in the request data as the product code of the product-sold-by-weight for which weight has decreased. The processor  101  includes the decreased measurement value included in the received notification data described above as it is in the request data as the decreased measurement value. The processor  101  includes the member ID set in the field FM of the data record DRC found at ACT 62  in the request data. 
     When receiving the request data described above, the sales management device  120  performs a registration process for registering the product-sold-by-weight identified by the product code included in the request data as a product-sold-by-weight to be sold to the member identified by the member ID included in the request data, by the decreased measurement value included in the request data. The corresponding registration process may be the same process as that performed by an existing transaction processing device such as a POS terminal. 
     At ACT 62 , if the processor  101  confirms that the member is not the authenticated one, the processor  101  determines NO and proceeds to ACT 64 . For example, if the data record DRC in which the same tracking ID as that set in the field FE of the data record DRB selected at ACT 60  is set in the field FN cannot be found from the membership management database  1034 , the processor  101  determines that the member is not the authenticated one. 
     In ACT 64 , the processor  101  performs a first alarm operation. The first alarm operation is an operation for urging the taker to pay for the product-sold-by-weight taken out from the display fixture  110 . As the first alarm operation, the processor  101  instructs the UI unit  5  to display a predetermined screen, for example. As the first alarm operation, the processor  101  instructs the UI unit  5  to output a predetermined voice message, for example. As the first alarm operation, the processor  101  may perform any operation other than those described above, or may perform a plurality of types of operations. Contents such as screens or voice messages may be appropriately determined according to the circumstances of the store where the display fixture  110  is installed. In the case of a store where there is a check-out corner where a clerk is stationed or a self-service-type check-out corner installed, for example, the content urges the taker to make a payment at the check-out corner. Further, in the case of a store where the purchase of the product-sold-by-weight displayed on the display fixture  110  is limited to members only, for example, the content urges the taker to return the product-sold-by-weight to the clerk. By this first alarm operation, if a customer who does not understand the service provided by the store system  100  takes out a product-sold-by-weight from the shelf  1 , it is possible to allow the customer to appropriately perform the subsequent action. 
     If customers other than members are allowed to pay the product-sold-by-weight displayed on the display fixture  110  at the check-out corner where the clerk is stationed or at the self-service-type check-out corner, the fact that the person-to-track who is not completed with the member authentication took out the product-sold-by-weight from the shelf  1  does not correspond to an abnormal state. 
     Therefore, the first alarm operation in this case is not an alarm for the abnormal state. In the case of a store where the purchase of the product-sold-by-weight displayed on the display fixture  110  is limited to members only, the fact that a person-to-track who is not completed with the member authentication takes out the product-sold-by-weight from the shelf  1  corresponds to the abnormal state. Therefore, the first alarm operation in this case corresponds to the alarm with respect to an abnormal state. 
     At ACT 60 , if the taker cannot be determined, the processor  101  determines NO at ACT 61  and proceeds to ACT 65 . This case corresponds to a case in which the processor  101  determines that the taker is unknown as described above at ACT 60 . In addition, this case corresponds to a case in which a person who is not tracked by the tracking process due to certain errors takes out the product-sold-by-weight. 
     In ACT 65 , the processor  101  performs a second alarm operation. The second alarm operation may be the same operation as the first alarm operation. However, the content of the second alarm operation is different from that of the first alarm operation. For example, the content in the second alarm operation is content that urges the taker or a person staying in the vicinity to consult with a clerk, for example. Alternatively, the second alarm operation may be an instruction to a terminal device used by the clerk to display a screen or output a voice message. The content in the second alarm operation in this case is content that urging the clerk to confirm the situation and deal with it, for example. Since the customer does not know whether or not he or she is correctly tracked by the tracking process, the abnormal state caused by the corresponding customer taking out the product-sold-by-weight from the shelf  1  is not the responsibility of the customer and the customer will not be able to comprehend the cause of the abnormality. The customer consults with the clerk in accordance with the second alarm and the clerk appropriately deals with the abnormal state so that the corresponding customer can resolve the abnormal state. 
     If ACT 63 , ACT 64  or ACT 65  are finished, the processor  101  returns to the standby state of ACT 51  to ACT 54  in  FIG. 13 . 
     If the notification data for the increase notification described above is received by the communication unit  104 , the processor  101  determines YES at ACT 53  in  FIG. 13  and proceeds to ACT 66  in  FIG. 14 . 
     In ACT 66 , the processor  101  confirms whether or not the increase in the weight of the product-sold-by-weight is reasonable. There may be a case if the customer returns a product-sold-by-weight once taken out of the display fixture  110  to a container that contains a different product-sold-by-weight in the display fixture  110 . In this case, the weight of the different product-sold-by-weight increases, but such an increase in weight is not reasonable. That is, while the previous measurement value is not decreased, if the measurement value in an increasing direction is acquired from the weighing scale  6 , the processor  101  determines it to be unreasonable. Further, there may be a case if the customer returns a different product together while returning a product-sold-by-weight once taken out from the display fixture  110  to the same container. In this case as well, the weight of the product-sold-by-weight increases, but such an increase in weight is also not reasonable. That is, if the measurement value in the increase direction greater than the measurement value decreased last time is acquired, the processor  101  determines it to be unreasonable. 
     At ACT 66 , if it is confirmed that the increase in the weight of the product-sold-by-weight is not reasonable, the processor  101  determines NO and proceeds to ACT 67 . In ACT 67 , the processor  101  performs a third alarm operation. The third alarm operation is an operation for notifying a clerk or the like of an unreasonable return operation performed on a product-sold-by-weight and for urging him or her to respond to the operation. As the third alarm operation, the processor  101  instructs the terminal device used by the clerk to display a screen or output a voice message, for example. As the third alarm operation, the processor  101  may perform any operation other than the above, or may perform a plurality of types of operations. Contents such as screens or voice messages may be appropriately determined according to the circumstances of the store where the display fixture  110  is installed. 
     At ACT 66 , if it is confirmed that the increase in the weight of the product-sold-by-weight is reasonable, the processor  101  determines YES and proceeds to ACT 68 . 
     In ACT 68 , the processor  101  determines a returner who returns the product-sold-by-weight to the display fixture  110 . For example, the processor  101  extracts all the data records DRB in which the monitoring flag set in the field FF is turned on from the tracking database  1033 , and selects, as the candidates for the returner, the people-to-track as identified by the tracking IDs set in the field FE of the corresponding data records DRB. When returning a product-sold-by-weight to the display fixture  110 , the customer extends his or her arm to the take-out tool for returning the product-sold-by-weight, returns the product-sold-by-weight using the take-out tool, and then releases the take-out tool and pulls his arm. Therefore, for example, the processor  101  specifies the person-to-track who performed the actions described above from among the people-to-track who are the candidates for the returner, based on the image captured by the surveillance camera  3 , and determines the corresponding person-to-track as the returner. 
     More specifically, for example, the processor  101  analyzes changes in a plurality of images captured by the surveillance camera  3  during a monitoring period predetermined in consideration of the period during which the actions described above for returning the product-sold-by-weight are performed, to specify the person who performed the actions described above, and further determine the position of the person. The processor  101  selects, from the extracted data records DRB described above, a data record DRB in which the detection data set in the field at the end shows the closest position to the specified position described above. Then, if a distance between the position shown in the detection data set in the field at the end of the corresponding data record DRB and the specified position described above is shorter than a specified distance, the processor  101  determines that a person-to-track identified by the tracking ID set in the field FE of the corresponding data record DRB is the returner. If the corresponding person-to-track is not found, the processor  101  determines that the returner is unknown. The processor  101  may measure the length of the arm of the returner, based on the relationship between the position shown in the detection data set in the field at the end in the selected data record DRB described above and the displaying position of the product-sold-by-weight for which weight has increased, and the image captured by the surveillance camera  3 , and determine that the returner is unknown if the length is longer than a specified length. 
     If the product-sold-by-weight is returned, the monitoring period described above starts before the processor  101  receives the increase notification, as in the case in which the product-sold-by-weight is taken out. Therefore, for example, the processor  101  buffers the images captured by the surveillance camera  3  in the auxiliary storage unit  103  or the like for a certain period of time. Then, after receiving the increase notification, the processor  101  analyzes the image related to the monitoring period among the buffered images. Alternatively, the process in ACT 68  may be executed by the processor  101  as a process of a thread different from the customer response process. 
     In ACT 69 , the processor  101  confirms whether or not the determination of the returner is successful. Then, if the returner can be determined, the processor  101  determines YES and proceeds to ACT 70 . 
     In ACT 70 , the processor  101  confirms whether or not the person-to-track determined as the returner is an authenticated member. The processor  101  searches the membership management database  1034  for data record DRC in which the same tracking ID as that set in the field FE of the data record DRB selected in ACT 68  is set in the field FN. Then, if the corresponding data record DRC is found, the processor  101  determines YES and proceeds to ACT 71 . 
     In ACT 71 , the processor  101  requests the sales management device  120  to cancel the sale of the product-sold-by-weight by the increased measurement value. For example, the processor  101  transmits the request data for the corresponding request from the communication unit  104  to the communication path  8  in the fixture toward the sales management device  120 . Then, the corresponding request data is relayed by the communication unit  7  and transmitted to the sales management device  120  via the communication network  140 . The processor  101  includes the identification data for identifying the cancellation request, the product code of the product-sold-by-weight to be canceled, the increased measurement value, and the member ID in the request data. The processor  101  includes the product code included in the received notification data described above as it is in the request data as the product code of the product-sold-by-weight to be canceled. The processor  101  includes the increased measurement value included in the received notification data described above as it is in the request data as the increased measurement value. The processor  101  includes the member ID set in the field FM of the data record DRC found at ACT 70  in the request data. 
     When receiving the request data described above, the sales management device  120  performs a cancellation process for withdrawing the product-sold-by-weight identified by the product code included in the request data from the weight of the product-sold-by-weight registered as being purchased by the member identified by the member ID included in the request data, by the increased measurement value included in the request data. 
     At ACT 70 , if the processor  101  confirms that the member is not the authenticated one, the processor  101  determines NO and proceeds to ACT 72 . For example, if the data record DRC in which the same tracking ID as that set in the field FE of the data record DRB selected at ACT 68  is set in the field FN cannot be found from the membership management database  1034 , the processor  101  determines that the member is not the authenticated one. This case corresponds to a case in which a customer is startled to the first alarm operation that is performed in response to the customer taking out the product-sold-by-weight from the shelf  1  without knowing the service provided by the store system  100 , and thus immediately returns the product-sold-by-weight to the shelf  1 . 
     At ACT 68 , if the returner cannot be determined, the processor  101  determines NO at ACT 69  and proceeds to ACT 72 . This case corresponds to a case in which the processor  101  determines that the returner is unknown as described above at ACT 68 . In addition, this case corresponds to a case in which a person who is not tracked by the tracking process due to certain errors returns the product-sold-by-weight. 
     In ACT 72 , the processor  101  performs a fourth alarm operation. The fourth alarm operation is an operation for notifying a clerk or the like of an unreasonable return of a product-sold-by-weight performed and for urging him or her to respond to the operation. As the fourth alarm operation, the processor  101  instructs the terminal device used by the clerk to display a screen or output a voice message, for example. As the fourth alarm operation, the processor  101  may perform any operation other than the above, or may perform a plurality of types of operations. Contents such as screens or voice messages may be appropriately determined according to the circumstances of the store where the display fixture  110  is installed. 
     If ACT 67 , ACT 71  or ACT 72  are finished, the processor  101  returns to the standby state of ACT 51  to ACT 54  in  FIG. 13 . 
     If the exit flag set in the field FJ is changed from off to on in any of the data records DRB included in the tracking database  1033 , the processor  101  determines YES at ACT 54  in  FIG. 13  and proceeds to ACT 73 . 
     In ACT 73 , the processor  101  confirms whether or not the person-to-track associated with the exit flag changed to ON state is an authenticated member. The processor  101  selects, from the tracking database  1033 , the data record DRB in which the exit flag changed to the ON state described above is set in the field FJ. Then, the processor  101  searches the membership management database  1034  for the data record DRC in which the same tracking ID as that set in the field FE of the selected data record DRB is set in the field FN. Then, if the corresponding data record DRC is found, the processor  101  determines YES and proceeds to ACT 74 . 
     In ACT 74 , the processor  101  requests the sales management device  120  to start the payment. For example, the processor  101  transmits the request data for the corresponding request from the communication unit  104  to the communication path  8  in the fixture toward the sales management device  120 . Then, the corresponding request data is relayed by the communication unit  7  and transmitted to the sales management device  120  via the communication network  140 . The processor  101  includes identification data for identifying the request to start payment and a member ID set in the field FM of the data record DRC found at ACT 73  in the request data. Then, after this, the processor  101  returns to the standby state of ACT 51  to ACT 54 . 
     If the member is not the authenticated one, and the corresponding data record DRC cannot be found, the processor  101  determines NO at ACT 73 , passes ACT 74 , and returns to the standby state of ACT 51  to ACT 54 . 
     When receiving the above request data, the sales management device  120  instructs the payment device  130  to pay the price for the registered product-sold-by-weight with respect to the member identified by the member ID included in the request data. When receiving the corresponding instruction, the payment device  130  pays the price described above using the payment information registered for the relevant member. The process for this payment may be a process for a well-known payment such as a credit payment OR an electronic money payment. 
     As is clear from the description provided above, the product monitoring unit  9  of the display fixture  110  forms a decrease amount acquisition portion by executing the processes of ACT 41 , ACT 43  and ACT 44  of  FIG. 12 . That is, the processor  91  of the product monitoring unit  9  acquires a decrease amount if the weight of the product measured by the measuring portion, that is, by the weighing scale  6  is changed in the decrease direction. 
     The main processing unit  10  of the display fixture  110  forms a specifying portion by executing the processes of ACT 60  to ACT 62  of  FIG. 14 . That is, the processor  101  of the main processing unit  10  specifies a customer who took out a product for which weight has changed in the decrease direction from the display section, that is, from the shelf  1 . 
     The main processing unit  10  of the display fixture  110  forms an output portion by executing the process of ACT 63  of  FIG. 14 . That is, the processor  101  of the main processing unit  10  outputs identification information of the customer specified by the specifying portion and the information related to the sale of the product based on the decrease amount acquired by the decrease amount acquisition portion, to the sales management device  120  that manages the information related to the sale in association with the identification information of the customer. 
     As described above, according to at least one embodiment, if the weight of the product-sold-by-weight measured by the weighing scale  6  of the display fixture  110  is changed in the decrease direction, the decreased amount is acquired. In addition, the customer who took out the product-sold-by-weight for which the weight has changed in the decrease direction is specified. Then, the member ID of the specified customer, the product code of the product-sold-by-weight, and the decreased amount are output to the sales management device  120 . Therefore, by installing the display fixture  110 , it is possible to support the sale of product-sold-by-weight for which the unit price per unit weight is determined. 
     In addition, the product monitoring unit  9  of the display fixture  110  forms an increase amount acquisition portion by executing the processes of ACT 42 , ACT 45  and ACT 46  of  FIG. 12 . That is, the processor  91  of the product monitoring unit  9  acquires the increase amount, if the weight of the product measured by the weighing scale  6  is changed in the increase direction. 
     The main processing unit  10  of the display fixture  110  forms an alarm portion by executing the processes of ACT 66  and ACT 67  of  FIG. 14 . That is, the processor  101  of the main processing unit  10  generates an alarm if the increase amount is unreasonable. 
     As described above, according to at least one embodiment, if the customer returns the product-sold-by-weight once taken out from the display fixture  110  to the container that contains a different product-sold-by-weight of the display fixture  110 , for example, the weight of the different product-sold-by-weight increases. If such an unreasonable increase amount is acquired, the alarm operation is performed. Therefore, it is possible to prevent the customer from unreasonably returning the product-sold-by-weight. In addition, since the clerk does not have to constantly monitor the customer, the burden on the clerk is decreased. 
     Further, the main processing unit  10  of the display fixture  110  forms a second specifying portion by executing the process of ACT 66 , ACT 68  and ACT 70  of  FIG. 14 . That is, the processor  101  of the main processing unit  10  specifies the customer who returned, to the shelf  1 , the product for which weight has changed in the increase direction, if the increase amount acquired by the increase amount acquisition portion is reasonable. Then, the processor  101  of the main processing unit  10  executes the process of ACT 71  in  FIG. 14 , and output, to the sales management device  120 , the identification information of the customer specified by the second specifying portion and the information related to the cancellation of the product, based on the increase amount acquired by the increase amount acquisition portion. 
     As described above, according to at least one embodiment, if a reasonable increase amount is acquired as the customer returns the product-sold-by-weight once taken out from the display fixture  110  to the container of the display fixture  110  which contains the same product-sold-by-weight, a request for cancellation process for withdrawing from the weight of the product-sold-by-weight registered as a purchase by the member identified by the member ID is output to the sales management device  120 . Therefore, if the customer is an authenticated member, the customer is allowed to freely return the product-sold-by-weight once taken out from the shelf  1  back to the shelf  1 . 
     The main processing unit  10  of the display fixture  110  forms a tracking portion by executing the processes of ACT 11  to ACT 25  of  FIG. 10  and ACT 27  to ACT 40  of  FIG. 11 . That is, the processor  101  of the main processing unit  10  tracks customers staying in an area defined with reference to the position of the shelf  1 . Then, the processor  101  of the main processing unit  10  specifies a customer among the customers staying in the area, who can take out the product for which weight has changed in the decrease direction from the shelf  1 , by executing the processes of ACT 60  to ACT 62  of  FIG. 14 . 
     As described above, according to at least one embodiment, by tracking the customers staying in the purchase area ARA, the customer who can take out the product-sold-by-weight for which the weight has changed in the decrease direction in the display fixture  110  is specified. Therefore, by installing the display fixture  110 , it is possible to make an unmanned store. 
     At least one embodiment can be modified in various ways as follows. 
     The appearance of the display fixture  110  illustrated in  FIG. 1  is an example, and the display fixture  110  according to at least one embodiment may be realized in any other forms. For example, it may be another type such as a trapezoidal type, a top opening type, or the like. Further, the open surface may be provided with a door that can be opened and closed. 
     A door that allows the open surface to be closed may be provided for the purpose of keeping it warm or cold. 
     The conditions for detecting exit of the person-to-track from the shelf  1  can be changed as appropriate. For example, the exit of the person-to-track from the shelf  1  may simply be detected in response to the person-to-track entering the confirm area ARD, without considering the preparatory area ARC. Further, for example, the exit of the person-to-track from the shelf  1  may simply be detected in response to the fact that the position of the person-to-track once located in the purchase area ARA is changed to outside the purchase area ARA. 
     The tracking process, the monitoring process, or the customer response process may be processed in a distributed manner by a plurality of computers. The tracking process, the monitoring process, and the customer response process may all be processed by the same computer. The tracking process and the customer response process may be processed by separate computers, respectively. The tracking process and the monitoring process, and the customer response process may be processed by separate computers, respectively, or the tracking process, and the monitoring process and the customer response process may be processed by separate computers, respectively. 
     The processor  91  or the processor  101  may execute at least a portion of the registration process in the sales management device  120 . The processor  91  or the processor  101  may execute at least a portion of the payment processing in the payment device  130 . At least a portion of the customer response process may be executed by the sales management device  120 . 
     Even if the member is an authenticated one, payment may be performed at the check-out corner where the clerk is stationed or at the self-service-type check-out corner. 
     The product-sold-by-weight may be registered in association with the tracking ID. Then, if the member authentication is performed after starting the registration of the product-sold-by-weight, the member ID may be associated with the product-sold-by-weight. Alternatively, the payment device installed in the tracking area may be used to pay the product-sold-by-weight associated with the person-to-track located in the area corresponding to the payment device. 
     The person as a target of tracking may be identified by the member ID without using the tracking ID. 
     The member may be authenticated by biometric authentication such as face authentication based on the image captured by the tracking camera  2 . 
     If the product-sold-by-weight is a food product, for example, the nutritional value per unit weight may be included in the data record DRA included in the product management database  932 . Then, the nutritional value corresponding to the decreased weight of the product-sold-by-weight taken out by the customer may be output to the sales management device  120 . 
     Each function realized by the processor  53 ,  91  or  101  by information processing can also be partially or completely realized by hardware that executes information processing that is not based on a program, such as a logic circuit. Further, each of the functions described above can be realized by combining software control with the hardware described above such as a logic circuit. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.