Communication apparatus, communication method, and computer program

A communication apparatus includes an antenna, a detecting section, and a determining section. The antenna receives a radio wave transmitted from a wireless tag. The detecting section detects a phase of the radio wave. The determining section determines that the wireless tag is present outside a predetermined range if a phase difference between a phase measured if a relative position of the antenna with respect to the wireless tag is a first position within a first range and a phase measured if the relative position is a second position within the first range is smaller than a threshold or if a phase difference between a phase measured if the relative position is a third position within a second range different from the first range and a phase measured if the relative position is a fourth position within the second range is smaller than the threshold.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2018-117073, filed in Jun. 20, 2018, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a communication apparatus, a communication method, and a computer program.

BACKGROUND

In recent years, there has been an increasing number of stores where a self-checkout apparatus (a self-point of sale (POS) apparatus or a self-register apparatus) or a semi-self-checkout apparatus (a semi-self-POS apparatus or a semi-self-register apparatus) for the customer himself or herself to perform registration of commodities to be purchased is provided. The stores adopt a sales form in which the customer registers the commodities to be purchased.

In general, in such a checkout apparatus, the customer scans code symbols such as barcodes or two-dimensional codes attached to commodities with a scanner one by one and performs sales registration of the commodities. Therefore, the customer has to find out, for each of the commodities, a code symbol of the commodity and adjust the directions of the code symbol and the scanning of the scanner every time. Such an operation is a burden for the customer. If the number of commodities to be registered increases, the burden of the customer also increases according to the increase in the number of commodities.

Therefore, the sales registration takes time, causing a deterioration in processing efficiency in the self-checkout apparatus or the semi-self-checkout apparatus.

Accordingly, a part of the stores introduces a check-out apparatus that collectively reads commodity information such as commodity codes from wireless tags such as radio frequency identifier (RFID) tags attached to a plurality of commodities and performs sales registration and accounting process based on the commodity information. Such a checkout apparatus includes, for example, a reading device that can read commodity information from wireless tags attached to a plurality of commodities placed on the upper surface of a checkout counter in which a flat antenna is embedded.

Such a reading device includes a shield box or the like that blocks a radio wave not to inadvertently read a wireless tag in the periphery such as a wireless tag held by a shopper present nearby or a wireless tag put on an adjacent reading device. Therefore, the size of the device increases and cost in constructing a system increases. It takes time for an operator such as a customer to put in articles such as commodities in the shield box and take out the commodities from the shield box.

DETAILED DESCRIPTION

According to one embodiment, a shield box or the like is made unnecessary by providing a communication apparatus, a communication method, and a computer program.

A communication apparatus according to an embodiment includes an antenna, a detecting section, and a determining section. The antenna receives a radio wave transmitted from a wireless tag. The detecting section detects a phase of the radio wave received by the antenna. The determining section determines that the wireless tag is present outside a predetermined range if a phase difference between a phase measured if a relative position of the antenna with respect to the wireless tag is a first position within a first range and a phase measured if the relative position is a second position within the first range is smaller than a threshold or if a phase difference between a phase measured if the relative position is a third position within a second range different from the first range and a phase measured if the relative position is a fourth position within the second range is smaller than the threshold.

A checkout system according to an embodiment is explained below with reference to the drawings. In the drawings used for the explanation of the embodiment below, scales of sections are sometimes changed as appropriate. In the drawings, components are sometimes simplified and illustrated for explanation.

FIG. 1is a block diagram illustrating an example configuration of a checkout system1according to an example embodiment. The checkout system1is a system for performing registration of commodities and settlement concerning the registered commodities. As an example (e.g., in various embodiments, etc.), the checkout system1includes a checkout apparatus10and a wireless tag600. The checkout apparatus10is a device that performs registration of commodities and settlement concerning the registered commodities. As an example, the checkout apparatus10includes a reading device100, a driving device200, an antenna300, and a POS terminal400.

The reading device100is explained with reference toFIG. 2.FIG. 2is a block diagram illustrating a circuit configuration of the reading device100. The reading device100is a device that controls the driving device200and the antenna300and reads commodity information such as a commodity code from the wireless tag600. A commodity code is an identification sign uniquely given to each of commodities. As an example, the reading device100includes a processor101, a read-only memory (ROM)102, a random-access memory (RAM)103, a first connection interface104, a second connection interface105, a high-frequency frontend section106, a digital amplitude modulating section107, a digital to analog (DA) conversion section108, an analog to digital (AD) conversion section109, and a demodulating section110. These sections are connected by a bus111or the like. The reading device100is an example of a communication device.

The processor101is equivalent to a central part of a computer that performs processes such as an arithmetic operation and control necessary for the operation of the reading device100. The processor101controls the sections based on computer programs such as system software, application software, or firmware stored in the ROM102or the like in order to realize various functions of the reading device100. The processor101may be, for example, a central processing unit (CPU), an micro processing unit (MPU), an SoC system on a chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or an field-programmable gate array (FPGA). Alternatively, the processor101is a combination of a plurality of devices among these devices.

The ROM102is equivalent to a main storage device of the computer including the processor101as the central part. The ROM102is a nonvolatile memory exclusively used for readout of data. The ROM102stores the computer programs explained above. The ROM102stores data, various setting values, or the like used by the processor101in performing various kinds of processes.

The computer programs stored in the ROM102include a control program1021for executing processes explained below. As an example, the reading device100is transferred to an administrator or the like of the reading device100in a state in which the control program1021is stored in the ROM102. However, the reading device100may be transferred to the administrator or the like in a state in which the control program1021is not stored in the ROM102. The reading device100may be transferred to the administrator or the like in a state in which a program different from the control program1021is stored in the ROM102. The control program1021may be separately transferred to the administrator or the like and written in the ROM102under operation by the administrator, a serviceperson, or the like. The transfer of the control program1021at this time can be realized by, for example, recording the control program1021in a removable storage medium such as a magnetic disk, a magneto-optical disk, an optical disk, or a semiconductor memory or downloading the control program1021via a network such as the Internet or a local area network (LAN).

The RAM103is equivalent to the main storage device of the computer including the processor101as the central part. The RAM103is a memory used for reading and writing of data. The RAM103is used as a so-called work area or the like in which data temporarily used by the processor101in performing the various kinds of process is stored.

As an example, the RAM103stores a table1031and a commodity list1032.

As an example, the table1031has a configuration illustrated inFIG. 3.FIG. 3is a diagram illustrating an example of a data configuration of the table1031. The table1031stores various kinds of information extracted from a radio wave transmitted by the wireless tag600. The table1031includes commodity codes, position information, and phase information. The table1031stores a commodity code, position information, and phase information received from the wireless tag600in association with one another. The position information is information indicating a position of the antenna300at the time when the commodity code is received from the wireless tag600. The phase information is information indicating a phase of a response wave received from the wireless tag600.

The commodity list1032stores commodity codes concerning settlement target commodities. The RAM103that stores the commodity list1032is an example of a storing section that stores settlement target commodity codes.

The ROM102or the RAM103stores a threshold used in the processes explained below. A value of the threshold is decided by, for example, a designer, an administrator, or an operator of the reading device100.

The first connection interface104is an interface for the reading device100to communicate with the driving device200.

The second connection interface105is an interface for the reading device100to communicate with the POS terminal400.

The high-frequency frontend section106outputs a signal to the antenna300. A signal is input to the high-frequency frontend section106from the antenna300.

The antenna300transmits and receives a radio wave between the antenna300and the wireless tag600. The antenna300converts a received radio wave into an electric signal and outputs the electric signal to the reading device100.

The digital amplitude modulating section107may be, for example, a circuit that adds information transmitted to the wireless tag600to a carrier wave transmitted to the wireless tag600.

The DA conversion section108is a circuit that converts a digital signal into an analog signal. The DA conversion section108converts a digital signal converted by the digital amplitude modulating section107into an analog signal. The DA conversion section108outputs a high-frequency signal to the antenna300via the high-frequency frontend section106.

The AD conversion section109is a circuit that converts an analog signal into a digital signal. The AD conversion section109converts a high-frequency signal input from the antenna300via the high-frequency frontend section106into a digital signal.

The demodulating section110may be, for example, a circuit that extracts various kinds of information from a radio wave received from the wireless tag600. The demodulating section110extracts information such as a commodity code from the digital signal converted by the AD conversion section109. The demodulating section110detects, with a quadrature detection method, a phase of the radio wave from the digital signal converted by the AD conversion section109. Therefore, the demodulating section110is an example of a detecting section that detects a phase of a radio wave received by the antenna300.

The bus111includes a control bus, an address bus, and a data bus and transmits signals exchanged by the sections of the reading device100.

The driving device200is explained with reference toFIGS. 4 and 5.FIG. 4is a block diagram illustrating a circuit configuration of the driving device200.FIG. 5is a schematic diagram of the driving device200.

The driving device200drives to move the antenna300. As an example, the driving device200includes, as illustrated inFIG. 4, a processor201, a ROM202, a RAM203, a connection interface204, a driving section205, and a home position sensor206. These sections are connected by a bus207or the like. As an example, the driving device200includes, as illustrated inFIG. 5, a rotating shaft211, a rail212, and a moving stage213.

The processor201is equivalent to a central part of a computer that performs processes such as an arithmetic operation and control necessary for the operation of the driving device200. The processor201controls the sections in order to realize various functions of the driving device200based on computer programs such as system software, application software, or firmware stored in the ROM202or the like. The processor201may be, for example, a CPU, a MPU, a SoC, a DSP, a GPU, an ASIC, a PLD, or a FPGA. Alternatively, the processor201is a combination of a plurality of devices among these devices.

The ROM202is equivalent to a main storage device of the computer including the processor201as the central part. The ROM202is a nonvolatile memory exclusively used for readout of data. The ROM202stores the computer programs explained above. The ROM202stores data, various setting values, or the like used by the processor201in performing various kinds of processes.

The computer programs stored in the ROM202include a control program2021for executing processes explained below. As an example, the driving device200is transferred to an administrator or the like of the driving device200in a state in which the control program2021is stored in the ROM202. However, the driving device200may be transferred to the administrator or the like in a state in which the control program2021is not stored in the ROM202. The driving device200may be transferred to the administrator or the like in a state in which a computer program different from the control program2021is stored in the ROM202. The control program2021may be separately transferred to the administrator or the like and written in the ROM202under operation by the administrator, a serviceperson, or the like. The transfer of the control program2021at this time can be realized by, for example, recording the control program2021in a removable recording medium such as a magnetic disk, a magneto-optical disk, an optical disk, or a semiconductor memory or downloading the control program2021via a network or the like.

The RAM203is equivalent to a main storage device of the computer including the processor201as the central part. The RAM203is a memory used for reading and writing of data. The RAM203is used as a so-called work area or the like in which data temporarily used by the processor201in performing the various kinds of processes is stored.

The connection interface204is an interface for connecting the driving device200to the reading device100.

As illustrated inFIG. 5, the driving device200and the antenna300are disposed, for example, below a counter table700. The counter table700is a table on which an article500attached with the wireless tag600is placed. The article500may be, for example, a commodity. The article500is placed on the counter table700, for example, in a state in which the article500is put in a shopping basket800.

The driving section205may be, for example, a stepping motor.

The rotating shaft211transmits a driving force to the driving section205. Screw grooves are formed on the rotating shaft211and the rail212. The screw grooves are opposed and coupled. Therefore, if the driving section205performs rotation driving, the rotating shaft211rotates and the rail212moves. The moving stage213, on which the antenna300is placed, is attached to the rail212.

The moving stage213includes a ball screw nut. If the rail212is rotated by the ball screw nut, the moving stage213moves in the horizontal direction. That is, the moving stage213moves in an x-axis direction illustrated inFIG. 5. The moving stage213moves in the opposite direction if a rotating direction of the rail212is reversed. In this way, the driving device200causes the antenna300to reciprocate in the x-axis direction along the rail212.

The home position sensor206is a sensor that detects whether the moving state213is present in a predetermined position called home position.

The bus207includes a control bus, an address bus, and a data bus and transmits signals exchanged by the sections of the driving device200.

FIG. 6is a diagram illustrating a phase change due to movement of the antenna300. If the driving device200moves the antenna300, a change in the distance from the antenna300to the wireless tag600is larger as the distance from the antenna300to the wireless tag600is shorter. For example, inFIG. 6, an amount of change (BY-AY) between a distance AY from a point A to a point Y and a distance BY from a point B to the point Y is larger than an amount of change (BX-AX) between a distance AX from the point A to a point X and a distance BX from the point B to the point X. That is, a phase difference of a radio wave received from the wireless tag600is also larger as the distance from the antenna300to the wireless tag600is shorter.

If the antenna300receives a commodity code from the wireless tag600, the reading device100stores the commodity code, a phase of a wireless tag response wave, and a receiving position of the antenna300at the time of the reception of the commodity code in association with one another. The reading device100compares phases associated with the same commodity code received in different receiving positions.

If an amount of change in the phases per displacement distance due to displacement of the receiving positions is equal to or larger than a threshold, the reading device100determines that the wireless tag600, which transmits the commodity code, is present on the inner side of a predetermined region. On the other hand, if the amount of change in the phases per displacement distance is smaller than the threshold, the reading device100determines that the wireless tag600, which transmits the commodity code, is present on the outer side of the predetermined region.

The POS terminal400is explained with reference toFIG. 7.FIG. 7is a block diagram illustrating a circuit configuration of the POS terminal400.

The POS terminal400is set in a store such as a retail store for register jobs such as registration of settlement target commodities and settlement of the registered commodities. The POS terminal400may be a terminal included in a POS system. However, the POS terminal400may be an electronic cash register not included in the POS system. The POS terminal400may be, for example, a self-type terminal operated by a shopper or the like in the store. Alternatively, the POS terminal400may be a semi-self-type terminal including a registering device that performs registration of commodities and a settling device that performs settlement concerning the registered commodities. In a typical operation of the semi-self-type POS terminal400, a store clerk operates the registering device and a shopper operates the settling device. Alternatively, the POS terminal400may be a terminal operated by the store clerk or the like of the store. As an example, the POS terminal400includes a processor401, a ROM402, a RAM403, an auxiliary storage device404, a communication interface405, a connection interface406, an input device407, a display section408, a customer-side display section409, a printer410, a reader writer411, and a noncontact reader writer412. These sections are connected by a bus413or the like.

The processor401is equivalent to a central part of a computer that performs processes such as an arithmetic operation and control necessary for the operation of the POS terminal400. The processor401controls the sections in order to realize various functions of the POS terminal400based on computer programs such as system software, application software, or firmware stored in the ROM402, the auxiliary storage device404, or the like. The processor401may be, for example, a CPU, a MPU, a SoC, a DSP, a GPU, an ASIC, a PLD, or an FPGA. Alternatively, the processor401is a combination of a plurality of devices among these devices.

The ROM402is equivalent to a main storage device of the computer including the processor401as the central part. The ROM402is a nonvolatile memory exclusively used for readout of data. The ROM402stores the computer programs explained above. The ROM402stores data, various setting values, or the like used by the processor401in performing various kinds of processes.

The RAM403is equivalent to a main storage device of the computer including the processor401as the central part. The RAM403is a memory used for reading and writing of data. The RAM403is used as a so-called work area in which data temporarily used by the processor401in performing the various kinds of processes is stored.

The auxiliary storage device404is equivalent to an auxiliary storage device of the computer including the processor401as the central part. The auxiliary storage device404may be, for example, an electric erasable programmable read-only memory (EEPROM), a hard disk drive (HDD), or a solid state drive (SSD). The auxiliary storage device404sometimes stores the computer programs explained above. The auxiliary storage device404stores data used by the processor401in performing the various kinds of processes and data, various setting values, or the like generated by the processes in the processor401.

The computer programs stored in the auxiliary storage device404include a control program4041for executing processes explained below. As an example, the POS terminal400is transferred to an administrator or the like of the POS terminal400in a state in which the control program4041is stored in the auxiliary storage device404. However, the POS terminal400may be transferred to the administrator or the like in a state in which the control program4041is not stored in the auxiliary storage device404. The POS terminal400may be transferred to the administrator or the like in a state in which a computer program different from the control program4041is stored in the auxiliary storage device404. The control program4041may be separately transferred to the administrator or the like and written in the auxiliary storage device404under operation by the administrator, a serviceperson, or the like. The transfer of the control program4041can be realized by, for example, recoding the control program4041in a removable storage medium such as a magnetic disk, a magneto-optical disk, an optical disk, or a semiconductor memory or downloading the control program4041via a network or the like.

The control program4041may be stored in the ROM402.

The auxiliary storage device404stores a commodity database. The commodity database is a database including various kinds of information such as commodity codes, commodity names, and amounts concerning commodities sold in the store. Alternatively, the POS terminal400may refer to, every time, the commodity database stored in the server or the like.

The communication interface405is an interface for the POS terminal400to communicate via a network or the like.

The connection interface406is an interface for the POS terminal400to communicate with the reading device100.

The input device407receives operation by an operator of the POS terminal400. The input device407may be, for example, a keyboard, a keypad, or a touch pad.

The display section408displays a screen for notifying various kinds of information to the operator of the POS terminal400. The display section408is a display such as a liquid crystal display or an organic electro-luminescence (EL) display. A touch panel can be used as the input device407and the display section408. That is, a display panel included in the touch panel can be used as the display section408. A touch pad included in the touch panel can be used as the input device407.

The customer-side display section409displays a screen for notifying (e.g., providing, displaying, etc.) various kinds of information to the shopper. The customer-side display section409is a display such as a liquid crystal display or an organic EL display. A touch panel can be used as the customer-side display section409. In this case, the customer-side display section409also operates as an input device that receives operation by the shopper.

The printer410prints a receipt or the like. The printer410is any one of printers of various types such as a dot-impact printer, an inkjet printer, a thermal printer, a laser printer, and other printers.

The reader writer411performs communication with a magnetic card (e.g., a magnetic stripe card, etc.), a contact integrated circuit (IC) card, or the like.

The noncontact reader writer412performs communication with a noncontact IC card or the like. The noncontact reader writer412performs communication with a noncontact IC chip mounted on an electronic device (e.g., a cellular phone, a smartphone, a tablet personal computer (PC), etc.).

The bus413includes a control bus, an address bus, and a data bus and transmits signals exchanged by the sections of the POS terminal400.

The wireless tag600is attached to the article500. The wireless tag600may be an RFID tag. The wireless tag600may be other wireless tags such as an IC tag. The wireless tag600may be, for example, a passive wireless tag that operates using, as an energy source, a predetermined radio wave transmitted from the antenna300. The wireless tag600transmits a signal including a commodity code by, for example, performing backscatter modulation on a non-modulation signal.

The operation of the checkout system1according to the embodiment is explained below with reference toFIGS. 8 to 10and the like. Content of processes in the following operation example is an example. Various kinds of processes capable of obtaining the same result can be used as appropriate.FIG. 8is a flowchart of a process implemented by the processor401of the POS terminal400. The processor401executes the process based on the computer programs stored in the ROM402, the auxiliary storage device404, or the like.FIG. 9is a flowchart of a process implemented by the processor101of the reading device100. The processor101executes the process based on the computer programs stored in the ROM102or the like.FIG. 10is a flowchart of a process implemented by the processor201of the driving device200. The processor201executes the process based on the computer programs stored in the ROM202or the like. If the processor101, the processor201, or the processor401proceeds to Act (N+1) after a process in Act N (N is a natural number), description for explaining this is sometimes omitted.

The processor401of the POS terminal400starts the process illustrated inFIG. 8in response to, for example, a start of the POS terminal400.

In Act11inFIG. 8, the processor401generates an image corresponding to a start screen. The processor401instructs the display section408to display the generated image. In response to the instruction, the display section408displays the start screen.

As an example, the start screen includes a start button. The start button is a button that the operator operates if the operator instructs a start of commodity registration.

For example, the operator of the POS terminal400places the article500, which the operator desires to set as a settlement target, on the counter table700. The operator performs operation for instructing the start of the commodity registration such as operation of the start button.

In Act12, the processor401waits for operation for instructing the start of the commodity registration to be performed. That is, the processor401waits for predetermined operation for operating an operation button to be performed. If the operation for instructing the start of the commodity registration is performed, the processor401determines Yes in Act12and proceeds to Act13.

In Act13, the processor401instructs the connection interface406to transmit a scan start command to the reading device100. In response to the instruction, the connection interface406transmits the scan start command to the reading device100. The transmitted scan start command is received by the second connection interface105of the reading device100. The scan start command is a command for instructing the reading device100to read a commodity code from the wireless tag600.

On the other hand, in Act21inFIG. 9, the processor101of the reading device100waits for the scan start command to be received by the second connection interface105. If the scan start command is received, the processor101determines Yes in Act21and proceeds to Act22.

In Act22, the processor101instructs the second connection interface105to transmit a driving start command to the driving device200. In response to the instruction, the second connection interface105transmits the driving start command to the driving device200. The transmitted driving start command is received by the connection interface204of the driving device200. The driving start command is a command for instructing the driving device200to start driving and start movement of the antenna300.

On the other hand, in Act41inFIG. 10, the processor201of the driving device200waits for the driving start command to be received by the connection interface204. If the driving start command is received, the processor201determines Yes in Act41and proceeds to Act42.

In Act42, the processor201controls the driving section205to start reciprocation of the antenna300. The driving section205starts driving according to the control. Consequently, the reciprocation of the antenna300is started.

On the other hand, in Act23inFIG. 9, the processor101of the reading device100controls the sections and starts transmission of a predetermined radio wave for reading information from the wireless tag600. The radio wave is transmitted from the antenna300.

In Act24, the processor101determines whether a commodity code is read. If determining that a commodity code is not read, the processor101determines No in Act24and proceeds to Act25.

In Act25, the processor101determines whether an end notification is received by the first connection interface104. If the end notification is not received, the processor101determines No in Act25and returns to Act24. In this way, the processor101repeats Act24and Act25until the processor101determines that a commodity code is read or until the end notification is received.

The antenna300receives a response wave transmitted from the wireless tag600. The response wave is demodulated by the demodulating section110. If a commodity code is included in the demodulated response wave, the processor101determines that a commodity code is read.

If determining that a commodity code is read in waiting states in Act24and Act25, the processor101determines Yes in Act24and proceeds to Act26.

In Act26, the processor101stores the input commodity code in the table1031in association with position information and phase information. That may be, for example, the processor101adds a record including the commodity code, the position information, and the phase information to the table1031. The position information indicates, for example, a position of the antenna300at the time when the response wave including the commodity code is received. The phase information indicates a phase of the response wave. The processor101returns to Act24after the process in Act26.

On the other hand, in Act43inFIG. 10, the processor201of the driving device200waits for the reciprocation of the antenna300to end. If the reciprocation of the antenna300ends, the processor201determines Yes in Act43and proceeds to Act44.

In Act44, the processor201instructs the connection interface204to transmit an end notification to the reading device100. In response to the instruction, the connection interface204transmits the end notification to the reading device100. The transmitted end notification is received by the first connection interface104of the reading device100. The end notification notifies that the reciprocation of the antenna300ends. After the process in Act44, the processor201returns to Act41.

On the other hand, if the end notification is received in the waiting states in Act24and Act25inFIG. 9, the processor101determines Yes in Act25and proceeds to Act27.

In Act27, the processor101ends the transmission of the predetermined radio wave, the transmission of which is started in Act23.

In Act28, the processor101determines whether unselected commodity codes are present among the commodity codes included in the table1031. If unselected commodity codes are present, the processor101determines Yes in Act28and proceeds to Act29.

In Act29, the processor101selects one of the unselected commodity codes among the commodity codes included in the table1032. The selected commodity code is hereinafter referred to as “commodity code under selection”. There is only one commodity code under selection. If the processor101executes the process in Act29a plurality of times, a commodity code selected last is the commodity code under selection.

In Act30, the processor101determines whether the commodity code under selection is read from the wireless tag600present within a reading range. That is, the processor101determines whether a phase change amount is equal to or larger than the threshold in all set areas. The phase change amount and the area are explained below with reference toFIGS. 11 and 12.

The reading device100sets a plurality of areas with respect to the position information. As an example, the reading device100sets a range of x=0 to 100 millimeters (mm) as an area AR11and sets a range of x=100 to 200 mm as an area AR12. In this case, there are two set areas. For example, the designer, the administrator, or the like of the reading device100decides how areas are set.

The processor101calculates a phase change amount concerning each of the set areas. As an example, a method of calculating a phase change amount concerning the area AR11is explained. The processor101extracts, referring to the table1031, a maximum and a minimum of values of a phase information field out of records that satisfy conditions (1) and (2) described below.

(1) A value of a commodity code field is the commodity code under selection.

(2) A value of a position information field is within a range of the area AR11. That is, the value of the position information field is in a range of 0 to 100.

The processor101calculates a difference between the maximum and the minimum. The difference is a phase change amount. The processor101calculates phase change amounts concerning the respective areas in the same manner.

InFIGS. 11 and 12, theoretical values of phase change amounts of positions on an xz plane where the wireless tag600is present are illustrated. Note that a y coordinate of a position of the wireless tag600illustrated inFIGS. 11 and 12is set to 0.FIG. 11illustrates a phase change amount concerning the area AR11.FIG. 12illustrates a phase change amount concerning the area AR12.

In the wireless tag600present in a distance (e.g., z>320 mm), the phase change amounts are small in both of the area AR11and the area AR12as illustrated inFIGS. 11 and 12. On the other hand, if focusing on a near position1000, the phase change amount in the area AR11is small (e.g., smaller than the threshold) but the phase change amount in the area AR12is large (e.g., equal to the threshold, larger than the threshold).

If both the calculated phase change amounts are equal to or larger than the threshold, that is, if the phase change amounts concerning all the set areas are equal to or larger than the threshold, the processor101determines Yes in Act30and proceeds to Act31.

On the other hand, if the phase change amount concerning one of the areas is smaller than the threshold, the processor101determines No in Act30and proceeds to Act32. If there is an area where the number of fields satisfying the conditions (1) and (2) is not plural, the processor101determines No in Act30and proceeds to Act32. That is, if there is an area where the number of fields satisfying the conditions (1) and (2) is one or less, the processor101determines No in Act30and proceeds to Act32. This is because such a wireless tag600is highly likely to be present in a far distance.

In the above explanation, the set areas are the two areas AR11and AR12. However, the number of set areas may be three or more. For example, three areas AR21to AR23are set as illustrated inFIGS. 13 to 15.

As an example, the processor101sets a range of x=0 to 100 mm as an area AR21, sets a range of x=50 to 150 mm as an area AR22, and sets a range of x=100 to 200 mm as an area AR23. In this case, in the wireless tag600present in a distance (e.g., z>320 mm), as illustrated inFIGS. 13 to 15, phase change amounts are small in all the area AR21to the area AR23. On the other hand, if focusing on a near position1001, phase change amounts in the area AR21and the area AR22are small (e.g., smaller than the threshold) but a phase change amount in the area AR23is large (e.g., equal to the threshold, larger than the threshold).

According to the above explanation, the processor101is an example of a determining section that determines that the wireless tag600is present outside a predetermined range.

The area AR11and the area AR12are examples of a first range and a second range. The area AR21to the area AR23are examples of a first range to a third range. Positions indicated by position information fields of records in which values of phase information fields in the areas indicate a maximum and positions indicated by position information fields of records in which the values of the phase information fields in the areas indicate a minimum are respectively examples of a first position to a sixth position.

In Act31, the processor101determines that the commodity code under selection is read from the wireless tag600present within the reading range. The processor101registers the commodity code under selection in a commodity list. The processor101makes it seen that the commodity code is already selected. For example, the processor101adds the commodity code to a selected commodity code list. The selected commodity code list is a list that stores selected commodity codes. After the process in Act31, the processor101returns to Act28.

On the other hand, if a plurality of records including the same commodity code are absent, the processor101determines No in Act30and proceeds to Act32. If the phase change amount is smaller than the threshold in any one of the areas, the processor101determines No in Act30and proceeds to Act32.

In Act32, the processor101determines that the commodity code under selection is read from the wireless tag600present outside the reading range. The processor101makes it seen that the commodity code is already selected. For example, the processor101adds the commodity code to the selected commodity code list. After the process in Act32, the processor101returns to Act28.

As explained above, the processor101repeats the process in Acts28to32to determine whether the commodity codes included in the table1031are present within the reading range.

If unselected commodity codes are absent, the processor101determines No in Act28and proceeds to Act33.

In Act33, the processor101instructs the second connection interface105to transmit the commodity list to the POS terminal400. In response to the instruction, the second connection interface105transmits the commodity list to the POS terminal400. The transmitted commodity list is received by the communication interface405of the POS terminal400.

In Act34, the processor101resets the commodity list, the table1031, and the selected commodity code list. That is, the processor101resets the commodity list to a state in which no commodity is registered in the commodity list. For example, the processor101deletes all records of the table1031. Further, the processor101resets the selected commodity code list to a state in which no selected commodity code is registered in the selected commodity code list. After the process in Act34, the processor101returns to Act21.

On the other hand, in Act14inFIG. 8, the processor401of the POS terminal400waits for the commodity list to be received by the communication interface405. If the commodity list is received, the processor401determines Yes in Act14and proceeds to Act15.

In Act15, the processor401generates an image corresponding to a confirmation screen. The processor401instructs the display section408to display the generated image. In response to the instruction, the display section408displays the confirmation screen.

The confirmation screen includes a list of commodities registered in the commodity list, amounts of the commodities, a total amount of the commodities, and a settlement button. The settlement button is a button that the operator operates if the operator instructs the POS terminal400to perform settlement concerning the commodities registered in the commodity list.

In Act16, the processor401waits for operation for instructing the POS terminal400to perform settlement to be performed. That is, the processor401waits for predetermined operation such as operation of the settlement button to be performed. If the operation for instructing the POS terminal400to perform settlement is performed, the processor401determines Yes in Act16and proceeds to Act17. On the other hand, if the operation for instructing the POS terminal400to perform settlement is not performed, the processor401determines No in Act16and proceeds to Act18.

In Act17, the processor401performs a settlement process based on a commodity code registered in the commodity list. The processor401acquires an amount, a commodity name, and the like of a commodity indicated by the commodity code from the commodity database. The processor401performs, in the settlement process, settlement using, for example, cash, a credit card, a debit card, a coupon, a gift certificate, an electronic money, or QR settlement. [0088] In Act18, the processor401controls the printer410to issue a receipt or the like based on a result of the settlement process. The printer410issues the receipt or the like based on the control. After the process in Act18, the processor401returns to Act11.

According to various embodiments, the reading device100sets two or more areas with respect to the position information. The reading device100determines, concerning a commodity code read from each wireless tag600, whether phase change amounts concerning the respective areas are equal to or larger than the threshold. If the phase change amount concerning any one of the areas is smaller than the threshold, the reading device100determines that the wireless tag600is present outside the reading range.

By performing the determination dividedly for the two or more areas as explained above, the reading device100can more highly accurately determine whether the wireless tag600is present within the reading range than in the past. Consequently, the reading device100can prevent the reading device100from erroneously reading information from wireless tags in the periphery.

According to various embodiments, the reading device100stores, as a settlement target commodity code, a commodity code read from the wireless tag600determined as being present within the reading range. The reading device100transmits the settlement target commodity code to the POS terminal400. Consequently, the POS terminal400can perform settlement based on the received settlement target commodity code.

According to various embodiments, the reading device100sets three or more areas. Consequently, the reading device100can more highly accurately determine whether the wireless tag600is present within the reading range.

In various embodiments, the reading device100determines that a target wireless tag600is present outside the reading range if a radio wave transmitted from the target wireless tag600is not received in the areas a plurality of times. With such determination, the reading device100can determine that the wireless tag600is present outside the reading range.

Modifications of the embodiment explained above are also possible as explained below.

In various embodiments, the antenna300performs reception and transmission. However, an antenna for reception and an antenna for transmission may be separately connected to the reading device100.

In various embodiments, the antenna300is moved. In some embodiments, the article500attached with the wireless tag600is moved. A relative position of the antenna300with respect to the wireless tag600changes irrespective of whether the antenna300is moved or the article500is moved. In some embodiments, both the antenna300and the article500are moved.

A plurality of antennas may be connected to the reading device100. The reading device100may receive, in each of the plurality of antennas, a radio wave transmitted from the wireless tag600. In various embodiments, the reading device100moves the antenna300to receive the radio wave transmitted from the wireless tag600in a plurality of positions. The reading device100can receive the radio wave transmitted from the wireless tag600in the plurality of positions using antennas provided in the plurality of positions instead of moving the antenna300. In this case, since the movement of the antenna300is unnecessary, the checkout apparatus10is may be excellent in quietness (e.g., may produce minimal noise, etc.). Since a time required for the movement of the antenna300is also unnecessary, the checkout apparatus10is capable of performing high-speed operation.

In various embodiments, the reading device100moves the antenna300once and stores a phase in Act26. The reading device100calculates a phase change amount in each of the set areas. In this way, the reading device100virtually moves the antenna300in a plurality of areas. However, the reading device100may move the antenna300in each of ranges corresponding to the set areas and perform measurement.

In various embodiments, the reading device100is used in the checkout system1. However, the reading device100may also be used in other various systems. In the other various systems as well, the reading device100is capable of collectively reading information from a plurality of wireless tags600within the reading range.