Wireless tag communication device, wireless tag communication system, and program

Abstract

To allow the time required to read all of a plurality of wireless tags that are targets for position detection to be shortened.SOLUTION: A wireless tag communication device includes a wireless communication unit, an acquisition unit, a discrimination unit, and an instruction unit. The wireless communication unit includes a flag that stores a flag state of either a first state or a second state, and communicates with a wireless tag that returns identification information only when the flag state corresponds to a flag state specified by an identification information read command. The acquisition unit transmits an identification information read command specifying the first state by the wireless communication unit, and acquires the identification information returned from the wireless tag whose flag state is the first state. The discrimination unit determines whether the position of the wireless tag that returned the identification information has been detected or not based on the acquired identification information. The instruction unit instructs the wireless tag whose position has been detected to rewrite the flag state to the second state by the wireless communication unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Embodiments of the present invention relate to a wireless tag communication device, a wireless tag communication system, and a program. [Background Art]

[0002] In recent years, a technology for detecting articles has been used in various applications, in which a wireless tag called an RFID (Radio Frequency Identification) tag recording unique identification information is attached to an article to be managed, and identification information is read from the wireless tag by a wireless tag communication device called an RFID reader that wirelessly communicates with the wireless tag.

[0003] With this technology, it is possible to read identification information from all wireless tags existing in the communication area of a wireless tag communication device by only transmitting a read command once from the wireless tag communication device. However, in practice, missed reading occurs due to various factors such as relative movement between the wireless tag and the wireless tag communication device, and radio wave reflection, so the wireless tag communication device has to transmit a read command a plurality of times. As a result, identification information that has already been completely read is also read by each read command, which reduces opportunities for reading identification information that has not been read yet. Therefore, the time required to complete reading the identification information of all wireless tags increases, and the reading rate per unit time decreases. In view of this, Patent Document 1 prevents this problem by instructing that flag information of a wireless tag from which identification information has been acquired once should not be reset by a read command.

[0004] Incidentally, one application of wireless tags and wireless tag communication devices is inventory management of numerous items stored on shelves in warehouses and store backrooms, and locating desired items. In this application, it is necessary not only to detect items but also to determine their location. To perform location detection, it is essential to read a single wireless tag multiple times. However, reading a wireless tag whose location has already been detected reduces the opportunity to read wireless tags whose location has not yet been detected. Therefore, if there are multiple wireless tags to be detected, i.e., to be read, it will take time to read all of them. This problem cannot be addressed by the technology disclosed in Patent Document 1. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2010-21901 [Overview of the project] [Problems that the invention aims to solve]

[0006] The problem that the embodiments of the present invention aim to solve is to provide a wireless tag communication device, a wireless tag communication system, and a program that can shorten the time required to read all of multiple wireless tags that are to be detected. [Means for solving the problem]

[0007] In one embodiment, the wireless tag communication device comprises a wireless communication unit, an acquisition unit, a discrimination unit, and an instruction unit. The wireless communication unit communicates with the wireless tag. The wireless tag has a flag that stores either a first state or a second state, and when it receives an identification information read command specifying the flag state, it returns identification information only if the flag state matches the specified flag state. The acquisition unit receives an identification information read command from the wireless communication unit specifying the first state as the flag state, and acquires the identification information returned from the wireless tag whose flag state is the first state. Based on the acquired identification information, the discrimination unit determines whether the wireless tag that returned the identification information has already been detected. If the wireless tag that returned the identification information has already been detected, the instruction unit instructs the wireless communication unit to change the flag state of the wireless tag that returned the identification information to the second state. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing a wireless tag communication system according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram illustrating the overview of the wireless tag reading operation. [Figure 3] Figure 3 is a schematic diagram illustrating the operation within the slot during the wireless tag reading process. [Figure 4] Figure 4 is a schematic diagram illustrating the position detection method using tripoint surveying. [Figure 5] Figure 5 is a schematic diagram illustrating a position detection method based on phase change. [Figure 6] Figure 6 is a schematic diagram showing the main data structure stored in the detection target storage unit of the wireless tag communication device according to the first embodiment. [Figure 7] Figure 7 is a schematic diagram showing the main data structure stored in the read data storage unit of a wireless tag communication device. [Figure 8] Figure 8 is a sequence diagram showing an overview of the operation of the wireless tag communication device. [Figure 9]Figure 9 is a sequence diagram showing an overview of the operation of the wireless tag communication device. [Figure 10] Figure 10 is a sequence diagram showing an overview of the operation of the wireless tag communication device. [Figure 11] Figure 11 is a flowchart showing the main steps of the information processing performed by the processor of a wireless tag communication device. [Figure 12] Figure 12 is a schematic diagram showing a wireless tag communication system according to the second embodiment. [Figure 13] Figure 13 is a sequence diagram showing an overview of the operation of the wireless tag communication system. [Figure 14] Figure 14 is a sequence diagram showing an overview of the operation of the wireless tag communication system. [Figure 15] Figure 15 is a flowchart showing the main steps of the information processing performed by the processor of the wireless tag communication device according to the second embodiment. [Figure 16] Figure 16 is a flowchart showing the essential steps of information processing performed by the processor of a higher-level device in a wireless tag communication system. [Modes for carrying out the invention]

[0009] The following describes an embodiment of the payment device with reference to the drawings.

[0010] [First Embodiment] Figure 1 is a schematic diagram showing a wireless tag communication system according to the first embodiment. The wireless tag communication system according to the first embodiment includes a wireless tag communication device 1 and a host device UE. The wireless tag communication device 1 detects the position of a wireless tag TG to be detected from among a plurality of wireless tags TG. The host device UE is an information processing device that utilizes the position of the target wireless tag TG detected by the wireless tag communication device 1.

[0011] Before describing each device, to facilitate understanding of this embodiment, we will first explain the reading operation of the wireless tag TG and the method for detecting the position of the wireless tag.

[0012] There are various types of RFID, and currently, a system called Class-1 Generation-2 (commonly known as Gen2) established by EPCglobal is the mainstream. Figure 2 is a schematic diagram showing an overview of the reading operation of a wireless tag TG in this Gen2 system. Reading of a wireless tag TG is usually performed multiple times in most cases. In each reading, following the initialization of the wireless tag communication device 1, which is an RFID reader, and the wireless tag TG, a process called a round is repeated. Within a round, following the initialization of the round, a process called a slot is repeated. Each slot is divided into an inquiry to the wireless tag TG and reading. The number of slots in a round is determined according to the Q value set by the wireless tag communication device 1 when the round is initialized. Specifically, the number of slots is 2 Q . The wireless tag TG randomly determines which slot it will respond in. When a plurality of wireless tags TG exist within the communication area of the wireless tag communication device 1, the randomly determined response slot may coincide among two or more wireless tags TG. In such a case, reading cannot be performed. In this case, the reading of those wireless tags TG will be postponed to the next round.

[0013] The reading of the wireless tag TG in each slot will be described in further detail. In a Gen2 system, the wireless tag TG has two rewritable flag states (value A and value B) referred to as inventoried flags, which can be rewritten by the wireless tag communication apparatus 1. For example, the flag state can be set such that value A indicates an unread state and value B indicates a read state. When the wireless tag communication apparatus 1 performs reading from a wireless tag TG, it specifies the flag state of this flag. If the flag state of the wireless tag TG is different from the specified flag state, it does not return a response. For example, in reading where value A is specified as the flag state, a wireless tag TG whose flag state is value A responds, while a wireless tag TG whose flag state is value B does not respond. The flag state of the responded wireless tag TG is rewritten from value A to value B by the wireless tag communication apparatus 1. Therefore, the wireless tag TG that has already responded will not respond to a reading specifying value A as the flag state in subsequent rounds. After a certain period of time has elapsed since the wireless tag TG whose flag state has been rewritten to value B stops receiving radio waves, it resets its flag state from value B back to value A.

[0014] Figure 3 is a schematic diagram showing an outline of the operation within a slot during the reading operation of the wireless tag TG. Each wireless tag TG. sets a value randomly determined based on a Q value at the time of round initialization as the counter value of its internal counter. For example, if Q=3, the number of slots is 2 3 =8, and the counter value is any one of 8 values from 0 to 7. In the example of Figure 3, the wireless tag TG with identification information "a", i.e., tag ID = a, has a counter value of "0", the wireless tag TG with tag ID = b has a counter value of "3", the wireless tag TG with tag ID = c has a counter value of "2", and so on. Figure 3 shows three of the wireless tags TG that have entered the communication area of the wireless tag communication apparatus 1. In the communication area, there may be fewer wireless tags TG than this, or conversely, there may even be no wireless tags TG at all. In addition, there may be cases where multiple wireless tags TG in the communication area have duplicate counter values.

[0015] Each wireless tag TG whose flag state is set to A (indicating it is not yet read) during read initialization will, in response to a read command query from the wireless tag communication device 1 specifying A as the flag state, transmit its identification information to the wireless tag communication device 1 if its counter value is "0". More specifically, a wireless tag TG whose counter value has become "0" will transmit a 16-bit random or pseudo-random number as a response signal to the wireless tag communication device 1. Upon receiving any response signal, the wireless tag communication device 1 will transmit an acknowledgment (ACK) containing the (pseudo)random number of the received response signal. If the wireless tag TG receives an ACK containing the (pseudo)random number it transmitted as a response signal, it will transmit its identification information to the wireless tag communication device 1. The wireless tag communication device 1 will then read this identification information. Note that the transmission by the wireless tag TG means that it will reflect the carrier wave of the signal transmitted from the wireless tag communication device 1, carrying the necessary information, for example, through backscattering.

[0016] In the example in Figure 3, in slot #1, which is the first slot in the round, in response to the query from wireless tag communication device 1, of the three wireless tags TG with tag IDs "a", "b", and "c", the only one with a counter value of "0" is the wireless tag TG with tag ID=a. Therefore, the wireless tag TG with tag ID=a transmits the identification information "a" to the wireless tag communication device 1. The wireless tags TG with tag ID=b and tag ID=c do not return a response to the query because their counter values ​​are not "0".

[0017] In the next slot, slot #2, in response to an inquiry from wireless tag communication device 1, the wireless tag TG with tag ID=a, whose counter value is "0", changes its flag state from value A to value B, which indicates that it has been read. In other words, the inquiry from wireless tag communication device 1 includes an instruction to rewrite the flag specifying the wireless tag TG that has been read. By being rewritten to value B, the wireless tag TG with tag ID=a will neither update its counter value to "0" nor transmit identification information. In other words, it will no longer respond to inquiries from wireless tag communication device 1. Also, for wireless tag TGs with tag ID=b and tag ID=c, whose counter values ​​are not "0", the counter value is decremented by "1" in response to the inquiry. In this case, the counter values ​​of the wireless tag TGs with tag ID=b and tag ID=c will be "2" and "1", respectively, and will not be "0". Therefore, the wireless tag TGs with tag ID=b and tag ID=c will not return a response to the inquiry.

[0018] In the next slot, slot #3, the wireless tag TG with tag ID=a, whose flag state is B, does nothing in response to the query from wireless tag communication device 1. In contrast, the wireless tag TGs with tag ID=b and tag ID=c, whose counter values ​​are not "0", decrement their counter values ​​by "-1". In this case, the counter values ​​of the wireless tag TGs with tag ID=b and tag ID=c become "1" and "0", respectively. Therefore, the wireless tag TG with tag ID=c, whose counter value is "0", transmits the identification information "c" to the wireless tag communication device 1. The wireless tag TG with tag ID=b does not return a response to the query because its counter value is not "0".

[0019] In the next slot, slot #4, in response to an inquiry from the wireless tag communication device 1, the wireless tag TG with tag ID=c, whose counter value is "0", changes its flag state from value A to value B, indicating that it has been read. Also, the wireless tag TG with tag ID=b, whose counter value is not "0", subtracts "1" from its counter value. As a result, the counter value of the wireless tag TG with tag ID=b becomes "0", and the wireless tag TG with tag ID=c transmits the identification information "b" to the wireless tag communication device 1.

[0020] In the next slot, slot #5, in response to an inquiry from wireless tag communication device 1, the wireless tag TG with tag ID=b and counter value "0" will overwrite its flag state from value A to value B, indicating that it has been read.

[0021] If the counter value of wireless tag TG with tag ID=n (not shown in Figure 3) overlaps with the counter value of another wireless tag TG, for example, wireless tag TG with tag ID=c, then both counter values ​​will be "0". In this case, each wireless tag TG will send a separate (pseudo) random response signal. When multiple response signals are received in this way, the wireless tag communication device 1 does not send an ACK. Therefore, the wireless tag TGs with tag ID=c and tag ID=n do not transmit identification information. Then, in the query in the next slot, the counter values ​​of these wireless tag TGs are decremented by "-1", moving from "0" to the maximum value of the counter value. Therefore, since the counter value is not "0", these wireless tag TGs do not transmit identification information. When the counter values ​​of these multiple wireless tag TGs with conflicting counter values ​​are randomly determined at the start of the next round, there is a high probability that they will have different counter values, making it possible for each of them to be read in one of the slots.

[0022] Figure 4 is a schematic diagram illustrating a position detection method using tripoint surveying. When the wireless tag communication device 1 reads the wireless tag TG, it stores the device information at that time (antenna position and orientation) and the received signal strength (RSSI), which is the strength of the response signal from the wireless tag TG detected by the wireless tag communication device 1. Then, the wireless tag communication device 1 calculates the position of the wireless tag TG using tripoint surveying from the stored results from three or more locations, for example, position information A, B, C and received signal strengths RSSI#A, RSSI#B, RSSI#C.

[0023] Figure 5 is a schematic diagram illustrating a position detection method based on phase change. This position detection method is disclosed in Japanese Patent Application Publication No. 2017-75927. When the wireless tag communication device 1 reads the wireless tag TG, it detects the phase of the response signal for each device position (antenna position and orientation) and stores the position and phase. The wireless tag communication device 1 then defines the position at the time when the slope of the stored phase change reverses (time t0) as the position with the shortest distance to the wireless tag TG (first position), and calculates the position of the wireless tag TG from this first position and the phase and distance detection parameters of a second position different from the first position.

[0024] In either position detection method, multiple device locations can be achieved by scanning the orientation of the wireless tag communication device 1 while it remains in one location, or by performing a read with the wireless tag communication device 1 oriented in one direction at one location, then moving the wireless tag communication device 1 to another location and performing a read in the same manner to achieve multiple device locations. In the latter case, it is also possible to perform continuous readings while moving.

[0025] In any case, detecting the position of each wireless tag TG requires multiple reading operations. Therefore, as explained using Figure 3, if a wireless tag TG that has already been read is not read again in subsequent rounds, the acquisition of multiple RSSIs or phases necessary for position detection, which are performed in response to the reading, will also not be performed, making position detection impossible. To this end, when detecting the position of a wireless tag TG, the wireless tag communication device 1 keeps the flag state at value A instead of rewriting it to value B, even if the wireless tag TG has already been read, so that the wireless tag TG can be read again in the next round.

[0026] However, this approach means that wireless tags TG whose location has already been detected will continue to be read even though they no longer need to be read. This reading operation of already-detected wireless tags TG reduces the opportunities to read wireless tags TG whose location has not yet been detected.

[0027] Furthermore, in an environment where location-detectable wireless tags (TG) and non-location-detectable wireless tags (TG) are mixed, attempting to read non-location-detectable wireless tags (TG) reduces the opportunities to read location-detectable wireless tags (TG) that have not yet been located. This is a significant problem, especially in usage scenarios where a specific wireless tag (TG) is attached to an item from among multiple wireless tags (TG).

[0028] The wireless tag communication system and wireless tag communication device 1 according to this embodiment address these issues.

[0029] Returning to the explanation of Figure 1, the wireless tag communication device 1 comprises a processor 10, a memory 20, an input device 30, an output device 40, a sensor 50, a wireless communication unit 60, a communication interface 70, and a system transmission line 80. In Figure 1, "interface" is abbreviated as "I / F". The system transmission line 80 includes an address bus, a data bus, control signal lines, etc. The system transmission line 80 connects the processor 10 and the other units directly or via signal input / output circuits, and transmits data signals exchanged between them. The computer of the wireless tag communication device 1 is formed by connecting the processor 10 and the memory 20 via the system transmission line 80. The memory 20 comprises a detection target storage unit 21, a position correction valid flag storage unit 22, a read data storage unit 23, and a position calculation result storage unit 24. The wireless communication unit 60 comprises an antenna 61, a wireless tag communication circuit 62, an RSSI detection unit 63, and a phase detection unit 64.

[0030] The processor 10 corresponds to the central part of the computer described above. The processor 10 controls each part in order to realize various functions as a wireless tag communication device 1 according to the operating system or control program. The processor 10 is, for example, a CPU (Central Processing Unit). The processor 10 may also be, for example, an MPU (Micro Processing Unit), SoC (System on a Chip), DSP (Digital Signal Processor), GPU (Graphics Processing Unit), ASIC (Application Specific Integrated Circuit), PLD (Programmable Logic Device), or FPGA (Field-Programmable Gate Array). Alternatively, the processor 10 may be a combination of several of these.

[0031] Memory 20 corresponds to the main memory portion of the computer described above. Memory 20 includes a non-volatile memory area and a volatile memory area. Memory 20 stores the operating system or control program in the non-volatile memory area. Memory 20 also stores data necessary for the processor 10 to perform processing to control each part in the non-volatile or volatile memory area. Memory 20 includes, for example, a detection target storage unit 21 and a position correction valid flag storage unit 22 as such memory areas. Furthermore, Memory 20 uses a volatile memory area as a work area where data is rewritten as appropriate by the processor 10. Memory 20 includes, for example, a read data storage unit 23 and a position calculation result storage unit 24 as such memory areas. The non-volatile memory area is, for example, a rewritable storage device such as ROM (Read Only Memory) or EEPROM (Electric Erasable Programmable Read-Only Memory). The volatile memory area is, for example, RAM (Random Access Memory).

[0032] The detection target storage unit 21 stores data such as which wireless tag TG is the target for location detection, and whether the location of that wireless tag TG has already been detected. Figure 6 is a schematic diagram showing the main data structure stored in the detection target storage unit 21. Note that the data structure shown in Figure 6 is just one example. The format is not particularly limited as long as the information necessary for the processor 10 can be obtained. As shown in Figure 6, the detection target storage unit 21 stores, for example, the identification information of the wireless tag TG to be detected, which is set by the higher-level device UE. Furthermore, the detection target storage unit 21 stores detected information, which indicates whether or not it has been detected, linked to this identification information of the wireless tag TG to be detected. If the detected information is marked with an "X", it means it has not been detected, and if it is marked with a circle, it means it has been detected. The detection target storage unit 21 can store this detected information as a 1-bit flag, for example, where "0" is for an "X" and "1" is for a circle. Therefore, the detection target storage unit 21 is an example of a storage unit that stores detected information indicating whether or not the location of a wireless tag TG has been detected, linked to the identification information of each of the one or more wireless tags TG whose location is to be detected.

[0033] The position correction enable flag storage unit 22 stores a position correction enable flag indicating whether or not it is necessary to correct the position of the detected wireless tag TG. The position correction enable flag storage unit 22 can store this position correction enable flag as a 1-bit flag, for example, where "0" indicates no correction is needed and "1" indicates correction is needed. Thus, the position correction enable flag storage unit 22 is an example of a setting storage unit that stores a position correction enable flag indicating whether or not to correct the position of the wireless tag TG whose position has already been detected.

[0034] The read data storage unit 23 stores data read from the wireless tag TG, which is the target of location detection. Figure 7 is a schematic diagram showing the main data structure stored in this read data storage unit 23. Note that the data structure shown in Figure 7 is just one example. The format is not particularly limited as long as the information necessary for the processor 10 can be obtained. As shown in Figure 7, the read data storage unit 23 stores location detection data linked to the identification information read from the wireless tag TG, which is the target of location detection. The location detection data includes, for example, the acquisition time, RSSI, phase, and device position.

[0035] The acquisition time is the time when identification information is acquired from the wireless tag TG whose location is being detected. As mentioned above, the identification information is read in different slots. Therefore, the acquisition time can also be said to be the time when the slot is created. More specifically, it can be said to be the time when the identification information is read within the slot. The wireless tag communication device 1, although not shown in Figure 1, is equipped with a clock, and the processor 10 obtains the acquisition time of the identification information from this clock and stores the identification information acquired by the wireless communication unit 60 and this acquisition time in the read data storage unit 23. Furthermore, the acquisition time may be the current time or the elapsed time since reading began.

[0036] RSSI is the signal strength of the response signal carrying identification information from the wireless tag TG to be detected. This RSSI is detected by the RSSI detection unit 63 of the wireless communication unit 60. The phase is the phase of the response signal and is detected by the phase detection unit 64 of the wireless communication unit 60. These RSSI and phase are examples of the communication state with the wireless tag TG acquired by the wireless communication unit 60. The processor 10 can store the RSSI and phase at the time of acquiring the identification information in the read data storage unit 23, linked to the identification information. Although Figures 1 and 7 show an example of position detection using both RSSI and phase, position detection is possible using only one of them, so a configuration that detects and stores at least one of RSSI and phase is also acceptable. Therefore, the RSSI detection unit 63 or the phase detection unit 64 is an example of a state detection unit that detects the communication state with the wireless tag TG by the wireless communication unit 60.

[0037] The device position is position information representing the position of the wireless tag communication device 1 when a response signal is obtained from the wireless tag TG whose position is to be detected. The position information may include information on the position and orientation of the antenna 61 provided by the wireless communication unit 60. The processor 10 calculates the position and orientation of the antenna 61 based on the detection result of the sensor 50. In reality, the positional relationship between the antenna 61 and the wireless tag TG will change depending on the performance of the antenna 61, such as its directivity, but here, the processor 10 calculates the position and orientation assuming that the wireless tag TG is in the front direction of the antenna 61. The processor 10 stores the calculated device position in the read data storage unit 23, linked to the identification information. Note that it takes a certain amount of time for the processor 10 to calculate the position and orientation of the antenna 61 based on the detection result of the sensor 50. Therefore, the acquisition time is in slot units, but this device position is in round units. That is, one or more pieces of identification information acquired in multiple slots within one round will have the same device position.

[0038] The position calculation result storage unit 24 stores the position detection results detected for the wireless tag TG that is the target of position detection.

[0039] The input device 30 is an operation switch, operation button, etc., located on a housing (not shown) of the wireless tag communication device 1. Alternatively, the input device 30 may be an interface for connecting to an operation switch, operation button, etc., separate from the housing of the wireless tag communication device 1. The output device 40 is a display device such as a liquid crystal display or LED, an audio device such as a buzzer or speaker, etc., located on the housing of the wireless tag communication device 1. Alternatively, the output device 40 may be an interface for connecting to a display device or audio device separate from the housing of the wireless tag communication device 1. Furthermore, the input device 30 and the output device 40 may be configured as a touch panel with touch keys arranged on a display screen such as a liquid crystal display.

[0040] The processor 10 can use the input device 30 and output device 40 to allow the user to set the wireless tag TG to be detected and to set the position correction enabled flag. The processor 10 can also use the output device 40 to notify the user of the detected position of the wireless tag TG and to notify the user when the position detection operation is complete.

[0041] Sensor 50 is a variety of sensors used to calculate the device position stored in the read data storage unit 23 described above. For example, such sensors 50 may include an accelerometer or a camera. For example, the processor 10 can calculate the amount of movement of the wireless tag communication device 1 based on the acceleration detected by the accelerometer and determine its position based on this amount of movement. For example, the processor 10 can estimate its own position based on the amount of movement of an object captured in an image taken by the camera. Sensor 50 may also include positioning sensors such as a GPS (Global Positioning System) sensor.

[0042] The wireless communication unit 60 has a communication area CA with a certain range, as shown by the dashed line in Figure 1, and communicates wirelessly with a wireless tag TG, such as a UHF band RFID tag, that has entered this communication area CA. The wireless communication unit 60 is an example of a wireless communication unit that communicates with a wireless tag TG, and is equipped with a flag that stores either a flag state of a first state, such as value A, or a flag state of a second state, such as value B, and when it receives an identification information read command specifying the flag state, it returns identification information only if the flag state matches the specified flag state. The wireless tag TG includes wireless tag TGs that are subject to location detection and wireless tag TGs that are not subject to location detection and are not subject to detection. The wireless communication unit 60 has an antenna 61 and a wireless tag communication circuit 62 for communicating wirelessly with the wireless tag TG that has entered the communication area CA. Furthermore, the wireless communication unit 60 has an RSSI detection unit 63 that detects the RSSI, which is the strength of the response signal from the wireless tag TG, and a phase detection unit 64 that detects the phase of the response signal from the wireless tag TG.

[0043] The communication interface 70 communicates data with the connected upper-level device UE according to a pre-configured communication protocol. The connection with the upper-level device UE may be a wired connection or a wireless connection.

[0044] The higher-level device UE is an information processing device such as a server computer or a smartphone. The higher-level device UE can implement various functions such as receiving and storing the detected position of the target wireless tag TG from the wireless tag communication device 1, presenting the stored position, supplying the stored position to other devices, and generating new information by combining the stored positions. The higher-level device UE may also have control functions for the wireless tag communication device 1, such as providing various settings to the processor 10, such as setting the target wireless tag TG for position detection and setting the position correction enable flag, and instructing the wireless tag communication device 1 to start operation.

[0045] The operation of the wireless tag communication system and wireless tag communication device 1 according to this embodiment, with the configuration described below, will be explained. Note that the operation of setting the wireless tag TG to be detected and the position correction enabled flag is simply a matter of setting them according to user specifications, so that explanation will be omitted. Therefore, this section will explain the operation related to the detection of the position of the wireless tag TG to be detected.

[0046] Figures 8 to 10 are sequence diagrams illustrating the operation overview of the wireless tag communication device 1. Figure 8 shows reading round 1 (ROU1), Figure 9 shows the nth round of reading (ROUn), and Figure 10 shows the (n+1)th round of reading (ROUn+1). Figures 8 to 10 show an example where four wireless tags TG are within the communication area CA: non-target wireless tag a with identification information (tag ID) "a", target wireless tag b with identification information "b", target wireless tag c with identification information "c", and target wireless tag d with identification information "d". Note that Figures 8 to 10 show an ideal case where the counter values ​​do not collide; in reality, it is possible that the wireless tag communication device 1 may not receive identification information (tag ID) due to a collision of the counter values ​​of multiple wireless tags TG.

[0047] As shown in Figure 8, the wireless tag communication device 1 sends an inquiry to the wireless tag TG located within the communication area CA in slot 1 (SLT#1) of round 1 (ROU1) (step S1).

[0048] In response to the inquiry transmitted from the wireless tag communication device 1, one of the four wireless tags TG within the communication area CA, for example, target wireless tag b, transmits identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0049] The wireless tag communication device 1 receives identification information transmitted from the target wireless tag b. Upon receiving this identification information, the wireless tag communication device 1 acquires location detection data, namely the acquisition time, RSSI, and phase (step S3). The wireless tag communication device 1 stores this acquired location detection data in the read data storage unit 23, associating it with the received identification information. The device position within the location detection data is stored in the read data storage unit 23 once its calculation is complete.

[0050] The wireless tag communication device 1 determines whether the received identification information is a target for location detection data acquisition based on the contents stored in the detection target storage unit 21 (step S4). Specifically, if the received identification information is stored in the detection target storage unit 21, that is, it is a wireless tag TG that is a target for location detection, and the detection flag associated with the corresponding identification information is not detected, the wireless tag communication device 1 determines that the received identification information is a target for data acquisition.

[0051] If the received identification information is a target for data acquisition, the wireless tag communication device 1 instructs wireless tag b not to change the flag (step S5). Note that when wireless tag TG transmits identification information in response to an inquiry from wireless tag communication device 1, it rewrites the flag state when it receives the inquiry command for the next slot. Therefore, wireless tag communication device 1 instructs wireless tag b, which is a target for data acquisition, not to change the flag state.

[0052] Then, the wireless tag communication device 1 determines whether it is possible to calculate the location of the target wireless tag b having the received identification information from the data stored in the read data storage unit 23 (step S6). If it is not possible to calculate it, the wireless tag communication device 1 terminates processing for this slot.

[0053] In the next slot 2 (SLT#2), the wireless tag communication device 1 sends an inquiry to the wireless tag TG that is within the communication area CA (step S1).

[0054] In response to the inquiry transmitted from the wireless tag communication device 1, one of the four wireless tags TG within the communication area CA, for example, non-target wireless tag a, transmits identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0055] When the wireless tag communication device 1 receives identification information transmitted from the non-target wireless tag a, it acquires location detection data, namely the acquisition time, RSSI, and phase, at the time of receiving the identification information (step S3). Then, the wireless tag communication device 1 determines whether the identification information is a target for acquisition of location detection data based on the contents stored in the detection target storage unit 21 (step S4). The wireless tag communication device 1 determines that the non-target wireless tag a for which the received identification information is not a target for data acquisition. Therefore, in this case, the wireless tag communication device 1 does not instruct the non-target wireless tag a, which is not a target for data acquisition, to change the flag.

[0056] If the wireless tag communication device 1 determines that the received identification information is not the target of data acquisition, it terminates processing for this slot.

[0057] In the next slot 3 (SLT#3), the wireless tag communication device 1 sends an inquiry to the wireless tag TG that is within the communication area CA (step S1).

[0058] Non-target wireless tag a, which has not received the instruction "no flag change", changes its flag state from value A to value B upon receiving this inquiry (step S7). In this way, the wireless tag communication device 1 can change the flag state of non-target wireless tag a from value A to value B by not sending "no flag change" to non-target wireless tag a, which is not a target for location detection, instructing it not to change its flag state to value B.

[0059] Furthermore, among the remaining two target wireless tags TG, excluding target wireless tag b which has already transmitted identification information, target wireless tag d, for example, transmits identification information (tag ID) to the wireless tag communication device 1 in response to the inquiry (step S2).

[0060] The wireless tag communication device 1 receives identification information from the target wireless tag d, acquires location detection data (step S3), and determines whether or not the target wireless tag d is a target for acquiring location detection data (step S4). If it is a target for data acquisition, the wireless tag communication device 1 transmits a flag change instruction (step S5). Then, the wireless tag communication device 1 determines whether or not the location of the target wireless tag d can be calculated (step S6), and if it cannot be calculated, it terminates processing for this slot.

[0061] In the next slot 4 (SLT#3), the wireless tag communication device 1 sends a query to wireless tag TG, which is within the communication area CA (step S1). In this case, non-target wireless tag a, whose flag state has been changed from value A to value B, does not respond to this query. In other words, non-target wireless tag a ignores this query.

[0062] Furthermore, in response to the inquiry, for example, when the target wireless tag c transmits identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires location detection data (step S3), and determines whether or not the location detection data should be acquired based on the identification information (step S4). If it is a target for data acquisition, the wireless tag communication device 1 sends a flag change instruction (step S5). Then, the wireless tag communication device 1 determines whether or not the location of the target wireless tag c can be calculated (step S6), and if it cannot be calculated, it terminates the processing of this slot.

[0063] Similarly, each wireless tag TG and wireless tag communication device 1 will process the remaining slots of this Round 1 (ROU1), and subsequently the rounds.

[0064] As shown in Figure 9, the wireless tag communication device 1 sends a query to the wireless tag TG located within the communication area CA in slot 1 (SLT#1) of round n (ROUn) (step S1). The non-target wireless tag a, whose flag status is B, does not respond to this query.

[0065] In response to an inquiry sent from the wireless tag communication device 1, for example, when the target wireless tag b transmits identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires location detection data (step S3). The wireless tag communication device 1 also determines whether or not the received identification information is a target for acquiring location detection data (step S4), and if it is a target for data acquisition, it sends a flag change instruction (step S5). Then, the wireless tag communication device 1 determines whether or not the location of the target wireless tag b can be calculated (step S6).

[0066] If calculation is possible, the wireless tag communication device 1 calculates the position of the target wireless tag b based on the position detection data stored in the read data storage unit 23 (step S8). The wireless tag communication device 1 stores the calculated position of the target wireless tag b in the position calculation result storage unit 24.

[0067] Furthermore, the wireless tag communication device 1 sets the detection flag associated with the identification information of the target wireless tag b, which is the corresponding wireless tag TG in the detection target storage unit 21, to "detected" (step S9). Then, the wireless tag communication device 1 terminates processing for this slot.

[0068] In the next slot 2 (SLT#2), when the wireless tag communication device 1 sends a query (step S1), the non-target wireless tag a, whose flag status is value B, does not respond to this query.

[0069] Furthermore, in response to the inquiry, for example, when the target wireless tag c transmits identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires location detection data (step S3). The wireless tag communication device 1 also determines whether or not the received identification information is a target for acquiring location detection data (step S4), and if it is a target for data acquisition, it sends a flag change instruction (step S5). Then, the wireless tag communication device 1 determines whether or not the location of the target wireless tag c can be calculated (step S6), and if it cannot be calculated, it terminates the processing of this slot.

[0070] In the next slot 3 (SLT#3), when the wireless tag communication device 1 sends a query (step S1), the non-target wireless tag a, whose flag status is B, does not respond to this query.

[0071] Furthermore, in response to the inquiry, for example, when the target wireless tag d transmits identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires location detection data (step S3). The wireless tag communication device 1 also determines whether or not the received identification information is a target for acquiring location detection data (step S4), and if it is a target for data acquisition, it sends a flag change instruction (step S5). Then, the wireless tag communication device 1 determines whether or not the location of the target wireless tag d can be calculated (step S6), and if it cannot be calculated, it terminates the processing of this slot.

[0072] Similarly, each wireless tag TG and wireless tag communication device 1 will continue processing the remaining slots of this round n (ROUn), and subsequent rounds, until the positions of all wireless tags TG with their identification information stored in the detection target storage unit 21 are calculated.

[0073] As shown in Figure 10, the wireless tag communication device 1 sends a query to the wireless tag TG located within the communication area CA in slot X (SLT#X) of round n+1 (ROUn+1) (where X is a natural number) (step S1). The non-target wireless tag a, whose flag status is B, does not respond to this query.

[0074] In response to an inquiry sent from the wireless tag communication device 1, for example, when the target wireless tag b transmits identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires location detection data (step S3). The wireless tag communication device 1 also determines whether or not the target wireless tag is a target for acquiring location detection data based on the received identification information (step S4). In step S9 of slot 1 (SLT#1) of the previous round n (ROUn), the detection flag associated with the identification information of the target wireless tag b, which is the corresponding wireless tag TG in the detection target storage unit 21, is set to "detected". Therefore, the wireless tag communication device 1 determines that the target wireless tag b is not a target for acquiring location detection data. Thus, in this case, the wireless tag communication device 1 does not instruct the target wireless tag b, which is no longer a target for data acquisition, to change the flag.

[0075] If the wireless tag communication device 1 determines that the received identification information is not the target of data acquisition, it terminates processing for this slot.

[0076] In the next slot X+1 (SLT#X+1), the wireless tag communication device 1 sends an inquiry to the wireless tag TG that is within the communication area CA (step S1). The target wireless tag b, which has not received the "no flag change" instruction, receives this inquiry and changes its flag state from value A to value B (step S7). The other operations are as described in round n (ROUn), so their explanation is omitted here. In this way, the wireless tag communication device 1 can change the flag state from value A to value B by not sending "no flag change" to wireless tag b, which is no longer a target for location detection after its location has been detected.

[0077] Next, a specific example of the operation of the wireless tag communication device 1 will be described. Figure 11 is a flowchart showing the main steps of the information processing performed by the processor 10 of the wireless tag communication device 1. The processor 10 receives, for example, a start operation from the input device 30 or a start instruction from the host device UE via the communication interface 70, and executes this process based on the control program stored in the memory 20. Unless otherwise specified, the processing operation of the processor 10 is assumed to transition from ACTx (where x is a natural number) to ACT(x+1). Also, the procedure shown in Figure 11 is just one example. The procedure is not particularly limited as long as similar results can be obtained.

[0078] As ACT10, the processor 10 activates the wireless communication unit 60 and starts reading the wireless tag TG, which has the value A specified as its flag state.

[0079] In ACT11, the processor 10 determines whether or not a response has been received from any of the wireless tags TG, that is, whether or not a response has been received by the wireless communication unit 60. If a response is received, the processor 10 determines YES in ACT11 and proceeds to ACT12. If there is no response, the processor 10 determines NO in ACT11 and repeats ACT11 again. In this way, the processor 10 waits for a response from any of the wireless tags TG.

[0080] As ACT12, the processor 10 obtains the tag ID, or identification information, of the wireless tag TG that returned a response. Specifically, the processor 10 sends an ACK to the wireless tag TG that returned a response via the wireless communication unit 60, and in response receives the tag ID transmitted from the corresponding wireless tag TG. The processor 10 stores the tag ID received by the wireless communication unit 60 in the work area of ​​the memory 20. Thus, the processor 10 is an example of an acquisition unit that sends an identification information read command via the wireless communication unit 60 specifying a first state, such as a value A, as the flag state, and obtains the identification information returned from the wireless tag TG whose flag state is the first state.

[0081] As ACT13, the processor 10 acquires location detection data. Specifically, the processor 10 acquires the time (current time or elapsed time) and detects the RSSI and phase using the RSSI detection unit 63 and phase detection unit 64 of the wireless communication unit 60. The processor 10 also calculates the position and orientation of the wireless tag communication device 1, more specifically the antenna 61, based on the detection results of the sensor 50.

[0082] As ACT14, the processor 10 associates the acquired location detection data with the tag ID, i.e., identification information, stored in the work area and stores it in the read data storage unit 23.

[0083] In ACT15, the processor 10 determines whether the received tag ID is the tag ID of the wireless tag TG to be detected. Specifically, it checks whether a tag ID, i.e., identification information matching the tag ID stored in the work area is stored in the detection target storage unit 21. If matching identification information is stored, the processor 10 determines that the received tag ID is the tag ID of the wireless tag TG to be detected, determines YES in ACT15, and proceeds to ACT17. If the received tag ID is not the tag ID of the wireless tag TG to be detected, the processor 10 determines NO in ACT15 and proceeds to ACT16. In this way, the processor 10 determines whether the wireless tag TG that returned the identification information is the wireless tag to be detected based on whether the acquired identification information is stored in the detection target storage unit 21.

[0084] As ACT16, the processor 10 discards the location detection data stored in the read data storage unit 23. Specifically, it deletes the location detection data stored in the read data storage unit 23 in association with identification information. After that, the processor 10 proceeds to ACT11. In this way, the processor 10 does not send "no flag change" to the wireless tag TG that it has determined is not a wireless tag to be detected, thereby causing the flag state of the wireless tag TG to be rewritten from value A to value B, and discards the location detection data of the wireless tag TG that is not being used.

[0085] As ACT17, the processor 10 determines whether the location of the wireless tag TG, which it has determined to be a location detection target, has already been detected. Specifically, the processor 10 checks the detection flag associated with the corresponding identification information stored in the detection target storage unit 21 and determines whether it indicates that it has been detected. In other words, the processor 10 determines whether the wireless tag TG that returned the identification information is a location detection target wireless tag whose location has already been detected, based on the detected information stored in the detection target storage unit 21 associated with the acquired identification information. Thus, the processor 10 is an example of a determination unit that determines whether the wireless tag TG that returned the identification information has already been detected, based on the acquired identification information. If the location has been detected, the processor 10 determines YES in ACT17 and proceeds to ACT25. If the location has not been detected, the processor 10 determines NO in ACT17 and proceeds to ACT18.

[0086] As ACT18, the processor 10, via the wireless communication unit 60, transmits "no flag change" to the wireless tag TG to be located, instructing it not to rewrite the flag state.

[0087] In ACT19, the processor 10 determines whether the position of the wireless tag TG can be detected based on the position detection data stored in the read data storage unit 23. For example, when the position is calculated using tripoint measurement, the processor 10 can determine that the position can be calculated if the number of RSSIs stored in the read data storage unit 23, linked to the identification information of the wireless tag TG, is greater than or equal to a predetermined number. Also, when the position is calculated based on phase, the processor 10 can determine that the position can be calculated if the slope of the phase change stored in the read data storage unit 23, linked to the identification information of the wireless tag TG, has reversed. In either case, considering the possibility of false detection of detection data due to noise, etc., it is desirable not to immediately determine that the position can be calculated, but rather to determine that the position can be calculated after acquiring a certain amount of detection data in excess. If the position can be calculated, the processor 10 determines YES in ACT19 and proceeds to ACT20. If the position cannot be calculated, the processor 10 determines NO in ACT19 and proceeds to ACT11.

[0088] As ACT20, the processor 10 calculates the position of the wireless tag TG based on the position detection data stored in the read data storage unit 23. The processor 10 is an example of a position detection unit that detects the position of the wireless tag TG based on the detected communication status.

[0089] As ACT21, the processor 10 stores the calculated location in the location calculation result storage unit 24, linking it with the identification information of the wireless tag TG.

[0090] As ACT22, the processor 10 notifies the calculation result via the output device 40. However, ACT22 is not necessary if the orientation of the wireless tag communication device 1 is scanned while remaining in one place, or if reading is performed continuously while the wireless tag communication device 1 is moving.

[0091] As ACT23, the processor 10 stores a location detected flag. Specifically, it sets the detection flag, which is stored in the detection target storage unit 21 in association with the identification information of the wireless tag TG whose location has been detected, to "detected". Thus, when the processor 10 detects the location of the wireless tag TG, it sets the detected information stored in the detection target storage unit 21 in association with the identification information of the wireless tag TG to "location detected". This is an example of a storage control unit.

[0092] In ACT24, the processor 10 determines whether or not there are any target wireless tags whose location has not been detected. Specifically, the processor 10 determines whether or not there is any identification information in the detection target storage unit 21 where the detection flag is not detected. If there are target wireless tags whose location has not been detected, the processor 10 determines YES in ACT24 and proceeds to ACT11. At this point, if one round has ended, the next round begins. Furthermore, when performing a reading method in which the wireless tag communication device 1 is pointed in one direction at one location and then moved to another location to read in the same way, if there are target wireless tags whose location has not been detected, the output device 40 may notify the user of this fact and prompt them to move to another location. Also, if there are no target wireless tags whose location has not been detected, that is, if the location has been detected for all of the target wireless tags TG, the processor 10 determines NO in ACT24 and proceeds to ACT26.

[0093] As ACT25, the processor 10 determines whether or not position correction is enabled by checking the position correction enabled flag stored in the position correction enabled flag storage unit 22, which indicates whether or not the position of the detected wireless tag TG needs to be corrected.

[0094] If position correction is not effective, that is, if position correction is not performed, there is no need to acquire any further position detection data for the target wireless tag TG whose position has already been detected. Therefore, if position correction is not effective, the processor 10 determines NO in ACT25 and proceeds to ACT16. As a result, in ACT16, the processor 10 discards the position detection data stored in the read data storage unit 23 by the wireless communication unit 60. In this way, the processor 10 does not send "no flag change" to the wireless tag TG that has already been detected and for which position correction will not be performed, thereby causing the flag state of the wireless tag TG to be rewritten from value A to value B in response to the query in the next slot, and discards the position detection data of the wireless tag TG that will not be used. Therefore, the processor 10 is an example of an instruction unit that instructs the wireless communication unit to rewrite the flag state of the wireless tag that returned the identification information to the second state when the wireless tag that returned the identification information has already been detected.

[0095] In contrast, if position correction is enabled, that is, if position detection is performed with higher accuracy by further utilizing position detection data acquired afterward, the processor 10 will determine YES in ACT25 and proceed to ACT18. Thus, if the setting stored in the position correction enabled flag storage unit 22 is a setting to correct the position, the processor 10 will send "no flag change" to the wireless tag TG, even if its position has already been detected, and will make it a target for position detection again.

[0096] As ACT26, the processor 10 terminates the operation of the wireless communication unit 60 and stops reading the wireless tag TG, which has the value A specified as its flag state.

[0097] As ACT27, the processor 10 notifies the completion of the reading operation via the output device 40. At this time, the position calculation result of the detected wireless tag TG may also be notified. Alternatively, ACT27 may be omitted. Then, the processor 10 terminates the reading operation.

[0098] The processor 10 may also transmit the position calculation result and the completion notification of reading to the higher-level device UE via the communication interface 70.

[0099] As described above, the processor 10 of the wireless tag communication device 1 according to the first embodiment has a flag that stores either a flag state, for example, value A, or a flag state, for example, value B, and when it receives an identification information read command specifying the flag state, it sends an identification information read command specifying the first state as the flag state via the wireless communication unit 60 that communicates with the wireless tag TG, which sends back identification information only if the flag state matches the specified flag state, and obtains the identification information sent back from the wireless tag whose flag state is the first state.Then, based on the acquired identification information, the processor 10 determines whether the wireless tag TG that sent back the identification information has already been detected, and if the wireless tag TG that sent back the identification information has already been detected, the wireless communication unit 60 instructs the wireless tag TG that sent back the identification information to change the flag state to the second state, for example, value B. Thus, according to the wireless tag communication device 1 of the first embodiment, wireless tags TG whose location has been detected will not respond to identification information reading commands specifying a first state, such as a value A, in subsequent slots or rounds. Therefore, these wireless tags TG whose location has been detected will not take away the reading opportunity of wireless tags TG whose location has not been detected, meaning that the reading opportunity of wireless tags TG whose location has not been detected will increase compared to conventional reading methods. As a result, the wireless tag communication device 1 of the first embodiment makes it possible to shorten the time required to read all of the multiple wireless tags whose location is to be detected.

[0100] Furthermore, the wireless tag TG is designed to change its flag state from a first state, such as value A, to a second state, such as value B, after returning identification information. Therefore, in the wireless tag communication device 1 according to the first embodiment, the processor 10 sends a "no flag change" message to wireless tags that it has determined are not wireless tags TG that are the target of location detection, instructing them not to change the flag state to value B. For wireless tags TG that it has determined are the target of location detection, the processor 10 does not send a "no flag change" message, thereby changing the flag state to value B. Thus, according to the wireless tag communication device 1 of the first embodiment, it operates in accordance with the specifications of the wireless tag TG.

[0101] Furthermore, the wireless tag communication device 1 according to the first embodiment further includes a detection target storage unit 21, which is a storage unit that stores detected information indicating whether or not the location of one or more wireless tags TG to be detected has been detected, linked to the identification information of each wireless tag TG to be detected. The processor 10 determines, based on the detected information stored in the detection target storage unit 21 linked to the acquired identification information, whether or not the wireless tag TG that returned the identification information is a wireless tag to be detected whose location has already been detected, and instructs the wireless tag TG to change its flag state to a second state, for example, a value B. Therefore, according to the wireless tag communication device 1 of the first embodiment, it is possible to easily determine whether the wireless tag TG that has returned identification information is a wireless tag that has already had its location detected, and the wireless tag TG that has already had its location detected will not respond to identification information reading commands specifying the A value in subsequent slots or rounds.

[0102] Furthermore, in the wireless tag communication device 1 according to the first embodiment, the processor 10 further determines whether the wireless tag TG that returned the identification information is a wireless tag that is subject to location detection, based on whether the acquired identification information is stored in the detection target storage unit 21. If the wireless tag TG that returned the identification information is not a wireless tag that is subject to location detection, the processor 10 instructs the wireless tag TG that returned the identification information to change its flag state to a B value. Therefore, according to the wireless tag communication device 1 of the first embodiment, wireless tags TG that are not subject to location detection can be prevented from responding to identification information reading commands specifying the A value in subsequent slots and rounds. As a result, wireless tags TG that are not subject to location detection will not deprive wireless tags TG that are not subject to location detection of the opportunity to read them, and thus the time required to read all of the multiple wireless tags that are subject to location detection can be further shortened.

[0103] Furthermore, the wireless tag communication device 1 according to the first embodiment further includes an RSSI detection unit 63 and / or a phase detection unit 64 as a state detection unit that detects the RSSI and / or phase, which are the communication state with the wireless tag TG by the wireless communication unit 60. The processor 10 detects the position of the wireless tag TG based on the detected communication state, and when the position of the wireless tag TG is detected, the detected information stored in the detection target storage unit 21, which is linked to the identification information of the wireless tag TG, is marked as "position detected". Therefore, according to the wireless tag communication device 1 of the first embodiment, by updating the contents of the detection target storage unit 21 in response to the detection of the position of the wireless tag TG, it is possible to use the updated contents for identifying detected wireless tags TG in subsequent slots and rounds.

[0104] Furthermore, the wireless tag communication device 1 according to the first embodiment further includes a position correction enable flag storage unit 22, which is a setting storage unit that stores a position correction enable flag indicating whether or not to correct the position of the position of the position of the position of the position of the position of the wireless tag TG whose position has been detected. If the setting stored in the position correction enable flag storage unit 22 is a setting to correct the position, the processor 10 does not issue an instruction to rewrite the flag state of the position of the position of the wireless tag TG to a second state, such as a B value. Therefore, according to the wireless tag communication device 1 of the first embodiment, even if the position of the wireless tag TG is detected, it is possible to perform position detection with higher accuracy by further utilizing the position detection data acquired thereafter.

[0105] Furthermore, the wireless tag communication system according to the first embodiment comprises a wireless tag communication device 1 according to the first embodiment and a higher-level device UE connected to the wireless tag communication device 1 and controlling the wireless tag communication device 1, and the detection target storage unit 21 stores identification information of the wireless tag TG to be detected, which is set by the higher-level device UE. Therefore, according to the wireless tag communication system of the first embodiment, the wireless tag TG to be used for location detection can be easily set.

[0106] [Second Embodiment] Next, a second embodiment will be described. Note that for configurations and operations similar to those in the first embodiment, the same reference numerals as in the first embodiment will be used, and their descriptions will be omitted.

[0107] Figure 12 is a schematic diagram showing a wireless tag communication system according to the second embodiment. In this embodiment, the wireless tag communication device 1 and the host device UE cooperate to perform location detection of the wireless tag TG according to the second embodiment.

[0108] The wireless tag communication device 1 has a memory 20 containing a detection target storage unit 21 and a position correction valid flag storage unit 22. In this embodiment, the wireless tag communication device 1 does not have an input device 30 and an output device 40.

[0109] The host device UE comprises a processor 101, memory 102, input device 103, output device 104, communication interface 105, and system transmission line 106. In Figure 12, "interface" is abbreviated as "I / F". The system transmission line 106 includes an address bus, data bus, control signal lines, etc. The system transmission line 106 connects the processor 101 to the other parts directly or via signal input / output circuits, and transmits data signals exchanged between them. The computer of the host device UE is formed by connecting the processor 101 and the memory 102 via the system transmission line 106. The memory 102 comprises a read data storage unit 1021 and a position calculation result storage unit 1022. The read data storage unit 1021 and the position calculation result storage unit 1022 correspond to the read data storage unit 23 and the position calculation result storage unit 24 in the first embodiment. The input device 103 is an operation switch or operation button, and the output device 104 is a display device such as a liquid crystal display or LED, or an audio device such as a buzzer or speaker. The input device 103 and the output device 104 may also be configured as a touch panel with touch keys arranged on a display screen such as a liquid crystal display.

[0110] Figures 13 and 14 are sequence diagrams illustrating the operation overview of the wireless tag communication system. Figure 13 shows reading round 1 (ROU1), and Figure 14 shows the nth round of reading (ROUn). Figures 13 and 14 assume that target wireless tag a with identification information (tag ID) "a", target wireless tag b with identification information "b", etc., are within the communication area CA. Due to space limitations, non-target wireless tag TG is not shown, but such non-target wireless tag TG may also be within the communication area CA. Figures 13 and 14 show the ideal case where counter values ​​do not collide; in reality, it is possible that the wireless tag communication device 1 may not receive identification information (tag ID) due to a collision of counter values ​​between multiple wireless tags TG.

[0111] As shown in Figure 13, in Round 1 (ROU1) Slot 1 (SLT#1), the wireless tag communication device 1 sends an inquiry to the wireless tag TG that is within the communication area CA (step S1), and for example, the target wireless tag a sends identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0112] When the wireless tag communication device 1 receives identification information transmitted from the target wireless tag a, it acquires location detection data, namely the acquisition time, RSSI, and phase (step S3). Then, based on the contents stored in the detection target storage unit 21, the wireless tag communication device 1 determines whether the received identification information is a target for acquisition of location detection data (step S4). If it is a target for data acquisition, it instructs the target wireless tag a to not change the flag (step S5).

[0113] The wireless tag communication device 1 transmits the identification information of the received target wireless tag a and the acquired location detection data to the host device UE (step S11). The host device UE receives this data, reads the location detection data in association with the identification information, and stores it in the data storage unit 1021. Alternatively, the wireless tag communication device 1 may transmit the detection result of the sensor 50 acquired in step S3 to the host device UE without calculating the device position, and the host device UE may calculate the device position.

[0114] The host device UE then determines whether it is possible to calculate the location of the target wireless tag a having the received identification information from the data stored in the read data storage unit 1021 (step S12). This operation in step S12 corresponds to step S6 in the first embodiment. If it is not possible to calculate the location, the host device UE terminates processing for this slot.

[0115] Similarly, for the remaining slots from the next slot 2 (SLT#2) onward, and for each slot in subsequent rounds, the wireless tag communication device 1 acquires identification information and location detection data for the wireless tag TG to be detected, and the higher-level device UE stores this information.

[0116] As shown in Figure 14, the wireless tag communication device 1 sends an inquiry to the wireless tag TG located within the communication area CA in slot 1 (SLT#1) of round n (ROUn) (step S1), and for example, the target wireless tag a sends identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0117] When the wireless tag communication device 1 receives identification information transmitted from the target wireless tag a, it acquires location detection data (step S3), and also determines whether the received identification information is a target for acquisition of location detection data based on the contents stored in the detection target storage unit 21 (step S4). If it is a target for data acquisition, the wireless tag communication device 1 instructs the target wireless tag a to not change the flag (step S5). Then, the wireless tag communication device 1 transmits the received identification information of the target wireless tag a and the acquired location detection data to the host device UE (step S11).

[0118] The higher-level device UE stores the received location detection data in association with the received identification information in the read data storage unit 1021, and determines whether or not the location of the target wireless tag a can be calculated from the data stored in the read data storage unit 1021 (step S12).

[0119] If possible, the host device UE calculates the position of the target wireless tag a based on the position detection data stored in the read data storage unit 1021 (step S13). The host device UE stores the calculated position of the target wireless tag a in the position calculation result storage unit 1022. This operation in step S13 corresponds to step S8 in the first embodiment.

[0120] Once the location has been calculated, the higher-level device UE sends a detection notification to the wireless tag communication device 1 (step S14).

[0121] Upon receiving this detection notification, the wireless tag communication device 1 sets the detection flag associated with the identification information of the target wireless tag a, which is the corresponding wireless tag TG in the detection target storage unit 21, to "detected" (step S9). Then, the wireless tag communication device 1 terminates processing for this slot. As a result, when the identification information of this target wireless tag a is received in any slot of the next round, round n+1 (ROUn+1), which is not shown, the wireless tag communication device 1 will determine in step S4 whether or not it is a target for acquisition of location detection data that it is not a target for acquisition because the detection flag is set to "detected". Therefore, no flag change is transmitted to this target wireless tag a, and upon receiving the query in the next slot, the flag state of the target wireless tag a is rewritten from value A to value B.

[0122] In the next slot 2 (SLT#2), the wireless tag communication device 1 sends an inquiry (step S1). In response to this inquiry, if any wireless tag TG (not shown), for example, an untargeted wireless tag TG, sends identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires location detection data (step S3). The wireless tag communication device 1 also determines whether or not the received identification information is a target for acquiring location detection data (step S4). If it is not a target for data acquisition, the wireless tag communication device 1 does not instruct this untargeted wireless tag to change the flag. Then, the wireless tag communication device 1 terminates processing for this slot.

[0123] In the next slot 3 (SLT#3), the wireless tag communication device 1 sends an inquiry (step S1). In response to this inquiry, for example, if the target wireless tag b sends identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires location detection data (step S3). The wireless tag communication device 1 also determines whether the target wireless tag b is a target for acquisition of location detection data based on the received identification information (step S3). If it is a target for data acquisition, the wireless tag communication device 1 instructs the target wireless tag b to not change the flag (step S5). Then, the wireless tag communication device 1 transmits the received identification information of the target wireless tag b and the acquired location detection data to the higher-level device UE (step S11).

[0124] The higher-level device UE stores the received location detection data in association with the received identification information in the read data storage unit 1021, and determines whether or not the location of the target wireless tag b can be calculated from the data stored in the read data storage unit 1021 (step S12). If the location cannot be calculated, the processing for this slot is terminated.

[0125] Similarly, the processing of the remaining slots, and then each slot in subsequent rounds, is carried out until the positions of all wireless tags TG of the identification information stored in the detection target storage unit 21 are calculated.

[0126] Next, specific examples of the operation of the wireless tag communication device 1 and the host device UE will be described. Figure 15 is a flowchart showing the main steps of the information processing performed by the processor 10 of the wireless tag communication device 1. Upon power-on, the processor 10 of the wireless tag communication device 1 executes this process based on the control program stored in memory 20. Figure 16 is a flowchart showing the main steps of the information processing performed by the processor 101 of the host device UE. The processor 101 of the host device UE executes this process based on the control program in response to a start operation by the input device 103, which starts the control program stored in memory 102 as an application program, for example. Note that the procedures shown in Figures 15 and 16 are examples, and the procedure is not particularly limited as long as similar results can be obtained.

[0127] As shown in Figure 15, the processor 10 of the wireless tag communication device 1 determines, as ACT31, whether or not it has received settings from the host device UE via the communication interface 70. If it has received settings from the host device UE, the processor 10 determines YES in ACT31 and proceeds to ACT33. If it has not received settings from the host device UE, the processor 10 determines NO in ACT31 and proceeds to ACT32.

[0128] In ACT32, the processor 10 determines via the communication interface 70 whether it has received a start command from the higher-level device UE to begin position detection of the wireless tag TG to be located. If it has received a start command from the higher-level device UE, the processor 10 determines YES in ACT32 and proceeds to ACT10. If it has not received a start command from the higher-level device UE, the processor 10 determines NO in ACT32 and proceeds to ACT31.

[0129] As shown in Figure 16, the processor 101 of the upper-level device UE determines, as ACT101, whether or not there was a setting instruction from the user via the input device 103. If there is a setting instruction, the processor 101 determines YES in ACT101 and proceeds to ACT103. If there is no setting instruction, the processor 101 determines NO in ACT101 and proceeds to ACT102.

[0130] As ACT102, the processor 101 determines whether or not there has been an instruction from the user to start location detection of the wireless tag TG to be detected by operation of the input device 103. If there has been an instruction to start location detection, the processor 101 determines YES in ACT102 and proceeds to ACT105. If there has been no instruction to start location detection, the processor 101 determines NO in ACT102 and proceeds to ACT101.

[0131] As ACT103, the processor 101 accepts settings from the user via the input device 103. The settings include specifying the wireless tag TG to be used for position detection and enabling or disabling position correction. Specifying the wireless tag TG to be used for position detection can be done by directly inputting identification information, or by displaying a list of available wireless tag TGs on the display device 104 (output device) and selecting from there, or in any other form.

[0132] As ACT104, processor 101 transmits the received settings to wireless tag communication device 1 via communication interface 105. After that, processor 101 proceeds to ACT101.

[0133] As shown in Figure 15, the processor 10 of the wireless tag communication device 1 stores the settings transmitted from the host device UE as ACT33 in the detection target storage unit 21 and the position correction enabled flag storage unit 22. After that, the processor 10 proceeds to ACT31.

[0134] As shown in Figure 16, the processor 101 of the higher-level device UE transmits a start command as ACT 105 to the wireless tag communication device 1 via the communication interface 105.

[0135] As ACT106, the processor 101 determines whether or not it has received location detection data transmitted from the wireless tag communication device 1 via the communication interface 105. If location detection data is received, the processor 101 determines YES in ACT106 and proceeds to ACT107. If location detection data is not received, the processor 101 determines NO in ACT106 and repeats ACT106. In this way, the processor 101 waits for the reception of location detection data.

[0136] As shown in Figure 15, the processor 10 of the wireless tag communication device 1, as ACT10, starts reading the wireless tag TG, which has an A value specified as its flag state, as described in the first embodiment.

[0137] As ACT11, the processor 10 determines whether or not a response has been received from any of the wireless tags TG, as described in the first embodiment. If a response is received, the processor 10 determines YES in ACT11 and proceeds to ACT12. If there is no response, the processor 10 determines NO in ACT11 and proceeds to ACT35 in this embodiment.

[0138] As ACT12, the processor 10 obtains the tag ID of the wireless tag TG that returned a response, as described in the first embodiment, and stores the tag ID, i.e., the identification information received by the wireless communication unit 60, in the work area of ​​the memory 20.

[0139] As ACT13, the processor 10 acquires position detection data as described in the first embodiment. Specifically, the processor 10 acquires the time and detects the RSSI and phase using the RSSI detection unit 63 and phase detection unit 64 of the wireless communication unit 60. The processor 10 also calculates the position and orientation of the wireless tag communication device 1, more specifically the antenna 61, based on the detection results of the sensor 50. Alternatively, the processor 10 does not need to calculate the position and orientation of the antenna 61. After that, in this embodiment, the processor 10 proceeds to ACT15.

[0140] As ACT15, the processor 10 determines whether the received tag ID is the tag ID of the wireless tag TG to be detected, as described in the first embodiment. If the received tag ID is the tag ID of the wireless tag TG to be detected, the processor 10 determines YES in ACT15 and proceeds to ACT16. If the received tag ID is not the tag ID of the wireless tag TG to be detected, the processor 10 determines NO in ACT15 and proceeds to ACT16.

[0141] As ACT16, the processor 10 discards the position detection data stored in the read data storage unit 23. After that, the processor 10 proceeds to ACT11.

[0142] As ACT17, the processor 10 determines whether or not the location of the wireless tag TG, which has been determined to be a location detection target, has been detected, as described in the first embodiment. If the location has been detected, the processor 10 determines YES in ACT17 and proceeds to ACT25. If the location has not been detected, the processor 10 determines NO in ACT17 and proceeds to ACT18.

[0143] As ACT18, the processor 10, via the wireless communication unit 60, transmits "no flag change" to the wireless tag TG to be located, instructing it not to rewrite the flag state. Subsequently, in this embodiment, the processor 10 proceeds to ACT34.

[0144] As ACT34, the processor 10 transmits the acquired position detection data, along with the tag ID (i.e., identification information) stored in the work area, to the higher-level device UE via the communication interface 70. The position detection data includes the position and orientation of the antenna 61 if calculated in ACT13, or the detection result of the sensor 50 if not calculated. After that, the processor 10 proceeds to ACT11. Thus, the communication interface 70 is an example of an interface unit that transmits the RSSI and / or phase, which are the communication state detected by the RSSI detection unit 63 and / or phase detection unit 64, which are state detection units that detect the communication state between the wireless communication unit 60 and the wireless tag TG, to the higher-level device UE, which is a detection device that detects the position of the wireless tag TG based on this communication state.

[0145] As shown in Figure 16, the processor 101 of the upper-level device UE, as ACT107, associates the received location detection data with the received tag ID, i.e., identification information, and stores it in the read data storage unit 1021. The operation of ACT107 corresponds to ACT17 in the first embodiment.

[0146] As ACT108, the processor 101 determines whether or not the position of the wireless tag TG can be detected based on the position detection data stored in the read data storage unit 1021. If position calculation is possible, the processor 101 determines YES in ACT108 and proceeds to ACT109. If position calculation is not possible, the processor 101 determines NO in ACT108 and proceeds to ACT106. This operation of ACT108 corresponds to ACT18 in the first embodiment.

[0147] As ACT109, the processor 101 calculates the position of the wireless tag TG based on the position detection data stored in the read data storage unit 1021. This operation of ACT109 corresponds to ACT19 in the first embodiment.

[0148] As ACT110, the processor 101 stores the calculated position in the position calculation result storage unit 1022, linking it with the identification information of the wireless tag TG. The operation of ACT110 corresponds to ACT20 in the first embodiment.

[0149] As ACT111, the processor 101 notifies the calculation result via the output device 104. The operation of ACT111 corresponds to ACT21 in the first embodiment.

[0150] As ACT112, the processor 101 transmits a location detection notification to the wireless tag communication device 1 via the communication interface 105. This location detection notification includes the tag ID, which is the identification information of the wireless tag TG whose location was detected.

[0151] As ACT113, the processor 101 determines whether or not it has received a termination notification from the wireless tag communication device 1 via the communication interface 105. If a termination notification is received, the processor 101 determines YES in ACT113 and proceeds to ACT114. If a termination notification is not received, the processor 101 determines NO in ACT113 and proceeds to ACT106.

[0152] As shown in Figure 15, the processor 10 of the wireless tag communication device 1 determines, as ACT35, whether or not it has received a location detection notification from the host device UE via the communication interface 70. If a location detection notification is received, the processor 10 determines YES in ACT35 and proceeds to ACT23. If a location detection notification is not received, the processor 10 determines NO in ACT35 and proceeds to ACT24. Thus, the communication interface 70 is an example of an interface unit that receives a location detection notification from the host device UE indicating that the wireless tag TG has been located.

[0153] As ACT23, the processor 10 stores a location detected flag. Specifically, it sets the detection flag, which is stored in the detection target storage unit 21 in association with the identification information of the wireless tag TG whose location was detected, as included in the location detected notification, to "detected". Thus, the processor 10 is an example of a storage control unit that sets the detected information stored in the detection target storage unit 21 in association with the identification information of the wireless tag TG to "location detected". After that, in this embodiment, the processor 10 proceeds to ACT11.

[0154] As ACT24, the processor 10 determines whether or not there are any target wireless tags whose location has not been detected, as described in the first embodiment. If there are target wireless tags whose location has not been detected, the processor 10 determines YES in ACT24 and proceeds to ACT11. At this point, if one round has ended, the next round begins. If there are no target wireless tags whose location has not been detected, the processor 10 determines NO in ACT24 and proceeds to ACT26.

[0155] As ACT25, the processor 10 determines whether or not position correction is effective, as described in the first embodiment. If position correction is not effective, the processor 10 determines NO in ACT25 and proceeds to ACT16. If position correction is effective, the processor 10 determines YES in ACT25 and proceeds to ACT18.

[0156] As ACT26, the processor 10 terminates the operation of the wireless communication unit 60, as described in the first embodiment, and stops reading the wireless tag TG, which has an A value specified as its flag state. After that, in this embodiment, the processor 10 proceeds to ACT36.

[0157] As ACT36, the processor 10 sends a termination notification to the higher-level device UE via the communication interface 70. After that, the processor 10 proceeds to ACT31.

[0158] As shown in Figure 16, the processor 101 of the higher-level device UE notifies the completion of the read operation via the output device 104 as ACT 114.

[0159] As ACT115, the processor 101 determines whether or not there is a termination instruction from the user via the input device 103. If there is no termination instruction, the processor 101 determines NO in ACT115 and proceeds to ACT101. If there is a termination instruction, the processor 101 determines YES in ACT115 and terminates the processing of the control program as an application program.

[0160] Furthermore, the user can terminate the operation of the processor 101 of the wireless tag communication device 1, as shown in Figure 15, by turning off the power to the wireless tag communication device 1.

[0161] As described above, according to the wireless tag communication device 1 of the second embodiment, the RSSI detection unit 63 and / or phase detection unit 64, which are state detection units that detect the communication state with the wireless tag TG by the wireless communication unit 60, detect the RSSI and / or phase, which are the communication state, and transmit them to the host device UE, which is a detection device that detects the position of the wireless tag TG based on this communication state. When the communication interface 70, which is an interface unit that receives a position detection notification from the host device UE indicating that the position of the wireless tag TG has been detected, receives the position detection notification, the processor 10 sets the detected information stored in the detection target storage unit 21, which is linked to the identification information of the wireless tag TG, to "position detected". Therefore, according to the wireless tag communication device 1 in the second embodiment, the contents of the detection target storage unit 21 can be updated in response to the detection of the position of the wireless tag TG by the higher-level device UE, and this can be used to identify detected wireless tags TG in subsequent slots and rounds.

[0162] Furthermore, according to the wireless tag communication system of the second embodiment, the part in which the position of the wireless tag TG is detected based on the RSSI and / or phase, which are the communication status with the wireless tag TG, is performed in a higher-level device UE connected to the wireless tag communication device 1. Even in this manner, as in the first embodiment, wireless tags TG whose location has been detected will not respond to identification information reading commands specifying a first state, such as a value A, in subsequent slots or rounds. Therefore, these detected wireless tags TG will not take away the reading opportunity of wireless tags TG whose location has not been detected, meaning that the reading opportunity of wireless tags TG whose location has not been detected will increase compared to the conventional reading method. Thus, according to the wireless tag communication device 1 of the first embodiment, it is possible to shorten the time required to read all of the multiple wireless tags whose location is to be detected. Furthermore, by having the location detection process, which requires particularly high processing power, executed on a higher-level device UE, such as a server computer or an information processing device like a smartphone, it is possible to use an inexpensive processor 10 with relatively low processing power for the wireless tag communication device 1, thereby reducing the cost of the wireless tag communication device 1.

[0163] The embodiments of the wireless tag communication system and wireless tag communication device have been described above, but the embodiments are not limited thereto. For example, in the flowchart of Figure 11, ACT21 and ACT23 can be performed in reverse order or in parallel. In this way, the order of processes can be changed or multiple processes can be performed in parallel, as long as there is no conflict with preceding or succeeding processes.

[0164] In the above embodiment, the control program executed by the processor 10 of the wireless tag communication device 1 or the processor 101 of the host device UE may be provided by recording it on a computer-readable recording medium such as a CD-ROM. Alternatively, the control program may be stored on a computer connected to a network such as the Internet and provided by allowing download via the network.

[0165] In addition, several embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be carried out in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope of the invention, as well as within the scope of the invention and its equivalents as described in the claims.

[0166] [Note] From the above-mentioned specific embodiments, the following configurations of inventions can be extracted. [1] A wireless communication unit that communicates with a wireless tag, comprising a flag that stores either a first state or a second state, and which, upon receiving an identification information read command specifying the flag state, returns identification information only if the flag state matches the specified flag state, The wireless communication unit transmits the identification information read command specifying the first state as the flag state, and the acquisition unit acquires the identification information returned from the wireless tag whose flag state is the first state. A determination unit determines whether the wireless tag that returned the identification information has already had its location detected, based on the acquired identification information. If the wireless tag that has returned the identification information has already been located, the wireless communication unit instructs the wireless tag that has returned the identification information to change the flag state to the second state, A wireless tag communication device equipped with the following features. [2] The system further comprises a storage unit that stores detected information, associated with the identification information of one or more wireless tags to be detected, indicating whether or not the location of the wireless tag has been detected. The discrimination unit determines, based on the detected information stored in the storage unit in association with the identification information acquired by the acquisition unit, whether the wireless tag that returned the identification information is a wireless tag whose location has already been detected. The wireless tag communication device according to [1], wherein the instruction unit instructs the wireless tag that the discrimination unit has determined to be a wireless tag whose position has already been detected to change the flag state to the second state. [3] The discrimination unit further determines whether the wireless tag that returned the identification information is the wireless tag targeted for location detection, based on whether the identification information acquired by the acquisition unit is stored in the storage unit. The wireless tag communication device according to [2], further comprising the instruction unit, if the wireless tag that returned the identification information is not the wireless tag targeted for location detection, instructing the wireless tag that returned the identification information to rewrite the flag state to the second state. [4] A state detection unit for detecting the communication status between the wireless communication unit and the wireless tag, A position detection unit that detects the position of the wireless tag based on the communication state, When the position detection unit detects the position of the wireless tag, the storage control unit sets the detected information stored in the storage unit in association with the identification information of the wireless tag to indicate that the position has been detected. A wireless tag communication device according to [2] or [3], further comprising the above. [5] A state detection unit for detecting the communication status between the wireless communication unit and the wireless tag, An interface unit that transmits the communication status to a detection device that detects the location of the wireless tag based on the communication status, and receives a detection notification from the detection device indicating that the wireless tag's location has been detected, When the interface unit receives the detection notification, the storage control unit sets the detected information stored in the storage unit in association with the identification information of the wireless tag to indicate that the location has been detected. A wireless tag communication device according to [2] or [3], further comprising the above. [6] The wireless tag, after returning the identification information, rewrites the flag state from the first state to the second state, The instruction unit transmits "no flag change" to a wireless tag that the discrimination unit has determined is not a wireless tag to be detected, instructing it not to change the flag state to the second state, and does not transmit "no flag change" to a wireless tag that the discrimination unit has determined is a wireless tag to be detected, thereby changing the flag state to the second state, as described in any of [1] to [5]. [7] The device further comprises a setting storage unit that stores whether or not to correct the position of the wireless tag whose position has been detected, The wireless tag communication device according to any one of [1] to [6], wherein the instruction unit does not issue an instruction to rewrite the flag state of the wireless tag whose position has been detected to the second state if the setting stored in the setting storage unit is a setting for correcting the position. [8] A wireless tag communication system comprising a wireless tag communication device that communicates with a wireless tag, and a higher-level device connected to the wireless tag communication device and controlling the wireless tag communication device, A wireless communication unit that communicates with the wireless tag, comprising a flag that stores either a first state or a second state, and which, upon receiving an identification information read command specifying the flag state, returns identification information only if the flag state matches the specified flag state, The wireless communication unit transmits the identification information read command specifying the first state as the flag state, and the acquisition unit acquires the identification information returned from the wireless tag whose flag state is the first state. A state detection unit for detecting the communication status between the wireless tag and the wireless tag by the wireless communication unit, A position detection unit that detects the position of the wireless tag based on the communication state, A storage unit that stores detected information indicating whether or not the location of one or more wireless tags has been detected, linked to the identification information of each wireless tag to be detected. A determination unit determines whether the wireless tag that returned the identification information has been detected, based on the detected information stored in the storage unit in association with the identification information acquired by the acquisition unit, If the wireless tag that has returned the identification information has already been located, the wireless communication unit instructs the wireless tag that has returned the identification information to change the flag state to the second state, A wireless tag communication system equipped with the following features. [9] The wireless tag communication device comprises the wireless communication unit, the acquisition unit, the state detection unit, the position detection unit, the storage unit, the discrimination unit and the instruction unit, The wireless tag communication system according to [7], wherein the storage unit stores the identification information of the wireless tag to be detected, which has been set by the higher-level device.

[10] The wireless tag communication device comprises the wireless communication unit, the acquisition unit, the state detection unit, the storage unit, the discrimination unit and the instruction unit, The above-mentioned higher-level device is the wireless tag communication system according to [7], comprising the position detection unit.

[11] A wireless communication unit that communicates with a wireless tag, a processor, and a memory, and a computer that controls a wireless tag communication device that communicates with the wireless tag, the wireless communication unit having a flag that stores a flag state of either a first state or a second state, and which, when it receives an identification information read command specifying the flag state, returns identification information only if the flag state matches the specified flag state, The wireless communication unit transmits the identification information read command specifying the first state as the flag state, and the acquisition unit acquires the identification information returned from the wireless tag whose flag state is the first state and stores it in the memory. A determination unit determines whether the wireless tag that returned the identification information has already had its location detected, based on the identification information stored in the memory. If the wireless tag that has returned the identification information has already been located, the wireless communication unit instructs the wireless tag that has returned the identification information to change the flag state to the second state. A program designed to function as such.

[12] Hardware processor and, Memory and A wireless communication unit that communicates with a wireless tag, comprising a flag that stores either a first state or a second state, and which, upon receiving an identification information read command specifying the flag state, returns identification information only if the flag state matches the specified flag state, The hardware processor comprises, The wireless communication unit transmits the identification information read command specifying the first state as the flag state, obtains the identification information returned from the wireless tag whose flag state is the first state, and stores it in the memory. Based on the identification information stored in the memory, it is determined whether the wireless tag that returned the identification information has already had its location detected. If the wireless tag that returned the identification information has already been located, the wireless communication unit instructs the wireless tag that returned the identification information to change the flag state to the second state. A wireless tag communication device configured as follows. [Explanation of Symbols]

[0167] 1... Wireless tag communication device, 10,101... Processor, 20,102... Memory, 21... Detected target storage unit, 22... Position correction enabled flag storage unit, 23,1021... Read data storage unit, 24,1022... Position calculation result storage unit, 30,103... Input device, 40,104... Output device, 50... Sensor, 60... Wireless communication unit, 61... Antenna, 62... Wireless tag communication circuit, 63... RSSI detection unit, 64... Phase detection unit, 70,105... Communication interface, 80,106... System transmission path, CA... Communication area, TG... Wireless tag, UE... Host device.

Claims

1. A wireless communication unit that communicates with a wireless tag, comprising a flag that stores either a first state or a second state, and which, upon receiving an identification information read command specifying the flag state, returns identification information only if the flag state matches the specified flag state, The wireless communication unit transmits the identification information read command specifying the first state as the flag state, and the acquisition unit acquires the identification information returned from the wireless tag whose flag state is the first state. A determination unit determines whether the wireless tag that returned the identification information has already had its location detected, based on the acquired identification information. If the wireless tag that has returned the identification information has already been located, the wireless communication unit instructs the wireless tag that has returned the identification information to change the flag state to the second state, A wireless tag communication device equipped with the following features.

2. The system further includes a storage unit that stores detected information, linked to the identification information of one or more wireless tags to be detected, indicating whether or not the location of the wireless tag has already been detected. The discrimination unit determines, based on the detected information stored in the storage unit in association with the identification information acquired by the acquisition unit, whether the wireless tag that returned the identification information is a wireless tag whose location has already been detected. The wireless tag communication device according to claim 1, wherein the instruction unit instructs the wireless tag that the discrimination unit has determined to be a wireless tag whose position has already been detected to change the flag state to the second state.

3. The discrimination unit further determines whether the wireless tag that returned the identification information is the wireless tag targeted for location detection, based on whether the identification information acquired by the acquisition unit is stored in the storage unit. The wireless tag communication device according to claim 2, further comprising the instruction unit, which, if the wireless tag that returned the identification information is not the wireless tag targeted for location detection, instructs the wireless tag that returned the identification information to change the flag state to the second state.

4. A state detection unit for detecting the communication status between the wireless tag and the wireless tag by the wireless communication unit, A position detection unit that detects the position of the wireless tag based on the communication state, When the position detection unit detects the position of the wireless tag, the storage control unit sets the detected information stored in the storage unit in association with the identification information of the wireless tag to indicate that the position has been detected. The wireless tag communication device according to claim 2 or 3, further comprising the above.

5. A state detection unit for detecting the communication status between the wireless tag and the wireless tag by the wireless communication unit, An interface unit that transmits the communication status to a detection device that detects the location of the wireless tag based on the communication status, and receives a detection notification from the detection device indicating that the wireless tag's location has been detected, When the interface unit receives the detection notification, the storage control unit sets the detected information stored in the storage unit in association with the identification information of the wireless tag to indicate that the location has been detected. The wireless tag communication device according to claim 2 or 3, further comprising the above.

6. A wireless tag communication system comprising a wireless tag communication device that communicates with a wireless tag, and a higher-level device connected to the wireless tag communication device and controlling the wireless tag communication device, A wireless communication unit that communicates with the wireless tag, comprising a flag that stores either a first state or a second state, and which, upon receiving an identification information read command specifying the flag state, returns identification information only if the flag state matches the specified flag state, The wireless communication unit transmits the identification information read command specifying the first state as the flag state, and the acquisition unit acquires the identification information returned from the wireless tag whose flag state is the first state. A state detection unit for detecting the communication status between the wireless tag and the wireless tag by the wireless communication unit, A position detection unit that detects the position of the wireless tag based on the communication state, A storage unit that stores detected information, which is linked to the identification information of one or more wireless tags to be detected, indicating whether or not the location of the wireless tag has been detected. A determination unit determines whether the wireless tag that returned the identification information has been detected, based on the detected information stored in the storage unit in association with the identification information acquired by the acquisition unit, If the wireless tag that has returned the identification information has already been located, the wireless communication unit instructs the wireless tag that has returned the identification information to change the flag state to the second state, A wireless tag communication system equipped with the following features.

7. A wireless communication unit that communicates with a wireless tag, a processor, and a memory, and a computer that controls a wireless tag communication device that communicates with the wireless tag, comprising: a wireless communication unit that has a flag that stores either a first state or a second state, and when it receives an identification information read command specifying the flag state, it returns identification information only if the flag state matches the specified flag state, The wireless communication unit transmits the identification information read command specifying the first state as the flag state, and the acquisition unit acquires the identification information returned from the wireless tag whose flag state is the first state and stores it in the memory. A determination unit determines whether the wireless tag that returned the identification information has already had its location detected, based on the identification information stored in the memory. If the wireless tag that has returned the identification information has already been located, the wireless communication unit instructs the wireless tag that has returned the identification information to change the flag state to the second state. A program designed to function as such.

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