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 reading to be shortened.SOLUTION: A wireless tag communication device includes a wireless communication unit, a first processing unit, and a second processing unit. The wireless communication unit communicates with a wireless tag. The first processing unit acquires identification information of the wireless tag in a first state by causing the wireless communication unit to transmit an identification information read command specifying the first state as a flag state, and when a wireless tag to be detected whose position has not been detected is identified as a wireless tag to be read based on the identification information, rewrites the flag state of the identified wireless tag from the first state to a second state. The second processing unit acquires the identification information only from the wireless tag to be read that is in the second state by causing the wireless communication unit to transmit an identification information read command specifying the second state as the flag state.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 this technology, a wireless tag called an RFID (Radio Frequency Identification) tag that records 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 performs wireless communication with the wireless tag.

[0003] With this technology, it is possible to read identification information from all wireless tags present 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 read commands multiple times. As a result, each read command also reads identification information that has already been completely read, which reduces the chances of reading identification information that has not been read yet. Therefore, the time required to complete reading identification information from all wireless tags increases, and the reading rate per unit time decreases. To address this problem, Patent Document 1 prevents this problem by instructing that flag information of a wireless tag from which identification information has been acquired once is not to 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, a first processing unit, and a second processing 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 first processing unit obtains the identification information of the wireless tag in the first state by having the wireless communication unit transmit an identification information read command specifying the first state as the flag state, and if it identifies a wireless tag that is not detected as a target wireless tag to be read based on the identification information, it rewrites the flag state of the identified wireless tag from the first state to the second state. The second processing unit obtains identification information only from the target wireless tag in the second state by having the wireless communication unit transmit an identification information read command specifying the second state as the flag 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 shows the first part of a flowchart illustrating the essential steps of information processing performed by the processor of a wireless tag communication device. [Figure 11] Figure 11 shows the second part of a flowchart illustrating the essential steps of 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 shows the first part of a flowchart illustrating the essential information processing steps performed by the processor of the wireless tag communication device according to the second embodiment. [Figure 16] Figure 16 shows the second portion of a flowchart illustrating the main steps of information processing performed by the processor of the wireless tag communication device according to the second embodiment. [Figure 17] Figure 17 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 the present embodiment, the reading operation of the wireless tag TG and the position detection method for wireless tags will first be described.

[0012] There are various types of RFID, and currently, a system called Class-1 Generation-2 (commonly known as Gen2) formulated by EPCglobal is the mainstream. Figure 2 is a schematic diagram showing the outline of the reading operation of the wireless tag TG in this Gen2 system. The 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, processing called a round is repeated. Within a round, following the initialization of the round, processing called a slot is repeated. Each slot is divided into an inquiry to the wireless tag TG and a reading operation. 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 A wireless tag TG randomly determines in which slot it will respond. If 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 deferred 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 (A value, B value) referred to as inventoried flags that can be rewritten by the wireless tag communication apparatus 1. For example, the A value of this flag state can be a state indicating unread, and the B value can be a state indicating already read. When the wireless tag communication apparatus 1 performs reading from the wireless tag TG, it specifies the flag state of this flag. If the flag state of the wireless tag TG does not match the specified flag state, it will not return a response. For example, in reading where the A value is specified as the flag state, a wireless tag TG whose flag state is the A value responds, while a wireless tag TG whose flag state is the B value does not respond. The flag state of a responding wireless tag TG is rewritten from the A value to the B value by the wireless tag communication apparatus 1. Therefore, a wireless tag TG that has already responded will not respond to reading specifying the A value as the flag state in subsequent rounds. A wireless tag TG whose flag state has been rewritten to the B value will reset its flag state from the B value back to the A value after a certain period of time has elapsed since it stopped receiving radio waves.

[0014] Figure 3 is a schematic diagram showing an overview of an operation within a slot in the reading operation of a 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 an internal counter. For example, when 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", that is, 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 shown, or conversely, there may even be no wireless tags TG at all. In addition, there may be multiple wireless tags TG with duplicate counter values in the communication area.

[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 a wireless tag has already been located, linked to the identification information of each of the one or more wireless tags that are 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 located. 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 location detection using both RSSI and phase, location detection is possible using only one of them, so a configuration in which at least one of RSSI and phase is detected and stored is also acceptable.

[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 and 9 are sequence diagrams illustrating the operation overview of the wireless tag communication device 1, respectively. Figure 8 shows the first processing step (PRO1), and Figure 9 shows the second processing step (PRO2). The first processing step identifies wireless tags TG whose location has not yet been detected and which are located within the communication area CA as targets for reading, and the second processing step is to communicate only with the identified wireless tag TG that is the target for reading. The second processing step is to calculate the location of the identified wireless tag TG that is the target for reading. Figures 8 and 9 show an example where four wireless tags TG are located within the communication area CA: 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 non-target wireless tag d with identification information "d". Figures 8 and 9 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, in the first round of the first processing step (PRO1), for example in slot 1 (SLT#1), the wireless tag communication device 1 sends an inquiry to the wireless tag TG that is in the communication area CA, specifying the value A as the flag status (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 a, transmits identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0049] When the wireless tag communication device 1 receives identification information transmitted from the target wireless tag a, it determines, based on the contents stored in the detection target storage unit 21 and the position correction enable flag storage unit 22, whether the identification information is a target for acquisition of position detection data, i.e., a target for reading in the second processing step (step S3). Specifically, if the received identification information is stored in the detection target storage unit 21, i.e., it is a wireless tag TG that is a target for position detection, and the detected information 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. Furthermore, even if the detected information is already detected, if the position correction enable flag stored in the position correction enable flag storage unit 22 indicates that correction is needed, i.e., the position of the detected wireless tag TG needs to be corrected, the wireless tag communication device 1 determines that the received identification information is a target for data acquisition. Once this determination is complete, the wireless tag communication device 1 terminates processing for this slot.

[0050] In the next slot 2 (SLT#2), the wireless tag communication device 1 sends an inquiry to the wireless tag TG, which is located within the communication area CA, specifying the value A as the flag status (step S1).

[0051] Upon receiving this query, the target wireless tag a changes its flag state from value A to value B (step S4). In other words, when wireless tag TG transmits identification information in response to an query from wireless tag communication device 1, it is configured to change its flag state when it receives the query command for the next slot. Therefore, the target wireless tag a that transmitted identification information in slot 1 (SLT#1) changes its flag state.

[0052] Furthermore, among the remaining three target wireless tags TG, excluding target wireless tag a which has already transmitted identification information, for example, non-target wireless tag d transmits identification information (tag ID) to the wireless tag communication device 1 in response to the inquiry (step S2).

[0053] When the wireless tag communication device 1 receives identification information transmitted from the non-target wireless tag d, it determines, based on the contents stored in the detection target storage unit 21 and the position correction valid flag storage unit 22, whether the identification information is a target for acquiring position detection data, i.e., a target for reading in the second processing step (step S3). The wireless tag communication device 1 determines that the non-target wireless tag d of the received identification information is not a target for data acquisition. If it is determined that it is not a target for data acquisition in this way, the wireless tag communication device 1 issues an instruction to the non-target wireless tag d not to change the flag (step S5). Then, it terminates processing for this slot.

[0054] In the next slot 3 (SLT#3), the wireless tag communication device 1 sends a query to the wireless tag TG, which is within the communication area CA, specifying the value A as the flag state (step S1). In this case, unlike in slot 2, the non-target wireless tag d has received instructions not to change its flag, so it maintains the value A as its flag state.

[0055] Furthermore, target wireless tag a, whose flag state has been rewritten from value A to value B, will not respond to queries specifying value A as the flag state. In other words, target wireless tag a will ignore this query. Therefore, of the remaining two target wireless tags TG, excluding the non-target wireless tag d which has already transmitted its identification information, for example, target wireless tag b will respond to the query and transmit its identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0056] When the wireless tag communication device 1 receives identification information transmitted from the target wireless tag b, it determines, based on the contents stored in the detection target storage unit 21 and the position correction valid flag storage unit 22, whether the identification information is a target for acquiring position detection data, i.e., a target for reading in the second processing step (step S3). The wireless tag communication device 1 determines that the target wireless tag b of the received identification information is a data acquisition target. Since the wireless tag communication device 1 has determined that it is a data acquisition target, it does not issue an instruction not to change the flag at this point. Once this determination is complete, the wireless tag communication device 1 terminates processing for this slot.

[0057] In the next slot 4 (SLT#4), the wireless tag communication device 1 sends an inquiry to the wireless tag TG, which is located within the communication area CA, specifying the value A as the flag status (step S1).

[0058] Since the target wireless tag b that received this query has not received an instruction not to change the flag, it rewrites the flag state from value A to value B (step S4).

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

[0060] When the wireless tag communication device 1 receives identification information transmitted from the target wireless tag c, it determines, based on the contents stored in the detection target storage unit 21 and the position correction valid flag storage unit 22, whether the identification information is a target for acquiring position detection data, i.e., a target for reading in the second processing step (step S3). The wireless tag communication device 1 determines that the target wireless tag c of the received identification information is a target for data acquisition. Once this determination is complete, the wireless tag communication device 1 terminates processing for this slot.

[0061] Similarly, each wireless tag TG and wireless tag communication device 1 will process the remaining slots of this round, and subsequent rounds. This first processing step will continue until a specified time has elapsed or until a specified number of rounds have been completed. The specified number of rounds may be one.

[0062] As shown in Figure 9, in the second processing step (PRO2), for example in the nth round, slot 1 (SLT#1), the wireless tag communication device 1 sends an inquiry to the wireless tag TG that is in the communication area CA, specifying the value B as the flag status (step S6).

[0063] Non-target wireless tag d, whose flag state remains at value A, will not respond to a query specifying value B as its flag state. In other words, non-target wireless tag d will ignore this query. Therefore, among the remaining three target wireless tags TG whose flag state has been rewritten to value B in the first processing step, for example, target wireless tag a will respond to the query and transmit identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0064] The wireless tag communication device 1 receives identification information transmitted from the target wireless tag a. Upon receiving this identification information, the wireless tag communication device 1 acquires location detection data, namely the acquisition time, RSSI, and phase (step S7). 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. In each slot of each round up to the nth round, the wireless tag communication device 1 similarly acquires the identification information and location detection data of the wireless tag TG to be detected, and stores them in the read data storage unit 23, associating them with the received identification information.

[0065] The wireless tag communication device 1 determines, based on the contents stored in the detection target storage unit 21 and the position correction valid flag storage unit 22, whether the received identification information is a target for acquiring position detection data, i.e., a target for reading (step S3). The wireless tag communication device 1 determines that the target wireless tag a of the received identification information is a target for data acquisition.

[0066] Then, the wireless tag communication device 1 determines whether it is possible to calculate the location of the target wireless tag TG having the received identification information from the data stored in the read data storage unit 23 (step S8). If it is not possible to calculate it, the wireless tag communication device 1 terminates processing for this slot.

[0067] In contrast, if the location of the target wireless tag a can be calculated, the wireless tag communication device 1 calculates the location of the target wireless tag a based on the location detection data stored in the read data storage unit 23 (step S9). The wireless tag communication device 1 stores the calculated location of the target wireless tag a in the location calculation result storage unit 24.

[0068] Furthermore, the wireless tag communication device 1 sets the detected information 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 S10). Then, the wireless tag communication device 1 terminates processing for this slot.

[0069] In the next slot 2 (SLT#2), the wireless tag communication device 1 sends an inquiry to the wireless tag TG, which is located within the communication area CA, specifying the value B as the flag status (step S6).

[0070] Upon receiving this inquiry, the target wireless tag a changes its flag state from value B to value A (step S11).

[0071] Furthermore, among the remaining two target wireless tags TG whose flag status is B, for example, target wireless tag c responds to the inquiry and transmits identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0072] When the wireless tag communication device 1 receives identification information transmitted from the target wireless tag c, it acquires location detection data, namely the acquisition time, RSSI, and phase, at the time of receiving the identification information (step S7). Then, based on the contents stored in the detection target storage unit 21 and the location correction valid flag storage unit 22, the wireless tag communication device 1 determines whether the identification information is a target for acquisition of location detection data, i.e., a target for reading (step S3). If the received identification information is a target for data acquisition, the wireless tag communication device 1 further determines whether the location of the target wireless tag c possessing the received identification information can be calculated from the data stored in the read data storage unit 23 (step S8). If it is not possible to calculate the location, the wireless tag communication device 1 issues an instruction not to change the flag (step S12) and terminates processing for this slot.

[0073] In the next slot 3 (SLT#3), the wireless tag communication device 1 sends a query specifying the value B as the flag state (step S6). In this case, target wireless tag c, which sent identification information in the previous slot, slot 2 (SLT#2), has received instructions not to change the flag, and therefore maintains the value B as its flag state. Also, target wireless tag a, whose flag state has been rewritten from the value B to the value A, does not respond to this query specifying the value B as its flag state. In other words, target wireless tag a ignores this query. Therefore, among the remaining target wireless tags TG, excluding the non-target wireless tag c which has already sent identification information, for example, target wireless tag b responds to the query and sends identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0074] When the wireless tag communication device 1 receives identification information transmitted from the target wireless tag b, it acquires location detection data at the time of receiving the identification information (step S7). Then, based on the contents stored in the detection target storage unit 21 and the location correction valid flag storage unit 22, the wireless tag communication device 1 determines whether the identification information is a target for acquisition of location detection data, i.e., a target for reading (step S3). If the received identification information is a target for data acquisition, the wireless tag communication device 1 further determines whether the location of the target wireless tag a possessing the received identification information can be calculated from the data stored in the read data storage unit 23 (step S8). If it is not possible to calculate the location, the wireless tag communication device 1 issues an instruction to change the flag (step S11) and terminates processing for this slot.

[0075] Similarly, each wireless tag TG and wireless tag communication device 1 will process the remaining slots of this round, and subsequent rounds. This second processing step will continue until a specified time has elapsed or until a specified number of rounds have been completed.

[0076] Next, a specific example of the operation of the wireless tag communication device 1 will be described. Figures 10 and 11 are flowcharts showing the main steps of the information processing performed by the processor 10 of the wireless tag communication device 1. The processor 10, for example, receives 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 Figures 10 and 11 is just one example. The procedure is not particularly limited as long as similar results can be obtained.

[0077] 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.

[0078] 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 there is no response, the processor 10 determines NO in ACT11 and proceeds to ACT12. If there is a response, the processor 10 determines YES in ACT11 and proceeds to ACT13.

[0079] In ACT12, the processor 10 determines whether or not to terminate the first processing step. Specifically, the processor 10 makes this determination based on whether a specified time has elapsed since the start of reading. Alternatively, the processor 10 makes this determination based on whether or not a specified number of rounds have been performed since the start of reading. The specified number of rounds may be 1 round. If the first processing step is not terminated, the processor 10 determines NO in ACT12 and proceeds to ACT11. If the first processing step is terminated, the processor 10 determines YES in ACT12 and proceeds to ACT18.

[0080] As ACT13, 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.

[0081] In ACT14, 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 no matching identification information is stored, the processor 10 determines that the received tag ID is not the tag ID of the wireless tag TG to be detected, and in ACT14, it determines NO and proceeds to ACT15. If the received tag ID is the tag ID of the wireless tag TG to be detected, the processor 10 determines YES in ACT14 and proceeds to ACT16.

[0082] As ACT15, the processor 10, via the wireless communication unit 60, transmits "no flag change" to the wireless tag TG, which is not subject to location detection, instructing it not to rewrite the flag state. After that, the processor 10 proceeds to ACT12.

[0083] As ACT16, 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 detected information associated with the corresponding identification information stored in the detection target storage unit 21 and determines whether it indicates that it has been detected. That is, the processor 10 determines whether the wireless tag TG that returned the identification information is a wireless tag that has already been detected, based on the detected information stored in the detection target storage unit 21 associated with the acquired identification information. If the location has been detected, the processor 10 determines YES in ACT16 and proceeds to ACT17. If the location has not been detected, the processor 10 determines NO in ACT16 and proceeds to ACT11. In this way, if the wireless tag TG that returned the identification information has not been detected, the processor 10 does not send "no flag change". This allows 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, that is, it can be made a target for reading. Thus, the processor 10 obtains identification information of a wireless tag TG whose flag state is A by having the wireless communication unit 60 send an identification information read command specifying A as the flag state, and when it identifies a wireless tag TG that is not detected as a target wireless tag to be read based on the identification information, it rewrites the flag state of the identified wireless tag from A to B.

[0084] As ACT17, 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 it is necessary to correct the position of the detected wireless tag TG.

[0085] If position correction is not enabled, that is, if position correction is not performed, there is no need to read the target wireless tag TG whose position has already been detected. Therefore, if position correction is not enabled, the processor 10 determines NO in ACT 17 and proceeds to ACT 15. As a result, in ACT 15, the processor 10 sends a "no flag change" message via the wireless communication unit 60 to the wireless tag TG whose position has already been detected, instructing it not to rewrite the flag state. In this way, the processor 10 can prevent the tag from being read if the setting stored in the position correction enabled flag storage unit 22 is not a setting to correct the position.

[0086] 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 ACT17 and proceed to ACT11. This will cause 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, that is, it will be made available for reading.

[0087] As ACT18, the processor 10 activates the wireless communication unit 60 and starts reading the wireless tag TG, which has a value of B specified as its flag state.

[0088] In ACT19, 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. The only wireless tags TG that will return a response are those whose flag state has been rewritten to a B value in the first processing step as being a target for reading, and whose location has not yet been detected. In other words, wireless tags TG that are not targeted for location detection and wireless tags TG whose location has already been detected and are not targets for reading will not return a response. If there is no response, the processor 10 determines NO in ACT19 and proceeds to ACT20. If there is a response, the processor 10 determines YES in ACT19 and proceeds to ACT21.

[0089] As ACT20, the processor 10 determines whether or not to terminate the second processing step. The second processing step continues until identification information has been obtained multiple times from the wireless tag TG to be read. Specifically, the processor 10 determines this based on whether a predetermined time has elapsed since the start of reading with a flag value of B specified. This predetermined time is preferably longer than the predetermined time in ACT12. Alternatively, the processor 10 determines this based on whether a predetermined number of rounds have been performed since the start of reading. This predetermined number of rounds is preferably greater than the number of rounds in ACT12. If the second processing step is not terminated, the processor 10 determines NO in ACT20 and proceeds to ACT19. If the second processing step is terminated, the processor 10 determines YES in ACT20 and proceeds to ACT10. In this way, the processor 10 causes the first processing unit to execute again after a predetermined time has elapsed since the flag state of the wireless tag TG was rewritten from a value of A to a value of B, or after executing the process of obtaining identification information only from the wireless tag TG to be read with a flag state of B a predetermined number of times.

[0090] As ACT21, 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.

[0091] As ACT22, 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. In this way, when the processor 10 receives a tag ID from a wireless tag TG whose flag value is B, it acquires location detection data using the sensor 50, the RSSI detection unit 63, and the phase detection unit 64. Therefore, when the processor 10 acquires identification information from the wireless tag TG to be read, whose flag state is B, it is an example of a state detection unit that detects the communication status with the wireless tag TG by the wireless communication unit 60. The processor 10 stores the acquired location detection data in the work area of ​​the memory 20.

[0092] As ACT23, the processor 10 determines whether the wireless tag TG is a target for acquiring location detection data based on the tag ID, i.e., identification information, stored in the work area. For example, the processor 10 can make this determination by performing the same determination as in ACT14, ACT16, and ACT17 described above. Basically, in the second processing step, only wireless tags TG whose identification information is being read should be included, but it is possible that an untargeted wireless tag TG with a flag status of B may respond via another wireless tag communication device. Therefore, it is checked here whether location detection data corresponding to the identification information response from the target wireless tag TG has been acquired. Thus, ACT23 is not mandatory. If the tag is not a target for acquiring location detection data, the processor 10 determines NO in ACT23 and proceeds to ACT20. At this time, the tag ID, i.e., identification information, and location detection data stored in the work area are cleared, i.e., deleted. If the tag is a target for acquiring location detection data, the processor 10 determines YES in ACT23 and proceeds to ACT24.

[0093] As ACT24, the processor 10 associates the acquired position detection data stored in the work area with the tag ID, i.e., identification information, also stored in the work area, and stores it in the read data storage unit 23.

[0094] In ACT25, 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 ACT25 and proceeds to ACT27. If the position cannot be calculated, the processor 10 determines NO in ACT25 and proceeds to ACT26. Thus, the processor 10 is an example of a second processing unit that obtains identification information only from the wireless tag TG to be read, where the flag state is B, by having the wireless communication unit 60 send an identification information read command specifying the value B as the flag state.

[0095] As ACT26, the processor 10 sends a "no flag change" message to the wireless tag TG, which has returned identification information via the wireless communication unit 60, instructing it not to rewrite the flag state. After that, the processor 10 proceeds to ACT20.

[0096] As ACT27, 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.

[0097] As ACT28, 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.

[0098] As ACT29, the processor 10 notifies the calculation result via the output device 40. However, ACT29 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.

[0099] As ACT30, the processor 10 stores a location detected flag. Specifically, it sets the detected information stored in the detection target storage unit 21, which is linked to 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, which is linked to the identification information of the wireless tag TG, to "location detected". This is an example of a storage control unit.

[0100] In ACT31, 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 detected information is not detected. If there are target wireless tags whose location has not been detected, the processor 10 determines YES in ACT31 and proceeds to ACT20. At this time, 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 ACT31 and proceeds to ACT32.

[0101] As ACT32, the processor 10 terminates the operation of the wireless communication unit 60 and stops reading the wireless tag TG, which has a value of B specified as its flag state.

[0102] As ACT33, the processor 10 notifies the end 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, ACT33 may be omitted. Then, the processor 10 terminates the reading operation.

[0103] 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.

[0104] As described above, according to the wireless tag communication device 1 of the first embodiment, the processor 10 has a flag that stores either a flag state, for example, a first state, such as value A, or a flag state, for example, 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. Based on the identification information of multiple wireless tag TGs obtained by having the wireless communication unit 60, which communicates with the wireless tag TG, send an identification information read command specifying value A as the flag state, the processor 10 identifies the wireless tag TG to be read from among the wireless tag TGs to be detected whose location has not been detected, and has the wireless communication unit 60 rewrite the flag state of the identified wireless tag TG from value A to value B. After that, the processor 10 has the wireless communication unit 60 send an identification information read command specifying value B as the flag state, and repeats the process of obtaining identification information only from the wireless tag TG to be read multiple times, for example, until a specified time has elapsed since the start of reading with value B, or until a specified number of rounds have been performed since the start of reading. Thus, according to the wireless tag communication device 1 of the first embodiment, first, identification information is obtained from the wireless tag TG by an identification information reading command specifying the value A. Only the wireless tag TG that has not yet had its position detected is changed to the value B in the flag state, thereby narrowing down the wireless tag TG to be read. Then, identification information is obtained from the wireless tag TG by an identification information reading command specifying this value B, and this process is repeated. As a result, wireless tag TGs that have already had their position detected and wireless tag TGs that are not targets for position detection will not respond to the first state, for example, the identification information reading command specifying the value A, in subsequent slots or rounds. Therefore, these wireless tag TGs that have already had their position detected and wireless tag TGs that are not targets for position detection will not take away the opportunity to read wireless tag TGs that have not yet had their position detected. In other words, the opportunity to read wireless tag TGs that have not yet had their position 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 it takes to read all of the multiple wireless tags that are targets for position detection.

[0105] 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 that has already had its location detected. Therefore, according to the wireless tag communication device 1 of the first embodiment, it is possible to easily determine whether or not the wireless tag TG that returned the identification information is a wireless tag that has already had its location detected.

[0106] 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 a wireless tag TG whose position has already 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 also identifies a wireless tag TG that has identification information indicating that its position has already been detected in the detection target storage unit 21 as a wireless tag TG to be read. 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.

[0107] 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 communication status with the wireless tag TG by the wireless communication unit 60 when identification information is obtained from the wireless tag TG to be read, and the processor 10 detects the position of the wireless tag TG based on the detected communication status. Therefore, according to the wireless tag communication device 1 of the first embodiment, the position of the wireless tag TG can be detected based on the communication status with the wireless tag TG to be read by the wireless communication unit 60.

[0108] Furthermore, in the second processing step (PRO2), the wireless tag communication device 1, after a predetermined time has elapsed since the flag state of the wireless tag TG was changed from value A to value B, or after a predetermined number of times the process of acquiring identification information only from the wireless tag TG to be read whose flag state is value B has been executed, the first processing step (PRO1) is executed again. Therefore, according to the wireless tag communication device 1 of the first embodiment, by repeating the first and second processing steps, it is possible to reliably read all of the multiple wireless tags TG that are to be detected. In particular, performing such repetitive processing can improve the reliability of reading a large number of wireless tags TG when moving the wireless tag communication device 1 to multiple locations and continuously reading a large number of wireless tags TG.

[0109] Furthermore, in the wireless tag communication device 1 according to the first embodiment, 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, which is linked to the identification information of the wireless tag TG, to "location 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.

[0110] 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. The detection target storage unit 21 of the wireless tag communication device 1 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.

[0111] [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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] Figures 13 and 14 are sequence diagrams illustrating the operation overview of the wireless tag communication system. Figure 13 shows the first processing step (PRO1), and Figure 14 shows the second processing step (PRO2). Figures 13 and 14 assume that non-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, only one non-target and / or target wireless tag TG is shown each, but such non-target and / or target wireless tags TG may also be within the communication area CA. Furthermore, 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.

[0116] As shown in Figure 13, in the first round of the first processing step (PRO1), for example in slot 1 (SLT#1), the wireless tag communication device 1 sends an inquiry to the wireless tag TG that is in the communication area CA, specifying the value A as the flag status (step S1).

[0117] In response to an inquiry sent from the wireless tag communication device 1, for example, if a non-target wireless tag a transmits identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 determines, based on the contents stored in the detection target storage unit 21, whether or not the identification information is a target for acquiring location detection data (step S3). The wireless tag communication device 1 determines that the non-target wireless tag a whose received identification information is not a target for data acquisition. Next, the wireless tag communication device 1 issues an instruction to the wireless tag a, which it determined is not a target for data acquisition, not to change the flag (step S5), and terminates processing for this slot.

[0118] In the next slot 2 (SLT#2), the wireless tag communication device 1 sends a query to the wireless tag TG, which is within the communication area CA, specifying the value A as its flag state (step S1). Note that the non-target wireless tag a has received an instruction not to change its flag, so even after receiving this query, it maintains the value A as its flag state.

[0119] Excluding the non-target wireless tag a, which has already transmitted its identification information, target wireless tag b, among the remaining target wireless tags TG, transmits its identification information (tag ID) to the wireless tag communication device 1 in response to the inquiry (step S2).

[0120] When the wireless tag communication device 1 receives identification information transmitted from the target wireless tag b, it determines, based on the contents stored in the detection target storage unit 21 and the position correction valid flag storage unit 22, whether the identification information is a target for acquiring position detection data, i.e., a target for reading in the second processing step (step S3). The wireless tag communication device 1 determines that the target wireless tag b of the received identification information is a data acquisition target. Since the wireless tag communication device 1 has determined that it is a data acquisition target, it does not issue an instruction not to change the flag at this point. Once this determination is complete, the wireless tag communication device 1 terminates processing for this slot.

[0121] In the next slot 3 (SLT#3), the wireless tag communication device 1 sends an inquiry to the wireless tag TG, which is located within the communication area CA, specifying the value A as the flag status (step S1).

[0122] Since the target wireless tag b that received this query has not received an instruction not to change the flag, it rewrites the flag state from value A to value B (step S4).

[0123] Furthermore, any of the remaining target wireless tags TG, excluding those that have already transmitted identification information, will transmit identification information (tag ID) to the wireless tag communication device 1 in response to the inquiry (step S2). Upon receiving this identification information, the wireless tag communication device 1 will determine, based on the contents stored in the detection target storage unit 21 and the position correction valid flag storage unit 22, whether or not the identification information is a target for acquiring position detection data, i.e., a target for reading in the second processing step (step S3).

[0124] Similarly, each wireless tag TG and wireless tag communication device 1 will process the remaining slots of this round, and subsequent rounds. This first processing step will continue until a specified time has elapsed or until a specified number of rounds have been completed. The specified number of rounds may be one.

[0125] As shown in Figure 14, in the second processing step (PRO2), for example in the nth round, slot 1 (SLT#1), the wireless tag communication device 1 sends an inquiry to the wireless tag TG that is in the communication area CA, specifying the value B as the flag status (step S6).

[0126] Non-target wireless tag a, whose flag state remains at value A, will not respond to a query specifying value B as its flag state. In other words, non-target wireless tag a will ignore this query. Therefore, among the remaining target wireless tags TG whose flag state has been rewritten to value B in the first processing step, for example, target wireless tag b will respond to the query and transmit identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0127] When the wireless tag communication device 1 receives identification information transmitted from the target wireless tag b, it acquires location detection data, namely the acquisition time, RSSI, and phase (step S7), and determines whether the received identification information is a target for acquisition of location detection data, i.e., a target for reading, based on the contents stored in the detection target storage unit 21 and the location correction valid flag storage unit 22 (step S3). The wireless tag communication device 1 determines that the target wireless tag b of the received identification information is a target for data acquisition.

[0128] The wireless tag communication device 1 transmits the identification information of the received target wireless tag b and the acquired location detection data to the host device UE (step S21). 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 S7 to the host device UE without calculating the device position, and the host device UE may calculate the device position. In each slot of each round up to the nth round, the wireless tag communication device 1 similarly acquires the identification information and location detection data of the wireless tag TG to be detected and transmits it to the host device UE, so the host device UE reads the location detection data in association with the identification information and stores it in the data storage unit 1021.

[0129] Then, the higher-level device UE determines whether or not it is possible to calculate the location of the target wireless tag TG having the received identification information from the data stored in the read data storage unit 1021 (step S22). The operation of step S22 corresponds to step S8 in the first embodiment. Once the determination of calculation feasibility is complete, the higher-level device UE transmits a location calculation feasibility notification to the wireless tag communication device 1 (step S23).

[0130] If the location of the target wireless tag b having received identification information can be calculated from the data stored in the read data storage unit 1021, the host device UE calculates the location of the target wireless tag a based on the location detection data stored in the read data storage unit 1021 (step S24). The host device UE stores the calculated location of the target wireless tag b in the location calculation result storage unit 1022. This operation in step S24 corresponds to step S9 in the first embodiment.

[0131] Furthermore, if the location of the target wireless tag b having the received identification information cannot be calculated from the data stored in the read data storage unit 1021, the higher-level device UE will wait for the next identification information and location detection data to be transmitted from the wireless tag communication device 1.

[0132] When the wireless tag communication device 1 receives a notification of whether or not the location can be calculated, if the location can be calculated, it sets the detected information 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 S10). Then, the wireless tag communication device 1 terminates processing for this slot. On the other hand, if the location cannot be calculated, the wireless tag communication device 1 issues an instruction to the target wireless tag b not to change the flag (not shown) and terminates processing for this slot.

[0133] In the next slot 2 (SLT#2), the wireless tag communication device 1 sends an inquiry to the wireless tag TG, which is located within the communication area CA, specifying the value B as the flag status (step S6).

[0134] If the target wireless tag b receives an inquiry without receiving an instruction not to change the flag, it rewrites the flag state from value B to value A (step S25).

[0135] Furthermore, when any wireless tag TG (not shown in the diagram), for example, an untargeted wireless tag TG, transmits identification information (tag ID) to the wireless tag communication device 1 in response to the inquiry (step S2), the wireless tag communication device 1 acquires location detection data (step S7). The wireless tag communication device 1 then determines, based on the identification information, whether or not the tag is a target for acquiring location detection data (step S3). If it is not a target for data acquisition, the wireless tag communication device 1 terminates processing for this slot.

[0136] In the next slot 3 (SLT#3), the wireless tag communication device 1 sends a query specifying the value B as the flag state (step S6). The target wireless tag b, whose flag state has been rewritten from value B to value A, does not respond to this query specifying the value B as the flag state. In other words, target wireless tag b ignores this query. Therefore, one of the remaining target wireless tags TG, either a target or a non-target wireless tag TG, will respond to the query and send identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0137] Similarly, each wireless tag TG and wireless tag communication device 1 will process the remaining slots of this round, and subsequent rounds. This second processing step will continue until a specified time has elapsed or until a specified number of rounds have been completed.

[0138] Next, specific examples of the operation of the wireless tag communication device 1 and the host device UE will be described. Figures 15 and 16 are flowcharts 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 17 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, 16, and 17 are examples, and the procedure is not particularly limited as long as similar results can be obtained.

[0139] As shown in Figure 15, the processor 10 of the wireless tag communication device 1 determines, as ACT41, 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 ACT41 and proceeds to ACT43. If it has not received settings from the host device UE, the processor 10 determines NO in ACT41 and proceeds to ACT42.

[0140] As ACT42, the processor 10 determines via the communication interface 70 whether or not it has received a start command from the higher-level device UE to begin position detection of the wireless tag TG to be detected. If it has received a start command from the higher-level device UE, the processor 10 determines YES in ACT42 and proceeds to ACT10. If it has not received a start command from the higher-level device UE, the processor 10 determines NO in ACT42 and proceeds to ACT41.

[0141] As shown in Figure 17, 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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 ACT43 in the detection target storage unit 21 and the position correction enabled flag storage unit 22. After that, the processor 10 proceeds to ACT41.

[0146] As shown in Figure 17, 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.

[0147] 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.

[0148] 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.

[0149] 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 ACT13. If there is no response, the processor 10 determines NO in ACT11 and proceeds to ACT12.

[0150] As ACT12, the processor 10 determines whether or not to terminate the first processing step, as described in the first embodiment. If the first processing step is not to be terminated, the processor 10 determines NO in ACT12 and proceeds to ACT11. If the first processing step is to be terminated, the processor 10 determines YES in ACT12 and proceeds to ACT18.

[0151] As ACT13, the processor 10 acquires the tag ID, or identification information, of the wireless tag TG that returned a response, as described in the first embodiment, and stores the tag ID received by the wireless communication unit 60 in the work area of ​​the memory 20.

[0152] As ACT14, 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 ACT14 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 ACT14 and proceeds to ACT15.

[0153] As ACT15, the processor 10, as described in the first embodiment, issues an instruction to the wireless tag TG, which is not subject to location detection and has returned a response via the wireless communication unit 60, not to change the flag, and then proceeds to ACT12.

[0154] As ACT16, 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 ACT16 and proceeds to ACT17. If the location has not been detected, the processor 10 determines NO in ACT16 and proceeds to ACT16.

[0155] As ACT17, the processor 10, as described in the first embodiment, checks the position correction enable flag stored in the position correction enable flag storage unit 22, which indicates whether or not the position of the detected wireless tag TG needs to be corrected, to determine whether or not position correction is enabled. If position correction is not enabled, the processor 10 determines NO in ACT17 and proceeds to ACT15, instructing the wireless tag TG that returned the response not to change the flag. If position correction is enabled, the processor 10 determines YES in ACT17 and proceeds to ACT11. This prevents the wireless tag TG that returned the response from being instructed not to change the flag, and allows 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. Therefore, even wireless tag TGs whose position has already been detected can be made targets for reading.

[0156] As shown in Figure 16, as ACT18, the processor 10 operates the wireless communication unit 60 as described in the first embodiment and starts reading the wireless tag TG, which has a value of B specified as its flag state.

[0157] As ACT19, 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 there is no response, the processor 10 determines NO in ACT19 and proceeds to ACT20. If there is a response, the processor 10 determines YES in ACT19 and proceeds to ACT21.

[0158] As ACT20, the processor 10 determines whether or not to terminate the second processing step, as described in the first embodiment. If the second processing step is not to be terminated, the processor 10 determines NO in ACT20 and proceeds to ACT19. If the second processing step is to be terminated, the processor 10 determines YES in ACT20 and proceeds to ACT10.

[0159] As ACT21, 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.

[0160] As ACT22, 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.

[0161] As ACT23, the processor 10 determines, as described in the first embodiment, whether the wireless tag TG is a target for acquiring location detection data based on the tag ID, i.e., identification information, stored in the work area. If it is not a target for acquiring location detection data, the processor 10 determines NO in ACT23 and proceeds to ACT20. At this time, the tag ID, i.e., identification information and location detection data stored in the work area are cleared, i.e., deleted. If it is a target for acquiring location detection data, the processor 10 determines YES in ACT23 and proceeds to ACT44 in this embodiment.

[0162] As ACT44, 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 ACT22, or the detection result of the sensor 50 if not calculated. The processor 10 then proceeds to ACT45. 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.

[0163] As shown in Figure 17, the processor 101 of the upper-level device UE stores the received location detection data in the read data storage unit 1021, as ACT107, linking it with the received tag ID, i.e., identification information. The operation of ACT107 corresponds to ACT23 in the first embodiment.

[0164] As ACT108, the processor 101 determines whether or not the location of the wireless tag TG can be detected based on the location detection data stored in the read data storage unit 1021.

[0165] As ACT109, the processor 101 transmits a calculation feasibility notification, which is the determination result, to the wireless tag communication device 1 via the communication interface 105.

[0166] As ACT110, the processor 101 determines whether the result of the judgment in ACT108 was capable of position calculation. If position calculation is possible, the processor 101 determines YES in ACT110 and proceeds to ACT111. If position calculation is not possible, the processor 101 determines NO in ACT110 and proceeds to ACT106. This operation of ACT110 corresponds to ACT25 in the first embodiment.

[0167] As ACT111, 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 ACT111 corresponds to ACT27 in the first embodiment.

[0168] As ACT112, 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. This operation of ACT112 corresponds to ACT28 in the first embodiment.

[0169] As ACT113, the processor 101 notifies the calculation result via the output device 104. The operation of ACT113 corresponds to ACT29 in the first embodiment.

[0170] As ACT114, 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 ACT114 and proceeds to ACT115. If a termination notification is not received, the processor 101 determines NO in ACT114 and proceeds to ACT106.

[0171] As shown in Figure 16, the processor 10 of the wireless tag communication device 1 determines, as ACT45, whether or not it has received a calculation feasibility notification from the host device UE via the communication interface 70. If a calculation feasibility notification is received, the processor 10 determines YES in ACT45 and proceeds to ACT46. If a calculation feasibility notification is not received, the processor 10 determines NO in ACT45 and proceeds to ACT20. 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 location of the wireless tag TG has been detected.

[0172] As ACT46, processor 10 determines whether the result of the position calculation feasibility determination indicated in the received calculation feasibility notification is that the position can be calculated. If the position can be calculated, processor 10 determines YES in ACT46 and proceeds to ACT30. If the position cannot be calculated, processor 10 determines NO in ACT46 and proceeds to ACT26.

[0173] As ACT26, the processor 10 transmits "no flag change" to the wireless tag TG that has returned identification information via the wireless communication unit 60, as described in the first embodiment. After that, the processor 10 proceeds to ACT20.

[0174] As ACT30, the processor 10 stores a location detected flag, as described in the first embodiment. Therefore, the processor 10 is an example of a storage control unit that marks detected information stored in the detection target storage unit 21, linked to the identification information of the wireless tag TG, as location detected.

[0175] As ACT31, 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 ACT31 and proceeds to ACT20. 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 ACT31 and proceeds to ACT32.

[0176] As ACT32, 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 a B value specified as its flag state. After that, in this embodiment, the processor 10 proceeds to ACT47.

[0177] As ACT47, processor 10 sends a termination notification to the higher-level device UE via the communication interface 70. After that, processor 10 proceeds to ACT41.

[0178] As shown in Figure 17, upon receiving this termination notification, the processor 101 of the higher-level device UE notifies the end of the read operation via the output device 104 as ACT 115.

[0179] As ACT116, 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 ACT116 and proceeds to ACT101. If there is a termination instruction, the processor 101 determines YES in ACT116 and terminates the processing of the control program as an application program.

[0180] Furthermore, the user can terminate the operation of the processor 101 of the wireless tag communication device 1, as shown in Figures 15 and 16, by turning off the power to the wireless tag communication device 1.

[0181] As described above, the wireless tag communication device 1 according to the second embodiment includes a communication interface 70 that, when identification information is acquired from the wireless tag TG to be read, 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 the state detection unit for detecting the communication state with the wireless tag TG by the wireless communication unit 60, to a higher-level device UE, which is a detection device for detecting the position of the wireless tag TG based on this communication state. Therefore, according to the wireless tag communication device 1 in the second embodiment, by transmitting the communication status to the higher-level device UE, the higher-level device UE can perform location detection of the wireless tag TG. In particular, by having the location detection process, which requires processing power, executed by the higher-level device UE, which is an information processing device such as a server computer or an information processing device such as a smartphone, it is possible to use an inexpensive processor 10 with not very high processing power for the wireless tag communication device 1, thereby reducing the cost of the wireless tag communication device 1.

[0182] Furthermore, according to the wireless tag communication device 1 of the second embodiment, the communication interface 70 receives a detection notification from the host device UE indicating a wireless tag TG whose location has been detected, and the processor 101, based on the detection notification received by the communication interface 70, sets the detected information stored in the detection target storage unit 21, which is linked to the identification information of the wireless tag TG whose location has been detected, to "location 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.

[0183] 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, similar to the first embodiment, the wireless tag communication device 1 first obtains identification information from the wireless tag TG using an identification information read command specifying value A, and then rewrites the flag state of only the wireless tag TG that has not yet had its position detected to value B, thereby narrowing down the wireless tag TG to be read. This process of obtaining identification information from the wireless tag TG using an identification information read command specifying value B is then repeated. As a result, wireless tag TGs that have already had their position detected and wireless tag TGs that are not targets for position detection will not respond to the first state, for example, the identification information read command specifying value A, in subsequent slots or rounds. Therefore, these wireless tag TGs that have already had their position detected and wireless tag TGs that are not targets for position detection will not take away the opportunity to read wireless tag TGs that have not yet had their position detected, thus shortening the time required to read all of the multiple wireless tags that are targets for position detection. Furthermore, since the position detection process, which requires particularly high processing power, is executed on a higher-level device UE, such as a server computer or an information processing device like a smartphone, the processor 10 of the wireless tag communication device 1 can be an inexpensive one with relatively low processing power, thereby reducing the cost of the wireless tag communication device 1.

[0184] 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 first and second embodiments, in the first processing step, all wireless tags TG whose flag state is value A, that is, all wireless tags TG that are not subject to location detection, and wireless tags TG whose location has been detected and those whose location has not yet been detected, are read, and the flag state of the wireless tags TG to be read in the second processing step is rewritten to value B. However, it is also possible to specify and read only the wireless tags TG whose location has not been detected and whose identification information is stored in the detection target storage unit 21, and rewrite the flag state of the wireless tags TG to be read in the second processing step to value B.

[0185] Furthermore, in the flowchart of Figure 11, ACT28 and ACT30 may be performed in reverse order or in parallel. In this way, the order of processes may be changed or multiple processes may be performed in parallel, as long as there is no conflict with preceding or succeeding processes.

[0186] Furthermore, in the second embodiment, the wireless tag communication device 1, after receiving a calculation feasibility notification transmitted from the higher-level device UE, issues an instruction not to change the flag if location calculation is impossible. However, it is also possible to send an instruction not to change the flag to the wireless tag at the stage when it is determined to be the target wireless tag in the data acquisition target determination. In this case, when NO is determined in ACT23, the process should proceed to ACT26 instead of ACT20. This makes it possible to reliably send an instruction not to change the flag to the wireless tag TG even when communication with the higher-level device UE or the higher-level device UE's location calculation feasibility determination takes time.

[0187] 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.

[0188] 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.

[0189] [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 first processing unit causes the wireless communication unit to transmit the identification information read command specifying the first state as the flag state, thereby obtaining the identification information of the wireless tag in the first state, and when it identifies a wireless tag that is not detected as a target wireless tag to be read based on the identification information, it rewrites the flag state of the identified wireless tag from the first state to the second state. The second processing unit causes the wireless communication unit to transmit the identification information read command specifying the second state as the flag state, thereby acquiring the identification information only from the wireless tag to be read that is in the second state, A wireless tag communication device equipped with the following features. [2] The device further comprises a storage unit that stores detected information indicating whether or not the wireless tag has been detected in location, linked to the identification information of each of the one or more wireless tags to be detected, The wireless tag communication device according to [1], wherein the first processing unit determines, based on the acquired identification information and the contents stored in the storage unit, whether the wireless tag having the acquired identification information is a wireless tag to be detected whose location has not been detected. [3] The system 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 [2], wherein the first processing unit further identifies the wireless tag having the identification information for which the position has been detected is stored in the storage unit as the wireless tag to be read, if the setting stored in the setting storage unit is a setting for correcting the position. [4] When the second processing unit obtains the identification information from the wireless tag to be read which is in the second state, a state detection unit detects the communication status with the wireless tag by the wireless communication unit, A position detection unit that detects the position of the wireless tag to be read based on the communication state, The wireless tag communication device described in [1] further comprises the following: [5] The wireless tag communication device according to [4], further comprising a storage control unit that, when the position detection unit detects the position of the wireless tag, sets the detected information stored in the storage unit in association with the identification information of the wireless tag to "position detected". [6] When the second processing unit obtains the identification information from the wireless tag to be read, a state detection unit detects the communication status with the wireless tag by the wireless communication unit, An interface unit that transmits the communication status to a detection device that detects the position of the wireless tag based on the communication status, The wireless tag communication device described in [1] further comprises the following: [7] The interface unit receives a detection notification from the detection device indicating a wireless tag whose location has been detected, The wireless tag communication device according to [6], further comprising a storage control unit that, based on the detection notification, associates the detected information stored in the storage unit with the identification information of the wireless tag whose location has been detected and sets it to "location detected". [8] The wireless tag communication device according to [1], wherein a predetermined time has elapsed since the flag state of the wireless tag was changed from the first state to the second state, or the second processing unit has performed a predetermined number of operations to acquire the identification information only from the wireless tag to be read that is in the second state, and then the processing of the first processing unit is performed again. [9] 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 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 first processing unit causes the wireless communication unit to transmit the identification information read command specifying the first state as the flag state, thereby obtaining the identification information of the wireless tag in the first state, and when it identifies a wireless tag that is not detected as a target wireless tag to be read based on the identification information, it rewrites the flag state of the identified wireless tag from the first state to the second state. The second processing unit causes the wireless communication unit to transmit the identification information read command specifying the second state as the flag state, thereby acquiring the identification information only from the wireless tag to be read that is in the second state, When the second processing unit obtains the identification information from the wireless tag to be detected whose position has not been detected, a state detection unit detects the communication status with the wireless tag by the wireless communication unit, A location detection unit detects the location of the wireless tag that is not detected based on the communication status, A wireless tag communication system equipped with the following features.

[10] The wireless tag communication device comprises the wireless communication unit, the first processing unit, the second processing unit, the state detection unit and the position detection unit, The wireless tag communication device further includes a storage unit that stores detected information indicating whether or not the wireless tag has been detected, linked to the identification information of each of the one or more wireless tags to be detected. The wireless tag communication system according to [9], wherein the storage unit stores the identification information of the wireless tag whose location is to be detected, as set by the higher-level device.

[11] The wireless tag communication device comprises the wireless communication unit, the first processing unit, the second processing unit and the state detection unit, The above-level device is the wireless tag communication system according to [9], comprising the position detection unit.

[12] 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 first processing unit causes the wireless communication unit to transmit the identification information read command specifying the first state as the flag state, thereby obtaining the identification information of the wireless tag, and when it identifies a wireless tag that is not detected as a target wireless tag to be read based on the identification information, it rewrites the flag state of the identified wireless tag from the first state to the second state. The second processing unit causes the wireless communication unit to transmit the identification information read command specifying the second state as the flag state, thereby acquiring the identification information only from the wireless tag to be read that is in the second state. A program designed to function as such.

[13] 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, thereby obtaining the identification information of the wireless tag, and when a wireless tag that is not detected is identified as the wireless tag to be read based on the identification information, the flag state of the identified wireless tag is rewritten from the first state to the second state. The wireless communication unit transmits the identification information read command specifying the second state as the flag state, thereby obtaining the identification information only from the wireless tag to be read that is in the second state and storing it in the memory. A wireless tag communication device configured as follows. [Explanation of symbols]

[0190] 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 first processing unit causes the wireless communication unit to transmit the identification information read command specifying the first state as the flag state, thereby obtaining the identification information of the wireless tag in the first state, and when it identifies a wireless tag that is not detected as a target wireless tag to be read based on the identification information, it rewrites the flag state of the identified wireless tag from the first state to the second state. The second processing unit causes the wireless communication unit to transmit the identification information read command specifying the second state as the flag state, thereby acquiring the identification information only from the wireless tag to be read that is in 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 indicating whether or not the wireless tag has already been located, linked to the identification information of each of the one or more wireless tags to be detected. The wireless tag communication device according to claim 1, wherein the first processing unit determines, based on the acquired identification information and the contents stored in the storage unit, whether the wireless tag having the acquired identification information is a wireless tag to be detected whose location has not been detected.

3. The system further comprises a setting storage unit that stores whether or not to correct the position of the wireless tag whose position has already been detected, The wireless tag communication device according to claim 2, wherein the first processing unit, when the setting stored in the setting storage unit is a setting for correcting the position, further identifies the wireless tag having the identification information for which the position has been detected is stored in the storage unit as the wireless tag to be read.

4. When the second processing unit obtains the identification information from the wireless tag to be read, which is in the second state, a state detection unit detects the communication status with the wireless tag by the wireless communication unit, A position detection unit that detects the position of the wireless tag to be read based on the communication state, The wireless tag communication device according to claim 1, further comprising the above.

5. When the second processing unit obtains the identification information from the wireless tag to be read, which is in the second state, a state detection unit detects the communication status with the wireless tag by the wireless communication unit, An interface unit that transmits the communication status to a detection device that detects the position of the wireless tag based on the communication status, The wireless tag communication device according to claim 1, further comprising the above.

6. The wireless tag communication device according to claim 1, wherein a predetermined time has elapsed since the flag state of the wireless tag was rewritten from the first state to the second state, or the second processing unit has performed a predetermined number of operations to acquire the identification information only from the wireless tag to be read that is in the second state, and then the first processing unit's operations are performed again.

7. 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 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 first processing unit causes the wireless communication unit to transmit the identification information read command specifying the first state as the flag state, thereby obtaining the identification information of the wireless tag in the first state, and when it identifies a wireless tag that is not detected as a target wireless tag to be read based on the identification information, it rewrites the flag state of the identified wireless tag from the first state to the second state. The second processing unit causes the wireless communication unit to transmit the identification information read command specifying the second state as the flag state, thereby acquiring the identification information only from the wireless tag to be read that is in the second state, When the second processing unit obtains the identification information from the wireless tag to be detected whose position has not been detected, a state detection unit detects the communication status with the wireless tag by the wireless communication unit, A location detection unit detects the location of the wireless tag to be detected that has not been detected based on the communication status, A wireless tag communication system equipped with the following features.

8. 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 first processing unit causes the wireless communication unit to transmit the identification information read command specifying the first state as the flag state, thereby obtaining the identification information of the wireless tag in the first state, and when it identifies a wireless tag that is not detected as a target wireless tag to be read based on the identification information, it rewrites the flag state of the identified wireless tag from the first state to the second state. The second processing unit causes the wireless communication unit to transmit the identification information read command specifying the second state as the flag state, thereby acquiring the identification information only from the wireless tag to be read that is in the second state. A program designed to function as such.

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