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

Abstract

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

Description

Technical Field

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

Background Art

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

[0003] In this technique, it is possible to read identification information from all wireless tags existing within the communication area of the wireless tag communication device by transmitting a read command from the wireless tag communication device only once. However, in reality, reading omissions occur 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 needs to transmit a read command multiple times. Therefore, each read command also reads identification information that has already been read, reducing the opportunity to read identification information that has not yet been read. As a result, the time until the reading of the identification information of all wireless tags is completed increases, and the reading rate per unit time decreases. Therefore, in Patent Document 1, this is prevented by instructing not to reset the flag information of the wireless tag that has once acquired the identification information with a read command.

[0004] Incidentally, as one of the uses of radio tags and radio tag communication devices, there is inventory taking of a large number of articles stored on shelves in warehouses, storeyards, etc., and searching for desired articles. In this use, not only is it necessary to detect the articles, but also position detection of where the articles are located is required. In order to perform position detection, it is essential to read one radio tag multiple times. However, reading a radio tag whose position has already been detected will reduce the opportunity to read radio tags whose position detection has not yet been completed. Therefore, when there are multiple radio tags to be position-detected, i.e., 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

Summary of the Invention

Problems to be Solved by the Invention

[0006] The problem to be solved by the embodiments of the present invention is to provide a radio tag communication device, a radio tag communication system, and a program that can shorten the time until all of a plurality of radio tags to be position-detected are read.

Means for Solving the Problems

[0007] In one embodiment, the wireless tag communication device includes a wireless communication unit, an acquisition unit, a determination unit, and an instruction unit. The wireless communication unit communicates with a wireless tag. The wireless tag includes a flag that stores a flag state of either the first state or the second state, and returns identification information only when the received identification information reading command designates a flag state that corresponds to the designated flag state. The acquisition unit transmits, via the wireless communication unit, an identification information reading command designating the first state as the flag state, and acquires the identification information returned from the wireless tag whose flag state is the first state. The determination unit determines, based on the acquired identification information, whether the wireless tag that returned the identification information has been detected in terms of its position. When the wireless tag that returned the identification information has been detected in terms of its position, the instruction unit instructs, via the wireless communication unit, the wireless tag that returned the identification information to rewrite the flag state to the second state.

Brief Description of the Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the settlement device will be described with reference to the drawings.

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

[0011] Before entering the description of each device, in order to facilitate the understanding of this embodiment, first, the reading operation of the wireless tag TG and the method for detecting the position of the wireless tag will be described.

[0012] There are various types of RFID, but currently, the 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 the wireless tag TG is usually carried out multiple times. In each reading, following the initialization of the wireless tag communication device 1, which is an RFID reader, and the wireless tag TG, a process called a round is repeated. Within a round, following the initialization of the round, a process called a slot is repeated. Each slot is divided into an inquiry to the wireless tag TG and a reading. The number of slots within a round is determined according to the Q value set by the wireless tag communication device 1 at the initialization of the round. Specifically, the number of slots is 2 Q pieces. The wireless tag TG randomly determines in which slot to respond. If there are multiple wireless tags TG within the communication area of the wireless tag communication device 1, it is possible that the randomly determined slot for response may match for two or more wireless tags TG. In such a case, the reading cannot be executed. In that case, the reading of those wireless tags TG will be carried over to the next round.

[0013] The reading of the wireless tag TG in each slot will be described in more detail. In the Gen2 system, the wireless tag TG has two rewritable flag states (A value, B value) called the inventoried flag by the wireless tag communication device 1. This flag state can be, for example, a state where the A value indicates unread and the B value indicates read. When the wireless tag communication device 1 performs reading from the wireless tag TG, it designates the flag state of this flag, and if the wireless tag TG has a flag state different from the designated flag state, it does not return a response. For example, in a reading where the A value is designated as the flag state, the wireless tag TG with the flag state of A value responds, but the wireless tag TG with the flag state of B value does not respond. The responding wireless tag TG has its flag state rewritten from the A value to the B value by the wireless tag communication device 1. Therefore, the wireless tag TG that has already responded will not respond to a reading where the A value is designated as the flag state in subsequent rounds. When a certain time has elapsed after the wireless tag TG whose flag state has been rewritten to the B value stops receiving radio waves, it returns the flag state from the B value to the A value.

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

[0015] When the flag state of each wireless tag TG is set to value A indicating unread at the initialization of reading, if the counter value is "0" in response to an inquiry by a read command specifying value A as the flag state from the wireless tag communication device 1, the wireless tag TG transmits its identification information to the wireless tag communication device 1. More specifically, the wireless tag TG with a counter value of "0" transmits a 16-bit random number or pseudo-random number to the wireless tag communication device 1 as a response signal. The wireless tag communication device 1 that receives any response signal transmits an approval (ACK) with the (pseudo-)random number of the received response signal. If the wireless tag TG receives an ACK with the (pseudo-)random number transmitted as a response signal, it transmits its identification information to the wireless tag communication device 1. The wireless tag communication device 1 reads this identification information. Note that the transmission of the wireless tag TG means, for example, backscattering by loading the necessary information on the carrier wave of the signal transmitted from the wireless tag communication device 1 and reflecting it.

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

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

[0018] In slot #3, which is the next slot, in response to an inquiry from the wireless tag communication device 1, the wireless tag TG with tag ID = a and a flag state of value B does nothing. In contrast, for the wireless tags TG with tag ID = b and tag ID = c whose counter values are other than "0", the counter value is set to "-1". In this case, the counter values of the wireless tags TG with tag ID = b and tag ID = c become "1" and "0", respectively. Therefore, the wireless tag TG with tag ID = c and a counter value of "0" transmits the identification information "c" to the wireless tag communication device 1. Since the wireless tag TG with tag ID = b has a counter value other than "0", it does not return a response to the inquiry.

[0019] In slot #4, which is the next slot, in response to an inquiry from the wireless tag communication device 1, the wireless tag TG with tag ID = c and a counter value of "0" rewrites its flag state from value A to value B indicating that it has been read. Also, for the wireless tag TG with tag ID = b whose counter value is other than "0", the counter value is set to "-1". 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 slot #5, which is the next slot, in response to an inquiry from the wireless tag communication device 1, the wireless tag TG with tag ID = b whose counter value is "0" rewrites its flag state from value A to value B indicating that it has been read.

[0021] Suppose the counter value of the wireless tag TG with tag ID = n, which is not shown in FIG. 3, overlaps with the counter value of another wireless tag TG, for example, the wireless tag TG with tag ID = c. Then, both counter values become "0". In this case, separate (pseudo) random number response signals are transmitted from each wireless tag TG. Thus, when the wireless tag communication device 1 receives a plurality of response signals, it does not transmit an ACK. Therefore, the wireless tags TG with tag ID = c and tag ID = n do not transmit identification information. Then, in response to an inquiry in the next slot, the counter values of these wireless tags TG are decremented by "1" and become the maximum value of the counter value from "0". Therefore, since the counter value is not "0", these wireless tags TG do not transmit identification information. These multiple wireless tags TG with collided counter values will, at the start of the next round, when the counter value is randomly determined, have different counter values with a high probability, so that they can be read in some slot respectively.

[0022] FIG. 4 is a schematic diagram for explaining a position detection method by three-point measurement. When the wireless tag communication device 1 reads a wireless tag TG, it stores the device information (position and orientation of the antenna) at that time 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 by three-point measurement from the stored results at three or more points, for example, position information A, B, C and received signal strengths RSSI#A, RSSI#B, RSSI#C.

[0023] FIG. 5 is a schematic diagram for explaining a position detection method based on phase change. This position detection method is the method disclosed in Japanese Patent Application Laid-Open 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 (the position and orientation of the antenna), and stores the position and the phase. Then, when the slope of the change in the stored phase is inverted (at time t0), the wireless tag communication device 1 sets the position at that time as the position where the distance to the wireless tag TG is the shortest (the 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 any position detection method, it is also possible to realize a plurality of device positions by staying at one location and scanning the orientation of the wireless tag communication device 1, or by reading the wireless tag communication device 1 in one direction at one location and then moving the wireless tag communication device 1 to another location and performing the same reading to realize a plurality of device positions. In the latter case, it is also possible to perform continuous reading while moving.

[0025] In any case, in order to detect the position of the wireless tag TG, a plurality of reading operations are required for each wireless tag TG. Therefore, as described with reference to FIG. 3, if the reading of the wireless tag TG after the first reading is not performed, a plurality of RSSIs or phases required for position detection performed in response to the reading will not be obtained, and position detection cannot be performed. Therefore, when detecting the position of the wireless tag TG, the wireless tag communication device 1 keeps the flag state as the A value without rewriting it to the B value even for the wireless tag TG that has been read, so that the wireless tag TG can be read again in the next round.

[0026] However, if this is done, the wireless tag TG whose position has already been detected will continue to be read even though it is no longer necessary to read it, and the reading operation of this wireless tag TG whose position has been detected will reduce the reading opportunity for the wireless tag TG whose position has not yet been detected.

[0027] Furthermore, in an environment where the wireless tag TG to be position-detected and other non-position-detected wireless tags TG are mixed, performing the reading of the non-position-detected wireless tag TG will also reduce the reading opportunity for the position-detected wireless tag TG whose position has not yet been detected. This becomes a major problem particularly in usage scenarios such as searching for an article to which a specific wireless tag TG is attached among a plurality of wireless tags TG.

[0028] The wireless tag communication system and the wireless tag communication device 1 according to this embodiment address such problems.

[0029] Returning to the description of FIG. 1. The wireless tag communication device 1 includes 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 path 80. In FIG. 1, "interface" is abbreviated as "I / F". The system transmission path 80 includes an address bus, a data bus, control signal lines, etc. The system transmission path 80 connects the processor 10 to other units directly or via a signal input / output circuit, and transmits data signals exchanged between them. When the processor 10 and the memory 20 are connected by the system transmission path 80, the computer of the wireless tag communication device 1 is configured. The memory 20 includes a detection target storage unit 21, a position correction enable flag storage unit 22, a read data storage unit 23, and a position calculation result storage unit 24. The wireless communication unit 60 includes an antenna 61, a wireless tag communication circuit 62, an RSSI detection unit 63, and a phase detection unit 64.

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

[0031] Memory 20 corresponds to the main memory part of the above computer. Memory 20 includes a non-volatile memory area and a volatile memory area. Memory 20 stores an operating system or a control program in the non-volatile memory area. Also, Memory 20 stores data necessary for the processor 10 to execute processes for controlling 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 enable flag storage unit 22 as such memory areas. Further, Memory 20 uses the volatile memory area as a work area where data is appropriately rewritten 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. Note that the non-volatile memory area is, for example, a rewritable storage device such as a ROM (Read Only Memory), an EEPROM (Electric Erasable Programmable Read-Only Memory), etc. Also, the volatile memory area is, for example, a RAM (Random Access Memory).

[0032] The detection target storage unit 21 stores data such as which radio tag TG is the position detection target and whether the position of the radio tag TG has been detected. FIG. 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 FIG. 6 is an example. The format is not particularly limited as long as the information necessary for the processor 10 can be obtained. As shown in FIG. 6, the detection target storage unit 21 stores, for example, the identification information of the radio tag TG that is the position detection target set from the host device UE. Further, the detection target storage unit 21 stores detection completed information indicating whether or not it has been detected, in association with the identification information of the radio tag TG that is the position detection target. When the detection completed information is a cross mark, it represents non-detection, and when it is a circle mark, it represents detection completed. The detection target storage unit 21 can store this detection completed information, for example, as a 1-bit flag with a cross mark as "0" and a circle mark as "1". Therefore, the detection target storage unit 21 is an example of a storage unit that stores detection completed information indicating whether or not the position of each of one or more radio tags TG that are the position detection targets has been detected, in association with the identification information of the radio tag TG.

[0033] The position correction valid flag storage unit 22 stores a position correction valid flag indicating whether it is necessary to correct the position of the detected radio tag TG. The position correction valid flag storage unit 22 can store this position correction valid flag, for example, as a 1-bit flag with "0" indicating no correction required and "1" indicating correction required. In this way, the position correction valid flag storage unit 22 is an example of a setting storage unit that stores a position correction valid flag indicating whether to correct the position of the radio tag TG for which the position has been detected.

[0034] The read data storage unit 23 stores the data read from the wireless tag TG to be position-detected. FIG. 7 is a schematic diagram showing the main data structure stored in the read data storage unit 23. Note that the data structure shown in FIG. 7 is an example. The format is not particularly limited as long as the information necessary for the processor 10 can be obtained. As shown in FIG. 7, the read data storage unit 23 stores the position detection data in association with the identification information read from the wireless tag TG to be position-detected. The position detection data includes, for example, the acquisition time, RSSI, phase, and device position.

[0035] The acquisition time is the time when the identification information is acquired from the wireless tag TG to be position-detected. As described above, the identification information is read in different slots. Therefore, the acquisition time can also be said to be the occurrence time of the slot. More specifically, it can be said to be the reading time of the identification information within the slot. Although not shown in FIG. 1, the wireless tag communication device 1 is equipped with a clock, and the processor 10 can obtain the acquisition time of the identification information by this clock and store the identification information acquired by the wireless communication unit 60 and this acquisition time in the read data storage unit 23. Also, the acquisition time may be the current time or the elapsed time since the start of reading.

[0036] The RSSI is the signal strength of the response signal carrying the identification information from the wireless tag TG to be position-detected. This RSSI is detected by the RSSI detection unit 63 of the wireless communication unit 60. Also, the phase is the phase of the response signal as well, and is detected by the phase detection unit 64 of the wireless communication unit 60. These RSSI and phase are an example of the communication state with the wireless tag TG acquired by the wireless communication unit 60. When the processor 10 acquires the identification information, it can associate the RSSI and phase at that time with the identification information and store them in the read data storage unit 23. Note that in FIGS. 1 and 7, the case of performing position detection using both RSSI and phase is shown as an example, but since position detection is possible with only either one, it may be configured to detect and store at least one of RSSI and phase. Therefore, the RSSI detection unit 63 or the phase detection unit 64 is an example of a state detection unit that detects the communication state with the wireless tag TG by the wireless communication unit 60.

[0037] The device position is position information representing the position of the wireless tag communication device 1 when acquiring the response signal from the wireless tag TG to be position-detected. The position information can include information on the position and orientation of the antenna 61 provided in 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, due to performance such as the directivity of the antenna 61, the positional and postural relationship between the antenna 61 and the wireless tag TG changes, but here, the processor 10 assumes that the wireless tag TG is in the front direction of the antenna 61 and calculates the position and orientation. The processor 10 associates the calculated device position with the identification information and stores it in the read data storage unit 23. 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 a plurality of slots within one round have the same device position.

[0038] The position calculation result storage unit 24 stores the position detection result detected for the wireless tag TG to be position-detected.

[0039] The input device 30 is operation switches, operation buttons, etc. arranged in a housing (not shown) of the wireless tag communication device 1. Alternatively, the input device 30 may be an interface for connecting to operation switches, operation buttons, etc. that are 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 an LED, an acoustic device such as a buzzer or a speaker, etc. arranged in 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 an acoustic device that is separate from the housing of the wireless tag communication device 1. Also, 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 these input device 30 and output device 40 to have the user set the wireless tag TG to be position-detected or set the position correction enable flag. Also, the processor 10 can use the output device 40 to notify the user of the position of the detected wireless tag TG to be position-detected or notify the end of the position detection operation.

[0041] The sensor 50 is various sensors used to calculate the device position stored in the aforementioned read data storage unit 23. For example, such a sensor 50 can include an acceleration sensor, a camera, etc. For example, the processor 10 can calculate the movement amount of the wireless tag communication device 1 based on the acceleration detected by the acceleration sensor and determine the position based on this movement amount. For example, the processor 10 can estimate its own position based on the movement amount of the subject shown in the image captured by the camera. Also, the sensor 50 may include a positioning sensor 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 FIG. 1, and wirelessly communicates with a wireless tag TG, such as a UHF band RFID tag, that has entered this communication area CA. The wireless communication unit 60 includes a flag that stores either one of a first state, for example, an A value, and a second state, for example, a B value, and when receiving an identification information reading command that designates a flag state, returns the identification information only when the flag state corresponds to the designated flag state. It is an example of a wireless communication unit that communicates with the wireless tag TG. The wireless tag TG includes a wireless tag TG that is a target for position detection and a non-detection target wireless tag TG that is not a target for position detection. The wireless communication unit 60 has an antenna 61 and a wireless tag communication circuit 62 for wirelessly communicating with the wireless tag TG that has entered the communication area CA. Further, the wireless communication unit 60 has an RSSI detection unit 63 that detects the RSSI, which is the intensity 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 performs data communication with the connected upper device UE according to a preset communication protocol. The connection with the upper device UE may be a wired connection or a wireless connection.

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

[0045] Hereinafter, the operation of the wireless tag communication system and the wireless tag communication device 1 according to this embodiment with such a configuration will be described. Note that the setting operations of the wireless tag TG to be detected and the position correction enable flag are simply operations that are set according to the user's designation, so the description thereof will be omitted. Therefore, here, the operation related to the position detection of the wireless tag TG to be detected will be described.

[0046] FIGS. 8 to 10 are each a sequence diagram showing an overview of the operation of the wireless tag communication device 1. FIG. 8 shows the first round of reading (ROU1), FIG. 9 shows the nth round of reading (ROUn), and FIG. 10 shows the (n + 1)th round of reading (ROUn+1). FIGS. 8 to 10 show an example in which four wireless tags TG, namely, a non-target wireless tag a with identification information (tag ID) "a", a target wireless tag b with identification information "b", a target wireless tag c with identification information "c", and a target wireless tag d with identification information "d", are within the communication area CA. Note that FIGS. 8 to 10 show an ideal case where the counter values do not collide. In reality, there may be a case where the wireless tag communication device 1 does not receive the identification information (tag ID) due to the collision of the counter values of a plurality of wireless tags TG.

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

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

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

[0050] Based on the content stored in the detection target storage unit 21, the wireless tag communication device 1 determines whether the received identification information is a target for acquiring position detection data (step S4). Specifically, when the received identification information is the wireless tag TG stored in the detection target storage unit 21, that is, the position detection target, and the detection flag associated with the corresponding identification information is not detected, the wireless tag communication device 1 determines that the received identification information is a data acquisition target.

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

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

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

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

[0055] When the wireless tag communication device 1 receives the identification information transmitted from this non-target wireless tag a, at the time of receiving the identification information, it acquires position detection data, that is, the acquisition time, RSSI, and phase (step S3). Then, the wireless tag communication device 1 determines whether the identification information is a target for acquiring position detection data based on the content stored in the detection target storage unit 21 (step S4). The wireless tag communication device 1 determines that the non-target wireless tag a of the received identification information is not a data acquisition target. Therefore, in this case, the wireless tag communication device 1 does not instruct the non-target wireless tag a, which is not a data acquisition target, without flag change.

[0056] When it is determined that the received identification information is not a data acquisition target, the wireless tag communication device 1 ends the processing of this slot.

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

[0058] The non-target wireless tag a that has not received the no flag change instruction receives this inquiry and rewrites the flag state from the A value to the B value (step S7). In this way, the wireless tag communication device 1 can rewrite the flag state of the non-target wireless tag a from the A value to the B value by not transmitting no flag change, which instructs not to rewrite the flag state to the B value for the non-target wireless tag a that is not a position detection target.

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

[0060] The wireless tag communication device 1 acquires position detection data by receiving identification information from the target wireless tag d (step S3), and also determines whether it is a target for acquiring the position detection data (step S4). If it is a target for data acquisition, the wireless tag communication device 1 transmits an instruction without flag change (step S5). Then, the wireless tag communication device 1 determines whether it is possible to calculate the position of the target wireless tag d (step S6), and if it is not possible to calculate, the processing for this slot ends.

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

[0062] Also, when, in response to the inquiry, for example, the target wireless tag c transmits identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires position detection data (step S3), and also determines whether it is a target for acquiring the position detection data based on the identification information (step S4). If it is a target for data acquisition, the wireless tag communication device 1 transmits an instruction without flag change (step S5). Then, the wireless tag communication device 1 determines whether it is possible to calculate the position of the target wireless tag c (step S6), and if it is not possible to calculate, the processing for this slot ends.

[0063] Hereinafter, in the same manner, each wireless tag TG and the wireless tag communication device 1 perform the processing for the remaining slots of this round 1 (ROU1) and further for subsequent rounds.

[0064] As shown in FIG. 9, in slot 1 (SLT#1) of round n (ROUn), the wireless tag communication device 1 transmits an inquiry to the wireless tag TG within the communication area CA (step S1). The non-target wireless tag a with the flag state being the B value does not respond to this inquiry.

[0065] In response to an inquiry transmitted from the wireless tag communication device 1, for example, when the target wireless tag b transmits identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires position detection data (step S3). Further, the wireless tag communication device 1 determines whether the acquired position detection data is a target for acquisition based on the received identification information (step S4). If it is a data acquisition target, an instruction without flag change is transmitted (step S5). Then, the wireless tag communication device 1 determines whether the position of the target wireless tag b can be calculated (step S6).

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

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

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

[0069] Also, in response to the inquiry, for example, when the target wireless tag c transmits identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires position detection data (step S3). Further, the wireless tag communication device 1 determines whether the acquired position detection data is a target for acquisition based on the received identification information (step S4). If it is a data acquisition target, an instruction without flag change is transmitted (step S5). Then, the wireless tag communication device 1 determines whether the position of the target wireless tag c can be calculated (step S6). If it is not calculable, the processing of this slot is ended.

[0070] In the next slot 3 (SLT#3), when the wireless tag communication device 1 transmits an inquiry (step S1), the non-target wireless tag a with the flag state being the B value does not respond to this inquiry.

[0071] Also, when, in response to the inquiry, for example, the target wireless tag d transmits identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires position detection data (step S3). Further, the wireless tag communication device 1 determines whether it is a target for acquiring position detection data based on the received identification information (step S4). If it is a data acquisition target, it transmits an instruction without flag change (step S5). Then, the wireless tag communication device 1 determines whether the position of the target wireless tag d can be calculated (step S6). If it cannot be calculated, the processing for this slot ends.

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

[0073] As shown in FIG. 10, in the slot X (SLT#X) (X is a natural number) of round n + 1 (ROUn + 1), the wireless tag communication device 1 transmits an inquiry to the wireless tags TG within the communication area CA (step S1). The non-target wireless tag a with the flag state being the B value does not respond to this inquiry.

[0074] In response to the query transmitted from the wireless tag communication device 1, for example, when the target wireless tag b transmits identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires position detection data (step S3). Further, the wireless tag communication device 1 determines whether it is a target for acquiring position detection data based on the received identification information (step S4). In step S9 of slot 1 (SLT#1) in the previous round n (ROUn), the detection flag associated with the identification information of the target wireless tag b, which is the corresponding wireless tag TG in the detection target storage unit 21, has "detected" set. Therefore, here, the wireless tag communication device 1 determines that it is not a target for acquiring position detection data. Thus, in this case, the wireless tag communication device 1 does not instruct the target wireless tag b, which is no longer a data acquisition target, without changing the flag.

[0075] When it is determined that the received identification information is not a data acquisition target, the wireless tag communication device 1 ends the processing for this slot.

[0076] In the next slot X + 1 (SLT#X + 1), the wireless tag communication device 1 transmits a query to the wireless tag TG within the communication area CA (step S1). The target wireless tag b that has not received an instruction not to change the flag will receive this query and rewrite the flag state from value A to value B (step S7). Since the other operations are as described in round n (ROUn), the description thereof is omitted. In this way, the wireless tag communication device 1 can rewrite the flag state from value A to value B by not transmitting without changing the flag to the wireless tag b that is no longer a position detection target due to the position detection being completed.

[0077] Next, a specific example of the operation of the wireless tag communication device 1 will be described. FIG. 11 is a series of flowcharts showing the main procedure of the information processing executed by the processor 10 of the wireless tag communication device 1. The processor 10 executes this process based on a control program stored in the memory 20, for example, in response to a start operation by the input device 30 or a start instruction from a host device UE by the communication interface 70. Unless otherwise specified, the processing operation of the processor 10 shall transition to ACT(x + 1) after ACTx (x is a natural number). Also, the procedure shown in FIG. 11 is an example. The procedure is not particularly limited as long as the same result can be obtained.

[0078] As ACT10, the processor 10 operates the wireless communication unit 60 to start reading a wireless tag TG with an A value specified as a flag state.

[0079] As ACT11, the processor 10 determines whether there is a response from any of the wireless tags TG, that is, whether a response is received by the wireless communication unit 60. If there is a response, the processor 10 determines YES in ACT11 and proceeds to ACT12. If there is no response, the processor 10 determines NO in ACT11 and repeats this ACT11 again. In this way, the processor 10 waits for a response from any of the wireless tags TG.

[0080] As ACT12, the processor 10 acquires the tag ID, that is, the identification information, of the wireless tag TG that returned the response. Specifically, the processor 10 transmits an ACK to the wireless tag TG that returned the response through the wireless communication unit 60, and receives the tag ID transmitted from the corresponding wireless tag TG in response. The processor 10 stores the tag ID received by the wireless communication unit 60 in the work area of the memory 20. Therefore, the processor 10 is an example of an acquisition unit that transmits an identification information reading command with, for example, an A value specified as the first state as a flag state through the wireless communication unit 60 and acquires the identification information returned from the wireless tag TG whose flag state is the first state.

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

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

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

[0084] As ACT16, the processor 10 discards the data for position detection stored in the read data storage unit 23. Specifically, the data for position detection stored in the read data storage unit 23 in association with the identification information is deleted. After that, the processor 10 proceeds to ACT11. In this way, the processor 10 does not transmit without flag change to the wireless tag TG determined not to be the wireless tag to be position-detected, causing the flag state of the wireless tag TG to be rewritten from the A value to the B value, and discarding the data for position detection of the unused wireless tag TG.

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

[0086] As ACT18, the processor 10 transmits, via the wireless communication unit 60, a no flag change instructing not to rewrite the flag state to the wireless tag TG that is the position detection target.

[0087] As ACT19, the processor 10 determines whether it is possible to detect the position of the wireless tag TG based on the position detection data stored in the read data storage unit 23. For example, when calculating the position by three-point surveying, if the number of RSSIs stored in the read data storage unit 23 associated with the identification information of the wireless tag TG is equal to or greater than a predetermined number, the processor 10 can determine that the position can be calculated. Also, when calculating the position based on the phase, if the slope of the phase change stored in the read data storage unit 23 associated with the identification information of the wireless tag TG has reversed, the processor 10 can determine that the position can be calculated. In any case, considering the possibility of misdetection of the detection data due to noise or the like, it is not immediately determined that the position can be calculated. Instead, it is desirable to determine that the position can be calculated when a certain amount of excess detection data has been acquired. If the position calculation is possible, the processor 10 determines YES in ACT19 and proceeds to ACT20. If the position calculation is not possible, the processor 10 determines NO in ACT19 and proceeds to ACT11.

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

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

[0090] As ACT22, the processor 10 notifies the calculation result by the output device 40. Note that when staying at one location and scanning the direction of the wireless tag communication device 1 or continuously performing reading while moving the wireless tag communication device 1, this ACT22 may not be necessary.

[0091] As ACT23, the processor 10 stores a position-detected flag. Specifically, the processor 10 sets "detected" in the detection flag stored in the detection target storage unit 21 in association with the identification information of the wireless tag TG for which the position has been detected. In this way, when the processor 10 detects the position of the wireless tag TG, the processor 10 is an example of a storage control unit that sets the detected information stored in the detection target storage unit 21 in association with the identification information of the wireless tag TG as "position detected".

[0092] As ACT24, the processor 10 determines whether there is a target wireless tag for which the position has not been detected. Specifically, the processor 10 determines whether there is identification information for which the detection flag in the detection target storage unit 21 is "not detected". If there is a target wireless tag for which the position has not been detected, the processor 10 determines YES in ACT24 and proceeds to ACT11. At this time, if one round has ended, the next round is started. Also, when implementing a reading method in which the wireless tag communication device 1 is directed in one direction at one location for reading and then moved to another location and read in the same way, if there is such a target wireless tag for which the position has not been detected, the output device 40 may notify the user of this fact to prompt the user to move to another location. If there is no target wireless tag for which the position has not been detected, that is, if the positions of all the wireless tags TG to be detected have been detected, the processor 10 determines NO in ACT24 and proceeds to ACT26.

[0093] As ACT25, the processor 10 determines whether position correction is effective by checking the position correction effective flag stored in the position correction effective flag storage unit 22, which indicates whether it is necessary to correct the position of the detected wireless tag TG.

[0094] When the position correction is not valid, that is, when the position correction is not performed, for the target wireless tag TG for which the position has been detected, there is no need to obtain the position detection data any further. Therefore, if the position correction is not valid, the processor 10 determines NO in ACT25 and proceeds to ACT16. As a result, in ACT16, the processor 10 discards the position detection data stored in the read data storage unit 23 by the wireless communication unit 60. In this way, for the wireless tag TG that has been determined to be the target of position detection and for which position correction is not performed, the processor 10 does not transmit without flag change, so that the flag state of the wireless tag TG is rewritten from the A value to the B value for the inquiry in the next slot, and the position detection data of the unused wireless tag TG is discarded. Therefore, the processor 10 is an example of an instruction unit that instructs the wireless communication unit to rewrite the flag state to the second state for the wireless tag that has returned the identification information when the wireless tag that has returned the identification information has been detected.

[0095] On the other hand, when the position correction is valid, that is, when even if the position is detected, the position detection data to be acquired later is further used to perform more accurate position detection, the processor 10 determines YES in ACT25 and proceeds to ACT18. In this way, when the setting stored in the position correction valid flag storage unit 22 is a setting for correcting the position, the processor 10 makes the wireless tag TG for which the position has been detected the target of position detection again by transmitting without flag change.

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

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

[0098] Note that the processor 10 may transmit the position calculation result and the read completion notification to the host device UE via the communication interface 70.

[0099] As described above, the processor 10 of the wireless tag communication device 1 according to the first embodiment includes a flag that stores a flag state of either one of, for example, an A value in the first state and a B value in the second state. When receiving an identification information read command specifying the flag state, the wireless communication unit 60 that communicates with the wireless tag TG returns the identification information only when the flag state corresponds to the specified flag state. The wireless communication unit 60 transmits an identification information read command specifying the first state as the flag state and acquires the identification information returned from the wireless tag whose flag state is the first state. Then, the processor 10 determines whether or not the wireless tag TG that has returned the identification information has been detected based on the acquired identification information. When the wireless tag TG that has returned the identification information has been detected, the processor 10 instructs the wireless communication unit 60 to rewrite the flag state to, for example, a B value in the second state for the wireless tag TG that has returned the identification information. As described above, according to the wireless tag communication device 1 according to the first embodiment, the wireless tag TG that has been detected can be made not to respond to an identification information read command specifying, for example, an A value in the first state in subsequent slots or rounds. Therefore, the wireless tags TG that have been detected do not seize the reading opportunity of the wireless tags TG that have not been detected, that is, the reading opportunity of the wireless tags TG that have not been detected increases as compared with the conventional reading method. Thus, according to the wireless tag communication device 1 according to the first embodiment, it is possible to shorten the time until all of the plurality of wireless tags to be detected are read.

[0100] Note that after the wireless tag TG returns the identification information, its flag state is specified to be rewritten from, for example, an A value in the first state to a B value in the second state. Therefore, in the wireless tag communication device 1 according to the first embodiment, the processor 10 transmits a no flag change instruction to instruct the wireless tag determined not to be the wireless tag TG to be detected not to rewrite the flag state to the B value, and does not transmit a no flag change instruction to the wireless tag TG determined to be the wireless tag TG to be detected, so as to rewrite the flag state to the B value. As described above, according to the wireless tag communication device 1 according to the first embodiment, it operates in accordance with the specifications of the wireless tag TG.

[0101] Further, the wireless tag communication device 1 according to the first embodiment further includes a detection target storage unit 21 that is a storage unit for storing detection completed information indicating whether or not the position of each of one or more wireless tags TG to be detected has been detected, associated with the identification information of each wireless tag TG to be detected. The processor 10 determines whether or not the wireless tag TG that has returned the acquired identification information is a wireless tag TG to be detected based on the detection completed information stored in the detection target storage unit 21 associated with the acquired identification information, and instructs the wireless tag TG to be detected whose position has been detected to rewrite the flag state to, for example, a B value in the second state. Therefore, according to the wireless tag communication device 1 according to the first embodiment, it is possible to easily determine whether or not the wireless tag TG that has returned the identification information is a wireless tag TG to be detected whose position has been detected, and the wireless tag TG to be detected whose position has been detected can be made not to respond to the identification information reading command designating the A value in subsequent slots or rounds.

[0102] Further, in the wireless tag communication device 1 according to the first embodiment, the processor 10 further determines whether or not the wireless tag TG that has returned the acquired identification information is a wireless tag TG to be detected based on whether or not the acquired identification information is stored in the detection target storage unit 21. When the wireless tag TG that has returned the identification information is not a wireless tag TG to be detected, the processor 10 instructs the wireless tag TG that has returned the identification information to rewrite the flag state to the B value. Therefore, according to the wireless tag communication device 1 according to the first embodiment, it is possible to prevent a wireless tag TG that is not a target for position detection from responding to an identification information reading command that designates an A value in subsequent slots or rounds. As a result, a wireless tag TG that is not a target for position detection does not seize the reading opportunity of a wireless tag TG that is a target for non-detection of position, so that it is possible to further shorten the time until all of a plurality of wireless tags that are targets for position detection are read.

[0103] Further, 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 RSSI and / or a phase, which is a communication state with the wireless tag TG by the wireless communication unit 60. The processor 10 detects the position of the wireless tag TG based on the detected communication state, and when the position of the wireless tag TG is detected, the detected information stored in association with the identification information of the wireless tag TG in the detection target storage unit 21 is set as detected. Therefore, according to the wireless tag communication device 1 according to the first embodiment, by updating the content of the detection target storage unit 21 in response to the detection of the position of the wireless tag TG, it can be used for determining a detected wireless tag TG in subsequent slots or rounds.

[0104] Further, the wireless tag communication device 1 according to the first embodiment further includes a position correction effective flag storage unit 22, which is a setting storage unit that stores a position correction effective flag indicating whether to correct the position of a detected wireless tag TG. When the setting stored in the position correction effective flag storage unit 22 is a setting for correcting the position, the processor 10 does not issue an instruction to rewrite to, for example, a B value, which is a second state of the flag state, for the detected wireless tag TG. Therefore, according to the wireless tag communication device 1 according to the first embodiment, even if the position of the wireless tag TG is detected, it is possible to perform more accurate position detection by further using the position detection data acquired thereafter.

[0105] The wireless tag communication system according to the first embodiment further includes a wireless tag communication device 1 according to the first embodiment and a host device UE that is connected to the wireless tag communication device 1 and controls the wireless tag communication device 1. The detection target storage unit 21 stores the identification information of the wireless tag TG that is the position detection target set by the host device UE. Therefore, according to the wireless tag communication system according to the first embodiment, the wireless tag TG to be the position detection target can be easily set.

[0106] [Second Embodiment] Next, the second embodiment will be described. Regarding the same configurations and the same operations as those in the first embodiment, the same reference numerals as those in the first embodiment are used, and the description thereof will be omitted.

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

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

[0109] The host device UE includes a processor 101, a memory 102, an input device 103, an output device 104, a communication interface 105, and a system transmission path 106. In FIG. 12 as well, the "interface" is abbreviated as "I / F". The system transmission path 106 includes an address bus, a data bus, control signal lines, and the like. The system transmission path 106 connects the processor 101 to other components directly or via a signal input / output circuit, and transmits data signals exchanged between them. When the processor 101 and the memory 102 are connected by the system transmission path 106, the computer of the host device UE is configured. The memory 102 includes 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, an operation button, etc., and the output device 104 is a display device such as a liquid crystal display or an LED, and an acoustic device such as a buzzer or a speaker. Also, the input device 103 and the output device 104 may be configured as a touch panel with touch keys arranged on a display screen such as a liquid crystal display.

[0110] FIGS. 13 and 14 are sequence diagrams showing an overview of the operation of the wireless tag communication system. FIG. 13 shows the first round of reading (ROU1), and FIG. 14 shows the nth round of reading (ROUn). FIGS. 13 and 14 assume that the target wireless tag a with identification information (tag ID) "a", the target wireless tag b with identification information "b",... are within the communication area CA. For convenience of the drawing, non-target wireless tags TG are not shown, but such non-target wireless tags TG may also enter the communication area CA. FIGS. 13 and 14 show an ideal case where the counter values do not collide. In reality, there may be cases where the wireless tag communication device 1 does not receive the identification information (tag ID) due to the collision of the counter values of multiple wireless tags TG.

[0111] As shown in FIG. 13, in slot 1 (SLT#1) of round 1 (ROU1), the wireless tag communication device 1 transmits an inquiry to the wireless tag TG that has entered the communication area CA (step S1), and for example, the target wireless tag a transmits identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0112] When the wireless tag communication device 1 receives the identification information transmitted from this target wireless tag a, it acquires position detection data, that is, the acquisition time, RSSI, and phase (step S3). Then, based on the content stored in the detection target storage unit 21, the wireless tag communication device 1 determines whether the received identification information is a target for acquiring position detection data (step S4). If it is a data acquisition target, it instructs the target wireless tag a without changing the flag (step S5).

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

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

[0115] In the same manner, for the remaining slots after the next slot 2 (SLT#2) and further for each slot in subsequent rounds, the wireless tag communication device 1 acquires the identification information and position detection data of the wireless tag TG that is the target for position detection, and the host device UE stores it.

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

[0117] When the wireless tag communication device 1 receives the identification information transmitted from the target wireless tag a, it acquires position detection data (step S3), and also determines whether the received identification information is a target for acquiring position detection data based on the content stored in the detection target storage unit 21 (step S4). If it is a data acquisition target, the wireless tag communication device 1 instructs the target wireless tag a without changing the flag (step S5). Then, the wireless tag communication device 1 transmits the identification information of the received target wireless tag a and the acquired position detection data to the host device UE (step S11).

[0118] The host device UE stores the received position detection data in association with the received identification information in the read data storage unit 1021, and determines whether it is possible to calculate the position of the target wireless tag a from the data stored in the read data storage unit 1021 (step S12).

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

[0120] If the position can be calculated in this way, the host device UE transmits a detection completion notification to the wireless tag communication device 1 (step S14).

[0121] Upon receiving this detected notification, the wireless tag communication device 1 sets the detection flag associated with the identification information of the target wireless tag a, which is the corresponding wireless tag TG in the detection target storage unit 21, to detected (step S9). Then, the wireless tag communication device 1 ends the processing of this slot. As a result, when the identification information of this target wireless tag a is received in any slot of round n + 1 (ROUn+1), which is the next round of the current round n (ROUn) (not shown), the wireless tag communication device 1 determines that it is not a target for acquiring the position detection data in the determination of whether it is a target for acquiring the position detection data in step S4 because the detection flag is set to detected. Therefore, without transmitting any flag change to this target wireless tag a, the flag state of the target wireless tag a will be rewritten from the A value to the B value by receiving an inquiry in the next slot.

[0122] In the next slot 2 (SLT#2), the wireless tag communication device 1 transmits an inquiry (step S1). In response to this inquiry, if any wireless tag TG (not shown), for example, a non-target wireless tag TG, transmits its identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires the position detection data (step S3). Also, the wireless tag communication device 1 determines whether it is a target for acquiring the position detection data based on the received identification information (step S4). If it is not a target for data acquisition, the wireless tag communication device 1 does not instruct the non-target wireless tag, which is not a target for data acquisition, to change the flag. Then, the wireless tag communication device 1 ends the processing of this slot.

[0123] In the next slot 3 (SLT#3), the wireless tag communication device 1 transmits an inquiry (step S1). In response to this inquiry, for example, when the target wireless tag b transmits identification information (tag ID) to the wireless tag communication device 1 (step S2), the wireless tag communication device 1 acquires position detection data (step S3). Further, the wireless tag communication device 1 determines whether it is a target for acquiring position detection data based on the received identification information (step S3). If it is a target for data acquisition, the wireless tag communication device 1 instructs the target wireless tag b without changing the flag (step S5). Then, the wireless tag communication device 1 transmits the received identification information of the target wireless tag b and the acquired position detection data to the upper device UE (step S11).

[0124] The upper device UE stores the received position detection data in association with the received identification information in the read data storage unit 1021, and determines whether it is possible to calculate the position of the target wireless tag b from the data stored in this read data storage unit 1021 (step S12). If the position cannot be calculated, the processing for this slot ends.

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

[0126] Next, a specific example of the operations of the wireless tag communication device 1 and the host device UE will be described. FIG. 15 is a series of flowcharts showing the main procedure of the information processing executed by the processor 10 of the wireless tag communication device 1. The processor 10 of the wireless tag communication device 1 executes this process based on the control program stored in the memory 20 when the power is turned on. Further, FIG. 16 is a flowchart showing the main procedure of the information processing executed 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 that activates the control program stored in the memory 102 as an application program. Note that the procedures shown in FIGS. 15 and 16 are examples, and the procedures are not particularly limited as long as the same results can be obtained.

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

[0128] As ACT32, the processor 10 determines, via the communication interface 70, whether a start command for starting the position detection of the wireless tag TG to be position-detected from the host device UE has been received. If a start command from the host device UE has been received, the processor 10 determines YES in ACT32 and proceeds to ACT10. If a start command from the host device UE has not been received, the processor 10 determines NO in ACT32 and proceeds to ACT31.

[0129] As shown in FIG. 16, the processor 101 of the host device UE, as ACT101, determines whether there is a setting instruction by an operation of the input device 103 from the user. If there is a setting instruction, the processor 101 determines YES in ACT101 and proceeds to ACT103. If there is no setting instruction, the processor 101 determines NO in ACT101 and proceeds to ACT102.

[0130] As ACT102, the processor 101 determines whether there is a position detection start instruction for the wireless tag TG to be detected by an operation of the input device 103 from the user. If there is a position detection start instruction, the processor 101 determines YES in ACT102 and proceeds to ACT105. If there is no position detection start instruction, the processor 101 determines NO in ACT102 and proceeds to ACT101.

[0131] As ACT103, the processor 101 accepts the setting by an operation of the input device 103 from the user. The setting content is the designation of the wireless tag TG to be detected and the designation of whether position correction is valid or invalid. The designation of the wireless tag TG to be detected may be to directly input the identification information, or it may be in any form such as displaying a list of wireless tags TG that can be specified on the display device which is the output device 104 and selecting from among them.

[0132] As ACT104, the processor 101 transmits the accepted setting content to the wireless tag communication device 1 via the communication interface 105. Then, the processor 101 proceeds to ACT101.

[0133] As shown in FIG. 15, the processor 10 of the wireless tag communication device 1, as ACT33, stores the setting content transmitted from the host device UE in the detection target storage unit 21 and the position correction valid flag storage unit 22. Then, the processor 10 proceeds to ACT31.

[0134] As shown in FIG. 16, the processor 101 of the upper device UE, as ACT105, transmits a start command to the wireless tag communication device 1 via the communication interface 105.

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

[0136] As shown in FIG. 15, the processor 10 of the wireless tag communication device 1, as ACT10, starts reading the wireless tag TG designating the A value as the flag state, as described in the first embodiment.

[0137] As ACT11, the processor 10 determines whether there is a response from any of the wireless tags TG, as described in the first embodiment. If there is a response, the processor 10 determines YES in ACT11 and proceeds to ACT12. If there is no response, the processor 10 determines NO in ACT11 and, in this embodiment, proceeds to ACT35.

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

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

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

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

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

[0143] As ACT18, the processor 10 transmits, via the wireless communication unit 60, a no flag change instructing not to rewrite the flag state to the wireless tag TG to be position-detected. Thereafter, in this embodiment, the processor 10 proceeds to ACT34.

[0144] As ACT34, the processor 10 transmits, via the communication interface 70, the acquired position detection data together with the tag ID, i.e., the identification information, stored in the work area, to the host device UE. Note that the position detection data includes the position and orientation of the antenna 61 calculated in ACT13 if such calculation is performed, or the detection result of the sensor 50 if such calculation is not performed. Thereafter, the processor 10 proceeds to ACT11. In this way, the communication interface 70 is an example of an interface unit that transmits the RSSI and / or phase, which are the communication states detected by the RSSI detection unit 63 and / or the phase detection unit 64 as the state detection unit for detecting the communication state with the wireless tag TG by the wireless communication unit 60, to the host device UE, which is a detection device for detecting the position of the wireless tag TG based on this communication state.

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

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

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

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

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

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

[0151] As ACT113, the processor 101 determines whether or not an end notification has been received from the wireless tag communication device 1 by the communication interface 105. If an end notification has been received, the processor 101 determines YES in ACT113 and proceeds to ACT114. If an end notification has not been received, the processor 101 determines NO in ACT113 and proceeds to ACT106.

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

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

[0154] As ACT24, the processor 10 determines whether there is a target wireless tag whose position has not been detected, as described in the first embodiment. If there is a target wireless tag whose position has not been detected, the processor 10 determines YES in ACT24 and proceeds to ACT11. At this time, if one round has ended, the next round is started. If there is no target wireless tag whose position has not been detected, the processor 10 determines NO in ACT24 and proceeds to ACT26.

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

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

[0157] As ACT36, the processor 10 transmits an end notification to the host device UE through the communication interface 70. After that, the processor 10 proceeds to ACT31.

[0158] As shown in FIG. 16, the processor 101 of the host device UE notifies the end of reading through the output device 104 as ACT114.

[0159] As ACT115, the processor 101 determines whether there is an end instruction due to the operation of the input device 103 from the user. If there is no end instruction, the processor 101 determines NO in ACT115 and proceeds to ACT101. If there is an end instruction, the processor 101 determines YES in ACT115 and ends the processing of the control program as the application program.

[0160] Also, the user can end the operation of the processor 101 of the wireless tag communication device 1 shown in FIG. 15 by turning off the power of the wireless tag communication device 1.

[0161] As described above, according to the wireless tag communication device 1 according to the second embodiment, the RSSI and / or phase, which are the communication states detected by the RSSI detection unit 63 and / or the phase detection unit 64 as the state detection unit that detects the communication state with the wireless tag TG by the wireless communication unit 60, are transmitted to the host device UE, which is a detection device that detects the position of the wireless tag TG based on this communication state. When the communication interface 70, which is an interface unit that receives a position detection completed notification indicating the wireless tag TG for which the position has been detected, receives the position detection completed notification, the processor 10 sets the detected information stored in association with the identification information of the wireless tag TG in the detection target storage unit 21 as having been detected. Therefore, according to the wireless tag communication device 1 in the second embodiment, the content 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 host device UE, and it becomes possible to use it for the discrimination of the wireless tag TG that has been detected in subsequent slots and rounds.

[0162] Also, according to the wireless tag communication system according to the second embodiment, the part that detects the position of the wireless tag TG based on the RSSI and / or phase, which are the communication states with the wireless tag TG, is implemented in the host device UE connected to the wireless tag communication device 1. Even in this case, similar to the first embodiment, the wireless tag TG for which the position has been detected can be made not to respond to an identification information reading command that designates, for example, an A value in the first state in subsequent slots or rounds. Therefore, the wireless tags TG for which the positions have been detected do not seize the reading opportunity of the wireless tags TG for which the positions have not been detected, that is, the reading opportunity of the wireless tags TG for which the positions have not been detected increases as compared with the conventional reading method. Thus, according to the wireless tag communication device 1 according to the first embodiment, it is possible to shorten the time until all of the plurality of wireless tags to be position-detected are read. Further, by causing a higher-level device UE, which is an information processing device such as a server computer or an information processing device such as a smartphone that requires particularly high processing capacity, to execute the position detection process, as the processor 10 of the wireless tag communication device 1, an inexpensive one with not so high processing capacity can be used, and the cost of the wireless tag communication device 1 can be reduced.

[0163] As described above, the embodiments of the wireless tag communication system and the wireless tag communication device have been described, but such embodiments are not limited thereto. For example, ACT21 and ACT23 in the flowchart of FIG. 11 may be in reverse order or may be performed in parallel. Thus, as long as there is no conflict with the preceding or subsequent processing, the processing order may be changed or a plurality of processes may be performed in parallel.

[0164] In the above embodiment, the control program executed by the processor 10 of the wireless tag communication device 1 or the processor 101 of the higher-level device UE may be configured to be recorded and provided on a computer-readable recording medium such as a CD-ROM. Further, the control program may be configured to be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network.

[0165] In addition, although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope of the invention and are included in the invention described in the claims and the equivalent scope thereof.

[0166] [Appendix] From the above specific embodiments, an invention having the following configuration can be extracted. [1] A wireless communication unit that communicates with a wireless tag, comprising a flag for storing either one of the flag states of the first state and the second state, and when receiving an identification information reading command specifying the flag state, returns identification information only when the flag state corresponds to the specified flag state; An acquisition unit that transmits the identification information reading command designating the first state as the flag state by the wireless communication unit and acquires the identification information returned from the wireless tag whose flag state is the first state; A determination unit that determines whether or not the wireless tag that has returned the identification information has been detected based on the acquired identification information; When the wireless tag that has returned the identification information has been detected, an instruction unit that instructs the wireless communication unit to rewrite the flag state to the second state for the wireless tag that has returned the identification information; A wireless tag communication device comprising: [2] Further comprising a storage unit that stores detection completed information indicating whether or not the position of each of one or more wireless tags to be position-detected has been detected, associated with the identification information of each wireless tag; The determination unit determines whether or not the wireless tag that has returned the identification information is a wireless tag to be position-detected whose position has been detected, based on the detection completed information stored in the storage unit associated with the identification information acquired by the acquisition unit; The instruction unit instructs to rewrite the flag state to the second state for the wireless tag determined by the determination unit to be the wireless tag of the position detection target for which the position has been detected, in the wireless tag communication device according to [1]. [3] The determination unit further determines whether the wireless tag that has returned the identification information is the wireless tag of the position detection target based on whether the identification information acquired by the acquisition unit is stored in the storage unit, The instruction unit further instructs to rewrite the flag state to the second state for the wireless tag that has returned the identification information when the wireless tag that has returned the identification information is not the wireless tag of the position detection target, in the wireless tag communication device according to [2]. [4] A state detection unit that detects a communication state with the wireless tag by the wireless communication unit, A position detection unit that detects the position of the wireless tag based on the communication state, A storage control unit that sets the detected information stored in association with the identification information of the wireless tag in the storage unit as detected when the position detection unit detects the position of the wireless tag, The wireless tag communication device according to [2] or [3], further comprising: [5] A state detection unit that detects a communication state with the wireless tag by the wireless communication unit, An interface unit that transmits the communication state to a detection device that detects the position of the wireless tag based on the communication state, and receives a detection completion notification indicating a wireless tag for which the position has been detected from the detection device, A storage control unit that sets the detected information stored in association with the identification information of the wireless tag in the storage unit as detected when the interface unit receives the detection completion notification, The wireless tag communication device according to [2] or [3], further comprising: [6] After returning the identification information, the wireless tag rewrites the flag state from the first state to the second state. The instruction unit transmits a "no flag change" instruction that instructs not to rewrite the flag state to the second state for a wireless tag determined by the determination unit not to be a wireless tag to be position-detected. For a wireless tag determined by the determination unit to be a wireless tag to be position-detected, the instruction unit does not transmit the "no flag change" instruction, thereby rewriting the flag state to the second state. The wireless tag device according to any one of [1] to [5]. [7] The wireless tag communication device further includes a setting storage unit that stores a setting for determining whether to correct the position of the wireless tag for which the position has been detected. When the setting stored in the setting storage unit is a setting for correcting the position, the instruction unit does not instruct to rewrite the flag state to the second state for the wireless tag for which the position has been detected. The wireless tag communication device according to any one of [1] to [6]. [8] A wireless tag communication system including a wireless tag communication device that communicates with a wireless tag, and a host device that is connected to the wireless tag communication device and controls the wireless tag communication device. A wireless communication unit that communicates with the wireless tag, includes a flag that stores one of the flag states of the first state and the second state, and returns identification information only when the flag state corresponds to the specified flag state when receiving an identification information reading command that specifies the flag state. An acquisition unit that transmits an identification information reading command that designates the first state as the flag state by the wireless communication unit, and acquires the identification information returned from the wireless tag whose flag state is the first state. A state detection unit that detects a communication state between the wireless communication unit and the wireless tag. A position detection unit that detects the position of the wireless tag based on the communication state. A storage unit that stores detection completed information indicating whether the position of each of one or more wireless tags to be position-detected has been detected, associated with the identification information of each wireless tag. A determination unit that determines whether the wireless tag that has returned the identification information has been position-detected based on the detection completed information stored in the storage unit associated with the identification information acquired by the acquisition unit. When the wireless tag that has returned the identification information has been detected for its position, an instruction unit that instructs the wireless communication unit to rewrite the flag state to the second state for the wireless tag that has returned the identification information; A wireless tag communication system comprising: [9] The wireless tag communication device includes the wireless communication unit, the acquisition unit, the state detection unit, the position detection unit, the storage unit, the determination unit, and the instruction unit. The storage unit stores the identification information of the wireless tag to be detected for position set by the host device. The wireless tag communication system according to [7].

[10] The wireless tag communication device includes the wireless communication unit, the acquisition unit, the state detection unit, the storage unit, the determination unit, and the instruction unit. The host device includes the position detection unit. The wireless tag communication system according to [7].

[11] A flag for storing one of the flag states of the first state and the second state, and when an identification information reading command specifying the flag state is received, the identification information is returned only when the flag state corresponds to the specified flag state. A wireless communication unit for communicating with a wireless tag, a processor, and a memory, and a computer for controlling the wireless tag communication device for communicating with the wireless tag, An acquisition unit that transmits the identification information reading command designating the first state as the flag state by the wireless communication unit, acquires the identification information returned from the wireless tag whose flag state is the first state, and stores it in the memory; A determination unit that determines whether or not the wireless tag that has returned the identification information has been detected for its position based on the identification information stored in the memory; When the wireless tag that has returned the identification information has been detected for its position, an instruction unit that instructs the wireless communication unit to rewrite the flag state to the second state for the wireless tag that has returned the identification information; A program for functioning as:

[12] A hardware processor; A memory; A wireless communication unit that communicates with a wireless tag, comprising a flag for storing either one of the first state and the second state, and when receiving an identification information reading command specifying the flag state, returns the identification information only when the flag state corresponds to the specified flag state. comprising, wherein the hardware processor sends, via the wireless communication unit, the identification information reading command specifying the first state as the flag state, acquires the identification information returned from the wireless tag whose flag state is the first state, and stores it in the memory. Based on the identification information stored in the memory, determines whether the wireless tag that returned the identification information has been detected. When the wireless tag that returned the identification information has been detected, instructs the wireless communication unit to rewrite the flag state to the second state for the wireless tag that returned the identification information. A wireless tag communication device configured as described above.

Description of Reference Numerals

[0167] 1... Wireless tag communication device, 10,101... Processor, 20,102... Memory, 21... Detection target storage unit, 22... Position correction enable 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... Upper device.

Claims

1. A wireless communication unit that communicates with a wireless tag, comprising a flag for storing a flag state of either the first state or the second state, and when receiving an identification information reading command specifying the flag state, returns identification information only when the flag state corresponds to the specified flag state; An acquisition unit that transmits the identification information reading command designating the first state as the flag state by the wireless communication unit and acquires the identification information returned from the wireless tag whose flag state is the first state; A determination unit that determines whether or not the wireless tag that has returned the identification information has been position-detected based on the acquired identification information; An instruction unit that, when the wireless tag that has returned the identification information has been position-detected, instructs the wireless tag that has returned the identification information to rewrite the flag state to the second state by the wireless communication unit; A wireless tag communication device comprising:

2. Further comprising a storage unit that stores detection-completed information indicating whether or not the position of each of one or more wireless tags to be position-detected has been detected, associated with the identification information of each wireless tag; The determination unit determines whether or not the wireless tag that has returned the identification information is a wireless tag to be position-detected that has been position-detected based on the detection-completed information stored in the storage unit associated with the identification information acquired by the acquisition unit; The instruction unit instructs the wireless tag determined by the determination unit to be a wireless tag to be position-detected that has been position-detected to rewrite the flag state to the second state. The wireless tag communication device according to claim 1.

3. The determination unit further determines whether or not the wireless tag that has returned the identification information is a wireless tag to be position-detected based on whether or not the identification information acquired by the acquisition unit is stored in the storage unit; The instruction unit further instructs the wireless tag that has returned the identification information to rewrite the flag state to the second state when the wireless tag that has returned the identification information is not a wireless tag to be position-detected. The wireless tag communication device according to claim 2.

4. A state detection unit that detects a communication state with the wireless tag by the wireless communication unit; A position detection unit that detects the position of the wireless tag based on the communication state; When the position detection unit detects the position of the wireless tag, a storage control unit that sets the detected information stored in association with the identification information of the wireless tag in the storage unit as detected; The wireless tag communication device according to claim 2 or 3, further comprising:

5. A state detection unit that detects a communication state with the wireless tag by the wireless communication unit; An interface unit that transmits the communication state to a detection device that detects the position of the wireless tag based on the communication state, and receives a detection completion notification indicating a wireless tag for which the position has been detected from the detection device; A storage control unit that sets the detected information stored in association with the identification information of the wireless tag in the storage unit as detected when the interface unit receives the detection completion notification; The wireless tag communication device according to claim 2 or 3, further comprising:

6. A wireless tag communication system including a wireless tag communication device that communicates with a wireless tag, and a host device that is connected to the wireless tag communication device and controls the wireless tag communication device, A wireless communication unit that includes a flag that stores a flag state of either a first state or a second state, and returns identification information only when the flag state corresponds to the designated flag state when an identification information reading command designating the flag state is received; An acquisition unit that transmits an identification information reading command designating the first state as the flag state by the wireless communication unit, and acquires the identification information returned from the wireless tag whose flag state is the first state; A state detection unit that detects a communication state with the wireless tag by the wireless communication unit; A position detection unit that detects the position of the wireless tag based on the communication state; A storage unit that stores detected information indicating whether or not the position of each of one or more wireless tags to be position-detected has been detected, in association with the identification information of each wireless tag; A determination unit that determines whether or not the wireless tag that has returned the identification information has been position-detected based on the detected information stored in the storage unit in association with the identification information acquired by the acquisition unit; An instruction unit that instructs the wireless communication unit to rewrite the flag state to the second state for the wireless tag that has returned the identification information when the wireless tag that has returned the identification information has been position-detected; A wireless tag communication system comprising:

7. A computer that controls a wireless tag communication device comprising a wireless communication unit that communicates with a wireless tag, a processor, and a memory, the wireless communication unit having a flag for storing either the first state or the second state of the flag state, and when receiving an identification information reading command specifying the flag state, returning the identification information only when the flag state corresponds to the specified flag state. An acquisition unit that transmits the identification information reading command designating the first state as the flag state by the wireless communication unit, acquires the identification information returned from the wireless tag whose flag state is the first state, and stores it in the memory. A determination unit that determines whether or not the wireless tag that has returned the identification information has been detected based on the identification information stored in the memory. An instruction unit that instructs the wireless communication unit to rewrite the flag state to the second state for the wireless tag that has returned the identification information when the wireless tag that has returned the identification information has been detected. A program for functioning as.

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