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

Abstract

To allow the time required to read all of a plurality of wireless tags that are targets for reading to be shortened.SOLUTION: A wireless tag communication device includes a wireless communication unit, a first processing unit, and a second processing unit. The wireless communication unit communicates with a wireless tag. The first processing unit acquires identification information of the wireless tag in a first state by causing the wireless communication unit to transmit an identification information read command specifying the first state as a flag state, and when a wireless tag to be detected whose position has not been detected is identified as a wireless tag to be read based on the identification information, rewrites the flag state of the identified wireless tag from the first state to a second state. The second processing unit acquires the identification information only from the wireless tag to be read that is in the second state by causing the wireless communication unit to transmit an identification information read command specifying the second state as the flag state.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] In recent years, a 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. Technologies for detecting articles are used in various applications.

[0003] In this technology, 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 practice, 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. Therefore, the wireless tag communication device transmits the read command a plurality of times. As a result, the identification information that has already been read is also read by each read command, reducing the opportunity to read the identification information that has not yet been read. Therefore, 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 search 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 reduces the opportunity to read radio tags whose position detection has not yet been completed. Therefore, when there are a plurality of radio tags to be position-detected, that is, radio tags to be read, it takes 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, a first processing unit, and a second processing 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 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. The first processing unit transmits an identification information reading command specifying the first state as the flag state through the wireless communication unit, obtains the identification information of the wireless tag in the first state, and based on the identification information, when identifying a wireless tag to be detected with undetected position as a wireless tag to be read, causes the flag state of the identified wireless tag to be rewritten from the first state to the second state. The second processing unit transmits an identification information reading command specifying the second state as the flag state through the wireless communication unit, and obtains the identification information only from the wireless tag to be read in the second state.

Brief Description of Drawings

[0008]

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[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 a wireless tag communication system according to the first embodiment. The wireless tag communication system according to the first embodiment includes a wireless tag communication device 1 according to the first embodiment and a host device UE. The wireless tag communication device 1 detects the position of the wireless tag TG to be position-detected from among a plurality of wireless tags TG. The host device UE is an information processing device that uses the position of the wireless tag TG to be detected detected by the wireless tag communication device 1.

[0011] Before entering into 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. FIG. 2 is a schematic diagram showing an overview 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 a plurality of 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. 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 wireless tag TG that has responded 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 period of 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 cases 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 cases where there are wireless tag TGs with overlapping 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" in response to an inquiry from the wireless tag communication device 1, the wireless tag TG with a counter value of "0" is the wireless tag TG with tag ID = a. Therefore, the wireless tag TG with tag ID = a transmits "a" which is the identification information to the wireless tag communication device 1. The wireless tags TG with tag ID = b and tag ID = c do not return a response to the inquiry because their counter values are not "0".

[0017] In slot #2, which is the next slot, in response to the query from the wireless tag communication device 1, the wireless tag TG with tag ID = a whose counter value is "0" rewrites the flag state to the B value indicating read from the A value. That is, the query from the wireless tag communication device 1 includes an instruction to rewrite the flag specifying the read wireless tag TG. By being rewritten to the B value, the wireless tag TG with tag ID = a will neither update the counter value to "0" nor transmit the identification information. That is, it will not respond to the query 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", 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 query.

[0018] In slot #3, which is the next slot, in response to the query from the wireless tag communication device 1, the wireless tag TG with tag ID = a whose flag state is the B value 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". Therefore, the wireless tag TG with tag ID = c whose counter value is "0" transmits the identification information "c" to the wireless tag communication device 1. The wireless tag TG with tag ID = b does not return a response to the query because its counter value is not "0".

[0019] In slot #4, which is the next slot, in response to the query from the wireless tag communication device 1, the wireless tag TG with tag ID = c whose counter value is "0" rewrites the flag state to the B value indicating read from the A value. 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, for the inquiry from the wireless tag communication device 1, the wireless tag TG with tag ID = b whose counter value is "0" rewrites the 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 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 receiving a plurality of response signals, the wireless tag communication device 1 does not transmit an ACK. Therefore, the wireless tag TGs with tag ID = c and tag ID = n do not transmit identification information. Then, by the inquiry in the next slot, the counter values of these wireless tag TGs 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 tag TGs do not transmit identification information. These multiple wireless tag TGs 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, and thus can be read in some slot respectively.

[0022] FIG. 4 is a schematic diagram for explaining the position detection method by three - point measurement. When the wireless tag communication device 1 reads the 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 a 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 of the position detection methods, a plurality of device positions may be realized 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 reading it in the same way. 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 reading is not performed in the subsequent rounds for the wireless tag TG that has been read once, 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 wireless tag TG to be position-detected whose position has not yet been detected. This becomes a major problem particularly in a usage situation where an article with a specific wireless tag TG attached is searched for 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, and the like. 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 therebetween. The connection between the processor 10 and the memory 20 via the system transmission path 80 constitutes the computer of the wireless tag communication device 1. The memory 20 includes a detection target storage unit 21, a position correction valid flag storage unit 22, a read data storage unit 23, and a position calculation result storage unit 24. The wireless communication unit 60 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. The 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. The processor 10 is, for example, a CPU (Central Processing Unit). The 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, the processor 10 may be a combination of a plurality of these.

[0031] Memory 20 corresponds to the main memory part of the above computer. The memory 20 includes a non-volatile memory area and a volatile memory area. The memory 20 stores an operating system or a control program in the non-volatile memory area. Also, the memory 20 stores data necessary for the processor 10 to execute processes for controlling each part in the non-volatile or volatile memory area. The memory 20 includes, as such a memory area, for example, a detection target storage unit 21 and a position correction enable flag storage unit 22. Further, the memory 20 uses the volatile memory area as a work area where data is appropriately rewritten by the processor 10. The memory 20 includes, as such a memory area, for example, a read data storage unit 23 and a position calculation result storage unit 24. 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), or the like. 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 completion 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. The detection completion information is represented by a cross mark for undetected and a circle mark for detected. The detection target storage unit 21 can store this detection completion 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 completion information indicating whether or not the radio tag has been position-detected, in association with the identification information of each of the one or more radio tags that are the detection targets.

[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" for no correction required and "1" for 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 whose 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 this read data storage unit 23. Note that the data structure shown in FIG. 7 is an example. As long as the information necessary for the processor 10 can be obtained, the format is not particularly limited. 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, which 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. The processor 10 can store the RSSI and phase at the time of acquiring the identification information in association with the identification information 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. However, since position detection is possible with only either one, it may be configured to detect and store at least one of RSSI and phase.

[0037] The device position is position information representing the position of the wireless tag communication device 1 when a response signal from the wireless tag TG to be position-detected is acquired. The position information can include information on the position and orientation of the antenna 61 provided in the wireless communication unit 60. Based on the detection result of the sensor 50, the processor 10 calculates the position and orientation of the antenna 61. 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. Here, however, the processor 10 calculates the position and orientation assuming that the wireless tag TG is in the front direction of the antenna 61. The processor 10 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 an operation switch, an operation button, etc. arranged on the housing of the wireless tag communication device 1 (not shown). Alternatively, the input device 30 may be an interface for connecting to an operation switch, an operation button, etc. separate from the housing of the wireless tag communication device 1. The output device 40 is a display device such as a liquid crystal display or an LED, an acoustic device such as a buzzer or a speaker, etc. arranged on the housing of the wireless tag communication device 1. Alternatively, the output device 40 may be an interface for connecting to a display device or an acoustic device 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 cause the user to set the wireless tag TG to be position-detected or set the position correction enable flag using these input device 30 and output device 40. Further, the processor 10 can 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 using the output device 40.

[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. Further, 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 broken line in FIG. 1, and wirelessly communicates with a wireless tag TG, which is, for example, a UHF band RFID tag, that has entered the communication area CA. The wireless communication unit 60 includes a flag for storing 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 designating the flag state, returns the identification information only when the flag state corresponds to the designated flag state, and is an example of a wireless communication unit that communicates with the wireless tag TG. The wireless tag TG includes a wireless tag TG to be position-detected and a non-detection target wireless tag TG that is not a position detection target. 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 for detecting the RSSI, which is the intensity of the response signal from the wireless tag TG, and a phase detection unit 64 for detecting 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 realize 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 a control function of the wireless tag communication device 1 such as a function of giving various settings such as setting of the wireless tag TG to be detected and setting of the position correction valid 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 the present embodiment having such a configuration will be described. Note that the setting operation of the wireless tag TG to be detected and the position correction valid flag is simply an operation of setting 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] Figures 8 and 9 are sequence diagrams showing the outline of the operation of the wireless tag communication device 1. Figure 8 shows the first processing step (PRO1), and Figure 9 shows the second processing step (PRO2). The first processing step identifies an undetected wireless tag TG located within the communication area CA as a reading target, and the second processing step enables communication only with the identified wireless tag TG that is the reading target. The second processing step calculates the position of the identified wireless tag TG that is the reading target. Note that Figures 8 and 9 show an example in which four wireless tags TG, namely, target wireless tag a with identification information (tag ID) "a", target wireless tag b with identification information "b", target wireless tag c with identification information "c", and non-target wireless tag d with identification information "d", are located within the communication area CA. Note that Figures 8 and 9 show an ideal case where the counter values do not collide, but 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.

[0047] As shown in Figure 8, in, for example, the first round of slot 1 (SLT#1) of the first processing step (PRO1), the wireless tag communication device 1 transmits an inquiry to the wireless tags TG located within the communication area CA by specifying the A value as a flag state (step S1).

[0048] In response to the inquiry transmitted from this wireless tag communication device 1, for example, target wireless tag a 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] When the wireless tag communication device 1 receives the identification information transmitted from the target wireless tag a, it determines whether the identification information is the acquisition target of the position detection data, that is, the reading target in the second processing step, based on the contents stored in the detection target storage unit 21 and the position correction effective flag storage unit 22 (step S3). Specifically, when the received identification information is stored in the detection target storage unit 21, that is, it is the wireless tag TG to be position-detected, and the detected information associated with the corresponding identification information is not detected, the wireless tag communication device 1 determines that the received identification information is the data acquisition target. Also, even if the detected information has been detected, when the position correction effective flag stored in the position correction effective flag storage unit 22 is "correction required", that is, when it is necessary to correct the position of the detected wireless tag TG, the wireless tag communication device 1 determines that the received identification information is the data acquisition target. When this determination is completed, the wireless tag communication device 1 ends the processing of this slot.

[0050] 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 by designating the A value as the flag state (step S1).

[0051] The target wireless tag a that has received this inquiry rewrites the flag state from the A value to the B value (step S4). That is, when the wireless tag TG transmits the identification information in response to the inquiry from the wireless tag communication device 1, it rewrites the flag state when receiving the inquiry command in the next slot. Therefore, the target wireless tag a that transmitted the identification information in slot 1 (SLT#1) changes the flag state.

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

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

[0054] 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, designating the A value as the flag state (step S1). In this case, unlike in the case of slot 2, since the non-target wireless tag d has received an instruction not to change the flag, it maintains the A value as the flag state.

[0055] Note that the target wireless tag a whose flag state has been rewritten from the A value to the B value does not respond to the inquiry designating the A value as the flag state. That is, the target wireless tag a ignores this inquiry. Therefore, among the remaining two target wireless tags TG excluding the non-target wireless tag d that has already transmitted the identification information, for example, the target wireless tag b responds to the inquiry and transmits the identification information (tag ID) to the wireless tag communication device 1 (step S2).

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

[0057] In the next slot 4 (SLT#4), the wireless tag communication device 1 transmits an inquiry to the wireless tag TG within the communication area CA by designating the A value as the flag state (step S1).

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

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

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

[0061] Hereinafter, in the same manner, each wireless tag TG and the wireless tag communication device 1 perform the processing of the remaining slots in this round and further the subsequent rounds. This first processing step is performed until a specified time elapses or until a specified number of rounds are performed. The specified number of rounds may be one round.

[0062] As shown in FIG. 9, in the slot 1 (SLT#1) of, for example, the nth round of the second processing step (PRO2), the wireless tag communication device 1 transmits an inquiry to the wireless tag TG within the communication area CA by designating the B value as the flag state (step S6).

[0063] The non-target wireless tag d whose flag state maintains the A value does not respond to an inquiry that designates the B value as this flag state. That is, the non-target wireless tag d ignores this inquiry. Therefore, among the remaining three target wireless tags TG whose flag states have been rewritten to the B value in the first processing step, for example, the target wireless tag a responds to the inquiry and transmits the identification information (tag ID) to the wireless tag communication device 1 (step S2).

[0064] The wireless tag communication device 1 receives the identification information transmitted from this target wireless tag a. When receiving this identification information, the wireless tag communication device 1 acquires the position detection data, that is, the acquisition time, RSSI, and phase (step S7). 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 among the position detection data, it is stored in the read data storage unit 23 at the stage when the calculation is completed. In each slot of each round up to the nth round, similarly, the wireless tag communication device 1 acquires the identification information and position detection data of the wireless tag TG to be position-detected, and stores it in the read data storage unit 23 in association with the received identification information.

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

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

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

[0068] Further, the wireless tag communication device 1 sets the detected information to detected in the detected information associated with the identification information of the target wireless tag a which is the corresponding wireless tag TG in the detection target storage unit 21 (step S10). Then, the wireless tag communication device 1 ends the processing of this slot.

[0069] 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, specifying the B value as the flag state (step S6).

[0070] The target wireless tag a that has received this inquiry rewrites the flag state from the B value to the A value (step S11).

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

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

[0073] In the next slot 3 (SLT#3), the wireless tag communication device 1 transmits an inquiry designating the B value as the flag state (step S6). In this case, since the target wireless tag c that transmitted the identification information in the previous slot, slot 2 (SLT#2), has received an instruction not to change the flag, it maintains the B value as the flag state. Also, the target wireless tag a whose flag state has been rewritten from the B value to the A value does not respond to the inquiry designating the B value as the flag state. That is, the target wireless tag a ignores this inquiry. Therefore, among the remaining target wireless tags TG excluding the non-target wireless tag c that has already transmitted the identification information, for example, the target wireless tag b responds to the inquiry and transmits the identification information (tag ID) to the wireless tag communication device 1 (step S2).

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

[0075] Hereinafter, in the same manner, each wireless tag TG and the wireless tag communication device 1 perform the processing of the remaining slots of this round and further the subsequent rounds. This second processing step is performed until a specified time elapses or until a specified number of rounds are performed.

[0076] Next, a specific example of the operation of the wireless tag communication device 1 will be described. FIGS. 10 and 11 are 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 processing based on a control program stored in the memory 20 in response to, for example, 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 is assumed to transition from ACTx (x is a natural number) to ACT(x + 1). Also, the procedure shown in FIGS. 10 and 11 is an example. The procedure is not particularly limited as long as the same result can be obtained.

[0077] As ACT10, the processor 10 operates the wireless communication unit 60 to start reading the wireless tag TG designated with the A value as the flag state.

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

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

[0080] As ACT13, 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 by 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.

[0081] As ACT14, 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 is, the identification information, that matches the tag ID stored in the work area is stored in the detection target storage unit 21. If the matching identification information is not stored, the processor 10 determines that the received tag ID is not the tag ID of the wireless tag TG to be position-detected, determines NO in ACT14, and proceeds to ACT15. If the received tag ID is the tag ID of the wireless tag TG to be position-detected, the processor 10 determines YES in ACT14 and proceeds to ACT16.

[0082] As ACT15, the processor 10 transmits, via the wireless communication unit 60, no flag change instructing not to rewrite the flag state for the wireless tag TG that is not a position detection target. Then, the processor 10 proceeds to ACT12.

[0083] As ACT16, the processor 10 determines whether the position of the wireless tag TG determined to be a position detection target has been detected. Specifically, the processor 10 checks the detected information associated with the corresponding identification information stored in the detection target storage unit 21 and determines whether it indicates detection. That is, the processor 10 discriminates, based on the detected information stored in the detection target storage unit 21 associated with the acquired identification information, whether the wireless tag TG that has returned the identification information is a position detection target wireless tag whose position has been detected. If the position has been detected, the processor 10 determines YES in ACT16 and proceeds to ACT17. If the position has not been detected, the processor 10 determines NO in ACT16 and proceeds to ACT11. In this way, if the wireless tag TG that has returned the identification information has not had its position detected, the processor 10 does not transmit no flag change. As a result, for an inquiry in the next slot, the flag state of the wireless tag TG can be rewritten from the A value to the B value, that is, it can be made a read target. In this way, the processor 10 is an example of a first processing unit that causes the wireless communication unit 60 to transmit an identification information read command designating the A value as the flag state, acquires the identification information of the wireless tag TG whose flag state is the A value, and rewrites the flag state of the specified wireless tag from the A value to the B value when the wireless tag TG of the detection target whose position has not been detected is specified as the wireless tag to be read based on the identification information.

[0084] As ACT17, 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.

[0085] When position correction is not effective, that is, when position correction is not performed, there is no need to read the target wireless tag TG for which the position has been detected any further. Therefore, if position correction is not effective, the processor 10 determines NO in ACT17 and proceeds to ACT15. As a result, in ACT15, the processor 10 causes the wireless communication unit 60 to transmit no flag change, which instructs not to rewrite the flag state for the wireless tag TG for which the position has been detected. In this way, when the setting stored in the position correction valid flag storage unit 22 is not a setting for correcting the position, the processor 10 can prevent it from being a reading target.

[0086] On the other hand, when position correction is effective, that is, when even if the position is detected, more accurate position detection is to be performed by further using the position detection data to be acquired later, the processor 10 determines YES in ACT17 and proceeds to ACT11. As a result, for the inquiry in the next slot, the flag state of the wireless tag TG can be rewritten from the A value to the B value, that is, it can be made a reading target.

[0087] As ACT18, the processor 10 operates the wireless communication unit 60 to start reading the wireless tag TG specified with the B value as the flag state.

[0088] As ACT19, 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. The wireless tag TG that returns this response is only the target wireless tag TG whose position has not been detected and whose flag state has been rewritten to the B value as a reading target in the first processing step. That is, the wireless tag TG that is not a position detection target or the wireless tag TG that has already had its position detected and is not a reading target does not return a response. If there is no response, the processor 10 determines NO in ACT19 and proceeds to ACT20. If there is a response, the processor 10 determines YES in ACT19 and proceeds to ACT21.

[0089] As ACT20, the processor 10 determines whether to end the second processing step. The second processing step continues until identification information is obtained from the wireless tag TG to be read a plurality of times. Specifically, the processor 10 makes this determination based on whether a specified time has elapsed since starting the reading with the B value specified as the flag state. It is desirable that this specified time be longer than the specified time in ACT12. Alternatively, the processor 10 makes this determination based on whether a specified number of rounds have been performed since starting the reading. It is desirable that this specified number of rounds be larger than the number of rounds in ACT12. If the second processing step is not ended, the processor 10 determines NO in ACT20 and proceeds to ACT19. If the second processing step is ended, the processor 10 determines YES in ACT20 and proceeds to ACT10. In this way, after a predetermined time has elapsed since the processor 10 caused the flag state of the wireless tag TG to be rewritten from the A value to the B value, or after the process of obtaining identification information only from the wireless tag TG whose flag state is the B value has been executed a predetermined number of times, the processor 10 causes the processing of the first processing unit to be executed again.

[0090] As ACT21, the processor 10 obtains the tag ID, that is, the identification information, of the wireless tag TG that has returned a response. Specifically, the processor 10 causes the wireless communication unit 60 to transmit an ACK to the wireless tag TG that has returned a response, and in response, receives the tag ID transmitted from the corresponding wireless tag TG. The processor 10 stores the tag ID received by the wireless communication unit 60 in the work area of the memory 20.

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

[0092] As ACT23, the processor 10 determines whether the wireless tag TG is the target for acquiring the position detection data based on the tag ID, that is, the identification information, stored in the work area. For example, the processor 10 can make this determination by performing the same determination as ACT14, ACT16, and ACT17 described above. Basically, in the second processing step, only the wireless tag TG that is the target for reading the identification information should be involved, but there may be cases where a non-target wireless tag TG whose flag state is the B value is returned by another wireless tag communication device. Therefore, here, it is confirmed whether the position detection data corresponding to the return of the identification information from the target wireless tag TG has been acquired. Therefore, this ACT23 is not essential. If it is not the target for acquiring the position detection data, the processor 10 determines NO in ACT23 and proceeds to ACT20. At this time, the tag ID, that is, the identification information, and the position detection data stored in the work area are cleared, that is, deleted. If it is the target for acquiring the position detection data, the processor 10 determines YES in ACT23 and proceeds to ACT24.

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

[0094] As ACT25, 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 is inverted, 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 desirable to immediately determine that the position can be calculated. Instead, it is desirable to determine that the position can be calculated when the detection data is acquired excessively to a certain extent. If the position calculation is possible, the processor 10 determines YES in ACT25 and proceeds to ACT27. If the position calculation is not possible, the processor 10 determines NO in ACT25 and proceeds to ACT26. In this way, the processor 10 is an example of a second processing unit that acquires identification information only from the wireless tag TG whose flag state is the B value by causing the wireless communication unit 60 to transmit an identification information reading command specifying the B value as the flag state.

[0095] As ACT26, the processor 10 causes the wireless communication unit 60 to transmit "no flag change" which instructs not to rewrite the flag state to the wireless tag TG that has returned the identification information. Then, the processor 10 proceeds to ACT20.

[0096] As ACT27, the processor 10 calculates the position of the wireless tag TG based on the position detection data stored in the read data storage unit 23. The processor 10 is an example of a position detection unit that detects the position of the wireless tag TG based on the detected communication state.

[0097] As ACT28, 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.

[0098] As ACT29, the processor 10 notifies the calculation result by the output device 40. Note that when staying at one location and scanning the orientation of the wireless tag communication device 1 or continuously performing reading while moving the wireless tag communication device 1, this ACT29 may not be necessary.

[0099] As ACT30, the processor 10 stores a position detected flag. Specifically, the detected information stored in the detection target storage unit 21 associated with the identification information of the wireless tag TG for which the position has been detected is set to detected. In this way, the processor 10 is an example of a storage control unit that sets the detected information stored in the detection target storage unit 21 in association with the identification information of the wireless tag TG to detected when the position of the wireless tag TG is detected.

[0100] As ACT31, the processor 10 determines whether there is a target wireless tag whose position has not been detected. Specifically, the processor 10 determines whether there is identification information in the detected information in the detection target storage unit 21 that has become undetected. If there is a target wireless tag whose position has not been detected, the processor 10 determines YES in ACT31 and proceeds to ACT20. At this time, if one round has ended, the next round 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 whose 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 whose 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 ACT31 and proceeds to ACT32.

[0101] As ACT32, the processor 10 terminates the operation of the wireless communication unit 60 and stops reading the wireless tag TG designated with the B value as the flag state.

[0102] As ACT33, the processor 10 notifies the output device 40 of the end of reading. At this time, the position calculation result of the detected wireless tag TG may also be notified. Also, this ACT33 may be omitted. Then, the processor 10 ends this reading operation.

[0103] Note that the processor 10 may transmit the position calculation result and the reading end notification to the host device UE via the communication interface 70.

[0104] As described above, according to the wireless tag communication device 1 according to the first embodiment, the processor 10 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 reading 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. Based on the identification information of a plurality of wireless tags TG obtained by causing the wireless communication unit 60 to transmit an identification information reading command specifying the A value as the flag state, the wireless tag TG to be read is specified from among the wireless tags TG to be detected whose positions have not been detected. Then, the wireless communication unit 60 is caused to rewrite the flag state of the specified wireless tag TG from the A value to the B value. After that, the processor 10 causes the wireless communication unit 60 to transmit an identification information reading command specifying the B value as the flag state a plurality of times, for example, until a specified time elapses after the reading starting with the specification of the B value, or until a specified number of rounds are performed after starting the reading, to obtain the identification information only from the wireless tag TG to be read. Thus, according to the wireless tag communication device 1 according to the first embodiment, first, the identification information is obtained from the wireless tag TG by the identification information reading command specifying the A value, and only the wireless tag TG to be detected whose position has not been detected yet has its flag state rewritten to the B value to narrow down the wireless tag TG to be read. Then, the identification information is repeatedly obtained from the wireless tag TG by the identification information reading command specifying this B value. Therefore, the wireless tag TG whose position has been detected and the wireless tag TG that is not a detection target do not need to respond to the identification information reading command specifying, for example, the A value in the first state in subsequent slots or rounds. Thus, the wireless tag TG whose position has been detected and the wireless tag TG that is not a detection target do not seize the reading opportunity of the wireless tag TG whose position has not been detected, that is, the reading opportunity of the wireless tag TG whose position has not been detected increases compared to the conventional reading method. Therefore, 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.

[0105] In addition, the wireless tag communication device 1 according to the first embodiment further includes a detection target storage unit 21, which is a storage unit that stores detection-completed information indicating whether the position of each of one or more wireless tags TG to be detected has been detected, in association with the identification information of each wireless tag TG. 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 in association with the acquired identification information. Therefore, according to the wireless tag communication device 1 according to the first embodiment, it is possible to easily determine 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.

[0106] In addition, the wireless tag communication device 1 according to the first embodiment further includes a position correction valid flag storage unit 22, which is a setting storage unit that stores a position correction valid flag indicating whether to correct the position of the wireless tag TG whose position has been detected. When the setting stored in the position correction valid flag storage unit 22 is a setting for correcting the position, the processor 10 also specifies the wireless tag TG having the identification information for which detection-completed is stored in the detection target storage unit 21 as a wireless tag TG to be read. 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.

[0107] In addition, when the wireless tag communication device 1 according to the first embodiment acquires identification information from the wireless tag TG to be read, it further includes an RSSI detection unit 63 and / or a phase detection unit 64 as a state detection unit that detects the communication state with the wireless tag TG by the wireless communication unit 60. The processor 10 detects the position of the wireless tag TG based on the detected communication state. Therefore, according to the wireless tag communication device 1 according to the first embodiment, the position of the wireless tag TG can be detected based on the communication state with the wireless tag TG to be read by the wireless communication unit 60.

[0108] Also, in the second processing step (PRO2), the wireless tag communication device 1 according to the first embodiment causes the flag state of the wireless tag TG to be rewritten from the A value to the B value, and after a predetermined time has elapsed, or after executing the process of acquiring the identification information only from the wireless tag TG whose flag state is the B value and which is the reading target a predetermined number of times, the first processing step (PRO1) is executed again. Therefore, according to the wireless tag communication device 1 according to the first embodiment, by repeating the first and second processing steps, it is possible to surely read all of the plurality of wireless tags TG to be position-detected. In particular, performing such repetitive processing can improve the reliability of reading those many wireless tags TG when continuously reading a large number of wireless tags TG while moving the wireless tag communication device 1 to a plurality of locations.

[0109] Also, in the wireless tag communication device 1 according to the first embodiment, when the processor 10 detects the position of the wireless tag TG, the detected information stored in the detection target storage unit 21 in association with the identification information of the wireless tag TG is set as having been 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 made available for discriminating the detected wireless tags TG in subsequent slots or rounds.

[0110] The wireless tag communication system according to the first embodiment includes the 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 of the wireless tag communication device 1 stores the identification information of the wireless tags TG to be position-detected set from the host device UE. Therefore, according to the wireless tag communication system according to the first embodiment, it is possible to easily set the wireless tags TG to be position-detected.

[0111] [Second Embodiment] Next, a second embodiment will be described. Regarding the same configurations and operations as those of the first embodiment, the same reference numerals as those in the first embodiment are used, and the description thereof is omitted.

[0112] FIG. 12 is a schematic configuration diagram showing a 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 detect the position of the wireless tag TG.

[0113] 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.

[0114] 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. Also in FIG. 12, "interface" is abbreviated as "I / F". The system transmission path 106 includes an address bus, a data bus, a control signal line, and the like. The system transmission path 106 directly connects the processor 101 and other units or via a signal input / output circuit, and transmits data signals exchanged therebetween. The processor 101 and the memory 102 are connected by the system transmission path 106, thereby constituting a computer of the host device UE. 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, or the like, 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. Further, the input device 103 and the output device 104 may be configured as a touch panel in which touch keys are arranged on a display screen such as a liquid crystal display.

[0115] Figures 13 and 14 are sequence diagrams showing the outline of the operation of the wireless tag communication system. Figure 13 shows the first processing step (PRO1), and Figure 14 shows the second processing step (PRO2). Figures 13 and 14 assume that non-target wireless tag a with identification information (tag ID) "a", target wireless tag b with identification information "b",... are within the communication area CA. For convenience of the drawing, only one non-target and / or target wireless tag TG is shown, but such non-target and / or target wireless tags TG may also enter the communication area CA. Also, Figures 13 and 14 show an ideal case where the counter values do not collide. In reality, the wireless tag communication device 1 may not receive the identification information (tag ID) due to the collision of the counter values of multiple wireless tags TG.

[0116] As shown in Figure 13, in, for example, the first round of slot 1 (SLT#1) of the first processing step (PRO1), the wireless tag communication device 1 transmits an inquiry to the wireless tags TG within the communication area CA by designating value A as the flag state (step S1).

[0117] In response to the inquiry transmitted from this wireless tag communication device 1, for example, when the non-target wireless tag a transmits the identification information (tag ID) to the wireless tag communication device 1 (step S2), 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 S3). 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. Next, the wireless tag communication device 1 issues an instruction not to change the flag for the wireless tag a determined not to be a data acquisition target (step S5) and ends the processing of this slot.

[0118] In the next slot 2 (SLT#2), the wireless tag communication device 1 transmits an inquiry to the wireless tags TG within the communication area CA by designating value A as the flag state (step S1). Since the non-target wireless tag a has received an instruction not to change the flag, it maintains value A as the flag state even when receiving this inquiry.

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

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

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

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

[0123] Also, any one of the remaining target wireless tags TG excluding the target wireless tags TG for which identification information has already been transmitted transmits identification information (tag ID) to the wireless tag communication device 1 in response to the inquiry (step S2). When the wireless tag communication device 1 receives this identification information, it determines whether the identification information is a target for acquiring position detection data, that is, a target for reading in the second processing step, based on the contents stored in the detection target storage unit 21 and the position correction valid flag storage unit 22 (step S3).

[0124] Similarly, each wireless tag TG and the wireless tag communication device 1 perform the remaining slots of this round and further the processing of subsequent rounds. This first processing step is performed until a specified time elapses or until a specified number of rounds are performed. The specified number of rounds may be one round.

[0125] As shown in FIG. 14, in the slot 1 (SLT#1) of, for example, the nth round of the second processing step (PRO2), the wireless tag communication device 1 transmits an inquiry to the wireless tag TG within the communication area CA by designating a B value as a flag state (step S6).

[0126] The non-target wireless tag a whose flag state maintains the A value does not respond to the inquiry designating the B value as this flag state. That is, the non-target wireless tag a ignores this inquiry. Therefore, among the remaining target wireless tags TG whose flag states are rewritten to the B value in the first processing step, for example, the target wireless tag b responds to the inquiry and transmits identification information (tag ID) to the wireless tag communication device 1 (step S2).

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

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

[0129] Then, the host device UE determines whether it is possible to calculate the position of the target wireless tag TG having the received identification information from the data stored in the read data storage unit 1021 (step S22). The operation of this step S22 corresponds to step S8 in the first embodiment. When the determination of whether calculation is possible is completed, the host device UE transmits a position calculation availability notification to the wireless tag communication device 1 (step S23).

[0130] When 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 1021, 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 S24). The host device UE stores the calculated position of the target wireless tag b in the position calculation result storage unit 1022. The operation of this step S24 corresponds to step S9 in the first embodiment.

[0131] If it is not 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 1021, the host device UE waits for the next identification information and position detection data to be transmitted from the wireless tag communication device 1.

[0132] When the wireless tag communication device 1 that has received the position calculation availability notification can perform position calculation, if the position calculation is possible, it sets "detected" in the detected information associated with the identification information of the target wireless tag b, which is the corresponding wireless tag TG, in the detection target storage unit 21 (step S10). Then, the wireless tag communication device 1 ends the processing of this slot. On the other hand, when the position calculation is impossible, the wireless tag communication device 1 issues an instruction not to change the flag for the target wireless tag b (not shown) and ends the processing of this slot.

[0133] 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, specifying the B value as the flag state (step S6).

[0134] The target wireless tag b that has received the inquiry without receiving the instruction not to change the flag rewrites the flag state from the B value to the A value (step S25).

[0135] Also, when any wireless tag TG (not shown), for example, a non-target wireless tag TG, transmits identification information (tag ID) to the wireless tag communication device 1 in response to the inquiry (step S2), the wireless tag communication device 1 acquires position detection data (step S7). Then, the wireless tag communication device 1 determines whether it is the acquisition target of the position detection data based on the identification information (step S3). If it is not the data acquisition target, the wireless tag communication device 1 ends the processing of this slot.

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

[0137] Similarly, each wireless tag TG and the wireless tag communication device 1 will perform the remaining slots of this round and further the processing of subsequent rounds. This second processing step is performed until a specified time elapses or until a specified number of rounds are performed.

[0138] Next, a specific example of the operations of the wireless tag communication device 1 and the host device UE will be described. FIGS. 15 and 16 are 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 processing based on the control program stored in the memory 20 when the power is turned on. FIG. 17 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 processing 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, for example, an application program. Note that the procedures shown in FIGS. 15, 16, and 17 are merely examples, and the procedures are not particularly limited as long as the same results can be obtained.

[0139] As shown in FIG. 15, as ACT41, the processor 10 of the wireless tag communication device 1 determines whether or not it has received settings from the host device UE via the communication interface 70. If it has received settings from the host device UE, the processor 10 determines YES in ACT41 and proceeds to ACT43. If it has not received settings from the host device UE, the processor 10 determines NO in ACT41 and proceeds to ACT42.

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

[0141] As shown in FIG. 17, the processor 101 of the upper 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.

[0142] 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.

[0143] As ACT103, the processor 101 receives the setting by the 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.

[0144] As ACT104, the processor 101 transmits the received setting content to the wireless tag communication device 1 via the communication interface 105. Then, the processor 101 proceeds to ACT101.

[0145] As shown in FIG. 15, the processor 10 of the wireless tag communication device 1, as ACT43, stores the setting content transmitted from the upper device UE in the detection target storage unit 21 and the position correction valid flag storage unit 22. Then, the processor 10 proceeds to ACT41.

[0146] As shown in FIG. 17, 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.

[0147] As ACT106, the processor 101 determines, via the communication interface 105, whether the position detection data transmitted from the wireless tag communication device 1 has been received. If the position detection data has been received, the processor 101 determines YES in ACT106 and proceeds to ACT107. If the position detection data has not been received, 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.

[0148] 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.

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

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

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

[0152] As ACT14, as described in the first embodiment, the processor 10 determines whether the received tag ID is the tag ID of the wireless tag TG to be position-detected. If the received tag ID is the tag ID of the wireless tag TG to be position-detected, the processor 10 determines YES in ACT14 and proceeds to ACT16. If the received tag ID is not the tag ID of the wireless tag TG to be position-detected, the processor 10 determines NO in ACT14 and proceeds to ACT15.

[0153] As ACT15, as described in the first embodiment, the processor 10 issues an instruction not to change the flag to the wireless tag TG not to be position-detected that has returned a response through the wireless communication unit 60, and then proceeds to ACT12.

[0154] As ACT16, as described in the first embodiment, the processor 10 determines whether the position of the wireless tag TG determined to be the position-detection target has been detected. If it has been detected, the processor 10 determines YES in ACT16 and proceeds to ACT17. If the position has not been detected, the processor 10 determines NO in ACT16 and proceeds to ACT18.

[0155] As ACT17, as described in the first embodiment, 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. If the position correction is not effective, the processor 10 determines NO in ACT17 and proceeds to ACT15, thereby issuing an instruction not to change the flag to the wireless tag TG that has returned a response. If the position correction is effective, the processor 10 determines YES in ACT17 and proceeds to ACT11. As a result, an instruction not to change the flag to the wireless tag TG that has returned a response is not issued, and the flag state of the wireless tag TG can be rewritten from the A value to the B value for the inquiry in the next slot. Therefore, even for a wireless tag TG whose position has been detected, it can be made the reading target.

[0156] As shown in FIG. 16, as ACT18, the processor 10 operates the wireless communication unit 60 to start reading a wireless tag TG specifying a B value as a flag state, as described in the first embodiment.

[0157] As ACT19, the processor 10 determines whether or not there is a response from any of the wireless tags TG, as described in the first embodiment. If there is no response, the processor 10 determines NO in ACT19 and proceeds to ACT20. If there is a response, the processor 10 determines YES in ACT19 and proceeds to ACT21.

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

[0159] As ACT21, the processor 10 obtains the tag ID of the wireless tag TG that has returned a 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.

[0160] As ACT22, the processor 10 obtains position detection data, as described in the first embodiment. Specifically, the processor 10 obtains the time, and detects the RSSI and the 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.

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

[0162] As ACT44, the processor 10 transmits the acquired position detection data together with the tag ID, i.e., identification information, stored in the work area, to the host device UE via the communication interface 70. Note that the position detection data includes the position and orientation of the antenna 61 calculated in ACT22 if they have been calculated, or the detection result of the sensor 50 if they have not been calculated. Thereafter, the processor 10 proceeds to ACT45. 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 state detection units 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.

[0163] As shown in FIG. 17, as ACT107, the processor 101 of the host device UE associates the received position detection data with the received tag ID, i.e., identification information, and stores it in the read data storage unit 1021. The operation of this ACT107 corresponds to ACT23 in the first embodiment.

[0164] As ACT108, the processor 101 determines whether or not 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.

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

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

[0167] As ACT111, the processor 101 calculates the position of the wireless tag TG based on the position detection data stored in the read data storage unit 1021. The operation of this ACT111 corresponds to ACT27 in the first embodiment.

[0168] As ACT112, the processor 101 stores the calculated position in the position calculation result storage unit 1022, associating it with the identification information of the wireless tag TG. The operation of this ACT112 corresponds to ACT28 in the first embodiment.

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

[0170] As ACT114, the processor 101 determines whether it has received an end notice from the wireless tag communication device 1 via the communication interface 105. If it has received the end notice, the processor 101 determines YES in ACT114 and proceeds to ACT115. If it has not received the end notice, the processor 101 determines NO in ACT114 and proceeds to ACT106.

[0171] As shown in FIG. 16, as ACT45, the processor 10 of the wireless tag communication device 1 determines, via the communication interface 70, whether it has received a calculation permission notification from the upper device UE. If it has received the calculation permission notification, the processor 10 determines YES in ACT45 and proceeds to ACT46. If it has not received the calculation permission notification, the processor 10 determines NO in ACT45 and proceeds to ACT20. Thus, the communication interface 70 is an example of an interface unit that receives a detection completed notification indicating the wireless tag TG for which the position has been detected from the upper device UE.

[0172] As ACT46, the processor 10 determines whether the result of the position calculation permission determination indicated by the received calculation permission notification indicates that position calculation is possible. If position calculation is possible, the processor 10 determines YES in ACT46 and proceeds to ACT30. If position calculation is not possible, the processor 10 determines NO in ACT46 and proceeds to ACT26.

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

[0174] As ACT30, the processor 10 stores the detected position flag as described in the first embodiment. Thus, the processor 10 is an example of a storage control unit that sets the detected information stored in association with the identification information of the wireless tag TG in the detection target storage unit 21 as detected.

[0175] As ACT31, the processor 10 determines whether there is a target wireless tag for which the position has not been detected as described in the first embodiment. If there is a target wireless tag for which the position has not been detected, the processor 10 determines YES in ACT31 and proceeds to ACT20. At this time, if one round has ended, the next round is started. If there is no target wireless tag for which the position has not been detected, the processor 10 determines NO in ACT31 and proceeds to ACT32.

[0176] As ACT32, as described in the first embodiment, the processor 10 terminates the operation of the wireless communication unit 60 and stops reading the wireless tag TG that designates the B value as the flag state. Thereafter, in this embodiment, the processor 10 proceeds to ACT47.

[0177] As ACT47, the processor 10 transmits an end notification to the host device UE via the communication interface 70. Thereafter, the processor 10 proceeds to ACT41.

[0178] As shown in FIG. 17, the processor 101 of the host device UE that has received this end notification, as ACT115, notifies the end of reading by the output device 104.

[0179] As ACT116, the processor 101 determines whether there is an end instruction by an operation of the input device 103 from the user. If there is no end instruction, the processor 101 determines NO in ACT116 and proceeds to ACT101. If there is an end instruction, the processor 101 determines YES in ACT116 and ends the processing of the control program as the application program.

[0180] Also, the user can end the operation of the processor 101 of the wireless tag communication device 1 shown in FIGS. 15 and 16 by turning off the power of the wireless tag communication device 1.

[0181] As described above, according to the wireless tag communication device 1 according to the second embodiment, when acquiring identification information from the wireless tag TG to be read, 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, the RSSI and / or the phase, which are the communication states detected thereby, are transmitted to the communication interface 70 as the interface unit to the host device UE that is the detection device for detecting the position of the wireless tag TG based on this communication state. Therefore, according to the wireless tag communication device 1 in the second embodiment, by transmitting the communication state to the host device UE, the host device UE can be made to perform the position detection of the wireless tag TG. In particular, by causing the position detection process that requires processing power to be executed in the host device UE, which is an information processing device such as a server computer or an information processing device such as a smartphone, as the processor 10 of the wireless tag communication device 1, an inexpensive one with not so high processing power can be used, and the cost of the wireless tag communication device 1 can be reduced.

[0182] Also, according to the wireless tag communication device 1 according to the second embodiment, the communication interface 70 receives a detected notification indicating the wireless tag TG whose position has been detected from the host device UE, and the processor 101 sets the detected information stored in the detection target storage unit 21 as detected in association with the identification information of the wireless tag TG whose position has been detected based on the detected notification received by the communication interface 70. 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 according to the position detection of the wireless tag TG in the host device UE, and it can be made available for discriminating the detected wireless tag TG in subsequent slots or rounds.

[0183] Also, according to the wireless tag communication system according to the second embodiment, the part for detecting the position of the wireless tag TG based on the RSSI and / or phase, which is the communication state with the wireless tag TG, is performed in the host device UE connected to the wireless tag communication device 1. Even in this case, as in the first embodiment, in the wireless tag communication device 1, first, identification information is acquired from the wireless tag TG by an identification information reading command specifying the A value, and only for the wireless tag TG of the detection target for which the position has not yet been detected, by rewriting the flag state to the B value, after narrowing down the wireless tag TG to be read, the identification information is repeatedly acquired from the wireless tag TG by an identification information reading command specifying this B value. Therefore, the wireless tag TG for which the position has been detected and the wireless tag TG that is not the position detection target can be made not to respond, for example, to an identification information reading command specifying the A value in the first state in subsequent slots or rounds. Thus, the wireless tags TG for which the positions have been detected and the wireless tags TG that are not the position detection targets do not seize the reading opportunity of the wireless tag TG for which the position has not been detected, so it becomes possible to shorten the time until all of the plurality of wireless tags to be position-detected are read. Further, since the position detection process that particularly requires processing power is executed in the upper device UE which is an information processing device such as a server computer or an information processing device such as a smartphone, as the processor 10 of the wireless tag communication device 1, an inexpensive one with not so high processing power can be used, and the cost of the wireless tag communication device 1 can be reduced.

[0184] 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, in the first and second embodiments, in the first processing step, reading is performed for all the wireless tags TG in which the flag state is the A value, that is, all of the wireless tags TG that are not the position detection targets, the wireless tags TG for which the position has been detected, and the wireless tags TG that have not yet been position-detected, and the flag state of the wireless tag TG to be the reading target in the second processing step is rewritten to the B value. However, reading may be performed by designating only the target wireless tag TG for which the position has not been detected and in which the identification information is stored in the detection target storage unit 21, and the flag state of the wireless tag TG to be the reading target in the second processing step may be rewritten to the B value.

[0185] Also, in the flowchart of FIG. 11, ACT28 and ACT30 may be in reverse order or may be performed in parallel. Thus, as long as there is no conflict with preceding or subsequent processes, the order of processes may be changed or a plurality of processes may be performed in parallel.

[0186] Also, in the second embodiment, after receiving the calculation permission notice transmitted from the host device UE, when the position calculation is impossible, the wireless tag communication device 1 was set to issue an instruction not to change the flag. However, at the stage when it is determined that the wireless tag is the target in the data acquisition target determination, an instruction not to change the flag may be transmitted to the wireless tag. In this case, when it is determined as NO in ACT23, instead of proceeding to ACT20, it may proceed to ACT26. As a result, even when it takes time for communication with the host device UE or determination of whether the host device UE can calculate the position, it becomes possible to surely transmit an instruction not to change the flag to the wireless tag TG.

[0187] Note that in the above embodiment, the control program executed by the processor 10 of the wireless tag communication device 1 or the processor 101 of the host device UE may be configured to be recorded and provided on a computer-readable recording medium such as a CD-ROM. Further, the control program may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network.

[0188] In addition, although some embodiments of the present invention have been described, these embodiments are presented as examples 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.

[0189] [Supplementary Note] From the above specific embodiments, an invention having the following configuration can be extracted. [1] It includes 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, it returns the identification information only when the flag state corresponds to the specified flag state. It also includes a wireless communication unit for communicating with a wireless tag, By transmitting the identification information reading command specifying the first state as the flag state through the wireless communication unit, the identification information of the wireless tag in the first state is obtained. When a wireless tag to be detected with undetected position is specified as a wireless tag to be read based on the identification information, a first processing unit for rewriting the flag state of the specified wireless tag from the first state to the second state, A second processing unit for obtaining the identification information only from the wireless tag to be read in the second state by transmitting the identification information reading command specifying the second state as the flag state through the wireless communication unit, A wireless tag communication device comprising: [2] It further includes a storage unit for storing detection completed information indicating whether the wireless tag is detected as being associated with the identification information of each of the one or more wireless tags to be detected, The first processing unit determines whether the wireless tag having the obtained identification information is a wireless tag to be detected with undetected position based on the obtained identification information and the stored content of the storage unit. The wireless tag communication device according to [1]. [3] It further includes a setting storage unit for storing a setting for determining whether to correct the position of the detected wireless tag, When the setting stored in the setting storage unit is a setting for correcting the position, the first processing unit further specifies the wireless tag having the identification information stored as detected in the storage unit as the wireless tag to be read. The wireless tag communication device according to [2]. [4] When the second processing unit obtains the identification information from the wireless tag to be read in the second state, a state detection unit for detecting the communication state with the wireless tag by the wireless communication unit, A position detection unit that detects the position of the wireless tag to be read based on the communication state; The wireless tag communication device according to [1], further comprising: [5] 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 [4]. [6] When the second processing unit acquires the identification information from the wireless tag to be read, a state detection unit that detects the 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; The wireless tag communication device according to [1], further comprising: [7] The interface unit receives a detection notification indicating a wireless tag for which position detection has been completed from the detection device, The wireless tag communication device according to [6], further comprising a storage control unit that sets the detected information stored in the storage unit in association with the identification information of the wireless tag for which position detection has been completed as detected based on the detection notification. [8] After a predetermined time has elapsed since rewriting the flag state of the wireless tag from the first state to the second state, or after the second processing unit has executed a process of acquiring the identification information only from the wireless tag to be read in the second state a predetermined number of times, the process of the first processing unit is executed again; the wireless tag communication device according to [1]. [9] 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 has a flag for storing 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 an identification information reading command specifying the flag state is received; By causing the wireless communication unit to transmit the identification information reading command designating the first state as the flag state, the identification information of the wireless tag in the first state is acquired. When a wireless tag that is a detection target with undetected position is specified as a wireless tag to be read based on the identification information, a first processing unit that causes the flag state of the specified wireless tag to be rewritten from the first state to the second state; A second processing unit that acquires the identification information only from the wireless tag to be read that is in the second state by causing the wireless communication unit to transmit the identification information reading command designating the second state as the flag state; A state detection unit that detects a communication state with the wireless tag by the wireless communication unit when the second processing unit acquires the identification information from the wireless tag that is a detection target with undetected position; A position detection unit that detects the position of the wireless tag that is a detection target with undetected position based on the communication state; A wireless tag communication system comprising:

[10] The wireless tag communication device includes the wireless communication unit, the first processing unit, the second processing unit, the state detection unit, and the position detection unit. The wireless tag communication device further includes a storage unit that stores detection-completed information indicating whether or not the wireless tag has been detected in association with the identification information of each of the one or more wireless tags that are detection targets. The storage unit stores the identification information of the wireless tag that is a position detection target set by the host device. The wireless tag communication system according to [9].

[11] The wireless tag communication device includes the wireless communication unit, the first processing unit, the second processing unit, and the state detection unit. The host device includes the position detection unit. The wireless tag communication system according to [9].

[12] A computer that controls a wireless tag communication device including a wireless communication unit that communicates with a wireless tag, a processor, and a memory, the wireless communication unit having a flag that stores 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. A first processing unit that acquires the identification information of the wireless tag by causing the wireless communication unit to transmit the identification information reading command designating the first state as the flag state, and when identifying a wireless tag whose position has not been detected as a wireless tag to be read based on the identification information, causes the flag state of the identified wireless tag to be rewritten from the first state to the second state. A second processing unit that acquires the identification information only from the wireless tag to be read, which is in the second state, by causing the wireless communication unit to transmit the identification information reading command designating the second state as the flag state. A program for causing it to function as such.

[13] A hardware processor, A memory, A wireless communication unit that communicates with a wireless tag, having a flag that stores 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. Comprising, the hardware processor Acquires the identification information of the wireless tag by causing the wireless communication unit to transmit the identification information reading command designating the first state as the flag state, and when identifying a wireless tag whose position has not been detected as a wireless tag to be read based on the identification information, causes the flag state of the identified wireless tag to be rewritten from the first state to the second state. By causing the wireless communication unit to transmit the identification information reading command designating the second state as the flag state, the identification information is acquired only from the wireless tag to be read in the second state and stored in the memory. A wireless tag communication device configured as described above.

Explanation of Signs

[0190] 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... Host device.

Claims

1. A wireless communication unit that communicates with a wireless tag, comprising 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, returns the identification information only when the flag state corresponds to the specified flag state; By causing the wireless communication unit to transmit the identification information reading command designating the first state as the flag state, the identification information of the wireless tag in the first state is acquired, and when a wireless tag to be detected with undetected position is specified as a wireless tag to be read based on the identification information, a first processing unit that causes the flag state of the specified wireless tag to be rewritten from the first state to the second state; A second processing unit that acquires the identification information only from the wireless tag to be read in the second state by causing the wireless communication unit to transmit the identification information reading command designating the second state as the flag state; A wireless tag communication device comprising:

2. Further comprising a storage unit that stores detection completed information indicating whether or not the wireless tag has been detected in association with the identification information of each of the one or more wireless tags to be detected; The first processing unit determines whether or not the wireless tag having the acquired identification information is a wireless tag to be detected with undetected position based on the acquired identification information and the stored content of the storage unit. The wireless tag communication device according to Claim 1.

3. Further comprising a setting storage unit that stores a setting for determining whether or not to correct the position of the wireless tag whose position has been detected; When the setting stored in the setting storage unit is a setting for correcting the position, the first processing unit further specifies, as the wireless tag to be read, the wireless tag having the identification information stored as detected in the storage unit. The wireless tag communication device according to Claim 2.

4. A state detection unit that detects a communication state between the wireless communication unit and the wireless tag when the second processing unit acquires the identification information from the wireless tag to be read in the second state; A position detection unit that detects the position of the wireless tag to be read based on the communication state; The wireless tag communication device according to Claim 1, further comprising:

5. A state detection unit that detects a communication state with the wireless tag by the wireless communication unit when the second processing unit acquires the identification information from the wireless tag to be read in the second state; 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; The wireless tag communication device according to claim 1, further comprising:

6. After a predetermined time has elapsed since the flag state of the wireless tag was rewritten from the first state to the second state, or after the second processing unit has executed the process of acquiring the identification information only from the wireless tag to be read in the second state a predetermined number of times, the wireless tag communication device according to claim 1, wherein the process of the first processing unit is executed again.

7. 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 a 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 flag state corresponds to the specified flag state when receiving an identification information reading command that specifies the flag state; A first processing unit that acquires the identification information of the wireless tag in the first state by transmitting the identification information reading command that designates the first state as the flag state by the wireless communication unit, and when identifying the wireless tag whose position has not been detected as the wireless tag to be read based on the identification information, rewrites the flag state of the identified wireless tag from the first state to the second state; A second processing unit that acquires the identification information only from the wireless tag to be read in the second state by transmitting the identification information reading command that designates the second state as the flag state by the wireless communication unit; A state detection unit that detects a communication state with the wireless tag by the wireless communication unit when the second processing unit acquires the identification information from the wireless tag whose position has not been detected; A position detection unit that detects the position of the wireless tag whose position has not been detected based on the communication state; A wireless tag communication system, comprising:

8. A computer that controls a wireless tag communication device including a wireless communication unit that communicates with a wireless tag, a processor, and a memory. The wireless communication unit has 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, returns the identification information only when the flag state corresponds to the specified flag state. A first processing unit that acquires the identification information of the wireless tag in the first state by causing the wireless communication unit to transmit the identification information reading command designating the first state as the flag state, and when identifying a wireless tag to be detected with undetected position as a wireless tag to be read based on the identification information, causes the flag state of the identified wireless tag to be rewritten from the first state to the second state. A second processing unit that acquires the identification information only from the wireless tag to be read in the second state by causing the wireless communication unit to transmit the identification information reading command designating the second state as the flag state. A program for causing the computer to function as described above.

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