JP2018163565A - Wireless tag reading device and wireless tag reading method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly identify a wireless tag to be excluded.SOLUTION: A wireless tag reading device 10 includes a wireless communication unit 107, an RSSI measurement unit 110, a tag exclusion unit 115, and a host device communication unit 101. The wireless communication unit 107 wirelessly receives a tag response including tag IDs stored in a wireless tag 30. The RSSI measurement unit 110 measures RSSI of the tag response wirelessly received to obtain an RSSI measurement value. The tag exclusion unit 115 calculates an RSSI effective value by correcting the RSSI measurement value. In addition, the tag exclusion unit 115 excludes tag IDs other than a transmission target from the tag IDs included in the wirelessly received tag response, based on a result of comparison between the RSSI effective value and a threshold value TH1. The host device communication unit 101 transmits the remaining tag ID after exclusion by the tag exclusion unit 115 to a POS terminal 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wireless tag reader and a wireless tag reading method.

  In recent years, in stores such as clothing stores, a wireless tag is attached to a product, and at the time of accounting for the purchased product, a store clerk at a cashier counter stores the product information stored in the wireless tag attached to the product. Product registration and inventory management may be performed by reading with a wireless tag reader. In retail stores other than clothing stores, registration and inventory management of products using wireless tags have become widespread. Note that the wireless tag may be referred to as a wireless ID tag or an RFID tag.

  When reading product information from a wireless tag at a checkout counter, product registration and inventory management will be incorrect unless the wireless tag to be read is limited to those attached to the purchased product. End up. In other words, if even a wireless tag attached to a displayed product that has not yet been purchased (hereinafter sometimes referred to as a “displayed product”) is also read, it means that the displayed product has been purchased. As a result, product registration and inventory management become incorrect.

  Here, the greater the distance between the wireless tag reader and the wireless tag, the lower the received intensity of the tag response transmitted from the wireless tag and received by the wireless tag reader. The tag response includes product information. Therefore, normally, in the wireless tag reader, the tag response received from the wireless tag attached to the display product is higher than the reception strength of the tag response received from the wireless tag attached to the purchased product at the checkout counter. The reception strength is smaller. Therefore, conventionally, a predetermined threshold is set for the reception strength of the tag response, and the tag response whose reception strength is less than the predetermined threshold is excluded, so that it is attached to the display product from the reading target at the register counter. A technique for excluding existing wireless tags (hereinafter sometimes referred to as “prior art 1”) has been proposed.

JP-A-11-343010 JP 2010-134675 A

  However, since the dielectric constant of the object to be attached varies depending on the material of the object to which the wireless tag is attached (hereinafter may be referred to as “attachment object”), the reception strength of the tag response is different between the wireless tag reader and the wireless tag. It varies not only by the distance between the two but also by the mounting object. Also, depending on the performance of the wireless tag, the reception strength of the tag response may change even under the same conditions. For this reason, in the above-described related art 1, the wireless tag to be excluded may not be correctly specified.

  The disclosed technology has been made in view of the above, and an object thereof is to correctly specify a wireless tag to be excluded.

  In the disclosed aspect, the wireless tag reading device includes a first communication unit, a measurement unit, an exclusion unit, and a second communication unit. The first communication unit wirelessly receives a tag response including a tag ID stored in the wireless tag. The measurement unit measures a reception strength of the tag response received wirelessly to obtain a measurement value of the reception strength. The excluding unit calculates an effective value of the reception intensity by correcting the measurement value, and determines the received tag response wirelessly based on a comparison result between the effective value and a predetermined threshold value of the reception intensity. Tag IDs other than the transmission target are excluded from the included tag IDs. The second communication unit transmits the remaining tag ID after being excluded by the exclusion unit to a host device.

  In another aspect of the disclosure, the wireless tag reading device includes a first communication unit, a measurement unit, an exclusion unit, and a second communication unit. The excluding unit calculates an effective value of the threshold value by correcting a predetermined threshold value, and based on a comparison result between the measured value and the effective value, the tag ID included in the response received wirelessly. Tag IDs other than the transmission target are excluded from the inside.

  According to the disclosed aspect, it is possible to correctly specify the wireless tag to be excluded.

FIG. 1 is a diagram illustrating a configuration example of a wireless tag system according to the first embodiment. FIG. 2 is a diagram illustrating an example of a processing sequence of the wireless tag system according to the first embodiment. FIG. 3 is a diagram illustrating an example of a tag ID according to the first embodiment. FIG. 4 is a diagram illustrating an example of the correction coefficient table A according to the first embodiment. FIG. 5 is a diagram illustrating an example of the correction coefficient table B according to the first embodiment. FIG. 6 is a diagram illustrating an example of a processing sequence of the wireless tag system according to the second embodiment. FIG. 7 is a diagram illustrating a hardware configuration example of the wireless tag reader according to the fourth embodiment.

  Embodiments of a wireless tag reading device and a wireless tag reading method disclosed in the present application will be described below in detail with reference to the drawings. In addition, the wireless tag reading device and the wireless tag reading method disclosed in the present application are not limited by this embodiment. In the following embodiments, the same reference numerals are given to the steps having the same function or the same processing, and the duplicate description is omitted.

[Example 1]
<Configuration of wireless tag system>
FIG. 1 is a diagram illustrating a configuration example of a wireless tag system according to the first embodiment. 1, the wireless tag system 1 includes a wireless tag reader 10, a POS (Point Of Sale) terminal 20, and wireless tags 30-1 to 30-3. The POS terminal 20 is an example of a host device of the wireless tag reader 10. Hereinafter, when the wireless tags 30-1 to 30-3 are not distinguished, they may be collectively referred to as a wireless tag 30.

<Configuration of wireless tag reader>
In FIG. 1, a wireless tag reader 10 includes a higher-level device communication unit 101, a higher-level command interpretation unit 103, a tag-addressed command generation unit 105, a wireless communication unit 107, an antenna 109, and an RSSI (Received Signal Strength Indication). The measuring unit 110, the tag information storage unit 111, the correction coefficient storage unit 113, the tag exclusion unit 115, and the format conversion unit 117 are included.

<Processing of wireless tag system>
FIG. 2 is a diagram illustrating an example of a processing sequence of the wireless tag system according to the first embodiment.

  In FIG. 2, in step S11, the POS terminal 20 transmits an “acquisition request command”, which is a command for requesting acquisition of the tag ID at the POS terminal 20, to the wireless tag reading device 10 as an upper command, and the wireless tag reading device. The ten higher-level device communication units 101 receive the acquisition request command. The acquisition request command is a kind of upper command transmitted from the POS terminal 20 to the wireless tag reader 10. The higher-level device communication unit 101 outputs the received acquisition request to the higher-level command interpretation unit 103. The upper command interpreting unit 103 interprets that the upper command input from the upper device communication unit 101 is an acquisition request command, and outputs the interpretation result to the tag addressed command generating unit 105.

  Next, in step S13, the tag-addressed command generation unit 105 requests transmission of the tag ID to the wireless tag reader 10 according to the fact that the higher-level command interpretation unit 103 interprets that the higher-level command is an acquisition request command. Request command "is generated, and the generated transmission request command is output to the wireless communication unit 107. The wireless communication unit 107 wirelessly transmits the transmission request command input from the tag-addressed command generation unit 105 via the antenna 109.

  Next, in step S15, of the wireless tags 30-1 to 30-3, the wireless tag 30 that wirelessly received the transmission request command transmitted from the wireless tag reader 10 in step S13 transmits a transmission request according to the transmission request command. A “tag response” that is a response to the command is wirelessly transmitted to the wireless tag reader 10, and the wireless communication unit 107 of the wireless tag reader 10 wirelessly receives the tag response via the antenna 109. The tag response includes a tag ID stored in the wireless tag 30. In the following description, it is assumed that all of the wireless tags 30-1 to 30-3 have transmitted tag responses. The wireless communication unit 107 outputs the received tag response to the RSSI measurement unit 110, and the RSSI measurement unit 110 measures the RSSI of the tag response for each tag response. RSSI is an example of reception strength. Then, the RSSI measuring unit 110 stores the combination of the tag ID and the measured RSSI value (hereinafter sometimes referred to as “RSSI measured value”) in the tag information storage unit 111 as tag information. That is, the tag information storage unit 111 stores the RSSI measurement value in association with the tag ID for each tag ID. Also, the RSSI measurement unit 110 notifies the tag exclusion unit 115 that the RSSI measurement value is stored in the tag information storage unit 111. This notification includes information indicating the number of tag IDs stored in the tag information storage unit 111 (hereinafter sometimes referred to as “number information”).

  FIG. 3 is a diagram illustrating an example of a tag ID according to the first embodiment. As shown in FIG. 3, the tag ID is formed of, for example, a product code, a serial number, a tag type code, a material identification code, and an IC chip identification code. The product code is a code representing the type of product to which the wireless tag 30 is attached. The serial number is a serial number assigned to the product in each product type. Each product is uniquely identified by the combination of the product code and the serial number. The tag type code is a code representing the type of the wireless tag 30 attached to the product. The material identification code is a code for identifying the material of the product to which the wireless tag 30 is attached. The IC chip identification code is a code for identifying an IC chip included in the wireless tag 30 attached to the product, and whether the performance of the IC chip included in the wireless tag 30 can be determined by the IC chip identification code. .

  Returning to FIG. 2, in step S <b> 17, the tag exclusion unit 115 refers to the correction coefficient table stored in the correction coefficient storage unit 113 in accordance with the notification from the RSSI measurement unit 110 in step S <b> 15 and stores the correction coefficient table in the correction coefficient table. The set correction coefficient is acquired for each tag ID stored in the tag information storage unit 111. The tag excluding unit 115 acquires a correction coefficient based on the tag type code, the material identification code, and the IC chip identification code included in the tag ID.

  FIG. 4 is a diagram illustrating an example of the correction coefficient table A according to the first embodiment, and FIG. 5 is a diagram illustrating an example of the correction coefficient table B according to the first embodiment.

  For example, as shown in FIG. 4, any one of 01 to 04 is set as the tag type code included in the tag ID. For example, tag type code = 01 indicates that the tag is tuned assuming that the attachment target is linen (that is, “linen tag”), and tag type code = 02 indicates that the attachment target is This indicates that the tag is tuned assuming that it is a document (that is, “document tag”), and the tag type code = 03 is a tag tuned assuming that the attachment object is metal ( In other words, the tag type code = 04 is a tag tuned assuming that the attachment object is an electronic medium (that is, the “tag for electronic medium”). Show. As shown in FIG. 4, the reason why the correction coefficient A is made different according to the tag type code is that the wireless tag 30 is preliminarily tuned so as to have an optimum performance assuming an attachment object.

  Further, for example, as shown in FIG. 4, any of material identification codes 01 to 09 is set in the tag ID. For example, the material identification code = 01 indicates that the material of the attachment object is cotton, the material identification code = 02 indicates that the material of the attachment object is polyester, and the material identification code = 03 indicates that the material is The material of the object is feather, the material identification code = 04 indicates that the material of the attachment object is wool, and the material identification code = 05 indicates that the material of the attachment object is paper. The material identification code = 06 indicates that the material of the attachment object is wood, the material identification code = 07 indicates that the material of the attachment object is aluminum, and the material identification code = 08 indicates the attachment The material of the object indicates that the material is steel, and the material identification code = 09 indicates that the material of the attachment object is plastic. As shown in FIG. 4, the reason why the correction coefficient A is made different according to the material identification code is that the dielectric constant of the attachment object differs when the material of the attachment object is different. This is because a “shift” occurs in the resonance frequency of 30. The higher the dielectric constant of the attachment object, the shorter the wavelength and the higher the resonance frequency of the wireless tag 30.

  Further, for example, as shown in FIG. 5, any one of 01 to 04 is set as the IC chip identification code included in the tag ID. For example, IC chip identification code = 01 indicates that the IC chip included in the wireless tag 30 is chip A, and IC chip identification code = 02 indicates that the IC chip included in the wireless tag 30 is chip B. IC chip identification code = 03 indicates that the IC chip included in the wireless tag 30 is the chip C, and IC chip identification code = 04 indicates that the IC chip included in the wireless tag 30 is the chip D. Here, among the chips A to D, the performance of the chip A is the best, the performance of the chip B is the second best after the chip A, the performance of the chip C is the second best after the chip B, and the performance of the chip D is the worst. And As shown in FIG. 5, the correction coefficient B is made different according to the IC chip identification code because the IC chip with good performance is transmitted waves from the wireless tag reader 10 (for example, the above transmission request command). This is because the operation is possible even when the power of the signal is weak (that is, even when the power is low), and the power of the response wave (for example, the above tag response) is also increased.

  For example, the tag excluding unit 115 has a tag type code “01” included in a tag ID (hereinafter also referred to as “first tag ID”) included in the tag response from the wireless tag 30-1, When the identification code is “01”, “1” is acquired from the correction coefficient table A (FIG. 4) as the correction coefficient A for the first tag ID. Further, for example, the tag excluding unit 115 has a tag type code “01” included in a tag ID (hereinafter also referred to as “second tag ID”) included in the tag response from the wireless tag 30-2, When the identification code is “03”, “0.9” is acquired from the correction coefficient table A (FIG. 4) as the correction coefficient A for the second tag ID. Further, for example, the tag excluding unit 115 has a tag type code “01” included in a tag ID included in the tag response from the wireless tag 30-3 (hereinafter may be referred to as “third tag ID”), When the identification code is “04”, “0.9” is acquired from the correction coefficient table A (FIG. 4) as the correction coefficient A for the third tag ID.

  Further, for example, the tag excluding unit 115 determines the first tag ID and the second tag ID when the IC chip identification codes included in the tag IDs included in the tag responses from the wireless tags 30-1 to 30-3 are all “03”. “0.85” is acquired from the correction coefficient table B (FIG. 5) as the correction coefficient B for the tag ID and the third tag ID.

  Returning to FIG. 2, in step S <b> 19, the tag excluding unit 115 corrects the RSSI measurement value by using the correction coefficient A and the correction coefficient B for each tag ID stored in the tag information storage unit 111. The effective value (hereinafter, sometimes referred to as “RSSI effective value”) is calculated. The tag exclusion unit 115 calculates an RSSI effective value according to the following equation (1). In Expression (1), “transmission output coefficient” is a positive number equal to or less than 1, and is stored in the correction coefficient storage unit 113 in advance. For example, the transmission power coefficient is calculated as a value obtained by dividing the actual transmission power value of the transmission request command by a predetermined maximum value of the transmission power of the transmission request command. The actual transmission power value of the transmission request command is set in the wireless communication unit 107, and the wireless communication unit 107 wirelessly transmits the transmission request command with the transmission power corresponding to the set transmission power value. In step S17, the tag exclusion unit 115 acquires the transmission power coefficient from the correction coefficient storage unit 113 in accordance with the notification from the RSSI measurement unit 110 in step S15.

  RSSI effective value = RSSI measurement value × correction coefficient A × correction coefficient B × transmission power coefficient (1)

  Here, the reason why the transmission power coefficient is used for correcting the RSSI measurement value is that the wireless tag 30 is powered by a transmission wave (for example, the above transmission request command) transmitted from the wireless tag reader 10. In order to transmit a reflected wave (for example, the above-described tag response) with respect to the transmission wave, the RSSI of the tag response transmitted from the wireless tag 30 in the wireless tag reader 10 increases as the transmission power from the wireless tag reader 10 increases. Because it grows.

  Next, in step S21, the tag excluding unit 115 compares the RSSI effective value with a predetermined threshold value TH1, and determines whether or not the RSSI effective value is greater than or equal to the threshold value TH1 and stored in the tag information storage unit 111. Judge for each ID. As a result of the comparison, when the RSSI effective value is greater than or equal to the threshold value TH1 (step S21: Yes), the process proceeds to step S23. On the other hand, as a result of the comparison, if the RSSI effective value is less than the threshold value TH1 (step S21: No), the process proceeds to step S25 without executing the process of step S23.

  In step S23, the tag exclusion unit 115 acquires the tag ID whose RSSI effective value is equal to or greater than the threshold TH1 in step S21 from the tag information storage unit 111, and outputs the acquired tag ID to the format conversion unit 117. The format conversion unit 117 converts the format of the tag ID input from the tag excluding unit 115 into a format suitable for communication between the wireless tag reading device 10 and the POS terminal 20, and converts the tag ID after the format conversion to a higher-level device. Output to the communication unit 101. The upper device communication unit 101 transmits the tag ID input from the format conversion unit 117 to the POS terminal 20.

  Next, in step S25, the tag exclusion unit 115 determines whether or not the determination in step S21 has been completed for all the tag IDs stored in the tag information storage unit 111 in step S15 based on the number information (that is, Whether all tags are completed). If all tags are not completed (step S25: No), the process returns to step S17. In the second and subsequent processes of steps S17 to S25, the tag excluding unit 115 executes the processes of steps S17 to S25 even if there is no notification from the RSSI measuring unit 110.

  On the other hand, when all the tags are completed (step S25: Yes), the process proceeds to step S27. In step S27, the tag excluding unit 115 clears the tag information storage unit 111, and the wireless tag reading device 10 It waits until an acquisition request command is received. For example, when all tags are completed, the tag exclusion unit 115 outputs a notification of completion of all tags to the control unit (not shown), and the control unit causes the wireless tag reader 10 to enter a standby state according to this notification.

  Here, as described above, when the RSSI effective value is less than the threshold TH1 (step S21: No), the process proceeds to step S25 without executing the process of step S23. Therefore, the RSSI effective value is determined in step S21. The tag ID for which is less than the threshold TH1 is excluded from the transmission target to the POS terminal 20. That is, the tag exclusion unit 115 excludes tag IDs other than those to be transmitted to the POS terminal 20 from the tag IDs included in the tag response wirelessly received in step S15. In addition, the upper device communication unit 101 transmits the remaining tag ID after being excluded by the tag exclusion unit 115 to the POS terminal 20.

  For example, the RSSI effective value of the tag response received from the wireless tag 30-1 is greater than or equal to the threshold value TH1, whereas the RSSI effective values of the tag responses received from the wireless tags 30-2 and 30-3 are both threshold values. When it is less than TH1, the tag exclusion unit 115 selects the second tag ID and the third tag ID from the first tag ID, the second tag ID, and the third tag ID stored in the tag information storage unit 111. , And only the remaining first tag ID after the exclusion is output to the format conversion unit 117. Therefore, in this case, only the first tag ID is transmitted from the wireless tag reading device 10 to the POS terminal 20 among the first tag ID, the second tag ID, and the third tag ID received by the wireless tag reading device 10. The

  In Equation (1), the RSSI measurement value is corrected using all of the correction coefficient A, the correction coefficient B, and the transmission power coefficient. However, any one of the correction coefficient A, the correction coefficient B, and the transmission power coefficient is used. Alternatively, the RSSI measurement value may be corrected using two coefficients.

  As described above, in the first embodiment, the wireless tag reader 10 includes the wireless communication unit 107, the RSSI measurement unit 110, the tag exclusion unit 115, and the higher-level device communication unit 101. The wireless communication unit 107 wirelessly receives a tag response including the tag ID stored in the wireless tag 30. The RSSI measurement unit 110 measures the RSSI of the wirelessly received tag response and obtains an RSSI measurement value. The tag exclusion unit 115 calculates the RSSI effective value by correcting the RSSI measurement value. Further, the tag exclusion unit 115 excludes tag IDs other than the transmission target from tag IDs included in the wirelessly received tag response based on the comparison result between the RSSI effective value and the threshold value TH1. The host device communication unit 101 transmits the remaining tag ID after being excluded by the tag exclusion unit 115 to the POS terminal 20.

  In this way, it is possible to exclude an inappropriate tag ID in consideration of the actual usage environment of the wireless tag reader 10 and the wireless tag 30, so that the wireless tag to be excluded can be correctly specified. .

  In the first embodiment, the tag excluding unit 115 corrects the RSSI measurement value based on the type of the wireless tag 30.

  In this way, an optimum RSSI effective value corresponding to the type of the wireless tag 30 can be calculated.

  Moreover, in Example 1, the tag exclusion part 115 correct | amends an RSSI measured value based on the raw material of an attachment target object.

  By carrying out like this, the optimal RSSI effective value according to the raw material of an attachment target object is computable.

  In the first embodiment, the tag excluding unit 115 corrects the RSSI measurement value based on the performance of the IC chip included in the wireless tag 30.

  By doing so, an optimum RSSI effective value corresponding to the performance of the IC chip included in the wireless tag 30 can be calculated.

[Example 2]
FIG. 6 is a diagram illustrating an example of a processing sequence of the wireless tag system according to the second embodiment. Hereinafter, only processing different from the first embodiment will be described.

  In FIG. 6, in step S31, the tag excluding unit 115 corrects the threshold value TH1 using the correction coefficient A and the correction coefficient B for each tag ID stored in the tag information storage unit 111, thereby obtaining an effective value of the threshold value. TH2 is calculated (hereinafter may be referred to as “effective threshold”). The tag exclusion unit 115 calculates the effective threshold TH2 according to the following equation (2).

  Effective threshold TH2 = threshold TH1 / correction coefficient A / correction coefficient B / transmission power coefficient (2)

  Next, in step S33, the tag exclusion unit 115 compares the RSSI measurement value with the effective threshold value TH2, and determines whether or not the RSSI measurement value is equal to or greater than the effective threshold value TH2 and is stored in the tag information storage unit 111. Judge for each ID. As a result of the comparison, if the RSSI measurement value is greater than or equal to the effective threshold value TH2 (step S33: Yes), the process proceeds to step S23. On the other hand, if the RSSI measurement value is less than the effective threshold TH2 as a result of the comparison (step S33: No), the process proceeds to step S25 without executing the process of step S23.

  In step S23, the tag exclusion unit 115 acquires the tag ID whose RSSI measurement value is equal to or greater than the effective threshold TH2 in step S33 from the tag information storage unit 111, and outputs the acquired tag ID to the format conversion unit 117.

  Next, in step S25, the tag exclusion unit 115 determines whether or not the determination in step S33 has been completed for all the tag IDs stored in the tag information storage unit 111 in step S15 based on the number information (that is, Whether all tags are completed). If all tags are not completed (step S25: No), the process returns to step S17. In the second and subsequent processes of steps S17, S31, S33, and S25, the tag excluding unit 115 executes the processes of steps S17, S31, S33, and S25 even if there is no notification from the RSSI measuring unit 110.

  Here, as described above, when the RSSI measurement value is less than the effective threshold value TH2 (step S33: No), the process proceeds to step S25 without executing the process of step S23. Therefore, the RSSI measurement is performed in step S33. Tag IDs whose values are less than the effective threshold TH2 are excluded from transmission targets to the POS terminal 20. That is, the tag excluding unit 115 excludes tag IDs other than those to be transmitted to the POS terminal 20 from the tag IDs included in the tag response wirelessly received in step S15, as in the first embodiment. Further, as in the first embodiment, the higher-level device communication unit 101 transmits the remaining tag ID after being excluded by the tag exclusion unit 115 to the POS terminal 20.

  For example, while the RSSI measurement value of the tag response received from the wireless tag 30-1 is equal to or greater than the effective threshold TH2, the RSSI measurement values of the tag response received from the wireless tags 30-2 and 30-3 are both If it is less than the effective threshold TH2, the tag exclusion unit 115 selects the second tag ID and the third tag ID from the first tag ID, the second tag ID, and the third tag ID stored in the tag information storage unit 111. The tag ID is excluded, and only the remaining first tag ID after the exclusion is output to the format conversion unit 117. Therefore, in this case, only the first tag ID is transmitted from the wireless tag reading device 10 to the POS terminal 20 among the first tag ID, the second tag ID, and the third tag ID received by the wireless tag reading device 10. The

  In Expression (2), the threshold value TH1 is corrected using all of the correction coefficient A, the correction coefficient B, and the transmission power coefficient, but any one of the correction coefficient A, the correction coefficient B, and the transmission power coefficient or The threshold value TH1 may be corrected using two coefficients.

  As described above, the tag exclusion unit 115 according to the second embodiment calculates the effective threshold value TH2 by correcting the predetermined threshold value TH1. Further, the tag excluding unit 115 excludes tag IDs other than the transmission target from the tag IDs included in the wirelessly received tag response based on the comparison result between the RSSI measurement value and the effective threshold value TH2.

  By doing so, it is possible to exclude an inappropriate tag ID in consideration of the actual usage environment of the wireless tag reader 10 and the wireless tag 30 as in the first embodiment. Can be identified correctly.

  In addition, the tag excluding unit 115 according to the second embodiment corrects the threshold value TH1 based on the type of the wireless tag 30.

  By doing so, it is possible to calculate the optimum effective threshold TH2 according to the type of the wireless tag 30.

  Further, the tag exclusion unit 115 in the second embodiment corrects the threshold value TH1 based on the material of the attachment target.

  By doing so, it is possible to calculate the optimum effective threshold TH2 according to the material of the attachment object.

  In addition, the tag excluding unit 115 according to the second embodiment corrects the threshold value TH1 based on the performance of the IC chip included in the wireless tag 30.

  By doing so, it is possible to calculate the optimum effective threshold TH2 according to the performance of the IC chip included in the wireless tag 30.

[Example 3]
The tag ID is formed from a product code, a serial number, a tag type code, and a material identification code, and may not include an IC chip identification code. When the tag ID does not include the IC chip identification code, in the wireless tag 30, the tag ID and the IC chip identification code are stored in different areas. When the tag ID does not include the IC chip identification code, the wireless tag reader 10 requests the wireless tag 30 to transmit the tag ID by transmitting a transmission request command, and in addition, the wireless tag reader 10 The wireless tag 30 may be requested to transmit the IC chip identification code by transmitting an “identification code request command” requesting transmission of the IC chip identification code to the wireless tag 30. This identification code request command includes the tag ID acquired from the tag response by the wireless tag reader 10. In response to the identification code request command, the wireless tag 30 reads the IC chip identification code stored in a different area from the tag ID storage area using the tag ID included in the identification code request command as a key, and reads the wireless tag. Transmit to device 10.

[Example 4]
<Hardware configuration of wireless tag reader>
The wireless tag reader 10 can be realized by the following hardware configuration, for example. FIG. 7 is a diagram illustrating a hardware configuration example of the wireless tag reader according to the fourth embodiment. In FIG. 7, the wireless tag reading device 10 includes a processor 10a, a memory 10b, a wireless communication module 10c, and a wired communication module 10d as hardware components. Examples of the processor 10a include a CPU (Central Processing Unit), a DSP (Digital Signal Processor), and an FPGA (Field Programmable Gate Array). Further, the wireless tag reader 10 may include an LSI (Large Scale Integrated circuit) including a processor 10a and peripheral circuits. Examples of the memory 10b include a RAM (Random Access Memory) such as an SDRAM (Synchronous Dynamic Random Access Memory), a ROM (Read Only Memory), a flash memory, and the like.

  The higher-level device communication unit 101 is realized by, for example, the wired communication module 10d. The wireless communication unit 107 is realized by, for example, the wireless communication module 10c. The tag information storage unit 111 and the correction coefficient storage unit 113 are realized by the memory 10b, for example. The upper command interpreting unit 103, the tag addressed command generating unit 105, the RSSI measuring unit 110, the tag excluding unit 115, and the format converting unit 117 are realized by the processor 10a, for example.

  In addition, each process in the above description in the wireless tag reader 10 may be realized by causing the processor 10a to execute a program corresponding to each process. For example, a program corresponding to each process in the above description may be stored in the memory 10b, and the program may be read from the memory 10b by the processor 10a and executed.

[Example 5]
The tag ID may not include both or one of the tag type code and the material identification code. In this case, for example, the memory 10b stores a table in which the tag type code and the material identification code are set in association with the product code, and the tag exclusion unit 115 acquires and acquires the product code from the tag ID. The tag type code and the material identification code corresponding to the product code may be acquired by searching the table using the product code as a key.

DESCRIPTION OF SYMBOLS 1 Wireless tag system 10 Wireless tag reader 101 Upper apparatus communication part 103 Upper command interpretation part 105 Tag addressed command generation part 107 Wireless communication part 109 Antenna 110 RSSI measurement part 111 Tag information storage part 113 Correction coefficient storage part 115 Tag exclusion part 117 Format converter

Claims (6)

A first communication unit for wirelessly receiving a tag response including a tag ID stored in the wireless tag;
A measurement unit that measures the reception strength of the tag response received wirelessly and obtains a measurement value of the reception strength;
The tag ID included in the wirelessly received tag response is calculated based on a comparison result between the effective value and a predetermined threshold value of the reception intensity by calculating the effective value of the reception intensity by correcting the measurement value. An exclusion unit that excludes tag IDs other than the transmission target from among,
A second communication unit that transmits the remaining tag ID after being excluded by the exclusion unit to a host device;
A wireless tag reader comprising: The exclusion unit corrects the measurement value based on all or part of the type of the wireless tag, the material of the attachment object of the wireless tag, and the performance of the IC chip included in the wireless tag,
The wireless tag reader according to claim 1. A first communication unit for wirelessly receiving a tag response including a tag ID stored in the wireless tag;
A measurement unit that measures the reception strength of the tag response received wirelessly and obtains a measurement value of the reception strength;
An effective value of the threshold value is calculated by correcting a predetermined threshold value, and a transmission target is selected from the tag IDs included in the tag response received wirelessly based on a comparison result between the measured value and the effective value. An exclusion unit that excludes tag IDs other than
A second communication unit that transmits the remaining tag ID after being excluded by the exclusion unit to a host device;
A wireless tag reader comprising: The exclusion unit corrects the predetermined threshold based on all or part of the type of the wireless tag, the material of the attachment object of the wireless tag, and the performance of the IC chip included in the wireless tag. ,
The wireless tag reader according to claim 3. Wirelessly receiving the tag ID stored in the wireless tag,
Measure the reception strength of the tag ID received wirelessly to obtain the measurement value of the reception strength,
The effective value of the received intensity is calculated by correcting the measured value, and based on the comparison result between the effective value and the predetermined threshold value of the received intensity, the tag IDs other than those to be transmitted are wirelessly received. Excluding the tag ID of
Send the remaining tag ID after the exclusion to the host device.
Wireless tag reading method. Wirelessly receiving the tag ID stored in the wireless tag,
Measure the reception strength of the tag ID received wirelessly to obtain the measurement value of the reception strength,
The effective value of the threshold value is calculated by correcting a predetermined threshold value, and tag IDs other than the transmission target are excluded from the wirelessly received tag IDs based on the comparison result between the measured value and the effective value. And
Send the remaining tag ID after the exclusion to the host device.
Wireless tag reading method.

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