JP2009193253A - Radio tag detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio tag detection device for efficiently and quickly searching only one specific among a plurality of articles. <P>SOLUTION: This radio tag detection device is configured to transmit an inquiry signal with directivity to a radio tag by radio, and to receive a response signal transmitted by radio from the radio tag based on the inquiry signal, and to detect the strength of the received response signal, and to decide the rank of the strength of the response signal from the radio tag to be searched among the detected strength of the response signals in comparison with the strength of response signals from the other radio tags, and to give the notification of the decided rank as an element for determining the direction where the radio tag to be searched exists. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wireless tag detection device that searches for a desired wireless tag from among wireless tags attached to a large number of articles.

  It is possible to read data from the memory mounted on the wireless tag or write data to the memory by performing wireless communication using radio waves with the wireless tag existing in the communication area of this antenna. Wireless communication devices have been developed and put into practical use. A unique ID, so-called tag identification information, is stored in the memory of each wireless tag, and the wireless tag can be individually specified by reading the tag identification information. Such a wireless tag is called RFID (Radio Frequency Identification). The wireless communication device is called an RFID reader / writer.

  A so-called RFID system composed of such wireless communication devices and wireless tags is introduced into a store that sells a large number of products, a library that stores a large number of books, and the like. Management becomes easy.

As an example of an RFID system, a signal transmitted from a wireless tag is received by an RFID reader, and it is determined whether or not the wireless tag exists in a predetermined area according to the power value of the received signal. (For example, patent document 1). In addition, there is a wireless tag that detects the intensity of a radio wave transmitted from a reader / writer and received by a wireless tag, and transmits the detected data from the wireless tag to the reader / writer (for example, Patent Document 2).
JP 2007-323423 A JP 2005-107772 A

  In a store that sells a large number of products, if there is a purchase request from a shopper or a return to the headquarters or a wholesaler is required, the product is displayed in a large number of boxes or in a number of boxes. There is a case where it is desired to select only one specific product from among a large number of products stored as stock. Similarly, in a library in which a large number of books are stored, there is a case where there is a request for browsing from a user, or there is a case where only one specific book is selected from a large number of books when arranging and arranging the books.

  In such a case, even if each item has a wireless tag, as described above, the RFID system that determines the presence of the wireless tag in a predetermined area or detects the intensity of the radio wave received by the wireless tag is specified. It is difficult to efficiently find only one item.

  The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a wireless tag detection apparatus capable of efficiently and quickly searching for one specific article from among a large number of articles.

  According to a first aspect of the present invention, there is provided a wireless tag detection apparatus that transmits wirelessly an inquiry signal for a wireless tag with directivity, and wirelessly transmits from the wireless tag based on an inquiry signal wirelessly transmitted from the transmission means. Receiving means for receiving the response signal, detecting means for detecting the strength of the response signal received by the receiving means, setting means for setting the search target wireless tag, and strength of the response signal detected by the detecting means Among the above, the determination means for determining the highest order of the strength of the response signal from the wireless tag to be searched is higher than the strength of the other response signals, and the determination result of this determination means is the search target. An informing means for informing as a determination element of the direction in which the wireless tag exists.

  According to the wireless tag detection device of the present invention, only one specific article can be efficiently and quickly searched out of a large number of articles. As a result, it is possible to greatly reduce the labor and time required to search for articles.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, 1 is a main unit which can be held with one hand, and has a touch panel type liquid crystal display unit 2 and a keyboard 3 on the front surface. The keyboard 3 includes a power key 3a for turning the power on and off. A leader unit 4 is provided as an attachment to the main unit 1. Similarly, the reader unit 4 has a handle 5 that can be held with one hand on the back surface, and performs wireless communication with a wireless tag 6 attached to an article, for example, a commodity in a store, using a built-in antenna. The main unit 1 and the reader unit 4 are capable of mutual data communication using weak radio waves. For example, the main unit 1 is held with the left hand, the reader unit 4 is held with the right hand, and the reader unit 4 is directed toward the search target. Is done.

A control circuit of the main unit 1 and the reader unit 4 is shown in FIG.
First, the main unit 1 includes a power supply unit 10 that outputs an operation voltage, and a control unit 11 that controls operations of the main unit 1 and the reader unit 4. The control unit 11 includes the touch panel liquid crystal display unit 2. The keyboard 3, the communication unit 12, the GUI (Graphical User Interface) 13, and the sound generation unit 14 are connected. The communication unit 12 performs data communication with the reader unit 4 using weak radio waves. The GUI 13 displays, for example, a wireless tag detection screen on the touch panel type liquid crystal display unit 2 as various screens according to instructions from the control unit 11. The sound generation unit 14 generates a sound signal corresponding to a command from the control unit 11, for example, an intermittent beep sound signal, and supplies it to the speaker 15. The speaker 15 converts the beep sound signal generated by the sound generation unit 14 into an actual sound.

  The reader unit 4 includes a power supply unit 20 that outputs an operation voltage and a control unit 21 that controls the operation of the reader unit 4. The control unit 21 includes a communication unit 22, a transmission unit 23, and an AGC (Automatic Gain Control) circuit 26 is connected. The communication unit 22 performs data communication with the main unit 1 using weak radio waves. The transmission unit 23 modulates a predetermined carrier wave with the analog transmission data signal supplied from the control unit 21, amplifies the modulated signal, and supplies the amplified signal to the antenna 24. The antenna 24 radiates a signal supplied from the transmission unit 23 as a radio wave and receives a radio wave transmitted from the radio tag 6 existing in its own communication area, and performs radio transmission and radio reception with directivity. Has fingering properties. This received signal is supplied to the receiving unit 25. The receiving unit 25 amplifies the received signal from the antenna 24, performs demodulation to remove a predetermined carrier component from the amplified signal, and outputs a signal in a predetermined low frequency band from the demodulated signal to an LPF (Low Pass Filter). ) To extract. The extracted signal is supplied to the AGC circuit 26. The AGC circuit 26 amplifies the signal supplied from the receiving unit 25 and adjusts the gain so that the amplified signal level becomes a constant appropriate level. An output signal of the AGC circuit 26 is supplied to the control unit 21. Further, as an element for detecting the intensity of the received signal from the wireless tag 6, an adjustment gain value in the AGC circuit 26, for example, any adjustment gain between “0 (no amplification)” to “255 (maximum amplification)” The value is supplied to the control unit 21.

  Here, FIG. 3 and FIG. 4 show examples of the radio wave range radiated from the antenna 24 and some radio tags 6 existing inside and outside the radio wave range. In the example of FIG. 3, among the plurality of wireless tags 6 located at the same distance from the antenna 24, the wireless tag 6 existing in the front direction of the antenna 24 can receive strong radio waves and has a high response level. The wireless tag 6 existing in the direction away from the front cannot receive strong radio waves and has a low response level, indicating that the wireless tag 6 existing outside the radio wave range of the antenna 24 cannot receive radio waves. Yes. In the example of FIG. 4, there are a plurality of wireless tags 6 in the front direction of the antenna 24, and the wireless tag 6 located near the antenna 24 can receive strong radio waves and has a high response level, and is away from the antenna 24. This indicates that the wireless tag 6 cannot receive strong radio waves and has a low response level.

  Further, the wireless tags 6 exist at the A position and the B position, respectively, and the change in the relationship between the radio wave range 6 and each wireless tag 6 when the direction of the antenna 24 is changed with respect to the wireless tags 6 is shown in FIGS. This is shown in FIG. In the example of FIG. 5, when the attendant turns the leader unit 4 to the left, the wireless tag 6 at position A exists in the front direction of the antenna 24, and the wireless tag at position B in the right direction slightly off the front of the antenna 24. 6 indicates that the wireless tag 6 at position A can receive strong radio waves and has a high response level, and the radio tag 6 at position B cannot receive strong radio waves and has a low response level. Yes. In the example of FIG. 6, when the clerk points the leader unit 4 in the front direction, both the wireless tags 6 at the A position and the B position exist in the front direction of the antenna 24, and each wireless tag 6 receives strong radio waves. This shows that the response level becomes high. In the example of FIG. 7, when the attendant turns the leader unit 4 to the right, the wireless tag 6 at the B position exists in the direction of the front of the antenna 24, and the wireless at the A position is slightly away from the front of the antenna 24. The tag 6 exists, the wireless tag 6 at the B position can receive strong radio waves and has a high response level, and the wireless tag 6 at the A position cannot receive strong radio waves and has a low response level. ing.

  In addition, as shown in FIG. 8, the RFID tag detection screen displayed on the touch panel type liquid crystal display unit 2 of the main unit 1 has EPC (Electronic Product Code), JAN (Japanese article number) code, SKU ( Stock Keeping Unit) A product designation method display area 31 for displaying whether a code or a product name is designated, a display window 32 for an input code, and a detection for instructing the start of detection of a specific wireless tag 6 It has a start button 33, a detection end button 34 for instructing the end of detection, and a tag detection status display area 35 for sequentially displaying the actual detection status. In the tag detection status display area 35, when the wireless tag 6 of the product to be searched does not exist within the communication area of the antenna 24 of the reader unit 4 and the wireless tag 6 is not detected, the tag detection status display area 35 is lit with the current position ▽ (black) mark. Undetected indicator 36, distance display indicator 37 for displaying the distance between the reader unit 4 and the wireless tag 6 of the product to be searched in analogy with a current position ▽ (black) mark on the scale, An “approached” indicator 38 that lights when the current position approaches the wireless tag 6 of the product to be searched, and lights when the current position of the reader unit 4 is away from the wireless tag 6 of the product to be searched There is an “Away” indicator 39.

  In addition, a direction reliability display that displays direction reliability (numerical values “1” to “5” and “0”) as a determination element of the direction in which the wireless tag 6 to be searched exists in the upper right area of the wireless tag detection screen. An area 40 is provided.

  Then, the control unit 11 of the main unit 1 and the control unit 21 of the reader unit 4 have the following means (1) to (8) as main functions related to wireless tag detection based on mutual data communication.

  (1) A specifying unit (setting unit for setting a search target wireless tag) for specifying a search target product by a code in accordance with an operation of the keyboard 3 in the main unit 1.

  (2) Extraction means for extracting tag identification information corresponding to the specified code from a product database stored in a memory in the control unit 11 (setting means for setting a wireless tag to be searched).

  (3) Transmission means for wirelessly transmitting inquiry signals for a plurality of wireless tags 6 from the antenna 24 of the reader unit 4.

  (4) Receiving means for receiving the response signal wirelessly transmitted from each wireless tag 6 by the antenna 24 based on the inquiry signal wirelessly transmitted from the transmitting means.

  (5) Detection means for detecting the intensity of the response signal received by the reception means by referring to an intensity detection table based on the adjustment gain value supplied from the AGC circuit 26. The intensity detection table is stored in a memory in the control unit 11.

  (6) Among the response signal intensities detected by the detecting means, the search target that is the source of the response signal according to the intensity of the response signal having the tag identification information extracted by the extracting means and the change thereof Informing means for informing the distance to the wireless tag 6 and whether or not the distance is approached or separated by displaying a wireless tag detection screen on the touch panel type liquid crystal display unit 2 and generating a beep sound from the speaker 15.

  (7) Of the response signal intensities detected by the detection means, the response signals having the tag identification information extracted by the extraction means are ranked higher in rank than the other response signal intensities. A determination means for determining whether or not there is.

  (8) Notification means for informing the order determined by the determination means as a determination element of the direction in which the search target wireless tag exists by displaying the direction reliability display area 40 on the wireless tag detection screen.

  On the other hand, the wireless tag 6 has an IC chip on which a power generation unit, a demodulation unit, a modulation unit, a memory unit, a control unit, and the like are mounted, and an antenna. The signal emitted from the control unit is modulated and wirelessly transmitted from the antenna, and an ID unique to the wireless tag, so-called tag identification information, is stored in the memory unit. For example, EPC (Electronic Product Code) for product identification is used as the tag identification information. The wireless tag 6 having such a configuration is attached to a large number of products in the store.

  Next, the operation will be described with reference to the flowcharts of FIGS. 9 and 10. The flowchart of FIG. 9 shows control executed by the control unit 11 of the main unit 1 when the detection start button 33 on the RFID tag detection screen in the touch panel type liquid crystal display unit 2 is touched. The flowchart of FIG. 10 shows control executed by the control unit 11 of the main unit 1 when the detection end button 34 on the RFID tag detection screen in the touch panel type liquid crystal display unit 2 is touched.

  When a store clerk wants to find one specific product among a number of products in the store, the EPC, JAN code, SKU code, or product name is specified using the keyboard 3 as the product specification method. 3 to enter the actual code. For example, when a JAN code is designated, as shown in FIG. 8, the indicator section of the JAN code in the product designation method display area 31 is turned on, and the actually input JAN code is displayed on the display window 32 as the designated code. The

  In this state, when the detection start button 33 on the RFID tag detection screen in the touch panel type liquid crystal display unit 2 is touch-operated by an attendant, the input designation code is taken in (step 101), and the designation code is EPC. Is determined (step 102).

  In this case, since the designation code is a JAN code, the product database shown in FIG. 11 in the control unit 11 is referred to based on the JAN code under the determination that the designation code is not EPC (NO in step 102), and the JAN The EPC corresponding to the code is searched (step 103).

  In this search, if there is no EPC corresponding to the JAN code (NO in step 104), the message “No applicable product” is displayed on the touch panel type liquid crystal display unit 2 instead of the RFID tag detection screen (step 105). This display is the end of the detection work.

  In the above search, if there is an EPC corresponding to the JAN code (YES in step 104), the EPC is extracted as tag identification information to be searched (step 106). If the specified code is EPC (YES in step 102), the EPC is extracted as it is as tag identification information to be searched (step 106). Along with this extraction, both the end flag serving as an index as to whether or not the detection end button 34 has been touched and the end process completion flag serving as an index as to whether or not the detection work has been completed are both turned off (step 107). ), The target tag detection flag serving as an index indicating whether or not the detection of the search target wireless tag 6 has been completed is turned off (step 108). Then, a read command is sent to the reader unit 4 (step 109).

  In this way, a read command is sent to the reader unit 4, whereby an inquiry signal for each wireless tag 6 is wirelessly transmitted from the antenna 24 of the reader unit 4. At this time, if the wireless tag 6 exists within the range of the radio wave radiated from the antenna 24, a response signal is wirelessly transmitted from the wireless tag 6.

  If no response signal is received in the reader unit 4, under the determination that there is no tag response (NO in step 110), the undetected indicator 36 on the RFID tag detection screen is lit together with the current position ▽ (black) mark (step 111). ). Then, the read command is sent again to the reader unit 4 (step 109).

  When at least one response signal is received by the reader unit 4, under the determination that there is a tag response (YES in step 110), the intensity of the received response signal is adjusted by the AGC circuit 26. This is detected by referring to the intensity detection table of FIG. 12 based on (step 112). The detected intensity is stored in the internal memory of the control unit 11 in a form numbered in the order of reception, for example.

  The intensity detection table is obtained by assigning 10 levels of intensity “10 (strongest)” to “1 (minimum)” to the adjustment gain values of “0 (no amplification)” to “255 (maximum amplification)”. is there. For these ten levels of intensity “10 (strongest)” to “1 (minimum)”, 10 levels of distance from “close distance” to “far distance” are assigned. The strongest intensity “10” corresponds to “close distance”, and the minimum intensity “1” corresponds to “far distance”. For example, “near distance” is “1”, “far distance” is “10”, and 10-step distances from “1” to “10” are assigned.

  After detecting the intensity, a value X for designating one of a plurality of received response signals, eg, N response signals, is set to an initial value “1” (step 113). Then, among the received N response signals, the response signal whose reception order is Xth (= 1) is designated (step 114), and the tag identification information included in the designated response signal is the above-described tag identification information. It is determined whether or not the search target tag identification information extracted in the process of step 106 matches (step 115).

  If this determination result is the same (YES in step 115), the target tag detection flag is turned on based on the determination that the response signal of the first reception order is transmitted from the search target wireless tag 6. (Step 116). Then, the strength of the first response signal in the order of reception is selected from the strengths of the response signals stored in the internal memory of the control unit 11, and the distance corresponding to the strength is analog-displayed on the distance display indicator 37. (Step 117). The scale of the distance display indicator 37 indicates “10 (distant distance)” on the left side position and “1 (close distance)” on the right end position, and the current position ▽ (black) at the scale position corresponding to the 10-step distance. The mark is displayed. Accordingly, the distance to the wireless tag 6 to be searched can be visually detected based on which position on the scale is indicated by the current position (black) mark.

  Subsequently, the strength of the response signal No. 1 in reception order (referred to as “current strength”) is compared with the strength of the response signal from the search target wireless tag 6 (referred to as “previous strength”) in the previous reception. (Step 118). Here, the “previous strength” is stored in the internal memory of the control unit 11 when the search target wireless tag 6 is detected from the previous reception. After the comparison in step 118 is completed, “current intensity” is updated and stored in the internal memory as “previous intensity”.

  If “current intensity” is equal to or greater than “previous intensity” (YES in step 118), the touch panel type liquid crystal display unit 2 is determined based on the determination that the reader unit 4 is approaching the wireless tag 6 to be searched. The “approached” indicator 38 on the RFID tag detection screen is turned on and the “away” indicator 39 is turned off (step 119). The undetected indicator 36 is turned off. At the same time, the timing of intermittent beep generated from the speaker 15 is shortened (step 120). When the response signal is received for the first time and the “previous strength” is not stored, the determination result is that the “current strength” is equal to or greater than the “previous strength”.

  By turning on the “approached” indicator 38 and shortening the generation timing of the beep, the staff can detect that the reader unit 4 is approaching the wireless tag 6 to be searched.

  If the “current intensity” is smaller than the “previous intensity” (NO in step 118), the wireless tag of the touch panel type liquid crystal display unit 2 is determined based on the determination that the reader unit 4 has moved away from the search target wireless tag 6. The “approaching” indicator 38 on the detection screen is turned off and the “leaving” indicator 39 is turned on (step 121). At the same time, the generation timing of the intermittent beep generated from the speaker 15 is extended more than before (step 122). When the response signal is received for the first time and there is no “previous strength”, the determination result that “current strength” is smaller than “previous strength” is not obtained. Is not executed.

  By turning on the “separated” indicator 39 and extending the generation timing of the beep sound, the attendant can detect that the reader unit 4 has left the wireless tag 6 to be searched.

  Subsequently, a value X for designating one of the received N response signals is incremented by “1” to become “2” (step 123), which is compared with the number N of response signals (step 123). 124). If this X (= “2”) is N or less (NO in step 124), the process returns to step 114, and the response signal in the second reception order is designated. Then, it is determined whether or not the tag identification information included in the designated response signal is the same as the tag identification information to be searched extracted in step 106 (step 115).

  In this case, since the determination result that the first response signal in the receiving order is transmitted from the search target wireless tag 6 has already been obtained, the determination result in step 115 is inconsistent (NO in step 115). The distance determination process in steps 116 to 122 is not executed, the process in step 123 is executed, and X (= 2) is increased by “1” to become “3”. If X (= 3) is equal to or less than N (NO in step 124), the process returns to step 114, and the third response signal in the order of reception is designated. Then, it is determined whether or not the tag identification information included in the designated response signal is the same as the tag identification information to be searched extracted in the process of step 106 (step 115).

  Also in this case, since the determination result that the first response signal in the reception order is transmitted from the search target wireless tag 6 has already been obtained, the determination result in step 115 is inconsistent (in step 115). NO) The distance determination process in steps 116 to 122 is not executed, but the process in step 123 is executed, and X (= 3) is increased by “1” to become “4”. Then, X (= 4) and N are compared (step 124).

If X exceeds N (YES in step 124), it is determined whether the target tag detection flag is on (step 125).
If the target tag detection flag is on (YES in step 125), one of the received N response signals is designated based on the determination that the detection target wireless tag 6 has been detected. Is set to the initial value “1” (step 126), and the direction reliability Y is set to the initial value “1” (step 127). The direction reliability Y is a numerical value indicating the rank of the highest rank of the response signal from the search target wireless tag 6 relative to the strength of other response signals among the detected response signal strengths. It is what. Y = “1” which is the highest direction reliability when the rank is first, Y = “2” which is the second direction reliability from the highest when the rank is second, and when the rank is third Y = “3” which is the third direction reliability from the highest, Y = “4” which is the fourth direction reliability from the highest when the ranking is fourth, and fifth from the highest when the ranking is fifth Y = “5”, which is the direction reliability of. In addition, Y = “0” indicating that the search target wireless tag 6 has not been detected is prepared as the lowest direction reliability.

  Then, it is determined whether or not the response signal whose reception order is X (= 1) is transmitted from the search target wireless tag 6 (step 128). As described above, since the response signal having the first reception order is transmitted from the search target wireless tag 6 (YES in step 128), X is increased by “1” to become “2” (step 131). ). This X (= 2) and N are compared (step 132), and if X (= 2) is less than or equal to N (NO in step 132), the process returns to step 128, and the response signal in the second reception order is searched. It is determined whether or not it is transmitted from the wireless tag 6 (step 128).

  Since the response signal No. 2 in the reception order is not transmitted from the search target wireless tag 6 (NO in Step 128), out of the response signal strengths stored in the internal memory of the control unit 11, The intensity of the second response signal is compared with the intensity of the first response signal in the receiving order that is the search target (step 129). If the strength of the response signal of the second reception order is greater than the strength of the response signal of the first reception order (YES in step 129), the order of the strength of the response signals wirelessly transmitted from the search target wireless tag 6 is other than The direction reliability Y is increased by “1” from the initial value “1” (= highest direction reliability) based on the determination that it is at least one lower than the strength of the response signal. Second direction reliability) (step 130). Then, X is increased by “1” to become “3” (step 131), and X (= 3) and N are compared (step 132). If X (= 3) is equal to or less than N (NO in step 132), the process returns to step 128, and it is determined whether or not the response signal in reception order No. 3 is transmitted from the search target wireless tag 6 (step). 128).

  Since the response signal No. 3 in the reception order is not transmitted from the search target wireless tag 6 (NO in Step 128), out of the response signal strengths stored in the internal memory of the control unit 11, The intensity of the response signal No. 3 is compared with the intensity of the response signal No. 1 in the receiving order (step 129). If the strength of the response signal of the reception order No. 3 is greater than the strength of the response signal of the reception order No. 1 (YES in Step 129), the rank order of the response signals wirelessly transmitted from the search target wireless tag 6 is other than The direction reliability Y is increased by “1” from “2” to “3” (= highest third direction reliability) under the judgment that it is one more lower than the strength of the response signal ( Step 130). Then, X is incremented by “1” to become “4” (step 131), and X (= 4) and N are compared (step 132). If X (= 4) is less than or equal to N (NO in step 132), the process returns to step 128, and it is determined whether or not the response signal in reception order No. 4 has been transmitted from the search target wireless tag 6 (step). 128).

  When X exceeds N (YES in step 132), the current direction reliability Y is displayed in the direction reliability display area 40 of the RFID tag detection screen (step 133).

  In this way, of the detected N response signal intensities, the rank of the response signal transmitted from the search target wireless tag 6 is ranked higher than the other response signal intensities. Is determined. Then, the determined order is displayed as a direction reliability Y that is a determination element of the direction in which the wireless tag 6 to be searched exists. The attendant can accurately grasp the direction in which the wireless tag 6 to be searched exists by looking at the display of the direction reliability Y.

  For example, if the indication of the direction reliability Y is “3”, it is determined that the orientation of the reader unit 4 is out of the direction in which the wireless tag 6 to be searched exists, and the reader unit 4 is moved in an arbitrary direction. Check the direction reliability Y display. When the indication of the direction reliability Y changes to “4” or “5”, it is determined that the orientation of the reader unit 4 has moved away from the direction in which the wireless tag 6 to be searched exists, and the reader unit 4 is opposed to the previous one. The display of the direction reliability Y is confirmed again while moving in the direction of. If the display of the direction reliability Y changes to “2”, it is determined that the direction of the reader unit 4 is approaching the direction in which the wireless tag 6 to be searched exists, and the reader unit 4 is moved in the same direction as before, Check the direction reliability Y display. When the display of the direction reliability Y changes to “1” which is the highest, it is determined that the orientation of the reader unit 4 matches the direction in which the wireless tag 6 to be searched exists. At this time, if the user proceeds as it is in the direction in which the reader unit 4 is facing, the wireless tag 6 to be searched is reached.

  Thus, the direction reliability Y is displayed, the distance display by the distance display indicator 37 described above, the “approaching” indicator 38 is turned on / off, and the “away” indicator 39 is turned on / off. Further, when a beep sound is generated and the generation timing is appropriately changed, the direction in which the wireless tag 6 to be searched exists and the distance to the wireless tag 6 can be sensed both visually and auditorily. However, the wireless tag 6 to be searched can be approached. Therefore, it is possible to efficiently and quickly find only one specific article among many articles.

  When the reader unit 4 reaches the wireless tag 6 to be searched, a beep sound is emitted at the shortest time interval, and the current position ▽ (black) mark of the distance display indicator 37 is the “target tag” on the rightmost side of the scale. Refers to the display position.

  However, if the target tag detection flag is OFF in the determination in step 125 (NO in step 125), the detection of the wireless tag 6 to be searched is not completed, and the direction reliability Y is “0”. (Step 136). Then, the direction reliability Y = “0” is displayed in the direction reliability display area 40 (step 133). The direction reliability Y = “0” is the lowest direction reliability and represents that the search target wireless tag 6 has not been detected. In this case, the clerk detects that the search target wireless tag 6 has not yet been captured and takes measures such as moving to another location.

  On the other hand, when the detection end button 34 on the RFID tag detection screen in the touch panel type liquid crystal display unit 2 is touched by an attendant during or after detection, the end flag is turned on (step 201). Then, it is determined whether or not the end process completion flag is on (YES in step 202).

  After the direction reliability Y is displayed in step 133, it is determined whether the end flag is on (step 134). If it is off (NO in step 134), the process returns to steps 108 and 109, and the target tag While the detection flag is turned off, a read command is sent to the reader unit 4 again. When the end flag is turned on (YES in step 134), the end processing completion flag is turned on (step 135) based on the determination that the detection end button 34 has been touched, and the detection work is ended.

  In the above embodiment, response signals are wirelessly transmitted from all the wireless tags 6 that have received the inquiry signal from the reader unit 4, and a response signal having tag identification information to be searched is extracted from these response signals. However, the inquiry signal designating each tag identification information is wirelessly transmitted for all the wireless tags, and the response signal from the wireless tag 6 having the designated tag identification information is transmitted, and these response signals are transmitted. The case where the response signal having the tag identification information to be searched is extracted from the above can be similarly implemented.

  In the above-described embodiment, the beep sound is generated from the main unit 1. However, the sound generation unit 14 and the speaker 15 may be provided in the reader unit 4 and the beep sound may be generated from the reader unit 4.

  Furthermore, in the above embodiment, the direction reliability Y is notified by numerical display. However, instead of numerical display, for example, a plurality of image patterns simulating the shape of the wireless tag 6 are prepared, and these image patterns are prepared. It is good also as a structure which alert | reports the direction reliability Y by the change of the display number of.

  In the above embodiment, the separation type RFID tag detection device including the main unit 1 and the reader unit 4 has been described as an example. However, as illustrated in FIG. 13, the function of the reader unit 4 is stored in the main unit 1. It can be similarly implemented with a body-type wireless tag detection device. In this case, the antenna 24 is provided on the upper surface of the main unit 1 so as to protrude.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible in the range which does not change a summary.

The figure which shows the external appearance of one Embodiment of this invention. The block diagram which shows the control circuit of one Embodiment. The figure which shows the relationship between the some radio | wireless tag and radio wave range which exist in the position of equidistant from the antenna of one Embodiment. The figure which shows the relationship between the some radio | wireless tag and radio wave range which exist in the direction of the front of the antenna of one Embodiment. The figure which shows the relationship between the electromagnetic wave range at the time of directing the antenna of one Embodiment to the left direction, and each wireless tag. The figure which shows the relationship between the radio wave range at the time of directing the antenna of one Embodiment to the front direction, and each wireless tag. The figure which shows the relationship between the radio wave range at the time of directing the antenna of one Embodiment to the right direction, and each wireless tag. The figure which shows the radio | wireless tag detection screen of one Embodiment. The flowchart for demonstrating control of the main unit when the detection start button of one Embodiment is touch-operated. The flowchart for demonstrating control of the main unit when the RFID tag detection screen of one Embodiment is touch-operated. The figure which shows the goods database in one Embodiment. The figure which shows the intensity | strength detection table in one Embodiment. The figure which shows the modification of the external appearance of one Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Main unit, 2 ... Touch-panel-type liquid crystal display part, 3 ... Keyboard, 4 ... Remote control unit, 6 ... Wireless tag, 11 ... Control part, 12 ... Communication part, 14 ... Sound generation part, 21 ... Control part, 22 ... Communication unit, 23 ... Transmitting unit, 24 ... Antenna, 25 ... Receiving unit, 26 ... AGC circuit, 31 ... Product designation method display area, 32 ... Display window for input code, 33 ... Detection start button, 34 ... Detection End button, 35 ... Tag detection status display area, 36 ... Undetected indicator, 37 ... Distance display indicator, 38 ... "Closed" indicator, 39 ... "Leave away" indicator

Claims (4)

A setting means for setting a search target wireless tag;
Transmitting means for wirelessly transmitting an inquiry signal for a wireless tag with directivity;
Receiving means for receiving a response signal wirelessly transmitted from the wireless tag based on an inquiry signal wirelessly transmitted from the transmission means;
Detecting means for detecting the intensity of the response signal received by the receiving means;
A setting means for setting a search target wireless tag;
A determination unit that determines, from among the response signal strengths detected by the detection unit, the highest order of the strength of the response signal from the RFID tag to be searched compared to the strength of other response signals; ,
Informing means for informing the order determined by the determining means as a determining element of the direction in which the wireless tag to be searched exists;
A wireless tag detection device comprising: Of the response signal intensities detected by the detection means, the distance to the search target radio tag and whether or not the distance is approached or separated according to the intensity of the response signal from the search target radio tag and its change Informing means for informing,
The wireless tag detection device according to claim 1, further comprising: 2. The setting unit according to claim 1, comprising: a specifying unit for specifying a search target; and an extraction unit for extracting tag identification information corresponding to the search target specified by the specifying unit. Wireless tag detection device. Depending on the intensity of the response signal having the tag identification information extracted by the extraction means and the change thereof among the intensity of the response signal detected by the detection means, the response signal is transmitted to the wireless tag to be searched. Informing means for informing the distance and whether the distance is approaching or leaving,
The wireless tag detection device according to claim 3, further comprising:

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