JP2009098951A - Interrogator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently and accurately execute a search job in an interrogator to make execution of a search function possible to search for a transponder having designated specific information. <P>SOLUTION: When a worker searches for an RF tag having the designated specific information (ID number), a control circuit transmits an interrogation wave from a transmitting part, based on reception of a response signal from the RF tag by the receiving part, the information on all the RF tags existing in a communication area is read (S1). At first, the communication area is presumed to be comparatively wider. When the RF tag as a target exists in the communication area (S2:Y), its existence and the number of the RF tags existing in the communication area are displayed on a display part (S4). When a plurality of the RF tags exist, a transmitting output regulator circuit is controlled and the communication area is automatically reduced, and the reduction of the communication area is reported (S6). Further, a job (S1) to reread is iterated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention comprises transmission means for transmitting an interrogation radio wave toward a responder, and reception means for receiving a response radio wave returned by the responder that has received the interrogation radio wave, and information recorded in the transponder by communication Relates to an interrogator.

  For example, in the field of merchandise management, logistics, etc., a tag-like RF tag (responder) is attached to an article such as merchandise, luggage, and a portable reader / writer (interrogator) called a handy terminal (IHT). A system has been put to practical use that performs communication with the RF tag by electromagnetic waves (for example, UHF band radio waves) and reads (and writes) information on products recorded on the RF tag. In this system, with the reader / writer placed close to the RF tag to be read, operating power is supplied to the RF tag by electromagnetic waves and data communication (writing and reading) is performed. Yes.

  As this type of reader / writer, for example, in Patent Document 1, when an inquiry signal is transmitted with a low output and a response signal is received from a non-contact IC card (RF tag), a non-contact IC card is placed in the communicable area. Has been disclosed, and a command command and a write data signal are transmitted at a high output, thereby preventing power shortage of the non-contact IC card and performing a stable operation.

Further, in Patent Document 2, in a reader / writer device, the reception sensitivity of a receiving circuit is reduced based on the intensity of a response radio wave from a specific (closer) RF tag, so that an RF tag of a non-target RF tag can be detected. A technique for preventing reading of information is disclosed. Furthermore, in Patent Document 3, the reception sensitivity of the transmission / reception circuit is lowered (the reception range is narrowed) based on the signal strength from a specific RFID tag that has moved close to the RFID tag reader. A technique is disclosed in which information is read only from an RFID tag.
JP 2004-220492 A JP 2006-120090 A JP 2006-5582 A

  By the way, as an operation performed using the above-described RFID system, for example, a specific RF tag is used by using a portable reader / writer from a shelf in which a large number of articles each having an RF tag attached are stored. There is a search work of searching for (article) from a remote position. In this case, for example, in the key operation unit of the reader / writer, the search mode is set, and a specific ID number assigned (stored) to the RF tag to be searched is specified and input, thereby making the target RF A tag (article) can be searched.

  However, in the above search operation, when the communication area of the reader / writer is relatively wide, there are many cases where a plurality of RF tags (articles) exist in the communication area. At this time, the reader / writer can easily find out whether the target RF tag (article) exists in the communication area, but where the target RF tag (article) exists in the communication area. You can't pinpoint what to do. For this reason, after detecting the area where the target RF tag (article) is present, it is necessary for the operator to visually search for the target article within the general range, which is troublesome for the operator. At the same time, there is a risk of mistakes. For example, since confidentiality is required, if the information identifying the article is not written on the RF tag or the article itself, the visual search itself cannot be performed.

  However, when the communication area of the reader / writer is narrow enough to communicate with only one RF tag, for example, the information on the RF tag is read in order from the article located at the end of the shelf. Until the target RF tag (article) is found, the reader / writer is moved to the adjacent RF tag (article) side and read again. It must be repeated many times. For this reason, the search operation cannot always be performed efficiently, and there is a problem that the search takes time. Note that the techniques described in Patent Documents 1 to 3 cannot cope with an operation of searching for an RF tag having specific information.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to enable execution of a search function for searching for a responder having specified specific information. To provide an interrogator that can be done.

  In order to achieve the above object, an interrogator according to the present invention enables execution of a search function for searching for a responder having specified specific information. Reading means for reading information on all responders existing in a communicable communication area based on transmitting a question radio wave having directivity and receiving a response signal from the responder by the receiving means; and In the case where there are a plurality of responders including a notifying unit for notifying that when there is a responder having the specific information in the communication area and a responder having the specific information in the communication area. When there are a plurality of responders including a number notifying unit for notifying the number and a responder having the specific information in the communication area, the communication area of the reading unit is automatically reduced. communication Has a rear changing means, characterized in was configured to include a communication area change notification means for notifying to that effect when the communication area is changed by the communication area changing means (invention of claim 1).

  According to this, when performing the search work, the information of all the responders existing in the predetermined communication area is read by the reading means, and when the target responder exists, the information means And when there are a plurality of responders in the communication area, the number is notified by the quantity notification means. Therefore, the worker can know whether or not a target responder exists in the communication area, and if there is, another operator exists in the area. If there is only one target responder in the communication area, the search ends.

  And when there are a plurality of responders including the target responder in the communication area, the communication area changing means is changed so that the communication area of the reading means is automatically reduced, This is notified by the communication area change notification means. At this time, since the operator knows that the target responder exists somewhere in the communication area before the change, the operator should make the reading means read again with the communication area narrowed. Thus, it is possible to search for the target responder within a narrower range while narrowing down the area where the target responder exists (excluding the nonexistent area).

  In this case, since it is not necessary for the operator to visually find the target responder, even if information specifying the article is not written on the responder or the article itself, the search can be reliably performed. it can. In addition, compared with the case where the communication area is narrowed from the beginning, the search can be performed in a relatively wide communication area at the beginning, so that an efficient search can be performed. Since the communication area is automatically changed, it is needless to say that the operator does not need to perform an operation for the change.

  Of course, the number of responders notified by the quantity notification means may be an accurate numerical value notification, but in the case of an approximate notification or one or more notifications. Is also included. In the present invention, it is desirable to adopt a UHF band or a microwave band having a certain degree of directivity as the wavelength (frequency) of the radio wave used for communication between the interrogator and the responder.

  In the present invention, the communication area changing means is configured to repeatedly reduce the communication area in stages until the responders existing in the communication area are only the responders having specific information. (Invention of claim 2). According to this, even when the distance (interval) between the responders is narrow, it is possible to continue the search to one target responder in the end, which is more effective. Moreover, in this invention, the said communication area change means can be comprised so that a communication area may be changed by reducing the transmission output of a transmission means, or the receiving sensitivity of a reception means (invention of Claim 3). . In either case, the intended purpose can be achieved.

  A first embodiment in which the present invention is applied to a reader / writer of an RFID system used for merchandise management, for example, will be described below with reference to FIGS. In this case, the RFID system uses an RF tag 2 (see FIG. 3) as a responder attached to an article, for example, a boxed product 1, and an electromagnetic wave (for example, a radio wave having a frequency in the UHF band) between the RF tag 2. In this case, it comprises a handy type (portable) reader / writer 3 that performs communication to supply power and read / write data.

  Here, although not shown in detail, the RF tag 2 as a responder will be briefly described. The RF tag 2 has, for example, a plastic tag shape (rectangular plate shape). In addition, an antenna for performing communication with the reader / writer 3 and an IC chip for holding data and generating a response signal are provided therein. The IC chip includes a rectifying / smoothing circuit for obtaining an operating power supply from radio waves (interrogation radio waves) transmitted from the reader / writer 3, a CPU for controlling communication, a modulation / demodulating circuit for modulating and demodulating transmission / reception signals, and an operation program. A ROM that stores the data, a readable / writable EEPROM that stores the data, and the like are configured as a one-chip IC. The data (information) stored in the RF tag 2 includes a unique ID number, data on the product 1 to be affixed in some cases, and the like.

  On the other hand, the reader / writer 3 as an interrogator according to the present embodiment is a portable type called a handy terminal (IHT). FIG. 2 schematically shows the electrical configuration of the reader / writer 3, and FIG. 3 shows the external appearance of the reader / writer 3. As shown in FIG. 3, the main body case 4 constituting the outer shell of the reader / writer 3 has a thin rectangular box shape that is a head portion that is slightly long in the front-rear direction and has a tip portion that swells in the lateral direction. Yes. The base end side portion of the main body case 4 has a size (shape) that an operator can hold and operate with one hand.

  As shown in FIG. 2, the upper surface of the main body case 4 is provided with a display unit 5 made of a small-sized liquid crystal display located on the distal end side (head unit) and on the proximal end side. A key operation unit 6 is provided which has a plurality of operation keys such as numeric keys and function keys. Although not shown in detail, a trigger switch for reading instructions is provided on the side surface of the main body case 4. In addition, the main body case 4 is also provided with a power switch, a notification LED, a buzzer, and the like.

  As shown in FIG. 2, the main body case 4 is provided with a control circuit 7 that is configured mainly by a microcomputer and controls the whole. The control circuit 7 is supplied with operation signals from the trigger switch, the key operation unit 6 and the like. The control circuit 7 controls the notification LED, buzzer, display unit 5 and the like. Although not shown, the main body case 4 is also provided with a battery serving as a power source, an external interface for performing data communication with the outside (host device), and the like. The body case 4 is connected to the control circuit 7 and communicates with the RF tag 2 by electromagnetic waves to read and write data (a transmitting unit 15 and a receiving unit). 16) is provided as follows.

  That is, a transmission circuit 9 is connected to the control circuit 7 via a modulation circuit 8, and a transmission antenna 10 is connected to the transmission circuit 9. At the same time, a receiving circuit 12 is connected to the control circuit 7 via a demodulating circuit 11, and a receiving antenna 13 is connected to the receiving circuit 12. Furthermore, in this embodiment, the transmission output adjustment circuit 14 is provided. The transmission antenna 10 and the reception antenna 13 are both planar patch antennas, for example, and are arranged in the head portion of the main body case 4.

  Thus, the interrogation radio wave is transmitted from the transmission antenna 10 through the modulation circuit 8 and the transmission circuit 9 under the control of the control circuit 7. A response radio wave from the RF tag 2 is received by the receiving antenna 13, and the received signal is demodulated through the receiving circuit 12 and the demodulating circuit 11 and input to the control circuit 7 as received data. Therefore, the transmission circuit 15 as a transmission unit is configured by the modulation circuit 8, the transmission circuit 9, the transmission antenna 10, and the like, and the reception unit 16 as a reception unit is configured by the demodulation circuit 11, the reception circuit 12, the reception antenna 13, and the like. .

  At this time, as shown in FIG. 3, a communication radio wave having directivity is transmitted in front of the main body case 4 from the transmission antenna 10, and a communication area in which communication with the RF tag 2 is possible (broken lines A1 to A1 in FIG. Power is supplied to all the RF tags 2 existing in (A3) by electromagnetic waves, and data communication (reading (and writing)) is performed. Further, the transmission output adjustment circuit 14 is controlled by the control circuit 7 so that the transmission output of the interrogation radio wave output from the transmission antenna 10 (and thus the communication area communicable with the RF tag 2) can be freely changed. It has become.

  In the present embodiment, as one of the executable functions of the reader / writer 3 having the above configuration, the RF tag 2 (and hence the product 1) having specific information (for example, an ID number) designated by the operator is searched (shelf). There is a search function to check. This search function is executed by the operator operating the key operation unit 6 to instruct a search mode and inputting and specifying the ID number of the RF tag 2 to be searched. At this time, the control circuit 7 By the software configuration (execution of search program), the search function is executed by controlling each mechanism as follows.

  That is, as will be described in the following explanation of the operation (flow chart explanation), the control circuit 7 first transmits the interrogation radio wave by the transmission unit 15 and receives the response signal from the RF tag 2 by the reception unit 16. The information of all the RF tags 2 existing in the communication area is read. At this time, the communication area is initially relatively wide. When the target RF tag 2 exists in the communication area, the fact is notified (displayed on the display unit 5) and the number of the RF tags 2 existing in the communication area is also notified. (indicate. In this case, when the RF tag 2 existing in the communication area is one target, the search process ends.

  On the other hand, when there are a plurality of RF tags 2 present in the communication area, the transmission output adjustment circuit 14 is controlled so that the communication area is automatically reduced (transmission output is reduced). At the same time, it notifies (displayed on the display unit 5) that the communication area has been reduced. Then, a display prompting the user to perform another reading operation (including changing the position of the reader / writer 3) is performed, and the reading process is repeated. In the present embodiment, when changing the communication area, the communication area is reduced in stages until the RF tag 2 existing in the communication area is only the RF tag 2 having specific information. Repeatedly.

  Accordingly, the control circuit 7, the transmission unit 15, and the reception unit 16 constitute reading means, and the control circuit 7 and the display unit 5 constitute notification means, quantity notification means, and communication area change notification means, and the control circuit 7 and transmission The output adjustment circuit 14 constitutes communication area changing means. In the above notification or notification, a buzzer sound or lighting (flashing) of the notification LED may be performed together.

  Next, the operation of the above configuration will be described with reference to FIG. Here, as shown in FIG. 3, a large number of products 1 with RF tags 2 are stored in a multi-stage (up, down, left, and right) in a shelf 17, from which the operator can A case where the product 1 (RF tag 2) is searched (so-called shelf check) is described as a specific example. At this time, it is assumed that the product 1 (RF tag 2 having specified specific information) that is the object of the search exists on the right side of the middle stage of the shelf 17.

  The flowchart of FIG. 1 shows a processing procedure executed by the control circuit 7 when the execution of the search function is instructed. As described above, when performing a search operation, the operator first operates the key operation unit 6 of the reader / writer 3 to instruct a search mode, and subsequently inputs and designates the ID number of the RF tag 2 to be searched. To do. Then, the operator reads the RF tag 2 by turning on the trigger key in the state in which the reader / writer 3 is desired to be searched and in that state (step S1).

  This reading is performed for all the RF tags 2 existing in the communication area. However, in the initial state, as shown in FIG. 3A, the transmission output in the transmission unit 15 is relatively high, and the communication area A1 and A2 are relatively wide (communication is possible up to a distance of about 1 to 2 m in front of the main body case 4). In the example of FIG. 3A, the communication areas A1 and A2 are sized so as to cover a half range of the shelf 17 (the entire product 1). Accordingly, the worker first directs the reader / writer 3 toward the left side of the shelf 17, for example, and reads the data of the RF tag 2 of the product 1 located in the left half portion (communication area A1) of the shelf 17.

  In the next step S2, it is determined whether or not the RF tag 2 storing the specified specific information exists in the RF tag 2 read in step S1. If the read RF tag 2 does not have the specified ID number (No in step S2), in step S3, the RF tag specified within the read range is displayed on the display unit 5. Since 2 does not exist, a display is made to prompt the user to change the position of the reader / writer 3 and perform the reading operation again, and the process returns to step S1.

  In the example of FIG. 3A, the designated RF tag 2 (target product 1) does not exist in the left half of the shelf 17 (communication area A1). The reader / writer 3 is moved to the right side (toward the right half of the shelf 17), and the right half of the shelf 17 (communication) The data of the RF tag 2 of the product 1 located in the area A2) is read.

  Then, this time, the RF tag 2 of the read communication area A2 has the designated ID number (Yes in step S2). In the next step S4, a message indicating that the designated RF tag 2 has been found is displayed on the display unit 5, and the number of RF tags 2 detected in the communication area (communication area A2 in the above example) (for example, 10). Are displayed together. In step S5, it is determined whether the number of (detected) RF tags 2 existing (detected) in the communication area A2 is plural (two or more).

  Here, when the number of RF tags 2 is one (No in step S5), one RF tag 2 (product 1) existing in the communication area A2 is intended. The search process is terminated. On the other hand, when there are a plurality of RF tags 2 (Yes in Step S5), the communication area is changed to be reduced by reducing the transmission output of the transmission unit 15 in Step S6. In addition, the display unit 5 displays that the communication area has been reduced. Further, in step S7, a display is displayed on the display unit 5 to prompt the user to read again by changing the position of the reader / writer 3, and the process returns to step S1.

  In the example of FIG. 3, the display in step S <b> 4 indicates that the worker has the target RF tag 2 (product 1) in the communication area A <b> 2 (the right half of the shelf 17). Since there are a large number (for example, a total of 10) of RF tags 2, it is still not possible to narrow down where they are on the shelf 17. In step S6, the communication area A3 is reduced to a level shown in FIG. 3B (for example, about 50 cm toward the front). Therefore, the operator repeatedly performs the same reading sequentially from the upper left side in the right half of the shelf 17.

  This time, the search for the target RF tag 2 is performed in a narrowed state in the right half of the shelf 17. As a result of searching at the position (communication area A3) shown in FIG. 3B, the designated RF tag 2 is found, and the number of detected RF tags 2 in the communication area A3 is as follows. Therefore, in step S4, it is displayed that the designated RF tag 2 has been found and that the number of RF tags 2 in the communication area A3 is one, and the search process ends (step S5). No).

  Although not described in detail, if a plurality of RF tags 2 including a specified RF tag 2 are detected in a certain communication area even after the communication area is reduced, the answer is Yes in step S5. ), The process again proceeds to step S6, the transmission output is further reduced, and the communication area is further reduced. In this way, each time step S6 is passed, the communication area is reduced stepwise such that the distance to the front is 30 cm or 10 cm, for example. As a result, even when the distance (arrangement interval) between the RF tags 2 (product 1) is narrow, it is possible to finally continue searching for one target RF tag 2. Of course, when another search process is started after the search process is performed, the communication area is restored to the initial size.

  As described above, according to this embodiment, when the search function of the reader / writer 3 is executed, the information of all the RF tags 2 existing in the predetermined communication area is read and the target RF tag 2 exists. Is notified, and when there are a plurality of RF tags 2 in the communication area, the number is notified. Therefore, the operator can know whether or not the target RF tag 2 exists in the communication area, and if it exists, whether or not another RF tag 2 exists in the area.

  If there are a plurality of RF tags 2 including the target RF tag 2 in the communication area, the communication area is changed so as to be automatically reduced, and a notification to that effect is given. At this time, since the operator knows that the target RF tag 2 exists somewhere in the relatively wide communication area before the change, the operator can read again with the communication area narrowed. Thus, it is possible to search for the target RF tag 2 within a narrower range while narrowing down the area where the target RF tag 2 exists (exclusion of an area that does not exist).

  At this time, since it is not necessary for the operator to visually find the target RF tag 2 (product 1), even if information specifying the product 1 is not written on the RF tag 2 or the product 1 itself. The search can be performed reliably. In addition, compared with the case where the communication area is narrowed from the beginning, the search can be performed in a relatively wide communication area at the beginning, so that an efficient search can be performed. Since the communication area is automatically changed, it is needless to say that the operator does not need to perform an operation for the change.

  As a result, according to this embodiment, the search function for searching for the RF tag 2 having the specified specific information can be executed, and the search operation can be performed efficiently and reliably. Excellent effect. Further, in the present embodiment, the configuration is such that the communication area is repeatedly reduced in stages until the RF tag 2 existing in the communication area is only the RF tag 2 having specific information. Even when the distance (interval) between the tags 2 is narrow, the search can be continued with one target RF tag 2 in the end, which is more effective.

  4 and 5 show a second embodiment of the present invention. This embodiment is different from the first embodiment in the configuration of the communication area changing means for changing the communication area. . That is, as shown in FIG. 5, in the second embodiment, a reception sensitivity adjustment circuit for adjusting the reception sensitivity of the reception circuit 12 in place of the transmission output adjustment circuit 14 of the first embodiment. 21 is provided. The reception sensitivity adjustment circuit 21 is controlled by the control circuit 7, and a communication area changing unit is configured to change the communication area so as to automatically reduce the communication area.

  At this time, as shown in FIG. 4, when performing the search process, the control circuit 7 reads all the RF tags 2 existing in the communication area as in the first embodiment (step S1). If the RF tag 2 in the read communication area has the specified ID number (Yes in step S2). The display unit 5 displays that the designated RF tag 2 has been found, and also displays the number of RF tags 2 detected in the communication area (step S4).

  In this embodiment, when there are a plurality of (detected) RF tags 2 existing (detected) in the communication area (Yes in step S5), the reception sensitivity adjustment circuit 21 is set in step S11. It is controlled so that the communication area is automatically reduced (reception sensitivity is lowered), and at the same time, the fact that the communication area has been reduced is notified. Therefore, according to the second embodiment, the search function for searching for the RF tag 2 having the specified specific information can be executed, and the search operation can be performed efficiently and reliably. The same actions and effects as in the first embodiment can be obtained.

  In the above embodiment, a tag-like RF tag (RFID tag) is given as a specific example of the responder. However, there are RF tags of various shapes such as a coin shape and a key (key holder) shape. Furthermore, a card-like thing (non-contact IC card) is also included in the responder. In addition, there is a system in which an information label (referred to as a smart label or the like) configured by attaching an RF tag to a label on which optical information is written is attached to an article and used. The information label becomes a responder.

  Further, in the above-described embodiment, the case where the product 1 with the RF tag 2 in the shelf 17 is searched as an example. However, in addition to this, for example, a large number of trucks loaded on trucks, carts, pallets, etc. Various objects, forms, and uses are conceivable when searching for a specific baggage from the other baggage. The configuration of the reader / writer as the interrogator can be variously changed. For example, a handy terminal having an optical code reading function may be used. Not only the handy type but also a stationary type may be used.

  In addition, in the above embodiment, the number of RF tags 2 is notified in step 4; however, the number of RF tags 2 is approximately notified or one or a plurality of notifications are performed. Also good. Further, it is possible to use a circulator that also serves as a transmission antenna and a reception antenna of the interrogator. Furthermore, the wavelength (frequency) of the radio wave used for communication between the interrogator and the responder may be anything that forms a communication area with a certain degree of directivity. In addition to the UHF band, the short wave band The present invention can be implemented with appropriate modifications within a range not departing from the gist of the invention, such as a microwave band and a microwave band.

The flowchart which shows the 1st Example of this invention and shows the process sequence of the search which a control circuit performs Block diagram schematically showing the electrical configuration of the reader / writer A perspective view schematically showing the state of the search process FIG. 1 equivalent view showing a second embodiment of the present invention. 2 equivalent diagram

Explanation of symbols

  In the drawings, 1 is a product, 2 is an RF tag (response device), 3 is a reader / writer (interrogator), 5 is a display unit, 6 is a key operation unit, 7 is a control circuit, 14 is a transmission output adjustment circuit (communication area) Change means), 15 is a transmission section (transmission means), 16 is a reception section (reception means), 21 is a reception sensitivity adjustment circuit (communication area change means), and A1 to A3 are communication areas.

Claims (3)

An interrogator for reading information recorded in the responder by communication, comprising: a transmitting means for transmitting an interrogation radio wave toward the responder; and a receiving means for receiving a response radio wave returned by the responder that has received the interrogation radio wave Because
It is possible to execute a search function for searching for a responder having specified specific information,
The search function is
Reading means for reading information of all responders existing in a communicable communication area based on transmitting an interrogation radio wave having a predetermined directivity by the transmitting means and receiving a response signal by the receiving means When,
Informing means for informing that when there is a responder having the specific information in the communication area,
A quantity notifying means for notifying the number when there are a plurality of responders including a responder having the specific information in the communication area;
A communication area changing means for automatically changing the communication area of the reading means when there are a plurality of responders including a responder having the specific information in the communication area;
An interrogator comprising communication area change notifying means for notifying when a communication area is changed by the communication area changing means.   The communication area changing means is configured to repeatedly reduce the communication area in stages until the responders existing in the communication area are only the responders having the specific information. The interrogator according to claim 1.   The said communication area change means is comprised so that the said communication area may be changed by reducing the transmission output of the said transmission means, or the receiving sensitivity of the said reception means. Interrogator.

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