JP2009129085A - Portable reader/writer, and rf tag data reading/writing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve excellent communication performance while having a relatively simple configuration in communication between an RF tag by using an antenna in a linearly-polarized wave system. <P>SOLUTION: A wireless tag processing unit and an optical code reading unit are provided in a main unit 2. A fist and a second reader/writer side antenna each composed of dipole antennas are connected to the wireless tag through an antenna changing-over switch. In the main unit 2, the first reader/writer side antenna is arranged so that it vertically extends (has a vertical polarized wavefront) in a longitudinal direction, and the second reader/writer antenna is arranged so the it horizontally extents (has a horizontal polarized wavefront) in a lateral direction. When communicating with an RF tag 14, a control unit captures an image (an image of a tag side antenna 21) of the RF tag 14 by an imaging element of the reading unit, recognizes a polarized wavefront direction of the antenna 21 from the captured image, and selects the reader/writer side antenna to be used in the communication so as to adjust the polarized wavefront direction of the antenna 21 to that of the reader/writer side antenna. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention includes an image pickup device for picking up optical information in a hand-operable main body, a reader / writer side antenna for wireless communication, and a function of reading the optical information; Portable reader / writer having a function of reading and writing data by performing wireless communication with an RF tag in which a polarization tag side antenna is incorporated, and reading / writing data of an RF tag in the portable reader / writer Regarding the method.

  In recent years, for example, as identification information provided on an article such as a product, in addition to optical information such as a barcode, an RF tag that records data about the product has been attached. Along with this, communication with optical tags (for example, microwave band (or UHF band)) is performed between the optical information reading function and the RF tag, and data relating to products recorded on the RF tag is read. In addition, portable reader / writers having both a writing function and a writing function have been provided.

  As this type of portable reader / writer, for example, Patent Document 1 includes a mechanism for reading optical information and a mechanism for reading and writing an RF tag in a case that can be hand-held. Is disclosed. In this device, a reflector used for reading optical information is provided with an antenna for communication with an RF tag so as to reduce the number of components (miniaturization of the apparatus).

  By the way, in the portable reader / writer and the RF tag described above, in order to reduce the size of the device (RF tag) and simplify the antenna, the reader / writer side antenna and the RF tag antenna may be a dipole antenna. Adopting a simple linear (linear) polarization antenna. However, when a linearly polarized antenna such as a dipole antenna is employed, the communication (reading) distance varies greatly depending on the angle between the antennas on the reader / writer side and the RF tag side (direction of polarization plane). There are circumstances where it is desirable to perform communication in a state in which the planes of polarization of each other are the same.

For example, Patent Document 2 includes a first antenna and a second antenna having a polarization characteristic orthogonal to the polarization characteristic of the first antenna, and the first antenna and the second antenna. A polarization control system configured to be switchable is disclosed.
JP 2005-157434 A JP 2002-64321 A

  In the above-described RF tag system, there is generally a situation in which a portable reader / writer is placed at an arbitrary position for communication (reading and writing) with respect to an RF tag facing an arbitrary direction. If the planes of polarization between the antennas on the side and the RF tag are shifted, there is a problem that communication cannot be performed successfully. In this case, as in Patent Document 2, two types of antennas having different polarization plane directions are provided on the reader / writer side, and by selectively using them, the polarization direction with the antenna on the RF tag side is matched. If communication can be performed in a state, it is considered that good communication performance can be obtained.

  However, if the direction of the polarization plane of the antenna on the RF tag side is not known on the reader / writer side, communication cannot be performed with the antenna direction (polarization direction) matched. In the above-mentioned Patent Document 2, the new terminal is transmitted with vertical polarization, the output (desired wave signal-to-interference wave and noise level ratio) SINR with respect to the transmission wave at that time is measured, and the minimum value SINR (V) is obtained. The terminal is made to transmit in the horizontally polarized wave, the output SINR with respect to the transmission wave at that time is measured, the minimum value SINR (H) is obtained, and the polarization corresponding to the larger one is assigned as the transmission / reception radio wave of the new terminal. ing. However, even if such a method is applied to a reader / writer in an RF tag system, it is necessary to perform SINR measurement or the like in order to recognize the direction of the polarization plane of the terminal, and it takes time and effort. I can't expect to communicate quickly on the Internet. In addition, problems such as a complicated circuit configuration occur.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to perform communication with an RF tag using a linearly polarized antenna, while having a relatively simple configuration. An object of the present invention is to provide a portable reader / writer capable of obtaining good communication performance and an RF tag data reading / writing method in the portable reader / writer.

  In order to achieve the above object, a portable reader / writer according to the present invention includes an image sensor for imaging optical information and a reader / writer side antenna for wireless communication in a hand-held main body. Configured to have a function of reading the optical information and a function of reading and writing data by performing wireless communication with an RF tag incorporating a linearly polarized wave tag side antenna, As antennas on the reader / writer side, two linearly polarized antennas are arranged in such a manner that their planes of polarization are crossed, and when performing communication with the RF tag, Image capturing means for capturing an image, recognition means for recognizing the arrangement direction of the RF tag from the image captured by the image capturing means, and based on recognition of the recognition means It said to match the polarization direction of the tag antenna, (the invention of claim 1) in which the reader writer antenna a was provided with selection means for selecting has a characteristic to be used for communication.

  According to this, when communicating with the RF tag, the image of the RF tag is captured by the image capturing unit, and the arrangement direction of the RF tag is recognized from the image by the recognition unit. In this case, the reader / writer can recognize the direction of the polarization plane of the antenna on the RF tag side by providing a correspondence in advance between the arrangement direction of the RF tag and the polarization plane direction of the tag side antenna. Is possible. As the reader / writer side antenna, two linearly polarized antennas are arranged so that their planes of polarization are crossed. Based on the recognition by the recognition unit, the selection unit uses the antenna for communication. The reader / writer side antenna to be selected is selected.

  At this time, by selecting the reader / writer side antenna with the smaller angle between the polarization planes of the tag side antenna and the reader / writer side antenna, both the tag side antenna and the reader / writer side antenna can be Even when linearly polarized antennas are employed, communication can be performed while matching the polarization plane directions of both antennas, and as a result, good communication performance can be obtained. In addition, since the image capturing means can be configured using an image pickup element originally provided for reading optical information, a simple configuration can be achieved.

  In this case, the image capturing means is configured to capture an image of an index provided on the surface of the RF tag so as to represent a direction corresponding to the polarization plane direction of the tag side antenna, and the recognition means is configured to It can be configured to recognize the polarization plane direction of the tag side antenna from the image (invention of claim 2). According to this, it is possible to easily recognize the polarization plane direction of the tag side antenna from the index image provided on the surface of the RF tag.

  More specifically, the following can be considered as an index provided on the surface of the RF tag. That is, on the surface of the RF tag, a mark whose direction can be discriminated as an index is provided in an orientation corresponding to the polarization plane direction of the tag side antenna, and the recognition means detects the arrangement direction of the mark based on the tag side. The antenna can be configured to recognize the polarization plane direction (the invention of claim 3). According to this, a simple configuration is sufficient in that a direction distinguishable mark is provided on the surface of the RF tag.

  Alternatively, by providing a barcode on the surface of the RF tag in a direction corresponding to the polarization plane direction of the tag-side antenna, the barcode also serves as an index, and the recognizing means changes the arrangement direction of the barcode. Based on the detection, the polarization plane direction of the tag-side antenna may be recognized (invention of claim 4). Furthermore, by providing a two-dimensional code on the surface of the RF tag in a direction corresponding to the polarization plane direction of the tag-side antenna, the two-dimensional code also serves as an index, and the recognition means includes the two-dimensional code. It is also possible to recognize the polarization plane direction of the tag side antenna based on detecting the arrangement direction of the cut out symbols. According to these, the identification barcode or two-dimensional code provided on the surface of the RF tag can be used as an index, and a simpler configuration can be achieved.

  Instead of providing the above-mentioned index on the RF tag, the image capturing means is configured to capture the entire image of the RF tag, and the recognition means is connected to the tag side based on the outer shape of the RF tag. It can also comprise so that the polarization plane direction of an antenna may be recognized (invention of Claim 6). Further, the image capturing means is configured to capture an image of the tag side antenna provided so as to be visible from the surface of the RF tag, and the recognition means recognizes the polarization plane direction from the image of the tag side antenna. It may be configured as described above (invention of claim 7). According to these, it is not necessary to provide an index on the surface of the RF tag.

  By the way, depending on the arrangement of the RF tag, the polarization plane direction of the tag side antenna is greatly deviated from the polarization plane direction of the two reader / writer side antennas, and communication is possible regardless of which reader / writer side antenna is selected. There may be cases where you cannot do well. Therefore, if the RF tag recognized by the recognizing unit is out of the communication allowable range of the two reader / writer side antennas, a notification unit that prompts the user to tilt the main body is provided (claim 8). The invention makes it possible to perform good communication by tilting the user's main body, which is effective.

  At this time, the notification means notifies the appropriate rotation direction and rotation angle of the main body so that the polarization plane direction of the reader / writer side antenna used for communication matches the polarization plane direction of the tag side antenna of the RF tag. (Invention of claim 9). According to this, the user can know the appropriate rotation direction and rotation angle of the main body, which is more effective.

  In the present invention, when the RF tag placement direction could not be recognized by the recognition means, communication with the RF tag was performed using one reader / writer side antenna, and the communication was unsuccessful. In this case, it can be configured to perform communication with the RF tag by switching to the other reader / writer side antenna (invention of claim 10). Thereby, even when recognition by a recognition means cannot be performed, communication with RF tag can be performed.

  A method for reading and writing RF tag data in a portable reader / writer according to the present invention includes an image pickup device for picking up optical information in a hand-held main body and a linear polarization type 2 for wireless communication. A reader / writer side antenna is provided in a configuration in which the polarization plane direction is crossed, and wireless communication is performed between the function of reading the optical information and an RF tag incorporating a linearly polarized tag side antenna. A method for reading and writing data of the RF tag in a portable reader / writer having a function of reading and writing data, and an image capturing step of capturing an image of the RF tag by the imaging device, A recognition step for recognizing the arrangement direction of the RF tag from the image captured in the image capture step, and based on the recognition in the recognition step. Te, characterized in to match the polarization direction of the tag antenna, where and a selection step of selecting a reader-writer antenna used for communication (the invention of claim 11).

  According to this, when communicating with the RF tag, an image of the RF tag is captured in the image capturing step, and in the recognition step, the arrangement direction of the RF tag from the image, and hence the polarization plane direction of the tag side antenna. Is recognized. As the reader / writer side antennas, two linearly polarized antennas are arranged so that their planes of polarization are crossed. In the selection step, the reader / writer used for communication is based on the recognition. The side antenna is selected. Therefore, even when a linearly polarized antenna such as a dipole antenna is used for both the tag side antenna and the reader / writer side antenna, communication can be performed while matching the polarization plane directions of both antennas. It is possible to obtain good communication performance.

  Hereinafter, several embodiments embodying the present invention will be described with reference to the drawings. In each embodiment described below, the present invention is a so-called gun capable of both reading and writing data of an RF tag (RFID tag) and reading optical information such as a barcode and a two-dimensional code. This is applied to a portable reader / writer of the type.

(1) First Embodiment First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an appearance of a portable reader / writer 1 according to the present embodiment, and FIG. 2 schematically shows an electrical configuration of the portable reader / writer 1. As shown in FIG. 1, the portable reader / writer 1 extends downward and slightly rearward toward the rear side of the lower surface side of the main body 2 having a substantially rectangular box shape that is slightly long in the front-rear direction and rounded at the corners. The grip portion 3 that can be gripped and operated with one hand is integrally formed.

  A reading port 2 a for reading optical information is provided at the front end surface of the main body 2. A trigger switch 4 for reading instructions is provided at the inner upper end of the grip portion 3. As shown in FIG. 2, the upper surface of the main body 2 has a display unit 5 composed of a small liquid crystal display, a key operation unit 6 having a plurality of operation keys such as numeric keys and function keys, and a notification LED 7. In addition, a speaker 8 or the like for notification sound output is provided.

  As shown in FIG. 2, the main body 2 is provided with a control unit 9 that mainly includes a microcomputer and controls the entire portable reader / writer 1. The control unit 9 is connected to a memory 10 in which an image database for verification is stored. An operation signal from the trigger switch 4 or the key operation unit 6 is input to the control unit 9. Further, the control unit 9 controls the display unit 5, the notification LED 7, the speaker 8, and the like. In the main body 2, a battery 11 and a power supply unit 12 serving as a power source, a wireless LAN 13 for performing communication with the outside (host device), and the like are also provided.

  Further, in the main body 2, a radio tag processing unit 15 that reads and writes data by performing electromagnetic wave communication with an RF tag 14 (see FIG. 1) disposed in front, and the RF tag 14. An optical code reading unit 16 and an image processing unit 17 are provided for reading optical information (barcode or two-dimensional code) written on a reading target such as the surface of the image. The RFID tag processing unit 15, the optical code reading unit 16 and the image processing unit 17 are controlled by the control unit 9.

  Of these, the optical code reading unit 16 includes an imaging element made up of, for example, a CCD area sensor, but also includes an imaging lens, an illumination unit made up of a plurality of LEDs, lenses, and the like, although not shown. . As a result, the illumination unit irradiates the reading target arranged in front of the reading port 2a with illumination light through the reading port 2a, and the reflected light from the optical information (barcode or two-dimensional code). Enters through the reading port 2a, is imaged by the imaging device through the imaging lens, and image data of optical information is taken in, and the image processing unit 17 reads (decodes) the data. Thus, a function of reading optical information from the control unit 9, the optical code reading unit 16, and the image processing unit 17 is realized.

  The RFID tag processing unit 15 is connected to first and second reader / writer side antennas 19 and 20 via an antenna changeover switch 18. These reader / writer side antennas 19 and 20 are both linearly polarized antennas, and a dipole antenna is adopted here. At this time, although not shown in detail, the first reader / writer side antenna 19 is disposed in the main body 2 so as to extend vertically in the vertical direction, and has a vertical polarization plane (a vertically polarized radio wave). Output (see FIG. 1 (a)).

  On the other hand, the second reader / writer side antenna 20 is disposed in the main body 2 so as to extend horizontally in the lateral direction and has a horizontal polarization plane (outputs a horizontally polarized radio wave). (See FIG. 1B). That is, the first and second reader / writer side antennas 19 and 20 are arranged in a form in which the planes of polarization are crossed (orthogonal in this case). One of the first and second reader / writer side antennas 19 and 20 is selectively used in accordance with the switching operation of the antenna switch 18.

  The wireless tag processing unit 15 includes a transmission circuit, a reception circuit, a signal processing circuit, and the like, and executes wireless communication processing for the RF tag 14. The RFID tag processing unit 15 is controlled by the control unit 9 and selects any one of the reader / writer side antennas 19 and 20 by the antenna changeover switch 18, and the selected reader / writer side antennas 19 and 20 through the selected reader / writer side antennas 19 and 20. Power is supplied to the RF tag 14 by electromagnetic waves, and data communication (reading and writing) is performed. In the present embodiment, a communication frequency in the microwave band (for example, 2.45 GHz) or UHF band (for example, 953 MHz) is used for communication with the RF tag 14.

  Here, the RF tag 14 will be briefly described. As shown in FIG. 1, the RF tag 14 is attached to an article such as a product, and has, for example, a plastic tag (rectangular plate shape). In addition, a tag-side antenna 21 for performing communication with the portable reader / writer 1 and an IC chip 22 connected to the tag-side antenna 21 are provided therein. The IC chip 22 includes a rectifying / smoothing circuit for obtaining an operating power supply from a power supply signal, a CPU for controlling communication, a modulation / demodulating circuit for modulating / demodulating transmission / reception signals, a ROM for storing operation programs, and the like. A readable / writable EEPROM or the like is configured as a one-chip IC to hold data, generate a response signal, or the like.

  The tag-side antenna 21 is also a linearly polarized dipole antenna, and is formed by printing a conductive paint on the sheet material constituting the RF tag 14, but here, from the surface of the RF tag 14 It is provided so as to be visible (in a state covered with a transparent sheet). In this case, the direction in which the tag side antenna 21 extends (the direction in which the dipole axis extends) coincides with the longitudinal direction (long side direction) of the RF tag 14. A dipole antenna can be easily formed by providing a pattern directly on a substrate (base material), and has the advantage of requiring an extremely small area for providing a linear pattern.

  The RF tag includes various shapes such as a coin shape and a key (key holder) shape in addition to a tag shape, and a card-like shape (non-contact IC card) is also included in the RF tag. 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.

  As described above, the portable reader / writer 1 according to the present embodiment performs wireless communication with the RF tag 14 by the RF tag reading mechanism including the wireless tag processing unit 15 and the reader / writer side antennas 19 and 20. Thus, data can be read and written. Here, in the portable reader / writer 1, when communicating with the RF tag 14 using the first reader / writer side antenna 19, a vertically polarized radio wave is output as shown in FIG. The Here, if the tag side antenna 21 (RF tag 14) which consists of the same dipole antenna is arrange | positioned in the perpendicular direction, the direction of a polarization plane will correspond and appropriate communication performance will be obtained.

  However, if the tag-side antenna 21 (RF tag 14) is arranged in the horizontal direction, the tag-side antenna 21 has a horizontal polarization plane. In this case, there is a situation in which the communication efficiency is greatly reduced. Similarly, when communicating with the RF tag 14 using the second reader / writer side antenna 20, as shown in FIG. 1B, a horizontally polarized radio wave is output. If the (RF tag 14) is arranged in the horizontal direction, appropriate communication performance can be obtained. However, if the tag side antenna 21 (RF tag 14) is arranged in the vertical direction, the communication efficiency is greatly reduced. It will be.

  Therefore, in this embodiment, as will be described later in the description of the operation (flowchart description), the control unit 9 communicates with the RF tag 14 (data) by its software configuration (execution of the control program). The following control is performed for reading and writing. That is, first, an image from the front surface of the RF tag 14 (image of the tag side antenna 21) is captured by the image sensor of the optical code reading unit 16 (image capturing step), and then the RF tag is captured from the captured image. 14 (recognition plane direction of the tag-side antenna 21) is recognized (recognition step), and based on the recognition, the reader / writer side used for communication so as to match the polarization plane direction with the tag-side antenna 21 The antennas 19 and 20 are selected (selection step).

  That is, as shown in FIG. 1A, when the arrangement direction of the RF tag 14 (the polarization plane direction of the tag side antenna 21) is close to the vertical direction, the first reader / writer side antenna 19 is selected. As shown in FIG. 1B, when the arrangement direction of the RF tag 14 (the polarization plane direction of the tag side antenna 21) is close to the horizontal direction, the second reader / writer side antenna 20 is selected. Therefore, the control unit 9 and the optical code reading unit 16 constitute an image capturing unit, the control unit 9 and the image processing unit 17 constitute a recognition unit, and the control unit 9 and the antenna selector switch 18 constitute a selection unit. It is done.

  In the present embodiment, the controller 9 recognizes the arrangement direction of the RF tag 14 well when recognizing the arrangement direction of the RF tag 14 (the polarization plane direction of the tag-side antenna 21) from the captured image. If not, the communication with the RF tag 14 is performed using the second reader / writer side antenna 20, for example. If the communication is not successful, the other, for example, the first reader / writer is performed. It is configured to switch to the side antenna 19 to communicate with the RF tag 14.

  In the present embodiment, the arrangement direction of the RF tag 14 is recognized by the image data of the RF tag 14 (tag side antenna 21) in the image database stored in the memory 10 in advance and the captured image data. And is performed depending on whether or not they match. At this time, the image data in the image database is stored on the basis that the RF tag 14 (tag-side antenna 21) is arranged in the horizontal direction, for example.

  Next, the operation of the above configuration will be described with reference to FIG. Now, when the user communicates (reads and writes data) with the RF tag 14 attached to a product using the portable reader / writer 1, the portable reader / writer 1 is connected to the RF tag 14. In the state of the communication mode, the reading port 2a of the main body 2 is brought close to the RF tag 14 so as to face the RF tag 14 (a state in which an image of the RF tag 14 (tag side antenna 21) can be captured), and the trigger switch 4 Turn on the. Then, the control part 9 selects the reader / writer side antennas 19 and 20 used for communication according to the processing procedure shown in the flowchart of FIG.

  That is, in step S1, a process of setting the pointer of the record of the image database in the memory 10 to the head (initializing the search position) is performed. In step S2, it is determined whether or not the trigger switch 4 is pressed. If the trigger switch 4 is pressed (Yes in step S2), the image capture of the RF tag 14 (tag side antenna 21) is performed by the optical code reading unit 16 (imaging device) in step S3. Is called.

  In the next step S4, the image data of the RF tag 14 (image data of the tag side antenna 21) indicated by the pointer and the polarization characteristic information (for example, information that the polarization plane direction is horizontal) are read from the image database. It is. In step S5, the actual captured image data fetched in step S3 is collated with the image data read from the image database in step S4.

  In step S6, it is determined whether the images match in the collation in step S5. If the images do not match (No in step S6), the pointer of the image database record is advanced to the next in step S7, and unless the image database record ends (No in step S8). The process from step S4 is repeated. By repeating this process, the images finally match in the collation in step S5 (Yes in step S6), and the process proceeds to step S9.

  In step S9, the rotation angle of the actual captured image data with respect to the image data in the image database is calculated. In step S10, it is calculated whether the rotation angle is closer to the horizontal direction (angle 0 degrees, 180 degrees) or the vertical direction (angle 90 degrees, -90 degrees). In step S11, it is determined whether or not the rotation angle calculated in step S10 is close to the horizontal direction. If the rotation angle is close to the vertical direction (No in step S11), the reader / writer side antenna bias is determined in step S12. Switching is made so that the wave characteristic is vertical polarization, that is, the first reader / writer side antenna 19 is used, and communication with the RF tag 14 (data read / write) is executed.

  On the other hand, when the rotation angle calculated in step S10 is close to the horizontal direction (Yes in step S11), in step S13, the polarization characteristics of the reader / writer side antenna are set to horizontal polarization. That is, the second reader / writer side antenna 20 is switched to use, and communication with the RF tag 14 (reading and writing of data) is executed. Since the reader / writer side antennas 19 and 20 used for communication are selected so that the polarization plane direction with the tag side antenna 21 is matched by the processing in steps S12 and S13, the communication with the RF tag 14 is always performed. Good (efficient) communication is performed.

  On the other hand, in the collation process in steps S4 to S8 described above, the polarization direction of the tag-side antenna 21 of the RF tag 14 cannot be recognized, that is, the images do not match (No in step S6). It is conceivable that the record ends (Yes in step S8). In such a case, in this embodiment, first, in step S14, the polarization characteristic of the reader / writer side antenna is switched to be horizontally polarized, that is, the second reader / writer side antenna 20 is used, Communication (reading / writing of data) with the RF tag 14 is executed.

  In step S15, it is determined whether or not communication with the RF tag 14 has been successfully performed. If communication is not successful (No in step S15), the reader / writer side in the next step S16. The antenna polarization characteristics are switched to be vertically polarized, that is, the first reader / writer side antenna 19 is switched, and communication (reading / writing of data) with the RF tag 14 is executed. ing. As a result, even when the polarization plane direction of the tag-side antenna 21 cannot be recognized, communication with the RF tag 14 can be performed.

  According to this embodiment, it is possible to recognize the arrangement direction of the RF tag 14 (the polarization plane direction of the tag-side antenna 21) based on capturing the image of the RF tag 14 (tag-side antenna 21). According to the recognition, the reader / writer side antennas 19 and 20 arranged in a form in which the polarization plane directions are crossed are selected and used. As a result, even when a linearly polarized antenna such as a dipole antenna is adopted for both the tag side antenna 21 and the reader / writer side antennas 19 and 20, communication is performed while matching the polarization plane directions of both antennas. As a result, good communication performance can be obtained. In addition, since the image capturing means is configured using the image pickup element (optical code reader 16) originally provided for reading optical information, a simple configuration can be achieved.

(2) Second Embodiment and Other Embodiments FIGS. 4 and 5 show a second embodiment of the present invention. The second embodiment differs from the first embodiment mainly in the software configuration of the control unit 9. Accordingly, since the hardware configuration of the portable reader / writer 1 is the same as that of the first embodiment, new illustrations and descriptions are omitted, and the reference numerals are also used in common.

  Also in the second embodiment, the control unit 9 communicates (reads and writes data) with the RF tag 14 by the image sensor of the optical code reading unit 16 using the image (tag) of the RF tag 14. Image of the side antenna 21) (image capture step), and recognizes the arrangement direction of the RF tag 14 (polarization plane direction of the tag side antenna 21) from the next captured image (recognition step). Based on this, the reader / writer side antennas 19 and 20 used for communication are selected (selection step) so that the polarization plane direction with the tag side antenna 21 is matched (to the near side).

  At this time, in the present embodiment, the control unit 9 determines that the recognized arrangement direction of the RF tag 14 (the polarization plane direction of the tag side antenna 21) is out of the communication allowable range of the two reader / writer side antennas 19 and 20. Determine whether or not. When the two reader / writer side antennas 19 and 20 are out of the allowable communication range (for example, about plus or minus 10 degrees in angle with respect to each of the vertical direction and the horizontal direction), the main body 2 is inclined to the user. The notification which prompts is performed.

  In this case, for example, notification to the user is performed by displaying a message on the display unit 5 and outputting a notification sound from the speaker 8. Accordingly, the control unit 9, the display unit 5, the speaker 8, and the like constitute a notification means. Further, particularly in the present embodiment, in the notification, the polarization direction of the reader / writer side antennas 19 and 20 used for communication and the polarization direction of the tag side antenna 21 of the RF tag 14 are matched. An appropriate rotation direction and rotation angle of the main body 2 are notified (displayed on the display unit 5) with respect to an axis extending in the front-rear direction.

  The flowchart of FIG. 5 shows the selection procedure of the reader / writer side antennas 19 and 20 used for communication and the notification process to the user, which is executed by the control unit 9 in this embodiment. In FIG. 5, since new steps (steps S21 to S23) are added to the flowchart of FIG. 3 described in the first embodiment, the same steps (steps) as in FIG. S1 to S16) are denoted by the same reference numerals, detailed description thereof will be omitted, and different points will be described below.

  Also in the second embodiment, the actual captured image data of the RF tag 14 captured in step S3 is collated with the image data read from the image database in step S4 (step S5). If the images match (Yes in step S6), the rotation angle of the actual captured image data, that is, the direction in which the tag side antenna 21 extends (polarization plane direction) is calculated (step S9), and the horizontal direction (angle 0 degree, 180 degrees). (Degrees) or the vertical direction (angle 90 degrees, -90 degrees) is calculated (step S10).

  In step S11, it is determined whether the rotation angle calculated in step S10 is close to the horizontal direction. If the rotation angle is close to the vertical direction (No in step S11), the rotation angle is within an allowable range in step S21. It is determined whether it is within (for example, within an angle ± 10 degrees from the vertical direction). If the rotation angle is within the allowable range (Yes in step S21), in step S12, the polarization characteristics of the reader / writer side antenna are set to be vertically polarized, that is, the first reader / writer side antenna 19 is moved. Switching to use is performed, and communication (reading / writing of data) with the RF tag 14 is executed as it is. If the rotation angle exceeds the allowable range (No in step S21), the process proceeds to step S23 described later.

  On the other hand, if it is determined in step S11 that it is close to the horizontal direction (Yes in step S11), in step S22, the rotation angle is within an allowable range (for example, within an angle ± 10 degrees from the horizontal direction). It is judged whether there is. If the rotation angle is within the allowable range (Yes in step S22), in step S13, the polarization characteristics of the reader / writer side antenna are set to horizontal polarization, that is, the second reader / writer side antenna 20 is set. Switching to use is performed, and communication (reading / writing of data) with the RF tag 14 is executed as it is. If the rotation angle exceeds the allowable range (No in step S22), the process proceeds to step S23.

  In step S23, the main body 2 is tilted so that the rotation angle (polarization plane direction) of the RF tag 14 (tag side antenna 21) can be matched with the polarization plane direction of the reader / writer side antennas 19 and 20 used for communication. Notification that prompts the user, that is, display of a message on the display unit 5 and output of a notification sound from the speaker 8 are performed. At this time, an appropriate rotation direction and rotation angle of the main body 2 are displayed on the display unit 5. After this notification is performed, the process returns to step S2.

  As a specific example, as shown in FIG. 4A, the arrangement direction of the RF tag 14 (the polarization plane direction of the tag-side antenna 21) is inclined about 20 degrees clockwise from the vertical direction, for example. In order to make the polarization plane direction of the first reader / writer side antenna 19 and the polarization plane direction of the tag side antenna 21 coincide with each other, the body 2 is inclined clockwise by about 20 degrees. An urging notification is made. Further, as shown in FIG. 4B, when the arrangement direction of the RF tag 14 (the polarization plane direction of the tag-side antenna 21) is tilted about 15 degrees counterclockwise from the horizontal direction, for example, A notification prompting the main body 2 to be tilted counterclockwise (counterclockwise) by about 15 degrees so that the polarization plane direction of the reader / writer side antenna 20 and the polarization plane direction of the tag side antenna 21 coincide with each other. It is done.

  According to the second embodiment as described above, even when linearly polarized antennas such as dipole antennas are used for the tag side antenna 21 and the reader / writer side antennas 19 and 20, both antennas are biased. Communication can be performed while matching the wavefront direction, and good communication performance can be obtained while a relatively simple configuration is required.

  In addition, even if the polarization plane direction of the tag side antenna 21 is greatly deviated from the polarization plane direction of the two reader / writer side antennas 19 and 20 due to the arrangement of the RF tag 14, the user can remove the main body 2 according to the notification. By performing the tilting operation, good communication can be performed, which is effective. In particular, in the present embodiment, since it is configured to notify the appropriate rotation direction and rotation angle of the main body 2, the user can know the appropriate rotation direction and rotation angle of the main body 2, which is more effective. It is.

  6 (a) and 6 (b) and FIGS. 7 (a) and 7 (b) show other different embodiments of the present invention. The surface of the RF tags 31, 32, 33 and 34 are respectively shown in FIGS. It shows a state. These RF tags 31, 32, 33, and 34 are provided with an index on the surface to indicate the direction corresponding to the polarization plane direction of the tag side antenna 21 (shown by a broken line). 6 and 7, for convenience, the RF tags 31, 32, 33, and 34 all have a horizontally long rectangular shape, and the tag-side antenna 21 extends in the horizontal direction in the figure (the polarization plane direction is the horizontal direction in the figure). As). Here, the tag-side antenna 21 is provided inside the RF tags 31, 32, 33, and 34, and is not visible from the surface.

  That is, the RF tag 31 shown in FIG. 6A is provided with an index 35 made of, for example, the characters “AAA” on the surface (lower right portion). In this case, the arrangement (arrangement) direction of the characters “AAA” corresponds (matches) to the polarization plane direction of the tag-side antenna 21.

  When the control unit 9 of the portable reader / writer 1 performs communication (data reading / writing) with the RF tag 31, first, the optical code reading unit 16 (image capturing means) uses the RF tag 31 including at least the index 35 portion. By capturing an image, extracting an index 35 (characters “AAA”) from the captured image data and obtaining the arrangement direction, the arrangement direction of the RF tag 31 (the polarization plane direction of the tag-side antenna 21) is recognized and used. The reader / writer side antennas 19 and 20 to be selected can be selected.

  The RF tag 32 shown in FIG. 6B is provided with a direction distinguishable mark 36 composed of, for example, a double arrow as an index on the surface (lower right side portion). In this case, the direction indicated by the mark 36 made of an arrow corresponds (matches) to the polarization plane direction of the tag-side antenna 21.

  When communicating with the RF tag 32, the control unit 9 of the portable reader / writer 1 captures an image of the RF tag 32 including at least the mark 36 by the optical code reading unit 16 (image capturing unit), and takes a photographed image thereof. By extracting the mark 36 from the data and obtaining the indicated direction, the arrangement direction of the RF tag 32 (the polarization plane direction of the tag side antenna 21) can be recognized and the reader / writer side antennas 19 and 20 to be used can be selected. it can.

  According to these, it is possible to easily recognize the polarization plane direction of the tag-side antenna 21 from the images of the index 35 and the mark 36 provided on the surfaces of the RF tags 31 and 32, respectively. In addition, a simple configuration in which the index 35 and the mark 36 are provided on the surfaces of the RF tags 31 and 32 is sufficient.

  The RF tag 33 shown in FIG. 7A is provided with an identification barcode 37 expressing information (product number) on the product to which the RF tag 33 is attached on the surface (lower right side portion). ing. At this time, the barcode 37 is provided in an orientation corresponding to the polarization plane direction of the tag side antenna 21 (the arrangement direction of the bar and the space coincides with the polarization plane direction). Has come to be combined.

  When communicating with the RF tag 33, the control unit 9 of the portable reader / writer 1 captures an image of the barcode 37 by the optical code reading unit 16 (image capturing means), and arranges the barcode 37 from the captured image data. By obtaining the direction, the arrangement direction of the RF tag 33 (the polarization plane direction of the tag side antenna 21) can be recognized, and the reader / writer side antennas 19 and 20 to be used can be selected. At this time, of course, it is possible to read (decode) the barcode 37 from the image of the barcode 37 together.

  The RF tag 34 shown in FIG. 7B is provided with a two-dimensional code 38 for identification representing information on a product to which the RF tag 34 is attached on the surface (lower right side portion). The two-dimensional code 38 is referred to as “QR code” (registered trademark). The two-dimensional code 38 has a square shape as a whole, and includes cut-out symbols 38a at three corners except for the lower right thereof. A data cell is provided in the data area defined by 38a. At this time, the two-dimensional code 38 is provided in a direction corresponding to the polarization plane direction of the tag side antenna 21. That is, among the three cut-out symbols 38a, the arrangement direction of the upper left one and the upper right one is the tag side antenna. It corresponds to the polarization plane direction of 21. As a result, the two-dimensional code 38 also serves as an index.

  When communicating with the RF tag 34, the control unit 9 of the portable reader / writer 1 captures an image of the two-dimensional code 38 by the optical code reader 16 (image capturing means), and extracts three images from the captured image data. The position of the symbol 38a is obtained, and the arrangement direction of the upper left one and the upper right one is obtained, whereby the arrangement direction of the RF tag 34 (polarization plane direction of the tag side antenna 21) is recognized, and the reader / writer side antenna 19, 20 can be selected. At this time, it goes without saying that the two-dimensional code 38 can be read (decoded) after obtaining the positions of the three cut-out symbols 38a.

  According to these, it is possible to easily recognize the polarization plane direction of the tag-side antenna 21 from the images of the barcode 37 and the two-dimensional code 38 provided on the surfaces of the RF tags 33 and 34, respectively. In addition, the identification barcode 37 or the two-dimensional code 38 expressing information related to the product can be used as an index, and a simpler configuration can be achieved.

  In each of the above embodiments, the recognition unit is configured to recognize the polarization plane direction of the tag side antenna 21 from the image of the tag side antenna 21 or the image of the index 35 provided on the RF tag. When the RF tag has an elongated shape and the polarization plane direction of the tag-side antenna coincides with the longitudinal direction thereof, the recognition means detects the outer shape from the image of the entire RF tag. It can also be configured to recognize the polarization plane direction of the antenna, and in this case, it is not necessary to provide an index or the like on the surface of the RF tag.

  Further, in the second embodiment, as a notification for urging the main body 2 to be tilted, a message is displayed on the display unit 5 and a notification sound is output from the speaker 8. A means may be provided to vibrate the main body 2 (grip part 3), or a combination of lighting or blinking the notification LEDs 7 of various colors. Furthermore, various figures, symbols, characters, and the like can be adopted as an index (mark) provided on the RF tag.

  In addition, the present invention is not limited to the above-described embodiments. For example, the RF tag can have various shapes such as a card shape and a coin shape. Various modifications can be made to the external structure of the main body and the like, and the like can be implemented with appropriate modifications within the scope not departing from the gist.

The 1st Example of this invention is a figure which shows the polarization plane direction of the antenna at the time of communication with a portable reader / writer and RF tag Block diagram schematically showing the electrical configuration of a portable reader / writer The flowchart which shows the process sequence of the selection of the reader / writer side antenna which a control part performs FIG. 1 equivalent view showing a second embodiment of the present invention. 3 equivalent figure The figure which shows the other Example of this invention, and shows the example which provided the parameter | index (a) and the mark (b) on the surface of RF tag The figure which shows another different Example and shows the example which provided barcode (a) and the two-dimensional code (b) on the surface of RF tag

Explanation of symbols

  In the drawings, 1 is a portable reader / writer, 2 is a main body, 5 is a display unit, 6 is a key operation unit, 8 is a speaker, 9 is a control unit (recognition means, selection means, notification means), 10 is a memory, 31, 32, 33, and 34 are RF tags, 15 is a wireless tag processing unit, 16 is an optical code reading unit (image capturing means), 18 is an antenna changeover switch, 19 and 20 are reader / writer side antennas, and 21 is a tag side antenna. , 35 is an index, 36 is a mark (index), 37 is a barcode (index), and 38 is a two-dimensional code (index).

Claims (11)

In the main body that can be operated by hand, it is provided with an image sensor for imaging optical information and a reader / writer side antenna for wireless communication.
A portable reader / writer having a function of reading the optical information and a function of reading and writing data by performing wireless communication with an RF tag incorporating a linearly polarized wave tag side antenna,
The reader / writer side antenna is arranged in a form in which two linearly polarized antennas cross their polarization plane directions,
In performing communication with the RF tag, image capturing means for capturing an image of the RF tag by the image sensor;
Recognizing means for recognizing the arrangement direction of the RF tag from the image captured by the image capturing means;
A portable reader / writer comprising selection means for selecting a reader / writer side antenna used for communication so that a polarization plane direction with the tag side antenna is matched based on recognition of the recognition means. The image capturing means is configured to capture an image of an index provided on the surface of the RF tag so as to represent a direction corresponding to a polarization plane direction of the tag antenna.
The portable reader / writer according to claim 1, wherein the recognition unit is configured to recognize a polarization plane direction of the tag-side antenna from the image of the index. On the surface of the RF tag, a mark capable of determining the direction as the index is provided in a direction corresponding to the polarization plane direction of the tag side antenna,
3. The portable reader / writer according to claim 2, wherein the recognition means is configured to recognize a polarization plane direction of the tag-side antenna based on detecting the arrangement direction of the mark. Since the barcode is provided on the surface of the RF tag in a direction corresponding to the polarization plane direction of the tag-side antenna, the barcode also serves as the index,
3. The portable reader / writer according to claim 2, wherein the recognition means is configured to recognize a polarization plane direction of the tag-side antenna based on detecting an arrangement direction of the barcode. . On the surface of the RF tag, a two-dimensional code is provided in a direction corresponding to the polarization plane direction of the tag-side antenna, so that the two-dimensional code also serves as the index,
The said recognition means is comprised so that the polarization plane direction of the said tag side antenna may be recognized based on detecting the arrangement direction of the cut-out symbol of the said two-dimensional code. Portable reader / writer. The image capturing means is configured to capture an entire image of the RF tag,
The portable reader / writer according to claim 1, wherein the recognition unit is configured to recognize a polarization plane direction of the tag-side antenna based on an outer shape of the RF tag. The image capturing means is configured to capture an image of the tag-side antenna provided so as to be visible from the surface of the RF tag,
2. The portable reader / writer according to claim 1, wherein the recognition means is configured to recognize a polarization plane direction from an image of the tag side antenna.   The information processing apparatus includes a notification unit that prompts a user to tilt the main body when the arrangement direction of the RF tag recognized by the recognition unit is out of a communication allowable range of two reader / writer side antennas. Item 8. The portable reader / writer according to any one of Items 1 to 7.   The notification means notifies the appropriate rotation direction and rotation angle of the main body so that the polarization plane direction of the reader / writer side antenna used for communication matches the polarization plane direction of the tag side antenna of the RF tag. 9. The portable reader / writer according to claim 8, wherein the portable reader / writer is configured as follows.   If the recognition unit cannot recognize the arrangement direction of the RF tag, the reader / writer side antenna is used to communicate with the RF tag, and if the communication is malfunctioning, 10. The portable reader / writer according to claim 1, wherein the portable reader / writer is configured to perform communication with the RF tag by switching to the other reader / writer side antenna. An image sensor for imaging optical information is provided in the hand-held main body, and two linearly polarized reader / writer side antennas for wireless communication are provided in a form in which the polarization plane directions are crossed. In the portable reader / writer having the function of reading the optical information and the function of reading and writing data by performing wireless communication with an RF tag incorporating a linearly polarized wave tag side antenna A method for reading and writing tag data,
An image capturing step of capturing an image of the RF tag by the image sensor;
A recognition step for recognizing the arrangement direction of the RF tag from the image captured in the image capture step;
And a selection step of selecting a reader / writer side antenna to be used for communication so that the polarization plane direction with the tag side antenna is matched based on the recognition in this recognition step, RF in portable reader / writer Tag data read / write method.

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