JP4548195B2 - RFID system and reader - Google Patents

Description

The present invention includes, for example, a RFID tag attached to the object to be identified, RFID system comprising a reader for reading the data by performing communication by an electromagnetic wave between that RFID tag, and Lee Da for use in the system about the.

  In an RFID system that performs communication using an electromagnetic wave between a reader and an RFID tag, generally, a radio wave having a frequency of a microwave or a UHF band is used. In this RFID system, there is a situation in which a reader is placed at an arbitrary position for communication (reading) with respect to the RFID tag, but due to the polarization characteristics of electromagnetic waves, the reader side antenna and the RFID tag antenna are linearly connected. When a (linear) polarization type antenna is employed, there is a problem that the communication (reading) distance varies greatly depending on the arrangement of the reader with respect to the RFID tag (angle between the antennas).

Therefore, conventionally, the above-mentioned problem has been solved by adopting a circularly polarized antenna as the reader-side antenna (see, for example, Patent Document 1). As this circularly polarized antenna, for example, a cross antenna of two dipole antennas or a patch antenna is used.
JP 2003-249871 A

  However, as described above, when a circularly polarized antenna is used as the reader-side antenna, the antenna becomes relatively large and requires a large area for installation, which is an obstacle to miniaturization of the reader. There was a problem. In particular, in a portable (handy) reader, it is desirable to reduce the size of the device. From this viewpoint, it is preferable to employ a linearly polarized antenna such as a dipole antenna.

  In this case, even when a linearly polarized antenna such as a dipole antenna is adopted as the reader antenna and the RFID tag antenna, if communication can be performed with the polarization directions of both antennas aligned, Good communication performance can be obtained. Conventionally, however, no effort has been made to perform communication by matching the direction of the antenna (polarization direction).

  For example, U.S. Pat. No. 6,318,636 shows a handy type reader capable of both reading an RFID tag and optically reading a bar code. A configuration for irradiating marker light for performing alignment is shown. However, the marker light is only useful for indicating the reading direction when reading the barcode, and is not useful for adjusting the direction of the antenna during communication.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an RFID system capable of obtaining good communication performance with an RFID tag while reducing the size of an antenna provided in a reader. and, to provide a suitable Lee da for use in the system.

  In the RFID system, even when a linearly polarized antenna such as a dipole antenna is adopted as both the RFID tag side antenna and the reader side antenna in the RFID system, the reader arranges the reader in the reading direction with respect to the RFID tag ( The present invention has been accomplished with the idea that good communication performance can be obtained if the angle between the antennas can be easily adjusted so that both antennas have the same polarization direction.

That is, in the RFID system of the present invention, the reader and the RFID tag are respectively configured to include a linearly polarized reader-side antenna and a tag-side antenna, and the reader is polarized by the reader-side antenna. Marker light emitting means for emitting marker light for indicating the direction corresponding to the direction toward the communication direction is provided, and an orientation display corresponding to the polarization direction of the tag-side antenna is provided on the surface of the RFID tag. The direction of the marker light emitted from the marker light emitting means and applied to the RFID tag is matched with the direction indication of the RFID tag, so that the reader side antenna and the tag side antenna are the same bias. together they are configured such that the wave direction, the marker light from two spots light emitted in parallel along the plane of polarization of the communication waves Ri, along with their showing a line polarization direction connecting the spotlight two points, the two spotlight, where that is obliquely emitted inwards from one another so as to intersect the maximum communicable distance between the RFID tag (Invention of claim 1)

  According to this, the user can know the direction corresponding to the polarization direction of the tag-side antenna by the orientation display provided on the surface of the RFID tag. On the other hand, since marker light for indicating the direction corresponding to the polarization direction of the reader-side antenna is emitted from the marker light emitting means provided in the reader toward the communication direction, the user can place the light on the surface of the RFID tag. If the alignment is performed so that the marker light is irradiated, and the direction indicated by the marker light is matched with the direction indication of the RFID tag, the reader side antenna and the tag side antenna have the same polarization direction. Thus, the direction of the antenna during communication can be easily adjusted.

As a result, according to the RFID system of the present invention, it is possible to obtain a good communication performance with the RFID tag while reducing the size of the reader-side antenna provided in the reader. In addition, the marker light is composed of two spot lights that are emitted in parallel along the polarization plane of the communication electromagnetic wave, and the line connecting the two spot lights indicates the polarization direction, and the two spots. Since the light is emitted obliquely inwardly so as to intersect at the maximum communicable distance, the polarization direction can be easily shown while the marker light emitting means has a relatively simple structure. It becomes easy to align the planes of polarization between the antenna on the side and the antenna on the tag side, and communication efficiency can be improved. Furthermore, the two spot lights irradiated on the RFID tag overlap each other at the maximum communicable distance, and the distance between the two spot lights increases as the distance from the spot light increases. As a result, it is possible to indicate the maximum communicable distance with a simple configuration, and the user can also know the maximum communicable distance by looking at the marker light, so that communication is performed at a position outside the communicable distance. Can be prevented in advance, and it becomes even more effective. The reader according to the present invention includes a reader / writer capable of both reading and writing data to the RFID tag as well as a reader-only one for reading data from the RFID tag.

  At this time, the dipole antenna, which is a linearly polarized antenna, can be easily formed by providing a pattern directly on the substrate, and requires only a very small area to provide a linear pattern. It has become. Therefore, if both the reader-side antenna and the tag-side antenna are composed of dipole antennas (the invention of claim 2), the antenna can be provided easily and inexpensively, and the reader and the RFID tag can be miniaturized. it can.

In the RFID system of the present invention, the reader can be configured as a handy type that a user holds and operates by hand (invention of claim 3 ). The user can easily adjust the orientation, direction, and distance of the reader when reading the RFID tag, and the reader-side antenna can be reduced in size, so that the entire reader can be reduced in size. It is desirable as a thing.

The reader of the present invention reads data by communicating with an RFID tag using electromagnetic waves, and includes a linearly polarized antenna and communicates marker light for indicating the polarization direction of the antenna. Marker light emitting means for emitting the light toward the direction, the marker light comprising two spot lights emitted in parallel along the polarization plane of the communication electromagnetic wave, and the line connecting the two spot lights is deviated. together showing the wave direction, said two spot light, (the invention of claim 4), wherein the Rutokoro emitted obliquely inward directions so as to intersect the maximum communicable distance between the RFID tag having the features.

According to this, since the marker light for indicating the polarization direction of the reader side antenna is emitted from the marker light emitting means toward the communication direction, the user irradiates the marker light on the surface of the RFID tag. And aligning the polarization direction indicated by the marker light with the polarization direction of the RFID tag antenna, the antenna on the reader side and the antenna on the tag side have the same polarization direction. Thus, the direction of the antenna during communication can be easily adjusted. As a result, it is possible to obtain a good communication performance with the RFID tag while reducing the size of the antenna.
In addition, while the marker light emitting means has a relatively simple configuration, the polarization direction can be easily understood, and the polarization planes can be aligned between the reader side antenna and the tag side antenna. This facilitates communication efficiency. Furthermore, it is possible to indicate the maximum communicable distance with a simple configuration, and the user can know the maximum communicable distance by looking at the marker light, so that communication can be performed at a position outside the communicable distance. It is possible to prevent an attempt to do so, and it becomes even more effective.

At this time, if the antenna is composed of a dipole antenna (the invention of claim 5 ), the antenna can be provided easily and inexpensively, and the entire reader can be miniaturized.

Furthermore, if the reader of the present invention is configured as a handy type that the user holds and operates by hand (the invention of claim 6 ), the user can easily adjust the orientation, direction and distance of the reader when reading the RFID tag. In addition, since the antenna can be reduced in size, the entire reader can be reduced in size, which is desirable as a handy type.

By the way, the marker light emission by the marker light emission means may be always (intermittently) performed when the power is turned on, or may be performed by a user's switch operation. The output can be made only at the time of the output (invention of claim 7 ). Thereby, the marker light can be emitted when necessary, but the power consumption due to the emission of the marker light can be kept small.

The reader of the present invention may be provided with an optical information reading unit that optically reads an information code. In this case, the marker light emitting means, when reading of the information code by an optical information reading unit, can be configured to also serve as means for emitting a marker light for indicating the reading position (the invention of claim 8 ). Thereby, the marker light emitting means can be used both for reading the data of the RFID tag and reading the information code, and the configuration can be simplified accordingly.

Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings.
The RFID system according to the present embodiment includes, for example, an electromagnetic wave (for example, a frequency of a microwave or a UHF band) between an RFID tag 1 (see FIGS. 1 and 4) attached to an article such as a product and the RFID tag 1. And a reader / writer 2 (see FIG. 2A) as a reader for performing power supply and data reading and data reading.

  The reader / writer 2 not only reads data but also writes data to the RFID tag 1. Further, the reader / writer 2 is configured as a handy type that can be operated by a user's hand. Furthermore, in this embodiment, the reader / writer 2 is also configured to have a function of an optical information reader that optically reads an information code (not shown) such as a bar code or a two-dimensional code.

  Although not shown in detail, the RFID tag 1 has, for example, a plastic tag shape (rectangular plate shape), and includes a tag-side antenna 3 for communicating with the reader / writer 2 inside thereof. And an RFID chip for generating data holding and response signals. The tag-side antenna 3 is a linearly polarized antenna, and a dipole antenna is used here. In this case, as shown in the figure, the tag-side antenna 3 is disposed so as to extend along the longitudinal direction of the RFID tag 1, for example. Then, as will be described later, on the surface of the RFID tag 1, for example, a direction indication 4 (see FIG. 4) composed of a double arrow for indicating the polarization direction of the tag side antenna 3 (direction in which the tag side antenna 3 extends). ) Is printed or the like.

  As is well known, the RFID chip includes a rectifying / smoothing circuit for obtaining an operation power from a power supply signal of the reader / writer 2, a CPU for controlling communication, a modulation / demodulation circuit for modulating and demodulating transmission / reception signals, A ROM that stores an operation program and the like, a readable / writable EEPROM that stores data, and the like are configured as a one-chip IC. In the EEPROM of the RFID chip, data relating to a product to be attached is stored.

  On the other hand, the reader / writer 2 is configured as follows. As shown in FIG. 2 (a), this reader / writer 2 optically transmits an information code such as a communication mechanism 6 serving as a communication means for performing radio wave communication with the RFID tag 1 in a case 5 and a barcode. The optical information reading mechanism 7 as an optical information reading means for reading in an integrated manner, and a control device 8 (see FIG. 3) configured mainly by a microcomputer and performing overall control and the like are incorporated.

  The case 5 has a proximal end side (right side in FIG. 2A) as a grip portion, a distal end side that is slightly wider and is bent so as to be slightly inclined downward, and a distal end portion thereof is a reading port 5a. ing. The reading port 5a has a slightly horizontally long rectangular shape. On the upper surface of the case 5, a key input unit 9 including a plurality of key switches 9a is provided, and a display unit 10 including, for example, an LCD is provided. Further, a trigger key (not shown) for instructing reading (writing) is provided on the side surface of the case 5. The key switch 9a, the display unit 10 and the like are mounted on a printed circuit board 11 disposed in the case 5, and although not shown in detail, the printed circuit board 11 includes the control device 8 and each of which will be described later. Circuits are also implemented. In the case 5, a secondary battery (not shown) serving as a power source is also incorporated.

  The optical information reading mechanism 7 includes an imaging element 12 such as a CCD area sensor mounted on the lower surface side of the printed board 11, a mirror 13 disposed in front of the imaging element 12, and an optical system disposed in the vicinity of the inside of the reading port 5a. A well-known configuration including the unit 14 and the like is provided. The optical system unit 14 is configured by providing an imaging light source 15 and an illumination light source 16 including a plurality of LEDs on a substrate 14a.

  Thus, when the user performs a reading operation (trigger key on operation) with the reading port 5a of the case 5 facing the reading target such as a barcode, the illumination light from the illumination light source is irradiated onto the reading target. Then, the reflected light is incident through the imaging lens 15, folded back by the mirror 13, and input to the image sensor 12. Then, the control device 8 decodes the barcode or the like from the photographed image data.

  As shown in FIG. 3, the communication mechanism 6 includes a reader-side antenna 17 and a transmission circuit 18 and a reception circuit 19 connected to the reader-side antenna 17. The reader antenna 17 is a linearly polarized antenna, and here a dipole antenna is employed. In this case, as shown in FIG. 2B and FIG. 1, the reader-side antenna 17 is disposed so as to extend horizontally along the lateral direction, for example, on the back side of the lower part.

  Further, as shown in FIG. 3, the transmission circuit 18 and the reception circuit 19 are controlled by the control device 8. At this time, the control device 8 outputs a power signal to the reader-side antenna 17 through the transmission circuit 18 and demodulates the reception signal received by the reader-side antenna 17 through the reception circuit 19 and extracts it as data. It has become. Thus, with the reader-side antenna 17 (the reading port 5a of the case 5) placed close to the RFID tag 1 to be read, power is supplied to the RFID tag 1 by radio waves and data communication ( Writing and reading).

  Note that the linearly polarized reader-side antenna 17 composed of the above-described dipole antenna is an antenna in which the electric field magnetic flux runs in parallel with the dipole axis. Therefore, when the reader / writer 2 is arranged in the horizontal direction, a solid line in FIG. As shown, a horizontally polarized radio wave is output. Here, if the tag side antenna 3 (RFID tag 1) which consists of the same dipole antenna is arrange | positioned in the horizontal direction, a polarization direction will correspond and appropriate communication performance will be acquired. On the other hand, when the tag side antenna 3 (RFID tag 1) is arranged perpendicular to the earth surface, it has a vertical polarization plane as shown by a broken line in FIG. The communication efficiency becomes the lowest, and the received signal of the RFID tag 1 causes a loss of 3 dB, for example.

  As shown in FIG. 2, the reader / writer 2 of the present embodiment emits marker light M for indicating the polarization direction of the reader-side antenna 17 in the communication direction (reading) in the vicinity of the reading port 5 a in the case 5. A marker light emitting unit 20 is provided as marker light emitting means for emitting to the front of the mouth 5a. Although not shown in detail, the marker light emitting unit 20 is configured by disposing a condensing lens in front of a light source composed of, for example, an LED or a laser diode, and is mounted on the substrate 14a. Thereby, as shown in FIG. 4, the marker light M emitted from the marker light emitting unit 20 is formed into a spot light shape having a circular cross section composed of parallel light beams with little (less) spread.

  At this time, in this embodiment, as shown in FIGS. 1 and 2B, the marker light emitting section 20 is positioned symmetrically on the left and right sides of the reader side antenna 17 and faces the reading port 5a. A pair is provided. These marker light emitting units 20 are provided so as to emit the marker light M in parallel along the polarization plane of the communication electromagnetic wave of the reader-side antenna 17, and thus a line connecting the two marker lights M (spot light) is provided. This indicates the polarization direction of the reader-side antenna 17.

  Further, at this time, as shown in FIG. 1, the pair of marker light emitting units 20 are arranged so as to face slightly inside each other with respect to the center line O in the radio wave radiation direction of the reader-side antenna 17. Accordingly, the two marker lights M intersect at a predetermined position in front of the reading port 5a. Here, the communicable range a of the reader / writer 2 is indicated by a broken line in FIG. The marker lights M intersect each other at a maximum communicable maximum distance (the farthest position within the communicable range a).

  Accordingly, for example, when the reader / writer 2 is gradually moved away from the state in which the reader / writer 2 is brought close to the RFID tag 1, the interval between the two marker lights M irradiated to the RFID tag 1 is gradually narrowed. In the maximum communicable distance, one point is overlapped, and thereafter the interval between the two marker lights M gradually increases. As described above, the marker light M has the polarization direction of the reader antenna 17, the reading direction of the RFID tag 1 (the spatial direction in which the reader / writer 2 is directed toward the RFID tag 1), and the maximum communicable distance. It will be shown at the same time.

  As shown in FIG. 3, these marker light emitting units 20 are controlled (on / off control) by the control device 8 via the marker driving circuit 21. In this embodiment, the control device 8 emits the marker light M by turning on the marker light emitting unit 20 only when the radio wave is output from the reader-side antenna 17 due to its software configuration (execution of the control program). It is supposed to let you.

  The reader / writer 2 is capable of both optical reading of an information code by the optical information reading mechanism 7 and communication (data reading) with the RFID tag 1 by the communication mechanism 6. However, switching of these functions is performed, for example, when the user operates the key input unit 9 to select a mode.

  Next, the operation of the above configuration will be described with reference to FIG. For example, when the user reads (or writes) data of the RFID tag 1 attached to a product using the reader / writer 2, the trigger key is placed in a state where the reading port 5 a of the case 5 is close to the RFID tag 1. Turn on the. Then, the reader / writer 2 supplies power to the RFID tag 1 by radio waves (electromagnetic field), and data communication (writing and reading) with the RFID tag 1 is performed. At this time, when the radio wave is output from the reader-side antenna 17, the marker light emitting unit 20 is turned on and the marker light M is emitted.

  The flowchart of FIG. 5 shows a control procedure of the marker light emitting unit 20 executed by the control device 8. That is, when the process is started, it is determined in step S1 whether or not radio waves are being output from the reader-side antenna 17. If radio waves are being output (Yes in step S1), the marker light emitting unit 20 is turned on and the marker light M is emitted in step S2. On the other hand, if the radio wave is not being output (No in step S1), the marker light emitting unit 20 is turned off and the emission of the marker light M is stopped in step S3.

  By the way, as described above, when communication is performed between the reader / writer 2 and the RFID tag 1, the polarization direction of the reader-side antenna 17 and the polarization direction of the tag-side antenna 3 are perpendicular ( If the angle is 90 degrees or 270 degrees, there is a situation in which the communication performance is significantly lowered. However, in the present embodiment, the direction indication 4 indicating the polarization direction of the tag side antenna 3 is provided on the surface of the RFID tag 1, and the polarization direction of the reader side antenna 17 is indicated from the reader / writer 2 together with this. Marker light M is emitted.

  Therefore, as shown in FIG. 4, the user causes the RFID tag 1 to be irradiated with the marker light M, and matches the direction of the direction display 4 of the RFID tag 1 with the direction indicated by the marker light M. In addition, the two (reader / writer 2) are aligned, and in particular, the orientation of the case 5 of the reader / writer 2 (the rotation angle of the reader-side antenna 17 around the center line O in the radio wave radiation direction) is adjusted. As a result, the polarization direction of the reader-side antenna 17 and the polarization direction of the tag-side antenna 3 can be easily matched, and good communication performance can be obtained by performing communication in that state.

  Further, since the user can know the communicable distance by looking at the marker light M (the interval between the two marker lights M) irradiated to the RFID tag 1, the user can always communicate within the communicable range a. Therefore, it is possible to prevent communication from being performed at a position outside the communicable range a.

  Thus, according to the present embodiment, the following effects can be obtained. That is, as the reader-side antenna 17 provided in the reader / writer 2, a dipole antenna that can be easily formed by providing a pattern directly on the substrate and that requires only a very small area to provide a linear pattern is provided. Adopted. Therefore, the reader-side antenna 17 can be provided easily and inexpensively, and the reader / writer 2 can be reduced in size. In particular, it is suitable as a hand-held reader / writer 2 that a user operates with a hand. Since the same dipole antenna is adopted as the tag side antenna 3 built in the RFID tag 1, the RFID tag 1 can be downsized.

  Since the reader / writer 2 is provided with the marker light emitting unit 20 and the RFID tag 1 is further provided with the orientation display 4, the reader side antenna 17 and the tag side antenna 3 have the same polarization direction. In addition, the directions of both antennas 17 and 3 during communication can be easily matched. As a result, it is possible to prevent the communication distance from fluctuating between the reader / writer 2 and the RFID tag 1 and to always obtain good communication performance.

  In particular, in this embodiment, the marker light M emitted from the marker light emitting unit 20 is composed of two spot lights emitted in parallel (on the polarization plane) with the polarization plane of the reader-side antenna 17, and these Since the line connecting the two spot lights indicates the polarization direction and intersects at the maximum communicable distance, the polarization direction is reduced while the marker light emitting unit 20 has a relatively simple configuration. In addition, the user can easily know the communicable distance by looking at the marker light M. Furthermore, in this embodiment, the marker light M is emitted only when the electromagnetic wave from the reader-side antenna 17 is output. Therefore, the marker light M can be emitted when necessary, but the marker light M is emitted. The power consumption due to can be kept small.

  Although not described in detail, in the reader / writer 2 of the above embodiment, when an information code such as a barcode is optically read using the optical information reading mechanism 7, the user can move the case 5 from a remote position. The reading operation may be performed in a state where the reading port 5a is directed to a reading target such as a barcode. At this time, the marker light emitting section 20 can also be used as a means for emitting the marker light M for aligning the reading port 5a and the information code (in order to indicate the reading position). I can finish it.

  However, in this case, since the communicable distance with the RFID tag 1 by the communication mechanism 6 and the information code readable distance by the optical information reading mechanism 7 are different, the marker light emitting unit 20 is also used for reading the information code. In order to achieve this, for example, the condenser lens arranged at the front of the light source can be moved in the optical axis direction, multiple types of lenses can be switched, and the light source can be moved in the optical axis direction. It is desirable to provide a device for making it happen.

  In addition, the present invention is not limited to the above-described embodiments, and the following various modifications are possible. That is, in the above-described embodiment, the RFID tag 1 has a tag shape, but can have various shapes such as a card shape and a coin shape. Further, in the above-described embodiment, the direction indication 4 of the RFID tag 1 and the direction indicated by the marker light M are made to coincide with the polarization direction. However, for example, both indicate the direction shifted by 90 degrees from the polarization direction. In short, in short, it is only necessary that both antennas have the same polarization direction in a state where the direction display 4 and the direction indicated by the marker light M are combined.

  The orientation display 4 provided on the RFID tag 1 is not limited to the arrow shape, and various modifications are possible. For example, when the RFID tag has an elongated shape and the user can easily understand the polarization direction (dipole axis direction) of the tag side antenna, the orientation display 4 can be omitted. By providing the marker light emitting means on the side, the intended purpose can be achieved.

  Furthermore, the pattern (shape) of the marker light M is not limited to two spot lights, and various modifications are possible. As the timing of marker light emission by the marker light emission means, marker light may be emitted constantly (intermittently) when the power is turned on, or marker light may be emitted by a user's switch operation. In the above-described embodiment, the reader / writer 2 has been described. However, a reader that only reads data may be used, and the optical information reading mechanism 7 may not be provided.

The top view which shows one Example of this invention and shows the structure of the principal part of RFID system A longitudinal side view schematically showing the internal configuration of the reader / writer (a) and a diagram (b) showing an arrangement relationship between the reader-side antenna and the marker light emitting portion as seen from the direction of the arrow A Block diagram showing the electrical configuration of the main part The figure which shows a mode that marker light was irradiated to the RFID tag Flow chart showing control procedure of marker light emitting unit Diagram for explaining the direction of polarization

Explanation of symbols

  In the drawings, 1 is an RFID tag, 2 is a reader / writer (reader), 3 is a tag side antenna (dipole antenna), 4 is an orientation display, 5 is a case, 5a is a reading port, 6 is a communication mechanism (communication means), 7 Is an optical information reading mechanism (optical information reading means), 8 is a control device (control means), 17 is a reader side antenna (dipole antenna), 20 is a marker light emitting section (marker light emitting means), 21 is a marker driving circuit, M indicates marker light.

Claims (8)

An RFID tag and a reader that reads data by performing communication using electromagnetic waves between the RFID tag and the reader and the RFID tag are configured to include a linearly polarized reader-side antenna and a tag-side antenna, respectively. RFID system
The reader includes marker light emitting means for emitting marker light for indicating the direction corresponding to the polarization direction of the reader antenna toward the communication direction,
On the surface of the RFID tag, direction indication corresponding to the polarization direction of the tag side antenna is made,
By combining the direction indicated by the marker light emitted from the marker light emitting means and applied to the RFID tag with the orientation indication of the RFID tag, the reader side antenna and the tag side antenna have the same polarization direction. together they are configured to,
The marker light is composed of two spot lights emitted in parallel along the polarization plane of the communication electromagnetic wave, and a line connecting the two spot lights indicates the polarization direction, and the two spot lights are The RFID system emits light obliquely inwardly so as to intersect at the maximum communicable distance with the RFID tag .   The RFID system according to claim 1, wherein the reader-side antenna and the tag-side antenna are both dipole antennas. The RFID system according to claim 1 , wherein the reader is configured as a handy type that a user holds and operates by hand . A reader that reads data by performing electromagnetic wave communication with an RFID tag,
With a linearly polarized antenna,
Marker light emitting means for emitting marker light for indicating the polarization direction of the antenna toward the communication direction,
The marker light is composed of two spot lights emitted in parallel along the polarization plane of the communication electromagnetic wave, and a line connecting the two spot lights indicates the polarization direction, and the two spot lights are The reader is emitted obliquely inwardly so as to intersect at the maximum communicable distance with the RFID tag. The reader according to claim 4, wherein the antenna is a dipole antenna . The reader according to claim 4 or 5, wherein the reader is configured as a handy type that a user holds and operates by hand . The reader according to claim 4, wherein the marker light is emitted only when an electromagnetic wave is output from the antenna . An optical information reading means for optically reading the information code is also provided, and the marker light emitting means emits marker light for indicating the reading position when the information code is read by the optical information reading means. The reader according to any one of claims 4 to 7, which is also used as a means for emitting light.

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