JP5639563B2 - Recording medium storage device, image forming apparatus, and RFID tag recording method - Google Patents

Description

  Embodiments described herein relate generally to a recording medium storage device, an image forming apparatus, a recording medium, and a wireless tag recording method.

  A wireless tag that is an information storage medium capable of wireless communication is also called RFID (Radio Frequency Identification), and a system for transmitting and receiving information to and from a reading apparatus has been put into practical use.

  This wireless tag may be affixed to an article in addition to being attached to the article alone, and the label may be attached to the article.

  This label can form an image. In addition to incorporating a wireless tag in a label formed in advance, an image may be formed later on a label incorporating the wireless tag.

  As an image forming apparatus for forming an image on a label incorporating the wireless tag, an apparatus for forming an image on a roll label is known.

  However, in recent years, there has been a demand for forming an image on a sheet-like label.

  In this regard, in an image forming apparatus having a plurality of paper feeding cassettes, a sheet writer in which a reader / writer and an antenna for reading and writing a wireless tag are arranged in a first paper feeding cassette and a wireless tag is built in a second paper feeding cassette. An image forming apparatus is placed on the market for storing the label paper, reading and writing the wireless tag on the label paper taken out from the second paper feed cassette by the reader / writer of the first paper feed cassette, and then forming an image on the label paper. Yes.

  However, in this model, the first paper feed cassette equipped with the reader / writer occupies one stage of the paper feed cassette mounting portion, which is wasteful in terms of space and changes from plain paper to label paper containing a wireless tag. When switching, the two paper feed cassettes must be exchanged, which is troublesome.

Japanese Patent No. 3935162

  Accordingly, there is a need for a recording medium storage device, an image forming apparatus, a recording medium, and a wireless tag recording method capable of forming an image on a sheet-like label paper containing a wireless tag with less space and reading and writing the wireless tag. .

  In order to solve the above-described problem, an embodiment of the present invention includes a stacking tray on which recording media are stacked and the inclination changes according to the increase or decrease of the recording media, and at least an upper surface of the recording medium stacked on the stacking tray. A movable antenna arranged so as to cover a part, and the movable antenna is displaced while keeping a constant distance from the upper surface of the recording medium following a change in the inclination of the upper surface of the recording medium due to increase / decrease of the recording medium Provided is a recording medium storage device including a supporting unit that supports and a reader / writer that communicates with a wireless tag of the recording medium by an antenna included in a movable antenna.

  Also, an embodiment of the present invention includes a stacking tray on which recording media are stacked and a plate-shaped shield that blocks radio waves, and is disposed so as to cover at least a part of the upper surface of the recording medium stacked on the stacking tray. A recording medium storage device comprising: a movable antenna that supports the movable antenna so as to be substantially parallel to the upper surface of the recording medium; and a reader / writer that communicates with a wireless tag of the recording medium by the antenna provided in the movable antenna. provide.

1 is a diagram illustrating a configuration of an image forming apparatus. 1 is an external perspective view of a recording medium storage device. 1 is an external perspective view of a recording medium storage device. FIG. 3 is a side view of the recording medium storage device when the recording medium is full. It is a side view when the number of recording media in the recording medium storage device is reduced. It is side surface sectional drawing of a movable antenna. It is a bottom view of a movable antenna. It is a figure which shows the positional relationship of a recording medium, an antenna, and a shield. It is a block diagram which shows the structure of a wireless tag and a reader / writer. 1 is a block diagram illustrating a configuration of an image forming apparatus. It is a figure which shows the movable antenna which concerns on other embodiment. It is a figure which shows the displacement of the movable antenna accompanying the change of the quantity of a recording medium. It is a figure which shows the displacement of the movable antenna accompanying the change of the quantity of a recording medium. It is a figure which shows the displacement of the movable antenna accompanying the change of the quantity of a recording medium. It is a figure which shows the movable antenna which concerns on other embodiment. It is a figure which shows the displacement of the movable antenna accompanying the change of the quantity of a recording medium. It is a figure which shows the displacement of the movable antenna accompanying the change of the quantity of a recording medium. It is a figure which shows the displacement of the movable antenna accompanying the change of the quantity of a recording medium.

  Hereinafter, an embodiment of a recording medium storage device, an image forming apparatus, a recording medium, and a wireless tag recording method will be described in detail with reference to the drawings.

  The recording medium storage device of the present embodiment includes a stacking tray on which recording media are stacked, a movable antenna disposed so as to cover at least a part of the upper surface of the recording medium stacked on the stacking tray, A support unit that supports the upper surface so as to be substantially parallel to the upper surface, and a reader / writer that communicates with the wireless tag of the recording medium by the antenna provided in the movable antenna.

  The recording medium storage device of the present embodiment is arranged so as to cover a stacking tray in which the recording medium is stacked and the inclination changes according to the increase or decrease of the recording medium, and at least a part of the upper surface of the recording medium stacked on the stacking tray. A movable antenna, a support unit for supporting the movable antenna so as to follow a change in the inclination of the upper surface of the recording medium due to increase / decrease of the recording medium, and keep the distance from the upper surface of the recording medium kept constant. A reader / writer that communicates with the wireless tag of the recording medium using an antenna included in the antenna.

  FIG. 1 is a diagram illustrating a configuration of an image forming apparatus 1 according to the present embodiment. As shown in FIG. 1, the image forming apparatus 1 includes an automatic document feeder 11, an image reading unit 12, an image forming unit 13, a discharge device 15, a paper feeding unit 16, a recording medium transport mechanism 18, And a control unit.

  The automatic document feeder 11 is installed at the top of the main body of the image forming apparatus 1 so as to be openable and closable. The automatic document feeder 11 includes a document conveyance mechanism that takes out documents one by one from a paper feed tray and conveys them to a paper discharge tray.

  The automatic document feeder 11 conveys documents one by one to the document reading unit of the image reading unit 12 by the document conveying function. It is also possible to open the automatic document feeder 11 and place the document on the document table of the image reading unit 12.

  The image reading unit 12 includes an exposure lamp that exposes a document and a carriage including a first reflection mirror, a plurality of second reflection mirrors that move in accordance with the movement of the carriage, a lens block, and a CCD ( Charge Coupled Device).

  The carriage rests on the document reading unit or reciprocates under the document table to reflect the light of the exposure lamp reflected by the document to the first reflecting mirror. The plurality of second reflection mirrors reflects the reflected light of the first reflection mirror to the lens block. The lens block changes the magnification of the reflected light and outputs it to the CCD. The CCD converts incident light into an electrical signal and outputs it as an image signal to the image forming unit 13.

  The image forming unit 13 includes a registration roller 13A that corrects the orientation of the recording medium so that the side in the width direction of the recording medium conveyed obliquely is parallel to the recording medium conveyance direction.

  The image forming apparatus 1 forms an image on the recording medium corrected by the registration roller 13 </ b> A by the image forming unit 13.

  The image forming method of the image forming unit 13 does not matter. The image forming unit 13 can be selected from methods such as an electronic method and an ink jet method.

  In the case of the electronic system, the image forming unit 13 includes, for each of yellow Y, magenta M, cyan C, and black K, a laser irradiation unit 13D, a photosensitive drum 13B that is an electrostatic latent image carrier, and a developer supply unit. 13C and the transfer part 14 are provided.

  The laser irradiation unit 13D irradiates the photosensitive drum 13B with laser light based on the image signal, and forms an electrostatic latent image on the photosensitive drum 13B. The developer supply unit 13C supplies the developer to the photosensitive drum 13B and forms a developer image from the electrostatic latent image.

  The paper feed unit 16 includes a plurality of detachable recording medium storage devices that store recording media.

  The paper feed unit 16 takes out the recording medium one by one from the paper feed cassette and delivers it to the paper transport mechanism. The paper transport mechanism transports the recording medium to the transfer unit 14.

  The transfer unit 14 includes a transfer belt 14B and a transfer roller 14A. The transfer belt 14B as an image carrier transfers and carries the developer image on the photosensitive drum 13B. The transfer roller 14A applies a voltage to transfer the developer image on the transfer belt 14B to the conveyed recording medium.

  The image forming apparatus 1 includes a fixing device 14 </ b> C downstream of the transfer unit 14 in the recording medium conveyance direction. The fixing device 14C heats and pressurizes the developer image to fix it on the recording medium.

  The recording medium on which the image is formed is supplied to the discharge device 15 and discharged.

  In the case of an ink jet type, the image forming unit 13 includes a head that sprays ink onto a recording medium.

  The head has an ink supply chamber in which piezo elements of different polarities are attached in the longitudinal direction, and the set of the attached piezo elements are arranged in a comb tooth shape, an ink discharge hole, and covers the ink supply chamber A cover is provided. The image forming unit 13 deforms the ink supply chamber by alternately applying a voltage to the head, and repeats the suction of the ink and the discharge from the ink supply port. The ejected ink adheres to the recording medium and image formation is performed.

  FIG. 2 is an external perspective view of the recording medium storage device 300 of the present embodiment. In FIG. 2, illustration of a movable antenna 311 described later is omitted.

  As shown in FIG. 2, the recording medium storage device 300 stacks a casing 301, a drawer portion 302 that is disposed on the front surface of the casing and has a handle, a regulation plate 303 that regulates the position of the recording medium, and a recording medium. A stacking tray 305, a tray lift 304 that moves the stacking tray 305 up and down, a reader / writer 120 that communicates with the wireless tag and reads and writes the wireless tag, and a movable antenna 311 are provided.

  The recording medium storage device 300 is attached to the paper feeding unit 16. When the recording medium storage device 300 is mounted on the paper feed unit 16, the image forming apparatus 1 drives the tray lift 304 to raise the stacking tray 305. When the stacking tray 305 is raised, the recording medium loaded on the stacking tray 305 turns on a sensor of a sheet feeding device including a pickup roller. When this sensor is turned on, the image forming apparatus 1 stops raising the stacking tray 305.

  Therefore, the upper end surface of the recording medium loaded on the stacking tray 305 contacts the pickup roller regardless of the number of recording media. When forming an image, the image forming apparatus 1 drives a pickup roller to take out recording media one by one.

  FIG. 3 is an external perspective view of the recording medium storage device 300. As shown in FIG. 3, the recording medium storage device 300 is installed on the movable antenna 311 and the movable antenna 311 disposed so as to cover at least a part of the upper end surface of the recording medium loaded on the stacking tray 305. A roller 311A that is in contact with the upper end surface of the recording medium loaded on the tray 305, a support unit 312 that displaces the movable antenna 311 in accordance with the inclination of the upper end surface of the recording medium, and a reader that communicates with the wireless tag of the recording medium A writer 120.

  In FIG. 3, a cable connecting the movable antenna 311 and the reader / writer 120 is not shown.

  The movable antenna 311 is provided with a protrusion 311B that fits up and down with the groove 312B of the support 312 at one end upstream in the recording medium conveyance direction.

  Therefore, the movable antenna 311 falls to the upper end surface of the recording medium loaded on the stacking tray 305 by its own weight, and the distance between the movable antenna 311 and the upper end surface of the recording medium is kept at a distance determined by the diameter of the roller 311A.

  FIG. 4 is a side view of the recording medium storage device 300 when the recording medium is full. FIG. 5 is a side view when the number of recording media in the recording medium storage device 300 is reduced.

  As shown in FIG. 4, the tray lift 304 has an L-shaped cross section, and one end of the tray lift 304 is locked to the casing 301 by a fulcrum 304A.

  When the recording medium is loaded on the stacking tray 305 in a state where the recording medium is almost full, the tray lift 304 does not lift the stacking tray 305.

  In this case, the movable antenna 311 rises to near the upper end within the movable range and covers at least a part of the upper end surface of the recording medium loaded on the stacking tray 305. The roller 311A is in contact with the upper end surface of the recording medium.

  As shown in FIG. 5, when the number of recording media decreases, the image forming apparatus 1 drives the tray lift 304 to raise one end of the stacking tray 305.

  In this case, the movable antenna 311 is displaced near the lower end within the movable range. Since the protrusion 311B is located at one end of the movable antenna 311, the movable antenna 311 tilts following this tilt even when the upper end of the recording medium is tilted.

  Further, since the movable antenna 311 falls to the upper end surface of the recording medium due to its own weight, it continues to cover at least a part of the upper end surface of the recording medium loaded on the stacking tray 305.

  Furthermore, since the movable antenna 311 has the roller 311A, the distance determined by the diameter of the roller 311A is kept between the upper surface of the recording medium regardless of the amount of the recording medium.

  That is, since the movable antenna 311 includes the roller 311A, the position of the movable antenna 311 is kept substantially parallel to the upper end surface of the recording medium by a distance determined by the diameter of the roller 311A regardless of the amount of the recording medium.

  FIG. 6 is a side sectional view of the movable antenna 311. FIG. 7 is a bottom view of the movable antenna 311.

  As shown in FIGS. 6 and 7, the movable antenna 311 includes a substrate 311A formed of a dielectric, a top surface shield 311B formed of metal and covering an upper surface, that is, a surface not facing the recording medium, and a conductor such as metal. Alternatively, a shield 311C formed of a ferroelectric material and disposed on the upstream side of the lower surface, ie, the surface facing the recording medium, in the recording medium conveyance direction, and the lower surface, ie, the shield 311C of the surface facing the recording medium, in the downstream of the recording medium conveyance direction. And an antenna 121 disposed on the side.

  The top shield 311B and the shield 311C have shapes and sizes that do not resonate with radio waves radiated from the antenna 121. Therefore, the top shield 311B and the shield 311C block radio waves radiated from the antenna 121.

  The shield 311C may surround the antenna 121. When the recording medium is stacked on the stacking tray 305, the shield 311C covers the wireless tag included in the recording medium.

  Therefore, even when radio waves are emitted from the antenna 121, the wireless tag of the loaded recording medium is not read or written.

  The antenna 121 receives a high-frequency signal transmitted from the reader / writer 120 through the cable 311E by the feeding point 311F.

  The antenna 121 should be narrow if the radio wave emission range is a range in which a wireless tag on one recording medium can be read and written. This is because the possibility of erroneously reading and writing other wireless tags is reduced.

  The antenna 121 is formed by a transmission line such as a microstrip line having an impedance that does not reflect the high-frequency signal, and includes a termination resistor 311G at the termination portion. The antenna 121 is formed in a meander shape.

  The antenna 121 may be a planar antenna such as a patch antenna. In this case, the termination resistor 311G is omitted.

  In either case, the antenna 121 has a predetermined length in the recording medium conveyance direction. This predetermined length is determined by a balance between the conveyance speed of the recording medium and the time required for writing to the wireless tag.

  6 and 7 show examples in which the movable antenna 311 integrally includes the shield 311C. However, the movable antenna 311 may have the shield 311C as a separate body, and the shield 311C can be omitted when the radiated radio wave is sufficiently weak and the directivity of the antenna 121 is strong.

  FIG. 8 is a diagram illustrating a positional relationship between the recording medium P, the antenna 121, and the shield 311C. FIG. 8 shows the recording medium P when it is stacked on the stacking tray 305. As shown in FIG. 8, the recording medium P has a label paper PL including a wireless tag 110.

  The movable antenna 311 includes a shield 311C upstream of the recording medium conveyance direction X1, and an antenna 121 downstream of the shield 311C in the recording medium conveyance direction X1.

  The shield 311C covers the wireless tag 110 of the recording medium. Therefore, the wireless tag 110 of the recording medium P loaded by the radio wave irradiated from the antenna 121 is not read or written.

  The reader / writer 120 reads / writes the wireless tag 110 at a timing when the uppermost recording medium P is transported in the recording medium transport direction X1 and the wireless tag 110 is positioned below the antenna 121.

  The recording medium P includes the wireless tag 110 at a position covered by the shield 311C when being stacked on the stacking tray 305.

  Specifically, the recording medium P includes the wireless tag 110 at a position near one of the edge portions from the center of the recording medium.

  FIG. 9 is a block diagram showing the configuration of the wireless tag 110 and the reader / writer 120. As shown in FIG. 9, the wireless tag 110 includes a memory 111 that is a storage device, a wireless tag control unit 112 that reads and writes data from and to the memory 111, and rectification and stabilization of received modulated electromagnetic waves. A power generation unit 115 that supplies a signal, a wireless tag antenna 116 that is an antenna for transmitting and receiving signals, a modulation unit 113 that modulates data transmitted from the wireless tag control unit 112 and transmits the modulated data to the wireless tag antenna 116, And a demodulator 114 that demodulates the received modulated electromagnetic wave and sends it to the wireless tag controller 112.

  The reader / writer 120 is modulated with a reader / writer control unit 126 that controls communication with the wireless tag 110 and controls each connected hardware, and a modulation unit 122 that modulates a signal transmitted from the reader / writer control unit 126. A transmission amplifier 123 that amplifies the received signal and sends it to the antenna 121 via the circulator 131, a reception amplifier 124 that amplifies the modulated electromagnetic wave received from each antenna via the circulator 131, and a demodulator that demodulates the received modulated signal 125, and an interface 130 that is connected to a host device such as a personal computer to exchange data. The reader / writer control unit 126 includes a CPU 127 and a ROM 128 and a RAM 129 which are memories for storing data.

  FIG. 10 is a block diagram illustrating a configuration of the image forming apparatus 1. As shown in FIG. 10, the image forming apparatus 1 includes a main CPU 201 that is an arithmetic device that performs overall control of the entire image forming apparatus 1, a ROM and RAM 202 </ b> A that are storage devices, and an image processing unit 204 that performs image processing. Prepare.

  The main CPU 201 is connected to a print CPU 205 that controls each part of the image forming system, a scan CPU 209 that controls each part of the image reading system, and a drive controller 212 that controls the drive unit.

  In the case of an electronic system, the print CPU 205 controls a print engine 206 that forms an electrostatic latent image on the photosensitive drum 13B and a process unit 207 that forms a developer image.

  The scan CPU 209 controls the CCD drive circuit 210 that drives the CCD 211. A signal from the CCD 211 is output to the image forming unit 13.

  The image forming apparatus 1 is further connected to the reader / writer 120 of the recording medium storage device 300 via a connector.

  The image forming apparatus 1 reads and writes the wireless tag 110 of the recording medium P via the reader / writer 120 based on information input from an external device such as a personal computer.

  FIG. 11 is a diagram illustrating a movable antenna 1101 according to another embodiment. In FIG. 11, the cable connecting the movable antenna 1101 and the reader / writer 120 is not shown.

  The configurations of the antenna 121 and the shield 311C of the movable antenna 1101 are the same as the configurations of the antenna 121 and the shield 311C of the movable antenna 311.

  The movable antenna 1101 is different from the movable antenna 311 in that the rear end in the recording medium conveyance direction is pivotally locked to the restriction plate 303 by a fulcrum 1102.

  12 to 14 are diagrams showing the displacement of the movable antenna 1101 in accordance with the change in the amount of the recording medium.

  As shown in FIGS. 12 to 14, the image forming apparatus 1 drives the tray lift 304 to raise the stacking tray 305 as the recording medium P decreases from the full state. The stacking tray 305 is rotated by a fulcrum upstream in the recording medium conveyance direction.

  However, since the movable antenna 1101 is pivotally locked to the restriction plate 303 by a fulcrum at the lower end of the recording medium conveyance direction, the movable antenna 1101 tilts following this inclination even when the upper end of the recording medium is inclined.

  Further, since the movable antenna 1101 falls to the upper end surface of the recording medium by its own weight, it continues to cover at least a part of the upper end surface of the recording medium loaded on the stacking tray 305.

  Further, since the movable antenna 1101 includes the roller 1106, the distance determined by the diameter of the roller 1106 is kept between the upper end surface of the recording medium regardless of the amount of the recording medium.

  In other words, since the movable antenna 1101 has the roller 1106, the positional relationship substantially parallel to the upper end surface of the recording medium is maintained by the distance determined by the diameter of the roller 1106 regardless of the amount of the recording medium.

  FIG. 15 is a diagram illustrating a movable antenna 1501 according to another embodiment. In FIG. 15, the cable connecting the movable antenna 1501 and the reader / writer 120 is not shown.

  The configurations of the antenna 121 and the shield 311C of the movable antenna 1501 are the same as the configurations of the antenna 121 and the shield 311C of the movable antenna 311.

  The movable antenna 1501 is different from the movable antenna 311 in that the movable antenna 1501 is pivotally locked by a pivotable support arm 1506.

  The movable antenna 1501 is supported by two instruction arms 1506. One end of the indicating arm 1506 is supported by the casing 301 and the other end is supported by the indicating wall 1601 by a fulcrum 1508 so as to be rotatable.

  The antenna 121 and the shield 311C are locked to the other end of the instruction arm 1506 by a fulcrum 1507 so as to be rotatable.

  FIG. 16 to FIG. 18 are diagrams showing the displacement of the movable antenna 1501 accompanying the change in the amount of the recording medium.

  As shown in FIGS. 16 to 18, the image forming apparatus 1 drives the tray lift 304 to raise the stacking tray 305 as the recording medium P decreases from the full state. The stacking tray 305 is rotated by a fulcrum upstream in the recording medium conveyance direction.

  However, since the movable antenna 1501 is pivotally locked to the pivotable instruction arm 1506, the movable antenna 1501 tilts following this tilt even if the upper end of the recording medium tilts.

  Since the movable antenna 1501 falls to the upper end surface of the recording medium by its own weight, it continues to cover at least a part of the upper end surface of the recording medium loaded on the stacking tray 305.

  Further, since the movable antenna 1501 includes the roller 1509, the distance determined by the diameter of the roller 1509 is kept between the upper surface of the recording medium regardless of the amount of the recording medium.

  That is, since the movable antenna 311 includes the roller 1509, the position of the movable antenna 311 is maintained substantially parallel to the upper end surface of the recording medium by a distance determined by the diameter of the roller 1509 regardless of the amount of the recording medium.

  As described above, the recording medium storage device 300 according to the present embodiment is arranged so as to cover at least a part of the stack tray 305 for stacking the recording medium and the upper end surface of the recording medium stacked on the stack tray 305. A movable antenna 311, a support unit that is installed on the movable antenna 311 and that displaces the movable antenna 311 following the inclination of the upper end surface of the recording medium, and a reader / writer 120 that communicates with the wireless tag of the recording medium. .

  The movable antenna 311 further includes an antenna 121 and a shield 311C that blocks radio waves radiated from the antenna 121 upstream of the antenna 121 in the recording medium conveyance direction.

  Accordingly, since the wireless tag 110 on the recording medium P can be read and written by one recording medium storage device 300, an image can be formed on a sheet-like label paper incorporating the wireless tag with less space, and the wireless tag can be read and written. There is an effect of becoming.

  Although several embodiments have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

121: Antenna 300: Recording medium storage device 311: Movable antenna 311C: Shield

Claims (11)

A loading tray for loading recording media;
A movable antenna having a plate-like shield for blocking radio waves and arranged to cover at least part of the upper surface of the recording medium loaded on the stacking tray;
A support portion for supporting the movable antenna so as to be substantially parallel to the upper surface of the recording medium;
A reader / writer that communicates with the wireless tag of the recording medium by an antenna included in the movable antenna;
A recording medium storage device comprising: The movable antenna is
The antenna;
The recording medium storage device according to claim 1, further comprising a shield that blocks radio waves radiated from the antenna upstream of the antenna in the recording medium conveyance direction. The movable antenna is
The recording medium storage device according to claim 2, further comprising a roller in contact with the recording medium. The antenna is
4. The recording medium storage device according to claim 3, wherein the recording medium storage device is a transmission line having a terminating resistor at an end. A stacking tray on which a recording medium is stacked and the inclination of the recording medium changes according to the increase or decrease of the recording medium, a movable antenna disposed so as to cover at least a part of the upper surface of the recording medium stacked on the stacking tray, and the movable The movable antenna includes a support unit that supports the antenna so as to follow a change in the inclination of the upper surface of the recording medium due to increase / decrease of the recording medium, and to displace the antenna while maintaining a constant distance from the upper surface of the recording medium. A reader / writer that communicates with the wireless tag of the recording medium by an antenna, and a recording medium storage device comprising:
A paper feeding unit for taking out the recording medium one by one from the recording medium storage device;
An image forming unit for forming an image on the recording medium taken out by the paper feeding unit;
An image forming apparatus comprising: The movable antenna is
The antenna;
The image forming apparatus according to claim 5, further comprising: a shield that blocks radio waves radiated from the antenna upstream of the antenna in a recording medium conveyance direction. The movable antenna is
The image forming apparatus according to claim 6, further comprising a roller in contact with the recording medium. The antenna is
The image forming apparatus according to claim 7, wherein the image forming apparatus is a transmission line having a terminating resistor at an end. The reader / writer is
The image forming apparatus according to claim 8, wherein the wireless tag of the recording medium communicates with the wireless tag when the wireless tag is positioned below the antenna. A recording medium having a wireless tag is loaded on a stacking tray whose inclination changes according to increase / decrease of the recording medium to be loaded, at a position near one of the edges from the center,
An antenna that radiates radio waves that communicate with the wireless tag and a movable antenna that is disposed upstream of the antenna in the recording medium conveyance direction and that shields radio waves radiated from the antenna follows the inclination of the upper surface of the recording medium. And displace it by the support part while keeping the distance from the recording medium constant,
A wireless tag recording method for communicating with the wireless tag when the wireless tag of the recording medium is positioned below the antenna by a reader / writer. A stacking tray on which recording media are stacked, and the inclination of the recording media changes according to the increase or decrease of the recording media;
A movable antenna arranged to cover at least a part of the upper surface of the recording medium loaded on the loading tray;
A support unit for supporting the movable antenna so as to be displaced while keeping a constant distance from the upper surface of the recording medium following a change in the inclination of the upper surface of the recording medium due to increase or decrease of the recording medium;
A reader / writer that communicates with the wireless tag of the recording medium by an antenna included in the movable antenna;
A recording medium storage device comprising:

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