Image forming apparatus

Abstract

This invention provides an image forming apparatus capable of suppressing failures in writing tag information to wireless tags. The image forming apparatus includes a transport unit, an antenna, a storage unit, and a control unit. The transport unit transports a printing medium to which a wireless tag is attached. The antenna radiates radio waves into a radiating region in the transport path through which the printing medium passes. The storage unit stores polarization wave direction information, representing the polarization wave direction of the radio waves, according to each type of printing medium. The control unit controls the antenna to radiate polarized waves into the radiating region as radio wave radiation, and writes tag information to the wireless tag within the radiating region. The control unit determines the type of printing medium, reads the polarization wave direction information corresponding to the determined type of printing medium from the storage unit, and changes the polarization wave direction of the polarized waves radiated from the antenna based on the read polarization wave direction information.

Description

Technical Field

[0001] Embodiments of the present invention relate to an image forming apparatus. Background Technology

[0002] Previously, it was known that image forming apparatuses could write tag information onto RFID tags during the transport of printed media with RFID (Radio Frequency Identification) tags. Summary of the Invention

[0003] Here, the image forming apparatus described in Patent Document 1 radiates radio waves onto the printing medium within a defined radiating area located in the region along the path through which the printing medium passes, and writes tag information to an RFID tag attached to the printing medium. However, within the radiating area, the gain of the antenna of the RFID tag attached to the printing medium includes a high-gain region (higher than desired) and a low-gain region (lower than desired). Therefore, the image forming apparatus sometimes fails to write tag information during the period when the printing medium passes through the radiating area. Furthermore, this problem can be solved by increasing the number of antennas radiating radio waves. However, increasing the number of antennas radiating radio waves increases the manufacturing cost of the image forming apparatus, and is therefore not preferred.

[0004] The problem to be solved by the present invention is to provide an image forming apparatus that can suppress the failure of writing tag information to wireless tags.

[0005] The image forming apparatus of this embodiment includes a transport unit, an antenna, a storage unit, and a control unit. The transport unit transports a printed medium with one or more wireless tags attached. The antenna radiates radio waves into a predetermined radiation area in the transport path through which the printed medium passes. The storage unit stores polarization direction information representing the polarization direction of the radio waves for each type of printed medium. The control unit controls the antenna to radiate polarized waves into the radiation area as radio wave radiation, and writes tag information to each of the one or more wireless tags within the radiation area. The control unit determines the type of printed medium, reads the polarization direction information corresponding to the determined type of printed medium from the storage unit, and changes the polarization direction of the polarized waves radiated from the antenna based on the read polarization direction information. Attached Figure Description

[0006] Figure 1 This is a diagram illustrating an example of the configuration of the image forming apparatus 1 according to an embodiment.

[0007] Figure 2This is a diagram illustrating an example of the distribution of high-gain and low-gain regions within the radiation region RA when the image forming apparatus 1 radiates a horizontally polarized wave into the radiation region RA.

[0008] Figure 3 This is a diagram illustrating an example of the distribution of high-gain and low-gain regions within the radiation region RA when the image forming apparatus 1 radiates a vertically polarized wave into the radiation region RA.

[0009] Figure 4 This is a diagram showing an example of the positions of two wireless tags attached to the surface of a first printed medium.

[0010] Figure 5 This is a diagram showing an example of the functional configuration of the control unit 110.

[0011] Figure 6 This diagram illustrates an example of the processing flow of the image forming apparatus 1 writing tag information to a wireless tag.

[0012] Figure 7 This is an example of an operation image showing the image forming apparatus 1 accepting the user's selection of the type of printing medium.

[0013] Explanation of reference numerals in the attached figures

[0014] 1…Image forming apparatus; 11…Printer unit; 12…Control panel; 13…Wireless tag communication device; 110…Control unit; 1101…Arithmetic unit; 1102…Storage device; 1103…Data receiving unit; 1104…Image data unfolding unit; 111…Paper tray; 112…Paper tray; 114…Image forming unit; 131…Antenna; AD…Fixing device; 20…Intermediate transfer belt; DF…Double-sided printing device; PA…Merging path; PB…Branch; PRA…First Printing media; PRB…Second printing media; 21…Driven roller; 22…Support roller; 23…Secondary transfer roller; 24…Registration roller; 25…Manual paper feed roller; RA…Radiation zone; 31, 32, 33, 34…Image forming station; 311…Photosensitive drum; 312…Powered charger; 313…Exposure scanning head; 314…Developing unit; 315…Photosensitive cleaner; 316…Primary transfer roller; TA…Panel; TB…Paper discharge tray; TGA…Wireless tag; TGB…Wireless tag. Detailed Implementation

[0015] The image forming apparatus of the embodiments will be described with reference to the accompanying drawings. In each drawing, the same reference numerals are used to label the same components. As an example of the image forming apparatus of the embodiments, image forming apparatus 1 will be described as an example.

[0016] (Composition of an image forming apparatus)

[0017] Reference Figure 1 The configuration of the image forming apparatus 1 will be described. Figure 1 This is a diagram illustrating an example of the configuration of the image forming apparatus 1 according to an embodiment.

[0018] Image forming apparatus 1 is an apparatus for forming images on a printing medium, such as a multifunction printer, copier, or printer. The printing medium is the medium on which the image forming apparatus 1 performs image forming and other processing. The printing medium can be any medium, if it is a sheet-like medium capable of forming an image on at least one of its two sides. For example, the printing medium is printing paper, plastic film, etc.

[0019] The image forming apparatus 1 determines the type of printed medium that the user intends to process based on the operation received from the user. The printed medium is classified according to its size, thickness, material, and the presence or absence of a wireless tag. A printed medium with a wireless tag is a printed medium with one or more wireless tags attached. A printed medium without a wireless tag is a printed medium without a wireless tag attached. Printed media with wireless tags are further classified according to the positions of the one or more wireless tags attached to the printed medium. The position of a wireless tag on a printed medium with a specific wireless tag is indicated, for example, by information indicating the area occupied by the wireless tag in at least one of the surface and back surfaces of the printed medium. Alternatively, the position may be indicated by other information that indicates the position of the wireless tag in at least one of the surface and back surfaces of the printed medium.

[0020] Wireless tags, such as RFID (Radio Frequency Identification) tags, are not limited to this. Wireless tags have a shape with a major axis and a minor axis on the surface or back of the printed medium to which they are attached. Given the same wavelength of radio waves, wireless tags interact more strongly with polarized waves whose polarization plane is parallel to the major axis than with polarized waves whose polarization plane is perpendicular to the major axis. Stronger interaction means that the probability of radio waves passing through the wireless tag is low, and the probability of radio waves reaching the wireless tag being absorbed or reflected by the tag is high.

[0021] Image forming apparatus 1 forms an image on a pre-determined type of print medium according to an operation received from a user. For example, if the pre-determined type of print medium is a first print medium PRA, image forming apparatus 1 forms an image on the first print medium PRA according to the operation. In this example, the first print medium PRA is A4-sized plain paper and is a print medium with two wireless tags. On the other hand, for example, if the pre-determined type of print medium is a second print medium PRB, image forming apparatus 1 forms an image on the second print medium PRB according to the operation. In this example, the second print medium PRB is A4-sized thick paper and is a print medium without wireless tags.

[0022] Based on an operation received from a user, if the predetermined type of print medium is a print medium with RFID tags, the image forming apparatus 1 writes tag information to one or more RFID tags attached to the print medium. For example, if the predetermined type of print medium is a first print medium PRA, the image forming apparatus 1 writes tag information to two RFID tags attached to the first print medium PRA according to this operation.

[0023] In order to write tag information to a wireless tag, the image forming apparatus 1 includes an antenna that radiates radio waves to a predetermined radiating region RA in a region along a path through which a printing medium passes. The image forming apparatus 1 causes the antenna to radiate polarized waves into the radiating region RA as the radiation of radio waves to the radiating region RA. However, the radiating region RA includes a high-gain region where the gain of the antenna of the wireless tag attached to the printing medium is higher than the desired gain, and a low-gain region where the gain of the antenna is lower than the desired gain.

[0024] like Figure 2 and Figure 3 As shown, the distribution of high-gain and low-gain regions within the radiation region RA varies according to the polarization wave direction of the polarization wave emitted from the image forming apparatus 1.

[0025] Figure 2 This is a diagram illustrating an example of the distribution of high-gain and low-gain regions within the radiation region RA when the image forming apparatus 1 radiates a horizontally polarized wave into the radiation region RA. Figure 2 In the diagram, region HA within the radiation region RA represents an example of a high-gain region in this case. A region within the radiation region RA marked with the same shaded line as region HA also represents an example of a high-gain region in this case. Figure 2In the diagram, region HB within the radiation region RA represents an example of a low-gain region in this case. A region within the radiation region RA marked with the same shaded line as region HB also represents an example of a low-gain region in this case. Figure 2 The arrow AA indicates the positive direction of the printing medium as it passes through the radiation zone RA, i.e., the direction of medium transport. For example... Figure 2 As shown, the high-gain region in this case extends in a direction orthogonal to the transport direction of the printing medium.

[0026] Figure 3 This is a diagram illustrating an example of the distribution of high-gain and low-gain regions within the radiation region RA when the image forming apparatus 1 radiates a vertically polarized wave into the radiation region RA. Figure 3 In the diagram, region HC within the radiation region RA represents an example of a high-gain region in this case. A region within the radiation region RA marked with the same shaded line as region HC also represents an example of a high-gain region in this case. Figure 3 In the diagram, region HD within the radiation region RA represents an example of a low-gain region in this case. A region within the radiation region RA marked with the same shaded line as region HD also represents an example of a low-gain region in this case. For example... Figure 3 As shown, in this case, the high-gain region extends in the transport direction of the printing medium.

[0027] like Figure 2 and Figure 3 As shown, the distribution of high-gain and low-gain regions within the radiation region RA varies according to the polarization wave direction of the polarization wave emitted from the image forming apparatus 1.

[0028] The location of the RFID tag on printed media varies depending on the type of printed media. For example, such as... Figure 4 As shown, the two wireless tags attached to the first printing medium are respectively attached to the surface of the first printing medium. Figure 4 This is a diagram showing an example of the positions of two wireless tags attached to the surface of a first printed medium. Figure 4 Arrow AB indicates the transport direction of the first printing medium PRA in the image forming apparatus 1. For example... Figure 4 As shown, the first printed media PRA has two labels. One of these two labels is... Figure 4 The label shown is LBA. The other of these two labels is... Figure 4 The label LBB is shown.

[0029] A Label LBA is, for example, an item label used to identify items stored in a turnover box affixed with a first printed media PRA. The Label LBA may also be replaced by other labels. The Label LBA is accompanied by a Wireless Tag TGA. The Wireless Tag TGA is an example of one of the two wireless tags affixed to the first printed media PRA. Figure 4 The wireless tag TGA shown is rectangular, but it can also be other shapes with a major axis and a minor axis. The tag LBA is attached to the first printed media PRA with the major axis of the wireless tag TGA horizontal relative to the transport direction.

[0030] The label LBB is, for example, a turnover box label used to identify a turnover box to which a first printed media PRA is attached. The label LBB may also be replaced by other labels instead of turnover box labels. The label LBB is attached to a wireless tag TGB. The wireless tag TGB is one of two wireless tags attached to the first printed media PRA. The wireless tag TGB is rectangular in shape, but may also be other shapes with a major axis and a minor axis. The label LBB is attached to the first printed media PRA such that the long side of the wireless tag TGB is orthogonal to the transport direction.

[0031] When writing tag information to a RFID tag TGA, the image forming apparatus 1 can reduce the possibility of tag information writing failure by radiating a vertically polarized wave. This is because, as mentioned earlier, the RFID tag interacts more strongly with a polarized wave whose polarization plane is parallel to the long axis than with a polarized wave whose polarization plane is perpendicular to the long axis. On the other hand, when writing tag information to a RFID tag TGB, the possibility of tag information writing failure is lower when the image forming apparatus 1 uses a horizontally polarized wave. Therefore, by varying the polarization direction of the radiated polarized wave according to the type of printing medium containing the RFID tag, failures in writing tag information to the RFID tag can be suppressed.

[0032] The image forming apparatus 1 determines the type of printing medium and, based on the polarization wave direction information corresponding to the determined type of printing medium, changes the polarization wave direction of the polarized wave emitted from the antenna. The polarization wave direction information indicates the polarization wave direction of the radio wave. Therefore, the image forming apparatus 1 can suppress failures in writing tag information to the wireless tag. As an example, the case where the image forming apparatus 1 changes the polarization wave direction of a linearly polarized wave according to the type of printing medium with the wireless tag will be explained. That is, in this example, the image forming apparatus 1 switches the emitted polarized wave to either a horizontally polarized wave or a vertically polarized wave according to the type. The image forming apparatus 1 can also be configured to change the polarization wave direction of a circularly polarized wave according to the type. The image forming apparatus 1 can also be configured to switch between linearly polarized waves and circularly polarized waves according to the type, thereby changing the polarization wave direction of the radio wave. The image forming apparatus 1 can also be configured to change the polarization wave direction of the radio wave according to the type and by other methods.

[0033] The polarization direction information can be any information that represents the polarization direction of a radio wave. For example, a certain polarization direction information could be a code that causes the control unit 110 to perform a process that aligns the polarization direction of the polarized wave emitted from the antenna 131 with the polarization direction indicated by the polarization direction information. In this case, the control unit 110 aligns the polarization direction of the polarized wave emitted from the antenna 131 with the polarization direction indicated by the polarization direction information based on this code. For example, the polarization direction information could be information indicating a first power supply point or a second power supply point of the antenna 131. In this case, the control unit 110 aligns the polarization direction of the polarized wave emitted from the antenna 131 with the polarization direction indicated by the polarization direction information based on this information. For example, the polarization direction information could be an ID (Identification) corresponding to the polarization direction. In this case, the control unit 110 stores the information corresponding to the ID and the polarization direction, aligning the polarization direction of the polarized wave emitted from the antenna 131 with the polarization direction corresponding to the ID. For example, the polarization wave direction information could be tag location information corresponding to that polarization wave direction. Tag location information indicates the location of one or more wireless tags attached to a printed medium containing wireless tags. In this case, the control unit 110 stores information corresponding to the tag location information and the polarization wave direction, ensuring that the polarization wave direction of the polarization wave emitted from the antenna 131 is aligned with the polarization wave direction corresponding to the tag location information.

[0034] Image forming apparatus 1 may include, for example, a printer unit 11, a control panel 12, a wireless tag communication device 13, a manual tray TA, and a paper output tray TB. Image forming apparatus 1 may also be configured to include other components and devices in addition to the printer unit 11, control panel 12, wireless tag communication device 13, manual tray TA, and paper output tray TB.

[0035] The printer unit 11 includes a control unit 110, a paper tray 111, a paper tray 112, and an image forming unit 114.

[0036] The control unit 110 controls the entire image forming apparatus 1. In other words, the control unit 110 controls the printer unit 11, the control panel 12, the wireless tag communication device 13, and the image forming unit 114 respectively.

[0037] The paper tray 111 stores the type of printing media desired by the user. As an example, the case where the first printing medium, PRA, is stored in the paper tray 111 will be described.

[0038] The paper feed tray 112 stores the type of printing media desired by the user. As an example, the case where a second printing medium, PRB, is stored in the paper feed tray 112 will be described.

[0039] The control panel 12 has an operation reception section and a display section.

[0040] The operation receiving unit receives operations from the user. The operation receiving unit is an input device, such as a touchpad or input keys. The operation receiving unit outputs information indicating the operation received from the user to the control unit 110.

[0041] The display unit displays an image corresponding to the operation received by the operation receiving unit. The display unit is an image display device, such as a liquid crystal display (LCD) or an organic EL (Electroluminescence) display. Alternatively, the display unit may be integrated with the operation receiving unit as a touch panel.

[0042] The image forming unit 114 performs the transport of the printing medium and the formation of an image on the printing medium based on the control from the control unit 110. For ease of explanation, the formation of an image on the printing medium will be referred to as printing. The configuration of the image forming unit 114 will be described later.

[0043] The wireless tag communication device 13 includes an antenna 131, which emits radio waves into a predetermined radiation area RA in the area along the transport path through which the printing medium passes via the image forming unit 114.

[0044] Antenna 131 is an example of the aforementioned antenna. Antenna 131 is, for example, a single antenna for radiating radio waves in the radiation region RA. In this case, the image forming apparatus 1 can suppress the increase in manufacturing costs compared to the case where antenna 131 is composed of multiple antennas. That is, by having this single antenna as antenna 131, the image forming apparatus 1 can not only suppress the increase in manufacturing costs but also suppress the failure to write tag information to the wireless tag. Antenna 131 can also be composed of multiple antennas.

[0045] Antenna 131 has two power supply points: a first power supply point and a second power supply point. When power is supplied to the first power supply point, antenna 131 emits a first polarized wave. When power is supplied to the second power supply point, antenna 131 emits a second polarized wave. Antenna 131 may also be configured with only one power supply point. Antenna 131 may also be configured with three or more power supply points. Figure 1 The direction indicated by arrow k represents an example of the direction in which antenna 131 radiates a first polarized wave or a second polarized wave.

[0046] The first polarized wave and the second polarized wave are polarized waves with different polarization directions. As an example, the case where the first polarized wave is vertically polarized and the second polarized wave is horizontally polarized will be described. In this case, both the first and second polarized waves are linearly polarized waves. That is, in this example, antenna 131 radiates linearly polarized waves to the radiation region RA. At least one of the first and second polarized waves can also be other types of polarized waves, such as circularly polarized waves. However, when both the first and second polarized waves are linearly polarized waves, the image forming apparatus 1 can locally radiate polarized waves from antenna 131. As a result, the image forming apparatus 1 can reduce the possibility of conflicts with radio frequency bands in multiple countries.

[0047] The wireless tag communication device 13, under control from the control unit 110, causes the antenna 131 to radiate either a first polarized wave or a second polarized wave. Thus, the wireless tag communication device 13 can write tag information to one or more wireless tags attached to a printed medium containing a wireless tag. The method for writing tag information to the wireless tag can be either a known method or a method to be developed in the future. Therefore, the description of the method for writing tag information to the wireless tag is omitted.

[0048] (The composition of an image forming unit)

[0049] The configuration of the image forming unit 114 will be described below.

[0050] The image forming unit 114 includes an intermediate transfer belt 20. The image forming unit 114 includes a driven roller 21, a support roller 22, a secondary transfer roller 23, two registration rollers 24, and a manual paper feed roller 25. The image forming unit 114 includes four image forming stations: image forming station 31, image forming station 32, image forming station 33, and image forming station 34. The image forming unit 114 includes a fixing device AD ​​and a duplex printing device DF.

[0051] The intermediate transfer belt 20 is a belt that transfers toner images in one pass through four sets of image forming stations. The intermediate transfer belt 20 is supported by driven roller 21 and support roller 22, etc. The intermediate transfer belt 20... Figure 1 The image forming unit 114 rotates the intermediate transfer belt 20 in that direction according to the control from the control unit 110 via a motor (not shown).

[0052] Image forming station 31 is an image forming station for forming Y (yellow) images. Image forming station 32 is an image forming station for forming M (magenta) images. Image forming station 33 is an image forming station for forming C (cyan) images. Image forming station 34 is an image forming station for forming K (black) images. In image forming unit 114, these four sets of image forming stations are arranged on the underside of intermediate transfer belt 20 along the rotation direction of intermediate transfer belt 20.

[0053] Image forming station 31 includes a photosensitive drum 311, a charged charger 312, an exposure scanning head 313, a developing unit 314, a photoreceptor cleaner 315, and a primary transfer roller 316. In image forming station 31, the charged charger 312, the exposure scanning head 313, the developing unit 314, the photoreceptor cleaner 315, and the primary transfer roller 316 are arranged along... Figure 1 The photosensitive drum 311 rotates in the direction indicated by arrow n. A primary transfer roller 316 is positioned opposite the photosensitive drum 311 via an intermediate transfer belt 20.

[0054] Image forming stations 32, 33, and 34 are each configured in the same way as image forming station 31. Therefore, the following description of the configuration of each of image forming stations 32, 33, and 34 will be omitted.

[0055] The secondary transfer roller 23 is positioned opposite the support roller 22 via the intermediate transfer belt 20. The secondary transfer roller 23 transfers the toner that was initially transferred to the intermediate transfer belt 20 to the printing medium passing between the secondary transfer roller 23 and the intermediate transfer belt 20 for a secondary transfer.

[0056] The two registration rollers 24 transport the printing media taken out from the paper feed box 111, paper feed box 112, and manual tray TA respectively through a conveying mechanism (not shown) to the space between the secondary transfer roller 23 and the intermediate transfer belt 20.

[0057] The manual feed roller 25 removes the printing media from the manual tray TA and feeds it to the two registration rollers 24.

[0058] The fixing device AD ​​is a device that fixes the toner image onto the printing medium after the toner image has been transferred a second time by the secondary transfer roller 23. More specifically, the fixing device AD ​​fixes the toner image that has been transferred a second time onto the printing medium while conveying the printing medium through the roller. As a result, an image is formed on the printing medium.

[0059] The double-sided printing apparatus DF is a device that transports the printing medium, after an image has been formed on the surface by the fixing device AD, to two registration rollers 24. The printing medium, after its surface and back sides have been flipped, is transported to the double-sided printing apparatus DF. Therefore, the printing medium, transported between the two registration rollers 24 via the double-sided printing apparatus DF, forms an image on the back side via the secondary transfer roller 23 and the fixing device AD.

[0060] (The action of the image forming unit)

[0061] The operation of the image forming unit 114 will be described below.

[0062] First, the actions of the image forming station 31 will be used as an example to explain the actions of the four image forming stations.

[0063] After the image forming station 31 charges the photosensitive drum 311 via the charged charger 312, it exposes the image via the exposure scanning head 313. This forms an electrostatic latent image on the photosensitive drum 311. The image forming station 31 then develops the electrostatic latent image on the photosensitive drum 311 into the developing apparatus 314. The developing apparatus 314 develops the electrostatic latent image on the photosensitive drum 311 as a toner image using a two-component developer composed of toner and carrier. A primary transfer roller 316 transfers the toner image thus formed on the photosensitive drum 311 to the intermediate transfer belt 20 in a single transfer. After this primary transfer, a photoreceptor cleaner 315 removes any remaining toner from the photosensitive drum 311.

[0064] Image forming stations 31, 32, 33, and 34 each form a color toner image on the intermediate transfer belt 20 via a primary transfer roller 316. The color toner image is formed by sequentially overlapping toner images of Y (yellow), M (magenta), C (cyan), and K (black).

[0065] Next, the operation of the secondary transfer roller 23 will be explained. The secondary transfer roller 23 transfers the color toner image from the intermediate transfer belt 20 to the printing medium passing between the secondary transfer roller 23 and the intermediate transfer belt 20. In the following description, "toner image" can refer to either a color toner image or a monochrome toner image. The toner image can also be a toner image using a neutralizing toner.

[0066] Next, the operation of conveying the printing medium in the operation of the image forming unit 114 will be described.

[0067] At the clamping section of the two registration rollers 24, the printing media taken from the paper tray 111, paper tray 112, and manual tray TA respectively by a conveying mechanism (not shown) are bent. This aligns the top edges of the printing media. Then, the two registration rollers 24 convey the printing media between the secondary transfer roller 23 and the intermediate transfer belt 20 according to the moment when the image forming unit 114 transfers the toner image onto the printing media. The conveying path up to the two registration rollers 24 from the printing media taken from the paper tray 111, paper tray 112, and manual tray TA is as follows: Figure 1 The confluence section PA shown is a confluence point.

[0068] Within the image forming unit 114, three transport paths—LA, LB, and LC—are formed by two registration rollers 24, a fixing unit AD, and multiple rollers within the double-sided printing unit DF. Transport path LA runs from the confluence section PA to... Figure 1 The diagram shows the conveyor path for branch section PB. Conveyor path LB is the conveyor path within the double-sided printing unit DF, and it is the conveyor path from branch section PB to confluence section PA. Conveyor path LC is the conveyor path from branch section PB to the paper discharge tray TB.

[0069] Two registration rollers 24 begin to rotate in accordance with the position of the toner image on the rotating intermediate transfer belt 20, moving the printing medium to the position of the secondary transfer roller 23. Thus, the toner image formed on the intermediate transfer belt 20 is transferred a second time onto the printing medium by the secondary transfer roller 23. After the toner image is transferred a second time onto the printing medium, the secondary transfer roller 23 conveys the printing medium along the transport path LA to the fixing unit AD. The fixing unit AD, while conveying the printing medium, fixes the toner image transferred a second time onto the printing medium conveyed from the secondary transfer roller 23 onto the printing medium. Thus, the secondary transferred toner image is formed as an image on the printing medium. After the image is formed on the printing medium, the fixing unit AD conveys the printing medium to the transport path LC. Then, the printing medium conveyed to the transport path LC is discharged by a roller (not shown).

[0070] In the case of double-sided printing, after the image is formed on the surface, the entire printing medium passes through the branch section PB, and a roller (not shown) conveys the printing medium to the transport path LB via a switch assembly. This flips the surface and back of the printing medium. Then, multiple rollers within the double-sided printing unit DF convey the printing medium along the transport path LB to the clamping section of two registration rollers 24. The printing medium, with its surface and back flipped, is then conveyed along the transport path LA via the two registration rollers 24, and the toner image is fixed by the fixing unit AD. This forms an image on the back of the printing medium. The fixing unit AD then conveys the printing medium with the image formed on the back to the transport path LC for paper output.

[0071] Thus, the secondary transfer roller 23, the two registration rollers 24, the fixing device AD, and the various rollers in the double-sided printing device DF constitute the transport section for transporting the printing medium in the image forming apparatus 1.

[0072] (Location of the radiation zone along the transport route)

[0073] The location of the radiation zone RA on the transport path LA is explained. The proportion of the high-gain region within the radiation zone RA varies depending on which region on the transport path LA is designated as the radiation zone RA.

[0074] exist Figure 1 In the example shown, the radial region RA is the area on the transport path LA located upstream of the two registration rollers 24. This is because when the radial region RA is defined as the area on the transport path LA located downstream of the two registration rollers 24, the proportion of high-gain region within the radial region RA tends to decrease. That is, by defining the area on the transport path LA located upstream of the two registration rollers 24 as the radial region RA, the image forming apparatus 1 can increase the proportion of high-gain region within the radial region RA. As a result, the image forming apparatus 1 can more reliably suppress failures in writing tag information to the wireless tag.

[0075] exist Figure 1In the example shown, the radiation region RA is the area located above the manual feed roller 25 when viewed from the antenna 131 in a direction orthogonal to the direction of gravity along the transport path LA. The manual tray TA is usually located above the feed cassettes 111 and 112. Therefore, the printing medium placed on the manual tray TA is sometimes exposed to radio waves emitted from the antenna 131. In this case, when a printing medium with a wireless tag is placed on the manual tray TA, unexpected tag information may sometimes be written to the wireless tag. When the area located above the manual feed roller 25 when viewed from the radiation direction along the transport path LA is the radiation region RA, the image forming apparatus 1 can suppress the writing of unexpected tag information to the wireless tag.

[0076] Furthermore, the radial zone RA can also be a region on the transport path LA located downstream of the two registration rollers 24. The radial zone RA can also be a region that partially or completely overlaps with the two registration rollers 24 when viewed in the radial direction of the transport path LA. In this case, the radial zone RA can also be a region located lower than the manual feed roller 25. In this case, the radial zone RA can also be a region that partially or completely overlaps with the manual feed roller 25.

[0077] (Functional Composition of the Control Department)

[0078] Next, refer to Figure 5 The functional structure of the control unit 110 will be explained. Figure 5 This is a diagram showing an example of the functional configuration of the control unit 110.

[0079] like Figure 5 As shown, the control unit 110 is connected to the printer unit 11, the control panel 12, and the wireless tag communication device 13 respectively. The control unit 110 includes a computing unit 1101, a storage unit 1102, a data receiving unit 1103, and an image data unfolding unit 1104.

[0080] The arithmetic unit 1101 is, for example, a CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit). The arithmetic unit 1101 controls the printer unit 11, the control panel 12, and the wireless tag communication device 13 according to the image processing program stored in the storage device 1102. The control unit 110 outputs, for example, transport start information indicating that transport of the printing medium has begun.

[0081] Storage device 1102 can be ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), etc. Storage device 1102 may be separate from the control unit 110. Storage device 1102 is an example of a storage unit.

[0082] The data receiving unit 1103 receives printing data (e.g., data described in a page description language) representing printed images from a host computer such as a PC (Personal Computer), and stores the received printing data in the storage device 1102.

[0083] The image data unfolding unit 1104 determines the printing conditions from the printing data stored in the storage device 1102 by the data receiving unit 1103, thereby unfolding it into data (e.g., raster data, etc.) that the printer unit 11 can print, and storing it in the storage device 1102.

[0084] (Processing of writing tag information to a wireless tag by an image forming apparatus)

[0085] Reference Figure 6 The process of writing tag information to the wireless tag by the image forming apparatus 1 is explained. Figure 6 This diagram illustrates an example of the processing flow of the image forming apparatus 1 writing tag information to a wireless tag.

[0086] As an example, we will explain the case where the polarization wave direction information is the tag position information. As an example, we will explain the case where the following processes (1) to (5) were performed before the start of processing. Figure 6 The flowchart shown illustrates the processing. The time before processing begins is earlier than the time before... Figure 6 The processing time of ACT101 shown is at the earlier stage.

[0087] (1) The image forming apparatus 1 receives image data of an image to be printed onto a printing medium.

[0088] (2) The image forming apparatus 1 accepts the operation of selecting the type of printing medium via the control panel 12.

[0089] (3) The image forming apparatus 1 accepts the operation of starting to write tag information to the wireless tag.

[0090] (4) Tag location information is pre-stored in storage device 1102 for each type of printing medium.

[0091] (5) Printing media information is pre-stored in storage device 1102 according to each type of printing media.

[0092] Printing media information refers to information related to the printing media, such as the size and thickness of the printing media. Printing media information can also include label position information. In other words, printing media information can also include polarization wave direction information.

[0093] The control unit 110 determines the type of printing medium selected by the user (ACT101) based on the operation received in advance via the control panel 12. As an example, the case where the type of printing medium determined in ACT101 is the first printing medium PRA will be explained.

[0094] Based on the type of printing medium determined in ACT101, control unit 110 determines tag location information (ACT102) for one or more wireless tags attached to that type of printing medium. At this time, control unit 110 determines the tag location information for one or more wireless tags attached to that type of printing medium from a plurality of tag location information pre-stored in storage device 1102. In this example, as mentioned above, the type of printing medium is a first printing medium PRA. In this case, control unit 110 determines the tag location information indicating the respective locations of wireless tags TGA and TGB attached to the first printing medium PRA from a plurality of tag location information pre-stored in storage device 1102. The tag location information indicating the location of wireless tag TGA can be any information indicating the location of wireless tag TGA. This tag location information can, for example, be information representing the location using coordinates on the surface of the first printing medium PRA. This tag location information can also be, for example, a code corresponding to the location based on a pre-determined rule. The tag location information indicating the location of the wireless tag TGB only needs to be information indicating the location of the wireless tag TGB, and can be any kind of information. This tag location information can be, for example, information representing the location using coordinates on the surface of the first printed media PRA. This tag location information can also be, for example, a code corresponding to the location based on a predetermined rule.

[0095] The control unit 110 determines printing media information (ACT103) related to the type of printing media determined in ACT101. At this time, the control unit 110 determines the printing media information related to that type of printing media from among multiple types of printing media information pre-stored in the storage device 1102. In this example, as mentioned above, the type of printing media is the first printing media PRA. In this case, the control unit 110 determines the printing media information related to the first printing media PRA from among multiple types of printing media information pre-stored in the storage device 1102. The processing of ACT103 can be performed by the control unit 110 in parallel with the processing of ACT102, or by the control unit 110 in the reverse order of the processing of ACT102.

[0096] The control unit 110 determines the parameters involved in the transport of the printing medium based on the printing medium information determined by ACT 103. These parameters include transport speed, etc. Based on these determined parameters, the control unit 110 controls the image forming unit 114 to begin transporting the printing medium (ACT 104). In this example, these parameters are those involved in transporting the first printing medium PRA. Therefore, in ACT 104, the control unit 110 controls the image forming unit 114 based on these parameters to begin transporting the first printing medium PRA.

[0097] Control unit 110 starts timing (ACT105) the elapsed time since the commencement of printing media transport via ACT104. Control unit 110 determines the moment when printing media transport begins via ACT104 as the moment a signal initiating printing media transport is output. Control unit 110 may also determine the moment when printing media transport begins via ACT104 using other methods. For example, control unit 110 may determine this moment based on the outputs of one or more position sensors detecting the position of the printing media on transport path LA. For example, control unit 110 may determine this moment based on a combination of the moment the signal was output and the outputs from one or more position sensors.

[0098] The control unit 110 remains in standby mode based on the elapsed time since the start of timing in ACT105 until a predetermined first time has elapsed since the commencement of printing medium transport in ACT104 (ACT106). The first time is the time from the start of transport until the wireless tag TGA begins to pass through the radiation zone RA. In ACT106, the control unit 110 determines the first time based on the type of printing medium determined in ACT101 and first correspondence information pre-stored in the storage device 1102. The first correspondence information is information that corresponds at least a portion of the parameters determined in ACT103 to the first time for each type of printing medium. For example, the first correspondence information is information that corresponds the transport speed included in the parameter to the first time for each type of printing medium. The control unit 110 may also calculate the first time in ACT106 based on the type of printing medium and the first correspondence information. In this case, the control unit 110 may, for example, use the distance of transporting the printing medium for the calculation of the first time. The control unit 110 may also detect the commencement of the wireless tag TGA passing through the radiation zone RA in ACT106 based on the output from one or more of the aforementioned position sensors. In this scenario, in ACT106, the control unit 110 determines whether the radio tag TGA has begun to pass through the radiation zone RA. Alternatively, the control unit 110 may detect the radio tag TGA beginning to pass through the radiation zone RA in ACT106 based on the elapsed time and outputs from one or more position sensors. In this case, the control unit 110 also determines whether the radio tag TGA has begun to pass through the radiation zone RA in ACT106.

[0099] When the control unit 110 determines that a first time has elapsed since the start of printing medium transport via ACT 104 (ACT 106 - YES), it writes tag information to the radio tag TGA (ACT 107). More specifically, in ACT 107, the control unit 110 determines the polarization wave direction corresponding to the tag position information indicating the location of the radio tag TGA. This tag position information is one of the two tag position information determined in ACT 102. The control unit 110 aligns the polarization wave direction of the polarization wave emitted from the antenna 131 with the determined polarization wave direction. The polarization wave direction determined by the control unit 110 is a vertical direction. That is, in ACT 107, the control unit 110 causes the antenna 131 to emit a vertically polarized wave based on the tag position information indicating the location of the radio tag TGA, and writes tag information to the radio tag TGA using the vertically polarized wave.

[0100] The control unit 110 remains in standby mode based on the elapsed time since the start of timing in ACT105 until a predetermined second time (ACT108) has elapsed since the commencement of printing medium transport in ACT104. The second time is longer than the first time. The second time is the time from the start of transport until the radio tag TGB begins to pass through the radiation zone RA. In ACT108, the control unit 110 determines the second time based on the type of printing medium determined in ACT101 and second correspondence information pre-stored in the storage device 1102. The second correspondence information corresponds at least a portion of the parameters determined in ACT103 to the second time for each type of printing medium. For example, the second correspondence information corresponds the transport speed included in the parameter to the second time for each type of printing medium. Alternatively, the control unit 110 may calculate the second time in ACT108 based on the type of printing medium and the second correspondence information. In this case, the control unit 110 may use, for example, the distance the printing medium is transported for the calculation of the second time. The control unit 110 may also detect the start of the radio tag TGB passing through the radiation zone RA in ACT 108 based on the outputs from one or more of the aforementioned position sensors. In this case, in ACT 108, the control unit 110 determines whether the start of the radio tag TGB passing through the radiation zone RA has been detected. Alternatively, the control unit 110 may detect the start of the radio tag TGB passing through the radiation zone RA in ACT 108 based on the elapsed time and the outputs from one or more position sensors. In this case, the control unit 110 also determines whether the start of the radio tag TGB passing through the radiation zone RA has been detected in ACT 108.

[0101] When the control unit 110 determines that a second time has elapsed since the start of the printing medium transport via ACT108 (ACT108-YES), it performs tag information writing to the radio tag TGB (ACT109). More specifically, in ACT109, the control unit 110 determines the polarization wave direction corresponding to the tag position information indicating the location of the radio tag TGB. This tag position information is the remaining one of the two tag position information determined in ACT102. The control unit 110 aligns the polarization wave direction of the polarization wave emitted from the antenna 131 with the determined polarization wave direction. The polarization wave direction determined by the control unit 110 is a horizontal direction. That is, in ACT109, the control unit 110 causes the antenna 131 to emit a horizontally polarized wave based on the tag position information indicating the location of the radio tag TGB, and performs tag information writing to the radio tag TGB via the horizontally polarized wave.

[0102] Control unit 110 terminates the elapsed time timing (ACT110) started in ACT105, and... Figure 6The process shown in the flowchart has ended.

[0103] exist Figure 6 In the flowchart shown, to make the process of writing tag information to the wireless tag clear, the processes related to the paper layout of the first printed media PRA and the process of forming an image on the first printed media PRA are omitted. When the first printed media PRA has a wireless tag TGA attached but does not have a wireless tag TGB attached, the processes ACT108 and ACT109 are omitted in this flowchart. When the first printed media PRA does not have a wireless tag TGA attached but does have a wireless tag TGB attached, the processes ACT106 and ACT107 are omitted in this flowchart.

[0104] (The image forming apparatus accepts the user's operation of selecting the type of printing medium)

[0105] Reference Figure 7 The operation images of the image forming apparatus 1 for accepting the user's selection of the type of printing medium are explained. Figure 7 This is an example of an operation image showing the image forming apparatus 1 accepting the user's selection of the type of printing medium. Figure 7 The operation image PCT shown is an example of an operation image of the image forming apparatus 1 receiving a user's selection of the type of printing media. The operation image PCT is displayed on the display section of the control panel 12. Figure 7 In the example shown, the display section of the control panel 12 and the operation receiving section of the control panel 12 together constitute a touch panel. For simplicity, the image forming apparatus 1 has already accepted the size of the printing medium. Figure 7 The different cases of the operation image PCT shown are explained.

[0106] Figure 7 The “first storage section” on the operation image PCT shown is information indicating the paper feed box 111. Figure 7 The “second storage section” on the operation image PCT shown is information indicating the paper feed box 112.

[0107] The operation image PCT includes buttons PCTA, PCTB, PCTC, PCTD, PCTE, and PCTF.

[0108] Buttons PCTA to PCTC are buttons corresponding to the paper feed tray 111. Button PCTA is used to select thick paper as the type of printing medium stored in the paper feed tray 111. When button PCTA is selected by touch or other means, the control unit 110 selects thick paper as the type of printing medium stored in the paper feed tray 111. Button PCTB is used to select plain paper as the type of printing medium stored in the paper feed tray 111. When button PCTB is selected by touch or other means, the control unit 110 selects plain paper as the type of printing medium stored in the paper feed tray 111. Button PCTC is used to select wireless tag paper as the type of printing medium stored in the paper feed tray 111. When button PCTC is selected by touch or other means, the control unit 110 selects wireless tag paper as the type of printing medium stored in the paper feed tray 111. Button PCTD is used to select thick paper as the type of printing medium stored in the paper feed tray 112. When button PCTD is selected via touch or other operation, control unit 110 selects thick paper as the type of printing medium stored in paper tray 112. Button PCTE selects plain paper as the type of printing medium stored in paper tray 112. When button PCTE is selected via touch or other operation, control unit 110 selects plain paper as the type of printing medium stored in paper tray 112. Button PCTF selects wireless tag paper as the type of printing medium stored in paper tray 112. When button PCTF is selected via touch or other operation, control unit 110 selects wireless tag paper as the type of printing medium stored in paper tray 112. Thick paper, for example, has a thickness exceeding 90 g / m². 2 Paper with a basic weight. Ordinary paper, for example, has a basic weight of 35–90 g / m³. 2 The basis weight of the paper. Wireless tag paper is a printing medium with wireless tags.

[0109] The image forming apparatus 1 receives an operation from the user who selects the type of printing medium via an operation image PCT displayed on the control panel 12. Therefore, the image forming apparatus 1 can, for example, [perform certain actions]. Figure 6 The type of printing media selected by the user is determined in ACT101 shown.

[0110] (Modification 1 of the implementation method)

[0111] A variation of the embodiment 1 will be described. The image forming apparatus 1 of variation 1 may be configured to include a printing media information detection unit that detects printing media information related to the printing media. The printing media information detection unit may be, for example, one or more sensors that detect the size and thickness of the printing media. The image forming apparatus 1 may be configured to use sensors provided on both the paper feed tray 111 and the paper feed tray 112 as the printing media information detection unit. The image forming apparatus 1 may also be configured to use sensors provided near the two registration rollers 24 as the printing media information detection unit. When the printing media information detection unit is included, the image forming apparatus 1 determines the type of printing media based on the printing media information detected by the printing media information detection unit. The image forming apparatus 1 reads tag position information corresponding to the determined type of printing media from the storage device 1102. The image forming apparatus 1 changes the polarization direction of the polarization wave emitted from the antenna 131 based on the read tag position information. That is, the image forming apparatus 1 can also suppress the failure to write tag information to the wireless tag in this case.

[0112] (Modification 2 of the implementation method)

[0113] A variation of the embodiment, denoted as 2, will be described. The image forming apparatus 1 in variation 2 may be configured with a tag position information detection unit that detects the tag position information of one or more wireless tags attached to a printed medium. The tag position information detection unit is, for example, a wireless communication device with an antenna different from antenna 131. This wireless communication device may be integrally configured with the wireless tag communication device 13 or separately configured from it. When the tag position information detection unit is included, the image forming apparatus 1 omits, for example... Figure 6 ACT102 is shown. In this case, the image forming apparatus 1 detects information indicating the position of each of the more than one wireless tags attached to the printed medium on the printed medium by radio waves emitted from the antenna, and uses this information as tag position information. The image forming apparatus 1 performs this tag position information detection from the start of processing ACT104 until the printed medium is transported to the radiation area RA. The image forming apparatus 1 performs this tag position information detection by emitting radio waves from the antenna to a second radiation area located upstream of the radiation area RA in the area on the transport path LA. The method for detecting information indicating the position of wireless tags based on radio waves emitted from the antenna can be a known method or a method to be developed in the future. Therefore, the description of the method for detecting information indicating the position of wireless tags based on radio waves emitted from the antenna is omitted.

[0114] Modification 2 of the embodiment, by combining with Modification 1 of the embodiment, reduces the amount of operation required by the user on the image forming apparatus 1. This combined image forming apparatus 1 can also determine whether the conveyed printing medium is a printing medium usable in the image forming apparatus 1. The image forming apparatus 1 may be configured to stop conveying, stop printing, and stop writing tag information to the wireless tag when it is determined that the printing medium is unusable in the image forming apparatus 1. The image forming apparatus 1 may also be configured to display an error message or other warning to the user on the display unit of the control panel 12 in such cases. Therefore, the image forming apparatus 1 can suppress printing on printing media unusable in the image forming apparatus 1 and writing tag information to the wireless tag. Printing media unusable in the image forming apparatus 1 may include printing media not registered in the image forming apparatus 1, but is not limited to these.

[0115] (Modification 3 of the implementation method)

[0116] Modification 3 of the embodiment will be described. In Modification 3, the image forming apparatus 1 determines whether the type of printing medium selected by the user is a type of printing medium usable in the image forming apparatus 1. More specifically, the image forming apparatus 1 determines whether a printing medium is usable in the image forming apparatus 1 based on the type of printing medium determined in ACT101. For example, if the tag position information corresponding to that type is not stored in the storage device 1102, the image forming apparatus 1 determines that the type of printing medium cannot be used in the image forming apparatus 1. For example, if the printing medium information corresponding to that type is not stored in the storage device 1102, the image forming apparatus 1 determines that the type of printing medium cannot be used in the image forming apparatus 1. When the image forming apparatus 1 determines that the printing medium is unusable in the image forming apparatus 1, it stops the transport, stops printing, and stops writing tag information to the wireless tag. In this case, the image forming apparatus 1 provides a warning to the user, such as displaying an error message on the display unit of the control panel 12. Therefore, the image forming apparatus 1 can suppress printing on printing media that cannot be used in the image forming apparatus, writing tag information to wireless tags, etc.

[0117] (Modification 4 of the implementation method)

[0118] Modification 4 of the embodiment will be described. Modification 4 of the image forming apparatus 1 includes a position and orientation change mechanism that changes the position and orientation of the antenna 131. In this case, the image forming apparatus 1 can, for example, ensure that the long axis of the wireless tag TGA is aligned with the polarization wave direction of the polarization wave emitted from the antenna 131, even if the transport direction of the wireless tag TGA is oblique to the first printed medium PRA. As a result, the image forming apparatus 1 can more reliably suppress failures in writing tag information to the wireless tag.

[0119] As described above, the image forming apparatus includes a transport unit, an antenna, a storage unit, and a control unit. The transport unit transports printed media with one or more wireless tags attached. The antenna radiates radio waves into a predetermined radiation area along the transport path through which the printed media passes. The storage unit stores polarization direction information, representing the polarization direction of the radio waves, for each type of printed media. The control unit controls the antenna to radiate polarized waves into the radiation area, writing tag information to one or more wireless tags within that area. The control unit determines the type of printed media, reads the polarization direction information corresponding to the determined type of printed media from the storage unit, and changes the polarization direction of the polarized waves radiated from the antenna based on the read polarization direction information. Therefore, the image forming apparatus can suppress failures in writing tag information to the wireless tags.

[0120] While several embodiments of the invention have been described, these embodiments are merely illustrative and not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, and likewise within the scope of the invention as set forth in the claims and its equivalents.

[0121] This can be achieved by recording a program for implementing the functions of any component in the apparatus described above (e.g., image forming apparatus 1) onto a computer-readable recording medium, allowing the computer system to read and execute the program. Here, "computer system" includes hardware such as an operating system (OS) or peripheral devices. "Computer-readable recording medium" refers to removable media such as floppy disks, optical disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into the computer system. "Computer-readable recording medium" also includes a recording medium that retains the program for a specific time, such as volatile memory (RAM) within the computer system, which acts as a server or client when transmitting the program via a network such as the Internet or a communication line such as a telephone line.

[0122] The aforementioned program can be transmitted from a computer system that has saved the program to a storage device or other computer system via a transmission medium, or via transmission waves in the transmission medium. The "transmission medium" for transmitting the program refers to a medium capable of transmitting information, such as a network (communication network) like the Internet or a communication line (communication line) like a telephone line.

[0123] The program described above can be a part of a program used to implement the aforementioned functions. Alternatively, the program described above can be a so-called difference file (difference program) that can be implemented by combining the aforementioned functions with a program already recorded in the computer system.

Claims

1. An image forming apparatus, characterized in that, have: The delivery unit delivers printed media with one or more wireless tags attached. An antenna that radiates radio waves into a designated radiation area in the transport path through which the printing medium passes via the transport unit; The storage unit stores polarization wave direction information representing the polarization wave direction of the radio wave according to each type of the printed medium; as well as The control unit controls one antenna to emit polarized waves into the radiation area as radio waves, and writes tag information to one or more wireless tags within the radiation area. The control unit determines the type of the printing medium, reads the polarization wave direction information corresponding to the determined type of the printing medium from the storage unit, and changes the polarization wave direction of the polarization wave emitted from the antenna based on the read polarization wave direction information. The control unit determines the parameters involved in transporting the printing medium based on the type of printing medium, and controls the image forming unit to start transporting the printing medium based on the parameters. When a predetermined time has elapsed since the signal initiating transport of the printing medium is output, the control unit changes the polarization direction of the polarization wave. The control unit pre-stores the predetermined time in the storage unit, corresponding to at least a portion of the parameters, for each type of printing medium. The printing media are classified according to their size, thickness, material, presence or absence of wireless tags, and the location of one or more wireless tags attached to the printing media. The radiation region is the area located above the manual feed roller and upstream of the registration roller on the conveyor path when viewed from the direction of the antenna in a direction orthogonal to the direction of gravity.

2. The image forming apparatus according to claim 1, characterized in that, The control unit causes the antenna to emit linearly polarized waves as the emission of the polarized waves.

3. The image forming apparatus according to claim 2, characterized in that, The image forming apparatus includes an operation receiving unit for accepting operations. The control unit determines the type of printing medium based on the operation received by the operation receiving unit, reads the polarization wave direction information corresponding to the determined type of printing medium from the storage unit, and changes the polarization wave direction of the linearly polarized wave emitted from the antenna based on the read polarization wave direction information.

4. The image forming apparatus according to claim 2, characterized in that, The image forming apparatus includes a detection unit that detects printing medium information related to the printing medium. The control unit determines the type of printing medium based on the printing medium information detected by the detection unit, reads the polarization wave direction information corresponding to the determined type of printing medium from the storage unit, and changes the polarization wave direction of the linearly polarized wave emitted from the antenna based on the read polarization wave direction information.

5. The image forming apparatus according to claim 4, characterized in that, The detection unit radiates radio waves to a detection area located upstream of the radiating area on the transport path, and detects information corresponding to the reflected wave of the radiated radio waves as the printing medium information.

6. The image forming apparatus according to any one of claims 2 to 5, characterized in that, The control unit changes the polarization direction of the linearly polarized wave emitted from the antenna based on the read polarization wave direction information, switching the linearly polarized wave emitted from the antenna to either a horizontally polarized wave or a vertically polarized wave.

7. The image forming apparatus according to claim 1, characterized in that, The antenna has two power supply points: a first power supply point and a second power supply point. When power is supplied to the first power supply point, it radiates horizontally polarized waves, and when power is supplied to the second power supply point, it radiates vertically polarized waves.

8. The image forming apparatus according to any one of claims 1 to 5, characterized in that, The control unit determines whether the printing medium is usable and issues a warning corresponding to the determination result.

9. The image forming apparatus according to any one of claims 1 to 5, characterized in that, The polarization wave direction information is tag location information indicating the location of the one or more wireless tags attached to the printed medium. The control unit determines the type of the printing medium, reads the polarization wave direction information corresponding to the determined type of the printing medium from the storage unit, and changes the polarization wave direction of the polarization wave emitted from the one antenna based on the read tag position information.

Images