printer

Abstract

A printer according to one embodiment of the present invention comprises: a conveyance roller that conveys a print medium having an RFID inlay; a print head that has a heating element and prints information onto the print medium; an oscillation member that can oscillate about the oscillation axis parallel to the rotation axis of the conveyance roller; and an antenna that can communicate with the RFID inlay. The antenna is disposed on the oscillation member on the printing surface side of the print medium being conveyed and on the upstream side in the conveyance direction of the print medium with respect to the position of the heating element of the print head.

Description

Printer

[0001] The present invention relates to a printer.

[0002] Conventionally, there is known a printer that performs printing on a label (RFID label) in which an RFID (Radio Frequency Identification) inlay having an IC chip and an antenna (hereinafter referred to as "RFID inlay" or simply "inlay") is incorporated.

[0003] For example, in the printer described in Japanese Patent Application Laid-Open No. 2011-183608, when printing on a label, data is read and written to the inlay incorporated in the label by an RFID reader / writer mounted on the printer. The RFID reader / writer is disposed below the conveyance surface of the continuous paper at a position downstream of the conveyance roller of the continuous paper in the conveyance direction and upstream of the platen roller in the conveyance direction (see FIG. 1).

[0004] By the way, there are cases where it is required to dispose the RFID antenna on the label printing surface side of the continuous paper. For example, when attaching a label to a conductive material such as metal, a metal sheet may be provided on the side of the adhesive layer with respect to the inlay in order to prevent the phenomenon that the electromagnetic wave to the inlay is canceled. In this case, the label is configured such that the inlay and the thermal layer are laminated in this order on the upper surface side of the base material, and the metal sheet (for example, an aluminum sheet) and the adhesive layer are laminated in this order on the lower surface side of the base material. Therefore, in order to enable communication with the inlay by the electromagnetic wave radiated from the RFID antenna, it is required to dispose the RFID antenna on the label printing surface side of the continuous paper.

[0005] Therefore, an object of the present invention is to provide a printer configured to dispose an antenna on the printing surface side of a printing medium.

[0006] One aspect of the present invention is a printer comprising: a transport roller for transporting a printing medium having an RFID inlay; a print head having a heating element for printing information on the printing medium; a oscillating member capable of oscillating around a pivot axis parallel to the rotation axis of the transport roller; and an antenna capable of communicating with the RFID inlay, wherein the antenna is positioned on the oscillating member on the print surface side of the transported printing medium and upstream of the heating element position of the print head in the transport direction of the printing medium.

[0007] According to one aspect of the present invention, a printer can be provided in which the antenna is positioned on the printing surface side of the printing medium.

[0008] This is a perspective view of a printer according to one embodiment. This is a side view of a printer according to one embodiment, showing the internal components. This is a schematic cross-sectional view of a printer according to one embodiment. This is a perspective view of the printing area when the print head unit is in the open position. This is a perspective view of the head holding part of a printer according to one embodiment. This is a diagram showing the head mechanism before and after operating the head release lever in a printer according to one embodiment. This is a perspective view and a front view of the label support mechanism of a printer according to one embodiment. This is a plan view and a bottom view of the label support mechanism of a printer according to one embodiment. This is a perspective view of the antenna drive unit built into the label support mechanism of a printer according to one embodiment. This is an enlarged cross-sectional view of a part of a printer according to one embodiment. This is a perspective view of the antenna assembly and the label support mechanism in a printer according to one embodiment. This is an exploded perspective view of the antenna assembly. This is an enlarged cross-sectional view of the antenna assembly. This is a schematic side view for illustrating the wiring route of the RFID communication unit and the antenna assembly. This is a diagram showing a modified example of the antenna assembly.

[0009] The forms described below are not limited to those shown in the brief description of the drawings.

[0010] A first aspect of one aspect of the present invention is a printer comprising: a transport roller for transporting a printing medium having an RFID inlay; a print head having a heating element for printing information on the printing medium; a oscillating member that can oscillate around an oscillating axis parallel to the rotation axis of the transport roller; and an antenna capable of communicating with the RFID inlay, wherein the antenna is positioned on the oscillating member on the print surface side of the transported printing medium and upstream of the heating element position of the print head in the transport direction of the printing medium.

[0011] According to a first aspect of one embodiment of the present invention, the antenna can be positioned on the printing surface side of the printing medium.

[0012] A second aspect of a certain embodiment of the present invention is the printer according to the first embodiment, wherein the antenna is located at the downstream end of the oscillating member in the transport direction of the printing medium.

[0013] According to a second aspect of one embodiment of the present invention, the antenna can be positioned close to the location of the heating element of the print head.

[0014] A third aspect of a certain embodiment of the present invention is the printer according to the first or second embodiment, wherein the oscillating member is configured to cover at least a portion of the print head.

[0015] According to a third aspect of a certain embodiment of the present invention, the spatial efficiency when arranging the antenna is good.

[0016] A fourth aspect of a certain embodiment of the present invention is a printer according to any one of the first to third embodiments, comprising an antenna cover that blocks at least a portion of the electromagnetic waves radiated from the antenna, wherein the antenna cover is provided on the oscillating member.

[0017] According to a fourth aspect of a certain embodiment of the present invention, the antenna and the antenna cover can be integrally arranged on the rocking member while appropriately limiting the communication range of the antenna.

[0018] A fifth aspect of a certain embodiment of the present invention is the printer according to the fourth embodiment, wherein the antenna is located at the downstream end of the antenna cover in the transport direction of the printing medium.

[0019] According to a fifth aspect of a certain embodiment of the present invention, space efficiency can be improved when arranging the antenna and antenna cover, and the antenna can be positioned close to the heating element of the print head.

[0020] A sixth aspect of a certain embodiment of the present invention is the printer according to the fourth embodiment, wherein, when the direction in which the printing medium advances is defined as forward at the position of the heating element of the print head, the antenna cover is positioned behind the antenna.

[0021] According to a sixth aspect of a certain embodiment of the present invention, unintended communication with another printing medium upstream of the printing medium to be communicated can be prevented.

[0022] A seventh aspect of a certain embodiment of the present invention is the printer according to the fourth embodiment, wherein, when the direction in which the printing medium moves forward is considered to be forward at the position of the heating element of the print head, the print head has a shape that becomes thinner towards the rear when the printer is viewed from the side, the antenna cover is arranged in the space formed by the thinning of the print head, and the antenna is arranged closer to the position of the heating element of the print head than the antenna cover.

[0023] According to a seventh aspect of a certain embodiment of the present invention, an antenna cover can be placed in the space behind the print head, and the space efficiency when placing the antenna cover is good.

[0024] The embodiments will be described in detail below with reference to the drawings. Figure 1 shows the external appearance of a printer 1 according to one embodiment. For the sake of explanation, the XYZ coordinates are defined below as shown in Figure 1. That is, +X and -X indicate the left-right direction of the printer 1, +Y and -Y indicate the front-back direction of the printer 1, and +Z and -Z indicate the up-down direction of the printer 1. The front of the printer 1 is provided with an output slot 5 for issuing (discharging) printed labels. An open cover 6 is attached to one side of the printer 1 so as to be able to open and close vertically by two hinges 7.

[0025] Figure 2 is a side view of the main part of printer 1 with the interior visible. Figure 3 is a partial cross-sectional view of printer 1. Figure 4 is a perspective view of the printing unit 11 when the print head unit 13 is in the open position. As shown in Figure 2, the inside of printer 1 is equipped with a paper supply unit 10a and a backing paper winding unit 10b located at the rear, a printing unit 11 located at the front, and an ink ribbon unit 12 located at the top. The paper supply unit 10a and the backing paper winding unit 10b are attached to the side wall 51 inside the housing.

[0026] The paper supply unit 10a holds the roll paper R and supplies the continuous paper CP unwound from the roll paper R to the printing unit 11. As shown in Figure 2, the roll paper R is made of continuous paper CP wound into a roll. The continuous paper CP includes a strip-shaped backing sheet PM and a plurality of labels PL (an example of a printing medium) that are attached to the backing sheet PM at intervals and can be peeled off. The surface of the backing sheet PM that comes into contact with the adhesive surface of the labels PL is coated with a release agent such as silicone, making it possible to easily peel off the labels PL. RFID inlays IL (hereinafter simply referred to as "inlay IL") are incorporated into the labels PL. On the back surface of the backing sheet PM where the labels PL are not attached, position detection marks IM indicating the position of the labels may be formed at predetermined intervals along the longitudinal direction. Plain paper is used as the labels PL, but thermal paper may also be used. In the case of thermal paper, a heat-sensitive color-developing layer is formed on its surface that changes to a specific color (such as black or red) when it reaches a predetermined temperature range. Although not shown in the diagram, the paper supply unit 10a can also be loaded with roll paper in which labels without a backing sheet are wound into a roll shape, with an adhesive surface formed by applying adhesive to the back of the printing surface.

[0027] The printing unit 11 comprises a print head unit 13, a damper 15, a head lock lever 16, and a label support mechanism 70, and prints on the label PL of the continuous paper CP. The print head unit 13 is installed inside the printer 1 in an openable and closable state, as will be described later. The print head unit 13 holds a thermal head 18 (an example of a print head) and is pivotable between an open position and a closed position. When the print head unit 13 is in the open position, the thermal head 18 is separated from the platen roller 23 (an example of a transport roller). When the print head unit 13 is in the closed position, the thermal head 18 grips the continuous paper CP with the platen roller 23 (see Figure 3). The head lock lever 16 is configured to maintain the closed state of the print head unit 13 when the print head unit 13 is in the closed position. When the head lock lever 16 is operated, the closed state of the print head unit 13 is released, and as shown in Figure 4, the front part of the print head unit 13 lifts up, causing the print head unit 13 to open (the thermal head 18 separates from the platen roller 23). The damper 15 is installed in a swingable state so as to be able to apply tension to the continuous paper CP.

[0028] As shown in Figures 2 and 3, the continuous paper CP is transported from the damper 15 through the label support mechanism 70 and discharged from the output opening 5 (Figure 1) after printing. The label support mechanism 70 is installed upstream of the thermal head 18 and platen roller 23 in the transport path of the continuous paper CP.

[0029] The ink ribbon unit 12 comprises a ribbon supply unit 12a and a ribbon winding unit 12b, and supplies and winds up an ink ribbon RB coated with printing ink. The ribbon supply unit 12a supports the ink ribbon RB, which is wound in a roll shape, in a rotatable state. The ribbon winding unit 12b winds up and collects the printed ink ribbon RB. When using the ink ribbon RB, the ink ribbon RB is pulled out from the ribbon supply unit 12a, passed under the print head unit 13, and wound up by the ribbon winding unit 12b. The ribbon supply unit 12a and the ribbon winding unit 12b are attached to the side wall 51 of the printer 1's housing.

[0030] In printer 1, continuous paper CP fed from the roll paper R in the paper supply unit 10a is transported via damper 15 to a paper transport route provided in the label support mechanism unit 70, and printing is performed on the labels PL of the continuous paper CP. At this time, the thermal head 18 prints on each label PL of the continuous paper CP while sandwiching the continuous paper CP and ink ribbon RB between the heating element and platen roller 23. In one embodiment, printer 1 is equipped with a peeling mechanism having a peeling unit 24, nip rollers 25a, 25b, and a backing paper winding unit 10b in order to peel each label PL from the continuous paper CP. As shown in Figure 3, the peeling unit 24 is installed downstream of the platen roller 23 in the transport direction of the continuous paper CP. In the peeling unit 24, the labels PL are peeled from the continuous paper CP and discharged to the outside of printer 1 from the output opening 5, and the path of the backing paper PM (shown by a dotted line in Figure 3) is directed downward. The backing paper PM, which is directed downwards, is held between the nip rollers 25a and 25b and then moves towards the backing paper winding section 10b at the rear, where it is wound up. As shown in Figure 3, a gap is formed below the label support mechanism 70 through which the backing paper PM passes from the peeling section 24 to the backing paper winding section 10b.

[0031] Although not shown in the figures, in one embodiment, a cutting unit is installed instead of the peeling mechanism shown in Figure 3. The cutting unit is located downstream of the platen roller 23 in the direction of transport of the continuous paper CP, and cuts each label PL from the printed continuous paper CP. When a cutting unit is installed, the continuous paper is not limited to the type with a backing sheet shown in Figure 2, but may also be a label without a backing sheet.

[0032] Next, the configuration of the printing unit 11 described above will be explained with reference to Figure 4. As shown in Figure 4, the print head unit 13 is able to swing (i.e., open and close) around the X-axis with respect to the pivot shaft S1 located at the rear, and the pivot shaft S1 is supported by a side wall 51 (see Figure 2), which is part of the conductive internal frame of the printer 1. The pivot shaft S1 is made of a conductive material.

[0033] The lower surface of the print head unit 13 (the surface facing the paper feed route) is installed with the thermal head 18 positioned so that its heating element faces the paper feed route. The heating element of the thermal head 18 includes multiple heating resistors (heating elements) that generate heat when power is applied, and prints on the label PL of the continuous paper CP. These multiple heating resistors are arranged in a line along the width direction of the continuous paper CP (a direction perpendicular to the transport direction of the continuous paper CP).

[0034] A pair of engaging claws 19 (see Figure 4) are provided on the lower front surface of the print head unit 13 so as to sandwich the thermal head 18. Behind the engaging claws 19 in the print head unit 13, pins 20 are provided that protrude outward from both sides of the print head unit 13.

[0035] The print head unit 13 is biased in the opening direction by a torsion spring 21 (see Figure 4) attached to the pivot shaft S1, but the closed state is maintained by a pair of locking claws 22 that catch on a pair of pins 20 at the bottom of the print head unit 13. When the print head unit 13 is in the closed position, a pair of engaging claws 19 of the print head unit 13 are fitted onto both ends of the rotation shaft of the platen roller 23. When the head lock lever 16 is operated backward, the locking claws 22 move backward in conjunction with it and disengage from the pins 20. When the locking claws 22 disengage from the pins 20, the print head unit 13 opens automatically due to the biasing force of the torsion spring 21, as shown in Figure 4.

[0036] The platen roller 23 transports the continuous paper CP fed from the paper supply unit 10a along the paper feeding route to the output opening 5 (see Figure 1). The platen roller 23 is installed in the internal frame so as to be rotatable in forward and reverse directions, and rotates together with the thermal head 18 while gripping the continuous paper CP during printing. When the continuous paper CP is plain paper, the platen roller 23 rotates together with the thermal head 18 while gripping the continuous paper CP and the ink ribbon RB during printing. In this case, the ink ribbon RB is transported from the ribbon supply unit 12a via the ribbon rollers 121 and 122 (see Figure 4) provided on the print head unit 13 and wound onto the ribbon winding unit 12b.

[0037] Next, with reference to Figure 5, the head mechanism 35 provided in the print head unit 13 will be described. The head mechanism 35 is a mechanism related to the thermal head 18 in the state where the support plate 17, ribbon rollers 121, 122, pivot shaft S1, etc. have been removed from the print head unit 13. As shown in Figure 5, the head mechanism 35 includes the thermal head 18, head bracket 26, head holding part 50, head cover 14, etc.

[0038] Although not clearly visible in Figure 5, a head bracket 26 with a pin 18P is detachably attached to the thermal head 18. Hereafter, the thermal head 18 with the head bracket 26 attached will be referred to as the "head assembly". The head cover 14 engages with the head bracket 26. The head holding portion 50 is configured to hold the thermal head 18 by holding the pin 18P of the head bracket 26. Connectors 52 and 53 are attached to the thermal head 18. Wiring with connectors (not shown) is connected to connectors 52 and 53, and the thermal head 18 is electrically connected to a control unit (not shown).

[0039] The head cover 14 is pivotable relative to the head holding portion 50 and is configured to cover at least a portion of the thermal head 18 from below. The head cover 14 has an insertion hole (not shown) through which 00 is inserted. The pivot axis 40 is parallel to the rotation axis of the platen roller 23. The head cover 14 is an example of a pivotable member that can pivot around the pivot axis 40.

[0040] The head holding portion 50 holds the thermal head 18 and is a component made of a conductive material such as metal. As shown in Figure 5, the head holding portion 50 has a pin pressing portion 37 that presses and holds the pins 18P of the head assembly. The pin pressing portion 37 has a pressing plate 37a and a coil spring 37b, and presses the pins 18P of the head assembly when the head assembly is held by the head holding portion 50. The pressing plate 37a is configured to be slightly movable along its longitudinal direction (the width direction of the continuous paper CP). The pressing plate 37a is integrated with a head release operation lever (not shown) and is displaceable in the +X direction in response to operation of the head release operation lever in the +X direction. The pressing plate 37a has a convex portion 37i that is convex in the -X direction. The pressing plate 37a is biased in the -X direction (opposite direction to direction D1 in Figure 5) by the coil spring 37b, and as a result the convex portion 37i engages with a recess (not shown) of the pins 18P. As a result, the pin 18P is locked to the retaining plate 37a, and the head assembly 18A is held in the head holding part 50.

[0041] To release the head holding portion 50 from the head assembly, a head release operation lever (not shown) is operated in the +X direction. In other words, the operation of the head release operation lever moves the retaining plate 37a in the +X direction against the biasing force of the coil spring 37b. As the retaining plate 37a moves in the +X direction, the engagement between the recess of the pin 18P and the protrusion 37i of the pin pressing portion 37 is released. As a result, the head assembly falls due to its own weight. Figure 6 shows the head mechanism 35 in state ST1 before operating the head release operation lever and in state ST2 after operating the head release operation lever. As shown in Figure 6, by operating the head release operation lever, the head assembly and head cover 14, which are engaged with each other, swing together around the pivot axis 40. The swinging of the head assembly and head cover 14 stops when the pin 144 formed on the head cover 39 contacts the pin contact portion 56 provided on the head holding portion 50.

[0042] When replacing the thermal head 18, the head release lever is operated, and then the head assembly is pulled forward. Furthermore, by pushing the head assembly inward and closing the head cover 14, the pins 18P of the head bracket 26 are held in place by the head holding section 50. The antenna assembly 30, described later, is attached to the head cover 14. Therefore, when attaching or detaching the thermal head 18, it is not necessary to remove the antenna assembly 30 from the printer 1, and the initial mounting accuracy of the RFID antenna 32 included in the antenna assembly 30 is maintained.

[0043] As mentioned above, the head holder 50 is a component formed from a conductive metal. As shown in Figure 5, wiring 42 from the antenna assembly 30 (see Figure 4), which will be described later, is fastened to the upper surface of the head holder 50 with screws. As will be described later, the wiring 42 is connected to the ground portion of the RFID antenna 32 included in the antenna assembly 30, and is connected to the head holder 50 in order to allow the ground function of the RFID antenna 32 to be fully utilized. The conductive head holder 50 is electrically connected to the print head unit 13, the oscillating shaft S1, and the conductive internal frame of the printer 1 (an example of the printer body), and is grounded via the internal frame.

[0044] As will be explained in detail below, the printer 1 is equipped with two RFID antennas 91 and 32 for communicating with the inlay IL of the label PL. RFID antenna 91 is located on the underside of the transport path of the continuous paper CP. RFID antenna 32 is located on the upper side (label printing side) of the transport path of the continuous paper CP. In actual operation, the printer is controlled to communicate with the inlay IL using either RFID antenna 91 or 32. RFID antenna 91 is built into the label support section 71 (described later) of the label support mechanism section 70 (see Figure 4). First, the label support mechanism section 70 will be described with reference to Figures 7 and 8. The label support mechanism section 70 is mounted on an internal frame (not shown). Figure 7 shows a perspective view and a front view of the label support mechanism section 70. Figure 8 shows a plan view and a bottom view of the label support mechanism section 70.

[0045] As shown in FIG. 7, the label support mechanism unit 70 includes a label support portion 71, a sensor assembly 72, and a label guide portion 73. The label support portion 71 has a support surface 711 that supports the continuous paper CP heading toward the platen roller 23 from below (the side opposite to the printing surface of the label PL), and incorporates a sensor for detecting the position detection mark IM of the continuous paper CP. Further, an RFID communication unit 80, which will be described later, is incorporated in the label support portion 71. The RFID communication unit 80 has a function of writing data to or reading data from the inlay IL incorporated in the label PL under the instruction from a control unit (not shown). The sensor assembly 72 is attached to the label support portion 71 in a state of being engaged with a guide groove (not shown) of the label support portion 71, and is slidable in the width direction of the continuous paper CP with respect to the label support portion 71. Further, the sensor assembly 72 incorporates a sensor for detecting the end portions of each label PL of the continuous paper CP. The label guide portion 73 is attached to the sensor assembly 72, and serves to sandwich the continuous paper CP conveyed toward the platen roller 23 between the support surface 711 of the label support portion 71 and guide the continuous paper CP from above (the front side). A slight gap g1 (see the front view of FIG. 7) is formed between the lower surface of the label guide portion 73 and the support surface 711 of the label support portion 71, and this gap g1 serves as the conveyance path of the continuous paper CP.

[0046] As shown in the front view of FIG. 7, the sensor assembly 72 has a swing shaft 723 and is configured to be swingable around the swing shaft 723 (swingable counterclockwise and clockwise in FIG. 7). Since the label guide portion 73 is attached to the sensor assembly 72, the sensor assembly 72 and the label guide portion 73 swing integrally in the direction in which the label guide portion 73 approaches the support surface 711 of the label support portion 71 and the direction in which it moves away from the support surface 711. By this swinging operation, a new continuous paper CP can be set in the printer 1. Even when the label guide portion 73 swings to the position closest to the support surface 711, a gap g1 for smoothly conveying the continuous paper CP is ensured.

[0047] Referring to the bottom view of FIG. 8, the RFID module 81 of the RFID communication unit 80 and the substrates 82 to 86 are exposed on the bottom surface of the label support mechanism unit 70. The RFID module 81 communicates with a control unit (not shown) and controls the entire RFID communication unit 80 under the control command from the control unit. This control also includes processing for the RFID antenna 32 (such as an instruction to write data to the inlay IL) described later.

[0048] Although not visible in FIG. 7, the RFID communication unit 80 further includes an antenna driving unit 90 built in the label support mechanism unit 70. FIG. 9 is a perspective view of the antenna driving unit 90. As shown in FIG. 9, the antenna driving unit 90 includes an RFID antenna 91, a first direction driving unit 92 and a second direction driving unit 93 for two-dimensionally displacing the RFID antenna 91 along the support surface 711. The first direction driving unit 92 displaces the RFID antenna 91 in the first direction by a motor, and the second direction driving unit 93 displaces the RFID antenna 91 in a second direction orthogonal to the first direction by a motor. The control unit of the printer 1 operates the first direction driving unit 92 and the second direction driving unit 93 to perform communication adjustment for determining the optimal position of the RFID antenna 91 when communicating with each label PL. When adopting a method of conveying the label to determine the optimal label position with respect to the antenna as the communication adjustment, it is not essential to provide the first direction driving unit 92 and the second direction driving unit 93 for displacing the antenna.

[0049] Next, an antenna assembly 30 including the RFID antenna 32 and disposed on the label printing surface side of the continuous paper CP will be described. As shown in FIG. 4, an antenna assembly 30 including the RFID antenna 32 is installed in the print head unit 13. In one embodiment, the RFID antenna 32 communicates with the inlay IL in the UHF band.

[0050] One reason why the RFID antenna 32 is positioned on the label printing side of the continuous paper CP is as follows: When attaching a label PL to a conductive material such as metal, a metal sheet is sometimes provided on the adhesive layer side relative to the inlay IL to prevent the phenomenon of electromagnetic waves being canceled out. In this case, the label PL is configured such that the inlay IL and thermal layer are laminated in that order on the upper side of the substrate, and the metal sheet (e.g., an aluminum sheet) and adhesive layer are laminated in that order on the lower side of the substrate. Therefore, the RFID antenna 32 is positioned on the label printing side of the continuous paper CP so that communication with the inlay IL is possible using electromagnetic waves emitted from the RFID antenna 32.

[0051] The antenna assembly 30, which is located on the label printing side of the continuous paper CP, will be described in detail below with reference to Figures 10 to 14. Figure 10 is an enlarged view of the cross-section (cross-section in the YZ plane) of the printer 1, which includes the thermal head 18 and the platen roller 23. Figure 11 is a perspective view of the antenna assembly 30 and the label support mechanism 70 in the printer 1.

[0052] As shown in Figure 10, the continuous paper CP is transported by the platen roller 23 towards the printing port 5 through the transport path (g1 in Figure 7) between the label support section 71 and the label guide section 73. The continuous paper CP is held between the heating element 18L of the thermal head 18 and the platen roller 23, and printing is performed on each label PL for continuous printing at the heating element 18L. The heating element 18L is a heating section in which multiple heating elements (resistors) are arranged in a row. The label PL is held between the heating element 18L of the thermal head 18 and the platen roller 23, and printing is performed on the label PL. In the following description, the position of the heating element 18L will be referred to as the "heating element position". In Figure 10, the label PL moves forward at the heating element position where the thermal head 18 prints on the label PL. When printing is performed, transport control is performed based on the output of a sensor that detects the position detection mark IM of each label PL of the continuous paper CP, and the output of a sensor that detects the edge of each label PL of the continuous paper CP.

[0053] As shown in Figure 10, the RFID antenna 32 is positioned on the head cover 14 on the print side of the continuous paper CP being transported, and upstream of the thermal head 18 in the transport direction of the continuous paper CP.

[0054] As shown in Figures 10 and 11, the antenna assembly 30 is mounted in front of the head cover 14. In particular, the RFID antenna 32 is positioned on the print surface side of the continuous paper CP being transported, and upstream of the heating element position of the thermal head 18 in the transport direction of the continuous paper CP. As a result, the RFID antenna 32 is positioned close to the heating element position. Therefore, there are two advantages.

[0055] Firstly, when the label PL is a small-pitch label (a label with a short length in the transport direction), there is an advantage in preventing the first label PL of the continuous paper CP from being wasted. Labels with UHF band inlays are often small-pitch labels. When the printer 1 issues each label PL of the continuous paper CP, it waits at the position of the heating element of the print head for the first label PL to begin printing. When the printer 1 issues each label PL, it reads and writes data to the inlay IL of each label PL before printing. Here, since the RFID antenna 32 is upstream of the heating element position, it is necessary to transport the continuous paper CP in reverse so that it is in an appropriate position for reading and writing data to the inlay IL of the label PL. However, especially with small-pitch labels, if the first label PL is transported in reverse, the leading edge of the first label PL may fall off from the heating element position of the thermal head 18. Therefore, if the RFID antenna cannot be brought close enough to the heating element, it will be necessary to print from the second label PL of the continuous paper CP, wasting the first label PL. In contrast, as shown in Figure 10, the RFID antenna 32 is close enough to the heating element 18L, so even if the label PL is a small-pitch label, it is possible to prevent the tip of the first label PL from falling off the heating element.

[0056] Secondly, there is the advantage of improving the throughput of label issuance. For each label PL from the second label onward, it may be necessary to transport each label PL in reverse in order to read and write data to the inlay IL. However, if the RFID antenna is far from the heating element, the reverse transport distance of the label PL for data reading and writing becomes long, reducing throughput. In contrast, as shown in Figure 10, the RFID antenna 32 is sufficiently close to the heating element 18L, so the reverse transport distance can be shortened, improving the throughput of label issuance.

[0057] As mentioned above, in printer 1, as shown in Figure 8, the RFID antenna 91 of the RFID communication unit 80 (see Figure 9) is located on the opposite side of the continuous paper CP from the printing surface (i.e., on the underside of the continuous paper CP transport path). However, since the RFID communication unit 80 is configured to displace the RFID antenna 91 in two dimensions, space is required to displace the RFID antenna 91, making it difficult to bring the RFID antenna 91 close to the heating element. Therefore, the RFID antenna 91 is positioned upstream of the RFID antenna 32 in the transport direction of the continuous paper CP (i.e., further from the heating element than the RFID antenna 32). Even if the RFID antenna were positioned so as not to be displaced in two dimensions (i.e., fixed), it would still be difficult to position the RFID antenna close to the heating element on the underside of the continuous paper CP transport path. The reason for this is that, as shown in Figure 10, the transport path slopes downward from the heating element upstream, so there is no space to place the RFID antenna near the heating element on the lower side of the transport path for continuous paper CP.

[0058] In contrast, by placing the RFID antenna 32 on the printing surface side of the continuous paper CP, it is possible to position it as close as possible to the heating element, thereby obtaining the above advantages. In particular, when the RFID antenna 32 is in the UHF band, it can be configured as a linear antenna such as a dipole antenna, for example, and the area occupied by the antenna in the transport direction can be reduced. For example, since the RFID antenna 32 can be arranged linearly along the width direction of the continuous paper CP (see Figure 12), it is convenient for positioning the RFID antenna 32 close to the heating element. In the HF band, where communication is performed by electromagnetic coupling, a coiled loop antenna is used as the RFID antenna, and the area occupied by the antenna in the transport direction tends to be large. Therefore, when communicating in the HF band, it is preferable to set the RFID antenna 91 located on the lower side of the transport path of the continuous paper CP as an HF band compatible antenna. Furthermore, even if the labels are in the UHF band, if the pitch is relatively large (relatively long in the transport direction) and the first label does not detach from the heating element, the RFID antenna 91 located away from the heating element can be set as a UHF band compatible antenna.

[0059] Next, the antenna assembly 30 will be described in detail with reference to Figures 12 and 13. Figure 12 is an exploded perspective view of the antenna assembly 30. Figure 13 is an enlarged view of the cross-section of the antenna assembly 30 in the YZ plane.

[0060] As shown in Figure 12, the antenna assembly 30 includes a protective sheet 31, an RFID antenna 32, a contact plate 33, an antenna cover 34, and wiring 42, and is provided on the head cover 14. The protective sheet 31 is a component for protecting the RFID antenna 32 from the continuous paper CP being transported, and is molded from, for example, thermoplastic plastic. The RFID antenna 32 is attached to the front end portion of the protective sheet 31 with, for example, an adhesive. The RFID antenna 32 is connected to the wiring 41. The wiring 41 is connected to the RFID module 81 (Figure 8) of the RFID communication unit 80, as will be described later. The contact plate 33 is provided to ground the ground portion 321 (see Figure 13) of the RFID antenna 32 via the conductive internal frame of the printer 1. The contact plate 33 has three protrusions 331 formed therein, and these protrusions 331 are soldered to the RFID antenna 32 (more specifically, the ground portion 321 (see Figure 13) of the RFID antenna 32).

[0061] The antenna cover 34 is a conductive metal member formed to block at least a portion of the electromagnetic waves radiated from the RFID antenna 32. The antenna cover 34 can limit the communication range of the RFID antenna 32 so that it does not communicate with unintended inlay ILs. An opening 342 is formed in the front portion of the antenna cover 34. Since the antenna cover 34 is made of a relatively strong metal, it can be made thinner to bring it closer to the heat source (see Figure 10). This also allows the RFID antenna 32 to be brought closer to the heat source.

[0062] The wiring 42 has crimp terminals 421 and 422 at both ends and is used to electrically connect the antenna cover 34 to the head holding part 50 (Figure 5).

[0063] As shown in Figure 12, the protective sheet 31, contact plate 33, and antenna cover 34 each have three through holes for the shaft of the screw switch to pass through. The head cover 14 has three threaded holes 141 for receiving the shaft of the screw switch. The protective sheet 31, contact plate 33, antenna cover 34, and wiring 42 are fastened together to the head cover 14 by the screw switch via the through holes and crimp terminals 421 provided in each. At this time, the crimp terminal 421 of the wiring 42 is connected to a projection 343 in which the central of the three through holes of the antenna cover 34 is formed. The crimp terminal 422 of the wiring 42 is fastened to the head holding part 50 with a screw, as shown in Figure 5. As shown in Figure 10, the antenna assembly 30 and the head holding part 50 are located relatively close to each other, so the wiring length of the wiring 42 can be short.

[0064] Adhesives 311 and 312 are formed on the surfaces of the protective sheet 31 that face the contact plate 33 and the antenna cover 34. While the provision of adhesives 311 and 312 is not essential, the adhesives 311 and 312 integrate the protective sheet 31, contact plate 33, and antenna cover 34, which is convenient because the components do not separate when fastening them together with a screw switch or when the fastening is removed.

[0065] Referring to Figure 10, the thermal head 18 has a shape that becomes thinner as it moves in the opposite direction (i.e., backward) to the direction in which the continuous paper CP advances (i.e., forward) at the position of the heating element (position of the heating element 18L). The antenna cover 34 is placed in the space formed by the thinning of the thermal head 18, and the RFID antenna 32 is placed closer to the heating element than the main part of the antenna cover 34. Therefore, the antenna cover 34 can be placed in the space behind the thermal head 18, resulting in good space efficiency when placing the antenna cover 34.

[0066] As shown in Figure 13, the RFID antenna 32 is positioned at the downstream end of the head cover 14 in the transport direction of the continuous paper CP. Therefore, the RFID antenna 32 can be positioned close to the location of the heating element of the thermal head 18 (see also Figure 10).

[0067] Furthermore, as shown in Figures 11 and 13, the antenna cover 34 is positioned adjacent to the RFID antenna 32. This allows for appropriate restriction of the communication range by the RFID antenna 32. More specifically, the antenna cover 34 is positioned behind the RFID antenna 32. This prevents unintended communication with another label PL upstream of the label PL that is the target of communication. In other words, it prevents electromagnetic waves radiated from the antenna element 322 of the RFID antenna 32 from bending around and mistakenly writing data to the inlay IL of the label PL behind it.

[0068] Referring to Figure 13, the protective sheet 31 is positioned on the side (below; see also Figure 10) over which the continuous paper CP passes, rather than on the RFID antenna 32. This prevents the antenna element 322 (electromagnetic wave emitting surface) of the RFID antenna 32 from being rubbed and damaged by the transported continuous paper CP. In addition, the protective sheet 31 prevents the continuous paper CP from getting caught on the antenna cover 34 or the antenna element 322, contributing to the smooth transport of the continuous paper CP.

[0069] A curved portion 341 is formed at the front end of the antenna cover 34. The curved portion 341 is provided to make it less likely for the continuous paper CP to get caught when it is being transported in reverse (to reduce the likelihood of paper jams). The front end of the antenna cover 34 is inclined rather than being horizontal (it curves upward as it goes forward) for the same reason. Because the antenna cover 34 is inclined, the gap between the tip of the antenna cover 34 and the thermal head 18 can be reduced, as shown in Figure 10, and the continuous paper CP is prevented from getting caught. In addition, providing the curved portion 341 also contributes to improving the strength of the antenna cover 34.

[0070] As shown in an enlarged view in Figure 13, the RFID antenna 32 includes an insulating substrate 320, a ground portion 321 formed on the upper side of the substrate 320, and an antenna element 322 formed on the lower side of the substrate 320. The wiring 41 (see Figure 12) connected to the RFID antenna 32 is a coaxial cable. A known configuration can be used for the coaxial cable, with the antenna element 322 connected to the inner conductor of the coaxial cable and the ground portion 321 connected to the outer conductor of the coaxial cable. The antenna element 322 of the RFID antenna 32 is powered from the RFID module 81 (Figure 8) via the wiring 41, and the ground portion 321 of the RFID antenna 32 is connected to the ground (not shown) inside the RFID module 81 via the wiring 41.

[0071] As mentioned above, the antenna cover 34 is connected to the head holder 50 via wiring 42. The conductive head holder 50 is electrically connected to the print head unit 13, the pivot shaft S1, and the conductive internal frame of the printer 1, and is grounded via the internal frame. In other words, by providing wiring 42, the antenna cover 34 is configured to be grounded to the entire printer 1. The reason for this configuration is as follows.

[0072] As described above, the ground portion 321 of the RFID antenna 32 is connected to the ground inside the RFID module 81 via the wiring 42. Furthermore, the ground portion 321 of the RFID antenna 32 is electrically connected to the contact plate 33 by soldering, and the contact plate 33 and the antenna cover 34 are electrically connected. Therefore, the antenna cover 34 is electrically connected to the ground by the contact plate 33, the ground portion 321 of the RFID antenna 32, and the wiring 42. However, in recent years, due to the increase in RFID antenna output (the higher the output, the more likely electromagnetic waves are to leak), the miniaturization of RFID antennas, and the miniaturization of the entire printer, which has led to thinner and longer wiring, the ground function may not be fully effective. Therefore, if the ground function by the wiring 42 is not fully effective, the antenna cover 34 may become electrically floating and radiate unwanted electromagnetic waves as a single antenna. To address this, the printer 1 is configured to ensure that the antenna cover 34 is properly grounded by providing the wiring 42, thereby grounding the antenna cover 34 to the entire printer 1. This prevents unwanted electromagnetic waves from being emitted from the antenna cover 34. In addition, the ground portion 321 of the RFID antenna 32 is also grounded to the entire printer 1 via the contact plate 33 and the antenna cover 34. As a result, the grounding function of the RFID antenna 32 can be fully utilized.

[0073] Figure 14 schematically shows the wiring path of the wiring 41 connecting the RFID antenna 32 included in the antenna assembly 30 and the RFID module 81 built into the label support unit 71. In Figure 14, the antenna assembly 30 when the print head unit 13 is in the closed position is shown by a solid line in a side view of the printer 1, and the antenna assembly 30 when the print head unit 13 is in the open position is shown by a dashed line. As shown in Figure 14, since the wiring 42 is provided so as to wrap around the outside of the pivot shaft S1, the wiring 42 does not become taut in response to the opening and closing of the print head unit 13. In one embodiment, a wiring holding unit 45 is attached to the pivot shaft S1 to hold the wiring 42 so as to contact (or press) the wiring 41 against the conductive pivot shaft S1. This suppresses the emission of unwanted electromagnetic waves from the wiring 41 and allows for more appropriate limitation of the communication range by the RFID antenna 32.

[0074] The arrangement of the RFID antenna 32 and antenna cover 34 shown in Figures 10 to 13 is just one example, and other arrangements are possible. Hereinafter, modified arrangements of the RFID antenna 32 and antenna cover 34 will be described with reference to Figure 15. Figure 15 shows the modified antenna assemblies 30A to 30C in the same cross-sectional view as in Figure 13.

[0075] In the antenna assembly 30A, the RFID antenna 32 is positioned at the downstream end of the antenna cover 34A in the continuous paper transport direction. In the antenna assembly 30A, the antenna cover 34A is fixed to the head cover 14A by a screw SW. The RFID antenna 32 is attached to the antenna cover 34A, for example, with adhesive.

[0076] In the antenna assembly 30B, the antenna cover 34B is positioned at the downstream end of the head cover 14B in the continuous paper transport direction. In the antenna assembly 30B, a protective sheet 31A is attached to the lower surface of the head cover 14B with adhesive or screws, and the RFID antenna 32 is positioned on the upper surface of the protective sheet 31A with adhesive or the like. The antenna cover 34B is provided on the upper surface of the head cover 14B (the surface opposite to the surface to which the protective sheet 31A is attached).

[0077] In the antenna assembly 30C, the antenna cover 34B is positioned at the downstream end of the head cover 14B in the continuous paper transport direction. In the antenna assembly 30C, both the RFID antenna 32 and the antenna cover 34B are positioned on the head cover 14B. In this example, the antenna cover 34B is attached to the head cover 14B on the side opposite to the side to which the RFID antenna 32 is attached, but this is not limited to this. The antenna cover 34B may be positioned on the same plane as the RFID antenna 32 (the upper or lower surface of the head cover 14B).

[0078] In any of the antenna assemblies 30A to 30C, the space efficiency when arranging the antenna cover is good, and the RFID antenna 32 can be brought as close as possible to the position of the heating element of the thermal head 18 located in front. In Figure 15, in any of the antenna assemblies 30A to 30C, a contact plate connected to the ground portion 321 of the RFID antenna 32 may be provided, similar to antenna assembly 30, and this contact plate may be electrically connected to the antenna covers 34A and 34B. In addition, the antenna covers 34A and 34B are electrically connected to the head holding portion 50, similar to the wiring 42 in Figure 5. This ensures that the ground function of the RFID antenna 32 is fully utilized.

[0079] Although embodiments of the printer of the present invention have been described above, the present invention is not limited to the above embodiments. Furthermore, the above embodiments can be improved or modified in various ways without departing from the spirit of the present invention. In the above-described antenna assembly 30, the case in which the RFID antenna 32 and the antenna cover 34 are integrally configured and electrically connected has been described, but this is not limited to that, and they may be configured as separate parts. In that case, in order to fully utilize the grounding function of the RFID antenna 32, a wiring is provided to electrically connect the ground portion 321 of the RFID antenna 32 to the head holding part 50, thereby configuring the entire printer 1 to be grounded. Even when the RFID antenna 32 and the antenna cover 34 are separate parts, the antenna cover 34 is electrically connected to the head holding part 50 by wiring 42 so as not to radiate unnecessary electromagnetic waves. In the above example, the antenna cover 34 is configured to be connected to the head holding part 50 by wiring 42, but this is not limited to that. The destination of the wiring 42 is not limited to the head holding part 50, as long as it constitutes part of the grounding path that grounds the entire printer 1. For example, the antenna cover 34 may be connected to the oscillating shaft S1 or the conductive housing of the printer 1 by wiring.

[0080] This invention relates to the patent application No. 2024-196559 filed with the Japan Patent Office on November 11, 2024, and all contents of that application are incorporated by reference into the specification of this application.

Claims

1. A printer comprising: a transport roller for transporting a printing medium having an RFID inlay; a print head having a heating element for printing information on the printing medium; a oscillating member capable of oscillating around an oscillating axis parallel to the rotation axis of the transport roller; and an antenna capable of communicating with the RFID inlay, wherein the antenna is positioned on the oscillating member on the print surface side of the transported printing medium and upstream of the heating element position of the print head in the transport direction of the printing medium.

2. The printer according to claim 1, wherein the antenna is positioned at the downstream end of the oscillating member in the transport direction of the printing medium.

3. The printer according to claim 1 or 2, wherein the oscillating member is configured to cover at least a portion of the print head.

4. The printer according to any one of claims 1 to 3, comprising an antenna cover that blocks at least a portion of the electromagnetic waves radiated from the antenna, wherein the antenna cover is provided on the oscillating member.

5. The printer according to claim 4, wherein the antenna is located at the downstream end of the antenna cover in the transport direction of the printing medium.

6. The printer according to claim 4, wherein, when the direction in which the printing medium moves is forward at the position of the heating element of the print head, the antenna cover is positioned behind the antenna.

7. The printer according to claim 4, wherein, when the direction of the printing medium is forward at the position of the heating element of the print head, the print head has a shape that becomes thinner towards the rear when the printer is viewed from the side, the antenna cover is arranged in the space formed by the thinning of the print head, and the antenna is arranged closer to the position of the heating element of the print head than the antenna cover.

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