thermal printer

Abstract

To provide a thermal printer capable of extending its life. [Solution] The device comprises a printing mechanism 200 having a thermal head 210 that prints on recording paper S and a platen roller 220 that transports the recording paper S sandwiched between the thermal head 210, and a friction mechanism 300 that is positioned upstream of the printing mechanism 200 in the transport direction of the recording paper S and applies friction to the printing surface S1 of the recording paper S.

Description

[Technical Field]

[0001] The present invention relates to a thermal printer. [Background technology]

[0002] Patent Document 1 discloses the configuration of a thermal printer in which recording paper is sandwiched between a thermal head and a platen roller. The thermal head is biased toward the platen roller. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-35803 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the configuration described in Patent Document 1 has a problem in that if hard foreign matter is present on the printing surface of the recording paper, the thermal head is likely to wear out due to contact between the thermal head and the hard foreign matter. [Means for solving the problem]

[0005] A thermal printer includes a printing mechanism having a thermal head that prints on recording paper and a platen roller that transports the recording paper sandwiched between the thermal head and the printing mechanism, and a friction mechanism that is positioned upstream of the printing mechanism in the transport direction of the recording paper and applies friction to the printing surface of the recording paper. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a cross-sectional view illustrating a configuration of a thermal printer. [Figure 2] FIG. 1 is a cross-sectional view illustrating a configuration of a thermal printer. [Figure 3A] FIG. 2 is a cross-sectional view showing the configuration of a friction mechanism and a printing mechanism. [Figure 3B] FIG. 3B is an enlarged cross-sectional view of part A in FIG. 3A. [Figure 3C] FIG. 3B is an enlarged cross-sectional view of part B in FIG. 3A. [Figure 4] FIG. 1 is a cross-sectional view illustrating a configuration of a thermal printer according to an embodiment of the present invention. [Figure 5] FIG. 10 is a cross-sectional view showing the configuration of a thermal printer according to a modified example. [Figure 6] FIG. 10 is a cross-sectional view showing the configuration of a thermal printer according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0007] The configuration of the thermal printer 1000 will be described below with reference to the drawings. In the following drawings, three mutually perpendicular axes will be referred to as the X-axis, Y-axis, and Z-axis. The direction along the X-axis will be referred to as the "X-direction," the direction along the Y-axis will be referred to as the "Y-direction," and the direction along the Z-axis will be referred to as the "Z-direction." The direction of the arrow is the positive direction, and the direction opposite to the positive direction is referred to as the negative direction.

[0008] First, the configuration of a thermal printer 1000 will be described with reference to Figures 1 and 2. Figure 1 shows the device main body 100 with a cover 110 open.

[0009] 1, the thermal printer 1000 is applied as a receipt printer used in, for example, a POS system, etc. The thermal printer 1000 prints on, for example, a roll of recording paper S using a thermal head 210 (see FIG. 4).

[0010] The thermal printer 1000 comprises a device main body 100 and a cover 110. A recording paper compartment 120 is located on the left side of the device main body 100, i.e., in the -X direction. A roll of recording paper S is stored in the recording paper compartment 120.

[0011] The cover 110 is attached so as to be rotatable, i.e., openable and closable, around a support shaft 111 provided at the upper end of the device body 100. A platen roller 220 is disposed at the tip 110a of the cover 110. When the cover 110 is closed on the device body 100, the platen roller 220 comes into contact with the thermal head 210 (see FIG. 2).

[0012] A printing mechanism 200 having a thermal head 210 and other components is disposed in the center of the device main body 100. The printing mechanism 200 has the thermal head 210 that prints on the recording paper S, and a platen roller 220 that transports the recording paper S sandwiched between the thermal head 210 and the platen roller 220.

[0013] As shown in FIG. 2, a friction mechanism 300 is disposed upstream of the print mechanism 200 in the transport direction of the recording paper S (see FIG. 4).

[0014] The friction mechanism 300 applies friction to the printing surface of the recording paper S. The friction mechanism 300 includes an opposing member 310 and a rotating roller 320. The opposing member 310 comes into contact with the printing surface of the recording paper S. The rotating roller 320 holds the recording paper S between the opposing member 310 and the rotating roller 320.

[0015] The opposing member 310 and the rotating roller 320 press against each other at least from one of the opposing member 310 and the rotating roller 320. In this embodiment, the opposing member 310 presses against the rotating roller 320.

[0016] The facing member 310 has a hardness equal to or greater than that of the thermal head 210. Examples of the facing member 310 include a silica-based film, a plate-like member, and a plate-like member with a silica-based film provided thereon. The facing member 310 has a shape that allows it to apply pressure uniformly and without omission in the width direction of the recording paper S to the pressure contact line (or surface) with the rotating roller 320.

[0017] In this way, because the friction mechanism 300 is disposed upstream of the printing mechanism 200, even if a hard foreign object 400 (see FIG. 3B) is present on the printing surface of the recording paper S, friction is applied to the foreign object 400 by the friction mechanism 300, so that the portion of the foreign object 400 protruding from the printing surface S1 can be scraped off or removed (see FIG. 3C). This makes it possible to prevent contact between the thermal head 210 and the foreign object 400, and to prevent accelerated wear of the thermal head 210.

[0018] Furthermore, the opposing member 310 and the rotating roller 320 press at least one side toward the other. Specifically, in this embodiment, the opposing member 310 is biased toward the rotating roller 320. Therefore, even if a hard foreign object 400 is present on the printed surface of the recording paper S, the friction between the opposing member 310 and the printed surface of the recording paper S can scrape off or remove the foreign object 400 from the portion protruding from the printed surface S1.

[0019] Furthermore, the platen roller 220 and the rotating roller 320 are rotatably attached to the cover 110. When the cover 110 is opened relative to the device body 100, the platen roller 220 and the rotating roller 320 rise up together. This releases the recording paper S from its clamped state, making it easier to replace the recording paper S. In other words, ease of replacing the recording paper S can be ensured.

[0020] 3A to 3C, the configuration of the printing mechanism 200 and the friction mechanism 300 and their relationship to each other will be described. Note that the thermal printer 1000 shown in Fig. 3A is a diagram for explaining the principles of the printing mechanism 200 and the friction mechanism 300, and the printing mechanism 200 and the friction mechanism 300 will be described as being at the same height.

[0021] As shown in FIG. 3A, in the thermal printer 1000, a friction mechanism 300 is disposed upstream in the transport direction of the recording paper S, and a printing mechanism 200 is disposed downstream.

[0022] As described above, the printing mechanism 200 has a thermal head 210 that prints on the recording paper S, a platen roller 220 that transports the recording paper S sandwiched between the thermal head 210, and a first pressing member 230 that presses the thermal head 210 against the platen roller 220.

[0023] The thermal head 210 is movably supported by the apparatus main body 100. The thermal head 210 includes a head unit in which the head is attached to a head attachment member. The thermal head 210 may be configured to be rotatable or slidable, for example, on a support shaft, so that it can move toward and away from the platen roller 220. The platen roller 220 is disposed opposite the thermal head 210. The platen roller 220 is configured, for example, as a cylindrical rubber roller. The platen roller 220 is rotatably supported by the cover 110 via a platen frame (not shown).

[0024] The first pressing member 230 is, for example, a coil spring. The first pressing member 230 is disposed on the opposite side of the thermal head 210 from the platen roller 220. The first pressing member 230 abuts against the thermal head 210. The first pressing member 230 presses the thermal head 210 toward the platen roller 220.

[0025] The recording paper S passes between the platen roller 220 and the thermal head 210. The platen roller 220 and the thermal head 210 are configured to pinch the recording paper S with a predetermined pressure. The recording paper S is transported by the rotation of the platen roller 220.

[0026] The friction mechanism 300 is disposed upstream of the print mechanism 200 in the transport direction of the recording paper S. The friction mechanism 300 applies friction to the printing surface S1 of the recording paper S.

[0027] The friction mechanism 300 has an opposing member 310 that contacts the printing surface S1 of the recording paper S, a rotating roller 320 that clamps the recording paper S between the opposing member 310, and a second pressing member 330 that serves as a pressing member that presses the opposing member 310 toward the rotating roller 320.

[0028] The opposing member 310 is movably supported by the device main body 100. The opposing member 310 may be configured to be rotatable or slidable, for example, by providing a support shaft, so that it can move toward and away from the rotating roller 320. The rotating roller 320 is disposed so as to face the opposing member 310. The rotating roller 320 is configured, for example, by a cylindrical rubber roller. The rotating roller 320 is rotatably supported by the cover 110 via a frame (not shown).

[0029] The second pressing member 330 is, for example, a coil spring. The second pressing member 330 is disposed on the opposite side of the opposing member 310 from the rotating roller 320. The second pressing member 330 abuts against the opposing member 310. The second pressing member 330 presses the opposing member 310 toward the rotating roller 320.

[0030] The recording paper S passes between the rotary roller 320 and the opposing member 310. The rotary roller 320 and the opposing member 310 are configured to pinch the recording paper S with a predetermined pressure. The recording paper S is transported by the rotation of the rotary roller 320.

[0031] The platen roller 220 of the printing mechanism 200 and the rotating roller 320 of the friction mechanism 300 may be the same part. The first pressing member 230 of the printing mechanism 200 and the second pressing member 330 of the friction mechanism 300 may be the same part.

[0032] In this way, the friction mechanism 300 is disposed upstream of the printing mechanism 200, and the recording paper S is sandwiched between the opposing member 310 and the rotating roller 320, with the opposing member 310 applying friction to the printing surface S1 of the recording paper S. Therefore, as shown in FIG. 3B, even if a hard foreign object 400 is present on the printing surface S1 of the recording paper S, the friction mechanism 300, i.e., the opposing member 310, applies friction to the foreign object 400, making it possible to scrape off or remove the portion of the foreign object 400 protruding from the printing surface S1 (see FIG. 3C). Therefore, in the printing mechanism 200 disposed downstream of the friction mechanism 300, it is possible to prevent contact between the thermal head 210 and the foreign object 400, thereby suppressing accelerated wear of the thermal head 210.

[0033] Furthermore, since the opposing member 310 is pressed against the rotating roller 320, it is possible to apply force to the printing surface S1 of the recording paper S, and by moving the recording paper S, it is possible to scrape off or remove foreign matter 400 in the part protruding from the printing surface S1.

[0034] Also, because the platen roller 220 and the rotating roller 320 are the same part, and the first pressing member 230 and the second pressing member 330 are the same part, it is possible to prevent an increase in the number of parts, thereby reducing costs. Furthermore, by using the same parts, it is possible to prevent variations in the pressing force on the recording paper S. Therefore, deterioration of the recording paper S in the friction mechanism 300 can be prevented.

[0035] In the transport direction, a foreign matter collection unit 500 that collects foreign matter 400 removed from the recording paper S is disposed between the friction mechanism 300 and the printing mechanism 200. An opening 501 of the foreign matter collection unit 500 is disposed so as to face the printing surface S1 of the recording paper S. A broom 510 that removes the foreign matter 400 is disposed inside the foreign matter collection unit 500. The tip of the broom 510 comes into contact with the printing surface S1 of the recording paper S.

[0036] When the tip of the broom 510 touches the recording paper S, hard foreign matter 400 stuck to the recording paper S can be removed. The removed foreign matter 400 is collected by the foreign matter collection unit 500. When the recording paper S passes through the foreign matter collection unit 500, the foreign matter 400 has been removed. Alternatively, the protruding parts of the foreign matter 400 have been polished to make them flat. The foreign matter 400 stuck to the recording paper S due to static electricity is removed by coming into contact with the broom 510 placed inside the foreign matter collection unit 500. An example of the broom 510 is an anti-static brush.

[0037] In this way, the foreign matter collection unit 500 is arranged, so that the foreign matter 400 removed from the recording paper S can be collected, and the foreign matter 400 can be prevented from scattering inside the thermal printer 1000. This can prevent the optical sensor 800 inside the thermal printer 1100 from detecting abnormal values ​​and the internal mechanisms, including the optical sensor 800, from breaking down.

[0038] Next, the configuration of the thermal printer 1000 will be described with reference to FIG.

[0039] 4, as described above, the thermal printer 1000 includes a roll of recording paper S, a friction mechanism 300 that clamps and transports the recording paper S downstream, and a printing mechanism 200. The roll of recording paper S is stored in a recording paper storage unit 120.

[0040] The friction mechanism 300 is disposed upstream of the printing mechanism 200 in the transport direction of the recording paper S. The friction mechanism 300 applies friction to the printing surface S1 of the recording paper S to remove foreign matter 400 contained in the recording paper S. As described above, the friction mechanism 300 has an opposing member 310 that comes into contact with the printing surface S1 of the recording paper S, a rotating roller 320 that holds the recording paper S between the opposing member 310 and the rotating roller 320, and a second pressing member 330 that presses the opposing member 310 against the rotating roller 320.

[0041] As described above, the printing mechanism 200 has a thermal head 210 that prints on the printing surface S1 of the recording paper S, a platen roller 220 that transports the recording paper S sandwiched between the thermal head 210, and a first pressing member 230 that presses the thermal head 210 toward the platen roller 220.

[0042] In the friction mechanism 300, the opposing member 310 and the second pressing member 330 are disposed in the -Z direction relative to the rotating roller 320. In the printing mechanism 200, the thermal head 210 and the first pressing member 230 are disposed in the +X direction relative to the platen roller 220. Note that the opposing member 310, the second pressing member 330, the thermal head 210, and the first pressing member 230 are not limited to being disposed in the above directions, and may be changed as appropriate depending on the transport direction of the recording paper S.

[0043] The platen roller 220 and the rotating roller 320 are rotated by the drive of a drive motor 610. The drive motor 610 is connected to a transmission mechanism 700. The transmission mechanism 700 is connected to a first transmission mechanism 710 connected to the platen roller 220 and a second transmission mechanism 720 connected to the rotating roller 320. In other words, the drive motor 610 drives the rotation of the platen roller 220 and the rotating roller 320 via the transmission mechanisms 700, 710, and 720. The transmission mechanisms 700, 710, and 720 are, for example, gears.

[0044] The platen roller 220 and the rotating roller 320 are driven by the drive motor 610, so the platen roller 220 and the rotating roller 320 can be rotated at a uniform speed. In this way, the platen roller 220 and the rotating roller 320 are driven by a single drive motor 610, so they can be driven efficiently with a small number of parts.

[0045] The rotating roller 320 and the platen roller 220 are arranged so that they overlap by at least a portion w1 when viewed in the first direction, in other words, the X direction. In this way, because the rotating roller 320 and the platen roller 220 are arranged so that they overlap by a portion w1, the thermal printer 1000 is prevented from becoming larger than when they are not arranged so that they overlap. Note that the first direction is not limited to the X direction; for example, if the thermal printer 1000 is installed with the side of the device main body 100 (the positive direction of the X axis) facing up so that the recording paper S is discharged horizontally from the thermal printer 1000, the portion w1 may overlap when viewed in the Z direction.

[0046] Between the friction mechanism 300 and the printing mechanism 200, a foreign matter collection unit 500 is arranged to collect foreign matter 400 removed from the recording paper S. Inside the foreign matter collection unit 500, a broom 510 is arranged to remove the foreign matter 400.

[0047] As described above, the thermal printer 1000 of this embodiment includes a printing mechanism 200 having a thermal head 210 that prints on the recording paper S and a platen roller 220 that transports the recording paper S sandwiched between the thermal head 210 and the printing mechanism 200, and a friction mechanism 300 that is positioned upstream of the printing mechanism 200 in the transport direction of the recording paper S and applies friction to the printing surface S1 of the recording paper S.

[0048] With this configuration, the friction mechanism 300 is located upstream of the printing mechanism 200, so even if a hard foreign object 400 is present on the printing surface S1 of the recording paper S, the friction mechanism 300 applies friction to the foreign object 400, making it possible to scrape off or remove the portion of the foreign object 400 that protrudes from the printing surface S1. This makes it possible to reduce contact between the thermal head 210 and the foreign object 400, thereby preventing accelerated wear of the thermal head 210.

[0049] Furthermore, since the acceleration of wear of the thermal head 210 is suppressed, it is possible to prevent damage to the thermal head 210 and extend the product life. Furthermore, because the rotating roller 320 and the platen roller 220 are both attached to the cover 110, the recording paper S can be easily replaced by simply opening the cover 110.

[0050] Furthermore, in the thermal printer 1000 of this embodiment, the friction mechanism 300 preferably includes an opposing member 310 that contacts the printing surface S1 of the recording paper S, and a rotating roller 320 that sandwiches the recording paper S between the opposing member 310, and presses from at least one of the opposing member 310 and the rotating roller 320 toward the other. With this configuration, the opposing member 310 and the rotating roller 320 are biased toward each other, so even if a hard foreign object 400 is present on the printing surface S1 of the recording paper S, the friction between the opposing member 310 and the printing surface S1 of the recording paper S can scrape off or remove the foreign object 400 from the portion of the foreign object 400 that protrudes from the printing surface S1.

[0051] Furthermore, in the thermal printer 1000 of this embodiment, the friction mechanism 300 preferably has a second pressing member 330 that presses the opposing member 310, and the second pressing member 330 presses the rotating roller 320 via the opposing member 310. With this configuration, the opposing member 310 is pressed against the rotating roller 320, so that a force can be applied to the printing surface S1 of the recording paper S, and as the recording paper S moves, the foreign matter 400 protruding from the printing surface S1 can be scraped off or removed.

[0052] Furthermore, in the thermal printer 1000 of this embodiment, it is preferable that the rotating roller 320 is the same part as the platen roller 220, and the second pressing member 330 is the same part as the first pressing member 230 that presses the thermal head 210 against the platen roller 220. With this configuration, the rotating roller 320 and the platen roller 220 are the same part, and the second pressing member 330 is the same part as the first pressing member 230, making it possible to prevent an increase in the number of parts and reducing costs. Furthermore, using the same parts reduces variations in the pressing force on the recording paper S. Therefore, deterioration of the recording paper S in the friction mechanism 300 can be prevented.

[0053] Furthermore, in the thermal printer 1000 of this embodiment, a foreign matter collection unit 500 that collects foreign matter 400 contained in the recording paper S is disposed between the friction mechanism 300 and the printing mechanism 200 in the transport direction, and the foreign matter collection unit 500 is preferably disposed so as to face the printing surface S1 of the recording paper S. With this configuration, the foreign matter collection unit 500 is disposed, making it possible to collect the foreign matter 400 removed from the recording paper S and preventing the foreign matter 400 from scattering inside the thermal printer 1000. This makes it possible to prevent the thermal printer 1000 from breaking down or malfunctioning.

[0054] Furthermore, in the thermal printer 1000 of this embodiment, it is preferable that the rotating roller 320 and the platen roller 220 are arranged so that at least a portion w1 overlaps when viewed horizontally. With this configuration, the rotating roller 320 and the platen roller 220 are arranged so that they overlap, which helps prevent the thermal printer 1000 from becoming larger in size compared to when they are not arranged so that they overlap.

[0055] Furthermore, the thermal printer 1000 of this embodiment preferably includes a drive motor 610 and transmission mechanisms 700, 710, and 720 connected to the drive motor 610, and the drive motor 610 drives the platen roller 220 and the rotating roller 320 via the transmission mechanisms 700, 710, and 720. With this configuration, the platen roller 220 and the rotating roller 320 are driven by the single drive motor 610, allowing for efficient driving with fewer parts.

[0056] Modifications of the above-described embodiment will now be described.

[0057] As described above, the configuration is not limited to driving the rotating roller 320 and the platen roller 220 with one drive motor 610, and may be the configuration shown in Fig. 5. As shown in Fig. 5, a modified thermal printer 1000A has a first drive motor 620 that drives the platen roller 220 and a second drive motor 630 that drives the rotating roller 320. In other words, the platen roller 220 and the rotating roller 320 are driven by separate drive motors 620, 630.

[0058] The first drive motor 620 drives the platen roller 220 via a first transmission mechanism 730. The second drive motor 630 drives the rotary roller 320 via a second transmission mechanism 740. As described above, the first transmission mechanism 730 and the second transmission mechanism 740 are, for example, gears.

[0059] In this way, the platen roller 220 and the rotating roller 320 are driven by separate drive motors 620, 630, which makes it possible to distribute the transport force compared to a method in which the recording paper S is transported by one of the platen rollers 220, thereby reducing the paper transport load on the platen roller 220.

[0060] Furthermore, because the recording paper S is transported by separate drive motors 620, 630, slack S2 can be created in the recording paper S between the rotating roller 320 and the platen roller 220. Therefore, as shown in Figure 5, it is preferable to dispose an optical sensor 800 between the friction mechanism 300 and the printing mechanism 200 as a sensor for detecting the amount of slack in the recording paper S.

[0061] In this way, because the optical sensor 800 is disposed to detect the amount of slack in the recording paper S, if the amount of slack is less than a predetermined amount, it is possible to increase the amount of slack by speeding up the rotation of the rotating roller 320. If the amount of slack is greater than the predetermined amount, it is possible to reduce the amount of slack by slowing down the rotation of the rotating roller 320. This makes it possible to maintain a constant amount of slack, and reduce the paper feed load on the platen roller 220.

[0062] As described above, the thermal printer 1000A of this modified example includes a first drive motor 620 that drives the platen roller 220 and a second drive motor 630 that drives the rotating roller 320. With this configuration, the platen roller 220 and the rotating roller 320 are driven by separate drive motors 620, 630. This allows for more distributed transport force and a reduced paper feed load on the platen roller 220 compared to a method in which the recording paper S is transported by a single platen roller 220. Furthermore, because the recording paper S is transported by separate drive motors 620, 630, a slack S2 can be created between the rotating roller 320 and the platen roller 220. In other words, the rotating roller 320 functions as a delivery mechanism. Furthermore, the performance requirements for the first drive motor 620 that drives the platen roller 220 can be reduced.

[0063] Furthermore, in the thermal printer 1000A of this modified example, an optical sensor 800 that detects the amount of slack in the recording paper S is preferably disposed between the friction mechanism 300 and the printing mechanism 200. With this configuration, because the optical sensor 800 that detects the amount of slack in the recording paper S is disposed, if the amount of slack is less than a predetermined amount, it is possible to increase the amount of slack by speeding up the rotation of the rotating roller 320, and if the amount of slack is greater than the predetermined amount, it is possible to reduce the amount of slack by slowing down the rotation of the rotating roller 320. This makes it possible to maintain a constant amount of slack, and reduces the paper feed load on the platen roller 220.

[0064] As described above, the rotating roller 320 is not limited to being driven using the drive motor 610, and the rotating roller 320 may not be driven using the drive motor 610, as shown in Fig. 6. As shown in Fig. 6, a thermal printer 1000B of a modified example uses a drive motor 640 to drive the platen roller 220. Specifically, the drive motor 640 drives the platen roller 220 via a transmission mechanism 750.

[0065] The platen roller 220 is positioned below the rotary roller 320, i.e., in the -Z direction. Therefore, the thermal head 210 and the first pressing member 230 are also positioned in the -Z direction. A driven roller 340 that supports the printing surface S1 of the recording paper S is positioned between the friction mechanism 300 and the printing mechanism 200. The position of the driven roller 340 is the same height as the opposing member 310. In other words, the position of the platen roller 220 is below the position of the driven roller 340.

[0066] In this way, because the platen roller 220 is positioned lower than the driven roller 340, the recording paper S winds around the driven roller 340. As a result, the recording paper S winds around approximately half of the circumference of the platen roller 220. In other words, it is possible to increase the contact area between the platen roller 220 and the recording paper S, which increases frictional force and therefore increases the force with which the platen roller 220 conveys the recording paper S. Furthermore, loss of power from the drive motor 640 can be reduced.

[0067] As described above, the thermal printer 1000B of this modified example includes a drive motor 640 that drives the platen roller 220, and the rotating roller is configured as a driven roller 340. With this configuration, the thermal printer 1000B can be configured with a small number of parts, thereby achieving low cost and space savings.

[0068] As described above, in the thermal printer 1000B of this modified example, the driven roller 340 that supports the printing surface S1 of the recording paper S is disposed between the friction mechanism 300 and the printing mechanism 200. With this configuration, by arranging the driven roller 340 and the platen roller 220 so that the recording paper S wraps around the driven roller 340, it is possible to increase the contact area between the platen roller 220 and the recording paper S, and the force with which the platen roller 220 conveys the recording paper S can be increased.

[0069] As described above, the friction mechanism 300 and the printing mechanism 200 are not limited to applications in receipt printers, but may also be applied to label printers, for example.

[0070] As described above, the friction mechanism 300 is not limited to having the opposing member 310 disposed below the recording paper S, i.e., in the -Z direction, but may also be disposed above the recording paper S, i.e., in the +Z direction. Also, although the rotating roller 320 is used exclusively for the opposing member 310, the present invention is not limited to this, and the opposing member 310 may also be disposed so that the platen roller 220 of the printing mechanism 200 can be shared.

[0071] As mentioned above, the sensor is not limited to the optical sensor 800, but may be, for example, a contact sensor. [Explanation of symbols]

[0072] 100... device main body, 110... cover, 111... support shaft, 120... recording paper storage section, 200... printing mechanism, 210... thermal head, 220... platen roller, 230... first pressing member as pressing member, 300... friction mechanism, 310... opposing member, 320... rotating roller, 330... second pressing member as pressing member, 340... driven roller, 400... foreign matter, 500... foreign matter collection section, 501 ...Opening, 510...broom, 610...drive motor, 620...first drive motor, 630...second drive motor, 640...drive motor, 700...transmission mechanism, 710...first transmission mechanism, 720...second transmission mechanism, 730...first transmission mechanism, 740...second transmission mechanism, 750...transmission mechanism, 800...optical sensor as sensor, 1000, 1000A, 1000B...thermal printer.

Claims

1. a printing mechanism having a thermal head that prints on recording paper and a platen roller that conveys the recording paper sandwiched between the thermal head and the platen roller; a friction mechanism that is disposed upstream of the printing mechanism in the conveyance direction of the recording paper and applies friction to the printing surface of the recording paper; A thermal printer.

2. The thermal printer according to claim 1, the friction mechanism includes an opposing member that contacts the printing surface of the recording paper, and a rotating roller that holds the recording paper between the opposing member and the rotating roller; A thermal printer in which at least one of the opposing member and the rotating roller is pressed against the other.

3. 3. The thermal printer according to claim 2, the friction mechanism has a pressing member that presses the opposing member, The pressing member presses the rotating roller via the opposing member.

4. The thermal printer according to claim 3, the rotating roller is the same part as the platen roller, A thermal printer, wherein the pressing member is the same part as the pressing member that presses the thermal head against the platen roller.

5. The thermal printer according to claim 1, a foreign matter recovery unit that recovers foreign matter contained in the recording paper, the foreign matter recovery unit being disposed between the friction mechanism and the printing mechanism in the transport direction; The foreign matter collection unit is disposed opposite the printing surface of the recording paper.

6. 3. The thermal printer according to claim 2, The thermal printer, wherein the rotating roller and the platen roller are arranged to at least partially overlap when viewed in a first direction.

7. 3. The thermal printer according to claim 2, a drive motor that drives the platen roller; A thermal printer, wherein the rotating roller is configured as a driven roller.

8. 3. The thermal printer according to claim 2, a drive motor and a transmission mechanism connected to the drive motor; The drive motor drives the platen roller and the rotating roller.

9. 3. The thermal printer according to claim 2, a first drive motor that drives the platen roller; a second drive motor that drives the rotating roller; A thermal printer.

10. The thermal printer according to claim 9, A thermal printer, wherein a sensor for detecting the amount of slack in the recording paper is disposed between the friction mechanism and the printing mechanism.

11. The thermal printer according to claim 1, A thermal printer, wherein a driven roller that supports the printing surface of the recording paper is disposed between the friction mechanism and the printing mechanism.

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