Web printer

Abstract

A web printer is provided. The web printer includes a housing that can accommodate a web wound in a manner that one face of a recording paper is on the outside; a feed roller that pulls out the recording paper from the web and feeds the recording paper in a feed direction; a guide portion that can abut against the other face of the recording paper at an upstream of the feed direction of the feed roller; a protrusion that can abut against the one face of the recording paper at the upstream of the feed direction of the feed roller and can move toward the guide portion; a rod that can be accommodated in the protrusion and can abut against and move the one face of the recording paper; and a sensor that is accommodated in the protrusion and detects movement of the rod.

Description

Technical Field

[0001] This disclosure relates to a roll paper printer. Background Technology

[0002] As shown in Patent Document 1, a technique has been known in which, in an apparatus having a mechanism for adjusting the tension of paper pulled from a roll and a mechanism for detecting paper, a rod for detecting paper traces a rotational trajectory in a portion of the area of ​​the mechanism for adjusting the tension of paper.

[0003] In the aforementioned device, the mechanisms for adjusting the paper tension and detecting the paper become complex structures, resulting in a larger space occupied within the device and a larger overall size.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2010-6612 Summary of the Invention

[0005] The roll paper printer includes: a receiving section for receiving a roll of paper wound with one side of the recording paper facing outwards; a transport roller for pulling the recording paper out of the roll and transporting it in a transport direction; a guide section upstream of the transport roller in the transport direction, capable of abutting against the other side of the recording paper; a protrusion upstream of the transport roller in the transport direction, capable of abutting against the one side of the recording paper and movable toward the guide section; a rod retractable in the protrusion, capable of abutting against and moving against the one side of the recording paper; and a sensor retractable in the protrusion for detecting the movement of the rod. Attached Figure Description

[0006] Figure 1 A cross-sectional view of a roll paper printer with recording paper.

[0007] Figure 2 An enlarged view of the plane centered on the protrusion when no recording paper is available.

[0008] Figure 3 An enlarged view of the plane centered on the protrusion when there is recording paper.

[0009] Figure 4 An enlarged view of the cross-section centered on the protrusion when no recording paper is available.

[0010] Figure 5 An enlarged view of the cross-section centered on the protrusion when there is recording paper. Detailed Implementation

[0011] 1. First Implementation Method

[0012] 1-1. Structure of a roll paper printer

[0013] The following is for reference Figures 1 to 5 The roll paper printer 1 according to the embodiment will be described. Furthermore, the directions in the figures will be explained using a three-dimensional coordinate system. For ease of explanation, the positive direction of the Z-axis will be referred to as "up" or simply "up," and the negative direction as "down" or simply "down." The positive direction of the X-axis will be referred to as "right" or simply "right," and the negative direction as "left" or simply "left." The positive direction of the Y-axis will be referred to as "front" or simply "front," and the negative direction as "rear" or simply "rear."

[0014] The roll-paper printer 1 described in this embodiment is used, for example, in a POS (Point of Sale) system. A POS system is used in retail businesses such as shopping malls, department stores, convenience stores, and mobile vending machines, or in food and beverage businesses such as restaurants, tea houses, and izakayas. The roll-paper printer 1 used in the POS system prints receipts, coupons, tickets, etc., depending on the goods or services offered.

[0015] like Figure 1 As shown, the roll paper printer 1 is configured to include a protrusion 3, a guide 5, a conveyor roller 6, a head 7, and a cutter 8. A rod 10 is retractably mounted on the protrusion 3.

[0016] A hinge 21 is provided on the housing 24 at the bottom and front position. The cover 20 is mounted so as to be able to rotate about the hinge 21.

[0017] The housing 24 is equipped with a protrusion 3, a head 7, a second blade 8b of the cutter 8, and a storage portion 22 (described later). On the other hand, the cover 20 is equipped with a guide portion 5, a conveying roller 6, and a first blade 8a of the cutter 8. A cut 11 (described later) is formed on the guide portion 5.

[0018] The recording paper 2 is, for example, a strip of thermal paper. A thermal material is coated on one surface 2a of the recording paper 2, allowing images to be printed via the head 7. The other surface 2b of the recording paper 2 is the surface that contacts the transport roller 6.

[0019] The roll of paper R is wound onto the core R0 with the surface 2a of the recording paper 2 facing outwards and the back surface 2b facing inwards. The closer the recording paper 2 is to the core R0 of the roll of paper R, that is, the smaller the outer diameter of the roll of paper R, the more curled it becomes. In the following text, the outer diameter will be referred to as the diameter.

[0020] The width of the recording paper 2 is, for example, 80 mm. The width of the recording paper 2 can also be 58 mm. The thickness of the recording paper 2 is, for example, 0.06 mm to 0.08 mm. The diameter D of the roll paper R is, for example, 80 mm. The diameter of the core R0 is, for example, 18 mm. Furthermore, in the following text, the diameter D of the roll paper R will simply be referred to as diameter D.

[0021] The roll of paper R can be stored in the storage section 22 located at the bottom inside the housing 24. The cover 20 can open and close the storage section 22. When the user opens the cover 20 forward, they can enter the storage section 22.

[0022] The user can place the recording paper 2 in the roll paper printer 1 by simply opening the cover 20, storing the roll paper R in the storage section 22, pulling out the recording paper 2 from the roll paper R, and closing the cover 20.

[0023] When the cover 20 is closed, the guide portion 5 mounted on the cover 20 is positioned opposite the protrusion 3 mounted on the housing 24, spaced apart from the recording paper 2. The guide portion 5 can abut against the back surface 2b of the recording paper 2, and the protrusion 3 can abut against the surface 2a of the recording paper 2.

[0024] As a result, the transport path 9 of the recording paper 2 is formed to be curved between the opposing guides 5 and the protrusions 3, as described later.

[0025] Furthermore, when the cover 20 is closed, if the recording paper 2 is on the transport path 9, the lever 10 abuts against the recording paper 2 and turns on the switch 13, as described later, thereby indicating that the recording paper 2 is on the transport path 9.

[0026] Furthermore, when the cover 20 is closed, the conveyor roller 6 mounted on the cover 20 is positioned opposite to the head 7 mounted on the housing 24, which holds the recording paper 2. As a result, the conveyor roller 6 can abut against the back side 2b of the recording paper 2 for conveying, and the head 7 can abut against the surface 2a of the recording paper 2 for printing.

[0027] The conveyor roller 6, which is positioned opposite the head 7 via the recording paper 2, is also called the impression roller.

[0028] Furthermore, the first blade 8a of the cutter 8 mounted on the cover 20 is positioned opposite the second blade 8b mounted on the housing 24, separated by a space from the recording paper 2. The first blade 8a can move toward the second blade 8b to cut the recording paper 2 located between them.

[0029] Furthermore, when the cover 20 is closed, a rectangular outlet 23 is formed at the boundary between the cover 20 and the housing 24.

[0030] The head 7 is, for example, a row-type thermal head with multiple heating elements arranged side by side. The multiple heating elements of the head 7 can be selected and heated based on the printing data, and an image is printed on the surface 2a of the recording paper 2, which is thermal paper.

[0031] The conveyor roller 6 is rotated counterclockwise in the direction indicated by the arrow by a motor for the conveyor roller (not shown).

[0032] The conveyor roller 6 pulls the recording paper 2 out of the roll paper R in the receiving section 22 and conveys it via the conveyor path 9 in the conveying direction indicated by the arrows from the conveyor roller 6 and the head 7 to the discharge port 23 and the cutter 8. At this time, the roll paper R also rotates counterclockwise as the recording paper 2 is pulled out.

[0033] Starting from the upstream and moving downstream in the conveying direction, the following components are arranged in sequence: a receiving section 22, a conveying path 9 formed by a guide section 5 and a protrusion 3, a conveying roller 6 and a head 7, a cutter 8, and a discharge port 23.

[0034] The protrusion 3 can move in either direction A (a first direction) or direction B (a second direction). Specifically, the protrusion 3 can move forward in direction A toward the guide 5 and can retreat in direction B away from the guide 5. Direction B is the opposite direction to direction A.

[0035] The protrusion 3 is mounted on the first elastic member 4. The protrusion 3 is pushed in the A direction by the thrust S1 of the first elastic member 4. The first elastic member 4 is telescopic and is made of spring or rubber, etc. The first elastic member 4 is, for example, a compression coil spring. One end of the first elastic member 4 is fixed to the housing 24, and the other end can push the protrusion 3 in the A direction.

[0036] The protrusion 3 is configured to move a distance of 6.0 mm in the direction B, based on the position where the recording paper 2 is not on the transport path 9 and is not in contact with the recording paper 2. This distance is also the length that the first elastic member 4 can compress.

[0037] Furthermore, the protrusion 3 is configured to extend in the width direction of the recording paper 2, which is the left-right direction. The protrusion 3 extends, for example, 80 mm in the width direction according to the width of the recording paper 2.

[0038] The first elastic member 4 can also be configured to be positioned at least on the left and right sides of the protrusion 3. When the first elastic member 4 is configured in this way, the protrusion 3 can apply a pushing force S1 of the first elastic member 4 evenly to the recording paper 2 in the paper width direction.

[0039] The guide portion 5 is also configured in the same way as the protrusion 3 to extend in the direction of the width of the recording paper 2.

[0040] For the recording paper 2 pulled from the roll R and tightened by the conveyor roller 6, a tension T is applied in the direction indicated by the arrow, which is the same as the conveying direction. As a result, the tension T of the recording paper 2 acts in a way that pushes the protrusion 3 in the direction B. In other words, by the action of the tension T, the protrusion 3 comes into contact with the recording paper 2 and is pushed in the direction B.

[0041] The lever 10 can be housed in the protrusion 3 and can abut against and move against the surface 2a of the recording paper 2. The lever 10 can move in direction C, which is a third direction, or in direction D, which is a fourth direction. Direction D is the opposite of direction C.

[0042] On the guide portion 5, a cutout 11 is formed at a position opposite to the rod 10 protruding from the protrusion 3 when the cover 20 is closed. The cutout 11 may also be, for example, a hole or a groove.

[0043] The rod 10 can move forward in the direction C, which is inserted into the cut 11 of the guide 5, and can retract in the direction D, which is pulled out from the cut 11 of the guide 5.

[0044] 1-2. Structure for testing recording paper

[0045] Figure 2 This indicates that the recording paper 2 is not on the transport path 9. Figure 3 This indicates that recording paper 2 is on transport path 9. (For) Figure 2 as well as Figure 3 A comparison will be made to illustrate this. Additionally, in Figure 2 as well as Figure 3 In order to facilitate understanding of the structure, the guide part 5 is omitted and only the cut 11 formed on the guide part 5 is shown.

[0046] like Figure 2 As shown, rod 10 has two sides, and is in the shape of an L-shape, with one side extending left and right and the other side extending front and back.

[0047] At the end of the other side of the rod 10, a rod tip 10a is formed that can abut against the surface 2a of the recording paper 2. At the end of one side of the rod 10, there is a shaft 10b, and the shaft 10b is mounted on the protrusion 3. The rod 10 is mounted on the protrusion 3 in a manner that allows it to rotate about the shaft 10b.

[0048] A second elastic member 12 is mounted on the rod 10. The second elastic member 12 is also housed in the protrusion 3. The second elastic member 12 is made of spring or rubber, etc. For example, the second elastic member 12 is a torsion coil spring. When the second elastic member 12 is a torsion coil spring, one arm is fixed to the protrusion 3, and the other arm is mounted on the rod 10.

[0049] As indicated by the arrow, the second elastic member 12 applies a thrust S2 to the rod 10 in a clockwise direction with the axis 10b of the rod 10 as the center. As a result, the top end 10a of the rod 10 is pushed toward the guide portion 5, i.e., in the direction C, by the thrust S2 of the second elastic member 12.

[0050] In addition, the thrust S2 of the second elastic member 12 is set to be less than the thrust S1 of the first elastic member 4.

[0051] exist Figure 2 In the example shown, since the recording paper 2 is not on the transport path 9, the tip of the rod 10a does not come into contact with the recording paper 2, and thus moves in the C direction by the thrust S2 of the second elastic member 12. Specifically, the tip of the rod 10a protrudes from the opening 3b formed on the tip of the protrusion 3, i.e., the protrusion tip 3a, and passes through the transport path 9 and is inserted into the cutout 11 of the guide portion 5.

[0052] The switch 13, which serves as a sensor, is housed in the protrusion 3. The switch 13 has a switch lever 13a. The switch 13 is configured in the protrusion 3 such that the switch lever 13a is positioned to abut against the lever 10.

[0053] The switch lever 13a is rotatable about the switch shaft 13b. Inside the switch 13, two metal contacts are formed. Under normal conditions, since the switch lever 13a does not rotate, the two contacts are separated, thus the switch is open. When the switch lever 13a rotates, the two contacts come into contact and conduct electricity, thus the switch is closed. Alternatively, the on / off states of the switch 13 can be reversed.

[0054] like Figure 2 As shown, when the recording paper 2 is not on the transport path 9 and the top of the lever 10a is not in contact with the recording paper 2, the lever 10 is in a position that has moved in the C direction. At this time, the lever 10 does not contact the switch lever 13a, so the switch lever 13a does not rotate. As a result, the switch 13 is open.

[0055] Switch 13 is connected via switch cable 13c to a CPU (Central Processing Unit, not shown), which controls all parts of the roll paper printer 1 in a comprehensive manner. The CPU can determine that the recording paper 2 is not on the transport path 9 by receiving information that switch 13 is off via switch cable 13c.

[0056] In this way, the switch 13 is turned on / off by the position of the lever 10, thereby enabling the detection of the movement of the lever 10.

[0057] like Figure 2As shown, one end of the first elastic member 4 is fixed to the housing 24. Since the recording paper 2 is not on the transport path 9, there is no tension T of the recording paper 2, so the first elastic member 4 pushes the protrusion 3 from the other end in the direction A by the thrust S1, causing it to move. Furthermore, the second elastic member 12 pushes the rod tip 10a by the thrust S2, thereby causing the rod tip 10a to move from the mounted protrusion 3 in the direction C.

[0058] In this way, taking the position of the housing 24 as a reference, and based on the fact that the protrusion 3 has moved in the A direction through the first elastic member 4, the top end 10a of the rod moves further in the C direction through the second elastic member 12.

[0059] The trajectory of the rod tip 10a moving in the C and D directions lies on an arc centered on axis 10b.

[0060] The tip of the lever 10a is configured to move a distance of 5.0 mm in the direction D, based on the position where the recording paper 2 is not on the transport path 9 and is not in contact with the recording paper 2. On the other hand, the width of the recording paper 2 is, for example, 80 mm, and the tip of the lever 10a is located approximately in the center.

[0061] The radius of the circle along one side of rod 10 centered on axis 10b is approximately half the width of the recording paper 2, which is 80mm. In this way, the radius of the circle along one side of rod 10 centered on axis 10b is approximately 40mm, which is considerably larger than the length of the arc of the movement trajectory of rod tip 10a (5.0mm), approximately eight times larger. Therefore, the movement trajectories of rod tip 10a in the C and D directions can be approximately approximated as straight lines.

[0062] As a result, the A direction in which the protrusion 3 moves and the C direction in which the rod tip 10a moves can be considered the same direction. Similarly, the B direction in which the protrusion 3 moves and the D direction in which the rod tip 10a moves can be considered the same direction.

[0063] Using the position of the housing 24 as a reference, and based on the fact that the mounted protrusion 3 has moved in the A direction through the first elastic member 4, the rod tip 10a moves further in the C direction, which can be considered to be the same direction as the A direction, through the second elastic member 12.

[0064] On the other hand, such as Figure 3 As shown, when the recording paper 2 is on the transport path 9, the top end 10a of the rod moves from... Figure 2 The position shown is moved from the cut 11 of the guide 5 to the position of being pulled out, and comes into contact with the recording paper 2.

[0065] The thrust S2 of the second elastic member 12 is set to be less than the force that pushes the recording paper 2 in the direction D when the tension T of the recording paper 2 is applied. Furthermore, as described above, the thrust S2 of the second elastic member 12 is set to be less than the thrust S1 of the first elastic member 4.

[0066] Therefore, when the recording paper 2 is on the transport path 9 and the tip of the rod 10a comes into contact with the recording paper 2, firstly, the tension T of the recording paper 2 resists the thrust S2 of the second elastic member 12 and is pushed, thereby moving the tip of the rod 10a in the D direction. Then, the tip of the rod 10a reaches the position of the opening 3b of the protrusion tip 3a of the protrusion 3.

[0067] At this time, the recording paper 2 abuts against the top of the rod 10a and the top of the protrusion 3a. Furthermore, the rod 10 is housed in the protrusion 3, including the top of the rod 10a.

[0068] Next, as the tension T of the recording paper 2 increases, the protrusion 3 is pushed against the thrust S1 of the first elastic component 4 and moves in the direction B.

[0069] The top of the rod 10a is pushed by the tension T of the recording paper 2. Based on the position of the housing 24, it first moves in the D direction, and then moves further in the B direction together with the protrusion 3 it is mounted on.

[0070] The recording paper 2 is on the transport path 9, and the top end 10a of the lever abuts against the recording paper 2 and is pushed by the tension T of the recording paper 2, moving in the direction D. Then, the lever 10 rotates counterclockwise about the axis 10b as indicated by the arrow and abuts against the switch lever 13a.

[0071] In addition, the switch lever 13a rotates clockwise around the switch shaft 13b, and the internal contacts of the switch 13 make contact and conduction, thereby turning on the switch.

[0072] The CPU can detect that switch 13 is on and determine that the recording paper 2 is on the transport path 9.

[0073] The recording paper 2 is conveyed in the upward conveying direction of the conveying path 9. At the top of the rod 10a, it is shaped such that it slopes towards the conveying direction to smoothly abut against the recording paper 2. The top of the rod 10a may also be shaped such that it has a predetermined curvature towards the conveying direction.

[0074] There is a situation where paper dust from the recording paper 2 enters through the opening 3b of the protrusion 3 at the tip 3a of the protrusion 3 that abuts against the recording paper 2, and enters the contact inside the switch 13, thus causing a malfunction.

[0075] To suppress the malfunction, in the protrusion 3, the switch 13 is positioned away from the opening 3b in the D direction and closer to the housing 24.

[0076] Furthermore, in lever 10, the portion that abuts against switch 13 extends upward. As a result, switch 13 is not positioned on the extension line of the movement trajectory in the D direction of lever tip 10a, thus preventing paper dust from being introduced from lever tip 10a to switch 13.

[0077] Additionally, the cover (not shown) is positioned above. Figure 3 The protrusion 3 shown is completely covered. As a result, only the opening 3b of the protrusion 3 opens to the outside. The protrusion 3 is configured such that paper dust cannot enter from outside the opening 3b.

[0078] The protrusion 3 moves in directions A and B depending on the presence or absence of recording paper 2 on the transport path 9 and the change in the tension T of the recording paper 2. Along with the movement of the protrusion 3, the switch 13 mounted on the protrusion 3 also moves in directions A and B. Regarding the switch cable 13c, one end connected to the CPU is fixed to the housing 24, etc., and the other end is connected to the switch 13 and moves together with the switch 13.

[0079] The other end of the switch cable 13c may bend as it moves together with the protrusion 3 and the switch 13. When the switch cable 13c is short and nearly straight, resulting in a wiring configuration without slack, there is a possibility that the stress caused by bending may lead to a breakage.

[0080] like Figure 3 As shown, the switch cable 13c bends in a direction that intersects with both directions A and B, creating a wiring configuration with ample slack. In this way, the switch cable 13c alleviates flexing through its bend, thereby reducing stress caused by the movement of the protrusion 3 and suppressing the possibility of wire breakage.

[0081] 1-3. Structure of the tension of the buffer recording paper

[0082] Figure 4 This indicates that the recording paper 2 is not on the transport path 9. Figure 5 This indicates that recording paper 2 is on conveyor path 9. (On one side...) Figure 4 as well as Figure 5 The structure of the tension T of the buffer recording paper 2 will be explained in comparison.

[0083] First, using Figure 4 The explanation will focus on the transport path 9 formed between the guide section 5 and the protrusion 3.

[0084] The guide portion 5 has a recess 5a and a protrusion 5b connected upstream of the recess 5a in the conveying direction. The recess 5a of the guide portion 5 is also called a concave portion, and the protrusion 5b is also called a convex portion. A cut 11 is formed on the recess 5a of the guide portion 5. The opening 3b of the protrusion tip 3a of the protrusion 3 is formed at a position opposite to the cut 11.

[0085] exist Figure 4 In this case, there is no recording paper 2 on the transport path 9, therefore, the tension T of the recording paper 2 does not play a role. Therefore, the protrusion 3 is pushed in the A direction and moves by the thrust S1 of the first elastic member 4. Furthermore, the rod 10 mounted on the protrusion 3 is pushed in the C direction and moves by the thrust S2 of the second elastic member 12.

[0086] In this way, when there is no recording paper 2 on the transport path 9, the top end 10a of the rod 10 moves in the A direction along with the protrusion 3 based on the position of the housing 24, and moves toward the cutout 11 of the recess 5a of the guide portion 5 along with the movement of the rod 10 in the C direction.

[0087] As a result, the tip of the rod 10a protrudes from the opening 3b of the tip of the protrusion 3 and is inserted into the cut 11 through the conveying path 9.

[0088] As described above, at this time, lever 10 moves away from switch lever 13a of switch 13 and no longer contacts it. Therefore, switch 13 becomes open. The CPU obtains the information that switch 13 is open, and thus can determine that the recording paper 2 is not on the transport path 9.

[0089] Figure 5 In the conveying path 9, there is a recording paper 2, and the top end 10a of the rod 10 is located at the position where it is pulled out from the cut 11 and abuts against the recording paper 2. In addition, after the recording paper 2 is pulled out from the roll paper R by the conveying roller 6, its back side 2b abuts against the protrusion 5b of the guide part 5, and its surface 2a abuts against the protrusion top end 3a of the protrusion 3 downstream in the conveying direction, and is conveyed.

[0090] In this way, the transport path 9 formed by the guide 5 and the protrusion 3, and the recording paper 2 on the transport path 9, meander and bend.

[0091] exist Figure 5 In, with Figure 4 In different situations, the tension T of the recording paper 2 acts on the rod 10 and the protrusion 3.

[0092] Therefore, the tension T of the recording paper 2 first resists the thrust S2 of the second elastic member 12 and acts in a way that pushes and moves the rod 10 mounted on the protrusion 3 in the D direction. As a result, the tip 10a of the rod 10 retracts to the position of the opening 3b of the protrusion tip 3a of the protrusion 3, and together with the protrusion tip 3a, abuts against the surface 2a of the recording paper 2.

[0093] Next, the tension T of the recording paper 2 resists the thrust S1 of the first elastic component 4 and functions in a way that pushes the protrusion 3 in the direction of B and moves it.

[0094] As a result, when there is recording paper 2 on the transport path 9, the rod tip 10a of the rod 10 moves in the direction D with reference to the position of the housing 24, and retracts towards the opening 3b of the protrusion tip 3a of the protrusion 3. Then, the rod tip 10a, together with the protrusion tip 3a of the protrusion 3 and the surface 2a of the recording paper 2, moves in the direction B together with the protrusion 3.

[0095] As described above, at this time, lever 10 abuts against switch lever 13a of switch 13, and switch 13 becomes on. The CPU obtains the status of switch 13 being on and can determine that the recording paper 2 is on the transport path 9.

[0096] When the diameter D of the roll paper R is large and heavy, the load on the conveyor roller 6 when conveying the recording paper is also large, and the tension T of the recording paper 2 also increases.

[0097] The diameter D is, for example, 80 mm before use. As the roll paper R is consumed, the diameter D shrinks to, for example, 30 mm. Compared to the case where the diameter D shrinks due to consumption, the roll paper R is larger and heavier, especially at the beginning of use. Therefore, especially at the beginning of use of the roll paper R, the load on the conveyor roller 6 when conveying the recording paper 2 is also larger, and the tension T of the recording paper 2 is also larger.

[0098] In addition, when the diameter D is large and heavy, the load increases sharply due to the inertia of the roll paper R when the conveyor roller 6 starts to convey the recording paper 2, and the tension T of the recording paper 2 also increases sharply.

[0099] In this situation, when the conveyor roller 6 starts conveying the recording paper 2, the load of the roll paper R will be affected by inertia, which may sometimes cause the conveyor roller 6 to fail to convey the recording paper 2.

[0100] like Figure 5 As shown, the protrusion 3 abuts against the surface 2a of the recording paper 2 and moves in the B direction due to the tension T of the recording paper 2. At the same time, the thrust S1 of the first elastic component 4 is exerted in the A direction, which can buffer the tension T.

[0101] In other words, in order to push the recording paper 2 towards direction B against the resistance tension T, the protrusion 3 uses the thrust S1 of the first elastic member 4 to push the recording paper 2 towards direction A, which is opposite to direction B, so as to play a role in canceling out the mutual forces.

[0102] As the protrusion 3 moves further towards direction B, the first elastic member 4 is compressed more, thus increasing the thrust S1 of the first elastic member 4. Therefore, as the tension T of the recording paper 2 increases, strongly pushing the protrusion 3 towards direction B, the thrust S1 of the first elastic member 4, which pushes it back towards direction A, also increases.

[0103] In this way, the protrusion 3 can buffer the tension T of the recording paper 2 according to the magnitude of the tension T, or in other words, according to the size of the diameter D.

[0104] As a result, even with a large diameter like D, the conveyor roller 6 can stably convey the recording paper 2. In particular, even when the effect of inertia is large at the beginning of conveying and the tension T of the recording paper 2 increases sharply, the conveyor roller 6 can still stably convey the recording paper 2 because the protrusion 3 buffers the tension T.

[0105] Furthermore, when the recording paper 2 is started to be conveyed by the conveying roller 6, and the protrusion 3 moves while buffering the tension T of the recording paper 2, the top tip 10a of the rod also comes into contact with the surface 2a of the recording paper 2 together with the protrusion tip 3a of the protrusion 3.

[0106] Therefore, under these conditions, lever 10 also comes into contact with the switch lever 13a of switch 13, thus turning switch 13 on. The CPU, upon receiving information that switch 13 is on, is able to determine that the recording paper 2 is on the transport path 9.

[0107] Furthermore, as described above, when the conveyor roller 6 conveys the recording paper 2, the roll of paper R is also unwound from the recording paper 2 and rolls counterclockwise within the storage section 22. As the roll of paper R rolls, the load on the conveyor roller 6 while conveying the recording paper 2 changes due to variations in friction between the roll of paper R and the storage section 22. As a result, the tension T of the recording paper 2 also changes.

[0108] In particular, when the diameter D is large, the variation in tension T also increases. With a large variation in tension T, the conveyor roller 6 may sometimes become unable to feed the recording paper 2 at a constant speed, leading to a deterioration in print quality. The constant speed at which the conveyor roller 6 feeds the recording paper 2 is, for example, 500 mm / s.

[0109] Even under these conditions, the protrusion 3 can move in direction A or B according to the change in tension T of the recording paper 2, while the thrust S1 of the first elastic member 4 buffers the change in tension T of the recording paper 2. As a result, the conveyor roller 6 can convey the recording paper 2 at a fixed speed.

[0110] Furthermore, even when the tension T of the recording paper 2 changes, the tip 10a of the lever, together with the tip 3a of the protrusion 3, abuts against the surface 2a of the recording paper 2. Therefore, even in this case, the lever 10 abuts against the switch lever 13a of the switch 13, thereby turning the switch 13 on. The CPU obtains the condition that the switch 13 is on, and thus can determine that the recording paper 2 is on the transport path 9.

[0111] 1-4. Structure for correcting the curl of the recording paper

[0112] As described above, the recording paper 2 wound near the core R0 of the roll paper R, on the portion with a smaller diameter D, will curl more intensely. Receipts, coupons, tickets, etc., printed on such recording paper 2 will also curl inwards in a wound posture, thereby degrading the quality of the printed matter. Furthermore, since there are no components to restrain the recording paper 2 downstream of the conveying roller 6 and the head 7 in the conveying direction, the curled recording paper 2 may also get caught on the cutter 8, the discharge port 23, etc.

[0113] The protrusion 3 enables the thrust S1 of the first elastic member 4 to act in the A direction and to abut against the surface 2a of the conveyed recording paper 2 to flatten it, thereby correcting the curl of the recording paper 2.

[0114] When the diameter D decreases, the roll of paper R becomes lighter, and the load on the conveyor roller 6 when conveying the recording paper 2 also decreases. As a result, the tension T of the recording paper 2 also decreases.

[0115] When the tension T decreases, the thrust S1 of the first elastic member 4 will push the protrusion 3, which is in contact with the recording paper 2, further in the A direction. As a result, the transport path 9 formed between the guide portion 5 and the protrusion 3 becomes narrower because the protrusion 3 is located closer to the guide portion 5.

[0116] Therefore, the curvature of the conveyor path 9 decreases, while the curvature becomes more abrupt. In this way, as the diameter D decreases, the protrusion 3 moves in the direction of A, and the curvature of the conveyor path 9 becomes more abrupt, thereby causing the recording paper 2 to bend further in the direction that effectively corrects the curl of the recording paper 2.

[0117] In other words, the protrusion 3 moves in response to changes in the roll paper R, such as a decrease in diameter D. Furthermore, the curvature of the conveying path 9 formed between the opposing guides 5 and the protrusion 3 changes according to the movement of the protrusion 3.

[0118] As a result, corresponding to the case where the diameter D becomes smaller and the curling of the recording paper 2 becomes stronger, the curvature of the transport path 9 becomes sharper, thereby enabling more effective correction of the curling.

[0119] Furthermore, even when the protrusion 3 moves to correct the curl of the recording paper 2, the tip 10a of the lever abuts against the surface 2a of the recording paper 2 together with the tip 3a of the protrusion 3. Therefore, even in this case, the lever 10 abuts against the switch lever 13a of the switch 13, thereby turning the switch 13 on. The CPU obtains the condition that the switch 13 is on, and thus can determine that the recording paper 2 is on the transport path 9.

[0120] As described above, the roll paper printer 1 of this embodiment has a protrusion 3 that can abut against the surface 2a of the recording paper 2 and can move toward the guide portion 5.

[0121] Furthermore, the roll paper printer 1 of this embodiment includes a rod 10 that can be housed in the protrusion 3 and can abut against and move against the surface 2a of the recording paper 2, and a switch 13 that is housed in the protrusion 3 and detects the movement of the rod 10.

[0122] As a result, while achieving the buffering of the tension T of the recording paper 2 and the detection of the recording paper 2 through a simple structure, the expansion of the internal space of the roll paper printer 1 can be suppressed, thereby suppressing the size of the roll paper printer 1. In addition, the roll paper printer 1 of this embodiment can also correct the curling of the recording paper 2.

[0123] Furthermore, the structure in which the tip 10a of the rod 10 is inserted into the cutout 11 of the guide portion 5 also reduces the space required for the rod 10 to move. When the recording paper 2 is not on the transport path 9, a portion of the rod 10 is exposed on the transport path 9, while the other portion is housed in the protrusion 3 and the cutout 11.

[0124] The embodiments described above with reference to the accompanying drawings are in detail. However, the specific structure is not limited to these embodiments. As long as it does not depart from the spirit of this disclosure, changes, substitutions, deletions, etc., can be made.

[0125] Although the example of a thermal printhead 7 has been described above, the printing method is not limited. For example, the printhead 7 can also be an inkjet printhead. In this case, since the inkjet printhead cannot contact the transport roller 6 and hold the recording paper 2, the driven roller that is opposite to the transport roller 6 and holds the recording paper 2 can be mounted on the housing 24.

[0126] Although the example of a mechanical switch with a switch lever 13a as the sensor has been described above, other sensors may also be used. For example, a reflective or transmissive optical sensor may be used. With such an optical sensor, the position of the lever 10 can be detected.

[0127] In the above description, rod 10 is L-shaped and generates thrust S2 via a torsion coil spring, which serves as the second elastic member 12. Alternatively, similar to the case of protrusion 3 and the first elastic member 4, rod 10 can be made straight, with the second elastic member 12 being a compression coil spring mounted on protrusion 3. In this case, rod 10 moves from protrusion 3 along straight lines in the C and D directions, and the second elastic member 12 also extends and retracts along the same straight line.

[0128] Although the first elastic member 4 is described above as being fixed to the housing 24, it could also be fixed to the storage section 22 that stores the roll of paper R. In this case, as long as it is set to... Figure 1 The storage section 22 shown extends to the upper position and fixes the first elastic member 4. At this time, since the protrusion 3 is mounted on the first elastic member 4, the protrusion 3 is also mounted on the storage section 22.

[0129] Alternatively, the shaft can be positioned below and behind the housing 24, with one end of the rod for the protrusion 3 rotatably mounted on the shaft, and the protrusion 3 mounted on the other end of the rod. The protrusion 3 mounted on the other end of the rod can move about the shaft. The first elastic member 4 can be configured to directly push the protrusion 3, or it can be configured to push the protrusion 3 via the rod for the protrusion 3.

[0130] Although the example above described using the roll paper printer 1 with the discharge outlet 23 facing forward, it can also be used with the discharge outlet 23 facing upward. In this case, Figure 1 The storage section 22 shown extends upwards, so that even when the discharge outlet 23 is in an upward position, the roll of paper R can be stored in the storage section 22.

[0131] Furthermore, the side of the recording paper 2 that abuts against the protrusion 3 may not be the side to be printed on. The roll paper R is wound in such a way that the side of the recording paper 2 to be printed on is the inside. In this case, the positions of the head 7 and the conveyor roller 6 become relative to... Figure 1 The position shown is the opposite.

Claims

1. A roll paper printer, comprising: The storage section is capable of storing rolls of paper that are wound with one side of the recording paper facing outwards. A conveyor roller that pulls the recording paper out of the paper roll and conveys it in the conveying direction; A guide portion, located upstream of the conveying roller in the conveying direction, is capable of abutting against the other side of the recording paper; A protrusion, located upstream of the conveying direction of the conveying roller, is capable of abutting against one surface of the recording paper and moving toward the guide portion; A rod that can be housed in the protrusion and can abut against and move with one side of the recording paper; A sensor, housed within the protrusion, detects movement of the rod. The rod is mounted on the protrusion in a manner that allows it to rotate about an axis. The sensor is mounted on the protrusion in a width direction orthogonal to the conveying direction, alongside the rod.

2. The roll paper printer as described in claim 1, wherein, The guide portion has a cut at a position opposite to the rod.

3. The roll paper printer as described in claim 2, wherein, The rod is inserted into the cut in the guide portion when it is not in contact with the recording paper.

4. The roll paper printer as described in claim 3, wherein, A curved transport path is formed between the opposing guide portions and the protrusions, and the rod passes through the transport path and is inserted into the cutout of the guide portion.

5. The roll paper printer according to any one of claims 1 to 4, wherein, It includes a first elastic member that pushes the protrusion toward the guide portion. The protrusion is pushed in a first direction by the first elastic member and in a second direction opposite to the first direction by the tension of the recording paper.

6. The roll paper printer as described in claim 1, wherein, It includes a second elastic member, which is housed within the protrusion and pushes the rod toward the guide portion. The rod is pushed in a third direction by the second elastic component and in a fourth direction opposite to the third direction by the tension of the recording paper.

7. The roll paper printer as described in claim 1, wherein, When the protrusion is viewed from the width direction, the rod is located within the thickness of the protrusion.

8. The roll paper printer as described in claim 1, wherein, With a head, The head performs printing on one side of the recording paper.

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