Roll paper printer

Abstract

To solve a problem that the size of a printer increases due to complexity of a structure which buffers a tensile force of recording paper and detects the recording paper.SOLUTION: A roll paper printer includes: a storage part capable of storing roll paper rolled in a manner that one surface of recording paper is located at the outer side; a transport roller which draws the recording paper from the roll paper and transports the recording paper in a transport direction; a guide which may contact with the other surface of the recording paper at the upstream of the transport roller in the transport direction; a projection which may contact with the one surface of the recording paper at the upstream of the transport roller in the transport direction and may move toward the guide; a lever which may be housed in the projection and move contacting with the one surface of the recording paper; and a sensor which is housed in the projection and detects movement of the lever.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, as shown in Patent Document 1, in a device equipped with a mechanism for adjusting the tension of paper pulled from a roll of paper and a mechanism for detecting the paper, it is known that the lever that detects the paper traces a rotational trajectory in a part of the area of ​​the mechanism that adjusts the paper tension. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-6612 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described device, the mechanism for adjusting the paper tension and the mechanism for detecting the paper are complicated in configuration, which occupies a large space within the device and increases the size of the device. [Means for solving the problem]

[0005] The roll paper printer comprises a storage section capable of storing roll paper with one side of the recording paper wound on the outside, a transport roller that pulls the recording paper from the roll paper and transports it in a transport direction, a guide that can abut against the other side of the recording paper upstream of the transport roller in the transport direction, a protrusion that can abut against the one side of the recording paper upstream of the transport roller in the transport direction and that can move toward the guide, a lever that can be housed in the protrusion and that can move while abutting against the one side of the recording paper, and a sensor that is housed in the protrusion and that detects movement of the lever. [Brief explanation of the drawings]

[0006] [Figure 1] Cross-sectional view of a roll paper printer with recording paper. [Figure 2] 10 is an enlarged view of a plane centered on the protrusion when there is no recording paper. [Figure 3] 10 is an enlarged view of a plane centered on the protrusion when recording paper is present. [Figure 4] 10 is an enlarged view of a cross section centered on a protrusion when there is no recording paper. [Figure 5] 10 is an enlarged view of a cross section centered on a protrusion when recording paper is present. DETAILED DESCRIPTION OF THE INVENTION

[0007] 1. First embodiment 1-1. Roll paper printer configuration A roll paper printer 1 according to an embodiment will be described below with reference to Figures 1 to 5. Directions in the figures will be described using a three-dimensional coordinate system. For ease of explanation, the positive direction of the Z axis will be referred to as the upward direction or simply "up," and the negative direction will be referred to as the downward direction or simply "down," the positive direction of the X axis will be referred to as the rightward direction or simply "right," and the negative direction will be referred to as the leftward direction or simply "left," and the positive direction of the Y axis will be referred to as the forward direction or simply "front," and the negative direction will be referred to as the rearward direction or simply "rear."

[0008] A roll paper printer 1 according to this embodiment is used in, for example, a POS (Point of Sale) system. POS systems are used in retail businesses such as shopping centers, department stores, convenience stores, and in-train sales, as well as food and beverage businesses such as restaurants, coffee shops, and izakayas. The roll paper printer 1 used in a POS system prints receipts, coupons, tickets, and other documents depending on the product or service.

[0009] As shown in Figure 1, the roll paper printer 1 is made up of a protrusion 3, a guide 5, a transport roller 6, a head 7, and a cutter 8. A lever 10 is mounted on the protrusion 3 so that it can be housed therein. A hinge 21 is provided at a position facing downward and forward on the case 24. The cover 20 is attached so as to be rotatable about the hinge 21. The case 24 is equipped with the protrusion 3, the head 7, the second blade 8b of the cutter 8, and the housing 22 described below. On the other hand, the cover 20 is equipped with the guide 5, the transport roller 6, and the first blade 8a of the cutter 8. The guide 5 is formed with a notch 11 described below.

[0010] The recording paper 2 is, for example, a long piece of thermal paper. A thermal material is applied to one side, the front side 2a, of the recording paper 2, and an image can be printed on it using a head 7. The other side, the back side 2b, of the recording paper 2 is the surface that comes into contact with the transport roller 6. The roll paper R is wound around the core R0 with the front surface 2a of the recording paper 2 facing outward and the back surface 2b facing inward. The closer the recording paper 2 is wound to the core R0 of the roll paper R, that is, the smaller the outer diameter of the roll paper R, the stronger the curl. Note that hereinafter, the outer diameter will simply be referred to as the diameter. The paper width of the recording paper 2 is, for example, 80 mm. The paper width of the recording paper 2 may 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. Note that, below, the diameter D of the roll paper R will be simply referred to as diameter D.

[0011] The roll paper R can be stored in a storage section 22 located downward inside the case 24. The cover 20 can open and close the storage section 22. The user can access the storage section 22 by opening the cover 20 toward the front. The user can load the recording paper 2 into the roll paper printer 1 by opening the cover 20 , placing the roll paper R in the storage compartment 22 , pulling out the recording paper 2 from the roll paper R, and then closing the cover 20 .

[0012] When the cover 20 is closed, the guide 5 mounted on the cover 20 is positioned opposite the protrusion 3 mounted on the case 24, with the recording paper 2 in between. The guide 5 can abut against the back surface 2b of the recording paper 2, and the protrusion 3 can abut against the front surface 2a of the recording paper 2. As a result, a conveying path 9 for the recording paper 2 is formed so as to be curved between the guide 5 and the protrusion 3 that face each other, as will be described later. Also, when the cover 20 is closed and the recording paper 2 is in the transport path 9, the lever 10 contacts the recording paper 2 and turns on the switch 13, as described below, thereby indicating that the recording paper 2 is in the transport path 9.

[0013] Furthermore, when the cover 20 is closed, the transport roller 6 mounted on the cover 20 is positioned opposite the head 7 mounted on the case 24, sandwiching the recording paper 2. As a result, the transport roller 6 comes into contact with the back surface 2b of the recording paper 2, enabling transport, and the head 7 comes into contact with the front surface 2a of the recording paper 2, enabling printing. The transport roller 6, which is positioned opposite the head 7 across the recording paper 2, is also called a platen roller.

[0014] Furthermore, the first blade 8a of the cutter 8 mounted on the cover 20 is positioned opposite the second blade 8b mounted on the case 24, with the recording paper 2 between them. The first blade 8a moves toward the second blade 8b, and can cut the recording paper 2 between them. When the cover 20 is closed, a rectangular outlet 23 is formed at the boundary between the cover 20 and the case 24 .

[0015] The head 7 is, for example, a line-type thermal head with multiple heating elements lined up on the left and right. The multiple heating elements of the head 7 are selected based on the print data and generate heat, allowing an image to be printed on the front surface 2a of the recording paper 2, which is thermal paper.

[0016] The transport roller 6 is rotated counterclockwise as indicated by the arrow by a transport roller motor (not shown). The transport roller 6 pulls out the recording paper 2 from the roll paper R in the storage section 22 and transports it via the transport path 9 in the transport direction indicated by the arrow from the transport roller 6 and head 7 to the discharge port 23 and cutter 8. At this time, as the recording paper 2 is pulled out, the roll paper R also rotates counterclockwise as indicated by the arrow. Arranged in this order from upstream to downstream in the conveying direction are a storage section 22, a conveying path 9 formed by a guide 5 and a protrusion 3, a conveying roller 6 and a head 7, a cutter 8, and a discharge port 23.

[0017] The protrusion 3 can move in a first direction, direction A, or a second direction, direction B. Specifically, the protrusion 3 can advance in direction A, which is the direction toward the guide 5, and can retreat in direction B, which is the direction away from the guide 5. Direction B is the opposite direction to direction A. The protrusion 3 is attached to a first elastic member 4. The protrusion 3 is pushed in the direction A by a pressing force S1 of the first elastic member 4. The first elastic member 4 is expandable and contractible and is made of a spring, rubber, or the like. The first elastic member 4 is, for example, a compression coil spring. One end of the first elastic member 4 is fixed to the case 24, and the other end can push the protrusion 3 in the direction A.

[0018] The protrusion 3 is configured to be movable up to a distance of 6.0 mm in direction B, based on the position when the recording paper 2 is not in the transport path 9 and is not in contact with the recording paper 2. This distance is also the length over which the first elastic member 4 can be compressed. The protrusion 3 is configured to extend in the left-right direction, that is, the width direction of the recording paper 2. The protrusion 3 extends in the paper width direction to match the width of the recording paper 2, for example, 80 mm. The first elastic members 4 may be provided at least on the left and right sides of the protrusion 3. By arranging the first elastic members 4 in this manner, the protrusion 3 can apply the pressing force S1 of the first elastic members 4 to the recording paper 2 in a balanced manner in the paper width direction. Like the protrusion 3, the guide 5 is configured to extend in the paper width direction in accordance with the width of the recording paper 2.

[0019] As the recording paper 2 is pulled from the roll paper R and pulled by the transport roller 6, tension T is applied in the direction of the arrow, which is the same direction as the transport direction. As a result, the tension T on the recording paper 2 acts to push the protrusion 3 in direction B. In other words, the tension T causes the protrusion 3 to come into contact with the recording paper 2 and be pushed in direction B.

[0020] Lever 10 can be housed in protrusion 3 and can move while abutting against surface 2a of recording paper 2. Lever 10 can move in direction C, which is the third direction, or direction D, which is the fourth direction. Direction D is the opposite direction to direction C. The guide 5 has a notch 11 formed at a position facing the lever 10 that protrudes from the projection 3 when the cover 20 is closed. The notch 11 may be, for example, a hole or a groove. The lever 10 can be advanced in the direction C, which is the direction in which it is inserted into the notch 11 of the guide 5, and can be retracted in the direction D, which is the direction in which it is removed from the notch 11 of the guide 5.

[0021] 1-2. Configuration for detecting recording paper Fig. 2 shows a case where the recording paper 2 is not in the transport path 9, and Fig. 3 shows a case where the recording paper 2 is in the transport path 9. The explanation will be made by comparing Fig. 2 and Fig. 3. Note that in Fig. 2 and Fig. 3, in order to explain the configuration more clearly, the guide 5 is omitted and only the notch 11 formed in the guide 5 is shown.

[0022] As shown in FIG. 2, the lever 10 has two sides, one of which extends left and right and the other of which extends front and rear, forming a so-called L-shape. The other end of the lever 10 is provided with a lever tip 10a that can come into contact with the surface 2a of the recording paper 2. One end of the lever 10 has a shaft 10b, which is attached to the protrusion 3. The lever 10 is mounted on the protrusion 3 so as to be rotatable around the shaft 10b.

[0023] A second elastic member 12 is attached to the lever 10. The second elastic member 12 is also housed in the protrusion 3. The second elastic member 12 is made of a spring, rubber, or the like. The second elastic member 12 is, for example, 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 attached to the lever 10. As shown by the arrow, the second elastic member 12 applies a pressing force S2 to the lever 10 in a clockwise direction around the axis 10b of the lever 10. As a result, the lever tip 10a of the lever 10 is pressed in the direction C, which is the direction toward the guide 5, by the pressing force S2 of the second elastic member 12. The pressing force S2 of the second elastic member 12 is set to be smaller than the pressing force S1 of the first elastic member 4.

[0024] 2, since the recording paper 2 is not in the transport path 9, the lever tip 10a is not in contact with the recording paper 2 and moves in the direction C due to the pressing force S2 of the second elastic member 12. Specifically, the lever tip 10a protrudes from the opening 3b formed in the protrusion tip 3a, which is the tip of the protrusion 3, passes through the transport path 9, and is inserted into the notch 11 of the guide 5.

[0025] The switch 13, which is a sensor, is housed in the protrusion 3. The switch 13 has a switch lever 13a. The switch 13 is disposed on the protrusion 3 so that the switch lever 13a is in a position where it can come into contact with the lever 10. The switch lever 13a is rotatable around the switch shaft 13b. Two contacts are made of metal inside the switch 13. In the normal state, the switch lever 13a is not rotating, so the two contacts are separated and the switch is in the OFF state. When the switch lever 13a rotates, the two contacts come into contact and conduct, turning the switch ON. The ON / OFF states of the switch 13 may be reversed.

[0026] As shown in Figure 2, when the recording paper 2 is not in the transport path 9 and the lever tip 10a is not in contact with the recording paper 2, the lever 10 is in a position moved in direction C. At this time, the lever 10 is not in contact with the switch lever 13a, so the switch lever 13a is not rotating. As a result, the switch 13 is turned OFF. The switch 13 is connected via a switch cable 13c to a CPU (Central Processing Unit) (not shown), which controls all parts of the roll paper printer 1. The CPU detects via the switch cable 13c that the switch 13 is OFF, and can determine that the recording paper 2 is not in the transport path 9. In this way, the switch 13 is turned on / off depending on the position of the lever 10, and the movement of the lever 10 can be detected.

[0027] 2, one end of the first elastic member 4 is fixed to the case 24. Since the recording paper 2 is not in the transport path 9 and therefore there is no tension T on the recording paper 2, the first elastic member 4 pushes the protrusion 3 from the other end in direction A with a pressing force S1, moving the protrusion 3. Furthermore, the second elastic member 12 pushes the lever tip 10a with a pressing force S2, moving the lever tip 10a in direction C from the protrusion 3 on which it is mounted. In this way, the lever tip 10a is moved in direction A by the first elastic member 4 with the protrusion 3 mounted thereon being based on the position of the case 24, and is then further moved in direction C by the second elastic member 12.

[0028] The movement locus of the lever tip 10a in the directions C and D is on an arc centered on the shaft 10b. Lever tip 10a is configured to be able to move up to a distance of 5.0 mm in direction D, based on the position when recording paper 2 is not in transport path 9 and is not in contact with recording paper 2. Meanwhile, the paper width of recording paper 2 is, for example, 80 mm, and lever tip 10a is positioned approximately in the center. The radius of the circle of one side of lever 10 centered on axis 10b is approximately half the 80 mm width of recording paper 2. Thus, the radius of the circle of one side of lever 10 centered on axis 10b is approximately 40 mm, which is approximately eight times the arc length of the movement locus of lever tip 10a, 5.0 mm, and is quite large. Therefore, the movement locus of lever tip 10a in directions C and D can be approximated to a substantially straight line.

[0029] As a result, direction A in which the protrusion 3 moves and direction C in which the lever tip 10a moves can be considered to be the same direction. Similarly, direction B in which the protrusion 3 moves and direction D in which the lever tip 10a moves can be considered to be the same direction. The lever tip 10a is moved in direction A by the first elastic member 4, with the protrusion 3 mounted thereon being based on the position of the case 24, and is then further moved in direction C, which can be considered the same direction as direction A, by the second elastic member 12.

[0030] On the other hand, as shown in Figure 3, when the recording paper 2 is in the transport path 9, the lever tip 10a moves from the position inserted into the notch 11 of the guide 5 shown in Figure 2 to the position removed, and abuts the recording paper 2. The pressing force S2 of the second elastic member 12 is set to be smaller than the force that presses the recording paper 2 in direction D when tension T of the recording paper 2 acts on the recording paper 2. Also, as described above, the pressing force S2 of the second elastic member 12 is set to be smaller than the pressing force S1 of the first elastic member 4.

[0031] Therefore, when the recording paper 2 is in the transport path 9 and the lever tip 10a comes into contact with the recording paper 2, the lever tip 10a is first pushed by the tension T of the recording paper 2 against the pressing force S2 of the second elastic member 12, and moves in the direction D. Then, the lever tip 10a reaches the position of the opening 3b of the protrusion tip 3a of the protrusion 3. At this time, the recording paper 2 comes into contact with the lever tip 10a and the protrusion tip 3a. The lever 10, including the lever tip 10a, is housed in the protrusion 3.

[0032] Next, as the tension T of the recording paper 2 increases, the protrusion 3 is pushed against the pressing force S1 of the first elastic member 4 and moves in the B direction. Pushed by the tension T of the recording paper 2, the lever tip 10a is first moved in the direction D based on the position of the case 24, and then moved further in the direction B together with the protrusion 3 mounted thereon.

[0033] The recording paper 2 is on the transport path 9, and the tip 10a of the lever comes into contact with 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 around the shaft 10b as shown by the arrow, and comes into contact with the switch lever 13a. Furthermore, the switch lever 13a rotates clockwise around the switch shaft 13b, and the internal contacts of the switch 13 come into contact with each other, becoming conductive and turning ON. The CPU detects that the switch 13 is ON and can determine that the recording paper 2 is in the transport path 9.

[0034] Incidentally, the recording paper 2 is transported in a transport direction from bottom to top along the transport path 9. The tip 10a of the lever is sloped in the transport direction and is shaped to smoothly contact the recording paper 2. The tip 10a of the lever may also be shaped to have a predetermined curvature in the transport direction.

[0035] Paper dust from the recording paper 2 can enter through the opening 3b at the tip 3a of the protrusion 3, through which the tip 10a of the lever that contacts the recording paper 2 moves in and out, and get into the internal contacts of the switch 13, causing malfunctions. To prevent this problem, the switch 13 is disposed on the protrusion 3 at a position away from the opening 3b in the direction D and closer to the case 24. Furthermore, the part of lever 10 that contacts switch 13 extends upward. As a result, switch 13 is not positioned on the extension line of the movement trajectory of lever tip 10a in direction D, preventing paper dust from being drawn from lever tip 10a to switch 13. Furthermore, a cover (not shown) covers the entire protrusion 3 shown in Fig. 3 from above. As a result, only the opening 3b of the protrusion 3 is open to the outside. The protrusion 3 is configured so that paper dust cannot enter from any other opening than the opening 3b.

[0036] The protrusion 3 moves in directions A and B depending on the presence or absence of the recording paper 2 on the transport path 9 and on fluctuations in the tension T of the recording paper 2. As the protrusion 3 moves, the switch 13 mounted on the protrusion 3 also moves in directions A and B. One end of the switch cable 13c, which is connected to the CPU, is fixed to the case 24 or the like, and the other end is connected to the switch 13 and moves together with the switch 13. The other end of the switch cable 13c bends when it moves together with the protrusion 3 and the switch 13. If the switch cable 13c is short, nearly straight, and routed with little slack, stress may be applied to the cable due to bending, which may result in breakage. 3, the switch cable 13c is curved in a direction intersecting with directions A and B, and is routed with ample space. In this way, the switch cable 13c is routed in a curved manner to soften bending, reduce stress caused by movement of the protrusion 3, and prevent breakage.

[0037] 1-3. Structure to cushion the tension of the recording paper Fig. 4 shows the case where the recording paper 2 is not on the transport path 9, and Fig. 5 shows the case where the recording paper 2 is on the transport path 9. The configuration for buffering the tension T of the recording paper 2 will be explained by comparing Fig. 4 and Fig. 5.

[0038] First, the transport path 9 formed between the guide 5 and the protrusion 3 will be mainly described with reference to FIG. The guide 5 has a recess 5a and a protrusion 5b continuing upstream of the recess 5a in the conveying direction. The recess 5a of the guide 5 is also called a recess, and the protrusion 5b is also called a convex. A notch 11 is formed in the recess 5a of the guide 5. An opening 3b of the protrusion tip 3a of the protrusion 3 is formed at a position facing the notch 11.

[0039] In Figure 4, there is no recording paper 2 in the transport path 9, and therefore no tension T of the recording paper 2 acts. Therefore, the protrusion 3 is pushed and moved in direction A by the pressing force S1 of the first elastic member 4. Furthermore, the lever 10 mounted on the protrusion 3 is pushed and moved in direction C by the pressing force S2 of the second elastic member 12.

[0040] In this way, when there is no recording paper 2 in the conveying path 9, the lever tip 10a of the lever 10 moves in the direction A together with the protrusion 3, based on the position of the case 24, and then moves toward the notch 11 in the recess 5a of the guide 5 as the lever 10 moves in the direction C. As a result, the lever tip 10 a protrudes from the opening 3 b of the projection tip 3 a of the projection 3 , passes through the conveying path 9 , and is inserted into the notch 11 . As described above, at this time, the lever 10 is away from the switch lever 13a of the switch 13 and is not in contact with it. Therefore, the switch 13 is OFF. The CPU detects that the switch 13 is OFF and can determine that the recording paper 2 is not in the transport path 9.

[0041] 5, recording paper 2 is in conveyance path 9, and tip 10a of lever 10 is in a position removed from notch 11 and abutting recording paper 2. Furthermore, recording paper 2 is pulled out from roll paper R by conveyance roller 6, and after back surface 2b abuts protrusion 5b of guide 5, it is conveyed downstream in the conveyance direction with front surface 2a abutting protrusion tip 3a of protrusion 3. In this way, the conveying path 9 formed by the guide 5 and the protrusion 3, and the recording paper 2 on the conveying path 9, are bent and curved.

[0042] 5, unlike the case of FIG. 4, tension T of the recording paper 2 acts on the lever 10 and the protrusion 3. Therefore, the tension T of the recording paper 2 first acts to push and move the lever 10 mounted on the protrusion 3 in the direction D against the pressing force S2 of the second elastic member 12. As a result, the lever tip 10a of the lever 10 retreats to the position of the opening 3b of the protrusion tip 3a of the protrusion 3, and abuts against the surface 2a of the recording paper 2 together with the protrusion tip 3a. Next, the tension T of the recording paper 2 acts against the pressing force S1 of the first elastic member 4 to push and move the protrusion 3 in the B direction.

[0043] As a result, when there is recording paper 2 in the transport path 9, the tension T of the recording paper 2 causes the lever tip 10a of the lever 10 to move in the direction D based on the position of the case 24 and retreat into the opening 3b of the protrusion tip 3a of the protrusion 3. Then, the lever tip 10a comes into contact with the surface 2a of the recording paper 2 together with the protrusion tip 3a of the protrusion 3, and then moves in the direction B together with the protrusion 3. As described above, at this time, the lever 10 abuts against the switch lever 13a of the switch 13, turning on the switch 13. The CPU detects that the switch 13 is on and can determine that the recording paper 2 is in the transport path 9.

[0044] Incidentally, if the diameter D of the roll paper R is large and heavy, the load on the transport roller 6 when transporting the recording paper 2 is also large, and the tension T on the recording paper 2 also becomes large. Before use, the diameter D is, for example, 80 mm. As the roll paper R wears down, the diameter D becomes smaller, for example, to 30 mm. Compared to when the diameter D has worn down and become smaller, the roll paper R is particularly large and heavy when first used. For this reason, particularly when the roll paper R is first used, the load on the transport roller 6 when transporting the recording paper 2 is large, and the tension T on the recording paper 2 also becomes large.

[0045] Furthermore, if the diameter D is large and heavy, when the transport roller 6 starts transporting the recording paper 2, the load increases suddenly due to the inertia of the roll paper R, and the tension T of the recording paper 2 also increases suddenly. In this case, when the transport roller 6 starts transporting the recording paper 2, the load of the roll paper R is affected by inertia, and the transport roller 6 may not be able to transport the recording paper 2.

[0046] As shown in Figure 5, the protrusion 3 abuts against the surface 2a of the recording paper 2 and moves in direction B under the tension T of the recording paper 2, while applying a pressing force S1 of the first elastic member 4 in direction A, thereby cushioning the tension T. In other words, just as the tension T resists pushing the recording paper 2 in direction B, the protrusion 3 can act to push the recording paper 2 in direction A, opposite direction B, with the pressing force S1 of the first elastic member 4, thereby canceling out each other's forces.

[0047] The pressing force S1 of the first elastic member 4 increases as the protrusion 3 moves in direction B, as the first elastic member 4 is compressed. Therefore, as the tension T of the recording paper 2 increases and presses the protrusion 3 more strongly in direction B, the pressing force S1 of the first elastic member 4 pushing back in direction A also increases. In this way, the projections 3 can buffer the tension T of the recording paper 2 according to the magnitude of the tension T of the recording paper 2, in other words, according to the size of the diameter D.

[0048] As a result, even if the diameter D is large, the transport roller 6 can stably transport the recording paper 2. In particular, even if the influence of inertia is large at the start of transport and the tension T of the recording paper 2 increases suddenly, the protrusions 3 buffer the tension T, allowing the transport roller 6 to stably transport the recording paper 2.

[0049] Furthermore, even when the protrusion 3 moves while buffering the tension T of the recording paper 2, such as when the transport roller 6 starts transporting the recording paper 2, the lever tip 10a contacts the surface 2a of the recording paper 2 together with the protrusion tip 3a of the protrusion 3. Therefore, even in such a case, the lever 10 abuts against the switch lever 13a of the switch 13, and the switch 13 is turned ON. The CPU detects that the switch 13 is ON and can determine that the recording paper 2 is in the transport path 9.

[0050] Furthermore, as described above, when the transport roller 6 transports the recording paper 2, the roll paper R is also pulled out and rolls counterclockwise inside the storage section 22. As the roll paper R rolls, the friction between the roll paper R and the storage section 22 changes, causing the load on the transport roller 6 when transporting the recording paper 2 to fluctuate. As a result, the tension T on the recording paper 2 also fluctuates.

[0051] In particular, when the diameter D is large, the fluctuations in the tension T also become large. If the fluctuations in the tension T are large, the transport roller 6 may not be able to transport the recording paper 2 at a constant speed, which may result in a deterioration in print quality. The constant speed at which the transport roller 6 transports the recording paper 2 is, for example, 500 mm / sec.

[0052] In this case, too, the protrusion 3 moves in direction A or B in response to fluctuations in tension T of the recording paper 2, and the pressing force S1 of the first elastic member 4 is used to buffer fluctuations in tension T of the recording paper 2. As a result, the transport roller 6 can transport the recording paper 2 at a constant speed. Furthermore, even if the tension T of the recording paper 2 fluctuates, the lever tip 10a, together with the protrusion tip 3a of the protrusion 3, abuts against the surface 2a of the recording paper 2. Therefore, even in such a case, the lever 10 abuts against the switch lever 13a of the switch 13, and the switch 13 is turned ON. The CPU detects that the switch 13 is ON and can determine that the recording paper 2 is in the transport path 9.

[0053] 1-4. Configuration for correcting curl of recording paper As mentioned above, recording paper 2 wound around the small diameter D near core R0 of roll paper R will curl more. Receipts, coupons, tickets, and other documents printed on such recording paper 2 will curl inward, as they were wound, degrading the quality of the printed matter. Furthermore, because there is nothing to regulate the recording paper 2 downstream of the transport roller 6 and head 7 in the transport direction, there is a risk that the curled recording paper 2 will get caught in the cutter 8, the discharge port 23, or the like.

[0054] The protrusion 3 applies a pressing force S1 of the first elastic member 4 in the direction A, and comes into contact with the surface 2a of the recording paper 2 as it is being conveyed, squeezing it, thereby making it possible to correct any curl in the recording paper 2. When the diameter D is reduced, the roll paper R becomes lighter, and the load on the transport roller 6 when transporting the recording paper 2 is reduced. As a result, the tension T on the recording paper 2 also becomes smaller. When the tension T decreases, the pressing force S1 of the first elastic member 4 pushes the protrusion 3, which is in contact with the recording paper 2, further in the direction A. As a result, the conveying path 9 formed between the guide 5 and the protrusion 3 becomes narrower because the protrusion 3 is positioned closer to the guide 5.

[0055] Therefore, the curvature of the conveying path 9 decreases, and the bend becomes tighter. In this way, as the diameter D decreases, the protrusion 3 moves in the direction A, and the bend of the conveying path 9 becomes tighter, further bending the recording paper 2 in a direction that effectively corrects the curl of the recording paper 2. In other words, the protrusion 3 moves in response to changes in the roll paper R, such as a decrease in diameter D. The curvature of the conveyance path 9 formed between the opposing guide 5 and protrusion 3 changes in response to the movement of the protrusion 3. As a result, as the diameter D becomes smaller and the curl of the recording paper 2 becomes stronger, the bending of the conveying path 9 becomes tighter, and the curl can be straightened more effectively.

[0056] Furthermore, even when the protrusion 3 moves to correct the curl of the recording paper 2, the lever tip 10a, together with the protrusion 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, and the switch 13 is turned ON. The CPU detects that the switch 13 is ON and can determine that the recording paper 2 is in the transport path 9.

[0057] As described above, the roll paper printer 1 of this embodiment is equipped with the protrusion 3 that can come into contact with the surface 2 a of the recording paper 2 and move toward the guide 5 . The roll paper printer 1 of this embodiment is equipped with a lever 10 that can be housed in the protrusion 3 and that can move by contacting 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 lever 10. As a result, this simple configuration allows for buffering of the tension T of the recording paper 2 and detection of the recording paper 2, while also preventing the expansion of the interior space of the roll paper printer 1 and reducing the size of the roll paper printer 1. The roll paper printer 1 of this embodiment can also straighten out curls in the recording paper 2. Furthermore, by configuring the lever tip 10a of the lever 10 to be inserted into the notch 11 of the guide 5, it is possible to reduce the space required for the lever 10 to move. When the recording paper 2 is not in the transport path 9, a portion of the lever 10 is exposed to the transport path 9, and the other portion is accommodated in the protrusion 3 and the notch 11.

[0058] The present embodiment has been described above in detail with reference to the drawings, but the specific configuration is not limited to these embodiments, and may be changed, replaced, deleted, etc., as long as it does not deviate from the gist of the present invention.

[0059] In the above description, the head 7 is described as a thermal head, but the printing method is not limited thereto. For example, the head 7 may be an inkjet head. In this case, since the inkjet head cannot come into contact with the transport roller 6 to sandwich the recording paper 2, a driven roller that faces the transport roller 6 and sandwiches the recording paper 2 can be mounted in the case 24.

[0060] In the above description, the switch 13, which is a sensor, is a so-called mechanical switch having a switch lever 13a, but other sensors may be used. For example, a reflective or transmissive optical sensor may be used. Such an optical sensor can detect the position of the lever 10.

[0061] In the above description, the lever 10 is L-shaped, and the pressing force S2 is generated by the torsion coil spring that is the second elastic member 12. As in the case of the protrusion 3 and the first elastic member 4, the lever 10 may be straight, and the second elastic member 12 may be a compression coil spring that is mounted on the protrusion 3. In this case, the lever 10 moves on a straight line in directions C and D from the protrusion 3, and the second elastic member 12 also expands and contracts on the same straight line.

[0062] In the above description, the first elastic member 4 is fixed to the case 24, but it may also be fixed to the storage section 22 that stores the roll paper R. In this case, the storage section 22 shown in FIG. 1 is extended to an upper position so that the first elastic member 4 is fixed. In this case, the protrusion 3 is attached to the first elastic member 4, and therefore the protrusion 3 is also mounted on the storage section 22.

[0063] Alternatively, an axis may be provided at a position below and rearward of the case 24, one end of a lever for the protrusion 3 may be rotatably attached to the axis, and the protrusion 3 may be attached to the other end of the lever for the protrusion 3. The protrusion 3 attached to the other end of the lever for the protrusion 3 can move around the axis. The first elastic member 4 may be configured to press the protrusion 3 directly, or may be configured to press the protrusion 3 via the lever for the protrusion 3.

[0064] In the above, the roll paper printer 1 was described as being used with the outlet 23 facing forward, but it can also be used with the outlet 23 facing upward. In this case, the storage compartment 22 shown in Figure 1 can be extended upward so that roll paper R can be stored in the storage compartment 22 even when the outlet 23 is facing upward.

[0065] Furthermore, the side of the recording paper 2 that contacts the protrusion 3 does not have to be the side to be printed. The roll paper R is wound so that the side to be printed of the recording paper 2 faces inward. In this case, the positions of the head 7 and transport roller 6 are reversed from those shown in Figure 1. [Explanation of symbols]

[0066] 1...roll paper printer, 2...recording paper, 2a...front side, 2b...back side, 3...protrusion, 4...first elastic member, 5...guide, 6...transport roller, 7...head, 8...cutter, 9...transport path, 10...lever, 11...notch, 12...second elastic member, 13...switch, D...diameter, S1, S2...pressing force, T...tension, R...roll paper.

Claims

1. a storage section capable of storing roll paper with one side of the recording paper wound on the outside; a transport roller that pulls out the recording paper from the roll paper and transports it in a transport direction; a roller that can come into contact with the other side of the recording paper upstream of the conveying roller in the conveying direction; With a guide, The conveying roller is capable of contacting the one surface of the recording paper at an upstream side in the conveying direction. a protrusion movable toward the guide; a lever that can be housed in the protrusion and that can move while contacting the one surface of the recording paper; 、 a sensor housed in the protrusion for detecting movement of the lever; The lever is attached to the protrusion so as to be rotatable about an axis; The sensor is arranged in front of the lever along the width direction perpendicular to the conveying direction. A roll paper printer is attached to the protrusion.

2. 2. The guide according to claim 1, wherein a notch is formed in the guide at a position facing the lever. Roll paper printer.

3. When the lever is not in contact with the recording paper, the lever is inserted into the notch of the guide. The roll paper printer according to claim 2 .

4. A curved conveying path is formed between the guide and the protrusion that face each other, and the level The bar according to claim 3 , wherein the bar passes through the transport path and is inserted into the notch of the guide. Roll paper printer.

5. a first elastic member that presses the protrusion toward the guide; The protrusion is pushed in a first direction by the first elastic member, and the tension of the recording paper causes the protrusion to 5. The device according to claim 1, wherein the device is pushed in a second direction opposite to the first direction. Roll paper printer.

6. a second elastic member that is accommodated in the protrusion and pushes the lever toward the guide; The lever is pushed in the third direction by the second elastic member and is pulled forward by the tension of the recording paper.

6. The device according to claim 1, wherein the device is pushed in a fourth direction opposite to the third direction. Roll paper printer.

7. When the protrusion is viewed from the width direction, the lever is located within the thickness of the protrusion. The roll paper printer according to any one of claims 1 to 6.

8. Equipped with a head, 8. The method according to claim 1, wherein the head prints on the one side of the recording paper.

10. The roll paper printer according to claim 1.

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