Thermal printer

Abstract

To provide a thermal printer capable of stably holding roll paper in a roll paper storage part after facilitating insertion and removal of roll paper into the roll paper storage part.SOLUTION: A thermal printer 1 according to one aspect of the present invention includes: a casing 11 with a roll paper storage part 31 and a discharge port 33; a printing unit 3 provided between the roll paper storage part 31 and the discharge port 33 in the casing 11; a flap 61a provided rotatably about an axis line O2 between the printing unit 3 and the roll paper storage section 31 in the casing 11, and pushing the roll paper R away from the discharge port 33 by abutting with an outer peripheral surface of the roll paper R; and an energization member energizing the flap 61a in a direction away from the discharge port 33 about the axis line O2.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] A thermal printer rotates a platen roller with recording paper sandwiched between the platen roller and the thermal head, and prints on the printing surface of the recording paper with the thermal head while transporting the recording paper. In a thermal printer, the recording paper is stored in a roll paper storage section provided in a casing in the form of roll paper wound around a core. For example, in Patent Document 1 listed below, the roll paper is rotatably held in the roll paper storage section by a support shaft that penetrates the core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-131569 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, for food POS labels and various display labels, so-called linerless labels are sometimes used as recording paper for the purpose of reducing environmental impact and improving convenience. A linerless label is a recording paper that has an adhesive layer on the side opposite to the printed side, but does not have a backing paper to cover the adhesive layer. When a linerless label recording paper is used as roll paper, the recording paper is wound with the adhesive layer on the outer periphery attached to the printed side of the recording paper on the inner periphery. Therefore, when a linerless label is used as recording paper, the tensile force acting on the recording paper during the recording paper transport is larger than that of a recording paper without an adhesive layer, making it difficult to stably hold the roll paper in the roll paper storage section.

[0005] On the other hand, in the conventional technology, when inserting or removing the roll paper into or from the roll paper storage section, such as when replacing the roll paper, it is necessary to insert and remove the support shaft from the roll paper, which makes the task of replacing the roll paper cumbersome.

[0006] The present invention provides a thermal printer that allows roll paper to be easily inserted and removed from a roll paper compartment, while also allowing the roll paper to be stably held within the roll paper compartment. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention employs the following aspects. A thermal printer according to one aspect of the present invention comprises a casing having a roll paper storage section into which roll paper consisting of wound recording paper can be inserted, and an outlet through which the portion of the recording paper pulled out from the roll paper is discharged to the outside; a printing unit provided in the casing between the roll paper storage section and the outlet, the printing unit having a thermal head that prints on the recording paper, and a platen roller that sandwiches the recording paper between the thermal head and the printing unit and transports the recording paper towards the outlet; a flap provided in the casing between the printing unit and the roll paper storage section so as to be rotatable about a first axis, the flap abutting against the outer peripheral surface of the roll paper to push the roll paper in a direction away from the outlet, and a biasing member that biases the flap about the first axis in a direction away from the outlet.

[0008] According to this aspect, the flap constantly pushes the roll paper away from the outlet, which makes it easier to stabilize the position of the roll paper inside the roll paper compartment. This makes it possible to stably transport the recording paper without being affected by the outer diameter of the roll paper, even in cases where a large tensile force is required to transport the recording paper, such as linerless labels. Furthermore, in this embodiment, since there is no need to hold the roll paper through its core, the roll paper can be easily inserted and removed from the roll paper compartment, and the configuration can be simplified.

[0009] In the thermal printer of the above aspect, it is preferable that a flap roller be provided at the tip of the flap, the flap being rotatable about a second axis along the central axis of the roll paper and capable of contacting the recording paper. According to this aspect, the frictional force acting between the tip of the flap and the recording paper can be reduced, and the recording paper can be transported smoothly.

[0010] In the thermal printer of the above aspect, it is preferable that a first guide roller rotatable about a third axis along the central axis of the roll paper, and a second guide roller rotatable about a fourth axis along the third axis are provided in a portion of the casing that is located closer to the roll paper storage section than the printing unit, and that the recording paper is guided to the printing unit between the first guide roller and the second guide roller. According to this aspect, the first guide roller and the second guide roller can limit the movement range of the recording paper pulled from the roll paper. This allows the recording paper to be guided within a specific angle range relative to the printing unit regardless of the position of the roll paper in the roll paper compartment. This allows the recording paper to be stably supplied to the printing unit.

[0011] In the thermal printer of the above aspect, it is preferable that the first guide roller is positioned closer to the roll paper storage section than the second guide roller, and the first guide roller is made of a softer material than the second guide roller. This aspect makes it easier to absorb the shock that acts on the first guide roller when the roll paper comes into contact with it, thereby reducing the generation of abnormal noise that accompanies the movement of the roll paper inside the roll paper compartment.

[0012] In the thermal printer of the above aspect, it is preferable that the casing is provided with a sensor for detecting the remaining amount of roll paper, the sensor being connected to the flap and having a lever that can rotate between an on position and an off position in response to the rotation of the flap. According to this aspect, the sensor lever rotates in conjunction with the flap, so that the sensor is switched between an on state and an off state according to the rotation angle of the flap, which simplifies the configuration compared to a case where a lever operating mechanism is provided separately from the flap unit.

[0013] In the thermal printer of the above aspect, it is preferable that the casing is configured to be movable in a first direction along the central axis of the roll paper, and is provided with a positioning mechanism that positions the roll paper in the first direction within the roll paper storage section by abutting the roll paper from both sides in the first direction. According to this aspect, the roll paper comes into contact with the positioning mechanism, which restricts the movement of the roll paper in the first direction within the roll paper storage unit. Therefore, by moving the positioning mechanism to match the width of the roll paper, the movement of the roll paper in the first direction within the roll paper storage unit can be restricted regardless of the width of the roll paper. As a result, printing misalignment and abnormal noises that accompany the movement of the roll paper within the roll paper storage unit can be restricted.

[0014] In the thermal printer of the above aspect, the printing unit comprises a fixed blade provided on one side of the discharge outlet, and a movable blade provided on the other side of the discharge outlet so as to be able to move towards and away from the fixed blade and capable of cutting the recording paper between the fixed blade, and it is preferable that a recess is formed in the central portion of the movable blade in the first direction so as to be recessed relative to the cutting edge of the movable blade. According to this aspect, the recording paper is cut so as not to come into contact with the bottom of the recess, so that a cut remnant is formed on the portion of the recording paper facing the recess. This makes it possible to prevent the cut recording paper from adhering to unexpected places, even when a linerless label is used as the recording paper. In particular, in this aspect, since the positioning mechanism is provided as described above, the center of the roll paper in the first direction is positioned near the center of the roll paper compartment in the first direction, which results in an uncut portion of the recording paper remaining near the center in the first direction regardless of the width of the roll paper. Effect of the Invention

[0015] According to one aspect of the present invention, roll paper can be easily inserted and removed from the roll paper compartment, and the roll paper can be stably held within the roll paper compartment. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a perspective view of the thermal printer showing the cover in a closed position. [Diagram 2] FIG. 2 is a perspective view of the thermal printer showing the cover in an open position. [Diagram 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] 6 is a perspective cross-sectional view corresponding to the line VI-VI in FIG. [Figure 7] 4 is a cross-sectional view corresponding to FIG. 3 and showing the roll paper in a medium diameter state when transport is stopped. [Figure 8] 4 is a cross-sectional view corresponding to FIG. 3 and showing the roll paper in a medium diameter state during transport. FIG. [Figure 9] 4 is a cross-sectional view corresponding to FIG. 3 and showing the roll paper in a medium diameter state when transport is stopped. [Figure 10] 4 is a cross-sectional view corresponding to FIG. 3 and showing the roll paper in a medium diameter state during transport. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the embodiments and modifications described below, the same reference numerals may be used to designate corresponding configurations, and the description thereof may be omitted. In the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," do not only strictly indicate such arrangements, but also indicate a state in which the components are relatively displaced with a tolerance or an angle or distance to the extent that the same function is obtained.

[0018] [Thermal Printer 1] Fig. 1 is a perspective view of the thermal printer 1 showing a state where the cover 11 is in a closed position, and Fig. 2 is a perspective view of the thermal printer 1 showing a state where the cover 11 is in an open position. As shown in FIGS. 1 and 2, a thermal printer 1 prints on recording paper P. The recording paper P in this embodiment is a so-called linerless label. That is, the front side of the recording paper P constitutes the printing surface, and the back side constitutes the adhesive layer. The printing surface is covered with a release layer (e.g., a silicone coat, etc.). The recording paper P is wound around a cylindrical core material R1 (see FIG. 3) with the printing surface facing outward and the adhesive layer facing inward to constitute roll paper R. It should be noted that the roll paper R may not have a core material R1.

[0019] FIG. 3 is a cross-sectional view taken along line III-III in FIG. As shown in Fig. 3, the thermal printer 1 includes a casing 2, a printing unit 3, a positioning mechanism 4 (see Fig. 6), and a paper holding mechanism 5. The thermal printer 1 is installed on an installation surface S. In the following description, the direction perpendicular to the installation surface S is defined as the up-down direction (arrow UP indicates the upward direction), and the two directions perpendicular to the up-down direction are defined as the front-rear direction (arrow FR indicates the forward direction) and the left-right direction (arrow LH indicates the leftward direction).

[0020] <Casing 2> The casing 2 is formed in a box shape. Specifically, the casing 2 includes a bottom unit 10 and a cover 11. The bottom unit 10 includes an exterior body 21 and a holder 22 .

[0021] The exterior body 21 is formed in a box shape that opens upward. The exterior body 21 constitutes the design surface (outer surface) of the bottom unit 10. The thermal printer 1 is installed on the installation surface S via the exterior bottom wall 21a of the exterior body 21. A control board 25 is provided inside the exterior body 21. The control board 25 is disposed along the exterior bottom wall 21a with the thickness direction being the up-down direction.

[0022] Holder 22 is provided inside exterior body 21. Holder 22 includes a holder body 22a and legs 22b. The holder body 22a is formed in a box shape that is slightly smaller than the exterior body 21. The holder body 22a defines a roll paper storage section 31 and a paper passage section 32.

[0023] The roll paper storage section 31 is located at the rear inside the holder body 22a. The roll paper R can be inserted into and removed from the roll paper storage section 31 through the upper opening of the holder body 22a (bottom unit 10). That is, in the thermal printer 1, the roll paper R can be inserted into and removed from the roll paper storage section 31 through the upper opening of the holder body 22a (the so-called drop-in method). The paper passing section 32 is located at the front of the holder body 22a. The portion of the recording paper P that is pulled out from the roll paper storage section 31 is transported forward through the paper passing section 32.

[0024] The legs 22b extend downward from a holder bottom wall 22c of the holder body 22a. A plurality of the legs 22b are provided at intervals in the front-rear and left-right directions. The legs 22b support the control board 25 at their lower ends.

[0025] 2 and 3, the cover 11 opens and closes the upper end opening of the bottom unit 10. Specifically, the cover 11 includes a cover body 11a, an attachment piece 11b, a guide wall 11c, and a partition wall 11d. The cover body 11a is formed in a box shape that opens downward. In a plan view, the cover body 11a has the same shape as the bottom unit 10 (exterior body 21). In the closed position, the cover body 11a is placed over the bottom unit 10 from above and closes the upper end opening of the bottom unit 10. On the other hand, in the open position, the cover body 11a retreats from above the bottom unit 10 and opens the upper end opening of the bottom unit 10.

[0026] When the cover 11 (cover body 11a) is in the closed position, an outlet 33 is formed between the front wall portion 11g of the cover body 11a and the front wall portion 21d of the exterior body 21. The outlet 33 connects the inside and outside of the casing 2 and is formed in the shape of a slit extending in the left-right direction. From the outlet 33, the recording paper P printed by the printing unit 3 is discharged forward.

[0027] The mounting pieces 11b protrude downward from the rear end of the top wall 11f of the cover body 11a, from both left and right sides. Each mounting piece 11b is connected to a pair of holder side walls 22d of the holder body 22a that face each other in the left and right direction. Specifically, the mounting pieces 11b are connected to the upper ends of the holder side walls 22d rotatably about an axis along the left and right direction. This allows the cover 11 to rotate relative to the bottom unit 10 between the open position and the closed position. The cover 11 may be configured to open and close the upper end opening of the bottom unit 10 by a sliding operation or the like.

[0028] The guide wall 11c protrudes downward from a portion of the top wall 11f that is located forward of the mounting piece 11b. The guide wall 11c curves downward as it extends forward. The guide wall 11c faces the roll paper storage section 31 in the vertical direction through the upper end opening of the bottom unit 10.

[0029] The partition wall 11d extends downward from a portion of the top wall 11f that is located in front of the guide wall 11c. When the cover 11 is in the closed position, the partition wall 11d enters the holder body 22a from above. The partition wall 11d separates the roll paper storage section 31 and the paper passing section 32 in the front-rear direction.

[0030] <Printing Unit 3> As shown in FIG. 3, the printing unit 3 includes a platen roller 41, a thermal head 42, a cutter unit 43, and a paper detection sensor 44. The platen roller 41 is a rubber roller that extends in the left-right direction. The platen roller 41 is provided at the front end of the paper passing section 32 (the portion located closer to the discharge opening 33). The platen roller 41 spans between the upper front ends of the holder side walls 22d. The platen roller 41 is supported by the holder side walls 22d so as to be rotatable about an axis O1 along the left-right direction. When the recording paper P is transported, the platen roller 41 rotates in response to the driving force of a driving motor (not shown).

[0031] The thermal head 42 is provided in a portion of the cover 11 that is located near the discharge port 33. The thermal head 42 has a plurality of heating elements that are arranged in a straight line along the left-right direction. The thermal head 42 is fixed to the front end of the cover 11 with the heating elements facing downward. The platen roller 41 and the thermal head 42 face each other in the vertical direction (one side and the other side of the discharge port 33) with the discharge port 33 between them. The thermal head 42 is in close contact with the platen roller 41 when the cover 11 is in the closed position. The recording paper P passes between the platen roller 41 and the thermal head 42 in response to the rotation of the platen roller 41. The heating pattern of the heating elements of the thermal head 42 is controlled based on a signal output from the control board 25. The heat of the heating elements is transmitted to the printing surface of the recording paper P, and information (characters, figures, etc.) corresponding to the heating pattern is printed on the printing surface.

[0032] FIG. 4 is a perspective view of the cutter unit 43. As shown in FIG. As shown in FIGS. 3 and 4, the cutter unit 43 includes a fixed blade 47 and a movable blade . The fixed blade 47 is disposed in a portion of the bottom unit 10 between the platen roller 41 and the discharge port 33. The fixed blade 47 is formed in a plate shape extending in the left-right direction. The fixed blade 47 is disposed with the cutting edge 47a facing upward. The movable blade 48 is disposed in a portion of the cover 11 between the thermal head 42 and the discharge port 33. The movable blade 48 is formed in a plate shape extending in the left-right direction. The movable blade 48 is configured to be movable up and down with the blade tip 48a facing downward. When the movable blade 48 moves downward, the cutter unit 43 rides up against the fixed blade 47 from the front, thereby cutting the recording paper P between the blade tips 47a, 48a.

[0033] As shown in FIG. 4, the blade tip 48a of the movable blade 48 is formed in a V-shape extending in a direction (upward) retracting from the blade tip 47a of the fixed blade 47 from both ends in the left-right direction toward the center. A recess 48b recessed into the blade tip 48a is formed in the left-right center of the blade tip 48a of the movable blade 48. The bottom of the recess 48b is configured not to come into contact with the recording paper P when the recording paper P is cut by the cutter unit 43. As a result, when the recording paper P is cut by the cutter unit 43, a cut residue is formed in a portion of the recording paper P facing the recess 48b (so-called partial cut). Note that in this embodiment, a configuration in which one recess 48b is formed to form one cut residue (one point remaining) is described, but this configuration is not limited to this. For example, a plurality of recesses 48b may be provided to form a plurality of cut residues (multiple remaining). Also, the recess 48b is not an essential component.

[0034] 3, the paper detection sensor 44 is provided in a portion of the cover 11 located in front of the movable blade 48. The paper detection sensor 44 is, for example, a reflective photosensor. The paper detection sensor 44 detects the presence or absence of a portion of the recording paper P that has passed through the cutter unit 43. In other words, the paper detection sensor 44 detects the presence or absence of a portion of the recording paper P that is located in front of (downstream of) the remaining cut portion after it has been cut by the cutter unit 43.

[0035] <Positioning mechanism 4> Fig. 5 is a plan view of the inside of the bottom unit 10. Fig. 6 is a perspective cross-sectional view corresponding to the line VI-VI in Fig. 1. 5 and 6, the positioning mechanism 4 positions the roll paper R in the left-right direction within the roll paper compartment 31. The positioning mechanism 4 includes a pair of guide walls 51, a pinion 52, and a rack 53.

[0036] The guide walls 51 are provided facing each other in the left-right direction within the roll paper storage section 31 (holder 22). Each guide wall 51 is formed with a protrusion 51a (see FIG. 6) that protrudes downward. The protrusion 51a protrudes below the holder bottom wall 22c through a through hole 22g formed in the holder bottom wall 22c. The through hole 22g is formed in a slit shape that extends in the left-right direction. The guide walls 51 are configured to be movable toward or away from each other (left-right direction) with the protrusion 51a guided by the through hole 22g.

[0037] The pinion 52 is provided facing downward on the holder bottom wall 22c. Specifically, the pinion 52 is a part of the holder bottom wall 22c that constitutes the roll paper accommodation section 31, and is provided in the center in the front-rear and left-right directions. The pinion 52 is supported by the holder bottom wall 22c so as to be rotatable about an axis that runs along the up-down direction.

[0038] The rack 53 is connected to each of the pair of guide walls 51 via the protrusions 51a. The rack 53 extends in the left-right direction toward the opposing guide wall 51 below the holder bottom wall 22c. One rack 53 extending from one guide wall 51 meshes with the pinion 52 from one side in the front-rear direction (e.g., the front). The other rack 53 extending from the other guide wall 51 meshes with the pinion 52 from the other side in the front-rear direction (e.g., the rear). Therefore, in the positioning mechanism 4, the pinion 52 rotates due to a linear driving force acting on one rack 53, and the rotational driving force of the pinion 52 is transmitted to the other rack 53. As a result, the racks 53 move in a direction approaching or separating in the left-right direction, and the pair of guide walls 51 move synchronously.

[0039] <Paper holding mechanism 5> The paper holding mechanism 5 includes a flap unit 61, a near-end sensor (sensor) 62, a first guide roller 63, and a second guide roller 64. The flap unit 61 separates the roll paper storage section 31 and the paper passing section 32 in the front-rear direction within the holder body 22a, and presses the roll paper R in a direction (rearward) away from the discharge opening 33. In this embodiment, the portion of the holder body 22a located rearward relative to the partition wall 11d and the flap unit 61 forms the roll paper storage section 31, and the portion of the holder body 22a located forward relative to the partition wall 11d and the flap unit 61 forms the paper passing section 32.

[0040] As shown in FIGS. 3, 5, and 6, the flap unit 61 includes a flap 61a, a biasing member 61b, and a flap roller 61c. The flap 61a extends upward in a cantilever manner from a portion of the holder bottom wall 22c located forward of the pinion 52 and rearward of the partition wall 11d. The flap 61a is supported by the holder bottom wall 22c at its lower end so as to be rotatable about an axis (first axis) O2 along the left-right direction. The length of the flap 61a is set so as not to interfere with the first guide roller 63 over the entire rotation range.

[0041] At the tip of the flap 61a, a curved surface 66 is formed on the surface (rear surface) facing in the clockwise direction about the axis O2. The curved surface 66 is formed in an arc shape that protrudes in the counterclockwise direction (forward) about the axis O2. The curved surface 66 holds the outer peripheral surface of the rolled paper R, for example, when the rolled paper R is in a short elapsed time.

[0042] The biasing member 61b is, for example, a torsion spring. The biasing member 61b is interposed between the flap 61a and the holder bottom wall 22c. The biasing member 61b biases the flap 61a backward (clockwise). The flap roller 61c is provided on the tip of the flap 61a at a portion located on the tip side of the curved surface 66 so as to be rotatable about an axis (second axis) O3 along the left-right direction. The flap roller 61c is configured with large diameter portions 67 and small diameter portions 68 alternately connected in the left-right direction. The flap roller 61c is capable of contacting the recording paper P via the large diameter portion 67.

[0043] The near-end sensor 62 is provided around the base end of the flap unit 61 (flap 61a) on the holder bottom wall 22c. The near-end sensor 62 detects the near-end of the roll paper R based on the rotation angle θ of the flap unit 61 relative to the holder bottom wall 22c in the clockwise direction about the axis O2. Note that the near-end state refers to a state in which the remaining amount of roll paper R has reached an amount (outer diameter) at which replacement of the roll paper R is recommended.

[0044] The near-end sensor 62 has a lever 62a that can rotate in the front-rear direction. The lever 62a is connected to the flap 61a. The near-end sensor 62 is switched between an ON state and an OFF state by the lever 62a rotating in the front-rear direction in response to the rotation of the flap 61a.

[0045] The near-end sensor 62 maintains the OFF state when the rotation angle θ of the flap 61a relative to the holder bottom wall 22c is less than a predetermined angle (the lever 62a is not operated to turn it ON). On the other hand, the near-end sensor 62 turns ON when the rotation angle θ of the flap 61a rotates by a predetermined angle. In this embodiment, the predetermined angle is, for example, about 100° relative to the holder bottom wall 22c, and is the position where the tip of the flap unit 61 is farthest from the discharge port 33.

[0046] When the lever 62a is turned on, the near-end sensor 62 outputs an on signal to the control board 25. When the control board 25 receives the on signal from the near-end sensor 62, it prompts the user to replace the roll paper R through a notification means (for example, a light source or sound source) provided in the casing 2. When the lever 62a reaches the rearmost position (on position), the flap 61a is restricted from further rotating in the clockwise direction (rearward). On the other hand, when the lever 62a reaches the frontmost position (off position), the flap 61a is restricted from further rotating in the counterclockwise direction. In other words, the lever 62a of the near-end sensor 62 also functions as a stopper that limits the rotation range of the flap 61a. However, the flap 61a may be provided with a stopper separate from the near-end sensor 62.

[0047] The first guide roller 63 guides the recording paper P pulled out from the roll paper R toward the printing unit 3. The first guide roller 63 is a driven roller that rotates due to friction generated between the recording paper P and the first guide roller 63 as the recording paper P is transported. The first guide roller 63 is supported at the lower end of the partition wall 11d so as to be rotatable about an axis (third axis) O4 along the left-right direction. That is, the first guide roller 63 advances and retreats into the holder main body 22a as the cover 11 is opened and closed. The axis O4 of the first guide roller 63 is located forward and above the axis O2 of the flap unit 61 (downstream in the transport direction of the recording paper P). The axis O4 of the first guide roller 63 is located rearward and below the axis O1 of the platen roller 41 (upstream in the transport direction of the recording paper P). In the illustrated example, the outer diameter of the first guide roller 63 is equal to the outer diameter of the platen roller 41.

[0048] The first guide roller 63 is preferably designed taking into consideration the shock absorbing performance against contact with the roll paper R. In this configuration, the first guide roller 63, like the platen roller 41, preferably has an outer surface formed of a material that is softer than the second guide roller 64 and is elastically deformable, such as a rubber material.

[0049] The second guide roller 64 is provided between the platen roller 41 and the first guide roller 63 in the paper passing section 32. The second guide roller 64 is a driven roller that rotates due to friction generated between the second guide roller 64 and the recording paper P as the recording paper P is transported. The second guide roller 64 is supported by the holder side wall 22d so as to be rotatable about an axis (fourth axis) O5 along the left-right direction. The axis O5 of the second guide roller 64 is disposed forward and below (downstream in the transport direction of the recording paper P) the axis O4 of the first guide roller 63. The axis O5 of the second guide roller 64 is disposed rearward and below (upstream in the transport direction of the recording paper P) the axis O1 of the platen roller 41. In the illustrated example, the second guide roller 64 is formed to have a smaller diameter than the first guide roller 63.

[0050] The second guide roller 64 is preferably designed in consideration of cost reduction, peelability from the adhesive layer, etc. In such a configuration, the outer surface of the second guide roller 64 may be formed of an elastically deformable material, such as a resin material, that is harder than the first guide roller 63. The first guide roller 63 and the second guide roller 64 may be rotated independently according to the driving force of a drive motor (not shown), etc.

[0051] In the paper passing section 32, the space between the first guide roller 63 and the second guide roller 64 constitutes a paper passing path through which the recording paper P passes between the roll paper storage section 31 and the printing unit 3. When the recording paper P passes through the paper passing path, it comes into contact with the first guide roller 63 or the second guide roller 64, thereby restricting movement of the recording paper P in the thickness direction (up and down direction). This limits the angle at which the recording paper P enters the printing unit 3 to within a specified angle range.

[0052] [Effect] Next, the operation of the above-mentioned thermal printer 1 will be described. First, a method for setting the roll paper R will be described. As shown in FIG. 2, after the cover 11 is opened, the roll paper R is inserted into the roll paper storage section 31. The roll paper R then falls downward inside the roll paper storage section 31 while its outer circumferential surface slides against the holder rear wall 22h and the flap 61a of the holder main body 22a. This causes the flap 61a to rotate counterclockwise against the biasing force of the biasing member 61b. That is, the roll paper R enters the roll paper storage section 31 so as to push the roll paper storage section 31 forward. The counterclockwise rotation of the flap 61a is restricted when the lever 62a reaches the frontmost position. As a result, the roll paper R is stored in the roll paper storage section 31 while being supported by the holder rear wall 22h and the flap 61a. At this time, the biasing force of the biasing member 61b acts on the roll paper R via the flap 61a, so that the roll paper R is pushed backward and held in the roll paper accommodation section 31. In the example shown, the roll paper R is floating above the holder bottom wall 22c, but depending on the outer diameter of the roll paper R, the outer circumferential surface of the roll paper R may be in contact with the holder bottom wall 22. When the lever 62a moves to the frontmost position, the near-end sensor 62 turns off.

[0053] After the roll paper R is inserted, the leading edge of the recording paper P is guided along the second guide roller 64 and the platen roller 41 to the discharge port 33. In this state, the cover 11 is moved to the closed position. Then, of the recording paper P pulled out from the roll paper R, the base portion (the boundary with the roll paper R) is pressed downward by the first guide roller 63, and the leading edge is sandwiched between the platen roller 41 and the thermal head 42. As a result, the roll paper R is set in the roll paper storage section 31 with its central axis aligned in the left-right direction.

[0054] Next, a method for positioning the roll paper R will be described. After the roll paper R is set in the roll paper storage section 31, the guide walls 51 are moved to match the width of the roll paper R. Specifically, while at least one of the guide walls 51 is gripped, the guide wall 51 is pushed left and right toward the end face of the roll paper R. Then, the pushing force acting on one guide wall 51 acts on the other guide wall 51 via the pinion 52, causing the guide walls 51 to move synchronously toward or away from each other. The guide wall 51 is stopped when it approaches or comes into contact with the end face of the roll paper R. This positions the left and right center of the roll paper R near the left and right center within the roll paper storage section 31. Note that in this embodiment, the guide wall 51 only serves to position the roll paper R left and right, and does not support the rotation of the roll paper R.

[0055] Next, a method of printing on the recording paper P will be described. As the platen roller 41 rotates, the recording paper P is conveyed toward the discharge port 33 while being sandwiched between the platen roller 41 and the thermal head 42. At this time, the heating elements of the thermal head 42 generate heat appropriately, thereby printing various information on the recording paper P. The recording paper P printed by the thermal head 42 passes between the fixed blade 47 and the movable blade 48, and is then discharged to the outside of the thermal printer 1 through the discharge port 33.

[0056] After printing on the recording paper P is completed, the recording paper P is cut. Specifically, the movable blade 48 is moved downward, causing the movable blade 48 to ride up against the fixed blade 47 from the front. As a result, the recording paper P is sandwiched between the blade edges 47a, 48a of the fixed blade 47 and the movable blade 48. This cuts the recording paper P. Note that in this embodiment, the bottom of the recess 48b of the movable blade 48 is configured not to come into contact with the blade edge 47a of the fixed blade 47, so that the printed portion of the recording paper P is connected to the roll paper R via the remaining cut portion. After cutting by the cutter unit 43, the remaining cut portion can be torn off to remove the recording paper P after printing.

[0057] In this embodiment, a linerless label is used for the recording paper P. Therefore, the recording paper P taken out of the thermal printer 1 can be attached directly to various articles via the adhesive layer.

[0058] Next, we will explain the operation of the paper holding mechanism 5. When printing is continuously performed on recording paper P pulled out from the roll paper R, the outer diameter of the roll paper R gradually decreases. That is, with continued use, the roll paper R changes from a medium diameter state shown in Figures 7 and 8 to a small diameter state shown in Figures 9 and 10.

[0059] In the medium diameter state shown in FIG. 7, the roll paper R is pressed backward by the flap 61a when transport is stopped. In this case, the roll paper R is held at the rear of the roll paper storage section 31 with the flap 61a in contact with the holder bottom wall 22c and the holder rear wall 22h. The portion of the recording paper P pulled out from the roll paper R is guided to the printing unit 3 while being guided by the flap roller 61c, the first guide roller 63, and the second guide roller 64. Note that when transport is stopped in the medium diameter state, the flap 61a is restricted from rotating in the clockwise direction by the roll paper R. This restricts the rotation angle θ of the flap 61a to a range less than a predetermined angle. In other words, when the roll paper R is in the medium diameter state, the near-end sensor 62 remains in the off state.

[0060] On the other hand, in the medium diameter state shown in FIG. 8, when the printing operation is started, the roll paper R moves toward the discharge port 33 according to the tensile force acting on the roll paper R by the rotation of the platen roller 41. Specifically, the tensile force acting on the roll paper R causes the flap 61a to rotate counterclockwise, and the roll paper R moves on the rear surface of the flap 61a from the base end to the tip end. The roll paper R then comes into contact with the first guide roller 63, restricting its forward movement. As a result, printing is performed on the recording paper P while the roll paper R is pushed rearward by the flap 61a while in contact with the first guide roller 63. In other words, as the recording paper P is pulled out by the rotation of the platen roller 41, the roll paper R rotates while in contact with the first guide roller 63 and the flap 61a.

[0061] 9, when the roll paper R is stopped, it is pressed backward by the flap 61a. In this case, the roll paper R is held in contact with the curved surface 66 and away from the holder bottom wall 22c and the holder rear wall 22h. This prevents the roll paper R from slipping out upward from the flap 61a. Furthermore, the portion of the recording paper P that is pulled out from the roll paper R is guided by the flap roller 61 c, the first guide roller 63, and the second guide roller 64, and is led to the printing unit 3.

[0062] When transport is stopped in the small diameter state and the rotation angle θ of the flap 61a reaches a predetermined angle, the lever 62a turns on the near-end sensor 62. When the near-end sensor 62 turns on, it outputs an on signal to the control board 25. When the control board 25 receives the on signal from the near-end sensor 62, it prompts the user to replace the roll paper R through notification means (for example, a light source or sound source) provided in the casing 2.

[0063] In the small diameter state shown in FIG. 10, when the printing operation is started, the roll paper R moves toward the discharge port 33 according to the tensile force acting on the roll paper R by the rotation of the platen roller 41. Specifically, the flap 61a rotates counterclockwise due to the tensile force acting on the roll paper R. The roll paper R then comes into contact with both the first guide roller 63 and the second guide roller 64, restricting its forward movement. As a result, printing is performed on the recording paper P while the roll paper R is pushed backward by the flap 61a while in contact with the first guide roller 63 and the second guide roller 64. In other words, as the recording paper P is pulled out by the rotation of the platen roller 41, the roll paper R rotates while in contact with the first guide roller 63, the second guide roller 64, and the flap 61a.

[0064] In this manner, in this embodiment, the casing 2 is configured to include a flap 61a that is rotatably arranged around the axis O2 between the printing unit 3 and the roll paper storage section 31, and a biasing member 61b that biases the flap 61a in a direction away from the discharge port 33 around the axis O2. With this configuration, the flap 61a constantly pushes the roll paper R in a direction away from the discharge opening 33, which tends to stabilize the position (front-to-back and up-down directions) of the roll paper R within the roll paper compartment 31. This makes it possible to stably transport the recording paper P without being affected by the outer diameter of the roll paper R, even in cases where a large tensile force is required to transport the recording paper P, such as linerless labels. Moreover, in this embodiment, since there is no need to hold the roll paper R through the core material R1 of the roll paper R, the roll paper R can be easily inserted and removed from the roll paper storage section 31, and the configuration can be simplified.

[0065] In this embodiment, a flap roller 61c rotatable about an axis O3 is provided at the tip of the flap 61a. According to this configuration, the frictional force acting between the leading end of the flap unit 61 and the recording paper P can be reduced, and the recording paper P can be transported smoothly.

[0066] In this embodiment, the recording paper P is guided to the printing unit 3 through between the first guide roller 63 and the second guide roller 64. With this configuration, the first guide roller 63 and the second guide roller 64 can limit the movement range of the recording paper P pulled out from the roll paper R. This allows the recording paper P to be guided within a specified angle range relative to the printing unit 3, regardless of the position of the roll paper R inside the roll paper compartment 31. This allows the recording paper P to be stably supplied to the printing unit 3.

[0067] In this embodiment, the first guide roller 63 is configured to be made of a softer material than the second guide roller 64. This configuration makes it easier to reduce the impact that acts on the first guide roller 63 when it comes into contact with the roll paper R. This makes it possible to reduce the generation of abnormal noises that accompany the movement of the roll paper R inside the roll paper compartment 31.

[0068] In this embodiment, the near-end sensor 62 is connected to the flap 61a and includes a lever 62a that is rotatable between an ON position and an OFF position in response to the rotation of the flap 61a. According to this configuration, the lever 62a of the near-end sensor 62 rotates in conjunction with the flap 61a, so that the near-end sensor 62 is switched between an on state and an off state according to the rotation angle of the flap 61a. This simplifies the configuration compared to a case where an operating mechanism for the lever 62a is provided separately from the flap unit 61.

[0069] In this embodiment, the roll paper R is configured to be movable in the left-right direction, and has a guide wall 51 that abuts against the roll paper R from both left-right sides, and is equipped with a positioning mechanism 4 that positions the roll paper R in the left-right direction (first direction) along the central axis of the roll paper R within the roll paper storage section 31. With this configuration, the roll paper R abuts against the guide wall 51, which restricts left-right movement of the roll paper R within the roll paper accommodation section 31. Therefore, by moving the guide wall 51 to match the width of the roll paper R, left-right movement of the roll paper R within the roll paper accommodation section 31 can be restricted regardless of the width of the roll paper R. As a result, printing misalignment and abnormal noises associated with the movement of the roll paper R within the roll paper accommodation section 31 can be restricted.

[0070] In this embodiment, a recess 48b is formed in the center of the blade tip 48a of the movable blade 48 in the left-right direction, the recess 48b being recessed relative to the blade tip 48a. According to this configuration, the recording paper P is cut so as not to come into contact with the bottom of the recess 48b, so that a cut uncut portion is formed in the portion of the recording paper P that faces the recess 48b. This makes it possible to prevent the cut recording paper P from adhering to unexpected locations, even when a linerless label is used as the recording paper P. In particular, in this embodiment, since the positioning mechanism 4 is provided as described above, the left-right center of the roll paper R is positioned near the left-right center of the roll paper accommodation section 31. As a result, regardless of the paper width of the roll paper R, it is possible to generate an uncut portion near the left-right center of the recording paper P.

[0071] (Other variations) The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. In the above embodiment, the thermal printer 1 is a drop-in type (insertion type) thermal printer 1, but the configuration is not limited to this. The thermal printer 1 may be a shaft support type that rotatably supports the roll paper R via the core material R1. In the above embodiment, a case has been described in which a linerless label is used as the recording paper P, but the present invention is not limited to this configuration. In the above embodiment, the discharge port 33 is configured to open toward the front, but the present invention is not limited to this configuration. The discharge port 33 may be formed to face in any direction. In the above embodiment, a configuration has been described in which the platen roller 41 and the fixed blade 47 are provided on the bottom unit 10 side, and the thermal head 42 and the movable blade 48 are provided on the cover 11 side, but this is not limited to the configuration. The platen roller 41 and the fixed blade 47 may be provided on the cover 11 side, and the thermal head 42 and the movable blade 48 may be provided on the bottom unit 10 side, or the entire printing unit 3 may be provided on either the bottom unit 10 or the cover 11. Also, the cutter unit 43 is not an essential component.

[0072] In the above embodiment, the configuration in which the flap unit 61 is provided on the bottom unit 10 side has been described, but the present invention is not limited to this configuration. The flap unit 61 may be provided on the cover 11 side so as to be rotatable. In the above embodiment, the flap unit 61 is configured to rotate about the axis O2 along the central axis of the roll paper R, but is not limited to this configuration. The flap unit 61 may be configured to rotate about an axis along the vertical direction. In the above embodiment, the flap roller 61c is provided at the tip of the flap 61a, but the flap roller 61c may be provided at a portion other than the tip of the flap 61a. In this case, a plurality of flap rollers 61c may be provided. However, the flap roller 61c is not an essential component.

[0073] In the above embodiment, the paper holding mechanism 5 is described as having the first guide roller 63 and the second guide roller 64, but is not limited to this configuration. The paper holding mechanism 5 may be configured to have only one of the first guide roller 63 and the second guide roller 64, or may be configured to have three or more rollers.

[0074] In addition, within the scope of the invention, the components in the above-described embodiments may be replaced with well-known components, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0075] 1: Thermal printer 2: Casing 3: Printing unit 4: Positioning mechanism 31: Roll paper storage compartment 33: Outlet 41: Platen roller 42: Thermal head 47: Fixed blade 48: Movable blade 48a: cutting edge 48b: Recess 61a: Flap 61b: biasing member 61c: Flap roller 62a: Lever 63: First guide roller 64: Second guide roller O2: Axis (1st axis) O3: Axis (second axis) O4: Axis (3rd axis) O5: Axis (4th axis) P: Recording paper R: Roll paper

Claims

1. a casing including a roll paper storage section into which roll paper having recording paper wound thereon can be inserted, and an outlet through which a portion of the recording paper pulled out from the roll paper is discharged to the outside; a printing unit provided in the casing between the roll paper storage section and the discharge outlet, the printing unit including a thermal head that prints on the recording paper, and a platen roller that sandwiches the recording paper between the thermal head and the printing unit and transports the recording paper toward the discharge outlet; a flap that is rotatably disposed in the casing between the printing unit and the roll paper storage section and that pushes the roll paper in a direction away from the paper outlet by contacting an outer circumferential surface of the roll paper; a biasing member that biases the flap in a direction away from the discharge port about the first axis; Equipped with a first guide roller that is rotatable about a third axis that is aligned with the central axis of the roll paper, and a second guide roller that is rotatable about a fourth axis that is aligned with the third axis, the first guide roller being provided in a portion of the casing that is closer to the roll paper storage section than the printing unit; the recording paper is guided to the printing unit through a gap between the first guide roller and the second guide roller; the first guide roller is disposed closer to the roll paper compartment than the second guide roller; The first guide roller is made of a softer material than the second guide roller. Thermal printer.

2. 2. The thermal printer according to claim 1, further comprising a flap roller at a tip end of the flap, the flap being rotatable about a second axis along a central axis of the roll paper and capable of contacting the recording paper.

3. a sensor for detecting the remaining amount of the roll paper is provided in the casing; 3. The thermal printer according to claim 1, wherein the sensor includes a lever connected to the flap and capable of rotating between an on position and an off position in response to rotation of the flap.

4. A thermal printer as described in any one of claims 1 to 3, wherein the casing is configured to be movable in a first direction along the central axis of the roll paper, and is provided with a positioning mechanism that positions the roll paper in the first direction within the roll paper storage section by abutting the roll paper from both sides in the first direction.

5. The printing unit includes: A fixed blade provided on one side of the discharge port; a movable blade that is provided on the other side of the discharge opening so as to be capable of approaching and receding from the fixed blade and capable of cutting the recording paper between the movable blade and the fixed blade, The thermal printer according to claim 4 , wherein a recess is formed in a central portion of the movable blade in the first direction, the recess being recessed toward a cutting edge of the movable blade.

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