printer

Abstract

To provide a printer which can prevent the occurrence of slacking of a long medium to be printed.SOLUTION: A printer includes a conveying section, a print head, and a brake member. The conveying section has first and second rollers arranged in a state of coming into press-contact with each other across a conveying path for conveying a long medium to be printed and applies conveying force to the medium to be printed by rotating the first and second rollers. The print head is arranged on an upstream side of a position where the conveying section applies conveying force in a normal direction along the conveying path and performs printing on the medium to be printed which is conveyed in the normal direction through the conveying path. The brake member is arranged to come into contact with the second roller, is moved to a first position for applying first brake force to the medium to be printed by frictional force generated by rotation of the second roller in the normal direction and is moved to a second position for applying second brake force larger than the first brake force to the medium to be printed by frictional force generated by rotation of the second roller in an opposite direction.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a printer that prints on a long print-receiving medium. [Background technology]

[0002] Conventionally, ribbon cartridges that are installed in printers, for example, have been equipped with a mechanism that prevents the roller that winds up the ink ribbon from rotating in the reverse direction to prevent slack in the ink ribbon as it passes over the print head. This mechanism prevents the ink ribbon from moving in the direction that would cause slack by prohibiting the driven roller that presses the ink ribbon against the drive roller from rotating in the reverse direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-40132 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, printers that print on label paper, which consists of multiple labels attached at equal intervals to a long, strip-shaped backing, perform a backfeed, which moves the label paper backward, to align each label with the print head. Repeated backfeeds can cause slack in the label paper, which can lead to false jam detections and reduced print quality.

[0005] The problem to be solved by the present invention is to provide a printer that can prevent sagging of a long print medium. [Means for solving the problem]

[0006] The printer of the embodiment includes a transport unit, a print head, and a braking member. The transport unit has first and second rollers arranged in pressure contact with each other across a transport path that transports a long print-receiving medium, and applies a transport force to the print-receiving medium by rotating the first and second rollers. The print head is arranged upstream of the position where the transport unit applies the transport force in the forward direction along the transport path, and prints on the print-receiving medium transported in the forward direction via the transport path. The braking unit is arranged in contact with the second roller, and moves to a first position where a first braking force is applied to the print-receiving medium by frictional force generated by rotation of the second roller in the forward direction, and moves to a second position where a second braking force greater than the first braking force is applied to the print-receiving medium by frictional force generated by rotation of the second roller in the reverse direction. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing the appearance of a printer according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing the printer of FIG. 1 with the cover open. [Figure 3] FIG. 3 is a perspective view showing a label paper roll used in the printer of FIG. [Figure 4] FIG. 4 is a schematic diagram showing the internal structure of the printer of FIG. [Figure 5] FIG. 5 is a perspective view of the peeling unit attached to the printer of FIG. 1, seen from inside the case. [Figure 6] FIG. 6 is a perspective view showing the peeling unit of FIG. 5 in an open state with label paper attached. [Figure 7] FIG. 7 is a perspective view showing a main part of the separation unit of FIG. [Figure 8] FIG. 8 is a side view of the main part of FIG. 7 as seen from the direction of arrow F8. [Figure 9] FIG. 9 is a cross-sectional view showing the peeling unit of FIG. 5 in a closed state. [Figure 10] FIG. 10 is an explanatory diagram for explaining the operation of the peeling unit when conveying label paper in the forward direction. [Figure 11] FIG. 11 is an explanatory diagram for explaining the operation of the peeling unit when feeding the label paper backward. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in Figures 1 and 2, the label printer 100 (hereinafter simply referred to as the printer 100) has a case 2 and a cover 4. The case 2 forms the lower housing of the printer 100, and the cover 4 forms the upper housing of the printer. The cover 4 is connected to the case 2 via a hinge (not shown) located at the rear end. The cover 4 is rotatable between a closed position shown in Figure 1 and an open position shown in Figure 2. In the following description, when the cover 4 is in the closed position as shown in Figure 1, the side of the discharge outlet 9 of the printer 100 is defined as the front side, and the up, down, left, and right directions of the printer 100 are defined as viewed from the front side.

[0009] The case 2 is a rectangular box with an open top, and has a cutout portion 3 in its front wall for attaching a peeling unit 10 (FIGS. 5 and 6), which will be described later. The case 2 has a front panel 5 that is attached to the cutout portion 3 when the peeling unit 10 is not attached. FIGS. 1 and 2 show the front panel 5 attached to the cutout portion 3. The front panel 5 is detachable from the cutout portion 3 and can be replaced with the peeling unit 10.

[0010] The cover 4 is a rectangular box-like structure with an open bottom. On the front sides of the left and right side walls of the cover 4, there are an opening lever 6 for opening the cover 4 and a fixed hook 16 that is operated by operating the opening lever 6. When the cover 4 is in the closed position, the fixed hook 16 engages with an engaging portion on the case 2, locking the cover 4 in the closed position. An operation / display panel 7 and a power button 8 are located on the top wall of the cover 4.

[0011] The printer 100 has a slit-shaped discharge opening 9 (FIG. 1) on the front side between the front panel 5 and cover 4 of the case 2, through which printed label paper 11 is fed. If a peeling unit 10 is attached to the case 2 instead of the front panel 5, a similar discharge opening 9 is formed between the peeling unit 10 and the cover 4. When the peeling unit 10 is attached, only the label 13 peeled from the backing paper 12 is discharged through the discharge opening 9. As shown in FIG. 9, the peeling unit 10 has a label sensor 20 that detects the label 13 discharged through the discharge opening 9.

[0012] As shown in FIG. 3, the label paper 11 to be installed inside the case 2 is formed by attaching multiple rectangular labels 13 at equal intervals to one side of a long, strip-shaped backing paper 12. The labels 13 have an adhesive layer on the surface facing the backing paper 12, making them detachable from the backing paper 12. After being peeled off from the backing paper 12, they can be attached to other items. The label paper roll 15 is formed by wrapping the label paper 11 around a paper tube 14 with the side of the backing paper 12 to which the labels 13 are attached facing outward. The label paper 11 is an example of a long, strip-shaped print-receiving medium. As shown in FIG. 2, the printer 100 has a pair of paper holders 17 on the left and right for attaching the label paper roll 15. The printer 100 prints on each label 13 on the label paper 11.

[0013] As shown in Figures 2 and 4, the printer 100 has a platen roller 21 (first roller) that applies a forward transport force to the label paper 11, pulling the label paper 11 from the label paper roll 15. The platen roller 21 can also apply a transport force to the liner 12 after the label 13 has been peeled off. The platen roller 21 can also rotate in the reverse direction to feed the label paper 11 back. The platen roller 21 is located on the front side of the case 2, adjacent to the discharge opening 9. The platen roller 21 rotates in contact with the surface of the label paper 11 opposite the surface of the liner 12 on which the label 13 is affixed.

[0014] The printer 100 has a transport path 1 that transports label paper 11 pulled out from a label paper roll 15. Rotating the cover 4 to the open position shown in FIG. 2 opens part of the transport path 1. When the peeling unit 10 is attached to the cutout portion 3 of the case 2, as shown in FIG. 6, with the peeling unit 10 open to the front, the label paper 11 pulled out from the label paper roll 15 is inserted inside the peeling unit 10. As shown in FIG. 9, the transport path 1 curves along the various components on the path along which the label paper 11 is transported.

[0015] The printer 100 has a print head 23 that prints on label paper 11 transported through transport path 1. The print head 23 is located on the opposite side (above) of transport path 1 from the platen roller 21, and is pressed against the platen roller 21. This allows the platen roller 21 to apply a transport force to the label paper 11 at a position where the print head 23 is pressed against the platen roller 21. The print head 23 is configured on the cover 4 side. The cover 4 is equipped with a pressure spring (not shown) that presses the print head 23 against the platen roller 21.

[0016] The print head 23 is capable of printing by thermal transfer and thermal printing. When printing by thermal transfer, as in this embodiment, an ink ribbon 25 is interposed between the print head 23 and the label paper 11, and the ink ribbon 25 is transported at the same speed and in the same direction as the label paper 11, and the heat from the print head 23 melts the ink on the ink ribbon 25 and fixes it to the label 13. When printing by thermal, paper containing a color former is attached to the printer 100, and heat is applied to this paper by the print head 23 to cause color to form. When printing by thermal, the ink ribbon 25 is removed from the printer 100.

[0017] 9, the label paper 11 pulled out from the label paper roll 15 passes between the platen roller 21 and the print head 23, where it is wound around the acute corner of the peeling guide 22 and folded back. The peeling guide 22 is provided in the case 2 adjacent to the front side of the platen roller 21. The label paper 11 wound around the corner of the peeling guide 22 passes between the platen roller 21 and a peeling roller 24 (second roller, driven roller) located below the platen roller 21 on the opposite side from the print head 23 in the figure, and is discharged to the outside of the case 2.

[0018] The peeling roller 24 is a component included in the peeling unit 10. When the peeling unit 10 is in the open state as shown in FIG. 6, the peeling roller 24 moves away from the platen roller 21 toward the front. When the peeling unit 10 is rotated to the closed position as shown in FIG. 9, the peeling roller 24 comes into rolling contact with the platen roller 21 with the backing paper 12 sandwiched therebetween. The label paper 11 is placed inside the peeling unit 10 as shown in FIG. 9 with the two or three labels 13 at the leading edge peeled from the backing paper 12 as shown in FIG. 3.

[0019] After printing, the label 13 is peeled from the backing paper 12 by a peel guide 22 and discharged through the discharge outlet 9. The label 13 discharged from the discharge outlet 9 is detected by a label sensor 20. The label sensor 20 may be, for example, a transmissive optical sensor or a reflective optical sensor.

[0020] The peeling roller 24 is pressed against the platen roller 21 by two pressure springs 29 shown in Figure 5, and a conveying force can be applied from the platen roller 21 to the backing paper 12 of the label paper 11 at the nip between the two. The platen roller 21 and peeling roller 24 are an example of a conveying unit that applies a conveying force to the backing paper 12 conveyed through the conveying path 1.

[0021] The peeling guide 22 slides a corner of the label paper 11 against the backing paper 12, folding the backing paper 12 back in approximately the opposite direction. The peeling guide 22 peels the label 13 from the backing paper 12 by virtue of the stiffness of the label 13, which does not tend to bend together with the backing paper 12. The label 13 peeled by the peeling guide 22 is discharged from the discharge port 9 and picked up by the operator.

[0022] 4, the printer 100 has a supply roll 26 in which a long, strip-shaped ink ribbon 25 is wound around a paper tube, and a recovery roll 27 in which the used ink ribbon 25 that has passed the print head 23 is wound around the paper tube. The ink ribbon 25, stretched between the supply roll 26 and the recovery roll 27, passes between the print head 23 and the platen roller 21 so as to be sequentially overlapped with the multiple labels 13 on the label paper 11 being transported via the transport path 1.

[0023] A pair of paper holders 17 (Fig. 2) inside the case 2 rotatably hold both ends of the paper tube 14 of the label paper roll 15. Inside the cover 4, there is a feed shaft 18 to which the paper tube of the supply roll 26 of the ink ribbon 25 is attached, and a take-up shaft 19 (not shown in Fig. 2) to which the paper tube of the recovery roll 27 is attached.

[0024] The label paper 11 may be fed backward in the direction opposite to the forward direction to align the print start position for each label 13. When feeding the label paper 11 backward, the platen roller 21 rotates in the reverse direction to transport the label paper 11 in the reverse direction. At this time, the print head 23 is moved to a retracted position above the platen roller 21, and the ink ribbon 25 is separated from the label paper 11.

[0025] As shown in FIG. 5, the peeling unit 10 has a housing 31 that is attached to the cutout portion 3 of the case 2. The housing 31 has a pair of left and right slide shafts 32 at its bottom end. The two slide shafts 32 are coaxial and protrude outward in the left-right direction, spaced apart from each other. The housing 31 is attached to the cutout portion 3 of the case 2 by inserting the pair of slide shafts 32 into left and right slide grooves 33 (see FIG. 6) in the cutout portion 3. The housing 31 is rotatable relative to the case 2 around the slide shafts 32. FIG. 6 shows the housing 31 of the peeling unit 10 in an open state after being rotated forward around the pair of slide shafts 32.

[0026] As shown in Figures 5, 7, and 8, the peeling unit 10 includes a holding block 34 located inside the center in the left-right direction of the housing 31. The base end of an arm member 35 is attached to the holding block 34 so as to be rotatable about a rotation shaft 36. The base end of a braking member 37 is attached to the tip end of the arm member 35 so as to be rotatable about a rotation shaft 38. As shown in Figure 5, the housing 31 also holds both ends of the rotation shaft 28 of the peeling roller 24 so as to be rotatable and movable in the up-down direction. Two pressing springs 39 are located between the holding block 34 and the braking member 37. The pressing springs 39 are an example of an elastic member that presses the braking member 37 against the peeling roller 24.

[0027] The holding block 34 is integrally provided with two bosses 341 that hold the lower end of the pressing spring 39 that presses the braking member 37 against the peeling roller 24. The braking member 37 has a circular hole (not shown) that receives the upper end of the pressing spring 39. Therefore, even if the braking member 37 moves back and forth relative to the holding block 34, the pressing spring 39 will not fall off. The braking member 37 can move up and down and back and forth relative to the peeling roller 24 as it rotates about the rotation shaft 36 of the arm member 35. In other words, by interposing the arm member 35 between the holding block 34 and the braking member 37, the braking member 37 can be moved approximately parallel to the back and forth direction while pressing against the peeling roller 24. The pressing spring 39 movably supports the braking member 37 by elastically deforming.

[0028] The braking member 37 has a resin portion 371 and a rubber portion 372. As shown in FIG. 8, an upper surface 3711 of the resin portion 371 and an upper surface 3721 of the rubber portion 372 are arranged on the same horizontal plane. The resin portion 371 and the rubber portion 372 are arranged side by side in the rotation direction of the peeling roller 24. In the initial state shown in FIG. 8 where the peeling unit 10 is arranged in the closed position, the upper surface 3721 of the rubber portion 372 is in contact with the outer circumferential surface 241 of the peeling roller 24.

[0029] Figure 9 shows the state in which the label paper 11 has been set and the peeling unit 10 is closed. In this state, the label paper 11 passes between the platen roller 21 and the print head 23, is wound around the peeling guide 22, passes between the platen roller 21 and the peeling roller 24, and is positioned along the conveying guide 30. Figure 9 shows the state in which the label paper 11 is being conveyed in the forward direction.

[0030] When the peeling unit 10 is closed and the label paper 11 is conveyed in the forward direction, the platen roller 21 rotates counterclockwise and the peeling roller 24 rotates clockwise, as shown in Fig. 10. When the peeling roller 24 rotates clockwise, the brake member 37, which is pressed against the outer circumferential surface 241 of the peeling roller 24, moves to the left in the figure due to the frictional force between the brake member 37 and the peeling roller 24, and the arm member 35 swings clockwise around the pivot shaft 36 until part of the arm member 35 comes into contact with the holding block 34 and stops. At this time, the position where the brake member 37 has stopped, as shown in Fig. 10, is the first position.

[0031] When the braking member 37 is placed in the first position in this manner, the outer peripheral surface 241 of the peeling roller 24 comes into contact with the upper surface 3711 of the resin portion 371 of the braking member 37. When the peeling roller 24 rotates clockwise in this state, a force acts in a direction that weakens the rotation of the peeling roller 24 due to the frictional force generated between the upper surface 3711 of the resin portion 371 and the outer peripheral surface 241 of the peeling roller 24. This force is applied to the backing paper 12 as a first braking force.

[0032] In contrast, when the label paper 11 is fed backward, the platen roller 21 rotates clockwise and the peeling roller 24 rotates counterclockwise, as shown in Fig. 11. When the peeling roller 24 rotates counterclockwise, the brake member 37, which is pressed against the outer circumferential surface 241 of the peeling roller 24, moves to the right in the figure due to the frictional force between the brake member 37 and the outer circumferential surface 241 of the peeling roller 24, and the arm member 35 swings counterclockwise around the pivot shaft 36, causing the end of the resin portion 371 of the brake member 37 on the right side in the figure to press against the conveyance guide 30 and stop. At this time, the position where the brake member 37 has stopped, as shown in Fig. 11, is the second position.

[0033] When the braking member 37 is placed in the second position in this manner, the outer peripheral surface 241 of the peeling roller 24 comes into contact with the upper surface 3721 of the rubber portion 372 of the braking member 37. When the peeling roller 24 is rotated counterclockwise in this state, a force acts in a direction that weakens the rotation of the peeling roller 24 due to the frictional force generated between the upper surface 3721 of the rubber portion 372 and the outer peripheral surface 241 of the peeling roller 24. This force is applied to the backing paper 12 as a second braking force that is greater than the above-mentioned first braking force.

[0034] The frictional force generated between the upper surface 3721 of the rubber portion 372 and the outer peripheral surface 241 of the peeling roller 24 is greater than the frictional force generated between the upper surface 3711 of the resin portion 371 and the outer peripheral surface 241 of the peeling roller 24. Therefore, the braking force applied to the peeling roller 24 when the upper surface 3721 of the rubber portion 372 is pressed against the outer peripheral surface 241 of the peeling roller 24 is greater than the braking force applied to the peeling roller 24 when the upper surface 3711 of the resin portion 371 is pressed against the outer peripheral surface 241 of the peeling roller 24.

[0035] Furthermore, when the braking member 37 is placed in the second position, the end of the resin portion 371 of the braking member 37 is pressed against the transport guide 30 with the liner 12 sandwiched therebetween, and a force is applied that tries to prevent the transport of the liner 12. This force also acts on the liner 12 as a second braking force that is greater than the first braking force described above. In other words, when the label paper 11 is fed backward, a braking force is applied to the liner 12 via the peeling roller 24 due to the sliding contact of the rubber portion 372, and a braking force is also applied to the liner 12 by pressing the resin portion 371 against the transport guide 30. The two types of braking forces applied to the liner 12 during backward feeding act at different positions on the liner 12.

[0036] When the label paper 11 is conveyed in the forward direction through the conveyance path 1 and labels 13 are printed on it, it is desirable to make the conveying force applied from the platen roller 21 to the liner 12 at the position where the peeling roller 24 faces the platen roller 21 slightly greater than the conveying force applied from the platen roller 21 to the label paper 11 at the position where the print head 23 faces the platen roller 21. This prevents the liner 12 that has passed the print head 23 from becoming loose between it and the peeling roller 24, allows the liner 12 to slide against the peeling guide 22, and ensures that the label 13 is peeled off from the liner 12.

[0037] On the other hand, if the conveying force applied from the platen roller 21 to the liner 12 at the position where the peeling roller 24 faces the platen roller 21 is made weaker than the conveying force applied from the platen roller 21 to the label paper 11 at the position where the print head 23 faces the platen roller 21, there is a possibility that the liner 12 that has passed the print head 23 will become loose between the peeling roller 24. If this slack becomes large, the slackened liner 12 will enter the detection range of the label sensor 20, as shown by the dashed line in Figure 11, and may be erroneously detected as a forgotten label 13, resulting in an erroneous detection of a jam.

[0038] On the other hand, if the conveying force applied from the platen roller 21 to the liner 12 at the position where the peeling roller 24 faces the platen roller 21 is greater than the conveying force applied from the platen roller 21 to the label paper 11 at the position where the print head 23 faces the platen roller 21, problems will occur when feeding the label paper 11 backward. In other words, in this case, the reverse conveying force applied from the platen roller 21 to the liner 12 at the position where the peeling roller 24 faces the platen roller 21 will be greater than the reverse conveying force applied from the platen roller 21 to the label paper 11 at the position where the print head 23 faces the platen roller 21, and the liner 12 returned by the peeling roller 24 may become loose between it and the print head 23, as shown by the dashed line in Figure 11.

[0039] For this reason, the printer 100 of this embodiment is equipped with the above-mentioned mechanism that applies a greater braking force to the peeling roller 24 during backfeed than to the peeling roller 24 during printing. Therefore, according to this embodiment, when the label paper 11 is fed in the forward direction for printing, the conveying force applied from the platen roller 21 to the liner 12 at the position opposite the peeling roller 24 can be made slightly greater than the conveying force applied from the platen roller 21 to the label paper 11 at the position opposite the print head 23, preventing slack in the liner 12. Furthermore, according to this embodiment, during backfeed, the conveying force applied from the platen roller 21 to the liner 12 at the position opposite the peeling roller 24 can be made weaker than the reverse conveying force applied from the platen roller 21 to the label paper 11 at the position opposite the print head 23, preventing slack in the liner 12 during backfeed.

[0040] Therefore, in this embodiment, the backing paper 12 does not become loose when the label paper 11 is transported in the forward direction, and the backing paper 12 does not become loose when the label paper 11 is fed backward. This prevents the label sensor 20 from erroneously detecting a loose backing paper 12 and causing a jam, thereby improving the operating rate of the printer 100.

[0041] Although the embodiments of the present invention have been described above, the above-described embodiments are presented as examples and are not intended to limit the scope of the invention. The above-described embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The above-described embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents set forth in the claims. [Explanation of symbols]

[0042] 2...case, 3...cutout portion, 4...cover, 9...ejection port, 10...peeling unit, 11...label paper, 12...backing paper, 13...label, 20...label sensor, 21...platen roller, 22...peeling guide, 23...print head, 24...peeling roller, 241...outer surface, 25...ink ribbon, 30...transport guide, 31...housing, 34...holding block, 341...boss, 35...arm member, 37...brake member, 371...plastic part, 3711...top surface, 372...rubber part, 3721...top surface, 39...pressing spring, 100...label printer.

Claims

1. a conveying unit having first and second rollers arranged in pressure contact with each other with a conveying path for conveying a long print-receiving medium sandwiched therebetween, and applying a conveying force to the print-receiving medium by rotating the first and second rollers; a print head that is disposed upstream of a position where the transport unit applies the transport force in the forward direction along the transport path, and that prints on a print-receiving medium that is transported in the forward direction via the transport path; a braking member that is disposed in contact with the second roller, that moves to a first position where a first braking force is applied to the print-receiving medium by a frictional force generated by the rotation of the second roller in the forward direction, and that moves to a second position where a second braking force greater than the first braking force is applied to the print-receiving medium by a frictional force generated by the rotation of the second roller in the reverse direction; A printer having

2. the print-receiving medium is label paper with a plurality of labels affixed to a long, strip-shaped backing, and the label paper is transported through the transport path with the labels facing the print head; the first roller is a platen roller that faces the print head across the conveyance path, the second roller is a driven roller that presses the backing sheet that has passed the print head in the forward direction against a platen roller, a peeling guide disposed on the platen roller side of the conveyance path between a position where the print head is pressed against the platen roller and a position where the driven roller is pressed against the platen roller, for peeling the label from the backing sheet; The printer of claim 1 .

3. an elastic member that supports the braking member movably between the first position and the second position and presses the braking member against the driven roller; The printer of claim 2 .

4. a conveyance guide that presses the mount between itself and the braking member and applies the second braking force to the mount when the braking member moves to the second position; The printer of claim 2 .

5. the braking member has a resin portion that comes into contact with the driven roller when the braking member is moved to the first position, and a rubber portion that comes into contact with the driven roller when the braking member is moved to the second position. The printer according to claim 3 .

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