Printer device

Abstract

To provide a printer apparatus capable of accurately performing backfeeding.SOLUTION: A printer apparatus includes: a conveyance part which conveys a mount where a plurality of labels are stuck at prescribed intervals, in a forward direction and a backward direction; a printing part for printing the labels in a process in which the mount is conveyed in the forward direction; a release part which bends the mount passing through the printing part and releases the printed labels; a discharge port for discharging the labels released by the release part; a winding shaft for winding up the mount from which the labels are released; a drive part for rotating and driving the winding shaft in a winding direction in which the mount is wound up; a drive row which is provided between the winding shaft and the drive part, transmits a rotary force in the winding direction to the winding shaft and brings a rotary force in a reverse direction to the winding direction into an idle state; and a control part which rotates and drives the drive part in the winding direction while the mount is carried in the forward direction and, when the label is discharged from the discharge port, conveys the mount for a prescribed amount in the backward direction.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a printer device. [Background technology]

[0002] Printers that print on labels are known. For example, in printers that print on a backing sheet to which multiple labels are attached at predetermined intervals, the rolled backing sheet is fed to a print head such as a thermal head to print on the surfaces of the labels.

[0003] In addition, in printers equipped with a mechanism for peeling the printed label from the backing, a drive source such as a motor rotates a winding shaft, and the backing from which the label has been peeled is wound up around the winding shaft. In addition, in such printers, once printing of a label is completed, a backfeed is performed, in which the backing is transported in the opposite direction from when printing was performed, to return the next label to the print head's printing start position.

[0004] Incidentally, when backfeeding the liner, the liner wound around the winding spindle is pulled out from the winding spindle while resisting a load caused by the non-excitation torque of the drive source, etc. Therefore, when backfeeding, the load can easily cause slippage during transport of the liner, which can make it difficult to transport the liner accurately. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a printer device that can perform backfeeding with high accuracy. [Means for solving the problem]

[0006] The printer device of the embodiment includes a transport unit, a printing unit, a peeling unit, an outlet, a winding shaft, a drive unit, a drive train, and a control unit. The transport unit transports a liner, on which multiple labels are attached at predetermined intervals, in a forward direction and a backward direction. The printing unit prints on the labels as the liner is transported in the forward direction. The peeling unit bends the liner that has passed the printing unit to peel off the printed labels, and the outlet discharges the labels peeled by the peeling unit. The winding shaft winds up the liner from which the labels have been peeled. The drive unit rotates and drives the winding shaft in a winding direction to wind up the liner. The drive train is provided between the winding shaft and the drive unit, and transmits rotational force in the winding direction to the winding shaft and rotational force in the direction opposite to the winding direction to cause the winding shaft to idle. The control unit controls the transport unit and the drive unit. Further, the control unit drives the drive unit to rotate in the winding direction while the backing sheet is being transported in the forward direction, and when the label is discharged from the discharge port, the control unit drives the drive unit to transport the backing sheet by a predetermined distance in the backward direction. Prior to the transport in the backward direction, the drive unit is rotationally driven in a direction opposite to the winding direction. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a label printer according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the hardware configuration of the label printer according to the embodiment. [Figure 3] FIG. 3 is a diagram for explaining the printing operation of the label printer according to the embodiment. [Figure 4] FIG. 4 is a diagram for explaining the printing operation of the label printer according to the embodiment. [Figure 5] FIG. 5 is a diagram for explaining the printing operation of the label printer according to the embodiment. [Figure 6] FIG. 6 is a diagram for explaining the printing operation of the label printer according to the embodiment. [Figure 7] FIG. 7 is a diagram showing an example of a drive train for rotationally driving the winding roller according to the embodiment. [Figure 8]FIG. 8 is a diagram showing an example of a drive train for rotationally driving the winding roller according to the embodiment. [Figure 9] FIG. 9 is a diagram showing another example of the configuration of the drive train of the winding roller according to the embodiment. [Figure 10] FIG. 10 is a flowchart showing an example of the operation executed by the label printer of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments described below.

[0009] 1 is a diagram showing a schematic configuration of a label printer 1 according to an embodiment. The label printer 1 is an example of a printer device in the present disclosure.

[0010] The label printer 1 houses a label roll LR, which is a roll of label paper LP, an example of printing paper, inside a housing 2. The label paper LP has multiple labels L attached at predetermined intervals to a long backing sheet M (see Figure 3). The label printer 1 prints on the labels L while pulling out the label paper LP from the label roll LR.

[0011] The label printer 1 includes, inside the housing 2, a transport roller 11, a platen roller 12, a print head 13, a label gap detection sensor 14, a peeling guide 15, a take-up roller 16, and a peeling detection sensor 17. The label printer 1 also includes, inside the housing 2, a ribbon holding shaft 21, a ribbon take-up shaft 22, and a guide shaft 23.

[0012] The conveying rollers 11 have a capstan roller 111 and two auxiliary rollers 112. The label paper LP pulled out from the label roll LR is inserted between the capstan roller 111 and the auxiliary rollers 112. The platen roller 12 is positioned opposite the print head 13. The label paper LP is inserted between the platen roller 12 and the print head 13.

[0013] The capstan roller 111 and platen roller 12 are driven to rotate by a first drive motor 106 (see FIG. 2), which will be described later. For example, when printing on label paper LP, the first drive motor 106 rotates the capstan roller 111 and platen roller 12 counterclockwise, transporting the label paper LP in the -Y direction toward the discharge outlet 3. After printing is complete, the first drive motor 106 rotates the capstan roller 111 and platen roller 12 clockwise, transporting the label paper LP in the reverse direction (+Y direction) to return the next label L to the printing start position.

[0014] Hereinafter, the rotation and rotation direction of the first drive motor 106, capstan roller 111, and platen roller 12 when transporting label paper LP in the -Y direction will also be referred to as "forward rotation." Additionally, the rotation and rotation direction of the first drive motor 106, capstan roller 111, and platen roller 12 when transporting label paper LP in the +Y direction will also be referred to as "reverse rotation."

[0015] The print head 13 is an example of a printing unit. The print head 13 of this embodiment is a thermal head having a structure in which multiple heating elements are aligned. The print head 13 prints on labels L on label paper LP held between the platen roller 12 and the print head 13 by heating the heating elements that correspond to the print pattern.

[0016] Specifically, the ink ribbon IR is inserted between the platen roller 12 and the print head 13. The ink applied to the ink ribbon IR is transferred by the heated print head 13 onto the label L on the label paper LP.

[0017] Here, the ink ribbon IR is suspended between a ribbon holding shaft 21 and a ribbon take-up shaft 22. The ribbon holding shaft 21 has an unused ink ribbon IR wound in a roll. The ribbon take-up shaft 22 is a shaft that takes up the ink ribbon IR. Furthermore, the guide shaft 23 is a guide member that guides the ink ribbon IR suspended between the ribbon holding shaft 21 and the ribbon take-up shaft 22 to a predetermined position. When printing on label paper LP, the ribbon take-up shaft 22 is rotated clockwise by a motor (not shown), and takes up the ink ribbon IR after printing.

[0018] The print head 13 moves up and down by a movement mechanism (not shown) such as a solenoid. This allows the label printer 1 to switch between a state in which the print head 13 is in contact with the platen roller 12 and a state in which the print head 13 is away from the platen roller 12. The print head 13 is in contact with the platen roller 12 when printing on label paper LP. The ribbon take-up shaft 22 also takes up the ink ribbon IR at a speed that corresponds to the transport speed of the label paper LP while printing is being performed, and stops taking up the ink ribbon IR when the print head 13 is in a non-contact state.

[0019] The label gap detection sensor 14 is provided on the transport path of the label paper LP between the transport roller 11 and the platen roller 12. The label gap detection sensor 14 detects the position of the gap between the label paper LP and the label L (the so-called label gap). Specifically, the label gap detection sensor 14 detects the portion of the label paper LP where the light reception level is equal to or greater than a predetermined threshold as the position of the gap between the labels. The label gap detection sensor 14 can be realized, for example, by a transmission sensor composed of a light-emitting element and a light-receiving element.

[0020] The label printer 1 determines the position of the label L from the position of the label gap detected by the label gap detection sensor 14, and adjusts the position of the label L to the print start position of the print head 13, adjusts the print timing, etc.

[0021] After printing is complete, the label paper LP is separated into the liner M and the label L by the peeling guide 15, which is an example of a peeling section. The peeling guide 15 is a V-shaped columnar member with two surfaces that intersect at an acute angle. The peeling guide 15 is installed along the X direction. The peeling guide 15 bends the label paper LP that has been transported toward the discharge outlet 3, peeling the liner M from the label L. The peeled liner M is taken up by the winding roller 16, while the label L peeled from the liner M is discharged (issued) from the discharge outlet 3 provided in the housing 2.

[0022] The winding roller 16 is an example of a winding shaft. The winding roller 16 winds up the liner M from which the label L has been peeled. The winding roller 16 is rotationally driven by a second drive motor 107 (see FIG. 2), which will be described later. For example, when printing on the label paper LP, the second drive motor 107 rotates the winding roller 16 counterclockwise, causing the winding roller 16 to wind up the liner M from which the label L has been peeled (label paper LP).

[0023] Hereinafter, the rotation and direction of the second drive motor 107 and the winding roller 16 when winding up the label paper LP will also be referred to as "forward rotation." Furthermore, the rotation and direction of the second drive motor 107 and the winding roller 16 when rotating in the direction opposite to forward rotation will also be referred to as "reverse rotation." Note that the rotation direction of the winding roller 16 when rotating forward corresponds to the winding direction of the label paper LP.

[0024] The peeling detection sensor 17 is installed near the discharge outlet 3 and detects whether or not a label L has been peeled from the backing sheet M. The peeling detection sensor 17 can be realized, for example, by a transmission type sensor composed of a light-emitting element and a light-receiving element.

[0025] When the peeling detection sensor 17 detects the label L, the label printer 1 temporarily stops feeding and printing on the label paper LP. Then, when the user removes the label L from the discharge outlet 3, the peeling detection sensor 17 detects that there is no label L. When the peeling detection sensor 17 detects that there is no label L, the label printer 1 resumes feeding and printing on the label paper LP.

[0026] Specifically, when the label printer 1 resumes printing, it feeds the label paper LP a predetermined distance in the direction opposite to the direction of feeding during printing, in order to return the label L following the peeled label L to the print start position of the print head 13. Then, once the label printer 1 has completed feeding in the reverse direction, it prints the next label L and issues the printed label L from the discharge outlet 3. Hereinafter, the feeding of the label paper LP during printing will be referred to as "feed," and the feed direction during this feeding will be referred to as the "feed direction." Additionally, feeding to return the label paper LP to the print start position will be referred to as "backfeed," and the feed direction during this feeding will be referred to as the "backfeed direction."

[0027] Next, the hardware configuration of the label printer 1 will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of the hardware configuration of the label printer 1.

[0028] As shown in FIG. 2, the label printer 1 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, and a RAM (Random Access Memory) 103.

[0029] The CPU 101 is an example of a processor, and is the main controller of the label printer 1. The ROM 102 stores various programs. The RAM 103 loads the programs and various data. The CPU 101, ROM 102, and RAM 103 are connected via a bus or the like. The CPU 101, ROM 102, and RAM 103 constitute the control unit 100. That is, the control unit 100 executes control processing related to the operation of the label printer 1 by the CPU 101 operating in accordance with a control program 1041 stored in the ROM 102 or in the storage unit 104 (described later) and loaded into the RAM 103.

[0030] The storage unit 104 is configured with a non-volatile memory such as a hard disk drive (HDD) or flash memory that retains stored information even when the power is turned off. The storage unit 104 stores a control program 1041 for controlling the operation of the label printer 1. The storage unit 104 also stores various setting information related to the operation of the label printer 1.

[0031] The control unit 100 is also connected to a controller 105, which controls the input and output of data, via a bus, etc. The controller 105 is connected to the print head 13, label gap detection sensor 14, and peel detection sensor 17, as well as a first drive motor 106, a second drive motor, etc.

[0032] The first drive motor 106 is the drive source for the transport roller 11 (capstan roller 111) and the platen roller 12. The second drive motor 107 is an example of a drive unit, and is the drive source for the take-up roller 16. The first drive motor 106 and the second drive motor 107 are, for example, stepping motors. Here, the first drive motor 106, together with the transport roller 11 and platen roller 12 described above, functions as an example of a transport unit that transports label paper LP in the feed direction (forward direction) and backfeed direction (rearward direction).

[0033] In this embodiment, the drive source for the conveying roller 11 and the platen roller 12 is the first drive motor 106, but a configuration in which a drive source is provided for each roller is also possible. In this embodiment, at least the conveying roller 11, the platen roller 12, and the take-up roller 16 are driven by different drive sources.

[0034] The controller 105 outputs the detection results of the label gap detection sensor 14 and peel detection sensor 17 to the control unit 100. The controller 105 also receives instructions from the control unit 100 and controls the operation of each unit of the label printer 1. For example, the controller 105 controls the operation of the first drive motor 106 and the second drive motor 107 to feed the label paper LP at a predetermined feed speed or to backfeed the label paper LP a predetermined feed amount.

[0035] The control unit 100 is also connected to a communication unit 108 via a bus or the like. The communication unit 108 communicates with an external device such as an information processing device via a communication line (not shown). For example, the communication unit 108 acquires print data to be printed on the label L from the external device, and acquires printing instructions. The communication line may be a wired communication line or a wireless communication line.

[0036] The hardware configuration of the label printer 1 is not limited to the configuration shown in Fig. 2. For example, the label printer 1 may also include an operation unit for receiving operations from the user, a display unit for displaying various types of information, and the like.

[0037] In the label printer 1 configured as described above, the control unit 100 cooperates with the control program 1041 to control each unit of the label printer 1 and prints on the label paper LP (labels L) while feeding it. The printing operation of the label printer 1 will be described below with reference to Figures 3 to 6.

[0038] For example, when an instruction to print print data is received via the communication unit 108 or an operation unit (not shown), the control unit 100 drives the first drive motor 106 and the second drive motor 107 via the controller 105, thereby causing the conveyance roller 11, the platen roller 12, and the take-up roller 16 to rotate forward. As a result, the label paper LP pulled out from the label roll LR is conveyed in the direction of the discharge slot 3.

[0039] As the label paper LP is transported, the label gap detection sensor 14 detects the position of the gap between labels, and the control unit 100 receives the detection signal via the controller 105. Next, the control unit 100 determines the print timing for printing with the print head 13 from the predetermined transport speed of the label paper LP and the position of the print head 13 on the transport path.

[0040] Next, the control unit 100 applies a voltage to the heating elements of the print head 13 via the controller 105, thereby printing an image (such as a character string) corresponding to the print data onto the label L of the label paper LP based on the identified print timing.

[0041] Figure 3 is a diagram for explaining the printing operation of the label printer 1. Note that in Figure 3, of the components shown in Figure 1, only the platen roller 12, print head 13, label gap detection sensor 14, peeling guide 15, take-up roller 16, and peeling detection sensor 17 are shown (the same applies to Figures 4 to 6).

[0042] 3 shows the state in which, of the labels La, Lb, and Lc arranged on the label paper LP, the leading edge of the leading label La has been transported to the position of the print head 13 (the print start position). The direction of the arrow indicated by the solid line in the figure indicates the transport direction of the label paper LP being fed. The fed label paper LP is folded back by the peeling guide 15 and taken up by the take-up roller 16.

[0043] When printing of the label L is complete, the control unit 100 conveys the label paper LP in the feed direction. As the label paper LP is conveyed, when the peel detection sensor 17 detects the label L peeled by the peel guide 15, the control unit 100 receives a detection signal via the controller 105. Next, the control unit 100 stops conveying the label paper LP.

[0044] Fig. 4 shows a state in which printing of the label La shown in Fig. 3 has been completed and the label La has been transported to the discharge outlet 3. In the state in Fig. 4, the control unit 100 stops transport in the feed direction and waits until the label La is removed.

[0045] In the state of Fig. 4, the user removes the label La that has been discharged from the discharge port 3. Fig. 5 shows the state after the label La has been removed from the state of Fig. 4. When the label La is removed, the peeling detection sensor 17 detects that the label La is no longer present.

[0046] Now, if we look at label Lb, which is the label that follows label La, the leading edge of label Lb is at a position where it has passed the print head 13. Therefore, as shown in Figure 6, the control unit 100 returns the leading edge of label Lb to the print start position of the print head 13 by backfeeding the label paper LP a predetermined amount. Note that the direction of the dashed arrow in the figure indicates the transport direction of the label paper LP that is backfed.

[0047] Then, when continuing to print on label L, the control unit 100 prints on label Lb while feeding label paper LP, as described with reference to Figures 3 to 5. When printing on labels Lc and beyond, the control unit 100 repeatedly executes the operations of Figures 6 and 3 to 5.

[0048] When feeding the label paper LP backward, the first drive motor 106 is rotated in the reverse direction to pull out the label paper LP (backing paper M) wound around the winding roller 16. At this time, the first drive motor 106 pulls out the label paper LP wound around the winding roller 16 from the winding roller 16 while resisting a load caused by the non-excitation torque of the second drive motor 107, etc. Therefore, when feeding backward, the label paper LP is likely to slip during transport due to the influence of the load, and there is a possibility that it will not be possible to transport it accurately.

[0049] Specifically, when backfeeding label paper LP, the next label L is backfeed a fixed amount until it reaches the print start position of the print head 13, but slippage in roller transport can cause deviations in the transport amount. In this case, the printing position on the label L can shift, potentially reducing printing accuracy.

[0050] One possible measure is to backfeed the label paper LP to a position where the label gap detection sensor 14 can detect it, and then adjust the position based on the detection results. However, this increases the amount of conveyance, which causes a problem of reduced throughput.

[0051] Therefore, in order to address the above-mentioned issues, the label printer 1 of this embodiment is equipped with a drive train for accurately feeding back the label paper LP. The drive train equipped in the label printer 1 will be described below with reference to Figures 7 and 8.

[0052] 7 and 8 are diagrams showing an example of a drive train related to the rotational drive of the winding roller 16. Note that Fig. 7 and Fig. 8 show the state of the winding roller 16 as viewed from the Z direction.

[0053] The winding roller 16 has a winding shaft 161 that serves as a rotation shaft, and a sleeve 162 that is provided around the winding shaft 161. The winding shaft 161 is the shaft of the winding roller 16 and is configured to be rotatable in the axial direction. The sleeve 162 is formed from a material such as rubber, and is provided around the winding shaft 161.

[0054] The winding shaft 161 is configured to be rotationally driven by the driving force of the second drive motor 107 via the drive train 30 shown in FIGS.

[0055] The drive train 30 is provided between the winding roller 16 and the second drive motor 107. The drive train 30 includes a first gear 31, a second gear 32, a shaft 33, a third gear 34, a fourth gear 35, and a one-way clutch 36. The first gear 31 is provided, for example, on the rotating shaft of the second drive motor 107, and rotates by receiving the driving force of the second drive motor 107. The first gear 31 meshes with the second gear 32. The second gear 32 includes a shaft 33. A third gear 34 is attached to the shaft 33. The third gear 34 meshes with a fourth gear 35 that is fixed to the shaft end of the winding shaft 161.

[0056] The third gear 34 is attached to the shaft 33 via a one-way clutch 36. The one-way clutch 36 is a clutch mechanism that transmits rotational force to the third gear 34 during feeding and cuts off drive from the third gear 34 during backfeeding.

[0057] In the above configuration, when feeding the label paper LP, the second drive motor 107 rotates the drive train 30 in the first direction (the direction of the solid arrow in FIG. 7) under the control of the control unit 100. In this case, the driving force of the second drive motor 107 is transmitted to the winding shaft 161 via the first gear 31, the second gear 32, the third gear 34, and the fourth gear 35, and rotates the winding roller 16 forward. As a result, the winding roller 16 performs a winding operation on the fed label paper LP (mounting paper M).

[0058] On the other hand, when backfeeding the label paper LP, since the label paper LP (mounting paper M) wound around the winding roller 16 is pulled out by the reverse rotation of the platen roller 12, the winding roller 16 also rotates reversely. At this time, the drive train 30 receives a rotational force that rotates in the second direction (the direction of the dashed arrow in FIG. 8) opposite to the first direction, but since the one-way clutch 36 is in a freewheel state by the second drive motor 107, the winding roller 16 rotates in a state separated from the first gear 31, the second gear 32, and the second drive motor 107.

[0059] When backfeeding the label paper LP, in order to surely realize the freewheel state of the one-way clutch 36, it is preferable to reverse the second drive motor 107 prior to the reverse rotation of the first drive motor 106.

[0060] Specifically, the control unit 100 realizes the freewheel state of the one-way clutch 36 by reversely driving the second drive motor 107 prior to the reverse driving of the first drive motor 106. More specifically, the control unit 100 reversely drives the second drive motor 107 such that a first rotational speed n1 of the shaft portion 33 generated by pulling out the label paper LP by backfeeding and a second rotational speed n2 of the shaft portion 33 generated by the reverse driving of the second drive motor 107 satisfy n1 < n2. Further, the first rotational speed n1 of the shaft portion 33 generated by pulling out the label paper LP varies depending on the amount of labels wound around the shaft portion 33, but the control unit 100 reversely drives the second drive motor 107 so as to satisfy the relationship n1 < n2 under any conditions. As a result, the one-way clutch 36 is in a freewheel state.

[0061] Then, after setting the one-way clutch 36 to the freewheeling state, the control unit 100 reversely drives the first drive motor 106 to backfeed the label paper LP (mounting paper M) by a predetermined amount. Thereby, the control unit 100 conveys the next label L to the printing start position of the printing head 13.

[0062] Note that in the freewheeling state of the one-way clutch 36, the take-up roller 16 is unloaded, so slack may occur in the mounting paper M due to the inertia of rotation at the end of backfeeding. Therefore, for example, as shown in FIG. 9, a torque limiter 37 that generates a constant load torque in the second direction is added to the drive train 30 of the take-up roller 16 or the like, and an appropriate load may be applied to prevent the occurrence of slack.

[0063] FIG. 9 is a diagram showing another configuration example of the drive train of the take-up roller 16. FIG. 9 shows an example in which a torque limiter 37 is provided at the other shaft end of the take-up shaft 161, which is different from the shaft end provided with the fourth gear 35, among both ends of the take-up shaft 161. The load torque T1 of the torque limiter 37 is set such that T2 < T1 < T3 with respect to the inertia torque T2 generated in the take-up roller 16 by the reverse drive of the second drive motor 107 and the torque T3 generated in the take-up roller 16 by pulling out the label paper LP. Thereby, the torque limiter 37 adds a load smaller than the torque T3 generated from the conveying force by the conveying roller 11 and the platen roller 12 to the take-up roller 16 during backfeeding. Further, the torque limiter 37 adds a load larger than the moment of inertia of rotation (inertia torque T2) remaining in the reversely rotating take-up roller 16 to the take-up roller 16 at the end of backfeeding. Therefore, in the label printer 1, backfeeding can be performed without slack occurring in the mounting paper M.

[0064] With the above configuration, the label printer 1 can backfeed the label paper LP without being affected by the load on the second drive motor 107, and therefore can accurately align the label paper LP to the print start position by backfeeding. Therefore, the label printer 1 can accurately print on the label L.

[0065] Next, an example of the operation of the label printer 1 will be described with reference to Fig. 10. Fig. 10 is a flowchart showing an example of the operation executed by the label printer 1.

[0066] First, the control unit 100 drives the first drive motor 106 and the second drive motor 107 in the forward direction to transport the label L (label paper LP) to the print start position (step S11). When the label L reaches the print start position, the control unit 100 drives the print head 13 to print on the label L (step S12).

[0067] When printing is complete, the control unit 100 conveys the label paper LP toward the discharge outlet 3 (step S13). As a result, the printed label L is exposed from the discharge outlet 3 with a portion of the label L peeled off from the backing paper M by the peel guide 15.

[0068] Next, the control unit 100 waits until the label L is removed based on the detection result of the peel detection sensor 17 (Step S14; No). When it detects that the label L has been removed (Step S14; Yes), the control unit 100 proceeds to Step S15 to perform backfeed of the label paper LP.

[0069] The control unit 100 reversely drives the second drive motor 107 to set the one-way clutch 36 in the drive train 30 to a freewheeling state (step S15). Next, the control unit 100 reversely drives the first drive motor 106 to feed back the label paper LP by a predetermined conveyance amount in order to position the next label L at the print start position (step S16). Note that the control unit 100 reversely drives the second drive motor 107 such that the first rotation speed n1 of the shaft portion 33 generated by pulling out the label paper LP and the second rotation speed n2 of the shaft portion 33 generated by reversely driving the second drive motor 107 satisfy n1 < n2.

[0070] Subsequently, the control unit 100 determines whether to end the printing (step S17). For example, when it is instructed to continuously print on a plurality of labels L, the control unit 100 determines to continue the printing (step S17; No), and returns the process to step S12. Then, the control unit 100 performs printing on the next label L positioned at the print start position.

[0071] Also, for example, when printing on the specified number of labels L is completed, the control unit 100 determines to end the printing (step S17; Yes), and ends this process.

[0072] As described above, the label printer 1 of the present embodiment includes a drive train 30 that transmits the rotational force in the winding direction for winding the label paper LP to the winding shaft of the winding roller 16 between the winding roller 16 and the second drive motor 107, and sets the rotational force in the direction opposite to the winding direction to a freewheeling state. Further, while the label printer 1 conveys the label paper LP in the feed direction, the second drive motor 107 is driven forward, and when the printed label L is discharged from the discharge port 3, the label paper LP is conveyed backward by a predetermined amount.

[0073] This allows the label printer 1 to backfeed the label paper LP without being affected by the load on the second drive motor 107, thereby enabling accurate backfeeding. Therefore, the label printer 1 can accurately align the label paper LP to the print start position by backfeeding, improving the printing accuracy on the label L. Furthermore, the label printer 1 can reduce the transport amount during backfeeding, thereby improving throughput.

[0074] The label printer 1 also drives the second drive motor 107 in the reverse direction prior to feeding the label paper LP backward. Furthermore, the label printer 1 drives the second drive motor 107 in the reverse direction so that the second rotation speed n2 of the shaft 33 generated by the reverse driving of the second drive motor 107 is greater than the first rotation speed n1 of the shaft 33 generated by pulling out the label paper LP. This allows the label printer 1 to achieve an idling state of the one-way clutch 36 prior to feeding the label paper LP backward, and allows the second drive motor 107 to perform backward feeding with no load on it.

[0075] The label printer 1 also includes a torque limiter 37 that applies a load to the take-up roller 16 that is smaller than the torque generated on the take-up roller 16 when the label paper LP is pulled out during backfeeding, and larger than the rotational moment of inertia remaining on the take-up roller 16 when backfeeding is completed. This allows the label printer 1 to perform backfeeding without slackening the backing paper M, preventing transport abnormalities such as meandering of the backing paper M.

[0076] The above-described embodiment can be modified as needed by changing some of the configurations or functions of the label printer 1. Therefore, several modifications of the above-described embodiment will be described below as other embodiments. The following mainly describes differences from the above-described embodiment, and detailed descriptions of commonalities with the content already described will be omitted. The modifications described below may be implemented individually or in appropriate combinations.

[0077] (Variation 1) In the above-described embodiment, the drive train 30 is configured with four gears, and the one-way clutch 36 is provided on the third gear 34, but the configuration of the drive train 30 is not limited to this. For example, the drive train 30 may include one to three gears, or five or more gears. Furthermore, the one-way clutch 36 may be provided on any of the gears that make up the drive train 30, such as the second gear 32 described in FIG. 7.

[0078] (Variation 2) In the above embodiment, as explained in the flowchart of Figure 10, the configuration is such that backfeeding is performed before printing is completed, but this is not limiting and backfeeding may not be performed when printing is completed. In this case, the label printer 1 may be configured to perform backfeeding to the print start position by performing the processes of steps S15 and S16 when printing is resumed. The label printer 1 may also be configured to perform backfeeding to a position where the label gap detection sensor 14 can detect the label gap when printing is resumed.

[0079] The programs executed by the label printer 1 of the above-described embodiment are provided in a state where they are pre-installed in a ROM, storage unit, etc. The programs executed by the label printer 1 of the above-described embodiment may also be provided by being recorded in an installable or executable file format on a computer-readable recording medium such as a CD-ROM, flexible disk (FD), CD-R, or DVD (Digital Versatile Disk).

[0080] Furthermore, the program executed by the label printer 1 of the above-described embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Also, the program executed by the label printer 1 of the above-described embodiment may be provided or distributed via a network such as the Internet.

[0081] Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments and their modifications can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0082] 1 label printer 2. Case 3 outlet 11 Conveyor roller 12 Platen roller 13 Print head 14 Label gap detection sensor 15 Peeling guide 16 Winding roller 17 Peel detection sensor 30 Drivetrain 31 First Gear 32 Second Gear 33 Shaft 34 Third Gear 35 4th Gear 36 One-way clutch 37 Torque limiter 100 control section 106 First drive motor 107 Second drive motor [Prior art documents] [Patent documents]

[0083] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-023327

Claims

1. a conveying unit that conveys a backing sheet having a plurality of labels attached thereto at predetermined intervals in a forward direction and a backward direction; a printing unit that prints on the label while the backing sheet is being transported in the forward direction; a peeling unit that bends the backing sheet that has passed through the printing unit to peel off the printed label; a discharge port for discharging the label peeled off by the peeling unit; a winding shaft that winds up the backing paper from which the label has been peeled; a drive unit that rotates the winding shaft in a winding direction in which the backing paper is wound; a drive train provided between the winding shaft and the drive unit, which transmits a rotational force in the winding direction to the winding shaft and causes a rotational force in a direction opposite to the winding direction to be in an idling state; a control unit that controls the transport unit and the drive unit; Equipped with The control unit drives the drive unit to rotate in the winding direction while transporting the backing paper in the forward direction, and when the label is discharged from the discharge outlet, drives the drive unit to rotate in the direction opposite to the winding direction prior to transporting the backing paper in the backward direction.

2. the drive train includes at least a one-way clutch that transmits a rotational force in the winding direction to the winding shaft and causes a rotational force in a direction opposite to the winding direction to rotate freely.

2. The printer device according to claim 1.

3. The printer device according to claim 2, wherein the control unit drives the drive unit to rotate in the reverse direction so that a second rotation speed generated on the rotating shaft by the drive unit's rotation in the reverse direction is greater than a first rotation speed generated on the rotating shaft by the transport of the backing paper in the backward direction.

4. a torque limiter that generates a constant load torque in a direction opposite to the winding direction, 2. The printer device according to claim 1, wherein the load torque of the torque limiter is set to be greater than the inertia torque generated on the winding shaft due to the rotational drive of the drive unit in the reverse direction, and smaller than the torque generated on the winding shaft due to the transport of the backing paper in the backward direction.

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