Printing device and method for controlling driving of printing device

Abstract

To properly control tension of label paper P and tension of a mount, and properly control a conveying speed VP of the label paper P.SOLUTION: A printing device comprises: a first roller 11 arranged upstream of a peeling part 4; a second roller 31 arranged downstream of the peeling part 4; a first motor M1 that drives the first roller 11; a second motor M2 that drives the second roller 31; and a control part 40. The control part 40 comprises: a first motor control portion 41 that adjusts a first voltage V1 that is applied to the first motor M1, on the basis of a conveying speed VP of label paper P and information concerning conveyance acceleration, so that load torque TL1 of the first motor M1 becomes equal to target torque TS; and a second motor control portion 42 that feedback-controls a second voltage V2 that is applied to the second motor M2, on the basis of information concerning a conveying speed VP of a mount Pa, so that the conveying speed VP of the mount Pa becomes equal to a target conveying speed VT.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a printing apparatus and a method for controlling the driving of the printing apparatus. [Background technology]

[0002] Printers having a label peeling mechanism are known. For example, the label printer described in Patent Document 1 comprises a print head that prints on label paper, a transport roller that is located upstream of the print head on the label paper transport path and transports the label paper downstream, a peel roller that is located downstream of the print head and transports the liner in a direction different from the label's direction of travel to peel the label from the liner, and a control unit that controls the rotation of the transport roller and the peel roller, and the control unit controls the current value supplied to the peel motor that rotates the peel roller so that the transport force used by the peel roller to transport the liner is equal to or greater than the minimum force required to peel the label and exceeds the maximum frictional force between the peel roller and the liner, and the maximum frictional force and the maximum frictional force between the transport roller and the label paper are set so that the maximum frictional force is equal to or less than the transport force of the peel roller that keeps the label paper transport error by the transport roller within an acceptable value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-28117 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the label printer described in Patent Document 1, the tension of the liner is controlled by the frictional force between the peeling roller and the liner. As a result, the tension of the liner depends on the coefficient of friction, the wrap angle, and the pressure, making it difficult to stabilize. If the tension of the liner is unstable, problems such as poor peeling due to a decrease in tension or poor paper feed accuracy due to an increase in tension may occur. [Means for solving the problem]

[0005] A printing device according to one aspect of this embodiment comprises a print head that prints on label paper having a label affixed to a backing paper, a peeling unit that peels the label from the backing paper, a first roller located upstream of the peeling unit in the label paper transport path, a second roller located downstream of the peeling unit in the backing paper transport path, a first drive unit that drives the first roller, a second drive unit that drives the second roller, and a control unit that controls the first drive unit and the second drive unit, wherein the control unit adjusts the voltage applied to the first drive unit based on information related to the label paper transport speed and transport acceleration so that the load torque of the first drive unit becomes a predetermined value, and feedback-controls the voltage applied to the second drive unit based on information related to the backing paper transport speed so that the backing paper transport speed becomes a predetermined speed.

[0006] A drive control method for a printing device according to another aspect of the present embodiment is a drive control method for a printing device comprising: a print head that prints on label paper having a label affixed to a backing paper; a peeling unit that peels the label from the backing paper; a first roller located upstream of the peeling unit in a transport path for the label paper; a second roller located downstream of the peeling unit in a transport path for the backing paper; a first drive unit that drives the first roller; a second drive unit that drives the second roller; and a control unit that controls the first drive unit and the second drive unit, the method comprising: a first step in which the control unit adjusts a voltage to be applied to the first drive unit based on information related to the transport speed and transport acceleration of the label paper so that the load torque of the first drive unit becomes a predetermined value; and a second step in which the control unit feedback-controls the voltage to be applied to the second drive unit based on information related to the transport speed of the backing paper so that the transport speed of the backing paper becomes a predetermined speed. [Brief explanation of the drawings]

[0007] [Figure 1]FIG. 1 is a diagram showing an example of the overall configuration of a label printer according to an embodiment of the present invention. [Figure 2] FIG. 1 is a diagram showing an example of the configuration of a main part of a label printer. [Figure 3] FIG. 2 is a diagram showing an example of the configuration of a control unit. [Figure 4] 4 is a graph showing an example of the rotation speed, voltage, and load torque of the first motor. [Figure 5] 6 is a flowchart showing an example of control of a first motor. [Figure 6] 10 is a flowchart showing an example of control of a second motor. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, this embodiment will be described with reference to the drawings.

[0009] FIG. 1 is a diagram showing an example of the overall configuration of a label printer 1 according to this embodiment. The label printer 1 is a printer that uses label paper P as a printing medium and prints characters, images, figures, etc., using, for example, an inkjet method. The label printer 1 corresponds to an example of a "printing device."

[0010] The label paper P has a backing paper Pa and multiple labels Pb. The backing paper Pa is a strip of continuous paper. The surface of the backing paper Pa is made peelable, and labels Pb cut to a specified size are affixed to the backing paper Pa at equal intervals along its length. The backing paper Pa and the labels Pb may be made of paper or a material other than paper. The label paper P is loaded into the label printer 1 as roll paper R wound into a roll.

[0011] The label printer 1 comprises a printing unit 3 as the main body of the label printer 1, and a peeling unit 4. The peeling unit 4 may be formed integrally with the printing unit 3, or may be a component that is detachable from the printing unit 3. The peeling unit 4 is a device that peels the labels Pb from the liner Pa of the label paper P printed by the printing unit 3, and is also called a peeler. The label printer 1 can operate in a non-peeling mode, in which the printed label paper P is discharged with the labels Pb still attached to the liner Pa, and a peeling mode, in which the printed label Pb is discharged peeled from the liner Pa. In this embodiment, the peeling mode will be described.

[0012] The printing unit 3 uses the print head 8 to print on each label Pb on the label paper P based on commands and print data sent from a computer (not shown). The printing unit 3 also transports the label paper P along a transport path for the label paper P. Below, the upstream and downstream of the transport path may be simply referred to as upstream and downstream.

[0013] As shown in FIG. 1, the printing unit 3 includes a storage unit 29, a feed roller 10, a first roller 11, a platen 12, a guide 13, a print head 8, and a control unit 40. The storage section 29 is a space that stores the roll paper R, and label paper P is paid out from the roll paper R set in the storage section 29. The pay-out roller 10 is made up of a pair of rollers arranged opposite each other, and transports the label paper P paid out from the roll paper R downstream. The first roller 11 is made up of a pair of rollers arranged opposite each other, and holds the label paper P conveyed by the feed roller 10 and conveys it towards the print head 8 downstream.

[0014] The payout roller 10 is connected to a payout motor (not shown) and is rotated by the power of the payout motor. The first roller 11 is connected to a first motor M1 directly or via a gear, belt, etc., and is rotated by the power of the first motor M1. The first motor M1 corresponds to an example of a "first driving unit." The first roller 11 and the first motor M1 will be further described with reference to FIGS.

[0015] The platen 12 is positioned downstream of the first roller 11 in the transport path of the label paper P. The platen surface 12a, which is the upper surface of the platen 12, contacts the backing paper Pa of the label paper P and supports the label paper P from below. Multiple air intake holes (not shown) are formed in the platen surface 12a. Each air intake hole is connected to a suction fan (not shown). When the suction fan operates, air is sucked in through the air intake holes, and the label paper P is adsorbed to the platen surface 12a.

[0016] The print head 8 is disposed opposite the platen surface 12a. The print head 8 has nozzle rows (not shown) corresponding to one or more colors of ink, and ejects ink from the nozzles that make up each nozzle row. The print head 8 prints on the label Pb located on the platen surface 12a by ejecting ink based on print data onto the label Pb. The label paper P printed by the print head 8 is transported downstream to the peeling unit 4 by a first roller 11. In this embodiment, the label printer 1 uses an inkjet method to print on the label Pb, but the method is not limited to the inkjet method.

[0017] A guide 13 is arranged downstream of the print head 8. The guide 13 supports the label paper P printed by the print head 8 from below, between the platen 12 and the peeling unit 4. The label paper P passes over the guide 13 and is transported downstream toward the peeling unit 4.

[0018] The peeling unit 4 includes a peeling member 30 and a second roller 31. The peeling member 30 is located downstream of the guide 13 of the printing unit 3. The peeling member 30 has a guide surface 30a that contacts the backing paper Pa of the label paper P and supports the label paper P from below, and an acute-angled peeling edge 30b formed at the tip of the guide surface 30a. The label paper P guided by the guide 13 is transported over the guide surface 30a of the peeling member 30.

[0019] The second roller 31 is composed of a pair of rollers arranged opposite each other, and sandwiches and transports the backing paper Pa. The second roller 31 is connected to the second motor M2 directly or via a gear, belt, etc., and is rotated by the power of the second motor M2. The second motor M2 corresponds to an example of a "second driving unit." The second roller 31 and the second motor M2 will be further described with reference to FIGS.

[0020] When operating the label printer 1 in peel-off mode, the user clamps the backing paper Pa of the label paper P between the second rollers 31 before starting printing. The second rollers 31 are positioned below the peeling member 30 and clamp the backing paper Pa while transporting it downward. As the backing paper Pa of the label paper P is transported along the guide surface 30a, it is folded at the peeling edge 30b and pulled downward by the second roller 31. The pulling force of the second roller 31 causes the label Pb to lift from the backing paper Pa at the peeling edge 30b and be peeled off. The peeled label Pb protrudes leftward from the peeling unit 4 in FIG. 1. The label Pb protruding from the peeling unit 4 is collected by the user. Meanwhile, the backing paper Pa, which is transported by the second roller 31 in a direction different from the label Pb, is discharged below the second roller 31.

[0021] In the above-described configuration, the feed roller 10, the first roller 11, the platen 12, the guide 13, and the guide surface 30a of the peeling member 30 form a transport path for the label paper P in the printing unit 3. The peeling edge 30b and the second roller 31 also form part of the transport path for the backing paper Pa.

[0022] The control unit 40 controls the operation of each component of the label printer 1. In this embodiment, the control unit 40 controls the driving of the first roller 11 and the second roller 31. In other words, the control unit 40 controls the first motor M1 and the second motor M2. The control unit 40 will be further described with reference to FIGS.

[0023] Next, a method for driving the first roller 11 and a method for driving the second roller 31 will be described with reference to FIGS. Fig. 2 is a diagram showing an example of the configuration of the main parts of the label printer 1. Fig. 3 is a diagram showing an example of the configuration of the control unit 40.

[0024] 2, the first roller 11 has a first drive roller 11a and a first driven roller 11b that sandwich the label paper P. A first motor M1 drives and rotates the first drive roller 11a. The first driven roller 11b is supported so that it can rotate in accordance with the transport of the label paper P caused by the rotation of the first drive roller 11a. The second roller 31 has a second drive roller 31a and a second driven roller 31b that hold the backing paper Pa of the label paper P. A second motor M2 drives and rotates the second drive roller 31a. The second driven roller 31b is supported so that it can rotate in accordance with the transport of the backing paper Pa caused by the rotation of the second drive roller 31a.

[0025] In order to clamp the label paper P between the first roller 11, the first driven roller 11b presses the first drive roller 11a with a force F1. In other words, the first drive roller 11a is pressed with a force F1 in a direction substantially perpendicular to the orientation of the label paper P at the point of contact with the label paper P. The surface of the first drive roller 11a is formed by thermal spraying or powder coating. In this case, the friction coefficient μ1 between the first drive roller 11a and the label paper P is large enough to prevent the label paper P from slipping on the surface of the first drive roller 11a. The surface of the first driven roller 11b is made of rubber, for example. The tension TP is the tension applied to the label paper P between the first roller 11 and the second roller 31. The tension TP satisfies the following formula (1). TP<μ1×F1 (1)

[0026] The control unit 40 controls the tension TP by controlling the driving of the first motor M1. For example, the control unit 40 controls the torque TE1 generated by the first motor M1 so that the tension TP coincides with the target tension value TT. In this embodiment, we will explain the case where the target tension value TT is a constant value. In this case, the control unit 40 controls the load torque TL1 applied to the first roller 11 by the label paper P so that it matches the target torque TS corresponding to the target tension value TT. In other words, the control unit 40 controls the torque TE1 generated by the first motor M1 so that the load torque TL1 becomes the target torque TS, which is a constant value. The target tension value TT is set to a value that prevents the label paper P from becoming loose or warped between the first roller 11 and the second roller 31. The processing of the control unit 40 will be further described with reference to FIG.

[0027] In the second roller 31, the second driven roller 31b presses the second drive roller 31a with a force F3 to hold the backing paper Pa. In other words, the second drive roller 31a is pressed by the second driven roller 31b with a force F3 in a direction substantially perpendicular to the direction of travel of the backing paper Pa at the point of contact with the backing paper Pa. The friction coefficient μ3 is the coefficient of friction between the second drive roller 31a and the backing paper Pa. The surface of the second drive roller 31a is formed by thermal spraying or powder coating. In this case, the friction coefficient μ3 between the second drive roller 31a and the backing paper Pa is sufficiently large so that the backing paper Pa does not slip on the surface of the second drive roller 31a. The surface of the second driven roller 31b is formed, for example, from rubber. The tension TP is the tension applied to the backing paper Pa between the first roller 11 and the second roller 31. The tension TP satisfies the following formula (2). TP<μ3×F3 (2)

[0028] The control unit 40 controls the driving of the second motor M2 so that the conveying speed VP of the base sheet Pa coincides with the target conveying speed VT. The target conveying speed VT changes, for example, in a substantially trapezoidal shape, and the target conveying speed VT corresponding to the rotation angle φ of the second drive roller 31a is stored in a table. For example, the target conveying speed VT is set to zero while the print head 8 is printing on the label paper P, and from the time the label Pb reaches the peeling position PP where the label Pb protrudes from the peeling section 4 until the label Pb is collected by the user. Furthermore, the target conveying speed VT is set so that the conveying speed VP accelerates at a constant acceleration, is maintained at a constant speed, and then decelerates at a constant acceleration after printing on the label paper P is complete. As a result, the drive of the second motor M2 is controlled so that the conveying speed VP accelerates at a constant acceleration, is maintained at a constant speed, and then decelerates at a constant acceleration, thereby conveying the label Pb to the peeling position PP. The target transport speed VT corresponds to an example of a "predetermined speed."

[0029] Next, the configuration of the control unit 40 will be described with reference to FIG. As shown in FIG. 3, the control unit 40 receives the rotation angle θ of the first drive roller 11a from the first rotary encoder 11c, and receives the rotation angle φ of the second drive roller 31a from the second rotary encoder 31c.

[0030] The first rotary encoder 11c is disposed, for example, at an end of the first drive roller 11a in the width direction, and detects the rotation angle θ of the first drive roller 11a. The first rotary encoder 11c outputs a detection signal indicating the rotation angle θ to the control unit 40. In this embodiment, the first rotary encoder 11c is disposed on the first drive roller 11a, but is not limited thereto. The first rotary encoder 11c may be disposed on the first motor M1 to detect the rotation angle of the drive shaft of the first motor M1.

[0031] The second rotary encoder 31c is disposed, for example, at an end of the second drive roller 31a in the width direction, and detects the rotation angle φ of the second drive roller 31a. The second rotary encoder 31c outputs a detection signal indicating the rotation angle φ to the control unit 40. In this embodiment, the second rotary encoder 31c is disposed on the second drive roller 31a, but is not limited thereto. The second rotary encoder 31c may be disposed on the second motor M2 to detect the rotation angle of the drive shaft of the second motor M2.

[0032] The control unit 40 controls the first voltage V1 applied to the first motor M1, and also controls the second voltage V2 applied to the second motor M2. In the present embodiment, the control unit 40 controls the first voltage V1 and the second voltage V2, but the present invention is not limited to this. The control unit 40 may also control the first voltage V1 and the second voltage V2 via a voltage control circuit.

[0033] The control unit 40 includes a processor 40A and a memory 40B. The memory 40B is a storage device that nonvolatilely stores programs and data executed by the processor 40A. The memory 40B is configured with a semiconductor storage element such as a magnetic storage device or a flash ROM (Read Only Memory), or other types of nonvolatile storage devices. The memory 40B may also include a RAM (Random Access Memory) that configures the work area of the processor 40A. The memory 40B may also include a nonvolatile storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The memory 40B stores data to be processed by the control unit 40 and the control program 43 to be executed by the processor 40A. The processor 40A may be configured as a single processor, or may be configured such that multiple processors function as the processor 40A.

[0034] The control unit 40 can be configured, for example, by an integrated circuit. Integrated circuits include LSIs, ASICs (Application Specific Integrated Circuits), and PLDs (Programmable Logic Devices). PLDs include, for example, FPGAs (Field-Programmable Gate Arrays). An analog circuit may be included as part of the configuration of the integrated circuit, or the integrated circuit may be a combination of a processor and an integrated circuit. The combination of a processor and an integrated circuit is called a microcontroller (MCU), SoC (System-on-a-chip), system LSI, chipset, etc.

[0035] The control unit 40 functionally includes a first motor control unit 41 and a second motor control unit 42. Specifically, the processor 40A functions as the first motor control unit 41 and the second motor control unit 42 by reading and executing a control program 43 stored in the memory 40B.

[0036] The first motor control unit 41 adjusts the first voltage V1 applied to the first motor M1 based on information about the conveying speed and conveying acceleration of the label paper P so that the load torque TL1 of the first motor M1 becomes the target torque TS. The target torque TS corresponds to an example of a "predetermined value." The information relating to the conveying speed and conveying acceleration of the label paper P is, for example, the angular velocity ω1 and angular acceleration α1 of the rotation of the first roller 11. The angular velocity ω1 is expressed by the following equation (3). ω1=dθ / dt (3) That is, the angular velocity ω1 is obtained by differentiating the rotation angle θ with respect to time t. The angular acceleration α1 is expressed by the following equation (4). α1=d 2 θ / dt 2 (4) That is, the angular acceleration α1 can be obtained by differentiating the rotation angle θ twice with respect to time t. In other words, the angular acceleration α1 can be obtained by differentiating the angular velocity ω1 with respect to time t.

[0037] For convenience, the following description will be given assuming that the rotation speed of the first motor M1 and the rotation speed of the first roller 11 are the same. In other words, the description will be given assuming that the reduction ratio is 1. The description will also be given assuming that the first motor M1 is a DC motor. The relationship between the first voltage V1(t) applied to the first motor M1 and the current I1(t) flowing through the first motor M1 is expressed by the following equation (5).

number

[0038] Since the period required for the current I1 to reach a steady value is much shorter than the period required for the angular velocity ω1 (= dθ1 / dt) to reach a steady value, in this embodiment, the term representing the time change of the current I1(t), i.e., the second term on the right side of equation (5), is set to zero, resulting in equation (6). V1(t)=R1×I1(t)+K1×ω1 (6) The torque TE1 generated by the first motor M1 is calculated by the following equation (7). TE1=K1×I1(t) (7) The equation of motion of the first motor M1 is expressed by the following equation (8). TM1=J1×α1+C1×ω1 (8) Here, the load torque TM1 indicates the load torque of the first motor M1, the constant J1 indicates the moment of inertia of the first motor M1, and the constant C1 indicates the viscous load of the first motor M1.

[0039] The torque TE1 generated by the first motor M1 is calculated using the load torque TM1 of the first motor M1 by the following equation (9). TE1=TM1+TL1 (9) Here, the load torque TL1 indicates the load torque applied from the label paper P to the first motor M1.

[0040] Using equation (6), the current I1(t) in equation (7) is eliminated, and the equation obtained by eliminating the current I1(t) from equation (7) and equation (8) are substituted into equation (9). Then, the first voltage V1(t) is solved, and the following equation (10) is obtained.

number

[0041] In this embodiment, the first motor control unit 41 controls the load torque TL1 so that it coincides with the target torque TS, which is a constant value. That is, the first motor control unit 41 adjusts the first voltage V1 applied to the first motor M1 to the first voltage V1 calculated by equation (10) so that the load torque TL1 coincides with the target torque TS, which is a constant value. By controlling the first voltage V1 applied to the first motor M1 in this manner, the tension TP can be controlled so that it coincides with the tension target value TT. In other words, the first motor control unit 41 can control the tension TP to match the target tension value TT by controlling the first voltage V1 applied to the first motor M1 using equation (10) based on the angular velocity ω1 and angular acceleration α1 of the rotation of the first roller 11.

[0042] The second motor control unit 42 feedback controls the second voltage V2 applied to the second motor M2 based on the rotation angle φ of the second drive roller 31a and information related to the conveying speed VP of the backing paper Pa so that the conveying speed VP of the backing paper Pa becomes a predetermined speed. The information related to the conveying speed VP of the backing paper Pa is the angular speed ω2 of the rotation of the second roller 31. The relationship between the conveying speed VP of the backing paper Pa and the angular speed ω2 of the rotation of the second roller 31 is expressed by the following equation (11). VP=R2×ω2 (11) Here, the constant R2 indicates the radius of the second roller 31.

[0043] On the other hand, in the same way as the above equation (6), the following equation (12) is obtained. V2(t)=R2×I2(t)+K2×ω2 (12) Here, the constant R2 indicates the resistance value of the second motor M2, and the constant K2 indicates the torque constant of the second motor M2, that is, the back electromotive force constant. Furthermore, the torque TE2 generated by the second motor M2 is expressed by the following equation (13). TE2=K2×I2(t) (13) For example, if the torque TE2 generated by the second motor M2 is a constant value, the current I1(t) flowing through the first motor M1 in equation (12) can be eliminated using equation (13), yielding the following equation (14). V2(t)=R2×TE2 / K2+K2×ω2 (14) That is, the second voltage V2 applied to the second motor M2 can be increased to increase the angular velocity ω2 of the rotation of the second roller 31. On the other hand, the second voltage V2 applied to the second motor M2 can be decreased to decrease the angular velocity ω2 of the rotation of the second roller 31. In other words, the conveying speed VP can be controlled using the second voltage V2 as a control variable.

[0044] The second motor control unit 42 calculates the angular velocity ω2 of the second roller 31 based on the rotation angle φ of the second roller 31, and calculates the actual measured value VQ of the conveying speed VP using equation (11). It also calculates the difference ΔV between the target conveying speed VT corresponding to the rotation angle φ of the second roller 31 and the actual measured value VQ of the conveying speed VP, and performs feedback control, for example PID control, on the second voltage V2 to be applied to the second motor M2 as a control variable so that the difference ΔV becomes zero. In this way, the second motor control unit 42 controls the conveying speed VP to the target conveying speed VT.

[0045] Next, a specific example of the operation of the first motor control unit 41 will be described with reference to Fig. 4. Fig. 4 is a graph showing an example of the angular velocity ω1, first voltage V1, and load torque TL1 of the first motor M1. Fig. 4 also shows simulation results of the angular velocity ω1, first voltage V1, and load torque TL1 of the first motor M1. The upper part of FIG. 4 shows a graph of angular velocity ω1, the middle part of FIG. 4 shows a graph of first voltage V1, and the lower part of FIG. 4 shows a graph of load torque TL1.

[0046] In the graph shown in the upper part of FIG. 4, the vertical axis represents angular velocity ω1, and the horizontal axis represents time t. Graph G1 shows the change in angular velocity ω1. FIG. 4 illustrates a case where the angular velocity ω1 changes, for example, like a waveform obtained by half-wave rectifying a sinusoidal current, as shown in graph G1. For example, the angular velocity ω1 accelerates from 0 to 1900 rpm when time t is from 0 to 0.025 seconds. Furthermore, the angular velocity ω1 decelerates from 1900 rpm to 0 rpm when time t is from 0.025 to 0.05 seconds. The angular velocity ω1 is maintained at 0 when time t is from 0.05 to 0.1 seconds.

[0047] In the graph shown in the middle of FIG. 4, the vertical axis represents the first voltage V1, and the horizontal axis represents time t. Graph G2 shows the change in first voltage V1. Note that first voltage V1 is controlled by first motor control unit 41 based on the above equation (10). As shown in graph G2, the first voltage V1 is held at -12 V during the period when the angular velocity ω1 is held at 0, for example, from time t 0.05 to 0.1 seconds. That is, during this period, the first motor M1 drives the first roller 11 in the negative direction. The negative direction is the direction opposite to the forward direction of the roll paper R.

[0048] Between time t 0 and 0.018 seconds, the first voltage V1 increases from −12 V to 1.22 V. Between time t 0.018 and 0.043 seconds, the first voltage V1 decreases from 1.22 V to −15.53 V. Between time t 0.043 and 0.05 seconds, the first voltage V1 increases from −15.53 V to −12 V. That is, when the first motor M1 accelerates, the first voltage V1 increases due to the moment of inertia of the first motor M1 and the viscous load of the first motor M1. When the first motor M1 decelerates, the first voltage V1 decreases due to the moment of inertia of the first motor M1, and increases due to the viscous load of the first motor M1.

[0049] In the graph shown in the lower part of FIG. 4, the vertical axis represents the load torque TL1, and the horizontal axis represents time t. In graph G3, the load torque TL1 is maintained at a substantially constant value, i.e., −0.02 Nm. The negative value of the load torque TL1 indicates that the first motor M1 is subjected to a load in the direction of travel of the label paper P due to the tension TP applied to the label paper P between the first roller 11 and the second roller 31.

[0050] As explained with reference to FIG. 4, the first motor control unit 41 controls the first voltage V1 based on the above equation (10), so that the load torque TL1 can be maintained at an approximately constant value even when the angular velocity ω1 of the first motor M1 changes.

[0051] Next, the processing of the control unit 40 will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a flowchart showing an example of control of the first motor M1 by the first motor control unit 41. In FIG. 5, a case will be described in which the load torque TL1 is preset to a target torque TS, which is a constant value, so that the tension TP becomes the tension target value TT. As shown in FIG. 5, first, in step S101, the first motor control unit 41 acquires the rotation angle θ of the first drive roller 11a from the first rotary encoder 11c. Next, in step S103, the first motor control unit 41 calculates the angular velocity ω1 of the first drive roller 11a by differentiating the rotation angle θ with respect to time t. Next, in step S105, the first motor control unit 41 calculates the angular acceleration α1 of the first drive roller 11a by differentiating the angular velocity ω1 with respect to time t.

[0052] Next, in step S107, the first motor control unit 41 calculates the first voltage V1 by substituting the load torque TL1, the angular velocity ω1, and the angular acceleration α1 into the above equation (10). Next, in step S109, the first motor control unit 41 adjusts the first voltage V1 applied to the first motor M1 to the calculated first voltage V1, after which the process returns to step S101. Step S107 and step S109 correspond to an example of the "first step."

[0053] In this way, the first motor control unit 41 adjusts the first voltage V1 applied to the first motor M1 to the first voltage V1 calculated using the above formula (10). Therefore, the tension TP can be controlled to match the target tension value TT1.

[0054] FIG. 6 is a flowchart showing an example of control of the second motor M2 by the second motor control unit 42. As shown in FIG. 6, first, in step S201, the second motor control unit 42 acquires the rotation angle φ of the second drive roller 31a from the second rotary encoder 31c. Next, in step S203, the second motor control unit 42 calculates the angular velocity ω2 of the second drive roller 31a by differentiating the rotation angle φ with respect to time t. Next, in step S205, the second motor control unit 42 calculates the actual measurement value VQ of the transport speed VP of the base sheet Pa from the calculated angular speed ω2.

[0055] Next, in step S207, the second motor control unit 42 calculates the difference ΔV between the calculated actual measurement value VQ of the transport speed VP and the target transport speed VT corresponding to the rotation angle φ. Next, in step S209, the second motor control unit 42 PID controls the second voltage V2 applied to the second motor M2 as a control amount so that the difference ΔV becomes 0. Thereafter, the process returns to step S201. Steps S207 and S209 correspond to an example of a "second step."

[0056] In this way, the second motor control unit 42 PID controls the second voltage V2 applied to the second motor M2 as a control variable so that the difference ΔV between the actual measured value VQ of the conveying speed VP and the target conveying speed VT becomes zero. Therefore, the second motor control unit 42 can control the conveying speed VP so that it coincides with the target conveying speed VT.

[0057] As described above with reference to FIGS. 1 to 6, the label printer 1 according to this embodiment comprises a print head 8 that prints on label paper P having labels Pb attached to a liner Pa, a peeling unit 4 that peels the labels Pb from the liner Pa, a first roller 11 that is arranged upstream of the peeling unit 4 in the transport path of the label paper P, a second roller 31 that is arranged downstream of the peeling unit 4 in the transport path of the liner Pa, a first motor M1 that drives the first roller 11, a second motor M2 that drives the second roller 31, and a second motor M3 that drives the first motor M1. and a control unit 40 that controls the second motor M2. The control unit 40 comprises a first motor control unit 41 that adjusts a first voltage V1 applied to the first motor M1 based on information related to the conveying speed VP of the label paper P and the conveying acceleration so that the load torque TL1 of the first motor M1 becomes the target torque TS, and a second motor control unit 42 that feedback-controls a second voltage V2 applied to the second motor M2 based on information related to the conveying speed VP of the backing paper Pa so that the conveying speed VP of the backing paper Pa becomes the target conveying speed VT.

[0058] With this configuration, the first motor control unit 41 adjusts the first voltage V1 applied to the first motor M1 based on information about the conveying speed VP and conveying acceleration of the label paper P so that the load torque TL1 of the first motor M1 becomes the target torque TS. This allows the load torque TL1 of the first motor M1 to be controlled so that it becomes the target torque TS. This also allows the tension TP between the first roller 11 and the second roller 31 to be appropriately controlled so that it matches the tension target value TT. Furthermore, the second motor control unit 42 feedback controls the second voltage V2 applied to the second motor M2 based on information related to the conveying speed VP of the base sheet Pa so that the conveying speed VP of the base sheet Pa becomes the target conveying speed VT. Therefore, the conveying speed VP of the base sheet Pa can be appropriately controlled so that it becomes the target conveying speed VT.

[0059] In the label printer 1 according to this embodiment, the information relating to the conveyance speed VP and conveyance acceleration of the label paper P is the angular velocity ω1 and angular acceleration α1 of the rotation of the first roller 11. According to this configuration, the first motor control unit 41 adjusts the first voltage V1 applied to the first motor M1 based on the angular velocity ω1 and angular acceleration α1 of the rotation of the first roller 11. Therefore, the load torque TL1 of the first motor M1 can be appropriately controlled to become the target torque TS.

[0060] In the label printer 1 according to this embodiment, the information relating to the transport speed PV of the backing paper Pa is the angular velocity ω2 of the rotation of the second roller 31. According to this configuration, the second motor control unit 42 feedback controls the second voltage V2 applied to the second motor M2 based on the angular velocity ω2 of the rotation of the second roller 31. Therefore, the transport speed VP of the base sheet Pa can be appropriately controlled to become the target transport speed VT.

[0061] Furthermore, in the label printer 1 according to this embodiment, the first motor control unit 41 adjusts the first voltage V1 applied to the first motor M1 using equation (A) so that the load torque TL1 of the first motor M1 becomes the target torque TS.

number

[0062] In the label printer 1 according to this embodiment, the surfaces of the first roller 11 and the second roller 31 are formed by thermal spraying or are powder coated. This configuration can prevent the label paper P from slipping against the surface of the first roller 11. It can also prevent the backing paper Pa from slipping against the surface of the second roller 31.

[0063] The control method for the label printer 1 according to this embodiment includes a print head 8 that prints on label paper P in which labels Pb are attached to liner Pa, a peeling unit 4 that peels the labels Pb from the liner Pa, a first roller 11 that is arranged upstream of the peeling unit 4 in the transport path of the label paper P, a second roller 31 that is arranged downstream of the peeling unit 4 in the transport path of the liner Pa, a first motor M1 that drives the first roller 11, a second motor M2 that drives the second roller 31, and a control circuit that controls the first motor M1 and the second motor M2. The drive control method for a label printer (1) includes a control unit (40), and includes a first step in which the control unit (40) adjusts a first voltage (V1) applied to the first motor (M1) based on information related to the conveying speed (VP) of the label paper (P) and the conveying acceleration so that the load torque (TL1) of the first motor (M1) becomes a target torque (TS), and a second step in which the control unit (40) feedback-controls a second voltage (V2) applied to the second motor (M2) based on information related to the conveying speed (VP) of the liner (Pa) so that the conveying speed (VP) of the liner (Pa) becomes the target conveying speed (VT). Therefore, the control method for the label printer 1 according to this embodiment has the same effects as the label printer 1 according to this embodiment.

[0064] It should be noted that the present embodiment merely shows one aspect of the present invention, and any modifications and applications are possible within the scope of the present invention. For example, although a case where the first driving unit according to the present embodiment is the first motor M1 will be described, the present invention is not limited to this. The first driving unit may include a voltage control circuit that controls the first voltage V1 supplied to the first motor M1. Although the second driving unit according to the present embodiment is, for example, the second motor M2, the present invention is not limited to this. The second driving unit may include a voltage control circuit that controls the second voltage V2 supplied to the second motor M2.

[0065] In this embodiment, the target torque TS is a constant value, but the present invention is not limited to this. The target torque TS may be determined according to the size of the label paper P, for example.

[0066] Furthermore, the functional units shown in FIG. 3 represent functional configurations, and the specific implementation form is not particularly limited. In other words, it is not necessary to implement hardware that corresponds to each functional unit individually; it is also possible to implement a configuration in which a single processor executes a program to realize the functions of multiple functional units. Furthermore, some of the functions realized by software in the above-described embodiments may be implemented by hardware, or some of the functions realized by hardware may be implemented by software. In addition, the specific detailed configuration of each unit of the label printer 1 can be changed as desired without departing from the spirit of the present invention.

[0067] 5 and 6 are divided according to the main processing content to facilitate understanding of the processing of the control unit 40, and the method of dividing the processing units or the names of the processing units does not limit the present invention. The processing may be divided into more processing units according to the processing content. Furthermore, one processing unit may be divided so as to include even more processing. Furthermore, the order of the processing may be changed as appropriate within the scope that does not impair the intent.

[0068] The control method for the label printer 1 can be realized by having the processor 40A of the control unit 40 execute a control program 43 stored in the memory 40B. The control program 43 can also be recorded on a computer-readable recording medium. The recording medium may be a magnetic or optical recording medium or a semiconductor memory device, specifically, a portable or fixed recording medium such as a flexible disk, a hard disk drive (HDD), a compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a Blu-ray (registered trademark) disc, a magneto-optical disk, a flash memory, or a card-type recording medium. The recording medium may also be a non-volatile storage device such as RAM, ROM, or HDD, which is an internal storage device provided in the label printer 1. The control program 43 may also be stored in a server device or the like, and the functional blocks of the control unit 40 of the label printer 1 may be realized by downloading the control program 43 from the server device to the control unit 40 of the label printer 1. [Explanation of symbols]

[0069] 1...label printer (printing device), 3...printing unit, 4...peeling unit, 8...print head, 10...feed roller, 11...first roller, 11a...first drive roller, 11b...first driven roller, 11c...first rotary encoder, 30...peeling member, 30b...peeling edge, 31a...second drive roller, 31b...second driven roller, 31c...second rotary encoder, 40...control unit, 40A...processor, 40B...memory, 41...first motor control unit , 42...Second motor control unit, 43...Control program, I1...Current, M1...First motor (first drive unit), M2...Second motor (second drive unit), P...Label paper, Pa...Backing paper, Pb...Label, PV...Conveying speed, TE1, TE2...Generated torque, TL1...Load torque, TM1...Load torque, TS...Target torque, TP...Tension, TT...Tension target value, V1...First voltage, V2...Second voltage, VP...Conveying speed, θ, φ...Rotation angle, ω1, ω2...Angular velocity, α1...Angular acceleration.

Claims

1. a print head that prints on label paper with labels attached to a backing; a peeling unit that peels the label from the backing; a first roller disposed upstream of the peeling unit in the label paper transport path; a second roller disposed downstream of the peeling unit in the transport path of the backing sheet; a first driving unit that drives the first roller; a second driving unit that drives the second roller; a control unit that controls the first drive unit and the second drive unit; Equipped with The control unit adjusting the voltage applied to the first drive unit based on information related to the label paper conveyance speed and conveyance acceleration so that the load torque of the first drive unit becomes a predetermined value; feedback-controlling the voltage applied to the second drive unit based on information regarding the transport speed of the backing sheet so that the transport speed of the backing sheet becomes a predetermined speed; Printing device.

2. the information relating to the label paper conveying speed and conveying acceleration is the angular velocity and angular acceleration of the rotation of the first roller; The printing device of claim 1 .

3. the information regarding the transport speed of the backing sheet is an angular velocity of rotation of the second roller; 3. The printing device according to claim 1 or claim 2.

4. the control unit adjusts the voltage applied to the first drive unit by equation (A) so that the load torque of the first drive unit becomes a predetermined value. The printing device according to any one of claims 1 to 3. [Equation 3] Here, V1(t) on the left side represents the voltage applied to the first driving unit, α1 on the right side represents the angular acceleration of the first roller, ω1 represents the angular velocity of the first roller, and TL1 represents the load torque of the first driving unit.

5. The surface of each of the first roller and the second roller is formed by thermal spraying or is powder coated. The printing device according to any one of claims 1 to 4.

6. a print head that prints on label paper with labels attached to a backing; a peeling unit that peels the label from the backing; a first roller disposed upstream of the peeling unit in the label paper transport path; a second roller disposed downstream of the peeling unit in the transport path of the backing sheet; a first driving unit that drives the first roller; a second driving unit that drives the second roller; a control unit that controls the first drive unit and the second drive unit; A drive control method for a printing device comprising: a first step in which the control unit adjusts the voltage applied to the first drive unit based on information about the label paper conveyance speed and conveyance acceleration so that the load torque of the first drive unit becomes a predetermined value; a second step in which the control unit feedback-controls the voltage applied to the second drive unit based on information regarding the transport speed of the base sheet so that the transport speed of the base sheet becomes a predetermined speed; A method for controlling the driving of a printing device, comprising:

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