JP2012126517A - Sheet winding device, sheet winding method, and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet winding device, along with a sheet winding method and a printer, capable of maintaining an appropriate tensile state during printing and after the end of printing, without increasing cost.SOLUTION: The sheet winding device 1 includes: a printing unit 106 for printing data on a sheet 105 and stopping the sheet 105 based on stop torque after the printing; a winding mechanism 103 for winding the printed sheet 105 as a winding body; a stepping motor 101 for driving the winding mechanism 103; and a motor driving control unit 201 for setting a winding speed and winding torque generated by the stepping motor 101 and driving the motor. During the printing, the motor driving control unit 201 adjusts a winding speed to generate slack in the sheet 105 between the printing unit 106 and the winding mechanism 103. After the printing, the motor driving control unit 201 sets winding torque to a first setting value larger than load torque necessary for rotating the winding body and smaller than a sum of the stop torque and the load torque, to remove the slack and then generate loss of synchronism.

Description

  The present invention relates to a paper take-up device, a paper take-up method, and a printer that are applied to a printer that feeds belt-shaped paper and prints on the surface of the paper.

  For example, Patent Document 1 discloses a printer that stores a hollow cylindrical winding body formed by winding a paper such as a receipt, pulls out the paper from the winding body, feeds the paper, and prints on the paper. There is something like that described.

  In pulling out the paper from the above-described winder, the printer uses a paper feed roller located on the downstream side of the paper and a feed roller provided on the upstream side of the paper feed roller with a tension guide interposed therebetween.

  While using this feeding roller, it is detected whether or not the paper tension has exceeded the allowable upper limit value, and if it exceeds, the feeding roller feeding operation is started and the paper tension does not exceed the allowable upper limit value. In such a case, an appropriate tension state is maintained by stopping the feeding operation.

JP 2009-269399 A

  However, in the prior art described in Patent Document 1, it is essential to detect the tension and to compare with an allowable upper limit value in order to maintain an appropriate tension state, resulting in an increase in the number of parts and a complicated control.

  It is also necessary to keep the tension in an appropriate state between the printing unit of the printer and the paper take-up device that takes up the paper after printing. In particular, after the printing is completed, the paper is held at the printing unit with the stop torque, and if the paper winding device operates in this state, excessive tension is applied to the paper.

  If the technique described in Patent Document 1 is applied to prevent the occurrence of this excessive tension, as described above, it is an essential requirement to detect the tension and compare the allowable upper limit value in order to maintain an appropriate tension state. This increases the number of parts and complicates control. Therefore, as a technique that does not require the detection of tension, a mechanical torque limiter is provided on the sheet winding device side.

  However, a mechanical torque limiter is generally expensive and has a relatively large external dimension that is equal to or larger than that of a stepping motor for paper feeding. This also increases the number of parts and the overall external dimension of the apparatus. Invitation and cost increase.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a paper winding device, a paper winding method, and a printer that can maintain an appropriate tension state after printing and printing without causing an increase in cost. To do.

In order to solve the above problem, a paper winding device according to the present invention is:
A printing unit that prints a sheet and stops the sheet based on a stop torque after the printing, a winding mechanism that winds the printed sheet as a winding body, and drives the winding mechanism And a motor drive control unit configured to set and drive a winding speed and a winding torque generated by the stepping motor, and the motor drive control unit is configured to perform printing while the printing is being performed. The winding speed is adjusted to generate a slack in the paper between the printing unit and the winding mechanism, and the motor drive control unit rotates the winding body after the printing by using the motor driving control unit. Therefore, the first set value is set to be larger than the load torque necessary for this and smaller than the sum of the stop torque and the load torque, and the step-out is generated after the slack is removed.

In order to solve the above problem, the paper winding method according to the present invention is:
A printing step for printing paper, a stop step for stopping the paper based on a stop torque after the printing step, a winding step for winding the paper after the printing step as a winding body by a stepping motor, and the printing Adjusting the winding speed of the stepping motor in the winding step during the step to generate a sag in the paper; and a winding torque in the winding step after the printing step; A control step for driving by setting to a first set value that is larger than the load torque necessary for rotation and smaller than the sum of the stop torque and the load torque, and out-of-step occurrence that generates out-of-step after removing the slack Including steps.

  The printer according to the present invention includes the paper take-up device.

  Alternatively, the printer according to the present invention uses the paper winding method.

  According to the paper winding device, the paper winding method, and the printer of the present invention, it is possible to maintain an appropriate tension state after printing and completion of printing without causing an increase in cost.

1 is a schematic diagram illustrating a printer 1 according to an embodiment. It is a schematic diagram which shows the operation | movement aspect in the printer 1 of a present Example. FIG. 3 is a schematic diagram illustrating an operation principle in the printer 1 of the present embodiment. It is a schematic diagram which shows an example of the setting aspect of the reference torque in the printer 1 of a present Example. It is a map which shows the correlation of the motor current acquired beforehand and the torque used in the printer 1 of a present Example. It is a map which shows the correlation of the motor temperature and torque which were previously acquired used in the printer 1 of a present Example. It is a map which shows the correlation of the motor frequency and torque which were used in the printer 1 of a present Example previously acquired. It is a schematic diagram which shows an example of the flowchart used for the setting of the motor current in the printer 1 of a present Example. 3 is a flowchart showing main control contents in the printer 1 of the present embodiment. FIG. 3 is a schematic diagram illustrating main effects and advantages of the printer 1 according to the present embodiment. FIG. 3 is a schematic diagram illustrating main effects and advantages of the printer 1 according to the present embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, the printer 1 of this embodiment includes a stepping motor 101, a driving force transmission mechanism 102, a winding shaft 103 (winding mechanism), a motor temperature detection element 104, and a roll paper 105 (paper). ), A printing unit 106, a stepping motor 107, and a control circuit 200 appropriately connected to these components.

  The MCU 207 is configured to include, for example, a CPU, a ROM, a RAM, a flash memory, a data bus that interconnects them, and an input / output interface, and the control circuit 200 is controlled based on the control of the MCU 207. A bipolar or unipolar drive circuit capable of driving 107, a current detection circuit, an input / output interface, and the like are included.

  The MCU 207 performs each control described below in accordance with a program stored in the ROM or the flash memory, and the control circuit 200 or the MCU 207 constitutes a functional block described below.

  As shown in FIG. 1, the functional block is composed of a winding motor drive control unit 201 (motor drive control unit), a motor current control unit 202, a motor step-out detection unit 203, a motor temperature detection unit 206, a winding motor. A drive frequency generation unit 204, an information storage unit 205, a printer motor drive frequency generation unit 208, a printer motor drive control unit 209, and a motor current control unit 210.

  As shown in FIG. 2, the printing unit 106 includes a thermal head 106a, a paper transport roller 106b, and a stepping motor 107 for the printing unit. The stepping motor 107 drives the paper transport roller 106b, the motor current is controlled by the printer drive control unit 209 and the motor current control unit 210, the motor frequency is controlled by the printer motor drive frequency generation unit 208, and the paper transport roller The torque for driving 106b and the conveyance speed are controlled.

  The paper winding device included in the printer 1 of this embodiment includes a stepping motor 101, a driving force transmission mechanism 102, a winding shaft 103, a motor temperature detection element 104, roll paper 105, and a control circuit 200.

  As shown in FIG. 2, the roll paper 105 constituting the paper is pulled out from the roll before printing and given a predetermined tension by the damper 108, and then inserted between the thermal head 106a and the paper transport roller 106b. 2 is wound on the outer peripheral surface of a winding body which is wound on the outer peripheral surface of the winding shaft 103 shown on the right side in FIG.

  Here, as shown in FIG. 3, when the printing unit 106 does not perform printing on the roll paper 105 or after the printing is finished, the paper transport roller 106 b is moved to the left of the roll paper 105 by the stepping motor 107. It is assumed that a counterclockwise stop torque Ta directed to is applied.

  Further, the load torque caused by the mass and friction of the winding body necessary for rotating the winding body of the roll paper 105 shown on the right side in FIG. 3 in the clockwise direction is tangential to the winding body and in FIG. Assume that the counterclockwise load torque Tb is directed to the left.

  Here, in the printer 1 of the present embodiment, during printing when the printing unit 106 is printing on the roll paper 105 and after printing is completed, the printing force is transmitted via the driving force transmission mechanism 102 based on the following concept. It is assumed that the stepping motor 101 that drives the winding shaft 103 is controlled to drive the winding shaft 103 to generate the clockwise winding torque Tx in FIG.

  First, during printing, in order to reduce the winding load of the stepping motor 101, the tension of the roll paper 105 positioned between the printing unit 106 and the roll paper 105 is excessively increased. To prevent. That is, during printing, the motor current control unit 210 stops driving the stepping motor 107 based on a command from the printer motor drive control unit 209 so that the paper transport roller 106b of the printing unit 106 does not generate the stop torque Ta.

  Further, the motor current control unit 202 performs stepping on the basis of a command to the winding motor drive control unit 201 so that the winding torque Tx during printing is set to the second set value T2 that is larger than the load torque Tb. The motor current of the motor 101 is controlled.

  In addition, in order to ensure that the roll paper 105 between the winding body and the printing unit 106 is slack, the clockwise peripheral speed of the outer peripheral surface of the winding body, that is, the winding speed Vr is set to It is adjusted so as to be equal to or less than the clockwise peripheral speed of the transport roller 106b, that is, the transport speed. More specifically, the printer motor driving frequency generation unit 208 controls the motor frequency of the stepping motor 107 so that the winding speed Vr is equal to the conveyance speed, and the winding motor driving frequency generation unit 204 controls the stepping motor 101. Control the motor frequency.

  After the printing unit 106 finishes printing on the roll paper 105, that is, after printing, the winding torque Tx is set to be greater than the load torque Tb and smaller than the sum of the stop torque Ta and the load torque Tb. The winding motor drive control unit 201 and the motor current control unit 202 control the stepping motor 101 so that the value T1 is obtained.

  Here, immediately after the end of printing, there is a slack in the roll paper 105 positioned between the winding body and the printing unit 106, and immediately after the end of printing, based on the winding operation with the winding torque Tx, The sagging gradually decreases. When the slack disappears, a total load torque obtained by adding a stop torque Ta to the load torque Tb acts counterclockwise in the circumferential direction of the winding shaft 103, and this total load torque is larger than the winding torque Tx. Therefore, in the stepping motor 101, a step-out occurs in which the rotation of the rotor cannot catch up with the excitation phase on the stator side of the stepping motor 101, and the rotor stops.

  The motor step-out detection unit 203 detects the occurrence of step-out by, for example, monitoring the motor current waveform and comparing it with a normal state waveform in which step-out has not occurred, and step-out occurs. In such a case, the motor current control unit 202 and the take-up motor drive control unit 201 are notified that the step-out has occurred.

  The winding motor drive control unit 201 stops driving the stepping motor 101 based on the notification of the occurrence of the step-out, and the motor current control unit 202 stops energizing the motor 101. In the printer 1 of the present embodiment, the paper winding method of the present invention is also executed.

  In the printer 1 of this embodiment, the control of the stepping motor 101 is based on open loop control. For this reason, a reference motor current I0 for generating the reference torque T0 is obtained by experiments in advance using a torque output jig 109 as shown in FIG. 4 for generating the reference torque T0 corresponding to the first set value T1 described above. Then, the information is stored in the information storage unit 205 in the control circuit 200, and the motor current control unit 202 controls the motor current of the stepping motor 101 using the reference motor current I0.

  More specifically, as shown in FIG. 4, one point on the path of the roll paper 105 is sandwiched by using a torque output jig 109, and a constant reference torque T0 is generated on the roll paper 105 by the friction, so that the motor The current controller 202 supplies the motor current Irs to the stepping motor 101 to generate a winding torque Tr larger than T0.

  Here, when the motor current Ir is gradually reduced by the motor current control unit 202 and the reference torque T0 becomes larger than the torque Tr, a step-out occurs. The current Irs when the step-out occurs is set as the reference motor current I0, and the reference frequency F0 that is the motor frequency at the step-out and the reference temperature T0 that is the motor temperature are stored in the information storage unit 205.

  A coil corresponding to the number of phases and the number of poles is wound on the stator side of the stepping motor 101. The electrical characteristics of this coil are almost the same as those of a general AC circuit. It is uniquely determined from the above characteristics.

  That is, the relationship between the motor current and the torque is generally a substantially proportional first relationship f1 as shown in FIG. 5, and the relationship between the motor temperature and the torque is generally inversely proportional as shown in FIG. The second relationship f2. Similarly, the relationship between the motor frequency and the torque is a third relationship f3 that is generally inversely proportional as shown in FIG.

  The first to third relationships f1 to f3 shown in FIGS. 5 to 7 are stored in the information storage unit 205 in advance, and the reference motor current I0 stored in advance is corrected as follows to obtain the motor current. To control. FIG. 8 shows motor current setting steps performed by the control circuit 200 in the printer 1 of this embodiment.

  As shown in step S1 of FIG. 8, the control circuit 200 starts setting the winding torque Tx (output), and as shown in step S2, the motor frequency Fr proportional to the current winding speed Vr and the reference frequency A third output torque coefficient Kv is calculated from the value of f3 at F0.

  More specifically, on the characteristic curve of f3 shown in FIG. 7, when Fr> F0 and the torque f3 (Fr) at Fr is smaller than the torque f3 (F0) at F0, for example, Kv = f3 (Fr ) / F3 (F0), the torque is corrected to increase.

  Similarly, when the torque f3 (Fr) at Fr is larger than the torque f3 (F0) at F0 when Fr <F0, for example, Kv = f3 (Fr) / f3 (F0) is set to decrease the torque. to correct.

  As shown in step S3, the second output torque coefficient Kt is calculated from the current motor temperature Tr detected by the motor temperature detecting element 104 and the motor temperature detecting unit 206 and the value f2 at the reference temperature T0.

  More specifically, on the characteristic curve of f2 shown in FIG. 6, when Tr> T0 and the torque f2 (Tr) at Tr is smaller than the torque f2 (T0) at T0, for example, Kt = f2 (Tr ) / F2 (T0), the torque is corrected to increase.

  Similarly, when Tr <T0 and the torque f2 (Tr) at Tr is larger than the torque f2 (T0) at T0, for example, Kt = f2 (Tr) / f2 (T0) is set to decrease the torque. to correct.

  In step S4, Tx / T0 / (Kv × Kt) is calculated from the required winding torque Tx to calculate the motor current coefficient Ki, and in step S5, the first relation f1 is used to correspond to Ki. In step S6, the motor current Ir of the stepping motor 101, which is a winding motor, is set.

  Next, main control contents in the printer 1 of this embodiment will be described with reference to a flowchart shown in FIG. As shown in step S11 of FIG. 9, the printing unit 106 performs printing on the roll paper 105 and performs an appropriate winding operation. In step S12, the printing speed, that is, the peripheral speed Vp of the paper transport roller 106b is set to V1. .

  In step S13, the printing unit 106 starts printing and paper conveyance based on a drive command to the stepping motor 107 of the printer motor drive control unit 209.

  In step S14, with the winding shaft 103 stopped, the printing unit 106 rolls Nmm or more (for example, a value obtained by multiplying the conveyance speed determined from the motor frequency by the conveyance time) based on the control of the printer motor drive control unit 209. The paper 105 is printed and fed, and it is determined whether or not printing of N mm or more is completed. If the result is affirmative, the process proceeds to step S15. If the result is negative, the process returns to step S14.

  In step S15, the winding speed Vr of the winding shaft 103 is set to V1, and in step S16, the output torque, that is, the winding torque Tx, is obtained by multiplying the sum of the stop torque Ta and the load torque Tb by 1.5. Let it be a certain second set value T2. In addition, although the setting coefficient which does not step out in step S16 is 1.5, this number can be changed as appropriate.

  In step S16, the winding shaft 103 starts winding based on the driving of the stepping motor 101 based on the control of the winding motor drive control unit 201. In step S18, the winding motor drive control unit 201 If there is a notification from the motor drive control unit 209 that printing has ended, it is determined whether printing has ended. If yes, the process proceeds to step S19. If not, the determination process in step S19 is continued.

  In step S19, the winding torque Tx of the winding shaft 103 is set to a first set value T1, which is a value obtained by multiplying the sum of the stop torque Ta and the load torque Tb by 0.5. The setting coefficient 0.5 in step S19 can be changed as appropriate. It is necessary as a precondition that (Ta + Tb) × 0.5 <T1 <Ta.

  In step S20, the motor step-out detection unit 203 determines whether or not step-out has occurred based on the monitoring of the motor current of the stepping motor 101. If the determination is affirmative, the process proceeds to step S21. The determination process of S20 is continued.

  In step S21, the winding motor drive control unit 201 outputs a drive stop command to the motor current control unit 202, and the motor current control unit 202 stops the supply of current to the stepping motor 101 based on the drive stop command. Stop driving. The sheet winding method of the present invention is executed according to the flowchart shown in FIG.

  In the printer 1 of the present embodiment, the following operational effects can be obtained. That is, in the printer 1 of this embodiment, the winding torque Tx generated by the stepping motor 101 is set to the first set value T1 that is larger than the load torque Tb after printing and smaller than the sum of the load torque Tb and the stop torque Ta. By setting, the winding shaft of the winding shaft 103 after the printing is finished, the slack formed in advance between the winding body and the printing unit 106 is gradually eliminated, and the winding shaft is instantly removed. The stepping motor 101 can be intentionally stepped out by making the total load torque Ta + Tb acting on 103 larger than the first set value T1.

  That is, since no torque is generated in the rotor of the stepping motor 101 after the displacement is generated and no winding torque is generated in the winding shaft 103, there is no sag after the printing unit 106 finishes printing. Thus, the stepping motor 101 can be provided with a torque limiter function.

  Therefore, the stepping motor 101 is not limited to the torque limiter only by determining the winding torque Tx after the printing based on the predetermined load torque Tb and the stop torque Ta without requiring a sensor for detecting the amount of sag. Can function as. With the torque limiter function of the stepping motor 101 of this embodiment, the printing unit 106 that has already stopped the roll paper 105 by generating the stop torque Ta by the winding operation of the stepping motor 101 after the end of printing. It is possible to prevent the winding torque Tx from being transmitted through the roll paper 105 and inadvertently pulling out the roll paper 105 stopped by the paper transport roller 106b to the winding body side.

  In the printer 1 of this embodiment, when the step-out is detected, the energization to the stepping motor 101 is stopped based on the control of the motor current control unit 210, so that the step-out state is prevented as much as possible. It is possible to suppress power consumption and noise generation accompanying the out-of-step condition to the minimum.

  As shown in FIG. 10, a normal mechanical torque limiter 501 has, for example, a cylindrical shape as shown in FIG. 10, and has substantially the same outer dimensions as the driving motor 502 as shown in FIG. However, in the printer 1 of this embodiment, since it is not necessary to use such a mechanical torque limiter 501 separately, the number of parts and the weight can be reduced, and the space in the printer 1 can be saved. The degree of freedom can be increased.

  In addition, during printing, the winding torque Tx is set larger than the load torque Tb, and the winding speed Vr of the winding shaft 103 and the printing are performed on the roll paper 105 between the printing unit 106 and the winding body. Since the slack is secured by ensuring the synchronization of the conveyance speed of the paper conveyance roller 106b of the section 106 and the Nmm feeding operation of the paper conveyance roller 106b in advance, it is possible to reliably prevent the stepping motor 101 from stepping out. can do. Thereby, the feeding operation of the roll paper 105 during printing can be made smoother.

  In addition, the tension of the roll paper 105 between the winding body during printing and the printing unit 106 is made appropriate, and an appropriate slack is given to prevent the occurrence of a high tension state. Can do.

  The step-out used in the printer 1 of the present embodiment mainly indicates that the total load torque exceeds the winding torque Tx, that is, the step-out that occurs due to overload. In step out of this mode, due to the increase in total load torque, the escape torque characteristic curve moves downward in the through region surrounded by the start characteristic and escape torque characteristic curve with the motor frequency on the horizontal axis and the torque on the vertical axis. This means that the plot point of torque and motor frequency deviates to the upper side of the through region.

  In the characteristics of the stepping motor, a step-out due to the plot point deviating to the upper side of the through region by raising the motor current also occurs, but in this embodiment, the step-out in this mode is not handled. Similarly, even when the motor frequency is increased, a step out of the mode in which the plot points of the torque and the motor frequency deviate from the through region to the right occurs. The key is not treated.

  In this embodiment, the step out is used to detect that the total load torque increases and becomes the sum of the load torque Tb and the stop torque Ta at the moment when the slack disappears. Only key is used.

  In the winding operation of the stepping motor 101 of the printer 1 of the present embodiment, the winding speed Vr of the winding shaft 103 needs to be equal to or less than the transport speed of the paper transport roller 106b. In terms of meaning, step-out accompanying increase in motor frequency is not used.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions are made to the above-described embodiments without departing from the scope of the present invention. be able to.

  For example, in the above-described embodiment, the roll paper 105 between the printing unit 106 and the winding body is synchronized with the winding speed Vr of the winding shaft 103 and the conveyance speed of the paper conveyance roller 106b of the printing unit 106. In addition, the slack is ensured by performing the Nmm feeding operation of the paper transport roller 106b in advance, but the slack may be secured simply by setting the winding speed Vr to be slower than the transport speed.

  Further, the mode of step-out detection by the motor step-out detection unit 203 is merely exemplary, and other methods can be used as long as the step-out can be detected without a sensor.

  The present invention relates to a printer, and can provide a paper take-up device, a printer, and a paper take-up method that can maintain an appropriate tension state after printing and completion of printing without incurring an increase in cost. For example, the present invention is useful when applied to a printer that stores and uses a winding body around which a sheet such as a receipt is wound.

DESCRIPTION OF SYMBOLS 1 Printer 101 Stepping motor 102 Driving force transmission mechanism 103 Winding shaft (winding mechanism)
DESCRIPTION OF SYMBOLS 104 Motor temperature detection element 105 Roll paper 106 Printing part 107 Stepping motor 200 Control circuit 201 Winding motor drive control part (motor drive control part)
202 Motor current control unit 203 Motor step-out detection unit 204 Winding motor drive frequency generation unit (frequency generation unit)
205 Information storage unit 206 Motor temperature detection unit 207 MCU
208 printer motor drive frequency generation unit 209 printer motor drive control unit 210 motor current control unit

Claims (12)

  A printing unit that prints a sheet and stops the sheet based on a stop torque after the printing, a winding mechanism that winds the printed sheet as a winding body, and drives the winding mechanism And a motor drive control unit configured to set and drive a winding speed and a winding torque generated by the stepping motor, and the motor drive control unit is configured to perform printing while the printing is being performed. The winding speed is adjusted to generate a slack in the paper between the printing unit and the winding mechanism, and the motor drive control unit rotates the winding body after the printing by using the motor driving control unit. A first set value that is larger than the load torque required for the operation and smaller than the sum of the stop torque and the load torque is set, and step-out occurs after the slack is removed. Winding device.   The paper winding device according to claim 1, wherein the motor drive control unit stops driving the stepping motor when the step-out occurs.   3. The paper winding device according to claim 1, wherein the motor drive control unit sets the winding torque to a second set value larger than the load torque during the printing. 4.   The paper winding device according to any one of claims 1 to 3, wherein the first set value set after the printing constitutes a torque limiter that is a limit torque.   A motor current control unit for controlling a motor current of the stepping motor; and the motor current control unit adjusts the limit torque based on a first characteristic indicating a correlation between the winding torque and the motor current. The paper take-up device according to claim 4.   6. The motor current control unit adjusts the limit torque based on a second characteristic indicating a correlation between a motor temperature of the stepping motor and the winding torque and the detected motor temperature. The paper take-up device described in 1.   The said motor current control part adjusts the said limit torque based on the 3rd characteristic which shows the correlation of the motor frequency of the said stepping motor, and the said winding torque, and a motor frequency, It is characterized by the above-mentioned. Paper take-up device.   Using a torque output jig that generates a reference torque that is set larger than the load torque required to rotate the winding body and smaller than the sum of the stop torque and the load torque, the winding target The motor current control unit varies the motor current based on a reference motor current measured and stored as a motor current at which the step-out occurs by gradually reducing the motor current by applying a reference torque to the paper. The paper winding device according to any one of claims 5 to 7, wherein the paper winding device is controlled.   A printing step for printing paper, a stop step for stopping the paper based on a stop torque after the printing step, a winding step for winding the paper after the printing step as a winding body by a stepping motor, and the printing Adjusting the winding speed of the stepping motor in the winding step during the step to generate a sag in the paper; and a winding torque in the winding step after the printing step; A control step for driving by setting to a first set value that is larger than the load torque necessary for rotation and smaller than the sum of the stop torque and the load torque, and out-of-step occurrence that generates out-of-step after removing the slack A paper winding method comprising a step.   The paper winding method according to claim 9, further comprising a driving stop step of stopping driving of the stepping motor after the step-out generation step.   A printer comprising the paper take-up device according to claim 1.   A printer using the paper winding method according to claim 9.

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