JP4819610B2 - Printer device - Google Patents

Description

  The present invention relates to a printer apparatus such as a thermal printer.

Since the thermal printer is relatively small, it is applied to a portable terminal device or a POS (Point Of Sales) device, and one that uses roll paper as printing paper is known.
In such a thermal printer, a belt-shaped printing paper made of thermal paper is sandwiched between a transport platen and a paper support plate, and the printing paper is printed in a printing unit by rotating the platen in a certain direction. Transport to. The platen is provided with a rubber roller in a conveyance portion of the printing paper, and conveys the printing paper by frictional force of rubber while rotating.
Moreover, in a transmission mechanism that transmits a driving force for rotating the platen to the platen, a resin gear train is used as disclosed in Patent Documents 1 and 2 and the like. For this reason, so-called backlash existing in the gear train and elastic deformation generated in the gear cause the positional deviation of the printing paper.
In Patent Document 1, after completion of printing, the pulse motor is rotated by a predetermined rotation angle in the rotation direction opposite to the rotation direction during printing to remove elastic deformation (distortion) generated in the gear train for driving the platen. Then, a technique is disclosed in which the pulse motor is rotated forward immediately before the start of printing to return the print start position to the original position and prevent the print start position from shifting.
In Patent Document 2, the platen is rotated in both forward and reverse directions at the time of paper feeding (at the start of printing) in order to suppress the occurrence of misalignment of the printing position due to so-called backlash existing in the gear train, and the rotation amount is A technique for setting a predetermined amount is disclosed.
JP 2000-6479 A JP-A-61-225079

By the way, since the roller portion for carrying the platen is made of rubber, when the conveyance of the printing paper by the platen is stopped in the excited state of the pulse motor, the roller portion of the platen supports the printing paper. There is a possibility that it is in an elastically deformed state due to the force (friction force or reaction force) received from the support member or the like. For this reason, as shown in FIG. 8, when the excitation of the pulse motor that drives the platen is cut off, the platen may reversely rotate due to the restoring force of the roller portion, and when the continuously formed printing paper is conveyed again In addition, there is a possibility that problems related to printing such as displacement of the printing position may occur. That is, not only the backlash and elastic deformation existing in the gear train but also the elastic deformation of the platen causes the printing position shift. When the platen rotates reversely due to the restoring force of the roller portion, the meshing state of the gear train is released and backlash occurs.
In addition, when trying to correct the misalignment of the printing position due to these various factors at the start of printing, the exact position at the start of printing due to disturbances that occur between the time when printing is completed and the time when printing is resumed. Misalignment correction may not be possible. Further, if the misalignment correction is executed at the start of printing, the printing start is delayed accordingly.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to suppress the occurrence of misalignment of the printing position and to perform printing promptly without correcting the misalignment at the start of printing. It is to provide a printer device that can start.

A printer apparatus according to the present invention includes a platen that sandwiches a print medium between opposed support members and conveys the print medium in a fixed direction by rotation, a motor that supplies a rotational driving force to the platen, and a rotational driving force that the motor supplies. A transmission mechanism for transmitting to the platen, and a correction means for stopping the rotation of the motor to stop the conveyance of the print medium and giving the motor a correction rotation consisting of forward and reverse rotations before interrupting the excitation current to the motor When the blocking means for blocking the exciting current to the motor, have a, the correction rotation is located at a rotation for removing transmission errors that occur in the elastic deformation and the transmission mechanism occurring at least on the platen The correction rotation control means rotates the motor forward by the first rotation amount as the correction rotation, and then reverses the rotation amount by adding the first rotation amount and the second rotation amount. It is rolling, further, the second by the rotation amount rotated forward, after the forward rotation of the second rotation amount, the blocking means is characterized by blocking the exciting current to the motor.
According to this configuration, before the excitation current to the motor is cut off, a correction rotation consisting of forward and reverse rotations is given to the motor, thereby causing a print position shift that may occur after the excitation current is cut off or may exist. This eliminates the mechanical transmission error. Thereby, when printing is resumed, printing can be started promptly.

A printer apparatus according to the present invention includes a platen that sandwiches a print medium between opposed support members and conveys the print medium in a fixed direction by rotation, a motor that supplies a rotational driving force to the platen, and a supply of the motor A transmission mechanism for transmitting a rotational driving force to the platen, and a correction mechanism comprising forward and reverse rotations before stopping the rotation of the motor and interrupting the excitation current to the motor in order to stop the conveyance of the printing medium. A correction rotation control unit that applies rotation to the motor; and a blocking unit that blocks an excitation current to the motor. The correction rotation is generated in at least the elastic deformation generated in the platen and the transmission mechanism. The correction rotation control means reversely rotates the motor by a first rotation amount as the correction rotation, and then performs the first rotation. And the second rotation amount are forwardly rotated, and further rotated backward by the second rotation amount. After the reverse rotation by the second rotation amount, the blocking means is the motor. It is characterized by cutting off the exciting current to. According to this configuration, before the excitation current to the motor is cut off, a correction rotation consisting of forward and reverse rotations is given to the motor, thereby causing a print position shift that may occur after the excitation current is cut off or may exist. This eliminates the mechanical transmission error. Thereby, when printing is resumed, printing can be started promptly.

  In the above configuration, a configuration in which the first rotation amount is larger than the second rotation amount can be adopted.

  In the above configuration, a configuration having correction means for correcting the first and second rotation amounts can be adopted, and the correction means includes the relationship between the elastic deformation amount of the platen and the printing speed, the elastic deformation amount of the platen and the ambient temperature. The first and second rotation amounts can be corrected based on at least one of the above relationship and the relationship between the amount of elastic deformation of the platen and the print medium.

  According to the present invention, there is provided a printer apparatus in which occurrence of a printing position shift is suppressed.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram of a printer apparatus according to an embodiment of the present invention.
As shown in FIG. 1, the printer apparatus includes a printer main body 100, a printer control circuit 201, and the like.

  The printer main body 100 includes a pulse motor (stepping motor) 102, a transmission mechanism 103 connected to the pulse motor 102, a platen 104 connected to the transmission mechanism 103, and a paper support plate as a support member disposed to face the platen 104. 105, a printing machine 106 for printing on the printing paper 300, an ambient temperature detector 110, a printing paper detector 310, and the like.

  The platen 104 is configured, for example, by providing a cylindrical rubber roller around a core shaft (not shown) that is rotatably supported. The platen 104 sandwiches the printing paper 300 as a printing medium between the paper support plates 105 arranged opposite to each other, and conveys the printing paper by a frictional force acting on the printing paper 300. Since the platen 104 is in contact with the paper support plate 105, elastic deformation occurs in the rubber roller portion.

  The pulse motor 102 is a motor whose rotation control (rotation angle, rotation speed) is controlled by the number of pulses of a constant angle (basic step angle) and its frequency, and is based on a pulse control signal formed by the printer control circuit 201. The rotation is controlled.

  The transmission mechanism 103 is constituted by a gear train in which a plurality of gears (not shown) are combined, and reduces the rotational driving force of the pulse motor 102 and transmits it to the platen 104. The plurality of gears constituting the transmission mechanism 103 are formed by, for example, an injection molding method using resin. There is a backlash between the plurality of gears, and this backlash may cause a transmission error in which the rotation of the pulse motor 102 is accurately transmitted to the platen 104. For this reason, as will be described later, correction for removing backlash in the conveyance direction of the printing paper 300 is required.

  The paper support plate 105 sandwiches the printing paper 300 conveyed in cooperation with the platen 104 and supports the printing paper 300 conveyed by the rotating platen 104. That is, the conveyed printing paper 300 slides on the paper support plate 105.

The printing machine 106 prints information input from the printer control circuit 201 on the printing paper 300 conveyed from the platen 104.
The ambient temperature detector 110 detects the ambient temperature of the printer main body 100 and outputs this detection signal 110s to the printer control circuit 201 (MCU).
The printing paper detector 310 detects the type of printing paper set in the printer main body 100, and outputs a detection signal 310s to the printer control circuit 201 (MCU).

  As shown in FIG. 1, the printer control circuit 201 includes a motor drive circuit 202, a volatile memory 203, a nonvolatile memory 204, an MCU (microcontroller unit) 205, a printing machine control circuit 206, a printing speed detector 210, and the like. Is done.

The volatile memory 203 stores a program read from the nonvolatile memory 204 and various control data.
The nonvolatile memory 204 stores programs to be read and executed by the MCU 205.
The MCU 205 receives various signals such as a detection signal 310 s of the printing paper detector 310, a detection signal 210 s of the printing speed detector 210, and a detection signal 110 s of the ambient temperature detector 110, and comprehensively controls the printer apparatus and will be described later. Various processes to be executed are executed.

The motor drive circuit 202 outputs a drive current for driving the pulse motor 102 in accordance with the pulse control signal input from the MCU 205.
The printing press control circuit 206 drives the printing press 106 based on a control command from the MCU 205.
The printing speed detector 210 detects the printing speed based on the signal obtained from the pulse motor 102 and outputs the detection signal 102 s to the MCU 205.

Next, an example of processing of the MCU 205 in the printer control circuit 201 will be described with reference to FIGS.
Here, FIG. 2 is a flowchart showing an example of the processing of the MCU 205, FIG. 3 is a diagram showing the movement of the platen at each step, and FIG. 4 is a flowchart showing an example of the processing for setting the correction rotation amounts M and N. FIG. 5 is a graph showing the relationship between various parameters and correction coefficients for correcting the values M and N that define the correction rotation amount.

  First, as shown in FIG. 2, the MCU 205 executes a paper conveyance process (step ST1). Specifically, as shown in FIG. 3A, the pulse motor 102 is driven to rotate the platen 104 in a certain direction, and the printing paper 300 is conveyed toward the printing machine 106 by the platen 104. As a result, characters and the like are printed on the printing paper 300 by the printing machine 106.

The MCU 205 determines whether the predetermined printing process is finished and the conveyance of the printing paper 300 is stopped (step ST2).
When the conveyance of the printing paper 300 is stopped and the pulse motor 102 is in an excited state, the platen 104 may be elastically deformed by receiving a reaction force from the paper support plate 105.
Before releasing the excitation of the pulse motor 102 from this state, the MCU 205 performs normal rotation (rotation in the transport direction) by N steps as shown in FIG. 3A (step ST3). The rotation amount for N steps is a predetermined amount, and is, for example, about 1.0 mm in the circumferential distance of the platen 104. This setting method will be described later.
When the platen 104 is rotated forward by N steps (rotated in the transport direction), the platen 104 is surely elastically deformed. Further, in this state, the gear train of the transmission mechanism 103 is surely engaged and no backlash occurs.

Next, the MCU 205 reversely rotates the platen 104 by the rotation amount of M + N steps as shown in FIG. 3A from the state in which the elastic deformation is surely generated in the platen 104. The rotation amount for M steps at this time is a rotation for removing elastic deformation generated in the platen 104. The rotation amount for M steps is, for example, about 0.5 mm in the circumferential distance of the platen 104, and the rotation amount for N steps is set to a small value. The setting method will be described later.
When a reverse rotation amount for M + N steps is given to the platen 104, the platen 104 passes through the original rotation stop position of the platen 104 and rotates reversely for M steps, whereby the elastic deformation of the platen 104 is removed.

When the platen 104 rotates backward by M steps from its original rotation stop position, the meshing state of the gear train of the transmission mechanism 103 is released and backlash occurs.
In order to remove the backlash, the MCU 205 rotates the platen 104 forward by M steps as shown in FIG. 3A (step ST5).
As a result, the gear train of the transmission mechanism 103 is brought into an engaged state, and backlash is removed.

  Next, the MCU 205 cuts off the excitation of the pulse motor 102 as shown in FIG. In this state, the platen 104 is positioned at the original rotation stop position and the backlash of the transmission mechanism 103 is removed.

  When the sheet conveyance process is resumed, the MCU 205 rotates the platen 104 in the forward direction and conveys the sheet 300 in the conveyance direction, as shown in FIG. At this time, since the platen 104 is positioned at the original rotation stop position and the conveyance of the paper 300 is resumed with the backlash of the transmission mechanism 103 removed, the printing position is set after the conveyance of the printing paper 300 is resumed. It is possible to prevent misalignment and it is possible to start printing promptly after resumption of conveyance because there is no need for correction rotation processing.

Next, an example of a method for setting the values M and N that define the correction rotation amount will be described with reference to FIGS.
Here, FIG. 4 is a flowchart showing an example of setting processing of M and N values, and FIG. 5 is a graph showing the relationship between various parameters and correction coefficients for correcting M and N values.

  As shown in FIG. 4A, the MCU 205 executes an initialization process (step ST21). In this initialization process, as shown in FIG. 4B, a predetermined value (eg, 0.5 mm) is substituted for the initial value M0 of M (step ST22), and a predetermined value (eg, 1) is assigned to the initial value N0 of N. .0 mm).

Next, the MCU 205 executes a printing speed detection process (step ST31).
In this initialization processing, as shown in FIG. 4C, the printing speed is detected from the detection signal 210s of the printing speed detector 210 (step ST32), and the correction for correcting the values of M and N from the detected printing speed. A coefficient K1 is calculated (step ST33).
That is, since it is known that there is a correlation between the printing speed and the elastic deformation amount of the platen 104, it is preferable that the values of M and N are corrected and optimized according to the printing speed. Therefore, for example, as shown in FIG. 5A, data of the correction coefficient K1 for the printing speed is stored in advance in the nonvolatile memory 204 or the like, and the correction coefficient K1 corresponding to the detected printing speed is determined.

Next, the MCU 205 executes ambient temperature detection processing (step ST41).
In this ambient temperature detection process, the ambient temperature of the printer main body 100 is detected by the ambient temperature detector 110 (step ST42), and a correction coefficient K2 for correcting the values of M and N is calculated from the detected ambient temperature (step ST43). .
That is, since it is known that there is a correlation between the ambient temperature of the printer main body 100 and the elastic deformation amount of the platen 104, the values of M and N are corrected and optimized according to the ambient temperature of the printer main body 100. Is preferred. For this reason, for example, as shown in FIG. 5B, data of the correction coefficient K2 for the ambient temperature is stored in advance in the nonvolatile memory 204 or the like, and the correction coefficient K2 corresponding to the detected ambient temperature is determined.

Next, the MCU 205 executes a print sheet detection process (step ST51).
In this printing paper detection process, the printing paper detector 310 detects the type of printing paper 300 (step ST52), and calculates a correction coefficient K3 for correcting the values of M and N from the detected printing paper 300 type (step ST52). ST53).
That is, since it is known that there is a correlation between the type of the printing paper 300 and the elastic deformation amount of the platen 104 that sandwiches the printing paper 300 in cooperation with the paper support plate 105, the values of M and N are set to the values of the printing paper 300. It is preferable to correct and optimize according to the type. For this reason, for example, as shown in FIG. 5C, data of the correction coefficient K3 corresponding to the types A to D of the printing paper 300 is stored in advance in the nonvolatile memory 204 or the like, and the detected printing paper 300 is detected. A correction coefficient K3 corresponding to the type is determined.

  Next, the MCU 205 multiplies the initial values M0 and N0 of M and N by the correction coefficients K1 to K3 to calculate values M and N that define the correction rotation amount (step ST61). Thereby, M and N used for the correction rotation process are determined.

  6 and 7 are diagrams for explaining the correction rotation processing according to another embodiment of the present invention. FIG. 6 is a flowchart showing the processing procedure of the MCU, and FIG. 7 is related to the processing of FIG. It is a figure which shows an example of operation | movement of a platen.

  As shown in FIG. 6, the MCU 205 first executes a paper transport process (step ST11), and drives the pulse motor 102 to rotate the platen 104 in a certain direction as shown in FIG. The platen 104 conveys the printing paper 300 toward the printing machine 106. As a result, characters and the like are printed on the printing paper 300 by the printing machine 106.

The MCU 205 determines whether the predetermined printing process is completed and the conveyance of the printing paper 300 is stopped (step ST12).
When the conveyance of the printing paper 300 is stopped and the pulse motor 102 is in an excited state, the platen 104 may be elastically deformed by receiving a reaction force from the paper support plate 105 as described above. is there.

  Before releasing the excitation of the pulse motor 102 from this state, the MCU 205 executes a process of performing reverse rotation (reverse to the transport direction) by N steps as shown in FIG. 7A (step ST13). . The rotation amount for N steps is a predetermined amount, and is set to the same value as in the above embodiment.

  When the platen 104 is rotated reversely by N steps (rotated in the direction opposite to the conveying direction), the elastic deformation generated in the platen 104 is removed or the elastic deformation amount is reduced.

Next, as shown in FIG. 7A, the MCU 205 rotates the platen 104 forward (rotates in the transport direction) by the amount of rotation of M + N steps (step ST14). The rotation amount for M steps at this time is a rotation amount corresponding to the elastic deformation amount generated in the platen 104 when the conveyance is stopped. The rotation amount for M steps is set by the same method as described above.
When a positive rotation amount for M + N steps is given to the platen 104, the platen 104 passes through the original rotation stop position of the platen 104 and rotates positively for M steps, so that the platen 104 is surely elastically deformed. Further, when the platen 104 rotates forward by M steps from its original rotation stop position, the gear train of the transmission mechanism 103 is in a meshed state due to a restoring force due to elastic deformation, and the backlash is removed.

  Next, as shown in FIG. 7A, the MCU 205 reversely rotates the platen 104 by M steps (a rotation amount corresponding to the elastic deformation amount) (step ST15). Thereby, even after the excitation of the pulse motor 102 is cut, the platen 104 is positioned at the original rotation stop position while the gear train of the transmission mechanism 103 is maintained in the meshing state.

  Then, when the sheet conveyance process is resumed, the MCU 205 conveys the sheet 300 in the conveyance direction by rotating the platen 104 forward as shown in FIG. 7B. At this time, since the platen 104 is positioned at the original rotation stop position and the conveyance of the paper 300 is resumed with the backlash of the transmission mechanism 103 removed, the printing position is set after the conveyance of the printing paper 300 is resumed. It is possible to prevent misalignment and it is possible to start printing promptly after resumption of conveyance because there is no need for correction rotation processing.

  In the above-described embodiment, the case where the paper support plate 105 is used as the support member has been described. However, for example, the present invention can be applied to a case where a thermal head is used as the support member.

1 is a schematic configuration diagram of a printer apparatus according to an embodiment of the present invention. 6 is a flowchart illustrating an example of correction rotation processing in the printer device. It is a figure which shows an example of operation | movement of the platen which concerns on a correction | amendment rotation process. It is a flowchart which shows the process for setting correction | amendment rotation amount M and N, (A) is a main routine, (B) is an initialization process, (C) is a printing speed detection process, (D) is ambient temperature detection. Processing and (E) are flowcharts showing the printing paper detection processing. It is a graph which shows the relationship between various parameters and the correction coefficient of correction | amendment rotation amount M and N. FIG. 10 is a flowchart illustrating another example of the correction rotation process in the printer device. It is a figure which shows operation | movement of the platen which concerns on the correction | amendment rotation process of FIG. FIG. 10 is a diagram for explaining the movement of the platen when the sheet conveyance by the platen is stopped and the excitation of the pulse motor is interrupted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Printer main body 102 ... Pulse motor 103 ... Transmission mechanism 104 ... Platen 105 ... Paper support plate 106 ... Printing machine 110 ... Ambient temperature detector 201 ... Printer control circuit 202 ... Motor drive circuit 203 ... Volatile memory 204 ... Non-volatile memory 205 ... MCU (microcontroller unit)
300: Printing paper 310: Printing paper detector

Claims (5)

A platen that conveys the print medium in a fixed direction by rotating the print medium between the support members arranged opposite to each other;
A motor for supplying a rotational driving force to the platen;
A transmission mechanism for transmitting the rotational driving force supplied by the motor to the platen;
A correction rotation control means for giving a correction rotation consisting of forward and reverse rotations to the motor before stopping the rotation of the motor to stop the conveyance of the print medium and shutting off the excitation current to the motor;
A blocking means for blocking the excitation current to the motor;
I have a,
The correction rotation is a rotation for removing at least elastic deformation generated in the platen and a transmission error generated in the transmission mechanism,
The correction rotation control means rotates the motor forward by the first rotation amount as the correction rotation, and then reversely rotates the rotation amount by adding the first rotation amount and the second rotation amount. And further forwardly rotate by the second rotation amount,
The printer device according to claim 1 , wherein after the forward rotation corresponding to the second rotation amount, the blocking means blocks an excitation current to the motor .   A platen that conveys the print medium in a fixed direction by rotating the print medium between the support members arranged opposite to each other;
  A motor for supplying a rotational driving force to the platen;
  A transmission mechanism for transmitting the rotational driving force supplied by the motor to the platen;
  A correction rotation control means for giving a correction rotation consisting of forward and reverse rotations to the motor before stopping the rotation of the motor to stop the conveyance of the print medium and shutting off the excitation current to the motor;
  A blocking means for blocking the excitation current to the motor;
Have
  The correction rotation is a rotation for removing at least elastic deformation generated in the platen and a transmission error generated in the transmission mechanism,
  The correction rotation control means reversely rotates the motor by a first rotation amount as the correction rotation, and then rotates forward by a rotation amount obtained by adding the first rotation amount and the second rotation amount. And reversely rotate by the second rotation amount,
  The printer device according to claim 1, wherein after the second rotation amount is reversely rotated, the shut-off unit cuts off an excitation current to the motor. It said first rotation amount, the second greater than the rotation amount, the printer apparatus according to claim 1 or 2, characterized in that. The printer apparatus according to any one of the having a first and a correcting means for correcting the second rotation amount, claims 1, characterized in that 3. The correction means is based on at least one of the relationship between the amount of elastic deformation of the platen and the printing speed, the relationship between the amount of elastic deformation of the platen and the ambient temperature, and the relationship between the amount of elastic deformation of the platen and the printing medium. The printer apparatus according to claim 4 , wherein the first and second rotation amounts are corrected.

Images