JP4529819B2 - Printing apparatus, stick-slip handling method, program, and printing system - Google Patents

Description

  The present invention relates to a printing apparatus in which a print head moves along a guide unit, a stick-slip handling method, a program, and a printing system.

  For example, an inkjet printer is known as a printing apparatus that performs printing on a medium such as paper or film. This ink jet printer includes a print head that ejects ink onto a medium, and the print head ejects ink while moving relative to the medium to perform printing on the medium.

The print head moves while being guided along a predetermined direction by a guide portion inside the printer. The print head is moved by a motor. The print head is accelerated to a predetermined speed by a controller of the motor, and moves to a target position while moving at a constant speed at a predetermined speed by, for example, PID control (see Patent Documents 1, 2, and 3).
JP 2001-103778 A JP 2001-158144 A JP 2001-169484 A

  In such an ink jet printer, the following problems may occur. That is, for example, when the ink jet printer is not used for a long period of time, the print head does not slide well along the guide portion, and the print head moves or stops repeatedly. (Also called). Such a stick-slip operation is caused by the fact that the grease at the sliding portion between the print head and the guide portion has solidified. In particular, such a stick-slip operation occurs when the print head tries to move at a low speed.

  When such a stick-slip operation occurs, the print head cannot be stopped at the target position, and a problem such as the print head moving back and forth around the target position may occur. In addition, when such a stick-slip operation occurs, there may be a problem that the user is anxious about the failure. For this reason, when the print head performs a stick-slip operation, it is necessary to quickly detect and respond to this.

  The present invention has been made in view of such circumstances, and an object of the present invention is to promptly cope with the case where the print head performs a stick-slip operation.

The main invention for achieving the object is as follows:
(A) a print head for printing on a medium;
(B) a motor for moving the print head;
(C) a guide portion for guiding the print head along a predetermined direction;
(D) a speed detector that detects the moving speed of the print head;
(E) a determination unit that determines whether the print head is performing a stick-slip operation;
(F) a motor controller that controls the motor by generating a control signal based on a change amount per unit time of the moving speed detected by the speed detector;
When controlling the motor to move the print head at a constant speed below the predetermined speed along the guide portion,
If the determination unit does not determine that the print head is performing a stick-slip operation, the control signal is generated based on the predetermined upper limit value when the amount of change exceeds a predetermined upper limit value. ,
When the determination unit determines that the print head is performing a stick-slip operation, the change amount exceeds the predetermined upper limit value and is based on the change amount regardless of the predetermined upper limit value. A motor control unit for generating the control signal;
The printing apparatus includes (G).

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

=== Summary of disclosure ===
At least the following matters will become apparent from the description of the present specification and the accompanying drawings.

(A) a print head for printing on a medium;
(B) a motor for moving the print head;
(C) a guide portion for guiding the print head along a predetermined direction;
(D) a speed detector that detects the moving speed of the print head;
(E) a determination unit that determines whether the print head is performing a stick-slip operation;
(F) a motor controller that controls the motor by generating a control signal based on a change amount per unit time of the moving speed detected by the speed detector;
When controlling the motor to move the print head at a constant speed below the predetermined speed along the guide portion,
If the determination unit does not determine that the print head is performing a stick-slip operation, the control signal is generated based on the predetermined upper limit value when the amount of change exceeds a predetermined upper limit value. ,
When the determination unit determines that the print head is performing a stick-slip operation, the change amount exceeds the predetermined upper limit value and is based on the change amount regardless of the predetermined upper limit value. A motor control unit for generating the control signal;
A printing apparatus comprising (G).

  In such a printing apparatus, when it is not determined that the print head is performing the stick-slip operation, the amount of change per unit time of the moving speed of the print head exceeds a predetermined upper limit value. By generating the control signal based on the predetermined upper limit value, the print head can be moved in a stable state. On the other hand, when it is determined that the print head is performing a stick-slip operation, a control signal is generated based on the amount of change in the moving speed of the print head per unit time regardless of the predetermined upper limit value. By controlling this, it is possible to suppress the print head from performing a stick-slip operation.

  In such a printing apparatus, the motor control unit may be provided with a calculation unit that calculates the amount of change based on the movement speed detected by the speed detection unit. If such a calculation unit is provided, the amount of change can be easily calculated based on the moving speed detected by the speed detection unit.

  In the printing apparatus, the motor control unit may be provided with a limiter that outputs the predetermined upper limit value as the change amount when the change amount exceeds the predetermined upper limit value. good. If such a limiter is provided, a predetermined upper limit value can be easily output as the change amount when the change amount exceeds a predetermined upper limit value.

  In this printing apparatus, the motor control unit determines that the moving speed detected by the speed detection unit is predetermined after the determination unit determines that the print head is performing a stick-slip operation. If the change amount exceeds the predetermined upper limit value when the time is within a predetermined allowable range for a time or more, the control signal may be generated based on the predetermined upper limit value. After determining that the stick-slip operation is performed in this manner, if the moving speed of the print head is within a predetermined allowable range for a predetermined time or more, the predetermined amount is detected when the change amount exceeds a predetermined upper limit value. By generating the control signal based on the upper limit value, when the moving speed of the print head returns to normal, it is possible to switch to the same control as the original control before performing the stick-slip operation. As a result, the motor can be controlled in a stable state.

  In the printing apparatus, the determination unit may determine whether or not the print head is performing a stick-slip operation based on the moving speed detected by the speed detection unit. By making such a determination, it can be easily determined whether or not the print head is performing a stick-slip operation.

  In the printing apparatus, the determination unit may determine whether the print head is performing a stick-slip operation based on the control signal. By making such a determination, it can be easily determined whether or not the print head is performing a stick-slip operation.

  The printing apparatus may further include an acceleration detection unit that detects an acceleration of the print head, and the determination unit may perform a stick-slip operation based on the acceleration detected by the acceleration detection unit. It may be determined whether or not this is done. By making such a determination, it can be easily determined whether or not the print head is performing a stick-slip operation.

  In addition, the printing apparatus includes a timer that measures a time during which the moving speed of the print head is equal to or lower than a predetermined allowable lower limit between the start of movement of the print head and the end of movement, The unit may determine whether or not the print head is performing a stick-slip operation based on the measurement time of the timer. By making such a determination, it can be easily determined whether or not the print head is performing a stick-slip operation.

  In the printing apparatus, when the motor control unit controls the motor to move the print head at a constant speed or less along the guide unit at a predetermined speed or less, the print head is It may be when moving to a capping device that closes an opening provided in the print head. Accordingly, even when the print head performs a stick-slip operation when the print head moves to the capping device that closes the opening provided in the print head, this can be handled.

  In this printing apparatus, when the motor control unit controls the motor to move the print head at a constant speed or less along the guide unit at a predetermined speed or less, it is provided in the print head. The print head may be moved along the guide portion in order to detect the width of the medium to be printed by the optical sensor. Accordingly, even if the print head performs a stick-slip operation when the print head moves along the guide portion in order to detect the width of the medium to be printed by the optical sensor provided in the print head. Can respond.

  In this printing apparatus, when the motor control unit controls the motor to move the print head at a constant speed below the predetermined speed along the guide unit, it is mounted on the print head. It may be when the print head is moved to a predetermined position in order to replace the formed cartridge. Accordingly, even when the print head performs a stick-slip operation when the print head moves to a predetermined position in order to replace the cartridge mounted on the print head, it is possible to cope with this.

  In this printing apparatus, the print head may include a nozzle that ejects ink toward the medium in order to perform printing on the medium. Even if the print head performs a stick-slip operation in a printing apparatus having a print head provided with such nozzles, this can be accommodated.

(A) a print head for printing on a medium;
(B) a motor for moving the print head;
(C) a guide portion for guiding the print head along a predetermined direction;
(D) a speed detector that detects the moving speed of the print head;
(E) a determination unit that determines whether the print head is performing a stick-slip operation;
(F) a motor controller that controls the motor by generating a control signal based on a change amount per unit time of the moving speed detected by the speed detector;
When controlling the motor to move the print head at a constant speed below the predetermined speed along the guide portion,
If the determination unit does not determine that the print head is performing a stick-slip operation, the control signal is generated based on the predetermined upper limit value when the amount of change exceeds a predetermined upper limit value. ,
When the determination unit determines that the print head is performing a stick-slip operation, the change amount exceeds the predetermined upper limit value and is based on the change amount regardless of the predetermined upper limit value. A motor control unit for generating the control signal;
(G)
(H) The motor control unit is provided with a calculation unit that calculates the amount of change based on the moving speed detected by the speed detection unit,
(I) The motor control unit is provided with a limiter that outputs the predetermined upper limit value as the change amount to generate the control signal when the change amount exceeds the predetermined upper limit value.
(J) After the motor control unit determines that the print head is performing a stick-slip operation by the determination unit, the movement speed detected by the speed detection unit is greater than or equal to a predetermined time and a predetermined allowable range. If the change amount exceeds a predetermined upper limit value, the control signal is generated based on the predetermined upper limit value,
(K) The determination unit determines whether the print head is performing a stick-slip operation based on the moving speed detected by the speed detection unit,
(L) When the motor control unit controls the motor to move the print head at a constant speed below the predetermined speed along the guide unit, an opening provided in the print head. It is when moving to a capping device that closes the part,
(M) When the motor control unit controls the motor to move the print head at a constant speed below the predetermined speed along the guide unit, printing is performed by an optical sensor provided in the print head. When moving the print head along the guide to detect the width of the medium to be attempted,
(N) When the motor control unit controls the motor to move the print head at a constant speed below the predetermined speed along the guide unit, the cartridge mounted on the print head is replaced. When the print head is moved to a predetermined position.
(O) The printing apparatus, wherein the print head includes a nozzle that ejects ink toward the medium in order to perform printing on the medium.

Generating a control signal to control a motor so as to move a print head that performs printing on a medium at a constant speed below a predetermined speed along a guide portion that guides the print head along a predetermined direction; and ,
Detecting a moving speed of the print head moved by the motor;
Determining whether the print head is performing a stick-slip operation;
The step of generating the control signal based on the detected change amount of the moving speed per unit time, and when the print head is not determined to perform a stick-slip operation, the change amount is When the predetermined upper limit value is exceeded, the control signal is generated based on the predetermined upper limit value, and when it is determined that the print head is performing a stick-slip operation, the amount of change is the predetermined upper limit value. Generating the control signal based on the amount of change regardless of the predetermined upper limit value even if exceeding a value;
A method for handling stick-slip, comprising:

Generating a control signal to control a motor so as to move a print head that performs printing on a medium at a constant speed below a predetermined speed along a guide portion that guides the print head along a predetermined direction; and ,
Detecting a moving speed of the print head moved by the motor;
Determining whether the print head is performing a stick-slip operation;
The step of generating the control signal based on the detected change amount of the moving speed per unit time, and when the print head is not determined to perform a stick-slip operation, the change amount is When the predetermined upper limit value is exceeded, the control signal is generated based on the predetermined upper limit value, and when it is determined that the print head is performing a stick-slip operation, the amount of change is the predetermined upper limit value. Generating the control signal based on the amount of change regardless of the predetermined upper limit value even if exceeding a value;
A program characterized by executing

A printing system comprising a computer and a printing device connectable to the computer,
The printing apparatus includes: a print head that performs printing on a medium;
A motor for moving the print head;
A guide portion for guiding the print head along a predetermined direction;
A speed detecting unit for detecting a moving speed of the print head;
A determination unit that determines whether or not the print head has performed a stick-slip operation;
A motor control unit for controlling the motor by generating a control signal based on a change amount per unit time of the moving speed detected by the speed detection unit, wherein the print head is moved along a predetermined direction along the guide unit; When the motor is controlled to move at a constant speed below the speed, if the determination unit does not determine that the print head is performing a stick-slip operation, the amount of change exceeds a predetermined upper limit. When the control signal is generated based on the predetermined upper limit value and the determination unit determines that the print head is performing a stick-slip operation, the amount of change is the predetermined upper limit value. A motor control unit that generates the control signal based on the amount of change regardless of the predetermined upper limit value,
A printing system comprising:

=== Overview of Printing Apparatus ===
An embodiment of a printing apparatus according to the present invention will be described using an inkjet printer 1 as an example. 1 to 4 show the ink jet printer 1. FIG. 1 shows the appearance of the inkjet printer 1. FIG. 2 shows the internal configuration of the inkjet printer 1. FIG. 3 shows the configuration of the transport section of the inkjet printer 1. FIG. 4 shows the system configuration of the inkjet printer 1.

  As shown in FIG. 1, the ink jet printer 1 has a structure for discharging a medium such as printing paper supplied from the back surface from the front surface, and an operation panel 2 and a paper discharge portion 3 are provided on the front surface portion. The paper feeding unit 4 is provided on the back side. Various operation buttons 5 and display lamps 6 are provided on the operation panel 2. The paper discharge unit 3 is provided with a paper discharge tray 7 that closes the paper discharge port when not in use. The paper feed unit 4 is provided with a paper feed tray 8 for holding a medium such as cut paper.

  Inside the ink jet printer 1, a carriage 41 is provided as shown in FIG. The carriage 41 is provided to be relatively movable along the left-right direction. Around the carriage 41, a carriage motor 42, a pulley 44, a timing belt 45, and a guide rail 46 are provided. The carriage motor 42 is constituted by a DC motor or the like, and is a drive source for relatively moving the carriage 41 in the left-right direction (hereinafter also referred to as the carriage movement direction). The timing belt 45 is connected to the carriage motor 42 via the pulley 44, and a part of the timing belt 45 is connected to the carriage 41. The carriage 41 is moved relative to the carriage 41 in the carriage movement direction (left-right direction) by the rotation of the carriage motor 42. Move. The guide rail 46 guides the carriage 41 along the carriage movement direction (left-right direction).

  In addition, in the periphery of the carriage 41, a linear encoder 51 that detects the position of the carriage 41 and a direction in which the medium S intersects the moving direction of the carriage 41 (the front-rear direction in the figure, hereinafter also referred to as the transport direction). A transport roller 17A for transporting along the transport path 17 and a transport motor 15 for rotationally driving the transport roller 17A are provided.

  On the other hand, the carriage 41 is provided with an ink cartridge 48 that stores various inks, and a head 21 that performs printing on the medium S. The ink cartridge 48 contains, for example, each color ink such as yellow (Y), magenta (M), cyan (C), black (K), and is detachable from a cartridge mounting portion 49 provided on the carriage 41. It is attached to. In the present embodiment, the head 21 performs printing by ejecting ink onto the medium S. For this purpose, the head 21 is provided with a number of nozzles for ejecting ink.

  The head 21 corresponds to a “print head” that performs printing on the medium S. In the present embodiment, since the head 21 is provided on the carriage 41, the carriage 41 also corresponds to a “print head”. The guide rail 46 corresponds to a “guide portion” because it guides the carriage 41 (head 21) along a predetermined direction. The carriage motor 42 is a motor for moving the carriage 41 (head 21), and therefore corresponds to a “motor”.

  In addition to this, in the inkjet printer 1, printing is performed in order to prevent clogging of the nozzles of the head 21 and the pump device 31 that sucks out ink from the nozzles in order to eliminate clogging of the nozzles of the head 21. A capping device 35 that seals the nozzles of the head 21 when not in use (such as during standby) is provided.

  Next, the conveyance unit of the inkjet printer 1 will be described. As shown in FIG. 3, the transport unit includes a paper feed roller 13, a paper detection sensor 53, a transport roller 17A, a paper discharge roller 17B, a platen 14, and free rollers 18A and 18B. Yes.

  The medium S to be printed is set in the paper feed tray 8. The medium S set in the paper feed tray 8 is conveyed along the direction of arrow A in the drawing by the paper feed roller 13 having a substantially D-shaped cross section, and is sent into the ink jet printer 1. The medium S sent to the inside of the ink jet printer 1 comes into contact with the paper detection sensor 53. The paper detection sensor 53 is installed between the paper feed roller 13 and the transport roller 17A, and detects the medium S fed by the paper feed roller 13.

  The medium S detected by the paper detection sensor 53 is sequentially transported to the platen 14 on which printing is performed by the transport roller 17A. A free roller 18A is provided at a position facing the conveying roller 17A. The medium S is smoothly transported by sandwiching the medium S between the free roller 18A and the transport roller 17A.

  The medium S sent to the platen 14 is sequentially printed by the ink ejected from the head 21. The platen 14 is provided to face the head 21 and supports the medium S to be printed from below.

  The medium S on which printing has been performed is sequentially discharged out of the printer by the paper discharge roller 17B. The paper discharge roller 17B is driven in synchronism with the transport motor 15, and sandwiches the medium S with the free roller 18B provided facing the paper discharge roller 17B, and discharges the medium S to the outside of the printer. To do.

<System configuration>
Next, the system configuration of the inkjet printer 1 will be described. As shown in FIG. 4, the inkjet printer 1 includes a buffer memory 122, an image buffer 124, a controller 126, a main memory 127, a communication interface 129, a carriage motor control unit 128, a transport control unit 130, A head driving unit 132.

  The communication interface 129 is for the inkjet printer 1 to exchange data with an external computer 140 such as a personal computer. The communication interface 129 is communicably connected to the external computer 140 by wire or wireless, and receives various data such as print data transmitted from the computer 140.

  Various data such as print data received by the communication interface 129 are temporarily stored in the buffer memory 122. The image buffer 124 sequentially stores print data stored in the buffer memory 122. The print data stored in the image buffer 124 is sequentially sent to the head driving unit 132. The main memory 127 is composed of ROM, RAM, EEPROM, and the like. The main memory 127 stores various programs for controlling the inkjet printer 1 and various setting data.

  The controller 126 reads a control program, each setting data, and the like from the main memory 127, and controls the entire inkjet printer 1 according to the control program and various setting data. The controller 126 receives detection signals from various sensors such as the rotary encoder 134, the linear encoder 51, and the paper detection sensor 53.

  When various data such as print data sent from the external computer 140 is received by the communication interface 129 and stored in the buffer memory 122, the controller 126 stores necessary information from the stored data in the buffer memory. Read from 122. Based on the read information, the controller 126 refers to the output from the linear encoder 51 and the rotary encoder 134 and controls the carriage motor control unit 128, the conveyance control unit 130, the head drive unit 132, and the like according to the control program. Control each one.

  The carriage motor control unit 128 drives and controls the rotation direction, number of rotations, torque, and the like of the carriage motor 42 in accordance with a command from the controller 126. The conveyance control unit 130 controls the conveyance motor 15 that rotationally drives the conveyance roller 17 </ b> A according to a command from the controller 126.

  The head drive unit 132 drives and controls the nozzles of each color provided in the head 21 based on the print data stored in the image buffer 124 in accordance with a command from the controller 126.

  In this embodiment, the carriage motor control unit 128 controls the carriage motor 42 for moving the carriage 41 (head 21), and thus corresponds to a “motor control unit”.

<Head>
FIG. 5 is a diagram showing the arrangement of the ink nozzles provided on the lower surface of the head 21. On the lower surface of the head 21, as shown in the figure, nozzles comprising a plurality of nozzles # 1 to # 180 for each color of yellow (Y), magenta (M), cyan (C), and black (K). A cyan nozzle row 211C, a magenta nozzle row 211M, a yellow nozzle row 211Y, and a black nozzle row 211K are provided.

  The nozzles # 1 to # 180 of the nozzle rows 211C, 211M, 211Y, and 211K are arranged in a line in a straight line at intervals from each other along a predetermined direction (here, the transport direction of the medium S). ing. The nozzle rows 211C, 211M, 211Y, and 211K are arranged in parallel at predetermined intervals along the moving direction (scanning direction) of the head 21. Each nozzle # 1 to # 180 is provided with a piezo element (not shown) as a drive element for ejecting ink droplets.

=== Linear encoder ===
<Configuration of encoder>
FIG. 6 schematically shows the configuration of the linear encoder 51. The linear encoder 51 includes a linear encoder code plate 464 and a detection unit 466. As shown in FIG. 2, the linear encoder code plate 464 is attached to the frame side inside the inkjet printer 1. On the other hand, the detection unit 466 is attached to the carriage 41 side. When the carriage 41 moves along the guide rail 46, the detection unit 466 moves relatively along the linear encoder code plate 464. Accordingly, the detection unit 466 detects the movement amount of the carriage 41.

<Configuration of detection unit>
FIG. 7 schematically shows the configuration of the detection unit 466. The detection unit 466 includes a light emitting diode 452, a collimator lens 454, and a detection processing unit 456. The detection processing unit 456 includes a plurality of (for example, four) photodiodes 458, a signal processing circuit 460, and, for example, two comparators 462A and 462B.

  When the voltage Vcc is applied to both ends of the light emitting diode 452 via a resistor, light is emitted from the light emitting diode 452. This light is condensed into parallel light by the collimator lens 454 and passes through the linear encoder code plate 464. The linear encoder code plate 464 is provided with slits at predetermined intervals (for example, 1/180 inch (1 inch = 2.54 cm)).

  The parallel light that has passed through the linear encoder code plate 464 enters each photodiode 458 through a fixed slit (not shown) and is converted into an electrical signal. The electric signals output from the four photodiodes 458 are subjected to signal processing in the signal processing circuit 460, the signals output from the signal processing circuit 460 are compared in the comparators 462A and 462B, and the comparison result is output as a pulse. Pulses ENC-A and ENC-B output from the comparators 462A and 462B are output from the linear encoder 51.

<Output signal>
8A and 8B are timing charts showing waveforms of two output signals of the detection unit 466 when the carriage motor 42 is rotating forward and when the carriage motor 42 is rotating forward. As shown in FIGS. 8A and 8B, the phase of the pulse ENC-A and the pulse ENC-B are different from each other by 90 degrees in both cases of forward rotation and reverse rotation of the carriage motor 42. When the carriage motor 42 is rotating forward, that is, when the carriage 41 is moving along the guide rail 46, the pulse ENC-A is 90 degrees more than the pulse ENC-B, as shown in FIG. 8A. When the phase advances and the carriage motor 42 reverses, the phase of the pulse ENC-A is delayed by 90 degrees from the pulse ENC-B, as shown in FIG. 8B. One cycle T of the pulse ENC-A and the pulse ENC-B is equal to the time during which the carriage 41 moves through the slit interval of the linear encoder code plate 464.

  Then, rising edges of the output pulses ENC-A and ENC-B of the linear encoder 51 are detected, the number of detected edges is counted, and the rotational position of the carriage motor 42 is calculated based on the counted value. The This count is incremented by "+1" when one edge is detected when the carriage motor 42 is rotating forward, and is "-1" when one edge is detected when rotating reversely. Is added. The period of each of the pulses ENC-A and ENC-B is equal to the time from when one slit passes through the detection unit 466 until the next slit passes through the detection unit 466 of the linear encoder code plate 464, and The pulse ENC-A and the pulse ENC-B are different in phase by 90 degrees. For this reason, the count value “1” of the count corresponds to ¼ of the slit interval of the linear encoder code plate 464. Thus, if the count value is multiplied by ¼ of the slit interval, the amount of movement of the carriage motor 42 from the rotational position corresponding to the count value “0” can be obtained based on the multiplication value. At this time, the resolution of the linear encoder 51 is ¼ of the slit interval of the linear encoder code plate 464.

=== Carriage motor control unit ===
The configuration of the carriage motor control unit 128 will be described in detail. FIG. 9 is a block configuration diagram illustrating an example of a circuit configuration of the carriage motor control unit 128. As shown in the figure, the carriage motor control unit 128 includes a position calculation unit 331, a subtracter 332, a gain 333, a speed calculation unit 334, a subtractor 335, a proportional element 336A, an integration element 336B, A differential element 336C, an adder 337, a limiter 342, a PWM circuit 338, an acceleration control unit 339A, and a timer 339B are included.

The position calculation unit 331 detects the edge of the output pulse of the linear encoder 51, counts the number thereof, and calculates the rotational position of the carriage motor 42 based on the count value. The position calculation unit 331 recognizes normal rotation / reverse rotation of the carriage motor 42 from the comparison processing of the two pulse signals from the linear encoder 51, and increments according to normal rotation / reverse rotation when one edge is detected. Counting process to decrement.
The subtractor 332 calculates a position deviation between the target position sent from the controller 126 and the detected position detected by the position calculation unit 331. The gain 333 multiplies the position deviation output from the subtracter 332 by the gain Kp, and outputs the target speed Vt. The gain Kp is determined according to the position deviation.
The speed calculation unit 334 measures the pulse period of the output pulse of the linear encoder 51 and calculates the rotation speed Vc of the carriage motor 42 based on this pulse period. The speed calculation unit 334 corresponds to a “speed detection unit” that detects the moving speed of the head 21 (printing head).
The subtractor 335 calculates a speed deviation ΔV between the target speed Vt output from the gain 333 and the detected speed Vc detected by the speed calculator 334.

  The proportional element 336A multiplies the speed deviation ΔV by a constant Gp and outputs a proportional component QP. The integration element 336B integrates the speed deviation ΔV multiplied by the constant Gi to the previous calculation result QI (j−1), and outputs an integration component QI. The differential element 336C multiplies the difference between the current speed deviation ΔV (j) (where j is the time) and the previous speed deviation ΔV (j−1) by a constant Gd to obtain a differential component QD Is output. Here, the difference between the current speed deviation ΔV (j) (where j indicates the time) and the previous speed deviation ΔV (j−1) is the unit of the moving speed of the carriage per unit time. It corresponds to the amount of change. Therefore, the differential element 336C corresponds to an “arithmetic unit” that calculates the amount of change per unit time based on the carriage moving speed. The calculation of the proportional element 336A, the integral element 336B, and the differential element 336C is performed for each cycle of the output pulse of the linear encoder 51.

Here, the calculation outputs of the calculation elements 336A, 336B, and 336C, that is, the proportional component QP, the integral component QI, and the differential component QD can be given by the following equations (1) to (3), for example.
QP (j) = ΔV (j) × Gp (1)
QI (j) = QI (j−1) + ΔV (j) × Gi (2)
QD (j) = {ΔV (j) −ΔV (j−1)} × Gd (3)

  The limiter 342 is provided to prevent the operation output of the differentiation element 336C, that is, the differentiation component QD from being input to the adder 337 beyond a predetermined upper limit value. That is, when the differential component QD exceeds the predetermined upper limit value, the predetermined upper limit value is input to the adder 337 as the calculation output of the differential element 336C.

  The reason why the calculation output (differential component QD) of the differential element 336C is limited in this way is as follows. In other words, even if the movement speed of the carriage 41 greatly fluctuates due to some factor and the value of the calculation output of the differential element 336C increases, the carriage motor 42 is not greatly affected by the control. By limiting so that the differential component QD input to the adder 337 does not exceed a predetermined upper limit value, the carriage 41 can be moved in a stable state.

  The adder 337 adds the proportional component QP of the proportional element 336A, the integral component QI of the integral element 336B, and the differential component QD of the differential element 336C. The addition result ΣQ of these three components, that is, the proportional component QP, the integral component QI, and the differential component QD is output to the PWM circuit 338 as a duty signal.

When the calculation output of the differentiation element 336C is not limited by the limiter 342, the addition result ΣQ can be obtained by the following equation (4).
ΣQ (j) = QP (j) + QI (j) + QD (j) (4)

  The PWM circuit 338 generates a control signal corresponding to the addition result ΣQ of the adder 337. The driver 340 drives the carriage motor 42 based on this control signal. The driver 340 includes a plurality of transistors, for example, and applies a voltage to the carriage motor 42 by turning on and off the transistors based on a control signal from the PWM circuit 338.

  The acceleration control unit 339A and the timer 339B are used during acceleration control of the carriage motor 42. The timer 339B generates a timer interrupt signal every predetermined time based on the clock signal sent from the controller 126. The acceleration control unit 339A integrates a predetermined duty DXP every time a timer interrupt signal is received, generates a duty signal as an integration result, and outputs the duty signal to the PWM circuit 338.

  When the carriage motor 42 is driven to accelerate, the PWM circuit 338 generates a control signal based on the duty signal output from the acceleration control unit 339A to control the carriage motor 42. When the carriage motor 42 is driven at a constant speed and when the carriage motor 42 is decelerated, the PWM circuit 338 has three components, that is, a proportional component QP of the proportional element 336A, an integral component QI of the integral element 336B, and A control signal generated based on the duty signal output from the adder 337 as the addition result ΣQ of the differential component QD of the differential element 336C is output to the carriage motor 42 to control the carriage motor 42.

=== Driving method of carriage motor ===
FIG. 10A is a graph of the time change of the duty signal input to the PWM circuit 338. FIG. 10B is a graph of the speed change of the carriage motor 42. Hereinafter, the driving of the carriage motor 42 will be described with reference to these drawings.

  When a start command signal for starting the carriage motor 42 is sent from the controller 126 to the carriage motor control unit 128 while the carriage motor 42 is stopped, a start initial duty signal whose signal value is DX0 is sent from the acceleration control unit 339A to the PWM. Sent to circuit 338. This startup initial duty signal is sent from the controller 126 to the acceleration control unit 339A together with the startup command signal. The start initial duty signal is converted into a control signal corresponding to the signal value DX0 by the PWM circuit 338, and the start of the carriage motor 42 is started.

  After the carriage motor control unit 128 receives the start command signal, a timer interrupt signal is generated from the timer 339B every predetermined time. Every time the acceleration control unit 339A receives a timer interrupt signal, the acceleration control unit 339A accumulates a predetermined duty DXP on the signal value DX0 of the startup initial duty signal, and sends a duty signal having the accumulated duty as a signal value to the PWM circuit 338. . The duty signal is converted into a control signal corresponding to the signal value by the PWM circuit 338, and the rotation speed of the carriage motor 42 increases. For this reason, the value of the duty signal sent from the acceleration control unit 339A to the PWM circuit 338 increases stepwise.

  The duty integration process in the acceleration control unit 339A is performed until the integrated duty reaches a predetermined duty DXS. When the duty integrated at time t1 reaches a predetermined value DXS, the acceleration control unit 339A stops the integration process, and thereafter sends a duty signal having a constant duty DXS as a signal value to the PWM circuit 338.

  When the carriage motor 42 reaches a predetermined rotation speed (see time t2), the acceleration control unit 339A decreases the duty signal output to the PWM circuit 338 and decreases the duty percentage of the voltage applied to the carriage motor 42. To control. At this time, the rotational speed of the carriage motor 42 further increases. At time t3, the PWM circuit 338 selects the output of the adder 337, and PID control is performed. At the time (t3) when the PID control is started, the integral value of the integral element 336B is set to an appropriate value, and the output value of the integral element 336B becomes a predetermined value.

  When the PID control is started, the carriage motor control unit 128 calculates the target speed Vt by multiplying the position deviation between the target rotational position and the actual rotational position obtained from the output of the linear encoder 51 by the gain Kp. . Then, the carriage motor control unit 128 sets the proportional element 336A, the integral element 336B, and the differential element 336C based on the speed deviation ΔV between the target speed Vt and the actual rotational speed Vc obtained from the output of the linear encoder 51. The proportional component QP, the integral component QI, and the differential component QD are calculated using this, and the carriage motor 42 is controlled based on the sum ΣQ of these calculation results. The proportional calculation, integral calculation, and differential calculation are performed in synchronization with the rising edge of the output pulse ENC-A of the linear encoder 51, for example. Thereby, the rotation speed of the carriage motor 42 is controlled to be a desired rotation speed at time t4.

  When the carriage motor 42 approaches the target rotation position (time t5), the position deviation decreases, so the target rotation speed also decreases. Therefore, the speed deviation, that is, the output of the subtractor 335 becomes negative, the carriage motor 42 decelerates, and stops at time t6.

=== Printing operation ===
Next, the printing operation of the above-described ink jet printer 1 will be described. Here, “bidirectional printing” will be described as an example. FIG. 11 is a flowchart showing an example of the processing procedure of the printing operation of the inkjet printer 1. Each process described below is executed by the controller 126 reading a program from the main memory 127 and controlling the carriage motor control unit 128, the conveyance control unit 130, the head drive unit 132, and the like according to the program. The

  Upon receiving print data from the computer 140, the controller 126 first performs a paper feed process to execute printing based on the print data (S102). The paper feed process is a process of supplying the medium S to be printed into the ink jet printer 1 and transporting it to a print start position (also referred to as a cue position). The controller 126 rotates the paper feed roller 13 to send the medium S to be printed to the transport roller 17A. The controller 126 rotates the transport roller 17A to position the medium S sent from the paper feed roller 13 at the print start position (near the upper side of the platen 14).

  Next, the controller 126 drives the carriage motor 42 through the carriage motor control unit 128 and moves the carriage 41 relative to the medium S to execute a printing process for printing on the medium S. Here, first, forward printing is performed to eject ink from the head 21 while moving the carriage 41 in one direction along the guide rail 46 (S104). The controller 126 drives the carriage motor 42 to move the carriage 41 and drives the head 21 based on the print data to eject ink. The ink ejected from the head 21 reaches the medium S and is formed as dots.

  After printing in this way, the controller 126 next executes a transport process for transporting the medium S by a predetermined amount (S106). Here, the controller 126 drives the conveyance motor 15 through the conveyance control unit 130 to rotate the conveyance roller 17A, and conveys the medium S by a predetermined amount relative to the head 21 in the conveyance direction. By this carrying process, the head 21 can print in an area different from the previously printed area.

  After performing the carrying process in this manner, the controller 126 determines whether or not to discharge paper (S108). Here, if there is no other data to be printed on the medium S being printed, the controller 126 executes a paper discharge process (S116). On the other hand, if there is other data to be printed on the medium S being printed, the controller 126 performs the backward printing without performing the paper discharge process (S110). In this backward printing, printing is performed by moving the carriage 41 along the guide rail 46 in the direction opposite to the previous forward printing. Again, the controller 126 rotates the carriage motor 42 through the carriage motor control unit 128 to move the carriage 41 in the reverse direction, and also drives the head 21 based on the print data to eject ink and print. Apply.

  After performing the return pass printing, a carrying process is executed (S112), and then a paper discharge determination is made (S114). Here, if there is other data to be printed on the medium S being printed, the paper discharge process is not performed, the process returns to step S104, and the forward printing is executed again (S104). On the other hand, if there is no other data to be printed on the medium S being printed, a paper discharge process is executed (S116).

  After the paper discharge process is performed, next, a print end determination is performed to determine whether or not to end printing (S118). Here, based on the print data from the computer 140, it is checked whether there is a medium S to be printed next. If there is a medium S to be printed next, the process returns to step S102, the paper feed process is executed again, and printing is started. On the other hand, if there is no medium S to be printed next, the printing process is terminated.

=== Stick-slip operation ===
In such an ink jet printer 1, the carriage 41 (printing head) does not slide well along the guide rail 46 when it is not used for a long period of time, and the moving speed of the carriage 41 is periodically increased. There is a case where a so-called stick-slip operation (also referred to as a sucking operation) is performed in which the operation of moving or stopping the carriage 41 is repeated.

  In this stick-slip operation, the speed is periodically increased or decreased. In an extreme case, it becomes a jerky sliding motion in which the carriage 41 is repeatedly moved and stopped. This stick-slip operation is also called fixed slip. The main cause of such stick-slip operation is considered to be the difference between the coefficient of static friction and the coefficient of dynamic friction of the sliding portion between the carriage 41 and the guide rail 46 that guides it. That is, since the static friction coefficient of the sliding portion between the carriage 41 and the guide rail 46 is very large compared to the dynamic friction coefficient, the carriage 41 does not move easily even if the torque of the carriage motor 42 increases. When the torque of the carriage motor 42 reaches a certain level, the carriage 41 starts to move. When the carriage 41 starts to move, the moving friction coefficient rapidly decreases because the coefficient of dynamic friction is low. When the moving speed of the carriage 41 is rapidly increased in this way, the carriage motor control unit 128 applies rapid braking to the carriage motor 42 in order to suppress the moving speed of the carriage 41. For this reason, the carriage 41 is stalled.

  FIG. 12 shows an example of a change in the moving speed of the carriage 41 when the carriage 41 performs a stick-slip operation. As shown in the figure, the carriage 41 does not start to move unless the torque of the carriage motor 42 increases to some extent. The moving speed of the carriage 41 is detected by the speed calculation unit 334 (see FIG. 9). The carriage motor control unit 128 monitors the moving speed of the carriage 41 through the speed calculation unit 334. When the moving speed of the carriage 41 does not increase, the carriage motor control unit 128 performs control to increase the torque of the carriage motor 42 in order to move the carriage 41. As a result, when the torque of the carriage motor 42 increases to some extent, the carriage 41 starts to move, and the moving speed of the carriage 41 rapidly increases. When the moving speed of the carriage 41 increases and reaches a predetermined level, the carriage motor control unit 128 applies braking to the carriage motor 42 in order to suppress the moving speed of the carriage 41. As a result, the moving speed of the carriage 41 decreases, and the carriage 41 stalls and stops again. Then, the carriage motor control unit 128 performs control to increase the torque of the carriage motor 42 again in order to move the carriage 41. As a result, when the carriage 41 starts to move again and the moving speed rapidly increases, the carriage 41 stalls again and stops. Such a movement operation and a stop operation are alternately repeated.

=== When stick-slip motion occurs ===
The carriage 41 performs such a stick-slip operation when the carriage motor control unit 128 attempts to move the carriage 41 at a constant speed below a predetermined speed via the carriage motor 42. That is, when the carriage 41 moves at a constant speed exceeding a predetermined speed, that is, for example, when the carriage 41 moves at a very high speed during execution of printing, the stick-slip operation hardly occurs. Here, the predetermined speed refers to an upper limit speed at which the carriage 41 may perform a stick-slip operation.
Examples of cases where the carriage 41 moves at a constant speed below a predetermined speed at which a stick-slip operation is performed include the following cases (1) to (4).

(1) Ink cartridge replacement In this case, the ink cartridge 48 (see FIG. 2) mounted on the carriage 41 is replaced by a user or the like. When the ink cartridge 48 is replaced by a user or the like, it is necessary to move the carriage 41 to a predetermined position so that the ink cartridge 48 can be easily replaced by the user or the like. In this case, it is necessary to move the carriage 41 slowly at a low speed below a predetermined speed so that the user or the like does not carelessly come into contact with the carriage 41.

(2) During capping When the carriage 41 moves to a position where the capping device 35 (see FIG. 2) is provided. When printing is not performed (such as during standby), the carriage 41 moves to the installation position of the capping device 35 to prevent the nozzles # 1 to # 180 of the head 21 from being clogged. An operation of sealing 1 to # 180 is performed. In such a case, the carriage 41 is slowly moved at a low speed below a predetermined speed.

(3) When the power is turned on When the power is turned on, the carriage 41 moves away from the capping device 35 to prepare for execution of the printing process, for example, to clean the nozzles # 1 to # 180 of the head 21, etc. Start operation. In such a case, the carriage 41 is slowly moved at a low speed below a predetermined speed.

(4) During paper width detection The carriage 41 moves along the guide rail 46 in order for the ink jet printer 1 to detect the width of the medium S to be printed by an optical sensor (not shown) provided on the carriage 41. . At this time, in order to accurately check the width of the medium S, the carriage 41 slowly moves at a low speed below a predetermined speed.

  In the case where the carriage 41 moves at a constant speed below a predetermined speed at which a stick-slip operation is performed, other cases than those described in (1) to (4) may be used.

=== Judgment method of stick-slip motion ===
When the carriage 41 performs such a stick-slip operation, the carriage 41 cannot be stopped at the target position, and problems such as moving the carriage 41 around the target position may occur. there were. In addition, when such a stick-slip operation occurs, there may be a problem that the user is anxious about the failure. For this reason, when the carriage 41 performs a stick-slip operation, it is necessary to quickly detect and respond to this.

  Therefore, in the inkjet printer 1 according to the present embodiment, whether or not the carriage 41 has performed the stick-slip operation in order to be able to respond smoothly when the carriage 41 performs such a stick-slip operation. Can be determined. Here, the controller 126 determines whether or not the carriage 41 has performed a stick-slip operation. As a determination method of the stick-slip operation, for example, there are the following methods (1) to (4).

(1) Determination Based on Moving Speed Based on the moving speed of the carriage 41, it is determined whether the carriage 41 has performed a stick-stick operation. As one of the determination methods, there is a method of determining that the carriage 41 is performing a stick-slip operation when the moving speed of the carriage 41 exceeds a predetermined threshold value V0. When the carriage 41 performs a stick-slip operation, as described in FIG. 13A, the moving speed of the carriage 41 increases rapidly when the carriage 41 starts to move. At this time, the moving speed of the carriage 41 reaches a speed much faster than the original moving speed of the carriage 41. From this, an appropriate predetermined threshold value V0 is set, and whether or not the carriage 41 has performed a stick-slip operation by checking whether or not the moving speed of the carriage 41 exceeds the predetermined threshold value V0. You can easily check whether or not.

  In addition to this, as a method for determining whether or not the carriage 41 has performed the stick-slip operation based on the moving speed of the carriage 41, as described in FIG. 13B, the moving speed of the carriage 41 is a predetermined upper limit allowable value. There is a method of determining that the carriage 41 is performing a stick-slip operation when V1 is exceeded and then falls below a predetermined lower limit allowable value V2. When the carriage 41 performs a stick-slip operation, as shown in the figure, the moving speed of the carriage 41 increases rapidly when the carriage 41 starts to move, and then decreases rapidly. Eventually, the carriage 41 may stall and become close to a stopped state. The moving speed of the carriage 41 reaches a speed much faster than the originally assumed upper limit allowable value V1 of the carriage 41, and then rapidly decreases to the lower limit allowable value of the expected moving speed of the carriage 41. A speed lower than V2 (including the stop state) is reached. From this, it can be easily determined whether or not the carriage 41 has performed a stick-slip operation.

  Here, in determining whether or not the carriage 41 has performed the stick-slip operation, the number of times that the moving speed of the carriage 41 has exceeded a predetermined threshold value V0 is counted, and the number of times is the predetermined number of times. When (for example, twice) is exceeded, it may be determined that the carriage 41 is performing a stick-slip operation. Further, the number of times that the moving speed of the carriage 41 exceeds the predetermined upper limit allowable value V1 and then falls below the predetermined lower limit allowable value V2 is counted, and the number of times exceeds a predetermined number (for example, twice). It may be determined that the carriage 41 is performing a stick-slip operation.

(2) Determination Based on Control Signal Based on the control signal generated for the carriage motor control unit 128 to control the carriage motor 42, it is determined whether or not the carriage 41 has performed a stick-slip operation. Here, the control signal is determined based on, for example, a duty signal input to the PWM circuit 338 (see FIG. 9) of the carriage motor control unit 128.

  FIG. 14A illustrates the relationship between the movement speed of the carriage 41 when the carriage 41 performs a stick-slip operation and the signal value of the duty signal input to the PWM circuit 338. When the carriage 41 performs a stick-slip operation, the moving speed of the carriage 41 increases rapidly and then decreases rapidly as shown in the upper part of FIG. The carriage 41 repeats such a movement operation and a stop operation alternately.

  On the other hand, the signal value of the duty signal input to the PWM circuit 338 of the carriage motor control unit 128 gradually increases until the carriage 41 starts to move, as shown in the lower part of FIG. Then, when the carriage 41 starts moving and the moving speed of the carriage 41 rapidly increases, the carriage motor control unit 128 rapidly decreases the driving force of the carriage motor 42 in order to suppress the moving speed of the carriage 41. . As a result, the signal value of the due signal input to the PWM circuit 338 decreases rapidly. Thereafter, when the carriage 41 stops, the carriage motor control unit 128 gradually increases the signal value of the duty signal input to the PWM circuit 338 so as to increase the moving speed of the carriage 41 and start the movement. When the signal value of the due signal reaches a predetermined level, the carriage 41 starts to move. When the movement of the carriage 41 starts, the carriage motor control unit 128 rapidly reduces the driving force of the carriage motor 42 in order to suppress the moving speed of the carriage 41 again. As a result, the signal value of the due signal input to the PWM circuit 338 rapidly decreases again. The signal value of the due signal input to the PWM circuit 338 is repeatedly increased and decreased according to the moving speed of the carriage 41 in this way.

  In practice, as a method for determining whether or not the carriage 41 has performed the stick-slip operation, here, the maximum value Vmax and the minimum value Vmin of the signal value of the duty signal input to the PWM circuit 338 are examined, and the maximum value is obtained. Based on the difference ΔV between Vmax and the minimum value Vmin, it is determined whether or not the carriage 41 has performed a stick-slip operation. That is, it is checked whether or not the difference ΔV between the maximum value Vmax and the minimum value Vmin of the signal value of the due signal exceeds a predetermined threshold value V0, and when the difference ΔV exceeds the predetermined threshold value V0. Then, it is determined that the carriage 41 is performing a stick-slip operation. On the other hand, if the difference ΔV between the maximum value Vmax and the minimum value Vmin of the signal value of the due signal does not exceed the predetermined threshold value V0, it is determined that the carriage 41 has not performed the stick-slip operation.

  FIG. 14B explains in detail an example of the determination method. First, the maximum value Vmax and the minimum value Vmin of the signal value of the due signal are acquired. A difference ΔV is obtained from the acquired maximum value Vmax and minimum value Vmin. When the carriage 41 performs a stick-slip operation, as shown in the figure, the difference ΔV is large between the maximum value Vmax and the minimum value Vmin of the signal value of the duty signal. By comparing this difference ΔV with a predetermined threshold value V0, it can be easily determined whether or not the carriage 41 has performed a stick-slip operation.

  Here, in determining whether or not the carriage 41 has performed the stick-slip operation, the difference ΔV between the maximum value Vmax and the minimum value Vmin of the signal value of the duty signal input to the PWM circuit 338 is a predetermined value. When the threshold value V0 is exceeded a predetermined number of times (for example, twice or more), it may be determined that the carriage 41 is performing a stick-slip operation.

  Further, as a method for determining whether or not the carriage 41 has performed the stick-slip operation based on the control signal, other than the determination based on the difference ΔV between the maximum value Vmax and the minimum value Vmin of the signal value of the due signal, there are other methods. It may be determined by a method.

(3) Determination Based on Acceleration Here, it is determined based on the acceleration of the carriage 41 whether or not the carriage 41 has performed a stick-slip operation. Here, the acceleration is acquired by the speed calculation unit 334 (see FIG. 9) of the carriage motor control unit 128. That is, the speed calculation unit 334 periodically outputs the moving speed of the carriage 41 detected based on the output from the linear encoder 51 at predetermined time intervals. The controller 126 acquires the acceleration of the carriage 41 from the difference in the moving speed of the carriage 41 periodically sent from the speed calculation unit 334, and determines whether or not the carriage 41 has performed a stick-slip operation based on this difference. To do.

  FIG. 15 illustrates an example of a method for determining whether or not a stick-slip operation has been performed based on the acceleration of the carriage 41. When the carriage 41 performs a stick-slip operation, the moving speed of the carriage 41 increases rapidly and then decreases rapidly as shown in FIG. Since the acceleration of the carriage 41 becomes very large in this way, it is possible to determine whether or not the carriage 41 has performed a stick-slip operation by paying attention to this acceleration.

  The controller 126 periodically acquires the movement speeds V1 to V6 of the carriage 41 from the speed calculation unit 334 of the carriage motor control unit 128 at a predetermined time interval T0. Then, the controller 126 sequentially calculates the difference as an acceleration from the acquired movement speeds V1 to V6 of the carriage 41. That is, the controller 126 calculates the difference ΔV21 from the moving speed V1 and the moving speed V2 by “V2−V1”, and the difference ΔV32 from the moving speed V2 and the moving speed V3 by “V3−V2”, and the moving speed V3. The difference ΔV43 from the moving speed V4 by “V4−V3”, the difference ΔV54 by “V5−V4” from the moving speed V4 and the moving speed V5, and the difference by “V6−V5” from the moving speed V5 and the moving speed V6. ΔV65 is calculated respectively.

  The controller 126 compares the obtained differences ΔV21, ΔV32, ΔV43, ΔV54, and ΔV65 with a predetermined threshold value V0, and the differences ΔV21, ΔV32, ΔV43, ΔV54, and ΔV65 exceed the predetermined threshold value V0. Check whether or not. When the differences ΔV21, ΔV32, ΔV43, ΔV54, and ΔV65 exceed a predetermined threshold value V0, the controller 126 determines that the carriage 41 is performing a stick-slip operation. On the other hand, when the differences ΔV21, ΔV32, ΔV43, ΔV54, and ΔV65 do not exceed the predetermined threshold value V0, the controller 126 determines that the carriage 41 is not performing the stick-slip operation. Here, it is determined whether or not the carriage 41 has performed a stick-slip operation while paying attention to the acceleration of the carriage 41, but in addition to this, when the carriage 41 is decelerated, that is, minus (−) acceleration (decrease). It may be determined whether or not the carriage 41 has performed a stick-slip operation by paying attention to (speed).

  In determining whether or not the carriage 41 has performed a stick-slip operation, the number of times that the obtained difference exceeds a predetermined threshold value V0 occurs a predetermined number of times or more (for example, two times or more). It may be determined that the carriage 41 is performing a stick-slip operation.

(4) Determination Based on Time Less Than Predetermined Allowable Speed Here, a timer that measures the time during which the movement speed of the carriage 41 becomes less than a predetermined allowable lower limit between the start of movement of the carriage 41 and the end of movement Based on the measurement time, it is determined whether or not the carriage 41 has performed a stick-slip operation.

  FIG. 16A illustrates the timer 60 provided in the carriage motor control unit 128. As shown in the figure, the timer 60 receives an output signal output from the linear encoder 51 to the speed calculation unit 334 or the position calculation unit 331. The timer 60 monitors the output signal of the linear encoder 51, and starts time measurement when the moving speed of the carriage 41 falls below a predetermined allowable lower limit value. Here, the timer 60 starts time measurement when the cycle of the pulse of the output signal from the linear encoder 51 becomes longer than a predetermined cycle. When the moving speed of the carriage 41 is not less than the predetermined allowable lower limit value, the timer 60 stops time measurement. Thereby, the timer 60 measures the time when the moving speed of the carriage 41 becomes equal to or less than a predetermined allowable lower limit value. Information regarding the measurement time of the timer 60 is transmitted to the controller 126. The controller 126 determines whether or not the carriage 41 has performed the stick-slip operation based on the information regarding the measurement time acquired from the timer 60.

  FIG. 16B illustrates an example of a method for determining whether or not the carriage 41 has performed a stick-slip operation. When the carriage 41 performs a stick-slip operation, as shown in the figure, the moving speed of the carriage 41 increases rapidly and decreases rapidly. The carriage 41 starts to move again after a while. The carriage 41 repeats such a movement operation and a stop operation alternately between the start of movement and the end of movement.

  On the other hand, when the carriage 41 does not perform the stick-slip operation, normally, such a moving operation and a stopping operation are not repeated alternately. That is, the carriage 41 does not move below the predetermined allowable lower limit for a predetermined time or more after the movement is started until the movement is completed. From this, after the carriage 41 starts moving, it is checked whether or not the carriage 41 has performed a stick-slip operation by measuring a time T when the moving speed of the carriage 41 has fallen below a predetermined allowable lower limit value VL. Can do. Here, the predetermined allowable lower limit value VL is set to a sufficiently low speed that cannot be assumed as the moving speed of the carriage 41 when the carriage 41 moves without performing the stick-slip operation. This predetermined allowable lower limit value VL may be set to a value close to “0 (zero)” in order to measure time when the carriage 41 stops, for example.

  The timer 60 monitors the output signal of the linear encoder 51, and when the pulse period of the output signal from the linear encoder 51 becomes longer than a predetermined period, the moving speed of the carriage 41 is below a predetermined allowable lower limit value VL. It is determined that there is, and time measurement is started. The time measurement by the timer 60 is performed until it is determined that the moving speed of the carriage 41 has exceeded a predetermined allowable lower limit value VL. Thereby, the timer 60 measures the time T when the moving speed of the carriage 41 falls below the predetermined allowable lower limit value VL. The measurement result of the timer 60 is transmitted from the timer 60 to the controller 126. Here, the measurement time T of the timer 60 may be transmitted from the timer 60 to the controller 126 in real time, or after the time measurement by the timer 60 is completed, the measurement time T of the timer 60 may be transmitted. .

  The controller 126 compares the measurement time T transmitted from the timer 60 with a predetermined threshold value T0, and if the measurement time T has reached the predetermined threshold value T0, the carriage 41 performs stick-slip. It is determined that the operation is being performed. On the other hand, if the measurement time T of the timer 60 has not reached the predetermined threshold value T0, the controller 126 determines that the carriage 41 is not performing a stick-slip operation.

  Here, in determining whether or not the carriage 41 has performed a stick-slip operation, the number of times that the measurement time T has reached a predetermined threshold value T0 is counted, and the number of times is equal to or greater than a predetermined number (for example, If it occurs, it may be determined that the carriage 41 is performing a stick-slip operation.

  Further, as a method for determining whether or not the carriage 41 has performed a stick-slip operation, a method other than these methods (1) to (4) may be used.

=== Corresponding to stick-slip operation ===
In the inkjet printer 1 according to the present embodiment, when it is determined that the carriage 41 is performing the stick-slip operation in this way, the following countermeasures are taken to suppress the stick-slip operation of the carriage 41. Execute.

  Here, when it is determined that the carriage 41 is performing the stick-slip operation, the calculation result output from the differential element 336C of the carriage motor control unit 128, that is, the differential component QD exceeds the predetermined upper limit value is added. The limiting function of the limiter 342 provided so as not to be input to the device 337 is turned off. That is, even when a differential component QD of a predetermined upper limit value or more is output as a calculation result from the differential element 336C of the carriage motor control unit 128, this is input to the adder 337 without any limitation. To be. In the present embodiment, when it is determined that the carriage 41 is performing a stick-slip operation, the controller 126 executes a process for turning off the limiting function of the limiter 342.

  FIG. 17 illustrates the moving speed of the carriage 41 and the output of the limiter 342 when the carriage 41 performs a stick-slip operation when the limiter 342 restriction function is on.

  When the carriage 41 performs the stick-slip operation, the moving speed of the carriage 41 rises sharply after reaching a peak after a stop state for a while, as shown in the upper part of FIG. , Falls rapidly. The carriage 41 stops moving for a while and then starts moving again. The carriage 41 repeats such a movement operation and a stop operation alternately.

  On the other hand, the differential component QD, which is the calculation result of the differential element 336C of the carriage motor control unit 128, is the plus (+) side when the carriage 41 is accelerated and decelerated, respectively, as shown by the broken line in the lower part of FIG. It changes greatly on the minus (-) side. However, the limiter 342 limits the differential component QD. For this reason, the differential component QD input to the adder 337 is limited so that the amount of change does not exceed a predetermined upper limit value, as indicated by the solid line in the lower part of FIG. In other words, when the output of the limiter fluctuates to the minus (−) side during acceleration of the carriage 41, it is limited so as not to fall below the predetermined lower limit value L2. Further, when the output of the limiter fluctuates to the plus (+) side when the carriage 41 is decelerated, it is restricted so as not to exceed a predetermined upper limit value L1.

  On the other hand, when the limiting function of the limiter 342 is turned off, the limiter 342 does not limit the function. For this reason, even when an output that exceeds the predetermined upper limit value L1 or an output that is lower than the predetermined lower limit value L2 is output as the differential component QD as the calculation result of the differential element 336C, Entered. In other words, when the carriage 41 performs a stick-slip operation and the moving speed of the carriage 41 changes as shown in the upper part of FIG. 17, the differential component QD becomes the limiter 342 as shown by the broken line in the lower part of the figure. Is input to the adder 337 without restriction.

  From this, when the carriage 41 performs the stick-slip operation, the differential component QD corresponding to the operation can be input to the adder 337. That is, when the moving speed of the carriage 41 increases rapidly, a large minus (−) output is obtained as the differential component QD as the calculation result of the differential element 336C in order to suppress a rapid increase in the moving speed of the carriage 41. Is input to the adder 337. Thereby, the movement speed of the carriage 41 can be stabilized. In addition, when the moving speed of the carriage 41 rapidly decreases, a large plus (+) output is obtained as a differential component QD as a calculation result of the differential element 336C in order to suppress a rapid decrease in the moving speed of the carriage 41. Is input to the adder 337. Thereby, the movement speed of the carriage 41 can be stabilized. In this way, the stick-slip operation of the carriage 41 can be suppressed.

  FIG. 18 shows an example of a change in the moving speed of the carriage 41 when the limit function of the limiter 342 is turned off when the carriage 41 performs a stick-slip operation. Here, the moving speed of the carriage 41 increases rapidly after being stopped for a while, and then reaches a peak and then decreases rapidly. Then, the controller 41 performs a stick-slip operation by the controller 126. It is determined that As described above, when the controller 126 determines that the carriage 41 is performing the stick-slip operation, the limiting function of the limiter 342 is turned off. When the limiting function of the limiter 342 is turned off, a sudden change in the moving speed of the carriage 41 can be suppressed when the moving speed of the carriage 41 rapidly increases or decreases rapidly. That is, when the moving speed of the carriage 41 increases rapidly, a large minus (−) output is input as the differential component QD to the adder 337 as the calculation result of the differential element 336C. The speed can be quickly suppressed. On the other hand, when the moving speed of the carriage 41 rapidly decreases, a large plus (+) output is input to the adder 337 as the differential component QD as the calculation result of the differential element 336C. The speed can be increased quickly. For this reason, the moving speed of the carriage 41 can be maintained in a stable state as shown in FIG.

  FIG. 19 is a flowchart illustrating an example of the handling process of the controller 126. When the carriage motor control unit 128 attempts to move the carriage 41 at a constant speed below a predetermined speed, the controller 126 first checks whether or not it is determined that the carriage 41 is performing a stick-slip operation. (S202). If it is not determined that the carriage 41 is performing the stick-slip operation, the controller 126 proceeds to step S204 and checks whether the movement of the carriage 41 is completed (S204). .

  If the movement of the carriage 41 is not completed, the controller 126 returns to step S202, and checks again whether or not it is determined that the carriage 41 is performing a stick-slip operation (S202). The controller 126 checks whether or not it is determined that the carriage 41 is performing the stick-slip operation until the movement of the carriage 41 is completed. When the movement of the carriage 41 is finished, the controller 126 finishes the processing promptly.

  On the other hand, if it is determined in step S202 that the carriage 41 is performing a stick-slip operation, the controller 126 then proceeds to step S206 and turns off the limiter limiting function (S206). Thereafter, the controller 126 ends the processing promptly.

<Response after speed stabilization>
When it is determined that the carriage 41 is performing the stick-slip operation in this manner, the movement speed Vc of the carriage 41 is stabilized after the limit function of the limiter 342 of the carriage motor control unit 128 is turned off to cope with it. Alternatively, the limiting function of the limiter 342 may be turned on again. That is, when the moving speed Vc of the carriage 41 is stabilized, it is determined that the possibility that the carriage 41 performs the stick-slip operation is reduced, and the original control before it is determined that the carriage 41 is performing the stick-slip operation. Return to method.

  As a method for determining whether or not the moving speed Vc of the carriage 41 is stable, there are the following methods. FIG. 20 illustrates an example of a method for determining whether or not the moving speed Vc of the carriage 41 is stable. In this case, when the movement speed Vc of the carriage 41 reaches a predetermined time within a predetermined allowable range, that is, a predetermined allowable upper limit value Vk1 or lower and a predetermined allowable lower limit value Vk2 or higher, the limiter 342 has a limiting function. Turn it on again. The controller 126 turns on the limiter 342 again.

  The controller 126 sequentially acquires information regarding the moving speed Vc of the carriage 41 from the speed calculation unit 334 of the carriage motor control unit 128. When the moving speed Vc of the carriage 41 is within a predetermined allowable range, that is, when Vk1 ≦ Vc ≦ Vk2, the controller 126 starts measuring time. Then, the controller 126 measures an elapsed time T after the moving speed of the carriage 41 enters a predetermined allowable range. When the elapsed time T reaches the predetermined time T0, the controller 126 determines that the moving speed Vc of the carriage 41 is sufficiently stable, and turns on the limiting function of the limiter 342 again. On the other hand, if the moving speed Vc of the carriage 41 deviates from a predetermined allowable range (Vk1 ≦ Vc ≦ Vk2) again before the elapsed time T reaches the predetermined time T0, the controller 126 moves the moving speed Vc of the carriage 41. Is not yet stable enough, the time measurement is terminated. When the moving speed Vc of the carriage 41 again falls within a predetermined allowable range (Vk1 ≦ Vc ≦ Vk2), the controller 126 starts time measurement again.

  Thus, when the moving speed Vc of the carriage 41 is stabilized, the carriage 41 can be moved in a stable state again by turning on the limiting function of the limiter 342 again.

=== Summary ===
As described above, in the inkjet printer 1 of the present embodiment, when it is determined that the carriage 41 is performing the stick-slip operation, the differential component QD output from the differential element 336C of the carriage motor control unit 128 is a predetermined value. The limiting function of the limiter 342 for preventing the input from exceeding the upper limit value to the adder 337 is turned off. Thereby, it is possible to suppress the carriage 41 from performing a stick-slip operation. Therefore, even if the carriage 41 performs a stick-slip operation, this can be handled smoothly.

  In addition, after the limit function of the limiter 342 of the carriage motor control unit 128 is turned off in this way, and the moving speed Vc of the carriage 41 is within a predetermined allowable range for a predetermined time or more, the carriage 41 It is determined that the moving speed Vc is sufficiently stable, and the limit function of the limiter 342 is turned on again. Thus, when the carriage 41 is moved at a constant speed below a predetermined speed, the carriage 41 can be moved again in a stable state.

=== Other installation examples of limiters ===
FIG. 21 illustrates an example in which the limiter 344 is arranged at another position. Here, the limiter 344 is installed on the input side of the differential element 336C. The limiter 344 limits the rotational speed Vc (moving speed of the carriage 41) output from the speed calculation unit 334 so that it does not exceed a predetermined upper limit value. The output from the limiter 344 is input to the subtracter 346. The subtracter 346 is for calculating the speed deviation ΔV input to the differentiation element 336C. The subtracter 346 subtracts the output from the limiter 344, that is, the detected speed Vc detected by the speed calculator 334, from the target speed Vt output from the gain 333, thereby calculating the speed deviation ΔV. The speed deviation ΔV calculated in this way is input to the differential element 336C. The speed deviation ΔV input to the proportional element and the integral element is calculated by another subtractor, and the rotation speed Vc (the moving speed of the carriage 41) output from the speed calculation unit 334 is not limited by the limiter 344. .

  In this way, even when the limiter 344 is installed on the input side of the differential element 336C, even if the movement speed of the carriage 41 greatly fluctuates due to some factor and the value of the calculation output of the differential element 336C increases, It is possible to prevent the carriage motor 42 from being greatly affected by the control. Therefore, when it is determined that the carriage 41 is performing the stick-slip operation, the stick-slip operation of the carriage 41 can be suppressed by turning off the limiting function of the limiter 344.

=== Configuration Example of Other Carriage Motor Control Unit ===
FIG. 22 illustrates another configuration example of the carriage motor control unit 350. As shown in FIG. 22, the carriage motor control unit 350 includes a normal speed control unit 352, a low speed control unit 354, a control selection unit 356, and a PWM circuit 338. Here, the normal speed control unit 352 is a control unit for moving the carriage 41 at a normal speed. The low speed control unit 354 is a control unit for moving the carriage 41 at a low speed below a predetermined speed as described above. The normal speed control unit 352 and the low speed control unit 354 will be described in detail later.

  The control selection unit 356 selects one of the normal speed control unit 352 and the low speed control unit 354 according to a command from the controller 126. Then, an output from one of the two control units selected by the control selection unit 356, that is, the normal speed control unit 352 and the low speed control unit 354 is input to the PWM circuit 338. The PWM circuit 338 generates a control signal for controlling the carriage motor 42 based on the output from the normal speed control unit 352 or the low speed control unit 354.

《Normal speed control unit》
Here, the normal speed control unit 352 is configured by a control unit that controls the carriage motor 42 by PID control, for example, as described in FIG. Specifically, for example, as described with reference to FIG. 9, the position calculation unit 331 that calculates the rotational position of the carriage motor 42 based on the output pulse of the linear encoder 51, and the target position sent from the controller 126. A subtractor 332 that calculates a position deviation from the detected position detected by the position calculation unit 331, a gain 333 that multiplies the position deviation output from the subtracter 332 by a gain Kp, and outputs a target speed Vt, A speed calculator 334 that calculates the rotational speed Vc of the carriage motor 42 based on the output pulse of the linear encoder 51, a target speed Vt output from the gain 333, and a detected speed Vc detected by the speed calculator 334 A subtractor 335 for calculating the deviation ΔV, and a proportional element 33 for multiplying the speed deviation ΔV by a constant Gp and outputting a proportional component QP. 6A and the speed deviation multiplied by a constant Gi are integrated, and an integration element 336B that outputs an integral component QI, the current speed deviation ΔV (j) (where j indicates time), and the previous one Is multiplied by a constant Gd, and a differential element 336C that outputs a differential component QD, and the operation outputs QP, QI, and QD of these operation elements 336A, 336B, and 336C are added. And an adder 337. Then, the addition result of the adder 337 is output from the normal speed control unit 352 and input to the PWM circuit 338 as shown in FIG.

  In the normal speed control unit 352, in order to control the acceleration of the carriage motor 42, a timer allocation is performed at predetermined intervals based on the clock signal sent from the controller 126 as described in FIG. A timer 339B that generates an interrupt signal and an acceleration control unit 339A that integrates a predetermined duty DXP every time a timer interrupt signal is received and generates and outputs a duty signal as the integration result may be provided. If the timer 339B and the acceleration control unit 339A are provided, the carriage motor 42 can be smoothly controlled for acceleration.

  On the other hand, the low speed control unit 354 is a control unit for moving the carriage 41 at a low speed. For example, the low speed control unit 354 is used when the carriage 41 as described above is moved at a constant speed below a predetermined speed. Hereinafter, a specific configuration example of the low speed control unit 354 will be described.

《Low speed control unit》
FIG. 23 illustrates an example of the low speed control unit 354. As shown in the figure, the low speed control unit 354 includes a hold control unit 360, a timer interrupt control unit 362, an encoder interrupt control unit 364, a period counter 366, a position counter 368, and a control selection unit 370. A timer counter 372, a first selection unit 374, a differential speed control unit 376, and a second selection unit 378.

  The hold control unit 360 is a control unit for controlling the carriage motor 42 when the carriage 41 reaches the target position. The timer interrupt control unit 362 is a control unit for controlling the carriage motor 42 when the carriage 41 is stopped or when the carriage 41 is moving very slowly. The encoder interrupt control unit 364 is a control unit for controlling the carriage motor 42 when the carriage 41 is moving at a certain speed.

  The position counter 368 counts the output pulses of the linear encoder 51 and outputs the counting result as pulses. The period counter 366 detects the period from the output pulse of the linear encoder 51 and outputs the detected period.

  Based on the output from the position counter 368, the control selection unit 370 selects an appropriate control unit from among the hold control unit 360, the timer interrupt control unit 362, and the encoder interrupt control unit 364. That is, when the carriage 41 is at the target position, the control selection unit 370 selects the hold control unit 360.

  On the other hand, when the carriage 41 has not yet reached the target position, the control selection unit 370 selects one of the timer interrupt control unit 362 and the encoder interrupt control unit 364. Here, the control selection unit 370 includes a timer counter 372, and determines whether to select the timer interrupt control unit 362 or the encoder interrupt control unit 364 based on the count value of the timer counter 372.

  The timer counter 372 starts counting when a set value is given, and counts until the count value reaches the set value. The timer counter 372 resets the count value when a pulse is output from the position counter. Then, the timer counter 372 starts counting again after being reset.

  When the count value of the timer counter 372 has reached a predetermined value, the control selection unit 370 determines that the carriage 41 has stopped or moved fairly slowly, and the timer selection as a control unit is performed. Select the control unit 362. On the other hand, when the count value of the timer counter 372 does not reach the predetermined value, it is determined that the carriage 41 is moving at a certain speed, and the encoder interrupt control unit 364 is selected as the control unit. In this way, the control selection unit 370 selects an appropriate control unit from among the hold control unit 360, the timer interrupt control unit 362, and the encoder interrupt control unit 364.

  The hold control unit 360 is a control value for controlling the carriage motor 42 so that the carriage 41 is held near the target position based on the output of the position counter 368 when selected by the control selection unit 370. RH is determined and output to the second selection unit 378.

  The timer interrupt control unit 362 controls the carriage motor 42 so that the carriage 41 starts moving at a predetermined speed based on the output of the position counter 368 when selected by the control selection unit 370. The control value RT is determined and output to the first selection unit 374.

  The encoder interrupt control unit 364 causes the carriage 41 to move at a predetermined speed based on the output from the position counter 368 and the output from the cycle counter 366 when selected by the control selection unit 370. A control value RE for controlling the carriage motor 42 is determined and output to the first selection unit 374.

  When the timer interrupt control unit 362 is selected by the control selection unit 370, the first selection unit 374 selects the output from the timer interrupt control unit 362, that is, the control value RT and outputs it to the differential speed control unit 376. To do. On the other hand, when the encoder interrupt control unit 364 is selected by the control selection unit 370, the first selection unit 374 selects the output from the encoder interrupt control unit 364, that is, the control value RE, and sends it to the differential speed control unit 376. Output.

  The differential speed control unit 376 obtains a speed deviation between the current moving speed of the carriage 41 and the target speed based on the output from the cycle counter 366, and this speed deviation and the previous interrupt, that is, one. A value corresponding to the difference from the speed deviation calculated during the previous operation is calculated as the control value RD. Then, the differential speed control unit 376 adds the control value RD to the control value RT of the timer interrupt control unit 362 or the control value RE of the encoder interrupt control unit 364 output from the first selection unit 374. Then, differential speed control section 376 outputs the added result value, that is, “RT + RD” or “RE + RD” to second selection section 378.

  When the hold control unit 360 is selected by the control selection unit 370, the second selection unit 378 selects the output of the hold control unit 360, that is, the control value RH, and outputs it to the PWM circuit 338. On the other hand, when the hold control unit 360 is not selected by the control selection unit 370, that is, when the timer interrupt control unit 362 or the encoder interrupt control unit 364 is selected by the control selection unit 370, the second selection unit 378. Selects the output from the differential speed control unit 376, that is, the control value “RT + RD” or the control value “RE + RD”, and outputs it to the PWM circuit 338. Control values “RH”, “RT + RD”, and “RE + RD” calculated through the control units 360, 362, 364, and 376 selected by the control selection unit 370 in this way are input to the PWM circuit 338, respectively.

《Limiter position》
In such a carriage motor control unit 350, the limiter 342 is installed in the low speed control unit 354 (see FIG. 22). The limiter 342 can be provided in a path through which the output from the period counter 366 is input to the differential speed control unit 376 in the low speed control unit 354, for example. That is, the limiter 342 can be provided at the position of the point “A” shown in FIG. Thus, if the limiter 342 is provided at the point “A”, it is possible to limit the output of the period counter 366 input to the differential speed control unit 376 so as not to exceed a predetermined upper limit value. Further, the limiter 342 can be provided, for example, in a path through which the output of the differential speed control unit 376 is input to the second selection unit. That is, the limiter 342 can be provided at the position of the point “B” shown in FIG. Thus, if the limiter 342 is provided at the position of the point “B”, it is possible to limit the output from the differential speed control unit 376 so as not to exceed a predetermined upper limit value.

  If the limiter 342 is installed at the point “A” or “B” in this way, even if the movement speed of the carriage 41 greatly fluctuates due to some factor and the value of the calculation output of the differential element 336C increases, the carriage motor It is possible to prevent the control of 42 from being greatly influenced. Thereby, the carriage 41 can be moved in a stable state.

  Further, if it is determined that the carriage 41 is performing a stick-slip operation, the limiter 342 limiting function provided at these points “A” or “B” is turned off to cause the carriage 41 to perform a stick-slip operation. Can be suppressed.

=== Configuration of Printing System etc. ===
Next, as an embodiment of a printing system according to the present invention, a case where an inkjet printer 1 is provided as a printing apparatus will be described as an example. FIG. 24 shows an external configuration of an embodiment of a printing system. The printing system 300 includes a computer 140, a display device 304, and an input device 306. The computer 140 includes various computers such as a personal computer.

  The computer 140 includes a reading device 312 such as an FD drive device 314 and a CD-ROM drive device 316. In addition, the computer 140 may include, for example, an MO (Magnet Optical) disk drive device or a DVD drive device. The display device 304 includes various display devices such as a CRT display, a plasma display, and a liquid crystal display. The input device 306 includes a keyboard 308, a mouse 310, and the like.

  FIG. 25 is a block diagram showing an example of the system configuration of the printing system according to the present embodiment. The computer 140 includes a CPU 318, a memory 320, and a hard disk drive 322 in addition to the reading device 312 such as the FD drive device 314 and the CD-ROM drive device 316.

  The CPU 318 performs overall control of the computer 140. The memory 320 stores various data. A printer driver or the like is installed in the hard disk drive 322 as a program for controlling a printing apparatus such as the ink jet printer 1 of the present embodiment. The CPU 318 reads a program such as a printer driver stored in the hard disk drive 322 and operates according to the program. The CPU 318 is connected to a display device 304, an input device 306, the ink jet printer 1, and the like installed outside the computer 140.

  The printing system 300 realized in this way is a system that is superior to the conventional system as a whole system.

=== Other Embodiments ===
As described above, the printing apparatus such as a printer according to the present invention has been described based on one embodiment. However, the above-described embodiment is for facilitating the understanding of the present invention, and the present invention is limited and interpreted. Not meant to be The present invention can be changed or improved without departing from the gist thereof, and needless to say, the present invention includes equivalents thereof. In particular, even the embodiments described below are included in the printing apparatus according to the present invention.

<About print head>
In the embodiment described above, the print head (head 21) has the nozzles # 1 to # 180 that eject ink, and prints by ejecting ink from the nozzles # 1 to # 180, respectively. However, the print head here is not necessarily limited to such a head 21. That is, any form of print head may be used as long as printing is performed on a medium.

<About motor>
In the above-described embodiment, the carriage motor 42 moves as the “motor” via the pulley 44 and the timing belt 45, but the carriage 41 moves to the “motor” for moving the “printing head”. However, it is not necessarily limited to such a motor. That is, any motor may be used as long as it is a motor for moving a print head that performs printing on a medium.

<About the guide>
In the embodiment described above, the guide for guiding the print head (head 21, carriage 41) linearly in the lateral direction is used as a “guide portion” for guiding the print head (head 21, carriage 41) along a predetermined direction. Although the rail 46 has been disclosed, the “guide portion” is not necessarily limited to such a guide rail 46 alone. That is, any type of guide unit may be used as long as it is a guide unit for guiding the print head (head 21, carriage 41) along a predetermined direction.

<About the motor controller>
In the above-described embodiment, the carriage motor control unit 128 is taken as an example of the “motor control unit”, and the motor control unit that performs PID control on the motor (carriage motor 42) has been described. The “control unit” is not necessarily limited to such a motor control unit. That is, as long as the control unit controls the “motor”, any control method for controlling the motor may be used. For example, a motor control unit that controls the motor by a method other than PID control or the like may be used.

<About printing devices>
In the embodiment described above, the case of the inkjet printer 1 as described above has been described as an example of the printing apparatus. However, the printing apparatus is not limited to such a printing apparatus, but may be an inkjet printer that ejects ink by other methods. May be.
In addition to this, as a printing apparatus, in addition to the ink jet printer 1 described above, any printing apparatus provided with a print head that performs printing on a medium and is movable along a predetermined direction may be used. Any type of printing apparatus may be used.

<About ink>
The ink to be used may be a pigment ink, or other various inks such as a dye ink.
Regarding the ink color, in addition to the above-described yellow (Y), magenta (M), cyan (C), and black (K), for example, light cyan (LC), light magenta (LM), and dark yellow (DY), for example, Ink of other colors such as red, violet, blue, and green may be used.

<About media>
For media, including plain paper, matte paper, cut paper, glossy paper, roll paper, paper, photo paper, roll-type photo paper, etc., in addition to these, film materials and cloth materials such as OHP film and gloss film, It may be a metal plate material or the like. That is, any medium can be used as long as it can be a printing target.

1 is a perspective view of an embodiment of a printing apparatus according to the present invention. FIG. 3 is a perspective view illustrating an internal configuration of the printing apparatus. Sectional drawing which shows the conveyance part of a printing apparatus. 1 is a block configuration diagram showing a system configuration of a printing apparatus. FIG. 3 is a plan view illustrating an example of a head of a printing apparatus. Explanatory drawing explaining an example of the linear encoder. The block diagram which shows the structure of the detection part of a linear encoder. FIG. 8A is a timing chart showing the output waveform of the linear encoder during forward rotation, and FIG. 8B is a timing chart showing the output waveform of the linear encoder during reverse rotation. The block block diagram of a carriage motor control part. FIG. 10A is a graph of time change of the duty signal, and FIG. 10B is a graph of speed change of the motor. 6 is a flowchart for explaining an example of printing processing. Explanatory drawing of the change of the moving speed when a carriage performs stick-slip operation | movement. Explanatory drawing of an example of the determination method of the stick slip operation | movement based on a moving speed. Explanatory drawing of the other example of the determination method of the stick slip operation | movement based on a moving speed. Explanatory drawing of the relationship between the moving speed of a carriage at the time of a stick-slip operation | movement, and the signal value of a duty signal. Explanatory drawing of an example of the determination method of the stick slip operation | movement based on the signal value of a duedy signal. Explanatory drawing of an example of the determination method of the stick slip operation | movement based on an acceleration. Explanatory drawing of the timer of a carriage motor control part. Explanatory drawing of an example of the determination method of the stick slip operation | movement based on the measurement result of a timer. Explanatory drawing of the output of a limiter at the time of stick-slip operation | movement. Explanatory drawing of the moving speed of the carriage at the time of stick-slip operation correspondence. The flowchart explaining an example of the procedure of a response process. FIG. 6 is an explanatory diagram illustrating an example of a method for determining whether or not the carriage moving speed is stable. Explanatory drawing of the other example of a limiter installation. An explanatory view of an example of composition of other carriage motor control parts. Explanatory drawing of an example of a low-speed control part. 1 is a perspective view showing an appearance of an example of a printing system. 1 is a block configuration diagram showing a system configuration of an example of a printing system.

Explanation of symbols

1 Inkjet printer, 2 operation panel, 3 paper discharge unit, 4 paper supply unit,
5 operation buttons, 6 indicator lamps, 7 paper discharge tray, 8 paper feed tray,
13 paper feed roller, 14 platen, 15 transport motor, 17A transport roller,
17B paper discharge roller, 18A free roller, 18B free roller, 21 heads,
31 pump device, 35 capping device, 41 carriage,
42 Carriage motor, 44 pulley, 45 timing belt,
46 guide rail, 48 ink cartridge, 49 cartridge mounting part,
51 linear encoder, 53 paper detection sensor, 60 timer,
122 buffer memory, 124 image buffer, 126 controller,
127 main memory, 128 carriage motor controller,
129 communication interface, 130 transport control unit, 132 head drive unit,
134 rotary encoder, 140 computer,
211Y yellow nozzle row, 211C cyan nozzle row,
211M magenta nozzle row, 211K black nozzle row,
331 Position calculation unit, 332 subtractor, 333 gain, 334 speed calculation unit,
335 subtractor, 336A proportional element, 336B integral element, 336C differential element,
337 Adder, 338 PWM circuit, 339A acceleration control unit, 339B timer,
340 driver, 342 limiter, 344 limiter, 346 subtractor,
350 Carriage motor controller, 352 Normal speed controller, 354 Low speed controller,
356 control selection unit, 360 hold control unit, 362 timer interrupt control unit,
364 encoder interrupt control unit, 366 period counter, 368 position counter,
370 control selection unit, 372 timer counter, 374 first selection unit,
376 differential speed control unit, 378 second selection unit, 452 light emitting diode,
454 collimator lens, 456 detection processing unit, 458 photodiode,
460 signal processing circuit, 462A comparator, 462B comparator,
464 linear encoder code plate, 466 detector

Claims (16)

(A) a print head for printing on a medium;
(B) a motor for moving the print head;
(C) a guide portion for guiding the print head along a predetermined direction;
(D) a speed detector that detects the moving speed of the print head;
(E) a determination unit that determines whether the print head is performing a stick-slip operation;
(F) a motor controller that controls the motor by generating a control signal based on a change amount per unit time of the moving speed detected by the speed detector;
When controlling the motor to move the print head at a constant speed below the predetermined speed along the guide portion,
If the determination unit does not determine that the print head is performing a stick-slip operation, the control signal is generated based on the predetermined upper limit value when the amount of change exceeds a predetermined upper limit value. ,
When the determination unit determines that the print head is performing a stick-slip operation, the change amount exceeds the predetermined upper limit value and is based on the change amount regardless of the predetermined upper limit value. A motor control unit for generating the control signal;
A printing apparatus comprising (G).   The printing apparatus according to claim 1, wherein the motor control unit is provided with a calculation unit that calculates the amount of change based on the movement speed detected by the speed detection unit.   3. The motor control unit is provided with a limiter that outputs the predetermined upper limit value as the change amount when the change amount exceeds the predetermined upper limit value. The printing apparatus as described.   The motor control unit determines that the moving speed detected by the speed detection unit is within a predetermined allowable range for a predetermined time or more after the determination unit determines that the print head is performing a stick-slip operation. 4. The printing according to claim 1, wherein the control signal is generated based on the predetermined upper limit value when the amount of change exceeds the predetermined upper limit value. 5. apparatus.   5. The determination unit according to claim 1, wherein the determination unit determines whether or not the print head is performing a stick-slip operation based on the moving speed detected by the speed detection unit. The printing apparatus as described in.   The printing apparatus according to claim 1, wherein the determination unit determines whether the print head is performing a stick-slip operation based on the control signal. An acceleration detection unit for detecting the acceleration of the print head;
5. The determination unit according to claim 1, wherein the determination unit determines whether the print head is performing a stick-slip operation based on the acceleration detected by the acceleration detection unit. The printing apparatus as described. A timer for measuring a time during which the moving speed of the print head is equal to or lower than a predetermined allowable lower limit between the start of movement of the print head and the end of movement;
The printing apparatus according to claim 1, wherein the determination unit determines whether the print head is performing a stick-slip operation based on a measurement time of the timer.   When the motor control unit controls the motor to move the print head along the guide unit at a constant speed at a predetermined speed or less, the motor control unit closes the opening provided in the print head. The printing apparatus according to claim 1, wherein the printing apparatus is moved to a capping apparatus.   When the motor control unit controls the motor to move the print head along the guide unit at a constant speed at a predetermined speed or less, the motor control unit tries to print by an optical sensor provided in the print head. The printing apparatus according to claim 1, wherein the printing head is moved along the guide portion in order to detect the width of the medium.   When the motor control unit controls the motor to move the print head along the guide unit at a constant speed below a predetermined speed, the motor control unit prints the print head to replace a cartridge mounted on the print head. The printing apparatus according to claim 1, wherein the head is moved to a predetermined position.   The printing apparatus according to claim 1, wherein the print head includes a nozzle that ejects ink toward the medium in order to perform printing on the medium. (A) a print head for printing on a medium;
(B) a motor for moving the print head;
(C) a guide portion for guiding the print head along a predetermined direction;
(D) a speed detector that detects the moving speed of the print head;
(E) a determination unit that determines whether the print head is performing a stick-slip operation;
(F) a motor controller that controls the motor by generating a control signal based on a change amount per unit time of the moving speed detected by the speed detector;
When controlling the motor to move the print head at a constant speed below the predetermined speed along the guide portion,
If the determination unit does not determine that the print head is performing a stick-slip operation, the control signal is generated based on the predetermined upper limit value when the amount of change exceeds a predetermined upper limit value. ,
When the determination unit determines that the print head is performing a stick-slip operation, the change amount exceeds the predetermined upper limit value and is based on the change amount regardless of the predetermined upper limit value. A motor control unit for generating the control signal;
(G)
(H) The motor control unit is provided with a calculation unit that calculates the amount of change based on the moving speed detected by the speed detection unit,
(I) The motor control unit is provided with a limiter that outputs the predetermined upper limit value as the change amount when the change amount exceeds the predetermined upper limit value.
(J) After the motor control unit determines that the print head is performing a stick-slip operation by the determination unit, the movement speed detected by the speed detection unit is greater than or equal to a predetermined time and a predetermined allowable range. The control signal is generated based on the predetermined upper limit value when the amount of change exceeds the predetermined upper limit value,
(K) The determination unit determines whether or not the print head is performing a stick-slip operation based on the moving speed detected by the speed detection unit,
(L) When the motor control unit controls the motor to move the print head at a constant speed below the predetermined speed along the guide unit, an opening provided in the print head. It is when moving to a capping device that closes the part,
(M) When the motor control unit controls the motor to move the print head at a constant speed below the predetermined speed along the guide unit, printing is performed by an optical sensor provided in the print head. When moving the print head along the guide to detect the width of the medium to be attempted,
(N) When the motor control unit controls the motor to move the print head at a constant speed below the predetermined speed along the guide unit, the cartridge mounted on the print head is replaced. When the print head is moved to a predetermined position.
(O) The printing apparatus, wherein the print head includes a nozzle that discharges ink toward the medium in order to perform printing on the medium. Generating a control signal to control a motor so as to move a print head that performs printing on a medium at a constant speed below a predetermined speed along a guide portion that guides the print head along a predetermined direction; and ,
Detecting a moving speed of the print head moved by the motor;
Determining whether the print head is performing a stick-slip operation;
The step of generating the control signal based on the detected change amount of the moving speed per unit time, and when the print head is not determined to perform a stick-slip operation, the change amount is When the predetermined upper limit value is exceeded, the control signal is generated based on the predetermined upper limit value, and when it is determined that the print head is performing a stick-slip operation, the amount of change is the predetermined upper limit value. Generating the control signal based on the amount of change regardless of the predetermined upper limit value even if exceeding a value;
A method for handling stick-slip, comprising: Generating a control signal to control a motor so as to move a print head that performs printing on a medium at a constant speed below a predetermined speed along a guide portion that guides the print head along a predetermined direction; and ,
Detecting a moving speed of the print head moved by the motor;
Determining whether the print head is performing a stick-slip operation;
The step of generating the control signal based on the detected change amount of the moving speed per unit time, and when the print head is not determined to perform a stick-slip operation, the change amount is When the predetermined upper limit value is exceeded, the control signal is generated based on the predetermined upper limit value, and when it is determined that the print head is performing a stick-slip operation, the amount of change is the predetermined upper limit value. Generating the control signal based on the amount of change regardless of the predetermined upper limit value even if exceeding a value;
A program characterized by executing A printing system comprising a computer and a printing device connectable to the computer,
The printing apparatus includes: a print head that performs printing on a medium;
A motor for moving the print head;
A guide portion for guiding the print head along a predetermined direction;
A speed detecting unit for detecting a moving speed of the print head;
A determination unit that determines whether or not the print head is performing a stick-slip operation;
A motor control unit for controlling the motor by generating a control signal based on a change amount per unit time of the moving speed detected by the speed detection unit, wherein the print head is moved along a predetermined direction along the guide unit; When the motor is controlled to move at a constant speed below the speed, if the determination unit does not determine that the print head is performing a stick-slip operation, the amount of change exceeds a predetermined upper limit. When the control signal is generated based on the predetermined upper limit value and the determination unit determines that the print head is performing a stick-slip operation, the amount of change is the predetermined upper limit value. A motor control unit that generates the control signal based on the amount of change regardless of the predetermined upper limit value,
A printing system comprising:

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