JP2006272763A - Printer, printing method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a printer or the like which can suppress generation of heat of a motor for driving while a throughput of printing processing is maintained. <P>SOLUTION: The printer is equipped with (A) the driving motor in a predetermined direction a head which delivers ink, (B) a transferring part for medium in a transfer direction which intersects the movement direction, and (C) a control part for carrying out printing by repeating the movement operation of making the motor move the head and the transfer operation of making the transfer part transfer the medium. (D) The control part changes a speed profile related to the movement of the head between a time point of the end of the delivering action of the ink in a certain movement operation and a time point of the start of the delivering action of the ink in the next movement operation, according to a time necessary for the transfer operation between the end and the start time points. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printing apparatus, a printing method, and a program.

  An inkjet printer as a printing apparatus includes a driving motor for moving a head that discharges ink in a predetermined movement direction, a conveyance unit for conveying a sheet as a medium in a conveyance direction that intersects the movement direction, It has. Then, printing is performed on paper by repeating a moving operation for ejecting ink while moving the head and a transport operation for transporting the medium to the transport unit.

Among such printers, there is a printer in which a paper transport operation is started from the end point of the ink discharge operation performed during the moving operation in order to increase the throughput of the printing process. In addition to this, the end time of the transport operation is predicted in advance, and the next movement operation is started in advance of the end time, so that the next time immediately after the end of the transport operation. Some ink jetting operations are started to further improve throughput (see Patent Document 1).
Japanese Patent Laid-Open No. 2001-232882

By the way, recently, miniaturization of motors has been pursued, and along with this, the heat capacity of the driving motor itself has become smaller, so suppression of heat generation is becoming an important issue. As a method of suppressing the heat generation of the driving motor, there is a method of slowly decelerating and accelerating the moving operation of the head over time.
However, in that case, in some cases, the acceleration end point of the moving operation is delayed, and accordingly, the start point of the subsequent ink ejection operation performed in the constant speed region is also delayed. Will reduce the throughput.

  The present invention has been made in view of such circumstances, and an object thereof is to realize a printing apparatus, a printing method, and a program capable of suppressing heat generation of a driving motor while maintaining a throughput of printing processing. There is to do.

The main invention for achieving the object is as follows:
(A) a driving motor for moving a head for discharging ink in a predetermined movement direction;
(B) a transport unit for transporting the medium in a transport direction that intersects the moving direction;
(C) a control unit for performing printing by repeatedly performing a moving operation of moving the head to the driving motor and a conveying operation of conveying the medium to the conveying unit;
A speed profile relating to the movement of the head between the end point of the ink discharge operation in a certain movement operation and the start point of the ink discharge operation in the next movement operation is represented by the transport operation between the end point and the start point. A control unit that changes according to the time required for
A printing apparatus comprising (D).

  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 driving motor for moving a head for discharging ink in a predetermined movement direction;
(B) a transport unit for transporting the medium in a transport direction that intersects the moving direction;
(C) a control unit for performing printing by repeatedly performing a moving operation of moving the head to the driving motor and a conveying operation of conveying the medium to the conveying unit;
A speed profile relating to the movement of the head between the end point of the ink discharge operation in a certain movement operation and the start point of the ink discharge operation in the next movement operation is represented by the transport operation between the end point and the start point. A control unit that changes according to the time required for
A printing apparatus comprising (D).

According to such a printing apparatus, the velocity profile relating to the movement of the head between the end point of the ink discharge operation in a certain movement operation and the start point of the ink discharge operation in the next movement operation is expressed as the end point and the It changes according to the time required for the said conveyance operation between the start time.
Accordingly, it is possible to move the head slowly between the end time and the start time within the time required for the transport operation, and as a result, the throughput of the printing process. Without lowering, it is possible to effectively suppress the heat generation of the drive motor.
Further, since the head can be moved slowly over time, the operation sound of the driving motor can be reduced, and the quietness during the printing process can be improved.

In such a printing apparatus,
A plurality of the speed profiles;
Select one of the multiple types of speed profiles according to the time required,
The movement of the head between the end point and the start point may be executed based on the selected speed profile.

In such a printing apparatus,
The control unit calculates the time required for each of the transport operations, and for the plurality of types of speed profiles, the control unit needs to move the head from the head position at the end time to the head position at the start time. Calculate the time,
It is preferable to select a speed profile that does not exceed the required time and that minimizes the deviation between the required time and the required time, among the calculated required times.

According to such a printing apparatus, the time required is calculated for each transport operation, and for each speed profile, it is necessary to move the head from the head position at the end time to the head position at the start time. Calculate the time required. Then, in the calculated required time, a transport speed profile that does not exceed the required time and minimizes the deviation between the required time and the required time is selected, and based on the speed profile, the Move the head.
Accordingly, the movement of the head is performed slowly over time within a range in which the time required for the movement of the head from the position at the end time to the position at the start time is rate-limiting and the throughput is not reduced. It becomes possible. As a result, it is possible to effectively suppress the heat generation of the drive motor without reducing the throughput of the printing process.
Further, since the required time and the required time of each speed profile are calculated for each transport operation and the speed profile is determined, the required time changes for each moving operation, or the required time for each transport operation. Even in the case of a change, the optimum speed profile can be selected without being affected by these changes.

In such a printing apparatus,
The speed profile includes a deceleration area in which the head moving at a predetermined speed in the certain movement operation is decelerated to a stop state, an acceleration area in which the head in the stop state is accelerated to the predetermined speed in the next movement operation, and And
It is desirable that ink is ejected while the head is moving at the predetermined speed.
According to such a printing apparatus, since the ink is ejected while the head is moving at the predetermined speed, the ink can be accurately landed on the target position on the medium.

In such a printing apparatus,
If the required time is longer than the required time,
Between the deceleration area and the acceleration area, a stop time in which the head is stopped is provided,
By adjusting the length of the stop time, it is preferable that the head is adjusted so as to reach the start position of the ink discharge operation at the end of the transport operation.
According to such a printing apparatus, the head can reliably reach the start position of the ink ejection operation in accordance with the end point of the transport operation.

In such a printing apparatus,
The length Tc1 of the stop time is preferably obtained by substituting the required time Ta and the required time Tt into the following equation.
Tc1 = Tt-Ta
According to such a printing apparatus, the head can reliably reach the start position of the ink ejection operation in accordance with the end point of the transport operation.

In such a printing apparatus,
While accelerating at a predetermined acceleration in the acceleration region, decelerating at a predetermined deceleration in the deceleration region,
The plurality of types of speed profiles are preferably different in terms of the acceleration and the deceleration.
According to such a printing apparatus, since the acceleration and the deceleration are different from each other, it is possible to set the heat generation amount between the speed profiles with a difference. Heat generation of the drive motor can be effectively suppressed without lowering the throughput.

In such a printing apparatus,
A first transport operation for performing the transport operation with a predetermined first transport amount; and a second transport operation for performing the transport operation with a second transport amount greater than the first transport amount;
When the first transport operation is selected, the movement of the head between the end time and the start time is executed using a predetermined speed profile,
When the second transport operation is selected, one of the plurality of speed profiles is selected and used according to the time required, and the time between the end time and the start time is selected. It is desirable that head movement is performed.
According to such a printing apparatus, since the conveyance amount is large in the second conveyance operation, the frequency of slowly moving the head over time is increased, thereby effectively generating heat from the drive motor. It becomes possible to suppress.

In such a printing apparatus,
The resolution that defines the formation pitch in the transport direction of dots formed by the ink landing on the medium can be set for at least two types of high and low,
When a low resolution is set, the second transport operation is selected,
When a high resolution is set, it is preferable that the first transport operation is selected.
According to such a printing apparatus, when a low resolution is set, since the transport amount is large, the movement of the head between the end time and the start time is slowly performed over time. The frequency of performing the operation is increased, so that the heat generation of the drive motor can be effectively suppressed.

In such a printing apparatus,
When discharging ink toward the downstream end and the upstream end in the transport direction of the medium, the first transport operation is selected,
In the case where ink is ejected toward a portion between the downstream end and the upstream end in the transport direction of the medium, it is preferable that the second transport operation is selected.
According to such a printing apparatus, when ink is ejected toward the portion between the downstream end and the upstream end, the transport amount is large. The frequency of slowly moving the head between the start point and the time becomes high, so that the heat generation of the drive motor can be effectively suppressed.

In such a printing apparatus,
It is desirable that the head alternately performs a moving operation in the forward direction of the moving direction and a moving operation in the backward direction that is opposite to the forward direction.
According to such a printing apparatus, so-called bidirectional printing can be performed, and thus the throughput of the printing process can be significantly increased.

(A) a driving motor for moving the head for discharging ink in a predetermined movement direction;
(B) a transport unit for transporting the medium in a transport direction that intersects the moving direction;
(C) a control unit for performing printing by repeatedly performing a moving operation of moving the head to the driving motor and a conveying operation of conveying the medium to the conveying unit;
A speed profile relating to the movement of the head between the end point of the ink discharge operation in a certain movement operation and the start point of the ink discharge operation in the next movement operation is represented by the transport operation between the end point and the start point. A control unit that changes according to the time required for
(D)
A plurality of the speed profiles;
Select one of the multiple types of speed profiles according to the time required,
Performing the movement of the head between the end time and the start time based on the selected speed profile;
The control unit calculates the time required for each of the transport operations, and for the plurality of types of speed profiles, the control unit needs to move the head from the head position at the end time to the head position at the start time. Calculate the time,
In the calculated required time, a speed profile that does not exceed the required time and minimizes a deviation between the required time and the required time is selected.
The speed profile includes a deceleration area in which the head moving at a predetermined speed in the certain movement operation is decelerated to a stop state, an acceleration area in which the head in the stop state is accelerated to the predetermined speed in the next movement operation, and And
While the head is moving at the predetermined speed, ink ejection is performed,
If the required time is longer than the required time,
Between the deceleration area and the acceleration area, a stop time in which the head is stopped is provided,
By adjusting the length of the stop time, the head is adjusted to reach the start position of the ink ejection operation at the end of the transport operation,
The stop time length Tc1 is obtained by substituting the required time Ta and the required time Tt into the following equation,
Tc1 = Tt-Ta
While accelerating at a predetermined acceleration in the acceleration region, decelerating at a predetermined deceleration in the deceleration region,
The plurality of speed profiles are different in terms of the acceleration and the deceleration,
A first transport operation for performing the transport operation with a predetermined first transport amount; and a second transport operation for performing the transport operation with a second transport amount greater than the first transport amount;
When the first transport operation is selected, the movement of the head between the end time and the start time is executed using a predetermined speed profile,
When the second transport operation is selected, one of the plurality of speed profiles is selected and used according to the time required, and the time between the end time and the start time is selected. Head movement is performed,
The resolution that defines the formation pitch in the transport direction of dots formed by the ink landing on the medium can be set for at least two types of high and low,
When a low resolution is set, the second transport operation is selected,
When a high resolution is set, the first transport operation is selected,
When discharging ink toward the downstream end and the upstream end in the transport direction of the medium, the first transport operation is selected,
When the ink is ejected toward the portion between the downstream end and the upstream end in the transport direction of the medium, the second transport operation is selected,
The printing apparatus according to claim 1, wherein the head alternately performs a movement operation in the forward direction of the movement direction and a movement operation in the backward direction that is opposite to the forward direction.
According to such a printing apparatus, since all the effects described above are exhibited, the object of the present invention can be achieved more effectively.

Further, while moving the head in a predetermined movement direction, printing is repeatedly performed by a movement operation for ejecting ink from the head toward the medium and a conveyance operation for conveying the medium in a conveyance direction that intersects the movement direction. In the printing method,
A speed profile relating to the movement of the head between the end point of the ink discharge operation in a certain movement operation and the start point of the ink discharge operation in the next movement operation is represented by the transport operation between the end point and the start point. It is also possible to realize a printing method characterized by changing according to the time required for the printing.

A driving motor for moving the ink discharge head in a predetermined movement direction;
A transport unit for transporting the medium in a transport direction that intersects the moving direction;
A program that is executed in a printing apparatus that includes a control unit for performing printing by repeatedly performing a moving operation of moving the head by the driving motor and a transporting operation of transporting the medium by the transporting unit. And
A speed profile relating to the movement of the head between the end point of the ink discharge operation in a certain movement operation and the start point of the ink discharge operation in the next movement operation is represented by the transport operation between the end point and the start point. It is also possible to realize a program characterized by executing a step that is changed according to the time required for.

=== Overview of Printing Apparatus ===
1 to 4 are explanatory diagrams of an ink jet printer 1 as a printing apparatus according to the present embodiment. FIG. 1 is an external perspective view of the ink jet printer 1. FIG. 2 is a perspective view of the internal configuration of the inkjet printer 1. FIG. 3 is a cross-sectional view of the conveyance unit of the inkjet printer 1. FIG. 4 is a block diagram showing 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 (not shown) such as a sheet supplied from the back from the front, and an operation panel 2 and a paper discharge unit 3 are provided on the front. Is provided, and a paper feeding unit 4 is provided on the back side thereof. Various operation buttons 5 and display lamps 6 are provided on the operation panel 2. Further, 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 that holds cut paper (not shown). The ink jet printer 1 may include a paper feed structure that can print not only on a single sheet of paper such as cut paper but also on a continuous medium such as roll 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 a predetermined movement direction (hereinafter referred to as a carriage movement direction). Around the carriage 41, a carriage motor 42 as a driving motor, 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 functions as a drive source for relatively moving the carriage 41 along 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 relatively moved along the carriage movement direction by the rotation of the carriage motor 42. Move. The guide rail 46 guides the carriage 41 along the carriage movement direction.

  In addition, around the carriage 41, a linear encoder 51 for detecting the position of the carriage 41, a transport roller 17A for transporting the paper S along a direction intersecting the moving direction of the carriage 41, and this transport A conveyance motor 15 that rotates the roller 17A is 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 paper 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 paper S. For this purpose, the head 21 is provided with a number of nozzles for ejecting ink. The ink ejection mechanism of the head 21 will be described in detail later.

  In addition, a cleaning unit 30 for eliminating clogging of the nozzles of the head 21 is provided inside the ink jet printer 1. The cleaning unit 30 includes a pump device 31 and a capping device 35. The pump device 31 is a device that sucks out ink from the nozzles in order to eliminate clogging of the nozzles of the head 21, and is operated by a pump motor (not shown). On the other hand, the capping device 35 seals the nozzles of the head 21 when printing is not performed (for example, during standby) in order to prevent clogging of the nozzles of the head 21.

  Next, the configuration of the transport unit of the inkjet printer 1 will be described. As shown in FIG. 3, the transport unit includes a paper insertion port 11A and a roll paper insertion port 11B, a paper feed motor (not shown), a paper feed roller 13, a platen 14, a transport motor 15, and a transport roller. 17A, a discharge roller 17B, a free roller 18A, and a free roller 18B.

  The paper insertion slot 11A is where the paper S is inserted. The paper feed motor (not shown) is a motor that transports the paper S inserted into the paper insertion slot 11A into the ink jet printer 1, and is configured by a pulse motor or the like. The paper feed roller 13 is a roller that automatically feeds the paper S inserted into the paper insertion slot 11A along the direction of arrow A in the figure (the direction of arrow B in the case of roll paper) into the ink jet printer 1. And is driven by a paper feed motor. The paper feed roller 13 has a substantially D-shaped cross section. Since the circumferential length of the circumferential portion of the paper feed roller 13 is set longer than the conveyance distance to the conveyance motor 15, the sheet S can be conveyed to the conveyance motor 15 using this circumferential portion.

  The paper S conveyed by the paper supply roller 13 contacts 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 paper S fed by the paper feed roller 13.

  The paper S detected by the paper detection sensor 53 is conveyed to the platen 14. The platen 14 is a support unit that supports the paper S during printing. The transport motor 15 is a motor that sends out the paper S in the transport direction, and is constituted by a DC motor. This transport direction is orthogonal to the aforementioned carriage movement direction. The transport roller 17 </ b> A is a roller that feeds the paper S transported into the inkjet printer 1 by the paper feed roller 13 to a printable area, and is driven by the transport motor 15. The free roller 18A is provided at a position facing the conveyance roller 17A and sandwiches the paper S between the conveyance roller 17A.

  The paper discharge roller 17 </ b> B is a roller that discharges the printed paper S to the outside of the inkjet printer 1. The paper discharge roller 17B is driven by the transport motor 15 by a gear (not shown). The free roller 18B is provided at a position facing the paper discharge roller 17B, and presses the paper S toward the paper discharge roller 17B by sandwiching the paper S between the paper discharge roller 17B.

<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, and an EEPROM 129. The buffer memory 122 receives and temporarily stores various data such as print data transmitted from the computer 140. The image buffer 124 acquires the received print data from the buffer memory 122 and stores it. The main memory 127 is composed of a ROM, a RAM, and the like.

  On the other hand, the controller 126 reads a control program from the main memory 127 or the EEPROM 129, and controls the entire inkjet printer 1 according to the control program. The controller 126 according to this embodiment includes a carriage motor control unit 128, a conveyance control unit 130, a head driving unit 132, a rotary encoder 134, and a linear encoder 51. The carriage motor controller 128 drives and controls the rotation direction and the number of rotations of the carriage motor 42. Further, the head drive unit 132 performs drive control of the head 21. The conveyance control unit 130 controls various drive motors arranged in the conveyance unit such as the conveyance motor 15 that rotationally drives the conveyance roller 17A.

  The print data sent from the computer 140 is temporarily stored in the buffer memory 122. The controller 126 reads out necessary information from the print data stored here. 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, and the head drive unit 132 according to the control program. Control.

  The image buffer 124 stores print data of a plurality of color components received by the buffer memory 122. The head drive unit 132 acquires print data of each color component from the image buffer 124 according to a control signal from the controller 126, and drives and controls the nozzles of each color provided in the head 21 based on the print data.

  The controller 126 receives a signal output from the paper detection sensor 53 and indicating whether or not the paper S is detected. As a result, the controller 126 can know whether or not the paper detection sensor 53 is detecting the paper S.

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

  The nozzles # 1 to # 180 of the nozzle rows 211Y, 211M, 211C, and 211K are arranged in a straight line along the transport direction of the paper S at a nozzle pitch k · D (4 · D in the illustrated example). Yes. Here, D is the minimum dot pitch (minimum interval between dots formed on the paper S) that can be formed in the transport direction. The nozzle rows 211Y, 211M, 211C, and 211K are arranged in parallel with a space between each other along the moving direction of the head 21 (carriage moving direction). Each nozzle # 1 to # 180 is provided with a piezo element (not shown) as a drive element for ejecting ink droplets.

  When a voltage having a predetermined time width is applied between the electrodes provided at both ends of the piezoelectric element, the piezoelectric element expands according to the voltage application time and deforms the side wall of the ink flow path. As a result, the volume of the ink flow path contracts in accordance with the expansion and contraction of the piezo element, and ink corresponding to the contraction is ejected from the nozzles # 1 to # 180 of the respective colors as ink droplets and is applied to the paper S Dots are formed.

=== Print processing ===
Next, the printing process of the inkjet printer 1 described above will be described. Here, “bidirectional printing” will be described as an example. FIG. 6 is a flowchart illustrating an example of a printing process procedure of the inkjet printer 1. Each operation described below is executed by the controller 126 reading out a program stored in the main memory 127 or the EEPROM 129 and controlling according to the program.

  When the controller 126 receives print data from the computer 140, the controller 126 first performs a paper feeding operation to execute printing based on the print data (S102). The paper feeding operation is an operation of supplying the paper S to be printed into the ink jet printer 1 and transporting it to a printing start position (also referred to as a cueing position). The controller 126 rotates the paper feed roller 13 to send the paper S to be printed to the transport roller 17A. The controller 126 rotates the transport roller 17A to position the paper S sent from the paper feed roller 13 at the print start position.

  Next, the controller 126 executes a carriage movement operation (hereinafter also referred to as a CR movement operation) for printing on the paper S while moving the carriage 41 relative to the paper S in the carriage movement direction. Here, first, forward printing is performed to eject ink from the head 21 while moving the carriage 41 along the guide rail 46 in the forward direction (S104). That is, the controller 126 drives the carriage motor 42 via the carriage motor control unit 128 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 paper S and is formed as dots.

  After printing is performed in this manner, a transport operation for transporting the paper S by a predetermined transport amount is executed (S106). In this transport operation, the controller 126 drives the transport motor 15 and rotates the transport roller 17A via the transport control unit 130 to rotate the transport roller 17A to a predetermined transport amount relative to the head 21 in the transport direction. Only carry. By this carrying operation, the head 21 can print in a region different from the region printed earlier.

  After carrying out the transport operation in this way, a paper discharge determination is made as to whether or not paper should be discharged (S108). If there is no other data to be printed on the paper S being printed, a paper discharge operation is executed (S116). On the other hand, if there is other data to be printed on the paper S being printed, the return pass printing is executed without performing the paper discharge operation (S110). In this return path printing, the above-described CR movement operation is performed in the return path direction opposite to the forward path direction. That is, printing is performed by moving the carriage 41 along the guide rail 46 in the return path direction. 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 drives the head 21 based on the print data to eject ink. Apply printing.

  After performing the return pass printing, the carrying operation is executed (S112), and then the paper discharge is judged (S114). Here, if there is other data to be printed on the paper S being printed, the paper discharge operation 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 paper S being printed, a paper discharge operation is executed (S116).

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

=== Drive control of the transport motor 15 ===
<Function of the conveyance control unit 130>
The drive control of the carry motor 15 is performed by the carry control unit 130. The transport control unit 130 drives the transport motor 15 by a predetermined drive amount based on a transport command from the controller 126. The carry motor 15 rotates the carry roller 17A and the paper discharge roller 17B according to the commanded driving amount. As a result, the transport roller 17A and the paper discharge roller 17B rotate, and the paper S is transported by a predetermined transport amount. The conveyance amount of the paper S is determined according to the rotation amount of the conveyance roller 17A. Therefore, if the rotation amount of the conveyance roller 17A can be detected, the conveyance amount of the paper S can also be detected. Here, a rotary encoder 134 is provided to detect the rotation amount of the transport roller 17A.

<Rotary encoder 134>
FIG. 7 is an explanatory diagram of the configuration of the rotary encoder 134. The rotary encoder 134 includes a rotary encoder code plate 402 and a detection unit 404.
The rotary encoder code plate 402 is formed in a disk shape as shown in the figure. A large number of small slits 406 are formed at predetermined intervals on the outer peripheral edge of the rotary encoder code plate 402. The rotary encoder code plate 402 is provided integrally adjacent to the large gear 408 provided integrally at the shaft end portion of the transport roller 17A that transports the paper S. The large gear 408 is connected to the transport motor 15 via the small gear 410, and rotates via the small gear 410 by the rotational drive of the transport motor 15. Thereby, the transport roller 17A is rotated by the rotational drive of the transport motor 15, and the rotary encoder code plate 402 is also rotated in synchronization with the large gear 408 and the transport roller 17A. On the other hand, the detection unit 404 is provided adjacent to the rotary encoder code plate 402 and detects the amount of rotation of the rotary encoder code plate 402.

<Configuration of Detection Unit 404>
FIG. 8 is an explanatory diagram of the configuration of the detection unit 404 of the rotary encoder 134. The detection unit 404 includes a light emitting diode 412, a collimator lens 414, and a detection processing unit 416. The detection processing unit 416 includes a plurality (for example, four) of photodiodes 418, a signal processing circuit 420, and, for example, two comparators 422A and 422B.

  When the voltage V1 is applied to both ends of the light emitting diode 412 via a resistor, light is emitted from the light emitting diode 412. This light is condensed into parallel light by the collimator lens 414 and passes through the rotary encoder code plate 402. The rotary encoder code plate 402 is provided with slits 406 at predetermined intervals (for example, 1/180 inch (1 inch = 2.54 cm)).

  The parallel light that has passed through the rotary encoder code plate 402 enters each photodiode 418 through a fixed slit (not shown) and is converted into an electrical signal. The electric signals output from the four photodiodes 418 are subjected to signal processing in the signal processing circuit 420, the signals output from the signal processing circuit 420 are compared in the comparators 422A and 422B, and the comparison result is output as a pulse. Pulses ENC-A and ENC-B output from the comparators 422A and 422B are output signals of the rotary encoder 134.

  FIGS. 9A and 9B are timing charts showing waveforms of two output signals of the rotary encoder 134 when the transport motor 15 is rotating forward and when it is rotating backward. FIG. 9A is a timing chart of the waveform of the output signal when the transport motor 15 is rotating forward. FIG. 9B is a timing chart of the waveform of the output signal when the transport motor 15 is reversed.

  As shown in FIGS. 9A and 9B, the phase of the pulse ENC-A and the pulse ENC-B differ by 90 degrees in both cases of the forward rotation and the reverse rotation of the transport motor 15. When the transport motor 15 is rotating forward, that is, when the paper S is transported in the transport direction as shown in FIG. 7, the phase of the pulse ENC-A advances by 90 degrees relative to the pulse ENC-B. On the other hand, when the transport motor 15 is reversed, that is, when the paper S is transported in the direction opposite to the transport direction, the phase of the pulse ENC-A is delayed by 90 degrees from the pulse ENC-B. One period T of each pulse is equal to a time during which the transport roller 17A rotates by an interval (for example, 1/1440 inch (1 inch = 2.54 cm)) of the slit 406 of the rotary encoder code plate 402.

  When the rising edge and rising edge of each of the output pulses ENC-A and ENC-B of the rotary encoder 134 are detected by the system controller 126 and the number of detected edges is counted, the system controller 126 Based on the counted value, the rotational position of the transport motor 15 can be calculated. This count is incremented by “+1” when one edge is detected when the transport motor 15 is rotating forward, and “−” when one edge is detected when the conveyor motor 15 is rotating in reverse. Add 1 ”. The period of each of the pulses ENC-A and ENC-B is the time from when a slit 406 of the rotary encoder code plate 402 passes through the detection unit 404 until the next slit 406 passes through the detection unit 404. 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 interval between the slits 406 of the rotary encoder code plate 402. Thus, if the count value is multiplied by 1/4 of the interval of the slits 406, the transport amount of the transport motor 15 from the rotational position corresponding to the count value “0” can be obtained based on the multiplication value. it can. At this time, the resolution of the rotary encoder 134 is ¼ of the interval between the slits 406 of the rotary encoder code plate 402.

<Configuration of transport control unit 130>
Next, the configuration of the transport control unit 130 will be described with reference to FIGS. 10 to 12B. FIG. 10 is a block diagram illustrating a configuration of the transport control unit 130. FIG. 11 shows a conveyance speed profile used for the conveyance operation. 12A and 12B are explanatory diagrams illustrating the relationship between the motor drive signal Sdr and the characteristics of the transport motor 15.

As shown in FIG. 10, the transport control unit 130 includes a transport motor control circuit 200 and a transport motor drive circuit 150.
The output signal Sen of the rotary encoder 134 is input to the position calculation circuit 230 and the speed calculation circuit 232 in the transport motor control circuit 200. These circuits 230 and 232 obtain the current rotational position P and the current rotational speed V of the transport motor 15 based on the pulse ENC-A and the pulse ENC-B (not shown) of the output signal Sen of the encoder 134, respectively. . The first subtracter 202 obtains a deviation ΔP between the given target rotational position Pt and the current rotational position P and inputs it to the target rotational speed generation circuit 204.
The target rotation speed generation circuit 204 generates a target rotation speed Vt corresponding to the rotation position deviation ΔP based on the conveyance speed profile shown in FIG.

 This transport speed profile defines an acceleration region in which the stopped paper S is accelerated to a predetermined transport speed Vcc and a deceleration region in which the paper S transported at the transport speed Vcc is decelerated to a stop state. In the transport speed profile table of the main memory 127, acceleration time Tacc, deceleration time Tbcc, and transport speed Vcc are recorded as parameters that define the transport speed profile. These parameters are transmitted from the memory 127 to the target rotational speed generation circuit 204 via the controller 126, and the target rotational speed generation circuit 204 forms a conveyance speed profile based on these parameters.

Note that the rotation amount Lacc in the acceleration region and the rotation amount Lbcc in the deceleration region are expressed by the areas of the respective regions, and are obtained by the following equations (11) and (12), respectively.
Lacc = (Tacc × Vcc) / 2 (11)
Lbcc = (Tbcc × Vcc) / 2 (12)

Further, the rotation amount Lc and the time Tc in the constant speed region in which the paper S is transported at the transport speed Vcc between the acceleration region and the deceleration region vary depending on the transport amount L. ), (14).
Lc = L-Lacc-Lbcc (13)
Tc = Lc / Vcc (14)

 The second subtracter 206 in FIG. 10 calculates a deviation ΔV between the target rotational speed Vt and the current rotational speed V, and inputs this rotational speed deviation ΔV to the proportional element 210, the integral element 212, and the differential element 214. To do. The calculation results QP, QI, and QD of these three calculation elements 210, 212, and 214 are added by an adder 216 to calculate an addition result ΣQ.

The outputs QP, QI, QD of the respective arithmetic elements 210, 212, 214 and their addition result ΣQ are given by, for example, the following equations (21) to (24).
QP (j) = ΔV (j) × Kp (21)
QI (j) = QI (j−1) + ΔV (j) × Ki (22)
QD (j) = {ΔV (j) −ΔV (j−1)} × Kd (23)
ΣQ (j) = QP (j) + QI (j) + QD (j) (24)
Here, Kp is a proportional gain, Ki is an integral gain, and Kd is a differential gain. The outputs QP, QI, and QD are output at a predetermined output period Δtc, where j represents the current time, and j−1 represents the previous time point before the current time j by the output period Δtc. .

 The duty adjustment circuit 220 adjusts the level of the duty signal Dt supplied to the drive circuit 150 according to the addition result ΣQ (j). The duty signal Dt is a signal proportional to the addition result ΣQ (j) and is a signal indicating the duty of the carry motor 15. Thus, the transport motor 15 is controlled by so-called PWM (Plus Width Modulation) control.

 The conveyance motor drive circuit 150 includes a DC-DC converter 154 configured with a transistor bridge and a base drive circuit 152. The base drive circuit 152 generates a base signal to be applied to the base of the transistor of the DC-DC converter 154 in accordance with the duty signal Dt supplied from the carry motor control circuit 200. The DC-DC converter 154 generates a motor drive signal Sdr according to the base signal and supplies it to the transport motor 15.

 FIG. 12A shows a signal change of the motor drive signal Sdr. The duty of the motor drive signal Sdr is a value obtained by dividing the period Ton at the on level by one cycle Tp of the drive signal. When a DC motor with a brush is used as the transport motor 15, the torque / rotational speed characteristic is proportional to the duty as shown in FIG. 12B. The conveyance motor drive circuit 150 generates the drive signal Sdr so that the duty of the drive signal Sdr is proportional to the duty signal Dt. As a result, the transport motor 15 transports the paper S by generating a driving force corresponding to the duty signal Dt given from the transport motor control circuit 200.

=== Drive control of carriage motor 42 ===
<Function of Carriage Motor Control Unit 128>
Driving control of the carriage motor 42 is performed by the carriage motor control unit 128. The carriage motor control unit 128 drives the carriage motor 42 by a predetermined driving amount based on a carriage movement command from the controller 126. The carriage motor 42 is driven by the commanded predetermined drive amount. The moving amount of the carriage 41 is determined according to the driving amount of the carriage motor 42. In the present embodiment, the movement amount of the carriage 41 is detected by the linear encoder 51. While monitoring the output from the linear encoder 51, the carriage motor control unit 128 drives the carriage motor 42 by an instructed predetermined driving amount to move the carriage 41 by a predetermined distance.

 The linear encoder 51 includes a linear encoder code plate 511 (see FIG. 2) and a detection unit (not shown), like the rotary encoder 134. As shown in FIG. 2, the linear encoder code plate 511 is attached to the frame side inside the inkjet printer 1. On the other hand, the detection unit (not shown) is attached to the carriage 41 side. The detection unit has a configuration that is substantially the same as the configuration of the detection unit 404 of the rotary encoder 134 described with reference to FIGS. 8, 9A, and 9B. That is, the detection unit outputs two pulses that differ depending on the rotation direction of the carriage motor 42, that is, the carriage movement direction. The linear encoder code plate 511 and the detection unit can detect the current position of the carriage 41.

<Configuration of Carriage Motor Control Unit 128>
Next, the configuration of the carriage motor control unit 128 will be described with reference to FIGS. 13 to 15B. FIG. 13 is a block diagram showing a configuration of the carriage motor control unit 128. FIG. 14 is a CR moving speed profile used for the CR moving operation. 15A and 15B are explanatory diagrams showing the relationship between the motor drive signal Sdr and the characteristics of the carriage motor 42.

As shown in FIG. 13, the carriage motor control unit 128 includes a carriage motor control circuit 200a and a carriage motor drive circuit 150a.
The output signal Sen of the linear encoder 51 is input to the position calculation circuit 230a and the speed calculation circuit 232a in the carriage motor control circuit 200a. These circuits 230a and 232a obtain the current rotational position P and the current rotational speed V of the carriage motor 42 based on the two pulses (not shown) of the output signal Sen of the encoder 51, respectively. The first subtractor 202a obtains a deviation ΔP between the given target rotational position Pt and the current rotational position P and inputs it to the target rotational speed generation circuit 204a. The target rotation speed generation circuit 204a generates a target rotation speed Vt corresponding to the rotation position deviation ΔP based on the CR movement speed profile shown in FIG.

 The CR moving speed profile includes a deceleration area in which the carriage 41 traveling at a predetermined moving speed Vca in a constant speed area is decelerated to a stopped state, an acceleration area in which the stopped carriage 41 is accelerated to a predetermined moving speed Vca, and In the CR movement speed profile table of the main memory 127, deceleration time Tbcca, acceleration time Tacca, and movement speed Vca are recorded as parameters for defining the CR movement speed profile. Then, these parameters are transmitted from the memory 127 to the target rotational speed generation circuit 204a via the controller 126, and based on these parameters, the target rotational speed generation circuit 204 transmits the CR movement speed profile in the deceleration region and the acceleration region. Form.

Note that the rotation amount Lbcca in the deceleration region and the rotation amount Lacca in the acceleration region are expressed by the areas of the respective regions, and are obtained by the following equations (31) and (32), respectively.
Lbcca = (Tbcca × Vca) / 2 (31)
Lacca = (Tacca × Vca) / 2 (32)

Further, the rotation amount La in the constant speed region that moves between the acceleration region and the deceleration region and moves the carriage 41 at the moving speed Vca is determined based on the print data, and the constant speed region time Tca is expressed by the following equation (33). Is required.
Tca = La / Vca (33)

 The second subtractor 206a shown in FIG. 13 obtains a deviation ΔV between the target rotational speed Vt and the current rotational speed V, and this rotational speed deviation ΔV is converted into a proportional element 210a, an integral element 212a, and a differential element 214a. input. The calculation results QP, QI, and QD of these three calculation elements 210a, 212a, and 214a are added by an adder 216a to calculate an addition result ΣQ.

The outputs QP, QI, QD of the respective arithmetic elements 210a, 212a, 214a and the addition result ΣQ are given by, for example, the following equations (41) to (44).
QP (j) = ΔV (j) × Kp (41)
QI (j) = QI (j−1) + ΔV (j) × Ki (42)
QD (j) = {ΔV (j) −ΔV (j−1)} × Kd (43)
ΣQ (j) = QP (j) + QI (j) + QD (j) (44)
Here, Kp is a proportional gain, Ki is an integral gain, and Kd is a differential gain. The outputs QP, QI, and QD are output at a predetermined output period Δtc, where j represents the current time, and j−1 represents the previous time point before the current time j by the output period Δtc. .

 The duty adjustment circuit 220a adjusts the level of the duty signal Dt supplied to the drive circuit 150a according to the addition result ΣQ (j). The duty signal Dt is a signal proportional to the addition result ΣQ (j) and is a signal indicating the duty of the carriage motor 42. Thus, the carriage motor 42 is controlled by so-called PWM (Plus Width Modulation) control.

 The carriage motor drive circuit 150a includes a DC-DC converter 154a configured by a transistor bridge and a base drive circuit 152a. The base drive circuit 152a generates a base signal to be applied to the base of the transistor of the DC-DC converter 154a in accordance with the duty signal Dt supplied from the carriage motor control circuit 200a. The DC-DC converter 154a generates a motor drive signal Sdr according to the base signal and supplies it to the carriage motor 42.

 FIG. 15A shows a signal change of the motor drive signal Sdr. The duty of the motor drive signal Sdr is a value obtained by dividing the period Ton at the on level by one cycle Tp of the drive signal. When a DC motor with a brush is used as the carriage motor 42, the torque / rotational speed characteristics are proportional to the duty as shown in FIG. 15B. The carriage motor drive circuit 150a generates the drive signal Sdr so that the duty of the drive signal Sdr is proportional to the duty signal Dt. As a result, the carriage motor 42 moves the carriage 41 by generating a driving force according to the duty signal Dt given from the carriage motor control circuit 200a.

=== About the operation of transporting the sheet S and the CR moving operation during the printing process ===
<Conventional control>
16A and 16B are explanatory diagrams of operation timings of the transport operation and the CR movement operation of the paper S during the printing process, and show the relationship between the transport speed during the printing process and the movement speed of the carriage 41. The horizontal axis is time, and the vertical axis is the speed.

  As shown in FIG. 16A, during the printing process, the conveyance operation and the CR movement operation of the paper S are alternately repeated according to a predetermined speed profile (the conveyance speed profile or the CR movement speed profile), respectively, and the CR The ink ejection operation is performed in the constant speed region of the movement operation.

  Here, for the sake of simplicity, as shown in FIG. 17, the size of the print area in the carriage movement direction (range on the sheet S on which the ink ejection operation is performed) is set for each CR movement operation. It shall be the same. Further, as shown in FIG. 16A, the ink discharge operation is started immediately after entering the constant speed region from the acceleration region in each CR movement operation, and the deceleration is started immediately after the completion of the ink discharge operation. Furthermore, it is assumed that the acceleration time Tacca and the deceleration time Tbcca are equal to each other in the CR movement operation.

 As shown in FIG. 16A, in this conventional control, for the purpose of increasing the throughput of the printing process, the transport operation of the sheet S is started from the end point tie of the ink discharge operation performed during the CR moving operation. ing. 16A, when the transport amount of the transport operation is large and the throughput of the printing process is limited by the transport operation, in addition to the above, the end time tte of the transport operation is predicted in advance, and The next CR movement operation is also started prior to the end time tte of the conveyance operation, and as a result, the next ink ejection operation is started immediately after the conveyance operation is completed, and further throughput is increased. We are trying to improve.

 This prediction is performed every stop time tce of the carriage 41, which is the end time tce of the previous CR movement operation, and the start time tcs of the next CR movement operation is adjusted based on this prediction. More specifically, by changing the length of stop time Tc1 starting from the stop time tce (hereinafter also referred to as stop time width Tc1), the carriage 41 is moved to the next time tte of the transport operation by the next time. It is adjusted to reach the start position of the ink ejection operation.

<How to obtain the stop time width Tc1>
As described above, the stop time width Tc1 is a start waiting time of the CR movement operation for adjusting the carriage 41 to reach the start position of the next ink discharge operation at the end point tte of the transport operation. . Therefore, the stop time width Tc1 can be expressed as a difference between the time Tt required for the transport operation and the time Ta required for the carriage 41 to move from the end position of the previous ink discharge operation to the start position of the next ink discharge operation. That is, it can be expressed by the following formula (51).
Tc1 = Tt−Ta (51)
The time Tt required for the transport operation in the above equation (51) can be obtained from the following equation (52) based on the transport speed profile and the transport amount L.
Tt = (Tacc + Tbcc) + (L-Lacc-Lbcc) / Vcc
(52)
That is, as described above with reference to FIG. 11, Tacc, Tbcc, and Vcc are the acceleration time in the acceleration region, the deceleration time in the deceleration region, and the transport speed in the constant speed region, respectively. Is stored in the transport speed profile table of the main memory 127. In addition, Lacc and Lbcc are respectively the carry amount in the acceleration region and the carry amount in the deceleration region, and can be obtained by calculation from the Tacc, Tbcc, and Vcc as described above with reference to FIG. . Therefore, Tt can be calculated.

On the other hand, Ta, that is, the time Ta required for the carriage 41 to move from the end position of the previous ink discharge operation to the start position of the next ink discharge operation is the above-mentioned assumption (from the acceleration region to the constant speed region in the CR movement operation). In consideration of the assumption that the ink discharge operation is started immediately after entering and the deceleration is started immediately after the ink discharge operation is completed, it can be obtained from the following equation (52) (see FIG. 16A).
Ta = Tbcca + Tacca (52)
Here, Tbcca and Tacca in the above equation (52) are the deceleration time and the acceleration time of the acceleration region, respectively, as described above with reference to FIG. It is stored in the CR movement speed profile table of the main memory 127. Therefore, Ta can also be calculated. From the above, the stop time width Tc1 can be obtained based on the equation (51).

 As a result of calculating the stop time width Tc1 based on the equation (51), the calculation result may be negative. This corresponds to the case where the transport amount is small as shown in FIG. 16B, Ta is longer than Tt, and the CR movement operation controls the throughput of the printing process. In such a case, The stop time width Tc1 is treated as zero instead of a negative value, and as shown in FIG. 16B, acceleration of the next CR moving operation is started immediately after the deceleration of the previous CR moving operation is completed and the moving speed becomes zero. It is like that.

<Length of Stop Time Width Tc1 Preferred from the Viewpoint of Heat Generation of Carriage Motor 42>
Here, considering the preferable length of the stop time width Tc1 from the viewpoint of heat generation of the carriage motor 42, as shown in FIG. 18A, each CR moving operation is decelerated and accelerated rapidly in a short time. Rather than increasing the stop time width Tc1 of the carriage motor 15, as shown in FIG. 18B, it is more effective to decelerate and accelerate the CR movement operation as slowly as possible to shorten the stop time width Tc1. It is desirable that the motor 42 does not become hot.

 Then, looking at FIG. 16A again, paying attention to this point, if the transport amount is large, the carriage motor 42 is between the deceleration area in the previous CR movement operation and the acceleration area in the next CR movement operation. The stop time width Tc1 is generated over a long time. Therefore, in this case, it is desirable from the viewpoint of suppressing heat generation that the carriage 41 is slowly decelerated and accelerated so that the stop time width Tc1 is as short as possible. Within the range of the width Tc1, even if the deceleration time Tbcca and the acceleration time Tacca of the carriage 41 are extended, the print processing throughput is not affected at all.

 Therefore, in the present embodiment, a plurality of types of CR movement speed profiles that define the deceleration area and the acceleration area are provided, and a CR movement speed profile that minimizes the stop time width Tc1 is selected from these. Based on this, the carriage 41 is moved in the deceleration area of the previous CR movement operation and the acceleration area of the next CR movement operation.

 As a result, as shown in FIG. 18B, within the range of the time Tt required for the transport operation, deceleration and acceleration of these CR moving operations are performed slowly over time, so that the throughput of the printing process is achieved. It is possible to effectively suppress the heat generation of the carriage motor 42 without lowering. Hereinafter, this is referred to as heat generation suppression processing.

=== About heat generation suppression processing ===
FIG. 19 is a control flowchart for performing heat generation suppression processing. FIG. 20 is an explanatory diagram of normal processing. In the control flow of FIG. 19, the controller 126 as a control unit reads out a program stored in the main memory 127 or the EEPROM 129 and executes it based on the program.

As shown in FIG. 20, this control flow is started at the end time tie of each ink ejection operation. If it does so, in step S200, the above-mentioned stop time width Tc1 will be calculated.
In this calculation, the parameters of the CR movement speed profile are used as described above, but in this embodiment, three types of CR movement speed profiles are provided as an example of a plurality of types. Therefore, the stop time width Tc1 is calculated for each CR moving speed profile.

 As the three types of CR movement speed profiles, first, second, and third CR movement speed profiles as shown in FIG. 21 are prepared. These CR moving speed profiles are different from each other in terms of deceleration in the deceleration area and acceleration in the acceleration area, and the moving speed Vca in the constant speed area is the same. Specifically, the magnitude of acceleration and deceleration is the largest in the first CR moving speed profile, and is in the order of the second and third CR moving speed profiles. Accordingly, among these, the first CR movement speed profile finishes the deceleration / acceleration of the CR movement operation in the shortest time, and the order of the second and third CR movement speed profiles is hereinafter described. This order is also the order in which the stop time width Tc1 is long. Incidentally, the deceleration time Tbcca and the acceleration time Tacca are equal to each other, that is, the magnitudes of acceleration and deceleration are equal to each other.

 In the next step S210, it is determined whether or not the heat generation suppression process can be executed based on the calculation result of the stop time width Tc1. That is, if at least one of the Tc1 calculation results is positive, the heat generation suppression process is executed. On the other hand, if any of the calculation results is negative, the heat generation suppression process is not executed and the printing is performed. Execute normal processing to improve processing throughput.

When the above calculation results are all negative, as described above with reference to FIG. 16B, the operation for limiting the throughput of the printing process is not the transport operation but the CR movement operation. Is the case. Therefore, in this case, the process proceeds to the normal process consisting of steps S220 and S225 in order to finish the deceleration of the previous CR movement operation and the acceleration of the next CR movement operation in a short time.
In step S220 in this normal processing, a predetermined first CR movement speed profile is selected to finish the deceleration / acceleration of the CR movement operation in a short time, and the stop time width Tc1 is set to zero, and the next step S225 is performed. Migrate to
In step S225, based on the first CR moving speed profile and the stop time width Tc1, the moving operation in the deceleration region in the previous CR moving operation and the acceleration region in the next CR moving operation is executed.

 More specifically, parameters (deceleration time Tbcca, acceleration time Tacca, and conveyance speed Vca) of the first CR movement speed profile are read from the CR movement speed profile table of the main memory 127, and these parameters are read out from the carriage motor. It transmits to the target rotational speed generation circuit 204a of the control unit 128. Then, based on these parameters, the target rotation speed generation circuit 204a drives the carriage motor 42 to execute the movement operation in the deceleration area in the previous CR movement operation and the acceleration area in the next CR movement operation. Note that the stop time width Tc1 between the deceleration region and the acceleration region is counted by a timer (not shown) that starts counting at the end of deceleration in the deceleration region, and when the count value reaches the Tc1, A start signal for moving the acceleration region is transmitted to the target rotation speed generation circuit 204a.

 Then, since the movement operation in the deceleration region in the previous CR movement operation and the acceleration region in the next CR movement operation performed in this way is based on the first CR movement speed profile, as shown in FIG. Each is executed at a large deceleration and acceleration and completed in a short time, and as a result, the throughput of the printing process can be increased.

 On the other hand, if at least one calculation result of Tc1 is positive in step S210, the process proceeds to a heat generation suppression process including steps S230 and S235. In step S230, in order to extend the deceleration range of the previous CR movement operation and the acceleration range of the next CR movement operation for a long time, the CR movement corresponding to the minimum calculation result among the positive calculation results is the stop time Tc1. Select a speed profile.

 For example, as shown in FIGS. 22A to 22C, when the calculation results of the first to third CR movement speed profiles are all positive, the third CR movement is performed as the CR movement speed profile having the minimum stop time Tc1. A speed profile is selected. In step S230, the calculation result of the stop time width Tc1 excludes the negative CR moving speed profile. When this CR moving speed profile is used, the CR moving operation determines the throughput of the printing process. Because it ends up.

 Then, in the next step S235, based on the CR movement speed profile selected in step S230, the movement operation in the deceleration region in the previous CR movement operation and the acceleration region in the next CR movement operation is executed. Specifically, the parameters (deceleration time Tbcca, acceleration time Tacca, and conveyance speed Vca) of the selected CR movement speed profile are read from the CR movement speed profile table of the main memory 127, and these parameters are read out as described above. The data is transmitted to the target rotation speed generation circuit 204a of the carriage motor control unit 128. Then, based on these parameters, the target rotational speed generation circuit 204a drives the carriage motor 42 to execute the movement operation in the deceleration area in the previous CR movement operation and the acceleration area in the next CR movement operation. Note that the stop time width Tc1 between the deceleration region and the acceleration region is counted by a timer (not shown) that starts counting at the end of deceleration in the deceleration region, and when the count value reaches the Tc1, A start signal for moving the acceleration region is transmitted to the target rotation speed generation circuit 204a.

 Then, the movement operation in the deceleration region in the previous CR movement operation and the acceleration region in the next CR movement operation performed in this manner is performed within a range in which the stop time width Tc1 does not disappear as shown in FIG. 22C. Therefore, the heat generation of the carriage motor 42 is effectively suppressed.

=== About the execution frequency of the heat generation suppression process ===
As is clear from the above description, the frequency of execution of the heat generation suppression process increases when the transport amount L of the transport operation is large, and decreases when the transport amount L is small. The transport amount L changes according to the print resolution in the transport direction, or changes when the type of printing method changes from so-called normal printing to so-called top-end printing or bottom-end printing.
On the other hand, generally, the printing resolution and the type of the printing method are associated with the printing mode. Then, the user sets a print mode through the user interface of the computer, thereby printing at a desired resolution or printing by a desired type of printing method. Therefore, it can be said that the execution frequency of the heat generation suppression process is determined according to these print modes.
In the following, an example in which the execution frequency of the heat generation suppression process changes due to the difference between these print modes will be described.

<Case 1>
In this case 1, the print mode is associated with the print resolution. In the first print mode for performing high-resolution printing, so-called interlaced printing is performed, and in the second print mode for performing low-resolution printing, so-called band printing is performed.

  Band printing and interlaced printing will be described with reference to FIGS. 23, 24A, and 24B. In these drawings, for convenience of explanation, the nozzle row shown as a substitute for the head 21 is depicted as moving with respect to the paper S, but this figure shows the relative relationship between the nozzle row and the paper S. This indicates the positional relationship, and the sheet S is actually moved in the transport direction. Further, the actual number of nozzles of the head 21 is 180, but here, description will be made assuming that the number of nozzles is eight. In the figure, nozzles indicated by black circles are nozzles that can eject ink droplets, and nozzles indicated by white circles are nozzles that cannot eject ink droplets. Hereinafter, the CR moving operation is also referred to as a path.

  As shown in FIG. 23, band printing is a printing method that completes a print area for the head height (= number of nozzles × nozzle pitch) for each pass. Since the head 21 has eight nozzles and the nozzle pitch k · D is 4 · D (see FIG. 5), the head height is 32 · D (= 8 × 4 · D). A print area is completed for each pass. Accordingly, the carry amount L is as large as 32 · D (= 8 × 4 · D). However, raster lines (rows of dots lined up along the carriage movement direction) can be formed only at a nozzle pitch of 4 · D in each print area completed in one pass, and the print resolution is low.

  On the other hand, as shown in FIGS. 24A and 24B, the interlace printing prints a print image with a dot pitch (1 · D in the illustrated example) smaller than the nozzle pitch 4 · D. That is, in interlaced printing, each time the paper S is transported at a constant transport amount L in the transport direction, each nozzle records a raster line adjacent to the raster line recorded in the immediately preceding pass. In order to perform recording with the carry amount L kept constant in this way, the number of nozzles N (integer) that can eject ink is relatively prime to k, and the carry amount L is set to N · D.

  Since the head 21 has eight nozzles and the nozzle pitch k · D is 4 · D, in order to satisfy the condition for performing interlaced printing, “N and k are relatively prime”, seven nozzles are provided. Interlaced printing is performed. Further, since seven nozzles (# 1 to # 7) are used, the sheet S is transported with a transport amount of 7 · D, which is smaller than 32 · D in the band printing. As a result, a raster line continuously arranged at a dot interval of 1 · D is formed on the paper S using a nozzle row having a nozzle pitch of 4 · D, and the printing resolution becomes high.

 Here, regarding the case 1, when considering the execution frequency of the heat generation suppression process, the transport amount in the second print mode for printing at a low resolution is 32 · D, and the transport in the first print mode for printing at a high resolution. The amount is 7 · D. Therefore, in the first case, the heat generation suppression process is executed more frequently in the second printing mode in which printing is performed at a low resolution.

<Case 2>
In this case 2, the printing mode is associated with the type of printing method. In the first printing mode, so-called upper end printing and lower end printing are executed, and in the second printing mode, so-called normal printing (interlaced printing described above) is performed. ). That is, when printing the downstream end and the upstream end in the transport direction, the first printing mode is selected, while the portion between the downstream end and the upstream end is selected. When printing is performed, the second print mode is selected.

First, normal printing will be described.
In the above description of interlaced printing, the number of nozzles is eight in order to simplify the description. However, the actual number of nozzles is 180. The interlaced printing method in this case will be described.
FIG. 25A is an explanatory diagram of actual normal printing. In the figure, the relative positions of the head 21 and the paper S are shown. Here, the head 21 has 180 nozzles arranged along the transport direction, but the nozzle pitch k · D is 4 · D. Therefore, the condition for performing interlaced printing is “N and k are relatively prime. In order to satisfy “Relationship”, interlaced printing is performed using 179 nozzles (# 2 to # 180). Further, since 179 nozzles are used, the paper S is transported by a transport amount of 179 · D.

  In a certain pass, the head 21 </ b> A ejects ink while moving in the carriage movement direction to form dots (raster lines) in the region 1 of the paper S. Next, the sheet S is conveyed at 179 · D, and the head 21A moves relative to the sheet S relative to the position of the head 21B in the drawing. In the next pass, the head 21 </ b> B ejects ink while moving in the carriage movement direction to form dots (raster lines) in the areas 1 and 2 of the paper S. Here, it is assumed that such an operation is continued until the head 21E forms dots on the paper S.

  FIG. 25B is an explanatory diagram of the dot formation status of each area after the head 21E forms dots on the paper S. FIG. In the figure, white circles indicate pixels in which dots are not formed. A black circle indicates a pixel in which dots are formed.

  In the area 1, dots (raster lines) are formed by the four passes by the heads 21A to 21D. In the area 2, dots are formed by the head 21B to the head 21E by four passes. As described above, in an area where four passes have passed, dots are formed in all the pixels in the area. In the area 3, dots are formed by the heads 21C to 21E by three passes. As described above, in an area where three passes have passed, dots are formed in pixels of three raster lines of the four raster lines. In region 4, dots are formed by the heads 21D and 21E by two passes. In this way, in the area where two passes have passed, dots are formed on the pixels of two raster lines of the four raster lines. In the area 5, dots are formed by one pass by 21E. As described above, in an area where one pass has passed, dots are formed in pixels of one raster line of the four raster lines. In the region 6, no dot has been formed yet.

As described above, in normal printing, if the head 21 passes only once, dots are not formed in all the pixels in the region. Specifically, it is necessary to pass k times (here, 4 times) in order to form dots in all the pixels in a certain region. For this reason, a continuous raster line cannot be formed at the upper end portion or the lower end portion of the printed image only by normal printing. For example, in FIG. 24A, a continuous raster line cannot be formed at the upper end portion and the lower end portion. In FIG. 25A and FIG. 25B, continuous raster lines cannot be formed in regions 3 to 6.
Therefore, top and bottom printing is performed before and after normal printing.
FIG. 26 is an explanatory diagram of upper end printing and lower end printing. Although the number of nozzles arranged in the transport direction is originally 180, the number of nozzles is assumed to be 8 here for the sake of simplicity.

  In the upper end printing, when the vicinity of the upper end of the print image is printed, the paper S is transported with a transport amount smaller than the transport amount during normal printing. For example, in the transport operation performed between pass 1 and pass 2, between pass 2 and pass 3, and between pass 3 and pass 4, the sheet S is transported by the transport amount D. In the transport operation performed between pass 4 and pass 5, the sheet S is transported by a transport amount 2 · D. In the upper end printing, the nozzles that eject ink are not constant. For example, nozzle # 2 to # 4 in pass 1, nozzle # 2 in pass 2, nozzles # 2 to # 7 in pass 3, nozzles # 2 to # 5 in pass 4, ink from nozzles # 2 to # 8 in pass 5 Is discharged. Since normal printing is performed from pass 5 onward, the paper S is transported by a transport amount of 7 · D, and ink is ejected from seven nozzles (nozzles # 2 to # 8). Thereby, a continuous raster line can be formed at the upper end portion of the printed image.

  In the lower end printing, as in the upper end printing, when the vicinity of the lower end of the print image is printed, the paper S is transported with a transport amount smaller than the transport amount during normal printing. Further, in the lower end printing, the nozzles for ejecting ink are not constant as in the upper end printing. Thereby, a continuous raster line can be formed at the lower end portion of the printed image.

  An area where a raster line is formed only by normal printing is called a normal printing area. An area located on the upper end side (downstream in the transport direction) of the paper S with respect to the normal print area is referred to as an upper end print area. In this upper end printing area, all raster lines formed by upper end printing and raster lines formed by normal printing are mixed. An area located on the lower end side (upstream side in the transport direction) of the normal printing area is referred to as a lower end printing area. In this lower end printing area, all raster lines formed by lower end printing and raster lines formed by normal printing are mixed.

  Thirty raster lines are formed in the upper end printing area. Similarly, 30 raster lines are also formed in the bottom print area. On the other hand, approximately several thousand raster lines are formed in the normal print area, although depending on the size of the paper S.

  The arrangement of raster lines in the normal printing area is regular. The first to seventh raster lines in the normal printing region in FIG. 26 are formed by nozzle # 3, nozzle # 5, nozzle # 7, nozzle # 2, nozzle # 4, nozzle # 6, and nozzle # 8, respectively. The The eighth and seventh raster lines in the normal printing area are formed by the nozzles in the same order. On the other hand, it is difficult to find regularity in the arrangement of raster lines in the upper end print area and the lower end print area as compared with the raster lines in the normal print area.

  As described above, when printing a print image on the paper S, upper end printing is performed, then normal printing is performed, and finally lower end printing is performed. As a result, after a continuous raster line is formed in the upper end printing area, a continuous raster line is formed in the normal printing area, and then a continuous raster line is formed in the lower end printing area.

 Here, regarding the case 2, when considering the execution frequency of the heat generation suppression process, the transport amount in the first printing mode for performing the top-end printing and the bottom-end printing is 1 · D to 2 · D, and the first print mode in which normal printing is performed. The transport amount in the 2-print mode is 7 · D. Therefore, in the second case, the heat generation suppression process is executed more frequently in the second printing mode in which normal printing is performed.

=== Other Embodiments ===
As described above, the inkjet printer 1 has been described as an example of a printing apparatus based on an embodiment. However, the above embodiment is for facilitating the understanding of the present invention, and the present invention is limited and interpreted. Not for. 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, the embodiments described below are also included in the present invention.

  In the above-described embodiment, the ink jet printer 1 has been described as an example of the printing apparatus. However, the printer is not limited to such a printing apparatus, and a printer that does not eject ink, such as a dot impact printer, a thermal transfer printer, or a laser beam printer Any device that has a printing function, such as a printer, is included in the printing device of the present invention.

  In the above-described embodiment, the paper S is exemplified as the medium. Examples of the paper S include plain paper, matte paper, cut paper, glossy paper, and photographic paper. The medium is not limited to the paper S, and may be a film material such as an OHP film or a gloss film, a cloth material, a metal plate material, or the like. That is, any medium can be used as long as it can be an ink ejection target.

 In the above-described embodiment, as an example of the method of “changing the CR moving speed profile according to the time Tt required for the conveyance operation” in relation to the heat generation suppressing process, “CR movement so that the stop time width Tc1 becomes the shortest” Although the method of “selecting the speed profile” is exemplified, the method is not limited to this method.

  In the above-described embodiment, the case where three types of CR movement speed profiles are prepared has been described as an example. However, the number of types may be two or more, and is not limited to any three types.

 In the above-described embodiment, the case where the acceleration in the conveyance speed profile and the acceleration in the CR movement speed profile and the deceleration in the deceleration area are constant values is illustrated, but the present invention is not limited to this, and the acceleration with time elapses. Further, the deceleration may be changed.

 In the above-described embodiment, to simplify the description, as shown in FIG. 17, the size of the print area in the carriage movement direction (the range on the sheet S on which the ink ejection operation is performed) is set for each CR movement operation. However, the present invention is not limited to this. As shown in FIGS. 27A and 28A, the print area may be different for each CR movement operation.

However, in this case, the following formula (52a) is used instead of the above formula (52) as a formula for obtaining Ta. That is, Ta in this case is longer by the time T2 than the sum of the deceleration time Tbcaa and the acceleration time Tacca based on the equation (52).
Ta = Tbcca + Tacca + T2 (52a)
As shown in FIG. 27A, when the print area of the next CR movement operation is shorter than the print area of the next CR movement operation by the distance Le in the carriage movement direction, as shown in FIG. This is because the ink ejection operation in the CR movement operation is started after elapse of time T2 corresponding to the distance Le after entering the constant speed region. Therefore, the “time Ta required for the carriage 41 to move from the end position of the previous ink discharge operation to the start position of the next ink discharge operation” can be expressed as an added value of the deceleration time Tbcca, the acceleration time Tacca, and the time T2. Therefore, it is expressed as in equation (52a).

The distance Le is known from the print data, and the moving speed Vca in the constant speed region is known from the CR moving speed profile. Therefore, the time T2 can be obtained from the following equation (52c).
T2 = Le / Vca (52c)

 In the case of FIG. 28A, as shown in FIG. 28B, the time T2 differs from FIG. 27B in that it appears in the previous CR movement operation, that is, the time during which ink is not ejected in the constant speed region is T2. In some ways it is the same. Therefore, also in the case of FIG. 28A, the “time Ta required for the carriage 41 to move from the end position of the previous ink discharge operation to the start position of the next ink discharge operation” is similarly expressed by the above equation (52a). Can be obtained from

It is explanatory drawing of the inkjet printer 1 which concerns on this embodiment. 2 is a perspective view of an internal configuration of the inkjet printer 1. FIG. 2 is a cross-sectional view of a transport unit of the inkjet printer 1. FIG. 2 is a block configuration diagram showing a system configuration of the inkjet printer 1. FIG. 4 is an arrangement diagram of nozzles provided on the lower surface of the head 21. FIG. 6 is a flowchart illustrating an example of a printing process procedure. 4 is an explanatory diagram of a configuration of a rotary encoder 134. FIG. It is explanatory drawing of the structure of the detection part 404 of the rotary encoder 134. FIG. FIG. 9A is a timing chart of the output waveform of the rotary encoder 134 during forward rotation, and FIG. 9B is a timing chart of the output waveform of the rotary encoder 134 during reverse rotation. 3 is a block diagram illustrating a configuration of a conveyance control unit 130. FIG. It is a conveyance speed profile used for conveyance operation. 12A and 12B are diagrams illustrating the relationship between the motor drive signal Sdr and the characteristics of the transport motor 15. 3 is a block diagram showing a configuration of a carriage motor control unit 128. FIG. It is CR movement speed profile used for CR movement operation. 15A and 15B are explanatory diagrams showing the relationship between the motor drive signal Sdr and the characteristics of the carriage motor 42. 16A and 16B are diagrams for explaining the operation timing of the transport operation and the CR movement operation of the paper S during the printing process. It is a figure for demonstrating the magnitude | size etc. of the carriage movement direction of the printing area | region formed by each CR movement operation | movement. 18A and 18B are diagrams for explaining the length of the stop time width Tc1 that is preferable from the viewpoint of heat generation of the carriage motor 42. FIG. It is a control flowchart for performing heat_generation | fever suppression processing. It is explanatory drawing of a normal process. It is explanatory drawing of three types of CR moving speed profiles. 22A to 22C are diagrams for explaining which CR moving speed profile is selected based on the stop time width Tc1. It is explanatory drawing of band printing. FIGS. 24A and 24B are both explanatory diagrams of interlaced printing, and FIG. 24B shows a state in which there is one more pass than FIG. 24A. FIG. 25A is an explanatory diagram of actual normal printing, and FIG. 25B is an explanatory diagram of the dot formation status of each area after the head 21E forms dots on the paper S. FIG. It is explanatory drawing of upper end printing and lower end printing. FIG. 27A and FIG. 27B are explanatory diagrams of Ta calculation formulas when the print area is different for each CR movement operation. 28A and 28B are explanatory diagrams of Ta calculation formulas when the print area is different for each CR movement operation.

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,
11A paper insertion slot, 11B roll paper insertion slot, 13 paper feed roller, 14 platen,
15 Conveyance motor, 17A Conveyance roller, 17B Discharge roller,
18A free roller, 18B free roller, 21 heads,
30 cleaning unit, 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, 122 buffer memory,
124 image buffer, 126 controller, 127 main memory,
128 Carriage motor controller, 129 EEPROM, 130 Transport controller,
132 head drive unit, 134 rotary encoder, 140 computer,
150 transport motor drive circuit, 152 base drive circuit,
154 DC-DC converter, 200 conveyance motor control circuit,
202 first subtractor, 204 target rotational speed generation circuit, 206 second subtractor,
210 proportional component, 212 integral component, 214 differential component, 216 adder,
220 duty adjustment circuit, 230 position calculation circuit, 232 speed calculation circuit,
150a carriage motor drive circuit, 152a base drive circuit,
154a DC-DC converter, 200a carriage motor control circuit,
202a first subtractor, 204a target rotational speed generation circuit,
206a second subtractor, 210a proportional element, 212a integral element,
214a differential element, 216a adder, 220a duty adjustment circuit,
230a position calculation circuit, 232a speed calculation circuit, 211Y nozzle row,
211C nozzle row, 211M nozzle row, 211K nozzle row,
402 rotary encoder code plate, 404 detector,
406 slit, 408 large gear, 410 small gear, 412 light emitting diode,
414 collimator lens, 416 detection processing unit, 418 photodiode,
420 signal processing circuit, 422A comparator, 422B comparator,
511 Linear encoder code plate, S paper

Claims (14)

(A) a driving motor for moving a head for discharging ink in a predetermined movement direction;
(B) a transport unit for transporting the medium in a transport direction that intersects the moving direction;
(C) a control unit for performing printing by repeatedly performing a moving operation of moving the head to the driving motor and a conveying operation of conveying the medium to the conveying unit;
A speed profile relating to the movement of the head between the end point of the ink discharge operation in a certain movement operation and the start point of the ink discharge operation in the next movement operation is represented by the transport operation between the end point and the start point. A control unit that changes according to the time required for
A printing apparatus comprising (D). The printing apparatus according to claim 1,
A plurality of the speed profiles;
Select one of the multiple types of speed profiles according to the time required,
A printing apparatus that performs movement of the head between the end time and the start time based on the selected speed profile. The printing apparatus according to claim 2,
The control unit calculates the time required for each of the transport operations, and for the plurality of types of speed profiles, the control unit needs to move the head from the head position at the end time to the head position at the start time. Calculate the time,
A printing apparatus that selects a speed profile that does not exceed the required time and that minimizes a deviation between the required time and the required time, among the calculated required times. The printing apparatus according to claim 3.
The speed profile includes a deceleration area in which the head moving at a predetermined speed in the certain movement operation is decelerated to a stop state, an acceleration area in which the head in the stop state is accelerated to the predetermined speed in the next movement operation, and And
Ink printing is performed while the head is moving at the predetermined speed. The printing apparatus according to claim 4,
If the required time is longer than the required time,
Between the deceleration area and the acceleration area, a stop time in which the head is stopped is provided,
The printing apparatus, wherein the head is adjusted to reach the start position of the ink discharge operation at the end of the transport operation by adjusting the length of the stop time. The printing apparatus according to claim 5, wherein
The length of the stop time Tc1 is obtained by substituting the required time Ta and the required time Tt into the following equations.
Tc1 = Tt-Ta The printing apparatus according to any one of claims 4 to 6,
While accelerating at a predetermined acceleration in the acceleration region, decelerating at a predetermined deceleration in the deceleration region,
The printing apparatus according to claim 1, wherein the plurality of types of speed profiles differ in terms of the acceleration and the deceleration. The printing apparatus according to any one of claims 2 to 7,
A first transport operation for performing the transport operation with a predetermined first transport amount; and a second transport operation for performing the transport operation with a second transport amount greater than the first transport amount;
When the first transport operation is selected, the movement of the head between the end time and the start time is executed using a predetermined speed profile,
When the second transport operation is selected, one of the plurality of speed profiles is selected and used according to the time required, and the time between the end time and the start time is selected. A printing apparatus in which movement of a head is executed. The printing apparatus according to claim 8, wherein
The resolution that defines the formation pitch in the transport direction of dots formed by the ink landing on the medium can be set for at least two types of high and low,
When a low resolution is set, the second transport operation is selected,
The printing apparatus is characterized in that the first transport operation is selected when a high resolution is set. The printing apparatus according to claim 8, wherein
When discharging ink toward the downstream end and the upstream end in the transport direction of the medium, the first transport operation is selected,
The printing apparatus, wherein the second transport operation is selected when ink is ejected toward a portion between a downstream end and an upstream end in the transport direction of the medium. . The printing apparatus according to claim 1,
The printing apparatus according to claim 1, wherein the head alternately performs a movement operation in the forward direction of the movement direction and a movement operation in the backward direction that is opposite to the forward direction. (A) a driving motor for moving a head for discharging ink in a predetermined movement direction;
(B) a transport unit for transporting the medium in a transport direction that intersects the moving direction;
(C) a control unit for performing printing by repeatedly performing a moving operation of moving the head to the driving motor and a conveying operation of conveying the medium to the conveying unit;
A speed profile relating to the movement of the head between the end point of the ink discharge operation in a certain movement operation and the start point of the ink discharge operation in the next movement operation is represented by the transport operation between the end point and the start point. A control unit that changes according to the time required for
(D)
A plurality of the speed profiles;
Select one of the multiple types of speed profiles according to the time required,
Performing the movement of the head between the end time and the start time based on the selected speed profile;
The control unit calculates the time required for each of the transport operations, and for the plurality of types of speed profiles, the control unit needs to move the head from the head position at the end time to the head position at the start time. Calculate the time,
In the calculated required time, a speed profile that does not exceed the required time and minimizes a deviation between the required time and the required time is selected.
The speed profile includes a deceleration area in which the head moving at a predetermined speed in the certain movement operation is decelerated to a stop state, an acceleration area in which the head in the stop state is accelerated to the predetermined speed in the next movement operation, and And
While the head is moving at the predetermined speed, ink ejection is performed,
If the required time is longer than the required time,
Between the deceleration area and the acceleration area, a stop time in which the head is stopped is provided,
By adjusting the length of the stop time, the head is adjusted to reach the start position of the ink ejection operation at the end of the transport operation,
The stop time length Tc1 is obtained by substituting the required time Ta and the required time Tt into the following equation,
Tc1 = Tt-Ta
While accelerating at a predetermined acceleration in the acceleration region, decelerating at a predetermined deceleration in the deceleration region,
The plurality of speed profiles are different in terms of the acceleration and the deceleration,
A first transport operation for performing the transport operation with a predetermined first transport amount; and a second transport operation for performing the transport operation with a second transport amount greater than the first transport amount;
When the first transport operation is selected, the movement of the head between the end time and the start time is executed using a predetermined speed profile,
When the second transport operation is selected, one of the plurality of speed profiles is selected and used according to the time required, and the time between the end time and the start time is selected. Head movement is performed,
The resolution that defines the formation pitch in the transport direction of dots formed by the ink landing on the medium can be set for at least two types of high and low,
When a low resolution is set, the second transport operation is selected,
When a high resolution is set, the first transport operation is selected,
When discharging ink toward the downstream end and the upstream end in the transport direction of the medium, the first transport operation is selected,
When the ink is ejected toward the portion between the downstream end and the upstream end in the transport direction of the medium, the second transport operation is selected,
The printing apparatus according to claim 1, wherein the head alternately performs a movement operation in the forward direction of the movement direction and a movement operation in the backward direction that is opposite to the forward direction. A printing method in which printing is performed by repeatedly performing a moving operation of ejecting ink from the head toward the medium and a transporting operation of transporting the medium in a transporting direction intersecting the moving direction while moving the head in a predetermined moving direction. In
A speed profile relating to the movement of the head between the end point of the ink discharge operation in a certain movement operation and the start point of the ink discharge operation in the next movement operation is represented by the transport operation between the end point and the start point. The printing method is characterized by changing according to the time required for the printing. A driving motor for moving a head for discharging ink in a predetermined moving direction;
A transport unit for transporting the medium in a transport direction that intersects the moving direction;
A program that is executed in a printing apparatus that includes a control unit for performing printing by repeatedly performing a moving operation of moving the head by the driving motor and a transporting operation of transporting the medium by the transporting unit. And
A speed profile relating to the movement of the head between the end point of the ink discharge operation in a certain movement operation and the start point of the ink discharge operation in the next movement operation is represented by the transport operation between the end point and the start point. A program characterized by executing a step that changes according to the time required for.

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