JP2016040083A - Liquid spray device and liquid spray method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid spray device and a liquid spray method that can suppress wasteful consumption of mediums and liquid and suppress printing unevenness.SOLUTION: The liquid spray device is equipped with: a first head 3A that is scanned in a first direction X in which liquid of the same kind is sprayed toward a medium S; a second head 3B that is scanned in the first direction X on the same shaft 8 as the shaft of the first head; scanning means that scans the first head and the second head independently from each other in the first direction X; control means 15 that controls the first head and the second head; and heating means 14 that heats the medium S. The control means can switch between a first mode where only the first head is scanned in the direction X so as to make only the first head spray the liquid, a second mode where the first head and the second head are scanned in the direction X so as to make the first head to spray the liquid, and a third mode where only the second head is scanned in the direction X so as to make only the second head spray the liquid. The control means is switched from the first mode into the second mode and from the second mode into the third mode.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid ejecting apparatus and a liquid ejecting method including a first head and a second head for ejecting liquid, and more particularly to an ink jet recording apparatus and an ink ejecting method for ejecting ink as a liquid.

  As a liquid ejecting apparatus that ejects a liquid onto an ejected medium, for example, an ink jet recording apparatus that ejects ink as a liquid and performs printing on a paper, a recording sheet, or the like as an ejected medium is known.

  In such an ink jet recording apparatus, there has been proposed one in which a plurality of heads for ejecting ink droplets are individually serially scanned and printed on a medium to be ejected (see, for example, Patent Documents 1 to 3).

Japanese Patent Application Laid-Open No. 11-058889 JP 2006-069226 A JP 2006-341543 A

  However, in the middle of printing in serial scanning, when an ink droplet ejection failure occurs in the nozzle opening, there is a problem that the ejection target medium is wasted and ink is wasted.

  In addition, if ink droplet ejection failure occurs during printing by serial scanning, if cleaning such as suction operation is performed during printing, until the printing area before cleaning and the printing area after cleaning are dried There is a problem that so-called banding such as printing unevenness due to a time difference of the printing medium and printing unevenness due to a deviation in the transport position of the ejected medium occurs.

  In particular, when the ink that has landed on the ejection medium is dried by a heating means such as a heater that heats the ejection medium, if the ejection failure is left unattended, the ink in the nozzle openings is solidified, and the cleaning operation is performed. Even if you go, you will not be able to resolve it.

  Such a problem is not limited to the ink jet recording apparatus, and similarly exists in a liquid ejecting apparatus that ejects liquid other than ink.

  SUMMARY An advantage of some aspects of the invention is that it provides a liquid ejecting apparatus and a liquid ejecting method capable of suppressing wasteful consumption of a medium to be ejected and liquid and suppressing print unevenness and improving print quality. And

[Aspect 1] Aspects of the present invention are a first head that scans a target medium in a first direction, and a second head that scans in the first direction coaxially with the first head. A second head that ejects the same type of liquid as the first head, a scanning unit that independently scans each of the first head and the second head in the first direction, the first head, A control unit that controls the second head; and a heating unit that heats the ejection target medium. The control unit scans only the first head in the first direction, and A first mode in which liquid is ejected only from the head; a second mode in which the first head and the second head are scanned in the first direction to eject liquid from the first head; and the second mode Only the head is scanned in the first direction, and the front The third mode in which liquid is ejected from only the second head can be switched, and the control unit switches from the first mode to the second mode, and switches from the second mode to the third mode. The liquid ejecting apparatus is characterized in that.
In this aspect, by switching the printing from the first head to the second head, it is possible to suppress a printing failure due to a droplet ejection failure during printing on the ejection target medium. Thereby, useless consumption of the ejection target medium and liquid can be suppressed. Further, before switching from printing by the first head in the first mode to printing by the second head in the third mode, the second head is scanned by the second mode to heat the second head by the heating unit. Can do. Therefore, the temperature difference between the first head and the second head during printing can be reduced, and the difference in ejection characteristics due to the temperature difference can be suppressed, thereby suppressing the banding that may occur at the joint of the print area. Can do. Further, if the second head is heated in the second mode and then printed in the third mode, the temperature change of the second head at the start and end of printing in the third mode can be suppressed. it can. Therefore, during the printing in the third mode, it is possible to suppress the change in the ejection characteristics of the droplets accompanying the temperature change, and it is possible to improve the print quality. Furthermore, since the second head is only heated to such an extent that the temperature difference from the first head is reduced in the second mode, the heating means does not eject the second head even if the second head does not eject droplets. The heating time can be shortened. Therefore, when the second head is heated excessively, it is possible to prevent the liquid near the nozzle opening from drying and thickening and causing an ejection abnormality.

  [Aspect 2] Here, in the liquid ejecting apparatus according to aspect 1, the control means ejects liquid from each head in each of a forward operation and a backward operation in a scan that reciprocates in the first direction. The scanning in the first mode is a scanning in which the forward operation and the backward operation are alternately performed, and any one of the last scanning in the first mode and the first scanning in the second mode is possible. One of the scans is a forward operation, and the other scan is preferably a backward operation. According to this, printing can be performed while moving each head in both directions in the first direction, so that printing can be performed in a short time. Further, when switching from the first mode to the second mode, it is possible to align the order of the forward operation and the backward operation in the first mode, so that the joint of the print areas when switching between the first mode and the second mode is achieved. Banding can be suppressed.

  [Aspect 3] In the liquid ejecting apparatus according to Aspect 1 or 2, the control means ejects liquid from each head in each of a forward operation and a backward operation in a scan that reciprocates in the first direction. The scan in the third mode is a scan in which the forward operation and the reverse operation are alternately performed, and the scan in the last scan in the second mode and the first scan in the third mode are possible. One of the scans is preferably a forward operation, and the other scan is preferably a backward operation. According to this, printing can be performed while moving each head in both directions in the first direction, so that printing can be performed in a short time. In addition, when switching from the second mode to the third mode, it is possible to align the order of the forward operation and the backward operation in the second mode, so the joint of the print areas at the time of switching between the second mode and the third mode. Banding can be suppressed.

  [Aspect 4] In the liquid ejecting apparatus according to any one of Aspects 1 to 3, it is preferable that the control unit changes the number of times of scanning in the second mode according to a scanning width. According to this, the second head can be sufficiently heated in the second mode, and excessive heating can be suppressed.

  [Aspect 5] Also, in the liquid ejecting apparatus according to any one of Aspects 1 to 4, the control means is configured to remove liquid from each head in each of a forward operation and a backward operation in a scan that reciprocates in the first direction. The time from the end of the forward operation injection only by the first head to the start of the backward operation injection, and the time from the end of the forward operation injection only by the first head It is preferable to perform control so that the time required for starting the backward operation injection with only the second head becomes the same time. According to this, the landing timing of the droplet when printing only the first head and the landing timing of the droplet when printing only the second head when switching from the first head to the second head are set to the same timing. Therefore, it is possible to improve the print quality by making the time until the landing of the next ink after the landed ink the same.

  [Aspect 6] The liquid ejecting apparatus according to any one of Aspects 1 to 5, further comprising a maintenance means for the first head and a maintenance means for the second head, wherein the maintenance means for the first head. Is provided on one side of the ejected medium in the first direction, and the maintenance means for the second head is preferably provided on the other side of the ejected medium in the first direction. . According to this, compared with the case where two maintenance means are provided on one side in the first direction and two maintenance means are provided on the other side in the first direction, a total of four maintenance means are provided. Miniaturization in the direction of 1 can be achieved. Further, the first maintenance means for maintaining the first head and the second maintenance means for maintaining the second head are provided on both sides in the first direction, respectively, so that printing is performed with one head. The maintenance of the other head can be performed, and the standby time for performing the maintenance can be shortened when the head mode is switched.

  [Aspect 7] In the liquid ejecting apparatus according to any one of Aspects 1 to 6, the liquid ejecting apparatus includes a detecting unit that detects an abnormality of the nozzle of each head, and the control unit detects the detection in the middle of printing in the first mode. When an abnormality is detected in the nozzle of the first head by the means, it is preferable to switch from the first mode to the second mode and from the second mode to the third mode. According to this, even if a liquid ejection abnormality occurs during printing, printing can be continued.

  [Aspect 8] In the liquid ejecting apparatus according to any one of aspects 1 to 7, when the control unit counts a predetermined number of counts during the ejection in the first mode, the control unit starts from the first mode. It is preferable to switch to the second mode and switch from the second mode to the third mode. According to this, even if the liquid ejection abnormality is not detected during printing, the mode can be switched before the liquid ejection abnormality occurs.

[Aspect 9] Another aspect of the present invention is a first head that scans the ejection target medium in a first direction and a second head that scans in the first direction coaxially with the first head. A liquid ejecting method for a liquid ejecting apparatus, comprising: a second head that ejects the same type of liquid as the first head; and a heating unit that heats the ejection target medium. Are scanned in the first direction, and the first mode in which liquid is ejected from only the first head, and the first head and the second head are scanned in the first direction, and the first A second mode in which liquid is ejected from the head and a third mode in which only the second head is scanned in the first direction and liquid is ejected only from the second head are switchably provided, Switch from the first mode to the second mode, and There is provided a liquid ejecting method, characterized in that switching from the second mode to the third mode.
In this aspect, by switching the printing from the first head to the second head, it is possible to suppress a printing failure due to a droplet ejection failure during printing on the ejection target medium. Thereby, useless consumption of the ejection target medium and liquid can be suppressed. Further, before switching from printing by the first head in the first mode to printing by the second head in the third mode, the second head is scanned by the second mode to heat the second head by the heating unit. Can do. Therefore, the temperature difference between the first head and the second head during printing can be reduced, and the difference in ejection characteristics due to the temperature difference can be suppressed, thereby suppressing the banding that may occur at the joint of the print area. Can do. Further, if the second head is heated in the second mode and then printed in the third mode, the temperature change of the second head at the start and end of printing in the third mode can be suppressed. it can. Therefore, during the printing in the third mode, it is possible to suppress the change in the ejection characteristics of the droplets accompanying the temperature change, and it is possible to improve the print quality. Furthermore, since the second head is only heated to such an extent that the temperature difference from the first head is reduced in the second mode, the heating means does not eject the second head even if the second head does not eject droplets. The heating time can be shortened. Therefore, when the second head is heated excessively, it is possible to prevent the liquid near the nozzle opening from drying and thickening and causing an ejection abnormality.

1 is a schematic diagram illustrating a schematic configuration of a recording apparatus according to a first embodiment of the invention. 1 is a plan view illustrating a schematic configuration of a recording apparatus according to a first embodiment of the invention. FIG. 3 is a block diagram illustrating a control configuration of the recording apparatus according to the first embodiment of the invention. FIG. 5 is a plan view showing the operation of the recording apparatus according to the first embodiment of the invention. FIG. 5 is a plan view showing the operation of the recording apparatus according to the first embodiment of the invention. FIG. 5 is a plan view showing the operation of the recording apparatus according to the first embodiment of the invention. 3 is a flowchart illustrating an ink ejection method according to the first embodiment of the invention. 3 is a flowchart illustrating an ink ejection method according to the first embodiment of the invention. 3 is a flowchart illustrating an ink ejection method according to the first embodiment of the invention. It is a flowchart which shows the ink ejection method which concerns on Embodiment 2 of this invention.

  Hereinafter, the present invention will be described in detail based on embodiments.

(Embodiment 1)
FIG. 1 is a schematic diagram illustrating an ink jet recording apparatus that is an example of a liquid ejecting apparatus according to Embodiment 1 of the invention, and FIG. 2 is a plan view of the ink jet recording apparatus.

  As shown in the drawing, an ink jet recording apparatus 1 which is an example of a liquid ejecting apparatus of the present invention includes an apparatus main body 2, a first head 3 </ b> A and a second head 3 </ b> B (which are provided on the apparatus main body 2 and are movably provided). Hereinafter, the head 3 is collectively referred to), a transport unit 4 that transports the ejection target medium S, and a support member 5.

  The first head 3A is detachably provided with an ink cartridge 6 that is a storage unit that stores ink as a liquid. The first head 3A and the ink cartridge 6 are held by the first carriage 7A. The first carriage 7A is provided on a carriage shaft 8 attached to the apparatus body 2 so as to be movable in the axial direction. In the present embodiment, the axial direction of the carriage shaft 8 is referred to as a first direction X. In other words, the first head 3 </ b> A can scan in the first direction X that is the axial direction of the carriage shaft 8. In the carriage shaft 8, a first head 3A is disposed on one X1 side, and a second head 3B described later in detail is disposed on the other X2 side.

  Further, a first drive motor 9A is provided on the X1 side in the first direction X of the carriage shaft 8 of the apparatus main body 2, and a groove is formed on the outer periphery of the tip of the rotation shaft of the first drive motor 9A. A first pulley 10a is provided. A second pulley 10b corresponding to the first pulley 10a of the first drive motor 9A is provided on the X2 side of the carriage shaft 8 in the first direction X. Furthermore, a first timing belt 11A such as a so-called endless belt formed of an elastic material such as rubber having a ring shape is hung between the first pulley 10a and the second pulley 10b. Is fixed to the first carriage 7A. Then, the driving force of the first drive motor 9A is transmitted to the first carriage 7A via the first timing belt 11A, so that the first carriage 7A on which the first head 3A is mounted moves along the carriage shaft 8. Moved.

  Note that the first head 3A ejects ink of four colors, black, cyan, magenta, and yellow, and an ink cartridge 6 having four colors of ink is mounted on the first carriage 7A.

  The second head 3B is detachably provided with an ink cartridge 6 that is a storage unit that stores ink as a liquid. Here, the ink cartridge 6 attached to the second head 3B holds the same ink as the ink held in the ink cartridge 6 attached to the first head 3A. That is, the second head 3B ejects the same ink as the first head 3A, that is, ink of four colors of black, cyan, magenta, and yellow in this embodiment. Such a second head 3B is held by the second carriage 7B. The second carriage 7B is provided on the same carriage shaft 8 as the first carriage 7A so as to be movable in the first direction X. That is, the second head 3B is provided so as to be able to scan coaxially with the first head 3A.

  Further, a second drive motor 9B is provided on the X2 side in the first direction X of the carriage shaft 8 of the apparatus main body 2, and a groove is formed on the outer periphery of the tip of the rotation shaft of the second drive motor 9B. A third pulley 10c is provided. A fourth pulley 10d corresponding to the third pulley 10c of the second drive motor 9B is provided on the X1 side of the carriage shaft 8 in the first direction X. Further, a second timing belt 11B such as a so-called endless belt formed of an elastic material such as an annular rubber ring is hung between the third pulley 10c and the fourth pulley 10d. Is fixed to the second carriage 7B. Then, the driving force of the second drive motor 9B is transmitted to the second carriage 7B via the second timing belt 11B, so that the second carriage 7B on which the second head 3B is mounted is along the carriage shaft 8. Moved.

  That is, in the present embodiment, the first drive motor 9A and the first timing belt 11A that drive the first head 3A, and the second drive motor 9B and the second timing belt 11B that drive the second head 3B are included. Scanning means for scanning the first head 3A and the second head 3B independently in the first direction X is provided. Of course, the scanning means is not limited to the one constituted by the first drive motor 9A, the second drive motor 9B, the first timing belt 11A, the second timing belt 11B, and the like, and moves the head 3 by a gear. Alternatively, the head 3 may be moved by liquid pressure or the like.

  Further, the apparatus main body 2 is provided with a conveying means 4. The transport unit 4 transports the ejection target medium S to the head 3 in a direction intersecting the first direction X that is the moving direction of the head 3, and is a first transport unit provided on both sides of the transport direction. 12 and second transport means 13. In the present embodiment, the transport direction of the ejection medium S is referred to as a second direction Y that is orthogonal to the first direction X, which is the movement direction of the head 3. The upstream side in the transport direction is referred to as Y1, and the downstream side is referred to as Y2. In the present embodiment, a direction orthogonal to both the first direction X and the second direction Y is referred to as a third direction Z, and in the third direction Z, the ejection medium S side is Z1 and the head 3. The side is referred to as Z2. Incidentally, although the first direction X, the second direction Y, and the third direction Z are orthogonal to each other in the present embodiment, the present invention is not particularly limited thereto.

  The first transport unit 12 includes a drive roller 12a, a driven roller 12b, and a transport belt 12c wound around the drive roller 12a and the driven roller 12b. Similarly to the first transport unit 12, the second transport unit 13 includes a drive roller 13a, a driven roller 13b, and a transport belt 13c.

  Driving means such as a driving motor (not shown) is connected to the driving rollers 12a and 13a of the first conveying means 12 and the second conveying means 13, and the conveying belt 12c, The ejection medium S is transported along the second direction Y on the upstream side and the downstream side of the second direction Y of the head 3 by the rotational drive of 13c.

  In the present embodiment, the first conveying unit 12 and the second conveying unit 13 including the driving rollers 12a and 13a, the driven rollers 12b and 13b, and the conveying belts 12c and 13c are exemplified. A holding means for holding the toner on the conveying belts 12c and 13c may be further provided. As the holding means, for example, a charging means for charging the outer peripheral surface of the ejection medium S is provided, and the ejection medium S charged by the charging means is adsorbed on the conveyor belts 12c and 13c by the action of dielectric polarization. Also good. Further, as a holding unit, a pressing roller may be provided on the conveying belts 12c and 13c, and the ejection target medium S may be sandwiched between the pressing roller and the conveying belts 12c and 13c.

  The support member 5 is made of a metal or resin having a rectangular cross section provided between the first transport unit 12 and the second transport unit 13 so as to face the moving region of the head 3. The support member 5 supports the ejection target medium S transported by the first transport unit 12 and the second transport unit 13 at a position facing the head 3. The support member 5 is provided with heating means 14 such as a heater for heating the transported medium S to be transported. In the present embodiment, the heating unit 14 heats the support member 5, and the ejected medium S is heated by the support member 5. The support member 5 may be further provided with a suction means for sucking the transported medium S on the support member 5. Examples of the suction unit include a unit that sucks and sucks the ejected medium S and a unit that electrostatically sucks the ejected medium S by electrostatic force.

  The apparatus main body 2 is provided with a control unit 15 connected to the first head 3A and the second head 3B. The control unit 15 controls the printing operation of the ink jet recording apparatus 1.

  Further, on both sides of the carriage shaft 8 of the apparatus main body 2 in the first direction X, that is, on the X1 side and the X2 side, the first maintenance means 16A and the second maintenance means 16B (hereinafter collectively referred to as maintenance means). 16). The maintenance means 16 of the present embodiment is a cap member 17 made of an elastic material such as rubber for capping a liquid ejecting surface provided with nozzle openings (not shown) for ejecting ink droplets of the first head 3A and the second head 3B. And a suction device 18 for sucking the inside of the cap member 17. Such a maintenance means 16 is a maintenance that removes foreign matters such as bubbles and dust from the nozzle openings together with ink by sucking the inside of the cap member 17 with a suction device while the liquid ejection surface is capped by the cap member 17. Is to do. In the present embodiment, the first maintenance means 16A provided on the X1 side performs maintenance of the first head 3A provided on the X1 side with respect to the carriage shaft 8, and the second maintenance means 16B provided on the X2 side. Performs maintenance of the second head 3B provided on the X2 side with respect to the carriage shaft 8. Of course, depending on the timing, the X2 side second head 3B is maintained by the first maintenance means 16A provided on the X1 side, and the X1 side first head 3A is maintained by the second maintenance means 16B provided on the X2 side. Maintenance may be performed.

  Further, in the present embodiment, the cap member 17 and the suction device 18 are provided as the maintenance unit 16, but the present invention is not particularly limited thereto, and the maintenance unit 16 may be a rubber or the like that wipes the liquid ejection surface of the head 3. A wiping means having a blade may be provided, or both a suction means and a wiping means may be provided.

  Furthermore, the maintenance means 16 of the present embodiment covers the nozzle opening by bringing the cap member 17 into contact with the liquid ejection surface without performing the suction operation by the suction device 18 when the head 3 is waiting for printing. , Has a role of suppressing drying and thickening of the ink in the vicinity of the nozzle opening. Of course, in addition to the cap member 17, an adhesion cap that covers the liquid ejection surface and suppresses drying and thickening of ink near the nozzle opening may be provided.

  In such an ink jet recording apparatus I, the ejected medium S is transported in the second direction Y by the transport means 4, and ink droplets ejected from one or both of the first head 3A and the second head 3B are collected. So-called printing is performed in which dots are formed by landing on the ejection target medium S supported on the support member 5. The printed ejection medium S is further transported by the transport means 4.

  Here, the control unit 15 of the present embodiment will be described with reference to FIG. FIG. 3 is a block diagram showing the configuration of the control unit.

  As shown in FIG. 3, the control unit 15, which is a control unit of this embodiment, includes a print control unit 100, a print position control unit 101, a maintenance control unit 102, a heating control unit 103, a count unit 104, a detection unit 105, and a mode. Switching means 106 is provided.

  The print control unit 100 controls the printing operation of the first head 3A and the second head 3B, and supplies drive waveforms (drive pulses) to the first head 3A and the second head 3B, for example, in response to the input of the print signal. Then, ink droplets are ejected from the first head 3A and the second head 3B.

  The printing position control unit 101 is configured to perform the first direction X and the second direction Y of the first head 3A and the second head 3B with respect to the ejection target medium S during printing and maintenance of the first head 3A and the second head 3B. Position the relative position. Specifically, the printing position control means 101 controls the first drive motor 9A to move or wait the first carriage 7A in the first direction X, thereby positioning the first head 3A in the first direction X. Do. Further, the printing position control means 101 controls the second drive motor 9B to move and stand by the second carriage 7B in the first direction X, thereby positioning the second head 3B in the first direction X. . The printing position control unit 101 controls the transport unit 4 to position the ejection target medium S in the second direction Y with respect to the head 3.

  The maintenance control unit 102 controls the operations of the first maintenance unit 16A and the second maintenance unit 16B. In the present embodiment, the maintenance unit 16 includes the cap member 17 and the suction device 18. Therefore, the maintenance control unit 102 causes the cap member 17 to come into contact with the liquid ejection surface of the head 3 and sucks the suction device 18. Maintenance is performed by performing the operation. The maintenance control unit 102 causes the maintenance unit 16 to perform maintenance at a predetermined timing. The timing at which the maintenance control unit 102 performs maintenance includes, for example, when the power is turned on, before execution of printing, after a predetermined time has elapsed, and when the ink cartridge 6 is replaced. As will be described in detail later, the maintenance control unit 102 performs maintenance when the count by the counting unit reaches a predetermined number.

  The heating control means 103 controls the heating means 14 provided on the support member 5, and controls the heating amount of the heating means 14 based on, for example, the temperature detected by a sensor (not shown). The sensor may be provided in the head 3, for example, or may be provided in the apparatus main body 2 to measure the temperature around the head 3.

  The counting means 104 counts a reference numerical value when switching between a first mode, a second mode, and a third mode, which will be described in detail later. For example, the printing time of the first head 3A and the second head 3B is counted. There is a timer to measure. Further, the counting means 104 is not limited to the one that measures the printing time of the head 3, and may be one that measures the number of ejections of ink droplets from the first head 3A and the second head 3B, for example. Further, the counting unit 104 may detect the liquid level of the ink cartridge 6 and measure the ink consumption. The counting means 104 may measure the amount of ink mist near the liquid ejection surface. That is, the counting means 104 is not particularly limited as long as it measures what serves as a guideline for occurrence of defective ejection of ink droplets, and includes one that measures any one or more of the above.

  The detecting means 105 detects an abnormality in ejecting ink droplets from the nozzle openings of the first head 3A and the second head 3B. Here, the ejection abnormality detected by the detection means 105 includes an abnormality in which an ink droplet is not ejected and an abnormality in which an ink droplet is unlikely to be ejected. An abnormality that does not cause ink droplets to be ejected is an abnormality that does not cause ink droplets to be ejected completely but appears as a sign that ink droplets are not ejected. For example, the weight of ink droplets decreases. And the case where the ejection direction of the ink droplet changes due to mist or the like adhering to the nozzle opening. As such a detection means 105, for example, there is one that detects whether or not an ink droplet ejected from the nozzle opening of the head 3 blocks light reception by the light receiving sensor. Further, as the detecting means 105, when a piezoelectric actuator is used as a pressure generating means for causing a pressure change in the flow path in the head 3, an excess voltage (electromotive voltage) generated in the piezoelectric actuator after the piezoelectric actuator is driven. ) And detecting an abnormal pressure change in the flow path from the state of vibration (residual vibration), for example, the period and amplitude of the residual vibration, to detect an abnormal injection. Further, as the detecting means 105, for example, the printing result of the ejection medium S by the ink jet recording apparatus I is read as an image, and ejection abnormality such as missing dots, or ejection that becomes a precursor of missing dots from the dot diameter or landing position. An optical sensor such as a scanner or a camera for detecting an abnormality can be used. Further, as the detecting means 105, for example, the ink is charged by applying a voltage between the inspection region made of the liquid absorber and the liquid ejecting surface provided with the nozzle openings, and the charged ink is ejected as ink droplets. Accordingly, a method of detecting an ejection abnormality based on the amplitude of the potential signal by outputting a potential signal representing a change in potential between the inspection region and the liquid ejection surface may be used. Furthermore, an optical sensor such as a scanner or a camera that detects an ejection abnormality by measuring the amount of mist adhering to the liquid ejection surface from an image obtained by imaging the liquid ejection surface can be used. Of course, the detection means 105 is not limited to that described above, and a conventionally known one can be used. In the present embodiment, the detecting means 105 is used to detect an excessive voltage of the piezoelectric actuator. As a result, the detection unit 105 can detect an ejection failure that is a precursor to dot missing or dot missing without interrupting printing during printing by the head 3. In addition, the detection of the ejection abnormality that is a precursor to missing dots can be realized by a method of detecting an excessive voltage of the piezoelectric actuator, a method of reading the printing result as an image, a method of reading the liquid ejection surface as an image, and the like.

  The mode switching unit 106 controls the print control unit 100 and the print position control unit 101 based on the measurement result of the count unit 104 and the detection result of the detection unit 105 to control the first mode, the second mode, and the third mode 3. Switch between two modes. The mode switching unit 106 controls the maintenance control unit 102 when switching to each mode, and performs maintenance of the head 3 waiting in the non-printing area.

  Here, each mode switched by the mode switching means 106 will be described. 4 to 6 are plan views showing the operation in each mode.

  In the first mode, as shown in FIG. 4, the first head 3A is scanned in the first direction X, and ink droplets are ejected from the first head 3A. In the first mode, the first head 3 </ b> A ejects ink droplets in each of the forward operation and the backward operation in a scan that reciprocates in the first direction X. The forward operation of the present embodiment is an operation from the X1 side to the X2 side with respect to the ejection medium S, and the backward operation is an operation from the X2 side to the X1 side with respect to the ejection medium S. is there.

  In the first mode, the second head 3B stands by in the non-printing area on the X2 side of the carriage shaft 8. In the present embodiment, in the first mode, the nozzle head opening of the second head 3B is covered by the cap member 17 (see FIG. 2) of the second maintenance means 16B, and drying and thickening of ink near the nozzle opening are suppressed. Has been.

  The second mode is switched from the first mode, and as shown in FIG. 5, the first head 3A and the second head 3B are scanned in the first direction X, and at least the ink from the first head 3A is detected. Spray drops. Here, in the second mode, the second head 3B is scanned in a region opposite to the support member 5 while ejecting ink droplets from the first head 3A, whereby the heating unit 14 causes the second head 3B to scan. Particularly, the vicinity of the nozzle opening of the liquid ejection surface is heated. That is, when switching from printing by the first head 3A to printing by the second head 3B, if printing is started without heating the second head 3B, the first head that has been printing while being heated by the heating means 14 is used. When ink droplets are ejected from the unheated second head 3B to 3A, the ejection characteristics of the ink droplets are greatly different, and banding is formed on the ejection target medium S. Therefore, in the second mode, the second head 3B is scanned when the first head 3A is printed, so that the second head 3B is heated and printing is performed at the same temperature as the first head 3A when the second head 3B is printed. Can be done. Therefore, the number of scans of the second head 3B in the second mode may be repeatedly performed so as to be the same temperature as the first head 3A. That is, when printing is performed on the ejection target medium S having a narrow width in the first direction X, the time to face the heating unit 14 is not sufficient if the second head 3B is reciprocated a small number of times. It is also conceivable that the desired temperature has not been reached without performing proper heating. Therefore, when the width of the ejected medium S is narrow, the number of times of scanning the second head 3B is increased, and when the width of the ejected medium S is wide, the number of times of scanning of the second head 3B is decreased. That's fine. That is, the number of times of scanning the second head 3B may be appropriately changed according to the width of scanning of the second head 3B determined by the width of the ejection target medium S in the first direction X. In addition, the number of times the second head 3B scans in the second mode is such that temperature sensors provided in the first head 3A and the second head 3B provide a temperature detected by the temperature sensor of the second head 3B. It may be performed until the temperature detected by the sensor is reached. Of course, if the relationship between the number of operations and the temperature is measured and understood in advance, the number of scans can be set without providing temperature sensors in the first head 3A and the second head 3B.

  Such a second mode is performed before the count number measured by the counting means 104 reaches the threshold value. That is, when the counting unit 104 measures the printing time of the first head 3A, the mode is switched from the first mode to the second mode immediately before a certain time elapses.

  In addition, it is preferable that one of the last scan in the first mode and the first scan in the second mode is a forward operation, and the other scan is a backward operation. For example, when the last scan of the first head 3A in the first mode is a backward operation, the first scan of the first head 3A in the second mode is preferably a backward operation. Thereby, at the time of switching between the first mode and the second mode, it is possible to arrange the landing order between the printing in the first mode and the printing in the second mode, and to suppress the occurrence of the waiting time. it can. That is, while the forward operation and the backward operation are repeatedly performed in the first mode, when the operation is switched to the second mode, the forward operation and the backward operation can be repeatedly performed continuously in the first mode. Therefore, by changing the landing order at the time of switching between the first mode and the second mode, it is possible to suppress the formation of banding such as uneven printing due to the change in landing order and uneven printing due to the time difference until drying at the joint of the printing areas. . Incidentally, in the first mode, the forward operation and the backward operation are alternately repeated. However, the last scan of the first head 3A in the first mode is set as the forward operation, and the first head 3A in the second mode is started. When the same scanning operation is performed, the landing operation is changed because the forward operation is repeated twice. In order to repeat the forward movement twice when switching from the first mode to the second mode, the first head 3A is positioned on the X2 side at the end of the first mode. This is because the head 3A must be moved to the X1 side, printing is interrupted, and there is a difference in the drying time of the ink that has already landed, so that banding is formed at the joint of the print areas. .

  In the second mode, ink droplets are not ejected from the second head 3B. However, for example, when the detecting unit 105 detects a detection error of missing dots in the first head 3A, the second head 3B You may make it eject an ink drop so that the dot used as the ejection abnormality of the head 3A may be complemented. In this case, the second mode may be immediately switched to the third mode. That is, in the second mode, at least ink droplets are ejected from the first head 3A, and ink droplets are ejected from the second head 3B.

  Incidentally, in the second mode, the scanning direction of the first head 3A in the first direction X and the scanning direction of the second head 3B in the first direction are preferably aligned in the same direction. That is, when the first head 3A is scanned in the forward movement, the second head 3B is similarly scanned in the forward movement to suppress the collision between the first head 3A and the second head 3B. In addition, the second head 3B can be opposed to the support member 5 for a long time. On the other hand, if the scanning directions of the first head 3A and the second head 3B are not aligned, the second head 3B has to scan so as not to obstruct the scanning of the first head 3A. This is because the opposing time is shortened and is not sufficiently heated. That is, by making the scanning direction of the first head 3A in the first direction X and the scanning direction of the second head 3B in the first direction the same direction, the second head 3B can be moved to a desired direction in a short time. Can be heated to temperature.

  The third mode is switched from the second mode. As shown in FIG. 6, the second head 3B is scanned in the first direction X, and ink droplets are ejected from the second head 3B. In the third mode, the second head 3B ejects ink droplets in each of the forward operation and the backward operation in a scan that reciprocates in the first direction X. The forward movement of the second head 3B of the present embodiment is the same as the forward movement of the first head 3A, and is the movement from the X1 side to the X2 side with respect to the ejection target medium S. The backward movement is from the X2 side. It is an operation toward the X1 side.

  The switching from the second mode to the third mode is performed immediately after the scanning of the second head 3B in the second mode set in advance is performed a prescribed number of times.

  In the third mode, the first head 3A is maintained by the first maintenance means 16A. Thereby, bubbles in the flow path, thickened ink in the vicinity of the nozzle opening, and the like are removed, and the first head 3A can stand by in a state where printing can be resumed immediately. Further, the first head 3A that has undergone maintenance in the third mode is a non-printing area on the X1 side of the carriage shaft 8 and the nozzle opening is covered by the cap member 17 of the first maintenance means 16A. The printer is on standby in a state where drying and thickening of the ink are suppressed.

  One of the last scan of the second head 3B in the second mode and the first scan of the second head 3B in the third mode is a forward operation, and the other scan is It is preferable to operate. As a result, even when switching between the second mode and the third mode, the landing order can be aligned between the printing in the second mode and the printing in the third mode, and a waiting time for switching occurs. Can be suppressed. Therefore, similarly to the switching between the first mode and the second mode, it is possible to suppress the formation of banding and improve the print quality.

  Note that such switching between the first mode, the second mode, and the third mode is performed based on the count number by the counting means 104 as described above. That is, when the time for which the head 3 performs printing becomes long, bubbles enter the flow path, or mist accompanying the ejection of ink droplets adheres and accumulates in the vicinity of the nozzle opening, causing an ejection failure of the ink droplets. . Further, even if the ink in the vicinity of the nozzle opening is dried and thickened, abnormal ejection of ink droplets occurs. Therefore, by measuring the printing time of the head 3 by the counting means 104, it is possible to switch from printing by the first head 3A to printing by the second head 3B before ink droplet ejection failure occurs. That is, in this embodiment, before the ink droplet ejection failure occurs, the printing is switched from the printing by the first head 3A to the printing by the second head. Of course, as described above, the counting means 104 is not limited to the one that measures time, and may be one that measures the number of ink ejections or that measures the amount of mist.

  The switching time from the second mode to the third mode is the same as the time from the end of the forward operation to the start of the backward operation when printing is performed by reciprocating only with the first head 3A. Is preferable. That is, when printing is performed by reciprocating only with the first head 3A, the time for switching from one of the forward operation and the backward operation to the other operation, and the last operation (forward operation or The time from the backward operation) to the first operation (forward operation or backward operation) of the second head 3B is preferably the same time. Thereby, the landing timing of ink droplets during printing of only the first head 3A is the same as the landing timing of ink droplets during printing of only the second head 3B when switching from the first head 3A to the second head 3B. Since the timing can be set, the print quality can be improved by making the time until the landing of the next ink after the landed ink the same. Of course, the time for switching from one of the forward operation and the backward operation during the printing of only the first head 3A to the other operation, and one of the forward operation and the backward operation during the printing of only the second head 3B. If the time for switching from the operation to the other operation is the same time, all the landing timings can be unified at the same time from the printing of the first head 3A until the printing of the second head 3B is completed. The quality can be further improved.

  Here, an ink ejection method in the ink jet recording apparatus 1 of the present embodiment will be described with reference to FIGS. 7 to 9 are flowcharts showing the ink ejection method.

  As shown in FIG. 7, when a print signal is input, in step S1, the mode switching unit 106 selects the first mode, and printing is executed by the first head 3A. Next, in step S2, it is determined whether the measurement result related to the first head 3A by the counting means 104 exceeds a threshold value. If it is determined in step S2 that the measurement result by the counting means 104 does not exceed the threshold value (step S2: No), the first mode of step S1 is maintained and printing by the first head 3A is continued. If it is determined in step S2 that the measurement result by the counting unit 104 exceeds the threshold value (step S2: Yes), the mode switching unit 106 switches from the first mode to the second mode in step S3. In the second mode, printing by the first head 3A is continued. In the second mode, the number of times the second head 3B is scanned is, for example, until the second head 3B is heated to the same temperature as the first head 3A. Next, in step S4, the mode switching unit 106 switches from the second mode to the third mode, and causes only the second head 3B to perform printing. In the present embodiment, maintenance of the first head 3A is performed in step S4. As a result, printing can be immediately executed by the first head 3A at the time of the next printing execution, so that the waiting time can be shortened.

  In this way, by switching printing from the first head 3A to the second head 3B, it is possible to suppress printing failure due to defective ejection of ink droplets during printing on the ejection target medium S. Thereby, useless consumption of the ejection target medium S and ink can be suppressed. In addition, before switching from printing by the first head 3A in the first mode to printing by the second head 3B in the third mode, the second head 3B is scanned in a region facing the support member 5 in the second mode. By heating, the temperature difference between the first head 3A and the second head 3B during printing can be reduced. Therefore, it is possible to suppress the occurrence of a difference in ejection characteristics due to the temperature difference between the first head 3A and the second head 3B, thereby suppressing the banding that may occur at the joint of the print areas, and improving the print quality. it can.

  Further, since the second head 3B is heated in the second mode and then printed in the third mode, the temperature change of the second head 3B at the start and end of printing in the third mode can be suppressed. it can. That is, since the second head 3B can perform printing at a high temperature from the start of printing, the ink droplet ejection characteristics do not change greatly during the printing in the third mode, and the printing quality is improved. Can do.

  Furthermore, since the second head 3B is only heated to such an extent that the temperature difference from the first head 3A is reduced in the second mode, the second head 3B does not eject ink droplets, and the heating unit 14 The heating time is short. Therefore, it is possible to prevent the ejection abnormality from occurring due to drying and thickening of the ink in the vicinity of the nozzle opening due to excessive heating of the second head 3B. That is, a method of always following the first head 3A and scanning the second head 3B in the first mode without providing the second mode is conceivable. However, when the second head 3B is always followed, the second head 3B is heated excessively, the ink in the vicinity of the nozzle opening is dried and thickened, ink ejection abnormality occurs, and printing by the second head 3B cannot be executed.

  Further, in the first mode and the second mode, the head 3 performs printing by a reciprocating operation, so that printing can be performed in a short time.

  In the third mode, the first head 3A does not perform printing, so the first head 3A can be maintained in the third mode. Therefore, printing by the first head 3A can be executed immediately after printing by the second head 3B.

  In the present embodiment, since the first maintenance means 16A is provided on the X1 side in the first direction X and the second maintenance means 16B is provided on the X2 side, the first maintenance means 16A is provided on the X1 side in the first direction X. And the second maintenance means 16B, the first maintenance means 16A and the second maintenance means 16B are provided on the X2 side in the first direction X, and the total number of maintenance means is four. 1 can be reduced in size in the first direction X. Further, since the first maintenance means 16A for maintaining the first head 3A is provided on the X1 side and the second maintenance means 16B for maintaining the second head 3B is provided on the X2 side, printing is executed with one head 3. In the meantime, the maintenance of the other head 3 can be performed, and when the printing of the head 3, that is, the mode is switched, the standby time for performing the maintenance can be shortened.

  Further, the mode may be switched based on the detection result of the detection means 105.

  A case where the detection unit 105 detects an ejection abnormality that is a precursor to missing dots will be described with reference to FIG.

  As shown in FIG. 8, in step S1, the mode switching unit 106 selects the first mode, and printing is executed by the first head 3A. Next, in step S5, it is determined whether or not the detection unit 105 has detected an ink droplet ejection abnormality (a precursor) of the first head 3A. If the detection unit 105 does not detect an ink droplet ejection abnormality in step S5 (step S5). : No) In step S2, it is determined whether the measurement result related to the first head 3A by the counting means 104 exceeds a threshold value. If the detection unit 105 detects an ink droplet abnormality in step S5, the mode switching unit 106 switches from the first mode to the second mode in step S3.

  If it is determined in step S2 that the measurement result by the counting unit 104 exceeds the threshold value (step S2: Yes), the mode switching unit 106 switches from the first mode to the second mode in step S3. In the second mode, printing by the first head 3A is continued. In the second mode, the number of times the second head 3B is scanned is, for example, until the second head 3B is heated to the same temperature as the first head 3A. Next, in step S4, the mode switching unit 106 switches from the second mode to the third mode, and causes only the second head 3B to perform printing.

  If it is determined in step S2 that the measurement result by the counting means 104 does not exceed the threshold value (step S2: No), step S1, step S5, and step S2 are repeated.

  In addition, a case where the detection unit 105 detects a dot missing ejection abnormality will be described with reference to FIG.

  As shown in FIG. 9, the printing in the second mode in step S3 is performed from the printing in the first mode in step S1. Next, in step S6, it is determined whether or not the detection unit 105 has detected an ink droplet ejection abnormality (dot missing) of the first head 3A. In step S6, the detection unit 105 does not detect an ink droplet ejection abnormality (step S6). (S6: No), printing in the second mode is continued in step S3. In addition, when the detection unit 105 detects an ejection abnormality of the first head 3A in step S6 (step S6: Yes), ink droplets are ejected from the second head 3B, and dots are lost by the first head 3A. Complement part. Thereafter, immediately in step S4, the mode switching means 106 switches from the second mode to the third mode and causes only the second head 3B to perform printing. Of course, the dot missing complement by the second head 3B may be performed in the third mode, but if the dot missing is complemented in the third mode, the landing order of the ink droplets may be changed, There is a possibility that the print quality may deteriorate due to a deviation in the landing timing of the ink droplet filling the missing dot. Therefore, as described above, when the second head 3B supplements the dot missing of the first head 3A, the second head 3B follows the first head 3A in the second mode and is scanned and moved. It is preferred to do so.

(Embodiment 2)
FIG. 10 is a flowchart illustrating an ink ejection method according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the process similar to Embodiment 1 mentioned above, and the overlapping description is abbreviate | omitted.

  In the present embodiment, after the third mode, the mode is switched to the fourth mode, and then the fourth mode is switched to the first mode. Specifically, when printing is performed, the switching is performed from the first mode in step S1 to the third mode in step S4 as in the first embodiment.

  Next, in step S7, it is determined whether the measurement result related to the second head 3B by the counting means 104 exceeds a threshold value. If it is determined in step S7 that the measurement result by the counting means 104 does not exceed the threshold value (step S7: No), the third mode of step S4 is maintained and printing by the second head 3B is continued. If it is determined in step S7 that the measurement result by the counting unit 104 exceeds the threshold value (step S7: Yes), the mode switching unit 106 switches from the third mode to the fourth mode in step S8.

  Here, the fourth mode is switched from the third mode, and the first head 3A and the second head 3B are scanned in the first direction X to eject ink droplets from at least the second head 3B. . Here, in the fourth mode, the first head 3A is scanned in a region opposite to the support member 5 while ejecting ink droplets from the second head 3B. Particularly, the vicinity of the nozzle opening of the liquid ejection surface is heated. That is, the fourth mode is performed in order to switch from printing by the second head 3B to printing by the first head 3A contrary to the second mode, and is performed under the same conditions as in the second mode.

  The fourth mode in step 8 is performed until, for example, the first head 3A is heated to the same temperature as the second head 3B. Next, in step S1, the mode switching unit 106 switches from the fourth mode to the first mode, and causes only the first head 3A to perform printing.

  In the first mode of step S1 after step S8, maintenance of the second head 3B is executed. As a result, printing can be immediately executed by the second head 3B when the next printing is executed, so that the waiting time can be shortened.

  As described above, by repeatedly executing the first mode, the second mode, the third mode, and the fourth mode in order, it is possible to perform printing continuously over a long period of time during which printing is interrupted. Therefore, it is possible to continuously perform printing on the long ejected medium S without failure.

(Other embodiments)
As mentioned above, although each embodiment of this invention was described, the basic composition of this invention is not limited to the thing mentioned above. For example, in the first and second embodiments described above, the first maintenance means 16A and the second maintenance means 16B are provided on the X1 side and the X2 side of the carriage shaft 8, respectively. Only one of the maintenance means 16A and the second maintenance means 16B may be provided. However, when only the first maintenance means 16A is provided, the second head 3B cannot be maintained by the first maintenance means 16A during printing by the first head 3A in the first mode. Further, since the ejection failure may be improved by performing a flushing operation for ejecting ink droplets from the head 3 in the non-printing region, the maintenance unit 16 is not necessarily required.

  In the first and second embodiments described above, the detection unit 105 is provided. However, if the counting unit 104 is provided, the first mode, the second mode, and the second mode are detected before the injection abnormality is detected. To the third mode. Therefore, the detection means 105 is not always necessary.

  Further, in the first and second embodiments described above, the heating unit 14 is provided on the support member 5, but is not particularly limited thereto. For example, the heating unit 14 is provided on the Z <b> 2 side with respect to the ejection medium S. It may be.

  In the first and second embodiments described above, the ink jet recording apparatus 1 in which the ink cartridge 6 is mounted on the first carriage 7A and the second carriage 7B has been described. However, the present invention is not particularly limited thereto. The liquid storage means may be fixed to the apparatus main body 2 and the liquid storage means and the head 3 may be connected via a supply pipe such as a tube. In this case, since one storage means can be provided for the two heads 3, the cost can be reduced.

  In the above-described embodiment, the ink jet recording apparatus has been described as an example of the liquid ejecting apparatus. However, the present invention broadly targets all liquid ejecting apparatuses and ejects liquids other than ink. Of course, the present invention can also be applied to a liquid ejecting apparatus. Other heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejection heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FEDs (field emission displays). Examples thereof include an electrode material ejection head used for electrode formation, a bio-organic matter ejection head used for biochip production, and the like, and can also be applied to a liquid ejection apparatus including such a head.

  DESCRIPTION OF SYMBOLS 1 Inkjet recording device (liquid ejecting apparatus), 2 Apparatus main body, 3 Head, 3A 1st head, 3B 2nd head, 4 Conveyance means, 5 Support member, 6 Ink cartridge, 7A 1st carriage, 7B 2nd carriage, 8 Carriage shaft, 9A 1st drive motor, 9B 2nd drive motor, 10a 1st pulley, 10b 2nd pulley, 10c 3rd pulley, 10d 4th pulley, 11A 1st timing belt, 11B 2nd timing belt, 12 1st 1 transport means, 13 second transport means, 14 heating means, 15 control unit, 16 maintenance means, 16A first maintenance means, 16B second maintenance means, 17 cap member, 18 suction device, S ejected medium, X First direction, Y Second direction, Z third direction

Claims (9)

A first head that scans the ejected medium in a first direction;
A second head that scans in the first direction coaxially with the first head, the second head ejecting the same type of liquid as the first head;
Scanning means for independently scanning each of the first head and the second head in the first direction;
Control means for controlling the first head and the second head;
Heating means for heating the ejected medium,
The control means includes
A first mode in which only the first head is scanned in the first direction and liquid is ejected from only the first head; and
A second mode in which the first head and the second head are scanned in the first direction and liquid is ejected from the first head;
A third mode in which only the second head is scanned in the first direction and liquid is ejected from only the second head can be switched.
The liquid ejecting apparatus, wherein the control unit switches from the first mode to the second mode, and switches from the second mode to the third mode. The control means is capable of ejecting liquid from each head in each of a forward operation and a backward operation in a scan that reciprocates in the first direction,
The scan in the first mode is a scan in which a forward operation and a backward operation are alternately performed,
2. The method according to claim 1, wherein one of the last scan in the first mode and the first scan in the second mode is a forward operation, and the other scan is a backward operation. The liquid ejecting apparatus according to 1. The control means is capable of ejecting liquid from each head in each of a forward operation and a backward operation in a scan that reciprocates in the first direction,
The scanning in the third mode is a scanning in which the forward operation and the backward operation are alternately performed,
The scanning operation according to any one of the last scanning in the second mode and the first scanning in the third mode is a forward operation, and the other scanning is a backward operation. The liquid ejecting apparatus according to 1 or 2.   The liquid ejecting apparatus according to claim 1, wherein the control unit changes the number of times of scanning in the second mode in accordance with a scanning width. The control means is capable of ejecting liquid from each head in each of a forward operation and a backward operation in a scan that reciprocates in the first direction,
The time from the completion of the forward movement injection only after the first head to the start of the backward movement injection, and the backward movement injection from the second head only after the forward movement injection is completed only by the first head. 5. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is controlled such that the time until the start of the liquid becomes the same time. 6. Maintenance means for the first head, and maintenance means for the second head,
The maintenance means for the first head is provided on one side of the ejected medium in the first direction, and the maintenance means for the second head is located on the other side of the ejected medium in the first direction. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is provided on the liquid ejecting apparatus. Provided with detecting means for detecting abnormalities in the nozzles of each head,
The control means switches from the first mode to the second mode when the detection means detects an abnormality in the nozzles of the first head during printing in the first mode, and the second mode. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is switched from the first mode to the third mode.   The control means switches from the first mode to the second mode and switches from the second mode to the third mode when a predetermined count is counted during the injection in the first mode. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus. A first head that scans the ejected medium in a first direction;
A second head that scans in the first direction coaxially with the first head, the second head ejecting the same type of liquid as the first head;
A liquid ejecting method for a liquid ejecting apparatus, comprising: a heating unit that heats the ejected medium,
A first mode in which only the first head is scanned in the first direction and liquid is ejected from only the first head; and
A second mode in which the first head and the second head are scanned in the first direction and liquid is ejected from the first head;
A third mode in which only the second head is scanned in the first direction and liquid is ejected from only the second head can be switched.
A liquid ejecting method comprising: switching from the first mode to the second mode, and switching from the second mode to the third mode.

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