Droplet ejection device, droplet ejection method, and droplet ejection program

Abstract

To provide a droplet discharge device, a droplet discharge method, and a droplet discharge program which can suppress deterioration of throughput.SOLUTION: A droplet discharge device includes: a discharge head having an actuator for discharging droplet from a nozzle; a carriage which is mounted with the discharge head and reciprocally moves in a movement direction; a storage device for storing information on a predetermined first timing as a timing for starting non-discharge flushing for imparting a pressure to a liquid in a pressure chamber by the actuator so as to vibrate the liquid in the nozzle of the discharge head during deceleration to stop the carriage in a non-discharge manner; and a control device for selecting any one timing of a first timing stored in the storage device and a second timing different from the first timing on the basis of predetermined state information, and starting the non-discharge flushing during deceleration to stop the carriage at the selected timing.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a droplet ejection device, a droplet ejection method, and a droplet ejection program used in an image recording device such as an inkjet printer. [Background technology]

[0002] Conventionally, inkjet printers equipped with ejection heads that eject ink droplets from nozzles onto a print medium are known. In such ejection heads, the solvent in the ink dries out in nozzles when printing is paused or in nozzles that rarely eject ink. This increases the viscosity of the ink, making it difficult to eject the ink. To prevent this problem, it is known to perform non-ejection flushing, which agitates the ink in the nozzles and pressure chambers by applying a drive signal different from that used when ejecting ink to an actuator (see, for example, Patent Document 1). In the droplet ejection device of Patent Document 1, non-ejection flushing is performed simultaneously with the carriage decelerating toward the target stop position. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-160819 Summary of the Invention [Problem to be solved by the invention]

[0004] However, due to various factors such as component wear, the carriage may stop at a position shorter than the target stop position. In other words, the carriage may stop earlier than planned. Therefore, if non-ejection flushing is uniformly performed when the carriage decelerates toward the target stop position, as in Patent Document 1, non-ejection flushing may not be complete by the time the carriage stops. As a result, the next printing operation cannot proceed until non-ejection flushing is complete, which can reduce throughput.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a droplet ejection device, a droplet ejection method, and a droplet ejection program that can suppress a decrease in throughput. [Means for solving the problem]

[0006] The droplet ejection device of the present invention comprises an ejection head having a nozzle connected to a pressure chamber that stores liquid and an actuator that applies pressure to the liquid in the pressure chamber to eject droplets from the nozzle; a carriage on which the ejection head is mounted and that moves back and forth in a movement direction; a memory device that stores information regarding a predetermined first timing as the timing to start non-ejection flushing, in which the actuator applies pressure to the liquid in the pressure chamber so as to vibrate the liquid in the nozzle of the ejection head without ejecting it during deceleration to stop the carriage; and a control device, wherein the control device selects either the first timing or a second timing different from the first timing stored in the memory device based on the predetermined status information, and starts the non-ejection flushing at the selected timing during deceleration to stop the carriage.

[0007] According to the present invention, unlike the conventional configuration in which non-ejection flushing is uniformly performed when the carriage decelerates toward the target stop position, non-ejection flushing is performed at either the first timing or the second timing based on the status information. This allows non-ejection flushing to be completed before the carriage stops. This prevents a situation in which non-ejection flushing is not completed when the carriage stops. Therefore, the next printing operation can be started immediately after the carriage stops, thereby suppressing or preventing a decrease in throughput. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a droplet ejection device, a droplet ejection method, and a droplet ejection program that are capable of suppressing a decrease in throughput. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view showing a schematic configuration of a droplet ejection device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of a discharge head of the droplet discharge device of FIG. [Figure 3] FIG. 2 is a block diagram showing the configuration of the droplet ejection device of FIG. [Figure 4] 10A and 10B are diagrams illustrating non-ejection flushing that is started at a first timing. [Figure 5] 10A and 10B are diagrams illustrating non-ejection flushing that is started at a second timing different from the first timing. [Figure 6] 10 is a flowchart showing an example of a control flow by the control device. [Figure 7] 10A and 10B are diagrams illustrating non-ejection flushing that is performed based on the difference between the target stop position and the actual stop position of the carriage. [Figure 8] 10 is a flowchart showing an example of a control flow by the control device. [Figure 9]FIG. 10 is a diagram showing a cartridge integrated with an ejection head. DETAILED DESCRIPTION OF THE INVENTION

[0010] A droplet ejection device, a droplet ejection method, and a droplet ejection program according to an embodiment of the present invention will be described below with reference to the drawings. The droplet ejection device, the droplet ejection method, and the droplet ejection program described below are merely one embodiment of the present invention. Therefore, the present invention is not limited to the following embodiment, and additions, deletions, and modifications are possible within the scope of the present invention.

[0011] (First embodiment) 1, a droplet ejection device 10 of this embodiment uses ink as an example of a liquid and ejects ink droplets as an example of a droplet, and includes a storage tank 12, a carriage 16, an ejection head 20, a pair of transport rollers 15, a pair of guide rails 17, and a sub-tank 18. In the droplet ejection device 10, a print medium W is placed on a platen (not shown).

[0012] An ejection head 20 is mounted on the carriage 16. The carriage 16 is supported by a pair of guide rails 17 extending in a movement direction Ds perpendicular to the transport direction Df of the print medium W, such as printing paper, and moves back and forth in the movement direction Ds along the guide rails 17. This causes the ejection head 20 to move back and forth in the movement direction Ds. The storage tank 12 and the ejection head 20 are connected by tubes 12a. More specifically, the carriage 16 is mounted with, for example, four sub-tanks 18. Each sub-tank 18 is connected to a corresponding storage tank 12 via the tube 12a and supplies ink to a pressure chamber 28 in the ejection head 20, which will be described later. In this configuration, the storage tank 12 is provided away from the carriage 16 in this embodiment. The storage tank 12 corresponds to a second cartridge.

[0013] The ejection head 20 is, for example, an inkjet head that ejects ink droplets. The ejection head 20 ejects ink droplets of each color, for example, yellow (Y), magenta (M), cyan (C), and black (K), which are sometimes collectively referred to as color inks. The ejection head 20 is provided with nozzle rows that extend along the transport direction Df and eject each of the ink droplets. The ejection head 20 may also be an inkjet head that ejects white (W) ink droplets and clear (Cr) ink droplets.

[0014] For example, four storage tanks 12 are provided, and the four storage tanks 12 are arranged on one side of the center of the guide rail 17 in the movement direction Ds (the right end side in FIG. 1). The movement direction Ds includes a first movement direction Ds1 and a second movement direction Ds2 that is the opposite direction to the first movement direction Ds1. The first movement direction Ds1 is the direction in which the carriage 16 moves away from the storage tank 12, and the second movement direction Ds2 is the direction in which the carriage 16 moves closer to the storage tank 12. The tube 12a connects the storage tank 12 and the portion of the sub-tank 18 on the second movement direction Ds2 side. Note that while FIG. 1 shows only one tube 12a for simplification, the tube 12a is provided corresponding to the combination of the storage tank 12 and the sub-tank 18. Therefore, in this embodiment, four tubes 12a are provided. In this configuration, the tube 12a includes a portion 12ak that is more bent when the carriage 16 moves in the second movement direction Ds2 than when the carriage 16 moves in the first movement direction Ds1.

[0015] The pair of transport rollers 15 are arranged parallel to each other along the movement direction Ds. The transport rollers 15 rotate when a transport motor 31 (FIG. 3) described below is driven, thereby transporting the print medium W on the platen in the transport direction Df.

[0016] Ink is stored in the storage tanks 12. The storage tanks 12 are connected to the ejection heads 20 via ink flow paths to supply ink to the ejection heads 20. A storage tank 12 is provided for each type of ink. For example, four storage tanks 12 are provided, each storing black, yellow, cyan, and magenta ink.

[0017] As shown in Figure 2, the ejection head 20 has a plurality of nozzles 21 that eject ink droplets. The ejection head 20 has a laminated body of a flow path forming body and a volume changing unit. A liquid flow path is formed inside the flow path forming body, and a plurality of nozzle holes 21a are opened in the nozzle surface 40a, which is the lower surface of the flow path forming body. The volume changing unit is driven to change the volume of the liquid flow path. At this time, the meniscus vibrates in the nozzle holes 21a, and ink is ejected.

[0018] The flow path forming body of the ejection head 20 is a laminate of multiple plates, and the volume changing section includes a vibration plate 55 and an actuator (piezoelectric element) 60. The actuator 60 applies pressure to ink stored in a pressure chamber 28 (described below), causing ink droplets to be ejected from a nozzle 21 communicating with the pressure chamber 28. An insulating film 56 is connected to the top of the vibration plate 55, and a common electrode 61 (described below) is connected to the top of the insulating film 56.

[0019] The multiple plates are stacked including, in order from the bottom, a nozzle plate 46, a spacer plate 47, a first flow path plate 48, a second flow path plate 49, a third flow path plate 50, a fourth flow path plate 51, a fifth flow path plate 52, a sixth flow path plate 53, and a seventh flow path plate 54. The first flow path plate 48, the second flow path plate 49, the third flow path plate 50, the fourth flow path plate 51, and the fifth flow path plate 52 configure the manifold plate 44.

[0020] Each plate has holes and grooves of various sizes formed therein. Inside the flow path forming body where the plates are stacked, the holes and grooves are combined to form a plurality of nozzles 21, a plurality of individual flow paths 64, and a manifold 22 as liquid flow paths.

[0021] The nozzles 21 are formed to penetrate the nozzle plate 46 in the stacking direction. In the nozzle surface 40a of the nozzle plate 46, a plurality of nozzle holes 21a, which are the tips of the nozzles 21, are lined up in an arrangement direction that is the same direction as the transport direction Df to form a nozzle row.

[0022] The manifold 22 supplies ink to the pressure chambers 28 to which an ejection pressure for ink droplets is applied. The manifold 22 extends in the arrangement direction and is connected to one end of each of the individual flow paths 64. In other words, the manifold 22 functions as a common flow path for ink. The manifold 22 is formed by through-holes that penetrate the first flow path plate 48 to the fourth flow path plate 51 in the stacking direction and recesses that are recessed from the lower surface of the fifth flow path plate 52, which are overlapped in the stacking direction.

[0023] The nozzle plate 46 is disposed below a spacer plate 47. The spacer plate 47 is formed of, for example, stainless steel. The spacer plate 47 has a recess 45 formed by, for example, half-etching, recessing the surface on the nozzle plate 46 side in the thickness direction of the spacer plate 47, thereby forming a thin portion constituting the damper portion 47a and a damper space 47b. With this configuration, the damper space 47b is formed as a buffer space between the manifold 22 and the nozzle plate 46.

[0024] A supply port 22a communicates with the manifold 22. The supply port 22a is formed, for example, in a cylindrical shape and is provided at one end in the arrangement direction.

[0025] The multiple individual flow paths 64 are each connected to the manifold 22. The upstream ends of the individual flow paths 64 are connected to the manifold 22, and the downstream ends are connected to the base ends of the nozzles 21. The individual flow paths 64 are composed of a first communication hole 25, a supply throttle path 26 which is an individual throttle path, a second communication hole 27, a pressure chamber 28, and a descender 29, and these components are arranged in this order, and the pressure chamber 28 is connected to the nozzles 21.

[0026] The first communication hole 25 has a lower end connected to the upper end of the manifold 22, extends upward in the stacking direction from the manifold 22, and penetrates an upper portion of the fifth flow path plate 52 in the stacking direction.

[0027] The upstream end of supply throttle path 26 is connected to the upper end of first communication hole 25. Supply throttle path 26 is formed by half etching, for example, and is configured as a groove recessed from the lower surface of sixth flow path plate 53. Furthermore, second communication hole 27 has its upstream end connected to the downstream end of supply throttle path 26, extends upward in the stacking direction from supply throttle path 26, and is formed to penetrate sixth flow path plate 53 in the stacking direction.

[0028] The upstream end of the pressure chamber 28 is connected to the downstream end of the second communication hole 27. The pressure chamber 28 is formed to penetrate the seventh flow path plate 54 in the stacking direction.

[0029] The descender 29 is formed to penetrate the spacer plate 47, the first flow path plate 48, the second flow path plate 49, the third flow path plate 50, the fourth flow path plate 51, the fifth flow path plate 52, and the sixth flow path plate 53 in the stacking direction, and is disposed on the left side of the manifold 22 in the width direction. The descender 29 has an upstream end connected to the downstream end of the pressure chamber 28, and a downstream end connected to the base end of the nozzle 21. The nozzle 21 overlaps the descender 29 in the stacking direction, for example, and is disposed in the center of the descender 29 in the width direction perpendicular to the stacking direction.

[0030] The vibration plate 55 is laminated on the seventh flow path plate 54 and covers the upper openings of the pressure chambers 28.

[0031] The actuator 60 includes a common electrode 61, a piezoelectric layer 62, and an individual electrode 63, which are arranged in this order. The common electrode 61 covers the entire surface of the vibration plate 55 via an insulating film 56. The piezoelectric layer 62 covers the entire surface of the common electrode 61. The individual electrode 63 is provided for each pressure chamber 28 and is arranged on the piezoelectric layer 62. One individual electrode 63, the common electrode 61, and the portion of the piezoelectric layer 62 sandwiched between the two electrodes constitute one actuator 60.

[0032] The individual electrodes 63 are electrically connected to a driver IC. This driver IC receives a control signal from a control device 71 (described later) to generate a drive signal and apply it to the individual electrodes 63. In contrast, the common electrode 61 is always maintained at ground potential. In this configuration, the active portion of the piezoelectric layer 62 expands and contracts in the planar direction together with the two electrodes 61, 63 in response to the drive signal. In response, the vibration plate 55 deforms in cooperation with the drive signal, and the volume of the pressure chamber 28 changes in a direction that increases or decreases. As a result, an ejection pressure that ejects ink droplets from the nozzle 21 is applied to the pressure chamber 28.

[0033] In the ejection head 20, the supply port 22a is connected to the sub-tank 18 via a pipe. When a pressure pump provided in the pipe is driven, ink passes from the sub-tank 18 through the pipe and flows into the manifold 22 via the supply port 22a. The ink then flows from the manifold 22 into the supply throttle passage 26 via the first communication hole 25, and from the supply throttle passage 26 into the pressure chamber 28 via the second communication hole 27. The ink then flows through the descender 29 and into the nozzle 21. When an ejection pressure is applied to the pressure chamber 28 by the actuator 60, an ink droplet is ejected from the nozzle hole 21a.

[0034] Next, the above-mentioned components and other components of the droplet ejection device 10 of this embodiment will be described with reference to a block diagram.

[0035] In addition to the above-mentioned components, the droplet ejection device 10 includes a control device 71 which is composed of a CPU and corresponds to a computer, as shown in FIG. 3, a RAM 72, a ROM 73, a head driver IC 74, a temperature sensor 75, a waveform generation circuit 76, an IC chip reader 78, motor driver ICs 30 and 32, a conveying motor 31, and a carriage motor 33.

[0036] The temperature sensor 75 measures the temperature of the environment in which the droplet ejection device 10 is placed. The temperature sensor 75 is provided, for example, on the carriage 16. The control device 71 receives the temperature measured by the temperature sensor 75.

[0037] The waveform generating circuit 76 generates a drive waveform including a drive signal for driving the actuator 60. The drive signals include an ejection drive signal that applies pressure to the ink in the pressure chamber 28 so as to eject ink droplets from the nozzle 21, a non-ejection drive signal that applies pressure to the ink in the pressure chamber 28 so as to vibrate or agitate the meniscus in the nozzle 21 and the ink in the pressure chamber 28, etc., without ejecting ink droplets from the nozzle 21, and a non-vibration signal that does not vibrate the meniscus of the nozzle 21. The control device 71 provides the non-ejection drive signal generated by the waveform generating circuit 76 to the actuator 60 while the carriage 16 is decelerating to stop. This causes non-ejection flushing to be performed in the ejection head 20.

[0038] The ROM 73 stores information regarding a predetermined first timing, which is the timing for starting the non-ejection flushing described above while decelerating to stop the carriage 16, and information regarding the correction distance. The predetermined first timing and the correction distance will be described later. The RAM 72 also stores thresholds related to predetermined status information, which will be described later, print jobs and ejection data received from an external personal computer, etc. The RAM 72 and ROM 73 correspond to storage devices. The ROM 73 also stores a droplet ejection program used in the droplet ejection device 10 of this embodiment, a control program for performing various data processing, etc.

[0039] The control device 71 selects either the first timing or a second timing different from the first timing stored in the RAM 72 based on status information, which is numerical information indicating the status of the droplet ejection device 10. Then, at the selected timing, the control device 71 starts non-ejection flushing while decelerating to stop the carriage 16. Details of the non-ejection flushing by the control device 71 and the status information will be described later. The control device 71 corresponds to the selection means and the non-ejection flushing instruction means.

[0040] When an ink cartridge integrated with the ejection head 20 is used as in the second embodiment described below, the IC chip reader 78 reads information from an IC chip provided in the ink cartridge and determines whether the ink cartridge has a large capacity or a small capacity based on the information from the IC chip. The control device 71 receives the determination by the IC chip reader 78 as a detection result. The IC chip reader 78 is provided on the carriage 16, for example. The IC chip reader 78 corresponds to a detection unit.

[0041] The head driver IC 74 receives instructions from the control device 71 to cause the ejection head 20 to eject ink droplets. The motor driver IC 30 receives instructions from the control device 71 to control the drive of the transport motor 31. The transport motor 31 operates the transport roller 15 to transport the print medium W in the transport direction Df. Furthermore, the motor driver IC 32 receives instructions from the control device 71 to control the drive of the carriage motor 33. The carriage motor 33 operates the carriage 16 to move the ejection head 20 in the movement direction Ds.

[0042] Next, non-ejection flushing by the control device 71 will be described with reference to the drawings. Fig. 4 is a diagram illustrating non-ejection flushing that starts at a first timing T1. Fig. 5 is a diagram illustrating non-ejection flushing that starts at a second timing T2 that is different from the first timing T1.

[0043] 4, when the control device 71 causes the ejection head 20 to start pass printing, it causes the motor driver IC 32 to drive the carriage motor 33. This causes the carriage 16 to start moving in the movement direction Ds (first movement direction Ds1 or second movement direction Ds2). In this case, the movement speed of the carriage 16 increases toward the target speed and is then maintained at a substantially constant speed.

[0044] Next, when the control device 71 causes the ejection head 20 to finish pass printing, it stops driving the carriage motor 33 by the motor driver IC 32 so that the carriage 16 stops at the target stop position P0. As a result, the carriage 16 starts to decelerate toward the target stop position P0.

[0045] The control device 71 then selects either the first timing T1 or the second timing T2, and starts non-ejection flushing at the selected timing while the carriage 16 is decelerating. This will be explained in detail below.

[0046] 4, the first timing T1 is the timing when the carriage 16 reaches a first start position P1, which is a first distance x1 away from the target stop position P0 in the movement direction Ds. If the predetermined status information is less than the threshold, the control device 71 starts non-ejection flushing at the first timing T1 when the carriage 16 reaches the first start position P1 after the carriage 16 starts moving. This makes it possible to end the non-ejection flushing before the carriage 16 stops.

[0047] 5, the second timing T2 is the timing when the carriage 16 reaches a second start position P2, which is a second distance x2 obtained by adding a predetermined correction distance α to the first distance x1, before the target stop position P0. The control device 71 may change the correction distance α based on the value of the status information. If the predetermined status information is equal to or greater than a threshold, the control device 71 starts non-ejection flushing at the second timing T2 when the carriage 16 reaches the second start position P2 after the carriage 16 starts moving. This allows the non-ejection flushing to be completed before the carriage 16 stops.

[0048] The following describes several examples of the predetermined status information. The predetermined status information is, for example, the number of prints (cumulative number of prints) on the print medium W on which an image is formed by ejecting ink droplets from the nozzles 21. The number of prints on the print medium W is the number of sheets that has been continuously counted since the droplet ejection device 10 was new. The number of prints on the print medium W can be detected, for example, using a print count counter. If the number of prints on the print medium W is less than a threshold, the carriage 16 may stop before the target stop position P0 due to various factors such as aging of components constituting the carriage 16. In this case, by starting non-ejection flushing at the first timing T1, it is possible to end the non-ejection flushing before the carriage 16 stops. Alternatively, if the number of prints on the print medium W reaches or exceeds the threshold, the carriage 16 may stop before the target stop position P0 due to various factors. Even in such a case, by starting the non-ejection flushing at the second timing T2, which is earlier than the first timing T1, the non-ejection flushing can be completed before the carriage 16 stops.

[0049] The number of times the carriage 16 is driven may also be used as the predetermined status information. In this case, the number of times only the forward movement or the number of times only the backward movement may be counted as one, or one round trip may be counted as one. The number of times the carriage 16 is driven may be acquired, for example, based on the ejection data. If the number of times the carriage 16 is driven is less than the threshold value, the carriage 16 may stop before the target stop position P0 due to the various factors described above. In this case, by starting non-ejection flushing at the first timing T1, it is possible to end the non-ejection flushing before the carriage 16 stops. Alternatively, if the number of prints on the print medium W reaches or exceeds the threshold value, the carriage 16 may stop before the target stop position P0 due to the various factors described above. Even in this case, by starting non-ejection flushing at the second timing T2, which is earlier than the first timing T1, it is possible to end the non-ejection flushing before the carriage 16 stops.

[0050] Furthermore, the environmental temperature detected by the temperature sensor 75 may be used as the predetermined state information. If the environmental temperature detected by the temperature sensor 75 is equal to or higher than a threshold value, the carriage 16 may stop before the target stop position P0. In this case, by starting non-ejection flushing at the first timing T1, it is possible to end the non-ejection flushing before the carriage 16 stops. Alternatively, if the environmental temperature is lower than the threshold value, there is a risk that the carriage 16 may stop before the target stop position P0. Even in this case, by starting non-ejection flushing at the second timing T2, which is earlier than the first timing T1, it is possible to end the non-ejection flushing before the carriage 16 stops.

[0051] Furthermore, the movement direction of the carriage 16 in the second movement direction Ds2 may be used as the predetermined state information. When the carriage 16 moves in the first movement direction Ds1, a relatively small repulsive force against the tube 12a is generated in the carriage 16. As a result, there is a risk that the carriage 16 will stop before the target stop position P0. In this case, by starting non-ejection flushing at the first timing T1, it is possible to end the non-ejection flushing before the carriage 16 stops. In contrast, when the carriage 16 moves in the second movement direction Ds2, a relatively large repulsive force against the tube 12a is generated in the carriage 16. As a result, there is a risk that the carriage 16 will stop before the target stop position P0. Even in this case, by starting non-ejection flushing at the second timing T2, which is earlier than the first timing T1, it is possible to end the non-ejection flushing before the carriage 16 stops.

[0052] Next, the control flow by the control device 71 in this embodiment will be described with reference to a flowchart. Fig. 6 is a flowchart showing an example of the control flow by the control device 71.

[0053] 6, the control device 71 first determines whether or not a print command has been issued (step S1). If a print command has been issued (YES in step S1), the control device 71 executes the process of step S2, which will be described later. On the other hand, if a print command has not been issued (NO in step S1), the control device 71 waits until a print command is issued.

[0054] The control device 71 acquires predetermined status information in step S2. Next, the control device 71 determines whether the acquired status information is less than a predetermined threshold value (step S3). If the status information is less than the threshold value (YES in step S3), the control device 71 acquires a first start position P1 that is before the target stop position P0 (step S4). Then, the control device 71 accelerates the carriage 16 (step S5).

[0055] On the other hand, if the status information is equal to or greater than the threshold value (NO in step S3), the control device 71 acquires a second start position P2 that is closer to the target stop position P0 (step S6) and accelerates the carriage 16 (step S5). The control device 71 can acquire the first start position P1 and the second start position P2 based on the rotation speed of the carriage motor 33, which can be acquired, for example, by an encoder. The control device 71 may also appropriately change the first start position P1 based on the value of the status information, which is numerical information. When changing the second start position P2 based on the value of the status information, the control device 71 can appropriately change the second start position P2 by changing the correction distance α related to the first start position P1, as described above.

[0056] After the process of step S5, the control device 71 causes the ejection head 20 to perform printing (step S7). Subsequently, the control device 71 decelerates the carriage 16 and starts non-ejection flushing at the first start position P1 or the second start position P2 (step S8).

[0057] After the process of step S8, the control device 71 determines whether or not there is any data remaining to continue printing (step S9). If printing should continue (YES in step S9), the control device 71 returns to the process of step S2 described above and repeats the subsequent processes. On the other hand, if printing should not continue (NO in step S9), the control device 71 ends the process.

[0058] When the movement direction of the carriage 16 in the second movement direction Ds2 is used as the predetermined state information, it is determined in step S3 described above whether the movement direction of the carriage 16 is the second movement direction Ds2. If the movement direction of the carriage 16 is not the second movement direction Ds2 (i.e., if it is the first movement direction Ds1) (YES in step S3), a first start position P1 is acquired (step S4), and if the movement direction of the carriage 16 is the second movement direction Ds2 (NO in step S3), a second start position P2 is acquired (step S6).

[0059] As described above, according to the present embodiment, unlike the conventional configuration in which non-ejection flushing is uniformly performed when the carriage decelerates toward the target stop position, non-ejection flushing is performed at either the first timing T1 or the second timing T2 based on predetermined status information. This allows non-ejection flushing to be completed before the carriage 16 stops. This makes it possible to avoid a situation in which non-ejection flushing is not completed when the carriage 16 stops. Therefore, the next printing operation can be started immediately after the carriage 16 stops, thereby suppressing or preventing a decrease in throughput.

[0060] Furthermore, in this embodiment, the number of prints on the print medium W, the number of times the carriage 16 has been driven, and the environmental temperature detected by the temperature sensor 75, which are factors that cause the carriage 16 to stop before the target stop position P0, can be used as predetermined status information. As a result, even if the carriage 16 stops before the target stop position P0 due to the above factors, non-ejection flushing can be completed before the carriage 16 stops.

[0061] Furthermore, in this embodiment, the movement direction Ds of the carriage 16, which is a factor that causes the carriage 16 to stop before the target stop position P0, can be used as predetermined state information. This makes it possible to end non-ejection flushing before the carriage 16 stops, even if the carriage 16 stops before the target stop position P0 due to the above factor.

[0062] Furthermore, in this embodiment, the correction distance α can be changed based on the value of the status information, which allows the correction distance α to be set appropriately in accordance with the variable value of the status information, thereby allowing the start position of non-ejection flushing to be set appropriately.

[0063] (Second embodiment) The second embodiment will be described below. Fig. 7 is a diagram illustrating non-ejection flushing that is performed based on the difference between the target stop position P0 of the carriage 16 and the actual stop position.

[0064] The control device 71 acquires the difference between the target stop position P0 of the carriage 16 and the actual stop position of the carriage 16 as the carriage 16 moves. The control device 71 can acquire information about the actual stop position of the carriage 16 from, for example, the rotation speed of the carriage motor 33, which can be acquired by an encoder. As shown in FIG. 7 , a difference G1 between the actual stop position Pa that exceeds the target stop position P0 and the target stop position P0, and a difference G2 between the actual stop position Pb before the target stop position P0 and the target stop position P0, are stored as history data in the RAM 72 or the ROM 73. The differences G1 and G2 as history data may each be singular or multiple. In this case, when multiple histories are used, an average value of the multiple histories may be used. The control device 71 may use, as predetermined status information, the difference G1 between the target stop position P0 of the carriage 16 and the actual stop position Pa in the history data, or the difference G2 between the target stop position P0 of the carriage 16 and the actual stop position Pb in the history data. The control device 71 obtains the start position of non-ejection flushing according to the difference and starts non-ejection flushing at the start position, thereby enabling non-ejection flushing to be completed before the carriage 16 stops.

[0065] Next, the control flow by the control device 71 in this embodiment will be described with reference to a flowchart. Fig. 8 is a flowchart showing an example of the control flow by the control device 71.

[0066] 8, the control device 71 first determines whether or not a print command has been issued (step S21). If a print command has been issued (YES in step S21), the control device 71 executes the process of step S22, which will be described later. On the other hand, if a print command has not been issued (NO in step S21), the control device 71 waits until a print command is issued.

[0067] In step S22, the control device 71 acquires the difference G1 (G2) between the target stop position P0 and the actual stop position Pa (Pb) of the carriage 16 as predetermined state information. Next, the control device 71 acquires the start position of non-ejection flushing according to the acquired difference G1 (G2) (step S23). Then, the control device 71 accelerates the carriage 16 (step S24).

[0068] After the process of step S24, the control device 71 causes the ejection head 20 to perform printing (step S25). Subsequently, the control device 71 decelerates the carriage 16 and starts non-ejection flushing at the start position (step S26).

[0069] After the processing of step S26, the control device 71 stores the difference between the target stop position P0 and the current stop position as a new history in the RAM 72 or ROM 73 (step S27). Then, the control device 71 determines whether or not there is data remaining for which printing should continue (step S28). If printing should continue (YES in step S28), the control device 71 returns to the processing of step S22 described above and repeats the subsequent processing. On the other hand, if printing should not continue (NO in step S28), the control device 71 ends the processing.

[0070] According to this embodiment, the difference G1 (G2) between the target stop position P0 of the carriage 16 in the history and the actual stop position Pa (Pb) can be used as the predetermined status information. This makes it possible to set an appropriate start position for non-ejection flushing according to the difference.

[0071] (Third embodiment) The third embodiment will now be described. As shown in Fig. 9, a droplet ejection device 10A of this embodiment includes a carriage 16, a guide rail 17 that movably supports the carriage 16, and an ink cartridge 180 having an ejection head. The ink cartridge 180 supplies ink to a pressure chamber 28 of the ejection head and is provided on the carriage 16. The ink cartridge 180 corresponds to a first cartridge.

[0072] A mounting section 130 is provided on the upper surface of the carriage 16, and, for example, four ink cartridges 180 are removably mounted in the mounting section 130. An ejection head is provided on the lower surface of the ink cartridge 180. Whether the ink cartridge 180 mounted in the mounting section 130 is a large capacity or small capacity is detected by an IC chip reader 78 in Figure 3.

[0073] In this embodiment, the control device 71 acquires the remaining amount of ink in the ink cartridge 180 as predetermined status information. In this case, the control device 71 can acquire the remaining amount of ink from, for example, a remaining ink detection sensor. When the remaining amount of ink is less than a threshold, the total weight of the carriage 16, including the weight of the ink cartridge 180, is relatively small. Therefore, there is a risk that the carriage 16 will stop before the target stop position P0. Therefore, by starting non-ejection flushing at the first timing T1, it is possible to complete non-ejection flushing before the carriage 16 stops. In contrast, when the remaining amount of ink is equal to or greater than the threshold, the total weight of the carriage 16, including the weight of the ink cartridge 180, is relatively large. Therefore, there is a risk that the carriage 16 will stop before the target stop position P0, compared to when the remaining amount of ink is less than the threshold. Therefore, by starting non-ejection flushing at the second timing T2, which is earlier than the first timing T1, it is possible to complete non-ejection flushing before the carriage 16 stops.

[0074] Alternatively, the control device 71 may acquire the detection results from the IC chip reader 78 as the predetermined status information. If the detection results indicate that the ink cartridge 180 has a small capacity, the total weight of the carriage 16, including the weight of the ink cartridge 180, is relatively small. Therefore, there is a risk that the carriage 16 will stop before the target stop position P0. Therefore, by starting non-ejection flushing at the first timing T1, it is possible to complete the non-ejection flushing before the carriage 16 stops. On the other hand, if the detection results indicate that the ink cartridge 180 has a large capacity, the total weight of the carriage 16, including the weight of the ink cartridge 180, is relatively large. Therefore, there is a risk that the carriage 16 will stop before the target stop position P0, compared to when the ink cartridge 180 has a small capacity. Therefore, by starting non-ejection flushing at the second timing T2, which is earlier than the first timing T1, it is possible to complete the non-ejection flushing before the carriage 16 stops.

[0075] According to this embodiment, the detection results of the amount of ink remaining in the ink cartridge 180 and whether the ink cartridge 180 has a large or small capacity, which can be factors that cause the carriage 16 to stop before the target stop position P0, can be used as predetermined status information. As a result, even if the carriage 16 stops before the target stop position P0 due to the above factors, it is possible to end non-ejection flushing before the carriage 16 stops.

[0076] (Variation) The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, the following modifications are possible.

[0077] In the above embodiment, the predetermined status information is described as the number of prints on the print medium W detected by the print number counter, but it is also possible to count the ejected dots and convert the number of ejected dots into the number of prints. In this case, for example, 100,000 dots can be converted into 1 sheet.

[0078] In the above embodiment, the RAM 72 stores information about the first timing T1 and information about the correction distance α, and the second timing T2 is obtained by adding the correction distance α to the first timing T1, but this is not limiting. The second timing T2 may be stored in the RAM 72 in advance.

[0079] Furthermore, in the above embodiment, a mode in which one ejection dot 20 is mounted on the carriage 16 has been described, but this is not limiting. Two or more ejection dots 20 may be mounted on the carriage 16, and when an ejection head that ejects ultraviolet-curable ink is used, a light source unit may also be mounted on the carriage 16.

[0080] Furthermore, in the first embodiment, when an ink cartridge integrated with the ejection head 20 is used as in the second embodiment described below, the IC chip reader 78 reads information from an IC chip provided on the ink cartridge and determines whether the ink cartridge has a large capacity or a small capacity based on the information from the IC chip. However, this is not limited to this. When an ink cartridge integrated with the ejection head 20 is used as in the second embodiment described below, the IC chip reader 78 may read information from an IC chip provided on the ink cartridge and transmit the information from the IC chip to the control device 71. In this case, a table for determining whether the ink cartridge has a large capacity or a small capacity by referring to the information from the IC chip is pre-stored in the ROM 73. The control device 71 determines whether the ink cartridge has a large capacity or a small capacity based on the information from the IC chip and the table. In other words, the control device 71 may acquire information from the IC chip as predetermined status information.

[0081] Furthermore, in the second embodiment, the difference G1 between the actual stop position Pa that has exceeded the target stop position P0 and the target stop position P0, and the difference G2 between the actual stop position Pb that is shorter than the target stop position P0 and the target stop position P0 are stored as history data in the RAM 72 or the ROM 73. However, this is not limiting. The control device 71 may store the actual stop position Pa that has exceeded the target stop position P0, the actual stop position Pb that is shorter than the target stop position P0, and the target stop position P0 as history data in the RAM 72 or the ROM 73. The control device 71 may read the actual stop position Pa that has exceeded the target stop position P0 and the target stop position P0, or the actual stop position Pb that is shorter than the target stop position P0 and the target stop position P0, from the RAM 72 or the ROM 73, and calculate the difference G1 based on the actual stop position Pa that has exceeded the target stop position P0 and the target stop position P0, or calculate the difference G2 based on the actual stop position Pb that is shorter than the target stop position P0 and the target stop position P0. [Explanation of symbols]

[0082] 10 Droplet discharge device 12 Storage Tank 12a tube 12ak tube bending part 16 Carriage 20 Discharge head 21 nozzles 28 Pressure Chamber 60 Actuator 71 Control device 72 RAM 73 ROM 75 Temperature Sensor 78 IC chip reader 130 Mounting part 180 ink cartridges Ds moving direction Ds1 1st movement direction Ds2 2nd movement direction G1,G2 difference P0 Target stop position Pa,Pb Actual stop position T1 First timing T2 2nd タイミング W was printed media x1 Distance 1 x2 Second distance α Correction distance

Claims

1. A droplet ejection device that ejects droplets, a discharge head having a nozzle communicating with a pressure chamber that stores liquid, and an actuator that applies pressure to the liquid in the pressure chamber to discharge droplets from the nozzle; a carriage on which the ejection head is mounted and which moves back and forth in a movement direction; a storage device that stores information about a predetermined first timing as timing to start non-ejection flushing in which the actuator applies pressure to the liquid in the pressure chamber so as to vibrate the liquid in the nozzle of the ejection head without ejecting it during deceleration to stop the carriage; and a control device; The control device selecting one of the first timing and a second timing different from the first timing stored in the storage device based on predetermined status information that is numerical information indicating a status of the droplet discharge device and that is a cause of the carriage stopping before a target stop position; the first timing is a timing when the carriage reaches a position a first distance before the target stop position in the movement direction, the second timing is a timing when the carriage reaches a position a second distance before the target stop position, the second distance being the first distance plus a predetermined correction distance; The control device further The droplet ejection device starts the non-ejection flushing at the selected timing while the carriage is decelerating to stop.

2. The control device If the state information is less than the threshold value, the non-ejection flushing is started at the first timing; The droplet ejection device according to claim 1 , wherein when the state information is equal to or greater than the threshold value, the non-ejection flushing is started at the second timing.

3. 3. The droplet ejection device according to claim 1, wherein the status information is the number of prints of a print medium on which an image is formed by ejecting droplets from the nozzles.

4. 3. The droplet ejection device according to claim 1, wherein the status information is the number of times the carriage has been driven.

5. the storage device stores a difference between the target stop position and an actual stop position of the carriage when the carriage moves; 3. The droplet ejection device according to claim 1, wherein the status information is a difference between the target stop position and an actual stop position of the carriage in history.

6. Further comprising a temperature sensor for measuring an environmental temperature; The droplet ejection device according to claim 1 , wherein the state information is a measurement result obtained by the temperature sensor.

7. a first cartridge that supplies liquid to the pressure chamber is provided on the carriage; The droplet ejection device according to claim 1 , wherein the state information is the remaining amount of liquid in the first cartridge.

8. the carriage further includes a mounting portion for a first cartridge that stores liquid to be supplied to the pressure chamber, and a detection portion that detects whether the first cartridge mounted on the mounting portion has a large capacity or a small capacity; The droplet ejection device according to claim 1 , wherein the state information is a result of detection by the detection unit.

9. the movement direction includes a first movement direction and a second movement direction, a second cartridge provided away from the carriage and configured to store liquid to be supplied to the pressure chamber; a tube that connects the second cartridge and the ejection head and includes a portion that is more bent when the carriage moves in the second movement direction than when the carriage moves in the first movement direction, The droplet ejection device according to claim 1 , wherein the state information is a movement direction of the carriage in the second movement direction.

10. The droplet ejection device according to claim 1 , wherein the control device changes the correction distance based on a value of the state information.

11. A droplet ejection device comprising: an ejection head having a nozzle communicating with a pressure chamber that stores liquid, and an actuator that applies pressure to the liquid in the pressure chamber to eject droplets from the nozzle; and a carriage on which the ejection head is mounted, the carriage reciprocating in a movement direction, based on predetermined state information, which is numerical information indicating a state of the droplet ejection device and which is a cause of the carriage stopping before a target stop position, selecting either a predetermined first timing or a second timing different from the first timing as the timing to start non-ejection flushing, in which the actuator applies pressure to the liquid in the pressure chamber so as to vibrate the liquid in the nozzle without ejecting it during deceleration to stop the carriage; the first timing is a timing when the carriage reaches a position a first distance before the target stop position in the movement direction, the second timing is a timing when the carriage reaches a position a second distance before the target stop position, the second distance being the first distance plus a predetermined correction distance; Furthermore, the droplet ejection method starts the non-ejection flushing at the selected timing while the carriage is decelerating to stop.

12. A droplet ejection program to be executed by a computer in a droplet ejection device including: a nozzle communicating with a pressure chamber that stores liquid; an ejection head having an actuator that applies pressure to the liquid in the pressure chamber to eject droplets from the nozzle; and a carriage on which the ejection head is mounted and that moves back and forth in a movement direction, The computer functioning as a selection means for selecting either a predetermined first timing or a second timing different from the first timing as the timing to start non-ejection flushing in which the actuator applies pressure to the liquid in the pressure chamber so as to vibrate the liquid in the nozzle without ejecting it during deceleration to stop the carriage, based on predetermined status information which is numerical information indicating the status of the droplet ejection device and which is a cause of the carriage stopping before a target stop position; the first timing is a timing when the carriage reaches a position a first distance before the target stop position in the movement direction, the second timing is a timing when the carriage reaches a position a second distance before the target stop position, the second distance being the first distance plus a predetermined correction distance; Furthermore, the droplet ejection program functions as a non-ejection flushing instruction means for starting the non-ejection flushing during deceleration to stop the carriage at the selected timing.

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