JP2019209692A - Liquid discharge device - Google Patents

Abstract

To make it possible to reduce a preservation liquid remaining in a head unit.SOLUTION: A liquid discharge device comprises: a head unit having a nozzle and a liquid channel which is communicated with the nozzle and supplies a discharge liquid accumulated in a tank to the nozzle; a discharge part which discharges at least any one of the discharge liquid and a preservation liquid different from the discharge liquid existing in the liquid channel outside the liquid channel; an agitation part which agitates the liquid in the liquid channel; and a control part. The control part executes an introduction processing in which the control part controls the discharge part so as to discharge the preservation liquid in the liquid channel at least outside the liquid channel, an agitation processing in which the control part controls the agitation part so as to agitate the liquid in the liquid channel after the introduction processing, and a discharge processing in which the control part controls the discharge part so as to discharge the liquid in the liquid channel, which is agitated by the agitation part, outside the liquid channel after the agitation processing.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a liquid ejection apparatus.

  As an example of the liquid ejecting apparatus, the ink jet printer described in Patent Document 1 includes an ink jet head and an ink flow path for supplying ink to the ink jet head for the purpose of maintaining the function of the ink jet head when shipped from the factory. The containing head unit is filled with a filling liquid (preservation liquid) different from the ink. In this ink jet printer, before the first printing is performed (before the first use), an initial purge is performed to introduce ink from the ink cartridge to the ink jet head while discharging the filling liquid filled in the head unit from the nozzle. Thus, the filling liquid filled in the head unit is replaced with ink.

JP 2012-91500 A

  Here, if the storage liquid remains in the head unit when the ink jet printer is used, the ink in a state where the storage liquid is mixed is ejected from the head unit, so that the print quality is deteriorated. For this reason, in order to ensure the print quality, it is necessary to sufficiently discharge the storage solution in the head unit before the first printing. However, the inventor of the present application has found that even if the initial purge is simply performed before the first printing, a large amount of storage solution may remain in the head unit.

  Accordingly, an object of the present invention is to provide a liquid ejection apparatus capable of reducing the storage liquid remaining in the head unit.

  In order to solve the above-described problems, a liquid discharge apparatus according to a first aspect of the present invention includes a nozzle capable of discharging a discharge liquid, and the discharge liquid that communicates with the nozzle and is stored in a tank. A liquid that is at least one of a head unit having a liquid flow path for performing the operation, a discharge liquid present in the liquid flow path, and a storage liquid different from the discharge liquid. A discharge part for stirring, a stirring part for stirring the liquid in the liquid flow path, and a control part for controlling the discharge part and the stirring part. The control unit controls the discharging unit when the preserving liquid is present in the liquid channel, and discharges at least the preserving liquid in the liquid channel out of the liquid channel, An introduction process for introducing the discharge liquid from a tank into the liquid flow path, a stirring process for controlling the stirring unit after the introduction process, and stirring the liquid in the liquid flow path; and Later, the discharge unit is controlled to execute a discharge process of discharging the liquid stirred by the stirring unit in the liquid channel out of the liquid channel.

  According to the above configuration, the storage liquid present in the liquid flow path is discharged after being stirred with the discharge liquid. Therefore, the storage liquid present in the flow path portion that is difficult to discharge only by controlling the discharge section. Can also be discharged out of the liquid flow path. As a result, it is possible to reduce the storage solution remaining in the head unit.

  In the liquid ejection device according to a second aspect of the present invention, in the first aspect of the invention, the control unit is configured such that, in the introduction process, the predetermined flow in the flow path in which the storage liquid exists before the introduction process starts in the liquid flow path. The discharge unit is controlled so that air stays in the path portion. According to the above configuration, during the agitation process, the storage liquid and the discharge liquid can be efficiently agitated in the predetermined flow path portion by the air existing in the predetermined flow path portion in the liquid flow path.

  In the liquid ejection device according to a third aspect, in the second aspect, the tank includes a storage chamber that stores the discharge liquid, and a supply unit that supplies the discharge liquid from the storage chamber to the outside of the tank. And a tank mounting portion having a connected portion for connecting the supply portion of the tank to flow the discharged liquid when the tank is mounted. The path is connected to the connected part, and the control unit is configured to supply the liquid when the supply part of the tank and the connected part of the tank mounting part are connected in the introduction process. In order to move at least a part of the air entering the flow path to the predetermined flow path portion of the liquid flow path, the total discharge amount of the liquid discharged from the liquid flow path to the outside of the liquid flow path is the liquid Said connected in flow path As the amount corresponding to the volume up to the predetermined flow path section from the connection position between, controls the discharge portion. According to said structure, air can be reliably made to stay in a predetermined flow-path part.

  According to a fourth aspect of the present invention, there is provided the liquid ejection device according to the second or third aspect, wherein the head unit includes the nozzle, a head main body for discharging the ejection liquid from the nozzle, and the head main body. A liquid supply member for supplying the discharge liquid, wherein the liquid flow path is formed in the head main body, and has a supply path through which the discharge liquid is supplied from the liquid supply member; A supply flow path formed in the liquid supply member and communicating the supply port and the tank, wherein the supply flow path is connected to the supply port of the head flow path, and the supply flow path A first flow path extending upward from the mouth, and a second flow path connected to an end of the first flow path on the tank side and extending in a direction crossing the extending direction of the first flow path A connection angle between the first flow path and the second flow path However, in the introduction process, the control unit uses the predetermined flow channel portion as the connection corner in the liquid flow channel, and is located at the uppermost position in the first flow channel and the second flow channel. The discharge unit is controlled so that air stays at the connection corner. According to the above configuration, the first flow path of the supply flow path is a flow path that extends upward from the supply port of the head flow path in the head main body, so that air present in the supply flow path is transferred to the head main body. It is difficult to move, and as a result, it is possible to suppress deterioration of the ejection characteristics of the head main body due to air mixed into the head main body. Further, although the preservative liquid is likely to stay at the connection position between the first flow path and the second flow path, the preservative liquid present at this connection position is not easily retained by the stirring process. Since it can be moved to a portion, the preservative solution remaining at this connection position after the discharge process can be reduced.

  According to a fifth aspect of the present invention, in the liquid ejecting apparatus according to the second or third aspect, the head unit includes the nozzle, a head main body for discharging the discharge liquid from the nozzle, and the head main body. A liquid supply member for supplying the discharge liquid, wherein the liquid flow path is formed in the head main body, and has a supply path through which the discharge liquid is supplied from the liquid supply member; A supply channel formed in the liquid supply member and communicating the supply port and the tank; and the supply channel includes a damper chamber for suppressing pressure fluctuation of the liquid supplied to the head body. In the introduction process, the control unit controls the discharge unit so that air in the liquid channel remains in the damper chamber, with the predetermined channel portion serving as the damper chamber. According to the above configuration, there is a flow path portion in which the storage liquid is likely to stay in the damper chamber. However, the storage liquid existing in the damper chamber can be moved to the flow path portion where the storage liquid is less likely to stay by the stirring process. For this reason, the preservation | save liquid which remains in this damper chamber after discharge processing can be reduced.

  A liquid ejection device according to a sixth aspect of the present invention is the liquid ejection device according to any one of the second to fifth aspects, wherein the exhaust channel is connected to the liquid channel and discharges air, and the exhaust channel is opened. And a switching means for switching to a closed state, the discharge section is connectable to the exhaust flow path opened by the switching means, and the control section, after the discharge process, An exhaust process for exhausting the air in the liquid flow path through the exhaust flow path by controlling the discharge unit and the switching unit is further executed. According to said structure, it can suppress that the discharge characteristic of the discharge liquid of a head unit deteriorates with the air which exists in a liquid flow path.

  According to a seventh aspect of the present invention, in any one of the second to fifth aspects, the discharge portion is connected to the cap and a cap attachable to the head unit so as to cover the nozzle. A suction pump, and driving the suction pump with the cap attached to the head unit to suck the inside of the cap, thereby discharging the liquid and air in the liquid channel from the nozzle. A purge unit for controlling the purge unit in the discharge process to discharge the liquid in the liquid flow path from the nozzle, and the discharge process. Thereafter, the purge unit is further controlled to perform an exhaust process for performing a purge for exhausting the air in the liquid flow path through the nozzle, In the purge of the exhaust process, the suction force of the suction pump is made stronger than the suction force of the suction pump during the purge of the discharge process in order to discharge the air in the liquid channel from the nozzle. . According to the above configuration, since the exhaust process is performed after the exhaust process, it is not necessary to exhaust the air present in the liquid flow path in the exhaust process. As a result, since it is not necessary to drive the suction pump with a strong suction force in the purge of the discharge process, it is possible to suppress the discharge liquid from being excessively discharged during the discharge process.

  According to an eighth aspect of the invention, in any one of the second to fifth aspects of the invention, the head unit, as the discharge portion, is an energy for causing the liquid in the liquid flow path to be discharged from the nozzle. The discharge portion has a cap that can be attached to the head unit so as to cover the nozzle, and a suction pump connected to the cap, and the cap is the head. A purge unit for discharging the liquid and air in the liquid flow path from the nozzle by driving the suction pump in a state of being attached to the unit to suck the inside of the cap, and the control unit In the discharging process, flushing is performed by discharging the liquid in the liquid channel from the nozzle by controlling the energy applying unit. And, and, after the discharge process, the control the purge unit further executes the exhaust treatment purging for discharging the air of the liquid flow path from the nozzle. According to the above configuration, since the exhaust process is performed after the exhaust process, it is not necessary to exhaust the air present in the liquid flow path in the exhaust process. As a result, in the discharge process, the liquid in the liquid flow path can be discharged outside the liquid flow path by flushing, which discharges less liquid than in the purge, so that the discharge liquid is excessively discharged during the discharge process. This can be suppressed.

  In the liquid ejection device according to a ninth aspect of the present invention, in any one of the sixth to eighth aspects, the control unit repeatedly executes the stirring process and the discharge process a plurality of times. According to said structure, the preservation | save liquid which remain | survives in a head unit can be reduced reliably by performing a stirring process and a discharge process in multiple times. Further, in the discharge process, the liquid is discharged out of the liquid flow path with a weaker force than in the exhaust process, so that the air can stay in the predetermined flow path portion of the liquid flow path. As a result, when each of the stirring processes is performed, air remains in the predetermined flow path portion, so that the storage liquid and the discharge liquid can be efficiently stirred in the predetermined flow path portion.

According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the agitation unit includes a carriage mounted with the head unit and reciprocating in a predetermined scanning direction together with the head unit. Including the control unit,
In the stirring process, the carriage is controlled to reciprocate the head unit in the scanning direction so that the liquid in the liquid flow path is stirred. According to said structure, the structure of a stirring part can be simplified.

  According to an eleventh aspect of the invention, in the tenth aspect of the invention, the stirring unit further includes a moving mechanism that moves the head unit in a direction different from the scanning direction, and the control unit includes the stirring process. When the head unit reciprocates in the scanning direction, the moving mechanism is controlled to move the head unit in a direction different from the scanning direction. According to said structure, the stirring efficiency of a preservation | save liquid and discharge liquid can be improved more.

  According to a twelfth aspect of the invention, in the tenth or eleventh aspect of the invention, the liquid discharge device is disposed in a part of a range of movement of the head unit in the scanning direction and is discharged from the nozzle of the head unit. A liquid receiver for receiving the liquid, and the control unit repeatedly executes the stirring process and the discharge process a plurality of times, and controls the stirring unit in each of the stirring processes. Then, with the liquid receiver as the origin position, the head unit is moved back from the origin position in the scanning direction, and then the head unit is moved back to the origin position. And the liquid in the liquid channel is discharged from the nozzle of the head unit toward the liquid receiver. According to the above configuration, since the reciprocating movement of the head unit is performed with the liquid receiver from which the liquid in the liquid flow path is discharged in the discharge process as the origin position, the processing time required for the stirring process and the discharge process can be shortened. Can do.

  According to a thirteenth aspect of the present invention, in any one of the first to twelfth aspects of the invention, the head unit serves as the discharge unit and causes the liquid in the liquid flow path to discharge energy from the nozzle. The control unit is configured to repeatedly execute the stirring process and the discharge process as a set a plurality of times. In each of the discharge processes, the control unit controls the energy supply unit. Flushing is performed by discharging and discharging the liquid in the liquid channel from the nozzle. According to said structure, the preservation | save liquid which remain | survives in a head unit can be reduced reliably by performing repeatedly a stirring process and discharge | emission process in multiple times. Further, in each discharge process, the liquid is discharged by flushing that allows easy adjustment of the discharge amount of the liquid, so that it is possible to prevent excessive discharge liquid from being discharged in each discharge process.

  In the present invention, it is possible to reduce the storage solution remaining in the head unit.

1 is a schematic configuration diagram of an inkjet printer according to an embodiment. 1 is a block diagram schematically illustrating an electrical configuration of an ink jet printer. It is a perspective view of an inkjet head. (A) And (b) is the IV-IV line vertical sectional view of FIG. It is a top view of the head main body of an inkjet head. (A) is the A section enlarged view of FIG. 5, (b) is the BB sectional drawing of (a). (A) And (b) is a top view explaining a stirring process, (c) is a figure which shows the relationship between the moving speed and position of a carriage. 4 is a flowchart for explaining a processing operation of the ink jet printer. (A) And (b) is a top view explaining a moving mechanism. It is a block diagram which shows roughly the electric constitution of the inkjet printer based on a modification.

  A schematic configuration of an inkjet printer 1 (liquid ejection device) according to a preferred embodiment of the present invention will be described. As shown in FIG. 1, the printer 1 includes a platen 2, a carriage 3, an inkjet head 5 (hereinafter also simply referred to as a head 5), a holder 6, a paper feed roller 7, a paper discharge roller 8, a cap unit 9, and a switching device 10. , A suction pump 11, a waste liquid tank 12, a flushing receptacle 30, a display 99 (see FIG. 2), a control device 100 (see FIG. 2), and the like. In the following, the front side of the sheet of FIG. 1 is defined as “upper” of the printer 1 and the other side of the sheet is defined as “lower” of the printer 1. Further, the front-rear direction and the left-right direction shown in FIG. 1 are defined as “front-rear direction” and “left-right direction” of the printer 1. Hereinafter, description will be made using the front, rear, left, right, and upper direction words as appropriate.

  A sheet P that is a recording medium is placed on the upper surface of the platen 2. Two guide rails 15 and 16 extending in parallel in the left-right direction (scanning direction) are provided above the platen 2.

  The carriage 3 is attached to the two guide rails 15 and 16, and can move in the scanning direction along the two guide rails 15 and 16 in a region facing the platen 2. A drive belt 17 is attached to the carriage 3. The drive belt 17 is an endless belt wound around two pulleys 18 and 19. One pulley 18 is connected to a carriage drive motor 20 (see FIG. 2). The pulley 18 is driven to rotate by the carriage drive motor 20 so that the drive belt 17 travels. As a result, the carriage 3 reciprocates in the scanning direction. At this time, the head 5 mounted on the carriage 3 reciprocates in the scanning direction together with the carriage 3.

  The holder 6 includes four cartridge mounting portions 41 to which ink cartridges 42 (corresponding to tanks) of four colors (black, yellow, cyan, magenta) are detachably mounted. Each ink cartridge 42 includes a storage chamber 42a for storing ink, and a discharge pipe 42b (corresponding to a supply unit) connected to the storage chamber 42a. The discharge pipe 42b defines a flow path for supplying the ink stored in the storage chamber 42a to the outside of the ink cartridge 42. The cartridge mounting portion 41 includes a needle 41a (corresponding to a connected portion) that circulates ink by connecting to the discharge pipe 42b when the ink cartridge 42 is mounted. Further, the cartridge mounting portion 41 is provided with a sensor 41b (see FIG. 2) for detecting whether or not the ink cartridge 42 is mounted on the cartridge mounting portion 41.

  As described above, the head 5 is detachably attached to the carriage 3. The head 5 includes a head main body 13 and a sub tank 14 (corresponding to a liquid supply member). A tube joint 21 is provided on the upper surface of the sub tank 14, and one end of each of the four ink supply tubes 22 is detachably connected to the tube joint 21. The other end of each of the four ink supply tubes 22 is connected to each of the needles 41 a of the four cartridge mounting portions 41 of the holder 6. The ink in the four ink cartridges 42 mounted on the cartridge mounting portion 41 is supplied to the sub tank 14 via the four ink supply tubes 22.

  Further, the sub tank 14 is provided with four exhaust portions 23 corresponding to the four colors of ink for exhausting the air existing in the ink flow path inside the sub tank 14 before moving to the head main body 13. Inside each of the four exhaust parts 23, a valve (not shown) for switching communication / closing with the outside is installed.

  The head main body 13 is attached to the lower part of the sub tank 14. The head main body 13 includes a plurality of nozzles 44 on the lower surface thereof, and discharges ink supplied from the sub tank 14. The plurality of nozzles 44 are arranged corresponding to the four color inks, respectively, to form four nozzle rows. The flow path structure inside the head body 13 will be described in detail later.

  The paper feed roller 7 and the paper discharge roller 8 are rotationally driven in synchronization by a transport motor 29 (see FIG. 2). The paper feed roller 7 and the paper discharge roller 8 cooperate to transport the paper P placed on the platen 2 in the transport direction shown in FIG.

  Then, the printer 1 ejects ink while moving the head 5 in the scanning direction together with the carriage 3 while transporting the paper P in the transport direction by the paper feed roller 7 and the paper discharge roller 8, so Record images etc. That is, the printer 1 of the present embodiment is a serial ink jet printer.

  The cap unit 9 is disposed at a position on one side in the scanning direction (the right side in FIG. 1) with respect to the platen 2, and vertically opposes the cap unit 9 when the carriage 3 moves to the right side with respect to the platen 2. The cap unit 9 is driven by a cap drive motor 24 (see FIG. 2) and can be moved up and down. The cap unit 9 includes a nozzle cap 25 and an exhaust cap 26 that can be attached to the head 5.

  In a state where the carriage 3 faces the cap unit 9, the nozzle cap 25 faces the lower surface of the head main body 13, and the exhaust cap 26 faces the lower surface of the four exhaust parts 23 of the sub tank 14. When the cap unit 9 is lifted with the carriage 3 and the cap unit 9 facing each other, the cap unit 9 is mounted on the head main body 13 and the sub tank 14. At this time, all the nozzles 44 belonging to the four nozzle rows are commonly covered by the nozzle cap 25, and the exhaust cap 26 is connected to the four exhaust portions 23. Four rod-like opening / closing members 27 for opening and closing the valves in the four exhaust portions 23 are attached to the exhaust cap 26. Although a detailed description is omitted, in a state where the exhaust cap 26 is connected to the four exhaust portions 23, the four rod-shaped opening / closing members 27 are driven up and down by an exhaust motor 28 (see FIG. 2), and from below. The internal valve is driven by being inserted into the exhaust part 23.

  The nozzle cap 25 and the exhaust cap 26 are connected to the suction pump 11 via the switching device 10. The switching device 10 selectively switches the communication destination of the suction pump 11 between the nozzle cap 25 and the exhaust cap 26. The suction pump 11 is connected to a waste liquid tank 12. By switching the communication destination of the switching device 10, a suction purge for forcibly discharging ink from all the nozzles 44 belonging to the four nozzle rows, and an exhaust purge for exhausting air from the ink flow path in the sub tank 14 Can be selectively executed.

  In the suction purge, with the nozzle cap 25 mounted on the head main body 13 and covering the plurality of nozzles 44, the suction pump 11 is driven by the switching device 10 after the suction pump 11 communicates with the nozzle cap 25, and the nozzle The inside of the cap 25 is depressurized (sucked), and the ink is sucked and discharged from the plurality of nozzles 44 of the head 5. As a result, foreign matter in the head 5, air bubbles, ink having increased viscosity due to drying, and the like are discharged from the nozzle 44, and the ejection characteristics of the nozzle 44 can be recovered.

  In the exhaust purge, after the exhaust cap 26 is connected to the exhaust part 23 and the valve in the exhaust part 23 is opened by the opening / closing member 27, the switching device 10 causes the suction pump 11 to communicate with the exhaust cap 26. The suction pump 11 is driven to apply a negative pressure to the exhaust part 23. Thereby, air such as bubbles grown in the ink flow path of the sub tank 14 can be exhausted from the exhaust part 23 before moving to the head main body 13.

  Ink and storage liquid discharged from the head 5 by suction purge and exhaust purge are sent to a waste liquid tank 12 connected to the suction pump 11.

  In the present embodiment, the head 5 performs flushing by ejecting ink from the plurality of nozzles 44 at an appropriate timing. The purpose of the flushing is various, for example, to prevent the ink in the nozzle 44 from drying, or to adjust the meniscus in the nozzle 44 after the suction purge.

  The flushing receiver 30 is a member for receiving ink discharged from the plurality of nozzles 44 during the flushing. The flushing receiver 30 is disposed at a left end position (hereinafter also referred to as an origin position) within a moving range of the head 5 in the scanning direction. That is, the flushing receiver 30 is disposed at a position on the other side in the scanning direction from the platen 2.

  In order to perform flushing, when the head 5 moves to the origin position (see FIG. 7A), the head 5 faces the flushing receiver 30 vertically. When flushing is performed in this state, ink ejected from the plurality of nozzles 44 of the head 5 is received by the flushing receiver 30.

As shown in FIG. 2, the control device 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a control circuit 104, a bus 105, and the like. The ROM 102 stores programs executed by the CPU 101, various fixed data, and the like. The RAM 103 temporarily stores data (image data and the like) necessary for executing the program. The control circuit 104 is connected to various devices or drive units of the printer 1 such as the driver IC 53 of the head 5, the carriage drive motor 20, and the cap drive motor 24 that moves the cap unit 9 up and down. The control circuit 104 is connected to an external device 31 such as a PC. The CPU 101 controls the head 5, the carriage drive motor 20, and the like via the control circuit 104 based on the recording command transmitted from the external device 31 to record an image or the like on the paper P. Further, the CPU 101 controls the switching device 10 and the suction pump 11 through the control circuit 104 to execute the above-described suction purge and exhaust purge.
In the present embodiment, the control device 100 is configured to execute each process by a single CPU. However, a plurality of CPUs, a single ASIC (application specific integrated circuit), a plurality of ASICs, or Each process may be executed by a combination of a CPU and a specific ASIC.

  Next, the head 5 will be described with reference to FIGS. In FIG. 3, the opening / closing member 27 for opening and closing the exhaust part 23 of the sub tank 14 is also indicated by a two-dot chain line. In FIG. 4, the head main body 13 is shown as a side view, not a cross-sectional view.

  As shown in FIGS. 5 and 6, the head body 13 of the head 5 includes a flow path unit 33 and a piezoelectric actuator 34 (corresponding to an energy applying unit). As shown in FIG. 6B, the flow path unit 33 has a structure in which five plates 35 to 39 are laminated. The lowermost plate 39 among the five plates 35 to 39 is a nozzle plate 39 in which a plurality of nozzles 44 are formed. On the other hand, the remaining upper four plates 35 to 38 are formed with flow paths such as a manifold 46 and a pressure chamber 47 communicating with the plurality of nozzles 44.

  As shown in FIG. 5, four ink supply holes 45 are formed in the upper surface of the flow path unit 33 side by side in the scanning direction. The four ink supply holes 45 are connected to the sub tank 14, and four colors of ink are supplied from the sub tank 14. Further, the flow path unit 33 has four manifolds 46 extending in the conveyance direction, respectively. The four manifolds 46 are connected to the four ink supply holes 45.

  As shown in FIG. 4, a filter 49 for removing dust and the like in the ink supplied from the supply channel 62 is stretched on the upper surface of the four ink supply holes 45. Further, the filter 49 makes it difficult for the air in the supply flow path 62 to flow into the head body 13.

  Further, the flow path unit 33 has a plurality of nozzles 44 opened on the lower surface thereof, and a plurality of pressure chambers 47 respectively communicating with the plurality of nozzles 44. As shown in FIG. 5, the plurality of nozzles 44 are arranged in four rows corresponding to the four manifolds 46 in plan view. Similarly to the plurality of nozzles 44, the plurality of pressure chambers 47 are also arranged in four rows corresponding to the four manifolds 46. As shown in FIG. 6B, each pressure chamber 47 communicates with a corresponding manifold 46. With the above configuration, as indicated by arrows in FIG. 6B, a plurality of individual flow paths are formed in the flow path unit 33, branching from the manifolds 46 and reaching the nozzles 44 through the pressure chambers 47. Yes. Hereinafter, the ink flow paths formed in the flow path unit 33, such as the manifold 46, the pressure chamber 47, and the nozzle 44, are collectively referred to as a head flow path 48 (see FIG. 4).

  As shown in FIGS. 5 and 6, the piezoelectric actuator 34 includes a diaphragm 50, piezoelectric layers 54 and 55, a plurality of individual electrodes 52, and a common electrode 56. The diaphragm 50 is joined to the upper surface of the flow path unit 33 in a state of covering the plurality of pressure chambers 47. The two piezoelectric layers 54 and 55 are stacked on the upper surface of the vibration plate 50. The plurality of individual electrodes 52 are disposed on the upper surface of the upper piezoelectric layer 55 so as to face the plurality of pressure chambers 47, respectively. The common electrode 56 is disposed across the plurality of pressure chambers 47 between the two piezoelectric layers 54 and 55.

  When a drive signal is supplied from the driver IC 53 to the individual electrode 52 of the piezoelectric actuator 34 in response to a signal from the control device 100, piezoelectric distortion occurs in a portion of the upper piezoelectric layer 55 facing the pressure chamber 47. Thus, the diaphragm 50 is deformed so as to be bent. At this time, when the volume of the pressure chamber 47 changes, pressure (energy) is applied to the ink in the individual flow path, and the ink is ejected from the nozzle 44.

  Next, the sub tank 14 will be described in detail. The sub tank 14 is a member formed of synthetic resin, and extends vertically downward from a plate-like main body portion 60 extending along a horizontal plane as shown in FIGS. 3 and 4 and one end portion of the main body portion 60. And a connecting portion 61.

  In the sub tank 14, four supply passages 62 for supplying four color inks to the head body 13 are formed. The main body portion 60 is formed with four ink introduction portions 64 corresponding to the four colors of ink, respectively. Four supply flow paths 62 are connected to the four color ink introduction portions 64, respectively. The four ink introduction portions 64 are provided on the upper surface of the flat plate-like main body portion 60. Note that FIG. 3 shows only the connection configuration of the supply flow path 62 corresponding to a certain color of ink. The four color inks introduced from the four ink introduction portions 64 of the sub tank 14 flow into the head flow path 48 of the head main body 13 via the supply flow path 62.

  The tube joint 21 is attached to the upper surface of the main body portion 60. Four ink supply tubes 22 each connected to an ink cartridge 42 (see FIG. 1) are connected to the tube joint 21, and four ink supply tubes 22, four ink introduction portions 64, and the inside thereof are connected to the tube joint 21. Are formed in four joint flow paths 21a.

  Each supply flow path 62 has a main body flow path 70 (corresponding to the second flow path) formed in the main body portion 60 and a connection flow path 75 (corresponding to the first flow path) formed in the connection portion 61. . As illustrated in FIG. 4, the main body flow path 70 extends along a horizontal plane. On the other hand, the connection channel 75 is connected to one end of the main body channel 70 and extends vertically downward from the one end. As a result, a connection corner 90 that forms 90 degrees is formed at the connection portion between the main body flow path 70 and the connection flow path 75. The connection corner 90 is the uppermost position in the main body flow path 70 and the connection flow path 75, similarly to the positions of the main body flow path 70. As a modification, at least a part of the main body channel 70 on the side of the connection channel 75 (for example, a channel 73 described later) may extend downward from a connection portion with the connection channel 75. .

  The main body flow path 70 includes a damper chamber 71 and flow paths 72 and 73 disposed before and after the damper chamber 71. The damper chamber 71 is a concave portion formed on the surface of the main body portion 60, and four damper chambers 71 respectively corresponding to the four colors of ink are provided on the upper surface side and the lower surface side of the main body portion 60. . Further, as shown in FIG. 4, the upper damper chamber 71 and the lower damper chamber 71 are arranged back to back. Further, the ink introduction portion 64 formed on the upper surface of the main body portion 60 and the damper chamber 71 are connected by a groove-like flow path 72 that is also formed on the upper surface of the main body portion 60.

  Further, the damper chamber 71 is connected to a connecting channel 75 formed in the connecting portion 61 by a channel 73 formed on the upper surface of the main body portion 60. Although not shown in FIG. 3 for simplification of the drawing, the ink introduction part 64, the damper chamber 71, and the connection channel 75 are also provided on the upper surface of the main body part 60 or the other color inks. A supply channel 62 is configured by being connected by a channel formed on the lower surface.

  The body portion 60 is also formed with four groove-shaped exhaust passages 74 that connect the four connection passages 75 and the four exhaust portions 23, respectively. For the sake of simplifying the drawing, only one exhaust passage 74 formed on the upper surface of the main body portion 60 is shown in the drawing, and the other illustrations are omitted.

  As shown in FIGS. 3 and 4, flexible films 78 and 79 made of a resin material are welded to the upper surface and the lower surface of the main body portion 60, respectively. Thereby, the concave damper chamber 71 and the groove-like flow paths 72 and 73 of the supply flow path 62 and the groove-like exhaust flow path 74 formed in the main body portion 60 are moved upward or downward by the films 78 and 79. The structure is covered from below.

  The concave damper chamber 71 and the flow paths 72 and 73 before and after it have substantially the same depth, but the flow path width of the damper chamber 71 is considerably larger than the groove-shaped flow paths 72 and 73. Thereby, the supply flow path 62 has a flow path shape in which the volume is locally increased in the damper chamber 71. When ink is consumed in the head main body 13, the pressure of the ink in the head main body 13 decreases, and accordingly, ink is supplied from the ink cartridge 42 to the supply flow path 62 in the sub tank 14. At this time, if a large pressure fluctuation occurs in the ink in the supply flow path 62, it is transmitted to the head body 13 and adversely affects ink ejection. However, since the damper chamber 71 having a large volume and covered with the flexible films 78 and 79 is provided in the supply channel 62, the pressure fluctuation generated in the ink in the supply channel 62 is caused by the damper chamber 71. Absorbed in.

  The four connection flow paths 75 formed in the connection portion 61 are closed at the upper ends by the films 78 and 79 and are connected to the four ink supply holes 45 of the head 5 at the lower ends. As previously mentioned, the connecting channel 75 extends in the vertical direction, and the connection corner 90 between the connecting channel 75 and the main body channel 70 is the uppermost in the channels 70 and 75. Because of the position, the air present in the supply flow path 62 does not flow into the head main body 13 and tends to stay at the upper end of the connection flow path 75. As a result, it is possible to prevent the discharge characteristics of the head 5 from deteriorating due to the air existing in the supply flow path 62 flowing into the head main body 13. As shown in FIG. 4, the connection channel 75 is composed of an upper channel 76 having a large channel cross-sectional area (channel width) and a lower channel 77 having a small channel cross-sectional area. .

  Hereinafter, for convenience of explanation, a flow path including the supply flow path 62 and the head flow path 48 is referred to as an in-head flow path 80. In addition, the entire flow path from the connection position of the ink supply tube 22 to the ink cartridge 42 to the plurality of nozzles 44, which is composed of the in-head flow path 80, the ink supply tube 22, and the in-joint flow path 21 a, This is referred to as a flow path 85 (see FIG. 1). All the ink channels 85 correspond to the “liquid channel” of the present invention. A unit including the head 5, the tube joint 21, and the ink supply tube 22 corresponds to the “head unit” of the present invention.

  In the head 5 described above, as shown in FIG. 4A, before the head 5 is shipped from the factory, for the purpose of maintaining the function of the head 5, the in-head flow path 80 and the like of all the ink flow paths 85 are provided. The storage solution is filled. Here, when, for example, a pigment-based ink is used as the preservation solution, there is a problem in the following points. Color materials used in pigment-based inks may aggregate over time. For this reason, if a pigment-based ink is filled in the in-head flow path 80 of the head 5 for a long period of time, there is a possibility of causing ejection failure.

  Therefore, in the present embodiment, a liquid that has a small amount or no colorant of a dye or pigment as compared with the ink is used as the storage liquid. This storage solution is considerably cheaper than ink because it contains less color material than ink. Further, the surface tension of the preserving liquid is lower than that of the ink by adding a surfactant so that it is easy to introduce the details of the flow path 80 in the head when filling the flow path 80 in the head. .

  After the shipment, when the power of the printer 1 on which the purchased head 5 is mounted is turned on for the first time by the user, the control device 100 stores the storage liquid filled in the in-head flow path 80 of the head 5. A replacement process for replacing the ink introduced from the ink cartridge 42 is executed.

  Here, when the control device 100 performs a discharge process for discharging the liquid in the in-head flow path 80 to the outside of the in-head flow path 80, such as suction purge or flushing, the head is removed from the ink cartridge 42 by the discharge amount of the liquid. Ink is introduced into the inner flow path 80. Therefore, the control device 100 can replace the liquid in the in-head flow path 80 with ink by executing this discharge process in the replacement process. However, the inventor of the present application has found that a large amount of the storage solution remains in the in-head flow path 80 only by performing this discharge process. The reason will be described below. In the following description, it is assumed that the storage liquid is filled in all the ink flow paths 85 at the start of the replacement process (before the introduction process described later).

  As described above, the damper chamber 71 is a locally inflated channel portion having a larger channel cross-sectional area than the channels 72 and 73 before and after the damper chamber 71, so that liquid stays therein. There is a stagnation part that is easy to do. Further, since the connection corner portion 90 between the main body flow path 70 and the connection flow path 75 is a flow path portion in which the direction of the liquid flow changes downward, a portion where the liquid flow is relatively slow is likely to occur. Liquid tends to stay. Even if the preserving liquid existing in the flow path portion in which such liquid tends to stay is caused to flow in the entire ink flow path 85 from the ink cartridge 42 to the nozzle 44 by flushing or suction purge, the nozzle 44. It is hard to let it drain from. As a result, if the discharge process is simply performed, a large amount of the storage liquid remains in the predetermined flow path portion where the liquid in the flow path 80 in the head tends to stay. As described above, when the storage liquid is used in the in-head flow path 80, the ink mixed with the storage liquid is ejected from the nozzle 44, so that the quality of the image recorded on the paper P is deteriorated. is there.

  Therefore, in the present embodiment, in the replacement process, the control device 100 stirs the liquid in the in-head flow path 80 and the introduction process for introducing ink into the in-head flow path 80 in addition to the discharge process. The stirring process is executed before the discharging process. Note that the control device 100 repeatedly executes the stirring process and the discharge process N times as these sets (N is an integer of 2 or more: 85 times in the present embodiment). Further, in the replacement process, the control device 100 executes an exhaust process for exhausting the air in the in-head flow path 80 after the agitation process and the exhaust process are repeatedly executed. Hereinafter, a series of flow of the replacement process will be described in detail.

  First, the control device 100 controls the cap unit 9 and the suction pump 11 to discharge at least a part of the preserving liquid in the in-head flow path 80 out of the in-head flow path 80, and removes all ink from the ink cartridge 42. An introduction process for introducing ink into the flow path 85 is executed. Specifically, in the introduction process, the control device 100 executes an exhaust purge to exhaust air that is excessively present in the supply flow path 62. Thereafter, the control device 100 performs the suction purge so that the ink in the ink cartridge 42 reaches the connection corner 90 between the main body flow path 70 and the connection flow path 75 in the supply flow path 62.

  In addition, during the introduction process, the control device 100 has a preserving liquid in the in-head flow path 80 before starting the introduction process for the purpose of improving the stirring efficiency of the liquid during the subsequent stirring process, and The suction pump 11 is controlled so that at least a part of the air in all the ink flow paths 85 stays in the predetermined flow path portion where the liquid tends to stay. In the present embodiment, the control device 100 controls the suction force and driving time of the suction pump 11 so that air stays at the connection corner 90 between the main body flow path 70 and the connection flow path 75. Specifically, the control device 100 determines that the total discharge amount of the liquid discharged from the supply channel 62 to the outside of the supply channel 62 during the exhaust purge and the suction purge is the connection position with the needle 41a in all the ink channels 85. From the above, the suction pump 11 is controlled so as to have an amount corresponding to the volume up to the connection corner 90. Thereby, when the ink cartridge 42 is mounted on the cartridge mounting portion 41 and the ink cartridge 42 is connected to the entire ink flow path 85, at least a part of the air (such as biting air) that enters the entire ink flow path 85 is removed. The main body channel 70 and the connecting channel 75 can be moved to the connecting corner 90. The “total discharge amount” is a discharge amount that is converted by regarding the air discharged by the exhaust purge or the like in the introduction process as a liquid. Therefore, this total discharge amount may differ from the amount of liquid actually discharged by the amount of discharged air. Further, in this embodiment, in the suction purge during this introduction process, the rotational speed (suction force) of the suction pump 11 is the same as the rotational speed during normal suction purge for the purpose of restoring the discharge characteristics of the nozzle 44. The same.

  The liquid in the supply channel 62 may evaporate with time. As described above, when the water evaporates, air is generated in the supply channel 62 by the evaporated water. Therefore, air may already exist in the supply flow path 62 before the introduction process is started. In addition, the stirring efficiency of the liquid during the stirring process is improved as the amount of air remaining in the supply flow path 62 (connection corner portion 90) is increased. Therefore, the control device 100 uses this connection angle for air already existing in the supply flow path 62 in addition to the biting air for the purpose of improving the stirring efficiency of the liquid during the stirring process. The suction pump 11 may be controlled so as to remain in the section 90. Specifically, in this introduction process, the control device 100 slows the rotation speed of the suction pump 11 (weakens the suction force) as compared with the normal suction purge so that air stays at the connection corner 90. However, if the rotational speed of the suction pump 11 is slowed in this way, the processing time required to discharge the liquid of the total discharge amount out of the supply flow path 62 becomes longer. Accordingly, in this introduction process, when the treatment time of the introduction process is to be shortened, the suction pump 11 is driven at the same rotational speed as that of the normal suction purge, and when it is desired to improve the liquid stirring efficiency during the stirring process. It is preferable to drive the suction pump 11 at a rotation speed slower than the normal suction purge.

  When this introduction process is completed, the control device 100 repeatedly executes the stirring process and the discharge process N times as a set.

  In the agitation process, the control device 100 first controls the carriage drive motor 20 to move the head 5 to the origin position that vertically faces the flushing receiver 30 as shown in FIG. Thereafter, the control device 100 controls the carriage drive motor 20 to reciprocate the head 5 together with the carriage 3 in the scanning direction (see FIGS. 7A and 7B). Thereby, force (energy) is applied to the liquid in the in-head flow path 80 to cause the liquid to flow, and the liquid in the in-head flow path 80 is agitated.

  Here, the movement operation of the carriage 3 in the scanning direction is divided into three operations, that is, an acceleration operation, a constant speed operation, and a deceleration operation in relation to the movement speed of the carriage 3. The constant speed operation is an operation for moving the carriage 3 at a constant speed, and is employed, for example, at the time of image recording in which ink is ejected from the head 5 toward the paper P. On the other hand, the acceleration operation is, for example, an operation adopted when accelerating the stopped carriage 3 to a predetermined speed, and the deceleration operation is adopted, for example, when the carriage 3 traveling at a predetermined speed is stopped. Operation.

  A large force (energy) is applied to the liquid in the in-head flow path 80 during an acceleration operation for accelerating the carriage 3 or a deceleration operation for decelerating. Therefore, in the present embodiment, during the forward movement, as shown in FIG. 7C, an acceleration operation for accelerating the carriage 3 from the origin position to a predetermined speed (the maximum speed of the carriage 3 in the present embodiment) is performed. Immediately after that, a deceleration operation for stopping the carriage 3 at the folding position (see FIG. 7B) is performed. Similarly, at the time of backward movement, an acceleration operation for accelerating the carriage 3 from the return position to the predetermined speed is performed, and a deceleration operation is performed immediately thereafter to return the carriage 3 to the origin position. By operating the carriage 3 as described above, the moving distance when the carriage 3 moves forward and the moving distance when the carriage 3 moves backward can be made the same. Can be made to coincide with the origin position. As will be described later, the discharge process executed after each agitation process is flushing in which ink is ejected from the plurality of nozzles 44 of the head 5 toward the flushing receiver 30. Therefore, the processing time required for the replacement process can be shortened by setting the position of the head 5 at the end of each stirring process to the origin position where the head 5 faces the flushing receiver 30. As described above, in the present embodiment, the liquid in the in-head flow path 80 can be stirred only by controlling the carriage 3 which is the existing configuration of the printer 1. In FIG. 7A and FIG. 7B, the configuration of the printer 1 that is not related to the stirring process is omitted for convenience of explanation.

  When the stirring process ends, the control device 100 executes a discharge process for discharging the liquid stirred by the stirring process in the in-head flow path 80 from the nozzle 44. At the time of this discharge process, the liquid in the in-head flow path 80 is in a state of being stirred by the agitation process. It becomes possible to discharge.

  By the way, if air remains in the predetermined flow path portion in the head internal flow path 80 during each stirring process, the presence of this air causes the liquid to flow near the predetermined flow path portion compared to the case where no air exists. It becomes easy to flow. As a result, when air is present in the predetermined flow path portion, the liquid in the in-head flow path 80 is stirred. As described above, at the time of the first stirring process, the connection corner portion between the main body flow path 70 and the connection flow path 75, which is a predetermined flow path portion in which the liquid in the flow path 80 in the head tends to stay by the introduction process. Since air remains at 90, the stirring efficiency of the liquid in the vicinity of the connection corner 90 is high. In addition, in the second and subsequent stirring processes, it is preferable that air stays at the connection corner portion 90 in view of stirring efficiency. In addition, after the agitation process and the discharge process are repeated N times, the exhaust process for exhausting the air in the in-head flow path 80 is executed, so the air present in the in-head flow path 80 is exhausted by the discharge process. There is no need to do. Therefore, in the present embodiment, the control device 100 controls the piezoelectric actuator 34 in each discharge process to perform flushing for discharging the liquid in the in-head flow path 80 from the nozzle 44.

  As described above, each discharge process is performed by flushing in which the liquid flow generated in the in-head flow path 80 is relatively small, so that the predetermined flow path of the in-head flow path 80 can be obtained even in the second and subsequent stirring processes. It becomes possible to keep air in the part. As a result, it is possible to improve the stirring efficiency of the liquid in the in-head flow path 80 during each stirring process. In addition, since flushing makes it easier to control (adjust) the amount of liquid discharged than suction purge, in each discharge process, it is possible to suppress discharge of more liquid than the set discharge amount from the in-head flow path 80. be able to. As a result, the amount of ink consumed during the discharge process can be reduced.

  In the present embodiment, the set discharge amount set in each discharge process is a liquid amount corresponding to the volume of the lower flow path 77 in the connection flow path 75. The lower channel 77 is a channel having a smaller channel cross-sectional area than the upper channel 76 and in which air does not easily stay. For this reason, in the lower flow path 77, the liquid is not stirred in the stirring process as compared with the upper flow path 76, and the preserving liquid present in the lower flow path 77 is mainly used in the discharge process. It is discharged by the flow of the liquid inside. Accordingly, by setting the set discharge amount in each discharge process to a liquid amount corresponding to the volume of the lower flow path 77, a large amount of preserving liquid existing in the lower flow path 77 is discharged out of the lower flow path 77. Can do. As a result, it is possible to efficiently reduce the storage liquid remaining in the in-head flow path 80 after the replacement process, while reducing the amount of ink discharged in the replacement process.

  As described above, since the amount (concentration) of the preserving solution existing in the flow path 80 in the head can be gradually decreased by repeating the stirring process and the discharge process N times, the head at the end of the replacement process. The preservation solution remaining in the inner flow path 80 can be reliably reduced. The number of repetitions N of the agitation process and the discharge process is the number of times required to make the color difference between the ink stored in the ink cartridge 42 and the liquid ejected from the nozzle 44 of the inkjet head 5 less than a predetermined value. It is preset by experiment, simulation, or the like.

  After repeatedly performing the stirring process and the discharging process N times, the control device 100 controls the cap unit 9 and the suction pump 11 to exhaust the air in the head in-channel 80 to the outside of the in-head channel 80. Perform exhaust processing. Specifically, in the exhaust process, the control device 100 performs the suction purge. In the suction purge in the exhaust process, the suction force of the suction pump 11 is made stronger than the suction purge in the introduction process, so that the air present in the in-head flow path 80 is forcibly discharged from the nozzle 44 together with the liquid. That is, the suction force of the suction pump 11 is increased so that the air in the supply flow path 62 also passes through the filter 49 and is discharged from the nozzle 44. Thereby, it is possible to suppress the deterioration of the ink ejection characteristics of the head 5 due to the air present in the in-head flow path 80.

(Inkjet printer operation)
Next, an example of processing operation of the printer 1 when the power of the printer 1 is turned on by the user will be described with reference to FIG.

  When the power of the printer 1 is turned on by the user (S1), the CPU 101 determines whether or not the ink cartridge 42 is mounted on the cartridge mounting portion 41 based on the detection result from the sensor 41b (S2). When it is determined that the ink cartridge 42 is not attached to the cartridge attachment portion 41 (S2: NO), the CPU 101 displays a screen for prompting the attachment of the ink cartridge 42 to the cartridge attachment portion 41 on the display 99 ( S3), the process returns to S2.

  On the other hand, when it is determined that the ink cartridge 42 is mounted on the cartridge mounting portion 41 (S2: YES), the CPU 101 refers to the RAM 103 and moves the in-head flow of the head 5 mounted on the carriage 3. It is determined whether or not ink is introduced into the path 80 (whether or not the head is new) (S4). Specifically, the RAM 103 stores an introduction flag indicating whether or not ink has been introduced into the in-head flow path 80. When the introduction flag is on, the CPU 101 determines that ink has been introduced into the in-head flow path 80 and that no preserving liquid is present in the in-head flow path 80. On the other hand, when the introduction flag is off, it is determined that no ink has been introduced into the in-head flow path 80 (not introduced) and that the preserving liquid is present in the in-head flow path 80.

  If it is determined that ink has not been introduced into the in-head flow path 80 of the head 5 (preservation liquid is present) (S5: YES), the CPU 101 determines that a replacement process is to be performed. By controlling the unit 9 and the suction pump 11 to discharge at least a part of the storage liquid in the in-head flow path 80 to the outside of the in-head flow path 80, the ink in the ink cartridge 42 is placed in all the ink flow paths 85. An introduction process to be introduced is executed (S6).

  Next, the CPU 101 controls the carriage 3 to move the head 5 in the scanning direction, thereby executing a stirring process for stirring the liquid in the in-head flow path 80 (S7). Next, the CPU 101 controls the piezoelectric actuator 34 to perform flushing, thereby executing a discharge process for discharging the liquid stirred by the stirring process in the in-head flow path 80 from the nozzle 44 (S8).

  Next, the CPU 101 determines whether or not the number of repetitions of the stirring process and the discharge process has reached N times (S9). If it is determined that N times have not been reached (S9: NO), the process returns to S7. On the other hand, when it is determined that N times have been reached (S9: YES), the CPU 101 controls the cap unit 9 and the suction pump 11 to perform the suction purge, whereby the air in the in-head flow path 80 is obtained. The exhaust process for forcibly discharging the gas from the nozzle 44 is executed (S10). Thereafter, the CPU 101 switches the introduction flag stored in the RAM 103 from off to on (S11), and ends this processing operation.

  On the other hand, if it is determined in step S4 that ink has been introduced into the in-head flow path 80 of the head 5 (S5: NO), the CPU 101 executes the exhaust purge and the suction purge in this order (S12). ). By this exhaust purge and suction purge, the air present in the in-head flow path 80 is reduced, and foreign matter, bubbles, ink having increased viscosity due to drying, etc. in the head 5 are discharged from the nozzle 44. The ejection characteristics are restored. The operation of the printer 1 has been described above.

  As described above, according to the present embodiment, in the replacement process, the preserving liquid present in the in-head flow path 80 is discharged after being agitated with the ink, so that the flow path portion is difficult to be discharged only by suction purge or flushing. It is possible to discharge the preserving solution present in the outside of the in-head flow path 80. As a result, it is possible to reduce the storage solution remaining in the in-head flow path 80. Further, in this embodiment, since the storage solution can be efficiently discharged in the replacement process, the amount of ink consumed in the replacement process can be reduced. As a result, the number of sheets of paper P on which images can be recorded can be increased by the ink cartridge 42 attached to the printer 1. Further, in the replacement process, the stirring process and the discharge process are repeatedly executed a plurality of times, so that the preserving liquid existing in the in-head flow path 80 can be reliably reduced.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, in the above-described embodiment, the discharge process is performed by flushing, but may be configured to be performed by suction purge. In this case, the control device 100 makes the control contents of the suction purge executed in the discharge process and the exhaust process different from each other. Specifically, as described above, in the discharge process, it is not necessary to exhaust the air present in the in-head flow path 80, and thus the suction force of the suction pump 11 is weakened. Thereby, it is possible to suppress excessive discharge of the liquid in the head flow path 80 in the discharge process. On the other hand, in the exhaust process, the suction force of the suction pump 11 is made stronger than in the discharge process. As a result, the air present in the in-head flow path 80 can be reliably exhausted.

  Further, in the above-described embodiment, the control device 100 performs suction so that at least a part of the air in the entire ink flow path 85 remains in the connection corner portion 90 between the main body flow path 70 and the connection flow path 75 in the introduction process. Although the pump 11 was controlled, the flow path part which keeps air is not limited to this. For example, in the introduction process, the control device 100 may control the suction pump 11 so that the air stays in the damper chamber 71 in which the liquid is likely to stay.

  Further, it is not essential to control the control device 100 to keep air in the predetermined flow path during the introduction process. In this case, air is not retained in the predetermined flow path portion of the in-head flow path 80 during the agitation process, and the agitation in the in-head flow path 80 may not proceed. It is necessary to increase the number of repetitions, or to increase the amount of liquid discharged outside the in-head flow path 80 during each discharge process. In this case, if the air in the head flow path 80 has been reduced to a level that does not affect the ejection failure due to the exhaust purge during the introduction process, it is necessary to execute the exhaust process in the replacement process. There is no. Further, the exhaust process may be executed by the exhaust purge in which the air in the supply flow path 62 is exhausted from the exhaust section 23 via the exhaust flow path 74. In this case, air can be discharged out of the supply flow path 62 with a weak suction force as compared with the case where the air in the supply flow path 62 is discharged from the nozzle 44 by suction purge.

  In the above-described embodiment, the control device 100 is configured to repeatedly execute the stirring process and the discharge process as a set a plurality of times in the replacement process. It may be configured to execute only once.

  In addition to the head 5, a moving mechanism 4 that moves the head 5 in a direction different from the scanning direction may be provided on the carriage 3 as shown in FIG. 9. The moving mechanism 4 includes two guide rails 91 and 92, two pulleys 93 and 94, a driving belt 95, and a head moving motor 96 (see FIG. 10). The guide rails 91 and 92 are provided on the carriage 3 and extend in the front-rear direction. The head 5 is detachably mounted on the two guide rails 91 and 92 and can move in the front-rear direction along the guide rails 91 and 92.

  The two pulleys 93 and 94 are arranged on the carriage 3 so as to be separated from each other in the front-rear direction. The pulley 93 is connected to a head moving motor 96. The drive belt 95 is an endless belt wound around the two pulleys 93 and 94. When the pulley 93 is rotationally driven by the head moving motor 96, the drive belt 95 travels, whereby the head 5 reciprocates in the front-rear direction. As described above, in this modification, the head 5 reciprocates in the scanning direction together with the carriage 3 when the carriage drive motor 20 is driven, and reciprocates in the front-rear direction when the head movement motor 96 is driven. .

  Then, in the stirring process, the control device 100 controls the moving mechanism 4 when the head 5 reciprocates in the scanning direction, as shown in FIGS. It is moved in the front-rear direction different from the scanning direction. The movement of the head 5 in the front-rear direction may be performed when the head 5 is moved in the scanning direction, or immediately after the head 5 is moved in the scanning direction. If the liquid is in motion. As described above, by moving the head 5 not only in the scanning direction but also in the front-rear direction, the stirring efficiency of the liquid in the in-head flow path 80 can be further improved. The moving direction of the head 5 by the moving mechanism 4 is not limited to the front-rear direction, and may be any direction different from the left-right direction (scanning direction).

  Further, in the above-described embodiment, the stirring of the liquid in the in-head flow path 80 is performed by moving the head 5, but the present invention is not particularly limited thereto. For example, an agitating blade is disposed in the in-head flow path 80, and the liquid is caused to flow in the in-head flow path 80 by rotating the agitating blade by a motor so that the liquid is agitated. Also good.

  Further, the flushing receiver 30 is not essential, and the liquid discharged from the nozzle 44 during the flushing may be received by the nozzle cap 25. Further, at the time of shipment, it is not necessary that all the flow paths of the in-head flow path 80 are filled with the storage liquid. For example, the storage liquid is stored in the damper chamber 71 and the flow path closer to the ink cartridge 42 than the damper chamber 71. It does not need to be filled.

  Further, the exhaust flow path 74 for performing the exhaust purge is not essential. However, when there is no exhaust flow path 74, it is necessary to draw all the air present in the damper chamber 71 and the like from the nozzle 44 at the end of the flow path 80 in the head only by suction purge during the replacement process.

  In the above embodiment, the discharge liquid introduced into the in-head flow path 80 of the head 5 is ink. However, the present invention is not particularly limited to this. For example, the quality of the image recorded on the paper P is improved. It may be a treatment liquid. Examples of the treatment liquid include a treatment liquid that aggregates or precipitates components in the ink.

In the above-described embodiment, the ink is supplied from the ink cartridge 42 that is detachably mounted to the cartridge mounting portion 41 to the all ink flow paths 85. A tank provided in the printer 1 may be connected, and ink may be supplied from the tank. When the ink in the tank runs out, the user inserts a bottle containing ink into a refill hole formed in the tank, and refills the tank with ink from the bottle.
Further, the present invention can also be applied to a so-called on-carriage type printer in which a cartridge mounting portion on which an ink cartridge is mounted is mounted on a carriage.
In addition, in the above-described embodiment, the tank that is an ink supply source is an ink cartridge. However, the present invention is not limited to this. For example, a pouch-type ink storage bag made of a flexible resin is used. It may be. The ink storage bag is provided with a cap to which the ink supply tube 22 can be connected. When the ink supply tube 22 is connected to the cap, the ink in the ink storage bag can be distributed to the ink supply tube 22. . Note that when the ink supply tube 22 is connected to the cap, air enters the ink supply tube 22, so that the control device 100 keeps the air at the connection corner 90 or the like in the introduction process of the replacement process. By controlling in this way, the stirring efficiency of the liquid in the stirring process can be improved.

  The present invention can also be applied to a so-called line-type inkjet printer that records an image on a sheet conveyed by a conveyance mechanism with an inkjet head fixed. In the above-described embodiment, the present invention is applied to an ink jet printer that records an image or the like by ejecting ink onto a sheet. However, in the liquid ejecting apparatus used for various purposes other than image recording. The present invention can be applied. For example, the present invention can also be applied to a liquid ejection apparatus that ejects a conductive liquid onto a substrate to form a conductive pattern on the surface of the substrate.

1 Inkjet printer (an example of a liquid ejection device)
5 Inkjet head 34 Piezoelectric actuator (energy application unit)
42 Ink cartridge (an example of a tank)
44 Nozzle 100 Control device (control unit)

Claims (12)

A nozzle capable of discharging a discharge liquid, and a head unit having a liquid flow path for communicating with the nozzle and supplying the discharge liquid stored in a tank to the nozzle;
A discharge portion for discharging the liquid that is at least one of the discharge liquid and the storage liquid different from the discharge liquid present in the liquid flow path to the outside of the liquid flow path;
A stirring section for stirring the liquid in the liquid flow path;
A control unit for controlling the discharge unit and the stirring unit,
The head unit is
A head body having the nozzle and discharging the discharge liquid from the nozzle;
A liquid supply member for supplying the discharge liquid to the head body,
The liquid channel is
A head channel formed in the head body and having a supply port through which the discharge liquid is supplied from the liquid supply member;
A supply passage formed in the liquid supply member and communicating the supply port and the tank;
The supply channel is
A first channel connected to the supply port of the head channel and extending upward from the supply port;
A second flow path connected to an end of the first flow path on the tank side and extending in a direction crossing the extending direction of the first flow path;
The connection corner between the first flow path and the second flow path is located at the uppermost position in the first flow path and the second flow path,
The controller is
When the storage liquid is present in the liquid flow path, the discharge unit is controlled to discharge at least the storage liquid in the liquid flow path to the outside of the liquid flow path, and the liquid flow from the tank. An introduction process for introducing the discharge liquid into the road;
After the introduction process, the stirring unit that controls the stirring unit to stir the liquid in the liquid flow path;
After the stirring process, the discharging unit is controlled to perform a discharging process of discharging the liquid stirred by the stirring unit in the liquid channel out of the liquid channel, and in the introducing process,
The discharge unit is controlled so that air in the liquid channel stays at the connection corner of the predetermined channel portion of the channel in which the preservation solution exists before the introduction process in the liquid channel is started. A liquid discharge apparatus characterized by that. A nozzle capable of discharging a discharge liquid, and a head unit having a liquid flow path for communicating with the nozzle and supplying the discharge liquid stored in a tank to the nozzle;
A discharge portion for discharging the liquid that is at least one of the discharge liquid and the storage liquid different from the discharge liquid present in the liquid flow path to the outside of the liquid flow path;
A stirring section for stirring the liquid in the liquid flow path;
A control unit for controlling the discharge unit and the stirring unit,
The head unit is
A head body having the nozzle and discharging the discharge liquid from the nozzle;
A liquid supply member for supplying the discharge liquid to the head body,
The liquid channel is
A head channel formed in the head body and having a supply port through which the discharge liquid is supplied from the liquid supply member;
A supply passage formed in the liquid supply member and communicating the supply port and the tank;
The supply channel is
Including a damper chamber for suppressing pressure fluctuation of the liquid supplied to the head body,
The controller is
When the preservative liquid is present in the liquid flow path, the discharge unit is controlled to discharge at least the preservative liquid in the liquid flow path to the outside of the liquid flow path, and the liquid flow from the tank. An introduction process for introducing the discharge liquid into the road;
After the introduction process, the stirring unit that controls the stirring unit to stir the liquid in the liquid flow path;
After the stirring process, the discharging unit is controlled to perform a discharging process for discharging the liquid stirred by the stirring unit in the liquid channel out of the liquid channel, and in the introducing process,
Controlling the discharge unit so that air in the liquid flow channel stays in the damper chamber, which is a predetermined flow channel portion of the flow channel in which the preservation liquid exists before the introduction process in the liquid flow channel is started. A liquid ejection apparatus characterized by the above. A nozzle capable of discharging a discharge liquid, and a head unit having a liquid flow path for communicating with the nozzle and supplying the discharge liquid stored in a tank to the nozzle;
A discharge portion for discharging the liquid that is at least one of the discharge liquid and the storage liquid different from the discharge liquid present in the liquid flow path to the outside of the liquid flow path;
A stirring section for stirring the liquid in the liquid flow path;
A control unit for controlling the discharge unit and the stirring unit,
The discharge part is
A cap that can be attached to the head unit so as to cover the nozzle; and a suction pump connected to the cap, and the suction pump is driven in a state where the cap is attached to the head unit. A purge unit for discharging the liquid and air in the liquid flow path from the nozzle,
The controller is
When the preservative liquid is present in the liquid flow path, the discharge unit is controlled to discharge at least the preservative liquid in the liquid flow path to the outside of the liquid flow path, and the liquid flow from the tank. An introduction process for introducing the discharge liquid into the road;
After the introduction process, the stirring unit that controls the stirring unit to stir the liquid in the liquid flow path;
After the stirring process, the discharging unit is controlled to perform a discharging process for discharging the liquid stirred by the stirring unit in the liquid channel out of the liquid channel, and in the introducing process, Before the start of the introduction process in the liquid flow path, the discharge unit is controlled so that air stays in a predetermined flow path part of the flow path in which the preservation solution exists, and in the discharge process, the purge unit is controlled, Purging to discharge the liquid in the liquid flow path from the nozzle, and
After the discharge process, the purge unit is further controlled to perform an exhaust process for performing a purge for exhausting the air in the liquid flow path through the nozzle,
In the purge of the exhaust process, the suction force of the suction pump is stronger than the suction force of the suction pump during the purge of the discharge process in order to discharge the air in the liquid channel from the nozzle. A liquid discharge apparatus characterized by: A nozzle capable of discharging a discharge liquid, and a head unit having a liquid flow path for communicating with the nozzle and supplying the discharge liquid stored in a tank to the nozzle;
A discharge portion for discharging the liquid that is at least one of the discharge liquid and the storage liquid different from the discharge liquid present in the liquid flow path to the outside of the liquid flow path;
A stirring section for stirring the liquid in the liquid flow path;
A control unit for controlling the discharge unit and the stirring unit,
The head unit is
As the discharge unit, provided with an energy applying unit that applies energy for discharging from the nozzle to the liquid in the liquid flow path,
Furthermore, the discharge part is
A cap that can be attached to the head unit so as to cover the nozzle; and a suction pump connected to the cap, and the suction pump is driven in a state where the cap is attached to the head unit. Is provided with a purge unit for discharging the liquid and air in the liquid flow path from the nozzle,
The controller is
When the preservative liquid is present in the liquid flow path, the discharge unit is controlled to discharge at least the preservative liquid in the liquid flow path to the outside of the liquid flow path, and the liquid flow from the tank. An introduction process for introducing the discharge liquid into the road;
After the introduction process, the stirring unit that controls the stirring unit to stir the liquid in the liquid flow path;
After the stirring process, the discharging unit is controlled to perform a discharging process for discharging the liquid stirred by the stirring unit in the liquid channel out of the liquid channel, and in the introducing process,
Controlling the discharge section so that air stays in a predetermined flow path portion of the flow path in which the preservative solution exists before the introduction process starts in the liquid flow path,
In the discharge process, the energy application unit is controlled to perform flushing for discharging the liquid in the liquid flow path from the nozzle and discharging the liquid, and
After the discharge process, the liquid discharge apparatus further executes an exhaust process for controlling the purge unit to perform a purge for discharging the air in the liquid channel from the nozzle. The controller is
The liquid ejection apparatus according to claim 3, wherein the stirring process and the discharge process are repeatedly performed a plurality of times. A nozzle capable of discharging a discharge liquid, and a head unit having a liquid flow path for communicating with the nozzle and supplying the discharge liquid stored in a tank to the nozzle;
A discharge portion for discharging the liquid that is at least one of the discharge liquid and the storage liquid different from the discharge liquid present in the liquid flow path to the outside of the liquid flow path;
A carriage mounted with the head unit and reciprocating in a predetermined scanning direction together with the head unit;
A control unit,
The controller is
When the preservative liquid is present in the liquid flow path, the discharge unit is controlled to discharge at least the preservative liquid in the liquid flow path to the outside of the liquid flow path, and the liquid flow from the tank. An introduction process for introducing the discharge liquid into the road;
After the introduction process, the stirring process of controlling the carriage to reciprocate the head unit in the scanning direction so that the liquid in the liquid flow path is stirred.
After the agitation process, the liquid discharge apparatus is characterized in that the discharge unit is controlled to discharge the liquid agitated by the carriage in the liquid channel to the outside of the liquid channel. . A moving mechanism for moving the head unit in a direction different from the scanning direction;
The controller is
In the stirring process, when the head unit reciprocates in the scanning direction, the moving mechanism is controlled to move the head unit in a direction different from the scanning direction. The liquid discharge apparatus as described. A liquid receiver for receiving the liquid discharged from the nozzle of the head unit, disposed in a partial range of the moving range of the head unit in the scanning direction;
The controller is
The stirring process and the discharge process are repeated a plurality of times as a set,
In each of the agitation processes, the carriage is controlled so that the liquid receiver is an origin position, the head unit is moved forward from the origin position in the scanning direction, and then the head unit is moved back to the origin position. Let
The liquid in the liquid flow path is discharged from the nozzle of the head unit toward the liquid receiver in each of the discharge processes by controlling the discharge unit.
Or the liquid ejection device according to 7. A nozzle capable of discharging a discharge liquid, and a head unit having a liquid flow path for communicating with the nozzle and supplying the discharge liquid stored in a tank to the nozzle;
A discharge portion for discharging the liquid that is at least one of the discharge liquid and the storage liquid different from the discharge liquid present in the liquid flow path to the outside of the liquid flow path;
A stirring section for stirring the liquid in the liquid flow path;
A control unit for controlling the discharge unit and the stirring unit,
The head unit is
As the discharge unit, provided with an energy applying unit that applies energy for discharging from the nozzle to the liquid in the liquid flow path,
The controller is
When the preservative liquid is present in the liquid flow path, the discharge unit is controlled to discharge at least the preservative liquid in the liquid flow path to the outside of the liquid flow path, and the liquid flow from the tank. An introduction process for introducing the discharge liquid into the road;
After the introduction process, the stirring unit that controls the stirring unit to stir the liquid in the liquid flow path;
After the stirring process, the discharging unit is controlled to perform a discharging process for discharging the liquid stirred by the stirring unit in the liquid channel out of the liquid channel, and
The stirring process and the discharge process are repeated a plurality of times as a set,
In each of the discharge processes,
A liquid ejection apparatus that controls the energy applying unit to perform flushing for ejecting and discharging the liquid in the liquid flow path from the nozzle. The controller is
In the introduction process,
The discharge unit is controlled so that air stays in a predetermined flow path portion of the flow path in which the preserving liquid exists before the introduction process in the liquid flow path is started. The liquid ejection device according to one item. The tank includes a storage chamber that stores the discharge liquid, and a supply unit that supplies the discharge liquid from the storage chamber to the outside of the tank,
The tank is further detachably mounted, and further includes a tank mounting portion having a connected portion that is connected to the supply portion of the tank and circulates the discharge liquid when the tank is mounted,
The liquid channel is connected to the connected part,
The controller is
In the introduction process,
To move at least part of the air that enters the liquid channel to the predetermined channel portion of the liquid channel when the supply unit of the tank and the connected portion of the tank mounting unit are connected In addition, the total discharge amount of the liquid discharged from the liquid channel to the outside of the liquid channel is an amount corresponding to the volume from the connection position with the connected portion in the liquid channel to the predetermined channel portion. The liquid ejecting apparatus according to claim 1, wherein the discharge unit is controlled to be like this. An exhaust passage for connecting to the liquid passage and for discharging air;
Switching means for switching between a state of opening and closing the exhaust flow path,
The discharge part can be connected to the exhaust passage in a state opened by the switching means,
The controller is
2. The exhaust process of further exhausting the air in the liquid flow path through the exhaust flow path by controlling the discharge section and the switching unit after the discharge process. ,
The liquid ejection device according to any one of 2 and 10.

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