JP2010155417A - Liquid discharge apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent air from entering a liquid discharge head. <P>SOLUTION: The liquid discharge apparatus includes a distribution channel 23C having a liquid inlet 23Ca, two liquid outlets 23Cb and 23Cc and an exhaust opening 25C, two gas-liquid separation chambers 24Ca and 24Cb communicating with the two liquid outlets 23Cb and 23Cc, respectively, the liquid discharge head having two liquid inlets communicating with the perpendicular lower end of the gas-liquid separation chambers 24Ca and 24Cb, respectively, and an exhaust channel 26C connected to the exhaust opening 25C. The liquid inlet 23Ca is provided at a position close to one of the two gas-liquid separation chambers 24Ca and 24Cb in the flow direction of a liquid in the distribution channel 23C, and an exhaust opening 25Y is provided at least at the middle position of the two gas-liquid separation chambers 24Ca and 24Cb in the flow direction of the distribution channel 23C. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid ejection apparatus including a liquid ejection head that ejects liquid, such as an inkjet printer.

  An ink jet printer that is an example of a liquid ejecting apparatus includes an ink jet head having nozzles that eject ink. As an ink jet head having a nozzle row for each of a plurality of types of ink, one having two ink inlets for one type of ink is known (for example, see Patent Document 1). In a printer including such an ink jet head, a distribution channel is connected to the downstream end of a supply channel for supplying ink from an ink supply source, and the supply channel is connected to two ink inlets via the distribution channel. And communicate with each other.

In some cases, air is mixed into the distribution channel together with the ink, and when the air reaches the ink jet head, ink ejection failure is caused. In order to prevent this, when a gas-liquid separation chamber is interposed between each ink introduction port and the distribution channel, the exhaust channel is connected to the distribution channel via the exhaust port, and negative pressure is applied to the exhaust channel. Air trapped in the gas-liquid separation chamber can be discharged to the outside through the exhaust port and the exhaust passage.
JP 2007-245445 A

  According to this prior art, an exhaust port is disposed immediately above each gas-liquid separation chamber, so that air separated in each gas-liquid separation chamber can be discharged through each exhaust port. And the two exhaust flow paths connected to each exhaust port merge to form one exhaust flow path, which is connected to a pump that applies a negative pressure.

  However, in this prior art, the inventors of the present application have come to know that a situation in which exhaust from only one of the two exhaust passages may occur due to the following reasons.

  That is, when a negative pressure is applied to the exhaust flow path by operating the pump, if the air trapped around one exhaust port is exhausted before the other exhaust port, It is possible that more ink will be sucked from one exhaust port before the air exhausted is completed and the air trapped around the other exhaust port is completed. Compared to the above, it has the property of being easy to flow under the influence of negative pressure, so priority is given to the discharge of ink from one exhaust port, and the air remaining around the other exhaust port is moved to the exhaust flow channel side. It was impossible to guide. For this reason, in the prior art, even if the pump is driven for a sufficient time, the air is not exhausted, and the ink ejection failure may not be solved.

  Accordingly, an object of the present invention is to improve air discharge performance in a liquid discharge apparatus having a liquid discharge head having two liquid inlets.

  The present invention has been made in view of such circumstances, and a liquid ejection apparatus according to the present invention has a liquid inlet, two liquid outlets, and an exhaust outlet, and supplies liquid from a liquid supply source to the liquid. A distribution flow path that takes in from the inlet and distributes by flowing out from the two liquid outlets, and two gas-liquid separations that communicate with the two liquid outlets and extend vertically downward from the communicating portions. And two liquid introduction ports supplied from the two gas-liquid separation chambers, each having two liquid introduction ports communicating with a liquid supply port provided at a vertical lower end of each of the two gas-liquid separation chambers A liquid discharge head that is introduced through a port; and an exhaust channel that is connected to the exhaust port and exhausts air separated in the two gas-liquid separation chambers. Regarding the flow direction of liquid in the distribution channel The exhaust port is provided in a position near one of the two gas-liquid separation chambers, and the exhaust port is provided at least at an intermediate position of the two gas-liquid separation chambers in the flow direction of the distribution channel. It is characterized by being.

  By adopting such a configuration, since the exhaust port is single, the air cannot be discharged from the other exhaust port after the exhaust of air from one of the two exhaust ports is completed as in the prior art. This phenomenon can be eliminated. Since the exhaust port is disposed at an intermediate position between the two gas-liquid separation chambers, the air trapped in each gas-liquid separation chamber can be discharged evenly. Moreover, since the liquid inlet is provided in the vicinity of one of the gas-liquid separation chambers, it is possible to realize a structure that does not suck air against the ink flow and is captured in each gas-liquid separation chamber. The air can be discharged in a more balanced manner.

  The distance between one of the two gas-liquid separation chambers in the flow direction of the distribution channel and the liquid inlet does not exceed a length corresponding to the radius of the liquid inlet. Also good. Thus, a configuration in which the liquid inlet is provided in the vicinity of the gas-liquid separation chamber can be realized, and it is possible to favorably avoid the ink flow from hindering the discharge of air. In addition, this action can be further improved if at least a part of the liquid inflow port overlaps the one gas-liquid separation chamber in plan view.

  The exhaust port may extend toward the downstream side in the flow direction of the distribution channel. Thereby, the air trapped in the gas-liquid separation chamber arranged on the downstream side in the ink flow direction can be discharged well.

  The distribution channel extends in a U shape in a plan view, the two gas-liquid separation chambers communicate with both ends of the distribution channel, and the exhaust port is connected to the distribution channel. Extending in an L shape in plan view from an intermediate position between the two gas-liquid separation chambers in the flow direction toward an end portion on the side where one of the two gas-liquid separation chambers communicates Also good. As a result, when one exhaust port is provided in the distribution channel formed in a U shape in plan view, the air trapped in the gas-liquid separation chamber disposed downstream in the ink flow direction is discharged well. The resulting structure is realized.

  According to the present invention, air discharge performance can be improved in a liquid discharge head having two liquid introduction ports and a liquid discharge apparatus having a liquid distribution channel.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this embodiment, the liquid ejection apparatus according to the present invention is applied to an ink jet printer.

  FIG. 1 is a schematic plan view showing a configuration of an inkjet printer 1 according to an embodiment of the present invention. The ink jet printer 1 shown in FIG. 1 has a pair of front and rear guide rails 2 and 3 extending parallel to the left and right, a head holder 4 is supported on the rear guide rail 2, and a head holder is mounted on the front guide rail 3. 4 A buffer tank 5 held at the top is supported. One guide rail is provided with a scanning mechanism 6 constituted by, for example, a pulley / belt mechanism, and the head holder 4 is moved along the guide rails 2 and 3 together with the buffer tank 5 by driving the scanning mechanism 6. Slide to the left or right. An ink jet head 7 is held below the head holder 4. A plurality of nozzle rows 8 are opened in the lower surface of the ink jet head 7, and a recording medium 9 such as a recording paper is horizontally sent from the lower side to the front side from below. The ink jet printer 1 discharges ink downward from the nozzle row 8 of the ink jet head 7 while scanning the head holder 4 left and right, and landes the ink on an appropriate portion of the recording medium 9 being conveyed, thereby A predetermined image and characters can be formed on the recording medium 9.

  The ink jet printer 1 is detachably mounted with four ink tanks 10 storing inks of different colors (that is, black ink, magenta ink, yellow ink, or cyan ink). When each ink tank 10 is mounted, one end of the ink tube 11 is connected to the rear part thereof. The ink tubes 11 are individually provided in the four ink tanks 10. The other end of each ink tube 11 is connected to a joint 12 fixed to the buffer tank 5, and the internal space of each joint 12 is formed in the buffer tank 5, and four buffer ink flow paths through which different inks flow. Each of the 13 inlets is in communication. In other words, the internal space of the ink tank 10 attached to the ink jet printer 1 communicates with the corresponding buffer ink flow path 13 through the internal space of the ink tube 11 and the joint 12, and the ink in each ink tank 10. Are supplied to the buffer ink flow path 13 in this order.

  FIG. 2 is a schematic side view showing the peripheral configuration of the head holder 4 as viewed in the direction of arrow II in FIG. As shown in FIG. 2, an ink supply port 14 serving as an outlet of the buffer ink flow path 13 is provided at the rear lower end portion of the buffer tank 5, and the ink introduction port 14 is opened on the upper surface of the inkjet head 7. It communicates with the mouth 15. More specifically, a rubber seal member 16 is interposed between the surface of the buffer tank 5 where the ink supply port 14 opens and the surface of the inkjet head 7 where the ink introduction port 15 opens, and this seal member. The openings 14 and 15 are in fluid-tight communication with each other through the holes formed in 16. The ink flowing in the buffer tank 5 sequentially passes through the ink supply port 14, the hole of the seal member 16, and the ink introduction port 15, and is supplied to the nozzle 8 through the flow path in the inkjet head 7.

  Returning to FIG. 1, a joint 18 is further fixed to the buffer tank 5, and one end of an exhaust tube 19 is connected to the joint 18. An exhaust pump 20 is connected to the other end of the exhaust tube 19 so that when the exhaust pump 20 is operated, air that has entered the buffer ink flow path 13 can be discharged to the outside.

  3 is a block diagram conceptually showing the ink and air flow paths of the inkjet printer 1, FIG. 4A is a top view of the inkjet head 7 taken along the line IVa-IVa in FIG. 2, and FIG. FIG. 4 is a bottom view of the inkjet head 7 shown along the line IVb-IVb in FIG. 2. The subscripts “K”, “M”, “Y”, and “C” added to the reference numerals in the following description of the ink tank and other flow paths are black ink, magenta ink, yellow ink, and cyan ink. In the description of matters common to the respective inks, these suffixes may not be added to the reference numerals.

  As shown in FIG. 3, the inkjet head 7 is first provided with a total of six ink inlets 15K, 15M, 15Ya, 15Yb, 15Ca, and 15Cb arranged side by side (see also FIG. 4A). Head ink channels 17K, 17M, 17Ya, 17Yb, 17Ca, and 17Cb that are independent of each other are communicated with the ink inlets 15K, 15M, 15Ya, 15Yb, 15Ca, and 24Cb. The inkjet head 7 is formed with a total of 12 nozzle rows 8Ka to 8Kc, 8Ma to 8Mc, 8Ya to 8Yc, and 8Ca to 8Cc that are arranged in the front and back and are arranged on the left and right (see also FIG. 4B). ).

  As indicated by the subscripts of the reference numerals, the inkjet head 7 is provided with one ink introduction port for two types of inks of black and magenta ink, and 2 for two types of inks of yellow and cyan inks. Ink inlets are provided, and three nozzle rows are formed for each ink. Specifically, the black ink introduction port 15K arranged at the left end communicates with the three black nozzle rows 8Ka to 8Kc via the black head ink flow path 17K, and at the left and right center of the remaining five ink introduction ports. The arranged magenta ink introduction port 15M communicates with the three magenta nozzle rows 8Ma to 8Mc through the magenta head ink flow path 17M. The first and second yellow ink introduction ports 15Ya and 15Yb are arranged so as to sandwich the magenta ink introduction port 15M from side to side, and the first yellow ink introduction port 15Ya is arranged in two rows of yellow nozzles via the first yellow head ink flow path 17Ya. The second yellow ink inlet 15Yb communicates with one row of yellow nozzles 8Yc via the second yellow head ink flow path 17Yb. The first and second cyan ink inlets 15Ca and 15Yb are disposed so as to sandwich the yellow ink inlets 15Ya and 15Yb and the magenta ink inlet 15M, and the first cyan ink inlet 15Ca passes through the first cyan head ink channel 17Ca. The second cyan ink introduction port 15Cb communicates with the two cyan nozzle rows 8Cb and 8Cc via the second cyan head ink flow path 17Cb.

  Next, in order from the upstream side, the internal space of the black ink tank 10K communicates with the black ink supply passage 21K. The ink supply flow path 21K includes an internal space of the black ink tube 11K, an internal space of the joint 12K, and a supply flow path 22K in the buffer tank 5, and a downstream end thereof is formed at a rear end portion of the buffer tank 5. The gas-liquid separation chamber 24K communicates with the upper end. The gas-liquid separation chamber 24K extends vertically and functions as a space for capturing air that has entered the ink supply flow path 21K. The lower end opening of the gas-liquid separation chamber 24K forms the ink supply port 14K described above, and the ink supply port 14K communicates with the black ink introduction port 15K in a liquid-tight manner. Since the flow path structure relating to magenta ink is the same as this, detailed description thereof is omitted (see reference numerals 10M to 15M, 21M, 22M, and 24M in FIG. 3).

  The internal space of the yellow ink tank 10Y communicates with the yellow supply channel 21Y. The supply flow path 21Y includes an internal space of the yellow ink tube 11Y, an internal space of the joint 12Y, and a supply flow path 22Y in the buffer tank 5. A distribution channel 23Y formed in the buffer tank 5 communicates with the downstream end thereof, and the distribution channel 23Y has an ink inlet 23Ya. The distribution channel 23Y is a channel for distributing the ink in the supply channel 21Y to the two ink inlets 15Ya and 15Yb. The distribution channel 23Y includes two ink outlets 23Yb and 23Yc. Set as the downstream end. The ink outlets 23Yb and 23Yc communicate with the upper ends of the gas-liquid separation chambers 24Ya and 24Yb, respectively, and the lower ends of the gas-liquid separation chambers 24Ya and 24Yb form the ink supply ports 14Ya and 14Yb described above. The supply ports 14Ya and 14Yb are in fluid-tight communication with the yellow ink introduction ports 15Ya and 15Yb. Since the flow path structure for cyan ink is the same as this, detailed description thereof will be omitted (reference numerals 10C to 13C, 14Ca, 14Cb, 15Ca, 15Cb, 21C to 23C, 23Ca to 23Cc, 24Ca and 24Cb in FIG. 3). reference).

  Although it has been described above that the buffer ink flow path 13 is formed in the buffer tank 5 for each ink, according to the above concept, one supply flow is supplied to the buffer ink flow paths 13K and 13M for black and magenta ink. Channels 22K and 22M and one gas-liquid separation chamber 24K and 24M are included, respectively. The buffer ink channels 13Y and 13C for yellow and cyan ink include one supply channel 22Y and 22C, one branch channel 23Y and 23C, and two gas-liquid separation chambers 24Ya and 24Yb, 24Ca and 24Cb are included, respectively.

  Each of the supply flow paths 22K, 22M, 22C, and 22Y has storage portions 22Kb, 22Mb, 22Cb, and 22Yb for temporarily storing ink, and further upstream portions 22Ka, 22Ma, and upstream of the storage portions. 22Ca, 22Ya and downstream outflow portions 22Kc, 22Mc, 22Cc, 22Yc. In the black and magenta ink supply channels 22K and 22M, the end portions 22Kd and 22Md are further communicated with the downstream ends of the outflow portions 22Kc and 22Mc, and the yellow and cyan ink supply channels 22Y and 22C are outflowed. Ink inlets 23Ya and 23Ca of the distribution channels 23Y and 23C communicate with the downstream ends of the portions 22Cc and 22Yc. The detailed structure of each part will be described later.

  In the buffer ink flow paths 13K and 13M for black and magenta ink, the exhaust ports 25K and 25M are opened at the end portions 22Kd and 22Md of the supply paths 22K and 22M, and the buffer ink flow paths 13Y and yellow ink for the yellow and cyan inks are formed. In 13C, exhaust ports 25Y and 25C are opened in the distribution channels 23Y and 23C. Exhaust passages 26K, 26M, 26Y, and 26C formed in the buffer tank 5 communicate with the exhaust ports 25K, 25M, 25Y, and 25C, and end portions of the exhaust tubes 19 pass through the internal space of the joint 18 and communicate with each other. It communicates with the interior space. Therefore, when the exhaust pump 20 is operated, negative pressure is applied to the internal space of the exhaust tube 19, the internal space of the joint 18, and the exhaust passages 26 </ b> K, 26 </ b> M, 26 </ b> Y, and 26 </ b> C and is captured in each gas-liquid separation chamber 24. Air is discharged outside through these spaces. As a result, it is possible to prevent the occurrence of ink ejection failure due to the air reaching the head ink flow paths 17K, 17M, 17Ya, 17Yb, 17Ca, and 17Cb in the inkjet head 7.

  Next, the configuration of the buffer tank 5 will be described with reference to FIGS. 5 is an exploded perspective view of the buffer tank 5 shown in FIG. 1, and FIG. 6 is a side view of the buffer tank 5 shown in a state where the buffer tank 5 shown in FIG. 5 is assembled. As shown in FIGS. 5 and 6, the buffer tank 5 is configured by assembling an upper tank portion 31 and a lower tank portion 32 vertically. When assembling the upper and lower tank portions 31 and 32, the boss portions 31a and 31b (see FIG. 8 for 31b) projecting from the front and rear center portions of the upper tank portion 31 and the upper front end portion of the lower tank portion 32 The projecting bosses 32 a and 32 b are abutted with each other, and a flow path forming part 31 g formed at the rear part of the upper tank part 31 and a flow path forming part 32 g formed at the rear part of the lower tank part 31. Are butted together. The upper tank portion 31 has a larger front-rear dimension than the lower tank portion 32, and the front end portion of the upper tank portion 31 protrudes forward with respect to the front end portion of the lower tank portion 32. The front end portion of the upper tank portion 31 protruding forward is supported by the front guide rail 3, and the lower tank portion 32 of the buffer tank 5 is mainly held in the head holder 4 (see also FIG. 2). ).

  A number of grooves and through holes are formed in the upper and lower tank portions 31 and 32, and these grooves and through holes are closed by assembling the upper and lower tank portions 31 and 32. It can also be closed by attaching flexible resin films 33 to 37 to the upper and lower surfaces of the upper and lower tank portions 31 and 32. Thereby, the buffer ink channel 13 (see FIG. 3) and the exhaust channel 26 (see FIG. 3) are formed in the buffer tank 5. The subsequent direction of the buffer tank 5 is based on the state provided in the ink jet printer 1 as shown in FIG. 1, and according to this direction, the buffer ink flow path 13 (see FIG. 3) is generally upstream on the front side. The side and rear side are downstream.

  FIG. 7 is a plan view showing the upper and lower tank portions 31 and 32 assembled, and FIG. 8 is a bottom view of the upper tank portion 31. As shown in FIG. 7, four non-penetrating joint mounting holes 40K, 40M, 40Y, and 40C are opened at the upper surface front end portion of the upper tank portion 31, and the through holes 41K, 41M, and 41Y are formed on the bottom surface thereof. , 41C are open. When the joint 12 (see FIG. 1) is fitted into the joint mounting holes 40K, 40M, 40Y, and 40C, one end of the internal space of each joint 12 communicates with the corresponding through hole 41K, 41M, 41Y, and 41C. That is, the upper openings of the through holes 41K, 41M, 41Y, and 41C form the inlets of the buffer ink flow paths 13K, 13M, 13Y, and 13C (that is, the inlets of the supply flow paths 22K, 22M, 22Y, and 22C). Yes.

  Referring to FIGS. 7 and 8, the through holes 41K, 41M, 41Y, and 41C are opened at the front ends of the concave grooves 42K, 42M, 42Y, and 42C, respectively. Each concave groove 42K, 42M, 42Y, 42C extends in the front-rear direction, and the rear end portion thereof communicates with the front end portion of the concave grooves 44K, 44M, 44Y, 44C via the through holes 43K, 43M, 43Y, 43C. The right end groove 44K extends diagonally right rear from the opening of the through hole 43K, and the remaining concave grooves 44M, 44C, 44Y extend diagonally left rear from the opening of the through holes 43M, 43C, 43Y. ing.

  A first film 33 is attached to the front surface of the upper tank portion 31 so as to cover the openings of the grooves 44K, 44M, 44Y, 44C, and the grooves 42K, 42M, The 2nd film 34 is affixed so that 42Y and 42C opening may be covered. As a result, upstream portions 22Ka, 22Ma, 22Ya, and 22Ca of the supply passages 22 are formed in the front portion of the buffer tank 5, and the ink that has flowed through the internal spaces of the ink tube 11 and the joint 12 is first the upstream portion 22Ka. , 22Ma, 22Ya, 22Ca. The ink in the upstream portions 22Ka, 22Ma, 22Ya, and 22Ca flows substantially toward the rear side while going back and forth between the front upper surface side and the front lower surface side of the upper tank portion 31.

  Reservoir portions 22Kb, 22Mb, 22Yb, and 22Cb communicate with the downstream ends of the upstream portions 22Ka, 22Ma, 22Ya, and 22Ca. Returning to FIG. 6, the four storage portions 22Kb, 22Mb, 22Yb, and 22Cb are arranged in the upper and lower layers at the front and rear central portions of the buffer tank 5. More specifically, a magenta storage portion 22Mb is disposed on the upper surface side of the upper tank portion 31, a cyan storage portion 22Cb is disposed on the lower surface side of the upper tank portion 31, and yellow is disposed on the upper surface side of the lower tank portion 32. Storage section 22 </ b> Yb is disposed, and a black storage section 22 </ b> Kb is disposed on the lower surface side of the lower tank section 32.

  Referring to FIG. 7, the magenta storage part 22 </ b> Mb is configured by closing the opening of the tank groove 49 </ b> M formed in the front and rear center part of the upper tank part 31 with the first film 33. The tank groove 49M is formed in a rectangular shape that is wide in front, rear, left, and right, and the rear end portion of the concave groove 44M communicates with the left front corner of the tank groove 49M.

  7 and 8, a through hole 45C is opened at the front end of the recessed groove 44C. As shown in FIG. 8, a tank groove 49C having a rectangular shape in plan view is formed on the lower surface of the upper tank portion 31 at a position overlapping the magenta tank groove 49M in the vertical direction, and the through hole 45C is formed in the tank groove 49C. Open to the left front corner. The cyan storage portion 22 </ b> Cb is configured by closing the opening of the tank groove 49 </ b> C with a third film 35 separate from the second film 34. The through hole 45 </ b> C serves as a flow path that connects the upstream portion 22 </ b> Ca formed on the upper surface side of the upper tank portion 31 and the storage portion 22 </ b> Cb disposed on the lower surface side of the upper tank portion 31.

  FIG. 9 is a plan view of the lower tank portion 32, and FIG. 10 is a bottom view showing the upper and lower tank portions 31, 32 in an assembled state. As shown in FIGS. 6, 8, and 9, a pair of left and right upper bosses 31 a and 31 b project from the area in front of the tank groove 49 </ b> C in a cylindrical shape on the lower surface of the upper tank portion 31. From the front end, a pair of left and right lower bosses 32a and 32b project in a cylindrical shape on the upper surface of the. When the upper and lower tank portions 31 and 32 are assembled, the end surfaces of the upper boss 31a and 31b and the lower boss 32a and 32b are aligned. The end surfaces of the upper bosses 31a and 31b are located below the surface to which the third film 35 is attached, and the end surfaces of the lower bosses 32a and 32b are located above the surface to which the fourth film 36 described later is attached. The cyan reservoir 22Cb and the yellow reservoir 22Yb are spaced apart from each other.

  Referring to FIGS. 7 to 10, a through hole 45K is opened at the front end of the groove 44K. The through hole 45K extends vertically on the right upper boss 31a and communicates vertically with a through hole 46K extending vertically on the lower boss 32a on the right side. The through hole 46 </ b> K opens at the right front corner of a tank groove 49 </ b> K having a rectangular shape in plan view formed on the lower surface of the lower tank portion 32. The black storage portion 22 </ b> Kb is configured by closing the opening of the tank groove 49 </ b> K with the fifth film 37. The through holes 45 </ b> K and 46 </ b> K communicate the upstream portion 22 </ b> Ka formed on the upper surface side of the upper tank portion 31 and the storage portion 22 </ b> Kb disposed on the lower surface side of the lower tank portion 32.

  Referring to FIGS. 7 to 10, a through hole 45Y is opened at the front end of the recessed groove 44Y. The through hole 45Y extends vertically from the left upper boss 31b and communicates vertically with a through hole 46Y extending vertically from the left lower boss 32b. The through hole 46Y opens to the bottom surface of the concave groove 47Y formed in the lower left front portion of the lower tank portion 32, and another through hole 48Y opens to the bottom surface of the concave groove 47Y. On the upper surface of the lower tank portion 32, a tank groove 49Y having a rectangular shape in plan view is formed at a position substantially overlapping with the other tank grooves, and the through hole 48Y opens at the right front corner of the tank groove 49Y. . The yellow storage portion 22Yb is configured by closing the opening of the tank groove 49Y with the fourth film 36, and the opening of the concave groove 47Y is closed with the fifth film 37. The through holes 45Y and 46Y, the concave groove 47Y, and the through hole 48Y communicate the upstream portion 22Ya formed on the upper surface side of the upper tank portion 31 and the storage portion 22Yb disposed on the upper surface side of the lower tank portion 32.

  Since the supply flow path 22 has such storage parts 22Kb, 22Mb, 22Yb, and 22Cb, the ink supplied to the inkjet head 7 can be temporarily stored here. In addition, the storage units 22Kb, 22Mb, 22Yb, and 22Cb are partitioned by flexible films 33, 35, 36, and 37. Therefore, even if the pressure of the ink in the flow path from the ink tank 10 to the ink inlet 15 of the inkjet head 7 fluctuates, the storage portions 2Kb, 22Mb, and 22Yb are caused by the elastic deformation of the films 33, 35, 36, and 37. , 22Cb can be varied to absorb ink pressure fluctuations.

  Outflow portions 22Kc, 22Mc, 22Yc, and 22Cc communicate with the storage portions 22Kb, 22Mb, 22Yb, and 22Cb. Referring to FIG. 7, the right rear corner portion of the tank groove 49M communicates with the front end portion of the concave groove 51M, and a through hole 52M is opened at the rear end portion of the concave groove 51M. The opening of the concave groove 51M is also closed by the first film 33. Thus, the magenta storage part 22Mb communicates with the outflow part 22Mc constituted by the concave groove 51M and the through hole 52M. The ink in the storage part 22Mb flows into the outflow part 22Mc and is sent to the lower surface side of the flow path forming part 31g formed at the rear part of the upper tank part 31 through the lower opening of the through hole 52M shown in FIG. .

  Referring to FIGS. 7 and 8, a through hole 50C is opened at the right rear corner of the tank groove 49C. The through hole 50C communicates with the front end portion of the recessed groove 51C formed at the right edge of the upper rear portion of the upper tank portion 31, and the through hole 52C opens at the rear end portion of the recessed groove 51C. The opening of the recessed groove 51 </ b> C is also closed by the first film 33. As described above, the cyan storage portion 22Cb communicates with the outflow portion 22Cc formed by the through hole 50C, the concave groove 51C, and the through hole 52C. The ink in the storage part 22Cb flows into the outflow part 22Cc and is sent to the lower surface side of the flow path forming part 31g of the upper tank part 31 through the lower opening of the through hole 52C shown in FIG.

  Referring to FIG. 10, a through hole 52K is formed in the upper left corner of the tank groove 49K, and the black storage portion 22Kb communicates with the outflow portion 22Kc formed by the through hole 52K. The ink in the storage part 22Kb flows into the outflow part 22Kc and is sent to the upper surface side of the flow path forming part 32g formed at the rear part of the lower tank part 32 through the upper opening of the through hole 52K shown in FIG.

  Referring to FIGS. 9 and 10, a through hole 50Y is opened at the right rear corner of the tank groove 49Y. The through hole 50Y communicates with the front end portion of the concave groove 51Y formed at the right edge of the upper rear portion of the upper tank portion 31, and the through hole 52Y opens at the rear end portion of the concave groove 51Y. The opening of the concave groove 51Y is also closed by the fifth film 37. As described above, the yellow storage portion 22Yb communicates with the outflow portion 22Yc formed by the through hole 50Y, the concave groove 51Y, and the through hole 52Y. The ink in the storage part 22Yb flows into the outflow part 22Yc and is sent to the upper surface side of the flow path forming part 32g of the lower tank part 32 through the upper opening of the through hole 52Y shown in FIG.

  In each of the damper grooves 49K, 49M, 49Y, and 49C, two straightening ribs 31c to 31f and 32c to 32f that extend in parallel along diagonal lines of the rectangular damper grooves 49K, 49M, 49Y, and 49C are provided. The upstream end portion and the downstream end portion of the storage portions 22Kb, 22Mb, 22Yb, and 22Cb are disposed in regions sandwiched between the two straightening ribs 31c to 31f and 32c to 32f, respectively. Therefore, the ink that has flowed into the reservoirs 22Kb, 22Mb, 22Yb, and 22Cb is guided by the rectifying ribs 31c to 31f and 32c to 32f, and is easily guided to the outflow portions 22Kc, 22Mc, 22Yc, and 22Cc.

  Referring to FIGS. 8 and 9 together, four spaces 53K, 53M, 53Y, and 53C partitioned from each other are formed on the lower surface side of the flow path forming portion 31g of the upper tank portion 31. The spaces 53K, 53M, 53Y, and 53C are opened downward. In addition, four spaces 54K, 54M, 54Y, 54C partitioned in the same shape as the spaces 53K, 53M, 53Y, 53C in plan view are formed on the upper surface side of the flow path forming portion 32g of the lower tank portion 32. The spaces 54K, 54M, 54Y, and 54C are opened upward. When the upper and lower tank portions 31 and 32 are assembled, these spaces communicate with each other vertically, and the end portions 22Kd and 22Md of the supply channels 22K and 22M for black and magenta and the distribution channels 23Y and 23C for yellow and cyan are provided. A total of four channels are constructed.

  The flow path forming part 31g of the upper tank part 31 has a horizontal wall 31k extending in a substantially horizontal direction and an outer wall 31m extending downward from the outer edge of the horizontal wall 31k. The outer wall 31m borders the horizontal wall 31k. Is arranged. In a region surrounded by the horizontal wall 31k and the outer wall 31m, three partition walls 31p, 31q, and 31r are provided to partition the region into four spaces 53K, 53M, 53Y, and 53C. These partition walls 31p ˜31r extends downward from the horizontal wall 31k. As a result, four spaces 53K, 53M, 53Y, and 53C that open downward are formed. Similarly, the flow path forming portion 32g of the lower tank portion 32 has a horizontal wall 32k, an outer wall 32m, and partition walls 32p, 32q, and 32r. When these upper and lower flow path forming portions 31g and 31h are brought into contact with each other, the outer walls 31m and 32m are combined vertically, and the partition walls 31p to 31r and 32p to 32r are combined vertically. The four spaces 53K, 53M, 53Y, 53C, 54K, 54M, 54Y, and 54C that are formed with each other communicate with each other, and the four flow paths 22Kd, 22Md, and 23Y that are independent from each other at the rear portion of the buffer tank 5. , 23C are formed. The horizontal walls 31k and 32k are not necessarily required to extend completely horizontally, and a step may be appropriately formed.

  FIG. 9 shows the shapes of these four flow paths 22Kd, 22Md, 23Y, and 23C in a plan view. Referring to FIG. 9, a black end portion 22Kd is disposed at the left end, and this end portion 22Kd extends substantially vertically in plan view. That is, the partition wall 32p for partitioning the space 54K constituting the terminal end portion 22Kd is disposed so as to extend substantially vertically in the left part of the region in plan view. The through hole 52K described above is formed so as to penetrate the horizontal wall 32k up and down, and the upper opening thereof is disposed at the front end portion of the space 54K constituting the terminal end portion 22Kd. Therefore, the outflow portion 22Kc communicates with the front end portion of the end portion 22Kd.

  The remaining two partition walls 32q and 32r are arranged on the right side of the region partitioned by the partition wall 32p. Of these, one partition wall 32q is formed in a U-shape in plan view so that a closed space 54M is defined in the left and right central portion of the rear end portion of the region. The other partition wall 32r is also formed in a U shape in a plan view and surrounds the partition wall 32q. Therefore, a U-shaped space 54C surrounding the space 54M and a U-shaped space 54Y surrounding the space 54C are formed on the right side of the region. That is, the yellow distribution channel 23Y is formed in a U shape and is disposed so as to surround the end portion 22Md of the magenta supply channel 22M. The cyan distribution channel 23C is also formed in a U shape, and is arranged so as to surround the yellow distribution channel 23Y.

  As shown in FIG. 8, the through hole 52M constituting the outflow portion 22Mc of the magenta supply flow path 22M passes through the horizontal wall 31k of the flow path forming section 31g. The lower opening of the magenta through hole 52M is disposed at the rear end portion of the space 53M constituting the terminal end portion 22Md. Therefore, the outflow portion 22Mc communicates with the front end portion of the end portion 22Mc.

  The through hole 52C constituting the outflow part 22Cc of the cyan supply flow path 22C also penetrates the horizontal wall 31k of the flow path forming part 31g, and the lower opening of the through hole 52C passes through the distribution flow path 22C. It arrange | positions in the space 54C to comprise. That is, the outflow portion 22Yc communicates with the distribution channel 22Y, and the upper opening of the through hole 52M forms the ink inlet 23Ca of the distribution channel 23C.

  As shown in FIG. 9, the through hole 52Y constituting the outflow part 22Yc of the yellow supply flow path 22Y passes through the horizontal wall 32k of the flow path forming part 32g, and the upper opening of the through hole 52Y is distributed. It arrange | positions in the space 54Y which comprises the flow path 22Y. That is, the outflow portion 22Yc communicates with the distribution channel 22Y, and the upper opening of the through hole 52Y forms the ink inlet 23Ya of the distribution channel 23Y.

  Referring to FIGS. 6, 9 and 10 together, the lower tank portion 32 is integrally formed with an extending portion 32h extending downward from the flow path forming portion 32g. Six spaces 55K, 55M, 55Ya, 55Yb, 55Ca, and 55Cb that constitute the gas-liquid separation chambers 24K, 24M, 24Ya, 24Yb, 24Ca, and 24Cb are partitioned in the extending portion 32h.

  Among them, the left end space 55K communicates with the space 54K constituting the black end portion 22Kd. The gas-liquid separation chamber 24K formed by the space 55K extends vertically downward with respect to the end portion 22Kd, and a black ink supply port 14K is provided at the vertical lower end thereof. The central space 55M communicates with the space 54M, and a magenta ink supply port 14M is opened at the vertical lower end of the gas-liquid separation chamber 24M formed by the space 54M.

  The distribution channel 23Y for yellow having a U-shape in plan view is formed so that both ends thereof are arranged at the rear ends of the channel formation portions 31g and 32g, but the space of the extension portion 32h is formed at each end portion. 55Ya and 55Yb communicate with each other. That is, ink outlets 23Yb and 23Yc are set at each end of the distribution flow path 23Y, and the two gas-liquid separation chambers 24Ya and 24Yb communicate with each other at these two ink outlets 23Yb and 23Yc. The distribution channel 23Y distributes and supplies the ink to the two gas-liquid separation chambers 24Ya and 24Yb by causing the yellow ink taken in from the ink introduction port 23Ya to flow out from the two ink outlets 23Yb and 23Yc. First and second yellow ink supply ports 14Ya and 14Yb are provided at the vertical lower ends of the gas-liquid separation chambers 24Ya and 24Yb, respectively. Since the cyan distribution channel 23C and the gas-liquid separation chambers 24Ca and 24Cb have the same configuration as this, redundant description is omitted (reference numerals 14Ca, 14Cb, 23C, 23Ca to 23Cc, 24Ca, 24Cb, 54C, 55Ca, 55Cb).

  Since the flow path structure for supplying ink to the ink introduction port 15 of the ink jet head 7 through the gas-liquid separation chamber 24 extending in the vertical direction in this way, the terminal portions 22Kd and 22Md and the distribution flow paths 23Y and 23C enter. The trapped air can be trapped in the vertical upper portion of the gas-liquid separation chamber 24, and the air can be prevented from passing through the ink supply port 14 provided at the vertical lower end and reaching the ink introduction port 15. For yellow and cyan inks with two ink inlets set, there are two gas-liquid separation chambers corresponding to each ink inlet, so air does not enter any ink inlet. I am doing so.

  Referring to FIGS. 7 and 8 together, exhaust ports 25K, 25M, 25C, and 25Y are opened in the end portions 22Kd and 22Md and the distribution channels 23Y and 23C. The exhaust ports 25K, 25M, 25C, and 25Y are formed so as to penetrate the horizontal wall of the flow path forming portion 31g of the upper tank portion 31 up and down, so that the air trapped in the vertical upper part is the exhaust port 25K, 25M, 25C, and 25Y are made as easy to pass as possible.

  Referring to FIG. 7, the upper openings of the black and magenta exhaust ports 25K and 25M communicate with the concave grooves 61K and 61M formed on the upper surface side of the flow path forming portion 31g, respectively. It extends toward the left edge of the flow path forming part 31g. Through holes 62K and 62M are opened at the left end portions of the concave grooves 61K and 61M. The through holes 62K and 62M are cylindrical portions 31w and 31x extending downward from the left end portion of the flow path forming portion 31g (FIGS. 6 and 6). 8). The above-described joint 18 (see FIGS. 1 and 3) is attached to the cylindrical portions 31w and 31x, and the exhaust tube 19 (see FIGS. 1 and 3) is connected to the joint 18. The upper openings of the concave grooves 61K and 61M are closed by the first film 33 described above, thereby forming the exhaust channels 26K and 26M for black and magenta. As described above, the end portions 22Kd and 22Md (see FIG. 8) are connected to the exhaust passages 26K and 26M via the exhaust ports 25K and 26K.

  As can be seen with reference to FIGS. 8 and 9, the black and magenta exhaust ports 25K and 25M are provided at positions overlapping the gas-liquid separation chambers 24K and 24M in a plan view, and are captured by these gas-liquid separation chambers 24K and 24M. The air thus collected is accumulated around the exhaust ports 25K and 25M. Therefore, when the exhaust pump 20 (see FIGS. 1 and 3) is operated and a negative pressure is applied to the exhaust passages 25K and 25M, the air trapped in the gas-liquid separation chambers 24K and 24M is exhausted from the exhaust ports 25K and 25M. It is easy to be led to the exhaust passages 25K and 25M. Therefore, the possibility that the air that has entered the terminal portions 22Kd and 22Md for black and magenta reaches the ink inlets 15K and 15M can be reduced.

  For the yellow and cyan inks, one exhaust port 25Y and 25C is provided for each distribution channel 23Y and 23C. Referring to FIG. 8, these exhaust ports 25Y and 25C communicate with concave grooves 61Y and 61C formed on the upper surface side of the flow path forming portion 31g, respectively. Each of the concave grooves 61K and 61M is formed so that it can be written with a single stroke while being bent, and extends toward the left edge of the flow path forming portion 31g. The through holes 62K and 62M that open to the left end portions of the recessed grooves 61K and 61M extend inside cylindrical portions 31y and 31z (see FIGS. 6 and 8) that extend downward from the left end portion of the flow path forming portion 31g. The exhaust tube 19 (see FIGS. 1 and 3) is connected to the portions 31y and 31z via the joint 18 (see FIGS. 1 and 3) described above. The upper openings of the concave grooves 61Y and 61C are closed by the first film 33 described above, thereby forming one exhaust passage 26Y and 26C that can be written with a single stroke without any branching portion or gathering portion. The distribution passages 26Y and 26C (see FIG. 8) are connected to the exhaust passages 26Y and 26C through one exhaust port 25Y and 26C.

  11 is a cross-sectional view of the buffer tank 5 cut along the line XI-XI in FIG. Since the XI-XI line in FIG. 9 extends along the U-shaped distribution channel 23Y, the horizontal direction in FIG. 11 is the direction in which the distribution channel 23Y extends, and the yellow in the distribution channel 23Y. The direction of ink flow. As shown in FIG. 11, the ink inlet 23Ya of the distribution channel 23Y is disposed between the first gas-liquid separation chamber 24Ya and the second gas-liquid separation chamber 24Yb with respect to the flow direction. It is provided on the side closer to the liquid separation chamber 24Yb.

  The ink inlet 23Ya is the upstream end of the distribution channel 23Y, and the left and right sides of the ink inlet 23Ya in FIG. 11 are downstream in the flow direction. The exhaust port 25Y is disposed at a position that partially overlaps the ink inflow port 23Ya, and extends from the overlapping portion to the side where the first gas-liquid separation chamber 24Ya is provided.

  As shown in FIG. 8, the exhaust port 25Y is formed in an L shape in a plan view, a portion corresponding to a portion extending in the left-right direction on the front side of the U-shaped distribution channel 23Y, and a distribution channel therefrom And a portion extending rearward along 23Y. That is, the exhaust port 25Y is provided at an intermediate position between the two gas-liquid separation chambers 24Ya and 24Yb in the flow direction of the distribution flow path 23Y. From this intermediate position, the two gas-liquid separation chambers 24Ya and 24Yb extend toward the end portion on the side communicating with the gas-liquid separation chamber 24Ya located far from the ink inlet 23Ya. Yes.

  The dimension d1 shown in FIG. 11 is the dimension in the flow direction of the exhaust port 25Y, the dimension d2 is the distance from the center position of the second gas-liquid separation chamber 24Yb (second ink outlet 23Yc) to the edge of the exhaust port 25Y, and dimension d3. Is the distance from the center position of the first gas-liquid separation chamber 24Ya (first ink outlet 23Yb) to the edge of the exhaust port 25Y. Since the L-shaped exhaust port 25Y is formed as described above, the dimension d3 is smaller than the dimension d2. More specifically, the upstream edge of the second ink outlet 23Yb is disposed so as to overlap the exhaust port 25Y vertically.

  Air trapped in the first gas-liquid separation chamber 24Ya tends to accumulate in a portion of the lower surface of the horizontal wall 31k of the flow path forming portion 31g that overlaps the first ink outlet 24Yb in plan view. Since this portion is close to the edge of the exhaust port 25Y, when a negative pressure is applied to the exhaust passage 26Y, the air accumulated in this portion passes through the exhaust port 25Y satisfactorily and passes through the exhaust passage 26Y. Discharged outside. On the other hand, the air trapped in the second gas-liquid separation chamber 24Yb tends to accumulate in a portion of the lower surface of the horizontal wall 31k of the flow path forming portion 31g that overlaps the second ink outlet 24Yc in plan view. Since this portion is separated from the edge of the exhaust port 25Y, when a negative pressure is applied to the exhaust passage 26Y, the air accumulated in this portion is sucked toward the exhaust port 25Y against the ink flow. However, since the exhaust port 25Y is disposed at an intermediate position between the two gas-liquid separation chambers, the air trapped in the second gas-liquid separation chamber 24Yb can be guided to the exhaust port 25Y in a well-balanced manner.

  Further, since the exhaust port 25Y is a single one with respect to the distribution channel 23Y, even if the suction of the air trapped in the first gas-liquid separation chamber 24Ya has been completed, the air accumulated in this portion is not collected. Continuous suction is possible. That is, compared with the conventional case where exhaust ports are provided corresponding to the respective gas-liquid separation chambers, the air trapped in the two gas-liquid separation chambers 24Ya and 24Yb can be discharged to the outside. . Therefore, the amount of air remaining in the distribution flow path 23Y after the operation of the exhaust pump 20 (see FIGS. 1 and 3) can be reduced, and the possibility of air reaching the ink inlet can be reduced.

  12 is a cross-sectional view of the buffer tank 5 cut along the line XII-XII in FIG. Since the XII-XII line in FIG. 9 also extends along the U-shaped distribution channel 23C, the horizontal direction in FIG. 12 is the direction in which the distribution channel 23C extends, and cyan in the distribution channel 23C. The direction of ink flow. As shown in FIG. 12, the ink inlet 23Ca of the distribution flow path 23C is arranged at a position overlapping with the second gas-liquid separation chamber Cb, and the right side of FIG. Downstream side.

  As shown in FIG. 8, the exhaust port 25C is also formed in an L shape in plan view. That is, the exhaust port 25C also has a portion corresponding to a portion extending in the left-right direction on the front side of the U-shaped distribution channel 23C, and a portion extending rearward along the distribution channel 23C therefrom. It is provided at an intermediate position between the two gas-liquid separation chambers 24Ca and 24Cb in the flow direction of the distribution flow path 23C. And from this intermediate position, it extends toward the end of the two gas-liquid separation chambers 24Ca and 24Cb on the side where the gas-liquid separation chamber 24Ca located far from the ink inlet 23Ya communicates. .

  The dimension d4 shown in FIG. 12 is the dimension in the flow direction of the exhaust port 25C, the dimension d5 is the distance from the center position of the second gas-liquid separation chamber 24Cb (second ink outlet 23Cc) to the edge of the exhaust port 25C, and dimension d6. Is the distance from the center position of the first gas-liquid separation chamber 24Ca (first ink outlet 23Cb) to the edge of the exhaust port 25C. Since the L-shaped exhaust port 25C is formed, the dimension d6 is smaller than the dimension d5.

  Air trapped in the first gas-liquid separation chamber 24Ca tends to accumulate in a portion of the lower surface of the horizontal wall 31k of the flow path forming portion 31g that overlaps the first ink outlet 24Cb in plan view. Since this portion is close to the edge of the exhaust port 25C, when a negative pressure is applied to the exhaust passage 26C, the air accumulated in this portion passes through the exhaust port 25C well and passes through the exhaust passage 26C. Discharged outside.

  On the other hand, the air trapped in the second gas-liquid separation chamber 24Cb tends to accumulate in a portion of the lower surface of the horizontal wall 31k of the flow path forming portion 31g that overlaps the second ink outlet 24Cc in plan view. Although this portion is separated from the edge of the exhaust port 25Y, this portion is located upstream of the exhaust port 25Y in the ink flow direction. Therefore, when a negative pressure is applied to the exhaust flow path 26Y, the air accumulated in this portion flows toward the exhaust port 25Y along the ink flow. Therefore, the air narrowed in the second gas-liquid separation chamber 24Cb also passes through the exhaust port 25C satisfactorily and is discharged to the outside through the exhaust passage 26C.

  In addition, since the exhaust port 25C is single with respect to the distribution channel 23C, even if the suction of the air trapped in the first gas-liquid separation chamber 24Ca has been completed, the air accumulated in this portion is not collected. Continuous suction is possible. That is, similarly to the yellow exhaust system, the air trapped in the two gas-liquid separation chambers can be discharged to the outside. Therefore, the amount of air remaining in the distribution channel 23C after the operation of the exhaust pump 20 (see FIGS. 1 and 3) can be reduced, and the possibility of air reaching the ink inlet can be reduced.

  The above embodiment is merely an example of the present invention, and can be appropriately changed within the scope of the present invention. For example, although the case where two ink inlets are provided in the inkjet head for each of the two types of ink is illustrated, the type of ink provided with the two ink inlets is not limited thereto. Further, the method of supplying ink is not limited to the so-called tube supply method, and other methods can be appropriately employed.

  The liquid ejecting apparatus according to the present invention is not limited to an ink jet printer, and a liquid other than ink, for example, a colored liquid is ejected to produce a color filter of a liquid crystal display device, or a conductive liquid is ejected to form an electrical wiring. The present invention can also be suitably applied to a liquid ejecting apparatus used for an apparatus that performs such processing.

  As described above, according to the present invention, in the liquid discharge head having the two liquid inlets and the liquid discharge apparatus having the distribution flow path, it is possible to prevent air from entering the liquid discharge head. It is useful to apply to an ink jet printer equipped with an ink jet head.

1 is a schematic plan view showing a configuration of an inkjet printer according to a first embodiment of the present invention. It is a typical side view which shows the periphery structure of the head holder seen in the arrow II direction of FIG. It is a conceptual diagram of the flow path of the ink and air of the inkjet printer shown in FIG. (A) is a top view of the inkjet head shown along the IVa-IVa line of FIG. 2, (b) is a bottom view of the inkjet head shown along the IVb-IVb line of FIG. It is a disassembled perspective view of the buffer tank shown in FIG. It is a side view shown in the state which assembled | attached the buffer tank shown in FIG. It is a top view of the upper tank part shown in FIG. It is a bottom view of the upper tank part shown in FIG. It is a top view of the lower tank part shown in FIG. It is a bottom view of the lower tank part shown in FIG. It is sectional drawing of the buffer tank shown along the XI-XI line of FIG. It is sectional drawing of the buffer tank shown along the XII-XII line of FIG.

Explanation of symbols

1 ... Inkjet printer (liquid ejection device)
5 ... Buffer tank 7 ... Inkjet head (liquid discharge head)
8 ... Nozzle array 10 ... Ink tank 11 ... Ink tube 12 ... Joint 13 ... Buffer ink flow path 14 ... Ink supply port (liquid supply port)
15 …… Ink inlet (liquid inlet)
16: Seal members 17K, 17M, 17Ya, 17Yb, 17Ca, 17Cb ... Head ink flow path 18 ... Joint 19 ... Exhaust tube 20 ... Exhaust pumps 21K, 21M, 21Y, 21C ... Supply flow path 22K, 22M, 22Y, 22C ... Supply channel 22Ka, 22Ma, 22Ya, 22Ca ... Upstream part 22Kb, 22Mb, 22Yb, 22Cb ... Reservoir 22Kc, 22Mc, 22Yc, 22Cc ... Outlet 22Kd, 22Md ... Termination 23Y, 23C: Distributing flow path 23Ya, 23Ca: Ink inlet (liquid inlet)
23Yb, 23Yc, 23Cb, 23Cc: Ink outlet (liquid outlet)
24K, 24M, 24Ya, 23Yb, 24Ca, 24Cc ... Gas-liquid separation chambers 25K, 25M, 25Y, 25C ... Exhaust ports 26K, 26M, 26Y, 26C ... Exhaust flow path 31 ... Upper tank part 32 ... Lower Tank part 33-37 …… Film

Claims (5)

A distribution channel having a liquid inlet, two liquid outlets, and an exhaust port, and distributing liquid by taking in liquid from a liquid supply source from the liquid inlet and flowing out from the two liquid outlets;
Two gas-liquid separation chambers communicating with the two liquid outlets and extending vertically downward from the communicating portions;
Two liquid inlets communicating with a liquid supply port provided at the lower vertical end of each of the two gas-liquid separation chambers are provided, and the two liquid inlets supplied from the two gas-liquid separation chambers are used. A liquid discharge head to be introduced
An exhaust passage connected to the exhaust port for discharging the air separated in the two gas-liquid separation chambers,
The liquid inlet is provided in the vicinity of one of the two gas-liquid separation chambers with respect to the liquid flow direction in the distribution channel,
The liquid discharge apparatus according to claim 1, wherein the exhaust port is provided at least at an intermediate position between the two gas-liquid separation chambers in the flow direction of the distribution channel.   A distance between one of the two gas-liquid separation chambers and the liquid inlet in the flow direction of the distribution channel does not exceed a length corresponding to the radius of the liquid inlet. The liquid ejection device according to claim 1.   3. The liquid ejection apparatus according to claim 2, wherein at least a part of the liquid inflow port overlaps the one gas-liquid separation chamber in a plan view.   4. The liquid ejection device according to claim 1, wherein the exhaust port extends toward a downstream side in the flow direction of the distribution channel. 5. The distribution channel extends in a U shape in plan view, and the two gas-liquid separation chambers communicate with both ends of the distribution channel,
The exhaust port is directed from an intermediate position between the two gas-liquid separation chambers in the flow direction of the distribution channel toward an end portion on the side where one of the two gas-liquid separation chambers communicates, The liquid ejection device according to claim 4, wherein the liquid ejection device extends in an L shape in plan view.

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