JP5151348B2 - Droplet discharge device - Google Patents

Description

  The present invention relates to a droplet discharge device such as an ink jet printer.

  2. Description of the Related Art Conventionally, as an ink-jet printer, an ink-jet head having a plurality of nozzles for ejecting ink droplets and an ink storage chamber for storing ink to be supplied from the ink cartridge to the ink-jet head are provided. The thing of the structure which communicates with a storage chamber by the tube is known (for example, refer patent document 1).

A part of the wall defining the ink storage chamber of the ink jet printer is formed of a flexible film that absorbs ink pressure fluctuations. Accordingly, when the ink cartridge is mounted on the cartridge mounting portion of the printer main body, even if the mounting pressure is transmitted to the ink storage chamber, it is absorbed by the elasticity of the flexible film. The opening time required to completely absorb the mounting pressure becomes faster as the area of the flexible film is smaller.
JP 2005-262723 A

  However, the flexible film is desirably set to have a large area in order to sufficiently absorb the dynamic pressure associated with acceleration / deceleration when the carriage on which the inkjet head is mounted is reciprocally scanned left and right. When the area of the flexible film is increased in response to such a request, the volume of the ink storage chamber also increases accordingly, so the ink cartridge mounting pressure release time (the mounting pressure propagated to the ink storage chamber is reflected). The time until the cartridge is returned to the cartridge mounting portion becomes longer. Therefore, when the user notices an error by installing the ink cartridge in the cartridge mounting portion of the printer main body and immediately removes the ink cartridge, the mounting pressure returns to the ink inflow portion after the ink cartridge is removed. For this reason, the ink drips from the ink inflow portion.

  Therefore, the present invention prevents liquid dripping from the liquid inflow portion when the cartridge is pulled out immediately after mounting the cartridge in the cartridge mounting portion, while ensuring the dynamic pressure absorption performance accompanying the acceleration / deceleration of the carriage. The purpose is that.

The present invention has been made in view of the circumstances as described above, and the droplet discharge device according to the present invention is detachably mounted with a liquid cartridge having a liquid storage chamber and a liquid outflow portion, and A cartridge mounting portion having a liquid inflow portion coupled to the liquid outflow portion, a liquid storage chamber in which the liquid flowing in from the liquid inflow portion is stored, and a communication channel for communicating the liquid inflow portion and the liquid storage chamber A liquid droplet ejection apparatus including a liquid droplet ejection head to which liquid is supplied from the liquid storage chamber, wherein the liquid storage chamber includes a liquid inlet into which the liquid from the liquid cartridge flows, and the liquid droplet A liquid outlet port for flowing liquid to the ejection head, a pair of walls that are substantially parallel to the liquid flow direction from the liquid inlet port to the liquid outlet port and that are spaced apart from each other and facing each other, and the pair of walls And a peripheral side wall surrounding the space between the, one wall of said pair of walls is a damper wall having flexibility, other wall of the pair of walls, to the damper wall And a pair of rectifying ribs extending in parallel with the flow direction in a state of being spaced apart from the damper wall, and a space sandwiched between the pair of rectifying ribs from the liquid inlet to the liquid flow It is a main flow area toward the outlet, a space between each of the rectifying ribs and the peripheral side wall is a sub-flow area, and between the both ends in the flow direction of each of the pair of rectifying ribs and the peripheral side wall A gap connecting the main flow area and the sub-flow area is formed, and the peripheral side wall is formed in the sub-flow area of a substantially rectangular corner in a plan view as viewed from the normal direction of the pair of walls. The corresponding corner is a shape that is chamfered linearly, Sectional area of the central portion of the flow direction in the basin, characterized in smaller than the cross-sectional area of the central portion of the flow direction in the main basin.

  According to the above configuration, the corner portion of the peripheral side wall having a substantially rectangular shape in plan view is a portion where the damper wall is less likely to displace than other portions and the dynamic pressure absorption performance is originally weak. By reducing the area, the volume of the ink storage chamber can be reduced while maintaining the dynamic pressure absorption performance as much as possible. As a result, the time required to release the mounting pressure of the liquid cartridge can be shortened, so that even when the liquid cartridge is pulled out immediately after being mounted in the cartridge mounting portion, the liquid is prevented from dripping from the liquid inflow portion of the cartridge mounting portion. Can do. Note that the communication flow path for communicating the liquid inflow portion with the liquid storage chamber only needs to be communicated at least when the liquid cartridge is mounted on the cartridge mounting portion, but may be always communicated.

  The other wall of the pair of walls has a pair of rectifying ribs that protrude toward the damper wall and extend substantially parallel to the flow direction in a state spaced from the damper wall. A space sandwiched between the rectifying ribs is a main flow region from the liquid inflow port to the liquid outflow port, a space between each of the rectifying ribs and the peripheral side wall is a sub flow region, and the peripheral side wall is the sub flow region. The shape which rounded off the corner | angular part corresponding to may be sufficient.

  According to the above configuration, the peripheral side wall is rounded at the corner corresponding to the sub-flow region, so that the volume of the sub-flow region is reduced, and even if air flows in from the liquid inlet, the air collected in the sub-flow region. The amount is reduced. Therefore, it is possible to reduce the amount of waste ink required for discharging air during the purge for discharging the liquid from the nozzles of the droplet discharge head for maintenance.

  The damper wall may be formed by welding a rectangular resin film to the peripheral side wall in plan view.

  According to the said structure, the process after a cutting | disconnection becomes unnecessary and the increase in a manufacturing process can be prevented by welding to a surrounding side wall with the square shape which is the state which cut | disconnected the roll film with the film cutter.

  The liquid storage chamber may be arranged at a position higher than the liquid inflow portion of the cartridge mounting portion.

  According to the above configuration, due to the water head pressure of the liquid in the liquid storage chamber, pressure is applied to the liquid in the liquid inflow portion of the cartridge mounting portion via the communication channel, and the liquid is likely to drip from the liquid inflow portion to the outside. As described above, since the time required to release the mounting pressure of the liquid cartridge is shortened, it is possible to more suitably prevent the liquid from dripping from the liquid inflow portion of the cartridge mounting portion.

  As is clear from the above description, according to the present invention, the time required to release the mounting pressure of the liquid cartridge can be shortened while ensuring the dynamic pressure absorption performance of the liquid storage chamber, so that the dynamic pressure absorption is achieved. It is possible to provide a high-quality liquid ejection device that achieves both performance and prevention of dripping from the liquid inflow portion when the liquid cartridge is removed immediately after mounting.

  Embodiments according to the present invention will be described below with reference to the drawings. In the following description, the direction in which ink is ejected from the inkjet head is defined as the downward direction, and the opposite side is defined as the upward direction.

(First embodiment)
FIG. 1 is a schematic perspective view showing a main part of an ink jet printer 1 according to a first embodiment of the present invention. As shown in FIG. 1, the ink jet printer 1 (droplet discharge device) has a pair of guide rails 2 and 3 arranged substantially in parallel, and the head unit 4 slides in the scanning direction on the guide rails 2 and 3. Supported as possible. The head unit 4 is joined to a timing belt 7 wound around a pair of pulleys 5 and 6, and the timing belt 7 is disposed substantially parallel to the extending direction of the guide rail 3. One pulley 6 is provided with a motor (not shown) that drives forward and reverse rotation. When the pulley 6 is driven forward and reverse, the timing belt 7 reciprocates, and the head unit 4 moves to the guide rail 2. , 3 is reciprocally scanned in one direction.

  The head unit 4 has four flexibility units for supplying four colors of ink (black, cyan, magenta, yellow) from four ink cartridges 9 (liquid supply sources) mounted on the cartridge mounting unit 8. The ink supply tube 10 (communication flow path) is connected. An ink jet head 21 (see FIG. 2) is mounted on the head unit 4, and a recording medium 11 (see FIG. 2) made of paper or the like conveyed in a direction (paper feeding direction) perpendicular to the scanning direction below the head. ), Ink (liquid) is ejected from the inkjet head 21.

  FIG. 2 is a partial cross-sectional view schematically illustrating the ink jet printer 1 shown in FIG. As shown in FIG. 2, a paper feed tray 13 is disposed on the bottom side of the inkjet printer 1. On the upper side of the paper feed tray 13, a paper feed driving roller 15 that supplies the uppermost one of the recording media 11 made of paper stacked on the paper feed tray 13 to the transport path 14 is provided. The transport path 14 is U-turned toward the front side after going upward from the back side of the paper feed tray 13, passes through the printing area 15, and is guided to a paper discharge tray (not shown).

  A head unit 4 is provided in the printing area 15. A platen 16 that supports the recording medium 11 is disposed below the head unit 4. On the upstream side of the head unit 4, a conveyance roller 17 and a pinch roller 18 that sandwich the recording medium 11 that flows through the conveyance path 14 and convey it onto the platen 16 are provided. On the downstream side of the head unit 4, a paper discharge roller 19 and a pinch roller 20 are provided that hold the printed recording medium 11 and convey it to a paper discharge tray (not shown).

  The head unit 4 includes a known inkjet head 21 (droplet ejection head) that ejects ink from a large number of nozzles toward the platen 16, a buffer tank 22 that stores ink to be supplied to the inkjet head 21, and these. And a head holder 23. The ink jet head 21 includes a flow path unit 24 having a plurality of flow paths (not shown) for guiding ink flowing from the buffer tank 22 to a plurality of nozzles (not shown), and a flow path in the flow path of the flow path unit 24. And a piezoelectric drive actuator 25 that selectively applies a discharge pressure toward the nozzles to the ink.

  One end of the ink supply tube 10 is connected to the buffer tank 22, and the other end of the ink supply tube 10 is connected to the cartridge mounting portion 8. The cartridge mounting portion 8 includes a connecting portion 26 connected to the other end of the ink supply tube 10 and a needle-like ink inflow portion 27 (liquid inflow portion) connected to the ink cartridge 9. The ink inflow portion 27 communicates with each other. The ink cartridge 9 has an ink storage chamber 28 formed therein and an ink outflow portion 29 through which ink in the ink storage chamber 28 flows out. When the ink cartridge 9 is mounted on the cartridge mounting portion 8 and the ink inflow portion 27 is inserted and coupled to the ink outflow portion 29, the ink storage chamber 28 has the ink outflow portion 29, the ink inflow portion 27, the connecting portion 26, and the ink supply. The tube 10 communicates with the buffer tank. The buffer tank 22 is disposed at a position higher than the ink inflow portion 27 of the cartridge mounting portion 8. That is, due to the ink head pressure in the ink storage chambers 41 to 44 (see FIG. 5), which will be described later, of the buffer tank 22, pressure is applied to the ink in the ink inflow portion 27 of the cartridge mounting portion 8 via the ink supply tube 10. ing.

  FIG. 3 is a perspective view of the ink jet printer 1 shown in FIG. 1 as viewed from above the head unit 4. 4 is a top view of the head unit 4 of the inkjet printer 1 shown in FIG. 4 does not show the joint 30 and its seal member shown in FIG. As shown in FIGS. 3 and 4, the head unit 4 includes a head holder 23 serving as a carriage guided by guide rails 2 and 3 (see FIG. 1). The head holder 23 is formed in a box shape in which the upper surface is opened and the buffer tank 22 is accommodated, and the ink jet head 21 (see FIG. 2) is attached to the lower surface of the bottom wall. A joint 30 is attached to the buffer tank 22. The joint 30 has a base portion 30a connected to the ink inlet 31 of the buffer tank 22, and four ink joint pipe portions 30b led out from the base portion 30a in the scanning direction. One end of the ink supply tube 10 (see FIG. 1) is connected to the ink joint pipe portion 30b.

  FIG. 5 is a cross-sectional view taken along line VV in FIG. In FIG. 5, the head holder 23 is indicated by a two-dot chain line in order to make the buffer tank 22 easier to see. As shown in FIG. 5, the buffer tank 22 is configured by joining a lower tank portion 32 and an upper tank portion 33 in parallel with each other, and in the front-rear direction, the ink introduction area S1, the buffer area S2, and the This is the ink lead-out area S3.

  In the buffer area S2, the lower tank portion 32 has an ink storage chamber 41 (liquid storage chamber) for storing cyan ink on the upper side of the intermediate wall portion 34, and an ink storage chamber for storing black ink on the lower side. 42 (liquid storage chambers) are respectively formed. The upper tank 33 has an ink storage chamber 43 (liquid storage chamber) for storing yellow ink on the upper side with the intermediate wall 35 interposed therebetween, and an ink storage chamber 44 (liquid storage chamber) for storing magenta ink on the lower side. Are formed respectively. These ink storage chambers 41 to 44 are arranged in parallel with each other and arranged in a stacked state in the vertical direction. In the ink introduction area S <b> 1, a flow path 36 that connects the four ink introduction ports 31 and the ink storage chambers 41 to 44 is formed in the upper tank portion 33. In the ink outlet area S3, four ink outlet paths 37 respectively corresponding to the ink storage chambers 41 to 44 are formed behind the buffer area S2 in the scanning direction of the inkjet head 21.

  FIG. 6 is a perspective view of the lower tank portion 32 shown in FIG. 5 as viewed from above. FIG. 7 is a top view of the lower tank portion 32 shown in FIG. As shown in FIGS. 6 and 7, on the upper side of the intermediate wall portion 34 of the lower tank portion 32, a flat ink storage chamber 41 for cyan ink is partitioned by a peripheral side wall portion 38 and opened upward. . The opening surface of the ink storage chamber 41 for cyan ink is sealed by welding a resin film 39 having a quadrangular flexibility in plan view to the upper end of the peripheral side wall portion 38. That is, the resin film 39 is a damper wall 39 that is spaced apart from the intermediate wall 34 in the vertical direction. At this time, the resin film forming the damper wall 39 is welded to the peripheral side wall portion 38 in a square shape obtained by cutting the roll film with a film cutter, thereby omitting the shape processing after cutting.

  The ink inflow port 45 and the ink outflow port 46 are provided at substantially diagonal positions of the ink storage chamber 41. The cyan ink inlet 45 (liquid inlet) is opened in the bottom surface near the right front corner in the ink storage chamber 41 and penetrates the intermediate wall 34 of the lower tank 32 in the thickness direction. The intermediate wall portion 34 is connected to the communication path 54a on the lower surface side. The communication passage 54a is formed by a cylindrical portion 54 standing on the intermediate wall portion 34 on the right front side of the ink storage chamber 41, and is connected to a communication path 117a (see FIG. 13) described later. That is, the ink inlet 45 communicates with the flow path 36 of the upper tank portion 33 (see FIG. 5) via the communication path 54a and the communication path 117a (see FIG. 13).

  The ink outlet 46 of the ink storage chamber 41 is opened on the bottom surface in the vicinity of the left rear corner in the ink storage chamber 41 and passes through the intermediate wall 34 of the lower tank portion 32 in the thickness direction. The connection lead-out path 55 is connected on the lower surface side of the side tank portion 32. The connection lead-out path 55 communicates with the ink lead-out path 37. The intermediate wall 34 and the damper wall 39 described above are provided substantially in parallel with the direction of ink flow from the ink inlet 45 to the ink outlet 46.

  A pair of rectifying ribs 47 and 48 are provided on the upper surface of the intermediate wall 34 in the ink storage chamber 41 so as to protrude toward the damper wall 39. The pair of rectifying ribs 47 and 48 extend substantially in parallel with the ink flow direction from the ink inlet 45 toward the ink outlet 46, and the cross section orthogonal to the extending direction has a quadrangular shape. . Further, the pair of rectifying ribs 47 and 48 are provided in a state of being separated from the damper wall 39 so as not to restrict the movement of the damper wall 39. As described above, a stepped portion is formed by the opposed inner side surfaces of the pair of rectifying ribs 47, 48, and the inner space sandwiched between the pair of rectifying ribs 47, 48 is the main flow area from the ink inlet 45 toward the ink outlet 46. A1 and the outer space between the rectifying ribs 47 and 48 and the peripheral side wall portion 38 becomes the sub-flow area B1. Further, the end portions of the rectifying ribs 47 and 48 in the ink flow direction have a slight gap 50 to 53 with the peripheral side wall portion 38 in the extending direction. Thereby, main flow area A1 and subflow area B1 are connected via the clearance gaps 50-53.

  Furthermore, the peripheral side wall portion 38 has a shape in which corner portions corresponding to the quadrangular sub-flow region B1 are cut off in plan view. Specifically, the chamfered portions 38a and 38b are formed in a straight line so that the peripheral side wall portion 38 has a substantially hexagonal shape in plan view. As described above, the chamfered portions 38a and 38b are formed so as to approach the rectifying ribs 47 and 48, so that the volume of the sub-flow region B1 is reduced and the flow path cross-sectional area perpendicular to the flow direction of the sub-flow region B1 is increased. It is getting smaller. That is, the volume of the ink storage chamber 41 is smaller than that of a square shape that is not rounded. Specifically, the area of the ink storage chamber 41 in a plan view is reduced by 10 to 30%, and preferably 15 to 25%, compared to the case where the peripheral side wall portion 38 has a square shape that is not rounded. The chamfered portions 38a and 38b may be formed to have a smooth curved shape.

  The ink flow accompanying ink ejection for normal printing is formed so as to flow from the ink inlet 45 to the ink outlet 46 through the main flow area A1 between the pair of rectifying ribs 47 and 48. There is a possibility that air stays in the auxiliary flow area B1 outside the rectifying ribs 47 and 48 as a stagnation part. However, the air is drawn into the ink outlet 46 at the flow rate of ink during normal printing. Is prevented by the rectifying ribs 47 and 48.

  Further, by a purge operation in which a known suction cap is brought into airtight contact with the nozzle surface of the ink jet head 21 and the residual ink is sucked from the nozzle by negative pressure by the suction pump, the ink flow accompanying the ink discharge for normal printing is obtained. When a fast flow is generated, a stable flow is formed in the main flow area A1 between the pair of rectifying ribs 47 and 48, and the air in the ink can be quickly discharged. Furthermore, since the ink and air in the sub-flow area B1 that is a stagnation part are also sucked through the gaps 50 to 53, even if mixed-color ink exists in the sub-flow area B1, it is discharged by the purge operation. In the purge operation, instead of performing negative pressure suction from the nozzle side of the inkjet head 21, positive pressure may be applied from the buffer tank 22 side to discharge ink from the nozzle.

  8 is a cross-sectional view taken along line VIII-VIII in FIG. As shown in FIG. 8, the bottom surface 34a in the main flow region A1 is flat, and the bottom surfaces 34b and 34c in the sub flow region B5 outside the rectifying ribs 47 and 48 are also flat. The maximum distance between the intermediate wall portion 34 and the damper wall 39 in the sub-flow region B1 is smaller than the minimum distance between the intermediate wall portion 34 and the damper wall 39 in the main flow region A1. As a result, the volume of the secondary flow region B1 is further reduced, and the flow path cross-sectional area perpendicular to the flow direction of the secondary flow region B1 is further reduced. Further, since the distance between the intermediate wall portion 34 and the damper wall 39 in the secondary flow region B1 is larger than the distance between the upper ends of the rectifying ribs 47 and 48 and the damper wall 39, the damper wall 39 is formed. When the resin film is welded to the upper end of the peripheral side wall portion 38, the molten mass of the resin film is prevented from reaching the intermediate wall portion 34 through the peripheral side wall portion 38.

  FIG. 9 is a perspective view of the lower tank portion 32 shown in FIG. 5 as viewed from below. 10 is a bottom view of the lower tank portion 32 shown in FIG. Since FIG. 9 is a view seen from below, the upward direction in the figure is the downward direction, and the downward direction in the figure is the upward direction. As shown in FIGS. 9 and 10, a flat ink storage chamber 42 for black ink is partitioned by a peripheral side wall portion 58 and opened downward below the intermediate wall portion 34 of the lower tank portion 32. Yes. The opening surface of the black ink storage chamber 42 is sealed by welding a rectangular flexible resin film 59 to the lower end of the peripheral side wall portion 58 in plan view. That is, the resin film 59 is the damper wall 59 that is spaced apart from the intermediate wall 34 in the vertical direction.

  The ink inlet 65 and the ink outlet 66 are provided at substantially diagonal positions of the ink storage chamber 42. The ink inlet 65 for black ink is opened at the bottom surface near the left front corner in the ink storage chamber 42 and penetrates the intermediate wall 34 of the lower tank 32 in the thickness direction. The front portion of the ink storage chamber 42 is positioned so as to overlap with the communication path 56 a (see FIG. 6) in plan view, and the lower end opening of the communication path 56 a is the ink inlet 65 of the ink storage chamber 42. The communication path 56a is formed by a cylindrical portion 56 standing on the intermediate wall 34 on the left front side of the ink storage chamber 42, and is connected to a communication path 116a (see FIG. 13) described later. In other words, the ink inlet 65 communicates with the flow path 36 of the upper tank portion 33 (see FIG. 5) via the communication path 56a and the communication path 116a (see FIG. 13).

  The ink outlet 66 of the ink storage chamber 42 is opened on the bottom surface near the right rear corner in the ink storage chamber 42 and passes through the intermediate wall 34 of the lower tank portion 32 in the thickness direction. The ink discharge path 37 communicates with the upper surface side of the side tank portion 32. The black ink ink storage chamber 42 and the cyan ink storage chamber 41 are vertically adjacent to each other via the intermediate wall portion 34 of the lower tank portion 32. A line connecting the outlet 66 and a line connecting the ink inlet 45 of the cyan ink and the ink outlet 46 extend in different directions along the intermediate wall portion 34 and intersect each other like a diagonal line.

  A pair of rectifying ribs 67 and 68 are provided on the upper surface of the intermediate wall portion 34 in the ink storage chamber 42 so as to protrude toward the damper wall 59. The pair of rectifying ribs 67 and 68 extend substantially in parallel with the direction of ink flow from the ink inlet 65 to the ink outlet 66, and the cross section orthogonal to the extending direction has a quadrangular shape. . The pair of rectifying ribs 67 and 68 are provided in a state of being separated from the damper wall 59 so as not to restrict the movement of the damper wall 59. In this way, a stepped portion is formed by the opposing inner side surfaces of the pair of rectifying ribs 67, 68, and the inner space sandwiched between the pair of rectifying ribs 67, 68 is the main flow area that goes from the ink inlet 65 to the ink outlet 66. A2 and the outer space between the rectifying ribs 67 and 68 and the peripheral side wall portion 58 becomes the secondary flow area B2. Further, since black ink remains black even when mixed with other colors and the problem of color mixing does not easily occur, the end portions in the extending direction of the rectifying ribs 67 and 68 are the peripheral side wall portions 58 in order to enhance the rectifying effect. It is connected to the inner wall surface of the and there is no gap.

  Further, the peripheral side wall portion 58 has a corner portion corresponding to the quadratic sub-flow region B2 in a plan view orthogonal to the normal line of the intermediate wall portion 34 and the damper wall 39, and is rounded into a substantially L shape recessed inward. It has a shape. In this manner, the chamfered portions 58a and 58b are formed so as to approach the rectifying ribs 67 and 68, so that the volume of the secondary flow region B2 is reduced and the flow path cross-sectional area orthogonal to the flow direction of the secondary flow region B2 is increased. It is partially smaller. That is, the volume of the ink storage chamber 42 is smaller than that of a square shape that is not rounded.

  11 is a cross-sectional view taken along line XI-XI in FIG. As shown in FIG. 11, the distance between the intermediate wall portion 34 and the damper wall 59 is the same in both the main flow area A2 and the sub-flow area B2. This is because the black ink is unlikely to cause a problem of color mixing with other colors, and therefore the flow velocity of the sub-flow area B2, which is a stagnation part, does not have to be as high as that of the cyan ink storage chamber 41. In addition, the distance between the intermediate wall 34 and the damper wall 59 in the vicinity of the peripheral side wall 58 in the secondary flow area B2 is larger than the distance between the upper ends of the rectifying ribs 67 and 68 and the damper wall 59. When the resin film to be the damper wall 59 is welded to the upper end of the peripheral side wall portion 58, the melted mass of the resin film is prevented from reaching the intermediate wall portion 34 through the peripheral side wall portion 58.

  FIG. 12 is a perspective view of the upper tank portion 33 shown in FIG. 5 as viewed from above. As shown in FIG. 12, in the buffer area S2 (see FIG. 5), a peripheral side wall portion 78 having a substantially square shape in plan view is provided on the upper surface of the intermediate wall portion 35 of the upper tank portion 33. A yellow ink storage chamber 43 is defined by the peripheral side wall portion 78 and opens downward. The opening surface of the yellow ink storage chamber 43 is sealed by welding a square-shaped flexible resin film 79 to the upper end of the peripheral side wall portion 78 in plan view. That is, the resin film 79 serves as a damper wall 79 that is spaced apart from the intermediate wall 35 in the vertical direction. The ink storage chamber 43 for yellow ink described below has substantially the same configuration as the ink storage chamber 41 for cyan ink described above.

  The downstream end of the flow path 36 in the ink introduction area S 1 communicating with the ink introduction port 31 communicates with the ink storage chamber 43 as an ink inflow port 85 in the vicinity of the right front corner of the peripheral side wall portion 78. The ink outlet 86 of the ink storage chamber 43 is opened on the bottom surface in the vicinity of the left rear corner in the ink storage chamber 43 and penetrates the intermediate wall 34 of the upper tank portion 33 in the thickness direction. The ink discharge path 37 communicates with the lower surface side of the upper tank portion 33.

  A pair of rectifying ribs 87 and 88 are provided on the upper surface of the intermediate wall portion 35 in the ink storage chamber 43 so as to protrude toward the damper wall 79. The pair of rectifying ribs 87 and 88 extend substantially parallel to the direction of ink flow from the ink inlet 85 to the ink outlet 86, and the cross section perpendicular to the extending direction has a quadrangular shape. . Further, the pair of rectifying ribs 87 and 88 are provided in a state of being separated from the damper wall 79 so as not to restrict the movement of the damper wall 79. In this manner, a stepped portion is formed by the opposing inner side surfaces of the pair of rectifying ribs 87, 88, and the inner space sandwiched between the pair of rectifying ribs 87, 88 is the main flow area from the ink inlet 85 toward the ink outlet 86. A3, and the outer space between the rectifying ribs 87 and 88 and the peripheral side wall portion 78 becomes the sub-flow area B3.

  The ends of the rectifying ribs 87 and 88 in the ink flow direction have a slight gap 90 to 93 with the peripheral side wall 78 in the extending direction. Thereby, main flow area A3 and subflow area B3 are connected via the gaps 90-93. Further, the peripheral side wall portion 78 has a shape in which a corner portion corresponding to the right rear side sub-flow region B3 in a square corner portion in a plan view is chamfered by a linear chamfer portion 78a. As described above, the chamfered portion 78a is formed so as to approach the rectifying rib 88, so that the volume of the sub-flow area B3 is reduced and the cross-sectional area of the flow path orthogonal to the flow direction of the sub-flow area B3 is partially reduced. It has become. That is, the volume of the ink storage chamber 43 is smaller than that of a square shape that is not rounded. Further, the resin film forming the damper wall 79 is opened not only above the upper opening of the peripheral side wall portion 78 in the buffer area S2, but also above the flow path 36 in the ink introduction area S1 and the ink discharge path 37 in the ink discharge area S3. The part is also sealed. An upper space sealed with a damper wall 79 made of a resin film in the ink outlet path 37 is used as the air trap chamber 94.

  FIG. 13 is a perspective view of the upper tank portion 33 shown in FIG. 5 as viewed from below. Since FIG. 13 is a view seen from below, the upward direction in the figure is the downward direction, and the downward direction in the figure is the upward direction. As shown in FIG. 13, in the buffer area S2 (see FIG. 5), on the upper side of the intermediate wall portion 35 of the upper tank portion 33, a flat ink storage chamber 44 of magenta ink is partitioned by a peripheral wall portion 98 and above. Is open. The opening surface of the magenta ink storage chamber 44 is sealed by welding a resin film 99 having a quadrangular flexibility in plan view to the upper end of the peripheral side wall portion 98. That is, the resin film 99 is the damper wall 99 that is spaced apart from the intermediate wall portion 35 in the vertical direction. The magenta ink reservoir 44 described below has the same configuration as the cyan ink reservoir 41 described above.

  The ink inlet 105 and the ink outlet 106 are provided at substantially diagonal positions of the ink storage chamber 44. The ink inlet 105 for magenta ink is opened at the bottom surface in the vicinity of the left front corner in the ink storage chamber 44 and penetrates the intermediate wall portion 35 of the upper tank portion 33 in the thickness direction. 35 is connected to the flow path 36 (see FIG. 5) on the upper surface side. The ink outlet 106 of the ink storage chamber 44 is opened on the bottom surface in the vicinity of the right rear corner in the ink storage chamber 44, and penetrates the intermediate wall 35 of the upper tank portion 33 in the thickness direction, and passes through the upper tank. The ink discharge path 37 communicates with the upper surface side of the portion 33.

  A pair of rectifying ribs 107 and 108 are provided on the lower surface of the intermediate wall portion 35 in the ink storage chamber 44 so as to protrude toward the damper wall 99. The pair of rectifying ribs 107 and 108 extend substantially parallel to the ink flow direction from the ink inlet 105 to the ink outlet 106, and the cross section orthogonal to the extending direction is a quadrangular shape. . The pair of rectifying ribs 107 and 108 are provided in a state of being separated from the damper wall 99 so as not to restrict the movement of the damper wall 99. In this way, a step portion is formed by the opposing inner side surfaces of the pair of rectifying ribs 107, 108, and the inner space sandwiched between the pair of rectifying ribs 107, 108 is the main flow area from the ink inlet 105 toward the ink outlet 106. A4, and the outer space between the rectifying ribs 107 and 108 and the peripheral side wall 98 becomes the sub-flow area B4. Further, the ends of the flow regulating ribs 107 and 108 in the ink flow direction have a slight gap 110 to 113 with the peripheral side wall 98 in the extending direction. Thereby, main flow area A4 and subflow area B4 are connected via gaps 110-113.

  The peripheral side wall portion 98 has a shape in which corner portions corresponding to the quadrangular sub-flow region B4 are rounded in plan view. Specifically, the chamfered portions 98a and 98b are linearly formed so that the peripheral side wall portion 98 has a substantially hexagonal shape in plan view. Further, the distance between the intermediate wall portion 35 and the damper wall 99 is smaller in the sub-flow region B4 than in the main flow region A4. As described above, the chamfered portions 98a and 98b are formed so as to approach the rectifying ribs 107 and 108, so that the volume of the sub-flow region B4 is reduced and the flow path cross-sectional area perpendicular to the flow direction of the sub-flow region B4 is increased. It is getting smaller. That is, the volume of the ink storage chamber 44 is smaller than that of a square shape that is not rounded. A cylindrical portion 116 is erected on the intermediate wall portion 35 on the right front side of the peripheral side wall portion 98. The cylindrical portion 116 forms a communication path 116a through which ink from the flow path 36 flows, and the communication path 116a is connected to the black ink communication path 56a (see FIG. 6) in the lower tank section 32. A cylindrical portion 117 is erected on the intermediate wall portion 35 on the left front side of the peripheral side wall portion 98. The cylindrical portion 117 forms a communication path 117a through which ink from the flow path 36 flows, and the communication path 117a is connected to the cyan ink communication path 54a (see FIG. 6) in the lower tank section 32. In addition, another resin film 115 is welded to the lower surface of the upper tank portion 33 in the ink introduction area S1 (see FIG. 5) to form a flow path 36.

  According to the configuration described above, the damper walls 39, 59, 79, 99 are restrained by the two sides constituting the corners of the peripheral side walls 38, 58, 78, 98 that are substantially rectangular in plan view. , 59, 79, 99 corresponding to the corners are portions that are harder to be displaced than the other portions and have a weak dynamic pressure absorption performance. Therefore, even if the corners are chamfered by the chamfered portions 38a, 38b, 58a, 58b, 78a, 98a, 98b, the dynamic pressure absorption performance does not deteriorate so much. On the other hand, the volume of the ink storage chambers 41, 42, 43, and 44 is reduced by chamfering with the chamfered portions 38a, 38b, 58a, 58b, 78a, 98a, and 98b, compared to the case where the chamfered portions are not chamfered. That is, when the ink cartridge 9 is mounted on the cartridge mounting portion 8, the volume of the flow path in the ink jet printer 1 to which the mounting pressure is transmitted (the mounted ink joint tube portion 30b, the ink supply tube 10, the ink storage chambers 41 to 44, etc. The total volume) will decrease. Therefore, the time required for releasing the mounting pressure, which is the time from when the mounting pressure of the ink cartridge 9 propagates in the flow path in the inkjet printer 1 to when it is reflected back, can be shortened. As described above, according to the configuration of the present embodiment, the ink cartridge 9 is pulled out immediately after being mounted in the cartridge mounting portion 8 without deteriorating the dynamic pressure absorption performance by the damper walls 39, 59, 79, 99 as much as possible. Thus, the prevention of ink dripping from the ink inflow portion 27 is realized.

  Further, since the peripheral side wall portions 38, 58, 78, and 98 have a shape in which corner portions corresponding to the auxiliary flow regions B1 to B4 are rounded, the volume of the auxiliary flow regions B1 to B4 is reduced, and the ink inlets 45 and 65 are formed. , 85, 105 even if air flows in, the amount of air accumulated in the secondary flow areas B1 to B4 is reduced. The volume of the air trap chamber 94 for capturing the air that has flowed out of the ink storage chambers 41 to 44 is suppressed, and therefore, air is discharged during the purge that discharges ink from the nozzles of the inkjet head 21 for maintenance. Therefore, the amount of waste ink required for this can be reduced.

  Furthermore, since the resin film forming the damper walls 39, 59, 79, 99 is welded to the peripheral side wall portions 38, 58, 78, 98 in a rectangular shape which is a state in which the roll film is cut with a film cutter, Processing after cutting is not necessary, and an increase in manufacturing steps can be prevented.

  Further, in the sub-flow areas B1, B3, and B4 in the cyan, yellow, and magenta ink storage chambers 41, 43, and 44, the distance between the intermediate wall portions 34 and 35 and the damper walls 39, 79, and 99 is small. Therefore, even if air flows in from the ink inlets 45, 85, and 105, the amount of air accumulated in the sub-flow areas B1, B3, and B4 is reduced. Therefore, the volume of the air trap chamber 94 for capturing the air flowing out from the ink storage chambers 41 to 44 can be suppressed, and the amount of waste ink in the purge operation for discharging ink from the nozzles of the inkjet head 21 can be reduced. It becomes.

  Further, in the secondary flow areas B1, B3, and B4, the flow path cross-sectional area is reduced due to the small distance between the intermediate wall portions 34 and 35 and the damper walls 39, 79, and 99. Therefore, the secondary flow areas B1, B3 , B4 will increase the flow velocity. Therefore, even when the wrong type of ink is supplied to the ink storage chambers 41, 43, and 44, the ink accumulated in the auxiliary flow areas B1, B3, and B4 is smoothly discharged by the purge operation, so that different types of ink are used. It becomes possible to quickly recover the mixed state.

  Further, the distance between the intermediate wall portions 34, 35 and the damper walls 39, 59, 79, 99 in the sub-flow areas B1 to B4 is the position of the rectifying ribs 47, 48, 67, 68, 87, 88, 107, 108. The position in the vicinity of the peripheral side wall portions 38, 58, 78, and 98 is larger than that. Then, when the damper walls 39, 59, 79, and 99 made of a resin film are welded to the peripheral side wall portions 38, 58, 78, and 98, the melted mass of the resin film slightly drops in the sub-flow areas B1 to B4. However, it becomes difficult to reach the intermediate wall portions 34 and 35. Accordingly, it is possible to prevent the lump in which the resin film is melted from being connected to the intermediate wall portions 34 and 35 and reduce the viable area of the damper walls 39, 59, 79, and 99, and the damper walls 39, 59, 79, and 99 It can prevent that pressure fluctuation absorption performance falls.

(Second Embodiment)
FIG. 14 is a drawing corresponding to FIG. 8 in the second embodiment of the present invention. As shown in FIG. 14, a pair of stepped portions 147 and 148 are provided on the upper surface of the intermediate wall portion 134 in the ink storage chamber 141, and the pair of stepped portions 147 and 148 are rectified in the first embodiment. Similar to the ribs 47 and 48, it extends substantially parallel to the direction of ink flow from the ink inlet to the ink outlet. The inner space sandwiched between the pair of stepped portions 147 and 148 becomes the main flow area A5, and the outer space between the stepped portions 147 and 148 and the peripheral side wall portion 38 becomes the sub-flow area B5. The bottom surface 134a in the main flow region A5 is flat, and the bottom surfaces 134b and 134c in the sub flow region B5 are also flat. That is, no depression is provided in the bottom surfaces 134b and 134c in the sub-flow area B5. The distance between the intermediate wall portion 134 and the damper wall 39 is smaller in the sub-flow area B5 than in the main flow area A5.

  According to the above configuration, the volume of the secondary flow area B5 is further reduced, and the cross-sectional area of the flow path orthogonal to the flow direction of the secondary flow area B5 is further reduced, so that even if air flows into the ink storage chamber 141. The amount of air that accumulates in the secondary flow area B5 is reduced. Therefore, the amount of waste ink in the purge operation can be reduced. Further, in the secondary flow region B5, since the cross-sectional area of the flow path is further reduced because the distance between the intermediate wall portion 134 and the damper wall 39 is further reduced, the flow velocity in the secondary flow region B5 is further increased. Therefore, even when an incorrect type of ink is supplied to the ink storage chamber 141, the ink accumulated in the sub-flow area B5 by the purge operation can be smoothly discharged, and a state where different types of ink are mixed more quickly. It can be recovered. Since other configurations are the same as those of the first embodiment described above, description thereof is omitted.

(Third embodiment)
FIG. 15 is a drawing corresponding to FIG. 8 in the third embodiment of the present invention. As shown in FIG. 15, a pair of stepped portions 247 and 248 are provided on the upper surface of the intermediate wall portion 234 in the ink storage chamber 241, and the pair of stepped portions 247 and 248 are rectified in the first embodiment. Similar to the ribs 47 and 48, it extends substantially parallel to the direction of ink flow from the ink inlet to the ink outlet. The inner space sandwiched between the pair of step portions 247 and 248 becomes the main flow area A6, and the outer space between the step portions 247 and 248 and the peripheral side wall portion 38 becomes the sub-flow area B6. The bottom surface 234a in the main flow region A6 is flat, and the bottom surfaces 234b and 234c in the sub-flow region B6 are inclined so that the distance from the damper wall 39 gradually increases from the step portions 247 and 248 toward the peripheral side wall portion 38. The maximum distance between the intermediate wall portion 134 and the damper wall 39 in the sub-flow region B6 is smaller than the distance between the intermediate wall portion 134 and the damper wall 39 in the main flow region A6.

  According to the above configuration, it is possible to reduce the volume of the secondary flow region B6 as much as possible while preventing the melted mass of the resin film forming the damper wall 39 from reaching the intermediate wall portion 134. Since other configurations are the same as those of the first embodiment described above, description thereof is omitted.

  In each of the above-described embodiments, the present invention is applied to an inkjet head. However, a liquid other than ink, for example, a colored liquid is discharged to manufacture a color filter of a liquid crystal display device, and a conductive liquid is discharged. You may apply to the droplet discharge apparatus used for the apparatus etc. which form an electrical wiring.

  As described above, the droplet discharge device according to the present invention can prevent liquid dripping from the liquid inflow portion of the cartridge mounting portion when the liquid cartridge is pulled out immediately after mounting while ensuring the dynamic pressure absorption performance. It is beneficial to apply to a wide range of ink jet printers that have excellent effects and can demonstrate the significance of these effects.

It is a schematic perspective view which shows the principal part of the inkjet printer which concerns on 1st Embodiment of this invention. FIG. 2 is a partial cross-sectional view schematically illustrating the ink jet printer illustrated in FIG. 1. It is the perspective view seen from the upper part of the head unit of the inkjet printer shown in FIG. FIG. 2 is a top view of the head unit of the ink jet printer shown in FIG. 1. It is the VV sectional view taken on the line of FIG. It is the perspective view which looked at the lower side tank part shown in FIG. 5 from upper direction. It is a top view of the lower tank part shown in FIG. It is the VIII-VIII sectional view taken on the line of FIG. It is the perspective view which looked at the lower tank part shown in FIG. 5 from the downward direction. FIG. 10 is a bottom view of the lower tank portion shown in FIG. 9. It is the XI-XI sectional view taken on the line of FIG. It is the perspective view which looked at the upper tank part shown in Drawing 5 from the upper part. It is the perspective view which looked at the upper tank part shown in FIG. 5 from the downward direction. It is drawing equivalent to FIG. 8 in 2nd Embodiment of this invention. It is drawing equivalent to FIG. 8 in 3rd Embodiment of this invention.

Explanation of symbols

1 Inkjet printer (droplet ejection device)
9 Ink cartridge (liquid cartridge)
10 Ink supply tube (communication flow path)
21 Inkjet head (droplet discharge head)
22 buffer tank 32 lower tank part 33 upper tank part 34, 35, 134, 234 intermediate wall part 38, 58, 78, 98 peripheral side wall part 38a, 38b, 58a, 58b, 78a, 98a, 98b chamfered part 39, 59, 79, 99 Damper wall (resin film)
41-44, 141, 242 Ink storage chamber (liquid storage chamber)
45, 65, 85, 105 Ink inlet (liquid inlet)
46, 66, 86, 106 Ink outlet (liquid outlet)

Claims (3)

A liquid cartridge having a liquid storage chamber and a liquid outflow portion is detachably mounted, and a cartridge mounting portion having a liquid inflow portion coupled to the liquid outflow portion of the liquid cartridge and the liquid flowing in from the liquid inflow portion are stored. A liquid discharge chamber comprising: a liquid storage chamber; a communication channel that communicates the liquid inflow portion with the liquid storage chamber; and a liquid droplet discharge head to which liquid is supplied from the liquid storage chamber,
The liquid storage chamber includes a liquid inlet through which liquid from the liquid cartridge flows, a liquid outlet through which liquid flows out to the droplet discharge head, and a flow direction of the liquid from the liquid inlet to the liquid outlet. A pair of walls that are substantially parallel to each other and are spaced apart from each other and facing each other, and a peripheral side wall that surrounds the space between the pair of walls,
One of the pair of walls is a damper wall having flexibility,
The other wall of the pair of walls has a pair of rectifying ribs that protrude toward the damper wall and extend substantially parallel to the flow direction in a state of being spaced from the damper wall;
The space between the pair of rectifying ribs is a main flow area from the liquid inlet to the liquid outlet, and the space between each of the rectifying ribs and the peripheral side wall is a sub-flow area.
Between the both ends in the flow direction of each of the pair of rectifying ribs and the peripheral side wall, a gap connecting the main flow region and the sub-flow region is formed,
The peripheral side wall is a shape obtained by linearly chamfering a corner corresponding to the sub-flow region among corner portions of a substantially square shape in a plan view seen from the normal direction of the pair of walls,
The droplet discharge device according to claim 1, wherein a cross-sectional area of the central portion in the flow direction in the sub-flow region is smaller than a cross-sectional area of the central portion in the flow direction in the main flow region . The droplet discharge device according to claim 1 , wherein the damper wall is formed by welding a rectangular resin film on the peripheral side wall in a plan view. The liquid storage chamber, The apparatus according to claim 1 or 2 is disposed at a position higher than the liquid inlet portion of the cartridge mounting portion.

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