JP3901202B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus in which an ink supply source and an ink jet head are connected to each other by a manifold having an ink supply path. The present invention relates to an ink jet recording apparatus having good quality.

  An ink jet recording apparatus such as an ink jet printer records characters and images on a recording medium such as paper by ejecting ink droplets from an ink jet head mounted on a carriage. The ink cartridge filled with is attached in a replaceable manner via a manifold having an ink supply path.

  The ink jet head is an actuator composed of a large number of ink storage chambers arranged in an aligned state, and an electromechanical conversion element, an electrothermal conversion element, or the like that ejects ink stored in each ink storage chamber from the nozzle as ink droplets. The ink in the ink cartridge is supplied to each ink storage chamber through the ink supply path of the manifold, and is ejected as ink droplets from the ink storage chamber by the actuator.

  By the way, the ink filled in the ink cartridge usually has a considerable amount of air dissolved therein. Also, when replacing the ink cartridge, a certain amount of air flows from the connection portion between the ink cartridge and the manifold. Since the air enters the ink supply path, the air grows in the ink supply path and obstructs the ink supply to the ink storage chamber of the ink jet head, or is taken into the ink storage chamber of the ink jet head together with the ink. There is a problem that printing failure occurs due to non-ejection of ink droplets by closing the storage chamber.

  Therefore, conventionally, a purge process has been generally performed in which the air in the manifold is discharged to the outside together with the ink by periodically sucking from the nozzle side of the ink jet head when the ink cartridge is replaced or after the ink cartridge is replaced. It has been broken.

JP-A-5-24190 JP-A-6-91874

  However, if the air present in the ink supply path of the manifold is only floating in the ink supply path as microbubbles, it can be easily discharged to the outside by the purge process, but the portion where the shape of the ink supply path changes, etc. Many of the ink bubbles easily form bubbles and adhere to the inner surface of the ink supply path, and the micro bubbles adhering to the inner surface of the ink supply path are purged as described above. However, it cannot be discharged sufficiently. In addition, since the ink supply path of the manifold extends in the column direction formed by the plurality of ink storage chambers of the inkjet head from the connection portion with the ink cartridge, when ink is introduced from the new ink cartridge to the inkjet head by the purge process The ink does not easily reach the end of the row and air tends to remain. As described above, the air adheres as bubbles to the inner surface of the ink supply path.

  Thus, the microbubbles that cannot be discharged by the purge process and remain in the ink supply path grow into large bubbles with the passage of time, and eventually block the ink storage chamber. Therefore, even if the purge process is performed, a printing defect often occurs again in a short time, and there is a problem that the purge process must be frequently performed while the image recording apparatus or the like is in use.

  Therefore, an object of the present invention is to provide an ink jet recording apparatus that is excellent in discharging microbubbles attached to the inner surface of the ink supply path of the manifold in the purge process and that has good introduction of ink into the ink supply path. Yes.

  In order to solve the above problems, an ink jet recording apparatus according to a first aspect of the present invention includes an ink jet head provided with a plurality of ink storage chambers that store ink to be ejected and arranged in a plurality of rows, and the ink jet head. An ink jet recording apparatus comprising: a plurality of ink storage chambers connected to each other; and a manifold having an ink supply path for supplying ink from the ink supply source to the aligned plurality of ink storage chambers. A connecting portion connected to the ink supply source, and an enlarged portion extending from the connecting portion toward a row end formed by the ink supply ports of the plurality of aligned ink storage chambers and surrounding the ink supply port. The enlarged portion is provided with a guide member that guides the ink supplied from the connecting portion along the inner surface of the enlarged portion; Inner member is smaller in specific gravity than the ink, and characterized by a float movable by the flow of ink.

According to a second aspect of the present invention, in the ink jet recording apparatus according to the first aspect of the invention, the enlarged portion has an ink supply port of the plurality of ink storage chambers whose inner surfaces are aligned from the connection portion side. A first curved surface that extends in a tapered manner toward the row end and is curved so as to protrude inward, and is continuous with the first curved surface and extends in a tapered manner toward the row end. And a second curved surface that is curved so as to protrude outward, and is positioned so as to cover the plurality of ink supply ports from above, and the guide member is supplied from the connection portion. The ink is guided in a direction substantially along the first curved surface of the enlarged portion facing the ink supply port.

  According to a third aspect of the present invention, in the inkjet recording apparatus of the second aspect of the invention, the connecting portion is located corresponding to a substantially center of a row formed by the plurality of ink supply ports, and the enlarged portion is The guide member extends substantially symmetrically toward the end of the row formed by the plurality of ink supply ports, and the guide member has a substantially symmetrical shape with respect to the connection part. It is said.

  According to a fourth aspect of the invention, there is provided the ink jet recording apparatus according to the first, second or third aspect of the invention, wherein the ink supply source is detachably connected to the ejection openings of the plurality of ink storage chambers. A suction unit configured to supply ink to the ink supply path, and the guide member guides the ink toward a row end of the ink supply port when ink is supplied from the ink supply source by suction of the suction unit; It is characterized by doing.

  The invention according to claim 5 is the ink jet recording apparatus according to claim 1, 2, 3, or 4, wherein the float is spherical.

  According to a sixth aspect of the present invention, in the ink jet recording apparatus of the first, second, third, fourth, or fifth aspect, the enlarged portion of the ink supply path has a plurality of the ink supply ports from above. The connection portion is opened so as to cover the ceiling portion of the enlarged portion, and the float can float away from the plurality of ink supply ports in a direction to close the connection portion. It is characterized by.

  According to a seventh aspect of the present invention, in the ink jet recording apparatus according to the first, second, third, fourth, fifth or sixth aspect, the enlarged portion protrudes from the inner surface toward the float. It is characterized by having a guide portion that regulates the movement path.

  According to an eighth aspect of the present invention, there is provided an ink jet recording apparatus according to the seventh aspect of the invention, wherein the ink storage chambers of the ink jet head are provided in a plurality of rows, and the guide portions are arranged in a plurality of rows. It is characterized in that it enters from both ends between the rows formed by the ink supply ports.

The invention according to claim 9 is the ink jet recording apparatus according to claim 1, 2, 3, or 4, wherein the float is a row formed by a plurality of the ink supply ports from a portion corresponding to the connection portion. Narrow flow paths leading to the plurality of ink supply ports are formed between the enlarged portion and the inner surface of the enlarged portion along substantially the entire length of the enlarged portion .

  According to a tenth aspect of the present invention, in the ink jet recording apparatus according to the ninth aspect of the present invention, the float has a portion inserted into the connecting portion.

  As described above, in the ink jet recording apparatus according to the first aspect of the present invention, the guide member provided in the enlarged portion guides the ink introduced into the enlarged portion along the inner surface of the enlarged portion during the purge process. As a result, the ink flow velocity near the inner surface of the enlarged portion in the purge process increases. As a result, the microbubbles adhering to the inner surface of the enlarged portion are easily separated by the ink flow, and the peeled microbubbles are taken into the ink storage chamber together with the ink flow and discharged to the outside. Accordingly, the discharge performance of the microbubbles adhering to the inner surface of the enlarged portion that is difficult to be discharged by the purge process is remarkably improved, and a good printing state can be maintained for a long time by a small number of purge processes. Accordingly, it is not necessary to frequently perform a purge process that requires a processing time of several minutes, and the ink jet recording apparatus can be used in a comfortable environment. Further, since the ink is introduced along the inner surface of the enlarged portion, air hardly remains at the corner of the enlarged portion, and the ink introduction property is good. In addition, since the guide member has a specific gravity smaller than that of the ink and is formed by a float that can be moved by the ink flow, the guide member is moved by the ink flow during the purging process. The microbubbles adhering to the surface are peeled off from the guide member and easily discharged to the outside together with the ink flow.

  In the ink jet recording apparatus according to the third aspect of the present invention, the connecting portion is provided so as to be at a position corresponding to the approximate center of the row formed by the plurality of ink supply ports, and the enlarged portion is supplied with the plurality of inks from the connecting portion. The shape is such that the opening extends substantially symmetrically toward the end of the row formed by the mouths, and the guide member has a substantially symmetrical shape with respect to the connection portion. Uniformly and promptly.

  Further, in the ink jet recording apparatus of the invention according to claim 4, there is provided a suction means that is detachably connected to the ejection openings of the plurality of ink storage chambers, and supplies the ink of the ink supply source to the ink supply path. When ink is supplied from the ink supply source by the suction of the suction means, the ink is guided toward the row end of the ink supply port. Through the chamber, an ink flow rate can be generated in almost the entire enlarged portion, and the discharge of microbubbles is improved.

  In the ink jet recording apparatus of the invention according to claim 5, since the float is spherical, the ink liquid introduced from the connecting portion is uniformly and quickly introduced into the entire enlarged portion without being biased to one side. The

  In the ink jet recording apparatus of the invention according to claim 6, the enlarged portion of the ink supply path is located so as to cover the plurality of ink supply ports from above, and the connection portion is opened in the ceiling portion of the enlarged portion. At the same time, since the float can float away from the plurality of ink supply ports in the direction of closing the connection portion, the guide member formed by the float floats and is connected after the purge process. By closing the part, the microbubbles that could not be discharged by the purge process will not float up and enter the connection part again, and will always stay in the enlarged part near the ink jet head. Is reliably discharged to the outside during the next purge process.

  In the ink jet recording apparatus of the invention according to claim 7, since the guide portion for restricting the movement path of the float is provided in the enlarged portion so as to protrude from the inner surface toward the float, the float is disposed on the ink jet head side by the purge process. When it is pulled down, it does not move to an unexpected position, and a constant ink flow path is always secured during the purge process, ensuring stable bubble discharge and ink introduction properties. can do. In addition, since the volume of the flow path becomes smaller due to the presence of the guide portion, the ink flow rate is increased as a whole, and the bubble discharge performance is further improved.

  In the ink jet recording apparatus of the invention according to claim 8, when the ink storage chambers of the ink jet head are provided in a plurality of rows, the guide portion is a row formed by the ink supply ports of the ink storage chambers arranged in the plurality of rows. Since the ink supply port of the ink storage chamber forms an individual flow path leading to each row by a guide portion and an enlarged portion, Since the ink flows along the flow path, the bubble discharge property and the ink introduction property in the vicinity of the end portion of the ink supply port array in which bubbles tend to stay are improved.

In the ink jet recording apparatus according to the ninth aspect of the invention, the float extends from the portion corresponding to the connection portion to the inner surface of the enlarged portion over substantially the entire length of the enlarged portion along the row formed by the plurality of ink supply ports. In addition, since a narrow flow path leading to a plurality of ink supply ports is formed, the ink moves only near the inner surface of the ink supply path where microbubbles are likely to adhere during the purging process, and the ink flow velocity Becomes considerably large, and the bubble discharge performance is further improved.

  In the ink jet recording apparatus of the invention according to claim 10, since the float has a portion to be inserted into the connecting portion, when the float moves, its posture is not easily collapsed, and the float posture is collapsed. However, since it is easy to return to the original posture, it is possible to ensure a stable bubble discharge property and ink introduction property during the purge process.

  Hereinafter, embodiments will be described with reference to the drawings. As shown in FIG. 1, the inkjet recording apparatus 1 ejects four color inks of cyan, magenta, yellow, and black onto a printing paper P as a recording medium to perform printing or image formation (hereinafter, image formation). And four ink cartridges 50 serving as ink supply sources for supplying four ink liquids to the respective ink jet heads 31, and a head unit 30 having four ink jet heads 31. Are mounted on the carriage 11.

  A platen roller 18 is rotatably provided below the head unit 30 so as to face the lower surface of the ink jet head 31 and parallel to the reciprocating direction thereof. The printing part is configured.

  The carriage 11 is slidably supported by a carriage shaft 12 and a guide plate 13 that are supported by frames (not shown) at both ends and extend in the reciprocating direction of the inkjet head 31, and between the pulleys 14 and 15. The carriage 11 is connected to the belt 16 and is driven to rotate by a motor 17 so that the carriage 11 is reciprocated linearly.

  The printing paper P is inserted between the ink-jet head 31 and the platen roller 18, printed thereon, and then discharged in the direction indicated by the arrow in FIG. In FIG. 1, the illustration of the paper feed mechanism for the printing paper P is omitted.

  As shown in FIG. 2, the head unit 30 is provided with four manifolds 40 for connecting the ink cartridges 50 described above to the inkjet heads 31, and each manifold 40 has one end thereof. Is fixed so as to cover the upper surface of the inkjet head 31, and the ink cartridge 50 is detachably connected to the other end via a joint member 50a. The ink cartridge 50 includes a first ink chamber 51 that contains a porous ink absorbing material such as polyurethane foam, and a second ink chamber 52 that communicates with the first ink chamber 51, as shown in FIG. The ink liquid is supplied from the ink absorbing material impregnated with the ink liquid in the first ink chamber 51 through the communication hole 51a through the second ink chamber 52 to the manifold 40 from the ink supply port 53. The Note that a mesh filter 53 a is attached to the ink supply port portion 53.

  As shown in FIGS. 2 and 3, the inkjet head 31 includes an actuator 32 made of piezoelectric ceramic for ejecting ink liquid, and a nozzle plate 34 attached to one end surface of the actuator 32. A plurality of ejection channels 33 serving as ink storage chambers extending from one end surface serving as a lower surface to the other end surface serving as an upper surface are formed in 32 in a state of being aligned in two rows. A large number of nozzle holes (not shown) are formed corresponding to the respective injection channels 33 opened on one end face of 32.

  In addition, each ejection channel 33 formed in the actuator 32 is connected to each ejection channel 33 formed in the manifold 40 from an ink supply port 33 a of each ejection channel 33 opened in the other end surface of the actuator 32. The ink liquid in the ink cartridge 50 is introduced, and the volume of the ejection channel 33 is changed by the deformation of the actuator 32, whereby the ejection of the ink liquid from the ejection channel 33 and the ejection channel 33 are performed. Ink liquid is introduced. That is, when the volume of the ejection channel 33 decreases, the ink liquid stored in the ejection channel 33 is ejected from the nozzle holes of the nozzle plate 34 as ink droplets, and the volume of the ejection channel 33 expands to the original state. Sometimes, the ink liquid is introduced into the ejection channel 33.

  As shown in FIG. 1, the reset state position of the inkjet head 31 set on the side of the platen roller 18 includes an ink suction device 21 as a suction unit for performing a purge process, and the inkjet head 31. A wiper device 26 for wiping the nozzle plate 34 and a protective cap device 27 for covering the nozzle plate 34 of the inkjet head 31 and preventing the nozzle holes from drying when printing is not performed are respectively provided. The forced ejection position set on the opposite side of the reset state position across the roller 18 is forced to prevent the nozzle plate 34 from being obstructed by periodically ejecting ink from the inkjet head 31. An ink holding member 28 that absorbs and holds the ejected ink is provided. The ink suction device 21, the wiper device 26, the protective cap device 27, and the ink holding member 28 constitute a recovery maintaining unit for recovering and maintaining the ejection function of the inkjet head 31.

  The ink suction device 21 includes a suction pump 22, a suction unit 23, a waste ink tank 24, and a cam 25. The suction pump 22 and the suction unit 23 are driven via a cam 25 from a power transmission mechanism (not shown). It is like that.

  When performing a purge process using the ink suction device 21, a negative pressure is generated by the suction pump 22 with the suction unit 23 covering the nozzle plate 34 of the inkjet head 31, and the ink supply path 43 of the manifold 40 or the like. By sucking in the defective ink liquid including bubbles or the like in the ejection channel 33, a new ink liquid is introduced into the ejection channel 33 from the ink cartridge 50, thereby recovering the ink jet head 31. The sucked defective ink liquid is sent to the waste ink tank 24. The same operation is performed when the ink liquid is introduced from the new ink cartridge 50 into the inkjet head 31 (initial introduction) after the ink cartridge 50 is replaced.

  As shown in FIGS. 3 to 7, the manifold 40 includes a frame body 41 and a main body 42 that is disposed inside the frame body 41 and is partially connected to the inner surface of the frame body 41. The frame body 41 has a pair of fixing pieces 41 a fixed to the side surface on the other end side of the inkjet head 31 by an adhesive and a pair for positioning when the manifold 40 is fixed to the inkjet head 31. The positioning piece 41b is continuously provided. In addition, by filling the space S formed between the frame body 41 and the main body 42 with an adhesive in a state where the fixing piece 41a and the inkjet head 31 are fixed with an adhesive, the other of the inkjet head 31 is obtained. Ink liquid leakage from the end face is prevented.

  The main body portion 42 is formed with an ink supply path 43 for supplying the ink liquid in the ink cartridge 50 to a plurality of ejection channels 33 formed in the ink jet head 31. A small-diameter connecting portion 44 having an ink inflow port 43a connected to the cartridge 50, and an ink outflow port 43b that extends outwardly from the connecting portion 44 in a tapered shape and surrounds the ink supply port 33a of the ejection channel 33. It is comprised from the expansion part 45. A mesh filter 40 a is attached to the ink inlet 43 a of the connection portion 44.

  The connecting portion 44 is located at a substantially central portion of a channel row constituted by a plurality of jetting channels 33, and the enlarged portion 45 is a row of jetting channel rows formed on the inkjet head 31 from the connecting portion 44. It spreads almost symmetrically toward the edge (see FIG. 5).

  As shown in FIG. 5, the enlarged portion 45 has a first inner surface curved in a taper shape toward the row end of the injection channel 33 on the connection portion 44 side and so as to protrude inward. And the second curved surface 45b that is continuous with the first curved surface 45a and is curved so as to protrude outwardly on the inkjet head 31 side. That is, with respect to the substantially linear taper surface that almost connects the end of the connection portion 44 on the inkjet head 31 side to the row end of the ejection channel 33, the connection portion 44 side and the inkjet head 31 side are respectively inward as described above. The first curved surface 45a projecting and the second curved surface 45b projecting outward are provided. A spherical float 46 having a specific gravity smaller than that of the ink liquid is provided in the enlarged portion 45 as a guide member for guiding the ink liquid introduced from the connection portion 44 along the inner surface of the enlarged portion 45.

  In the normal state, the float 46 floats and closes the connection portion 44, and is caused by the ink flow generated when the ink liquid in the enlarged portion 45 is sucked toward the ejection channel 33 during the purging process. A new ink liquid is introduced into the enlarged portion 45 from the connecting portion 44 by being pulled downward and opening the connecting portion 44 to the enlarged portion 45. Needless to say, such a movement of the float 46 occurs not only when the purge process is performed, but also when the ink liquid in the enlarged portion 45 is taken into the ejection channel 33 by a normal printing operation. .

  The new ink liquid introduced into the enlarged portion 45 from the connection portion 44 thus opened is the float 46 pulled down on the lower side and the ceiling surface of the enlarged portion 45 as shown by arrows in FIG. Since the ink penetrates along the inner surface of the enlarged portion 45 through the gap, the ink flow velocity in the vicinity of the inner surface of the enlarged portion 45 becomes larger than in the case where the float 46 does not exist. The attached micro bubbles are peeled off from the inner surface of the enlarged portion 45 and are easily taken into the ejection channel 33 together with the ink liquid. Further, since the ink liquid is directed to the end portion of the enlarged portion 45, air hardly remains at the end portion, and the ink liquid is satisfactorily filled in the ink supply path 43.

  In addition, since the float 46 has a spherical shape that is symmetrical with respect to the connection portion 44, the ink liquid introduced from the connection portion 44 is uniformly and quickly distributed throughout the enlarged portion 45 without being biased to one side. To be introduced.

  Further, as described above, the enlarged portion 45 spreads almost symmetrically from the connection portion 44 toward the row end of the ejection channel row formed in the inkjet head 31, so that the ink flow along the inner surface of the enlarged portion 45 is made. The microbubbles that reach the both ends of the ejection channel row while maintaining a relatively large flow velocity and stay in the corner formed by the inner surface of the enlarged portion 45 and the other end surface of the inkjet head 33 are easily introduced into the ejection channel 33. It is burned. Therefore, the discharge property of the microbubbles staying in the corner portion that is difficult to discharge with a normal manifold is improved.

  Further, in a purge process (at the time of initial introduction of ink liquid) performed immediately after replacement of the ink cartridge 50, air having a certain volume from the connection portion between the manifold 40 and the ink cartridge 50 enters the ink supply path 43 of the manifold 40. As described above, the ink liquid introduced into the enlarged portion 45 from the connection portion 44 is introduced from the both ends of the ejection channel row along the inner surface of the enlarged portion 45 due to the presence of the float 46. Since the introduced air is introduced, there is an effect that the invading air hardly remains in the corner portion in the manifold 40 as bubbles.

  Further, as shown in FIGS. 4 and 6, the enlarged portion 45 has a guide that restricts the movement path of the float 46 by entering the inner surface between both ends of the channel row arranged in two rows from both ends thereof. The guide portion 45 c is connected to the ceiling surface of the enlarged portion 45 facing the ink supply ports 33 a of the plurality of ejection channels 33 and extends to a position close to the connection portion 44.

  Due to the presence of the guide portion 45c, the float 45a always moves in the vertical direction in the central portion of the enlarged portion 45. Therefore, the float 45a does not move to a biased position in the enlarged portion 45, and stable bubble discharge and ink introduction properties. Can be secured. In addition, since the volume of the flow path becomes smaller due to the presence of the guide portion 45c, the ink flow rate is increased as a whole, and the bubble discharge performance is further improved.

  In addition, on the end side of both the injection channel rows aligned in two rows, individual flow paths leading to the respective injection channel rows are formed by the guide portions 45c and the inner surfaces of the enlarged portions 45, and along the flow paths. Since the flow of the ink liquid is generated, the bubble discharge property and the ink introduction property in the vicinity of the end portion of the ejection channel row where the bubbles tend to stay are improved.

  In the purge process, the suction force is usually large in the initial stage, but since the suction force gradually decreases with time, the bubbles are separated from the ink supply port 33a of the ejection channel 33 to some extent as in the connection portion 44. If present, the bubbles may not be able to be taken into the ejection channel 33 in the initial stage where the suction force is large, and thus the remaining bubbles cannot be easily discharged. .

  However, in this manifold 40, when the purge process is completed, that is, when the suction by the ink suction device 21 is stopped, the connection portion 44 is closed by the float 46 that has been re-floated, so that the exhaust process is performed by the purge process. The air bubbles remaining in the enlarged portion 45 without rising again do not enter the connecting portion 44, and always stay in the enlarged portion 45 near the ink supply port 33a of the ejection channel 33. Therefore, by repeating the suction and stop of the purge process a plurality of times, bubbles that could not be discharged by the first purge process are surely discharged at the next purge process.

  In addition, the microbubbles existing in the enlarged portion 45 also adhere to the surface of the float 46, but the microbubbles adhering to the float 46 may move to the lower side during the purging process. Is peeled off from the surface thereof, taken into the ejection channel 33 together with the ink flow, and discharged to the outside.

  In addition, since the second curved surface 45b of the enlarged portion 45 is curved so as to protrude outward and is connected to the other end surface of the inkjet head 31 with a steep slope, the second curved surface 45b and the inkjet head 31 other than the second curved surface 45b are connected. The ink liquid flows into the corner portion formed by the end face from substantially above, and the bubbles remaining in the portion can be made extremely small. And even if the bubble grows, since the second curved surface 45b is curved so as to protrude outward as described above, a certain amount of depth h is secured above the corner portion. Even if the bubbles rise and adhere to the second curved surface 45 b and grow, it takes some time for the grown bubbles to reach the ink supply port 33 a of the ejection channel 33.

  Further, since the inner surface of the enlarged portion 45 that forms the corner portion is steep with respect to the other end surface of the ink jet head 31, microbubbles that could not be discharged by the purge process remain in the corner portion. Even when the bubbles grow, the bubbles easily rise to the connection portion 44 side by buoyancy, so that bubbles are not taken into the ejection channel 33 in a short time after the purge process is performed.

  As described above, by bending the inner surface of the enlarged portion 45 so that the inkjet head 31 side protrudes outward, bubbles remaining in the enlarged portion 45 grow and are taken into the ejection channel 33 of the inkjet head 31. Therefore, the time until the ink liquid is not ejected after the purge process can be extended. Therefore, it is not necessary to frequently perform a purge process that requires a processing time of several minutes, and the inkjet recording apparatus 1 can be used in a comfortable environment.

  8 to 12 show other embodiments of the manifold used in the ink jet recording apparatus 1. The manifold 60 is also composed of a frame body 61 and a main body 62 as in the manifold 40 described above. The frame body 61 has a pair of fixing pieces fixed to the side surface on the other end side of the inkjet head 31. 61a and a pair of positioning pieces 61b for positioning the manifold 60 on the inkjet head 31 are connected.

  The main body 62 includes a small-diameter connecting portion 64 connected to the ink cartridge 50 and an enlarged portion 65 that extends substantially symmetrically outward from the connecting portion 64 and surrounds the ink supply ports 33a of the plurality of ejection channels 33. Although the ink supply path 63 is provided, the length of the connecting portion 64 is longer than that of the connecting portion 44 of the manifold 40 and the shape of the enlarged portion 65 is the same as the enlarged portion 45 of the manifold 40. It is very different. The point that the connection part 64 is located in the approximate center of the ejection channel row and the point that the mesh filter 60a is provided at the ink inlet 63a of the connection part 64 are the same as in the case of the manifold 40.

  As shown in FIG. 10, the enlarged portion 65 extends in the longitudinal direction of the ejection channel row in a substantially horizontal direction from the connecting portion 64 toward both ends of the ejection channel row, and then protrudes outward at both ends. In addition to having a curved shape, as shown in FIG. 12, in the width direction of the injection channel row, it has a substantially trapezoidal shape that is curved so that both side surfaces protrude inward. The overall volume is set to be considerably smaller than the enlarged portion 45 of the manifold 40 described above.

  As shown in FIGS. 10 to 12, narrow ink flow paths leading to both ejection channel rows arranged in two rows are formed in the enlarged portion 65 between the inner surface of the enlarged portion 65, as shown in FIGS. 10 to 12. In addition, a spacer 66 having a shape substantially similar to the enlarged portion 65 and slightly smaller than the enlarged portion 65 and having a specific gravity larger than that of the ink liquid is accommodated as a guide member between the two ejection channel rows. It has a cylindrical part 67 that protrudes upward from the upper surface of the central part in the direction and is inserted into the connection part 64.

  Further, as shown in FIGS. 11 and 13, the spacer 66 has projecting portions 66a slightly protruding from both side surfaces of the central portion in the longitudinal direction while being partially curved outward. The inner surface of the enlarged portion 65 corresponding to the protruding portion 66a also has a recessed portion 65a that is slightly recessed along the protruding portion 66a. However, since the gap between the protrusion 66a and the depression 65a is set to be smaller than the gap between the other side surface of the spacer 66 and the inner surface of the enlarged portion 65, the spacer 66 is displaced in the width direction. Thus, even when the protrusion 66a and the recess 65a are in contact with each other, the side surface of the spacer 66 and the inner surface of the enlarged portion 65 are in contact with each other in the portion other than the protrusion 66a, and the ink flow path leading to the ejection channel row on one side is formed. The ink liquid can be reliably supplied to the ink supply port 33a of each ejection channel 33 without being completely blocked.

  Further, as shown in FIGS. 9, 11 and 12, the bottom surface of the spacer 66 has a tapered surface 66b which is slightly inclined upward from the central portion in the width direction toward both sides. 66, even when the ink supply port 33a of the ejection channel 33 is partially covered by being displaced in the width direction, a slight gap is secured between the bottom surface of the spacer 66 and the ink supply port 33a. Since the ink liquid is supplied from the ink supply port 33a into the ejection channel 33 through the gap, the supply of the ink liquid to the ejection channel 33 is not extremely hindered by the presence of the spacer 66.

  In the manifold 60 configured as described above, as described above, the ink liquid introduced into the ink supply path 63 from the ink inlet 63a is a narrow ink formed by the inner surface of the ink supply path 63 and the spacer 66. By being supplied to each ejection channel 33 through the flow path, the flow rate of the ink liquid passing through the ink supply path 63 is considerably increased, and all of the ink liquid passing through the ink supply path 63 is also supplied to the ink supply path 63. In the purge process, the microbubbles adhering to the inner surface of the ink supply path 63 of the manifold 60 are almost peeled off by the ink flow and reliably discharged to the outside through the ejection channel 33 together with the ink liquid. Is done.

  Further, since the ink liquid is supplied almost uniformly from one end to the other end of the ejection channel row through the narrow ink flow path formed by the inner surface of the ink supply path 63 and the spacer 66, in the conventional manifold, The bubble discharge performance in the vicinity of both end portions of the ejection channel row where microbubbles easily stay is improved.

  Further, the manifold 60 has a very small volume of the ink flow path in the manifold 60 due to the presence of the spacer 66, but a considerable volume is secured in the connection portion 44 extending in a direction away from the inkjet head 31. Therefore, the structure is less susceptible to crosstalk. Further, as shown in FIGS. 9 to 11, a recess 66c is formed on the bottom surface of the central portion of the spacer 66, and the influence of crosstalk can be suppressed by bubbles that stay and grow in the recess 66c. It has become. Since the recess 66c is substantially closed by the other end surface of the inkjet head 31, the bubbles that have entered and grown into the recess 66c are discharged from the recess 66c into the enlarged portion 65 by the printing operation, and the inside of the ejection channel 33. Is hardly taken in, and does not cause printing defects.

  In this embodiment, the spacer 66 is simply accommodated in the manifold 60, but a predetermined gap is formed between the inner surface of the ink supply path 63 and the other end surface (upper end surface) of the inkjet head 31. As described above, the spacer 66 is bonded and fixed to a rib or the like partially protruded from the ceiling surface of the ink supply path 63, or the protrusion 66 a is press-fitted into the recess 65 a and fixed by the press-fitting. Is also possible.

  In this embodiment, the spacer 66 is formed of a material having a specific gravity higher than that of the ink liquid. However, the spacer 66 is formed of a material having a specific gravity lower than that of the ink liquid, thereby floating in the ink supply path 63 as a float. It is also possible to keep it. In this case, the floated spacer 66 is locked to the lower end of the connecting portion 64 by the base end portion 66d (see FIG. 13) of the cylindrical portion 67, but the protruding portion 66a is located below the base end portion 66d. Thus, the connection portion 64 is not completely blocked by the spacer 66, and the ink liquid is introduced into the enlarged portion 65 from above the protrusion 66a. Therefore, the spacer is generated by the suction force during the printing operation. Even if 66 cannot be lowered, the supply of ink liquid is not blocked. In addition, since a large suction force acts during the purge process, the spacer 66 is reliably pulled down, and the purge process can be performed without any problem.

  Further, when the spacer 66 is floated as a float, the floating spacer 66 may be tilted due to some factor, but a force that always tries to stand up acts on the cylindrical portion 67 inserted in the connection portion 64. Therefore, the inclination of the cylinder portion 67 is immediately corrected and the problem that the ink channel is blocked by the spacer 66 does not occur.

  In each of the above-described embodiments, the case where the inkjet heads 31 in which the ejection channel rows are aligned in two rows has been described. However, the ejection channel rows are not limited to two rows, and may be one or three rows. The present invention can also be applied to an inkjet head provided in rows or more.

  In the ink jet recording apparatus 1 described above, the purging process is performed by the ink sucking device 21 that sucks from the nozzle plate 34 side of the ink jet head 31, but the purging process is not necessarily performed by such a sucking unit. The purge process may be performed by an ink pushing means for pushing a new ink liquid from the cartridge side to the ink jet head side.

1 is a schematic view showing an embodiment of an ink jet recording apparatus according to the present invention. It is a fragmentary sectional view which shows an inkjet recording device same as the above. It is a perspective view which shows the manifold currently used for the inkjet recording device same as the above. It is a bottom view which shows a manifold same as the above. FIG. 5 is a cross-sectional view taken along line XX in FIG. 4. FIG. 5 is a cross-sectional view taken along line YY in FIG. 4. It is sectional drawing along the ZZ line of FIG. It is a fragmentary sectional view which shows the inkjet recording device which uses a different manifold. It is a bottom view which shows a manifold same as the above. FIG. 10 is a cross-sectional view taken along line XX in FIG. 9. It is sectional drawing along the YY line of FIG. FIG. 10 is a cross-sectional view taken along line ZZ in FIG. 9. It is a perspective view which shows the spacer accommodated in the manifold same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet recording apparatus 21 Ink suction apparatus 30 Head unit 31 Inkjet head 32 Actuator 33 Ejection channel 33a Ink supply port 34 Nozzle plate 40, 60 Manifold 43, 63 Ink supply path 43a, 63a Ink inlet 44, 64 Connection part 45, 65 Enlarged part 45c Guide part 46 Float 50 Ink cartridge 66 Spacer

Claims (10)

An ink jet head provided with a plurality of ink storage chambers for storing ink to be ejected and arranged in a plurality of rows, and the ink jet head and an ink supply source are connected to each other. In an inkjet recording apparatus comprising a manifold having an ink supply path for supplying ink from the ink supply source,
The ink supply path extends from a connection portion connected to the ink supply source to a row end formed by the ink supply ports of the plurality of aligned ink storage chambers. A guide member for guiding the ink supplied from the connecting portion along the inner surface of the enlarged portion, and the guide member has a specific gravity smaller than that of the ink. An ink jet recording apparatus characterized by being a float that can be moved by the flow of ink. The enlarged portion is curved so that the inner surface of the enlarged portion extends from the connecting portion side toward the row end formed by the ink supply ports of the plurality of aligned ink storage chambers and protrudes inward. A first curved surface, and a second curved surface that is continuous with the first curved surface, extends in a tapered shape toward the row end, and is curved to protrude outwardly,
The guide member is positioned so as to cover the plurality of ink supply ports from above, and the guide member allows the ink supplied from the connection portion to be applied to the first curved surface of the enlarged portion facing the ink supply port. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus guides in a direction substantially along.   The connection portion is positioned corresponding to the approximate center of the row formed by the plurality of ink supply ports, and the enlarged portion is substantially extended from the connection portion toward an end portion of the row formed by the plurality of ink supply ports. The inkjet recording apparatus according to claim 2, wherein the ink jet recording apparatus extends symmetrically and the guide member has a substantially symmetrical shape with respect to the connection portion.   A plurality of ink storage chambers that are detachably connected to the ejection openings, and that have suction means for supplying ink from the ink supply source to the ink supply path; 4. The ink jet recording apparatus according to claim 1, wherein when ink is supplied from a supply source, the ink is guided toward a row end of the ink supply port. 5.   The inkjet recording apparatus according to claim 1, wherein the float is spherical.   The enlarged portion of the ink supply path is positioned so as to cover the plurality of ink supply ports from above, the connection portion is opened in a ceiling portion of the enlarged portion, and the float 6. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is capable of floating in a direction to close the connecting portion away from an ink supply port.   The said expansion part has a guide part which protrudes toward the said float from the inner surface, and controls the movement path | route of the said float, The 1, 2, 3, 4, 5 or 6 characterized by the above-mentioned. Inkjet recording apparatus.   The ink storage chamber of the ink jet head is provided in a plurality of rows, and the guide portion is inserted from both ends between rows formed by ink supply ports of the ink storage chambers arranged in a plurality of rows. 8. An ink jet recording apparatus according to item 7. The float communicates with the plurality of ink supply ports from the portion corresponding to the connection portion to the inner surface of the enlarged portion over substantially the entire length of the enlarged portion along a row formed by the plurality of ink supply ports. The inkjet recording apparatus according to claim 1, 2, 3, or 4, wherein a narrow flow path is formed.   The inkjet recording apparatus according to claim 9, wherein the float includes a portion inserted into the connection portion.

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