JP2004276620A - Ink feed structure of image recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce manufacturing costs of connecting members to be arranged along an ink introduction tube and an ink discharge tube, both to circularly feed ink from a storage tank to a recording head, and also to prevent bubble retention in an ink passage in the connecting members, in an ink feed structure of an image recording apparatus. <P>SOLUTION: A seal rubber 30a to be used for the connecting member 30 on the ink introduction tube 21a side, and a seal rubber 31a for the connecting member 31 on the ink discharge tube 22a side are made into the same shape for common use. Further, the one seal rubber 30a and one first joint member 30b are tapered, and a filter 32 is provided inside. The other first joint member 31b is made to have a top of protruded shape 31b-1 to be fitted in the seal rubber 31a. As a result, no steps are generated in the ink passage, and thereby no bubbles in the ink are retained therein when the bubbles ascend under their buoyancy. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet type image recording apparatus, and more particularly to an ink supply structure for connecting a storage tank for storing ink and a recording head with an ink supply pipe.

  2. Description of the Related Art Conventionally, in an image recording apparatus, there is an ink supply structure in which an ink storage tank and a recording head are connected by an ink supply pipe. As such a structure, the ink supply pipe is composed of an ink introduction pipe that guides ink from the ink storage tank to the print head, and an ink discharge pipe that discharges ink from the print head to the ink storage tank. 2. Description of the Related Art There has been known a configuration in which ink is circulated between recording heads. FIG. 26 is a diagram showing a schematic configuration of the ink supply structure considered by the present inventors. In the image recording apparatus 100, connecting members 40 and 41 are provided in the middle of the ink introduction pipe 21a and the ink discharge pipe 22a from the sub ink tank 4a to the recording head 5a. Two flow paths are provided, each communicating with the ink discharge pipe 22a, and each of the flow paths is provided with a filter 42 for removing foreign substances and the like in the ink. In this case, the flow direction of the ink when passing through the filter 42 is such that one of the ink introduction pipe 21a and the ink discharge pipe 22a is directed upward and the other is directed downward. Alternatively, both may be turned sideways.

  In this type of ink supply structure, a detachable connection member is provided on the way of the ink introduction pipe and the ink discharge pipe regardless of the presence or absence of a filter. And an ink introduction pipe on the ink storage tank side, and an ink discharge pipe on the recording head side and the ink storage tank side. In the configuration of this connection portion, the number of parts increases, a step or a gap is easily formed in the flow path, and bubbles are easily retained. If these bubbles gradually become larger, it becomes impossible to secure the ink flow rate.

  Japanese Patent Application Laid-Open No. 5-318761 discloses that when a recording head is mounted on a carriage, the displacement of the connection member and the ink introduction tube and the ink discharge tube is eliminated by the elasticity of a seal rubber provided on the connection member. Has been proposed.

JP-A-5-318762

  The present invention provides a connecting member for connecting the respective flow paths of the ink introduction tube and the ink discharge tube, wherein the components of the connection member can be shared between the ink introduction tube side and the ink discharge tube side, thereby reducing the number of parts and connecting. An object of the present invention is to provide an ink supply structure of an image recording apparatus that can reduce the manufacturing cost of a member and can obtain a good recording result without bubbles remaining in a connecting member.

  In order to achieve the above object, an ink supply structure of an image recording apparatus according to claim 1, wherein a storage tank for storing ink and a recording head for ejecting ink are connected by an ink introduction pipe and an ink discharge pipe. An ink supply structure of an image recording apparatus that circulates ink between a storage tank and a recording head by a circulation pump using an ink introduction tube and an ink discharge tube, and supplies the ink to the recording head. The ink discharge pipe is configured to be connected via a connecting member in the middle of the flow path, and the connection member in one of the flow paths of the ink introduction pipe and the ink discharge pipe has an ink flow path having a shape whose opening end side is expanded. A passage member having a seal member formed on the inner surface, and an open end coupled to the open end of the seal member, the inner surface of the open end having an open end side expanding. And a joint member having a flow path formed therein. A filter is provided at both ends of the opening, and the other connecting member is a seal member formed substantially in the same shape as the seal member and an ink flow of the seal member. A convex shape corresponding to the shape of the path is formed on the outer surface, fitted into the open end of the seal member, and a joint member having an ink flow path formed on the inner surface.

  An ink supply structure for an image recording apparatus according to a second aspect is the ink supply structure for an image recording apparatus according to the first aspect, wherein the outer surface on the opening end side has a convex shape instead of the other connecting member. A seal member having an ink flow path formed on the inner surface thereof, and a joint member formed substantially in the same shape as the joint member on the one connecting member side, and the opening end of the seal member being fitted to the inner surface of this shape. Is used.

  The ink supply structure of the image recording apparatus according to claim 3 is the ink supply structure of the image recording apparatus according to claim 1 or 2, wherein the shape expanding toward the opening end is a tapered shape, The convex shape is a shape that comes into pressure contact with the tapered surface.

  An ink supply structure for an image recording apparatus according to a fourth aspect is the ink supply structure for an image recording apparatus according to any one of the first to third aspects, wherein a joint member forming each connection member is integrally formed. Formed.

  An ink supply structure for an image recording apparatus according to a fifth aspect is the ink supply structure for an image recording apparatus according to any one of the first to fourth aspects, wherein each connection member includes a joint member of a seal member. The second joint member is connected to the open end opposite to the side to which is coupled.

  An ink supply structure for an image recording apparatus according to a sixth aspect is the ink supply structure for an image recording apparatus according to any one of the first to fifth aspects, wherein each connection member has a recording head mounted thereon. Attached to the head unit.

  In the configuration of the first aspect, the seal member of the other connection member has substantially the same shape as the one seal member, and the seal member has a convex shape corresponding to the shape of the ink flow path of the seal member. Since the joint member formed on the outer surface and having the ink flow path formed on the inner surface thereof is fitted, when the two members are fitted, a step does not occur in the ink flow path in the seal member, and the connection member has The bubbles contained in the ink are less likely to stay in the ink flow path, and the flow of the ink is not hindered. Moreover, the same shape of the seal member can be used on the ink introduction tube side and the ink discharge tube side, so that these members can be shared and the number of parts of the connection member can be reduced.

  Further, in the configuration of the second aspect, as the sealing member of the other connecting member, one having an outer surface on the opening end side formed in a convex shape and an ink flow path formed on the inner surface is used. Since a joint member having substantially the same shape as the joint member on one connecting member side is fitted, both joint members can be shared, and the number of parts can be reduced.

  According to the third aspect of the present invention, when the seal member and the joint member are fitted, the convex shape presses against the tapered ink flow path, so that both members can be securely fitted. it can.

  In the configuration of the fourth aspect, the assembly of the joint member to the seal members on both the ink supply side and the ink discharge side can be performed in one step.

  In the configuration according to the fifth aspect, the ink introduction pipe and the ink discharge pipe on the storage tank side are connected to the opening end of the seal member opposite to the side to which the joint member is joined via the second joint member. By doing so, the ink introduction pipe and the ink discharge pipe on the recording head side and the storage tank side can be connected to each other.

  According to the configuration of the sixth aspect, the connection of the ink introduction pipe and the ink discharge pipe on the recording head side and the storage tank side can be stably held by the head unit.

  Hereinafter, an ink supply structure of an image recording apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an ink supply structure of an image recording apparatus to which the present invention is applied. The image recording apparatus 1 includes a head unit 2 for performing recording by ejecting ink to a recording medium (paper) P, ink tanks 3a to 3d filled with ink supplied to the head unit 2, Sub-ink tanks (storage tanks) 4a to 4d are provided in a path for supplying the ink in the tanks 3a to 3d to the head unit 2 and temporarily store the supplied ink. The ink is circulated between the sub ink tanks 4a to 4d.

  The head unit 2 is provided with four recording heads 5a to 5d for color recording, and ink is supplied to each of these recording heads 5a to 5d from the ink tanks 3a to 3d and the sub ink tanks 4a to 4d. Configuration. The head unit 2 is detachably mounted on a carriage 6 configured to be movable in a horizontal and horizontal direction along the recording medium P. The carriage 6 is supported slidably in the horizontal direction by guide bars 8 and guide rails 9 extending in the horizontal direction, and faces the recording medium P using a driving force from the carriage motor 11 transmitted by the timing belt 10 as a driving source. Scanning movement. At a position facing the recording heads 5a to 5d, a paper feed roller 13 for conveying the recording medium P is provided, and the paper feed roller 13 is rotated by a driving mechanism including a paper feed motor (not shown) and the like. The recording medium P is sequentially moved in a direction orthogonal to the moving direction of the carriage 6.

  A purge device 15 and a wiper 16 are provided on the side of the paper feed roller 13 as a maintenance unit. In the recording heads 5a to 5d, jetting failure may occur due to the formation of air bubbles inside the recording head or the adhesion of ink droplets on the nozzle surface where the jetting nozzle is opened. There is a purge device 15 and a wiper 16 for restoring a good injection state. The purging device 15 has a suction cap 15a that is in close contact with the nozzle surfaces of the recording heads 5a to 5d, and sucks bubbles, defective ink, and the like inside the recording heads 5a to 5d by the negative pressure generated by the pump 15b. The sucked defective ink is sent to the storage unit 15c. The wiper 16 is for wiping ink residue or the like adhered to the nozzle surfaces of the recording heads 5a to 5d. A capping device 17 is provided beside the purge device 15 to prevent the recording heads 5a to 5d from drying during a pause.

  The ink tanks 3a to 3d and the sub ink tanks 4a to 4d are connected by ink conduits 19a to 19d, and a pump 20a for supplying ink from the ink tanks 3a to 3d is connected to the ink conduits 19a to 19d. To 20d are provided. The sub ink tanks 4a to 4d and the recording heads 5a to 5d are connected by ink supply tubes, that is, ink introduction tubes 21a to 21d and ink discharge tubes 22a to 22d. Pumps 23a to 23d that supply ink from the sub ink tanks 4a to 4d are provided in the ink introduction tubes 21a to 21d. Further, valves that can be opened and closed (represented by 29a in FIG. 2) are arranged in the middle of the ink discharge pipes 22a to 22d. A plurality of partition plates are arranged in each of the sub ink tanks 4a to 4d, and the ink flowing from the ink tanks 3a to 3d and the ink discharge tubes 22a to 22d into the sub ink tank is supplied to the ink introduction tubes 21a to 21d. When the ink flows in a meandering manner between the partition plates before being supplied, air bubbles contained in the ink are separated by buoyancy and released to the atmosphere.

  FIG. 2 shows a first reference example of the ink supply system of the image recording apparatus 1, and shows a schematic configuration of the ink supply system for the recording head 5a among the recording heads 5a to 5d. Hereinafter, the ink supply system for the recording head 5a will be described, but the ink supply system for the recording heads 5b to 5d has the same configuration. The recording head 5a includes an actuator 25 in which a plurality of ink chambers are formed, a nozzle plate 26 in which a nozzle hole for ejecting ink in the ink chamber is formed, and ink from the ink introduction pipe 21a. It has a manifold 27 for distribution to the chambers. The ink introduction pipe 21a and the ink discharge pipe 22a are connected to the manifold 27. The ink introduction pipe 21a on the head unit 2 side, the ink introduction pipe 21a on the ink tank 3 side, and the ink discharge pipe 22a on the head unit 2 side. The ink discharge pipes 22a on the ink tank 3 side are connected via connection members 304 and 314 provided on the carriage 6, respectively.

  The connection member 304 is provided on the ink introduction tube 21a. The connection member 304 includes a first joint member 306 having an inner surface formed with a tapered ink flow path whose opening end side is expanded, and connected to the ink introduction tube 21a on the head unit 2 side. A second ink channel having an open end coupled to the ink inlet tube 21a on the side of the sub ink tank 4a is formed with an open end connected to the ink inlet tube 21a on the side of the sub ink tank 4a. And a joint member 305. The first joint member 306 is provided with a filter 32 for removing foreign matters and the like in the ink. The second joint member 305 is attached to the carriage 6, and the first joint member 306 is attached to a lower part of the head unit 2. As a result, the ink introduction pipe 21a on the sub ink tank 4a side on the upstream side is arranged on the carriage 6, and the ink introduction pipe 21a on the head unit 2 side on the downstream side is arranged from the upper part of the carriage 6. When passing through the filter 32 in the first joint member 306, the filter 32 moves upward from below.

  The connection member 314 provided on the ink discharge pipe 22a is connected to the ink discharge pipes 22a on both the sub ink tank 4a side and the head unit 2 side, and is provided on the carriage 6 adjacent to the connection member 304. . Further, the ink discharge pipe 22a and the manifold 27 are connected via a connection member 35 formed on the inner surface thereof with a tapered ink flow path whose opening end side on the manifold 27 side is expanded. A filter 36 for removing foreign matters and the like in the ink is provided. The manifold 27 has a tapered shape in which the opening end side of the ink flow path at the connection portion 27a with the connection member 35 is expanded. A connecting portion 27a of the manifold 27 with the connecting member 35 is disposed above the manifold 27, and has an open end formed upward. The connecting member 35 is attached to the upper part of the connecting portion. Thus, when the ink flows from the manifold 27 to the ink discharge pipe 22a, the ink moves from below the filter 36 to above.

  The flow of ink in the ink circulation system will be described. When the valve 29a is opened and the pump 23a is driven, the manifold 27 is filled with ink from the sub ink tank 4a via the ink introduction pipe 21a. The surplus ink returns to the sub ink tank 4a via the ink discharge pipe 22a. While the manifold 27 is being filled with ink, the ink circulates between the sub-ink tank 4a and the recording head 5a through the filters 32 and 36. Then, the purge device 15 is brought into contact with the nozzle plate 26 to perform a suction operation, whereby the ink filled in the manifold 27 is filled in each ink chamber of the recording head 5a. Thereafter, the operation of the pump 23a is stopped at a position where the ink introduction tube 21a is not closed, and the valve 29a is closed. When ink is ejected from the recording head 5a by the recording operation, that is, when the ink is consumed, the ink is supplied from the sub-ink tank 4a to the manifold 27 via the ink introduction pipe 21a. In order to prevent bubbles contained in the ink in the circulation path from gradually coalescing and growing to narrow or close the flow path, the valve 29a is opened periodically or by manual operation, and the pump is operated. By driving 23a, the ink is circulated between the sub-ink tank 4a and the recording head 5a as described above. Thereby, the air bubbles in the ink introduction pipe 21a, the manifold 27, and the ink discharge pipe 22a are collected in the sub ink tank 4a, and are separated by buoyancy while the ink flows meandering as described above. As a result, the ink with reduced bubbles is supplied to the manifold 27 from the ink introduction tube 21a.

  The amount of ink stored in the sub ink tank 4a is detected by a liquid level sensor (not shown), and the pump 20a (see FIG. 1) based on the detection value of the liquid level sensor so that a predetermined stored amount is always maintained. ) Is controlled, and ink is supplied from the ink tank 3 to the sub ink tank 4a.

  In the illustrated example, the pump 23a is of a type in which a plurality of rollers are sequentially moved while crushing the flexible ink introduction tube 21a, but other known types can also be used.

  As described above, according to the image recording apparatus 1 of the present embodiment, when the ink passes through the filter 32 provided on the connection member 304 and the filter 36 provided on the connection member 35, the ink is filtered by the filters 32 and 36. Moves upward from below, the air bubbles flowing from the upstream along with the ink easily pass through the filters 32 and 36 located above due to the buoyancy, and are less likely to be trapped by the filters 32 and 36. This prevents bubbles from remaining in the filters 32 and 36, so that the effective area of the filters 32 and 36 is increased, the flow rate of ink required for recording can be ensured, and recording defects are less likely to occur. In addition, a smooth ink flow can be realized because a damper effect does not occur during ink circulation or ink suction by the purge device 15.

  Note that the image recording apparatus 1 is not limited to the configuration of the above-described reference example, and various modifications are possible. For example, in the above reference example, the filters 32 and 36 provided in the ink introduction pipe 21a and the ink discharge pipe 22a are arranged on the first joint member 306 and the connection member 35 connected to the manifold 27. If the filter 30 is sandwiched between the member 30a and the coupling portion 27a, or both, or if the ink passes through the filter portion so as to move from below to above, the other portion in the image recording apparatus 1 May be arranged at the position.

  Next, a second reference example of the ink supply structure will be described with reference to FIG. FIG. 3 is a diagram showing a schematic configuration of the ink supply system, and shows the ink supply system for the recording head 5a. In the drawing, the connection member is not connected to the ink introduction pipe 21a and the ink discharge pipe 22a on the side of the sub ink tank 4a. The manifold 27 ′ of the recording head 5 a provided in the image recording apparatus 1 ′ is not configured to be connected to the ink discharge pipe 22 a via the connecting member 35 as in the manifold 27 of the first reference example. The discharge pipe 22a is configured to be directly connected. The ink introduction pipe 21a and the ink discharge pipe 22a on the sub ink tank 4a side and the ink introduction pipe 21a and the ink discharge pipe 22a on the head unit 2 side are connected via connection members 40 and 41.

  The connection member 40 is formed with an ink flow path for guiding ink to the recording head 5a and an ink flow path for discharging ink from the recording head 5a. The connection member 41 has an ink introduction channel and a discharge channel formed corresponding to each ink channel in the connection member 40. At a connection portion between the connection member 40 and the connection member 41, a filter 42 having a size set to cover both the ink supply passage and the discharge passage of the connection members 40 and 41 is provided. I have. With the connection members 40 and 41, the ink circulating in the ink introduction pipe 21a and the ink discharge pipe 22a is configured to pass through the filter 42 on both the outward path and the return path to the recording head 5a. In the same manner as in the first embodiment, the ink introduction pipe 21a and the ink discharge pipe 22a are connected to the connection members 40 and 41 so as to move upward from below the filter 42 and pass through the filter 42. Details of the configuration of the connection members 40 and 41 and the filter 42 will be described in detail below.

  The configurations of the connection members 40 and 41 and the filter 42 in the image recording apparatus 1 'will be described with reference to FIGS. 4 is an exploded perspective view of the connection member and the filter, FIG. 5 is a side sectional view before the connection member and the filter are incorporated, and FIG. 6 is a plan view of the connection member 41. As described above, the ink flow paths for ink supply and ink discharge are formed in the connection members 40 and 41, respectively. When the connection members 40 and 41 are combined, they are formed in the connection members 40 and 41. The positions of the respective ink flow paths are set to match.

  4 and 5, the connection pipe 40a provided at one end (the left end in FIG. 4) of the connection member 40 is different from the connection pipe 41a provided at the other end (the right end in FIG. 4) of the connection member 41. It is set to correspond. By connecting the connection member 40 and the connection member 41, an ink flow path 44 connecting the connection pipe 40a and the connection pipe 41a is formed inside the connection members 40 and 41. 5, the ink flowing from the connection pipe 41a of the connection member 41 moves from the right end to the left end through the ink flow path 44 and is connected to the connection pipe 40a of the connection member 40. Spilled out of. Further, the connection pipe 40b of the connection member 40 and the connection pipe 41b of the connection member 41 are connected in the same manner as described above, and the ink flowing from the connection pipe 41b of the connection member 41 is adjacent to the ink flow path 44. The ink flows out of the connection pipe 40b of the connection member 40 through the ink flow path 45 provided.

  Further, on the surface where the connecting member 40 is connected to the connecting member 41, a convex portion 40c for aligning the ink flow paths 44 and 45 formed in the two connecting members 40 and 41 with each other is provided. A concave portion 41c having a shape corresponding to the convex portion 40c is provided on a surface of the connecting member 41 connected to the connecting member 40. By fitting the filter 42 inside the concave portion 41c to cover the entire ink flow paths 44 and 45 and incorporating the convex portion 40c into the concave portion 41c, the three members can be easily and reliably positioned. . After assembly, the ink flow paths 44 and 45 are securely sealed by welding or bonding the connecting members 40 and 41 across the filter 42 using a means such as heat or ultrasonic waves. it can.

In the connecting members 40 and 41 configured as described above, the connecting pipes 40a and 41a of the ink flow path 44 and the connecting pipes 40b and 41b of the ink flow path 45 are connected to the ink flow paths 44 and 45, respectively. Are positioned at both ends of the filter 42, that is, are shifted from each other, so that when the ink moves in the connection members 40 and 41, the ink passes through the relatively long areas of the filters 42 corresponding to the ink flow paths 44 and 45, respectively. Will be.
Accordingly, the contact area between the ink and the filter 42 increases, so that foreign substances and the like generated in the ink can be efficiently removed.

  Next, a third reference example will be described with reference to FIGS. FIG. 7 is an exploded sectional view of a head unit provided in an ink supply structure of an image recording apparatus according to a third reference example, FIG. 8 is a sectional view showing a process of mounting an ink cartridge on this head unit, and FIG. FIG. 3 is a cross-sectional view illustrating a state where an ink cartridge is mounted on the unit. The ink supply structure of this image recording apparatus is configured such that ink is supplied to a recording head 5a from an ink cartridge (storage tank) 50 that is removably mounted on the head unit 2, and the recording head 5a is a side surface of the head holder 2a. Is mounted via a manifold 51. An ink supply port 50a is provided at an upper portion of the ink cartridge 50. An ink flow path 51a in the manifold 51 has an open end opened downward, extends upward from below, and has a recording head along the flow path. It is bent in the direction of the 5a side. The opening end of the ink flow path 51a is communicated with the ink supply port 50a through a seal rubber 52, and a filter 53 is provided on an end face of the seal rubber 52 that abuts with the ink flow path 51a. The manifold 51 and the seal rubber 52 function as an ink introduction path. The mounting position of the manifold 51 to the head holder 2a is fixed by the manifold holder 54.

  The ink cartridge 50 is loaded into the head holder 2a by inserting the ink cartridge into the head holder 2a such that the ink supply port 50a of the ink cartridge 50 faces the lower part of the seal rubber 52 and the filter 53. This is performed by engaging the convex portion 50b at the rear of the cartridge 50 with a fixed claw 2b provided on the head holder 2a. With this configuration, when the ink is sucked from the ink ejection side of the nozzle provided on the print head 5a by the purge device 15 (FIG. 1) at the time of printing, the ink flows out of the ink supply port 50a of the ink cartridge 50. The ink passes through the seal rubber 52 and the filter 53 located above the ink, and is introduced into the recording head 5a through the ink flow path 51a. Further, ink is supplied from the ink cartridge 50 due to the pressure drop generated during the ink ejection. Therefore, when the ink passes through the filter 53, the ink moves upward from below the filter 53, so that the bubbles flowing with the ink easily pass through the filter 53 located above due to its buoyancy, and are trapped by the filter 53. Is less likely to be done. In particular, when the ink cartridge 50 is loaded, a large amount of air bubbles sandwiched between the ink supply port 50a and the filter 53 is less likely to be trapped.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a diagram showing a schematic configuration of an ink supply system as in FIG. 2, FIG. 11 is a cross-sectional view showing the configuration of the connection members 30 and 31, and FIG. 13 is a perspective view of each member of the connection members 30, 31, the joint holder, and the head holder.

  In this embodiment, particularly, the connection members 30, 31 in the first reference example are changed. The connection member 30 provided in the ink introduction tube 21a includes a seal rubber (seal member) 30a formed of an elastic material such as a rubber material in a cylindrical shape, and a first joint member 30b connected to the seal rubber 30a. Consists of The seal rubber 30a has a tapered ink flow path 30a-1 at the end coupled to the first joint member 30b, the tapered ink flow path 30a-1 expanding toward the open end, and the tapered ink flow path 30a-1. It has a cylindrical portion 30a-2 outside of 30a-1. The first joint member 30b has a tapered ink flow path 30b-1 that expands toward the seal rubber 30a side at an open end, and the tapered ink flow paths 30a-1 and 30b-1 of both the tapered ink flow paths 30a-1 and 30b-1. The largest diameter portion is opposed to the inner periphery of the cylindrical portion 30a-2 so as to be detachable. The sealed state between the two is ensured on the outer periphery of the largest diameter portion that abuts on the inner periphery of the cylindrical portion 30a-2. A filter 32 for removing foreign matter and the like in the ink is provided at the maximum diameter portion of the tapered ink flow paths 30a-1 and 30b-1. The filter 32 may be fixed to either the first joint member 30b or the seal rubber 30a, or may be sandwiched between both. Since the diameter of the ink flow path provided in the seal rubber 30a and the first joint member 30b is largest at the portion where the filter 32 is provided, the contact area between the ink and the filter 32 is increased, and the ink is efficiently discharged. It is possible to remove foreign substances and the like inside. The other end 30a-3 of the seal rubber 30a is also formed in a tapered shape that expands toward the opening end, and the second joint member 30c is detachably fitted to the inner periphery through the tapered portion in a sealed state. Are combined. The first joint member 30b is connected to the ink introduction tube 21a on the head unit 2 side, and the second joint member 30c is connected to the ink introduction tube 21a on the sub ink tank 4a side.

  The connection member 31 provided in the ink discharge pipe 22a includes a seal rubber 31a equivalent to the seal rubber of the connection member 30, and a first joint member 31b connected to the seal rubber 31a. The first joint member 31b has a tapered convex shape 31b-1 corresponding to the seal rubber 31a so as to be inserted into the tapered ink flow path 31a-1 on the outer periphery of the end portion connected to the seal rubber 31a. It is formed and is detachably fitted to the inner periphery of the cylindrical portion 31a-2 of the seal rubber 31a. The seal between the first joint member 31b and the seal rubber 31a is made by one or both of the tapered ink flow path 31a-1 and the cylindrical portion 31a-2. As in the case of the connection member 30, the second joint member 31c is detachably fitted in a sealed state to the inner periphery of the seal rubber 31a through the tapered portion 31a-3 of the seal rubber 31a. On the inner surface of the first joint member 31b, a straight ink flow path having substantially the same diameter as the inner surface of the intermediate portion of the seal rubber 31a is formed, and when the first joint member 31b is fitted to the seal rubber 31a, the inner surface of the intermediate portion of the seal rubber 31a is formed. It is designed not to make large steps. The inner diameter of the second joint member 31c is also formed close to the inner diameter of the intermediate portion of the seal rubber 31a, and a substantially straight ink flow path is formed in the connection member 31. The first joint member 31b is connected to the ink inlet tube 22a on the head unit 2 side, and the second joint member 31c is connected to the ink inlet tube 22a on the sub ink tank 4a side.

  The seal rubbers 30a, 31a of the connection members 30, 31 and the first joint members 30b, 31b are attached to a head holder 2c, which is an outer case of the head unit 2, by a joint holder (attachment member). The joint holder 38 has a convex portion 38b that fits into a concave groove on the outer periphery of the seal rubbers 30a, 31a so as to hold the two seal rubbers 30a, 31a in parallel. The joint holder 38 is provided with a convex portion 38c protruding inward at an end on the first joint member 30b, 31b side, and the first joint member 30b, 31b fitted to the seal rubber 30a, 31a. The convex portion 38c is engaged with the outer peripheral step portion to prevent the first joint members 30b and 31b from coming off. The convex portion 38c is provided so as to have an elastic force so as to be deformable in the outward direction so as to allow the first joint members 30b, 31b to be fitted to the seal rubbers 30a, 31a.

  An outwardly protruding engaging portion 38a is provided on the outer peripheral surface of the joint holder 38, and an engaging portion (holding portion) 2a is provided on the upper surface of the head holder 2c so as to surround the two openings 2b, 2b. The locking portion 38a is locked to the locking portion (holding portion) 2a, so that the joint holder 38 is mounted on the head holder 2c. The locking portion 38a and the locking portion 2a are provided so as to have an elastic force so as to be deformable in a direction in which locking is possible, that is, inward and outward of the joint holder 38 at the time of locking. The joint holder 38 is attached to the head holder 2c by fitting the joint holder 38 into the locking portion 2a of the head holder 2c from above.

  As shown in FIG. 11, after the joint holder 38 is attached to the head holder 2c, the locking portion 38a of the joint holder 38 has a slight play r with respect to the locking portion 2a of the head holder 2c. Is configured. The joint holder 38 restricts the movement of the connecting members 30 and 31 in the axial direction by the locking between the locking portion 38a and the locking portion 2a. However, due to the play, the joint holder 38 is substantially perpendicular to the axial direction. A slight movement in the horizontal plane on the head holder 2c is possible.

  A positioning pin 2d for positioning the head unit 2 with respect to the carriage 6 is provided below the head holder 2c, which is an external case of the head unit 2. The carriage 6 is provided with a concave portion 6a having a size corresponding to the positioning pin 2d, and further, a second joint member 30c to which the ink introduction tube 21a and the ink discharge tube 22a on the sub ink tank 4a side are connected. , 31c are integrally formed or fixed.

  When the head unit 2 is mounted on the carriage 6, the positioning pins 2 d are fitted into the recesses 6 a to position the head holder 2 with respect to the carriage 6. Then, the second joint members 30 c and 31 c are moved to the head holder 2 c Through the openings 2b, 2b formed in the lower part, they are fitted into the seal rubbers 30a, 31a from the tapered openings at the lower ends of the seal rubbers 30a, 31a, respectively, and combined with the seal rubbers 30a, 31a (see FIG. 12). At this time, since the seal rubbers 30a and 31a held by the joint holder 38 can move in the horizontal and horizontal directions within the range of the play described above, the seal rubbers 30a and 31a are displaced from the second joint members 30c and 31c. Even if there is s, it can be corrected. Further, since the lower ends of the seal rubbers 30a and 31a are tapered, the second joint members 30c and 31c are further easily fitted into the seal rubbers 30a and 31a. Due to the connection of the two members, the ink introduction pipe 21a and the ink discharge pipe 22a on the head unit 2 side communicate with the ink introduction pipe 21a and the ink discharge pipe 22a on the sub ink tank 4a side via the connection members 30 and 31. Will be done. Further, when the head unit 2 is separated from the carriage 6, the ink introduction pipe 21a and the ink discharge pipe 22a can be easily divided into the head unit 2 side and the sub ink tank 4a side.

  As described above, according to the ink supply structure of the image recording apparatus of the present embodiment, the connection members 30 and 31 allow the ink to flow from bottom to top in the ink introduction pipe 21a and to flow from top to bottom in the ink discharge pipe 22a. , Are arranged vertically. As a result, in the connection member 30 on the side of the ink introduction tube 21a, the ink and the bubbles flowing from the bottom to the top pass through the filter 32 by buoyancy. In the connection member 31 on the side of the ink discharge pipe 22a, since the first joint member 31b does not form a large step with respect to the inner surface of the seal rubber 31a, bubbles in the ink stay there. The air bubbles flowing in the flow path are less likely to pass through the connecting member 31 smoothly. Therefore, a wide ink flow path is always ensured, and good recording results can be obtained.

  Further, the connection member 31 connected to the ink discharge tube 22a and the connection member 30 on the ink introduction tube 21a can be used in common because the seal rubber 30a has the same shape, so that the connection member is configured. The number of parts can be reduced, and the manufacturing cost can be reduced accordingly. Further, since the connecting members 30 and 31 are attached to the head holder 2c with a slight play r by the joint holder 38, when the head unit 2 is mounted on the carriage 6, the second joint members 30c and 31c are mounted. And the position of the connection members 30, 31 can be changed within the range of the play r, even if there is a displacement s between the opening ends of the seal rubbers 30a, 31a. Thereby, when attaching the head unit 2 to the carriage 6, even if there is a displacement s between the second joint members 30c, 31c and the opening ends of the seal rubbers 30a, 31a, the two members can be easily connected. be able to.

  In addition, in the connection member 30 provided on the way of the flow path of the ink introduction pipe 21a, a tapered ink flow path whose opening end side is expanded is formed on the inner surface of the seal member 30a and the first joint member 30b. Since the shape expands toward the filter 32, the ink can be appropriately introduced into the filter 32, and a separate component is not required for introducing the ink into the filter 32. Thus, the number of components of the connection member 30 is reduced, so that the process of assembling the components of the connection member 30 can be simplified, and the size of the connection member 30 can be reduced. Further, as will be apparent from a seventh reference example described later, also in the present embodiment, since the joint member and the seal member are in contact at the open end, an area where air bubbles stay is difficult to be formed, and ink bubbles are not generated by air bubbles. There is less obstruction of the flow.

  Next, a connection member according to a second embodiment will be described with reference to FIGS. FIG. 14 is a cross-sectional view showing the configuration of the connection member, and FIG. 15 is a cross-sectional view showing the connection state of the connection member. In this embodiment, the same connection member as the connection member 30 of the first embodiment is used as the connection member on the ink introduction tube 21a side. As the connection member 31 'on the ink discharge tube 22a side, the same as the first joint member 30b of the connection member 30 is used as the first joint member 31b', and the first joint member 31b 'is used as a seal rubber. A convex shape 31a'-4 is formed in which the outer surface of the end on the side coupled with the first joint member 31b 'is inserted into the tapered ink flow path 31b'-1 formed on the inner surface of the end of the first joint member 31b'. A seal rubber 31a 'is used.

  The convex shape 31a'-4 of the seal rubber 31a 'has a tapered shape fitted and pressed against the tapered surface of the first joint member 31b', and a straight ink flow path is formed on the inner surface thereof. ing. Other member configurations are the same as those of the connection members 30 and 31 in the first embodiment. Also in this case, no step is formed between the first joint member 31b 'and the seal rubber 31a' such that air bubbles stay.

  Next, a connection member according to a third embodiment will be described with reference to FIG. FIG. 16 is a cross-sectional view illustrating the configuration of the connection member. In this embodiment, the first joint members 30b and 31b related to the connection members 30 and 31 in the first embodiment are arm portions as first joint members on the ink introduction tube 21a side and the ink discharge tube 22a side. A first joint member 39 which is integrally formed through a portion 39a is used. Other components are the same as those of the connection members 30 and 31 described above. This can be similarly applied to the second embodiment. By thus integrally configuring the first joint member 39, the number of steps for attaching the connection member to the joint holder 38 can be reduced, and the productivity can be improved.

  Note that the above embodiments can be variously modified. For example, in each of the above embodiments, the shape of the ink flow path formed on the inner surfaces of the seal rubbers 30a, 31a and the first joint members 30b, 31b is a tapered shape expanding toward the opening end, but is limited to this shape. However, any other shape may be used as long as it can smoothly guide the ink. Further, the filter 32 may be provided on the connection member 31 side on the ink discharge tube 22a side, and the flow path on the ink introduction tube 21a side may be formed in a straight shape.

  Next, a connection member according to a fourth reference example will be described with reference to FIGS. In this reference example, the connection member 310 on the ink discharge tube 22a side has a seal rubber 310a in which a straight ink flow path is formed and a first joint member 310b. The configuration of other members is the same as that of the first embodiment. In this case, as in the first and second embodiments, the seal rubber or the first joint member cannot be used in common on the ink introduction tube side and the ink discharge tube side, but the connection member 30 on the ink introduction tube 21a side. At the point where, together with the ink flowing from bottom to top, the bubbles also pass through the filter 32 by buoyancy, the first joint member 310b forms a large step with respect to the inner surface of the seal rubber 310a in the connection member 310 on the ink discharge pipe 22a side. This is equivalent to the first and second embodiments in that air bubbles in the ink are less likely to stay there.

  Next, a connection member according to a fifth reference example will be described with reference to FIGS. In this reference example, the seal rubber 30a on the ink introduction tube side is commonly used as the connection member on the ink discharge tube 22a side, but the first joint member 310b has an internal seal member similar to the third embodiment. Has a straight ink flow path. The configuration of other members is the same as that of the first embodiment. In this case, the seal rubber can be used in common on the ink introduction tube side and the ink discharge tube side, but in the connection member on the ink discharge tube 22a side, the first joint member 310b is larger than the inner surface of the seal rubber 310a. A step is formed, and in this regard, the first and second embodiments are more preferable.

  FIG. 21 shows a connection member 300 on the ink supply tube side according to a sixth reference example. The connection member 300 is connected to the ink introduction tube 21a on the recording head side, and includes a joint member 301 having the filter 32, a joint member 302 connected to the joint member 301, and a seal rubber 303 connected to the joint member 302. Have. Each of the joint members 301 and 302 has a tapered ink flow path in which the open end side is expanded. The second joint member connected to the ink introduction pipe on the sub ink tank side is fitted to the lower end of the seal rubber 303 as in the above-described embodiment. The joint member 302 plays a role of guiding the ink flowing from the sub ink tank side to the filter 32 of the joint member 301. In this case, the connection member 300 is the same as in each embodiment and the reference example in that bubbles flowing from the bottom to the top together with the ink flowing through the filter 32 by buoyancy are the same as in each embodiment and the reference example. As compared with the other embodiments and the reference example, there is a disadvantage that the connection member 300 becomes large and the number of assembling steps increases.

FIGS. 22 and 23 show a connection member 30 'according to a seventh reference example.
The connection member 30 ′ integrally forms first joint members 30 b ′ and 31 b ′ connected to the ink introduction pipe 21 a and the ink discharge pipe 22 a on the head unit side (upper side in the drawing), respectively. A first composite joint member 39 provided with a filter 32 on the end face is used. As a seal rubber to be connected to the first composite joint member 39, a composite seal member 140 in which seal rubbers 30a 'and 31a' connected to the ink introduction pipe 21a and the ink discharge pipe 22a are integrally formed. Is used. The composite seal member 140 is held by a holding member 141, and the holding member 141 is attached to a carriage (not shown). The first composite joint member 39 is formed with a locking claw 39a, and the holding member 141 is formed with a locking claw 141a that engages with the locking claw 39a. Further, on the end face of the first composite joint member 39 joined to the end face of the composite seal member 140, a ridge 39b for locally deforming the member 140 to enhance the sealing effect is formed. The ink introduction pipe 21a and the ink discharge pipe 22a on the sub ink tank side (the lower side in the drawing) are directly connected to the composite seal member 140.

  The first composite joint member 39 and the composite seal member 140 having the above-described configuration are joined by abutting the ends of the respective members, and the joined state is determined by the locking claw portion of the first composite joint member 39. The holding member 141 is held by engagement with the locking claw 141a of the holding member 141. In a state where the two members are joined, the composite seal member 140 is deformed corresponding to the shape of the ridge 39b provided on the end surface of the first composite joint member 39, whereby the ink provided on the inner surfaces of both members is formed. Since the sealing effect is strengthened very close to the flow path and the filter 32, a gap is hardly generated between the ridge 39b and the ink flow path or the filter 32, and the accumulation of bubbles is reduced. Therefore, there is less possibility that the bubbles grow with time and narrow the ink flow path. Further, since the composite seal member 140 is directly connected to the ink introduction tube 21a and the discharge tube 22a, the number of components is reduced.

  FIGS. 24 and 25 show a connection member on the ink introduction tube 21a side according to the eighth reference example. In this reference example, the seal rubber 400 and the first joint member 30b are directly fixed to a cylindrical grip portion 2a 'provided on the head holder 2c'. The second joint member 130c as the connection member 130 is attached to the carriage 6 with a slight play r in a direction substantially perpendicular to the axial direction of the second joint member 130c. Specifically, an engaging portion (holding portion) 6b for holding the second joint member 130c is provided at a lower portion of the carriage 6, and the engaging portion 6b is provided on the outer periphery of the second joint member 130c. The mounting member 130d provided in a protruding manner in a flange shape is included, and the protruding portion 6b-1 provided to protrude from the inner periphery of the distal end of the engaging portion 6b falls off the second joint member 130c in the axial direction. Has been blocked. The protruding portion 6b-1 is elastically deformable in a direction that allows the second joint member 130c to be detachably fitted to the engaging portion 6b. The convex portion 130d is engaged with the engaging portion 6b with a slight play r in the horizontal direction. With this configuration, when the head unit 2 is mounted on the carriage 6, even if there is a displacement s between the opening end of the seal rubber 400 and the second joint member 130c, the second Since the joint member 130c can move freely in the horizontal and horizontal directions within the range of the play, the seal rubber 400 and the second joint member 130c can be accurately coupled.

  As described above, since the second joint member 130c is attached to the carriage 6 with some play r, when the head unit 2 is mounted on the carriage 6, the second joint member 30c and the seal rubber are mounted. The position of the second joint member 130c can be changed within the range of the play even if there is a displacement s between the opening end of the second joint member 130c and the opening end of the second joint member 130c. Accordingly, when the head unit 2 is mounted on the carriage 6, even if there is a displacement between the second joint member 130c and the opening end of the seal rubber 40, the two members can be easily connected. In this reference example, the second joint member 130c is movable, but the first joint member 130b may be movable in a similar configuration. Further, the configuration of the attachment member and the holding portion in the first embodiment can be applied to the second joint member side.

  Note that the present invention is not limited to the configuration of the above embodiment, and various modifications are possible. For example, the connection members 30 and 130 of the ink introduction tube 21a and the connection member 31 of the ink discharge tube 22a are independent of each other, or only one of them has some play with respect to the head holder 2c or the carriage 6. It is good also as composition which can be attached.

  As described above, the embodiments and the reference examples of the present invention have the following effects.

  (1) In an embodiment of the present invention, a storage tank for storing ink and a recording head for ejecting ink are connected by an ink introduction tube and an ink discharge tube, and a circulating pump is used by using the ink introduction tube and the ink discharge tube. Circulating the ink between the storage tank and the recording head, and supplying the ink to the recording head. The ink supply structure of the image recording apparatus, wherein the ink introduction pipe and the ink discharge pipe are connected to each other on the way of the flow path. And a connecting member in the middle of one of the flow paths of the ink introduction pipe and the ink discharge pipe, a seal member having an ink flow path formed on the inner surface with an opening end side expanding, A joint member having an open end coupled to the open end of the seal member, and an ink flow path having a shape in which the open end side is expanded on the inner surface of the open end. A filter is provided at both ends of the opening, and the other connecting member is formed on the outer surface with a seal member formed substantially in the same shape as the seal member and a convex shape corresponding to the shape of the ink flow path of the seal member. And a joint member fitted into the opening end of the seal member and having an ink flow path formed on the inner surface.

  Thereby, the seal member of the other connection member has substantially the same shape as the one seal member, and a convex shape corresponding to the shape of the ink flow path of the seal member is formed on the outer surface of the seal member. Since the joint member in which the ink flow path is formed on the inner surface is fitted, no step occurs in the ink flow path in the seal member in a state where both members are fitted, and the ink flow in the ink flow path in the connection member is eliminated. The air bubbles contained in the ink are less likely to stay, and the flow of ink is not hindered. Moreover, the same shape of the seal member can be used on the ink introduction tube side and the ink discharge tube side, so that these members can be shared and the number of parts of the connection member can be reduced.

  (2) In the above-described configuration, in the second embodiment, instead of the other connecting member, a sealing member having an outer surface on the opening end side formed in a convex shape and an ink flow path formed on an inner surface, and one connecting member side And a joint member which is formed in substantially the same shape as the above-mentioned joint member and has a joint member into which the open end of the seal member is fitted. Thus, as the sealing member of the other connecting member, one having an outer surface on the opening end side formed in a convex shape and an ink flow path formed on the inner surface is used. Since the joint members having substantially the same shape as the members are fitted, both joint members can be shared, and the number of parts can be reduced.

  (3) In the configuration of (1) or (2) above, the shape expanding to the opening end side is a tapered shape, and the convex shape is a shape pressed against the tapered surface. When the and the joint member are fitted, the convex shape presses against the tapered ink flow path, so that both members can be securely fitted.

  (4) In the configuration of any of the above (1) to (3), in the third embodiment, the joint members forming the connection members are integrally formed, so that the ink supply side and the ink discharge side are formed. Assembling of the joint member to both seal members can be performed in one step.

  (5) In any one of the constitutions (1) to (4), the ink introduction pipe and the ink discharge pipe on the storage tank side are connected to the joint member of the seal member via the second joint member. By connecting to the opening end opposite to the side, the ink introduction pipe and the ink discharge pipe on the recording head side and the storage tank side can be connected to each other.

  (6) Further, in any one of the above constitutions (1) to (5), each connection member is attached to a head unit on which a recording head is mounted, so that ink is introduced into each of the recording head and the storage tank. The connection between the tube and the ink discharge tube can be stably held by the head unit.

  (7) An ink supply structure of an image recording apparatus in which a storage tank for storing ink and a recording head for ejecting ink are connected by an ink supply pipe, and a filter for removing foreign matters and the like in the ink. Is provided in the ink supply pipe, and a part of the ink supply pipe is configured so that the ink flows upward from below the filter, and since the filter is disposed in that part, the ink passes upward from below the filter. Bubbles flowing along with the ink from the upstream of the filter in the ink supply pipe easily pass through the filter located above due to its buoyancy, and are less likely to be trapped by the filter. This prevents bubbles from remaining in the filter portion, and can increase the effective area of the filter.

  (8) In the configuration of the above (7), in the embodiment of the present invention and the first, second and eighth reference examples, the ink supply pipe is an ink introduction pipe for guiding ink from the storage tank to the recording head. And an ink discharge pipe for discharging ink from the recording head to the storage tank, wherein the ink is circulated between the storage tank and the recording head by a circulation pump through the ink supply pipe and the ink discharge pipe. This makes it possible to circulate the ink between the storage tank and the recording head, and collect the air bubbles that have passed through the filter as described above in the storage tank.

  (9) In the configuration of the above (8), a filter is provided in the ink introduction pipe and the ink discharge pipe, and a part of the ink introduction pipe and the ink discharge pipe is configured so that ink flows upward from below the filter. By arranging the filter in that portion, it becomes possible to circulate the ink between the storage tank and the recording head, and also in the ink discharge pipe, the retention of bubbles in the filter portion is prevented, The substantial effective area of the filter can be increased.

  (10) In the configuration of (9), the filter is provided in an ink introduction pipe and an ink discharge pipe on a carriage on which a recording head is mounted, so that ink passes through the filter from below to above. Thus, it is easy to configure the ink supply pipe.

  (11) In the embodiment of the present invention in the configuration of (10), in the first and fourth to eighth reference examples, the ink introduction tube on the carriage, the ink introduction tube on the storage tank side, and the ink on the carriage The discharge pipe and the ink discharge pipe on the storage tank side are connected via connection members provided on the carriage, respectively, and one of the filters provided on the ink introduction pipe and the ink discharge pipe is disposed in the connection member portion, By arranging the other at the connection portion with the recording head, the ink introduction tube and the ink discharge tube on the carriage and the ink introduction tube and the ink discharge tube on the storage tank side can be configured to be separable, Even when the head unit provided with the recording head is configured to be detachable from the carriage, there is no problem in the configuration, and the filter passes from below to above. It is easier to configure the ink inlet and the ink discharge tube so that.

  (12) In the second reference example of the above-mentioned (11), in the second reference example, the ink introduction tube on the carriage and the ink introduction tube on the storage tank side, and the ink discharge tube on the carriage and the ink discharge tube on the storage tank side Are connected via a connecting member in which an ink introduction flow path and a discharge flow path are respectively formed, and the recording head side opening of the ink introduction flow path is arranged with respect to the storage tank side opening of the ink introduction flow path. Also, the recording head-side opening of the ink discharge flow path is shifted from the storage tank-side opening of the ink discharge flow path, and the filter covers the ink introduction flow path and the discharge flow path, respectively. As described above, since the ink is provided in the connecting member, the ink moves between the recording head side opening and the storage tank side opening which are shifted in the connecting member. For this reason, the moving distance of the ink in the connecting member becomes long, so that when the ink passes through the connecting member, the contact area between the ink and the filter is widened, and foreign matters and the like can be efficiently removed.

  (13) In the above configuration (7), the storage tank is configured to be detachably connected to the ink supply pipe, so that a large amount of air bubbles entering when the storage tank is connected to the ink supply pipe is generated as described above. The filter easily passes from the bottom to the top, and trapping can be reduced.

  (14) The embodiment and the seventh reference example of the present invention relate to an ink supply structure of an image recording apparatus that performs recording by ejecting ink supplied from an ink storage tank through an ink supply path from a recording head. The ink supply path includes an ink supply pipe disposed between the ink storage tank and the printhead, and an ink supply pipe on the ink storage tank side and an ink supply pipe on the printhead side along the flow path of the ink supply pipe. A connection member for connecting the supply pipe is provided. The connection member has a seal member in which an ink flow path having an open end side is formed on an inner surface, and an open end coupled to the open end of the seal member. And a joint member in which an ink flow path having a shape in which the opening end side is expanded is formed on the inner surface of the opening end, and a filter is provided at one of the both tapered opening ends.

  Thereby, the connecting member provided on the way of the flow path of the ink supply pipe is constituted by two members, a seal member and a joint member, and an ink flow path having a shape in which the open end side is expanded on the inner surface of the seal member is formed. A filter is mounted on one of the open ends of the seal member and the joint member that abut against each other. Therefore, the ink flow path in the seal member has a shape that expands toward the filter, has a function of sealing a connection portion of the ink supply pipe between the recording head side and the ink storage tank side, and has a function as an ink introduction path to the filter. It does so without the need for a separate component to introduce ink to the filter. In addition, since the sealing function is performed at the portions where they are abutted with each other, air bubbles are unlikely to stay and normal ink supply can be ensured.

  (15) In the configuration of the above (14), there is provided a head holder for holding the recording head, and an attachment member for attaching the joint member and the seal member to the head holder, and the attachment member and the joint member are engaged. Thus, the joint state between the joint member and the seal member is maintained, so that the joint state can be reliably maintained.

  (16) In the configuration of the above (14) or (15), the ink supply pipe is provided between the ink storage tank and the recording head, and has an ink introduction pipe and an ink discharge pipe for circulating and supplying ink. A connection member is disposed on each of the flow paths of the introduction pipe and the ink discharge pipe, and ink can be circulated between the storage tank and the print head to fill the print head.

  (17) In the configuration of the above (16), in the seventh reference example, the seal members forming the connecting members arranged on the respective flow paths of the ink introduction pipe and the ink discharge pipe are integrally formed, and the ink introduction pipe is formed. And the joint member forming a connecting member arranged on each flow path of the ink discharge pipe is integrally formed, so that the assembly of the seal member and the joint member can be performed on both the ink introduction pipe side and the ink discharge pipe side. , The steps of assembling each member can be simplified, and the productivity can be improved.

  (18) In the seventh reference example in any one of the constitutions (14) to (17) described above, one of the end faces at which the seal member and the joint member are joined is provided with a projection for sealing the joint surface. By forming the strip, the joint between the seal member and the joint member is sealed, so that the distance from the ridge to the filter and the distance from the ridge to the ink are short, and the distance from the ridge to the filter or the ink is reduced. Since a gap is less likely to be formed therebetween, the risk of bubbles remaining can be reduced.

  (19) In the configuration of the above (14), one of the ink supply pipe on the ink storage tank side and the ink supply pipe on the recording head side has a joint member, and the other has a joint member connected to the joint member. By having the second joint member connected to the open end of the seal member on the opposite side, the ink supply pipe on the storage tank side is connected via the second joint member to the side opposite to the side to which the joint member is coupled. The ink supply pipes on the recording head side and the storage tank side can be connected to each other by connecting to the opening end of the seal member.

  (20) The embodiment and the eighth reference example of the present invention relate to a head holder on which a recording head to which ink is supplied from an ink storage tank through an ink supply path is mounted, and a carriage on which the head holder is mounted. An ink supply structure of an image recording apparatus comprising: an ink supply path, an ink supply pipe disposed between an ink storage tank and a recording head, and an ink storage pipe in the flow path of the ink supply pipe. An ink supply pipe that is held on the carriage side on the tank side and a connection member that connects the ink supply pipe on the recording head side, and has an attachment member for attaching the connection member to the head holder or the carriage, The connection member is attached to the head holder or the carriage with some play provided by the attachment member.

  This allows the attachment member to attach the connection member with some play to the head holder or the carriage, thereby slightly changing the relative position of the connection member to the head holder or the carriage within the range of the play. can do. Therefore, when attaching the head holder to the carriage, even if the position of the ink supply pipe on the head holder side and the position of the ink supply pipe on the ink storage tank side and held on the carriage side are misaligned, By changing the position of the connecting member in accordance with the position of the supply path, the displacement between the two members can be absorbed, and the two members can be reliably connected.

  (21) In the configuration of (20), the mounting member is fitted to the inner surface of the holding portion formed on the head holder or the carriage with a slight play in a plane substantially perpendicular to the axial direction of the connecting member. By providing at least one of the member and the holding portion with a protruding portion that prevents the mounting member from falling off in the axial direction, the mounting portion is prevented from falling off in the axial direction of the connecting member, and It is possible to move in a direction substantially perpendicular to the direction, so that it is possible to move in the lateral direction while reliably preventing the connection member from falling off.

  (22) In the configuration of the above (20), when the mounting member and the holding portion are fitted, the projecting portion elastically deforms in a direction allowing the fitting, so that the mounting member can be easily attached and detached.

  (23) In any one of the constitutions (20) to (22), the ink supply path is connected to the first joint member connected to the ink supply pipe on the recording head side and to the ink supply pipe on the ink storage tank side. A first joint member is attached to an attachment member, and the second joint member is attached to a carriage, so that an ink supply pipe on the recording head side and an ink supply tank on the ink storage tank side are provided. The ink supply tube can be easily and reliably connected, and the head holder and the carriage can be easily separated.

  (24) In any one of the constitutions (20) to (23), the ink supply pipe has an ink introduction pipe and an ink discharge pipe for circulating ink between the ink storage tank and the recording head, and By arranging the connecting member on each of the flow paths of the introduction tube and the ink discharge tube, the ink supplied to the recording head by the ink introduction tube can be returned to the ink storage tank again by the ink discharge tube. It becomes possible.

  (25) In the configuration of (24), the ink supply path includes a first joint member connected to the ink introduction pipe or ink discharge pipe on the recording head side, and an ink introduction pipe or ink discharge pipe on the ink storage tank side. Since it is composed of the second joint member to be connected and the seal member arranged between the two joint members and connecting the two joint members, the members of the connection member can be reliably connected to each other.

  (26) In the configuration of (25), the first joint member is attached to the head holder, the second joint member is attached to the carriage, and at least one of the first and second joint members has a slight play. Since the first and second joint members can be slightly changed in position by being held and attached, the positions of the first joint member and the second joint member are shifted. Also, both members can be easily and reliably connected.

FIG. 1 is a diagram illustrating a schematic configuration of an image recording apparatus to which the present invention is applied. FIG. 3 is a diagram illustrating a schematic configuration of an ink supply structure of a first reference example of one recording head of the image recording apparatus. FIG. 9 is a diagram illustrating a schematic configuration of an ink supply structure for one recording head in an image recording apparatus according to a second reference example of the present invention. FIG. 9 is an exploded perspective view of a connection member and a filter according to a second reference example. It is a sectional side view before the connection member and filter of a 2nd reference example are built. It is a top view of the connection member of a 2nd reference example. FIG. 13 is an exploded cross-sectional view illustrating a configuration of a head unit provided in an image recording apparatus according to a third reference example. FIG. 3 is a cross-sectional view illustrating a process of mounting an ink cartridge on the head unit. FIG. 3 is a cross-sectional view illustrating a state where an ink cartridge is mounted on the head unit. FIG. 2 is a diagram illustrating a schematic configuration of an ink supply structure for one recording head in the image recording apparatus according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a configuration of a connection member provided in the ink supply structure according to the first embodiment. It is sectional drawing which shows the connection state of the connection member of 1st Embodiment. It is a perspective view of each member of a connection member, a joint holder, and a head holder of a 1st embodiment. It is sectional drawing which shows the structure of the connection member which concerns on 2nd Embodiment. It is sectional drawing which shows the connection state of the connection member which concerns on 2nd Embodiment. It is sectional drawing which shows the connection state of the connection member which concerns on 3rd Embodiment. It is sectional drawing which shows the structure of the connection member which concerns on a 4th reference example. It is sectional drawing which shows the connection state of the connection member which concerns on a 4th reference example. It is sectional drawing which shows the structure of the connection member which concerns on a 5th reference example. It is sectional drawing which shows the connection state of the connection member which concerns on a 5th reference example. It is sectional drawing which shows the connection state of the connection member which concerns on a 6th reference example. It is sectional drawing which shows the structure of the connection member which concerns on a 7th reference example. It is sectional drawing which shows the connection state of the connection member which concerns on a 7th reference example. It is a sectional view showing the composition of the connecting member concerning an 8th example. It is sectional drawing which shows the connection state of the connection member which concerns on an 8th reference example. FIG. 3 is a diagram illustrating a schematic configuration of an ink supply structure of an image recording apparatus considered earlier by the inventor.

Explanation of reference numerals

1 Image recording device 4 Sub ink tank (storage tank)
5a, 5b, 5c, 5d Recording head 21a, 21b, 21c, 21d Ink inlet tube 22a, 22b, 22c, 22d Ink outlet tube 23a, 23b, 23c, 23d Pump (circulation pump)
30, 31, 35, 40, 41, 130, 304 Connecting member 30a, 31a, 31a 'Seal rubber (seal member)
30b, 31b, 31b ', 39 First joint member 30c, 31c Second joint member 32, 36, 42, 53 Filter

Claims (6)

  A storage tank in which ink is stored and a recording head for ejecting ink are connected by an ink introduction pipe and an ink discharge pipe, and a circulation pump is used between the storage tank and the recording head by using the ink introduction pipe and the ink discharge pipe. In the ink supply structure of the image recording apparatus that circulates the ink in the recording head and supplies the ink to the recording head, the ink introduction pipe and the ink discharge pipe are configured to be connected to each other via a connection member in a flow path, A connecting member in the middle of one of the ink introduction pipe and the ink discharge pipe is connected to a seal member having an ink flow path formed on the inner surface with an opening end side expanding, and an open end of the seal member. A joint member having an open end, and an ink flow path having a shape in which the open end side is widened on the inner surface of the open end. The other connecting member has a seal member formed substantially in the same shape as the seal member, and a convex shape corresponding to the shape of the ink flow path of the seal member formed on the outer surface. An ink supply structure for an image recording apparatus, comprising: a joint member fitted into an opening end of the image recording apparatus and having an ink flow path formed on an inner surface thereof.   Instead of the other connection member, a seal member in which an outer surface on an opening end side is formed in a convex shape and an ink flow path is formed on an inner surface, is formed in substantially the same shape as the joint member on the one connection member side, 2. The ink supply structure for an image recording apparatus according to claim 1, wherein a connection member comprising a joint member into which the opening end of the seal member is fitted is used on the inner surface of the shape.   The image recording apparatus according to claim 1, wherein the shape expanding toward the opening end is a tapered shape, and the convex shape is a shape pressed against a surface of the tapered shape. Ink supply structure.   The ink supply structure according to any one of claims 1 to 3, wherein joint members forming the connection members are integrally formed.   5. The connection member according to claim 1, wherein a second joint member is connected to an opening end of the seal member opposite to a side to which the joint member is coupled. An ink supply structure for an image recording apparatus according to any one of the above.   The ink supply structure according to claim 1, wherein each of the connection members is attached to a head unit on which the recording head is mounted.

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