JP4792775B2 - Flow path structure and droplet discharge device - Google Patents

Description

  The present invention relates to a flow path structure and a droplet discharge device, and more specifically, a flow path structure for removing dust and foreign substances in a liquid flowing in a circulation flow path with a filter, and the filter of the flow path structure. The present invention relates to a droplet discharge device that discharges the supplied liquid from a nozzle of a droplet discharge head.

  In an inkjet recording apparatus that prints on a recording medium by ejecting ink droplets from the recording head, a serial scan that performs printing line by line by reciprocating the recording head in a direction perpendicular to the conveying direction while conveying the recording medium The so-called printing method is widely used mainly for personal use. In recent years, a non-scanning type recording head corresponding to a recording medium width in which a large number of ink discharge ports (nozzles) are arranged in a direction (width direction) orthogonal to the recording medium conveyance direction is used to continuously convey the recording medium. However, a so-called full-line head type ink jet recording apparatus has been commercialized, which performs printing while improving the printing speed to be compatible with office use.

  In these ink jet recording apparatuses, a vacuum that sucks ink in the nozzle by applying a negative pressure to the nozzle from outside in order to prevent ink drying, nozzle clogging due to foreign matter present in the ink, or deterioration in ink ejection performance. Operation (maintenance) is performed. However, in the full-line type recording head as described above, the ink consumption during the vacuum operation increases as the number of nozzles increases, leading to an increase in running cost. The ink filter (hereinafter abbreviated as “filter”) provided in the circulation flow path is used to remove dust and foreign matter in the ink so that nozzle clogging is less likely to occur and the number of vacuums can be reduced. Some have tried to reduce the amount of waste ink.

  However, in the configuration in which the filter is provided in the circulation channel in this way, when bubbles are mixed into the ink in the circulation channel, the filter function is deteriorated when the bubbles adhere to the filter, and the bubbles are located downstream of the filter ( For example, since the ink discharge performance is affected when the nozzle is stopped in the vicinity of the nozzle, it is necessary to discharge the bubbles well from the vicinity of the filter.

In this connection, for example, in a circulation channel not provided with a filter, a bubble channel for discharging bubbles to the atmosphere is connected to the circulation channel, or a filter is provided in a non-circulation ink supply channel. In the configuration, there is a technique in which the bubble discharge property is improved by connecting the bubble channel to the downstream channel or the upstream channel of the filter (see, for example, Patent Document 1). In addition, there is a technique in which a filter provided in a circulation flow path is clogged in order to circulate ink on the upstream side of the filter (see, for example, Patent Document 2).
JP 2002-144576 A JP 2002-321382 A

  However, in the technique of Patent Document 1 described above, the bubble discharge property when a filter is provided in the circulation channel is not considered. Further, in the technique of Patent Document 2, an outlet is disposed almost directly below the inlet in a flow path provided substantially perpendicular to the upstream side of the filter (substantially parallel to the filter), and the ink is directed downward from above. Since it is made to flow, the discharge | emission property of the bubble which exists in the upstream flow path of this filter is bad.

  In view of the above-described facts, an object of the present invention is to provide a flow path structure and a droplet discharge device that improve bubble discharge performance while reducing the amount of waste liquid.

In order to achieve the above object, the invention according to claim 1 is a flow channel structure provided in a circulation channel for circulating a liquid while supplying the liquid to a droplet discharge head. A first liquid chamber comprising a first ink chamber that constitutes a part and has an inflow port through which a liquid flows, a second ink chamber that communicates with the first ink chamber, and a first liquid chamber adjacent to the second ink chamber. provided so as to be sandwiched Tekatsu the second ink chamber, provided a second liquid chamber which communicates with the second ink chamber, the interface between the second liquid chamber and the second ink chamber A second filter for supplying liquid that has flowed from the second ink chamber into the second liquid chamber through the filter and is supplied to the droplet discharge head. an outlet from the liquid chamber to flow out the liquid, the first i of the second ink chamber Provided in the upper than the portion communicating with the compartments, a circulation outlet to flow out the liquid from the second ink chamber to circulate the liquid in the circulation flow path comprises a, in the case where the liquid is circulating, The liquid flows into the first ink chamber from one inlet and then branches to bypass the second liquid chamber provided so as to be sandwiched between the second ink chambers. It flows into the ink chamber, further flows along the filter toward the upper portion of the second ink chamber, and merges at one circulation outlet, and the surface of the filter is the second when the liquid circulates. The part located in the downstream of the flow direction of the liquid in an ink chamber is arrange | positioned more than substantially the same height as the part located in an upstream .

  In the first aspect of the present invention, the liquid that has flowed into the first liquid chamber from the inlet flows into the second liquid chamber communicated with the first liquid chamber, and further flows out from the second liquid chamber to the outlet. Is supplied to the droplet discharge head through a filter provided between the first liquid chamber and the second liquid chamber when the liquid flows from the first liquid chamber to the second liquid chamber. By passing, dust, foreign matter, etc. present in the liquid are captured by the filter and removed from the liquid.

  Here, when the circulation outlet is provided on the downstream side of the first liquid chamber, the liquid passes through the first liquid chamber provided on the upstream side of the filter and is circulated through the circulation flow path. By disposing the downstream portion of the filter at substantially the same height or higher as the upstream portion, the bubble discharge property on the upstream side of the filter accompanying the circulation of the liquid is improved.

  In this way, in the configuration in which the liquid supplied to the droplet discharge head is circulated in the circulation flow path, the bubbles near the filter are discharged well using the circulation of the liquid, and the liquid used for discharging the bubbles is Since the liquid is circulated in the circulation flow path, for example, it is not necessary to wastefully discharge the liquid for discharging the bubbles, and thus the amount of waste liquid accompanying the discharge of the bubbles is reduced.

In the flow path structure according to claim 1 or 2 , as in the invention according to claim 3 , a bubble reservoir for collecting bubbles existing in the liquid is provided between the first liquid chamber and the circulation outlet. You may make it provide.

In the flow path structure according to claim 3 , as in the invention according to claim 4 , the bubble reservoir may be arranged at a position higher than the first liquid chamber.

In the flow path structure according to claim 3 or 4 , as in the invention according to claim 5 , an inclined surface that is inclined upward from the upstream side to the downstream side is provided on the upper surface of the inner wall of the bubble reservoir. It may be.

In the flow channel structure according to any one of claims 1 to 5, as in the invention according to claim 6 , the circulation outlet may be arranged at a position higher than the outlet.

In the flow path structure according to any one of claims 1 to 6 , as in the invention according to claim 7 , the first liquid chamber, the second liquid chamber, and the filter are integrally formed. It may be assembled and unitized.

According to a ninth aspect of the present invention, in the liquid droplet ejection apparatus according to the eighth aspect , the filter is disposed in a direction substantially orthogonal to a nozzle surface on which the nozzles of the liquid droplet ejection head are formed. It is characterized by that.

In the invention according to claim 9 , by arranging the filter in a direction substantially orthogonal to the nozzle surface, the projected area on the nozzle surface does not increase even if the filter has a large area. Thereby, for example, when a plurality of droplet discharge heads are arranged, the nozzles can be arranged with high density at a plurality of heads, and the entire head can be made compact.

  Since the flow path structure and the droplet discharge device of the present invention have the above-described configuration, the amount of waste ink is reduced and the bubble discharge performance is improved.

  Hereinafter, a flow channel structure used in an ink jet recording apparatus according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows a state where an ink jet recording head is connected to the flow channel structure (ink circulation flow channel) according to the first embodiment. As shown in FIG. 1, a filter unit (flow path unit) 10 included in the flow path structure of the present embodiment is configured by a flow path member 12 and a filter 14 provided in the flow path member 12. .

  An inlet 16 formed at the upper part on one end side of the flow path member 12 and a circulation outlet 18 formed at the upper part on the other end side are a liquid supply pipe 112 and a liquid discharge pipe 114 connected to the common ink tank 110. Are connected to each.

  Between the inflow port 16 and the circulation outlet 18, an ink chamber 20 is provided in which the inner wall upper surface (ceiling surface) and the inner wall lower surface (bottom surface) are arranged substantially horizontally. A part of the lower surface of the ink chamber 20 is constituted by a filter 14, and the ink chamber 20 constitutes a part of a circulation flow path 118 through which ink circulates together with the inlet 16 and the circulation outlet 18. ing. Further, a pump 116 for circulating and flowing the ink in the circulation flow path 118 is connected to the drainage pipe 114 in the circulation flow path 118.

  An ink chamber 22 is further provided in the flow path member 12 on the opposite side (lower side) of the ink chamber 20 with the filter 14 interposed therebetween. The ink chamber 22 communicates with an outlet 24 formed at the lower center of the flow path member 12, and the inkjet recording head 100 has a nozzle surface 102 with a large number of nozzles facing downward at the outlet 24. Is connected.

  Next, with reference to FIG. 2, the flow of ink and its action when discharging bubbles (when circulating ink) and when filling ink (when ejecting ink) will be described.

  First, when discharging bubbles, the pump 116 is operated to suck ink from the circulation outlet 18 side of the filter unit 10. Here, the ink circulates in the circulation channel 118 in the order of the common ink tank 110 → the liquid supply pipe 112 → the inlet 16 → the ink chamber 20 → the circulation outlet 18 → the drain pipe 114 → the common ink tank 110 (FIG. 2). (See (A)). Thereby, bubbles are discharged from the ink chamber 20.

  When ink is filled, for example, after performing the above-described bubble discharging operation, a vacuum device (not shown) is brought into close contact with the nozzle surface 102 of the inkjet recording head 100 and sucked from the nozzle side. In this case, the ink flows through the common ink tank 110 → the liquid supply pipe 112 → the inlet 16 → the ink chamber 20 → the filter 14 → the ink chamber 22 → the outlet 24 → the inkjet recording head 100 and fills the inkjet recording head 100. (See FIG. 2B). In such a flow of ink in the filter unit 10, dust and foreign matters existing in the ink are captured by the filter 14 by passing through the filter 14 when the ink flows from the ink chamber 20 to the ink chamber 22. Removed from the ink. As a result, the filter function of the filter unit 10 for removing foreign matters and the like in the ink is performed.

  When such ink filling into the ink jet recording head 100 is performed after the bubble discharging operation, since no bubbles remain in the vicinity of the filter 66 and upstream of the filter 66, in the ink filling operation, for example, Even if the ink is sucked from the nozzle with such a large pressure that the bubbles pass through the filter 66, the bubbles do not pass through the filter 66 and enter the downstream side of the filter 66. As a result, it is possible to set a large suction pressure at the time of print head maintenance, and as a result, it is possible to perform ink filling and bubble discharge of the print head at higher speed and more reliably. Further, in the present embodiment, the filter 14 is disposed substantially horizontally, and the downstream portion (end portion on the circulation outlet 18 side) of the filter 14 is disposed at substantially the same height as the upstream portion (end portion on the inflow port 16 side). Therefore, the bubble discharge property on the upstream side of the filter accompanying the circulation of ink is improved. Further, the above-described bubble discharging operation upstream of the filter is performed by circulating the ink, thereby reducing the amount of waste ink.

(Second Embodiment)
3 and 4 show a filter unit included in the flow channel structure according to the second embodiment.

  As shown in FIG. 3, the filter unit 30 of the present embodiment includes a flow path member 32 and a filter 34 as in the filter unit 10 of the first embodiment.

  In the filter unit 30, the inflow port 36 is formed in the lower part on one end side of the flow path member 32, and the circulation outlet 38 is formed in the upper part on the other end side of the flow path member 32. Although not shown, the inlet 36 and the circulation outlet 38 are also connected to the supply pipe 112 and the drain pipe 114 of the circulation channel 118, respectively, as in the first embodiment.

  The ink chamber 40 provided between the inlet 16 and the circulation outlet 18 is inclined upward from the inlet 36 side toward the circulation outlet 38 as shown in the figure. Specifically, the inner wall upper surface portion and inner wall lower surface portion of the ink chambers 40 arranged substantially in parallel are inclined upward at a predetermined angle (for example, 45 degrees) from the inflow port 36 side to the circulation outlet 38 side. ing. Also in the case of the ink chamber 40, a part of the lower surface of the inner wall is constituted by the filter 34. As shown in the drawing, the downstream portion (the end on the circulation outlet 38 side) of the filter 34 is the upstream portion ( It is arranged to be inclined with respect to the horizontal direction so as to be higher than the end portion on the inflow port 36 side.

  Further, as in the first embodiment, an ink chamber 42 is provided in the flow path member 32 on the opposite side (lower side) of the ink chamber 40 with the filter 34 interposed therebetween, and is communicated with the ink chamber 42 so as to communicate with the flow path member. An ink jet recording head 100 is connected to an outlet 44 formed at a lower portion on the other end side of 32 with the nozzle surface 102 facing downward.

  The filter unit 30 of the present embodiment is configured as described above, and also in the case of this filter unit 30, the bubble discharge and ink filling operations are performed as shown in FIGS. 4 (A) and 4 (B). It is done in the same way as the form. In this embodiment, the circulation outlet 38 is disposed higher than the inlet 36, and the end (downstream part) of the filter 66 on the circulation outlet 38 side is set to be higher than the end (upstream part) on the inlet 36 side. By increasing the height, bubbles that rise due to buoyancy in the ink can easily move in the ink chamber 40 (upstream of the filter 34) toward the circulation outlet 38, and the bubble discharge performance is improved. Further, by arranging the filter 34 to be inclined with respect to the horizontal direction, the bubbles attached to the filter 34 are easily moved to the circulation outlet 38 side by buoyancy, and the discharge property of the bubbles attached to the filter 34 is facilitated. Will also improve.

(Third embodiment)
FIG. 5 shows a filter unit included in the flow channel structure according to the third embodiment. The filter unit 50 of the present embodiment shown in FIG. 5 is a modification of the filter unit 30 of the second embodiment, and has the same configuration or the same function as the configuration described in the second embodiment. Are given the same reference numerals and their description is omitted.

  As shown in FIG. 5, the flow path member 52 provided in the filter unit 50 of the present embodiment is provided with a bubble reservoir 54 on the upper right side, which is the downstream side of the ink chamber 40 in the ink flow direction. The bubble reservoir 54 is located between the ink chamber 40 and the circulation outlet 38 as shown in the figure, and is disposed almost directly below the circulation outlet 38. In addition, the upper surface of the inner wall of the bubble reservoir 54 on the ink chamber 40 side is provided with an inclined surface that is continuous with the upper surface of the inner wall of the ink chamber 40 and is inclined upward from the upstream side to the downstream side.

  Here, for example, when bubbles are mixed or generated in the ink chamber 40 during printing, if the bubbles are applied to the filter 34, the effective area of the filter 34 is reduced, so that the amount of ink supplied to the inkjet recording head 100 is reduced. It becomes a problem. On the other hand, in the filter unit 50 of the present embodiment, the bubble reservoir 54 is provided at a position higher than the ink chamber 40, so that bubbles mixed or generated in the ink chamber 40 during printing are generated in the bubble reservoir 54. Moving. Thereby, the phenomenon that bubbles are applied to the filter 34 is reduced, and an appropriate amount of ink can be supplied to the inkjet recording head 100. Further, by providing an inclined surface inclined upward from the upstream side to the downstream side on the upper surface of the inner wall of the bubble reservoir 54, the bubbles rising due to buoyancy in the ink circulate in the bubble reservoir 54. It becomes easy to move to the outlet 38 side, and the discharging property of the bubbles from the bubble reservoir 54 is improved.

(Fourth embodiment)
The filter unit with which the flow-path structure which concerns on 4th Embodiment is provided by FIGS. 6-10.

  As shown in FIGS. 6 and 7, the filter unit 60 according to the present embodiment is formed in a flat, substantially trapezoidal column shape. This filter unit 60 is also used for supplying ink from the common ink tank 110 shown in FIG. 1 to the inkjet recording head 100 through the ink circulation flow path.

  As shown in FIGS. 6 to 8, the filter unit 60 includes a case member 62, two side plate members 64, and two filters 66.

  The case member 62 includes a substantially trapezoidal cylindrical case main body 70 that is open at the front and rear surfaces and is hollow inside in the orientation shown in FIG. The left part and the right part on the upper surface of the case body 70 are substantially horizontal surfaces, and the right part is slightly higher than the left part. Between these left part and right part, the left part is directed from the left to the right part. An inclined surface inclined upward is provided.

  A cylindrical upstream connection portion 71 projects from the upper left portion of the case body 70. The upper end portion of the circular through hole formed in the upstream side connection portion 71 and penetrating in the vertical direction shown in the figure is an ink inlet 72, which is shown in FIGS. 8A and 8B. As described above, the ink is communicated with the internal space of the case main body 70 through the ink inflow passage 76 formed by the circular through hole.

  A cylindrical circulation side connection portion 73 projects from the upper right portion of the case body 70. An upper end portion of the circular through hole formed in the circulation side connection portion 73 that penetrates in the vertical direction is an ink circulation outlet 74, and the circulation outlet 74 is shown in FIGS. 8A and 8E. As described above, the ink is communicated with the internal space of the case main body 70 through the ink circulation path 77 formed by the circular through hole.

  On the left side in the case main body 70, a partition wall portion 78 extending in the vertical direction in parallel with the left inner wall surface is provided at a position spaced a predetermined distance from the left inner wall surface to the right side. A notch having a U-shaped cross section is formed on the front side and the rear side of the lower end portion of the partition wall 74, and this notch serves as a communication port between an ink chamber 94 and an ink chamber 96 described later, and An ink chamber entrance (communication port) 80 that is the entrance of the ink chamber 96 is configured.

  A frame wall portion 82 formed in a frame shape is provided on the right side of the partition wall portion 78 in the case member 62. An opening that penetrates in the front-rear direction is formed in the upper part of the frame wall portion 82, and a bubble reservoir 97 described later is formed by this opening.

  8D and 8E, the front surface and the rear surface of the frame wall portion 82 are offset from the front surface and the rear surface of the case body 70 inward by a predetermined distance (equal distance).

  In the frame wall portion 82, a cylindrical passage portion 84 extending in the vertical direction along the right inner wall surface is provided. Further, as shown in FIGS. 7A and 7B, a downstream side connection portion 86 projects from a position corresponding to the passage portion 84 at the lower right end portion of the case member 62.

  An upper end portion of a circular through hole formed in the passage portion 84 and the downstream side connection portion 86 in the illustrated vertical direction is an ink chamber outlet 88 serving as an outlet of an ink chamber 98 described later. Further, the lower end portion of the ink outflow path 90 formed by the circular through hole is an ink outflow opening 92, and the outflow opening 92 is formed as shown in FIGS. 8A and 8E. The ink chamber 98 communicates with the ink chamber 98.

  As shown in FIG. 8C, the filter 66 used in the filter unit 60 of this embodiment is manufactured by cutting a film-like mesh material along the opening shape of the frame wall portion 82. The outer shape of the filter 66 is slightly larger than the opening shape of the frame wall portion 82.

  And this filter 66 is attached to the front surface and the rear surface of the frame wall portion 82 so as to cover the front surface opening and the rear surface opening, as shown in FIGS. 6 and 8C to 8E. The two filters 66 are arranged substantially parallel to face each other. Further, the filter 66 is adjusted so that the outer peripheral ends of the filter 66 are positioned at the front edge and the rear edge of the frame wall portion 82, and in this state, the filter 66 is joined by bonding or heat welding.

  Further, the side plate member 64 is bonded to the front surface and the rear surface of the case member 62 to which the filter 66 is attached in the orientation shown in FIG. 6B by bonding or the like, and as a result, shown in FIGS. 6A and 7. The filter unit 60 is assembled.

  In the filter unit 60, as shown in FIG. 8, an ink chamber 94 defined by a case main body 70 and a partition wall portion 78 of the case member 62 and a side plate member 64 is provided on the left side. Yes. In addition, an ink chamber 96 partitioned by a case main body 70, a partition wall portion 78, a frame wall portion 82, a filter 66, and a side plate member 64 is provided on the front side, the rear side, and the upper side in the approximate center in the filter unit 60. The upper space of the ink chamber 96 is a bubble reservoir 97, and the upper surface of the inner wall of the bubble reservoir 97 is upstream ( The inclined surface is inclined upward from the ink chamber inlet 80 side toward the downstream side (ink circulation path 77 side). Further, an ink chamber 98 is provided inside the ink chamber 96, that is, inside the frame wall portion 82 and the filter 66. As a result, the ink chamber 94 communicates with the inflow port 72 via the ink inflow passage 76, the ink chamber 96 communicates with the ink chamber 94 via the two ink chamber inlets 80, and the bubble reservoir 97 above the ink chamber 96. Is connected to the circulation outlet 74 via the ink circulation path 77, the ink chamber 98 is connected to the outlet 92 via the ink outflow path 90, and the ink chamber 96 sandwiches the ink chamber 98.

  The filter 66 is provided on the boundary surface between the ink chamber 96 and the ink chamber 98 (the front surface and the rear surface of the frame wall portion 82), and is disposed on the ink chamber 96 side that is upstream in the ink flow direction. The chamber outlet 88 is disposed at a position higher than the two ink chamber inlets 80 and is disposed near the highest position of the ink chamber 98.

  The filter unit 60 of the present embodiment is configured as described above, and although not shown, this filter unit 60 also has an inlet 72 (upstream side connection portion 71) and a circulation outlet 74 as in the first embodiment. The (circulation side connection part 73) is connected to the liquid supply pipe 112 and the drainage pipe 114 of the circulation flow path 118, respectively, and the ink jet recording head 100 is connected to the outlet 92 (downstream side connection part 86) (see FIG. 1). ).

  In the present embodiment, as described above, the two ink chambers 96 of the filter unit 60 are arranged in parallel in the circulation flow path 118, but each of the inlet 72 and the circulation outlet 74 is formed. ing. As described above, when the ink flow path branches, if the bubbles remain in one flow path, the pressure is dispersed in the other flow paths, so that it is difficult to remove the bubbles in the flow path where the bubbles are retained. On the other hand, in the present embodiment, the number of circulation outlets 74 can be reduced even in the ink circulation flow path in which the two ink chambers 96 branch in parallel. Can be improved.

  9A to 9D show the ink flow when discharging bubbles (during ink circulation) on the upstream side of the filter 66 in the filter unit 60 of the present embodiment. When ink is sucked from the circulation outlet 74, the ink flowing from one inflow port 72 is branched at two ink chamber inlets 80 and flows into two ink chambers 96. After that, the gas is merged in the bubble reservoir 97 and flows out from one circulation outlet 74. As described above, in the present embodiment, since the parallel flow path does not exist in addition to the two ink chambers 96 in the circulation flow path, the configuration is excellent in the bubble discharge performance.

  In addition, as with the filter unit 50 of the third embodiment, this filter unit 60 is also provided with a bubble reservoir 97 at a position higher than the ink chamber 96, so that bubbles mixed in or generated in the ink chamber 96 during printing are formed. As a result, the phenomenon that bubbles are applied to the filter 66 is reduced, and an appropriate amount of ink can be supplied to the inkjet recording head 100. Further, since the upper surface of the inner wall of the bubble reservoir 97 is also an inclined surface inclined upward from the upstream side toward the downstream side, bubbles rising due to buoyancy in the ink circulate in the bubble reservoir 97. It becomes easy to move to the path 77 side, and the discharge property of bubbles from the bubble reservoir 97 is improved.

  10A to 10D show the flow of ink when ink is charged into the inkjet recording head 100 in the filter unit 60 of the present embodiment. Here, in this embodiment, since the two filters 66 in the ink flow path are arranged in parallel, the filter area can be increased, which is advantageous for downsizing the inkjet recording head 100.

  In the present embodiment, as shown in FIG. 7, the nozzle surface 102 and the upper surface of the ink jet recording head 100 and the lower surface of the filter unit 60 have substantially the same area. When the ink jet recording head 100 is connected and attached to 86, the lower surface of the filter unit 60 and the upper surface of the ink jet recording head 100 are arranged close to each other in parallel, and the two filters 66 provided in the filter unit 60 are nozzles. They are arranged in a direction substantially orthogonal to the surface 102.

  Thus, even if the area of the filter 66 provided in the filter unit 60 is increased, the projected area onto the nozzle surface 102 of the inkjet recording head 100 does not increase. For example, inkjet recording with the filter unit 60 attached thereto. When a plurality of heads 100 are arranged, the nozzles can be arranged with a high density by a plurality of heads, and the entire head can be made compact. Therefore, in the ink jet recording apparatus using the filter unit 60, it is possible to increase the printing speed and reduce the size of the apparatus.

(Fifth embodiment)
FIG. 11 shows a filter unit included in the flow path structure according to the fifth embodiment, and FIG. 12 shows a state in which the filter unit to which the ink jet recording head is connected is connected to the circulation flow path. ing.

  As shown in FIG. 11, the filter unit 150 of the present embodiment is also configured by a flow path member 152 and a filter 154, similarly to the filter units of the first to third embodiments described above.

  In the filter unit 150, the flow path member 152 extends in the vertical direction (vertical direction) as shown in the figure, and the inflow port 156 is formed near one end (left end) of the lower portion of the flow path member 152, and the circulation outlet 158 is formed near the other end (right end) of the upper part of the flow path member 152. Also, as shown in FIG. 12, the inlet 156 and the circulation outlet 158 are connected to the liquid supply pipe 112 and the drain pipe 114 of the circulation flow path 118, respectively, similarly to the first embodiment.

  An ink chamber 160 disposed substantially vertically is provided above the inflow port 156, and an ink chamber 162 disposed substantially vertically adjacent to the right side of the ink chamber 160 is provided below the circulation outlet 158. Is provided. A filter 154 is provided between the ink chamber 160 and the ink chamber 162 so as to be arranged substantially vertically.

  A part of the right inner wall of the ink chamber 160 is configured by a filter 154. These ink chambers 160 and 162, together with the inflow port 156 and the circulation outlet 158, are part of the circulation flow path 118 in which the ink circulates and flows. Part.

  The ink chamber 162 communicates with an outflow port 164 formed on the upper right side of the flow path member 152, and the nozzle surface 102 is directed downward through the supply pipe 119 to the outflow port 164. The ink jet recording head 100 is connected toward the head. The supply pipe 119 is connected to a check valve 120 that prevents ink flow (back flow) from the ink jet recording head 100 side to the filter unit 150 side.

  Next, with reference to FIG. 13, the flow of ink and its action when discharging bubbles and filling ink in this embodiment will be described.

  When the air is circulated and the bubbles are discharged, the ink is, as shown in FIG. 13A, the common ink tank 110 → the liquid supply pipe 112 → the inlet 156 → the ink chamber 160 → the filter 154 → the ink chamber 162 → Circulation outlet 158 → drainage pipe 114 → common ink tank 110 is circulated through the circulation flow path. Thereby, bubbles in the ink chamber 160, the filter 154, and the ink chamber 162 are discharged, and the ink chambers 160 and 162 are filled with ink.

  In addition, when filling the ink jet recording head 100 with ink, for example, after performing the above-described bubble discharging (ink circulation) operation, the ink is sucked from the nozzle side of the ink jet recording head 100. Here, as shown in FIG. 13B, the ink is common ink tank 110 → liquid supply pipe 112 → inlet 16 → ink chamber 20 → filter 14 → ink chamber 22 → outlet 164 → supply pipe 119 → inkjet. It flows with the recording head 100 and fills the inkjet recording head 100.

  When ink filling into the ink jet recording head 100 is performed after the bubble discharging operation, since no bubbles remain in the flow path to the ink chamber 162, ink filling is performed as in the first embodiment. In operation, for example, even if ink is sucked from the nozzles with such a large pressure that bubbles pass through the filter 66, the bubbles do not pass through the filter 66 and enter the downstream side of the filter 66. Further, since air bubbles are discharged to the ink chamber 162 using an ink circulation system, the suction from the nozzle is performed by sucking the ink amount corresponding to the flow path to the ink chamber 162 including the inkjet recording head 100. Bubbles can be discharged. Thereby, the amount of ink sucked from the nozzles can be reduced, and the amount of waste ink consumed for discharging bubbles can be reduced.

(Sixth embodiment)
FIG. 14 shows a filter unit included in the flow path structure according to the fifth embodiment, and FIG. 15 shows a state in which the filter unit to which the ink jet recording head is connected is connected to the circulation flow path. ing.

  As shown in FIG. 14, the filter unit 150 of the present embodiment is also configured by a flow path member 152 and a filter 154.

  In this filter unit 170, an inflow port 176 is formed near one end (left end) of the lower portion of the flow path member 172, and two circulation outlets are disposed near one end (left end) and the other end (right end) of the upper portion of the flow path member 172. 178 and 179 are formed.

  An ink chamber 180 is provided between the inlet 176 and the circulation outlet 178 (below the circulation outlet 178), and an ink chamber 182 is provided below the circulation outlet 179 adjacent to the right side of the ink chamber 180. It has been. A filter 174 is provided between the ink chamber 180 and the ink chamber 182, and the filter 174 is inclined so that the upper part is on the left side with respect to the vertical plane as shown in the figure. . Thus, the ink chamber 180 is configured such that the chamber cross-sectional area gradually decreases from the lower side toward the upper side, and the ink chamber 182 is configured so that the chamber cross-sectional area gradually increases from the lower side toward the upper side, and the filter 174. It is made into the substantially symmetrical shape on both sides.

  The ink chamber 182 communicates with an outflow port 184 formed on the upper right side of the flow path member 152. The outflow port 184 is connected to a supply pipe 119 as in the fifth embodiment. An ink jet recording head 100 is connected through this.

  As shown in FIG. 15, the inflow port 176 and the circulation outlet 178 are connected to the liquid supply pipe 112 and the drainage pipe 114 of the circulation flow path 118, respectively. A drainage pipe 122 branched from the middle of the drainage pipe 114 is connected to the circulation outlet 178. In the middle of the drainage pipe 122, the flow of ink (from the filter unit 150 side to the pump 116 side) A check valve 124 for preventing backflow is connected.

  Next, with reference to FIG. 16, the flow of ink and its action when discharging bubbles and filling ink in this embodiment will be described.

  When the ink is circulated and the bubbles are discharged, when the pump 116 is driven, the ink is stored in the common ink tank 110 → the liquid supply pipe 112 → the inlet 176 → the ink chamber 180 → the circulation outlet 178 → the drain pipe 114 → common. The circulation path of the ink tank 110 and the common ink tank 110 → the liquid supply pipe 112 → the inlet 176 → the ink chamber 180 → the filter 174 → the ink chamber 182 → the circulation outlet 179 → the drain pipe 122 → the drain pipe 114 → the common ink. It circulates through a circulation channel called a tank 110. Thereby, the bubbles in the ink chambers 180 and 182 and the filter 174 are discharged, and the ink chambers 180 and 182 are filled with ink.

  In addition, when the ink jet recording head 100 is filled with ink, for example, after performing the above-described bubble discharging (ink circulation) operation, the ink is sucked from the nozzle side of the ink jet recording head 100 as in the fifth embodiment.

  In the case of this embodiment, the same effect as that of the fifth embodiment can be obtained by ink circulation using the circulation outlet 179. On the other hand, in the ink circulation using the circulation outlet 178, the check valve 124 causes the ink in the flow path from the circulation outlet 178 to the pump 116 through the drain pipe 114 to the drain 116 from the connection part (merging part) 124. Since it is prevented from flowing into the ink chamber 122 and into the ink chamber 182, no dust or foreign matter flows into the downstream side of the filter 174. Thereby, it is possible to prevent the inflow of dust or foreign matter into the ink jet recording head 100, and the reliability of the head is improved.

(Seventh embodiment)
FIG. 17 shows a flow channel structure according to the seventh embodiment. Note that the flow channel structure of the present embodiment shown in FIG. 17 is a modification of the sixth embodiment, and the same components as those described in the sixth embodiment are denoted by the same reference numerals and description thereof. Is omitted.

  As shown in FIG. 17, in this embodiment, the check valve 124 described in the sixth embodiment is not provided in the middle of the drainage pipe 122, and instead, the connection between the drainage pipe 114 and the drainage pipe 122. A switching mechanism 128 that switches the flow path on the ink discharge side of the filter unit 170 to the circulation outlet 178 side or the circulation outlet 179 side, that is, switches the flow path configuration of the circulation flow path is provided in the section.

  Here, for example, in the flow path structure of the sixth embodiment, when air bubbles block the flow path (liquid supply pipe 112) from the circulation outlet 179 to the connection portion 126, the pressure is applied to the circulation flow path side through the circulation outlet 178. , So that the bubbles cannot be easily removed. In contrast, in the flow path structure of the present embodiment, the switching mechanism 128 switches the flow path to the flow path through which the ink circulates through the circulation outlet 178 or the flow path that circulates through the circulation outlet 179. When the above problem occurs, by closing the flow path from the circulation outlet 178 to the connection portion 126, it is possible to reliably remove bubbles that have blocked the flow path from the circulation outlet 179 to the connection portion 126.

(Eighth embodiment)
FIG. 18 shows a filter unit included in the flow channel structure according to the eighth embodiment. Note that the filter unit 190 of the present embodiment shown in FIG. 18 is a modification of the filter unit 150 of the fifth embodiment, and has the same configuration or the same function as the configuration described in the fifth embodiment. The same reference numerals are given and description thereof is omitted.

  As shown in FIG. 18, in the flow path member 192 provided in the filter unit 190, the circulation outlet 194 is disposed almost immediately above the outlet 196.

  As a result, in the filter unit 190 of the present embodiment, bubbles that have risen due to buoyancy from the downstream side of the outlet 196 (inkjet recording head 100 side) flow into the circulation outlet 194 as they are. As described above, since the bubbles do not remain in the flow path of the inlet 156 → the ink chamber 160 → the filter 154 → the ink chamber 162 → the outlet 196, the inkjet recording head 100 connected to the downstream side of the outlet 196. Does not flow into the inkjet recording head 100 while the ink is being ejected. Further, since air bubbles are trapped on the circulation outlet 194 side, the air bubbles are discharged well by the ink circulation.

(Ninth embodiment)
FIG. 19 shows a filter unit included in the flow channel structure according to the ninth embodiment.

  As shown in FIG. 19A, the flow path member 202 included in the filter unit 200 has a rectangular cross section, and the inflow port 206 and the outflow port 208 are formed at diagonal positions. The ink chamber provided between the inflow port 206 and the outflow port 208 is divided into an ink chamber 210 located on the upstream side and an ink chamber located on the downstream side by the filter 204 provided in the flow path member 202. It is divided into 212. The filter 204 is substantially parallel to the inner wall side surface (upper surface in FIG. 19) of the ink chamber 210 and the inner wall side surface (lower surface in FIG. 19) of the ink chamber 212, and from the inner wall side surfaces of the ink chambers 210 and 212. Each of the distances (WA) to the filter 204 is arranged at substantially the same position.

  With the above configuration, in the filter unit 200 of the present embodiment, in any flow path (path) from the inlet 206 to the outlet 208 through the filter 204, regardless of the passage position of the filter 204. Also, the channel resistance is almost the same. For example, the three flow paths PassA, PassB, and PassC shown in FIG. 19B all have the same flow path resistance. Thereby, the flow volume in each part of a filter becomes the same, and the bubble discharge property in a filter inside or a filter downstream improves. In addition, since the effective area of the filter 204 is not reduced, an increase in pressure loss at the filter portion can be suppressed.

(Tenth embodiment)
FIG. 20 shows a filter unit included in the flow channel structure according to the tenth embodiment.

  As shown in FIG. 20, the flow path member 222 included in the filter unit 220 is also substantially rectangular in cross section as in the ninth embodiment, and the inlet 226 and the outlet 228 are formed at diagonal positions. However, in this embodiment, the outflow port 228 is disposed at a position higher than the inflow port 226. Further, the ink chamber provided between the inflow port 226 and the outflow port 228 also has an ink chamber 230 positioned on the upstream side and an ink positioned on the downstream side by the filter 224 provided in the flow path member 222. In this embodiment, the filter 224 is disposed between the ink chamber 230 and the ink chamber 232 so as to be inclined with respect to the horizontal direction. Further, the ink chamber 230 and the ink chamber 232 have a shape that is substantially point-symmetric about the midpoint of the line segment that connects the inflow port 226 and the outflow port 228. A circulation outlet 234 is formed above the upstream ink chamber 230 at the upper part of the flow path member 222. The circulation outlet 234 is higher than the inlet 226 and the outlet 228 as shown in the figure. Placed in position.

  With the above configuration, in the filter unit 220 of the present embodiment, in addition to the same effects as those of the ninth embodiment, the filter 224 is inclined with respect to the horizontal direction, so that the air bubbles contacting the filter surface It becomes easy to gather at the upper part, and it can be reduced that bubbles are applied to the filter part and the effective area of the filter is changed. In addition, since air bubbles mixed or generated in the ink chamber 230 are likely to gather at the top due to buoyancy, the air outlet in the ink chamber 230 can be reliably discharged by providing the circulation outlet 234 above the ink chamber 230.

(Eleventh embodiment)
The eleventh embodiment will be described using the filter unit 60 in the fourth embodiment.

  As shown in FIGS. 21D and 21E, in the filter unit 60, since the two filters 66 are arranged substantially vertically, bubbles contacting the filter surface gather at the upper part on the ink chamber 96 side. It becomes easy. Thereby, also in this filter unit 60, it can prevent that the bubble covers a filter part and the effective area of the filter 66 falls.

  Further, since the circulation outlet 74 is provided on the upper side of the ink chamber 96 via the bubble reservoir 97, the bubbles mixed or generated in the ink chamber 96 rise by buoyancy and gather in the bubble reservoir 97 and circulate from there. It is reliably discharged through the outlet 74.

Further, as shown in FIG. 21D, when the widths of the ink chambers 96 and 98 are WB / 2 and WB, respectively, the ink chambers 80 and the ink chamber 80 are cross-sectionally shown in FIG. In the flow path through which the liquid toward the chamber outlet 88 passes, the flow resistances of the flow path through the point A, the flow path through the point B, and the flow path through the point C of the filter 66 are R _BA (from the ink chamber inlet 80). R _CA (from point A to outlet 92), R _FA (from filter passing through point A), R _BB (from ink chamber inlet 80 to point B), R _CB (from point B to outlet 92) ), R _FA (filter passage at point B), R _BC (from ink chamber inlet 80 to point C), R _CC (from point C to ink chamber outlet 88), R _FA (filter passage at point C) Then, the following (1 The expression of the relationship.

2 x (R _BA + R _FA ) + R _CA ≒ 2 x (R _BB + R _FB ) + R _CB ≒ 2 x (R _BC + R _FC ) + R _CC (1)
Thereby, since the flow volume which passes the filter 66 shows the same value at each point, the bubble discharge | emission property in a filter inside or a filter downstream improves.
(Twelfth embodiment)
FIG. 22 shows a filter unit included in the flow channel structure according to the twelfth embodiment.

  As shown in FIG. 22, the filter unit 240 includes a flow path member 242 having a substantially circular shape in plan view, the inlet 246 is formed on the outer peripheral surface of the flow path member 242, and the outlet 248 is a flow path. The lower surface of the member 242 is formed at the end opposite to the inlet 246. The flow path from the inlet 246 to the outlet 248 is divided into ink chambers 250 and 252 by a circular filter 244, and the ink flow in the ink chamber 250 flows into the ink chamber 250 on the upstream side of the filter. A pair of curved flow straightening plates 254 for adjusting (flow velocity) is provided.

  FIG. 23 shows the flow of ink in the filter unit 240 of the present embodiment. Here, when there is no baffle plate in the ink chamber, the flow in the ink chamber 250 from the inlet 246 toward the outlet 248 is different from the inside of the side wall portion of the ink chamber 250, and the difference is particularly large when the filter area is large. Since it becomes remarkable, the bubble discharge | emission property in a filter upstream part worsens. Furthermore, since the flow rate passing through the filter 244 varies depending on the ink path and is distributed in the filter 244, the bubble discharge property in the filter 244 is also deteriorated. As a result, the effective area of the filter 244 is reduced and the flow path resistance is increased, which adversely affects repeated discharge and maintainability.

  On the other hand, in the filter unit 240 of this embodiment, by providing the pair of rectifying plates 254 in the ink chamber 250, the difference in the flow velocity in the ink path in the ink chamber 250 is reduced, and repeated ejection and The problem of maintainability can be improved.

  In addition, since the filter 244 has a circular shape with no corners on the outer peripheral edge, chipping, minute residue, and the like that occur during outer shape processing are reduced. Thereby, dust generated by the filter 244 can be reduced.

(13th Embodiment)
FIG. 24 shows a filter unit included in the flow channel structure according to the thirteenth embodiment.

  As shown in FIG. 24, the filter unit 260 of the present embodiment includes a flow path member 262 having a substantially hexagonal shape when viewed from the front. In this flow path member 262, an inflow port 266 is formed at the lower end portion of the outer peripheral surface, an outflow port 268 is formed near the upper end portion of the side surface (near the end portion on the opposite side of the inflow port 266), A circulation outlet 274 is formed at the upper end of the surface.

  The flow path from the inflow port 266 to the outflow port 268 is divided into ink chambers 270 and 272 by a filter 264 arranged substantially vertically, and the ink chamber 270 on the upstream side of the filter has the inside of the ink chamber 270. Three rectifying plates 276 for adjusting the flow (velocity) of ink are provided along the vertical direction.

  With the above configuration, in the filter unit 260 of the present embodiment, in addition to the effect obtained by improving the bubble discharge performance in the ink chamber 270 as in the twelfth embodiment, the bubble discharge on the ink chamber 272 side is achieved. Can also be improved. Furthermore, by providing the circulation outlet 274 above the ink chamber 270, the bubble discharge property of the ink chamber 270 can be further improved. In addition, since the filter 264 is arranged substantially vertically, air bubble retention in the filter portion is reduced, and adverse effects due to an increase in flow path resistance due to this factor can be improved.

(Fourteenth embodiment)
The fourteenth embodiment is a modification in which the shape of the rectifying plate 276 is changed in the filter unit 260 of the thirteenth embodiment described above.

  As shown in FIG. 26, in this embodiment, the cross-sectional shape of the rectifying plate 278 is trapezoidal, and is thin on the side close to the filter 264 (front end side) and thick on the opposite side (base end side). Therefore, the effective area of the filter 264 can be increased without reducing the rigidity of the rectifying plate 278.

(Fifteenth embodiment)
The fifteenth embodiment is a modification in which a rectifying plate is provided in the filter unit 60 of the fourth embodiment.

  In the filter unit 280 of the present embodiment shown in FIG. 27, a rectifying plate 282 is provided on the inner surface of the side plate member 64 (see FIG. 6). The rectifying plate 282 is located in the ink chamber 96 and is disposed at a substantially central portion of the filter 66 as shown in the drawing, and is bent in an inverted S shape as shown in the drawing so that the ink flows from the ink chamber inlet 80 side. It extends toward the chamber outlet 88 side.

  With the above configuration, in the filter unit 280 of the present embodiment, the flow velocity distribution of the ink flow from the ink chamber inlet 80 toward the ink chamber outlet 88 can be made more uniform in the ink chamber 96, so that the bubbles in the ink chamber 96 Excellent exhaustability. Further, since the flow velocity distribution in the filter unit can be made uniform in addition to the flow upstream of the filter, the effective area of the filter can be increased, and the flow path resistance including the filter 66 can be reduced.

  In addition, since all the filter units demonstrated by 1st-15th embodiment are unitized, compared with a division | segmentation structure, replacement | exchange work becomes easy.

  The present invention has been described in detail with reference to the first to fifteenth embodiments. However, the present invention is not limited to these embodiments, and other various forms are possible within the scope of the present invention. It can be implemented.

  For example, in the filter units according to the twelfth to fifteenth embodiments, the rectifying plate is provided in the upstream ink chamber, but the rectifying plate may be provided in the downstream ink chamber.

  The present invention is not limited to the ink jet recording apparatus described above, and can be applied to other liquid droplet ejection apparatuses such as a pattern forming apparatus that ejects liquid droplets for pattern formation of a semiconductor or the like.

It is a schematic block diagram which shows the circulation flow path which concerns on the 1st Embodiment of this invention. 1A and 1B show the flow of ink in a filter unit provided in the circulation flow path of FIG. 1, wherein FIG. 2A is a cross-sectional view when discharging bubbles, and FIG. 2B is a cross-sectional view when filling ink. It is sectional drawing which shows the filter unit which concerns on the 2nd Embodiment of this invention. 3A and 3B show the flow of ink in the filter unit of FIG. 3, in which FIG. 3A is a cross-sectional view when bubbles are discharged, and FIG. 3B is a cross-sectional view when ink is filled. It is sectional drawing which shows the filter unit which concerns on the 3rd Embodiment of this invention. (A) which shows the external appearance of the filter unit which concerns on the 4th Embodiment of this invention is a perspective view, (B) is an exploded perspective view which shows a decomposition | disassembly state. FIG. 6A is a front view and FIG. 6B is a right side view showing the appearance of the filter unit of FIG. 6 shows a cross section of the filter unit of FIG. 6, (A) is a cross sectional view taken along line 8A-8A of FIG. 7 (B), (B) is a cross sectional view taken along line 8B-8B of FIG. 8 (A), and (C) is FIG. 8B is a sectional view taken along line 8C-8C, FIG. 8D is a sectional view taken along line 8D-8D in FIG. 8A, and FIG. 8E is a sectional view taken along line 8E-8E in FIG. FIG. 6 shows the flow of ink when bubbles are discharged in the filter unit of FIG. 6, (A) is a cross-sectional view corresponding to FIG. 8 (A), (B) is a cross-sectional view corresponding to FIG. ) Is a cross-sectional view corresponding to FIG. 8D, and FIG. 9D is a cross-sectional view corresponding to FIG. FIG. 6 shows the flow of ink when ink is filled in the filter unit of FIG. 6, (A) is a cross-sectional view corresponding to FIG. 8 (A), (B) is a cross-sectional view corresponding to FIG. ) Is a cross-sectional view corresponding to FIG. 8D, and FIG. 9D is a cross-sectional view corresponding to FIG. It is sectional drawing which shows the filter unit which concerns on the 5th Embodiment of this invention. It is a schematic block diagram which shows the state in which the filter unit of FIG. 11 was provided in the circulation flow path which concerns on the 5th Embodiment of this invention. FIGS. 12A and 12B show a flow of ink in the circulation flow path of FIG. 12, where FIG. 13A is a schematic configuration diagram when discharging bubbles, and FIG. 13B is a schematic configuration diagram when filling ink. It is sectional drawing which shows the filter unit which concerns on the 6th Embodiment of this invention. It is a schematic block diagram which shows the state in which the filter unit of FIG. 14 was provided in the circulation flow path which concerns on the 6th Embodiment of this invention. It is a schematic block diagram which shows the flow of the ink at the time of bubble discharge | emission in the circulation flow path of FIG. It is a schematic block diagram which shows the state in which the filter unit of FIG. 14 was provided in the circulation flow path which concerns on the 7th Embodiment of this invention. It is sectional drawing which shows the filter unit which concerns on the 8th Embodiment of this invention. (A) is sectional drawing which shows the filter unit which concerns on the 9th Embodiment of this invention, (B) is sectional drawing which shows the flow of the ink in the filter unit of (A). (A) is sectional drawing which shows the filter unit which concerns on the 10th Embodiment of this invention, (B) is sectional drawing which shows the flow of the ink in the filter unit of (A). The cross section of the filter unit which concerns on the 11th Embodiment of this invention is shown, (A) is sectional drawing corresponding to FIG. 8 (A), (B) is sectional drawing corresponding to FIG. 8 (B), (C) Is a cross-sectional view corresponding to FIG. 8C, FIG. 8D is a cross-sectional view corresponding to FIG. 8D, and FIG. 8E is a cross-sectional view corresponding to FIG. The cross section of the filter unit which concerns on the 12th Embodiment of this invention is shown, (A) is the 22A-22A sectional view taken on the line of FIG.22 (B), (B) is the 22B-22B sectional view taken on the line of FIG.22 (A). It is. 22 shows the flow of ink in the filter unit of FIG. 22, (A) is a cross-sectional view corresponding to FIG. 22 (A), and (B) is a cross-sectional view corresponding to FIG. 22 (B). The cross section of the filter unit which concerns on the 13th Embodiment of this invention is shown, (A) is the 24A-24A sectional view taken on the line of FIG. 24 (B), (B) is the 24B-24B sectional view taken on the line of FIG. It is. 24 shows the flow of ink in the filter unit of FIG. 24, (A) is a cross-sectional view corresponding to FIG. 24 (A), and (B) is a cross-sectional view corresponding to FIG. 24 (B). It is the 26-26 sectional view taken on the line of FIG. 24 which showed the cross section of the filter unit which concerns on the 14th Embodiment of this invention. The cross section of the filter unit which concerns on the 15th Embodiment of this invention is shown, (A) is front sectional drawing, (B) is the 27B-27B sectional view taken on the line of FIG. 27 (A), (C) is FIG. ) Is a cross-sectional view taken along line 27C-27C, and (D) is a cross-sectional view taken along line 27D-27D of FIG.

Explanation of symbols

10 Filter unit 14 Filter 16 Inlet 18 Circulating outlet 24 Outlet 20 Ink chamber (first liquid chamber)
22 Ink chamber (second liquid chamber)
30 Filter unit 34 Filter 36 Inlet port 38 Circulating outlet 44 Outlet port 40 Ink chamber (first liquid chamber)
42 Ink chamber (second liquid chamber)
54 Bubble Reservoir 60 Filter Unit 66 Filter 72 Inlet 74 Circulation Outlet 92 Outlet 80 Ink Chamber Inlet 88 Ink Chamber Outlet 96 Ink Chamber (First Liquid Chamber)
98 Ink chamber (second liquid chamber)
DESCRIPTION OF SYMBOLS 100 Inkjet recording head 102 Nozzle surface 124 Check valve 126 Connection part 128 Switching mechanism 150 Filter unit 154 Filter 156 Inlet 158 Circulation outlet 160 Ink chamber (first liquid chamber)
162 Ink chamber (second liquid chamber)
164 Outlet 170 Filter unit 174 Filter 176 Inlet 178 Circulation outlet 179 Circulation outlet 180 Ink chamber (first liquid chamber)
182 Ink chamber (second liquid chamber)
184 Outflow port 190 Filter unit 194 Inlet port 196 Outlet port 200 Filter unit 204 Filter 206 Inlet port 208 Outlet port 210 Ink chamber (first liquid chamber)
212 Ink chamber (second liquid chamber)
220 Filter unit 224 Filter 226 Inlet 228 Outlet 230 Ink chamber (first liquid chamber)
232 Ink chamber (second liquid chamber)
234 Circulation outlet 240 Filter unit 244 Filter 246 Inflow port 248 Outflow port 250 Ink chamber (first liquid chamber)
252 Ink chamber (second liquid chamber)
254 Current plate 260 Filter unit 264 Filter 266 Inlet 268 Outlet 270 Ink chamber (first liquid chamber)
272 Ink chamber (second liquid chamber)
274 Circulation outlet 276 Rectifier plate 278 Rectifier plate

Claims (9)

In the flow path structure provided in the circulation flow path for circulating while supplying the liquid to the droplet discharge head,
A first liquid chamber comprising a first ink chamber that forms a part of the circulation flow path through which the liquid circulates and has an inflow port through which the liquid flows; and a second ink chamber that communicates with the first ink chamber; ,
A second liquid chamber provided adjacent to the second ink chamber and sandwiched between the second ink chambers and in communication with the second ink chamber ;
A filter provided on a boundary surface between the second ink chamber and the second liquid chamber ;
The second liquid chamber is provided in communication with the second liquid chamber and supplies the liquid that has flowed from the second ink chamber through the filter into the second liquid chamber to the droplet discharge head. An outlet for flowing liquid,
A circulation outlet provided above the portion of the second ink chamber that communicates with the first ink chamber, and for allowing the liquid to flow out of the second ink chamber in order to circulate the liquid in the circulation channel;
With
When the liquid circulates, the liquid bypasses the second liquid chamber provided so as to be sandwiched between the second ink chambers after flowing into the first ink chamber from the one inlet. Branching into the second ink chamber, flowing along the filter toward the top of the second ink chamber, and joining at the one circulation outlet,
The surface of the filter is arranged such that a portion located downstream in the liquid flow direction in the second ink chamber when the liquid circulates is substantially equal to or higher than a portion located upstream. Characteristic channel structure. Provided to be sandwiched between the second ink chamber, and partitioning the second liquid chamber, provided with a frame wall having an opening on both sides facing the second ink chamber,
The second liquid chamber communicates with the second ink chamber at each opening of the frame wall portion,
2. The flow path structure according to claim 1, wherein the filter is attached to the frame wall portion so as to cover the opening of the frame wall portion, and is opposed to the second liquid chamber.   The flow path structure according to claim 1 or 2, wherein a bubble reservoir for collecting bubbles present in the liquid is provided between the first liquid chamber and the circulation outlet.   The flow path structure according to claim 3, wherein the bubble reservoir is disposed at a position higher than the first liquid chamber.   The flow path structure according to claim 3 or 4, wherein an inclined surface inclined upward from the upstream side to the downstream side is provided on the upper surface of the inner wall of the bubble reservoir.   The flow path structure according to any one of claims 1 to 5, wherein the circulation outlet is arranged at a position higher than the outlet.   The flow path structure according to claim 1, wherein the first liquid chamber, the second liquid chamber, and the filter are integrally assembled to form a unit. A liquid droplet ejection head that ejects liquid droplets from a nozzle toward an object to be ejected;
A filter unit having the flow channel structure according to claim 1,
The droplet discharge device, wherein the filter unit is attached to the liquid discharge head such that an outer wall surface provided with the outflow port is along the outer wall surface of the droplet discharge head.   9. The liquid droplet ejection apparatus according to claim 8, wherein the filter is disposed in a direction substantially orthogonal to a nozzle surface on which the nozzles of the liquid droplet ejection head are formed.

Images