JP5975659B2 - Filter unit, liquid ejecting head, and liquid ejecting apparatus - Google Patents

Description

  The present invention relates to a filter unit that flows in liquid and flows out through a filter, a liquid ejecting head that uses the filter unit, and a liquid ejecting apparatus using the same.

  In recent years, ink jet type liquid ejecting heads have been used in which ink droplets are ejected onto recording paper or the like to record characters and figures, or liquid materials are ejected onto the surface of an element substrate to form a functional thin film. In this method, ink or liquid material is supplied from a liquid tank to a liquid ejecting head via a supply pipe, and the liquid filled in the channel is discharged from a nozzle communicating with the channel. When ejecting the liquid, the liquid ejecting head or the recording medium for recording the ejected liquid is moved to record characters or figures, or a functional thin film having a predetermined shape is formed.

  For example, Patent Document 1 discloses this type of liquid jet head. FIG. 10 is a diagram showing an outline of the liquid flow path of the print head 101 described in Patent Document 1 (FIG. 2 of Patent Document 1). A liquid discharge nozzle 201 that discharges liquid downward and a nozzle liquid chamber 202 that supplies liquid to the liquid discharge nozzle 201 are installed below the print head 101. An OUT liquid chamber 301 that supplies liquid to the nozzle liquid chamber 202 and an IN liquid chamber 204 that supplies liquid to the OUT liquid chamber 301 via a head filter 203 are installed on the upper right side of the print head 101. The head filter 203 is installed vertically or with an inclination. The liquid flows from the tube 114 to the lower part of the IN liquid chamber 204 through the IN side joint 303, a part flows into the OUT liquid chamber 301 through the head filter 203, and the other flows from the upper part of the IN liquid chamber 204 to the OUT side. It flows out to the tube 115 through the joint 304.

  The liquid circulates through the tube 114, the IN liquid chamber 204, and the tube 115. The OUT side joint 304 is installed above the IN liquid chamber 204 and the IN side joint 303 is installed below. Thereby, bubbles can be removed from the OUT side joint 304 side by utilizing the buoyancy of the bubbles during liquid circulation cleaning, and the liquid flow rate used in the liquid circulation cleaning can be remarkably reduced as compared with the conventional case. That's it.

JP 2004-351541 A

  In the above conventional example, a head filter 203 is provided between the IN liquid chamber 204 and the OUT liquid chamber 301 to remove dust mixed in the liquid. However, as the print head 101 is used, air bubbles adhere to and accumulate on the IN liquid chamber 204 and on the IN liquid chamber 204 side of the head filter 203, and the effective area of the head filter 203 is reduced. Insufficient supply of liquid occurs. In addition, bubbles accumulated in the IN liquid chamber 204 pass through the head filter 203 and flow into the nozzle liquid chamber 202, which causes a drop in the recording quality such as missing a tod that clogs the nozzle.

  The present invention has been made in view of the above problems, and bubbles are accumulated on the upstream side of the filter, the effective area of the filter is reduced, the flow resistance of the filter is increased, and the flow rate on the downstream side of the filter is insufficient. It is an object of the present invention to provide a filter unit that does not cause a decrease in the liquid pressure on the downstream side.

  The liquid ejecting head of the present invention includes a first liquid chamber into which liquid flows, a second liquid chamber from which liquid flows out, and a filter installed between the first liquid chamber and the second liquid chamber. A first series of passages communicating with the chamber, the bubble reservoir chamber installed above the filter chamber, the first liquid chamber and the bubble reservoir chamber, and opening to the first opening of the first liquid chamber And a second communication path that communicates the first liquid chamber and the bubble reservoir chamber and opens to a second opening that is disposed below the first opening of the first liquid chamber. It was decided.

  In addition, the first opening is installed at a substantially uppermost position of the first liquid chamber.

  In addition, the second communication path opens in a third opening of the bubble reservoir, and the third opening is installed at a lowermost position of the bubble reservoir.

  In addition, the second communication path is opened to a third opening of the bubble reservoir, and the third opening is installed upward from approximately the center of the vertical width of the bubble reservoir.

  In addition, an inflow path through which the liquid flows is provided, and the inflow path communicates with the second communication path.

  In addition, an outflow passage that opens to the fourth opening of the second liquid chamber and flows out of the liquid is provided, and the fourth opening is installed at a substantially uppermost position of the second liquid chamber.

  Further, the bubble accumulation chamber is formed of a flat space, and the flat surface of the flat space is installed upright with respect to the filter chamber.

  In addition, the bubble storage chamber has a U-shape that is inverted, and the U-shaped open port side is disposed in the direction of the filter chamber.

  Further, the bubble reservoir chamber has a width in a direction in which the bubble reservoir chamber is positioned with respect to the filter chamber, which is larger than a maximum width in a direction perpendicular to the bubble chamber.

  Further, the first opening has a shape that is wide in the direction in which the bubble accumulation chamber is located with respect to the filter chamber and narrow in a direction perpendicular to the bubble chamber.

  The effective surface of the filter has a shape that is wide in the direction in which the bubble accumulation chamber is located with respect to the filter chamber and narrow in a direction perpendicular to the bubble chamber.

  The liquid jet head according to the present invention includes any one of the filter units described above and a liquid discharge unit that discharges liquid that flows out from the filter unit as liquid droplets.

  The liquid ejecting apparatus according to the aspect of the invention includes the liquid ejecting head, a moving mechanism that reciprocates the liquid ejecting head, a liquid supply pipe that supplies the liquid to the liquid ejecting head, and the liquid that is supplied to the liquid supply pipe. And a liquid tank.

  The filter unit of the present invention is a filter chamber having a first liquid chamber into which liquid flows, a second liquid chamber from which liquid flows out, and a filter installed between the first liquid chamber and the second liquid chamber; A bubble reservoir chamber installed above the filter chamber, a first liquid chamber and a bubble reservoir chamber communicate with each other, a first communication path opened to a first opening of the first liquid chamber, a first liquid chamber, A second communication path that communicates with the bubble reservoir and opens to a second opening that is disposed below the first opening of the first liquid chamber. As a result, the bubbles flowing into the first liquid chamber accumulate in the bubble reservoir chamber above the first liquid chamber, and the first liquid chamber is filled with the liquid. For this reason, the effective area of the filter is reduced by the bubbles accumulated on the upstream side of the filter, the flow resistance is increased, and the liquid pressure on the downstream side of the filter is prevented from being lowered.

It is a conceptual diagram showing the basic composition of the filter unit concerning the present invention. It is a conceptual diagram showing the filter unit which concerns on 1st embodiment of this invention. It is a conceptual diagram showing the filter unit which concerns on 2nd embodiment of this invention. It is a conceptual diagram showing the filter unit which concerns on 3rd embodiment of this invention. It is a cross-sectional schematic diagram of the filter unit which concerns on 4th embodiment of this invention. It is a disassembled perspective view of the base | substrate which comprises the filter unit which concerns on 4th embodiment of this invention. It is explanatory drawing of the filter unit which concerns on 5th embodiment of this invention. FIG. 10 is a schematic diagram of a liquid jet head according to a sixth embodiment of the present invention. FIG. 10 is a schematic perspective view of a liquid ejecting apparatus according to a seventh embodiment of the invention. It is a figure which shows the outline of the liquid flow path of a conventionally well-known print head.

  FIG. 1 is a conceptual diagram showing a basic configuration of a filter unit 1 according to the present invention. In the following description, “upward” means the direction opposite to the gravity direction g, “downward” means the gravity direction g, and “up and down direction” means the vertical direction. Moreover, the same code | symbol is attached | subjected to the part which has the same function of FIGS. 2-8 or the same function.

  The filter unit 1 includes a filter chamber 10, a bubble reservoir chamber 3 installed above the filter chamber 10, a first series passage 4 installed between the filter chamber 10 and the bubble reservoir chamber 3, and a second chamber 4. And a communication path 5. The filter chamber 10 includes a first liquid chamber 6 through which liquid flows in, a second liquid chamber 8 through which liquid flows out, and a filter 7 installed between the first liquid chamber 6 and the second liquid chamber 8.

  The first series passage 4 communicates the first liquid chamber 6 and the bubble reservoir chamber 3 and opens to the first opening 13 of the first liquid chamber 6. The second communication passage 5 communicates the first liquid chamber 6 and the bubble reservoir chamber 3 and opens to a second opening 14 installed below the first opening 13 of the first liquid chamber 6.

  The liquid flowing into the first liquid chamber 6 from the inflow port IN flows into the second liquid chamber 8 through the filter 7 and flows out from the outflow port OUT. The bubble K mixed in the liquid flowing in from the inflow port IN and the bubble K foamed inside the first liquid chamber 6 move upward due to the buoyancy and pass through the first series passage 4 from the first opening 13. It moves to the upper part of the reservoir 3. Then, the liquid in the bubble pool chamber 3 is pushed out to the first liquid chamber 6 through the second communication passage 5 or the first series passage 4. Furthermore, if the first opening 13 is installed at the uppermost position in the first liquid chamber 6, the bubbles K in the first liquid chamber 6 can be collected in the first series passage 4.

  With this configuration, the bubbles K do not stay in the first liquid chamber 6, and the effective area of the filter 7 is not reduced by the bubbles K. Therefore, the flow path resistance of the filter 7 increases, the pressure loss does not increase, and the pressure on the downstream side of the filter 7 does not decrease.

  The inlet IN of the first liquid chamber 6 may be at any position in the first liquid chamber 6 and may be provided in the second communication passage 5 as will be described later. It is desirable that the outlet OUT of the second liquid chamber 8 be installed at a position that is substantially at the top of the second liquid chamber 8. As a result, when the first and second liquid chambers 6 and 8 are initially filled with liquid, or when the first and second liquid chambers 6 and 8 are replaced, the bubbles K remaining in the second liquid chamber 8 are exposed to the outside. It becomes easy to discharge. In addition, a bubble removal valve or the like may be installed in the bubble accumulation chamber 3 to periodically remove the bubbles K filled in the bubble accumulation chamber 3.

(First embodiment)
FIG. 2 is a conceptual diagram showing the filter unit 1 according to the first embodiment of the present invention. 1 is different from FIG. 1 in that an inflow path 2 through which liquid flows in and an outflow path 9 through which liquid flows out are provided, and the rest is substantially the same as in FIG.

  As shown in FIG. 2, the filter chamber 10, the bubble reservoir 3 installed above the filter chamber 10, and the first and second communication paths installed between the filter chamber 10 and the bubble reservoir 3 4 and 5. The filter chamber 10 includes a first liquid chamber 6 into which liquid flows in, a second liquid chamber 8 through which liquid flows out, and a filter 7 installed between the first and second liquid chambers 6 and 8.

  The first series passage 4 communicates the first liquid chamber 6 and the bubble reservoir chamber 3 and opens to the first opening 13 of the first liquid chamber 6. The second communication passage 5 communicates the first liquid chamber 6 and the bubble reservoir 3, and communicates with the second opening 14 of the first liquid chamber 6 and the third opening 15 of the bubble reservoir 3. The second opening 14 is installed below the first opening 13. The inflow path 2 through which the liquid flows in communicates with the second communication path 5. The outflow path 9 through which the liquid flows out opens to the fourth opening 16 of the second liquid chamber 8.

  The first opening 13 is installed above the second opening 14. Furthermore, the 1st and 4th opening parts 13 and 16 are installed in the substantially uppermost position of the 1st and 2nd liquid chambers 6 and 8, respectively. The third opening 15 opens at a lowermost position on the first liquid chamber 6 side (filter chamber 10 side) of the bubble accumulation chamber 3, and in the vicinity of the third opening 15, the second communication path 5 is formed in the first liquid chamber. It faces the 6 side (filter chamber 10 side), that is, the gravitational direction g. In addition, it is desirable to form the volume of the bubble pool chamber 3 larger than the volume of the first liquid chamber 6. This is because bubbles corresponding to the volume of the first liquid chamber 6 can be stored in the bubble storage chamber 3.

  The liquid flowing into the inflow path 2 from the inflow port IN flows into the first liquid chamber 6 through the second opening 14, flows into the second liquid chamber 8 through the filter 7, and passes through the fourth opening 16. It flows out to the outflow channel 9 and flows out from the outflow port OUT. Bubbles K in the first liquid chamber 6 move to the first opening 13 due to the buoyancy, move to the bubble reservoir 3 and stay in the upper part thereof. At the same time, the liquid filling the bubble reservoir 3 is pushed out to the first liquid chamber 6 via the second communication passage 5 or the first series passage 4. As a result, the first liquid chamber 6 is filled with liquid, the filter 7 is not blocked by the bubbles K, and the effective area of the filter 7 does not decrease. Therefore, the flow path resistance is increased by the filter 7, the pressure loss is not increased, and the pressure on the downstream side of the filter 7 is not reduced.

  Further, the inflow path 2 is connected to the second communication path 5, and the third opening 15 opens at the lowest position on the filter chamber 10 side of the bubble accumulation chamber 3. Therefore, by pumping a high-pressure liquid from the inflow path 2, the bubbles K filling the bubble accumulation chamber 3 can be pushed out from the first series passage 4 to the first liquid chamber 6 side. In particular, when the bubble reservoir 3 is filled with the bubble K and the bubble K also accumulates in the first liquid chamber 6, the liquid is pumped from the inflow passage 2, so that the bubble K is discharged through the filter 7. The liquid can be replenished to the bubble reservoir chamber 3. That is, part or most of the bubbles K accumulated in the bubble accumulation chamber 3 during maintenance can be replaced with liquid.

(Second embodiment)
FIG. 3 is a conceptual diagram showing the filter unit 1 according to the second embodiment of the present invention. The difference from the first embodiment is that the third opening 15 is located on the side surface of the bubble accumulation chamber 3, and the other configuration is the same as that of the first embodiment. Therefore, different points will be described below, and description of the same configuration will be omitted.

  As shown in FIG. 3, the third opening 15 in which the second communication passage 5 opens into the bubble accumulation chamber 3 is installed upward from the vertical center of the bubble accumulation chamber 3, that is, from the approximate center of the width in the vertical direction. Therefore, by pumping a high-pressure liquid from the inflow path 2, the bubbles K filling the bubble accumulation chamber 3 are discharged to the outflow path 9 through the first series passage 4 and the filter 7 to replenish the liquid in the bubble accumulation chamber 3. It becomes easy.

(Third embodiment)
FIG. 4 is a conceptual diagram showing the filter unit 1 according to the third embodiment of the present invention. A different part from 1st embodiment is a point which has the U-shape in which the bubble accumulation chamber 3 inverts, and the other structure is the same as that of 1st embodiment. Therefore, different points will be described below, and description of the same configuration will be omitted.

  As shown in FIG. 4, the bubble accumulation chamber 3 has an inverted U shape, and is installed with the U-shaped opening side facing the direction in which the filter chamber 10 is located. Therefore, it becomes easier to replace the bubbles K with liquid. That is, if high-pressure liquid is pumped from the inflow path 2, the bubbles K filling the bubble reservoir 3 are easily discharged to the outlet 9 through the first series passage 4 and the filter 7, and the bubble reservoir 3 is filled with liquid. be able to.

  In the first embodiment to the third embodiment, the bubble accumulation chamber 3 has a width in the direction in which the bubble accumulation chamber 3 is located with respect to the filter chamber 10 larger than the maximum width in the direction orthogonal thereto. . In other words, the vertical width of the bubble reservoir 3 is formed larger than the maximum width in the horizontal direction perpendicular thereto. Thereby, the bubble K can be retained without leaking from the bubble accumulation chamber 3 to the first liquid chamber 6.

  Further, the bubble accumulation chamber 3 can be configured from a flat space, and the flat surface of the flat space can be installed upright with respect to the filter chamber 10. In other words, the direction of the flat surface of the flat space of the bubble accumulation chamber 3 is directed parallel to the direction in which the filter chamber 10 is installed with respect to the bubble accumulation chamber 3. Therefore, if the filter unit 1 is installed, the bubble accumulation chamber 3 is positioned above the filter chamber 10, and the flat surface of the flat space of the bubble accumulation chamber 3 faces in the vertical direction. By making the bubble reservoir chamber 3 a flat space, the liquid is filled up to the upper portion of the bubble reservoir chamber 3 against the gravity by capillary action.

  The flat space means a cross-sectional area of a plane perpendicular to the direction in which the liquid in the second communication passage 5 near the third opening 15 flows and a cross-sectional area in a plane perpendicular to the direction in which the liquid in the bubble reservoir 3 flows. And the cross-sectional area of the bubble accumulation chamber 3 can be specified by being equal to or smaller than the cross-sectional area of the second communication passage 5. Here, “the cross-sectional area of the plane perpendicular to the direction in which the liquid flows in the second communication path 5” is the cross-sectional area of the second communication path 5 having a plane parallel to the gravitational direction g shown in FIG. In the case of the bubble storage chamber 3 of the U-shaped tube shown in FIG. 4, “the cross-sectional area in the direction perpendicular to the direction in which the liquid in the storage chamber 3 flows” is the sectional area of the U-shaped tube. In addition, when the bubble reservoir 3 is not a U-shaped tube but has a substantially square shape as shown in FIG. 3, the cross-sectional area of the second communication path 5 is a plane parallel to the gravity direction g.

  In addition, the effective surface of the filter 7 can be wide in the direction in which the bubble accumulation chamber 3 is located with respect to the filter chamber 10 and narrow in the direction perpendicular to the bubble chamber 3. Thereby, when the filter unit 1 is installed, the effective surface of the filter 7 is wide in the gravitational direction g and narrow in the horizontal direction perpendicular thereto. The bubble K has a greater buoyancy per unit area than the one that overlaps the gravitational direction g and spreads in the horizontal direction, and is easily moved upward. Therefore, for example, when bubbles K accumulate in the first liquid chamber 6 and the effective surface of the filter 7 decreases, the area of the filter 7 that is concealed by the bubbles K is larger in the gravitational direction than in the horizontal direction even with the same effective area. Can be reduced.

(Fourth embodiment)
FIG. 5 is a schematic cross-sectional view of the filter unit 1 according to the fourth embodiment of the present invention. As shown in FIG. 5, the filter unit 1 includes a bubble reservoir chamber 3 formed of a recess above the base 12, and a first liquid chamber 6 formed of a recess below, a filter 7 and a second liquid chamber 8 not shown. A filter chamber 10 is installed.

  This will be specifically described below. A filter 7 (not shown) is installed on the stepped portion 17 of the base 12. The first liquid chamber 6 is formed on the back side of the paper with respect to the stepped portion 17, and the second liquid chamber 8 is formed on the front side of the paper with respect to the stepped portion 17. That is, the filter chamber 10 has a structure in which the first liquid chamber 6 and the second liquid chamber 8 face each other through the filter. The first liquid chamber 6 and the second liquid chamber 8 have a substantially parallelogram in plan view, with the upper right corner being the uppermost and the lower left corner being the lowermost.

  A first series passage 4 and a second communication passage 5 are formed between the bubble accumulation chamber 3 and the filter chamber 10. The first series passage 4 opens to the first opening 13 installed on the inner surface of the first liquid chamber 6 on the back side of the paper surface, and opens to the fifth opening 11 installed below the bubble accumulation chamber 3. To do. The first opening 13 is installed at a substantially uppermost position of the first liquid chamber 6, and the fifth opening 11 is installed at a substantially lowermost position of the bubble accumulation chamber 3. The first opening 13 has a shape that is wide in the direction in which the bubble accumulation chamber 3 is located with respect to the filter chamber 10, that is, in the vertical direction, and narrow in the direction perpendicular thereto. By making the first opening 13 elongated in the vertical direction, that is, in the direction in which the bubbles K move, the bubbles K and the liquid can be exchanged even in the flow path of the first series passage 4.

  The second communication path 5 is installed on the back side of the inner surface of the first liquid chamber 6 on the back side of the paper, opens to the second opening 14 on the inner surface, and is installed at the lowermost position of the bubble reservoir chamber 3. The third opening 15 is opened. The second opening 14 is located below the first opening 13, and is installed at the approximate center in the vertical direction in the first liquid chamber 6. The second communication passage 5 in the vicinity of the third opening 15 faces upward and opens at the bottom of the bubble accumulation chamber 3.

  The inflow path 2 through which the liquid flows is installed at the side of the bubble reservoir 3 and joins the second communication path 5 below the bottom of the bubble reservoir 3. The flow passage cross section of the second communication passage 5 downstream from the junction with the inflow passage 2 is formed larger than the flow passage cross section of the second communication passage 5 at the bottom of the bubble accumulation chamber 3, and the inlet of the inflow connection portion 18 is formed. The liquid flowing from IN is easily flowed into the first liquid chamber 6. The outflow channel 9 is installed along the bottom side from the right side of the filter chamber 10. The outflow channel 9 opens to a fourth opening 16 that is installed at a position that is substantially uppermost in the second liquid chamber 8. Since the fourth opening 16 is located at the uppermost position of the second liquid chamber 8, the bubbles mixed in the second liquid chamber 8 can be easily discharged from the outflow passage 9. An outflow connection portion 19 is installed in the lower part of the base body 12, and the liquid flowing out from the outflow passage 9 is discharged from the outflow port OUT.

  The filter unit 1 operates as follows. The liquid flowing in from the inflow port IN of the inflow connection portion 18 flows into the first liquid chamber 6 from the second opening portion 14 via the inflow passage 2 and the second communication passage 5. The liquid in the first liquid chamber 6 flows into the second liquid chamber 8 formed on the front side of the paper from the first liquid chamber 6 through a filter (not shown), and flows out from the fourth opening 16 through the outflow passage 9. It flows out from the outlet OUT of the connection part 19. When the bubbles K mixed in the liquid flow into the first liquid chamber 6, the bubbles K move to the top of the first liquid chamber 6 due to the buoyancy, and the bubbles are accumulated from the first opening 13 through the first series passage 4. Accumulate in chamber 3. As a result, the first liquid chamber 6 is not filled with liquid and the effective area of the filter 7 is not reduced by bubbles. As a result, the flow path resistance is increased by the filter 7, the pressure loss is not increased, and the pressure on the downstream side of the filter 7 is not reduced.

  FIG. 6 is an exploded perspective view of the base 12 constituting the filter unit 1 according to the fourth embodiment shown in FIG. The filter unit 1 includes a base body 12a, a filter 7 attached to the stepped portion 17 of the base body 12a, and a base body 12b that closes a side surface of the base body 12a. The base 12 a has a recess on the side surface below, the central recess constitutes the filter chamber 10, and the peripheral recess constitutes the outflow path 9. The first liquid chamber 6 is configured between the bottom surface of the central recess and the filter 7 installed in the step portion 17, and the second liquid chamber 8 is the side surface of the filter 7 installed in the step portion 17 and the base body 12 b. It is composed between. The outflow path 9 is constituted by a recess along the right side and the lower side of the filter chamber 10 and a side surface of the base body 12b.

  The first and second communication passages 4 and 5 are installed on the back side of the bottom surface of the recess, the first series passage 4 opens to the first liquid chamber 6 at the first opening 13, and the second communication passage 5 is the second communication passage 5. Open to the opening 14. The first opening 13 is formed at the uppermost position of the first liquid chamber 6, and the width in the direction in which the bubble accumulation chamber 3 is located with respect to the filter chamber 10 is larger than the width in the direction perpendicular thereto. The second opening 14 is located below the first opening 13. The fourth opening 16 is formed at the uppermost position of the second liquid chamber 8, and the outflow passage 9 opens. An outflow connection portion 19 is installed at the lower portion of the base body 12 a and communicates with the outflow passage 9.

  The base body 12b is provided with a recess on the upper side surface thereof, and the bubble reservoir 3 is constituted by the bottom surface of the central recess and the upper side surface of the base body 12a. The inflow path 2 is constituted by a recess formed along the left side of the bubble accumulation chamber 3 and the upper side surface of the base 12a. Further, the first series passage 4 and the second communication passage 5 are opened at the bottom portion below the bubble accumulation chamber 3. The inflow path 2 merges with the second communication path 5. An inflow connection 18 is installed at the upper end of the base body 12 b and communicates with the inflow passage 2.

  The filter chamber 10 is constructed by attaching the filter 7 to the stepped portion 17 of the base 12a and bonding the base 12a and the base 12b, and the first and second communication passages 4 and 5 formed in the base 12a and the base are formed. The first and second communication passages 4 and 5 formed in 12b communicate with each other. In this way, the filter unit 1 can be constituted by the two bases 12 a and 12 b and the single filter 7.

  The bubble accumulation chamber 3 is formed of a flat space, and the flat surface of the flat space is installed upright with respect to the filter chamber 10. In other words, the direction of the flat surface of the flat space of the bubble accumulation chamber 3 is parallel to the direction in which the filter chamber 10 is installed with respect to the bubble accumulation chamber 3. Therefore, if the filter unit 1 is installed, the bubble accumulation chamber 3 is positioned above the filter chamber 10, and the flat surface of the flat space of the bubble accumulation chamber 3 faces in the vertical direction. By making the bubble reservoir chamber 3 a flat space, the liquid in the bubble reservoir chamber 3 is easily filled up against the gravity due to capillary action.

  In addition, the bubble reservoir chamber 3 has a width in the direction in which the bubble reservoir chamber 3 is located with respect to the filter chamber 10 larger than the maximum width in the direction orthogonal thereto. In other words, the bubble accumulation chamber 3 has a width in the vertical direction larger than the maximum width in the horizontal direction. Therefore, the volume of the bubbles K staying in the bubble accumulation chamber 3 can be increased, and the bubbles can be prevented from leaking into the first and second communication passages 4 and 5. In addition, since the second communication path 5 is installed below the bubble reservoir 3 and the third opening 15 is installed at the lowest position of the bubble reservoir 3, it is easy to replace the bubbles and liquid in the bubble reservoir 3; Since the fourth opening 16 is installed at the uppermost position of the second liquid chamber 8, bubbles in the second liquid chamber 8 can be easily discharged during maintenance such as liquid replacement. The effective surface of the filter 7 is wide in the direction in which the bubble accumulation chamber 3 is located with respect to the filter chamber 10 and narrow in the direction perpendicular to the direction. As a result, the effective surface of the filter 7 is wide in the gravitational direction g and narrow in the horizontal direction perpendicular to the gravitational direction g, so that the effective surface of the filter 7 is unlikely to decrease even when bubbles accumulate in the first liquid chamber 6. .

(Fifth embodiment)
FIG. 7 is an explanatory view of the filter unit 1 according to the fifth embodiment of the present invention, FIG. 7A is a schematic cross-sectional view of the filter unit 1, and FIG. 7B is a diagram of FIG. It is a cross-sectional schematic diagram of the part XX. The difference from the fourth embodiment is that the central portion of the first liquid chamber 6 has a convex portion 23 close to the surface of the filter 7, and the other configuration is the same as that of the fourth embodiment. Therefore, different parts will be described below, and description of the same parts will be omitted.

  As shown in FIGS. 7A and 7B, a convex portion 23 is formed at the center of the first liquid chamber 6 on the upstream side of the filter 7, and the upper end surface of the convex portion 23 is the first liquid of the filter 7. Proximity to the surface of the chamber 6 side. A recess 24 is formed in a donut shape around the convex portion 23 and along the outer periphery of the first liquid chamber 6. Accordingly, the first liquid chamber 6 is mainly constituted by the recess 24. The second opening 14 and the first opening 13 open at the bottom surface of the recess 24.

  With this configuration, the bubbles that have entered the first liquid chamber 6 are guided to the recess 24 and can easily move from the first opening 13 to the bubble reservoir chamber 3 via the first series passage 4. When the bubbles move through the recess 24, the liquid pushed upward when the bubbles are lifted can circulate, so that the bubbles and the liquid are exchanged, and the bubbles can easily move upward. Further, by setting the recess 24 to a predetermined depth, the bubble and the liquid can be exchanged at the position of the bubble in the recess 24, and the bubble can easily move upward. Here, the bubble storage chamber 3 has a volume larger than the volume of the first liquid chamber 6 and can store bubbles corresponding to the volume of the first liquid chamber 6.

(Sixth embodiment)
FIG. 8 is a schematic view of a liquid jet head 20 according to the sixth embodiment of the present invention. The liquid ejecting head 20 includes a liquid discharge head chip 21, a filter unit 1 that supplies liquid to the head chip 21, and a fixing portion 22 that fixes the head chip 21. The filter unit 1 described in the first to fourth embodiments can be used. According to this configuration, even if the head chip 21 is used for a long period of time, the bubbles flowing into the first liquid chamber of the filter unit 1 are accumulated in the bubble accumulation chamber on the upper part, and the bubbles are not retained in the first liquid chamber. Therefore, the effective area of the filter does not decrease due to the retention of bubbles, the flow path resistance is increased by the filter, the pressure loss increases, and the pressure on the downstream side of the filter does not decrease. Thereby, the meniscus formed in the nozzle of the head chip 21 can be maintained in a fixed shape, and the discharge conditions are stabilized.

(Seventh embodiment)
FIG. 9 is a schematic perspective view of a liquid ejecting apparatus 30 according to the seventh embodiment of the present invention. The liquid ejecting apparatus 30 includes a moving mechanism 40 that reciprocates the liquid ejecting heads 20 and 20 ′, a flow path portion 35 and 35 ′ that supplies liquid to the liquid ejecting heads 20 and 20 ′, and a flow path portion 35 and 35 ′. Liquid pumps 33 and 33 'for supplying liquid to the liquid tanks and liquid tanks 34 and 34'. Each liquid ejecting head 20, 20 ′ includes a plurality of ejection grooves, and ejects droplets from nozzles communicating with the ejection grooves. The liquid ejecting heads 20 and 20 ′ are the same as those described in the sixth embodiment.

  The liquid ejecting apparatus 30 includes a pair of conveying units 41 and 42 that convey a recording medium 44 such as paper in the main scanning direction, liquid ejecting heads 20 and 20 ′ that eject liquid onto the recording medium 44, and a liquid ejecting head. A carriage unit 43 on which 20 and 20 ′ are placed; liquid pumps 33 and 33 ′ that supply the liquid stored in the liquid tanks 34 and 34 ′ to the flow path portions 35 and 35 ′ by supplying the liquid; And a moving mechanism 40 that scans 20 ′ in the sub-scanning direction orthogonal to the main scanning direction. A control unit (not shown) controls and drives the liquid ejecting heads 20 and 20 ′, the moving mechanism 40, and the conveying units 41 and 42.

  The pair of conveying means 41 and 42 includes a grid roller and a pinch roller that extend in the sub-scanning direction and rotate while contacting the roller surface. A grid roller and a pinch roller are moved around the axis by a motor (not shown), and the recording medium 44 sandwiched between the rollers is conveyed in the main scanning direction. The moving mechanism 40 couples a pair of guide rails 36 and 37 extending in the sub-scanning direction, a carriage unit 43 slidable along the pair of guide rails 36 and 37, and the carriage unit 43 to move in the sub-scanning direction. An endless belt 38 is provided, and a motor 39 that rotates the endless belt 38 via a pulley (not shown) is provided.

  The carriage unit 43 mounts a plurality of liquid jet heads 20 and 20 ′, and discharges, for example, four types of liquid droplets of yellow, magenta, cyan, and black. The liquid tanks 34 and 34 'store liquids of corresponding colors and supply them to the liquid jet heads 20 and 20' via the liquid pumps 33 and 33 'and the flow path portions 35 and 35'. Each liquid ejecting head 20, 20 ′ ejects droplets of each color according to the drive signal. An arbitrary pattern is recorded on the recording medium 44 by controlling the timing of ejecting the liquid from the liquid ejecting heads 20 and 20 ′, the rotation of the motor 39 that drives the carriage unit 43, and the conveyance speed of the recording medium 44. I can.

  In the present embodiment, the liquid jet head 20 in which the filter unit 1 is fixed to the head chip 21 is used, but the present invention is not limited to this. The filter unit 1 may be installed between the head chip 21 and the liquid tanks 34 and 34 '. Thereby, even if the liquid ejecting apparatus 30 is used for a long time, the effective area of the filter is reduced due to the bubbles remaining in the upstream side of the filter, and the liquid pressure on the downstream side of the filter is not lowered. Droplet ejection can be stabilized.

DESCRIPTION OF SYMBOLS 1 Filter unit 2 Inflow path 3 Bubble storage chamber 4 First serial path 5 Second communication path 6 First liquid chamber 7 Filter 8 Second liquid chamber 9 Outflow path 10 Filter chamber 11 Fifth opening part 12 Base 13 First opening part , 14 Second opening, 15 Third opening, 16 Fourth opening 17 Stepped portion 18 Inflow connection portion 19 Outflow connection portion

Claims (12)

A filter chamber having a first liquid chamber into which liquid flows, a second liquid chamber from which liquid flows out, and a filter installed between the first liquid chamber and the second liquid chamber;
A bubble reservoir chamber installed above the filter chamber;
A first series passage that communicates the first liquid chamber and the bubble reservoir and opens to a first opening of the first liquid chamber;
A filter unit comprising: a second communication path that communicates between the first liquid chamber and the bubble reservoir and opens to a second opening that is disposed below the first opening of the first liquid chamber. Because
The second opening of the second communication path opens to the first liquid chamber facing the filter ,
An outflow path that opens to the fourth opening of the second liquid chamber and flows out the liquid;
The filter unit, wherein the fourth opening is installed at the uppermost position of the second liquid chamber .   The filter unit according to claim 1, wherein the first opening is installed at an uppermost position of the first liquid chamber.   3. The filter unit according to claim 1, wherein the second communication path opens to a third opening of the bubble reservoir, and the third opening is installed at a lowermost position of the bubble reservoir.   The said 2nd communicating path opens to the 3rd opening part of the said bubble reservoir chamber, and the said 3rd opening part is installed upwards from the center of the width | variety of the up-down direction of the said bubble reservoir chamber. Filter unit. It has an inflow path for flowing liquid,
The filter unit according to claim 1, wherein the inflow path communicates with the second communication path. The filter unit according to any one of claims 1 to 5 , wherein the bubble storage chamber is formed of a flat space, and the flat surface of the flat space is installed upright with respect to the filter chamber. The filter unit according to any one of claims 1 to 6 , wherein the bubble storage chamber has a U-shape that is inverted, and is installed with the U-shaped opening side facing toward the filter chamber. The filter according to any one of claims 1 to 7 , wherein the bubble reservoir chamber has a width in a direction in which the bubble reservoir chamber is located with respect to the filter chamber, which is larger than a maximum width in a direction orthogonal thereto. unit. The filter unit according to any one of claims 1 to 8 , wherein the first opening portion has a shape that is wide in a direction in which the bubble reservoir chamber is located with respect to the filter chamber and narrow in a direction perpendicular to the bubble chamber. The filter unit according to any one of claims 1 to 9 , wherein an effective surface of the filter is wide in a direction in which the bubble accumulation chamber is located with respect to the filter chamber and narrow in a direction perpendicular to the bubble chamber. A filter unit according to claim 1;
A liquid discharge section for discharging the liquid flowing out from the filter unit and discharging it as droplets;
A liquid jet head comprising: A liquid jet head according to claim 11 ;
A moving mechanism for reciprocating the liquid jet head;
A liquid supply pipe for supplying a liquid to the liquid ejecting head;
And a liquid tank that supplies the liquid to the liquid supply pipe.

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