JP7163745B2 - Liquid storage tank and droplet discharge head - Google Patents

Description

The present invention relates to liquid storage tanks and liquid droplet ejection heads.

2. Description of the Related Art There is a liquid ejection device that ejects a liquid such as ink from a nozzle at a desired timing and lands it at a desired position. 2. Description of the Related Art Some liquid storage tanks that supply liquid to droplet ejection heads provided with nozzles are provided with filters. The liquid from which contaminants have been removed by this filter is supplied to each nozzle.

In addition, air bubbles may be mixed in the liquid inside the droplet discharge head. These bubbles can adversely affect the supply and ejection of the liquid. Conventionally, there is a droplet discharge head provided with a path for discharging the bubbles. Japanese Patent Application Laid-Open No. 2002-200002 describes a technique for properly discharging air bubbles remaining on the upstream side of a filter from a bypass path when ink is filled. In addition, there is a technique (Patent Document 2) in which a bypass channel for discharging air bubbles is provided on both the upstream side and the downstream side of the filter.

JP 2011-230337 A JP 2011-148224 A

However, with the conventional flow path configuration, air bubbles mixed in the liquid downstream of the filter are not properly discharged, and it is difficult to adjust the flow rate to properly flow out the liquid and air from the front and back of the filter. There is a problem that it is applied.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid storage tank and a droplet ejection head that can more easily and reliably remove air bubbles from liquid.

In order to achieve the above object, the invention according to claim 1,
a storage section for storing the liquid to be supplied to the ejection operation section of the droplet ejection head;
a degassing path for discharging the air inside the reservoir;
a discharge path through which the liquid discharged from the discharge operation unit passes;
with
The storage section includes a first storage section into which the liquid supplied from the outside flows, a second storage section into which the liquid supplied to the ejection operation section flows out, the first storage section, and the liquid storage section. a first filter provided between the second reservoirs;
the degassing path connects the first reservoir and the discharge path,
a supply path connecting the second reservoir and a first outflow port of the liquid to the ejection operation part is connected to an upper portion of the second reservoir;
The discharge path is provided on one side in a predetermined direction with respect to the reservoir,
the supply path is connected to the second reservoir at an end of the upper portion of the second reservoir that is closer to the discharge path;
The predetermined direction is equal to the longitudinal direction of the storage section when viewed from the inward normal direction of a predetermined ejection surface onto which the ejection operation section ejects droplets when attached to the droplet ejection head. A liquid storage tank characterized by:

Further, the invention according to claim 2 is the liquid storage tank according to claim 1.
The degassing path is characterized by having a second filter that allows the liquid and air to pass through .

Further, the invention according to claim 3 is the liquid storage tank according to claim 1 or 2 ,
The degassing passage is connected to an end of the upper portion of the first storage portion that is closer to the discharge passage.

Further, the invention according to claim 4 is the liquid storage tank according to any one of claims 1 to 3 ,
The first outflow port is provided on the opposite side of the discharge passage in the predetermined direction with respect to the reservoir.

Further, the invention according to claim 5 is the liquid storage tank according to any one of claims 1 to 4 ,
The supply path is characterized in that a connection end to the second reservoir is provided over a width of the second reservoir in a direction perpendicular to the predetermined direction within a plane perpendicular to the vertical direction. and

Further, the invention according to claim 6 is the liquid storage tank according to any one of claims 1 to 5 ,
The first filter is provided in a plane that intersects a plane perpendicular to the vertical direction and includes the longitudinal direction of the reservoir, and separates the first reservoir and the second reservoir. It is characterized by

Further, the invention according to claim 7 is the liquid storage tank according to any one of claims 1 to 6 ,
A position where the liquid flows into the first reservoir and a position where the supply path is connected to the second reservoir are diagonal positions in the reservoir. do.

Further, the invention according to claim 8 is
A droplet ejection head comprising the liquid storage tank according to any one of claims 1 to 7 .

Further, the invention according to claim 9 is
an ejection operation unit having a nozzle for ejecting a liquid and a common flow path communicating with the nozzle for supplying the liquid to the nozzle ;
A liquid storage tank having a storage section for storing the liquid to be supplied to the ejection operation section, a degassing passage for discharging air bubbles from the storage section, and a discharge passage for passing the liquid discharged from the ejection operation section. When,
with
The nozzle ejects the liquid from an opening provided on a predetermined ejection surface of the ejection operation section,
The storage section includes a first storage section into which the liquid supplied from the outside flows, a second storage section into which the liquid supplied to the ejection operation section flows out, the first storage section, and the liquid storage section. a first filter provided between the second reservoirs;
the degassing path connects the first reservoir and the discharge path ,
A supply path connecting the second storage section and a first outflow port of the liquid to the ejection action section in the liquid storage tank is arranged in the direction of the inward normal to the ejection surface of the second storage section. and connected to the second reservoir at the end of the upper part of the second reservoir that is closer to the discharge channel,
The common flow path has a second outlet for flowing out the liquid from the discharge operation part separately from the opening of the nozzle, and the connecting portion of the individual flow path connecting the common flow path and the nozzle is extending in a predetermined direction within a plane parallel to the ejection surface;
the discharge path is provided on the side of the second outlet in the predetermined direction with respect to the reservoir, and allows the liquid flowing out from the second outlet to pass therethrough;
The predetermined direction is equal to the longitudinal direction of the reservoir in a plan view viewed from the inward normal direction.
The liquid droplet ejection head is characterized by:

Further, according to the tenth aspect of the invention, there is provided the droplet ejection head according to the ninth aspect,
The degassing path is characterized by having a second filter that allows the liquid and air to pass through .

Further, according to the eleventh aspect of the invention, there is provided the droplet ejection head according to the ninth or tenth aspect ,
The degassing passage is connected to the end of the first reservoir on the second outflow port side in the predetermined direction.

Further, the invention according to claim 12 is the droplet discharge head according to any one of claims 9 to 11, wherein:
The first outflow port is provided on the opposite side of the second outflow port in the predetermined direction with respect to the reservoir.

Further, according to the thirteenth aspect of the invention, there is provided the droplet ejection head according to any one of the ninth to twelfth aspects,
the common flow path has a connecting portion of the individual flow path connecting the common flow path and the nozzle extending in a predetermined direction within a plane parallel to the ejection surface;
The supply path has a connection end to the second reservoir provided over a width of the second reservoir in a direction perpendicular to the predetermined direction within a plane parallel to the discharge surface. Characterized by

Further, according to the invention of claim 14 , the droplet discharge head according to any one of claims 9 to 13 ,
The first filter is provided in a plane that includes the longitudinal direction of the reservoir and intersects the discharge surface.

Further, according to the fifteenth aspect of the invention, there is provided the droplet ejection head according to any one of the ninth to fourteenth aspects,
A position where the liquid flows into the first reservoir and a position where the supply path is connected to the second reservoir are diagonal positions in the reservoir. do.

According to the present invention, it is possible to more easily and reliably remove air bubbles from the liquid in the liquid storage tank and the liquid droplet ejection head.

1 is a perspective view showing a droplet ejection head of this embodiment; FIG. Fig. 3 is a cross-sectional perspective view of the liquid storage tank, excluding the legs, as seen from the bottom side; FIG. 3 is a cross-sectional view for explaining an ink flow path of a droplet ejection head; FIG. 3 is a cross-sectional view for explaining an ink flow path of a droplet ejection head; FIG. 11 shows a cross-sectional view when the inkjet head is installed with inclination. FIG. 10 is a cross-sectional view showing a modification of the inkjet head;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a droplet ejection head 100 of this embodiment.

The droplet ejection head 100 is, for example, an inkjet head that is attached to an inkjet recording apparatus and ejects ink. The droplet ejection head 100 includes an ejection operation section 10, a liquid storage tank 20, and the like.

The ejection operation unit 10 has nozzles N (see FIGS. 3 and 4), and the bottom side (−Z side) is an ejection surface (predetermined ejection surface) on which nozzle openings are arranged. The ejection operation unit 10 ejects the liquid (ink) supplied from the liquid storage tank 20 from the nozzles N. As shown in FIG. In addition, the ejection operation section 10 can discharge the supplied ink that has not been ejected from the nozzles to the liquid storage tank 20 . The ejection operation unit 10 further includes a configuration and an electric circuit (not shown) that apply pressure fluctuations for ejecting ink from the nozzles.

The liquid storage tank 20 is attached to the side (+Z side) opposite to the nozzle opening side (ejection surface side) of the ejection operation section 10 . The liquid storage tank 20 includes a supply port 21 (inlet) for ink supplied from an external ink tank, and a liquid storage portion 23 (storage portion: see FIGS. 3 and 4) for storing (storing) the supplied ink (liquid). ), an outlet 25 (first outlet) through which ink flows from the liquid container 23 to the ejection operation section 10, and an inlet through which the ink discharged from the ejection operation section 10 flows. 26, and a discharge port 28 (outlet) for discharging the discharged ink to the outside.

Inside the liquid storage tank 20, there are an ink flow path (supply path) leading from the supply port 21 to the outlet 25 via the liquid storage portion 23, and an ink flow path (discharge path) leading from the inlet 26 to the outlet 28. are provided respectively. The outflow port 25 is connected to the ink inflow port 11 of the ejection operation section 10 , and the inflow port 26 is connected to the ink outflow port 17 (second outflow port) of the ejection operation section 10 . As a result, in the droplet ejection head 100, the ink flow path from the supply port 21 to the discharge port 28 of the liquid storage tank 20 is connected. The liquid storage tank 20 may be detachable from the ejection operation section 10 .

The liquid storage tank 20 has a long shape in the Y direction and a thin shape in the X direction when viewed from the top side (the side looking down on the supply port 21 and the discharge port 28), that is, when viewed from above (viewed from the +Z direction). It's becoming The supply port 21 and the discharge port 28 are arranged separately near both ends in the longitudinal direction (Y direction) of the liquid storage tank 20 . Similarly, the outflow port 25 and the inflow port 26 are also arranged separately near both ends in the longitudinal direction (Y direction) of the liquid storage tank 20 .

Further, although the liquid storage tank 20 is provided upward with the inward normal direction of the ejection surface as the reference direction (+Z direction), it is not excluded that the liquid storage tank 20 is slightly inclined. Further, the mounting surface of the liquid storage tank 20, that is, the surface of the ejection operation section 10 opposite to the ejection surface may not be parallel to the ejection surface, and may have irregularities. Hereinafter, the upper end means the highest position in the +Z direction (maximum Z coordinate), and the upper part means a partial range of the object including this upper end. In addition, the lower end means the range including the lowest position in the +Z direction (the Z coordinate is the smallest), and the lower end means the partial range of the object including this lower end.

The droplet ejection head 100 is often provided in the +Z direction with respect to the image forming surface (ink landing surface) of the inkjet recording apparatus, that is, the ejection surface is parallel to the XY plane, but this is not the only option. . It is also conceivable that they are slightly inclined (by 90 degrees or less) in the XZ plane (around the Y axis) and/or in the YZ plane (around the X axis). The vertical positional relationship (vertical relationship) between the supply port 21 and the discharge port 28 depends on the mounting direction of the droplet discharge head 100 .

When rotating within the XZ plane (around the Y axis), the position of the supply port 21 in the vertical direction is normally below the position of the discharge port 28, but this is not a limitation. Here, it is assumed that the supply port 21 and the discharge port 28 have the same height (that is, the ejection surface is parallel to the horizontal plane and the Z direction is the vertical direction). When the position of the discharge port 28 is higher than the position of the supply port 21, air bubbles mixed with or remaining in the ink in the ink flow path flow to the discharge port 28 due to buoyancy. easier.

FIG. 2 is a cross-sectional perspective view of the inside of the main body 20a of the liquid storage tank 20 as viewed from the bottom side. 3 and 4 are cross-sectional views illustrating ink flow paths of the droplet ejection head 100. FIG. 3A and 3B are cross-sectional views taken along a plane parallel to the YZ plane. In FIG. , the plane including the supply port 21 and the discharge port 28 is cut. 4 is a cross-sectional view along a plane parallel to the XZ plane, and FIGS. 4A to 4E are cross-sectional views along cross-sectional lines AA to EE in FIG. 3, respectively.

The liquid storage portion 23 provided in the body portion of the liquid storage tank 20 for storing ink is divided into an upstream side storage portion 23a (first storage portion) and a downstream side storage portion 23b (second storage portion) by a filter 231 provided inside. 2 reservoirs) and (FIGS. 2, 4(b), 4(c)). The filter 231 traps contaminants (foreign matter) in the ink to the downstream storage portion 23b. Here, the filter 231 is provided in a plane parallel to the YZ plane, that is, perpendicular to the horizontal plane (in a direction intersecting a plane perpendicular to the vertical direction), and extends in the longitudinal direction (a plane including the longitudinal direction). provided within).

The supply port 21 and the upstream housing portion 23a are connected by a first supply path 22 (FIGS. 2, 3(a), 3(b), and 4(a)), and are supplied from the outside. Ink flows into the upstream storage portion 23a. An open end 232 where the first supply path 22 connects to the upstream accommodating portion 23a is provided below the end of the upstream accommodating portion 23a on the side closer to the supply port 21 in the Y direction (see FIGS. 2 and 3 ( a)). Here, the lower part is a range including the lowermost part in the vertical direction as well. Further, the downstream accommodating portion 23b and the outflow port 25 are connected by a second supply path 24 (Figs. 2, 3(a), 3(b), 4(a) and 4(c). )), the ink to be supplied to the ejection operation section 10 flows out from the downstream storage section 23b. An open end 233 where the second supply path 24 connects to the downstream accommodating portion 23b is provided above the end of the downstream accommodating portion 23b in the Y direction that is closer to the discharge port 28 (discharge path 27) (Fig. 3(a), FIG. 4(c)). In this case, the top is also the top in the vertical direction.

Since the opening end 232 and the opening end 233 are provided at diagonal positions in the liquid containing portion 23 (FIGS. 2, 3A, and 4C), the ink flowing from the opening end 232 is It becomes easier for the filter 231 to pass through a wide range of the liquid containing portion 23 . As a result, even if the filter 231 is locally clogged with contaminants, the ink supply capacity is not greatly reduced. In addition, it is possible to prevent the ink from stagnation in the remaining portion due to the flow occurring only in a portion of the liquid containing portion 23 . The diagonal position here means that the opening is provided so as to include the diagonal vertex, and the opening may be provided on any of the three surfaces forming the vertex (those three may span multiple of the two planes).

Here, the supply port 21 and the outflow port 25 are on the same side in the Y direction (predetermined direction), and the opposite side (here, the +Y side) to the inflow port 26 and the discharge port 28 (discharge path 27). ), and the open end 233 is provided on the side opposite to the supply port 21 and the outflow port 25 in the Y direction (FIGS. 3(a) and 3(b)). In addition, the opening end 233 (connecting end to the second reservoir) is arranged in a plane perpendicular to the vertical direction (XY plane, that is, a plane parallel to the ejection surface) in a direction perpendicular to the Y direction (X direction). It is provided over the width of the downstream accommodation portion 23b (FIG. 4(c)). The second supply path 24 extends in the Y direction from the open end 233 above the downstream accommodation section 23b (+Z side), then bends downward to enter below the first supply path (−Z side). It is connected to the outflow port 25 (Fig. 3(a), Fig. 3(b), Fig. 4(a)). At this time, the second supply channel 24 and the common channel 12 have an appropriate diameter so as to obtain a flow velocity capable of moving bubbles in the direction in which the ink flows against the buoyancy in the portion where the ink flows downward. defined in

The inflow port 26 and the discharge port 28 are provided on the same side in the Y direction (predetermined direction) and on the side opposite to the supply port 21 and the outflow port 25 (here, the -Y side), The inflow port 26 and the discharge port 28 are connected by a discharge passage 27 extending in the Z direction (FIGS. 3(a), 3(b), and 4(e)). The discharge path 27 allows the ink discharged from the ejection operation section 10 to pass therethrough.

A check valve 271 is provided in the middle of the discharge path 27 (FIGS. 3(b) and 4(e)) to prevent the ink that has not passed through the filter 231 from flowing back into the ejection operation section 10. are preventing.

The upstream accommodation portion 23a and the discharge passage 27 are connected by a degassing passage 29 (FIGS. 3(a), 3(b), 4(c), and 4(d)). The degassing path 29 allows air (bubbles) to be discharged from the upstream accommodating portion 23a. A filter chamber 29a having a filter 291 is provided in the middle of the degassing passage 29 (FIGS. 3(a) and 4(d)). Here, the opening of the degassing channel 29 on the discharge channel 27 side is between the inlet 26 and the check valve 271 . Further, the opening 234 of the degassing passage 29 on the side of the upstream storage portion 23a is provided at the upper portion of the upstream storage portion 23a and at the end closer to the discharge passage 27 in the Y direction. This makes it easier for bubbles to flow into the degassing passage 29 due to buoyancy. Note that the filter 231 and the filter 291 may be continuous.

A common flow path 12 (manifold) connects the ink inlet 11 and the ink outlet 17 in the ejection operation section 10 (FIG. 3B). The common channel 12 communicates with a plurality of nozzles N, and distributes and supplies ink to each nozzle N via individual channels 15 (FIG. 4B). The common flow path 12 extends in the Y direction (the predetermined direction described above) parallel to the ejection surface at the connection portion with each individual flow path 15 . That is, the common flow path 12 in this portion extends parallel to the longitudinal direction of the liquid containing portion 23 .

The ink inlet 11 and the ink outlet 17 are located on opposite sides of the common flow path 12 in the Y direction so as to be connected to the outlet 25 and the inlet 26 of the liquid storage tank 20, respectively (see FIG. 3B). ), FIGS. 4(a) and 4(e)). That is, the ink outlet 17 is provided on the side opposite to the outlet 25 in the Y direction with respect to the liquid storage section 23 , and allows ink to be discharged from the ejection operation section 10 separately from the nozzle N.

As described above, the air bubbles in the upstream housing portion 23a flow through the degassing passage 29 to the discharge passage 27 and are discharged from the discharge port 28. As shown in FIG. On the other hand, when air bubbles flow into and remain in the downstream housing portion 23 b , the air bubbles flow once from the second supply passage 24 into the discharge operation portion 10 and then flow out to the discharge passage 27 via the common flow passage 12 . In other words, this air bubble flows along the same path as the ink that has not been ejected from the nozzle N.

FIG. 5 shows a cross-sectional view when the droplet ejection head 100 is attached at an angle. This cross section is the same as the cross section parallel to the YZ plane shown in FIG.

As shown in FIG. 5(a), even if the droplet discharge head 100 is rotated counterclockwise (counterclockwise) by 10 degrees around the X axis in the cross section parallel to the YZ plane, the above embodiment can be applied. The opening end 233 of the liquid storage tank 20 is maintained at the highest position (upper end position) in the vertical direction in the liquid storage portion 23 (downstream side storage portion 23b). When rotating around the X axis, as described above, the rotation is such that the discharge port 28 (discharge path 27 side) is relatively higher in the vertical direction than the supply port 21 (first supply path 22) side. Since the opening end 233 is provided at the upper end of the discharge port 28 side in the Y direction, the opening end 233 is kept at the upper end position of the liquid storage portion 23 (downstream side storage portion 23b). be

Similarly, the opening end 233 is maintained at the upper end position of the downstream accommodating portion 23b even when the droplet discharge head 100 is mounted in a state rotated by a predetermined angle (less than 90 degrees) around the Y-axis. When the nozzle surface is arranged to face a curved surface (such as the outer peripheral surface of a cylinder), the plurality of droplet ejection heads 100 are inclined at different angles around the Y axis. In 100, the opening end 233 of the liquid storage tank 20 is positioned in a range including the upper end of the downstream storage portion 23b.

Further, as shown in FIG. 5B, in the case where the inclination angle of the droplet discharge head 100 is fixed when the droplet discharge head 100 is attached in the inkjet recording apparatus, the opening end 233 is arranged so that the opening end 233 is horizontal. may be provided obliquely with respect to the wall surface (or so as to drop the vertices of the rectangular parallelepiped).

FIG. 6 is a cross-sectional view showing a modification of the droplet ejection head 100. As shown in FIG. The cross section is the same as in FIGS. 3(a) and 5. FIG.

Contrary to the example of FIG. 5B, in the case where the droplet discharge head 100 is not rotated around the X-axis when it is mounted, the opening end 233 to the second supply path 24 is the Y-axis. It may be provided at the upper end on the supply port 21 side with respect to the direction. Here, according to this, the opening end 232 of the first supply path 22 to the upstream storage portion 23a is positioned diagonally with the opening end 233 of the liquid storage portion 23, that is, the side of the discharge port 28 in the Y-axis direction. is located at the bottom of the

As described above, the liquid storage tank 20 of the present embodiment includes the liquid storage portion 23 that stores the ink to be supplied to the ejection operation portion 10 of the droplet ejection head 100 and the desorption unit that discharges the air inside the liquid storage portion 23 . an airway 29; The liquid containing portion 23 includes an upstream containing portion 23a into which ink supplied from the outside flows, a downstream containing portion 23b into which ink supplied to the ejection operation portion 10 flows out, an upstream containing portion 23a and a downstream containing portion 23b. and a filter 231 provided between the portions 23b. is connected to the upper portion of the droplet discharge head 100 of the downstream housing portion 23b.
In this way, in the liquid storage section 23 separated by the filter 231, the deaeration path 29 is provided only on the upstream side to bypass air bubbles, and from the downstream side storage section 23b, air bubbles are sent to the ejection operation section 10, Air bubbles are discharged via the ejection operation unit 10 . At this time, by arranging the opening end 233 of the second supply path 24 so as to include the upper end in the vertical direction, the air bubbles smoothly flow into the second supply path 24 due to the buoyancy in the liquid storage section 23 where the flow velocity is relatively slow. sent to. Thereby, the air bubbles can be reliably discharged from the liquid containing portion 23 .

The liquid storage tank 20 also includes a discharge path 27 through which ink discharged from the ejection operation section 10 passes, and a degassing path 29 connects the upstream storage section 23 a and the discharge path 27 . As a result, the air bubbles discharged from the upstream housing portion 23a are removed, and the ink that has passed through the degassing passage 29 is merged with the ink that has flowed out from the discharge operation portion 10 without being discharged, thereby efficiently collecting ( discharge).

Further, the discharge path 27 is provided on one side in the Y direction with respect to the liquid storage section 23, and the second supply path 24 is provided at the end of the upper portion of the downstream side storage section 23b on the side closer to the discharge path 27. It is connected to the downstream accommodating portion 23b. As a result, even if the droplet ejection head 100 to which the liquid storage tank 20 is attached is tilted around the X axis, it is normally rotated so that the discharge path 27 side faces upward in the vertical direction. Therefore, the air in the downstream accommodating portion 23b reliably flows into the second supply passage 24 due to buoyancy. Therefore, the air can be reliably discharged from the downstream accommodation portion 23b.

Further, the degassing path 29 is connected to the end of the upper portion of the upstream storage portion 23a that is closer to the discharge path 27 . As a result, when the droplet discharge head 100 is mounted tilted about the X-axis, not only the air inside the downstream accommodation portion 23b but also the air inside the upstream accommodation portion 23a is caused to flow into the degassing passage 29 by buoyancy. You can make sure that the air is exhausted.

Also, the outflow port 25 is provided on the side opposite to the discharge path 27 in the Y-axis direction with respect to the liquid storage portion 23 . That is, the ejection operation section 10 is connected to both ends of the liquid storage tank 20, and ink is supplied from one side and discharged from the other side.

Further, the second supply path 24 has an opening end 233, which is a connection end to the downstream accommodating portion 23b, in a direction perpendicular to the Y direction (X direction) within a plane perpendicular to the vertical direction (Z direction). It is provided over the width of the side accommodating portion 23b. As a result, even if the liquid droplet ejection head 100 to which the liquid storage tank 20 is attached is arranged obliquely around the Y axis, the opening end 233 is maintained at the top (upper end in the vertical direction), and the air flows smoothly without hindrance. It is discharged from the liquid containing portion 23 .

Also, the Y direction is the same as the longitudinal direction of the liquid containing portion 23 in plan view. That is, it is possible to obtain the thin liquid storage tank 20 and the ejection operation section 10, ie, the droplet ejection head 100, which do not take up much space in the thickness direction (X-axis direction).

Further, the filter 231 intersects a plane (plane parallel to the XY plane) perpendicular to the up-down direction (Z direction) and is provided in a plane including the longitudinal direction (Y direction) of the liquid storage section 23, and is arranged on the upstream side. It separates the accommodation portion 23a and the downstream accommodation portion 23b. As a result, the effective area of the filter 231 can be increased, allowing ink to pass through efficiently. In particular, even if the filter 231 is locally clogged with contaminants, the ink passes through many other parts, so the liquid storage tank 20 having the filter 231 can be used for a long period of time without deteriorating performance.

Further, the position where the ink flows into the upstream storage portion 23 a and the position (open end 233 ) where the second supply path 24 is connected to the downstream storage portion 23 b are diagonal in the liquid storage portion 23 . position. As a result, a wide ink flow is generated in the liquid containing portion 23, and stagnation at the end portion can be reduced. Also, this allows the wide range of the filter 231 to be used more effectively.

Further, the droplet ejection head 100 of this embodiment includes the liquid storage tank 20 described above.
Alternatively, the droplet ejection head 100 of the present embodiment includes an ejection operation section 10 having nozzles N for ejecting ink, a liquid storage section 23 for storing ink to be supplied to the ejection operation section 10, and air bubbles from the liquid storage section 23. and a liquid storage tank 20 having a degassing passage 29 for discharging the liquid.
The nozzle N ejects ink from an opening provided on the ejection surface (bottom surface) of the ejection operation section 10. The liquid storage section 23 includes an upstream storage section 23a into which ink supplied from the outside flows, and an ejection operation section. and a filter 231 provided between the upstream storage portion 23a and the downstream storage portion 23b. The degassing path 29 is connected to the upstream storage portion 23a, and the second supply path 24 connecting the downstream storage portion 23b and the ink outlet 25 to the ejection operation portion 10 in the liquid storage tank 20 is the ejection surface. is connected to the upper portion of the downstream accommodating portion 23b with respect to the inward normal direction.
Therefore, in this droplet discharge head 100 , air can be reliably discharged from both upstream and downstream sides of the filter 231 .

In addition, the ejection operation unit 10 has a common flow path 12 (manifold) that communicates with the nozzles N and supplies ink to the nozzles N. The common flow path 12 ejects ink separately from the openings of the nozzles N. It has an ink outflow port 17 for flowing out from the working part 10 . The liquid storage tank 20 has a discharge passage 27 through which the ink flowing out from the ink outlet 17 is passed, and a degassing passage 29 connects the upstream storage portion 23 a and the discharge passage 27 . Therefore, the air in the upstream storage section 23a is sent to the discharge path 27 via the degassing path 29, and the air in the downstream storage section 23b is sent from the second supply path 24 to the discharge path 27 via the common flow path 12. sent to Therefore, air bubbles in the ink on either side of the filter 231 of the liquid containing portion 23 are reliably discharged.

Further, in the common flow path 12, the connecting portion of the individual flow path 15 connecting the common flow path 12 and the nozzles N extends in a predetermined direction (Y direction) within a plane parallel to the ejection surface (bottom surface). The path 27 is provided on the ink outlet 17 side in the Y direction with respect to the liquid storage section 23, and the second supply path 24 is provided on the ink outlet 17 side in the Y direction with respect to the downstream storage section 23b. It is connected to the.
That is, the ink goes up from the bottom of the common flow path 12 extending in the Y direction to the ink outlet 17 and directly flows out to the discharge path 27, and the second supply path 24 is connected to the downstream storage portion 23b near the discharge path 27. As a result, even if the droplet discharge head 100 is slightly tilted about the X-axis and the discharge path 27 side is raised, the air can be properly discharged from the downstream housing portion 23b, and the common flow path 12 air is properly discharged to the discharge passage 27.

Further, the degassing path 29 is connected to the end on the ink outlet 17 side in the Y-axis direction with respect to the upstream housing portion 23a.
As a result, the air in the upstream housing portion 23a is easily and reliably sent to the discharge path 27, and the air in the common flow path 12 and the discharge path 27 is also smoothly and reliably discharged.

The outflow port 25 is provided on the opposite side of the ink outflow port 17 in the Y-axis direction with respect to the liquid containing portion 23 . As a result, the ink supply side and the ink discharge side are opposite to each other with respect to the Y-axis direction (longitudinal direction) of the ejection operation section 10, so that the ink flows smoothly. Also, this makes it easier and more reliable to discharge the air from the common flow path 12 .

Further, the common channel 12 extends in a predetermined direction (Y direction) in a plane parallel to the ejection surface at a connection portion of the individual channel 15 connecting the common channel 12 and the nozzles N, forming a second supply channel. 24 is the width of the downstream housing portion 23b in the direction (X direction) perpendicular to the Y direction in a plane parallel to the ejection surface (XY plane) of the opening end 233, which is the connecting end to the downstream housing portion 23b. are set across. As a result, even if the liquid droplet ejection head 100 to which the liquid storage tank 20 is attached is arranged obliquely around the Y axis, the opening end 233 is maintained at the top (upper end in the vertical direction), and the air flows smoothly without hindrance. It is discharged from the liquid containing portion 23 .

It should be noted that the present invention is not limited to the above embodiments, and various modifications are possible.
For example, in the above embodiment, the liquid storage tank 20 is provided directly above the ejection surface (+Z side), but it may be provided diagonally above (for example, at a position shifted in the ±X direction). Alternatively, the liquid storage tank 20 may be attached at an angle with respect to the inward normal direction of the ejection surface. Moreover, the shape of the liquid containing portion 23 (the downstream containing portion 23b) does not have to be a rectangular parallelepiped shape regardless of the mounting direction. In these cases, the open end 233 may be provided in a range including the upper surface and the upper end in the +Z direction (inward normal direction) in the attached state. Further, in the above embodiment, the ejection surface is horizontal, and the portion including the upper end in the direction perpendicular to the horizontal surface is defined as the upper portion. The upper portion and the lower portion may be determined based on the horizontal plane and the vertical direction when the droplet ejection head 10 is attached to a reference inkjet recording apparatus and placed in a reference posture.

In the above embodiment, the supply port 21 and the outlet 25 (the ink inlet 11) are on the same side in the Y direction, and the outlet 28 and the inlet 26 (the ink outlet 17) are on the same side. However, the supply port 21 and the discharge port 28 may be provided on opposite sides. Alternatively, the supply port 21 and the discharge port 28 may be provided on the same side in the Y direction, such that they are not on opposite sides.

Further, in the above-described embodiment, the opening end 233 where the second supply path 24 is connected to the downstream housing portion 23b is the end of the downstream housing portion 23b in the -Y direction, that is, the discharge path 27 side. Although it has been described as being provided at the end, if the liquid storage tank 20 (the inward normal direction of the ejection surface) is not provided inclined in the -Y direction, the position in the Y direction is not limited. good too. This is the same for the opening 234 on the side of the upstream accommodation portion 23a of the degassing passage 29 as well. If the shape of the upstream housing portion 23a and the shape of the downstream housing portion 23b are different, only one of them may be provided at the end in the -Y direction.

Similarly, in the above-described embodiment, the opening end 233 to which the second supply path 24 is connected to the downstream accommodation portion 23b is provided over the entire width of the downstream accommodation portion 23b in the X direction. If it is not assumed that the liquid storage tank 20 rotates around the Y axis and is tilted in the X direction, the opening end 233 is provided only in part of the width of the downstream side storage portion 23b in the X direction. may If the upper surface of the downstream housing portion 23b is not flat, the opening end 233 is provided in a range where ink can flow in by buoyancy at any angle according to the assumed maximum rotation angle around the Y axis. It is good if it is

Further, in the above embodiment, the first supply path 22, the lower part of the second supply path 24, and the discharge path 27 are provided at the same position in the X direction, but they are provided at different positions in the X direction. may Also, the upper portion of the second supply path 24 may not be provided directly above the liquid storage portion 23 .

In addition, in the above embodiment, the filters 231 and 291 are arranged perpendicular to the ejection surface, but they may be slightly inclined in the X-axis direction.

Further, in the above-described embodiment, the connection position of the first supply path 22 to the upstream storage section 23a and the connection position of the second supply path 24 to the downstream storage section 23b are diagonally opposite the liquid storage section 23. Although described as being in position, it is not limited to this. Each apex of the liquid containing portion 23 may be rounded, for example, so that the connecting position of the second supply path 24 is slightly shifted in order to provide the connection position of the liquid containing portion 23 at the top of the liquid containing portion 23, or simply It may be provided at a deviated position.

Further, the structure of the ejection operation section 10 is not limited to that of the above embodiment. For example, connecting portions to the individual channels 15 may be provided and arranged on the side surface (X side) instead of the bottom surface (−Z side) of the common channel 12 (manifold). Further, another discharge channel may be provided for collecting and discharging ink from the individual channel 15 . In this case, the bubbles that have flowed through the second supply channel 24 normally reach the ink outlet 17 directly from the common channel 12 without flowing into the sufficiently thin individual channels 15 .

Further, in the above embodiment, the ink is contained and discharged as a liquid, but the ink may include colorless clear ink or the like. Also, other than ink, for example, a liquid for forming a thin film such as a protective film, a liquid for forming a three-dimensional structure, a fixer, or the like may be ejected.
In addition, specific details such as the structure, configuration, and arrangement shown in the above embodiments can be changed as appropriate without departing from the scope of the present invention.

10 ejection operation unit 11 ink inlet 12 common channel 15 individual channel 17 ink outlet 20 liquid storage tank 20a main body 21 supply port 22 first supply channel 23 liquid storage unit 23a upstream storage unit 23b downstream storage unit 231 Filters 232, 233 Open end 234 Opening 24 Second supply passage 25 Outlet 26 Inlet 27 Discharge passage 271 Check valve 28 Discharge port 29 Degassing passage 29a Filter chamber 291 Filter 100 Droplet discharge head N Nozzle

Claims (15)

a storage section for storing the liquid to be supplied to the ejection operation section of the droplet ejection head;
a degassing path for discharging the air inside the reservoir;
a discharge path through which the liquid discharged from the discharge operation unit passes;
with
The storage section includes a first storage section into which the liquid supplied from the outside flows, a second storage section into which the liquid supplied to the ejection operation section flows out, the first storage section, and the liquid storage section. a first filter provided between the second reservoirs;
the degassing path connects the first reservoir and the discharge path,
a supply path connecting the second reservoir and a first outflow port of the liquid to the ejection operation part is connected to an upper portion of the second reservoir;
The discharge path is provided on one side in a predetermined direction with respect to the reservoir,
the supply path is connected to the second reservoir at an end of the upper portion of the second reservoir that is closer to the discharge path;
The predetermined direction is equal to the longitudinal direction of the storage section when viewed from the inward normal direction of a predetermined ejection surface onto which the ejection operation section ejects droplets when attached to the droplet ejection head. A liquid storage tank characterized by: 2. A liquid storage tank according to claim 1, wherein said degassing path has a second filter for passing said liquid and air. 3. The liquid storage tank according to claim 1, wherein the degassing passage is connected to an end of the upper portion of the first storage portion that is closer to the discharge passage. The liquid storage tank according to any one of claims 1 to 3, wherein the first outflow port is provided on a side opposite to the discharge path with respect to the predetermined direction with respect to the reservoir. . The supply path is characterized in that a connection end to the second reservoir is provided over a width of the second reservoir in a direction perpendicular to the predetermined direction within a plane perpendicular to the vertical direction. The liquid storage tank according to any one of claims 1 to 4. The first filter is provided in a plane that intersects a plane perpendicular to the vertical direction and includes the longitudinal direction of the reservoir, and separates the first reservoir and the second reservoir. The liquid storage tank according to any one of claims 1 to 5, characterized in that: A position where the liquid flows into the first reservoir and a position where the supply path is connected to the second reservoir are diagonal positions in the reservoir. The liquid storage tank according to any one of claims 1 to 6. A droplet ejection head comprising the liquid storage tank according to any one of claims 1 to 7. an ejection operation unit having a nozzle for ejecting a liquid and a common flow path communicating with the nozzle for supplying the liquid to the nozzle;
A liquid storage tank having a storage section for storing the liquid to be supplied to the ejection operation section, a degassing passage for discharging air bubbles from the storage section, and a discharge passage for passing the liquid discharged from the ejection operation section. When,
with
The nozzle ejects the liquid from an opening provided on a predetermined ejection surface of the ejection operation section,
The storage section includes a first storage section into which the liquid supplied from the outside flows, a second storage section into which the liquid supplied to the ejection operation section flows out, the first storage section, and the liquid storage section. a first filter provided between the second reservoirs;
the degassing path connects the first reservoir and the discharge path,
A supply path connecting the second storage section and a first outflow port of the liquid to the ejection action section in the liquid storage tank is arranged in the direction of the inward normal to the ejection surface of the second storage section. and connected to the second reservoir at the end of the upper part of the second reservoir that is closer to the discharge channel,
The common flow path has a second outlet for flowing out the liquid from the discharge operation part separately from the opening of the nozzle, and the connecting portion of the individual flow path connecting the common flow path and the nozzle is extending in a predetermined direction within a plane parallel to the ejection surface;
the discharge path is provided on the side of the second outlet in the predetermined direction with respect to the reservoir, and allows the liquid flowing out from the second outlet to pass therethrough;
The liquid droplet discharge head, wherein the predetermined direction is equal to the longitudinal direction of the reservoir when viewed from above in the inward normal direction. 10. The droplet ejection head according to claim 9, wherein the deaeration path has a second filter that allows the liquid and air to pass through. 11. The liquid droplet ejection head according to claim 9, wherein the degassing path is connected to the end of the first reservoir on the side of the second outlet in the predetermined direction. . The first outflow port according to any one of claims 9 to 11, wherein the first outflow port is provided on the opposite side of the second outflow port in the predetermined direction with respect to the storage portion. Droplet ejection head. the common flow path has a connecting portion of the individual flow path connecting the common flow path and the nozzle extending in a predetermined direction within a plane parallel to the ejection surface;
The supply path has a connection end to the second reservoir provided over a width of the second reservoir in a direction perpendicular to the predetermined direction within a plane parallel to the discharge surface. The droplet ejection head according to any one of claims 9 to 12. 14. The droplet ejection according to any one of claims 9 to 13, wherein the first filter is provided in a plane that includes the longitudinal direction of the reservoir and intersects the ejection surface. head. A position where the liquid flows into the first reservoir and a position where the supply path is connected to the second reservoir are diagonal positions in the reservoir. The droplet ejection head according to any one of claims 9 to 14.

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