JP2009184202A - Flow channel forming member, liquid injection head, and liquid injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain an influence of a bubble, even when narrowing the width of a flow channel forming member. <P>SOLUTION: This flow channel forming member 21 provided with a flow channel 30 for supplying ink of an ink cartridge to an injection head 5 is formed with a shelf part 36 extended along an ink conveying direction in a main flow channel 24, the shelf part 36 deters the bubble 38 from intruding, when the bubble 38 exists in the main flow channel 24, and allows a flow of the ink, and the ink flows through the shelf part 36 where the bubble 38 is deterred from intruding, when the bubble is mixed into the flow channel 30. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a flow path forming member, a liquid ejecting head, and a liquid ejecting apparatus.

  As a typical example of a liquid ejecting head, for example, an ink jet recording head that ejects ink droplets from nozzle openings using pressure generated by displacement of a piezoelectric element is known. A conventionally known ink jet recording head is supplied with ink from a fluid source such as an ink cartridge filled with ink to the head body, and the ink supplied from the head body is pressure generating means such as a piezoelectric element or a heating element. Is discharged from the nozzle by driving.

  For example, by inserting the ink supply needle into the ink cartridge, the ink in the ink cartridge is introduced from the introduction hole of the ink supply needle to the pressure chamber side of the head body. Also, there is a technique in which an ink cartridge arranged on the recording apparatus main body side and an ink supply needle on the head main body side are connected by an ink tube, and ink in the ink cartridge is introduced to the pressure chamber side of the head main body by a pumping means such as a pump. Are known.

  In this ink jet recording head, if bubbles that are present in the ink of the ink cartridge or bubbles that are mixed in the ink when the ink cartridge is attached or detached are supplied to the head body, defective ejection such as missing dots due to the bubbles. There is a problem that occurs. In order to solve such a problem, there has been proposed one in which a filter is attached to the ink flow path between the ink supply needle and the head body (see, for example, Patent Document 1). By attaching a filter to the ink flow path, it is possible to remove bubbles in the ink and prevent bubbles from flowing into the head body.

  By the way, the flow path forming member for connecting the ink cartridge and the head main body is provided with a valve body that allows the ink to flow when the pressure of the flow path on the head main body side is relatively lowered. There is known a filter provided with a foreign matter trapping filter having a surface along the ink flow direction at the inlet and the outlet. In an ink jet recording head equipped with such a flow path forming member, the area of the filter for trapping foreign matter can be increased without increasing the size of the flow path forming member in the width direction, thereby suppressing pressure loss. Thus, trapping of foreign matters can be performed reliably.

  Even in such a flow path forming member, it is the actual situation that mixing of bubbles blocks the flow path and adversely affects ink ejection. However, because the filter is provided in parallel with the flow path to suppress pressure loss, it is difficult to take measures for removing bubbles, and the demand for removing bubbles is increasing. Is the current situation.

Japanese Patent Laid-Open No. 11-10904

  The present invention has been made in view of the above situation, and an object of the present invention is to provide a flow path forming member capable of suppressing the influence of bubbles even when the dimension in the width direction is narrowed.

  In addition, the present invention has been made in view of the above situation, and provides a liquid ejecting head and a liquid ejecting apparatus provided with a flow path forming member capable of suppressing the influence of bubbles even when the dimension in the width direction is narrowed. For the purpose.

In order to achieve the above object, a flow path forming member of the present invention is a flow path forming member in which a flow path for supplying a fluid of a fluid source to a head body is formed. The step portion formed in the path is characterized in that, when bubbles are present in the fluid conveyance portion, intrusion of bubbles is prevented and fluid circulation is allowed.
For this reason, when air bubbles are mixed into the flow path, the fluid flows through the step where the intrusion of the air bubbles is prevented, and the influence of the air bubbles can be suppressed even when the width of the flow path forming member is narrowed.

  In the flow path forming member, the flow path is provided with a wide portion in a fluid flow direction, and the stepped portion is formed at an end of the flow path.

  Further, in the flow path forming member, a first filter having a surface along a flow direction of the fluid is provided between an outlet portion of the flow path and a fluid inlet of the head body. And

  Further, in the flow path forming member, the step portion holds the bubbles in the flow path when the flow path on the head main body side is at a relatively low pressure so that the fluid flows, and the head main body When the suction pressure is applied from the channel on the side, the bubble is circulated through the first filter.

In the flow path forming member, a second filter is provided between the fluid inlet of the flow path and the fluid source, and the first filter and the fluid inlet of the flow path There is provided a valve body that allows the fluid to flow when the pressure in the flow path on the head body side is relatively lowered, and the second filter is provided in parallel with the first filter. It is characterized by.
Accordingly, it is possible to suppress the influence of bubbles in the flow path forming member that includes a filter parallel to the flow path and has a narrow width.

In order to achieve the above object, a liquid jet head according to the present invention includes the flow path forming member, and a head body having a nozzle opening connected to the downstream side of the first filter of the fluid forming member. It is characterized by.
For this reason, even when the dimension in the width direction is narrowed, the influence of bubbles can be suppressed, and the liquid ejecting head including the flow path forming member that can be integrated with the head main body is obtained.

Further, in the liquid ejecting head, the flow path forming member is fixed to the head main body, and the downstream side of the first filter communicates with a reservoir chamber that communicates with a nozzle opening of the head main body. .
For this reason, even when the dimension in the width direction is narrowed, the influence of bubbles can be suppressed, and the liquid ejecting head including the flow path forming member that can be arbitrarily connected to the head main body is obtained.

In order to achieve the above object, a liquid ejecting apparatus according to an aspect of the invention includes the liquid ejecting head and a fluid source connected to the upstream side of the second filter of the flow path forming member. To do.
For this reason, even when the dimension in the width direction is narrowed, the liquid ejecting apparatus includes the flow path forming member that can suppress the influence of bubbles.

  1 is a schematic configuration of an ink jet recording apparatus provided with an ink jet head according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the main part of the ink jet head, and FIG. 3 is an external view of a flow path forming member. 4 is a plan view in FIG. 2, FIG. 5 is a view taken along line VV in FIG. 2, FIG. 6 is a detailed situation in FIG. 5, FIG. 7 is a conceptual situation in FIG. 9 shows a conceptual state of the main part of the flow path forming member, and FIG. 9 shows a view taken along arrow IX-IX in FIG.

An ink jet recording apparatus will be described with reference to FIG.
As shown in the figure, an ink jet recording apparatus (apparatus main body) 1 as a liquid ejecting apparatus is a liquid ejecting head in which a carriage 3 on which an ink cartridge 2 is mounted, a recording head 4 attached to the carriage 3 and the like are integrated. As an ink jet head 5. The carriage 3 is connected to a stepping motor 7 via a timing belt 6 and is guided by a guide bar 8 to reciprocate in the paper width direction (main scanning direction) of the recording paper 9. The carriage 3 has a box shape that opens to the top, and is attached so that the nozzle surface of the recording head 4 is exposed on the surface (lower surface) facing the recording paper 9 and accommodates the ink cartridge 2.

  Ink is supplied from the ink cartridge 2 to the recording head 4, and ink droplets are ejected onto the upper surface of the recording paper 9 while moving the carriage 3 to print images and characters on the recording paper 9 in a dot matrix. . In FIG. 1, reference numeral 10 denotes a cap that prevents the nozzle from drying by sealing the nozzle opening of the recording head 4 during a printing pause and performs a cleaning operation by applying a negative pressure to the nozzle surface of the recording head 4. 11 is a wiper blade for wiping the nozzle surface of the recording head 4, 12 is a waste ink storage unit for storing the waste ink sucked by the cleaning operation, and 13 is a control device for controlling the operation of the apparatus main body 1. It is.

  The illustrated ink ejecting head 5 includes a flow path forming member in which a flow path for supplying ink from the ink cartridge 2 to the recording head 4 is formed. In the example of FIG. 1, the example in which the ink cartridge 2 as a fluid source is accommodated in the carriage 3 has been described. However, the ink cartridge is accommodated in a location different from the carriage 3 and ink is supplied via a supply pipe. However, the present invention can also be applied to an ink jet recording apparatus that is configured to be fed to the flow path forming member of the recording head 4.

The ink jet head 5 will be described with reference to FIG.
As shown in the drawing, the ink ejecting head 5 is provided with a pressure generating means such as a piezoelectric element, for example, and ejects ink droplets from the nozzle openings of the nozzle plate 15 using the pressure generated by the displacement of the piezoelectric element. ing. The ink ejecting head 5 is provided with a reservoir chamber, and a flow path forming member 21 is fixed to the upper portion of the ink ejecting head 5. Ink as a fluid is supplied from the flow path forming member 21 to the head flow path of the ink ejection head 5, and the ink is sent from the head flow path to the reservoir chamber. The flow path forming member 21 is supplied with ink from the ink cartridge 2. For example, ink is supplied from the ink cartridge 2 to the flow path forming member 21 via a supply tube or an ink supply needle.

The flow path forming member 21 will be specifically described with reference to FIGS.
The flow path forming member 21 has a rectangular parallelepiped block shape having a rectangular board surface, and the main flow path 24 (flow path) is formed by the film 20 being welded to both board surfaces of the resin main body 22. It has become. The main channel 24 is in a wide state (in the wide portion) from the inlet portion 25 toward the outlet portion 26 (in the direction of ink flow), and the outlet portion 26 is provided with a first filter 27. The first filter 27 is arranged on a wide portion of the board surface with an area including the wide outlet portion 26, and a large area is secured. The first filter 27 mainly traps foreign matters contained in the ink that has circulated through a valve body 34 (mechanical constituent member) described later.

  The first filter 27 has a surface along the ink flow direction (a surface parallel to the disk surface), and the ink flowing through the main flow path 24 passes through the first filter 27 from the outside of the disk surface to the inside of the main body 22. It is sent to the lower part and sent from two discharge holes 28 to the ink jet head 5 (see FIG. 2). The ink sent to the main flow path 24 spreads from a narrow flow path to a wide flow path (expands in the width direction of the outlet portion) and is discharged from the discharge hole 28 at the end portion to one reservoir of the ink ejection head 5 (see FIG. 2). Sent to the room. That is, two discharge holes 28 connected to one reservoir chamber are provided for each main flow path 24, and four discharge holes 28 are provided in one flow path forming member 21 (see FIG. 3).

  Ink introduction holes 31 are respectively provided at upper ends of the flow path forming member 21, and ink is supplied from the ink cartridge 2 to the ink introduction holes 31. The ink supplied to one (left side in FIG. 4) of the ink introduction hole 31 is sent to the inlet 25 of the main channel 24 shown in FIG. 2 via the predetermined channel 30 and the other (right side in FIG. 4). The ink supplied to the ink introduction hole 31 is sent to the inlet 25 of the main flow path 24 provided on the back side of the paper surface of FIG.

  A flow path 30 connected to the ink introduction hole 31 is formed. As indicated by an arrow A in FIG. 4, the flow path 30 is directed to the lower side after the ink supplied to one of the ink introduction holes 31 (left side in FIG. 4) circulates in the upper side in FIGS. 4 and 5. It is formed so as to flow through the second filter 32 and to be sent to the ink chamber 33 shown in FIG. Further, as shown by the arrow B in FIG. 4, the flow path 30 is shown in FIG. 4 after the ink supplied to the other (right side in FIG. 4) ink introduction hole 31 circulates in the lower side in FIGS. 2 is distributed through the second filter 32 shown in FIG. 2 so as to be directed upward in FIGS. 4 and 5 and sent to the ink chamber 33 existing on the back side of the paper surface of FIG. The second filter 32 has a plane parallel to the board surface and is arranged in parallel with the first filter 27.

  A valve body 34 is provided in each of the flow paths 30 between the ink introduction hole 31 (second filter 32) and the ink chamber 33 (the inlet 25 of the main flow path 24), and the ink ejection head 5 (see FIG. 2). When the pressure in the reservoir chamber decreases, that is, when the ink is ejected and the pressure on the main flow path 24 side relatively decreases, the valve element 34 operates to allow the ink to flow. That is, when the ink is supplied from the ink introduction hole 31 at a predetermined pressure, the valve body 34 is closed when the ink is stored in the reservoir chamber of the ink ejecting head 5 (see FIG. 2). When the pressure on the wake side is lowered due to ink discharge, the valve body 34 is opened by the negative pressure and ink is supplied.

  In the main flow path 24 of the flow path forming member 21 of the present embodiment, a shelf portion 36 is formed as a stepped portion extending in the ink transport direction (vertical direction in FIG. 2). The shelf 36 is formed at the end of the main flow path 24 (both ends of the wide portion), and the depth is reduced. By providing the shelf 36 at the end of the main flow path 24, when bubbles are mixed in the main flow path 24, the shelf 36 has a shallow depth due to the bubbles floating in the narrow flow path near the inlet 25. Air bubbles are prevented from entering the glass. For this reason, even if bubbles are mixed into the main flow path 24, the ink flows through the shelf 36 and is supplied to the ink ejecting head 5 (see FIG. 2).

The main flow path 24 will be conceptually described based on FIGS.
As shown in the figure, the main flow path 24 is formed by welding the film 20 to the main body 22. Since the main channel 24 is formed to extend in the vertical direction, the ink flows in the direction along the gravity direction. A shelf portion 36 having a shallow depth is formed at the end of the main flow path 24, and when the bubble 38 exists in the main flow path 24, the bubble 38 does not enter the shelf section 36 and buoyancy causes the inlet portion 25 of the main flow path 24. Ascend to the side and stay in the main flow path 24. For this reason, even if the pressure in the reservoir chamber of the ink ejecting head 5 (see FIG. 2) is reduced in a state where the bubbles 38 are present in the main flow path 24, the ink passes through the shelf 36 and becomes a foreign matter in the first filter 27. Is trapped and sent to the discharge hole 28 side (see arrow in FIG. 9).

  If the buoyancy F of the bubble 38 is large due to the drag force f exerted on the bubble 38 by the ink flow, it will not flow downstream, that is, will not be sent to the reservoir chamber of the ink ejecting head 5 (see FIG. 2). The floating state is maintained. When the drag force f exerted by the ink flow exceeds the buoyancy F of the bubbles 38, the bubbles 38 are caused to flow downstream and are discharged downstream of the first filter 27.

  The width and depth (parameters) of the shelf 36 are set so as to be in the following state. That is, the state of the shelf 36 parameter is when the pressure in the reservoir chamber of the ink ejecting head 5 (see FIG. 2) is lowered and the valve body 34 is opened and ink is circulated (when printing is performed). The buoyancy F of the bubble 38 is larger than the drag force f exerted on the bubble 38 by the ink flow, and the floating state is maintained. When the negative pressure is applied to the nozzle surface and the cleaning operation is performed, the negative pressure on the downstream side increases. Thus, the bubble 38 is discharged (the drag force f exerted on the bubble 38 by the ink flow is greater than the buoyancy F of the bubble 38).

  Accordingly, it is possible to control the bubbles 38 by appropriately setting the shelf 36 parameter.

  In the embodiment described above, even when the first filter 27 is provided parallel to the surface along the ink flow direction and the width of the flow path forming member 21 is narrowed, the shelf portions formed at both ends of the main flow path 24. 36 makes it possible to prevent the flow path of the bubbles 38 from being blocked. Further, by setting the depth and width of the shelf 36 so that the bubbles 38 are stagnated at the flow rate at the time of printing and discharged at the negative pressure flow rate at the time of cleaning, The allowable range for printing can be greatly expanded. Furthermore, the influence of the bubbles 38 can be suppressed with a simple configuration that forms the shelf 36.

  In the above-described embodiment, the ink jet recording head has been described as an example of the liquid ejecting head. However, the present invention is widely intended for the entire liquid ejecting head, and ejects liquid other than ink. Of course, the present invention can also be applied to a liquid ejecting head. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FEDs (field emission displays). Examples thereof include an electrode material ejection head used for electrode formation, a bioorganic matter ejection head used for biochip production, and the like.

1 is a schematic configuration diagram of an ink jet recording apparatus. FIG. 3 is a cross-sectional view of a main part of the ink ejecting head. It is an external view of a flow path forming member. FIG. 3 is a plan view in FIG. 2. It is a VV line arrow directional view in FIG. FIG. 6 is a detailed view in FIG. 5. FIG. 7 is a conceptual diagram of FIG. 6. It is a principal part conceptual diagram of a flow-path formation member. It is the IX-IX line arrow directional view in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Inkjet recording head, 2 Ink cartridge, 4 Recording head, 5 Ink jet head, 15 Nozzle plate, 20 Film, 21 Flow path formation member, 22 Main body, 24 Main flow path, 25 Inlet part, 26 Outlet part, 27 1st Filter, 28 discharge hole, 30 flow path, 31 ink introduction hole, 32 second filter, 33 ink chamber, 34 valve element, 36 shelf, 38 bubble

Claims (8)

In the flow path forming member in which the flow path for supplying the fluid of the fluid source to the head body is formed,
A step portion extending in the fluid conveyance direction is formed in the flow path, and the step portion prevents a bubble from entering when a bubble is present in the fluid conveyance portion and allows a fluid to flow. Road forming member. In the flow path forming member according to claim 1,
The flow path forming member, wherein the flow path is provided with a wide portion in a fluid flow direction, and the stepped portion is formed at an end of the flow path. The flow path forming member according to claim 2,
A flow path forming member comprising a first filter having a surface along a flow direction of the fluid between an outlet portion of the flow path and a fluid inlet of the head body. In the flow path forming member according to claim 3,
The step portion is
When the flow path on the head body side becomes relatively low pressure and the fluid flows, the bubbles are retained in the flow path, and when suction pressure is applied from the flow path on the head body side, A flow path forming member characterized in that the air bubbles are circulated through the first filter. The flow path forming member according to claim 4,
A second filter is provided between the fluid inlet of the flow path and the fluid source,
Between the first filter and the fluid inlet of the flow path is provided with a valve body that allows the fluid to flow when the pressure of the flow path on the head body side is relatively reduced,
The flow path forming member, wherein the second filter is provided in parallel with the first filter. The flow path forming member according to any one of claims 1 to 5,
A liquid ejecting head comprising: a head main body connected to the downstream side of the first filter of the fluid forming member and having a nozzle opening. The liquid ejecting head according to claim 6,
The liquid jet head, wherein the flow path forming member is fixed to a head body, and a downstream side of the first filter communicates with a reservoir chamber that communicates with a nozzle opening of the head body. A liquid ejecting head according to claim 6;
And a fluid source connected to the upstream side of the second filter of the flow path forming member.

Images