JP2007230101A - Liquid jet-head unit and liquid jet apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jet-head unit and a liquid jet apparatus capable of discharging bubbles in a liquid passage comparatively easily to maintain a good discharge performance all the time. <P>SOLUTION: The liquid jet-head unit is equipped with a liquid storing member 11 wherein liquid is stored, a head body for discharging the liquid supplied from the liquid storing member 11 as liquid droplets, a holding member 21 to which the liquid storing member 11 is fitted and having a supply route 24 constituting a part of the liquid passage connecting the liquid storing member 11 to the head body, and a liquid supply needle 35 having a penetration hole communicating with the supply route 24 via a filter 36. A bubble storing section 41 wherein the bubbles in the liquid passage is stored is provided on the upstream side of the filter 36, and an open/close valve 44, which opens on the upper side in the vertical direction and is released with the liquid storing member 11 fitted to the holding member 21, is provided above the bubble storing member 41. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid ejecting head unit and a liquid ejecting apparatus that eject liquid supplied from a liquid storage unit to a head body as droplets from a nozzle opening, and in particular, an ink jet recording head and ink jet that eject ink droplets as droplets. The present invention relates to a type recording apparatus.

  In an ink jet recording head unit (hereinafter referred to as a head unit) having an ink jet recording head, which is a typical example of a liquid ejecting head, generally, an ink inserted from an ink cartridge filled with ink into the ink cartridge. Ink is supplied to the head main body through an ink flow path formed in a holding member that holds the supply needle and the ink cartridge, and the ink supplied to the head main body is ejected from the nozzle opening by driving a piezoelectric element or the like. The

  In such a head unit, if bubbles that exist with the ink in the ink cartridge or bubbles that are mixed in the ink when the ink cartridge is attached or detached are supplied to the head unit together with the ink, the bubbles may cause dot dropout or the like. There is a problem that defective discharge occurs. In order to solve such problems, a filter is installed between the ink supply needle inserted into the ink cartridge and the base on which the ink supply needle is fixed to remove bubbles mixed in the ink. There is something which was made to do (for example, refer to patent documents 1).

  In this way, bubbles are trapped when ink is ejected by the filter, so that bubbles can be prevented from flowing into the head body (recording head). The bubbles trapped in the filter are generally discharged to the outside by a so-called suction operation that sucks ink from the nozzle openings of the head body. That is, by sucking ink from the nozzle opening and causing the ink to generate a flow rate that is faster than the flow rate of ink during normal ink discharge, the bubbles pass through the filter together with the ink and are discharged from the nozzle opening.

  Here, when the volume of bubbles accumulated in the filter portion increases, the pressure loss in the filter portion at the time of ink suction (ink discharge or suction operation) increases accordingly. When the pressure loss exceeds a certain value, there is a problem that even when ink is ejected, bubbles pass through the filter together with the ink, resulting in ejection defects such as missing dots.

  Such a problem can be solved by executing the suction operation described above relatively frequently. However, during the suction operation, as described above, the ink has a faster flow rate than during ink discharge. Therefore, if the suction operation is frequently performed, a large amount of ink is consumed, and the amount of ink used for actual printing or the like decreases. There is a problem that it ends up. That is, there is a problem that the amount of ink consumed increases and the running cost increases.

  Such a problem exists not only in an ink jet recording head that ejects ink droplets but also in other liquid ejecting heads.

Japanese Patent Laid-Open No. 11-10904 (FIG. 1 etc.)

  In view of such circumstances, the present invention provides a liquid ejecting head unit and a liquid ejecting apparatus that can discharge bubbles in a liquid channel relatively easily and can always maintain good ejection characteristics. Is an issue.

A first aspect of the present invention that solves the above problems is a head having a liquid storage member having a storage chamber in which liquid is stored, and a plurality of nozzle openings for discharging liquid supplied from the liquid storage member as droplets. A holding member having a main body, a mounting portion to which the liquid storage member is mounted, and a supply path that forms part of a liquid flow path connecting the storage chamber of the liquid storage member and the head main body; A liquid supply needle having a through hole that is fixed to the member and communicates with the supply path via a filter, and has a bubble storage section that stores bubbles in the liquid flow path upstream of the filter. A liquid jet head unit having a discharge port provided at an upper part of the bubble storage part and provided with an open / close valve that opens upward in a vertical direction and is opened when the liquid storage member is mounted on the holding member. Located in Tsu door.
In the first aspect, the bubbles in the liquid channel are stored in the bubble storage unit, and the bubbles in the bubble storage unit are discharged to the outside through the discharge port in a state where the liquid storage member is attached to the holding member. . Therefore, it is possible to reduce the amount of consumption of the liquid stored in the liquid storage member while maintaining good discharge characteristics without performing a so-called suction operation.

A second aspect of the present invention includes a filling member having a filling chamber filled with the same liquid as the liquid stored in the storage chamber, and the filling member has a vertical direction at the bottom of the filling chamber. A first opening characterized by having a connecting port provided with an on-off valve that opens downward and is connected to the discharge port and that is opened while the liquid storage member is held by the holding member. In the liquid jet head unit of the aspect.
In the second aspect, the bubbles in the liquid channel can be more reliably removed by allowing the bubbles in the bubble storage portion to flow into the filling chamber via the discharge port and the connection port.

According to a third aspect of the present invention, in the liquid ejecting head unit according to the second aspect, the filling member is formed integrally with the liquid storage member.
In the third aspect, the opening / closing operation of the opening / closing valve can be easily linked to the attachment / detachment of the liquid storage member.

According to a fourth aspect of the present invention, the through hole of the liquid supply needle also serves as the bubble storage portion, the discharge port is provided at a tip portion of the liquid supply needle, and the discharge port and the filling chamber are The liquid ejecting head unit according to the third aspect is characterized in that the liquid ejecting head unit is provided in the liquid storing member and communicates via a part of an introduction path connecting the through hole and the storing chamber.
In the fourth aspect, the liquid in the storage chamber is supplied from the discharge port into the through hole, and the bubbles in the through hole (bubble storage unit) flow into the filling chamber of the liquid storage member. As a result, it is possible to reduce the consumption of the liquid stored in the liquid storage member while maintaining good discharge characteristics, and to reduce the size of the head unit.

According to a fifth aspect of the present invention, in the liquid ejecting head unit according to the fourth aspect, the filling chamber is disposed in a region facing the liquid supply needle.
In the fifth aspect, the bubbles in the through hole (bubble storage part) surely flow into the filling chamber of the liquid storage member.

According to a sixth aspect of the present invention, in the liquid ejecting head unit according to any one of the first to third aspects, the bubble storage section is provided in a region facing the supply path.
In the sixth aspect, since most of the bubbles are trapped by the filter in the region facing the supply channel, the bubbles in the liquid channel are formed by providing the bubble reservoir in the region facing the supply channel. It becomes easy to gather in the bubble reservoir.

According to a seventh aspect of the present invention, in the liquid ejecting head according to the sixth aspect, the bubble storage portion and the through hole of the liquid supply needle communicate with each other via a communication path extending in a horizontal direction. In the unit.
In the seventh aspect, the bubbles stored in the bubble storage portion are less likely to flow into the through hole, and the occurrence of defective discharge such as missing dots can be further reliably prevented.

An eighth aspect of the present invention is a liquid ejecting apparatus including the liquid ejecting head unit according to any one of the first to seventh aspects.
In the eighth aspect, it is possible to realize a liquid ejecting apparatus that improves reliability and durability and reduces running costs.

Hereinafter, the present invention will be described based on embodiments.
(Embodiment 1)
FIG. 1 is a schematic perspective view of a recording apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, an ink jet recording apparatus 10 that is a liquid ejecting apparatus according to the present embodiment has a plurality of different colors such as black (B), cyan (C), magenta (M), and yellow (Y). A carriage 13 on which an ink jet recording head unit 12 (hereinafter referred to as a head unit) on which an ink cartridge (liquid storage means) 11 having a storage chamber for storing the ink is mounted is mounted. The mounted carriage 13 is provided on a carriage shaft 15 attached to the apparatus main body 14 so as to be movable in the axial direction. Then, the driving force of the driving motor 16 is transmitted to the carriage 13 via a plurality of gears and a timing belt 17 (not shown), so that the carriage 13 is moved along the carriage shaft 15. On the other hand, the apparatus main body 14 is provided with a platen 18 along the carriage shaft 15, so that a recording medium S such as paper fed by a paper feeding device (not shown) is conveyed on the platen 18. ing.

  Further, a capping member 19 has a cap member 19 that seals a nozzle forming surface in which a later-described nozzle opening of the head unit 12 opens in a position corresponding to the home position of the carriage 13, that is, in the vicinity of one end of the carriage shaft 15. A device 20 is provided. The cap forming member 19 seals the nozzle forming surface, thereby preventing the ink from drying.

  Here, the head unit 12 according to the present embodiment will be described. 2 is an assembled perspective view of the head unit (excluding the ink cartridge) according to the present embodiment, and FIG. 3 is an exploded perspective view thereof. FIG. 4 is a cross-sectional view showing an outline of a main part of the head unit, that is, a connection portion between the ink cartridge and the ink supply needle.

  As shown in the figure, the cartridge case 21 has a cartridge mounting portion 22 in which the ink cartridge 11 is mounted. Further, a tubular flow path forming section 25 in which a plurality of ink supply paths 24 each having one end opened to each cartridge mounting section 22 and the other end opened to the head case side described later are formed on the bottom surface of the cartridge case 21. Is protruded (see FIG. 4). In such a cartridge case 21, a plurality of ink cartridges 11 are mounted as described above.

  A head body 27 that holds a piezoelectric element unit 26 having a plurality of piezoelectric elements on the lower surface side of the cartridge case 21 and discharges ink droplets from nozzle openings by driving the piezoelectric elements on an end surface opposite to the cartridge case 21. Is fixed, and a seal member 29 and a circuit board 30 are sandwiched between the cartridge case 21 and the head case 28.

  The head case 28 fixed to the lower surface side of the cartridge case 21 is provided with a storage chamber 31 for storing the piezoelectric element unit 26 (26A, 26B) and positioning and fixing the piezoelectric element. For example, the head main body 27 of the present embodiment includes a piezoelectric element unit 26A for discharging black ink and a piezoelectric element unit 26B for discharging color ink. Two accommodation chambers 31 for accommodating the units 26A and 26B are provided side by side. The seal member 29, the circuit board 30, the head case 28, and the head main body 27 are stacked on the lower surface side of the cartridge case 21, and a frame 33 having a window portion 32 that exposes the nozzle opening of the head main body 27 on the outer side. It is held by being fitted and fixed to the cartridge case 21 with a screw 34 (see FIG. 1).

  On the other hand, as shown in FIG. 4, a plurality of ink supply needles 35 inserted into the insertion opening of the ink cartridge 11 are provided on the upper surface side of the cartridge case 21, that is, on the opening portion of the ink supply path 24 of each cartridge mounting portion 22. However, it is fixed via a filter 36 for removing bubbles and foreign matters in the ink. In the present embodiment, each ink supply needle 35 has a flange near the end on the cartridge case 21 side, and melts a fusion projection provided on a joint surface of the flange with the cartridge case 21. That is, it is fixed to the cartridge case 21 by ultrasonic fusion.

  The ink supply needle 35 has a needle portion 38 that is inserted into the insertion portion 37 of the ink cartridge 11, and a plurality of minute holes 39 are formed in the tip portion of the needle portion 38, and the inside thereof is hollow. Yes. That is, a through hole 40 communicating with the plurality of minute holes 39 is formed inside the needle portion 38. In addition, the ink supply needle 35 according to the present embodiment has a bubble storage portion 41 in which bubbles included in the ink are stored in a region facing the ink supply path 24, and the bubble storage portion 41, the through hole 40, and the like. The communication path 42 is connected. The communication path 42 extends substantially in the horizontal direction with the head unit 12 mounted on the carriage 13.

  Here, the bubble storage unit 41 according to the present embodiment is formed such that the height in the vertical direction from the filter 36 is higher than the height of the communication path 42, and the width becomes narrower toward the upper side in the vertical direction. Has been. As a result, bubbles in the ink flow path constituted by the through hole 40, the communication path 42, and the like are collected and stored in the upper part of the bubble storage unit 41. A discharge port 43 that opens upward in the vertical direction is provided above the bubble storage unit 41. The discharge port 43 is opened and closed when the ink cartridge 11 is attached to the cartridge case 21. A valve 44 is provided. That is, when the ink cartridge 11 is not attached to the cartridge case 21, the discharge port 43 is closed by the on-off valve 44.

  Further, the ink cartridge 11 into which the needle portion 38 of the ink supply needle 35 is inserted has a storage chamber (not shown) that communicates with the insertion portion 37 and holds ink to be supplied to the head main body 27. In addition, a filling chamber 45 filled with the same liquid as the liquid in the storage chamber is provided. The filling chamber 45 is provided in a region facing the bubble storage portion 41 of the ink supply needle 35. The bottom of the filling chamber 45 opens toward the lower side in the vertical direction and opens to the discharge port 43 of the bubble storage portion 41. The connecting port 46 is connected. The connecting port 46 is also provided with an open / close valve 47 that is opened in a state where the ink cartridge 11 is mounted on the cartridge case 21, similarly to the discharge port 43.

  These on-off valves 44 and 47 are not particularly limited as long as the ink cartridge 11 is opened in a state where the ink cartridge 11 is mounted on the cartridge case 21. For example, in the present embodiment, the on-off valves 44 and 47 are provided on the discharge port 43. 44 and the on-off valve 47 provided at the connection port 46 are operated by the interaction between the two, and the discharge port 43 and the connection port 46 are opened while the ink cartridge 11 is mounted on the cartridge case 21. ing. Specifically, each of the on-off valves 44 and 47 includes a valve member 48 and an urging member 49 that urges the valve member 48 toward the discharge port 43 or the connection port 46. Each valve member 48 is disposed in the bubble reservoir 41 or the filling chamber 45 and is always urged toward the discharge port 43 or the connection port 46 by an urging member 49 made of, for example, a spring. Therefore, in a state where the ink cartridge 11 is not attached to the cartridge case 21, the discharge port 43 and the connection port 46 are sealed by the on-off valves 44 and 47, respectively. Thus, in the state where the discharge port 43 and the connection port 46 are sealed, the tip of the valve member 48 according to the present embodiment protrudes slightly outward from the discharge port 43 or the connection port 46. When the ink cartridge 11 is attached to the cartridge case 21, as shown in FIG. 4, the valve members 48 come into contact with each other and are pressed to open the discharge port 43 and the connection port 46. Of course, the urging force of the urging member 49 constituting each of the on-off valves 44 and 47 is adjusted as appropriate so that the discharge port 43 and the connection port 46 are opened when the valve members 48 are pressed together in this way. It is necessary to keep it.

  When the discharge port 43 and the connection port 46 are opened and the bubble storage unit 41 and the filling chamber 45 communicate with each other, the bubbles stored in the bubble storage unit 41 are filled through the discharge port 43 and the connection port 46. It will flow into 45. At the same time, the liquid filled in the filling chamber 45 flows into the bubble reservoir 41, that is, into the ink flow path. As described above, the filling chamber 45 is filled with the same liquid as the liquid stored in the storage chamber, for example, the same color ink in this embodiment. Such a problem does not occur.

  Thus, by providing the bubble storage part 41 on the upstream side of the filter 36, the bubbles in the ink flow path are stored in the bubble storage part 41. That is, when the ink is supplied from the ink cartridge 11 to the head main body 27, the bubbles trapped by the filter 36 are stored in the bubble storage unit 41. Further, the stored bubbles are discharged from the discharge port 43 to the outside (filling chamber 45). Thereby, it is possible to prevent bubbles in the ink flow path from being supplied to the head main body 27 together with the ink and causing ejection failures such as missing dots. In addition, it is not necessary to discharge bubbles by a so-called suction operation, so that useless ink can be prevented and running costs can be reduced.

  Furthermore, in this embodiment, since the bubble storage part 41 is provided in the area | region which opposes the ink supply path 24, a bubble can be discharged | emitted efficiently outside. That is, when the ink is supplied to the ink supply path 24, the bubbles mixed in the ink are trapped by the filter 36. Therefore, by providing the bubble storage section 41 on the ink supply path 24, The bubbles in the ink flow path can be collected in the bubble storage unit 41 more reliably. Further, in the present embodiment, the backflow of bubbles is suppressed by connecting the through hole 40 and the bubble storage portion 41 via a communication path 42 extending in a substantially horizontal direction. Therefore, it is possible to prevent the bubbles stored in the bubble storage unit 41 from entering the through hole 40, and to more reliably prevent the occurrence of dot omission due to the bubbles.

  The position where the bubble storage unit 41 and the filling chamber 45 are provided is not particularly limited as long as it is upstream of the filter 36. For example, as shown in FIG. 5, the through hole 40 (needle portion 38) of the ink supply needle 35 is disposed in a region facing the ink supply path 24, and the ink flow path is branched on the filter 36 to thereby form the through hole. The bubble storage part 41 may be formed in the region facing the ink supply path 24 together with 40. Of course, even in such a configuration, the bubbles in the ink flow path are stored in the bubble storage section 41, and the stored bubbles are discharged out of the flow path (filling chamber 45) via the discharge port 43 and the connection port 46. Is done.

  In the present embodiment, the example in which the filling chamber 45 is provided in the ink cartridge 11 has been described. However, the present invention is not limited to this. For example, a filling member having a filling chamber can be used together with the ink cartridge 11. It may be attached to the cartridge case 21.

(Embodiment 2)
FIG. 6 is a cross-sectional view schematically illustrating a main part of the head unit according to the second embodiment, that is, a connection portion between the ink cartridge and the ink supply needle.

  This embodiment is an example in which the through hole 40A of the ink supply needle 35A to which ink is supplied from the ink cartridge 11 also serves as the bubble storage portion 41. Specifically, as shown in FIG. 6, in the present embodiment, for example, the diameter of the ink supply needle 35 </ b> A (needle portion 38 </ b> A) has a diameter of about 2 to 2.5 mm instead of a plurality of minute holes. A discharge port 43A is provided. The discharge port 43A is provided with an on-off valve 44A that is opened when the ink cartridge 11 is mounted on the cartridge case 21.

  The structure of the on-off valve 44A is not particularly limited, and is configured by a valve member 48A and an urging member 49A as in the first embodiment. However, the present embodiment is different from the configuration of the first embodiment in that the valve member 48A is pressed by the biasing member 49A from the lower side.

  On the other hand, in the ink cartridge 11A, a filling chamber 45A is provided in a region facing the ink supply needle 35A, that is, on the upper side in the vertical direction of the insertion portion 37A of the ink cartridge 11A, and the filling chamber 45A and the insertion portion 37A are It communicates via a part of an ink introduction path 50 that connects a storage chamber (not shown) and the insertion portion 37A. That is, the ink introduction path 50 is formed from the insertion portion 37A toward the upper side in the vertical direction, and is branched into the first introduction path 51 and the second introduction path 52 in the middle thereof, and the first introduction path 51 remains as it is. It extends toward the upper side in the direction and communicates with the filling chamber 45A. On the other hand, the second introduction path 52 extends in a direction intersecting with the first introduction path 51 and communicates with a storage chamber (not shown).

  In such a configuration of the present embodiment, when the ink cartridge 11 is mounted on the cartridge case 21 and the ink supply needle 35A is inserted into the insertion portion 37A, the distal end portion of the valve member 48A of the on-off valve 44A becomes the insertion portion. Abutting on the abutting portion 53 provided in 37A, it is pushed into the inside of the through hole 40A, thereby opening the outlet 43A. The ink in the storage chamber of the ink cartridge 11 is supplied into the through hole 40A through the discharge port 43A, and bubbles stored in the through hole 40A (bubble storage part 41A) are supplied through the discharge port 43A. Then, it flows into the filling chamber 45 </ b> A through the first introduction path 51.

  Even in such a configuration, as in the case of the first embodiment, the bubbles in the ink flow path can be discharged well out of the ink flow path, and ejection defects such as missing dots can be reliably prevented. . Further, since it is not necessary to perform a so-called suction operation, the running cost can be reduced.

  In the configuration of the present embodiment, a part of the ink flow path (ink introduction path 50) for supplying ink to the head main body 27 also serves as a flow path for discharging bubbles. It is conceivable that problems such as bubbles flowing into the second introduction path 52, which is a flow path, occur. However, as described above, the filling chamber 45A is provided above the ink supply needle 35A in the vertical direction, so that the bubbles in the through hole 40A do not flow into the second introduction path 52 without fail. Can flow in.

(Other embodiments)
As mentioned above, although it demonstrated in detail based on embodiment of this invention, of course, this invention is not limited to embodiment mentioned above. In the above-described embodiment, the ink jet recording head unit is exemplified as the liquid ejecting head unit. However, the present invention broadly covers the entire liquid ejecting head unit. For example, various recording head units used in image recording apparatuses such as printers, color material ejection head units used in the manufacture of color filters such as liquid crystal displays, organic EL displays, FED (surface emitting displays), etc. The present invention can also be applied to an electrode material ejection head unit that is used, a bioorganic matter ejection head unit that is used in biochip production, and the like.

1 is a perspective view illustrating an outline of a recording apparatus according to a first embodiment. 3 is an assembled perspective view of the recording head unit according to Embodiment 1. FIG. FIG. 3 is an exploded perspective view of the recording head unit according to the first embodiment. FIG. 3 is a cross-sectional view illustrating a main part of the recording head unit according to the first embodiment. FIG. 6 is a cross-sectional view of a main part showing a modification of the recording head unit according to Embodiment 1. 6 is a cross-sectional view illustrating an outline of a main part of a recording head unit according to Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inkjet recording device, 11 Ink cartridge, 12 Head unit, 21 Cartridge case, 22 Cartridge mounting part, 24 Ink supply path, 27 Head main body, 35 Ink supply needle, 36 Filter, 37 Insertion part, 38 Needle part, 39, Micropore, 40 Through-hole, 41 Bubble storage part, 42 Communication path, 43 Discharge port, 44, 47 On-off valve, 45 Filling chamber, 46 Connection port, 48 Valve member, 49 Energizing member, 50 Ink passage

Claims (8)

A liquid storage member having a storage chamber in which liquid is stored; a head body having a plurality of nozzle openings for discharging liquid supplied from the liquid storage member as droplets; and a mounting portion to which the liquid storage member is mounted A holding member having a supply path that forms part of a liquid flow path that connects the storage chamber of the liquid storage member and the head body, and is connected to the supply path via a filter that is fixed to the holding member. A liquid supply needle having a through-hole,
An upstream side of the filter has a bubble storage part for storing bubbles in the liquid flow path, and an upper part of the bubble storage part opens upward in the vertical direction, and the liquid storage member is attached to the holding member. A liquid ejecting head unit having a discharge port provided with an on-off valve that is opened in a closed state. A filling member having a filling chamber filled with the same liquid as the liquid stored in the storage chamber, and the filling member is opened at the bottom of the filling chamber in a vertically downward direction; 2. The liquid jet head unit according to claim 1, further comprising a connection port that is connected to a discharge port and is provided with an on-off valve that is opened in a state where the liquid storage member is held by the holding member. The liquid ejecting head unit according to claim 2, wherein the filling member is formed integrally with the liquid storage member. The through hole of the liquid supply needle also serves as the bubble storage portion, the discharge port is provided at the tip of the liquid supply needle, and the discharge port and the connection port are provided in the liquid storage member. The liquid ejecting head unit according to claim 3, wherein the liquid ejecting head unit communicates via a part of an introduction path connecting the through hole and the storage chamber. The liquid ejecting head unit according to claim 4, wherein the filling chamber is disposed in a region facing the liquid supply needle. The liquid ejecting head unit according to claim 1, wherein the bubble storage unit is provided in a region facing the supply path. The liquid jet head unit according to claim 6, wherein the bubble storage unit and the through hole of the liquid supply needle communicate with each other through a communication path extending in a horizontal direction. A liquid ejecting apparatus comprising the liquid ejecting head unit according to claim 1.

Images