JP6299414B2 - Liquid ejecting head and liquid ejecting apparatus - Google Patents

Description

  The present invention relates to a liquid ejecting head that introduces liquid from a liquid storage source into a pressure chamber via a liquid flow path and ejects the liquid in the pressure chamber, and a liquid ejecting apparatus including the liquid ejecting head.

  The liquid ejecting apparatus includes a liquid ejecting head and ejects various liquids from the ejecting head. As this liquid ejecting apparatus, for example, there is an image recording apparatus such as an ink jet printer or an ink jet plotter, but recently, various types of manufacturing have been made by taking advantage of the ability to accurately land a very small amount of liquid on a predetermined position. It is also applied to devices. For example, a display manufacturing apparatus for manufacturing a color filter such as a liquid crystal display, an electrode forming apparatus for forming an electrode such as an organic EL (Electro Luminescence) display or FED (surface emitting display), a chip for manufacturing a biochip (biochemical element) Applied to manufacturing equipment. The recording head for the image recording apparatus ejects liquid ink, and the color material ejecting head for the display manufacturing apparatus ejects solutions of R (Red), G (Green), and B (Blue) color materials. The electrode material ejecting head for the electrode forming apparatus ejects a liquid electrode material, and the bioorganic matter ejecting head for the chip manufacturing apparatus ejects a bioorganic solution.

  The above-described liquid ejecting head introduces a liquid from a liquid storage source such as an ink cartridge into a pressure chamber via a liquid flow path, causes a pressure fluctuation in the liquid in the pressure chamber, and communicates with the pressure chamber. It is comprised so that a liquid may be ejected from. In the middle of the liquid flow path, a filter space having a diameter larger than that of other portions in the liquid flow path is provided, and a filter for filtering the liquid in the liquid flow path is provided in the filter space. (For example, refer to Patent Document 1). By this filter, it is possible to suppress the foreign matter mixed in the liquid flow path from moving to the pressure chamber side (downstream side), and it is possible to suppress poor liquid ejection due to the foreign matter. Also, the downstream side opened to the filter space due to the design difference such as the difference between the parallel pitch of the filter and the parallel pitch of the liquid storage source and the common use of other members in which the liquid flow path is formed. In some cases, the outlet of the liquid channel is formed eccentrically from the center of the filter space toward the outer periphery of the filter space (see, for example, Patent Document 2).

JP 2007-130824 A JP 2007-125775 A

  However, when the downstream outlet is eccentric from the center of the filter space as described above, the bubbles mixed in the filter space are difficult to flow, and the bubbles remaining in the filter space may grow greatly. This will be described with reference to a schematic diagram of a conventional filter space illustrated in FIG.

  Conventionally, as shown in FIG. 7, for example, liquid is introduced into a liquid flow path 92 in the liquid ejecting head 90 via a liquid introduction needle 91 inserted into a liquid storage source (not shown) (for example, an ink cartridge). The In the middle of the liquid flow path 92, a filter space 93 having a diameter larger than that of other portions in the liquid flow path 92 is formed, and a filter 94 is provided. The inlet 95 of the upstream liquid flow path 92 opens to the approximate center of the ceiling 97 facing the filter 94 in the filter space 93, while the outlet 96 of the downstream liquid flow path 92 passes the filter 94. It opens eccentrically on the filter outer peripheral side (left side in FIG. 7) of the bottom portion 98 formed on the opposite side to the ceiling portion 97. For this reason, the liquid flowing in from the inflow port 95 tends to flow in a path (see the solid arrow in FIG. 7) passing through the space on the outflow port 96 side in the filter space 93, and the outflow port 96 side sandwiches the inflow port 95. It is difficult to flow along a path (see a broken line arrow in FIG. 7) passing through the space on the opposite side. For this reason, for example, when bubbles are mixed in the liquid flow path 92 due to replacement of the liquid storage source or the like, the bubbles are likely to stay at a position on the opposite side of the filter space 93 from the outlet 96. Even if such a bubble is subjected to a maintenance process such as a flushing operation for forcibly discharging the liquid in the liquid flow path 92, the air outlet 96 side is opposite to the outlet 96 side in the filter space 93. Since the liquid flow rate is small, there is a possibility that the liquid will not be discharged. As a result, there is a concern that liquid bubbles may grow badly and cause liquid injection failure due to blocking of the liquid flow path 92 or causing a pressure loss in the liquid flow path 92.

  The present invention has been made in view of such circumstances, and the object thereof is to suppress the growth of bubbles mixed in the liquid flow path while ensuring the degree of freedom in designing the liquid flow path. A liquid ejecting head and a liquid ejecting apparatus are provided.

The liquid ejecting head of the present invention has been proposed to achieve the above object, and communicates with the pressure chamber and ejects liquid by pressure fluctuation in the pressure chamber; and
A liquid flow path for introducing liquid from a liquid storage source in which liquid is stored into the pressure chamber;
A filter space that is provided in the middle of the liquid flow path, includes a filter that filters the liquid in the liquid flow path, and has a larger diameter than the other part of the liquid flow path; and
The filter space includes an upstream filter space formed on the upstream side of the filter, and a downstream filter space formed on the downstream side of the filter,
An inlet of an upstream liquid channel is opened in a ceiling portion of the upstream filter space facing the filter, and a downstream liquid channel is formed in a bottom portion of the downstream filter space facing the filter. The outlet opens eccentrically with respect to the inlet,
At least a part of the ceiling portion on the side opposite to the outlet side with respect to the inflow port has a distance between the filter and the distance between the ceiling portion on the outlet side with respect to the inflow port and the filter. It is also characterized by being formed to be wide.

  According to this structure, the flow rate of the liquid to the opposite side to the outflow port side in filter space can be increased. Thereby, it can suppress that a bubble retains in the part on the opposite side across an inflow port from the outflow side in filter space. As a result, liquid ejection failure due to bubbles can be suppressed.

In the above configuration, a groove is formed in a region opposite to the outlet side with respect to the inlet of the ceiling portion,
Due to the groove, a distance between at least a part of the ceiling portion on the side opposite to the outlet side with respect to the inlet and the filter is such that the ceiling portion on the outlet side with respect to the inlet and the filter It is desirable that it be formed so as to be wider than the interval.

  According to this configuration, it is possible to make a liquid flow using the groove, and it is possible to suppress the bubbles from staying in a portion of the filter space opposite to the outlet side. Even if the bubbles stay, the bubbles are easily discharged by a maintenance process such as a flushing operation for forcibly discharging the liquid in the liquid flow path.

  According to another aspect of the invention, a liquid ejecting apparatus includes the liquid ejecting head having the above-described configuration.

FIG. 3 is a perspective view illustrating a configuration of a printer. FIG. 3 is an exploded perspective view of a recording head. It is sectional drawing explaining the structure of the principal part of a unit head. 2A and 2B are schematic diagrams illustrating a configuration of a filter space of a recording head, in which FIG. 3A is a cross-sectional view, and FIG. 4A and 4B are schematic diagrams illustrating a configuration of a filter space of a recording head according to a second embodiment, in which (a) is a cross-sectional view and (b) is a plan view. FIG. 10 is a schematic diagram illustrating a configuration of a filter space of a recording head according to a third embodiment, where (a) is a cross-sectional view and (b) is a plan view. It is the schematic explaining the structure of the filter space of the conventional liquid jet head.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In the embodiments described below, various limitations are made as preferred specific examples of the present invention. However, the scope of the present invention is not limited to the following description unless otherwise specified. However, the present invention is not limited to these embodiments. In the following description, an ink jet printer (hereinafter referred to as a printer) equipped with an ink jet recording head (hereinafter referred to as a recording head), which is a kind of liquid ejecting head, is taken as an example of the liquid ejecting apparatus of the present invention.

  The configuration of the printer 1 will be described with reference to FIG. The printer 1 is a device that records an image or the like by ejecting liquid ink onto the surface of a recording medium 2 (a kind of landing target) such as recording paper. The printer 1 includes a recording head 3, a carriage 4 to which the recording head 3 is attached, a carriage moving mechanism 5 that moves the carriage 4 in the main scanning direction, a conveyance mechanism 6 that transfers the recording medium 2 in the sub scanning direction, and the like. Yes. Here, the ink is a kind of the liquid of the present invention, and is stored in the ink cartridge 7 as a liquid storage source (liquid supply source). The ink cartridge 7 is detachably attached to the recording head 3. It is also possible to employ a configuration in which the ink cartridge is disposed on the main body side of the printer and supplied from the ink cartridge to the recording head through the ink supply tube.

  The carriage moving mechanism 5 includes a timing belt 8. The timing belt 8 is driven by a pulse motor 9 such as a DC motor. Accordingly, when the pulse motor 9 is operated, the carriage 4 is guided by the guide rod 10 installed on the printer 1 and reciprocates in the main scanning direction (width direction of the recording medium 2).

  FIG. 2 is an exploded perspective view showing the configuration of the recording head 3 of the present embodiment. FIG. 3 is a cross-sectional view illustrating a configuration of a main part of the unit head 16. Further, FIG. 4A is a cross-sectional view illustrating the configuration of the filter space 21 of the recording head 3, and FIG. 4B is a plan view. The recording head 3 in this embodiment includes a holder 12 in which a plurality of ink introduction needles 18 are formed, an upper flow path member 13 attached to the lower side of the holder 12, and a lower side of the upper flow path member 13 with the filter 14 interposed therebetween. And a unit head 16 attached to the lower side of the lower flow path member 15. In the present embodiment, four unit heads 16 are attached to the lower flow path member 15.

  The holder 12 has a cartridge mounting portion 17 on the upper surface side to which the ink cartridge 7 is detachably attached. A plurality of ink introduction needles 18 are erected in the cartridge mounting portion 17. In the present embodiment, since the ink cartridges 7 for supplying ink to the four unit heads 16 are respectively attached, four ink introduction needles 18 are erected correspondingly. As shown in FIG. 4A, the holder 12 has a holder channel 19 that introduces the ink introduced from the ink introduction needle 18 into the upper channel member 13. In this embodiment, since the arrangement pitch of the ink introduction needles 18 and the arrangement pitch of the filter 14 are different from each other, the horizontal flow path extending in a direction parallel to the surface of the filter 14 is used as the holder flow path 19. Has in part. The connection method between the recording head and the ink cartridge 7 does not depend on the type in which the ink introduction needle 18 is inserted into the ink cartridge 7. For example, a portion made of a porous material such as a nonwoven fabric or sponge is exposed to the holder, and the ink cartridge It is also possible to employ a so-called foam-type connection method in which the ink is brought into contact with a portion made of a porous material formed in the above and taken into the liquid flow path in the holder.

  The upper flow path member 13 and the lower flow path member 15 are members made of synthetic resin or the like in which a part of the liquid flow path is formed. More specifically, as shown in FIG. 4A, the upper flow path member 13 includes an upstream filter space 22 that forms a portion upstream of the filter 14 in the filter space 21, and an upstream liquid flow path. The upstream flow path 20 which forms a part of is formed inside. The upstream channel 20 is a channel whose upper end communicates with the holder channel 19 and whose lower end communicates with the filter space 21 (upstream filter space 22). The upstream flow path 20 of the present embodiment extends in a direction perpendicular to the surface of the filter 14.

  As shown in FIG. 4A, the lower flow path member 15 includes a downstream filter space 23 that forms a part downstream of the filter 14 in the filter space 21, and a downstream that forms a part of the downstream liquid flow path. The side channel 24 is a member made of synthetic resin or the like formed inside. The downstream channel 24 is a channel whose upper end communicates with the filter space 21 (downstream filter space 23) and whose lower end communicates with the liquid introduction channel 30 of the unit head 16 described later. The filter space 21 composed of the upstream filter space 22 and the downstream filter space 23 will be described in more detail later.

  The filter 14 sandwiched between the upper flow path member 13 and the lower flow path member 15 is a flat plate member that prevents foreign matters mixed in the ink from passing therethrough. The filter 14 is disposed between the upstream filter space 22 and the downstream filter space 23, and filters the ink in the liquid flow path. Such a filter 14 is formed by weaving fine lines made of, for example, fibers or metal in a mesh shape. In the present embodiment, as shown in FIG. 4B, in a plan view (that is, viewed from the front surface side or the back surface side of the filter 14), it is formed in an elongated and substantially elliptical shape. The filter space 21 is also formed in a substantially elliptical shape with an outer peripheral edge corresponding to the filter shape.

  As shown in FIG. 3, the unit head 16 in the present embodiment includes a pressure generating unit 27 and a flow path unit 28, and is configured by being attached to a head case 29 in a state where these members are laminated. Since each unit head 16 has the same configuration, only the configuration of one unit head 16 will be described.

  The head case 29 is a box-shaped member made of synthetic resin, and a liquid introduction path 30 is formed therein. The upper end portion of the liquid introduction path 30 communicates with the downstream side flow path 24. The flow path unit 28 includes a nozzle plate 31 in which a plurality of nozzles 32 are opened in a straight line (row shape) and a communication substrate 34 on which a liquid supply flow path 35 is provided. The plurality of nozzles 32 arranged in a row are equally spaced along the sub-scanning direction orthogonal to the main scanning direction at a pitch (for example, 180 dpi) corresponding to the dot formation density from the nozzle 32 on one end side to the nozzle 32 on the other end side. Is provided.

  The pressure generating unit 27 is unitized by laminating a pressure chamber forming substrate 39 on which the pressure chamber 40 is formed, an elastic film 41, a piezoelectric element 42 (a kind of pressure generating means), and a protective substrate 43. Each piezoelectric element 42 has a terminal portion electrically connected to a wiring member such as a flexible cable (not shown). The pressure chamber 40 communicates with the nozzle 32 through a nozzle communication path 45 formed in the communication substrate 34 at the end opposite to the liquid supply flow path 35.

  As described above, inside the recording head 3, from the ink introduction needle 18 inserted into the ink cartridge 7, the holder flow path 19, the upstream flow path 20, the filter space 21, the downstream flow path 24, the liquid introduction path 30, and the like. A series of liquid flow paths reaching the pressure chamber 40 via the liquid supply flow path 35 is formed. Then, the ink from the ink cartridge 7 is introduced into the pressure chamber 40 through this liquid flow path, and a drive signal (ejection pulse) from the control unit is supplied to the piezoelectric element 42, thereby driving the piezoelectric element 42 and the pressure chamber. 40 causes pressure fluctuations. By utilizing this pressure fluctuation, ink droplets are ejected from the nozzle 32 via the nozzle communication path 45.

  Next, the filter space 21 of the present embodiment will be described with reference to FIG. As described above, the filter space 21 is composed of the upstream filter space 22 of the upper flow path member 13 and the downstream filter space 23 of the lower flow path member 15. The space is larger in diameter than the channel 20 and the downstream channel 24. The upstream filter space 22 is substantially the same as the upper surface of the filter 14, the ceiling 22 a facing the filter 14 on the upstream flow path 20 side, and the filter 14 from the outer peripheral portion of the filter 14 upward (upstream). It is demarcated by a cylindrical upstream peripheral wall 22b extending vertically. Further, the downstream filter space 23 has a lower surface of the filter 14, a bottom 23 a facing the filter 14 on the downstream flow path 24 side, and the filter 14 toward the lower side (downstream side) from the outer peripheral portion of the filter 14. It is demarcated by a cylindrical downstream peripheral wall 23b extending substantially vertically. As shown in FIG. 4B, the filter space 21 of the present embodiment is formed in an elongated and oval shape in plan view.

  In addition, a lower end portion of the upstream flow path 20, that is, an inlet 20 a of the upstream liquid flow path is opened in the ceiling portion 22 a of the upstream filter space 22. On the other hand, at the bottom 23a of the downstream filter space 23 facing the filter 14, the upper end of the downstream channel 24, that is, the outlet 24a of the downstream liquid channel opens. As shown in FIG. 4B, the inflow port 20a of the present embodiment opens at the approximate center of the filter space 21 in plan view. In addition, as shown in FIG. 4B, the outlet 24a of the present embodiment opens from the approximate center of the filter space 21 to one side in the longitudinal direction (left side in FIG. 4B) in plan view. ing. That is, the outlet 24a is eccentrically opened to the outer peripheral edge side of the filter space 21 that is relatively far away from the inlet 20a.

  Here, conventionally, when the outlet 24a is eccentrically opened with respect to the inlet 20a in the filter space 21 as described above, the ink is opposite to the outlet 24a side across the central axis of the inlet 20a. It was difficult to flow through the space (region) on the side, and bubbles were likely to stay in this space. If such bubbles continue to stay, the bubbles may grow greatly and cause a clogging of the liquid channel or a pressure loss in the liquid channel. Therefore, in the present invention, the filter space 21 is formed so that the ink flowing into the filter space 21 can easily flow into the space on the side opposite to the outlet 24a side.

  Specifically, at least a part of the ceiling 22a on the side opposite to the outlet 24a with respect to the inlet 20a is spaced from the filter 14, and the distance between the ceiling 22a and the filter 14 on the outlet 24a side. It is formed so as to be wider. In the present embodiment, the gap between the edge of the inlet 20a and the filter 14 on the opposite side across the central axis of the inlet 20a from the outlet 24a side (the ceiling 22a and the filter 14 on the opposite side of the outlet 24a). H2 is the distance between the edge of the inlet 20a located on the side opposite to the edge (outlet 24a side) and the filter 14 (between the ceiling 22a and the filter 14 on the outlet 24a side). The maximum interval) is wider than H1. In short, in the upstream filter space 22, the volume of the space on the side opposite to the outlet 24a with respect to the inlet 20a is made larger than the volume of the space on the outlet 24a side, and is opposite to the outlet 24a. The amount of ink flowing to the side is increased.

  The ceiling portion 22a is gently inclined downward from the outer peripheral edge of the inflow port 20a toward the upstream peripheral wall 22b. That is, the upstream filter space 22 gradually increases in diameter from the inflow port 20 a toward the filter 14. The bottom 23a is also gently inclined upward from the outer peripheral edge of the outlet 24a toward the downstream peripheral wall 23b. That is, the downstream filter space 23 also gradually increases in diameter from the outlet 24 a toward the filter 14.

  In this way, a part of the ceiling portion 22a on the side opposite to the outlet port 24a with respect to the inlet port 20a is separated from the filter 14 by a distance between the ceiling portion 22a and the filter 14 on the outlet port 24a side with respect to the inlet port 20a. As compared with the conventional case in which both the intervals are the same, the outlet 24a side in the filter space 21 is on the opposite side across the central axis of the outlet 24a. The ink flow rate can be increased. Thereby, it can suppress that a bubble retains in the part on the opposite side to the outflow port 24a in the filter space 21. FIG. As a result, blockage of the liquid channel due to bubble growth, pressure loss in the liquid channel, and the like can be suppressed, and ink ejection failure due to bubbles can be suppressed.

  By the way, the structure which increases the flow volume of the ink of the space on the opposite side to the inflow port 24a with respect to the inflow port 20a in the filter space 21 is not restricted to above-described embodiment. In the second embodiment shown in FIG. 5, a groove 22c is formed in a region opposite to the outlet 24a 'of the downstream channel 24' with respect to the inlet 20a 'of the upstream channel 20' in the ceiling portion 22a '. ′, And the distance between at least a part of the ceiling portion 22a ′ and the filter 14 on the side opposite to the outlet 24a ′ side with respect to the inlet 20a ′ by the groove 22c ′ is relative to the inlet 20a ′. It is formed so as to be wider than the distance between the ceiling portion 22 a ′ and the filter 14 on the outlet 24 a ′ side.

  Specifically, as shown in FIG. 5 (b), the inlet 20a 'extends along the longitudinal direction of the filter space 21' to the ceiling portion 22a 'opposite to the outlet 24a'. A groove 22c ′ is formed in which the ceiling portion 22a ′ is recessed from the edge of ′ to the upstream outer peripheral wall 22b ′. The distance between the ceiling portion 22a ′ and the filter 14 in the groove 22c ′ is wider than the distance between the ceiling portion 22a ′ and the filter 14 on the outlet 24a ′ side with respect to the inlet 20a ′. In particular, the distance between the end of the groove 22c 'on the inlet 20a' side and the filter 14 (the maximum distance between the ceiling 22a 'and the filter 14 on the side opposite to the outlet 24a') H2 'is the outlet 24a'. The distance between the edge of the inlet 20a 'on the side and the filter 14 (the maximum distance between the ceiling 22a' on the outlet 24a 'and the filter 14) H1' is wider.

  As in the above-described embodiment, the ceiling portion 22a ′ extends from the outer peripheral edge of the inlet 20a ′ to the upstream peripheral wall 22b so that the upstream filter space 22 ′ gradually increases in diameter from the inlet 20a ′ toward the filter 14. Inclined gently toward ′. Further, the bottom portion 23a ′ is gently inclined upward from the outer peripheral edge of the outlet 24a ′ toward the downstream peripheral wall 23b ′ so that the downstream filter space 23 ′ also gradually increases in diameter from the outlet 24a ′ toward the filter 14. doing. Further, in the present embodiment, the portion other than the groove 22c ′ in the ceiling portion 22a ′ on the side opposite to the outlet 24a ′ side with respect to the inlet 20a ′ is the same as the ceiling portion 22a ′ on the outlet 24a ′ side. It is height. That is, the upstream filter space 22a ′ is formed symmetrically with respect to the inflow port 20a ′ except for the groove 22c ′. Since other configurations are the same as those in the above-described embodiment, the description thereof is omitted.

  With this configuration, the flow rate of ink to the opposite side of the central axis of the inflow port 20a ′ can be increased with respect to the outflow port 24a ′ side in the filter space 21 ′. In particular, it is possible to create an ink flow using the groove 22c ′, and it is possible to suppress bubbles from remaining in a portion of the filter space 21 ′ opposite to the outlet 24a ′. Even if the bubbles stay, the bubbles are easily discharged by a maintenance process such as a flushing operation for forcibly discharging the ink in the liquid flow path.

  In the above embodiment, the inflow port 20a is opened at the approximate center of the filter space 21, but the present invention is not limited to this. In short, in the configuration in which the outlet is eccentrically opened with respect to the inlet, the distance between at least a part of the ceiling portion and the filter on the side opposite to the outlet is the inlet. As long as it is formed so as to be wider than the distance between the ceiling portion and the filter on the outlet side, any configuration may be used.

  For example, in the third embodiment shown in FIG. 6, in plan view, the outlet 24a ″ of the downstream flow path 24 ″ is one side in the longitudinal direction from the approximate center of the filter space 21 ″ (as in the above-described embodiment). 6 (b), the inlet 20a ″ of the upstream flow path 20 ″ is open from the approximate center of the filter space 21 ″ to the other side in the longitudinal direction (right side in FIG. 6 (b)). That is, the opening is shifted to the opposite side to the inlet 20a ". Also in this embodiment, the filter space 21" is provided in the ceiling portion 22a "opposite to the outlet 24a" with respect to the inlet 20a ". A groove 22c ″ is formed in which the ceiling portion 22a ″ is recessed from the edge of the inlet 20a ″ to the upstream peripheral wall 22b ″ along the longitudinal direction. The ceiling portion 22a ″ in the groove 22c ″ and the filter 14 are formed. Is the inlet 20a. It is wider than the distance between the filter 14 "ceiling portion 22a of the side" outlet 24a against. In particular, the distance between the end of the groove 22c ″ on the inlet 20a ″ side and the filter 14 (the maximum distance between the ceiling portion 22a ″ on the side opposite to the outlet 24a ″ and the filter 14) H2 ″ is the outlet 24a. The distance between the edge of the inlet 20a "on the" side "and the filter 14 (the maximum distance between the ceiling portion 22a" and the filter 14 on the outlet 24a "side) is wider than H1".

  In this embodiment, the ceiling portion 22a ″ extends from the outer periphery of the inlet 20a ″ to the upstream peripheral wall 22b ″ so that the upstream filter space 22 ″ gradually increases in diameter from the inlet 20a ″ toward the filter 14. Also, the bottom 23a ″ is downstream from the outer peripheral edge of the outlet 24a ″ so that the downstream filter space 23 ″ gradually expands from the outlet 24a ″ toward the filter 14. Inclined gently toward the peripheral wall 23b ″. Since other configurations are the same as those in the above-described embodiment, the description thereof is omitted.

  Also in the present embodiment, the ink flow rate to the side opposite to the outlet 24a "side in the filter space 21" can be increased. In particular, the ink flow can be made by using the groove 22c ″, and bubbles can be prevented from staying in the portion of the filter space 21 ″ opposite to the outlet 24a ″. However, air bubbles can be easily discharged by a maintenance process such as a flushing operation for forcibly discharging the ink in the liquid flow path. Further, in the present embodiment, the inlet 20a ″ is opened from substantially the center of the filter space 21 ″. Since the opening is shifted to the outer peripheral side on the other side in the longitudinal direction, the space on the opposite side of the filter space 21 ″ from the outlet 24 a ″ side is reduced, and bubbles are prevented from staying and growing in the space. it can.

  In the second and third embodiments described above, one groove 22c ″ is formed in the ceiling portion 22a ″ on the side opposite to the outlet 24a ″ with respect to the inlet 20a ″. It is not limited to. For example, you may provide a some groove | channel in the ceiling part in the opposite side to an inflow port side with respect to an inflow port (central axis of an inflow port). Further, the shape of the groove is not limited to a linear shape in a plan view, and may be a curved shape or meandering. Further, the distance between at least a part of the ceiling part on the side opposite to the outlet side with respect to the inlet and the filter is wider than the distance between the ceiling part on the outlet side and the filter with respect to the inlet. As long as it is formed, the filter space may have any shape. However, the distance between the edge of the inlet on the side opposite to the outlet side and the filter (the maximum distance between the ceiling and the filter on the side opposite to the outlet) is the distance between the edge of the inlet and the filter on the outlet side. It is desirable that the distance is larger than the distance (the maximum distance between the ceiling and the filter on the outlet side).

  In the above-described embodiment, the ink jet recording head mounted on the ink jet printer is exemplified. However, as long as the ink jet recording head has the piezoelectric element and the pressure chamber having the above-described configuration, the ink jet recording head is also applied to a liquid ejecting liquid other than ink. be able to. For example, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an electrode material ejecting head used for forming an electrode such as an organic EL (Electro Luminescence) display, FED (surface emitting display), a biochip (biochemical element) The present invention can also be applied to bioorganic matter ejecting heads and the like used in the production of

  DESCRIPTION OF SYMBOLS 1 ... Printer, 3 ... Recording head, 12 ... Holder, 13 ... Upper flow path member, 14 ... Filter, 15 ... Lower flow path member, 16 ... Unit head, 17 ... Cartridge mounting part, 18 ... Ink introduction needle, 19 ... Holder channel, 20 ... upstream channel, 20a ... inlet, 21 ... filter space, 22 ... upstream filter space, 22a ... ceiling, 22c ... groove, 23 ... downstream filter space, 23a ... bottom, 24 ... Downstream channel, 24a ... outlet, 27 ... pressure generating unit, 28 ... channel unit, 30 ... liquid introduction channel, 32 ... nozzle, 35 ... liquid supply channel, 40 ... pressure chamber, 42 ... piezoelectric element

Claims (2)

A nozzle that communicates with the pressure chamber and ejects liquid by pressure fluctuation in the pressure chamber;
A liquid flow path for introducing liquid from a liquid storage source in which liquid is stored into the pressure chamber;
A filter space that is provided in the middle of the liquid flow path, includes a filter that filters the liquid in the liquid flow path, and has a larger diameter than the other part of the liquid flow path; and
The filter space includes an upstream filter space formed on the upstream side of the filter, and a downstream filter space formed on the downstream side of the filter,
An inlet of an upstream liquid channel is opened in a ceiling portion of the upstream filter space facing the filter, and a downstream liquid channel is formed in a bottom portion of the downstream filter space facing the filter. The outlet opens eccentrically with respect to the inlet,
At least a part of the ceiling portion on the side opposite to the outlet side with respect to the inflow port has a distance between the filter and the distance between the ceiling portion on the outlet side with respect to the inflow port and the filter. Is also formed to be wide ,
Forming a groove in a region opposite to the outlet side with respect to the inlet of the ceiling portion;
Due to the groove, a distance between at least a part of the ceiling portion on the side opposite to the outlet side with respect to the inlet and the filter is such that the ceiling portion on the outlet side with respect to the inlet and the filter A liquid ejecting head, wherein the liquid ejecting head is formed to be wider than the interval. A nozzle that communicates with the pressure chamber and ejects liquid by pressure fluctuation in the pressure chamber;
A liquid flow path for introducing liquid from a liquid storage source in which liquid is stored into the pressure chamber;
A filter space that is provided in the middle of the liquid flow path, includes a filter that filters the liquid in the liquid flow path, and has a larger diameter than the other part of the liquid flow path; and
The filter space includes an upstream filter space formed on the upstream side of the filter, and a downstream filter space formed on the downstream side of the filter,
An inlet of an upstream liquid channel is opened in a ceiling portion of the upstream filter space facing the filter, and a downstream liquid channel is formed in a bottom portion of the downstream filter space facing the filter. The outlet opens eccentrically with respect to the inlet,
At least a part of the ceiling portion on the side opposite to the outlet side with respect to the inflow port has a distance between the filter and the distance between the ceiling portion on the outlet side with respect to the inflow port and the filter. Is also formed to be wide,
Forming a groove in a region opposite to the outlet side with respect to the inlet of the ceiling portion;
Due to the groove, a distance between at least a part of the ceiling portion on the side opposite to the outlet side with respect to the inlet and the filter is such that the ceiling portion on the outlet side with respect to the inlet and the filter A liquid ejecting apparatus formed so as to be wider than the interval .

Images