JP2008080797A - Droplet ejection head and droplet ejection apparatus provided with the same - Google Patents

Abstract

Ink adhering to an ink ejection surface can be wiped with a wiper.
An ink jet head is joined to a pressure generating block having a plurality of pressure chambers and a piezoelectric actuator for applying pressure fluctuation to ink in the pressure chambers, and each pressure generating block. The nozzle plate 55 formed with a plurality of nozzles 59 and communication holes 57 respectively communicating with the chamber 21 and the ink ejection surface 55a opposite to the side where the pressure generating block 50 of the nozzle plate 55 is joined are joined. And a manifold block 60 in which a manifold 65 for holding ink to be supplied to each pressure chamber 21 through the communication hole 57 is formed. The manifold block 60 is inclined with respect to the ink discharge surface 55a, and has inclined surfaces 62 and 64 that are continuous with the ink discharge surface 55a at one end thereof.
[Selection] Figure 3

Description

  The present invention relates to a droplet discharge head that discharges droplets from a nozzle, and a droplet discharge device including the droplet discharge head.

An inkjet head disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 10-119269 (FIG. 1)) is bonded to a flow path forming base material in which a pressure chamber is formed and a flow path forming base material. In addition, the nozzle plate communicating with the pressure chamber and formed with nozzles for discharging ink in the pressure chamber, and the surface opposite to the surface bonded to the flow path forming substrate of the nozzle plate, that is, the ink A manifold block joined to the discharge surface and formed with a manifold for holding a liquid to be supplied to the pressure chamber is provided, and a communication hole for communicating the manifold and the pressure chamber is formed in the nozzle plate. Note that a surface that is continuous with the ink discharge surface of the manifold block is a surface that is perpendicular to the ink discharge surface. Then, when pressure fluctuation is applied to the ink in the pressure chamber by the piezoelectric actuator disposed on the side opposite to the side where the nozzle plate of the flow path forming substrate is bonded, the ink is ejected from the nozzle.
JP-A-10-119269 (FIG. 1)

  Here, in the ink jet head, if ink is attached in the vicinity of the nozzles on the ink discharge surface, the ink discharge direction may be shifted due to wetting, and the print quality and reliability may be reduced. In addition, dust or dust may adhere to the vicinity of the nozzle, and when ink or dust or the like is attached, cleaning around the nozzle is necessary. The droplet discharge device has a rubber wiper, and ink and dust attached to the ink discharge surface are wiped off by the wiper. If the periphery of the nozzle is wiped excessively with a wiper, the durability of the nozzle plate is reduced. Therefore, it is desirable to reduce the number of wiping with a wiper. Since the ink jet head described in Patent Document 1 has a manifold block arranged on the ink ejection surface of the nozzle plate, when the ink or dust attached to the vicinity of the nozzle is wiped with a wiper, the wiper is a corner portion of the manifold block. This causes a problem that ink and dust cannot be wiped off from the ink ejection surface. It is desirable to keep the ink discharge surface without using ink or the like, regardless of the wiper.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems of the prior art, and to provide a liquid droplet ejection head that prevents liquid adhering to an ink ejection surface in the vicinity of a nozzle from remaining. . Another object of the present invention is to provide a droplet discharge device that prevents ink and dust from remaining on the ink discharge surface. Although each aspect of the present invention is shown below, the reference numerals with parentheses attached to each element are merely examples of the element and do not limit each element.

  According to the first aspect of the present invention, a first block having a plurality of pressure chambers (21) and a pressure applying mechanism (40) that applies pressure fluctuation to the liquid in the plurality of pressure chambers (21). (50), a nozzle plate (55) joined to the first block (50) and formed with a plurality of nozzles (59) respectively communicating with the plurality of pressure chambers (21), and the nozzle Manifolds (65, 165, 465) are formed on the side opposite to the first block (50) with respect to the plate (55) and hold liquid supplied to each of the plurality of pressure chambers (21). Second block (60, 160, 260, 360, 460), and the nozzle plate (55) includes the manifold (65, 165, 465) and the plurality of pressure chambers (21). Each The second block (60, 160, 260, 360, 460) is inclined with respect to the surface of the nozzle plate (55). A droplet discharge head having an inclined surface continuous with the surface of the nozzle plate at one end thereof is provided.

  Here, “the surface of the nozzle plate” means “the surface of the nozzle plate on which the liquid is discharged”.

  According to this structure, the surface of the second block continuous with the surface of the nozzle plate is an inclined surface inclined with respect to the surface of the nozzle plate. For example, the nozzle plate is provided to face the medium to be ejected in the horizontal direction. Ink may adhere to the surface of the nozzle plate after the ink is ejected onto the medium to be ejected via the nozzle plate. The adhering liquid flows downward along the inclined surface of the second block due to its own weight (gravity) and leaves the surface of the nozzle plate, that is, the nozzle. As a result, it is possible to prevent ink from remaining in the vicinity of the nozzles of the nozzle plate. Also, dust adhering to the nozzle plate also flows with the ink and leaves the nozzle plate. Therefore, the ink discharge surface near the nozzle can be kept clean.

  In the droplet discharge head of the present invention, the inclined surface may include a transfer structure that transfers the liquid adhering to the surface of the nozzle plate (55) in a direction away from the nozzle (59). According to this structure, the liquid can be transferred in a direction away from the nozzle by the transfer structure.

  In the droplet discharge head of the present invention, the transfer structure may be a groove (166) extending along a direction away from the nozzle (59) from the one end of the inclined surface. The groove as the transfer structure is extended to keep the liquid away from the nozzle. According to this structure, when the liquid adhering to the surface of the nozzle plate comes into contact with one end of the groove, it is sucked into the groove by capillary force and reliably transferred away from the nozzle. Further, the liquid sucked into the groove is held in the groove by capillary force. Therefore, it is possible to prevent the discharged medium and the like from being soiled by dripping the liquid. Further, when the medium to be ejected is disposed opposite to the surface of the nozzle plate, the medium to be ejected is difficult to touch the liquid held in the groove formed on the inclined surface. It can prevent getting dirty. In addition, the extension length of the groove can be increased as compared with the case where the groove is formed in parallel to the surface of the nozzle plate. Therefore, more liquid can be held in the groove. For example, in the case of a serial type droplet discharge head, wind is generated around the droplet discharge head. For example, since the nozzle plate is provided facing the medium to be ejected in the horizontal direction, the liquid can be more easily transferred by the wind force in a direction away from the nozzle along the groove formed on the inclined surface. it can.

  In the droplet discharge head of the present invention, the transfer structure has a liquid repellency that is equal to or lower than a liquid repellency at the surface of the nozzle plate (55) at the one end of the inclined surface. The transfer surface (266) may be such that the liquid repellency becomes lower toward the other end away from the nozzle (59) than at one end. According to this structure, when the liquid adhering to the surface of the nozzle plate comes into contact with one end of the transfer surface, the liquid is transferred in a direction away from the nozzle so as to go to a region having lower liquid repellency.

  In the droplet discharge head of the present invention, the transfer structure has a first region (366) having a liquid repellency equal to or lower than a liquid repellency on the surface of the nozzle plate (55), and the first A second region (367) having a liquid repellency lower than the liquid repellency of the region (366), and the first and second regions (366, 367) have the nozzle plate ( The liquid adhering to the surface of 55) may be patterned so as to move in a direction from the one end toward the other end away from the nozzle (59). According to this structure, since the transfer structure is composed of two types of regions having different liquid repellency, for example, first, the first region is formed on the surface having liquid repellency corresponding to the second region. After the liquid repellent film having the corresponding liquid repellent property is formed, the transfer structure can be formed by a relatively easy process such as deleting the liquid repellent film formed at the location corresponding to the second region. .

  In the droplet discharge head of the present invention, the first and second regions (366, 367) both extend from the one end to the other end, and the first region (366). The width of the second region (367) decreases from the one end side toward the other end side, and the width of the second region (367) increases from the one end side toward the other end side. May be. According to this structure, when the liquid adhering to the surface of the nozzle plate comes into contact with the region where the first and second regions are patterned, the liquid spreads in the second region having low liquid repellency. At this time, the width of the second region is narrow at one end continuous with the surface of the nozzle plate, so that the liquid adhering to the surface of the nozzle plate is sucked into the second region by capillary force. Therefore, the liquid can be reliably transferred in the direction away from the nozzle. In addition, since the width of the second region becomes wider toward the other end, even if the amount of liquid sucked into the second region is relatively large, the liquid does not sag without dropping. Spread out in the area of 2.

  In the liquid droplet ejection head according to the aspect of the invention, it is preferable that the other end side of the first region (366) is a pointed end and the one end side of the second region (367) is a pointed end. According to this structure, the droplet attached to the surface of the nozzle plate breaks at the tip of the second region, so that the surface can smoothly spread over the second region.

  In the droplet discharge head of the present invention, it is preferable that the second block (60, 160, 260, 360, 460) is manufactured by injection molding. According to this structure, the second block can be manufactured with a smaller number of processing steps than in the case of manufacturing by joining a plurality of members to each other. Moreover, when forming a groove | channel on the surface of a 2nd block, the etching process for forming a groove | channel etc. is unnecessary, and a groove | channel can be integrally formed at the time of injection molding. Therefore, the groove can be easily formed.

  In the droplet discharge head of the present invention, the second block (60, 160, 260, 360, 460) may be made of resin. According to this structure, the second block can be manufactured at a lower cost than in the case of being made of metal. If a block having pressure chambers is manufactured by laminating a plurality of metal plates, if the pressure chambers and the manifold are formed in the same block so as to overlap in the laminating direction, a large number of metal plates are formed. Since it is necessary to laminate, the cost becomes high. (In particular, in order to form a manifold with a large volume, the number of stacked metal plates further increases.) However, in the present invention, the manifold is formed on a member made of resin different from the block having the pressure chamber. Therefore, the number of stacked metal plates of the block having the pressure chamber can be reduced, and the cost of the entire droplet discharge head can be reduced.

  In the liquid droplet ejection head of the present invention, the inclined surface may be formed such that the distance from the surface of the nozzle plate increases as the distance from the nozzle increases in a predetermined direction in which the liquid droplet ejection head moves. Good. With this structure, the liquid adhering to the surface of the nozzle plate flows in a direction away from the nozzle on the inclined surface, so that the liquid is prevented from remaining on the surface of the nozzle plate of the droplet discharge head. Can be kept clean.

  In the droplet discharge head of the present invention, the inclined surface may be planar with respect to the surface of the nozzle plate.

  In the droplet discharge head of the present invention, the inclined surface may include a first inclined surface and a second inclined surface. With this structure, the contact resistance between the wiper and the inclined surface is lowered, and the life of the wiper is extended.

  In the droplet discharge head of the present invention, one end of the first inclined surface is continuous with the surface of the nozzle plate, the other end of the first inclined surface is connected to one end of the second inclined surface, The other end of the second inclined surface may be continuous with the surface of the nozzle plate. With this structure, droplets, dust, and dust flow in a direction away from the nozzle by their own weight.

  In the droplet discharge head of the present invention, the pair of inclined surfaces may be provided on the surface of the nozzle plate with the axis of the nozzle being symmetrical. With this structure, the two inclined surfaces can cause droplets, dust, and dust to flow away from the nozzle.

  The droplet discharge head of the present invention may be an inkjet head.

  According to the second aspect of the present invention, a first block having a plurality of pressure chambers (21) and a pressure applying mechanism (40) for applying a pressure fluctuation to the liquid in the plurality of pressure chambers (21). (50), a nozzle plate (55) joined to the first block (50) and formed with a plurality of nozzles (59) respectively communicating with the plurality of pressure chambers (21), and the nozzle Manifolds (65, 165, 465) are formed on the side opposite to the first block (50) with respect to the plate (55) and hold liquid supplied to each of the plurality of pressure chambers (21). Second block (60, 160, 260, 360, 460), and the nozzle plate (55) includes the manifold (65, 165, 465) and the plurality of pressure chambers (21). Each The second block (60, 160, 260, 360, 460) is inclined with respect to the surface of the nozzle plate (55). A droplet discharge device having an inclined surface continuous with the surface of the nozzle plate (55) at one end thereof, and a moving unit (10) for reciprocating the droplet discharge head along a predetermined direction; The medium transport unit (70) for transporting the medium (90) on which the liquid droplets ejected from the liquid droplet ejection head land along the orthogonal direction perpendicular to the direction, and the plurality of nozzles (59) are wiped off. A nozzle array in which the plurality of nozzles (59) are arranged along the orthogonal direction, and the inclined surface is at least one side of the nozzle array with respect to the one direction. The droplet discharge device is provided which is located.

  According to this structure, when wiping the surface of the nozzle plate along one direction, the wiper can smoothly move between the surface of the nozzle plate and the inclined surface of the second block without being caught by the second block. Can move. Therefore, the liquid adhering to the surface of the nozzle plate can be wiped with the wiper, and the vicinity of the nozzle can be kept clean even if the number of wiping operations is reduced.

  The direction may be the scanning direction of the droplet discharge head.

  In the droplet discharge device of the present invention, it is preferable that the inclined surface is formed in an annular shape around the nozzle row. In general, a liquid repellent film is formed on the surface of the nozzle plate. According to the above-described structure, the second block disposed on the surface of the nozzle plate can prevent the medium on which the droplets land from coming into contact with the surface of the nozzle plate. Therefore, it is possible to prevent the liquid-repellent film near the nozzle from being damaged and thereby causing a deviation in the droplet discharge direction.

  The droplet discharge device of the present invention may be an ink jet printer.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a diagram showing a schematic configuration of an ink jet printer according to the present embodiment. As shown in FIG. 1, the ink jet printer 1 according to the present embodiment includes a carriage 10 that can be moved in a scanning direction (left and right direction in FIG. 1) by a drive motor (not shown), and a carriage 10 that faces a recording sheet 90. A serial-type inkjet head 20 that is supported and discharges ink; and a conveyance roller 70 that conveys the recording paper 90 in a paper feed direction (a direction from the right back to the left front in FIG. 1) perpendicular to the scanning direction; It is mainly equipped with. In the ink jet printer 1, the ink jet head 20 ejects ink onto the recording paper 90 while moving in the scanning direction integrally with the carriage 10 within the print region. Then, the recording paper 90 recorded by the inkjet head 20 is discharged in the paper feeding direction by the transport roller 70. The maintenance mechanism 3 provided close to the conveying roller 70 on one end side (maintenance area) in the scanning direction is provided with a suction mechanism (not shown), for example, a suction cap 5 connected to a pump and a rubber wiper 80. Yes. When the inkjet head 20 is moved to the maintenance area by the carriage, the inkjet head 20 is covered by the suction cap 5, and the ink formed on the ejection surface of the inkjet head 20 is forcibly discharged into the suction cap 5. For example, the wiper 80 moves so as to approach the head at a predetermined timing when the inkjet head 20 is present in the maintenance area using the drive motor described above as a power source. When the inkjet head 20 moves from the maintenance area to the printing area, the wiper 80 wipes ink, dust, and dust adhering to an ejection surface (a nozzle plate 55 described later) of the inkjet head 20.

  Next, the inkjet head 20 will be described in detail with reference to FIGS. FIG. 2 is a top view of the inkjet head 20 (viewed from the side opposite to the side facing the recording paper 90). 3 is a cross-sectional view taken along line III-III in FIG. 2, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 5 is a bottom view of the inkjet head 20 (viewed from the side facing the recording paper 90).

  The inkjet head 20 includes a plurality of pressure chambers 21 and a pressure generation block 50 (first block) having a piezoelectric actuator 40 that applies pressure fluctuation to the ink in each pressure chamber 21 and a plurality of nozzles 59 that eject ink. The nozzle plate 55 is formed, and a manifold block 60 (second block) in which a manifold 65 for holding ink is formed. Here, the nozzle plate 55 is joined to the lower surface of the pressure generating block 50 (more specifically, a plate laminate 30 described later), and the manifold block 60 is joined to the lower surface of the nozzle plate 55 (joining with the pressure generating block 50). It is joined to the surface on the side opposite to the side that is made. A nozzle 59 that communicates with the pressure chamber 21 and a communication hole 57 that communicates the manifold 65 and the pressure chamber 21 are formed at locations corresponding to the pressure chambers 21 in the nozzle plate 55. In the inkjet head 20, the surface of the nozzle plate 55 on the side where the manifold block 60 is joined is an ink discharge surface 55a from which ink is discharged.

  As shown in FIGS. 3 and 4, the pressure chamber 21 is formed inside a plate laminate 30 produced by joining a cavity plate 31 and a base plate 33 to each other in a laminated state. Therefore, in the present embodiment, the pressure generating block 50 is disposed on the plate laminate 30 and the upper surface of the plate laminate 30 (the surface opposite to the side on which the nozzle plate 55 is bonded). And an actuator 40. The planar shape of the cavity plate 31 and the base plate 33 is a rectangular shape in which both sides along the scanning direction are short sides and sides along the paper feed direction are long sides. Further, the cavity plate 31 and the base plate 33 are both plate members made of stainless steel, and an ink flow path such as the pressure chamber 21 can be easily formed by etching.

  As shown in FIG. 2, the cavity plate 31 is formed with a plurality of pressure chambers 21 arranged in a staggered pattern along the longitudinal direction (paper feeding direction). That is, two pressure chamber rows adjacent in the scanning direction are formed by the plurality of pressure chambers 21. The plurality of pressure chambers 21 are open to the piezoelectric actuator 40 side (above FIGS. 3 and 4). As shown in FIG. 2, each pressure chamber 21 is formed in a substantially elliptical shape that is long in the scanning direction in plan view.

  As shown in FIGS. 2 and 3, communication holes 23 and 25 having circular planar shapes are formed in the base plate 33 at positions overlapping with both longitudinal ends of each pressure chamber 21 in a plan view. More specifically, the communication hole 23 is located on the opposite side of the pressure chamber row to which the pressure chamber 21 belongs (that is, the pressure chambers 21 arranged on the right side in FIGS. 2 and 3). Is formed at a position overlapping the end of the pressure chambers 21 arranged on the right and left sides thereof, and communicates the manifold 65 and the pressure chambers 21 through the communication holes 57 of the nozzle plate 55. . The communication hole 25 is arranged on the opposite side of the pressure chamber 21 from the side where the communication hole 23 is formed (that is, in the pressure chamber 21 arranged on the right side in FIGS. The pressure chamber 21 is formed at the right end) and communicates the pressure chamber 21 and the nozzle 59 formed in the nozzle plate 55.

  Some conventional inkjet heads have a pressure chamber and a manifold formed so as to overlap each other in the stacking direction inside a plate stack in which a plurality of plates are joined together in a stacked state ( For example, Japanese Patent Application Laid-Open No. 2004-148591). In such a case, since the number of expensive metal plates constituting the plate laminate increases as compared with the plate laminate 30 provided in the inkjet head 20 of the present embodiment, the cost increases. In particular, when a manifold is formed over a plurality of metal plates in order to form a large volume manifold, the number of metal plates further increases.

  The nozzle plate 55 is a plate having a rectangular planar shape, like the two plates 31 and 33 constituting the plate laminate 30, and is bonded to the lower surface of the base plate 33. Here, the nozzle plate 55 is formed of a polymer synthetic resin material such as polyimide, for example. Alternatively, the nozzle plate 55 may also be formed of a metal material such as stainless steel, similarly to the plates 31 and 33 constituting the plate laminate 30. As shown in FIG. 5, a liquid repellent film 58 having high liquid repellency for preventing wetting of the ink in the vicinity of the nozzle 59 is formed on the ink discharge surface 55 a of the nozzle plate 55. The liquid repellent film 58 is formed of a fluorine resin (for example, ethylene tetrafluoride) or the like.

  As shown in FIGS. 2 and 3, the nozzle plate 55 has a communication hole 57 for communicating the manifold 65 and the pressure chamber 21 at a position overlapping the communication hole 23 of the base plate 33 in plan view, and the communication hole 25 of the base plate 33. A nozzle 59 communicating with the pressure chamber 21 is formed at the overlapping position. That is, as shown in FIGS. 2 and 5, the nozzle plate 55 has a plurality of nozzles 59 arranged in a staggered pattern along the paper feed direction in the vicinity of the center in the scanning direction, thereby forming two nozzle rows. Has been. A plurality of communication holes 57 are arranged in a row in the vicinity of the scanning plate end of the nozzle plate 55 along the paper feed direction. The communication hole 57 and the nozzle 59 are formed by excimer laser processing.

  The manifold block 60 is made of resin such as PP (polypropylene), POM (polyacetal), PPS (polyphenylene sulfide), and is manufactured by injection molding. Further, as shown in FIG. 5, the manifold block 60 includes two extending portions 61 formed at both ends in the scanning direction and extending in the paper feeding direction, and one end portion of the two extending portions 61 (the lower end in FIG. 5). And a connecting portion 63 extending in the scanning direction for connecting the portion), and the planar shape as a whole is a substantially U-shaped member. The length of the outer shape of the manifold block 60 along the scanning direction and the length along the paper feed direction are almost the same as the pressure generation block 50 and the nozzle plate 55. 3 and 5, the manifold block 60 is bonded to the ink ejection surface 55a of the nozzle plate 55 so as not to block the nozzles 59, that is, so as to surround the nozzle row from three directions. . That is, as shown in FIG. 3, the manifold block 60 protrudes downward from the ink ejection surface 55a. At this time, the two extending portions 61 of the manifold block 60 extend parallel to each other across the nozzle row.

  A substantially U-shaped manifold 65 is formed inside the manifold block 60. As shown in FIG. 3, the manifold 65 opens to the nozzle plate 55 side. Further, as shown in FIGS. 2 and 3, the manifold 65 formed in the extension portion 61 includes a right half of the pressure chambers 21 arranged on the right side and a pressure chamber arranged on the left side in a plan view. It overlaps with the left half of 21 respectively. As a result, the manifold 65 and the pressure chamber 21 communicate with each other through the communication holes 57 and 23. As will be described later, an ink supply path 27 is connected to the manifold 65, and ink is supplied from an ink tank (not shown) via the ink supply path 27.

  Further, as shown in FIG. 5, the two extending portions 61 and the connecting portion 63 have inclined surfaces 62 and 64 that are inclined with respect to the ink discharge surface 55a, respectively. The inclined surfaces 62 respectively formed on the two extending portions 61 extend in the paper feeding direction, and are continuous with the ink ejection surface 55a at the end portion on the side close to the row of the nozzles 59. In addition, the inclined surface 64 formed in the connecting portion 63 connects one end portion (the lower end portion in FIG. 5) of the inclined surface 62 formed in each of the two extending portions 61 to each other. Is continuous with the ink discharge surface 55a at the end near the end. That is, the inclined surfaces 62 and 64 are formed in a substantially U shape around the row of nozzles 59. As shown in FIG. 3, the inclined surface 62 is inclined so as to be separated from the nozzle plate 55 in the height direction (a direction orthogonal to the ink discharge surface 55 a) as it is separated from the row of nozzles 59 in the scanning direction. In other words, the inclined surface 62 is formed such that the distance from the surface of the nozzle plate 55 increases as the distance from the row of nozzles 59 increases in the scanning direction in which the droplet discharge head moves.

  Here, as shown in FIG. 3, in the present embodiment, the length along the scanning direction of the extending portion 61 of the manifold block 60 is 3 mm, and in the scanning direction of the portion where the inclined surface 62 is formed. The length along is assumed to be 2 mm. The height of the manifold block 60 (the length along the direction orthogonal to the ink ejection surface 55a) is 0.5 mm. In other words, the inclined surface 62 has a degree of inclination such that it is 0.5 mm away from the nozzle plate 55 when it is 2 mm away in the scanning direction.

  With the above-described configuration, the manifold 65 communicates with the end of the pressure chamber 21 through the communication holes 57 and 23, and the end of the pressure chamber 21 opposite to the side communicating with the manifold 65 communicates with the end of the pressure chamber 21. The nozzle 59 communicates with the hole 25. As described above, a plurality of individual ink flow paths from the manifold 65 to the nozzle 59 through the pressure chamber 21 are formed in the inkjet head 20 across the pressure generating block 50, the nozzle plate 55, and the manifold block 60. Yes. The piezoelectric actuator 40 is configured to eject ink droplets from the nozzles 59 communicating with the pressure chambers 21 when pressure is applied to the ink in the pressure chambers 21.

  Next, the piezoelectric actuator 40 will be described. As shown in FIGS. 3 and 4, the piezoelectric actuator 40 includes a vibration plate 41 disposed on the upper surface of the plate laminate 30 and a piezoelectric element formed on the upper surface of the vibration plate 41 (the surface opposite to the pressure chamber 21). A layer 43 and a plurality of individual electrodes 45 formed respectively corresponding to the plurality of pressure chambers 21 on the upper surface of the piezoelectric layer 43 are provided.

  The diaphragm 41 is a plate made of a metal material having a rectangular shape in plan view, and is made of, for example, an iron-based alloy such as stainless steel, a copper-based alloy, a nickel-based alloy, or a titanium-based alloy. The vibration plate 41 is disposed on the upper surface of the cavity plate 31 so as to cover the plurality of pressure chambers 21, and is joined to the upper surface of the cavity plate 31. The metal diaphragm 41 has conductivity, and also serves as a common electrode for applying an electric field to the piezoelectric layer 43 sandwiched between the diaphragm 41 and the individual electrode 45. The diaphragm 41 is grounded and is always held at the ground potential.

  On the surface of the vibration plate 41, a piezoelectric layer 43 mainly composed of lead zirconate titanate (PZT), which is a solid solution and is a ferroelectric substance, is formed of lead titanate and lead zirconate. As shown in FIG. 2, the piezoelectric layer 43 is continuously formed across the plurality of pressure chambers 21 on the upper surface of the vibration plate 41. Here, the piezoelectric layer 43 can be formed using, for example, an aerosol deposition method (AD method) in which very small particles of a piezoelectric material are sprayed onto a substrate to collide with the substrate at a high speed and deposited on the substrate. Alternatively, it can be formed by a sputtering method, a chemical vapor deposition method (CVD method), a sol-gel method, a hydrothermal synthesis method, or the like.

  On the upper surface of the piezoelectric layer 43, a plurality of individual electrodes 45 having an elliptical planar shape that is slightly smaller than the pressure chambers 21 are formed at positions overlapping the central portion of each pressure chamber 21 in plan view. Here, the individual electrode 45 is made of a conductive material such as gold, copper, silver, palladium, platinum, or titanium. Further, a terminal portion 47 is formed on one end side of each individual electrode 45 on the upper surface of the piezoelectric layer 43 (on the side overlapping the end portion on the side communicating with the manifold 65 of the pressure chamber 21 in plan view). Yes. The terminal portion 47 is connected to a driving circuit such as a driver IC via a flexible wiring member such as a flexible printed wiring board, and a driving potential is selectively applied to the plurality of individual electrodes 45. It is configured as follows. The plurality of individual electrodes 45 and the plurality of terminal portions 47 can be formed by, for example, screen printing, sputtering, vapor deposition, or the like.

  Here, the operation of the piezoelectric actuator 40 will be described. When a driving potential is selectively applied to the plurality of individual electrodes 45, the individual electrode 45 to which the driving potential is applied is opposed to the individual electrode 45 and is held at the ground potential, and functions as a common electrode. The electric potential of the vibrating plate 41 is different, and an electric field in the thickness direction is generated in the portion of the piezoelectric layer 43 sandwiched between the individual electrode 45 and the vibrating plate 41. The portion of the piezoelectric layer 43 corresponding to the individual electrode 45 to which the drive potential is applied contracts in the horizontal direction orthogonal to the thickness direction that is the polarization direction. At this time, as the piezoelectric layer 43 contracts, the diaphragm 41 is deformed so as to protrude toward the pressure chamber 21, so that the volume in the pressure chamber 21 decreases and pressure is applied to the ink in the pressure chamber 21. Is done. As a result, ink droplets are ejected from the nozzle 59 communicating with the pressure chamber 21.

  As shown in FIG. 2, an elliptical through-hole is formed on one end side in the longitudinal direction of the vibration plate 41 (the lower side in the drawing in FIG. 2). Such a through hole communicates with a manifold 65 formed in the manifold block 60 and constitutes a part of the ink supply path 27. That is, the through holes constituting the ink supply path 27 are also formed at positions that overlap the through holes of the diaphragm 41 in plan view in the cavity plate 31, the base plate 33, and the nozzle plate 55. The ink supply path 27 is connected to an ink tank (not shown). Further, a filter 29 is installed at the end of the ink supply path 27 located on the surface of the vibration plate 41. As a result, foreign matter such as dust can be prevented from entering the inkjet head 20.

  Further, in the inkjet printer 1, a rubber wiper 80 (see FIG. 3) is fixedly provided outside the conveyance path of the recording paper 90 in the movement path of the inkjet head 20 by the carriage 10. The wiper 80 is installed so as to be orthogonal to the ink ejection surface 55a. When the inkjet head 20 is at the wiping position where the wiper 80 is installed, the vicinity of the tip of the wiper 80 is the lower surface of the inkjet head 20, more specifically, the inclined surface 62 of the manifold block 60 or the ink. It comes into contact with the discharge surface 55a. Therefore, wiping for wiping off ink adhering to the ink ejection surface 55a is performed by moving the inkjet head 20 in the scanning direction at the wiping position.

  Here, the movement of the wiper 80 when wiping is performed will be described. As shown in FIG. 3, the wiper 80 first rubs the inclined surface 62 of the extending portion 61 located on one side (left side in the drawing) of the nozzle row in the scanning direction. At this time, the flexible wiper 80 moves while being deformed along the inclined surface 62. Subsequently, from one end portion of the inclined surface 62 that is continuous with the ink discharge surface 55a, the ink smoothly moves onto the ink discharge surface 55a, and the ink on the ink discharge surface 55a is wiped off. Then, it can move smoothly to the inclined surface 62 of the extending portion 61 located on the other side (right side in the drawing) of the nozzle row.

  As described above, in the ink jet printer 1 according to the present embodiment, the ink jet head 20 includes the pressure generating block 50 having the pressure chambers 21 and the piezoelectric actuators 40 that apply pressure fluctuations to the ink in the pressure chambers 21, the pressure A nozzle plate 55 that is joined to the generation block 50 and has a plurality of nozzles 59 communicating with the respective pressure chambers 21, and ink on the opposite side of the nozzle plate 55 to the side on which the pressure generation block 50 is joined. A manifold block 60 formed with a manifold 65 that is bonded to the ejection surface 55a and holds ink to be supplied to each pressure chamber 21 is provided. The nozzle plate 55 includes the manifold 65 and each pressure chamber 21. A communication hole 57 that communicates is formed. The manifold block 60 is inclined with respect to the ink discharge surface 55a, and has an inclined surface 62 that is continuous with the ink discharge surface 55a at one end thereof. The inclined surfaces 62 are arranged on both sides of the nozzle row with respect to the scanning direction of the inkjet head 20. Therefore, when wiping the ink discharge surface 55a along the scanning direction using the wiper 80, the wiper 80 does not get caught by the manifold block 60, and is inclined from the inclined surface 62 to the ink discharge surface 55a and from the ink discharge surface 55a. It can move smoothly to the inclined surface 62. Therefore, the ink attached to the ink ejection surface 55a can be wiped off with the wiper 80.

  In addition, the shape of the inclined surface of the manifold block which is planar is not limited to this. Although not shown, the shape of the inclined surface may be concave or convex with respect to the nozzle plate. By doing so, the contact resistance between the wiper and the inclined surface is lowered, and the life of the wiper is extended. Further, as shown in FIG. 11, the inclined surface of the manifold block has a first inclined surface 62a having one end continuous with the nozzle plate 55 and the other end connected to one end of the second inclined surface 62b, and one end being You may comprise by the 2nd inclined surface 62b connected with the other end of the 1st inclined surface 62a, and the other end continuing to the nozzle plate 55. With such a structure, the contact resistance between the inclined surfaces 62a and 62b and the wiper can be reduced. In this case, it is good also as a curved surface so that the connection part of the 1st inclined surface 62a and the 2nd inclined surface 62b may continue smoothly. By using a curved surface, the wiper can move more smoothly.

  In the above-described embodiment, the pressure chamber 21 and the manifold 65 are disposed on the opposite sides with respect to the nozzle plate 55 on which the nozzles 59 are formed, and therefore, between the pressure chamber 21 and the nozzle plate 55. Compared with the case where the manifold 65 is disposed, the flow path length between the outlet of the pressure chamber 21 and the nozzle 59 is shortened. Accordingly, the pressure required for ejecting ink from the nozzle 59 is relatively small, so that power consumption can be reduced.

  Furthermore, in the inkjet printer 1 of the present embodiment, the manifold block 60 is manufactured by injection molding. Therefore, the manifold block 60 can be manufactured with a smaller number of processing steps than in the case of manufacturing by bonding a plurality of members to each other. In addition, the manifold block 60 having a desired shape can be easily manufactured.

  In addition, in the inkjet printer 1 of the present embodiment, the manifold block 60 is made of resin. Therefore, the manifold block 60 can be manufactured at a lower cost than the case of being made of metal. Further, for example, when the manifold 65 is formed inside the plate laminated body 30 so as to overlap the pressure chamber 21 in the lamination direction, the number of stacked metal plates of the plate laminated body 30 increases, so that the cost is high. turn into. In the present embodiment, since the manifold 65 is formed in the manifold block 60 which is a member made of a resin different from the plate laminate 30, the number of metal plates constituting the plate laminate 30 is reduced, and the inkjet The cost of the entire head 20 can be reduced.

  In the inkjet printer 1 of the present embodiment, the manifold block 60 having the inclined surfaces 62 and 64 formed in a substantially U shape around the nozzle row is joined to the ink discharge surface 55a. It is possible to prevent the sheet 90 from coming into contact with the ink ejection surface 55a. Therefore, damage to the liquid repellent film 58 formed on the ink discharge surface 55a can be prevented. When the liquid repellent film 58 is damaged, ink wets easily at the damaged portion. Therefore, it is possible to prevent the ink from remaining in the vicinity of the nozzle 59 due to damage to the liquid repellent film 58 in the vicinity of the nozzle 59, thereby causing variations in the ink ejection direction and ejection amount.

<Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a partial cross-sectional view along the scanning direction of the inkjet head of the present embodiment, and FIG. 7 is a bottom view of the portion shown in FIG. 6 of the inkjet head of the present embodiment. The inkjet head 120 of the present embodiment is the same as that of the first embodiment except that a groove 166 is formed on the inclined surface 162 of the manifold block 160. In the following description, components having the same configurations as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted as appropriate.

  As shown in FIGS. 6 and 7, the inclined surface 162 has a plurality of extending along the direction (scanning direction) away from the nozzle 59 from the end of the inclined surface 162 on the side continuous with the ink discharge surface 55 a. A groove 166 is formed. Further, the groove 166 is integrally formed when the manifold block 160 is manufactured by resin injection molding.

  As described above, the ink jet head 120 according to the present embodiment can wipe the ink adhering to the ink ejection surface 55a with the wiper 80, similarly to the ink jet head 20 according to the first embodiment.

  Further, in the inkjet head 120 of the present embodiment, when the ink adhering to the ink ejection surface 55 a comes into contact with one end of the groove 166, the ink is sucked into the groove 166 by capillary force and transferred in a direction away from the nozzle 59. . That is, the groove 166 formed on the inclined surface 162 functions as a transfer structure that transfers the ink attached to the ink discharge surface 55a in a direction away from the nozzle 59. By providing the inclined surface 162 with the transfer structure, the vicinity of the nozzle 59 can be kept clean even if the number of wiping operations is reduced. Further, the ink sucked into the groove 166 is held in the groove 166 by capillary force. Therefore, it is possible to prevent the recording paper 90 and the conveyance path of the recording paper 90 from becoming dirty due to ink dripping. In addition, the recording paper 90 disposed opposite to the ink ejection surface 55a is difficult to touch the ink held in the groove 166 formed on the inclined surface 162, so that the recording paper 90 is prevented from being soiled. Can do. Further, the extension length of the groove 166 can be increased as compared with the case where the groove 166 is formed in parallel to the ink discharge surface 55a. Therefore, more ink can be held in the groove 166.

  Furthermore, in the inkjet head 120 of the present embodiment, the manifold block 160 is manufactured by injection molding, so that the groove 166 can be easily formed.

(First modification)
Here, a first modification of the second embodiment will be described with reference to FIG. FIG. 8 is a view showing a part of the lower surface of the ink jet head according to the present modification, and corresponds to FIG. 7 of the second embodiment. In this modification, the groove 166 formed on the inclined surface 162 as the transfer structure in the second embodiment is changed to the transfer surface 266.

  As shown in FIG. 8, the transfer surface 266 is divided into a plurality of regions adjacent to each other along the direction (scanning direction) away from the nozzle 59 from the end of the inclined surface 262 on the side continuous with the ink discharge surface 55a. It has been. Of the plurality of regions, the liquid repellency of the region located at the end portion on the side continuous with the ink discharge surface 55a (the left end portion in FIG. 8) is formed on the ink discharge surface 55a. The liquid repellency is lower in a region that is equal to or lower than the liquid repellency of the liquid repellent film 58 and that is located away from the nozzle 59 (the right end in FIG. 8). Note that the width of each region (the length along the scanning direction) is preferably smaller than the diameter of the droplet on the ink ejection surface 55a. The transfer surface 266 is formed of a liquid repellent film made of, for example, a fluorine resin. In the present modification, the liquid repellent film that forms the transfer surface 266 is formed in a separate process from the liquid repellent film 58 on the ink ejection surface 55a.

  Furthermore, a groove 269 extending along the paper feeding direction is formed on the lower surface of the manifold block 260 of this modification. As shown in FIG. 8, the groove 269 is formed at the end of the inclined surface 262 opposite to the side that is continuous with the ink discharge surface 55a, that is, the end of the transfer surface 266 on the region having the lowest liquid repellency. It is formed in close proximity. Accordingly, the ink transferred by the transfer surface 266 is held in the groove 269 by capillary force. The ink held in the groove 269 is removed by pressing an absorber (not shown) against the groove 269.

  According to this modification, when the ink adhering to the ink discharge surface 55a comes into contact with one end of the transfer surface 266, the ink is transferred in a direction away from the nozzle 59 (right side in FIG. 8) so as to go to a region having lower liquid repellency. Is done. That is, the transfer surface 266 formed on the inclined surface 262 functions as a transfer structure for transferring the ink adhering to the ink discharge surface 55a in the direction away from the nozzle 59, so that the vicinity of the nozzle 59 is cleaned even if the number of wiping operations is reduced. It becomes possible to keep it.

  In the above-described modification, the ink transferred by the transfer surface 266 is held in the groove 269 formed in the vicinity of the region having the lowest liquid repellency on the transfer surface 266. Therefore, it is possible to prevent the recording paper 90 and the conveyance path of the recording paper 90 from becoming dirty due to ink dripping.

(Second modification)
Next, a second modification of the second embodiment will be described with reference to FIG. FIG. 9 is a view showing a part of the lower surface of the ink jet head according to the present modification, and corresponds to FIG. 7 of the second embodiment. In this modification, the groove 166 formed in the inclined surface 162 as the transfer structure in the second embodiment is changed to a high liquid repellency region 366 and a low liquid repellency region 367.

  Here, the high liquid repellency region 366 has liquid repellency equivalent to or lower than the liquid repellency film 58 formed on the ink ejection surface 55a, and the low liquid repellency region 367 has a high liquid repellency region 367. It has a liquid repellency lower than 366. As shown in FIG. 9, the high liquid repellency region 366 and the low liquid repellency region 367 are both in a direction (scanning direction) away from the nozzle 59 from the end of the inclined surface 362 on the side continuous with the ink ejection surface 55a. Are formed along the paper feed direction. The width of the highly liquid repellent region 366 becomes narrower in the direction away from the nozzle 59 than the end on the ink discharge surface 55a side, and the end farthest from the nozzle 59 (the right side in FIG. 9). Edge) is pointed. Further, the width of the low liquid repellency region 367 increases from the end portion on the ink discharge surface 55a side toward the direction away from the nozzle 59, and the end portion on the ink discharge surface 55a side (the left side in FIG. 9). Edge) is pointed. That is, the high liquid repellency region 366 and the low liquid repellency region 367 are both patterned in a zigzag shape.

  In this modification, first, a liquid repellent film having liquid repellency corresponding to the high liquid repellency region 366 is formed on the entire inclined surface 362 using, for example, a fluorine resin. The liquid repellent film has higher liquid repellency than the surface of the manifold block 360, and has a liquid repellency equivalent to or lower than the liquid repellent film 58 formed on the ink discharge surface 55a. To do. Thereafter, a portion corresponding to the low liquid repellency region 367 of the liquid repellency film is removed with a laser or the like, whereby the high liquid repellency region 366 and the low liquid repellency region 367 are formed. In the present modification, the water repellent film formed on the inclined surface 362 is formed in a separate process from the liquid repellent film 58 on the ink ejection surface 55a.

  Furthermore, a groove 369 extending along the paper feeding direction is formed on the lower surface of the manifold block 360 of this modification. As shown in FIG. 9, the groove 369 is an end of the inclined surface 362 opposite to the side continuous with the ink ejection surface 55a, that is, the end of the side having the largest width of the low liquid repellency region 367. It is formed close to the part. Accordingly, the ink transferred by the high liquid repellency region 366 and the low liquid repellency region 367 is held in the groove 369 by the capillary force. The ink held in the groove 369 is removed by pressing an absorber (not shown) against the groove 369.

  According to this modification, when the ink adhering to the ink ejection surface 55a comes into contact with the region where the high liquid repellency region 366 and the low liquid repellency region 367 are patterned, the ink in the low liquid repellency region 367 extends along the scanning direction. Spread out wet. That is, the high liquid repellency region 366 and the low liquid repellency region 367 formed on the inclined surface 362 function as a transfer structure for transferring the ink adhering to the ink discharge surface 55a in the direction away from the nozzle 59. Even if the number is reduced, the vicinity of the nozzle 59 can be kept clean.

  Further, in the above-described modification, first, a liquid repellent film having liquid repellency corresponding to the high liquid repellency region 366 is formed, and then the liquid repellency film formed at a position corresponding to the low liquid repellency region 367 is deleted. Thus, the high liquid repellency region 366 and the low liquid repellency region 367 that function as a transfer structure can be formed. Therefore, for example, the transfer structure can be easily formed as compared with the case where the transfer structure has three or more regions having different liquid repellency.

  Further, since the width of the low liquid repellency region 367 is narrow on the ink discharge surface 55a side, the ink attached to the ink discharge surface 55a is sucked into the low liquid repellency region 367 by capillary force. Therefore, the ink can be reliably transferred in the direction away from the nozzle 59. Further, since the width of the low liquid repellency region 367 becomes wider toward the direction away from the nozzle 59, even when the amount of ink sucked into the low liquid repellency region 367 is relatively large, the low liquid repellency region 367 is low without dripping. Wet and spread in the liquid repellent area 367.

  In addition, since the end portion of the low liquid repellency region 367 on the ink discharge surface 55a side is a point, the surface of the ink droplet attached to the ink discharge surface 55a is the point of the low liquid repellency region 367 (FIG. 9). At the left end) and can spread smoothly in the low liquid repellency region 367 (right side in FIG. 9).

  In the above-described modification, the ink transferred by the high liquid repellency region 366 and the low liquid repellency region 367 is the groove 369 formed in the vicinity of the end of the low liquid repellency region 367 where the width is the widest. Held by. Therefore, it is possible to prevent the recording paper 90 and the conveyance path of the recording paper 90 from becoming dirty due to ink dripping.

<Third Embodiment>
Next, a third embodiment will be described with reference to FIG. FIG. 10 is a bottom view of the ink jet head according to the present embodiment. The inkjet head 420 of the present embodiment is the same as that of the first embodiment except for the shape of the manifold block 460. The main difference between the manifold block 460 of the present embodiment and the manifold block 60 of the first embodiment is that the manifold block 60 is a member having a generally U-shaped planar shape as a whole. However, the manifold block 460 of the present embodiment is a member having a generally square shape in plan view, and has an inclined surface formed in an annular shape. 462, 464. In the following description, components having the same configurations as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted as appropriate.

  As shown in FIG. 10, the manifold block 460 is adjacent to the scanning direction while being separated from each other, and has two extending portions 461 extending in the paper feeding direction, and both ends of the two extending portions 461. It has two connecting portions 463 to be connected, and the planar shape as a whole has a substantially square shape. The outer shape of the manifold block 460 in plan view is substantially the same as that of the pressure generating block 50 and the nozzle plate 55. The manifold block 460 is bonded to the ink ejection surface 55a of the nozzle plate 55 so as not to block the nozzles 59, that is, so as to completely surround the nozzle rows. At this time, the two extending portions 461 of the manifold block 460 extend in parallel with each other across the nozzle row. A substantially square-shaped manifold 465 is formed inside the manifold block 460.

  Further, the two extending portions 461 and the two connecting portions 463 have inclined surfaces 462 and 464 that are inclined with respect to the ink ejection surface 55a, respectively. The inclined surfaces 462 formed on the two extending portions 461 respectively extend in the paper feeding direction, and are continuous with the ink ejection surface 55a at the end portion on the side close to the row of the nozzles 59. In addition, the inclined surfaces 464 formed on the two connecting portions 463 connect both ends of the inclined surfaces 462 formed on the two extending portions 461, respectively, and the end on the side close to the row of the nozzles 59. This part is continuous with the ink discharge surface 55a. That is, the inclined surfaces 462 and 464 are formed in a substantially square shape around the nozzle 59 row, that is, in an annular shape. The inclined surface 462 is inclined so as to be away from the nozzle plate 55 in the height direction (a direction orthogonal to the ink ejection surface 55a) as the distance from the row of nozzles 59 in the scanning direction increases. The inclination degree of the inclined surface 462 is the same as that of the inclined surface 62 of the first embodiment.

  As described above, the ink jet head 420 according to the present embodiment can wipe the ink adhering to the ink ejection surface 55a with the wiper 80, similarly to the ink jet head 20 according to the first embodiment.

  Further, in the ink jet head 420 of the present embodiment, the manifold block 460 having the inclined surfaces 462 and 464 formed in an annular shape around the nozzle row is joined to the ink discharge surface 55a. It can prevent more reliably that it contacts the discharge surface 55a. Therefore, damage to the liquid repellent film 58 formed on the ink discharge surface 55a can be prevented. Therefore, it is possible to prevent variation in ink discharge characteristics due to damage to the liquid repellent film 58 in the vicinity of the nozzle 59.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made as long as they are described in the claims. Is. For example, in the above-described first to third embodiments, the case where the manifold block 60 (160, 260, 360, 460) is joined to the ink discharge surface 55a of the nozzle plate 55 has been described. Is not limited. Spacers may be provided between the nozzle plate 55 and the manifold block 60 (160, 260, 360, 460).

  In the first to third embodiments described above, the case where the manifold block 60 (160, 260, 360, 460) is manufactured by resin injection molding has been described. However, the present invention is not limited to this. The material of the manifold block 60 (160, 260, 360, 460) may be any material that can be injection-molded, such as a mixture of metal powder and resin. Furthermore, the manifold block 60 (160, 260, 360, 460) may be manufactured by joining a plurality of members to each other instead of injection molding. In this case, the material may be a material that cannot be injection molded.

  Further, in the above-described second embodiment (see FIGS. 6 and 7), the case where the transfer structure that transfers the ink attached to the ink discharge surface 55a in the direction away from the nozzle 59 is the groove 166 has been described. In the first modification (see FIG. 8) of the second embodiment, the transfer structure is a transfer surface 266. In the second modification (see FIG. 9), the transfer structure is highly liquid repellent. Although the case of the region 366 and the low liquid repellent region 367 has been described, the configuration of the transfer structure is not limited to these.

  For example, in the first modification of the second embodiment, the transfer surface 266 that is a transfer structure is composed of a plurality of regions adjacent to each other along the scanning direction, and is continuous with the ink discharge surface 55a. In the above description, the liquid repellency is lower in the region located farther from the nozzle 59 than in the region located at the end of the liquid crystal. It may be formed of a liquid repellent film that changes with time.

  Further, for example, in the second modification of the second embodiment, the case where both the high liquid repellency region 366 and the low liquid repellency region 367 that are transfer structures are patterned in a zigzag shape has been described. This is not a limitation. The end portion of the high liquid repellency region 366 farthest from the nozzle 59 and the end portion of the low liquid repellency region 367 on the ink discharge surface 55a side may not be sharp. Further, for example, a plurality of dot-like highly liquid-repellent regions 366 are formed on the inclined surface 362 so that the density decreases in the direction away from the nozzle 59 from the end on the ink ejection surface 55a side. A region other than the high liquid repellent region 366 on the inclined surface 362 may be a low liquid repellent region 367.

  In addition, in the above-described first and second embodiments, the case where the substantially U-shaped inclined surfaces 62 (162, 262, 362), 64 are formed around the row of nozzles 59, In the third embodiment, the cases where the annular inclined surfaces 462 and 464 having a substantially square shape are formed around the row of the nozzles 59 are described, but the present invention is not limited to this. The inclined surfaces 62 (162, 262, 362, 462), 64, 462, 464 may be formed on at least one side of the nozzle row in the scanning direction.

  In the first to third embodiments described above, the serial inkjet head 20 (120, 220, 320, 420) that ejects ink onto the recording paper 90 while moving in the scanning direction has been described. The invention can also be applied to a line-type inkjet head that is fixedly arranged along a direction orthogonal to the conveyance direction of the recording paper 90. In this case, a fixed wiper can be omitted.

1 is a diagram illustrating a schematic configuration of an ink jet printer according to a first embodiment of the present invention. It is a top view of the inkjet head shown in FIG. It is sectional drawing which follows the III-III line of FIG. It is sectional drawing which follows the IV-IV line of FIG. It is a bottom view of the inkjet head shown in FIG. It is a fragmentary sectional view which follows the scanning direction in the inkjet head concerning the 2nd Embodiment of this invention. It is a bottom view of the inkjet head shown in FIG. It is a figure which shows a part of lower surface of the inkjet head concerning the 1st modification of the 2nd Embodiment of this invention. It is a figure which shows a part of lower surface of the inkjet head concerning the 2nd modification of the 2nd Embodiment of this invention. It is a bottom view of the inkjet head concerning the 3rd Embodiment of this invention. It is a side view when the shape of the inclined plane of a manifold block is changed.

Explanation of symbols

1 Inkjet printer (droplet ejection device)
10 Carriage (moving means)
20, 120, 220, 320, 420 Inkjet head (droplet ejection head)
21 Pressure chamber 40 Piezoelectric actuator (pressure applying means)
50 Pressure generation block (first block)
55a Ink ejection surface 55 Nozzle plate 57 Communication hole 58 Liquid repellent film 59 Nozzle 60, 160, 260, 360, 460 Manifold block (second block)
62, 64, 162, 262, 362, 462, 464 Inclined surface 65, 165, 465 Manifold 70 Conveying roller (conveying means)
90 Recording paper (medium)
166 groove (transfer means)
266 Transfer surface (transfer means)
366 Highly liquid repellent area (transfer means)
367 Low liquid repellent area (transfer means)

Claims (19)

A first block having a plurality of pressure chambers, and a pressure applying mechanism that applies pressure fluctuation to the liquid in the plurality of pressure chambers;
A nozzle plate joined to the first block and formed with a plurality of nozzles respectively communicating with the plurality of pressure chambers;
A second block which is disposed on the opposite side of the first block with respect to the nozzle plate and has a manifold for holding liquid to be supplied to each of the plurality of pressure chambers.
The nozzle plate has a plurality of communication holes for communicating the manifold and the plurality of pressure chambers, respectively.
The second block is inclined with respect to the surface of the nozzle plate, and has an inclined surface continuous with the surface of the nozzle plate at one end thereof.   2. The droplet discharge head according to claim 1, wherein the inclined surface includes a transfer structure that transfers the liquid adhering to the surface of the nozzle plate in a direction away from the nozzle. 3.   The droplet discharge head according to claim 2, wherein the transfer structure is a groove extending along a direction away from the nozzle from the one end of the inclined surface.   The transfer structure has liquid repellency equal to or lower than the liquid repellency on the surface of the nozzle plate at the one end of the inclined surface, and is directed toward the other end farther from the nozzle than the one end. The droplet discharge head according to claim 2, wherein the transfer surface has a lower liquid repellency. The transfer structure has a first region having a liquid repellency equal to or lower than a liquid repellency on the surface of the nozzle plate, and a first region having a liquid repellency lower than the liquid repellency of the first region. Two regions,
The first and second regions are patterned so as to move the liquid adhering to the surface of the nozzle plate from the one end toward the other end farther from the nozzle than the one end. The droplet discharge head according to claim 2.   Each of the first and second regions extends in a direction from the one end to the other end, and the width of the first region increases from the one end side to the other end side. The droplet discharge head according to claim 5, wherein the droplet discharge head is narrowed, and the width of the second region becomes wider from the one end side toward the other end side.   The droplet discharge head according to claim 6, wherein the other end side of the first region is a pointed end, and the one end side of the second region is a pointed end.   The liquid droplet ejection head according to claim 1, wherein the second block is manufactured by injection molding.   The liquid droplet ejection head according to claim 1, wherein the second block is made of a resin.   The inclined surface is formed so that the distance from the surface of the nozzle plate increases as the distance from the nozzle increases in a predetermined direction in which the droplet discharge head moves. The droplet discharge head according to any one of the above.   The droplet discharge head according to claim 1, wherein the inclined surface is planar.   The droplet discharge head according to claim 1, wherein the inclined surface includes a first inclined surface and a second inclined surface.   One end of the first inclined surface is continuous with the surface of the nozzle plate, the other end of the first inclined surface is connected to one end of the second inclined surface, and the other end of the second inclined surface is The droplet discharge head according to claim 12, wherein the droplet discharge head is continuous with a surface of the nozzle plate.   The liquid droplet ejection head according to claim 1, wherein a pair of the inclined surfaces are provided on the surface of the nozzle plate so that the axis of the nozzle is symmetrical.   The droplet discharge head according to claim 1, wherein the droplet discharge head is an inkjet head. A first block having a plurality of pressure chambers, and a pressure applying mechanism that applies pressure fluctuation to the liquid in the plurality of pressure chambers;
A nozzle plate joined to the first block and formed with a plurality of nozzles respectively communicating with the plurality of pressure chambers;
A second block which is disposed on the opposite side of the first block with respect to the nozzle plate and has a manifold for holding liquid to be supplied to each of the plurality of pressure chambers.
The nozzle plate has a plurality of communication holes for communicating the manifold and the plurality of pressure chambers, respectively.
The second block is a droplet discharge device that is inclined with respect to the surface of the nozzle plate and has an inclined surface that is continuous with the surface of the nozzle plate at one end thereof,
A moving unit for reciprocating the droplet discharge head along a predetermined direction;
A medium transport unit that transports a medium on which the liquid droplets discharged from the liquid droplet discharge head land along an orthogonal direction orthogonal to the direction;
A wiper for wiping the plurality of nozzles,
The plurality of nozzles constitutes a nozzle row arranged along the orthogonal direction,
The liquid droplet ejection apparatus, wherein the inclined surface is located at least on one side of the nozzle row with respect to the direction.   The liquid droplet ejection apparatus according to claim 16, wherein the direction is a scanning direction.   18. The droplet discharge device according to claim 16, wherein the inclined surface is formed in an annular shape around the nozzle row.   The liquid droplet ejection apparatus according to claim 16, wherein the liquid droplet ejection apparatus is an ink jet printer.

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