JP2014177076A - Liquid jet head and liquid jet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid jet head 1 having a structure which is easily processed and assembled.SOLUTION: A liquid jet head 1 comprises: a piezoelectric plate 2 in which a discharge groove 7 discharging liquid and a dummy groove 8 discharging no liquid are alternatively arrayed in a reference direction K of one surface OS, and one side of the discharge groove 7 is opened to a side face SS; a cover plate 3 which supplies the discharge groove 7 with the liquid, discharges the liquid, and is connected with the one surface OS of the piezoelectric plate 2; and a nozzle plate 4 which includes a plurality of nozzles 11 arrayed in the reference direction K and is connected with the side face SS of the piezoelectric plate 2. The discharge groove 7 includes a going discharge groove 7a and a coming discharge groove 7b adjacent to each other in the reference direction K of the one surface OS. The going discharge groove 7a and the coming discharge groove 7b are communicated with each other in the vicinity of the nozzle 11.

Description

  The present invention relates to a liquid ejecting head and a liquid ejecting apparatus that eject and record liquid droplets on a recording medium.

  In recent years, an ink jet type liquid ejecting head has been used in which ink droplets are ejected onto recording paper or the like to record characters and figures, or a liquid material is ejected onto the surface of an element substrate to form a functional thin film. In this method, a liquid such as ink or a liquid material is guided from a liquid tank to a channel via a supply pipe, pressure is applied to the liquid filled in the channel, and the liquid is discharged from a nozzle communicating with the channel. When discharging the liquid, the liquid ejecting head or the recording medium is moved to record characters and figures, or a functional thin film having a predetermined shape is formed.

  As this type of liquid ejecting head, a through-flow type is known in which a piezoelectric element is used on a wall constituting a channel and the liquid in the channel is constantly circulated. The through-flow type can be quickly discharged out of the channel even when bubbles or foreign substances are mixed in the liquid. Therefore, maintenance can be performed without using a cap structure or a service station, the amount of liquid consumed during maintenance can be reduced, and running costs can be suppressed. Furthermore, wasteful consumption of the recording medium due to ejection failure can be minimized.

  Patent Document 1 describes a liquid circulation type liquid jet head. FIG. 15 is an exploded perspective view of the liquid jet head disclosed in Patent Document 1. In FIG. In the liquid jet head, two piezoelectric elements are overlapped to form PZT wafers 88 and 89 constituting three flow paths 90, 92, and 94, and openings that communicate with the flow paths 90 and 94 are formed. A mask plate 100 that closes the flow path, an opening plate 66 that has an opening that communicates the flow path 90 and the flow path 94 across the flow path 92, and a nozzle 102 that communicates with the opening of the opening plate 66 are formed. And a nozzle plate 64. The liquid flows from the flow path 90 to the flow path 94 through the opening of the opening plate 66 as indicated by the arrow 52. That is, the liquid circulates around the flow path 92. A line electrode is provided on the side surface of the two walls 96, 98 on the flow channel 92 side, and a ground electrode is provided on the side surface on the flow channel 90, 94 side. By driving the walls 96, 98 with these electrodes, the nozzles are provided. A small droplet is discharged from 102.

  Patent Document 2 discloses another liquid circulation type liquid jet head. The liquid ejecting head has a piezoelectric plate having a plurality of grooves on the surface, a cover plate that is bonded to the surface of the piezoelectric plate and covers an upper opening of each groove, and is disposed on a side surface of the piezoelectric plate and communicates with each groove. A nozzle plate having a plurality of nozzles. The cover plate includes a liquid supply hole, and the liquid is supplied to each groove through the liquid supply hole. A plurality of discharge paths corresponding to the respective grooves are formed on the surface of the nozzle plate on the piezoelectric plate side. The liquid ejecting head is further provided with a flow path member having a liquid discharge chamber on the back surface of the piezoelectric plate. The discharge path formed in the nozzle plate communicates a groove installed on the surface of the piezoelectric plate and a liquid discharge chamber installed on the back surface. The liquid is diverted from the liquid supply hole to each groove, and merges from each groove through the corresponding discharge path in the liquid discharge chamber.

Japanese translation of PCT publication No. 2003-505281 JP 2011-131533 A

  The liquid ejecting head described in Patent Document 1 forms a plurality of flow paths in units of three flow paths 90, 92, and 94 by stacking two PZT wafers. In addition, an opening plate 66 and a nozzle plate 64 are installed on the upper surface thereof, and other flow path members not shown are required. Therefore, it has a complicated structure that requires a high number of parts and requires a high degree of alignment during assembly. The liquid ejecting head described in Patent Document 2 must have the same number of discharge paths as the nozzles at the same pitch as the nozzles on the surface of the nozzle plate on the piezoelectric plate side, and has a complicated structure and is extremely difficult to manufacture.

  The liquid jet head of the present invention includes a piezoelectric plate in which discharge grooves for discharging liquid and dummy grooves for not discharging liquid are alternately arranged in a reference direction on one surface, and one side of the discharge groove is open on a side surface, and the discharge A liquid supply hole for supplying liquid to the groove, a liquid discharge hole for discharging liquid from the discharge groove, a cover plate joined to one surface of the piezoelectric plate, and a plurality of nozzles arranged in a reference direction, A nozzle plate that communicates with the discharge groove and is joined to a side surface of the piezoelectric plate, and the discharge groove includes a forward discharge groove and a reverse discharge groove that are provided adjacent to a reference direction of the one surface. The forward discharge groove and the reverse discharge groove communicate with each other in the vicinity of the nozzle, the liquid supply hole communicates with the forward discharge groove, and the liquid discharge hole communicates with the backward discharge groove.

  In addition, the nozzle plate includes a first series passage that communicates the forward discharge groove and the backward discharge groove that are open on the side surfaces of the nozzle and the piezoelectric plate.

  The nozzle plate includes a first nozzle plate having the nozzle and a second nozzle plate having the first series passage.

  In addition, the piezoelectric plate has a second communication path that connects the forward discharge groove and the reverse discharge groove in the vicinity of the nozzle.

  The liquid supply hole communicates with the other end of the forward discharge groove and is arranged in a reference direction, and the liquid discharge hole communicates with the other end of the reverse discharge groove. They were arranged in the reference direction in parallel with the arrangement.

  A flow path that has a liquid supply path that communicates with the plurality of liquid supply holes and a liquid discharge path that communicates with the plurality of liquid discharge holes, and is joined to the opposite side of the cover plate from the piezoelectric plate side. A member was provided.

  The liquid supply hole and the liquid discharge hole communicate with the other end of the forward discharge groove and the other end of the reverse discharge groove, respectively, and are arranged in a line in a reference direction.

  In addition, the liquid is supplied from the divided supply holes that supply the liquid to the forward discharge grooves that are adjacent to each other across the dummy groove located on one side, and the return discharge grooves that are adjacent to each other across the dummy groove located on the other side. A separation plate joined to the cover plate is provided, which has a merged discharge channel for merging and discharging, and a merged discharge hole communicating with the merged discharge channel.

  Further, the flow path has a liquid supply path communicating with the plurality of divided supply holes and a liquid discharge path communicating with the plurality of merged discharge holes, and is joined to the opposite side of the separation plate from the cover plate side. A member was provided.

  The liquid supply path is partly formed by a damper film that relieves pressure fluctuations of the liquid.

  Further, the other side of the ejection groove terminates in the surface of one surface of the piezoelectric plate, and includes an active electrode on a side surface of the dummy groove, a common electrode on a side surface of the forward ejection groove and the backward ejection groove, The piezoelectric plate has a common terminal electrically connected to the common electrode and an active terminal electrically connected to the active electrode on one surface of the piezoelectric plate.

  In addition, a wiring electrode for electrically connecting the active electrode formed on the side surface of the adjacent dummy groove is provided on one surface of the piezoelectric plate.

  In addition, a separation groove for electrically separating the common terminal and the active terminal is provided on one surface of the piezoelectric plate between the common terminal and the active terminal.

  A first liquid ejecting head comprising the liquid ejecting head according to any one of the above, and a second liquid ejecting head; and the other surface of the piezoelectric plate of the first liquid ejecting head and the piezoelectric plate of the second liquid ejecting head. The other surface faces each other, and the nozzle of the first liquid ejecting head and the nozzle of the second liquid ejecting head are joined with a shift of a half pitch in the reference direction.

  The nozzle plate of the first liquid ejecting head and the nozzle plate of the second liquid ejecting head are integrally formed.

  According to another aspect of the invention, a liquid ejecting head includes: the liquid ejecting head described above; a moving mechanism that relatively moves the liquid ejecting head and the recording medium; a liquid supply pipe that supplies liquid to the liquid ejecting head; A liquid tank for supplying the liquid to the liquid supply pipe.

  In the liquid ejecting head according to the present invention, the ejection grooves for ejecting liquid and the dummy grooves for not ejecting the liquid are alternately arranged in the reference direction on one surface, and one side of the ejection groove is opened on the side surface, and the ejection groove A liquid supply hole for supplying liquid and a liquid discharge hole for discharging liquid from the discharge groove, a cover plate joined to one surface of the piezoelectric plate, and a plurality of nozzles arranged in a reference direction, where the nozzle is the discharge groove A nozzle plate that communicates with the side surface of the piezoelectric plate, and the discharge groove includes a forward discharge groove and a reverse discharge groove that are provided adjacent to each other in the reference direction on one side, and the forward discharge groove and the reverse discharge groove Is communicated in the vicinity of the nozzle, the liquid supply hole communicates with the forward discharge groove, and the liquid discharge hole communicates with the backward discharge groove. As a result, the structure of the liquid ejecting head is simplified, the assembly is facilitated, and the cost can be reduced.

FIG. 3 is a partially exploded perspective view of the liquid jet head according to the first embodiment of the present invention. FIG. 3 is an explanatory diagram of a liquid ejecting head according to the first embodiment of the invention. FIG. 6 is a partially exploded perspective view of a liquid jet head according to a second embodiment of the present invention. FIG. 6 is a diagram for explaining a liquid jet head according to a second embodiment of the invention. FIG. 10 is a partially exploded perspective view of a liquid jet head according to a third embodiment of the present invention. FIG. 10 is a partial exploded perspective view of a liquid jet head according to a fourth embodiment of the present invention. FIG. 10 is a schematic cross-sectional view of a liquid jet head according to a fourth embodiment of the present invention. FIG. 10 is a partial perspective view of a liquid jet head according to a fifth embodiment of the invention. FIG. 9 is a partial plan view schematically illustrating a liquid jet head according to a fifth embodiment of the invention. FIG. 10 is a schematic cross-sectional view of a reverse discharge groove of a liquid jet head according to a sixth embodiment of the present invention. It is a figure for demonstrating the liquid jet head which concerns on 6th embodiment of this invention. FIG. 10 is a diagram for explaining a liquid jet head according to a seventh embodiment of the invention. 10 is a modification of the liquid jet head according to the seventh embodiment of the present invention. FIG. 10 is a schematic perspective view of a liquid ejecting apparatus according to an eighth embodiment of the present invention. It is an exploded perspective view of a conventionally known liquid jet head.

(First embodiment)
FIG. 1 is a partially exploded perspective view of the liquid jet head 1 according to the first embodiment of the present invention, and FIG. 2 is an explanatory diagram of the liquid jet head 1.

  As shown in FIGS. 1 and 2, the liquid ejecting head 1 includes a piezoelectric plate 2, a cover plate 3 that is bonded to one surface OS of the piezoelectric plate 2, and a nozzle that is bonded to the side surface SS of the piezoelectric plate 2 and the cover plate 3. Plate 4. In the piezoelectric plate 2, the discharge grooves 7 that discharge liquid and the dummy grooves 8 that do not discharge liquid are alternately arranged in the reference direction K of the one surface OS, and one side of the discharge groove 7 opens in the side surface SS. The cover plate 3 has a liquid supply hole 3 a for supplying liquid to the discharge groove 7 and a liquid discharge hole 3 b for discharging liquid from the discharge groove 7, and the side surface is flush with the side surface SS of the piezoelectric plate 2. Bonded to one surface OS of the piezoelectric plate 2. The nozzle plate 4 has a plurality of nozzles 11 arranged in the reference direction K, and the nozzles 11 communicate with the ejection grooves 7.

  Here, the discharge groove 7 includes a forward discharge groove 7 a and a reverse discharge groove 7 b provided adjacent to the reference direction K of the one surface OS, and the forward discharge groove 7 a and the reverse discharge groove 7 b communicate with each other in the vicinity of the nozzle 11. To do. Specifically, in the nozzle plate 4, a first nozzle plate 4a having nozzles 11 and a second nozzle plate 4b having first series passages 9a are laminated. The nozzle 11 and the first series passage 9a communicate with each other, and the first series passage 9a communicates with the forward discharge groove 7a opened on the side surface SS of the piezoelectric plate 2 and the adjacent reverse discharge groove 7b. Further, the liquid supply hole 3a of the cover plate 3 communicates with the forward discharge groove 7a, and the liquid discharge hole 3b communicates with the reverse discharge groove 7b.

  This will be specifically described. The piezoelectric plate 2 is made of piezoelectric ceramics such as PZT ceramics, and is previously polarized in the direction perpendicular to the one surface OS. On one surface OS of the piezoelectric plate 2, discharge grooves 7 and dummy grooves 8 composed of forward discharge grooves 7 a and reverse discharge grooves 7 b are alternately formed in the reference direction K, and one side of the discharge grooves 7 (nozzle plate 4 side). Opens to the side surface SS, and the other side (the side opposite to the nozzle plate 4) terminates in the plane of the one surface OS. One side and the other side of the dummy groove 8 are opened on both side surfaces of the piezoelectric plate 2. The common electrode 15 is formed up to the upper half of the side of the forward discharge groove 7a and the reverse discharge groove 7b on the dummy groove 8 side (approximately half the depth from the upper end). The active electrode 13 is formed up to the upper half.

  2A is a schematic cross-sectional view along the forward discharge groove 7a, FIG. 2B is a schematic cross-sectional view along the reverse discharge groove 7b, and FIG. 2C is a schematic top view of the piezoelectric plate 2. FIG. is there. As shown in FIG. 2A, the liquid supply hole 3a of the cover plate 3 communicates with the liquid supply hole 3a at the other end of the forward discharge groove 7a. Further, as shown in FIG. 2B, the liquid discharge hole 3b of the cover plate 3 communicates with the reverse discharge groove 7b at the other end of the reverse discharge groove 7b. The cover plate 3 can be made of the same material as the piezoelectric plate 2, that is, a piezoelectric ceramic such as PZT ceramic. Further, a machinable ceramic having a thermal expansion coefficient comparable to that of the piezoelectric plate 2 may be used.

  Further, as shown in FIG. 2C, the active electrodes 13 are provided on the side surfaces of the dummy grooves 8a and 8b, and the common electrode 15 is provided on the side surfaces of the forward discharge groove 7a and the reverse discharge groove 7b on the dummy groove 8 side. A wiring electrode for providing a common terminal 16 electrically connected to the common electrode 15 on one surface OS of the piezoelectric plate 2 and further electrically connecting an active electrode 13 formed on the side surfaces of the adjacent dummy grooves 8a and 8b. 17. In the present embodiment, the wiring electrode 17 functions as the active terminal 14.

  The first nozzle plate 4a and the second nozzle plate 4b can be formed of a polyimide film. Other polymer materials and metal materials can also be used. The nozzle 11 formed in the first nozzle plate 4a is positioned substantially in the center in the reference direction K of the first series passage 9a formed in the second nozzle plate 4b. The nozzle plate 4 is formed by grinding the tip of the partition wall 20c to form a second communication path as described in the third embodiment, instead of the two-layer structure of the first and second nozzle plates 4a and 4b. For example, the nozzle plate 4 can be only the first nozzle plate 4a. Moreover, it is good also as the single layer nozzle plate 4 which integrated the 1st and 2nd nozzle plates 4a and 4b.

  The liquid ejecting head 1 operates as follows. First, the liquid flows into the forward discharge groove 7a from the liquid supply hole 3a, flows into the reverse discharge groove 7b through the first series passage 9a of the second nozzle plate 4b, and is discharged from the liquid discharge hole 3b. At the time of driving, the liquid is always circulated through the above route. On the other hand, the dummy groove 8 does not communicate with either the liquid supply hole 3a or the liquid discharge hole 3b, and no liquid flows in. Then, a drive signal is applied to the active terminal 14 and the common terminal 16 to apply an electric field in the thickness direction of both walls 20a and 20b. That is, it is driven to the wall 20a between the active electrode 13 of the dummy groove 8a and the common electrode 15 of the forward discharge groove 7a, and to the wall 20b between the active electrode 13 of the dummy groove 8b and the common electrode 15 of the reverse discharge groove 7b. Give a signal. Then, the walls 20a and 20b are deformed in thickness, and the volumes of the forward discharge groove 7a and the backward discharge groove 7b are instantaneously changed. As a result, a pressure wave is generated in the liquid in the forward discharge groove 7 a and the reverse discharge groove 7 b, and a droplet is discharged from the nozzle 11. The other forward discharge grooves 7a, reverse discharge grooves 7b and dummy grooves 8 are driven in the same manner.

  A partition wall 20c that partitions the forward discharge groove 7a and the reverse discharge groove 7b is provided to partition the flow of liquid. Therefore, unlike the wall 20a and the wall 20b, it can be set to an arbitrary thickness. The pitch of the nozzles 11 of the liquid jet head 1 is determined by one dummy groove 8 and one ejection groove 7. Then, only the thickness of the partition wall 20c is changed, and the pitch of the nozzles 11 can be adjusted without changing the width of the dummy grooves 8 and the discharge grooves 7.

  The partition wall 20c does not need to be a piezoelectric body because it does not contribute to driving. Therefore, the partition wall 20c is provided in the cover plate 3, the discharge groove 7 of the piezoelectric plate 2 is formed widely, and when the cover plate 3 is joined to the piezoelectric plate 2, the discharge groove 7 becomes the forward discharge groove 7a and the reverse discharge groove 7b. You may comprise so that it may divide | segment. Further, instead of forming the entire piezoelectric plate 2 from piezoelectric ceramics, the walls 20a and 20b may be formed of piezoelectric ceramics, and the other regions may be formed of an insulating material. The dummy groove 8a is formed straight from one side surface of the piezoelectric plate 2 to the other side surface, but instead, the other end of the dummy groove 8 is formed on the one surface OS like the other end of the ejection groove 7. It may be terminated in the plane.

  As described above, the liquid ejecting head 1 according to this embodiment is configured such that the liquid flows in from the one surface OS side of the piezoelectric plate 2 and flows out to the same one surface OS side. A space can be secured on the side of the other surface TS on the opposite side. Further, since the liquid circulates in the forward discharge groove 7a and the reverse discharge groove 7b adjacent to each other in the reference direction K, even if bubbles or foreign matters are mixed in the liquid, it can be quickly discharged to the outside. Furthermore, the structure of the liquid ejecting head 1 is simplified, so that advanced processing and alignment are not required, and assembling becomes easy and the cost can be reduced.

(Second embodiment)
3 and 4 are views for explaining the liquid jet head 1 according to the second embodiment of the present invention. FIG. 3 is a partially exploded perspective view of the liquid jet head 1. 4A is a schematic cross-sectional view along the longitudinal direction of the forward discharge groove 7a of the liquid jet head 1, and FIG. 4B is a schematic cross-sectional view along the longitudinal direction of the reverse discharge groove 7b. 4C is a schematic plan view of the liquid ejecting head 1 viewed from the separation plate 6 side.

  The difference from the first embodiment is that the separation plate 6 is installed on the upper surface of the cover plate 3, and the flow path member 5 is installed on the upper surface of the separation plate 6. Other configurations are the same as those of the first embodiment. Therefore, hereinafter, the different part from the first embodiment will be described, and the description of the same part will be omitted. The same portions or portions having the same function are denoted by the same reference numerals.

  As shown in FIGS. 3 and 4, the liquid ejecting head 1 includes a separation plate 6 joined to the upper surface of the cover plate 3 and a flow path member 5 joined to the upper surface of the separation plate 6. Dummy grooves 8 and ejection grooves 7 are alternately arranged in the reference direction K on one surface OS of the piezoelectric plate 2. Specifically, the forward discharge groove 7a, the dummy groove 8a, the forward discharge groove 7a, the reverse discharge groove 7b, the dummy groove 8b, the reverse discharge groove 7b, the forward discharge groove 7a,. To do. That is, the forward discharge groove 7 a and the reverse discharge groove 7 b are arranged while being switched with respect to the reference direction K every time the dummy groove 8 is exceeded. Similarly, the liquid supply hole 3a and the liquid discharge hole 3b formed in the cover plate 3 are provided with two liquid supply holes 3a sandwiching the dummy groove 8a, and two liquid discharge holes sandwiching the next dummy groove 8b. 3b is installed, and this is repeated in the reference direction K and arranged in a line. Therefore, the number of liquid supply holes 3a and liquid discharge holes 3b can be reduced to about half of the number of forward discharge grooves 7a and reverse discharge grooves 7b.

  The separation plate 6 has a divided supply hole 6a for dividing and supplying the liquid to the adjacent forward discharge grooves 7a across the dummy groove 8a, and a confluence discharge path for discharging the liquid from the adjacent reverse discharge grooves 7b across the dummy groove 8b. 6c and a confluence discharge hole 6b communicating with the confluence discharge path 6c. The plurality of divided supply holes 6 a and the plurality of merged discharge holes 6 b are installed in parallel in the reference direction K. More specifically, the divided supply hole 6a communicates with the two forward discharge grooves 7a via the two liquid supply holes 3a installed with the dummy groove 8a interposed therebetween. The merged discharge path 6c communicates with the two reverse discharge grooves 7b via the two liquid discharge holes 3b installed across the dummy groove 8b, and further communicates with the merged discharge hole 6b. The divided supply holes 6a and the merging / discharging holes 6b are installed in parallel in two rows in the reference direction K.

  The flow path member 5 has a liquid supply path 5a communicating with the plurality of divided supply holes 6a and a liquid discharge path 5b communicating with the plurality of merged discharge holes 6b, and is opposite to the cover plate 3 side of the separation plate 6 Join to the side. The liquid supply path 5a and the liquid discharge path 5b are formed of channels that are elongated in the reference direction K and are formed in parallel. The flow path member 5 and the separation plate 6 may be formed of the same material as the cover plate 3, or may be formed of a synthetic resin material or a metal material.

  Accordingly, the liquid is divided into the divided supply holes 6a of the separation plate 6 via the liquid supply path 5a of the flow path member 5, and is divided into two liquid supply holes 3a of the cover plate 3, and two liquids sandwiching the dummy groove 8a. It is supplied to the forward discharge groove 7a. Further, the liquid flows from the forward discharge groove 7a into the reverse discharge groove 7b through the first series passage 9a of the second nozzle plate 4b, and passes through the two liquid discharge holes 3b sandwiching the dummy groove 8b. It merges in the merged discharge path 6c and flows out to the liquid discharge path 5b through the merged discharge hole 6b. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  In this way, by using the separation plate 6, the inflowing liquid and the outflowing liquid can be completely separated in the groove direction, so that the liquid flow path configuration is simplified. Further, as in the first embodiment, since the liquid circulates in the forward discharge groove 7a and the reverse discharge groove 7b adjacent to each other in the reference direction K, even if bubbles or foreign matters are mixed in the liquid, the liquid is quickly discharged to the outside. be able to. Furthermore, the structure of the liquid ejecting head 1 is simplified, so that advanced processing and alignment are not required, and assembling becomes easy and the cost can be reduced.

  In the present embodiment, the liquid supply path 5a and the divided supply hole 6a of the flow path member 5 and the separation plate 6 are provided farther from the nozzle plate 4, and the liquid discharge path 5b and the combined discharge hole 6b are provided in the nozzle plate 4. The liquid supply path 5a and the divided supply hole 6a are provided closer to the nozzle plate 4 and the liquid discharge path 5b and the merged discharge hole 6b are provided farther than the nozzle plate 4. It may be provided. Further, the liquid supply path 5a and the divided supply hole 6a can be used as a liquid discharge flow path, and the confluence discharge hole 6b, the confluence discharge path 6c, and the liquid discharge path 5b can be used as a liquid supply flow path.

(Third embodiment)
FIG. 5 is a partially exploded perspective view of the piezoelectric plate 2 and the nozzle plate 4 of the liquid jet head 1 according to the third embodiment of the present invention. The difference from the second embodiment is the structure of the nozzle plate 4 and the opening portion in which the forward discharge groove 7a and the reverse discharge groove 7b open on the side surface SS of the piezoelectric plate 2, and the other configurations are the same as in the second embodiment. It is. Therefore, hereinafter, a different part from 2nd embodiment is demonstrated, and description is abbreviate | omitted about the same part. The same part or the part having the same function is denoted by the same reference numeral.

  As shown in FIG. 5, the piezoelectric plate 2 has a second opening in which the forward discharge groove 7 a and the backward discharge groove 7 b communicate with each other in an opening where the forward discharge groove 7 a and the backward discharge groove 7 b open in the side surface SS, that is, in the vicinity of the nozzle 11. A communication path 9b is provided. Specifically, the tip portion on the nozzle plate 4 side of the partition wall 20c sandwiched between the forward discharge groove 7a and the reverse discharge groove 7b is deleted. Only the first nozzle plate 4a of the nozzle plate 4 is joined to the side surface SS. As a result, the liquid in the forward discharge groove 7a flows into the reverse discharge groove 7b through the second communication path 9b. As a result, the nozzle plate 4 can be a single layer, and the number of parts is reduced, making assembly easier.

(Fourth embodiment)
6 and 7 are explanatory views of the liquid jet head 1 according to the fourth embodiment of the present invention. FIG. 6 is a partially exploded perspective view of the liquid jet head 1. 7A is a schematic cross-sectional view along the longitudinal direction of the forward discharge groove 7a of the liquid jet head 1, and FIG. 7B is a schematic cross-sectional view along the longitudinal direction of the reverse discharge groove 7b. The difference from the second embodiment is that the position of the liquid discharge hole 3b of the cover plate 3 is installed on the nozzle plate 4 side, and that the separation plate 6 is removed. Other configurations are the same as those of the first embodiment. It is the same. Therefore, different parts will be mainly described below, and description of the same parts will be omitted. The same portions or portions having the same function are denoted by the same reference numerals.

  As shown in FIGS. 6 and 7, the liquid jet head 1 is bonded to the piezoelectric plate 2, the cover plate 3 that is bonded to one surface OS of the piezoelectric plate 2, and the cover plate 3 that is opposite to the piezoelectric plate 2 side. And a nozzle plate 4 joined to the side surface SS of the piezoelectric plate 2 and the side surface of the cover plate 3. The piezoelectric plate 2 and the nozzle plate 4 are the same as those in the first and second embodiments, and a description thereof will be omitted.

  The cover plate 3 has a liquid supply hole 3a for supplying liquid to the forward discharge groove 7a and a liquid discharge hole 3b for discharging liquid from the reverse discharge groove 7b. The liquid supply holes 3a communicate with the other end (end far from the nozzle plate 4) of the forward discharge groove 7a and are arranged in the reference direction K. The liquid discharge hole 3b communicates with one end side (nozzle plate 4 side) from the other end of the reverse discharge groove 7b, and is arranged in the reference direction K in parallel with the arrangement of the liquid supply holes 3a. The flow path member 5 includes a liquid supply path 5a that communicates with the plurality of liquid supply holes 3a and a liquid discharge path 5b that communicates with the plurality of liquid discharge holes 3b. The flow path member 5 further includes a supply connection portion (not shown) communicating with the liquid supply passage 5a and a discharge connection portion (not shown) communicating with the liquid discharge passage 5b on the upper surface thereof.

  Accordingly, the liquid flows into a supply connection portion (not shown) of the flow path member 5 and is divided into the liquid supply holes 3a of the cover plate 3 from the liquid supply path 5a, and is supplied to the two forward discharge grooves 7a sandwiching the dummy grooves 8a. Is done. The liquid further flows from the forward discharge groove 7a into the reverse discharge groove 7b via the first series passage 9a of the second nozzle plate 4b, and through the two liquid discharge holes 3b sandwiching the dummy groove 8b, the liquid discharge path 5b. And are discharged from the liquid discharge path 5b. As in the other embodiments, the liquid supply path 5a and the liquid supply hole 3a may be used as a liquid discharge flow path, and the liquid discharge path 5b and the liquid discharge hole 3b may be used as a liquid supply flow path. .

  By providing the liquid discharge hole 3b of the cover plate 3 closer to the nozzle plate 4 than the liquid supply hole 3a, the separation plate 6 can be omitted, and the number of parts can be reduced and the entire volume can be reduced. Further, as in the first embodiment, since the liquid circulates in the forward discharge groove 7a and the reverse discharge groove 7b adjacent to each other in the reference direction K, even if bubbles or foreign matters are mixed in the liquid, the liquid is quickly discharged to the outside. be able to. Furthermore, the structure of the liquid ejecting head 1 is simplified, so that advanced processing and alignment are not required, and assembling becomes easy and the cost can be reduced.

(Fifth embodiment)
8 and 9 are diagrams for explaining a liquid jet head 1 according to a fifth embodiment of the present invention. FIG. 8 is a partial perspective view of the piezoelectric plate 2 of the liquid jet head 1. FIG. 9 is a partial schematic plan view in which a flexible substrate 21 is bonded to the piezoelectric plate 2. The difference from the piezoelectric plate 2 in the first embodiment is that a separation groove 18 is provided on the other side (opposite side of the nozzle plate 4) of one surface OS of the piezoelectric plate 2, and the other configuration is the first embodiment. It is the same. The same portions or portions having the same function are denoted by the same reference numerals.

  As shown in FIG. 8, ejection grooves 7 and dummy grooves 8 that are alternately arranged in the reference direction K are formed on one surface OS of the piezoelectric plate 2. The discharge groove 7 includes a forward discharge groove 7a and a reverse discharge groove 7b. The dummy groove 8 is formed from the side surface on one side (nozzle plate 4 side) to the other side surface of the one surface OS. One side of the forward discharge groove 7a and the reverse discharge groove 7b opens on the side surface of the piezoelectric plate 2, and the other side terminates in the plane of the one surface OS. The active electrode 13 is provided on the side surface of the dummy groove 8, and the common electrode 15 is provided on the side surface of the forward discharge groove 7 a and the reverse discharge groove 7 b on the dummy groove 8 side.

  One surface OS of the piezoelectric plate 2 has a wiring electrode 17 that electrically connects the active electrode 13 formed on the side surface of two adjacent dummy grooves 8, and functions as an active terminal 14. Further, a common terminal 16 electrically connected to a common electrode 15 formed on each side surface of the forward discharge groove 7a and the reverse discharge groove 7b on one surface OS near the other end of the forward discharge groove 7a and the reverse discharge groove 7b. Have A separation groove 18 is provided on one surface OS of the piezoelectric plate 2 between the common terminal 16 and the active terminal 14. The separation groove 18 is linearly formed in the reference direction K, and the active terminal 14 and the common terminal 16 are electrically separated through the separation groove 18.

  As shown in FIG. 9, the flexible substrate 21 is installed on the active terminals 14 and the common terminals 16 of the piezoelectric plate 2. The flexible substrate 21 includes a common electrode 21a and an individual electrode 21b. The common electrode 21a is electrically connected to each common terminal 16 in common, and the individual electrode 21b is electrically connected to each active terminal 14 individually. The common electrode 21 a is disposed on the upper part of the separation groove 18 except for the connection portion with the common terminal 16. As a result, the common electrode 21a is separated from the active electrode 13 at the intersection with the active electrode 13 formed in the dummy groove 8, and insulation measures such as forming a thick insulating film on the surface of the common electrode 21a are alleviated. .

(Sixth embodiment)
10 and 11 are views for explaining the liquid jet head 1 according to the sixth embodiment of the present invention. FIG. 10 is a schematic cross-sectional view of the forward discharge groove 7 a of the liquid jet head 1. FIG. 11A is a schematic perspective view of the flow path member 5, and FIG. 11B is a schematic cross-sectional view of the portion AA of the flow path member 5. The difference from the fourth embodiment is the structure of the flow path member 5, and other configurations are the same as those of the fourth embodiment. Therefore, different parts will be mainly described below, and description of the same parts will be omitted. The same portions or portions having the same function are denoted by the same reference numerals.

  As shown in FIG. 10, the liquid jet head 1 includes a piezoelectric plate 2, a cover plate 3 that is bonded to one surface OS of the piezoelectric plate 2, and a flow path that is bonded to the opposite side of the cover plate 3 from the piezoelectric plate 2 side. A member 5 and a nozzle plate 4 joined to the side surfaces of the piezoelectric plate 2 and the cover plate 3 are provided. The piezoelectric plate 2, the cover plate 3, and the nozzle plate 4 are the same as in the fourth embodiment.

  The flow path member 5 includes a liquid supply path 5a communicating with the liquid supply hole 3a of the cover plate 3, a liquid discharge path 5b communicating with a liquid discharge hole 3b (not shown), and upper surfaces of the liquid supply path 5a and the liquid discharge path 5b. The damper film 12 to be covered, the air layer 22 formed above the damper film 12, the communication hole 19 that communicates the air layer 22 and the atmosphere, and the upper surface of the flow path member 5 communicate with the liquid supply path 5a. And a discharge connection portion 5d communicating with the liquid discharge path 5b.

  The liquid flows from the supply connection portion 5 c into the liquid supply path 5 a whose upper surface is covered with the damper film 12, and is divided into each forward discharge groove 7 a via each liquid supply hole 3 a of the cover plate 3. The liquid further flows from the forward discharge groove 7a into the reverse discharge groove 7b (not shown) via the first series passage 9a, and the upper surface is covered with the damper film 12 via the liquid discharge hole 3b (not shown) of the cover plate 3. It merges in the discharge path 5b and flows out from the discharge connection portion 5d. Since the upper surfaces of the liquid supply path 5a and the liquid discharge path 5b are covered with the damper film 12, the pressure wave when the liquid in the discharge groove 7 is discharged is buffered by the damper film 12, and selftalk and crosstalk are reduced. The communication hole 19 is provided to prevent the upper space of the damper film 12 from being sealed and to allow the damper film 12 to freely vibrate.

  In addition, the flow path member 5 with the damper film | membrane 12 of this embodiment can be installed in the liquid jet head 1 demonstrated in 2nd embodiment. In addition, it goes without saying that the nozzle plate 4 and the piezoelectric plate 2 of the third embodiment and the fifth embodiment can be applied to the nozzle plate 4 and the piezoelectric plate 2.

(Seventh embodiment)
12 and 13 are views for explaining a liquid jet head 1 according to a seventh embodiment of the present invention. FIG. 12A is a schematic cross-sectional view of the ejection groove of the liquid ejecting head 1 in the groove direction, and FIG. 12B is a schematic side view of the liquid ejecting head 1 viewed from the nozzle plate 4 side. FIG. 13 is a modification of the liquid jet head 1 according to the seventh embodiment, and shows a case where the installation positions of the supply connection portion 5c and the discharge connection portion 5d installed in the flow path member 5 are different. The same portions or portions having the same function are denoted by the same reference numerals.

  As shown in FIG. 12, the liquid ejecting head 1 includes a first liquid ejecting head 1a and a second liquid ejecting head 1b. The other surface TS of the piezoelectric plate 2 of the first liquid ejecting head 1a and the other surface TS of the piezoelectric plate 2 of the second liquid ejecting head 1b face each other, and the nozzle 11 of the first liquid ejecting head 1a and the second liquid ejecting head 1b. The nozzle 11 is joined to the reference direction K with a half pitch shift. The first and second liquid jet heads 1a and 1b have the same structure as the liquid jet head 1 of the sixth embodiment. Thereby, the number of nozzles can be doubled. Furthermore, since the nozzle 11 of the first liquid ejecting head 1a and the nozzle 11 of the second liquid ejecting head 1b are shifted by a half pitch in the reference direction K, the recording density in the reference direction K can be improved by a factor of two. Needless to say, the liquid jet heads 1 described in the first to sixth embodiments can be applied as the first and second liquid jet heads 1a and 1b. Further, if the nozzle plate 4 of the first liquid ejecting head 1a and the nozzle plate 4 of the second liquid ejecting head 1b are integrally formed by a single nozzle plate 4, the number of parts can be further reduced.

  As shown in FIG. 13, the attachment positions of the supply connection portion 5 c and the discharge connection portion 5 d to the flow path member 5 can be separately installed on two side surfaces facing in the reference direction K of the flow path member 5. . Thus, by providing the supply connection portion 5c and the discharge connection portion 5d on the side surface of the flow path member 5, the thickness of the liquid jet head 1 can be reduced. Moreover, the upper surface of the flow path member 5 can be utilized as a flat surface. Therefore, a multilayer liquid ejecting head in which the liquid ejecting heads 1 are stacked in three or more stages can be configured.

(Eighth embodiment)
FIG. 14 is a schematic perspective view of a liquid ejecting apparatus 30 according to the eighth embodiment of the present invention. The liquid ejecting apparatus 30 includes a moving mechanism 40 that reciprocates the liquid ejecting heads 1 and 1 ′, and a flow path unit that supplies the liquid to the liquid ejecting heads 1 and 1 ′ and discharges the liquid from the liquid ejecting heads 1 and 1 ′. 35, 35 ′, liquid pumps 33, 33 ′ and liquid tanks 34, 34 ′ communicating with the flow path portions 35, 35 ′. Each liquid ejecting head 1, 1 ′ includes a liquid ejecting head 1, a piezoelectric plate 2, a nozzle plate 4, and a flow path member 5. As the liquid pumps 33 and 33 ′, either or both of a supply pump that supplies the liquid to the flow path portions 35 and 35 ′ and a discharge pump that discharges the liquid are installed, and the liquid is circulated. In addition, a pressure sensor and a flow rate sensor (not shown) may be installed to control the liquid flow rate. In the liquid jet heads 1 and 1 ', the discharge grooves 7 and the dummy grooves 8 are alternately arranged. Each discharge groove 7 includes a forward discharge groove 7a and a reverse discharge groove 7b, and the forward discharge groove 7a and the reverse discharge groove 7b are nozzles. It communicates in the vicinity of 11 and is configured so that the liquid can circulate. Any one of the first to seventh embodiments described above can be used as the liquid jet heads 1 and 1 ′.

  The liquid ejecting apparatus 30 includes a pair of conveying units 41 and 42 that convey a recording medium 44 such as paper in the main scanning direction, liquid ejecting heads 1 and 1 ′ that eject liquid onto the recording medium 44, and a liquid ejecting head. 1, 1 ′ carriage unit 43, liquid tanks 34, 34 ′ and liquid pumps 33, 33 ′ that supply the liquid stored in the liquid tanks 34, 34 ′ to the flow path parts 35, 35 ′, And a moving mechanism 40 that scans 1 ′ in the sub-scanning direction orthogonal to the main scanning direction. A control unit (not shown) controls and drives the liquid ejecting heads 1, 1 ′, the moving mechanism 40, and the conveying units 41 and 42.

  The pair of conveying means 41 and 42 includes a grid roller and a pinch roller that extend in the sub-scanning direction and rotate while contacting the roller surface. A grid roller and a pinch roller are moved around the axis by a motor (not shown), and the recording medium 44 sandwiched between the rollers is conveyed in the main scanning direction. The moving mechanism 40 couples a pair of guide rails 36 and 37 extending in the sub-scanning direction, a carriage unit 43 slidable along the pair of guide rails 36 and 37, and the carriage unit 43 to move in the sub-scanning direction. An endless belt 38 is provided, and a motor 39 that rotates the endless belt 38 via a pulley (not shown) is provided.

  The carriage unit 43 mounts a plurality of liquid jet heads 1, 1 ′, and ejects, for example, four types of liquid droplets of yellow, magenta, cyan, and black. The liquid tanks 34 and 34 'store liquids of corresponding colors and supply them to the liquid jet heads 1 and 1' via the liquid pumps 33 and 33 'and the flow path portions 35 and 35'. Each liquid ejecting head 1, 1 ′ ejects droplets of each color according to the drive signal. An arbitrary pattern is recorded on the recording medium 44 by controlling the timing at which liquid is ejected from the liquid ejecting heads 1, 1 ′, the rotation of the motor 39 that drives the carriage unit 43, and the conveyance speed of the recording medium 44. I can.

  In this embodiment, the moving mechanism 40 moves the carriage unit 43 and the recording medium 44 to perform recording, but instead, the carriage unit is fixed and the moving mechanism is the recording medium. It may be a liquid ejecting apparatus that records the image by moving it two-dimensionally. That is, the moving mechanism may be any mechanism that relatively moves the liquid ejecting head and the recording medium.

DESCRIPTION OF SYMBOLS 1 Liquid ejecting head, 1a 1st liquid ejecting head, 1b 2nd liquid ejecting head 2 Piezoelectric plate 3 Cover plate, 3a Liquid supply hole, 3b Liquid discharge hole 4 Nozzle plate, 4a 1st nozzle plate, 4b 2nd nozzle plate 5 Flow path member, 5a Liquid supply path, 5b Liquid discharge path, 5c Supply connection section, 5d Discharge connection section 6 Separation plate, 6a Divided supply hole, 6b Merge discharge hole, 6c Merge discharge path 7 Discharge groove, 7a Forward discharge groove, 7b Reverse discharge groove 8, 8a, 8b Dummy groove 9a First series passage, 9b Second communication passage 11 Nozzle 12 Damper film 13 Active electrode 14 Active terminal 15 Common electrode 16 Common terminal 17 Wiring electrode 18 Separation groove 19 Communication hole 20a, 20b Wall, 20c Partition wall 21 Flexible substrate, 21a Common electrode, 21b Individual electrode 22 Air layer SS Side surface, S one surface, TS other surface, K reference direction

Claims (16)

Piezoelectric plates in which discharge grooves that discharge liquid and dummy grooves that do not discharge liquid are alternately arranged in a reference direction on one surface, and one side of the discharge groove is open on a side surface;
A cover plate that has a liquid supply hole for supplying liquid to the discharge groove and a liquid discharge hole for discharging liquid from the discharge groove, and is joined to one surface of the piezoelectric plate;
A nozzle plate having a plurality of nozzles arranged in a reference direction, wherein the nozzle communicates with the ejection groove and is joined to a side surface of the piezoelectric plate;
The discharge groove includes a forward discharge groove and a reverse discharge groove provided adjacent to the reference direction of the one surface, and the forward discharge groove and the reverse discharge groove communicate with each other in the vicinity of the nozzle, and the liquid supply hole A liquid ejecting head in which the liquid discharge hole communicates with the forward discharge groove, and the liquid discharge hole communicates with the reverse discharge groove.   2. The liquid ejecting head according to claim 1, wherein the nozzle plate includes a first series passage that communicates the forward ejection groove and the backward ejection groove that are opened on a side surface of the nozzle and the piezoelectric plate.   The liquid ejecting head according to claim 2, wherein the nozzle plate includes a first nozzle plate having the nozzle and a second nozzle plate having the first series passage.   4. The liquid jet head according to claim 1, wherein the piezoelectric plate has a second communication path that communicates the forward discharge groove and the reverse discharge groove in the vicinity of the nozzle. 5. The liquid supply hole communicates with the other end of the forward discharge groove and is arranged in a reference direction,
5. The liquid according to claim 1, wherein the liquid discharge hole communicates with the other side of the reverse discharge groove on the other side and is arranged in a reference direction in parallel with the arrangement of the liquid supply holes. Jet head.   A flow path member that has a liquid supply path that communicates with the plurality of liquid supply holes and a liquid discharge path that communicates with the plurality of liquid discharge holes, and is joined to the opposite side of the cover plate from the piezoelectric plate side. The liquid ejecting head according to claim 5.   The liquid supply hole and the liquid discharge hole communicate with the other end of the forward discharge groove and the other end of the reverse discharge groove, respectively, and are arranged in a line in a reference direction. Liquid jet head.   Liquid is merged and discharged from a divided supply hole that divides and supplies the liquid to the forward discharge groove adjacent to the dummy groove located on one side, and the return discharge groove that is adjacent to the dummy groove located on the other side The liquid ejecting head according to claim 7, further comprising: a separation plate that has a joining discharge path that communicates with the joining discharge path, and has a joining discharge hole that communicates with the joining discharge path.   A flow path member that has a liquid supply path that communicates with a plurality of the divided supply holes and a liquid discharge path that communicates with a plurality of the confluence discharge holes, and which is joined to the opposite side of the separation plate from the cover plate side; The liquid ejecting head according to claim 8, further comprising:   The liquid ejecting head according to claim 6, wherein a part of the liquid supply path is formed by a damper film that relieves pressure fluctuation of the liquid. The other side of the discharge groove terminates in the surface of one surface of the piezoelectric plate, includes an active electrode on the side surface of the dummy groove, and includes a common electrode on the side surface of the forward discharge groove and the reverse discharge groove,
The liquid ejection according to claim 1, further comprising a common terminal electrically connected to the common electrode and an active terminal electrically connected to the active electrode on one surface of the piezoelectric plate. head.   The liquid ejecting head according to claim 11, further comprising: a wiring electrode that electrically connects the active electrode formed on a side surface of the adjacent dummy groove on one surface of the piezoelectric plate.   The liquid ejecting head according to claim 11, wherein a separation groove for electrically separating the common terminal and the active terminal is provided on one surface of the piezoelectric plate between the common terminal and the active terminal.   A first liquid ejecting head comprising the liquid ejecting head according to claim 1 and a second liquid ejecting head, the other surface of the piezoelectric plate of the first liquid ejecting head, and the second liquid ejecting head. A liquid ejecting head in which the other surface of the piezoelectric plate of the head faces and the nozzle of the first liquid ejecting head and the nozzle of the second liquid ejecting head are joined with a half-pitch shift in a reference direction.   The liquid ejecting head according to claim 14, wherein the nozzle plate of the first liquid ejecting head and the nozzle plate of the second liquid ejecting head are integrally formed. A liquid ejecting head according to claim 1;
A moving mechanism for relatively moving the liquid ejecting head and the recording medium;
A liquid supply pipe for supplying a liquid to the liquid ejecting head;
And a liquid tank that supplies the liquid to the liquid supply pipe.

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