JP6859639B2 - Liquid injection head and liquid injection device - Google Patents

Description

The present invention relates to a technique for injecting a liquid such as ink.

Conventionally, a liquid injection head that injects a liquid such as ink from a plurality of nozzles has been proposed. For example, in Patent Document 1, liquid injection in which a liquid stored in a common liquid chamber is supplied to a plurality of pressure chambers and the pressure in each pressure chamber is fluctuated by a pressure generating element such as a piezoelectric element to inject the liquid from a nozzle. The head is disclosed. In the technique of Patent Document 1, a penetrating air portion is formed in a unit case constituting a common liquid chamber, and a flexible cable on which a drive IC (Integrated Circuit) for driving a pressure generating element is mounted is mounted inside the penetrating air portion. ..

Japanese Unexamined Patent Publication No. 2013-129191

However, in the technique of Patent Document 1, since it is necessary to form a through-air portion for installing the flexible cable in the unit case, there is a problem that it is difficult to secure a sufficient capacity of the common liquid chamber. In consideration of the above circumstances, an object of the present invention is to secure the capacity of the space for storing the liquid.

In order to solve the above problems, the liquid injection head according to a preferred embodiment of the present invention includes a drive element for injecting liquid in the pressure chamber from a nozzle, a liquid storage chamber for storing the liquid supplied to the pressure chamber, and the like. A drive IC for driving the drive element is provided, and at least a part of the liquid storage chamber overlaps both the drive element and the drive IC in a plan view. In the above aspect, since at least a part of the liquid storage chamber overlaps both the drive element and the drive IC in a plan view, the common liquid chamber does not overlap with the piezoelectric element and the drive IC, as compared with the configuration of Patent Document 1. There is an advantage that it is easy to secure the capacity of the liquid storage chamber.

In a preferred embodiment of the present invention, the drive IC is located between the drive element and the liquid storage chamber. In the above aspect, for example, the drive IC is installed at a position closer to the drive element as compared with the configuration in which the liquid storage chamber is located between the drive IC and the drive element. Therefore, there is an advantage that the electric connection between the drive IC and the drive element is easy.

In a preferred embodiment of the present invention, the liquid storage chamber includes a first space located on the side opposite to the drive element with respect to the drive IC, and a second space located on the side of the drive IC and the drive element. At least a part of one space overlaps the driving element and the driving IC in a plan view. In the above aspect, the liquid storage chamber has a first space in which the drive element and the drive IC are overlapped on the side opposite to the drive element when viewed from the drive IC, and a second space located on the side of the drive IC and the drive element. Since it is included, the above-mentioned effect that it is easy to secure the capacity of the liquid storage chamber is particularly remarkable.

The liquid injection head according to a preferred embodiment of the present invention includes a protective member in which a storage space for accommodating the drive element is formed, and the drive IC is installed on the surface of the protective member on the side opposite to the accommodation space. .. In the above aspect, the drive IC is installed on the surface of the protective member in which the accommodation space for accommodating the drive element is formed. That is, the drive IC is installed near the drive element. Therefore, as compared with the configuration in which the drive IC is mounted on the wiring board installed on the protective member, for example, the electrical path length from the drive IC to the drive element is shortened, which is caused by the resistance component and the capacitance component of the path. It is possible to reduce signal distortion.

The liquid injection head according to a preferred embodiment of the present invention includes a plurality of drive elements, and is a wiring member installed at the end of the protective member in the direction in which the plurality of drive elements are arranged and electrically connected to the drive IC. And. In the above aspect, since the wiring member is installed at the end of the protective member in the direction in which the plurality of drive elements are arranged, it is necessary to secure a space for the wiring member at an intermediate position in the arrangement of the plurality of drive elements. There is no. Therefore, the above-mentioned effect that the capacity of the liquid storage chamber can be easily secured is particularly remarkable.

The liquid injection head according to a preferred embodiment of the present invention includes a flexible first vibration absorber which is installed on the first surface on the drive element side when viewed from the drive IC and constitutes the wall surface of the liquid storage chamber. In the above aspect, the pressure fluctuation in the liquid storage chamber is absorbed by the first vibration absorbing body installed on the first surface on the driving element side when viewed from the driving IC. Therefore, the possibility that the pressure fluctuation in the liquid storage chamber propagates to the pressure chamber and affects the injection characteristics of the liquid (for example, injection amount, injection speed, injection direction) is reduced.

The liquid injection head according to a preferred embodiment of the present invention includes a flexible second vibration absorber which is installed on a second surface opposite to the drive element when viewed from the drive IC and constitutes a wall surface of the liquid storage chamber. .. In the above aspect, the pressure fluctuation in the liquid storage chamber is absorbed by the second vibration absorbing body installed on the second surface opposite to the driving element when viewed from the driving IC. Therefore, the possibility that the pressure fluctuation in the liquid storage chamber propagates to the pressure chamber and affects the injection characteristics of the liquid is reduced. According to the configuration in which both the first vibration absorbing body and the second vibration absorbing body are installed, the effect of suppressing the pressure fluctuation in the liquid storage chamber is particularly remarkable.

The liquid injection head according to a preferred embodiment of the present invention includes a drive element for injecting liquid in the pressure chamber from a nozzle, a liquid storage chamber for storing the liquid supplied to the pressure chamber, and a drive IC for driving the drive element. At least a part of the liquid storage chamber is provided and overlaps both the nozzle and the drive IC in a plan view. In the above aspect, since at least a part of the liquid storage chamber overlaps both the nozzle and the drive IC in a plan view, there is an advantage that the capacity of the liquid storage chamber can be easily secured as compared with the configuration of Patent Document 1. ..

The liquid injection head according to a preferred embodiment of the present invention includes a drive element for injecting liquid in the pressure chamber from a nozzle, a liquid storage chamber for storing the liquid supplied to the pressure chamber, and a drive IC for driving the drive element. At least a part of the liquid storage chamber is provided and overlaps both the pressure chamber and the drive IC in a plan view. In the above aspect, since at least a part of the liquid storage chamber overlaps both the pressure chamber and the drive IC in a plan view, there is an advantage that the capacity of the liquid storage chamber can be easily secured as compared with the configuration of Patent Document 1. is there.

The liquid injection device according to the preferred embodiment of the present invention includes the liquid injection head according to each of the above-exemplified embodiments. A good example of a liquid injection device is a printing device that injects ink, but the application of the liquid injection device according to the present invention is not limited to printing.

It is a block diagram of the liquid injection apparatus in 1st Embodiment of this invention. It is an exploded perspective view of the liquid injection head. It is sectional drawing of the liquid injection head (cross-sectional view of line III-III of FIG. 2). It is an enlarged cross-sectional view of the vicinity of a piezoelectric element. It is explanatory drawing of the positional relationship between the center line of a liquid injection head and each element. It is explanatory drawing of the positional relationship between the center line of a liquid injection head and each element. It is explanatory drawing of the positional relationship between the center line of a liquid injection head and each element. It is sectional drawing of the liquid injection head in 2nd Embodiment. It is an exploded perspective view of the liquid injection head in 3rd Embodiment.

<First Embodiment>
FIG. 1 is a configuration diagram illustrating the liquid injection device 100 according to the first embodiment of the present invention. The liquid injection device 100 of the first embodiment is an inkjet printing device that injects ink, which is an example of a liquid, onto the medium 12. The medium 12 is typically printing paper, but any printing object such as a resin film or cloth can be used as the medium 12. As illustrated in FIG. 1, a liquid container 14 for storing ink is fixed to the liquid injection device 100. For example, a cartridge that can be attached to and detached from the liquid injection device 100, a bag-shaped ink pack made of a flexible film, or an ink tank that can be refilled with ink is used as the liquid container 14. A plurality of types of ink having different colors are stored in the liquid container 14.

As illustrated in FIG. 1, the liquid injection device 100 includes a control device 20, a transfer mechanism 22, a moving mechanism 24, and a plurality of liquid injection heads 26. The control device 20 includes, for example, a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array) and a storage circuit such as a semiconductor memory, and controls each element of the liquid injection device 100 in an integrated manner. The transport mechanism 22 transports the medium 12 in the Y direction under the control of the control device 20.

The moving mechanism 24 reciprocates a plurality of liquid injection heads 26 in the X direction under the control of the control device 20. The X direction is a direction that intersects (typically orthogonally) the Y direction in which the medium 12 is conveyed. The moving mechanism 24 of the first embodiment includes a substantially box-shaped transport body (carriage) 242 that accommodates a plurality of liquid injection heads 26, and an endless belt 244 to which the transport body 242 is fixed. It is also possible to mount the liquid container 14 on the transport body 242 together with the liquid injection head 26.

Each of the plurality of liquid injection heads 26 ejects the ink supplied from the liquid container 14 from the plurality of nozzles (injection holes) into the medium 12 under the control of the control device 20. A desired image is formed on the surface of the medium 12 by each liquid injection head 26 injecting ink onto the medium 12 in parallel with the transfer of the medium 12 by the transfer mechanism 22 and the repetitive reciprocation of the transfer body 242. The direction perpendicular to the XY plane (for example, the plane parallel to the surface of the medium 12) is hereinafter referred to as the Z direction. The ink injection direction (typically the vertical direction) by each liquid injection head 26 corresponds to the Z direction.

FIG. 2 is an exploded perspective view of any one liquid injection head 26, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG. As illustrated in FIG. 2, the liquid injection head 26 includes a plurality of nozzles N arranged in the Y direction. The plurality of nozzles N of the first embodiment are divided into a first row L1 and a second row L2. It is possible to make the position of the nozzle N in the Y direction different between the first row L1 and the second row L2 (that is, staggered arrangement or stagger arrangement), but the nozzles in the first row L1 and the second row L2. The configuration in which the positions of N in the Y direction are matched is illustrated in FIG. 3 for convenience. As can be understood from FIG. 2, in the liquid injection head 26 of the first embodiment, the elements related to the plurality of nozzles N in the first row L1 and the elements related to the plurality of nozzles N in the second row L2 are outlined. It is a symmetrically arranged structure.

As illustrated in FIGS. 2 and 3, the liquid injection head 26 of the first embodiment includes a flow path substrate 32. The flow path substrate 32 is a plate-shaped member including a first surface F1 and a joint surface FA. The first surface F1 is the surface on the positive side in the Z direction (the surface on the medium 12 side), and the joint surface FA is the surface on the opposite side (negative side in the Z direction) from the first surface F1. A pressure chamber substrate 34, a vibrating portion 36, a plurality of piezoelectric elements 37, a protective member 38, and a housing portion 40 are installed on the surface of the joint surface FA of the flow path substrate 32, and are mounted on the surface of the first surface F1. The nozzle plate 52 and the vibration absorbing body 54 are installed in the. Each element of the liquid injection head 26 is generally a plate-shaped member elongated in the Y direction like the flow path substrate 32, and is joined to each other by using, for example, an adhesive. It is also possible to grasp the direction in which the flow path substrate 32, the pressure chamber substrate 34, the protective member 38, and the nozzle plate 52 are laminated as the Z direction.

The nozzle plate 52 is a plate-shaped member in which a plurality of nozzles N are formed, and is installed on the first surface F1 of the flow path substrate 32 by using, for example, an adhesive. Each nozzle N is a through hole through which ink passes. The nozzle plate 52 of the first embodiment is manufactured by processing a single crystal substrate of silicon (Si) by utilizing a semiconductor manufacturing technique (for example, etching). However, a known material or manufacturing method can be arbitrarily adopted for manufacturing the nozzle plate 52.

The flow path substrate 32 is a plate-shaped member for forming a flow path of ink. As illustrated in FIGS. 2 and 3, the flow path substrate 32 of the first embodiment has a space RA, a plurality of supply flow paths 322, and a plurality of communication flows for each of the first row L1 and the second row L2. Roads 324 and 324 are formed. The space RA is an opening formed in a long shape along the Y direction in a plan view (that is, when viewed from the Z direction), and the supply flow path 322 and the communication flow path 324 are through holes formed for each nozzle N. is there. The plurality of supply flow paths 322 are arranged in the Y direction, and the plurality of communication flow paths 324 are also arranged in the Y direction. Further, as illustrated in FIG. 3, an intermediate flow path 326 extending over a plurality of supply flow paths 322 is formed on the first surface F1 of the flow path substrate 32. The intermediate flow path 326 is a flow path that connects the space RA and the plurality of supply flow paths 322. On the other hand, the communication flow path 324 communicates with the nozzle N.

As illustrated in FIGS. 2 and 3, the pressure chamber substrate 34 is a plate-like member in which a plurality of openings 342 arranged in the Y direction are formed for each of the first row L1 and the second row L2, for example. It is installed on the joint surface FA of the flow path substrate 32 using an adhesive. The opening 342 is a long through hole formed for each nozzle N and along the X direction in a plan view. The flow path substrate 32 and the pressure chamber substrate 34 are manufactured by processing a silicon (Si) single crystal substrate using, for example, semiconductor manufacturing technology, similarly to the nozzle plate 52 described above. However, known materials and manufacturing methods can be arbitrarily adopted for manufacturing the flow path substrate 32 and the pressure chamber substrate 34.

As illustrated in FIGS. 2 and 3, the vibrating portion 36 is installed on the surface of the pressure chamber substrate 34 opposite to the flow path substrate 32. The vibrating portion 36 of the first embodiment is a plate-shaped member (diaphragm) that can elastically vibrate. The pressure chamber substrate 34 and the vibrating portion 36 can be integrally formed by selectively removing a part of the plate-shaped member having a predetermined plate thickness in the plate thickness direction in the region corresponding to the opening 342. It is possible.

As can be understood from FIG. 3, the joint surface FA of the flow path substrate 32 and the vibrating portion 36 face each other at a distance inside each opening 342. The space located inside the opening 342 between the joint surface FA of the flow path substrate 32 and the vibrating portion 36 functions as a pressure chamber C for applying pressure to the ink filled in the space. The pressure chamber C is, for example, a space in which the X direction is the longitudinal direction and the Y direction is the lateral direction. The pressure chamber C is individually formed for each nozzle N. A plurality of pressure chambers C are arranged in the Y direction for each of the first row L1 and the second row L2. As can be understood from FIG. 3, any one pressure chamber C communicates with the space RA via the supply flow path 322 and the intermediate flow path 326, and also communicates with the nozzle N via the communication flow path 324. .. It is also possible to add a predetermined flow path resistance by forming a throttle flow path having a narrow flow path width in the opening 342.

As illustrated in FIGS. 2 and 3, a plurality of piezoelectric elements 37 corresponding to different nozzles N are arranged in the first row L1 and the second row on the surface of the vibrating portion 36 opposite to the pressure chamber C. It is installed for each of L2. The piezoelectric element 37 is a passive element that is deformed by supplying a drive signal. The plurality of piezoelectric elements 37 are arranged in the Y direction so as to correspond to each pressure chamber C.

FIG. 4 is an enlarged cross-sectional view of the vicinity of the piezoelectric element 37. As illustrated in FIG. 4, the piezoelectric element 37 is a laminated body in which a piezoelectric layer 373 is interposed between the first electrode 371 and the second electrode 372 facing each other. When the vibrating portion 36 vibrates in conjunction with the deformation of the piezoelectric element 37, the pressure in the pressure chamber C fluctuates, so that the ink filled in the pressure chamber C passes through the communication flow path 324 and the nozzle N and is ejected. Will be done. The piezoelectric element 37 is defined as a portion where the first electrode 371, the second electrode 372, and the piezoelectric layer 373 overlap in a plan view. Further, it is also possible to define the portion deformed by the supply of the drive signal (that is, the active portion that vibrates the vibrating portion 36) as the piezoelectric element 37.

The protective member 38 of FIGS. 2 and 3 is a plate-shaped member for protecting the plurality of piezoelectric elements 37, and is installed on the surface of the vibrating portion 36 (or the surface of the pressure chamber substrate 34). The material and manufacturing method of the protective member 38 are arbitrary, but like the flow path substrate 32 and the pressure chamber substrate 34, the protective member 38 is formed by processing, for example, a silicon (Si) single crystal substrate by semiconductor manufacturing technology. obtain.

As illustrated in FIG. 4, on the surface (hereinafter referred to as “joining surface”) G1 on the vibrating portion 36 side of the protective member 38, accommodation spaces 382 accommodating a plurality of piezoelectric elements 37 are provided in the first row L1 and the second Formed for each of the columns L2. The accommodation space 382 is a space recessed with respect to the joint surface G1 and is formed in a long shape in the Y direction along the arrangement of the plurality of piezoelectric elements 37. A drive IC 62 is installed on the surface (hereinafter referred to as “mounting surface”) G2 of the protective member 38 on the side opposite to the accommodation space 382. The drive IC 62 is a substantially rectangular IC chip on which a drive circuit for driving each piezoelectric element 37 by generating and supplying a drive signal under the control of the control device 20 is mounted. As can be seen from FIGS. 3 and 4, at least a part of the piezoelectric elements 37 of the liquid injection head 26 overlap the drive IC 62 in a plan view. Further, as illustrated in FIGS. 3 and 4, the drive ICs 62 are driven in both the piezoelectric element 37 corresponding to the nozzle N in the first row L1 and the piezoelectric element 37 corresponding to the nozzle N in the second row L2 in a plan view. Overlap. That is, the drive IC 62 is installed so as to cover both the nozzle N in the first row L1 and the nozzle N in the second row L2 in the X direction.

Wiring 384 connected to the output terminal of the drive IC 62 is formed on the mounting surface G2 of the protective member 38 for each piezoelectric element 37. Each wiring 384 is electrically connected to the connection terminal 386 of the joint surface G1 via a conduction hole (contact hole) H penetrating the protective member 38. The connection terminal 386 formed on the joint surface G1 is electrically connected to the second electrode 372 of the piezoelectric element 37. For example, a known resin core bump in which a protrusion formed on the joint surface G1 made of a resin material is coated with a conductive material is suitable as the connection terminal 386. The drive signal output from the output terminal of the drive IC 62 is supplied to the piezoelectric element 37 via the wiring 384, the conduction hole H, and the connection terminal 386.

Further, as illustrated in FIG. 2, a plurality of wirings 388 connected to the input terminals of the drive IC 62 are formed on the mounting surface G2 of the protective member 38. The plurality of wirings 388 extend to a region E located at the end of the mounting surface G2 of the protective member 38 in the Y direction (that is, the direction in which the plurality of piezoelectric elements 37 are arranged). The wiring member 64 is joined to the region E of the mounting surface G2. The wiring member 64 is a mounting component on which a plurality of wirings (not shown) for electrically connecting the control device 20 and the drive IC 62 are formed. For example, a flexible wiring board such as an FPC (Flexible Printed Circuit) or an FFC (Flexible Flat Cable) is preferably adopted as the wiring member 64. As understood from the above description, the protective member 38 of the first embodiment also functions as a wiring board on which wirings (384,388) for transmitting drive signals are formed. However, it is also possible to install the wiring board used for mounting the drive IC 62 and forming the wiring separately from the protective member 38.

The housing portion 40 illustrated in FIGS. 2 and 3 is a case for storing ink supplied to a plurality of pressure chambers C (further, a plurality of nozzles N). The surface (hereinafter referred to as "joining surface") FB on the positive side in the Z direction of the housing portion 40 is fixed to the joining surface FA of the flow path substrate 32 with, for example, an adhesive. As illustrated in FIGS. 2 and 3, a groove-shaped recess 42 extending in the Y direction is formed on the joint surface FB of the housing portion 40. The protective member 38 and the drive IC 62 are housed inside the recess 42. The wiring member 64 joined to the region E of the protective member 38 extends in the Y direction so as to pass through the inside of the recess 42. As can be understood from FIG. 2, the width W1 (maximum value of the dimension in the X direction) of the wiring member 64 is smaller than the width W2 of the housing portion 40 (W1 <W2).

The housing portion 40 of the first embodiment is formed of a material different from the flow path substrate 32 and the pressure chamber substrate 34. For example, the housing portion 40 can be manufactured by injection molding of a resin material. However, a known material or manufacturing method can be arbitrarily adopted for manufacturing the housing portion 40. As the material of the housing portion 40, for example, a synthetic fiber such as polyparaphenylene benzobisoxazole (Zylon [registered trademark]) or a resin material such as a liquid crystal polymer is suitable.

As illustrated in FIG. 3, in the housing portion 40 of the first embodiment, a space RB is formed for each of the first row L1 and the second row L2. The space RB of the housing portion 40 and the space RA of the flow path substrate 32 communicate with each other. The space composed of the space RA and the space RB functions as a liquid storage chamber (reservoir) R for storing ink supplied to the plurality of pressure chambers C. The liquid storage chamber R is a common liquid chamber that spans a plurality of nozzles N. An introduction port 43 for introducing the ink supplied from the liquid container 14 into the liquid storage chamber R on the surface (hereinafter referred to as “second surface”) F2 of the housing portion 40 on the side opposite to the flow path substrate 32. Is formed for each of the first row L1 and the second row L2.

As illustrated in FIG. 3, the space RB of the housing portion 40 includes the first space RB1 and the second space RB2. The first space RB1 and the second space RB2 are long spaces in the Y direction. The first space RB1 communicates with the introduction port 43. The second space RB2 is located on the downstream side of the first space RB1 and communicates with the space RA of the flow path substrate 32. When viewed from the positive side in the Z direction, the recess 42 for accommodating the protective member 38 and the drive IC 62 is located between the second space RB2 corresponding to the first row L1 and the second space RB2 corresponding to the second row L2. To do. Therefore, the second space RB2 is located on the side (positive side or negative side in the X direction) of the piezoelectric element 37, the protective member 38, and the drive IC 62. As described above, in the first embodiment, the liquid storage chamber R (space RB of the housing portion 40) includes the first space RB1 and the second space RB2. Therefore, it is possible to increase the capacity of the liquid storage chamber R as compared with the configuration in which the space RB is formed by only one of the first space RB1 and the second space RB2.

The ink supplied from the liquid container 14 to the introduction port 43 along the positive side in the Z direction is substantially in the XY plane in the first space RB1 of the liquid storage chamber R as shown by the broken arrow in FIG. It flows in parallel directions (for example, horizontal direction and X direction) and flows into the second space RB2, and in the second space RB2, it flows in the positive side in the Z direction (for example, downward in the vertical direction) and flows in the flow path substrate 32. Reach space RA. The ink stored in the liquid storage chamber R flows in the X direction in the intermediate flow path 326, branches from the intermediate flow path 326 to a plurality of supply flow paths 322, and flows to the negative side in the Z direction, and each pressure The chamber C is supplied and filled in parallel. The ink filled in the pressure chamber C flows in the Z direction in the communication flow path 324, passes through the nozzle N, and is ejected.

As illustrated above, the liquid injection head 26 of the first embodiment includes the first surface F1 and the second surface F2. The piezoelectric element 37, the protective member 38, and the drive IC 62 are arranged between the first surface F1 and the second surface F2. The first surface F1 is located on the piezoelectric element 37 side with respect to the drive IC 62, and the second surface F2 is located on the side opposite to the piezoelectric element 37 with respect to the drive IC 62. In addition to the above-mentioned introduction port 43 being formed on the second surface F2, an opening 44 corresponding to the space RB (first space RB1 and second space RB2) is formed.

As illustrated in FIG. 2, a vibration absorbing body 54 (example of the first vibration absorbing body) is installed on the first surface F1. The vibration absorber 54 is a flexible film (compliance substrate) that absorbs pressure fluctuations of ink in the liquid storage chamber R. As illustrated in FIG. 3, the vibration absorbing body 54 is installed on the first surface F1 of the flow path substrate 32 so as to close the space RA of the flow path substrate 32, the intermediate flow path 326, and the plurality of supply flow paths 322. It constitutes the wall surface (specifically, the bottom surface) of the liquid storage chamber R.

A vibration absorbing body 46 (an example of the second vibration absorbing body) is installed on the second surface F2 of the housing portion 40. Like the vibration absorbing body 54, the vibration absorbing body 46 is a flexible film that absorbs pressure fluctuations of ink in the liquid storage chamber R, and is installed on the second surface F2 so as to close the opening 44 to store the liquid. It constitutes the wall surface (specifically, the ceiling surface) of the room R. Since it is easy to secure a sufficient area on the second surface F2, according to the first embodiment in which the vibration absorbing body 46 is installed on the second surface F2, the liquid storage chamber is compared with the configuration in which only the vibration absorbing body 54 is installed. There is an advantage that the pressure fluctuation in R can be effectively absorbed.

As illustrated in FIG. 3, at least a part of the liquid storage chamber R of the first embodiment overlaps both the piezoelectric element 37 and the drive IC 62 in a plan view. Specifically, a part of the first space RB1 of the liquid storage chamber R located on the side opposite to the piezoelectric element 37 when viewed from the drive IC 62 overlaps the piezoelectric element 37 and the drive IC 62 in a plan view. That is, the portion of the liquid storage chamber R that overlaps the piezoelectric element 37 in a plan view also overlaps the drive IC 62 in a plan view. In other words, the first space RB1 projects in the X direction from the second space RB2 so as to overlap the piezoelectric element 37 and the drive IC 62.

The configuration illustrated in FIG. 3 can be paraphrased as a configuration in which at least a part of the liquid storage chamber R overlaps both the drive IC 62 and the nozzle N in a plan view. That is, the portion of the liquid storage chamber R that overlaps the drive IC 62 in a plan view also overlaps the nozzle N in a plan view. As can be understood from FIG. 3, focusing on the positional relationship of each element along the Z direction, the drive IC 62 is located between the liquid storage chamber R and the nozzle N. Further, the configuration illustrated in FIG. 3 can be paraphrased as a configuration in which at least a part of the liquid storage chamber R overlaps both the drive IC 62 and the pressure chamber C in a plan view. That is, the portion of the liquid storage chamber R that overlaps the drive IC 62 in a plan view also overlaps the pressure chamber C in a plan view. As can be understood from FIG. 3, focusing on the positional relationship of each element along the Z direction, the drive IC 62 is located between the liquid storage chamber R and the pressure chamber C.

FIG. 5 shows a center line XC extending from the midpoint of the liquid injection head 26 in the X direction along the Z direction (not necessarily limited to the center of the liquid injection head 26, and may be a center line in a substantially axisymmetric structure. ) And the position of each element in the X direction (P1-P5). The position P1 in FIG. 5 is the position of the end of the liquid storage chamber R on the median line XC side, and the position P5 is the position of the end of the liquid storage chamber R on the opposite side of the median line XC. The position P2 is the position of the central axis of the nozzle N in the X direction, and the position P3 is the position of the central axis of the introduction hole 43 in the X direction. Further, the position P4 is the position of the end portion of the drive IC 62. As can be understood from FIG. 5, in the first embodiment, from the side closer to the center line XC, the end portion P1 of the liquid storage chamber R on the center line XC side → the central axis P2 of the nozzle N → the central axis of the introduction hole 43. Arrange in the X direction in the order of P3 → end P4 of the drive IC 62 → end P5 of the liquid storage chamber R on the side opposite to the center line XC.

As described above, in the first embodiment, at least a part of the liquid storage chamber R overlaps the piezoelectric element 37 and the drive IC 62 in a plan view. Therefore, as compared with the configuration of Patent Document 1 in which the common liquid chamber does not overlap with the piezoelectric element and the drive IC, there is an advantage that the capacity of the liquid storage chamber R can be easily secured while the liquid injection head 26 is miniaturized. In the first embodiment, in particular, the liquid storage chamber R is located on the side of the first space RB1 which overlaps the piezoelectric element 37 and the drive IC 62 on the side opposite to the piezoelectric element 37 when viewed from the drive IC 62, and on the sides of the drive IC 62 and the piezoelectric element 37. Includes the second space RB2 where it is located. Therefore, the above-mentioned effect that the capacity of the liquid storage chamber R can be easily secured is particularly remarkable.

Further, the drive IC 62 is installed on the mounting surface G2 of the protective member 38 in which the accommodation space 382 for accommodating the piezoelectric element 37 is formed. That is, the drive IC 62 is installed near the piezoelectric element 37. Therefore, for example, as compared with the configuration in which the drive IC 62 is mounted on the wiring board fixed to the protective member 38, the path length from the drive IC 62 to the piezoelectric element 37 is shortened, and the signal caused by the resistance component and the capacitance component of the path is shortened. It is possible to reduce the distortion.

In the first embodiment, since the wiring member 64 is installed in the region E at the end of the protective member 38 in the Y direction in which the plurality of piezoelectric elements 37 are arranged, wiring is performed at an intermediate position in the arrangement of the plurality of piezoelectric elements 37. It is not necessary to secure a space for the member 64. Therefore, the above-mentioned effect that the capacity of the liquid storage chamber R can be easily secured is particularly remarkable.

Further, in the first embodiment, since the pressure fluctuation in the liquid storage chamber R is absorbed by the vibration absorbing body 54 and the vibration absorbing body 46, the pressure fluctuation in the liquid storage chamber R propagates to the pressure chamber C to inject ink. The possibility of affecting (for example, injection amount, injection speed, injection direction) is reduced. In the first embodiment, in particular, since the vibration absorbing body 54 is installed on the first surface F1 and the vibration absorbing body 46 is installed on the second surface F2, the effect of suppressing the pressure fluctuation in the liquid storage chamber R is exceptional. It is remarkable. It is also possible to install the vibration absorbing body by forming an opening on the side surface of the housing portion 40.

The positions (P1 to P5) of each element of the liquid injection head 26 are not limited to the examples shown in FIG. For example, as illustrated in FIG. 6, it is possible to reverse the relationship between the central axis P3 of the introduction hole 43 and the end P4 of the drive IC 62 as compared with the configuration of FIG. That is, in the configuration of FIG. 6, from the side closer to the center line XC, the end portion P1 on the center line XC side of the liquid storage chamber R → the central axis P2 of the nozzle N → the end portion P4 of the drive IC 62 → the center of the introduction hole 43. Arrange in the X direction in the order of the axis P3 → the end P5 of the liquid storage chamber R on the side opposite to the center line XC.

Further, as illustrated in FIG. 7, it is also possible to reverse the relationship between the end portion P1 on the center line XC side of the liquid storage chamber R and the central axis P2 of the nozzle N as compared with the configuration of FIG. is there. That is, in the configuration of FIG. 7, from the side closer to the center line XC, the central axis P2 of the nozzle N → the end portion P1 of the liquid storage chamber R on the center line XC side → the end portion P4 of the drive IC 62 → the center of the introduction hole 43. Arrange in the X direction in the order of the axis P3 → the end P5 of the liquid storage chamber R on the side opposite to the center line XC. In the configuration of FIG. 7, it is also possible to position the central axis P3 of the introduction hole 43 on the center line XC side when viewed from the end P4 of the drive IC 62, as in the configuration of FIG. That is, from the side close to the center line XC, the central axis P2 of the nozzle N → the end portion P1 of the liquid storage chamber R on the center line XC side → the central axis P3 of the introduction hole 43 → the end portion P4 of the drive IC 62 → the liquid storage chamber. It is also possible to arrange in the X direction in the order of the end P5 of R opposite to the center line XC.

<Second Embodiment>
A second embodiment of the present invention will be described. For the elements whose actions and functions are the same as those in the first embodiment in each of the embodiments exemplified below, the reference numerals used in the description of the first embodiment will be diverted and detailed description of each will be omitted as appropriate.

FIG. 8 is a cross-sectional view of the liquid injection head 26 according to the second embodiment (similar cross-sectional view as in FIG. 3). As illustrated in FIG. 8, a beam-shaped portion 48 is installed in the housing portion 40 of the second embodiment. The beam-shaped portion 48 is a beam-shaped portion extending between inner wall surfaces facing each other in the liquid storage chamber R. FIG. 8 illustrates a configuration in which a beam-shaped portion 48 is formed in the second space RB2 of the liquid storage chamber R. Specifically, focusing on the inner wall surface 411 and the inner wall surface 412 of the housing portion 40 facing each other at intervals in the X direction, the beam-shaped portion 48 of the second embodiment is the inner wall surface 411 and the inner wall surface. It protrudes from one of the 412s in the X direction and reaches the other. The distance between the inner wall surface 411 and the inner wall surface 412 corresponds to the second space RB2. For example, a configuration in which the beam-shaped portion 48 formed separately from the housing portion 40 is fixed to the housing portion 40 or a configuration in which the beam-shaped portion 48 is integrally formed with the housing portion 40 can be adopted. Although one beam-shaped portion 48 is shown in FIG. 8, a configuration in which a plurality of beam-shaped portions 48 are arranged in the Y direction at intervals from each other is also preferable.

As illustrated in FIG. 8, a single or a plurality of beam-shaped portions 328 are also formed in the space RA of the flow path substrate 32. The beam-shaped portion 328 is a beam-shaped portion of the space RA extending between the inner wall surfaces facing each other at intervals in the X direction. The beam-shaped portion 328 is formed integrally with the flow path substrate 32 by, for example, processing a silicon single crystal substrate.

In the second embodiment, the same effect as in the first embodiment is realized. Further, in the second embodiment, since the beam-shaped portion 48 is installed in the housing portion 40, for example, even in a configuration in which the plate thickness of each portion of the housing portion 40 is reduced in order to reduce the size of the liquid injection head 26, the housing There is an advantage that the mechanical strength of the body 40 can be maintained. In the second embodiment, since the beam-shaped portion 328 is installed on the flow path substrate 32 in addition to the beam-shaped portion 48 of the housing portion 40, the mechanical strength of the flow path substrate 32 (and by extension, the liquid injection head 26) There is also the advantage that the overall strength) can be maintained.

<Third Embodiment>
FIG. 9 is an exploded perspective view of the liquid injection head 26 according to the third embodiment. As illustrated in FIG. 9, the liquid injection head 26 of the third embodiment includes a wiring member 64A and a wiring member 64B in place of the wiring member 64 of the first embodiment.

Each of the wiring member 64A and the wiring member 64B is a mounting component (for example, FPC or FFC) in which a plurality of wirings (not shown) for electrically connecting the control device 20 and the drive IC 62 are formed. The wiring member 64A is joined to the region EA located at the positive end in the Y direction of the mounting surface G2 of the protective member 38. The wiring member 64B is joined to a region EB located at the end of the mounting surface G2 on the negative side in the Y direction (that is, the side opposite to the wiring member 64A). The width W1 of each of the wiring member 64A and the wiring member 64B is smaller than the width W2 of the housing portion 40.

As illustrated in FIG. 9, a plurality of wirings 388A and a plurality of wirings 388B are formed on the mounting surface G2 of the protective member 38. Each wire 388A and each wire 388B is electrically connected to the drive IC 62. Each wiring 388A extends to the region EA of the mounting surface G2 and is electrically connected to each wiring of the wiring member 64A. Each wiring 388B extends to the region EB of the mounting surface G2 and is electrically connected to each wiring of the wiring member 64B. As understood from the above description, the drive IC 62 is electrically connected to the control device 20 via the wiring member 64A and the wiring member 64B.

In the above configuration, the control signal and the power supply voltage used to drive each piezoelectric element 37 are supplied from the control device 20 to the drive IC 62 via each of the wiring member 64A and the wiring member 64B. Specifically, the control signal and the power supply voltage for driving each of the piezoelectric elements 37 located on the positive side in the Y direction among the plurality of piezoelectric elements 37 are driven by the wiring member 64A and each wiring 388A. Is supplied to. Further, a control signal and a power supply voltage for driving each of the piezoelectric elements 37 located on the negative side in the Y direction among the plurality of piezoelectric elements 37 are supplied to the drive IC 62 via the wiring member 64B and each wiring 388B. To.

The same effect as that of the first embodiment is realized in the third embodiment. By the way, in the configuration of the first embodiment in which the wiring member 64 is installed only on the positive side in the Y direction when viewed from the drive IC 62, the control signal or the power supply voltage supplied via the wiring member 64 is transmitted in the Y direction inside the drive IC 62. It is necessary to transmit from the positive end to the negative end. Therefore, there is a possibility that the voltage drop in the internal wiring of the drive IC 62 becomes remarkable. In contrast to the first embodiment, in the third embodiment, the wiring member 64A is installed on one side of the drive IC 62, and the wiring member 64B is installed on the other side. That is, the control signal and the power supply voltage are supplied from both sides of the drive IC 62 in the Y direction. Therefore, there is an advantage that the voltage drop in the internal wiring of the drive IC 62 can be reduced as compared with the first embodiment.

In the above description, both the wiring member 64A and the wiring member 64B are used for transmitting the control signal and the power supply voltage, but the applications of the wiring member 64A and the wiring member 64B are not limited to the above examples. For example, it is possible to use the wiring member 64A for supplying the control signal and the wiring member 64B for supplying the power supply voltage. Further, the drive IC connected to the wiring member 64A and the drive IC connected to the wiring member 64b can be separately mounted on the protection member 38. For example, the drive IC located on the positive side in the Y direction drives each piezoelectric element 37 on the positive side in the Y direction using the control signal and the power supply voltage supplied from the wiring member 64A. On the other hand, the drive IC located on the negative side in the Y direction drives each piezoelectric element 37 on the negative side in the Y direction by using the control signal and the power supply voltage supplied from the wiring member 64B. It is also possible to apply the third embodiment to the second embodiment including the beam-shaped portion 48 and the beam-shaped portion 328.

<Modification example>
Each of the above-exemplified forms can be variously modified. A specific mode of modification is illustrated below. Two or more embodiments arbitrarily selected from the following examples can be appropriately merged to the extent that they do not contradict each other.

(1) In each of the above-described embodiments, the configuration in which both the vibration absorbing body 46 and the vibration absorbing body 54 are installed is illustrated. However, for example, when the pressure fluctuation in the liquid storage chamber R does not pose a particular problem, the vibration absorbing body 46 and It is also possible to omit one or both of the vibration absorbers 54. According to the configuration in which one or both of the vibration absorbing body 46 and the vibration absorbing body 54 are omitted, there is an advantage that the manufacturing cost can be reduced as compared with the configuration in which both are installed.

(2) The element (driving element) that applies pressure to the inside of the pressure chamber C is not limited to the piezoelectric element 37 exemplified in each of the above-described embodiments. For example, it is also possible to use a heat generating element that generates air bubbles inside the pressure chamber C by heating to fluctuate the pressure as a driving element. The heat generating element is a portion (specifically, a region where air bubbles are generated in the pressure chamber C) in which the heat generating body generates heat by supplying a drive signal. As understood from the above examples, the driving element is comprehensively expressed as an element that injects the liquid in the pressure chamber C from the nozzle N (typically, an element that applies pressure to the inside of the pressure chamber C). It does not matter what the operation method (piezoelectric method / thermal method) or the specific configuration is.

(3) In each of the above-described embodiments, the serial type liquid injection device 100 that reciprocates the transport body 242 equipped with the liquid injection head 26 is illustrated, but the line type liquid in which a plurality of nozzles N are distributed over the entire width of the medium 12 is illustrated. The present invention can also be applied to an injection device.

(4) The liquid injection device 100 illustrated in each of the above-described embodiments can be adopted in various devices such as a facsimile machine and a copier, in addition to a device dedicated to printing. However, the application of the liquid injection device of the present invention is not limited to printing. For example, a liquid injection device that injects a solution of a coloring material is used as a manufacturing device for forming a color filter of a liquid crystal display device. Further, a liquid injection device for injecting a solution of a conductive material is used as a manufacturing device for forming wiring and electrodes on a wiring board.

100 ... liquid injection device, 12 ... medium, 14 ... liquid container, 20 ... control device, 22 ... transfer mechanism, 24 ... movement mechanism, 242 ... transfer body, 244 ... endless belt, 26 ... liquid injection head, 32 ... flow path Substrate, RA ... Space, 322 ... Supply flow path, 324 ... Communication flow path, 326 ... Intermediate flow path, 328 ... Beam-shaped part, 34 ... Pressure chamber board, 36 ... Vibration part, 37 ... Piezoelectric element, 38 ... Protective member, 382 ... Storage space, 384,388 ... Wiring, 386 ... Connection terminal, 40 ... Housing part, 43 ... Introduction port, 46 ... Vibration absorber, 48 ... Beam-shaped part, 52 ... Nozzle plate, 54 ... Vibration absorber, 62 ... Drive IC, 64 ... Wiring member, R ... Liquid storage chamber, C ... Pressure chamber, N ... Nozzle.

Claims (10)

A drive element that injects liquid in the pressure chamber from a nozzle,
A liquid storage chamber for storing the liquid supplied to the pressure chamber and
A drive IC for driving the drive element,
It is provided with a protective member in which an accommodation space for accommodating the driving element is formed.
At least a part of the liquid storage chamber overlaps both the driving element and the driving IC in a plan view, and the driving IC is located in a space between the driving element and the protective member. Liquid injection head.
The liquid injection head according to claim 1, wherein the drive IC is located between the drive element and the liquid storage chamber.
The liquid storage chamber
The first space located on the side opposite to the driving element when viewed from the driving IC,
Including the drive IC and a second space located on the side of the drive element.
The liquid injection head according to claim 1 or 2, wherein at least a part of the first space overlaps the driving element and the driving IC in a plan view.
A protective member having an accommodation space for accommodating the driving element is provided.
The drive IC is a liquid injection head according to any one of claims 1 to 3, which is installed on the surface of the protective member opposite to the accommodation space.
Including the plurality of the driving elements
The liquid injection according to any one of claims 1 to 4, which includes a wiring member installed at an end of the protective member in the direction in which the plurality of drive elements are arranged and electrically connected to the drive IC. head.
The liquid injection according to any one of claims 1 to 5, which is provided with a flexible first vibration absorbing body which is installed on the first surface of the driving element side when viewed from the driving IC and constitutes the wall surface of the liquid storage chamber. head.
Any of claims 1 to 6, which is provided with a flexible second vibration absorbing body which is installed on a second surface opposite to the driving element when viewed from the driving IC and constitutes a wall surface of the liquid storage chamber. Liquid injection head.
A drive element that injects liquid in the pressure chamber from a nozzle,
A liquid storage chamber for storing the liquid supplied to the pressure chamber and
A drive IC for driving the drive element,
It is provided with a protective member in which an accommodation space for accommodating the driving element is formed.
At least a part of the liquid storage chamber overlaps both the nozzle and the drive IC in a plan view, and the liquid in which the drive IC is located in a space between the at least a part of the liquid storage chamber and the protective member. Injection head.
A drive element that injects liquid in the pressure chamber from a nozzle,
A liquid storage chamber for storing the liquid supplied to the pressure chamber and
A drive IC for driving the drive element,
It is provided with a protective member in which an accommodation space for accommodating the driving element is formed.
The drive IC is located in a space between the at least a part of the liquid storage chamber and the protective member, in which at least a part of the liquid storage chamber overlaps both the pressure chamber and the drive IC in a plan view. liquid-jet head to be.
A liquid injection device including the liquid injection head according to any one of claims 1 to 9.

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