JP7306001B2 - HEAD UNIT, HEAD MODULE, AND LIQUID EJECTION APPARATUS - Google Patents

Description

The present invention relates to a head unit, a head module, and a liquid ejection device.

2. Description of the Related Art Conventionally, there has been proposed a head unit that forms an image on a recording medium by ejecting liquid such as ink from nozzles. For example, Patent Document 1 discloses a piezoelectric element driven by a drive signal, an integrated circuit provided on a rigid wiring board and including a switch circuit for switching whether to supply the drive signal to the piezoelectric element, and a piezoelectric element. A head unit is disclosed that includes a pressure chamber capable of ejecting liquid from a nozzle in response to driving.

JP 2018-039174 A

A drive signal for driving the piezoelectric element is a large-amplitude signal. Therefore, the switch circuit generates heat as the drive signal is supplied to the piezoelectric element. When the heat of the switch circuit is transmitted to the liquid in the pressure chamber via the rigid wiring board and the temperature of the liquid in the pressure chamber rises, the discharge characteristics of the liquid from the pressure chamber change and the liquid is discharged from the head unit. There is a problem that the image quality of the image formed by the applied liquid is deteriorated.

In order to solve the above problems, a head unit according to a preferred aspect of the present invention includes a first pressure chamber for containing the liquid discharged from the first nozzles, and a pressure chamber for containing the liquid discharged from the second nozzles. a first member formed with a second pressure chamber and a first partition separating the first pressure chamber and the second pressure chamber; a second piezoelectric element provided on the second pressure chamber and displaced according to the drive signal; and the first piezoelectric element and the second piezoelectric element on the first member. a first substrate provided to cover; an integrated circuit provided on the first substrate for supplying the drive signal to the first piezoelectric element and the second piezoelectric element; a second member formed with a storage chamber for storing the liquid; a third member provided on the second member and made of metal; and between the first member and the first substrate, the It is characterized by comprising a first wall that separates a first space in which the first piezoelectric element is provided and a second space in which the second piezoelectric element is provided.

1 is a configuration diagram showing an example of a liquid ejection device 100 according to an embodiment of the present invention; FIG. FIG. 4 is an explanatory diagram showing an example of an outline of a storage case 242; 2 is an exploded perspective view showing an example of the configuration of a head unit 26; FIG. 2 is a cross-sectional view showing an example of the configuration of a head unit 26; FIG. 3 is a cross-sectional view showing an example of a configuration in the vicinity of a piezoelectric element 37; FIG. FIG. 4 is a cross-sectional view showing an example of the configuration of a head unit 26W according to a reference example; 4 is an explanatory diagram showing an example of temperature distribution in the head module 260; FIG. FIG. 11 is a cross-sectional view showing an example of the configuration of a head unit 26A according to Modification 1; FIG. 4 is an explanatory diagram showing an example of temperature distribution in a head module 260A; FIG. 11 is a cross-sectional view showing an example of a configuration of a head unit 26B according to modification 2; FIG. 4 is an explanatory diagram showing an example of temperature distribution in a head module 260B; FIG. 11 is a cross-sectional view showing an example of a configuration of a head unit 26C according to modification 3; FIG. 11 is a configuration diagram showing an example of a liquid ejection device 100D according to Modification 4; FIG. 11 is a cross-sectional view showing an example of the configuration of a head unit 26D according to modification 5; FIG. 21 is a cross-sectional view showing an example of the configuration of a head unit 26E according to modification 5; FIG. 21 is a cross-sectional view showing an example of a sealed space 382 according to modification 6; FIG. 21 is a cross-sectional view showing an example of a sealed space 382 according to modification 6; FIG. 21 is a cross-sectional view showing an example of a sealed space 382 according to modification 6; FIG. 21 is a cross-sectional view showing an example of a sealed space 382 according to modification 6; FIG. 21 is a cross-sectional view showing an example of the configuration of a head module 260 according to Modification 7; FIG. 21 is a cross-sectional view showing an example of the configuration of a head module 260 according to Modification 7;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, in each drawing, the dimensions and scale of each part are appropriately different from the actual ones. In addition, since the embodiments described below are preferred specific examples of the present invention, they are subject to various technically preferable limitations. It is not limited to these forms unless stated otherwise.

<<A. Embodiment>>
A liquid ejecting apparatus 100 according to the present embodiment will be described below with reference to FIGS. 1 to 7. FIG.

<<1. Outline of Liquid Ejector>>
FIG. 1 is a configuration diagram illustrating a liquid ejection device 100 according to this embodiment. A liquid ejecting apparatus 100 according to the present embodiment is an inkjet printing apparatus that ejects ink, which is an example of liquid, onto a medium 12 . The medium 12 is typically printing paper, but any print object such as a resin film or fabric can be used as the medium 12 .
As illustrated in FIG. 1, the liquid ejection device 100 includes a liquid container 14 that stores ink. As the liquid container 14, for example, a cartridge detachable from the liquid ejection device 100, a bag-shaped ink pack formed of a flexible film, or an ink tank capable of replenishing ink can be used. A plurality of types of ink with different colors are stored in the liquid container 14 .

As illustrated in FIG. 1, the liquid ejection device 100 includes a control device 20, a transport mechanism 22, a moving mechanism 24, and a plurality of head units 26. As shown in FIG.

In this embodiment, the control device 20 includes a processing circuit such as a CPU or FPGA, and a memory circuit such as a semiconductor memory, and controls each element of the liquid ejection device 100 . Here, CPU is an abbreviation for Central Processing Unit, and FPGA is an abbreviation for Field Programmable Gate Array.
In this embodiment, the transport mechanism 22 transports the medium 12 in the +Y direction under the control of the control device 20 . In the following description, the +Y direction and the −Y direction opposite to the +Y direction are collectively referred to as the Y-axis direction.

In this embodiment, the moving mechanism 24 reciprocates the plurality of head units 26 in the +X direction and the -X direction, which is the direction opposite to the +X direction, under the control of the control device 20 . Here, the +X direction is a direction crossing the +Y direction in which the medium 12 is conveyed. Typically, the +X direction is a direction perpendicular to the +Y direction. Note that the +X direction and the medium 12 are hereinafter collectively referred to as the X-axis direction.
The moving mechanism 24 includes a storage case 242 that stores a plurality of head units 26, and an endless belt 244 to which the storage case 242 is fixed. It should be noted that the liquid container 14 can be stored in the storage case 242 together with the head unit 26 .

Ink is supplied to the head unit 26 from the liquid container 14 . A drive signal Com for driving the head unit 26 and a control signal SI for controlling the head unit 26 are supplied from the control device 20 to the head unit 26 . The head unit 26 is driven by the driving signal Com under the control of the control signal SI, and ejects ink from some or all of the 2M nozzles N in the +Z direction. Here, M is a natural number of 1 or more. The +Z direction is a direction crossing the +X direction and the +Y direction. Typically, the +Z direction is a direction orthogonal to the +X and +Y directions. Hereinafter, the +Z direction and the −Z direction, which is the opposite direction to the +Z direction, may be collectively referred to as the Z-axis direction. The nozzle N will be described later with reference to FIGS. 3 and 4. FIG.
The head unit 26 ejects ink from some or all of the 2M nozzles N in conjunction with the transport of the medium 12 by the transport mechanism 22 and the reciprocation of the storage case 242, and the ejected ink is discharged. A desired image is formed on the surface of the medium 12 by landing on the surface of the medium 12 .

FIG. 2 is an explanatory diagram for explaining the storage case 242 and the plurality of head units 26 stored in the storage case 242. As shown in FIG.

As illustrated in FIG. 2 , in this embodiment, the storage case 242 stores a head module 260 having four head units 26 inside the storage case 242 . The storage case 242 also has an intake port 246 for taking in the air outside the storage case 242 into the storage case 242 and an exhaust port 248 for exhausting the air inside the storage case 242 to the outside of the storage case 242. And prepare. Furthermore, the exhaust port 248 includes a fan 250 for exhausting the air inside the storage case 242 to the outside of the storage case 242 . In addition, in this embodiment, air is an example of "gas."

<<2. Head unit structure>>
The outline of the head unit 26 will be described below with reference to FIGS. 3 to 5. FIG.

3 is an exploded perspective view of the head unit 26, and FIG. 4 is a sectional view taken along line III--III in FIG.

3 and 4, the head unit 26 includes a nozzle substrate 50 including a nozzle plate 52 and a vibration absorber 54, a flow path substrate 32, a pressure chamber substrate 34, a vibrating portion 36, and a plurality of piezoelectric transducers. It includes an element 37 , a rigid wiring board 38 , an integrated circuit 62 including a switch circuit, a reservoir forming board 40 , and an exterior case 80 .
In this embodiment, the flow path substrate 32, the pressure chamber substrate 34, and the vibrating portion 36 are examples of the "first member", the rigid wiring substrate 38 is an example of the "first substrate", and the storage chamber The formation substrate 40 is an example of the "second member", and the exterior case 80 is an example of the "third member".

The nozzle plate 52 is a plate-like member elongated in the Y-axis direction and extending substantially parallel to the XY plane, and 2M nozzles N are formed thereon. Here, "substantially parallel" is a concept that includes not only the case of being completely parallel, but also the case of being considered to be parallel if an error is considered.
Each nozzle N is a hole provided in the nozzle plate 52 . The nozzle plate 52 is manufactured, for example, by processing a silicon single crystal substrate using a semiconductor manufacturing technique such as etching. However, known materials and manufacturing methods can be arbitrarily adopted for manufacturing the nozzle plate 52 . For example, the nozzle plate 52 may be made of a metal material.

In this embodiment, the 2M nozzles N are arranged on the nozzle plate 52 in two rows, a row L1 and a row L2 located on the +X side of the row L1. Hereinafter, each of the M nozzles N belonging to the row L1 may be referred to as a nozzle N1, and each of the M nozzles N belonging to the row L2 may be referred to as a nozzle N2.
In this embodiment, as an example, of the M nozzles N1 belonging to the row L1, the m-th nozzle N1 from the -Y side, and of the M nozzles N2 belonging to the row L2, the m-th nozzle from the -Y side It is assumed that the position in the Y-axis direction substantially coincides with the nozzle N2. Here, m is a natural number that satisfies 1≤m≤M. In addition, "substantially matching" is a concept that includes not only the case of perfect match but also the case of being regarded as identical if an error is taken into consideration. However, the 2M nozzles N are the m-th nozzle N1 from the -Y side of the M nozzles N1 belonging to the row L1, and the m-th nozzle N1 from the -Y side of the M nozzles N2 belonging to the row L2. may be arranged so that the position in the Y-axis direction is different from that of the nozzle N2.

In this embodiment, it is assumed that M nozzles N corresponding to each of the rows L1 and L2 are provided on the nozzle plate 52 at a density of 400 or more per inch. Further, in this embodiment, it is assumed that 800 or more nozzles N are provided in the nozzle plate 52 . That is, in this embodiment, it is assumed that M is a natural number of 400 or more.

The exterior case 80 is provided on the −Z side surface of the nozzle substrate 50 .
The exterior case 80 includes a plate-shaped upper cover portion 820 that is long in the Y-axis direction and extends substantially parallel to the XY plane, and a plate-like upper lid portion 820 that is long in the Y-axis direction and extends substantially parallel to the YZ plane. and a plate-shaped side portion 802 that is long in the Y-axis direction and extends substantially parallel to the YZ plane on the +X side of the side portion 801 . That is, the exterior case 80 includes a concave portion 82 made up of the +Z side surface of the upper lid portion 820 , the +X side surface of the side surface portion 801 , and the −X side surface of the side surface portion 802 . In the following, of the space on the +Z side of the upper lid portion 820, the space on the +X side of the side surface portion 801 and the -X side of the side surface portion 802 is referred to as "the space inside the recess 82". As is clear from FIG. 4 , the space inside the recess 82 can also be grasped as the space between the nozzle substrate 50 and the exterior case 80 .
In the present embodiment, the side surface portion 801 is an example of the “first structure” and is fixed to the −Z side surface of the nozzle substrate 50 . In addition, in the present embodiment, the side surface portion 802 is an example of the “second structure” and is fixed to the −Z side surface of the nozzle substrate 50 .
In addition, the exterior case 80 includes a rectangular parallelepiped protrusion 810 elongated in the Y-axis direction on the +Z side surface of the upper cover 820 in the space inside the recess 82 .

The exterior case 80 including the upper lid portion 820, the side portion 801, the side portion 802, and the convex portion 810 is made of, for example, a metal material having thermal conductivity equal to or higher than a predetermined thermal conductivity. Here, the predetermined thermal conductivity is, for example, It has a higher thermal conductivity than it has. In this embodiment, as an example, it is assumed that the predetermined thermal conductivity is set to 200 W/mK. Therefore, in this embodiment, metal such as aluminum or copper can be used as the material of the exterior case 80 .

As illustrated in FIGS. 3 and 4, the channel substrate 32 is provided on the −Z side surface of the nozzle substrate 50 in the space inside the recess 82 .
The flow path substrate 32 is a plate-like member elongated in the Y-axis direction and extending substantially parallel to the XY plane, and forms an ink flow path. Specifically, the channel substrate 32 is formed with a channel RA1 corresponding to the row L1 and a channel RA2 corresponding to the row L2. The flow path RA1 is an elongated opening along the Y-axis direction. The flow path RA2 is an opening located in the +X direction when viewed from the flow path RA1 and formed in an elongated shape along the Y-axis direction.
In addition, 2M channels 322 and 2M channels 324 are formed in the channel substrate 32 so as to correspond to the 2M nozzles N one-to-one. As illustrated in FIG. 4 , the channels 322 and 324 are openings formed through the channel substrate 32 . The channel 324 communicates with the nozzle N corresponding to the channel 324 .
Two channels 326 are formed on the +Z side surface of the channel substrate 32 . One of the two flow paths 326 is a flow path that connects the flow path RA1 and the M flow paths 322 that correspond one-to-one to the M nozzles N1 belonging to the row L1. The other of the two flow paths 326 is a flow path that connects the flow path RA2 and the M flow paths 322 that correspond one-to-one to the M nozzles N2 belonging to the row L2.
The channel substrate 32 is manufactured, for example, by processing a silicon single crystal substrate using semiconductor manufacturing technology. However, known materials and manufacturing methods can be arbitrarily adopted for manufacturing the channel substrate 32 .

As illustrated in FIGS. 3 and 4, the pressure chamber substrate 34 is provided on the −Z side surface of the channel substrate 32 in the space inside the recess 82 .
The pressure chamber substrate 34 is a plate-like member elongated in the Y-axis direction and extending substantially parallel to the XY plane, and has 2M openings 342 corresponding to the 2M nozzles N one-to-one. It is formed.
The pressure chamber substrate 34 is manufactured, for example, by processing a silicon single crystal substrate using semiconductor manufacturing technology. However, known materials and manufacturing methods can be arbitrarily adopted for manufacturing the pressure chamber substrate 34 .

As illustrated in FIGS. 3 and 4, the vibrating portion 36 is provided on the −Z side surface of the pressure chamber substrate 34 in the space inside the recess 82 . The vibrating portion 36 is a plate-like member elongated in the Y-axis direction and extending substantially parallel to the XY plane, and is a member that can vibrate elastically.
As illustrated in FIG. 4 , the −Z side surface of the channel substrate 32 and the +Z side surface of the vibrating section 36 are arranged to face each other with the opening 342 interposed therebetween. The space inside the opening 342, which is located between the -Z side surface of the channel substrate 32 and the +Z side surface of the vibrating section 36, applies pressure to the ink filled in the space. It functions as a "pressure chamber" for That is, in the present embodiment, the vibrating portion 36 is an example of a "diaphragm" forming the wall surface of the pressure chamber.
The head unit 26 is provided with 2M pressure chambers corresponding to the 2M nozzles N on a one-to-one basis. As illustrated in FIG. 4, the pressure chamber provided corresponding to the nozzle N1 communicates with the flow path RA1 through the flow paths 322 and 326, and communicates with the nozzle N1 through the flow path 324. . A pressure chamber provided corresponding to the nozzle N2 communicates with the flow path RA2 via the flow path 322 and the flow path 326, and communicates with the nozzle N2 via the flow path 324.

As illustrated in FIGS. 3 and 4, in the space inside the recess 82, 2M pressure chambers are provided on the -Z side surface of the vibrating portion 36 so as to correspond to the 2M pressure chambers one-to-one. A piezoelectric element 37 is provided. The piezoelectric element 37 is a passive element that deforms according to the supply of the drive signal Com.

FIG. 5 is a cross-sectional view enlarging the vicinity of the piezoelectric element 37. As shown in FIG. As illustrated in FIG. 5, the piezoelectric element 37 is a laminated body in which a piezoelectric layer 373 is interposed between electrodes 371 and 372 . The piezoelectric element 37 is, for example, a portion where the electrode 371, the electrode 372, and the piezoelectric layer 373 overlap when viewed from the -Z direction.
As described above, the piezoelectric element 37 is driven and deformed according to the supply of the drive signal Com. The vibrating portion 36 vibrates in conjunction with the deformation of the piezoelectric element 37 . When the vibrating portion 36 vibrates, the pressure in the pressure chamber fluctuates. As the pressure in the pressure chamber fluctuates, the ink filled in the pressure chamber is ejected from the nozzle N through the flow path 324 .
The pressure chamber, flow path 324, nozzle N, vibrating section 36, and piezoelectric element 37 function as an "ejection section" for ejecting ink filled in the pressure chamber. Also, the 2M ejection portions provided in the head unit 26 and the nozzle plate 52 may be referred to as an "ejection head".

As illustrated in FIGS. 3 and 4, a rigid wiring board 38 is provided on the −Z side surface of the vibrating portion 36 in the space inside the recess 82 .
The rigid wiring board 38 is a plate-like member elongated in the Y-axis direction and extending substantially parallel to the XY plane, and is a member for protecting the 2M piezoelectric elements 37 formed in the vibrating portion 36. is.
The rigid wiring board 38 is manufactured, for example, by processing a single-crystal silicon substrate using semiconductor manufacturing technology. However, known materials and manufacturing methods can be arbitrarily adopted for manufacturing the rigid wiring board 38 .

As illustrated in FIG. 5, two concave portions 380 are formed on the +Z side surface of the rigid wiring board 38 . The space inside the recess 380 , that is, the space between the rigid wiring board 38 and the vibrating portion 36 is hereinafter referred to as a sealing space 382 . That is, the head unit 26 according to this embodiment is provided with two sealing spaces 382 between the rigid wiring board 38 and the vibrating section 36 . One of the two sealing spaces 382 is a space for accommodating M piezoelectric elements 37 corresponding to M nozzles N1. The other of the two sealing spaces 382 is a space for accommodating M piezoelectric elements 37 corresponding to M nozzles N2. The sealing space 382 is a space for sealing the piezoelectric element 37 to prevent the piezoelectric element 37 from being deteriorated due to the influence of oxygen, moisture, or the like. In other words, the rigid wiring board 38 functions as a protective member for protecting the piezoelectric element 37 .

As illustrated in FIGS. 3 and 4, an integrated circuit 62 including a switch circuit is provided on the −Z side surface of the rigid wiring board 38 in the space inside the recess 82 .
A switch circuit provided in the integrated circuit 62 switches whether or not to supply the drive signal Com to each piezoelectric element 37 under the control of the control signal SI. In this embodiment, it is assumed that the drive signal Com is generated in the control device 20 , but the drive signal Com may be generated in the integrated circuit 62 .
As exemplified in FIGS. 4 and 5, in the present embodiment, the integrated circuit 62 includes at least some of the 2M piezoelectric elements 37 provided in the head unit 26 when viewed from the Z-axis direction. It overlaps the piezoelectric element 37 .

As illustrated in FIGS. 4 and 5, in the present embodiment, the -Z side surface of the integrated circuit 62 is coated with a thermal conductive agent 90 such as grease. The outer case 80 is provided so that the +Z side surface of the convex portion 810 is in contact with the heat conductive agent 90 . Specifically, the heat conductive agent 90 is applied such that the distance D1 between the convex portion 810 and the integrated circuit 62 is shorter than the distance D2 between the integrated circuit 62 and the piezoelectric element 37. FIG. Further, in the present embodiment, as described above, the heat conductivity of the exterior case 80 is higher than the heat conductivity of the rigid wiring board 38, the piezoelectric element 37, and the vibrating portion .
Therefore, in this embodiment, of the heat emitted from the integrated circuit 62, the amount of heat radiated from the integrated circuit 62 to the outside of the head unit 26 via the convex portion 810 and the upper lid portion 820 is , the rigid wiring board 38, the piezoelectric element 37, and the vibrating portion 36, and the amount of heat transferred to the ink filled in the pressure chamber. That is, in the present embodiment, since the exterior case 80 is provided in the head unit 26, for example, as compared with the case where the exterior case 80 is not provided, the heat generated in the pressure chamber caused by the heat emitted from the integrated circuit 62 is reduced. It is possible to reduce the degree of temperature rise of the ink that is being heated.
Further, in the present embodiment, the side surface portion 801 and the side surface portion 802 are fixed to the vibration absorber 54 as described above. Therefore, even if the heat emitted from the integrated circuit 62 is transmitted to the ink filled in the pressure chamber, the heat transmitted to the ink filled in the pressure chamber is transferred to the flow path 322. Also, heat can be dissipated to the outside of the head unit 26 via the ink in the flow path 326 , the vibration absorber 54 , and the side surface portion 801 or 802 . That is, in the present embodiment, since the exterior case 80 is provided, for example, compared to the case where the exterior case 80 is not provided, the heat generated from the integrated circuit 62 causes the ink filled in the pressure chamber to deteriorate. It is possible to reduce the degree of temperature rise.

As illustrated in FIG. 3, 2M wirings 384 are formed on the -Z side surface of the rigid wiring board 38 so as to correspond to the 2M piezoelectric elements 37 one-to-one, for example. Each wiring 384 is electrically connected to the integrated circuit 62 . 5, each wiring 384 is electrically connected to a connection terminal 386 provided on the +Z side surface of the rigid wiring board 38 via a contact hole H passing through the rigid wiring board 38. be done. The connection terminal 386 is electrically connected to the electrode 372 of the piezoelectric element 37 . Therefore, the drive signal Com output from the integrated circuit 62 is supplied to the piezoelectric element 37 via the wiring 384 , the contact hole H and the connection terminal 386 . The contact hole H is an example of a "through hole". Also, the wiring 384 is an example of a "connection wiring".

Further, as illustrated in FIG. 3, a plurality of wirings 388 electrically connected to the integrated circuit 62 are formed on the −Z side surface of the rigid wiring substrate 38 . The plurality of wirings 388 extend to the region E, which is the +Y side end of the −Z side surface of the rigid wiring board 38 . A flexible wiring board 64 is bonded to the area E of the −Z side surface of the rigid wiring board 38 . The flexible wiring board 64 is a component formed with a plurality of wirings that electrically connect the control device 20 and the plurality of wirings 388 .

As illustrated in FIGS. 3 and 4, in the space inside the recess 82, the storage chamber forming substrate 40 is provided on the −Z side surface of the channel substrate 32. As shown in FIGS.
The reservoir forming substrate 40 is a member elongated in the Y-axis direction. The storage chamber forming substrate 40 has storage chambers elongated in the Y-axis direction for storing ink supplied to the M pressure chambers corresponding to the M nozzles N1 via the flow paths RA1. RB1 and a storage chamber RB2, which is a space elongated in the Y-axis direction, for storing ink supplied to M pressure chambers corresponding to M nozzles N2 via the flow path RA2 are provided. be done. The storage chamber RB1 is an example of the "first storage chamber", and the storage chamber RB2 is an example of the "second storage chamber".
A recess 42 is formed on the +Z side surface of the reservoir forming substrate 40 . The pressure chamber substrate 34 , the vibrating portion 36 , the plurality of piezoelectric elements 37 , the rigid wiring substrate 38 , and the integrated circuit 62 are housed in the space inside the recess 42 . Specifically, as can be understood from FIG. 4, the pressure chamber substrate 34, the vibrating portion 36, the plurality of piezoelectric elements 37, the rigid wiring substrate 38, and the integrated circuit 62 are formed into reservoir chambers RB1 and RB2. It is provided in the space between
The flexible wiring board 64 joined to the region E of the rigid wiring board 38 extends in the Y-axis direction so as to pass through the recess 42 . As understood from FIG. 3, the width W1 of the flexible wiring board 64 in the X-axis direction is less than the width W2 of the storage chamber forming substrate 40 in the X-axis direction. Also, the width W2 is less than the width W3 of the exterior case 80 in the X-axis direction.
Further, the storage chamber forming substrate 40 is provided with a heat radiation opening 48 penetrating the storage chamber forming substrate 40 in the Z-axis direction. In this embodiment, the convex portion 810 of the exterior case 80 passes inside the heat dissipation opening 48 in the space between the upper lid portion 820 and the thermal conductive agent 90 applied to the +Z side of the integrated circuit 62. provided to do so. Moreover, as understood from FIG. 4, at least part of the projection 810 is located in the space between the storage chambers RB1 and RB2.

In this embodiment, the storage chamber forming substrate 40 is made of a material different from that of the flow path substrate 32 and the pressure chamber substrate 34 . The storage chamber forming substrate 40 is formed by, for example, injection molding of a resin material. However, known materials and manufacturing methods can be arbitrarily adopted for manufacturing the storage chamber forming substrate 40 . Suitable materials for the storage chamber forming substrate 40 include, for example, synthetic fibers such as polyparaphenylenebenzobisoxazole, and resin materials such as liquid crystal polymers.

Note that the exterior case 80 is provided with an introduction port 831 and an introduction port 832 . The reservoir forming substrate 40 is also provided with an inlet 431 communicating with the inlet 831 and the reservoir RB1, and an inlet 432 communicating with the inlet 832 and the reservoir RB2. Ink is supplied from the liquid container 14 to the storage chamber RB1 through the introduction port 831 and the introduction port 431 . Further, ink is supplied from the liquid container 14 to the storage chamber RB2 through the introduction port 832 and the introduction port 432 .

Ink supplied from the liquid container 14 to the inlet 831 flows into the flow path RA1 via the inlet 431 and the storage chamber RB1. A part of the ink that has flowed into the flow path RA1 is supplied to the pressure chamber corresponding to the nozzle N1 via the flow paths 326 and 322. FIG. The ink filled in the pressure chamber corresponding to the nozzle N1 flows through the channel 324 in the +Z direction and is ejected from the nozzle N1.
Ink supplied from the liquid container 14 to the inlet 832 flows into the flow path RA2 via the inlet 432 and the storage chamber RB2. A part of the ink that has flowed into the flow path RA2 is supplied to the pressure chamber corresponding to the nozzle N2 via the flow paths 326 and 322. The ink filled in the pressure chamber corresponding to the nozzle N2 flows through the channel 324 in the +Z direction and is ejected from the nozzle N2.

As illustrated in FIGS. 3 and 4, on the -Z side surface of the channel substrate 32, channels RA1, RA2, two channels 326, and 2M channels 322 are formed. A vibration absorber 54 is provided so as to block. The vibration absorber 54 is a compliance substrate that absorbs ink pressure fluctuations in the flow path RA1 and the reservoir chamber RB1, or the flow path RA2 and the reservoir chamber RB2.

<<3. Effect of Embodiment >>
As described above, since the head unit 26 according to the present embodiment includes the outer case 80, it is possible to reduce the possibility that the temperature of the ink in the ejection section becomes high.
In order to clarify the advantages of the head unit 26 according to this embodiment, a head unit 26W provided in a head module 260W provided in a liquid ejection apparatus according to a reference example will be described below.

FIG. 6 is a cross-sectional view of a head unit 26W provided in a liquid ejection device according to a reference example. The liquid ejecting apparatus according to the reference example is configured in the same manner as the liquid ejecting apparatus 100 according to the embodiment except that a head module 260W including a head unit 26W is provided instead of the head module 260 including the head unit 26. ing.
As shown in FIG. 6, the head unit 26W is different from the head unit 26 according to the present embodiment in that it does not include an exterior case 80 and that it includes a storage chamber forming substrate 40W instead of the storage chamber forming substrate 40. differ. The storage chamber forming substrate 40W differs from the storage chamber forming substrate 40 provided in the head unit 26 according to the present embodiment in that it does not have the openings 48 for heat radiation.

As described above, the head unit 26W does not include the external case 80 made of a material having thermal conductivity equal to or higher than a predetermined thermal conductivity. In other words, head unit 26W has only components made of materials having thermal conductivity less than a predetermined thermal conductivity. That is, the head unit 26W cannot efficiently dissipate the heat generated from the integrated circuit 62 to the outside of the head unit 26W. Therefore, in the head unit 26W, the heat generated in the integrated circuit 62 may cause the ink filled in the pressure chamber to reach a high temperature.

On the other hand, the head unit 26 according to this embodiment includes an exterior case 80 made of a material having thermal conductivity equal to or higher than a predetermined thermal conductivity. In the head unit 26 according to this embodiment, the outer case 80 is arranged such that the distance D1 between the outer case 80 and the integrated circuit 62 is shorter than the distance D2 between the integrated circuit 62 and the piezoelectric element 37. Therefore, of the heat emitted from the integrated circuit 62 in the head unit 26, the amount of heat radiated to the outside of the head unit 26 is larger than the amount of heat dissipated to Therefore, in the head unit 26, the amount of heat transferred from the integrated circuit 62 to the ink filled in the pressure chamber is larger than the amount of heat transferred from the integrated circuit 62 to the ink filled in the pressure chamber in the head unit 26W. become smaller. In other words, according to the present embodiment, for example, compared to the reference example, it is possible to reduce the degree of temperature rise of the ink filled in the pressure chamber due to heat generation in the integrated circuit 62. Become. Thus, according to the present embodiment, for example, compared to the reference example, it is possible to reduce the possibility that the image quality of the image formed by the liquid ejection apparatus 100 is deteriorated due to heat generation in the integrated circuit 62. becomes.

FIG. 7 is a temperature distribution diagram MP-W showing the temperature distribution of the head module 260W when ink is ejected a predetermined number of times over a predetermined period of time from each nozzle N of the head module 260W placed in a predetermined environment. , and a temperature distribution map MP showing the temperature distribution of the head module 260 when ink is ejected from each nozzle N provided in the head module 260 placed in a prescribed environment for a prescribed number of times in a prescribed period of time. is.
In FIG. 7, the dotted area Ar-1 is an area having a temperature equal to or higher than the temperature T0 and lower than the temperature T1, and the dotted area Ar-2 is an area having a temperature equal to or higher than the temperature T1 and lower than the temperature T2. The dotted area Ar-3 is an area having a temperature equal to or higher than the temperature T2 and lower than the temperature T3, and the shaded area Ar-4 is an area having a temperature equal to or higher than the temperature T3. Regions with temperatures, not dotted or shaded, are regions with temperatures below temperature T0. Here, between the temperatures T0 to T3, when ΔT is a positive value, for example, the relationships "T3 = T2 + ΔT", "T2 = T1 + ΔT", and "T1 = T0 + ΔT" are established. .

As described above, the head unit 26W provided in the liquid ejecting apparatus according to the reference example has only components formed of a material having a thermal conductivity lower than a predetermined thermal conductivity. heat cannot be dissipated efficiently. Therefore, in the head unit 26W, when viewed from the Z-axis direction, the temperature near the center of the head unit 26W tends to be higher than that at the ends. In particular, when the head unit 26W has a density of 400 or more per inch and 800 or more ejection portions, the temperature near the center of the head unit 26W becomes higher than the temperature at the ends. more likely to become
Specifically, as shown in the temperature distribution diagram MP-W of FIG. 7, in the head unit 26W, of the 2M nozzles N provided in the head unit 26W, the nozzle N-Wa belongs to the region Ar-2. , nozzle N-Wb belongs to area Ar-3, and nozzle N-Wc belongs to area Ar-4. That is, in the head unit 26W, the temperature of the nozzles N-Wc located near the center of the head unit 26W is higher than the temperature of the nozzles N-Wa located at the end of the head unit 26W by about "2*ΔT". Become. Therefore, in the head unit 26W, the temperature of the ink filled in the pressure chamber corresponding to the nozzle N-Wc becomes higher than the temperature of the ink filled in the pressure chamber corresponding to the nozzle N-Wa. Therefore, in the head unit 26W, the ink ejection characteristics of the ejection portion corresponding to the nozzle N-Wc are different from the ink ejection characteristics of the ejection portion corresponding to the nozzle N-Wa. Therefore, in the liquid ejecting apparatus according to the reference example, the image quality of the image formed by the liquid ejecting apparatus is degraded due to heat generation in the integrated circuit 62 .

On the other hand, the head unit 26 provided in the liquid ejecting apparatus 100 according to this embodiment includes an exterior case 80 made of a material having thermal conductivity equal to or higher than a predetermined thermal conductivity. Therefore, the head unit 26 can efficiently dissipate the heat generated from the integrated circuit 62 compared to the head unit 26W. As a result, in the present embodiment, even when 800 or more ejection portions are provided at a density of 400 or more per inch, the temperature difference between the vicinity of the center and the edge of the head unit 26 is It is possible to make the temperature difference smaller than the temperature difference between the vicinity of the center of the head unit 26W and the edge.
Specifically, as shown in the temperature distribution map MP of FIG. Any of Nc belong to region Ar-1. That is, in the head unit 26, the temperature difference between the temperature of the nozzles N-c located near the center of the head unit 26 and the temperature of the nozzles N-a located at the end of the head unit 26 is set to less than "ΔT". can be suppressed. In other words, in the head unit 26, the temperature difference between the temperature of the ink filled in the pressure chamber corresponding to the nozzle Nc and the temperature of the ink filled in the pressure chamber corresponding to the nozzle Na is The temperature difference between the temperature of the ink filled in the pressure chamber corresponding to N-Wc and the temperature of the ink filled in the pressure chamber corresponding to the nozzle N-Wa can be kept smaller than the temperature difference. Therefore, in the head unit 26, the degree of difference between the ink ejection characteristics of the ejection portion corresponding to the nozzle N-c and the ink ejection characteristic of the ejection portion corresponding to the nozzle N-a is assigned to the nozzle N-Wc. It is possible to reduce the difference between the ink ejection characteristics of the ejection portion corresponding to the nozzle N-Wa and the ink ejection characteristics of the ejection portion corresponding to the nozzle N-Wa. Therefore, in the liquid ejecting apparatus 100 according to the present embodiment, the degree of deterioration in the image quality of the image formed by the liquid ejecting apparatus 100 due to heat generation in the integrated circuit 62 can be reduced as compared with the liquid ejecting apparatus according to the reference example. It is possible to keep it small.

Further, the liquid ejecting apparatus 100 according to this embodiment is provided with the fan 250 in the housing case 242 . Therefore, the liquid ejecting apparatus 100 according to the present embodiment can lower the temperature of the entire head unit 26 compared to, for example, an aspect in which the storage case 242 is not provided with the fan 250 . Accordingly, in the liquid ejecting apparatus 100 according to the present embodiment, the image quality of the image formed by the liquid ejecting apparatus 100 due to the heat generated in the integrated circuit 62 is improved compared to the mode in which the storage case 242 is not provided with the fan 250 . It is possible to suppress the degree of decrease in the

In this embodiment, one nozzle N among the M nozzles N arranged in the Y-axis direction is an example of a "first nozzle", and another nozzle adjacent to the one nozzle N in the Y-axis direction. N is an example of a "second nozzle", and a nozzle N adjacent to one nozzle N on the opposite side of another nozzle N in the Y-axis direction when viewed from one nozzle N is an example of a "third nozzle". is. In this embodiment, the pressure chamber provided corresponding to the first nozzle is an example of the "first pressure chamber", and the pressure chamber provided corresponding to the second nozzle is an example of the "second pressure chamber". The pressure chamber provided corresponding to the third nozzle is an example of the "third pressure chamber." Further, in the present embodiment, the piezoelectric element 37 provided corresponding to the first nozzle is an example of the "first piezoelectric element", and the piezoelectric element 37 provided corresponding to the second nozzle is an example of the "second The piezoelectric element 37 provided corresponding to the third nozzle is an example of the "third piezoelectric element". Further, in the present embodiment, the "common channel" is a generic term for the channel RA1 and the channel RA2.

<<B. Modification>>
Each form illustrated above can be variously modified. Specific modification modes are exemplified below. Two or more aspects arbitrarily selected from the following examples can be combined as appropriate within a mutually consistent range.

<Modification 1>
In the above-described embodiment, the exterior case 80 provided on the head unit 26 has the convex portion 810, but the present invention is not limited to such an aspect. The exterior case 80 may be configured without the protrusion 810 .

FIG. 8 is a cross-sectional view of a head unit 26A provided in the liquid ejection device according to this modification. The liquid ejecting apparatus according to this modification has the same configuration as the liquid ejecting apparatus 100 according to the embodiment except that a head module 260A including a head unit 26A is provided instead of the head module 260 including the head unit 26. It is
As shown in FIG. 8, the head unit 26A includes an exterior case 80A instead of the exterior case 80, and a storage chamber formation substrate 40W instead of the storage chamber formation substrate 40. is different from the head unit 26 according to The exterior case 80A is different from the exterior case 80 according to the embodiment in that it does not include the convex portion 810 .

In the head unit 26A, a side portion 801 and a side portion 802 of the exterior case 80A are fixed to the vibration absorber 54. As shown in FIG. Therefore, according to this modified example, even if the heat emitted from the integrated circuit 62 is transmitted to the ink filled in the pressure chamber, the heat is transmitted to the ink filled in the pressure chamber. The generated heat can be radiated to the outside of the head unit 26A through the ink in the flow paths 322 and 326, the vibration absorber 54, and the side surface portion 801 or 802.

FIG. 9 shows the temperature distribution map MP-W and the temperature distribution of the head module 260A when ink is ejected a predetermined number of times in a predetermined time from each nozzle N of the head module 260A placed in a predetermined environment. FIG. 3 is an explanatory diagram showing a temperature distribution diagram MP-A shown in FIG.
As shown in the temperature distribution diagram MP-A of FIG. 9, in the head unit 26A, of the 2M nozzles N provided in the head unit 26A, the nozzles N-Aa and N-Ab are located in the area Ar-1. and nozzle N-Ac belongs to region Ar-2. That is, in the head unit 26A, the temperature difference between the temperature of the nozzle N-Ac located near the center of the head unit 26A and the temperature of the nozzle N-Aa located at the end of the head unit 26A is reduced to about "ΔT". can be suppressed. In other words, in the head unit 26A, the temperature difference between the temperature of the ink filled in the pressure chamber corresponding to the nozzle N-Ac and the temperature of the ink filled in the pressure chamber corresponding to the nozzle N-Aa is The temperature difference between the temperature of the ink filled in the pressure chamber corresponding to N-Wc and the temperature of the ink filled in the pressure chamber corresponding to the nozzle N-Wa can be kept smaller than the temperature difference. Therefore, in the head unit 26A, the degree of difference between the ink ejection characteristics of the ejection section corresponding to the nozzle N-Ac and the ink ejection characteristic of the ejection section corresponding to the nozzle N-Aa is determined to correspond to the nozzle N-Wc. It is possible to reduce the difference between the ink ejection characteristics of the ejection portion corresponding to the nozzle N-Wa and the ink ejection characteristics of the ejection portion corresponding to the nozzle N-Wa. Therefore, in the liquid ejecting apparatus according to this modified example, the deterioration of the image quality of the image formed by the liquid ejecting apparatus due to the heat generated in the integrated circuit 62 can be suppressed as compared with the liquid ejecting apparatus according to the reference example. becomes possible.

<Modification 2>
In the above-described embodiment, the exterior case 80 provided in the head unit 26 includes the convex portion 810, the side portion 801, and the side portion 802, but the present invention is not limited to such an aspect. The exterior case 80 may be configured without the convex portion 810 , the side portion 801 and the side portion 802 .

FIG. 10 is a cross-sectional view of a head unit 26B provided in the liquid ejection device according to this modification. The liquid ejecting apparatus according to this modification has the same configuration as the liquid ejecting apparatus 100 according to the embodiment except that a head module 260B including a head unit 26B is provided instead of the head module 260 including the head unit 26. It is
As shown in FIG. 10, the head unit 26B includes an exterior case 80B instead of the exterior case 80, and a storage chamber formation substrate 40W instead of the storage chamber formation substrate 40. is different from the head unit 26 according to The exterior case 80B differs from the exterior case 80 according to the embodiment in that it does not include the protrusion 810, the side surface 801, and the side surface 802. As shown in FIG.

In the head unit 26B, the upper lid portion 820 of the exterior case 80B is fixed to the reservoir forming substrate 40W. Therefore, according to this modification, if heat generated from the integrated circuit 62 is transferred to the head unit 26B through the rigid wiring board 38, the vibrating section 36, the pressure chamber board 34, and the reservoir forming board 40W, It is possible to dissipate heat to the outside.

FIG. 11 shows the temperature distribution map MP-W and the temperature distribution of the head module 260B when ink is ejected a predetermined number of times in a predetermined time from each nozzle N of the head module 260B placed in a predetermined environment. FIG. 3 is an explanatory diagram showing a temperature distribution diagram MP-B shown in FIG.
As shown in the temperature distribution diagram MP-B of FIG. 11, in the head unit 26B, among the 2M nozzles N provided in the head unit 26B, the nozzles N-Ba belong to the region Ar-1, and the nozzles N- Bb belongs to area Ar-2 and nozzle N-Bc belongs to area Ar-3. That is, in the head unit 26B, the temperature of each nozzle N can be kept lower than in the head unit 26W. Therefore, in the liquid ejecting apparatus according to this modified example, the deterioration of the image quality of the image formed by the liquid ejecting apparatus due to the heat generated in the integrated circuit 62 can be suppressed as compared with the liquid ejecting apparatus according to the reference example. becomes possible.

<Modification 3>
In the above-described embodiment, the head unit 26 provided in the liquid ejection device 100 includes the thermal conductive agent 90, but the present invention is not limited to this aspect. The liquid ejecting apparatus 100 may be configured without the heat conducting agent 90 .

FIG. 12 is a diagram showing an example of the configuration of a head unit 26C according to this modification. The head unit 26C is configured in the same manner as the head unit 26 according to the embodiment except that it does not include the heat conductive agent 90. As shown in FIG. In the head unit 26</b>C, the exterior case 80 is provided so that the protrusion 810 provided on the exterior case 80 is in contact with the integrated circuit 62 . In this modified example, the -Z side surface of the integrated circuit 62 is made of a non-conductive material.

<Modification 4>
In the above-described embodiment and modified examples 1 to 3, the serial type liquid ejecting apparatus in which the storage case 242 in which the head unit is mounted is reciprocated is illustrated, but the present invention is not limited to such an aspect. The liquid ejection device may be a line-type liquid ejection device in which a plurality of nozzles N are distributed over the entire width of the medium 12 .

FIG. 13 is a diagram showing an example of the configuration of a liquid ejection device 100D according to this modification. The liquid ejection device 100D includes a liquid container 14, a transport mechanism 22, a transport mechanism 22, a plurality of head units 26, and a storage case 242D that stores the plurality of head units 26. FIG. That is, the liquid ejection device 100D according to this modification is the same as the liquid ejection device 100 shown in FIG. have a configuration. In the liquid ejecting apparatus 100D, the transport mechanism 22 transports the medium 12 in the +X direction. Further, in the liquid ejecting apparatus 100D, a plurality of head units 26 whose longitudinal direction is the Y-axis direction are provided so as to be distributed over the entire width of the medium 12 in the storage case 242D. It should be noted that instead of the head unit 26, the head unit 26A, 26B, or 26C may be mounted in the storage case 242D.

<Modification 5>
In the above-described embodiment and modified examples 1 to 4, the head units 26, 26A, and 26C exemplify configurations in which the ink flowing out from the pressure chambers into the flow paths 324 is ejected from the nozzles N corresponding to the pressure chambers. However, the present invention is not limited to such a configuration. The liquid ejection device may have a configuration capable of ejecting part or all of the ink in the pressure chamber from a location other than the nozzle N corresponding to the pressure chamber.

FIG. 14 is a diagram showing an example of the configuration of a head unit provided in a liquid ejection device according to this modification. As shown in FIG. 14, a head unit 26D according to this modification includes a flow path substrate 32D instead of the flow path substrate 32, and two pressure chamber substrates 34D instead of the pressure chamber substrate 34. , two vibrating portions 36D instead of the vibrating portion 36, two rigid wiring substrates 38D instead of the rigid wiring substrate 38, and a storage chamber forming substrate 40D instead of the storage chamber forming substrate 40. , two integrated circuits 62</b>D instead of the integrated circuit 62 , and an outer case 80</b>D instead of the outer case 80 .

Of these, the flow path substrate 32D is a member elongated in the Y-axis direction, and includes M flow paths RX1 corresponding to the M nozzles N1 one-to-one, and M nozzles N2 one-to-one. It differs from the channel substrate 32 according to the embodiment in that M corresponding channels RX2 and one channel RC elongated in the Y-axis direction are provided. Here, the channel RX1 provided corresponding to one nozzle N1 is a channel connecting the channel 324 corresponding to the one nozzle N1 and the channel RC. Further, the channel RX2 provided corresponding to the one nozzle N2 is a channel connecting the channel 324 corresponding to the one nozzle N2 and the channel RC. Note that the flow path RX1 and the flow path RX2 are examples of the "discharge flow path". Here, the channel RX1 and the channel RX2 are collectively referred to as the channel RX. In this case, the channel RX provided corresponding to one nozzle N is an example of a "first discharge channel", and corresponds to another nozzle N adjacent to one nozzle N in the Y-axis direction. The provided channel RX is an example of a "second discharge channel".
Further, the storage chamber forming substrate 40D is a member elongated in the Y-axis direction, and instead of one heat radiation opening 48, there are heat radiation openings 48 corresponding to the row L1 and heat radiation openings corresponding to the row L2. 48 are provided with two heat release openings 48, communicate with the flow path RC and are provided with one long flow path RD in the Y-axis direction, and communicate with the flow path RD. It differs from the storage chamber forming substrate 40 according to the embodiment in that an introduction port 433 is provided. In addition, the flow path RD is an example of the "discharge chamber".
The two pressure chamber substrates 34D provided in the head unit 26D are elongated in the Y-axis direction. and a pressure chamber substrate 34D which is elongated in the axial direction and provided with M openings 342 corresponding to the M nozzles N2. That is, each pressure chamber substrate 34D has only M pressure chambers corresponding to either row L1 or row L2 among the 2M pressure chambers provided in the head unit. It is different from the pressure chamber substrate 34 .
The two vibrating portions 36D provided in the head unit 26D are elongated in the Y-axis direction, and constitute the wall surfaces of the M openings 342 corresponding to the M nozzles N1. and a vibrating portion 36D that is elongated in the direction and forms the walls of the M openings 342 corresponding to the M nozzles N2. That is, each vibration part 36D constitutes the walls of only M pressure chambers corresponding to either row L1 or row L2 among the 2M pressure chambers provided in the head unit. It is different from the vibrating section 36 .
The two rigid wiring boards 38D provided in the head unit 26D are elongated in the Y-axis direction and protect the M piezoelectric elements 37 corresponding to the M nozzles N1. and a rigid wiring board 38D which is long in the axial direction and which protects the M piezoelectric elements 37 corresponding to the M nozzles N2. That is, of the 2M piezoelectric elements 37 provided in the head unit, the rigid wiring board 38D can accommodate only the M piezoelectric elements 37 corresponding to either the row L1 or the row L2. It is different from the rigid wiring board 38 according to .
Two integrated circuits 62D provided in the head unit 26D are integrated circuits 62D that supply drive signals Com to the M piezoelectric elements 37 corresponding to the M nozzles N1, and an integrated circuit 62D that supplies drive signals Com to the M nozzles N2. and an integrated circuit 62D that supplies a drive signal Com to the corresponding M piezoelectric elements 37. That is, each integrated circuit 62D can supply the drive signal Com only to M piezoelectric elements 37 corresponding to either the row L1 or the row L2 among the 2M piezoelectric elements 37 provided in the head unit. In one respect, it differs from the integrated circuit 62 according to the embodiment.
Also, the exterior case 80D is a member elongated in the Y-axis direction, and instead of one protrusion 810, there are two protrusions, a protrusion 810 corresponding to the row L1 and a protrusion 810 corresponding to the row L2. It differs from the exterior case 80 according to the embodiment in that a portion 810 is provided and an introduction port 833 that communicates with the introduction port 433 is provided.

In the head unit 26D shown in FIG. 14, the ink flowing into the pressure chamber corresponding to the nozzle N1 from the storage chamber RB1 via the flow path RA1, the flow path 326, and the flow path 322 is applied to the pressure chamber corresponding to the pressure chamber. By driving the element 37, it flows into the channel 324 corresponding to the nozzle N1. When the piezoelectric element 37 corresponding to the nozzle N1 is driven, part of the ink that has flowed into the flow path 324 corresponding to the nozzle N1 is ejected from the nozzle N1 and flows into the flow path 324 corresponding to the nozzle N1. A part of the discharged ink is discharged to the flow path RC through the flow path RX1. In the head unit 26D, the ink flowing from the storage chamber RB2 through the flow path RA2, the flow path 326, and the flow path 322 into the pressure chamber corresponding to the nozzle N2 is transferred to the piezoelectric element 37 corresponding to the pressure chamber. is driven, it flows into the flow path 324 corresponding to the nozzle N2. When the piezoelectric element 37 corresponding to the nozzle N1 is driven, part of the ink that has flowed into the flow path 324 corresponding to the nozzle N2 is ejected from the nozzle N2 and flows into the flow path 324 corresponding to the nozzle N2. A part of the discharged ink is discharged to the flow path RC via the flow path RX2. Further, the ink discharged to the channel RC is discharged to the outside of the head unit 26D via the channel RD and the inlet 833. FIG.
In this way, in the head unit 26D, in addition to ejecting the ink inside the pressure chamber from the nozzle N, the ink is discharged from the flow path RC and the flow path RD to the outside of the head unit 26D via the flow path RX1 or the flow path RX2. can be discharged to Therefore, in the head unit 26D, it is possible to activate the circulation of ink in the pressure chambers, compared to a mode in which the flow paths RC and the flow paths RD are not provided in the head unit. In addition, it is possible to reduce the possibility of fluctuations in ejection characteristics, such as an increase in the ejection speed due to an increase in the temperature of the ink in the pressure chamber. .
In addition, in the head unit 26D, the ink discharged from the inlet 833 to the outside of the head unit 26D may be introduced into the head unit 26 again from the inlet 831 and the inlet 832. FIG.

FIG. 15 is a diagram showing another example of the configuration of the head unit provided in the liquid ejecting apparatus according to this modification. As shown in FIG. 15, a head unit 26E according to this modification includes a flow path substrate 32E instead of the flow path substrate 32, a pressure chamber substrate 34E instead of the pressure chamber substrate 34, and nozzles. In place of the plate 52, a nozzle plate 52E is provided; in place of the 2M nozzles N, only M nozzles N1 corresponding to the row L1 are provided; and only M pressure chambers corresponding to M nozzles N1 instead of 2M pressure chambers. is different from the head unit 26 according to

Among these, the channel substrate 32E is a member elongated in the Y-axis direction, and includes M channels RZ corresponding to the M nozzles N1 one-to-one, and M nozzles N1 one-to-one. It is different from the channel substrate 32 according to the embodiment in that M corresponding channels 328 are provided. Here, the flow path RZ provided corresponding to the one nozzle N1 is a flow path that connects the flow path 324 corresponding to the one nozzle N1 and the flow path 328 corresponding to the one nozzle N1. be. Further, the channel 328 provided corresponding to one nozzle N1 is a channel that connects the channel RZ corresponding to the one nozzle N1 and the channel RA2. That is, in the aspect shown in FIG. 15 of this modified example, each flow path RZ and each flow path 328 function as a "discharge flow path". The flow path RZ and the flow path 328 provided corresponding to one nozzle N1 are an example of the "first discharge flow path", and the nozzle N1 adjacent to the one nozzle N1 in the Y-axis direction. The flow path RZ and the flow path 328 provided correspondingly are an example of the "second discharge flow path".
Further, the pressure chamber substrate 34E is a member elongated in the Y-axis direction, and instead of 2M pressure chambers, only M pressure chambers corresponding to the row L1 are formed. It is different from the pressure chamber substrate 34 .
Further, the nozzle plate 52E is a member elongated in the Y-axis direction, and instead of 2M nozzles N, only M nozzles N1 corresponding to the row L1 are formed. It differs from the nozzle plate 52 .

In the head unit 26E shown in FIG. 15, the ink flowing into the pressure chamber corresponding to the nozzle N1 from the storage chamber RB1 via the flow path RA1, the flow path 326, and the flow path 322 is applied to the pressure chamber corresponding to the pressure chamber. By driving the element 37, it flows into the channel 324 corresponding to the nozzle N1. A part of the ink flowing into the flow path 324 corresponding to the nozzle N1 is ejected from the nozzle N1, and a part of the ink flowing into the flow path 324 corresponding to the nozzle N1 is discharged from the flow path RZ. It is discharged to the outside of the head unit 26E via the flow path 328, the flow path RA2, the storage chamber RB2, and the introduction port 832. FIG. That is, in the aspect shown in FIG. 15 of this modified example, the storage chamber RB2 functions as a "discharge chamber".
In this way, in the head unit 26E, the ink inside the pressure chamber is ejected from the nozzle N, and also discharged from the inlet 832 via the flow path RZ and the flow path 328 to the outside of the head unit 26E. can be done. Therefore, in the head unit 26E, it is possible to activate the circulation of ink in the pressure chambers, compared to a mode in which the flow path RZ and the flow path 328 are not provided in the head unit. In addition, it is possible to reduce the possibility of fluctuations in ejection characteristics, such as an increase in the ejection speed due to an increase in the temperature of the ink in the pressure chamber. Become.
In the head unit 26E, the ink discharged from the inlet 832 to the outside of the head unit 26E may be re-introduced to the head unit 26E from the inlet 831.

<Modification 6>
In this modified example, details of the sealing space 382 between the vibrating portion 36 or 36D and the rigid wiring board 38 or 38D in the above-described embodiment and modified examples 1 to 5 will be described.

FIG. 16 is a diagram showing an example of the cross-sectional structure of the head unit 26 when the head unit 26 is cut along line IV-IV shown in FIG. In this modified example, the cross-sectional structure of the head unit 26 will be described as an example, but the description of this modified example also applies to the head units 26A, 26B, 26C, 26D, and 26E. do.

As shown in FIG. 16, in the channel substrate 32, between a channel 324 corresponding to one nozzle N and a channel 324 corresponding to another nozzle N adjacent to the one nozzle N in the Y-axis direction. A wall 321 is formed in the . A wall 341 is formed between the opening 342 corresponding to one nozzle N and the opening 342 corresponding to another nozzle N in the pressure chamber substrate 34 . In this modified example, as an example, the width Y1 of the wall 341 in the Y-axis direction is narrower than the width Y2 of the wall 321 in the Y-axis direction. An electrode 371 is provided on the −Z side surface of the vibrating portion 36 so that the piezoelectric element 37 corresponding to one nozzle N and the piezoelectric element 37 corresponding to another nozzle N are common.
Note that, also in this modification, one nozzle N among the M nozzles N arranged in the Y-axis direction is an example of a “first nozzle”, and another nozzle N adjacent to the one nozzle N in the Y-axis direction The nozzle N is an example of a "second nozzle", and a nozzle N adjacent to one nozzle N on the opposite side of another nozzle N in the Y-axis direction is a "third nozzle". An example. In this modified example, the pressure chamber provided corresponding to the first nozzle is an example of the "first pressure chamber", and the pressure chamber provided corresponding to the second nozzle is an example of the "second pressure chamber". The pressure chamber provided corresponding to the third nozzle is an example of the "third pressure chamber." Further, in the present embodiment, the piezoelectric element 37 provided corresponding to the first nozzle is an example of the "first piezoelectric element", and the piezoelectric element 37 provided corresponding to the second nozzle is an example of the "second The piezoelectric element 37 provided corresponding to the third nozzle is an example of the "third piezoelectric element".

Thus, in the example shown in FIG. 16, in the head unit, the sealing space 382 for accommodating M piezoelectric elements 37 corresponding to the nozzle N1 and the M piezoelectric elements 37 corresponding to the nozzle N2 are accommodated. Two sealing spaces 382 are provided, one for sealing.

FIG. 17 is a diagram showing another example of the cross-sectional structure of the head unit 26 when the head unit 26 is cut along line IV--IV as shown in FIG.
In the example shown in FIG. 17, a wall KB is formed between the piezoelectric element 37 corresponding to one nozzle N and the piezoelectric element 37 corresponding to another nozzle N adjacent to the one nozzle N in the Y-axis direction. It differs from the example shown in FIG. That is, in the example shown in FIG. 17, the sealed space 382 includes one space 3821 in which the piezoelectric element 37 corresponding to one nozzle N is provided and another space 3821 in which the piezoelectric element 37 corresponding to the other nozzle N is provided. 3821 and a wall KB that partitions the one space 3821 and the other space 3821 . More specifically, the wall KB includes an electrode 372 and a piezoelectric layer 373 forming the piezoelectric element 37 corresponding to one nozzle N, and an electrode 372 and a piezoelectric layer 373 forming the piezoelectric element 37 corresponding to the other nozzle N. An electrode 371 common to the piezoelectric element 37 corresponding to one nozzle N and the piezoelectric element 37 corresponding to another nozzle N is provided between the layer 373 and the rigid wiring board 38 .
The space 3821 in which the piezoelectric element 37 corresponding to the first nozzle is provided is an example of the "first space", and the space 3821 in which the piezoelectric element 37 corresponding to the second nozzle is provided is an example of the "second space". It is an example, and the space 3821 in which the piezoelectric element 37 corresponding to the third nozzle is provided is an example of the "third space". The wall KB that separates the first space and the second space is an example of the "first wall", and the wall KB that separates the first space and the third space is an example of the "second wall". be. The wall 341 that separates the first pressure chamber and the second pressure chamber is an example of the "first partition", and the wall 341 that separates the first pressure chamber and the third pressure chamber is an example of the "second partition". An example. Also, the electrode 371 common to the first piezoelectric element, the second piezoelectric element, and the third piezoelectric element is an example of a "common electrode."

In the example shown in FIG. 17, the width Y0 of the wall KB in the Y-axis direction is wider than the width Y1 of the wall 341 in the Y-axis direction. Therefore, in the example shown in FIG. 17, the pressure chamber corresponding to one nozzle N and , the amount of deformation of the wall 341 between pressure chambers corresponding to other nozzles N can be kept small, and crosstalk occurring between these two pressure chambers can be reduced.

Also, in the example shown in FIG. 17, the wall KB is made of the same material as the rigid wiring board 38 . The rigid wiring board 38 and the wall KB may not be separate layers and may be the same layer. That is, the wall KB may be formed integrally with the rigid wiring board 38 . However, when the wall KB and the rigid wiring board 38 are separate layers, the wall KB may be formed of a material different from that of the rigid wiring board 38. FIG.
Also, in the example shown in FIG. 17, it is assumed that a predetermined reference potential such as a ground potential is set for the electrode 371 . In this case, wall KB may be made of the same material as electrode 371 .

Thus, in the example shown in FIG. 17, in the head unit, M spaces 3821 for accommodating M piezoelectric elements 37 corresponding to nozzle N1 and M piezoelectric elements 37 corresponding to nozzle N2 are provided. 2M spaces 3821 are provided with M spaces 3821 to accommodate.

FIG. 18 is a diagram showing another example of the cross-sectional structure of the head unit 26 when the head unit 26 is cut along line IV--IV as shown in FIG.
In the example shown in FIG. 17 described above, the electrode 371 is provided on the +Z side of the piezoelectric layer 373, and the electrode 372 is provided on the −Z side of the piezoelectric layer 373. In the example shown in FIG. The electrode 371 is provided on the −Z side of the piezoelectric layer 373 , and the electrode 372 is provided on the +Z side of the piezoelectric layer 373 .
In the example shown in FIG. 18, similarly to the example shown in FIG. An electrode 371 common to the piezoelectric element 37 corresponding to the nozzle N and the piezoelectric element 37 corresponding to another nozzle N is provided to connect the rigid wiring board 38 .

FIG. 19 is a diagram showing another example of the cross-sectional structure of the head unit 26 when the head unit 26 is cut along line IV--IV as shown in FIG.
The example shown in FIG. 19 is the same as the example shown in FIG. 17 except that the wall KB is provided so as to connect the vibrating portion 36 and the rigid wiring board 38 . That is, in the example shown in FIG. 19, the wall KB is formed between the piezoelectric element 37 corresponding to one nozzle N and the piezoelectric element 37 corresponding to another nozzle N adjacent to the one nozzle N in the Y-axis direction. , the vibrating portion 36 and the rigid wiring board 38 are connected.
Incidentally, in the example shown in FIG. 19, the wall KB may be made of the same material as the rigid wiring board 38 or the same material as the vibrating portion 36 . The rigid wiring board 38 and the wall KB may be of the same layer.

<Modification 7>
In this modified example, details of the head modules 260, 260A, and 260B in the embodiment and modified examples 1 to 6 described above will be described.

FIG. 20 is a diagram showing an example of the cross-sectional structure of the head module 260 when the head module 260 is cut along line II-II shown in FIG. In this modified example, the cross-sectional structure of the head module 260 will be described as an example, but the description of this modified example also applies to the head modules 260A and 260B.

As shown in FIG. 20, the head module 260 includes a plurality of head units 26, a support 71 that supports the plurality of head units 26 from the +Z side, and a housing provided on the -Z side of the plurality of head units 26. 72 and.

Among them, the support 71 is, for example, a plate-like member extending substantially parallel to the XY plane. The support 71 may be made of, for example, a metal material such as stainless steel. The nozzle substrate 50 of each head unit 26 is fixed to the −Z side surface of the support 71 . Although not shown, the nozzle substrate 50 may include a fixture that fixes the vibration absorber 54 to the channel substrate 32 . In this case, a fixture provided on each head unit 26 may be fixed to the support 71 .
Further, the support 71 is provided with an opening Op on the +Z side of each nozzle N of the head unit 26 fixed to the support 71 . More specifically, for example, the support 71 is provided with an opening Op in a region overlapping the nozzle plate 52 of the head unit 26 when viewed from the +Z side. Therefore, the head unit 26 can cause the ink ejected from each nozzle N to land on the medium 12 without being hindered by the support 71 .

The container 72 includes a flat plate portion 720 positioned on the −Z side of the plurality of head units 26, a side wall portion 721 positioned on the +X side of the plurality of head units 26 and connecting the flat plate portion 720 and the support 71, A sidewall portion 722 located on the −X side of the plurality of head units 26 and connecting the flat plate portion 720 and the support 71, and located between the sidewall portions 721 and 722, among the plurality of head units 26, and a plurality of partition plates 723 that partition two head units 26 that are adjacent to each other in the X-axis direction. The container 72 may be made of a metal material having a higher thermal conductivity than the support 71, such as aluminum or copper. Note that the container 72 preferably has a thermal conductivity equal to or higher than that of the exterior case 80 .
In this modification, the exterior case 80 of each head unit 26 is fixed to the surface of the flat plate portion 720 on the +Z side with an adhesive BD. In the flat plate portion 720 and the adhesive BD, a through channel RK1 for supplying ink from the liquid container 14 to the inlet 831 and a through channel RK2 for supplying ink from the liquid container 14 to the inlet 832 are provided. and are provided.

Thus, in this modification, the head module 260 includes the support 71 that supports the head unit 26 and the container 72 fixed to the head unit 26 and the container 72 . Therefore, the heat emitted from the integrated circuit 62 is transmitted to the containing body 72 via the exterior case 80, the nozzle substrate 50, and the support body 71, and is also transmitted to the containing body 72 via the exterior case 80 and the adhesive BD. do. Further, since the containing body 72 is provided so as to cover the plurality of head units 26 , the surface area of the containing body 72 is larger than the surface area of each head unit 26 . That is, the containing body 72 functions as a heat sink for the head unit 26 . Therefore, according to this modification, the heat generated from the integrated circuit 62 is efficiently dissipated to the outside of the head module 260 as compared with the aspect in which the head module 260 does not include the support 71 and the housing 72. can do

In this modification, when the head unit 26K that ejects black ink is included in the four head units 26, the head unit 26K is located between the side wall portion 721 and the partition plate 723, or between the side wall portions. 722 and partition plate 723 . In other words, the head unit 26K is arranged at the +X side end or the -X side end of the head module 260 .
Generally, in the printing process for forming an image on the medium 12, black ink is consumed more than other color inks. For this reason, the effect of temperature or viscosity changes of black ink on image quality is greater than the effect of temperature or viscosity changes of other color inks on image quality.
On the other hand, in this modified example, since the head unit 26K is arranged at the end of the head module 260, compared with the aspect in which the head unit 26K is arranged at the center of the head module 260, the print processing It is possible to suppress the degree of deterioration of image quality in .

Note that FIG. 20 illustrates the case where the container 72 includes a plurality of partition plates 723, but this modification is not limited to such an aspect. For example, as shown in FIG. 21, container 72 may be configured without partition plate 723 .

<Modification 8>
In the above-described embodiment and Modifications 1 to 7, the configuration in which the nozzle substrate 50 is provided with the vibration absorber 54 was exemplified, but the present invention is not limited to such an aspect. The nozzle substrate 50 may be configured without the vibration absorber 54 .

<Modification 9>
In the embodiment and Modifications 1 to 8 described above, the piezoelectric element 37 was exemplified as a component that applies pressure to the inside of the pressure chamber, but the present invention is not limited to such an aspect. As a component that applies pressure to the inside of the pressure chamber, for example, a heating element that generates air bubbles inside the pressure chamber by heating to change the pressure may be employed. A heating element is a component that generates heat by a heating element supplied with a driving signal Com. As understood from the above examples, the component that applies pressure to the inside of the pressure chamber may be an element that ejects the liquid in the pressure chamber from the nozzle N, that is, an element that applies pressure to the inside of the pressure chamber. , the operation method and specific configuration are irrelevant.

<Modification 10>
The liquid ejecting apparatuses exemplified in the above-described embodiment and modified examples 1 to 9 can be employed in various types of equipment such as facsimile machines and copiers, in addition to equipment dedicated to printing. However, the application of the liquid ejecting apparatus of the present invention is not limited to printing. For example, a liquid ejecting apparatus that ejects a colorant solution is used as a manufacturing apparatus for forming a color filter of a liquid crystal display device. Also, a liquid ejecting apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus for forming wiring and electrodes of a wiring board.

DESCRIPTION OF SYMBOLS 14... Liquid container, 20... Control apparatus, 22... Transfer mechanism, 24... Moving mechanism, 26... Head unit, 32... Flow path substrate, 34... Pressure chamber substrate, 36... Vibration part, 37... Piezoelectric element, 38... Rigid Wiring substrate 40 Reservoir forming substrate 62 Integrated circuit 80 Exterior case 100 Liquid ejection device 260 Head module 246 Intake port 248 Exhaust port 250 Fan 382 Sealed space .

Claims (21)

a first pressure chamber for containing the liquid ejected from the first nozzle;
a second pressure chamber for containing the liquid ejected from the second nozzle; and
a first member formed with a first partition separating the first pressure chamber and the second pressure chamber;
a first piezoelectric element provided on the first pressure chamber and displaced according to a drive signal;
a second piezoelectric element provided on the second pressure chamber and displaced according to the drive signal;
a first substrate provided on the first member so as to cover the first piezoelectric element and the second piezoelectric element;
an integrated circuit provided on the first substrate and supplying the drive signal to the first piezoelectric element and the second piezoelectric element;
a second member provided on the first member and formed with a storage chamber for storing the liquid;
a third member provided on the second member and made of metal;
Between the first member and the first substrate,
a first space in which the first piezoelectric element is provided; and
a first wall portion that divides a second space in which the second piezoelectric element is provided;
with
The second member includes
A heat dissipation opening is provided for dissipating heat from the integrated circuit,
The third member is
a convex portion provided in the heat radiation opening;
an upper cover provided on the side opposite to the integrated circuit when viewed from the protrusion;
comprising
A head unit characterized by: The first wall portion is
connecting the first member and the first substrate;
The head unit according to claim 1, characterized by: The first piezoelectric element and the second piezoelectric element are
comprising a common electrode provided on the first member,
The first wall portion is
connecting the common electrode and the first substrate;
The head unit according to claim 1, characterized by: The first wall portion is
integrally formed with the first substrate;
4. The head unit according to any one of claims 1 to 3, characterized in that: The second member is
provided to surround the integrated circuit,
5. The head unit according to any one of claims 1 to 4, characterized in that: The distance between the third member and the integrated circuit is
shorter than the distance between the integrated circuit and the first piezoelectric element;
6. The head unit according to any one of claims 1 to 5, characterized in that: The head unit includes
having a plurality of nozzles including the first nozzle and the second nozzle;
The nozzle, in the head unit,
800 or more are provided at a density of 400 or more per inch,
7. The head unit according to any one of claims 1 to 6, characterized in that: The thermal conductivity of the third member is
higher than the thermal conductivity of the liquid and higher than the thermal conductivity of the first substrate;
The head unit according to any one of claims 1 to 7, characterized in that: The third member is
having a first structure and a second structure;
the first piezoelectric element, the second piezoelectric element, the integrated circuit, and the first substrate,
provided between the first structure and the second structure;
9. The head unit according to any one of claims 1 to 8, characterized in that: The third member is
heat of the integrated circuit
It is provided to transmit with a thermal conductivity equal to or higher than a predetermined thermal conductivity with respect to the third member,
10. The head unit according to any one of claims 1 to 9, characterized in that: comprising a nozzle substrate on which the first nozzle and the second nozzle are formed;
The third member is
The heat of the nozzle substrate
It is provided to transmit with a thermal conductivity equal to or higher than a predetermined thermal conductivity with respect to the third member,
11. The head unit according to any one of claims 1 to 10, characterized in that: The second member includes
a first storage chamber for storing the liquid;
a second storage chamber for storing the liquid;
is provided,
the first piezoelectric element, the second piezoelectric element, the integrated circuit, and the first substrate,
provided between the first storage chamber and the second storage chamber;
12. The head unit according to any one of claims 1 to 11, characterized in that: The third member is
having a first structure and a second structure;
the first piezoelectric element, the second piezoelectric element, the integrated circuit, and the first substrate,
provided between the first structure and the second structure;
13. The head unit according to any one of claims 1 to 12 , characterized in that: The second member includes
A discharge chamber is provided for storing the liquid discharged from the first pressure chamber and the liquid discharged from the second pressure chamber,
The first member includes
a first discharge channel for causing the liquid discharged from the first pressure chamber to flow into the discharge chamber;
a second discharge channel for causing the liquid discharged from the second pressure chamber to flow into the discharge chamber;
is provided,
14. A head unit according to any one of claims 1 to 13 , characterized in that: The first member includes
A common flow path is provided that communicates with the storage chamber and accommodates liquid to be supplied to the first pressure chamber and the second pressure chamber,
15. The head unit according to any one of claims 1 to 14 , characterized in that: The width between the first space and the second space of the first wall is
larger than the width of the first partition between the first pressure chamber and the second pressure chamber;
16. A head unit according to any one of claims 1 to 15 , characterized in that: The first member includes
a third pressure chamber for containing liquid ejected from a third nozzle provided on the opposite side of the second nozzle when viewed from the first nozzle;
a second partition separating the first pressure chamber and the third pressure chamber;
is provided,
Above the third pressure chamber,
A third piezoelectric element is provided that is displaced according to the drive signal,
The first substrate is
covering the third piezoelectric element on the first member;
The integrated circuit comprises:
supplying the drive signal to the third piezoelectric element;
Between the first member and the first substrate,
A second wall is provided that separates the first space and a third space in which the third piezoelectric element is provided,
17. A head unit according to any one of claims 1 to 16 , characterized in that: comprising a nozzle plate on which the first nozzle and the second nozzle are formed;
The nozzle plate is made of metal,
18. A head unit as claimed in any one of claims 1 to 17 , characterized in that: a support provided on the opposite side of the first substrate as viewed from the nozzle plate in the direction in which the liquid is ejected from the first nozzle;
The support is made of metal,
19. A head unit according to claim 18 , characterized in that: A plurality of head units according to any one of claims 1 to 19 ,
A head module characterized by: a head module according to claim 20 ;
a storage case for storing the head module;
with
The storage case is
an intake port for taking in gas outside the storage case into the interior of the storage case;
an exhaust port having a fan for exhausting the gas inside the storage case to the outside of the storage case;
comprising
A liquid ejection device characterized by:

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