JP2021165027A - Liquid ejection head and liquid ejection device - Google Patents

Abstract

To reduce mixing of air bubbles into a flow channel from a nozzle while obtaining desired ejection characteristics.SOLUTION: A liquid ejection head includes: a flow channel that flows liquid; and a nozzle which ejects the liquid from the flow channel in a direction along a first axis; wherein the nozzle includes: a first portion; a second portion located closer to the flow channel than the first portion in a first direction; and a third portion located closer to the flow channel than the second portion in the first direction; wherein a width of the first portion in the second direction intersecting the first direction is a first width; a width of the second portion in the second direction is a second width greater than the first width, and a width of the third portion in the second direction is a third width less than the second width.SELECTED DRAWING: Figure 4

Description

The present invention relates to a liquid discharge head and a liquid discharge device.

A liquid ejection device represented by an inkjet printer generally has a liquid ejection head that ejects a liquid such as ink. The liquid discharge head is provided with a plurality of nozzles for discharging liquid, for example, as disclosed in Patent Document 1.

Japanese Unexamined Patent Publication No. 2013-184372

If the opening width on the downstream side of the nozzle is too large, the first problem that the amount of liquid discharged from the nozzle becomes too large or the speed at which the liquid is discharged from the nozzle does not reach the desired speed arises. In order to solve this first problem, it is necessary to reduce the opening width on the downstream side of the nozzle to some extent.

Here, as the width of the nozzle becomes smaller, the liquid meniscus formed in the nozzle is more likely to be drawn in by the capillary phenomenon. Therefore, when the width of the nozzle is reduced over the entire length, the meniscus easily reaches the flow path for supplying the liquid to the nozzle, and as a result of the meniscus being destroyed by reaching the flow path, the flow path is reached. A second problem arises in which air bubbles are mixed.

Therefore, conventionally, for the purpose of solving both of these problems, a nozzle having a shape in which the width becomes narrower from the opening on the upstream side to the opening on the downstream side is adopted.

However, even if a nozzle having such a shape is adopted, bubbles may be generated in the nozzle due to the destruction of the meniscus, and the bubbles reach the above-mentioned flow path without being hindered at all. Therefore, conventionally, there is a problem that it is not possible to sufficiently reduce the mixing of air bubbles into the flow path.

In order to solve the above problems, the liquid discharge head according to a preferred embodiment of the present invention has a flow path for flowing the liquid and a nozzle for discharging the liquid from the flow path in the first direction. The nozzle has a first portion, a second portion located closer to the flow path than the first portion in the first direction, and closer to the flow path than the second portion in the first direction. The width of the first portion in the second direction intersecting the first direction, including the third portion located, is the first width, and the width of the second portion in the second direction is the first width. It is a second width larger than one width, and the width of the third portion in the second direction is a third width smaller than the second width.

The liquid discharge head according to another preferred embodiment of the present invention includes a flow path for flowing the liquid and a nozzle for discharging the liquid from the flow path in the first direction, and the nozzle is the first portion. A second portion located closer to the flow path than the first portion in the first direction, and a third portion located closer to the flow path than the second portion in the first direction. The area when the first portion is viewed in the first direction is the first area, and the area when the second portion is viewed in the first direction is larger than the first area. It is an area, and the area when the third portion is viewed in the first direction is a third area smaller than the second area.

The liquid discharge head according to another preferred embodiment of the present invention includes a flow path for flowing the liquid and a nozzle for discharging the liquid from the flow path in the first direction, and the nozzle is the first portion. A second portion located closer to the flow path than the first portion in the first direction, and a third portion located closer to the flow path than the second portion in the first direction. The circumference when the first portion is viewed in the first direction is the first circumference, and the circumference when the second portion is viewed in the first direction is the first circumference. The second circumference is larger than, and the circumference when the third portion is viewed in the first direction is the third circumference, which is smaller than the second circumference.

The liquid discharge device according to a preferred embodiment of the present invention includes the liquid discharge head according to any one of the above embodiments.
It has a control unit that controls a liquid discharge operation in the liquid discharge head.

It is a schematic diagram which shows the structural example of the liquid discharge device which concerns on 1st Embodiment. It is a schematic diagram of the flow path in the liquid discharge head which concerns on 1st Embodiment. FIG. 2 is a cross-sectional view taken along the line AA in FIG. FIG. 3 is a cross-sectional view taken along the line BB in FIG. It is a perspective view of the nozzle in 1st Embodiment. FIG. 5 is a cross-sectional view taken along the line CC in FIG. It is a perspective view of the nozzle in 2nd Embodiment. It is a top view of the nozzle in 2nd Embodiment. It is a perspective view of the nozzle in 3rd Embodiment. It is a top view of the nozzle in 3rd Embodiment. It is a schematic diagram of the flow path in the liquid discharge head which concerns on 4th Embodiment. FIG. 11 is a cross-sectional view taken along the line A1-A1 in FIG. FIG. 11 is a cross-sectional view taken along the line A2-A2 in FIG. It is sectional drawing of the liquid discharge head which concerns on 5th Embodiment. It is sectional drawing of the liquid discharge head which concerns on 6th Embodiment. FIG. 15 is a cross-sectional view taken along the line B1-B1 in FIG.

Hereinafter, preferred embodiments according to the present invention will be described with reference to the accompanying drawings. In the drawings, the dimensions or scale of each part are appropriately different from the actual ones, and some parts are schematically shown for easy understanding. Further, the scope of the present invention is not limited to these forms unless it is stated in the following description that the present invention is particularly limited.

In the following description, the X-axis, Y-axis and Z-axis that intersect each other will be appropriately used. The Z-axis is an example of the "first axis". The Y-axis is an example of the "second axis". The X-axis is an example of the "third axis". Further, one direction along the X axis is referred to as an X1 direction, and a direction opposite to the X1 direction is referred to as an X2 direction. Similarly, the directions opposite to each other along the Y axis are referred to as the Y1 direction and the Y2 direction. Further, the directions opposite to each other along the Z axis are referred to as the Z1 direction and the Z2 direction. The X1 direction is an example of the "third direction". The Y1 direction is an example of the "second direction". The Z2 direction is an example of the "first direction". Here, typically, the Z axis is a vertical axis, and the Z2 direction corresponds to a downward direction in the vertical direction. However, the Z axis does not have to be a vertical axis. Further, the X-axis, the Y-axis and the Z-axis are typically orthogonal to each other, but are not limited to this, and may intersect at an angle within a range of 80 ° or more and 100 ° or less, for example.

A: First Embodiment A1: Overall configuration of the liquid discharge device FIG. 1 is a schematic view showing a configuration example of the liquid discharge device 100 according to the first embodiment. The liquid ejection device 100 is an inkjet printing apparatus that ejects a liquid such as ink as droplets onto the medium 11. The medium 11 is, for example, printing paper. The medium 11 is not limited to printing paper, and may be a printing target of any material such as a resin film or cloth.

A liquid container 12 is attached to the liquid discharge device 100. The liquid container 12 stores ink. Specific embodiments of the liquid container 12 include, for example, a cartridge that can be attached to and detached from the liquid ejection device 100, a bag-shaped ink pack made of a flexible film, and an ink tank that can be refilled with ink. .. The type of ink stored in the liquid container 12 is arbitrary.

As shown in FIG. 1, the liquid discharge device 100 includes a control unit 21, a transfer mechanism 22, a moving mechanism 23, and a liquid discharge head 24. The control unit 21 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 the operation of each element of the liquid discharge device 100. Here, the control unit 21 is an example of a “control unit” and controls the ink ejection operation of the liquid ejection head 24.

The transport mechanism 22 transports the medium 11 along the Y axis under the control of the control unit 21. The moving mechanism 23 reciprocates the liquid discharge head 24 along the X axis under the control of the control unit 21. The moving mechanism 23 includes a substantially box-shaped transport body 231 for accommodating the liquid discharge head 24, and an endless transport belt 232 to which the transport body 231 is fixed. The number of liquid discharge heads 24 mounted on the transport body 231 is not limited to one, and may be a plurality. Further, in addition to the liquid discharge head 24, the above-mentioned liquid container 12 may be mounted on the transport body 231.

Under the control of the control unit 21, the liquid ejection head 24 ejects the ink supplied from the liquid container 12 to the medium 11 from each of the plurality of nozzles. An image is formed on the surface of the medium 11 by performing this discharge in parallel with the transfer of the medium 11 by the transfer mechanism 22 and the reciprocating movement of the liquid discharge head 24 by the moving mechanism 23.

A2: Flow path of the liquid discharge head FIG. 2 is a schematic view of the flow path in the liquid discharge head 24 according to the first embodiment. As shown in FIG. 2, the liquid discharge head 24 is provided with a plurality of nozzles N, a plurality of individual flow paths P, a first common liquid chamber R1 and a second common liquid chamber R2, and a circulation mechanism 26 is connected to the liquid discharge head 24. Will be done.

Specifically, the liquid discharge head 24 has a surface facing the medium 11, and as shown in FIG. 2, a plurality of nozzles N are provided on the surface. The plurality of nozzles N are arranged along the Y axis. Each of the plurality of nozzles N ejects ink in the Z2 direction.

Here, a set of a plurality of nozzles N constitutes a nozzle row L. Further, the plurality of nozzles N are arranged at equal intervals at a pitch θ. The pitch θ is the distance between the centers of the plurality of nozzles N in the direction along the Y axis.

An individual flow path P communicates with each of the plurality of nozzles N. Each of the plurality of individual flow paths P extends along the X axis and communicates with different nozzles N. The set of the plurality of individual flow paths P constitutes the individual flow path row 25. Further, the plurality of individual flow paths P are arranged along the Y axis.

As shown in FIG. 2, each individual flow path P has a pressure chamber Ca, a pressure chamber Cb, and a nozzle flow path Nf. Each of the pressure chamber Ca and the pressure chamber Cb in each individual flow path P extends along the X axis, and is a space in which ink discharged from the nozzle N communicating with the individual flow path P is stored. In the example shown in FIG. 2, the plurality of pressure chambers Ca are arranged along the Y axis. Similarly, the plurality of pressure chambers Cb are arranged along the Y axis. In each individual flow path P, the positions of the pressure chamber Ca and the pressure chamber Cb in the direction along the Y axis are the same in the example shown in FIG. 2, but may be different from each other. Further, in the following, when the pressure chamber Ca and the pressure chamber Cb are not particularly distinguished, they are also simply referred to as “pressure chamber C”.

A nozzle flow path Nf is arranged between the pressure chamber Ca and the pressure chamber Cb in each individual flow path P. In each individual flow path P, the nozzle flow path Nf extends along the X-axis and communicates the pressure chamber Ca and the pressure chamber Cb. Further, the plurality of nozzle flow paths Nf are arranged along the Y axis at intervals from each other. A nozzle N is provided in each nozzle flow path Nf. In each nozzle flow path Nf, ink is ejected from the nozzle N by changing the pressure in the pressure chamber Ca and the pressure chamber Cb described above.

The first common liquid chamber R1 and the second common liquid chamber R2 communicate with the plurality of individual flow paths P. Each of the first common liquid chamber R1 and the second common liquid chamber R2 is a space extending along the Y axis over the entire range in which the plurality of nozzles N are distributed. The above-mentioned individual flow path rows 25 and a plurality of nozzles N are located between the first common liquid chamber R1 and the second common liquid chamber R2 when viewed in the direction along the Z axis (when viewed from the direction along the Z axis). do. In other words, the individual flow path rows 25 and the plurality of nozzles N are located between the first common liquid chamber R1 and the second common liquid chamber R2 in the direction along the X axis. In the following, viewing in the direction along the Z axis is also referred to as "planar view".

Here, the first common liquid chamber R1 is connected to the end E1 of each individual flow path P in the X2 direction. Ink for supplying to each individual flow path P is stored in the first common liquid chamber R1. On the other hand, the second common liquid chamber R2 is connected to the end E2 of each individual flow path P in the X1 direction. In the second common liquid chamber R2, ink discharged from each individual flow path P without being discharged is stored.

A circulation mechanism 26 is connected to the first common liquid chamber R1 and the second common liquid chamber R2. The circulation mechanism 26 is a mechanism for supplying ink to the first common liquid chamber R1 and collecting the ink discharged from the second common liquid chamber R2 for resupply to the first common liquid chamber R1. The circulation mechanism 26 includes a first supply pump 261, a second supply pump 262, a storage container 263, a recovery flow path 264, and a supply flow path 265.

The first supply pump 261 is a pump that supplies the ink stored in the liquid container 12 to the storage container 263. The storage container 263 is a sub-tank for temporarily storing the ink supplied from the liquid container 12. The recovery flow path 264 communicates the second common liquid chamber R2 and the storage container 263, and is a flow path for collecting the ink from the second common liquid chamber R2 into the storage container 263. Ink stored in the liquid container 12 is supplied to the storage container 263 from the first supply pump 261, and ink discharged from each individual flow path P to the second common liquid chamber R2 passes through the recovery flow path 264. Will be supplied. The second supply pump 262 is a pump that delivers the ink stored in the storage container 263. The supply flow path 265 communicates the first common liquid chamber R1 and the storage container 263, and is a flow path for supplying the ink from the storage container 263 to the first common liquid chamber R1.

A3: Specific structure of the liquid discharge head FIG. 3 is a cross-sectional view taken along the line AA in FIG. FIG. 3 shows a cross section of the liquid discharge head 24 cut along the individual flow path P in a plane parallel to the X-axis and the Z-axis. As shown in FIG. 3, the liquid discharge head 24 includes a flow path structure 30, a plurality of piezoelectric elements 41, a housing portion 42, a protective substrate 43, and a wiring substrate 44.

The flow path structure 30 is provided with the above-mentioned first common liquid chamber R1, second common liquid chamber R2, a plurality of individual flow paths P, and a plurality of nozzles N. Specifically, the flow path structure 30 is a structure in which the first nozzle substrate 31, the second nozzle substrate 32, the communication plate 33, the pressure chamber substrate 34, and the diaphragm 35 are laminated in this order in the Z1 direction. be. Each member of the first nozzle substrate 31, the second nozzle substrate 32, the communication plate 33, the pressure chamber substrate 34, and the diaphragm 35 extends along the Y axis, and for example, a single crystal of silicon is used by using semiconductor processing technology. Manufactured by processing a substrate. Further, these members are joined to each other by an adhesive or the like.

A plurality of nozzles N are provided on the first nozzle substrate 31 and the second nozzle substrate 32. Each of the plurality of nozzles N penetrates the first nozzle substrate 31 and the second nozzle substrate 32 collectively, and is a through hole through which ink passes. The shape of each nozzle N and the configuration related thereto will be described in detail later.

The communication plate 33 is provided with a part of each of the first common liquid chamber R1 and the second common liquid chamber R2 and a portion of the plurality of individual flow paths P excluding the pressure chamber Ca and the pressure chamber Cb. Here, each individual flow path P includes the above-mentioned pressure chamber Ca, pressure chamber Cb, and nozzle flow path Nf, as well as the first communication flow path Na1, the second communication flow path Na2, the supply flow path Ra1, and the discharge flow path Ra2. Has. Of these, the nozzle flow path Nf, the first communication flow path Na1, the second communication flow path Na2, the supply flow path Ra1 and the discharge flow path Ra2 are provided in the communication plate 33.

Each part of the first common liquid chamber R1 and the second common liquid chamber R2 is a space penetrating the communication plate 33. A vibration absorbing body 361 and a vibration absorbing body 362 that close the opening by the space are installed on the surface of the communication plate 33 facing the Z2 direction.

Each of the vibration absorbing body 361 and the vibration absorbing body 362 is a layered member made of an elastic material. The vibration absorber 361 constitutes a part of the wall surface of the first common liquid chamber R1 and absorbs the pressure fluctuation in the first common liquid chamber R1. Similarly, the vibration absorbing body 362 constitutes a part of the wall surface of the second common liquid chamber R2, and absorbs the pressure fluctuation in the second common liquid chamber R2. In the example shown in FIG. 3, the vibration absorbing body 361 and the vibration absorbing body 362 are joined to the communication plate 33 via the second nozzle substrate 32. The vibration absorbing body 361 and the vibration absorbing body 362 may be directly joined to the communication plate 33 without passing through the second nozzle substrate 32.

The nozzle flow path Nf is a space in the groove provided on the surface of the communication plate 33 facing the Z2 direction. Here, the second nozzle substrate 32 constitutes a part of the wall surface of the nozzle flow path Nf.

Each of the first communication flow path Na1 and the second communication flow path Na2 extends along the Z axis and is a space penetrating the communication plate 33. The first communication flow path Na1 communicates the pressure chamber Ca and the nozzle flow path Nf, and guides the ink from the pressure chamber Ca to the nozzle flow path Nf. On the other hand, the second communication flow path Na2 communicates the pressure chamber Cb and the nozzle flow path Nf, and guides the ink from the nozzle flow path Nf to the pressure chamber Cb.

Each of the supply flow path Ra1 and the discharge flow path Ra2 extends along the Z axis and is a space penetrating the communication plate 33. The supply flow path Ra1 communicates the first common liquid chamber R1 and the pressure chamber Ca, and supplies the ink from the first common liquid chamber R1 to the pressure chamber Ca. Here, one end of the supply flow path Ra1 is opened to the surface of the communication plate 33 facing the Z1 direction. On the other hand, the other end of the supply flow path Ra1 is the upstream end portion E1 of the individual flow path P, which opens to the wall surface of the first common liquid chamber R1 in the communication plate 33. On the other hand, the discharge flow path Ra2 communicates the second common liquid chamber R2 and the pressure chamber Cb, and discharges the ink from the pressure chamber Cb to the second common liquid chamber R2. Here, one end of the discharge flow path Ra2 is opened to the surface of the communication plate 33 facing the Z1 direction. On the other hand, the other end of the discharge flow path Ra2 is an end portion E2 on the downstream side of the individual flow path P, which opens to the wall surface of the second common liquid chamber R2 in the communication plate 33.

The pressure chamber substrate 34 is provided with pressure chambers Ca and pressure chambers Cb of a plurality of individual flow paths P. Each of the pressure chamber Ca and the pressure chamber Cb penetrates the pressure chamber substrate 34 and is a gap between the communication plate 33 and the diaphragm 35.

The diaphragm 35 is a plate-shaped member that can vibrate elastically. The diaphragm 35 is a laminate including, for example, a first layer made of _{silicon oxide (SiO 2} ) and a second layer made of _{zirconium oxide (ZrO 2).} Here, another layer such as a metal oxide may be interposed between the first layer and the second layer. A part or all of the diaphragm 35 may be integrally made of the same material as the pressure chamber substrate 34. For example, the diaphragm 35 and the pressure chamber substrate 34 can be integrally formed by selectively removing a part in the thickness direction of the region corresponding to the pressure chamber C in the plate-shaped member having a predetermined thickness. Further, the diaphragm 35 may be composed of a layer of a single material.

A plurality of piezoelectric elements 41 corresponding to different pressure chambers C are installed on the surface of the diaphragm 35 facing the Z1 direction. The piezoelectric element 41 corresponding to each pressure chamber C overlaps the pressure chamber C in a plan view. For example, each piezoelectric element 41 is composed of a laminate of a first electrode and a second electrode facing each other and a piezoelectric layer arranged between the two electrodes. Each piezoelectric element 41 is an example of an energy generating element that generates energy for ejecting ink in the pressure chamber C from the nozzle N by varying the pressure of the ink in the pressure chamber C. When the drive signal is supplied, the piezoelectric element 41 vibrates the diaphragm 35 as it deforms. The pressure chamber C expands and contracts with this vibration, so that the pressure of the ink in the pressure chamber C fluctuates.

The housing portion 42 is a case for storing ink. The housing portion 42 is provided with a space forming the rest other than a part provided on the communication plate 33 for each of the first common liquid chamber R1 and the second common liquid chamber R2. Further, the housing portion 42 is provided with a supply port 421 and a discharge port 422. The supply port 421 is a pipeline communicating with the first common liquid chamber R1 and is connected to the supply flow path 265 of the circulation mechanism 26. Therefore, the ink sent from the second supply pump 262 to the supply flow path 265 is supplied to the first common liquid chamber R1 via the supply port 421. On the other hand, the discharge port 422 is a pipeline communicating with the second common liquid chamber R2, and is connected to the recovery flow path 264 of the circulation mechanism 26. Therefore, the ink in the second common liquid chamber R2 is discharged to the recovery flow path 264 via the discharge port 422.

The protective substrate 43 is a plate-shaped member installed on the surface of the diaphragm 35 facing the Z1 direction, protects a plurality of piezoelectric elements 41, and reinforces the mechanical strength of the diaphragm 35. Here, a plurality of piezoelectric elements 41 are housed between the protective substrate 43 and the diaphragm 35.

The wiring board 44 is mounted on the surface of the diaphragm 35 facing the Z1 direction, and is a mounting component for electrically connecting the control unit 21 and the liquid discharge head 24. For example, a flexible wiring board 44 such as FPC (Flexible Printed Circuit) or FFC (Flexible Flat Cable) is preferably used. A drive circuit 45 for supplying a drive signal to each piezoelectric element 41 is mounted on the wiring board 44.

In the liquid discharge head 24 having the above configuration, the ink is supplied to the first common liquid chamber R1, the supply flow path Ra1, the pressure chamber Ca, the first communication flow path Na1, the nozzle flow path Nf, and the first by the operation of the circulation mechanism 26 described above. It circulates in this order to the two communication flow paths Na2, the pressure chamber Cb, the discharge flow path Ra2, and the second common liquid chamber R2. Further, by simultaneously driving the piezoelectric element 41 corresponding to both the pressure chamber Ca and the pressure chamber Cb by the drive signal from the drive circuit 45, the pressures of the pressure chamber Ca and the pressure chamber Cb are changed, and the pressure fluctuation is caused. Along with this, ink is ejected from the nozzle N. The operation period or operation timing of the circulation mechanism 26 is arbitrary, and whether or not it overlaps with the period or timing of ejecting ink from the nozzle N is also arbitrary.

By circulating the ink used for the liquid ejection head 24 in this way, it is possible to reduce the thickening of the ink or the precipitation of the components in the vicinity of the nozzle N. Therefore, it is possible to prevent deterioration of the ejection characteristics such as the ejection amount or the ejection speed of the ink in the liquid ejection head 24. As a result, it is possible to stabilize the ink ejection characteristics of the liquid ejection head 24 for a long period of time.

A4: Details of the nozzle FIG. 4 is a cross-sectional view taken along the line BB in FIG. FIG. 4 shows a partial cross section of the liquid discharge head 24 cut along the nozzle row L in a plane parallel to the Y and Z axes. As shown in FIG. 4, each nozzle N has a first portion n1, a second portion n2, and a third portion n3. These portions are arranged in the order of the first portion n1, the second portion n2, and the third portion n3 in the Z1 direction.

The first portion n1 and the second portion n2 are through holes that communicate with each other and penetrate the first nozzle substrate 31 along the Z axis. Here, the first portion n1 is opened on the surface of the first nozzle substrate 31 facing the Z2 direction. On the other hand, the second portion n2 opens on the surface of the first nozzle substrate 31 facing the Z1 direction. On the other hand, the third portion n3 is a through hole that communicates with the above-mentioned second portion n2 and penetrates the second nozzle substrate 32 along the Z axis. The sum of the thickness T1 of the first nozzle substrate 31 and the thickness T2 of the second nozzle substrate 32 is equal to the length L of the nozzle N along the Z-axis direction.

As shown in FIG. 4, the width Wy2 of the second portion n2 in the direction along the Y axis is larger than the width Wy1 of the first portion n1 in the direction along the Y axis. Therefore, the capillary force of the ink in the nozzle N is reduced while making the characteristics such as the amount of ink ejected from the nozzle N or the ejection speed desired. Further, since the width Wy2 of the second portion n2 is larger than the width Wy1 of the first portion n1, even if the thickness T1 of the first nozzle substrate 31 is thick, the flow path resistance or inertia in the nozzle N can be reduced. There is also the advantage of being able to do it.

Further, the width Wy3 of the third portion n3 in the direction along the Y axis is smaller than the width Wy2 of the second portion n2 in the direction along the Y axis. Therefore, the pressure resistance of the ink meniscus in the third portion n3 can be made higher than that in the second portion n2.

The width Wy1 of the first portion n1 is not particularly limited, but is appropriately determined, for example, according to characteristics such as the amount of ink ejected or the ejection speed required for the nozzle N. Further, the length L1 of the first portion n1 in the direction along the Z axis is not particularly limited, but is appropriately determined according to the characteristics such as the ink ejection amount or the ejection speed required for the nozzle N.

The width Wy2 of the second portion n2 may be larger than the width Wy1 of the first portion n1 and larger than the width Wy3 of the third portion n3, but may be larger than the width of the individual flow paths P in the direction along the Y axis. It is preferably small, and more specifically, as shown in FIG. 4, it is preferably smaller than the width Da of the nozzle flow path Nf in the direction along the Y axis. By making the width Wy2 smaller than the width Da, it is possible to reduce the occurrence of crosstalk between two second portions n2 adjacent to each other in the direction along the Y axis.

Further, the length L2 of the second portion n2 in the direction along the Z axis is appropriately determined according to the width Wy2 of the second portion n2, the thickness T1 of the first nozzle substrate 31, and the like.

The width Wy3 of the third portion n3 may be smaller than the width Wy2 of the second portion n2, and may be equal to or different from the width Wy1 of the first portion n1. Further, when the width Wy3 of the third portion n3 is different from the width Wy1 of the first portion n1, it may be larger than the width Wy1 of the first portion n1 or smaller than the width Wy1 of the first portion n1. ..

When the width Wy3 of the third portion n3 is larger than the width Wy1 of the first portion n1, the flow path in the third portion n3 is smaller than the case where the width Wy3 of the third portion n3 is smaller than the width Wy1 of the first portion n1. It has the advantage that resistance can be easily reduced.

On the other hand, when the width Wy3 of the third portion n3 is smaller than the width Wy1 of the first portion n1, the width Wy3 of the third portion n3 is larger than the width Wy1 of the first portion n1 in the third portion n3. It has the advantage that it is easy to increase the meniscus resistance of the ink. The “meniscus resistance” refers to the maximum pressure at which the meniscus of the ink is maintained without being destroyed. 5 and 6 show a case where the width Wy3 of the third portion n3 is smaller than the width Wy1 of the first portion n1.

The width Wy3 of the third portion n3 of the present embodiment is smaller than the width of the individual flow path P in the direction along the Y axis, and more specifically, as shown in FIG. 4, the nozzle flow in the direction along the Y axis. It is smaller than the width Da of the road Nf. Therefore, even if the positional relationship between the third portion n3 and the individual flow path P deviates from the desired relationship in the direction along the Y axis during the manufacture of the liquid discharge head 24, the effect on the discharge characteristics of the liquid discharge head 24 is affected. Can be reduced.

Further, the length L3 of the third portion n3 in the direction along the Z axis is appropriately determined according to the width Wy3 of the third portion n3, the flow path resistance or inertia in the third portion n3, and the like. For example, the length L3 of the third portion n3 is reduced as the width Wy3 of the third portion n3 becomes smaller from the viewpoint of reducing the flow path resistance in the third portion n3. Here, the length L3 is equal to the thickness T2 of the second nozzle substrate 32. Therefore, if the mechanical strength required for the second nozzle substrate 32 can be secured, the length L3 is preferably made as small as possible from the viewpoint of reducing the flow path resistance in the third portion n3.

FIG. 5 is a perspective view of the nozzle N in the first embodiment. FIG. 6 is a cross-sectional view taken along the line CC in FIG. In FIGS. 5 and 6, the case where the above-mentioned width Wy3 is smaller than the width Wy1 is illustrated.

In the present embodiment, as shown in FIG. 5, each of the first portion n1, the second portion n2, and the third portion n3 of the nozzle N forms a columnar shape extending about the central axis CA. Therefore, as shown in FIG. 6, in a plan view, the center P1 of the first portion n1, the center P2 of the second portion n2, and the center P3 of the third portion n3 correspond to the central axis CA, respectively. In the present specification, "matching" is a concept that includes not only the case of exact matching but also the case of having a difference in degree such as manufacturing error.

Note that FIG. 5 illustrates a configuration in which the widths of the first portion n1, the second portion n2, and the third portion n3 are constant over the entire area in the direction along the Z axis, but the present invention is not limited to this. .. For example, the first portion n1, the second portion n2, or the third portion n3 may have a shape whose width changes toward the Z1 direction or the Z2 direction. Further, the center P1, P2 or P3 does not necessarily have to coincide with the central axis CA as long as the required characteristics of the nozzle N can be obtained.

Here, each of the first portion n1, the second portion n2, and the third portion n3 forms a circle in a plan view. Therefore, the width Wx1 of the first portion n1 in the direction along the X axis is equal to the above-mentioned width Wy1. Similarly, the width Wx2 of the second portion n2 in the direction along the X axis is equal to the width Wy2 described above. Further, the width Wx3 of the third portion n3 in the direction along the X axis is equal to the above-mentioned width Wy3. In the present specification, "equal" is a concept including not only the case of being strictly equal but also the case of having a difference in degree such as manufacturing error.

As described above, the above liquid discharge head 24 has an individual flow path P and a nozzle N, which are examples of flow paths. The individual flow path P circulates ink, which is an example of a liquid. The nozzle N ejects ink from the individual flow path P in the direction along the Z axis. Here, the Z axis is an example of the first axis.

As described above, the nozzle N includes a first portion n1, a second portion n2, and a third portion n3. The second portion n2 is located closer to the individual flow path P than the first portion n1 in the direction along the Z axis. The third portion n3 is located closer to the individual flow path P than the second portion n2 in the direction along the Z axis.

The width Wy1 of the first portion n1 in the direction along the Y axis is the first width, the width Wy2 of the second portion n2 in the direction along the Y axis is the second width, and the width of the third portion n3 in the direction along the Y axis. When Wy3 is the third width, the second width is larger than the first width and the third width is smaller than the second width. Here, the Y-axis is an example of a second axis that intersects the first axis.

As described above, in the liquid ejection head 24 of the present embodiment, by reducing the width Wy1 of the first portion n1, the amount of ink ejected from the nozzle N becomes too large, or the ink ejection speed from the nozzle N increases. It is possible to reduce the occurrence of the first problem that the desired speed is not reached.

Further, in the liquid discharge head 24 of the present embodiment, the width Wy2 of the second portion n2 is made larger than the width Wy1. The meniscus of the ink formed in the tube is drawn toward the individual flow path P side as the inner diameter of the tube becomes smaller, as can be seen by considering the capillary phenomenon. Therefore, if the width of the second portion n2 is small, the meniscus exceeds not only the first portion n1 but also the second portion n2 and is drawn into the individual flow path P, the meniscus breaks down, and air bubbles are mixed into the individual flow path P. There is a risk of On the other hand, in the present embodiment, the height at which the meniscus is drawn can be lowered by increasing the width Wy2. In other words, it is possible to reduce the occurrence of the second problem that air bubbles are mixed in the individual flow path P due to the destruction of the meniscus in the individual flow path P.

Further, in the liquid discharge head 24 of the present embodiment, the width Wy3 of the third portion n3 is made smaller than the width Wy2. As described above, even if the width Wy2 of the second portion n2 is increased, there is a possibility that the meniscus may break in rare cases. In that case, if the width Wy3 of the third portion n3 is large, the bubbles generated by the collapse of the meniscus easily flow through the third portion n3, so that the possibility that the bubbles reach the individual flow path P is high. On the other hand, in the present embodiment, by reducing the width Wy3 of the third portion n3, it is possible to reduce the mixing of air bubbles into the individual flow paths P even if the meniscus breaks.

In the present embodiment, the first width, which is the width Wy1 of the first portion n1, is larger than the third width, which is the width Wy3 of the third portion n3. As described above, in the third portion n3, the width Wy3 is preferably small to some extent in order to prevent air bubbles from being mixed into the individual flow path P when the meniscus breaks, but unlike the first portion n1, it has a large effect on the discharge characteristics. It is not always necessary to make the width Wy3 as small as the width Wy1 because it is not a portion that gives. Rather, in order to reduce the height at which the meniscus is drawn in, it is preferable that the width Wy3 has a certain size. Therefore, in the present embodiment, the width Wy3 is smaller than the width Wy2 and larger than the width Wy1.

Further, as described above, the centers P1, P2 and P3 of the first portion n1, the second portion n2 and the third portion n3 coincide with each other when viewed in the direction along the Z axis. Therefore, it is easy to smoothly distribute the ink in the order of the third portion n3, the second portion n2, and the first portion n1. As a result, the ejection characteristics such as the ink ejection amount or the ejection speed of the liquid ejection head 24 can be improved. Further, such an arrangement of the centers P1, P2 and P3 has an advantage that the flight bending of the ink ejected from the nozzle N can be easily reduced as compared with the case where the centers P1, P2 and P3 are not arranged.

Further, the width Wx1 of the first portion n1 in the direction along the X axis is equal to the first width which is the width Wy1 of the first portion n1 in the direction along the Y axis. Here, the X-axis is an example of a third axis that intersects both the first axis and the second axis. Since the width Wy1 and the width Wx1 are equal to each other, there is an advantage that the flight bending of the ink ejected from the nozzle N can be easily reduced as compared with the case where these widths are different from each other. In addition, there is an advantage that the first portion n1 can be easily formed by etching or the like.

Further, the width Wx2 of the second portion n2 in the direction along the X axis is equal to the second width which is the width Wy2 of the second portion n2 in the direction along the Y axis. Since the width Wy2 and the width Wx2 are equal to each other, there is an advantage that the capillary force of the ink in the second portion n2 can be easily reduced as compared with the case where these widths are different from each other. In addition, there is an advantage that the second portion n2 can be easily formed by etching or the like.

Further, the width Wx3 of the third portion n3 in the direction along the X axis is equal to the third width, which is the width Wy3 of the third portion n3 in the direction along the Y axis. Since the width Wy3 and the width Wx3 are equal to each other, there is an advantage that the third portion n3 can be easily formed by etching or the like as compared with the case where these widths are different from each other.

Further, the area when the first portion n1 is viewed in the direction along the Z axis is defined as the first area, the area when the second portion n2 is viewed in the direction along the Z axis is defined as the second area, and the third portion n3 is defined as Z. When the area seen in the direction along the axis is the third area, the second area is larger than the first area and the third area is larger than the second area. When these areas have such a magnitude relationship, the first portion n1, the second portion n2, and the third portion n3, which have the above-mentioned width relationship, can be realized.

Further, the peripheral length when the first portion n1 is viewed in the direction along the Z axis is defined as the first peripheral length, and the peripheral length when the second portion n2 is viewed in the direction along the Z axis is defined as the second peripheral length. When the circumference when the portion n3 is viewed along the Z axis is the third circumference, the second circumference is larger than the first circumference and the third circumference is smaller than the second circumference. .. When these perimeters have such a magnitude relationship, the first portion n1, the second portion n2, and the third portion n3, which have the above-mentioned width relationship, can be realized.

Here, the third length, which is the length L3 of the third portion n3 in the direction along the Z axis, is the first length, which is the length L1 of the first portion n1 in the direction along the Z axis, and along the Z axis. It is preferably smaller than each of the second length L2, which is the length L2 of the second portion n2 in the direction. As described above, the third portion n3 is a portion for reducing the mixing of air bubbles into the individual flow path P in the unlikely event that the meniscus breaks. The effect is produced by reducing the width Wy3, and has almost no effect on the length L3. On the other hand, if the length L3 is increased, the flow path resistance is increased by that amount, and the third portion n3 may affect the discharge characteristics. In view of this point, the length L3 is preferably smaller than the length L1 and the length L2.

Further, the second length, which is the length L2 of the second portion n2 in the direction along the Z axis, is preferably larger than the first length, which is the length L1 of the first portion n1 in the direction along the Z axis. Since the first portion n1 has a great influence on the discharge characteristics, it is preferable to have a certain length from the viewpoint of flow path resistance and inertia, but on the other hand, it is not necessary to increase the length so much. On the other hand, if the length of the second portion n2 is small, the pull-in of the meniscus immediately reaches the end of the second portion n2 in the Z1 direction, and the pull-in of the meniscus is suitably suppressed in the second portion n2. There is a risk that it will not be possible. Further, since the width Wy2 is large, the flow path resistance does not increase significantly even if the length L2 is increased. In view of the above points, in the present embodiment, it is preferable that the length L1 is larger than the length L3 and the length L2 is larger than both the length L1 and the length L3.

Further, the width Da of the individual flow path P in the direction along the Y axis is larger than the third width, which is the width Wy3 of the third portion n3 in the direction along the Y axis. Therefore, even if the positional relationship between the third portion n3 and the individual flow path P deviates from the desired relationship in the direction along the Y axis during the manufacture of the liquid discharge head 24, the effect on the discharge characteristics of the liquid discharge head 24 is affected. Can be reduced.

Further, the width Da of the individual flow path P in the direction along the Y axis is larger than the second width, which is the width Wy2 of the second portion n2 in the direction along the Y axis. Therefore, it is possible to reduce the occurrence of crosstalk between two second portions n2 that are adjacent to each other in the direction along the Y axis.

Further, as described above, the liquid discharge head 24 has a pressure chamber substrate 34, a communication plate 33, a first nozzle substrate 31, and a second nozzle substrate 32. The pressure chamber substrate 34 is provided with a pressure chamber C for applying pressure to the ink. The communication plate 33 is provided with an individual flow path P. The first nozzle substrate 31 is provided with a first portion n1 and a second portion n2. The second nozzle substrate 32 is provided with a third portion n3. The first nozzle substrate 31, the second nozzle substrate 32, the communication plate 33, and the pressure chamber substrate 34 are laminated in this order. Here, the nozzle N is divided into a first portion n1 and a second portion n2 provided on the first nozzle substrate 31, and a third portion n3 provided on the second nozzle substrate 32. According to this division, the nozzle N can be easily formed as compared with the case where the nozzle N is formed on the single-layer substrate.

As described above, the individual flow path P includes a nozzle flow path Nf which is an example of the first flow path and a first communication flow path Na1 which is an example of the second flow path. The nozzle flow path Nf extends along the X axis. The first communication flow path Na1 extends along the Z axis and supplies ink to the nozzle flow path Nf. The nozzle N is provided in the nozzle flow path Nf. That is, the nozzle N opens toward the nozzle flow path Nf. When pressure for ejecting ink is applied from both ends of the nozzle flow path Nf as in the present embodiment, the ink can be efficiently ejected from the nozzle N by providing the nozzle N in the nozzle flow path Nf. .. The nozzle N may be provided in the first communication flow path Na1 as in the fifth embodiment described later, as long as the desired discharge characteristics can be obtained.

Here, the individual flow path P includes a second communication flow path Na2, which is an example of the third flow path. The second communication flow path Na2 extends along the Z axis and discharges ink from the nozzle flow path Nf. Therefore, it is possible to reduce the thickening of the ink or the precipitation of the components in the vicinity of the nozzle N. As a result, it is possible to prevent deterioration of ejection characteristics such as the amount of ink ejected or the ejection speed of the liquid ejection head 24. Further, in the configuration in which the ink is circulated from the first communication flow path Na1 to the second communication flow path Na2 via the nozzle flow path Nf in this way, the pressure of the ink in the individual flow path P is affected by the above-mentioned circulation mechanism 26 and the like. Is likely to fluctuate, so that the ink meniscus in the nozzle N may become unstable. Further, when the second communication flow path Na2 is provided, in the individual flow path P, in addition to the supply ink flow from the first communication flow path Na1 to the nozzle N, the second communication flow path Na2 from the nozzle N There is a discharge ink flow towards. When air bubbles are mixed in the individual flow path P, if only the above-mentioned supply ink flow is used, the supply ink flow flows toward the nozzle N, so that the air bubbles are likely to stay in the vicinity of the nozzle N, which is a relatively problem. It is hard to occur. However, when the discharged ink flow is generated, since the discharged ink flow is a flow generated from the nozzle N, there is a high possibility that the bubbles leave the nozzle N and move to the downstream side on the discharged ink flow. As can be seen from the above description, when the second communication flow path Na2 is provided, the possibility that air bubbles are mixed in the individual flow path P is increased, and the influence when the bubbles are mixed is also increased. Therefore, when the second communication flow path Na2 is provided, the configuration of the nozzle N of the present embodiment makes it possible to exert a particularly advantageous effect.

Further, as described above, the liquid discharge head 24 further has a pressure chamber Ca which is an example of the first pressure chamber and a pressure chamber Cb which is an example of the second pressure chamber. The pressure chamber Ca communicates with the first communication flow path Na1 and applies pressure to the liquid to the ink. The pressure chamber Cb communicates with the second communication flow path Na2 to apply pressure to the ink. With such a pressure chamber Ca and a pressure chamber Cb, pressure for ejecting ink can be applied from both ends of the nozzle flow path Nf. Therefore, even in the configuration having the first communication flow path Na1 and the second communication flow path Na2, the ink can be efficiently ejected from the nozzle N. Further, as described above, since the discharged ink flow goes from the nozzle N to the second communication flow path Na2, the bubbles mixed in the communication flow path may reach the pressure chamber Cb. If air bubbles stay in the pressure chamber Cb, pressure may not be preferably applied to the liquid, which may greatly reduce the discharge characteristics. Therefore, when the pressure chamber Cb is provided, a particularly advantageous effect can be obtained by the configuration of the nozzle N of the present embodiment.

As described above, the liquid discharge device 100 described above includes a liquid discharge head 24 and a control unit 21 which is an example of a control unit. The control unit 21 controls the ink ejection operation from the liquid ejection head 24. In the above liquid discharge device 100, as described above, the liquid discharge head 24 obtains desired discharge characteristics and reduces the mixing of air bubbles from the nozzle N into the individual flow path P, so that excellent reliability is exhibited. Can be done.

B: Second Embodiment Hereinafter, the second embodiment of the present invention will be described. For the elements whose actions and functions are the same as those of the first embodiment in the embodiments illustrated 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. 7 is a perspective view of the nozzle NA in the second embodiment. FIG. 8 is a plan view of the nozzle NA in the second embodiment. In FIG. 8, similarly to FIG. 6 described above, the nozzle NA seen in the cross section corresponding to the cross section taken along the line CC in FIG. 4 is shown. As shown in FIGS. 7 and 8, the nozzle NA is the same as the nozzle N of the first embodiment described above, except that the nozzle NA has a third portion n3A instead of the third portion n3.

The third part n3A has a rectangular parallelepiped shape as shown in FIG. Further, as shown in FIG. 8, in a plan view, the center P3 of the third portion n3A coincides with the central axis CA. Here, the third portion n3A forms a rectangle having a long side along the Y axis in a plan view. Therefore, the width Wx3 of the third portion n3A in the direction along the X axis is different from the width Wy3 of the third portion n3A in the direction along the Y axis. In the example shown in FIG. 8, the width Wx3 of the third portion n3A in the direction along the X axis is smaller than the width Wy3 of the third portion n3A in the direction along the Y axis.

The same effect as that of the above-mentioned first embodiment can be obtained also by the above-mentioned second embodiment. Further, in the present embodiment, since the width Wx3 and the width Wy3 are different from each other, the meniscus pressure resistance of the ink in the third portion n3A can be increased as compared with the case where the width Wx3 and the width Wy3 are equal to each other. Here, when the area of the third portion n3A in the plan view is S3 and the peripheral length of the third portion n3A in the plan view is LC3, when the areas in the plan view are the same, the larger the LC3 / S3, the more. The meniscus pressure resistance of the ink in the third portion n3A becomes high.

C: Third Embodiment Hereinafter, the third embodiment of the present invention will be described. For the elements whose actions and functions are the same as those of the first embodiment in the embodiments illustrated 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. 9 is a perspective view of the nozzle NB in the third embodiment. FIG. 10 is a plan view of the nozzle NB according to the third embodiment. In FIG. 10, similarly to FIG. 6 described above, the nozzle NB seen in the cross section corresponding to the cross section taken along the line CC in FIG. 4 is shown. As shown in FIGS. 9 and 10, the nozzle NA is the same as the nozzle N of the first embodiment described above, except that the nozzle NA has a third portion n3B instead of the third portion n3.

As shown in FIG. 9, the third portion n3B is composed of three columnar holes. Here, each of the holes is configured in the same manner as the third portion n3 of the first embodiment described above. That is, it can be said that the nozzle NB has three third portions n3. The number, arrangement, shape, and the like of the holes constituting the third portion n3B are not limited to the examples shown in FIGS. 9 and 10, and are arbitrary.

The same effect as that of the above-mentioned first embodiment can be obtained also by the above-mentioned third embodiment. Further, in the present embodiment, since the third portion n3B is composed of a plurality of holes, a desired meniscus pressure resistance is realized as compared with the third portion n3 of the first embodiment composed of one hole. , The flow path resistance can be reduced.

C: Fourth Embodiment Hereinafter, the fourth embodiment of the present invention will be described. For the elements whose actions and functions are the same as those of the first embodiment in the embodiments illustrated 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.

C1: Flow path of the liquid discharge head FIG. 11 is a schematic view of the flow path in the liquid discharge head 24C according to the fourth embodiment. The liquid discharge head 24C is the same as the liquid discharge head 24C of the first embodiment described above, except that it has a plurality of individual flow paths Pa and a plurality of individual flow paths Pb instead of the plurality of individual flow paths P. That is, as shown in FIG. 11, the liquid discharge head 24C is provided with a plurality of nozzles N, a plurality of individual flow paths Pa, a plurality of individual flow paths Pb, a first common liquid chamber R1 and a second common liquid chamber R2. At the same time, the circulation mechanism 26 is connected.

Specifically, the liquid discharge head 24C has a surface facing the medium 11, and as shown in FIG. 11, a plurality of nozzles Na and a plurality of nozzles Nb are provided on the surface. Each of these nozzles has the same configuration as the nozzle N, NA or NB in the above-described embodiment, and ejects ink in the Z2 direction. In the following, when the nozzle Na and the nozzle Nb are not particularly distinguished, they are also simply referred to as “nozzle N”.

The plurality of nozzles Na are arranged along the Y axis, and their set constitutes the first nozzle row La. Similarly, a plurality of nozzles Nb are arranged along the Y axis, and a set thereof constitutes a second nozzle row Lb.

The first nozzle row La and the second nozzle row Lb are arranged at predetermined intervals in the direction along the X axis. Here, the arrangement pitch of the nozzle Na and the arrangement pitch of the nozzle Nb are equal to each other, but the nozzle Na and the nozzle Nb closest to each other are arranged so as to be displaced from each other at the above-mentioned pitch θ in the direction along the Y axis.

An individual flow path Pa communicates with each of the plurality of nozzles Na. Each of the plurality of individual flow paths Pa extends along the X axis and communicates with different nozzles Na. Similarly, the individual flow paths Pb communicate with each of the plurality of nozzles Nb. Each of the plurality of individual flow paths Pb extends along the X axis and communicates with different nozzles Nb. The individual flow paths Pa and the individual flow paths Pb are alternately arranged along the Y axis, and the set of the plurality of individual flow paths Pa and the plurality of individual flow paths Pb constitutes the individual flow path row 25C.

The individual flow path Pa is the same as the individual flow path P of the above-described embodiment except that the pressure chamber Cb is omitted. Specifically, the individual flow path Pa includes a first portion Pa1 and a second portion Pa2. The first portion Pa1 in each individual flow path Pa is a flow path between the upstream end E1 and the nozzle Na in the individual flow path Pa. The first portion Pa1 includes a pressure chamber Ca. On the other hand, the second portion Pa2 in each individual flow path Pa is a flow path between the downstream end E2 and the nozzle Na in the individual flow path Pa.

The individual flow path Pb is the same as the individual flow path P of the above-described embodiment except that the pressure chamber Ca is omitted. Specifically, the individual flow path Pb includes a third portion Pb1 and a fourth portion Pb2. The third portion Pb1 in each individual flow path Pb is a flow path between the upstream end E1 and the nozzle Nb in the individual flow path Pb. On the other hand, the fourth portion Pb2 in each individual flow path Pb is a flow path between the downstream end E2 and the nozzle Nb in the individual flow path Pb. The fourth portion Pb2 includes a pressure chamber Cb.

The first common liquid chamber R1 is connected to each upstream end E1 of each individual flow path Pa and each individual flow path Pb. Therefore, on the other hand, the second common liquid chamber R2 is connected to each downstream end E2 of each individual flow path Pa and each individual flow path Pb.

C2: Specific structure of the liquid discharge head FIG. 12 is a cross-sectional view taken along the line A1-A1 in FIG. FIG. 12 shows a cross section of the liquid discharge head 24C cut along the individual flow path Pa in a plane parallel to the X-axis and the Z-axis. FIG. 13 is a cross-sectional view taken along the line A2-A2 in FIG. FIG. 13 shows a cross section of the liquid discharge head 24C cut along the individual flow path Pb in a plane parallel to the X-axis and the Z-axis.

As shown in FIGS. 12 and 13, the liquid discharge head 24C described above, except that a part of the pressure chamber Ca was replaced with the horizontal communication flow path Cq1 and a part of the pressure chamber Cb was replaced with the horizontal communication flow path Cq2. It is the same as the liquid discharge head 24 of the embodiment.

As shown in FIGS. 12 and 13, the liquid discharge head 24C includes a flow path structure 30C, a plurality of piezoelectric elements 41, a housing portion 42, a protective substrate 43, and a wiring substrate 44.

The flow path structure 30C is provided with the above-mentioned first common liquid chamber R1, second common liquid chamber R2, a plurality of individual flow paths Pa, a plurality of individual flow paths Pb, and a plurality of nozzles N. Specifically, the flow path structure 30C replaces the first nozzle substrate 31, the second nozzle substrate 32, the communication plate 33, and the pressure chamber substrate 34 with the first nozzle substrate 31C, the second nozzle substrate 32C, and the communication plate 33C. It is the same as the flow path structure 30 of the above-described embodiment except that the pressure chamber substrate 34C is provided.

The first nozzle substrate 31C and the second nozzle substrate 32C are provided with a plurality of nozzles Na and a plurality of nozzles Nb. Here, the first nozzle substrate 31C is configured in the same manner as the first nozzle substrate 31 described above, except that the arrangement of the nozzle Na and the nozzle Nb is different. Similarly, the second nozzle substrate 32C is configured in the same manner as the second nozzle substrate 32 described above, except that the arrangement of the nozzle Na and the nozzle Nb is different.

The communication plate 33C includes a part of each of the first common liquid chamber R1 and the second common liquid chamber R2, a portion other than the pressure chamber Ca in the plurality of individual flow paths Pa, and the pressure chamber Cb in the plurality of individual flow paths Pb. A part to be excluded is provided.

As shown in FIG. 12, each individual flow path Pa includes the nozzle flow path Nfa, the horizontal communication flow path Cq1, the first communication flow path Na1, the second communication flow path Na2, and the supply flow path, in addition to the pressure chamber Ca described above. It has Ra1 and a discharge flow path Ra2. Of these, the nozzle flow path Nfa, the horizontal communication flow path Cq1, the first communication flow path Na1, the second communication flow path Na2, the supply flow path Ra1, and the discharge flow path Ra2 are provided in the communication plate 33C.

The nozzle flow path Nfa is a space in the groove provided on the surface of the communication plate 33C facing the Z2 direction. Here, the second nozzle substrate 32C constitutes a part of the wall surface of the nozzle flow path Nfa. Nozzle Na is provided in the nozzle flow path Nfa.

The first communication flow path Na1 communicates the pressure chamber Ca and the nozzle flow path Nfa, and guides the ink from the pressure chamber Ca to the nozzle flow path Nfa. On the other hand, the second communication flow path Na2 communicates the horizontal communication flow path Cq1 and the nozzle flow path Nfa, and guides the ink from the nozzle flow path Nfa to the horizontal communication flow path Cq1.

The horizontal communication flow path Cq1 is a space extending along the X axis. The horizontal communication flow path Cq1 communicates the second communication flow path Na2 and the discharge flow path Ra2, and guides the ink from the second communication flow path Na2 to the discharge flow path Ra2.

The supply flow path Ra1 communicates the first common liquid chamber R1 and the pressure chamber Ca, and supplies the ink from the first common liquid chamber R1 to the pressure chamber Ca. On the other hand, the discharge flow path Ra2 communicates the second common liquid chamber R2 and the horizontal communication flow path Cq1, and discharges the ink from the horizontal communication flow path Cq1 to the second common liquid chamber R2.

On the other hand, each individual flow path Pb is symmetrically configured with the above-mentioned individual flow path Pa in the direction along the X axis. Specifically, as shown in FIG. 13, each individual flow path Pb includes the nozzle flow path Nfb, the horizontal communication flow path Cq2, the third communication flow path Nb1, and the fourth communication flow path, in addition to the pressure chamber Cb described above. It has Nb2, a supply flow path Rb1, and a discharge flow path Rb2. Of these, the nozzle flow path Nfb, the horizontal communication flow path Cq2, the third communication flow path Nb1, the fourth communication flow path Nb2, the supply flow path Rb1 and the discharge flow path Rb2 are provided in the communication board 33C.

The nozzle flow path Nfb is a space in the groove provided on the surface of the communication plate 33C facing the Z2 direction. Here, the second nozzle substrate 32C constitutes a part of the wall surface of the nozzle flow path Nfb. A nozzle Nb is provided in the nozzle flow path Nfb.

The third communication flow path Nb1 communicates the horizontal communication flow path Cq2 and the nozzle flow path Nfb, and guides the ink from the horizontal communication flow path Cq2 to the nozzle flow path Nfb. On the other hand, the fourth communication flow path Nb2 communicates the pressure chamber Cb and the nozzle flow path Nfb, and guides the ink from the nozzle flow path Nfb to the pressure chamber Cb.

The horizontal communication flow path Cq2 communicates the supply flow path Rb1 and the third communication flow path Nb1 and guides the ink from the supply flow path Rb1 to the third communication flow path Nb1.

The supply flow path Rb1 communicates the first common liquid chamber R1 and the horizontal communication flow path Cq2, and supplies the ink from the first common liquid chamber R1 to the horizontal communication flow path Cq2. On the other hand, the discharge flow path Rb2 communicates the second common liquid chamber R2 and the pressure chamber Cb, and discharges the ink from the pressure chamber Cb to the second common liquid chamber R2.

The pressure chamber substrate 34C is the same as the pressure chamber substrate 34 of the above-described embodiment except that the arrangement of the pressure chamber Ca and the pressure chamber Cb is different. Specifically, as shown in FIGS. 12 and 13, the pressure chamber substrate 34C is provided with a pressure chamber Ca in the plurality of individual flow paths Pa and a pressure chamber Cb in the plurality of individual flow paths Pb. The plurality of piezoelectric elements 41 are arranged corresponding to the arrangement of the plurality of pressure chambers Ca and the plurality of pressure chambers Cb provided on the pressure chamber substrate 34C.

The same effect as that of the above-mentioned first embodiment can be obtained also by the above-mentioned fourth embodiment. Further, in the liquid discharge head 24C of the present embodiment, the flow paths of the individual flow paths Pb adjacent to the individual flow path Pa do not overlap the pressure chamber Ca and the horizontal communication flow path Cq1 of each individual flow path Pa. Similarly, the pressure chamber Cb and the lateral communication flow path Cq2 of each individual flow path Pb do not overlap the flow paths of the individual flow paths Pa adjacent to the individual flow path Pb in the direction along the Y axis. Therefore, even if the pitch θ is made smaller than that of the above-described embodiment, crosstalk between the individual flow paths Pa and the individual flow paths Pb adjacent to each other is unlikely to occur. As a result, the image quality can be improved by increasing the nozzle resolution in the direction along the Z axis as the pitch θ becomes narrower.

E: Fifth Embodiment Hereinafter, the fifth embodiment of the present invention will be described. For the elements whose actions and functions are the same as those of the first embodiment in the embodiments illustrated 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. 14 is a cross-sectional view of the liquid discharge head 24D according to the fifth embodiment. FIG. 14 shows the liquid discharge head 24D as seen in a cross section corresponding to the cross section of the A1-A1 line in FIG. 11, as in the case of FIG. 12 described above. As shown in FIG. 14, the liquid discharge head 24D is the same as the liquid discharge head 24C of the fourth embodiment described above, except that the position of the nozzle N is different. FIG. 14 shows that the position of the nozzle Na is different from that of the fourth embodiment described above. Although not shown, the position of the nozzle Nb is also different from that of the fourth embodiment. Hereinafter, the nozzle Na will be typically described.

As described above, the individual flow path P includes a nozzle flow path Nf which is an example of the first flow path and a first communication flow path Na1 which is an example of the second flow path. The nozzle flow path Nf extends along the X axis. The first communication flow path Na1 extends along the Z axis and supplies ink to the nozzle flow path Nf. The nozzle Na is provided in the first communication flow path Na1. That is, the nozzle Na opens toward the first communication flow path Na1.

The same effect as that of the above-mentioned first embodiment can be obtained also by the above-mentioned fifth embodiment. Further, as in the present embodiment, when the pressure for ejecting ink is applied from one end of the nozzle flow path Nf, the nozzle Na is provided in the first communication flow path Na1 which is susceptible to the pressure from the pressure chamber C. Ink can be efficiently ejected from the nozzle Na.

F: Sixth Embodiment Hereinafter, the sixth embodiment of the present invention will be described. For the elements whose actions and functions are the same as those of the first embodiment in the embodiments illustrated 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. 15 is a cross-sectional view of the liquid discharge head 24E according to the sixth embodiment. FIG. 16 is a cross-sectional view taken along the line B1-B1 in FIG. As shown in FIG. 15, the liquid discharge head 24E is the same as the liquid discharge head 24D of the fifth embodiment described above, except that the liquid discharge head 24E has the flow path structure 30E instead of the flow path structure 30D. Here, the flow path structure 30E is the same as the above-mentioned flow path structure 30D except that the shape of the flow path provided is different. In the following, the individual flow path Pa, which is the flow path related to the nozzle Na, will be typically described, but the individual flow path Pb, which is the flow path related to the nozzle Nb, is also an individual flow path except that it has a symmetrical shape. It is configured in the same way as Pa.

As shown in FIG. 15, the flow path structure 30E has a first nozzle substrate 31E, a second nozzle substrate 32E, and a communication plate 33E in place of the first nozzle substrate 31D, the second nozzle substrate 32D, and the communication plate 33D. Other than that, it is the same as the flow path structure 30D of the fifth embodiment described above.

The first nozzle substrate 31E is the same as the first nozzle substrate 31D of the fifth embodiment described above, except that a plurality of flow paths Na3 are provided. The second nozzle substrate 32E is the same as the second nozzle substrate 32D of the fifth embodiment described above, except that openings for a plurality of flow paths Na3 are provided.

The communication plate 33E is the same as the communication plate 33D of the fifth embodiment described above, except that the second communication flow path Na2 is omitted. Here, the nozzle flow path Nf provided in the communication plate 33E and the horizontal communication flow path Cq1 communicate with each other via the above-mentioned flow path Na3. As shown in FIG. 16, the flow path Na3 is adjacent to the second portion n2 of the nozzle N in the direction along the Y axis.

The same effect as that of the above-mentioned first embodiment can be obtained also by the above-mentioned sixth embodiment. Further, in the present embodiment, the flow path Na3 can be provided by effectively utilizing a part of the first nozzle substrate 31E and the second nozzle substrate 32E.

D: Other Embodiment The liquid discharge head 24 is not limited to the configurations exemplified in the above-mentioned first to sixth embodiments. The liquid discharge head 24 may have a configuration in which two or more configurations arbitrarily selected from the configurations exemplified in the first to sixth embodiments are combined within a range that does not contradict each other.

E: Modification example Each of the above-exemplified forms can be variously transformed. Specific modifications that can be applied to each of the above-described forms are illustrated below. The embodiments arbitrarily selected from the following examples can be appropriately merged to the extent that they do not contradict each other.

(Modification example 1)
In each of the above-described embodiments, a configuration in which the second portion n2 is provided on the first nozzle substrate 31 is exemplified, but the configuration is not limited to this configuration. For example, the second portion n2 may be provided on the second nozzle substrate 32. Further, the second portion n2 may be provided on a substrate separate from the first nozzle substrate 31 and the second nozzle substrate 32. Further, the number of substrates constituting the structure provided with the nozzle N is not limited to two of the first nozzle substrate 31 and the second nozzle substrate 32, and may be one or three or more. Further, the first nozzle substrate 31 or the second nozzle substrate 32 may be composed of a plurality of substrates or layers.

(Modification 2)
In each of the above-described embodiments, the case where the plan view shape of the third portion of the nozzle is circular or rectangular is exemplified, but the present invention is not limited to this. For example, the plan view shape of the third portion may be another polygon such as a triangle, an ellipse, or a variant such as a star or a clover. Similarly, the plan-view shape of the first part or the second part of the nozzle is not limited to each of the above-mentioned forms, and may be, for example, a polygonal shape, an elliptical shape, a star shape, a clover shape, or the like. good.

(Modification example 3)
In each of the above-described embodiments, a configuration in which the ink used for the liquid ejection head is circulated by a circulation mechanism is exemplified, but the configuration is not limited to this configuration, and a configuration without such a circulation mechanism may be used.

(Modification example 4)
The energy generating element that changes the pressure of the ink in the pressure chamber C is not limited to the piezoelectric element 41 exemplified in each of the above-described embodiments. For example, a heat generating element that fluctuates the pressure of ink by generating bubbles inside the pressure chamber C by heating may be used as an energy generating element.

(Modification 5)
In each of the above-described embodiments, the serial type liquid discharge device 100 for reciprocating the transport body 231 equipped with the liquid discharge head 24 has been illustrated, but the line type liquid discharge device in which a plurality of nozzles N are distributed over the entire width of the medium 11 is used. The present invention also applies.

(Modification 6)
In the first embodiment described above, a configuration in which width Wy1 <width Wy, width Wy3 <width Wy2, and width Wx1 <width Wx2, width Wx3 <Wx2 is described, but is not necessarily limited to this configuration. For example, a configuration in which width Wy1 <width Wy, width Wy3 <width Wy2 is satisfied but width Wx1 <width Wx2, width Wx3 <Wx2 is not satisfied, or width Wx1 <width Wx2, width Wx3 <Wx2 is satisfied, but width Wy1 < Even if the width Wy and the width Wy3 <width Wy2 are not satisfied, the width Wy1 <width Wy and the width Wy3 <width Wy2 are not satisfied, and the width Wx1 <width Wx2 and the width Wx3 <Wx2 are not satisfied. Then, the effect described in each embodiment can be obtained. However, it goes without saying that the configuration that satisfies the width Wy1 <width Wy and width Wy3 <width Wy2 described in the first embodiment and also satisfies the width Wx1 <width Wx2 and width Wx3 <Wx2 is most effective.

The liquid discharge device 100 illustrated in the above-described embodiment may be adopted in various devices such as a facsimile machine and a copier, in addition to a device dedicated to printing, and the use of the present invention is not particularly limited. However, the application of the liquid discharge device is not limited to printing. For example, a liquid discharge device that discharges a solution of a coloring material is used as a manufacturing device for forming a color filter of a display device such as a liquid crystal display panel. Further, a liquid discharge device that ejects a solution of a conductive material is used as a manufacturing device for forming wiring and electrodes on a wiring substrate. Further, a liquid discharge device that ejects a solution of an organic substance related to a living body is used, for example, as a manufacturing device for manufacturing a biochip.

21 ... Control unit (control unit), 22 ... Conveying mechanism, 23 ... Moving mechanism, 24 ... Liquid discharge head, 24C ... Liquid discharge head, 24D ... Liquid discharge head, 24E ... Liquid discharge head, 25 ... Individual flow path row, 25C ... individual flow path row, 26 ... circulation mechanism, 30 ... flow path structure, 30C ... flow path structure, 30D ... flow path structure, 30E ... flow path structure, 31 ... first nozzle substrate, 31C ... 1 nozzle substrate, 31D ... 1st nozzle substrate, 31E ... 1st nozzle substrate, 32 ... 2nd nozzle substrate, 32C ... 2nd nozzle substrate, 32D ... 2nd nozzle substrate, 32E ... 2nd nozzle substrate, 33 ... communication plate , 33C ... communication plate, 33D ... communication plate, 33E ... communication plate, 34 ... pressure chamber substrate, 34C ... pressure chamber substrate, 35 ... vibration plate, 41 ... piezoelectric element, 42 ... housing, 43 ... protective substrate, 44 ... Wiring board, 45 ... Drive circuit, 100 ... Liquid discharge device, 231 ... Transport body, 232 ... Transport belt, 261 ... First supply pump, 262 ... Second supply pump, 263 ... Storage container, 264 ... Recovery flow path, 265 ... Supply flow path, 361 ... Vibration absorber, 362 ... Vibration absorber, 421 ... Supply port, 422 ... Discharge port, C ... Pressure chamber, CA ... Central axis, Ca ... Pressure chamber, Cb ... Pressure chamber, Cq1 ... Horizontal communication Flow path, Cq2 ... Horizontal communication flow path, E1 ... End, E2 ... End, L ... Nozzle row, La ... First nozzle row, Lb ... Second nozzle row, N ... Nozzle, NA ... Nozzle, NB ... Nozzle , Na ... nozzle, Na1 ... first communication flow path (second flow path), Na2 ... second communication flow path (third flow path), Na3 ... flow path, Nb ... nozzle, Nb1 ... third communication flow path, Nb2 ... 4th communication flow path, Nf ... Nozzle flow path (1st flow path), Nfa ... Nozzle flow path (1st flow path), Nfb ... Nozzle flow path (1st flow path), P ... Individual flow path ( Flow path), P1 ... center, P2 ... center, P3 ... center, Pa ... individual flow path (flow path), Pa1 ... first part, Pa2 ... second part, Pb ... individual flow path (flow path), Pb1 ... 3rd part, Pb2 ... 4th part, R1 ... 1st common liquid chamber, R2 ... 2nd common liquid chamber, Ra1 ... supply flow path, Ra2 ... discharge flow path, Rb1 ... supply flow path, Rb2 ... discharge flow path, T1 ... thickness, T2 ... thickness, n1 ... first part, n2 ... second part, n3 ... third part, n3A ... third part, n3B ... third part, θ ... pitch.

Claims (23)

The flow path for liquid flow and
It has a nozzle for discharging the liquid from the flow path in the first direction, and has a nozzle.
The nozzle
The first part and
A second portion located closer to the flow path than the first portion in the first direction, and
Includes a third portion located closer to the flow path than the second portion in the first direction.
The width of the first portion in the second direction intersecting the first direction is the first width.
The width of the second portion in the second direction is a second width larger than the first width.
The width of the third portion in the second direction is a third width smaller than the second width.
A liquid discharge head characterized by that. The third width is smaller than the first width.
The liquid discharge head according to claim 1. The third width is larger than the first width.
The liquid discharge head according to claim 1. The centers of the first portion, the second portion and the third portion coincide with each other when viewed in the first direction.
The liquid discharge head according to any one of claims 1 to 3. When the direction intersecting both the first direction and the second direction is defined as the third direction,
The width of the first portion in the third direction is equal to the first width.
The liquid discharge head according to any one of claims 1 to 4. When the direction intersecting both the first direction and the second direction is defined as the third direction,
The width of the second portion in the third direction is equal to the second width.
The liquid discharge head according to any one of claims 1 to 5. When the direction intersecting both the first direction and the second direction is defined as the third direction,
The width of the third portion in the third direction is equal to the third width.
The liquid discharge head according to any one of claims 1 to 6, wherein the liquid discharge head is characterized in that. The area when the first portion is viewed in the first direction is the first area.
The area when the second portion is viewed in the first direction is a second area larger than the first area.
The area when the third portion is viewed in the first direction is a third area smaller than the second area.
The liquid discharge head according to any one of claims 1 to 7. The circumference when the first portion is viewed in the first direction is the first circumference.
The circumference when the second portion is viewed in the first direction is a second circumference larger than the first circumference.
The circumference when the third portion is viewed in the first direction is a third circumference smaller than the second circumference.
The liquid discharge head according to any one of claims 1 to 8. The length of the first portion in the first direction is the first length.
The length of the second portion in the first direction is the second length.
The length of the third portion in the first direction is the third length.
The liquid discharge head according to any one of claims 1 to 9. The third length is smaller than each of the first length and the second length.
The liquid discharge head according to claim 10. The second length is larger than the first length.
The liquid discharge head according to claim 10 or 11. The width of the flow path in the second direction is larger than the third width.
The liquid discharge head according to any one of claims 1 to 12, wherein the liquid discharge head. The width of the flow path in the second direction is larger than the second width.
The liquid discharge head according to claim 13. A pressure chamber substrate provided with a pressure chamber that applies pressure to the liquid,
A communication plate provided with the flow path and
A first nozzle substrate on which the first portion and the second portion are provided, and
It has a second nozzle substrate on which the third portion is provided, and has.
The first nozzle substrate, the second nozzle substrate, the communication plate, and the pressure chamber substrate are laminated in this order.
The liquid discharge head according to any one of claims 1 to 14. The flow path is
A first flow path extending in a third direction that intersects both the first direction and the second direction,
Includes a second flow path that extends in the first direction and supplies the liquid to the first flow path.
The nozzle is provided in the first flow path.
The liquid discharge head according to any one of claims 1 to 15. The flow path is
A first flow path extending in a third direction that intersects both the first direction and the second direction,
Includes a second flow path that extends in the first direction and supplies the liquid to the first flow path.
The third portion is provided in the second flow path.
The liquid discharge head according to any one of claims 1 to 15. The flow path is
A third flow path extending in the first direction and discharging a liquid from the first flow path is included.
The liquid discharge head according to claim 16 or 17. A first pressure chamber that communicates with the second flow path and applies pressure to the liquid,
It further has a second pressure chamber that communicates with the third flow path and applies pressure to the liquid.
The liquid discharge head according to claim 18. The third part is composed of a plurality of holes.
The liquid discharge head according to any one of claims 1 to 19. The flow path for liquid flow and
It has a nozzle for discharging the liquid from the flow path in the first direction, and has a nozzle.
The nozzle
The first part and
A second portion located closer to the flow path than the first portion in the first direction, and
Includes a third portion located closer to the flow path than the second portion in the first direction.
The area when the first portion is viewed in the first direction is the first area.
The area when the second portion is viewed in the first direction is a second area larger than the first area.
The area when the third portion is viewed in the first direction is a third area smaller than the second area.
A liquid discharge head characterized by that. The flow path for liquid flow and
It has a nozzle for discharging the liquid from the flow path in the first direction, and has a nozzle.
The nozzle
The first part and
A second portion located closer to the flow path than the first portion in the first direction, and
Includes a third portion located closer to the flow path than the second portion in the first direction.
The circumference when the first portion is viewed in the first direction is the first circumference.
The circumference when the second portion is viewed in the first direction is a second circumference larger than the first circumference.
The circumference when the third portion is viewed in the first direction is a third circumference smaller than the second circumference.
A liquid discharge head characterized by that. The liquid discharge head according to any one of claims 1 to 22 and
It has a control unit that controls a liquid discharge operation in the liquid discharge head.
A liquid discharge device characterized by the fact that.

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