Patent Description:
A head chip to be installed in an inkjet printer is provided with an actuator plate having a plurality of channels, and a nozzle plate bonded to the actuator plate. The nozzle plate is provided with a plurality of nozzle holes respectively communicated with the plurality of channels.

In the head chip, by changing volumes of the channels ink in the channels can by ejected through the nozzle holes.

In recent years, due to miniaturization of the channels and a decrease in pitch of the channels, the tolerance of a displacement between the actuator plate (the channels) and the nozzle plate (the nozzle holes) has decreased. For example, when a bonding position of the nozzle plate with respect to the actuator plate is shifted in an arrangement direction of the channels, there is a possibility of leading to a deterioration of ejection characteristics and a leakage of the ink.

<CIT> discloses a head chip having the features of the precharacterizing clauses of appended claim <NUM>.

<CIT>, <CIT> and <CIT> all disclose a head chip in which an intermediate plate is disposed between the actuator plate and the nozzle plate.

In <CIT>, there is disclosed a configuration in which an intermediate plate is disposed between the actuator plate and the nozzle plate. The intermediate plate is provided with communication holes communicated with both of the channels and the nozzle holes. The communication holes are formed to be larger than the channels and the nozzle holes in the arrangement direction of the channels. According to this configuration, it is conceivable that it is possible to increase the tolerance of the displacement between the channels and the nozzle holes by making the channels and the nozzle holes communicate with each other through the communication holes compared to when making the channels and the nozzle holes directly communicate with each other.

When adopting the intermediate plate, it is conceivable to adopt a method (a first method) in which the communication holes are provided to the intermediate plate, and then the intermediate plate is bonded to the actuator plate, and a method (a second method) in which the intermediate plate is bonded to the actuator plate, and then the communication holes are formed.

When the first method is adopted, a high accuracy is required in the alignment between the communication holes and the channels when bonding the intermediate plate to the actuator plate. When making the communication holes large in order to decrease the accuracy required, it is difficult to ensure the bonding area between the intermediate plate and the actuator plate. The decrease in bonding area becomes a factor of causing a detachment of the intermediate plate, a leakage of the ink, and so on.

When the second method is adopted, it is necessary to penetrate portions of the intermediate plate overlapping the channels with larger dimensions than those of the channels. Therefore, there is a possibility that the bonding surface of the actuator plate to the intermediate plate is also processed when penetrating the intermediate plate to form the communication holes. When the bonding surface is processed, there occurs a factor of causing the detachment of the intermediate plate, the leakage of the ink, and so on.

The present disclosure provides a head chip, a liquid jet head, a liquid jet recording device, and a method of manufacturing a head chip each capable of ensuring the tolerance of the displacement between the nozzle holes and the communication holes while ensuring the bonding area between the actuator plate and the intermediate plate.

In view of the problems described above, the present disclosure adopts the following aspects.

According to the present aspect, since the dimension in the second direction in the second opening part is no larger than the dimension in the second direction of the channel opening part, it is easy to ensure the bonding area of the intermediate plate to the actuator plate. As a result, it is possible to ensure the bonding strength between the intermediate plate and the actuator plate to prevent the detachment of the intermediate plate and the leakage or the like of the liquid through an area between the intermediate plate and the actuator plate.

Further, even when forming the penetrating parts as post-processing after bonding the intermediate plate and the actuator plate to each other, it is possible to prevent the damage from being inflicted on the actuator plate when processing the penetrating parts.

Moreover, since the dimension in the second direction in the first opening part is larger than the dimension in the second direction in the second opening part, it is easy to perform the alignment between the groove part and the jet hole when bonding the intermediate plate and the jet hole plate to each other compared to when directly communicate the jet holes and the jet channels with each other. In other words, it is possible to allow the displacement between the groove part and the jet hole within the dimension in the second direction in the groove part. As a result, it is possible to achieve the miniaturization of the jet channels and the reduction in pitch of the jet channels while ensuring the positioning accuracy between the jet holes and the jet channels.

As a result, it is possible to ensure the tolerance of the displacement between the jet hole and the communication hole to achieve the miniaturization of the jet channels and the reduction in pitch of the jet channels while ensuring the bonding area between the actuator plate and the intermediate plate to enhance the durability of the head chip.

In addition, since the dimension in the third direction in the penetrating part is shorter than the dimension in the third direction of the channel opening part, even when forming the penetrating part as the post processing after bonding the intermediate plate and the actuator plate to each other, it is possible to prevent the damage from being inflicted on the channel opening surface of the actuator plate when processing the penetrating part.

Further, since the formation area of the penetrating part can be made small, it is possible to shorten the processing time of the communication holes. As a result, it is possible to increase the manufacturing efficiency of the head chip.

(<NUM>) In the head chip according to aspect (<NUM>) described above, it is preferable that the channel opening surface faces to a thickness direction of the actuator plate, and the penetrating part protrudes toward both sides in the first direction with respect to the groove part.

According to the present aspect, since the dimension in the first direction in the groove part becomes smaller than that of the penetrating part, it is possible to shorten the processing time of the groove part. As a result, it is possible to increase the manufacturing efficiency.

Moreover, since the dimension in the first direction in the penetrating part becomes larger than that of the groove part, it is possible to make the penetrating part function as an ink flow channel together with the jet channel when the liquid flows along the first direction through the jet channel. Thus, it becomes easy to ensure the flow channel cross-sectional area of the ink flow channel, and thus, the pressure loss can be reduced.

(<NUM>) In the head chip according to aspect (<NUM>) described above, it is preferable that the channel opening surface faces to a thickness direction of the actuator plate, and the penetrating part protrudes toward one side in the first direction with respect to the groove part.

In particular, by making the groove part protrude in a direction in which the pressure is apt to be high out of the both sides in the first direction with respect to the groove part, it is possible to shorten the processing time of the penetrating part as much as possible while reducing the pressure loss at the one side in the first direction.

(<NUM>) In the head chip according to any of the aspects (<NUM>) through (<NUM>) described above, it is preferable that in a thickness direction of the intermediate plate, a dimension from the first opening part to a bottom surface of the groove part is larger than a dimension from the bottom surface of the groove part to the second opening part.

According to the present aspect, since the depth of the groove part can be ensured, it is possible to use a space located at the outer side in the second direction with respect to the penetrating part in the groove part as the adhesive containing part when bonding the intermediate plate and the jet hole plate to each other. Therefore, it is possible to prevent the adhesive from inflowing into the penetrating part to thereby prevent the adhesive from affecting the jet performance.

(<NUM>) In the head chip according to any of the aspects (<NUM>) through (<NUM>) described above, it is preferable that in a portion located closer to the penetrating part in the second direction in the bottom surface of the groove part, a bulging part bulging from the bottom surface is formed.

According to the present aspect, when bonding the intermediate plate and the jet hole plate to each other, a space located outside in the second direction of the bulging part in the groove part can be used as the adhesive containing part. In this case, since it is possible to restrict the adhesive from inflowing into the penetrating part with the bulging part, it is possible to prevent the adhesive from affecting the jet performance.

(<NUM>) A liquid jet head according to an aspect of the present disclosure includes the head chip according to any of the aspects (<NUM>) through (<NUM>) described above.

According to the present aspect, since the head chip according to the aspect described above is provided, it is possible to provide the liquid jet head high in quality and excellent in reliability.

(<NUM>) A liquid jet recording device according to an aspect of the present disclosure includes the liquid jet head according to the aspect (<NUM>) described above.

According to the present aspect, it is possible to provide a liquid jet recording device high in quality and excellent in reliability.

(<NUM>) A method of manufacturing a head chip according to an aspect of the present invention is defined by claim <NUM>.

(<NUM>) In the method of manufacturing the head chip according to the aspect (<NUM>) described above, it is preferable to further include an intermediate plate stacking step of stacking the intermediate plate on the channel opening surface of the actuator plate, wherein the groove part formation step is performed before the intermediate plate stacking step.

According to the present aspect, by providing the groove parts in advance to the intermediate plate, it is possible to shorten the processing time after stacking the intermediate plate until the head chip is completed.

(<NUM>) In the method of manufacturing the head chip according to the aspect (<NUM>) described above, it is preferable to further include an intermediate plate stacking step of stacking the intermediate plate on the channel opening surface of the actuator plate, wherein the groove part formation step and the penetrating part formation step are performed after the intermediate plate stacking step.

According to the present aspect, by forming the groove parts and the penetrating parts in the state in which the intermediate plate is stacked on the actuator plate, it is possible to increase the positional accuracy between the jet channels, and the communication holes.

According to an aspect of the present disclosure, it is possible to ensure the tolerance of the displacement between the jet hole and the communication hole to achieve the miniaturization of the jet channels and the reduction in pitch of the jet channels while ensuring the bonding area between the actuator plate and the intermediate plate to enhance the durability of the head chip.

Some embodiments according to the present disclosure will hereinafter be described by way of example only with reference to the drawings. In the embodiments and modified examples described hereinafter, constituents corresponding to each other are denoted by the same reference symbols to omit the description thereof in some cases. It should be noted that in the following description, expressions representing relative or absolute arrangement such as "parallel," "perpendicular," "center," and "coaxial" not only represent strictly such arrangements, but also represent the state of being relatively displaced with a tolerance, or an angle or a distance to the extent that the same function can be obtained. In the following embodiments, the description will be presented citing an inkjet printer (hereinafter simply referred to as a printer) for performing recording on a recording target medium using ink (liquid) as an example. It should be noted that the scale size of each member is arbitrarily modified so as to provide a recognizable size to the member in the drawings used in the following description.

<FIG> is a schematic configuration diagram of the printer <NUM>.

The printer (a liquid jet recording device) <NUM> shown in <FIG> is provided with a pair of conveying mechanisms <NUM>, <NUM>, ink tanks <NUM>, inkjet heads (liquid jet heads) <NUM>, ink circulation mechanisms <NUM>, and a scanning mechanism <NUM>.

In the following explanation, the description is presented using an orthogonal coordinate system of X, Y, and Z as needed. In this case, the X direction coincides with the conveying direction (a sub-scanning direction) of a recording target medium P (e.g., paper). The Y direction coincides with a scanning direction (a main scanning direction) of the scanning mechanism <NUM>. The Z direction represents a height direction (a gravitational direction) perpendicular to the X direction and the Y direction. In the following explanation, the description will be presented defining an arrow side as a positive (+) side, and an opposite side to the arrow as a negative (-) side in the drawings in each of the X direction, the Y direction, and the Z direction. In the present specification, the +Z side corresponds to an upper side in the gravitational direction, and the -Z side corresponds to a lower side in the gravitational direction.

The conveying mechanisms <NUM>, <NUM> convey the recording target medium P toward the +X side. The conveying mechanisms <NUM>, <NUM> each include a pair of rollers <NUM>, <NUM> extending in, for example, the Y direction.

The ink tanks <NUM> respectively contain four colors of ink such as yellow ink, magenta ink, cyan ink, and black ink. The inkjet heads <NUM> are configured so as to be able to respectively eject the four colors of ink, namely the yellow ink, the magenta ink, the cyan ink, and the black ink in accordance with the ink tanks <NUM> coupled thereto.

<FIG> is a schematic configuration diagram of the inkjet head <NUM> and the ink circulation mechanism <NUM>.

As shown in <FIG> and <FIG>, the ink circulation mechanism <NUM> circulates the ink between the ink tank <NUM> and the inkjet head <NUM>. Specifically, the ink circulation mechanism <NUM> is provided with a circulation flow channel <NUM> having an ink supply tube <NUM> and an ink discharge tube <NUM>, a pressure pump <NUM> coupled to the ink supply tube <NUM>, and a suction pump <NUM> coupled to the ink discharge tube <NUM>.

The pressure pump <NUM> pressurizes the inside of the ink supply tube <NUM> to deliver the ink to the inkjet head <NUM> through the ink supply tube <NUM>. Thus, the ink supply tube <NUM> is provided with positive pressure with respect to the inkjet head <NUM>.

The suction pump <NUM> depressurizes the inside of the ink discharge tube <NUM> to suction the ink from the inkjet head <NUM> through the ink discharge tube <NUM>. Thus, the ink discharge tube <NUM> is provided with negative pressure with respect to the inkjet head <NUM>. It is arranged that the ink can circulate between the inkjet head <NUM> and the ink tank <NUM> through the circulation flow channel <NUM> by driving the pressure pump <NUM> and the suction pump <NUM>.

As shown in <FIG>, the scanning mechanism <NUM> reciprocates the inkjet heads <NUM> in the Y direction. The scanning mechanism <NUM> is provided with a guide rail <NUM> extending in the Y direction, and a carriage <NUM> movably supported by the guide rail <NUM>.

The inkjet heads <NUM> are mounted on the carriage <NUM>. In the illustrated example, the plurality of inkjet heads <NUM> is mounted on the single carriage <NUM> so as to be arranged side by side in the Y direction. The inkjet heads <NUM> are each provided with a head chip <NUM> (see <FIG>), an ink supply section (not shown) for coupling the ink circulation mechanism <NUM> and the head chip <NUM>, and a control section (not shown) for applying a drive voltage to the head chip <NUM>.

<FIG> is a perspective view of the head chip <NUM> viewed from the -Z side in the state in which a nozzle plate <NUM> is detached. <FIG> is an exploded perspective view of the head chip <NUM>.

The head chip <NUM> shown in <FIG> and <FIG> is a so-called circulating side-shooting type head chip <NUM> which circulates the ink with the ink tank <NUM>, and at the same time, ejects the ink from a central portion in the extending direction (the Y direction) in an ejection channel <NUM> described later. The head chip <NUM> is provided with the nozzle plate <NUM> (see <FIG>), an intermediate plate <NUM>, an actuator plate <NUM>, and a cover plate <NUM>. The head chip <NUM> is provided with a configuration in which the nozzle plate <NUM>, the intermediate plate <NUM>, the actuator plate <NUM>, and the cover plate <NUM> are stacked on one another in this order in the Z direction. In the following explanation, the description is presented in some cases defining a direction (+Z side) from the nozzle plate <NUM> toward the cover plate <NUM> along the Z direction as an upper side, and a direction (-Z side) from the cover plate <NUM> toward the nozzle plate <NUM> along the Z direction as a lower side.

The actuator plate <NUM> is formed of a piezoelectric material such as PZT (lead zirconate titanate). The actuator plate <NUM> is a so-called chevron substrate formed by, for example, stacking two piezoelectric plates different in polarization direction in the Z direction on one another. It should be noted that the actuator plate <NUM> can be a so-called monopole substrate in which the polarization direction is unidirectional throughout the entire area in the Z direction.

<FIG> is a bottom view of the actuator plate <NUM>.

As shown in <FIG> and <FIG>, the actuator plate <NUM> is provided with a plurality of (e.g., two) channel columns <NUM>, <NUM>. In the present embodiment, the channel columns <NUM>, <NUM> correspond to a first channel column <NUM> and a second channel column <NUM>. The channel columns <NUM>, <NUM> extend in the X direction, and at the same time, are arranged at a distance in the Y direction.

The configuration of the channel columns <NUM>, <NUM> will hereinafter be described citing the first channel column <NUM> as an example.

The first channel column <NUM> has the ejection channels (jet channels) <NUM> filled with the ink, and non-ejection channels (non-jet channels) <NUM> not filled with the ink. The channels <NUM>, <NUM> each extend linearly in the Y direction (a first direction, a third direction), and at the same time, are alternately arranged side by side at intervals in the X direction (a second direction) in a plan view viewed from the Z direction. In the actuator plate <NUM>, a portion located between the ejection channel <NUM> and the non-ejection channel <NUM> constitutes a drive wall <NUM> (see <FIG>) which partitions the ejection channel <NUM> and the non-ejection channel <NUM> from each other in the X direction. It should be noted that the configuration in which the channel extension direction coincides with the Y direction will be described in the present embodiment, but the channel extension direction can cross the Y direction.

<FIG> is a cross-sectional view corresponding to a line VI-VI shown in <FIG>.

As shown in <FIG>, the ejection channel <NUM> is formed to have a circular arc shape convex downward in a side view viewed from the X direction. The ejection channels <NUM> are formed by, for example, making a dicer having a disk-like shape enter the actuator plate <NUM> from above (the +Z side) the actuator plate <NUM>. Specifically, the ejection channels <NUM> each have a first uprise part 75a located in a +Y-side end portion, a second uprise part 75b located in a -Y-side end portion, and an ejection-side penetrating part 75c located between the uprise parts 75a, 75b.

The uprise parts 75a, 75b each have a circular arc shape constant in curvature radius viewed from the X direction. The uprise parts 75a, 75b each decrease in depth in the Z direction as getting away from the ejection-side penetrating part 75c in the Y direction.

The ejection-side penetrating part 75c penetrates the actuator plate <NUM> in the Z direction in a central portion in the Y direction in the ejection channel <NUM>. Therefore, the ejection channel <NUM> has an upper-side opening part in which the whole (the uprise parts 75a, 75b and the ejection-side penetrating part 75c) of the ejection channel <NUM> opens on an upper surface of the actuator plate <NUM>, and a lower-side opening part (a channel opening part) in which only the ejection-side penetrating part 75c opens on a lower surface (a channel opening surface) of the actuator plate <NUM>.

<FIG> is a cross-sectional view corresponding to a line VII-VII shown in <FIG>.

As shown in <FIG>, the non-ejection channel <NUM> is adjacent to the ejection channel <NUM> across the drive wall <NUM> in the X direction. The non-ejection channels <NUM> are formed by, for example, making a dicer having a disk-like shape enter the actuator plate <NUM> from above the actuator plate <NUM>. The non-ejection channel <NUM> is provided with a non-ejection-side penetrating part 76a and an uprise part 76b.

The non-ejection-side penetrating part 76a penetrates the actuator plate <NUM> in the Z direction. In other words, the non-ejection-side penetrating part 76a is formed to have a uniform groove depth in the Z direction. The non-ejection-side penetrating part 76a constitutes a portion other than the +Y-side end portion in the non-ejection channel <NUM>. The non-ejection-side penetrating part 76a is opened outside the head chip <NUM> through an end surface opening part formed on an end surface facing to the -Y side in the actuator plate <NUM>.

The uprise part 76b constitutes the +Y-side end portion in the non-ejection channel <NUM>. The uprise part 76b has a circular arc shape constant in curvature radius viewed from the X direction. The uprise part 76b decreases in depth in the Z direction as getting away from the non-ejection-side penetrating part 76a in the Y direction.

As shown in <FIG> and <FIG>, the dimension in the Y direction of the non-ejection channel <NUM> (the non-ejection-side penetrating part 76a) is made larger than that of the ejection channel <NUM>. Specifically, the +Y-side end portion of the non-ejection-side penetrating part 76a constitutes a first protruding part <NUM> of the non-ejection channel protruding relative to the ejection channel <NUM> and located at the +Y side of the ejection channel <NUM> (the ejection-side penetrating part 75c). The -Y-side end portion of the non-ejection-side penetrating part 76a constitutes a second protruding part <NUM> of the non-ejection channel protruding relative to the ejection channel <NUM> and located at the -Y side of the ejection channel <NUM> (the ejection-side penetrating part 75c).

As shown in <FIG>, the second channel column <NUM> has a configuration in which the ejection channels (jet channels) <NUM> and the non-ejection channels (non-jet channels) <NUM> are arranged alternately in the X direction similarly to the first channel column <NUM>. Specifically, the ejection channels <NUM> and the non-ejection channels <NUM> in the second channel column <NUM> are arranged so as to be shifted as much as a half pitch with respect to the arrangement pitch of the ejection channels <NUM> and the non-ejection channels <NUM> in the first channel column <NUM>. Therefore, in the inkjet head <NUM> according to the present embodiment, the ejection channels <NUM> of the first channel column <NUM> and the second channel column <NUM> are arranged in a zigzag manner (a staggered manner), and the non-ejection channels <NUM> of the first channel column <NUM> and the second channel column <NUM> are arranged in a zigzag manner (a staggered manner). In other words, the ejection channel <NUM> and the non-ejection channel <NUM> are opposed to each other in the Y direction between the channel columns <NUM>, <NUM> adjacent to each other. It should be noted that the arrangement pitch of the ejection channels <NUM> and the arrangement pitch of the non-ejection channels <NUM> can arbitrarily be changed between the channel columns <NUM>, <NUM>. For example, between the channel columns <NUM>, <NUM>, the ejection channels <NUM> can be arranged so as to be opposed to each other in the Y direction, and the non-ejection channels <NUM> can be arranged so as to be opposed to each other in the Y direction.

In the channel columns <NUM>, <NUM>, the ejection channels <NUM> are formed in a plane-symmetrical manner with respect to an X-Z plane. In the channel columns <NUM>, <NUM>, the non-ejection channels <NUM> are formed in a plane-symmetrical manner with respect to the X-Z plane. In the channel columns <NUM>, <NUM>, the respective uprise parts 76b at least partially overlap each other when viewed from the X direction. It should be noted that the respective uprise parts 76b of the channel columns <NUM>, <NUM> are not required to overlap each other when viewed from the X direction.

In the actuator plate <NUM>, a portion located at the -Y side (at an opposite side to the second channel column <NUM>) of the ejection channel <NUM> (the ejection-side penetrating part 75c) of the first channel column <NUM> constitutes a first tail part <NUM>.

In the actuator plate <NUM>, a portion located at the +Y side (at an opposite side to the first channel column <NUM>) of the ejection channel <NUM> of the second channel column <NUM> constitutes a second tail part <NUM>.

<FIG> is a cross-sectional view along a line VIII-VIII shown in <FIG>.

As shown in <FIG>, on inner side surfaces (surfaces opposed to each other in the X direction in the inner surfaces of the ejection channel <NUM>) facing each of the ejection channels <NUM> in the drive walls <NUM> of the actuator plate <NUM>, there are respectively formed common electrodes <NUM>. The common electrodes <NUM> are made equivalent in length in the Y direction to the ejection-side penetrating part 75c (equivalent in length to an opening of the ejection channel <NUM> on the lower surface of the actuator plate <NUM>). The common electrodes <NUM> are each formed throughout the entire area in the Z direction on the inner side surface of the ejection-side penetrating part 75c.

As shown in <FIG>, on the lower surface of the actuator plate <NUM>, there is formed a plurality of common terminals <NUM>. The common terminals <NUM> are made to have strip-like shapes extending in the Y direction in parallel to each other. The common terminals <NUM> are each coupled to the pair of common electrodes <NUM> at an opening edge of the ejection channel <NUM> corresponding to the common terminal <NUM>. The common terminals <NUM> are each terminated on a lower surface of corresponding one of the tail parts <NUM>, <NUM>.

As shown in <FIG>, on inner side surfaces (surfaces opposed to each other in the X direction in the non-ejection channel <NUM>) facing each of the non-ejection channels <NUM> in the drive walls <NUM> of the actuator plate <NUM>, there are respectively formed individual electrodes <NUM>. The individual electrodes <NUM> are made equivalent in length in the Y direction to the non-ejection-side penetrating part 76a. The individual electrodes <NUM> are each formed throughout the entire area in the Z direction on the inner side surface of the non-ejection-side penetrating part 76a.

As shown in <FIG>, in portions located at an outer side of the common terminals <NUM> on the lower surfaces of the tail parts <NUM>, <NUM>, there are formed individual terminals <NUM>. The individual terminal <NUM> is made to have a strip-like shape extending in the X direction. The individual terminal <NUM> couples the individual electrodes <NUM> opposed to each other in the X direction across the ejection channel <NUM> at the opening edges of the non-ejection channels <NUM> which are opposed to each other in the X direction across the ejection channel <NUM>. It should be noted that in a portion located between the common terminal <NUM> and the individual terminal <NUM> in each of the tail parts <NUM>, <NUM>, there is formed a compartment groove <NUM>. The compartment grooves <NUM> extend in the X direction in the tail parts <NUM>, <NUM>. The compartment groove <NUM> separates the common terminal <NUM> and the individual terminal <NUM> from each other.

As shown in <FIG>, on the inner surface of the ejection channel <NUM>, there is formed a first protective film <NUM>. The first protective film <NUM> is formed throughout the entire inner surface of the ejection channel <NUM>. The first protective film <NUM> covers the common electrode <NUM>. The first protective film <NUM> prevents, for example, the common electrode <NUM> and the ink from making contact with each other. It should be noted that it is sufficient for the first protective film <NUM> to cover at least the common electrode <NUM> on the inner side surface of the ejection channel <NUM>.

On an inner surface of the non-ejection channel <NUM>, there is formed a second protective film <NUM>. The second protective film <NUM> is formed throughout the entire inner surface of the non-ejection channel <NUM>. The second protective film <NUM> covers the individual electrode <NUM>. The second protective film <NUM> prevents, for example, the individual electrode <NUM> and the ink from making contact with each other. It should be noted that it is sufficient for the second protective film <NUM> to cover at least the individual electrode <NUM> on the inner side surface of the non-ejection channel <NUM>.

The protective films <NUM>, <NUM> each include an organic insulating material such as a para-xylylene resin material (e.g., parylene (a registered trademark)) as a material having an insulating property. The protective films <NUM>, <NUM> can be formed of tantalum oxide (TazOs), silicon nitride (SiN), silicon carbide (SiC), silicon oxide (SiOz), diamond-like carbon, or the like, or can include at least any one of these materials.

As shown in <FIG>, a first flexible printed board <NUM> is pressure-bonded to the lower surface of the first tail part <NUM>. The first flexible printed board <NUM> is coupled to the common terminals <NUM> and the individual terminals <NUM> corresponding to the first channel column <NUM> on the lower surface of the first tail part <NUM>. The first flexible printed board <NUM> is extracted upward passing through the outside of the actuator plate <NUM>.

A second flexible printed board <NUM> is pressure-bonded to the lower surface of the second tail part <NUM>. The second flexible printed board <NUM> is coupled to the common terminals <NUM> and the individual terminals <NUM> corresponding to the second channel column <NUM> on the lower surface of the second tail part <NUM>. The second flexible printed board <NUM> is extracted upward through the outside of the actuator plate <NUM>.

As shown in <FIG> and <FIG>, the cover plate <NUM> is bonded to an upper surface of the actuator plate <NUM> so as to close the channel columns <NUM>, <NUM>. In the cover plate <NUM>, at positions corresponding to the channel columns <NUM>, <NUM>, there are formed entrance common ink chambers <NUM> and exit common ink chambers <NUM>, respectively.

The entrance common ink chamber <NUM> is formed at a position overlapping, for example, the +Y-side end portion of the first channel column <NUM> in the plan view. The entrance common ink chamber <NUM> extends in the X direction with a length sufficient for straddling, for example, the first channel column <NUM>, and at the same time, opens on an upper surface of the cover plate <NUM>.

The exit common ink chamber <NUM> is formed at a position overlapping, for example, the -Y-side end portion of the first channel column <NUM> in the plan view. The exit common ink chamber <NUM> extends in the X direction with a length sufficient for straddling the first channel column <NUM>, and at the same time, opens on the upper surface of the cover plate <NUM>.

In the entrance common ink chamber <NUM>, at positions overlapping the ejection channels <NUM> (the first uprise parts 75a) in the first channel column <NUM> in plan view, there are formed entrance slits <NUM>. The entrance slits <NUM> each make the ejection channel <NUM> and the entrance common ink chamber <NUM> communicate with each other.

In the exit common ink chamber <NUM>, at positions overlapping the ejection channels <NUM> (the second uprise parts 75b) in the first channel column <NUM> in the plan view, there are formed exit slits <NUM>. The exit slits <NUM> each make the ejection channel <NUM> and the exit common ink chamber <NUM> communicate with each other. Therefore, the entrance slits <NUM> and the exit slits <NUM> are communicated with the respective ejection channels <NUM> on the one hand, but are not communicated with the non-ejection channels <NUM> on the other hand.

The intermediate plate <NUM> is bonded to the lower surface of the actuator plate <NUM> so as to close the channel columns <NUM>, <NUM>. The intermediate plate <NUM> is formed of a piezoelectric material such as PZT similarly to the actuator plate <NUM>. The intermediate plate <NUM> is thinner in thickness in the Z direction than the actuator plate <NUM>. The intermediate plate <NUM> is made smaller in dimension in the Y direction than the actuator plate <NUM>. Therefore, at the both sides in the Y direction of the intermediate plate <NUM>, there are exposed the both end portions (the tail parts <NUM>, <NUM>) in the Y direction in the actuator plate <NUM>. In the both end portions in the Y direction in the actuator plate <NUM>, the portions exposed from the intermediate plate <NUM> function as pressure-bonding areas for the first flexible printed board <NUM> and the second flexible printed board <NUM>, respectively. It should be noted that the intermediate plate <NUM> can be formed of a material (e.g., a nonconductive material such as polyimide or alumina) other than the piezoelectric material.

As shown in <FIG>, the nozzle plate <NUM> is fixed by bonding or the like to a lower surface of the intermediate plate <NUM>. The nozzle plate <NUM> is made equivalent in width in the Y direction to the intermediate plate <NUM>. In the present embodiment, the nozzle plate <NUM> is formed of a resin material such as polyimide so as to have a thickness of about <NUM>. It should be noted that it is possible for the nozzle plate <NUM> to have a single layer structure or a laminate structure with a metal material (SUS, Ni-Pd, or the like), glass, silicone, or the like besides the resin material.

The nozzle plate <NUM> is provided with two nozzle arrays (a first nozzle array <NUM> and a second nozzle array <NUM>) extending in the X direction formed at a distance in the Y direction.

The nozzle arrays <NUM>, <NUM> each include a plurality of nozzle holes (first nozzle holes <NUM> and second nozzle holes <NUM>) each penetrating the nozzle plate <NUM> in the Z direction. The nozzle holes <NUM> and the nozzle holes <NUM> are each arranged at intervals in the X direction. Each of the nozzle holes <NUM>, <NUM> is formed to have, for example, a taper shape having an inner diameter gradually decreasing in a direction from the upper (+Z) side toward the lower (-Z) side. In the illustrated example, the maximum inner diameter (the inner diameter of an upper-side opening part) of each of the nozzle holes <NUM>, <NUM> is set no smaller than the dimension in the X direction in the ejection channel <NUM>.

<FIG> is an enlarged bottom view of the head chip <NUM> in a state in which the nozzle plate <NUM> is detached.

Here, as shown in <FIG> and <FIG>, in the intermediate plate <NUM>, at positions overlapping the nozzle holes <NUM>, <NUM> in the plan view, there are formed communication holes <NUM>. The communication holes <NUM> each make the ejection channel <NUM> and the nozzle hole <NUM>, <NUM> corresponding to each other communicate with each other out of the plurality of ejection channels <NUM> and the plurality of nozzle holes <NUM>, <NUM>. Therefore, the non-ejection channels <NUM> are not communicated with the nozzle holes <NUM>, <NUM>, but are covered with the intermediate plate <NUM> from below. It should be noted that the communication holes <NUM> have substantially the same configurations as each other. Therefore, in the following description, the detail of the communication holes <NUM> will be explained citing one of the communication holes <NUM> as an example.

The communication hole <NUM> is formed to have a step shape having a width in the X direction gradually increasing in a direction from the upper side toward the lower side when viewed from the Y direction. Specifically, the communication hole <NUM> is provided with a groove part <NUM> and a penetrating part <NUM>.

The groove part <NUM> is recessed from the lower surface of the intermediate plate <NUM>, and extends in the Y direction. The groove part <NUM> has a lower-side opening part (a first opening part) 151a opening on the lower surface of the intermediate plate <NUM>. The lower-side opening part 151a is communicated with the nozzle holes <NUM>, <NUM> through the upper-side opening part of the nozzle holes <NUM>, <NUM>. The dimension in the Y direction in the groove part <NUM> is set equivalent to a dimension in the Y direction in the ejection-side penetrating part 75c. It should be noted that the dimension in the Y direction in the groove part <NUM> can be larger or smaller than the dimension in the Y direction in the ejection-side penetrating part 75c.

A dimension in the X direction in the groove part <NUM> is larger than a maximum inner diameter of the nozzle holes <NUM>, <NUM> and a dimension in the X direction in the ejection channel <NUM>. In the present embodiment, it is preferable for the dimension in the X direction in the groove part <NUM> to be <NUM> times or more as large as the maximum inner diameter of the nozzle holes <NUM>, <NUM>, and no larger than an arrangement pitch of the ejection channels <NUM> and the non-ejection channels <NUM>.

The dimension in the Z direction in the groove part <NUM> is set no smaller than a half of a dimension in the Z direction in the intermediate plate <NUM>. In other words, a dimension in the Z direction from the lower surface of the intermediate plate <NUM> to a bottom surface of the groove part <NUM> is larger than a dimension in the Z direction from the bottom surface of the groove part <NUM> to the upper surface (the upper-side opening part 152a of the penetrating part <NUM>) of the intermediate plate <NUM>. Therefore, the bottom surface of the groove part <NUM> is located at the upper side with respect to the center in the Z direction in the intermediate plate <NUM>. It should be noted that the dimension in the Z direction in the groove part <NUM> can arbitrarily be changed.

The penetrating part <NUM> extends in the Z direction in an area including the groove part <NUM> of the intermediate plate <NUM>. The penetrating part <NUM> is communicated with the groove part <NUM> to thereby penetrate the intermediate plate <NUM>. The penetrating part <NUM> has an upper-side opening part (an upper-side opening part) 152a opening on the upper surface of the intermediate plate <NUM>. The upper-side opening part 152a is communicated with the ejection channel <NUM> through the lower-side opening part of the ejection channel <NUM> (the ejection-side penetrating part 75c).

In the present embodiment, the whole of the penetrating part <NUM> overlaps the groove part <NUM> in the plan view. Specifically, a dimension in the Y direction in the penetrating part <NUM> is made equivalent to the dimension in the Y direction in the groove part <NUM>.

A dimension in the X direction in the penetrating part <NUM> is set no larger than the dimension in the X direction in the ejection channel <NUM>. In the present embodiment, the dimension in the X direction in the penetrating part <NUM> is preferably no lower than <NUM> % and no higher than <NUM> % with respect to the dimension in the X direction in the ejection channel <NUM>, and more preferably no lower than <NUM> % and no higher than <NUM> % thereof.

A dimension in the X direction in the penetrating part <NUM> is made smaller than the dimension in the X direction in the groove part <NUM>. In the present embodiment, the penetrating part <NUM> is communicated with the groove part <NUM> in the central portion in the X direction in the groove part <NUM>. Therefore, the groove part <NUM> projects at both sides in the X direction with respect to the penetrating part <NUM>. In the internal space of the groove part <NUM>, a portion (a space located between the bottom surface of the groove part <NUM> and the upper surface of the nozzle plate <NUM>) located at both sides in the X direction with respect to the penetrating part <NUM> constitutes an adhesive containing part <NUM>. The adhesive containing part <NUM> contains a superfluous adhesive when bonding the nozzle plate <NUM> to the intermediate plate <NUM>. Thus, it is possible to prevent the adhesive from flowing into a portion overlapping the ejection-side penetrating part 75c and the nozzle holes <NUM>, <NUM> in the plan view in the communication hole <NUM>.

Then, there will hereinafter be described a case when recording a character, a figure, or the like on the recording target medium P using the printer <NUM> configured as described above.

It should be noted that it is assumed that as an initial state, the sufficient ink having colors different from each other is respectively encapsulated in the four ink tanks <NUM> shown in <FIG>. Further, there is provided the state in which the inkjet heads <NUM> are filled with the ink in the ink tanks <NUM> via the ink circulation mechanisms <NUM>, respectively.

Under such an initial state, when making the printer <NUM> operate, the recording target medium P is conveyed toward the +X side while being pinched by the rollers <NUM>, <NUM> of the conveying mechanisms <NUM>, <NUM>. Further, by the carriage <NUM> moving in the Y direction at the same time, the inkjet heads <NUM> mounted on the carriage <NUM> reciprocate in the Y direction.

While the inkjet heads <NUM> reciprocate, the ink is arbitrarily ejected toward the recording target medium P from each of the inkjet heads <NUM>. Thus, it is possible to perform recording of the character, the image, and the like on the recording target medium P.

Here, the operation of each of the inkjet heads <NUM> will hereinafter be described in detail.

In such a circulating side-shooting type inkjet head <NUM> as in the present embodiment, first, by making the pressure pump <NUM> and the suction pump <NUM> shown in <FIG> operate, the ink is circulated in the circulation flow channel <NUM>. In this case, the ink circulating through the ink supply tube <NUM> is supplied to the inside of each of the ejection channels <NUM> through the entrance common ink chambers <NUM> and the entrance slits <NUM>. The ink supplied to the inside of each of the ejection channels <NUM> circulates through the ejection channels <NUM> in the Y direction. Subsequently, the ink is discharged to the exit common ink chambers <NUM> through the exit slits <NUM>, and is then returned to the ink tank <NUM> through the ink discharge tube <NUM>. Thus, it is possible to circulate the ink between the inkjet head <NUM> and the ink tank <NUM>.

Then, when the reciprocation of the inkjet head <NUM> is started due to the translation of the carriage <NUM> (see <FIG>), the drive voltages are applied to the electrodes <NUM>, <NUM> via the flexible printed boards <NUM>, <NUM>. On this occasion, the individual electrode <NUM> is set at a drive potential Vdd, and the common electrode <NUM> is set at a reference potential GND to apply the drive voltage between the electrodes <NUM>, <NUM>. Then, a thickness shear deformation occurs in the two drive walls <NUM> partitioning the ejection channel <NUM>, and the two drive walls <NUM> each deform so as to protrude toward the non-ejection channel <NUM>. Specifically, by applying the voltage between the electrodes <NUM>, <NUM>, the drive walls <NUM> each make a flexural deformation to form a V-shape centering on an intermediate portion in the Z direction. Thus, the volume of the ejection channel <NUM> increases. Further, since the volume of the ejection channel <NUM> has increased, the ink retained in the entrance common ink chamber <NUM> is induced into the ejection channel <NUM> through the entrance slit <NUM>. The ink having been induced into the ejection channel <NUM> propagates inside the ejection channel <NUM> forming a pressure wave. The voltage applied between the electrodes <NUM>, <NUM> is set to zero at the timing when the pressure wave reaches corresponding one of the nozzle holes <NUM>, <NUM>. Thus, the drive walls <NUM> are restored, and the volume of the ejection channel <NUM> having once increased is restored to the original volume. Due to this operation, the internal pressure of the ejection channel <NUM> increases to pressurize the ink. As a result, it is possible to record the character, the image, and the like on the recording target medium P as described above by the ink shaped like a droplet being ejected outside through the communication hole <NUM> and a corresponding one of the nozzle holes <NUM>, <NUM>.

Then, a method of manufacturing such a head chip <NUM> as described above will be described. <FIG> is a flowchart for explaining the method of manufacturing the head chip <NUM>.

<FIG> are each a diagram for explaining a step of the method of manufacturing the head chip <NUM>, and are each a cross-sectional view corresponding to <FIG>. In the following description, there is described a case when manufacturing the head chip <NUM> chip by chip as an example for the sake of convenience.

As shown in <FIG>, the method of manufacturing the head chip <NUM> is provided with an intermediate plate bonding step (an intermediate plate stacking step), a communication hole formation step, a protective film formation step, and a nozzle plate bonding step (a jet hole plate stacking step). It should be noted that it is assumed that the processing necessary in advance of the intermediate plate bonding step has already been performed on each of the plates <NUM> through <NUM>.

As shown in <FIG>, in the intermediate plate bonding step, the intermediate plate <NUM> is bonded to a stacked body <NUM> having the actuator plate <NUM> and the cover plate <NUM> stacked on one another. Specifically, the intermediate plate <NUM> is bonded to the lower surface of the actuator plate <NUM> via an adhesive or the like. When performing the intermediate plate bonding step, the intermediate plate <NUM> has not yet been provided with the communication holes <NUM>.

In the communication hole formation step, the communication holes <NUM> are formed in the intermediate plate <NUM>. Specifically, in the communication hole formation step, laser processing is performed on portions overlapping the ejection channels <NUM> in the plan view in the lower surface of the intermediate plate <NUM> to thereby penetrate the intermediate plate <NUM>. In the communication hole formation step, a groove part formation step of forming the groove parts <NUM> is performed first, and then, a penetrating part formation step of forming the penetrating parts <NUM> is performed. As shown in <FIG>, in the groove part formation step, the formation areas of the groove parts <NUM> are scanned with the laser to thereby form the groove parts <NUM> recessed in a direction of getting away from the lower surface of the intermediate plate <NUM>. As shown in <FIG>, in the penetrating part formation step, by scanning the bottom surfaces of the groove parts <NUM> with the laser from below the intermediate plate <NUM>, the intermediate plate <NUM> is penetrated. Thus, the groove part <NUM> becomes communicated with the ejection channel <NUM> through the penetrating part <NUM>. An irradiation width of the laser in the X direction in the penetrating part formation step is set no larger than the dimension in the X direction in the ejection channel <NUM>. As in the present embodiment, by forming the groove parts <NUM> and the penetrating parts <NUM> in the state in which the intermediate plate <NUM> is stacked on the actuator plate <NUM>, it is possible to improve the positional accuracy between the ejection channels <NUM> and the communication holes <NUM>. It should be noted that the communication hole formation step can be achieved by etching or the like besides the laser processing.

As shown in <FIG>, in the protective film formation step, the first protective film <NUM> is formed in each of the ejection channels <NUM>, and at the same time, the protective film <NUM> is formed on the inner surface of each of the non-ejection channels <NUM>. The protective films <NUM>, <NUM> are formed by depositing a para-xylylene resin material using, for example, a chemical vapor deposition method (CVD). Specifically, in the state in which the stacked body is set in a chamber (not shown), a raw material gas to be the formation material of the protective films <NUM>, <NUM> is introduced. On this occasion, the raw material gas is introduced into the ejection channels <NUM> through the slits <NUM>, <NUM> and the communication holes <NUM>. By the raw material gas introduced into the ejection channels <NUM> adhering to the inner surfaces of the ejection channels <NUM>, the raw material is deposited on the inner surfaces of the ejection channels <NUM> as the first protective films <NUM>.

Into the non-ejection channels <NUM>, there is introduced the raw material gas through the non-ejection-side penetrating parts 76a. By the raw material gas introduced into the non-ejection channels <NUM> adhering to the inner surfaces of the non-ejection channels <NUM>, the raw material is deposited as the second protective films <NUM>.

In the nozzle plate bonding step, the nozzle plate <NUM> and the intermediate plate <NUM> are bonded to each other so that the nozzle holes <NUM>, <NUM> are communicated with the inside of the ejection channels <NUM> through the communication holes <NUM>.

Due to the steps described hereinabove, the head chip <NUM> is manufactured.

It should be noted that the head chips <NUM> can be manufactured in terms of a wafer. When manufacturing the head chips <NUM> in terms of a wafer, an actuator wafer having a plurality of actuator plates <NUM> connected to each other, a cover wafer having a plurality of cover plates <NUM> connected to each other, and an intermediate wafer having a plurality of intermediate plates <NUM> connected to each other are bonded to one another to form a wafer assembly. Subsequently, the protective films <NUM>, <NUM> are provided to the wafer assembly, and then, the wafer assembly is cut to thereby form a plurality of head chips <NUM>.

As described above, in the present embodiment, there is adopted the configuration in which the dimension in the X direction in the lower-side opening part 151a of the groove part <NUM> is larger than the dimension in the X direction in the upper-side opening part 152a of the penetrating part <NUM>, and the dimension in the X direction in the upper-side opening part 152a is no larger than the dimension in the X direction of the ejection channel <NUM> (the ejection-side penetrating part 75c).

According to this configuration, since the dimension in the X direction in the upper-side opening part 152a is no larger than the dimension in the X direction of the ejection-side penetrating part 75c, it is easy to ensure the bonding area of the intermediate plate <NUM> to the actuator plate <NUM>. As a result, it is possible to ensure the bonding strength between the intermediate plate <NUM> and the actuator plate <NUM> to prevent the detachment of the intermediate plate <NUM> and the leakage or the like of the ink through an area between the intermediate plate <NUM> and the actuator plate <NUM>.

Further, even when forming the penetrating parts <NUM> as post-processing after bonding the intermediate plate <NUM> and the actuator plate <NUM> to each other, it is possible to prevent the damage from being inflicted on the actuator plate <NUM> when processing the penetrating parts <NUM>.

Moreover, since the dimension in the X direction in the lower-side opening part 151a is larger than the dimension in the X direction in the upper-side opening part 152a, it is easy to performing the alignment between the groove part <NUM> and the nozzle holes <NUM>, <NUM> when bonding the intermediate plate <NUM> and the nozzle plate <NUM> to each other compared to when making the nozzle holes <NUM>, <NUM> and the ejection channel <NUM> directly communicate with each other. In other words, it is possible to allow the displacement between the groove part <NUM> and the nozzle holes <NUM>, <NUM> within the dimension in the X direction in the groove part <NUM>. As a result, it is possible to achieve the miniaturization of the ejection channels <NUM> and the reduction in pitch of the ejection channels <NUM> while ensuring the positioning accuracy between the nozzle holes <NUM>, <NUM> and the ejection channels <NUM>.

As a result, it is possible to ensure the tolerance of the displacement between the nozzle holes <NUM>, <NUM> and the communication hole <NUM> to achieve the miniaturization of the ejection channels <NUM> and the reduction in pitch of the ejection channels <NUM> while ensuring the bonding area between the actuator plate <NUM> and the intermediate plate <NUM> to enhance the durability of the head chip <NUM>.

In the present embodiment, there is adopted the configuration in which a dimension from the lower-side opening part 151a to the bottom surface of the groove part <NUM> is larger than a dimension from the bottom surface of the groove part <NUM> to the upper-side opening part 152a in the thickness direction (the Z direction) of the intermediate plate <NUM>.

According to the present embodiment, since the depth of the groove part <NUM> can be ensured, it is possible to use a space located at the outer side in the X direction with respect to the penetrating part <NUM> in the groove part <NUM> as the adhesive containing part <NUM> when bonding the intermediate plate <NUM> and the nozzle plate <NUM> to each other. Therefore, it is possible to prevent the adhesive from inflowing into the penetrating part <NUM> to thereby prevent the adhesive from affecting the ejection performance.

Since the inkjet head <NUM> and the printer <NUM> according to the present embodiment are each provided with the head chip <NUM> described above, it is possible to provide the liquid jet head high in quality and excellent in reliability.

In the first embodiment described above, there is described the method including the groove part formation step and the penetrating part formation step as the communication hole formation step after the intermediate plate bonding step, but this configuration is not a limitation. As shown in <FIG>, in the communication hole formation step, it is sufficient to at least have the penetrating part formation step after the intermediate plate bonding step, and it is possible to perform the groove part formation step before the intermediate plate bonding step. In other words, it is possible to form the groove parts <NUM> in advance of the bonding of intermediate plate <NUM>, and then bond the intermediate plate <NUM> provided with the groove parts <NUM> to the actuator plate <NUM>. By providing the groove parts <NUM> to the intermediate plate <NUM> in advance, it is possible to shorten the processing time after stacking the intermediate plate <NUM> until the head chip <NUM> is completed.

As shown in <FIG>, in the head chip <NUM> according to a second embodiment, the outer shape in the plan view of the communication hole <NUM> is a square shape. Specifically, in the communication hole <NUM>, the dimensions in the Y direction of the groove part <NUM> and the penetrating part <NUM> are equivalent to each other, and are made smaller than the dimension in the Y direction in the ejection-side penetrating part 75c, and larger than the maximum inner diameter of the nozzle holes <NUM>, <NUM>. It should be noted that regarding the dimensions in the X direction and the Z direction of the groove part <NUM> and the penetrating part <NUM>, it is possible to adopt dimensions substantially the same as in the first embodiment.

According to the present embodiment, since the dimension in the Y direction in the penetrating part <NUM> is shorter than the dimension in the Y direction (the third direction) of the ejection-side penetrating part 75c, even when forming the penetrating part <NUM> as the post processing after bonding the intermediate plate <NUM> and the actuator plate <NUM> to each other, it is possible to prevent the damage from being inflicted on the lower surface of the actuator plate <NUM> when processing the penetrating part <NUM>.

Moreover, by making the dimension in the Y direction (the first direction, the third direction) of each of the groove part <NUM> and the penetrating part <NUM> smaller than the dimension in the Y direction in the ejection-side penetrating part 75c, it is possible to shorten the processing time of the communication holes <NUM> in the communication hole formation process. Thus, it is possible to increase the manufacturing efficiency.

As shown in <FIG>, in the head chip <NUM> according to a third embodiment, the shape in the plan view of the communication hole <NUM> is an X shape. Specifically, the dimension in the Y direction in the groove part <NUM> is made smaller than the dimension in the Y direction in the ejection-side penetrating part 75c, and larger than the maximum inner diameter of the nozzle holes <NUM>, <NUM>.

The penetrating part <NUM> penetrates the intermediate plate <NUM> in the state of straddling an area overlapping the groove part <NUM> in the plan view in the Y direction in the intermediate plate <NUM>. In other words, the penetrating part <NUM> penetrates the intermediate plate <NUM> through the groove part <NUM> in an area overlapping the groove part <NUM>, and at the same time, penetrates the intermediate plate <NUM> at the both sides in the Y direction (the first direction) with respect to the groove part <NUM>. A portion protruding in the Y direction with respect to the groove part <NUM> in the penetrating part <NUM> constitutes a protruding part 152c. In the present embodiment, the dimension in the Y direction in the penetrating part <NUM> is made equivalent to the dimension in the Y direction in the ejection-side penetrating part 75c.

In the present embodiment, since the dimension in the Y direction in the groove part <NUM> becomes smaller than that of the penetrating part <NUM>, it is possible to shorten the processing time of the groove part <NUM>. As a result, it is possible to increase the manufacturing efficiency.

Moreover, since the dimension in the Y direction in the penetrating part <NUM> becomes larger than that of the groove part <NUM>, it is possible to make the penetrating part <NUM> function as an ink flow channel together with the ejection channel <NUM> when the liquid flows along the Y direction through the ejection channel <NUM>. Thus, it becomes easy to ensure the flow channel cross-sectional area of the ink flow channel, and thus, the pressure loss can be reduced.

As shown in <FIG>, in the head chip <NUM> according to a fourth embodiment, the penetrating part <NUM> protrudes toward one side in the Y direction (the first direction) with respect to the groove part <NUM>. A portion protruding in the Y direction with respect to the groove part <NUM> in the penetrating part <NUM> constitutes a protruding part 152c. An orientation in the Y direction of the protruding part 152c preferably coincides with a high-pressure side with reference to the nozzle holes <NUM>, <NUM> in the ejection channel <NUM>.

In the present embodiment, substantially the same functions and advantages as those in the third embodiment described above are exerted, and in addition, the penetrating part <NUM> (the protruding part 153c) is made to protrude in a direction in which the pressure is apt to become high out of the both sides in the Y direction with respect to the groove part <NUM>. Thus, it is possible to shorten the processing time of the penetrating part <NUM> as much as possible while reducing the pressure loss at one side in the Y direction.

As shown in <FIG>, in the head chip <NUM> according to a fifth embodiment, a bulging part <NUM> is formed on the bottom surface of the groove part <NUM>. The bulging part <NUM> is formed in a portion (an inner side in the X direction) located closer to the penetrating part <NUM> in the bottom surface of the groove part <NUM>. The bulging part <NUM> is formed to have a triangular shape in a cross-sectional view. Specifically, the bulging part <NUM> gradually increases in bulging amount from the bottom surface of the groove part <NUM> as proceeding toward an inner side in the X direction. The bulging part <NUM> functions as a flow stopper for preventing the adhesive contained in the adhesive containing part <NUM> from flowing into the penetrating part <NUM>. It should be noted that the cross-sectional shape of the bulging part <NUM> is not limited to the triangular shape, and can arbitrarily be changed to a rectangular shape, a semicircular shape, and so on.

In the present embodiment, when bonding the intermediate plate <NUM> and the nozzle plate <NUM> to each other, a space located outside in the X direction of the bulging part <NUM> in the groove part <NUM> can be used as the adhesive containing part <NUM>. In this case, since it is possible to restrict the adhesive from inflowing into the penetrating part <NUM> with the bulging part <NUM>, it is possible to prevent the adhesive from affecting the ejection performance.

In the embodiments described above, there is described the configuration in which the up-and-down direction of the actuator plate <NUM> coincides with the thickness direction of the actuator plate <NUM>, and the ejection channels <NUM> open in the thickness direction of the actuator plate <NUM> in a central portion (the ejection-side penetrating part 75c) in the channel extending direction as the head chip <NUM> of the side-shooting type, but this configuration is not a limitation.

As shown in <FIG> and <FIG>, a head chip <NUM> can be a so-called edge-shooting type for ejecting the ink from an end portion in the extending direction in an ejection channel <NUM>. In the following explanation, the description will be presented in some cases defining the +Y side as an obverse surface side, the -Y side as a reverse surface side, the +Z side as an upper side, and the -Z side as a lower side.

In the head chip <NUM>, an actuator plate <NUM> is provided with the ejection channel <NUM> and a non-ejection channel <NUM>. The channels <NUM>, <NUM> are alternately formed in the X direction (the second direction) in the actuator plate <NUM>.

The ejection channel <NUM> extends in the Z direction (the first direction) in the actuator plate <NUM>. The ejection channel <NUM> has a channel opening part opening on the lower end surface (the channel opening surface) of the actuator plate <NUM>. The non-ejection channel <NUM> penetrates the actuator plate <NUM> in the Z direction.

A cover plate <NUM> is bonded to the obverse surface of the actuator plate <NUM> so as to close the obverse-side opening part of each of the channels <NUM>, <NUM>. In the cover plate <NUM>, at a position overlapping the upper end portion of the ejection channel <NUM> viewed from the Y direction, there is formed a common ink chamber <NUM>. The common ink chamber <NUM> extends in the X direction with a length sufficient for straddling, for example, the channels <NUM>, <NUM>, and at the same time, opens on the obverse surface of the cover plate <NUM>.

In the common ink chamber <NUM>, at positions overlapping the respective ejection channels <NUM> viewed from the Y direction, there are formed slits <NUM>. The slits <NUM> each communicate the upper end portion of corresponding one of the ejection channels <NUM> and the inside of the common ink chamber <NUM> with each other. The slits <NUM> are communicated with the respective ejection channels <NUM> on the one hand, but are not communicated with the non-ejection channels <NUM> on the other hand.

The intermediate plate <NUM> is fixed to the lower end surface of the actuator plate <NUM> with bonding or the like. In the intermediate plate <NUM>, at positions overlapping the respective ejection channels <NUM> viewed from the Z direction, there are formed communication holes <NUM>. The communication holes <NUM> each have a groove part <NUM> and a penetrating part <NUM>, and penetrate the intermediate plate <NUM> in the Z direction similarly to, for example, the first embodiment described above. In the groove part <NUM>, a dimension in the X direction in a lower-side opening part 332a is made larger than a dimension in the X direction in an upper-side opening part 333a in the penetrating part <NUM>. The dimension in the X direction in the upper-side opening part 333a in the penetrating part <NUM> is made no larger than the dimension in the X direction of the channel opening part opening on the lower surface of the actuator plate <NUM> in the ejection channel <NUM>. It should be noted that the dimension in the Y direction (the third direction) in the penetrating part <NUM> can be larger or smaller than the dimension in the Y direction of the channel opening part.

The nozzle plate <NUM> is fixed to a lower end surface of the intermediate plate <NUM> with bonding or the like. The nozzle plate <NUM> is provided with nozzle holes <NUM>. The nozzle holes <NUM> are respectively communicated with the ejection channels <NUM> through the communication holes <NUM>.

Even when adopting the configuration according to the present disclosure in the head chip <NUM> of the edge-shooting type as in the present embodiment, substantially the same functions and advantages as in the embodiments described above can be exerted.

It should be noted that the scope of the present disclosure is not limited to the embodiments described above, but a variety of modifications can be applied within the scope of the present disclosure.

For example, in the embodiments described above, the description is presented citing the inkjet printer <NUM> as an example of the liquid jet recording device, but the liquid jet recording device is not limited to the printer. For example, a facsimile machine, an on-demand printing machine, and so on can also be adopted.

In the embodiments described above, the description is presented citing the configuration (a so-called shuttle machine) in which the inkjet head moves with respect to the recording target medium when performing printing as an example, but this configuration is not a limitation. The configuration related to the present disclosure can be adopted as the configuration (a so-called stationary head machine) in which the recording target medium is moved with respect to the inkjet head in the state in which the inkjet head is fixed.

In the embodiments described above, there is described a case when the recording target medium P is paper, but this configuration is not a limitation. The recording target medium P is not limited to paper, but can also be a metal material or a resin material, and can also be food or the like.

In the embodiments described above, there is described the configuration in which the liquid jet head is installed in the liquid jet recording device, but this configuration is not a limitation. Specifically, the liquid to be jetted from the liquid jet head is not limited to what is landed on the recording target medium, but can also be, for example, a medical solution to be blended during a dispensing process, a food additive such as seasoning or a spice to be added to food, or fragrance to be sprayed in the air.

In the embodiments described above, there is described the configuration in which the Z direction coincides with the gravitational direction, but this configuration is not a limitation, and it is also possible to set the Z direction along the horizontal direction.

In the embodiments described above, there is described the configuration in which the ejection channels <NUM> and the non-ejection channels <NUM> are arranged in a staggered manner, but this configuration is not a limitation. For example, it is possible to apply the present disclosure to the head chip <NUM> of a so-called three-cycle type in which the ink is jetted in sequence from all of the channels.

In the embodiments described above, there is described the configuration in which the actuator plate <NUM>, the intermediate plate <NUM>, and the nozzle plate <NUM> are sequentially bonded to one another, but this configuration is not a limitation. It is possible to dispose another member between the actuator plate <NUM> and the intermediate plate <NUM>, or between the intermediate plate <NUM> and the nozzle plate <NUM>. In this case, regarding the jet hole plate stacking step and the intermediate plate stacking step related to the present disclosure, it is not limited to a case where a stacking object is directly bonded to a stacking target object (e.g., the case where the stacking object is the jet hole plate, the stacking target object is the intermediate plate), and as long as the configuration in which the stacking object is stacked on at least the stacking target object, it is possible to bond the stacking object on another member in a state in which the another member is bonded on the stacking target object. Further, even when the stacking object is directly stacked on the stacking target object, the stacking object and the stacking target object can be stacked with a method other than bonding.

Claim 1:
A head chip (<NUM>) comprising:
an actuator plate (<NUM>) in which a plurality of jet channels (<NUM>) extending in a first direction (Y) is arranged in a second direction (X) crossing the first direction;
a jet hole plate (<NUM>) which has a plurality of jet holes (<NUM>, <NUM>) configured to jet liquid, and which is disposed so as to be opposed to a channel opening surface on which the jet channels open in the actuator plate; and
an intermediate plate (<NUM>) which has communication holes (<NUM>) configured to respectively communicate the jet channels (<NUM>) and the jet holes (<NUM>, <NUM>) with each other, and which is disposed between the actuator plate and the jet hole plate, wherein
the communication holes each include
a groove part (<NUM>) which has a first opening part opening (151a) toward the jet hole (<NUM>, <NUM>), and which is recessed toward a direction getting away from the jet hole plate, and
a penetrating part (<NUM>) which has a second opening part (152a) opening toward the jet channel (<NUM>), and which is communicated with the groove part in an area including at least the groove part to thereby penetrate the intermediate plate, and
a dimension in the second direction (X) in the first opening part (151a) is larger than a dimension in the second direction (X) in the second opening part (152a), characterized in that
a dimension in the second direction (X) in the second opening part (152a) is no larger than a dimension in the second direction (X) of a channel opening part (75c) opening on the channel opening surface in the jet channel, and
defining a direction crossing the second direction (X) when viewed from a thickness direction (Z) of the intermediate plate as a third direction (Y), a dimension in the third direction in the penetrating part (<NUM>) is smaller than a dimension in the third direction in the channel opening part (75c).