LIQUID EJECTION HEAD AND LIQUID EJECTION APPARATUS

The present invention provides a liquid ejection head and a liquid ejection apparatus that can join the ejection member to the ejection member joining surface with a sufficient joining area, and suppress a decrease in joining reliability. To this end, second supply ports are provided in side portions of an ejection member.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a liquid ejection head and a liquid ejection apparatus that eject liquid.

Description of the Related Art

Japanese Patent Laid-Open No. 2019-14172 discloses the following configuration as a liquid ejection head that ejects circulated liquid. In the configuration, a flow passage is formed by stacking multiple plate-shaped members in which through-holes are formed, and the liquid is supplied from a common flow passage to each of liquid ejection element substrates via a pitch conversion flow passage.

In recent years, there is a demand for reducing the width of an ejection element substrate as one means of cost reduction. Moreover, there is a demand for increasing the number of supply ports to improve printing speed and handle high-viscosity liquid.

However, in the case where these demands are handled in the method of Japanese Patent Laid-Open No. 2019-14172, since the flow passage and a joining area between each ejection element substrate and the flow passage member are on the same plane, there is a possibility that the joining area becomes small and joining reliability decreases.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a liquid ejection head and a liquid ejection apparatus that can suppress a decrease in joining reliability.

A liquid ejection head of the present invention includes: an ejection element plate on which an ejection element is arranged, the ejection element configured to generate energy for ejecting liquid; an ejection port formation member that is stacked on the ejection element plate and that is provided with an individual liquid chamber and an ejection port corresponding to the ejection element; and a first common flow passage that is capable of supplying the liquid to the individual liquid chamber via a first supply port penetrating the ejection element plate, in which a second supply port that supplies the liquid to the first common flow passage in a first direction is arranged in the first common flow passage, the first direction intersecting an ejection direction in which the liquid is ejected from the ejection port.

The present invention can provide a liquid ejection head and a liquid ejection apparatus that can suppress a decrease in joining reliability.

DESCRIPTION OF THE EMBODIMENTS

First Embodiment

A first embodiment of the present invention is described below with reference to the drawings.

FIGS.1A and1Bare diagrams illustrating a liquid ejection head1in the present embodiment,FIG.1Ais a perspective diagram illustrating an ejection member2in an understandable manner, andFIG.1Bis a bottom diagram illustrating the ejection member2in an understandable manner. In the diagrams described below, an X direction is a width direction of the liquid ejection head1, a Y direction is an arranging direction of ejection ports that is a direction intersecting the X direction, and a Z direction is an ejection direction of liquid. The liquid ejection head1includes the ejection member2, a flow passage member3, a face cover4, and an electric connection member5. The liquid is supplied from a not-illustrated liquid supply unit connected to the flow passage member3to the ejection member2by passing through the flow passage member3, and is collected into the liquid supply unit by passing through the flow passage member3again. A liquid ejection apparatus drives ejection elements formed in the ejection member2via the electric connection member5. The ejection elements thereby generate energy for ejection of the liquid, and the liquid is ejected from the ejection ports. A sealing member61seals a gap between the face cover4and the ejection member2.

FIG.2Ais a cross-sectional diagram along the line IIa-IIa inFIG.1B,FIG.2Bis a cross-sectional diagram illustrating the ejection member2, andFIG.2Cis a perspective diagram illustrating the ejection member2. The arrows Fa and Fb illustrate a flow of the liquid.

In the ejection member2, an ejection element plate221is supported on a bottom surface plate226, and multiple ejection elements212are linearly arranged in the Y direction on the ejection element plate221to form an ejection element array. The ejection member2is divided into an ejection side region21and a back surface side region22with a surface on which the ejection elements212are formed being a boundary. In the ejection side region21, an ejection port formation member214is formed on the ejection element plate on which the ejection elements212are formed, and an individual liquid chamber213and an ejection port211are provided at a position corresponding to each of the ejection elements212. In the back surface side region22, two first common flow passages222aand222bare provided on the opposite surface side of the ejection element plate221to the ejection elements212. The first common flow passages222aand222bare surrounded by a partition225provided to stand in the Z direction along the ejection element array and the bottom surface plate226provided parallel to the ejection element plate221.

Moreover, the first common flow passages222aand222bare provided to be capable of supplying the liquid to the individual liquid chambers213, and communicate with the ejection side region21via first flow passage ports224aand224b, provided to penetrate the ejection element plate221, to allow the liquid to pass. Furthermore, the first common flow passages222aand222bcommunicate with second common flow passages31aand31bto be described later via second flow passage ports223aand223b, provided in both end portions of the ejection member2in the X direction in the back surface side region22, to allow the liquid to pass. The second flow passage ports223aand223bare provided to extend in the Y direction.

In the present embodiment, the ejection element plate221, the partition225, and the bottom surface plate226use Si as a base material, are bonded to one another in a state of wafers, and are cut out to form the ejection member2. Bonding of the wafers can achieve high flatness accuracy of bonding surfaces and high registration accuracy. Accordingly, bonding is possible also in a configuration including fine parts such as the first flow passage ports224and the partition225, and joining with high reliability can be performed.

Manufacturing processes of the ejection member2are described below. First, the ejection elements212and the first flow passage ports224are formed such that such that multiple ejection element plates221are arranged on one Si wafer. The ejection port formation member214is joined onto this Si wafer, and the individual liquid chamber213and the ejection port211are formed at positions corresponding to each ejection element212. The first common flow passages222and the second flow passage ports223are formed in another Si wafer to be arranged at positions corresponding to the ejection element plates221such that portions to be the partition225and the bottom surface plate226are left.

The two wafers formed as described above are bonded to each other, and individual ejection members2are then cut out in a dicing process. The first flow passage ports224, the first common flow passages222, and the second flow passage ports223are formed by a wet etching or dry etching process. The ejection member2is thus formed.

Although the partition225and the bottom surface plate226are integrally formed in the present embodiment, other configurations may be used. For example, the configuration may be such that the ejection element plate221and the partition225are formed integrally in the same wafer, and are bonded to a wafer in which the bottom surface plate226is formed, and then the individual ejection members are cut out by dicing. Moreover, the configuration may be such that the ejection element plate221, the partition225, and the bottom surface plate226are formed on separate wafers, respectively, the three wafers are bonded to one another, and then the individual ejection members2are cut out by dicing.

The flow passage member3is provided with grooves for forming the second common flow passages31aand31b. An ejection member joining surface32is provided between these grooves by a recessed step having a depth that is substantially the same as the thickness of the ejection member2, from a flow passage member ceiling surface33. The ejection member2is joined onto the ejection member joining surface32by adhesive62. Moreover, the face cover4having an opening matching an outer shape of the ejection member2is joined to the flow passage member ceiling surface33, and the sealing member61seals a gap between the face cover4and the ejection member2.

The aforementioned configuration forms a liquid supply flow passage that is illustrated by the arrow Fa in the drawings and that supplies the liquid to the individual liquid chambers213and a liquid collection flow passage that is illustrated by the arrow Fb in the drawings and that is provided to be capable of collecting the liquid from the individual liquid chambers213.

FIGS.3A and3Bare drawings illustrating a comparative example, and are drawings illustrating a general configuration in a conventional circulation-type liquid ejection head. In the general liquid ejection head, second flow passage ports227are provided in the bottom surface plate226. In this case, the flow passage port (supply port)227aon the liquid supply side and the flow passage port (collection port)227bon the liquid collection side are provided on the same plane. In the case where a distance between the flow passage port227aon the liquid supply side and the flow passage port227bon the liquid collection side are small, in the joining of the ejection member2and the flow passage member3to each other, occurrence of a leak due to insufficient joining or blocking of the flow passage ports due to running over of the adhesive to the flow passage ports227is conceivable.

Meanwhile, in the case where a sufficient distance (arrow portion inFIG.3B) is provided between the flow passage port227aon the liquid supply side and the flow passage port227bon the liquid collection side to secure joining reliability, the number of installable flow passage ports is limited. Accordingly, the distance for which the liquid flows in the first common flow passages increases, and a liquid supply performance in the case where a high-viscosity liquid is used or in the case where the printing is performed at high speed may be insufficient.

FIG.4is a perspective diagram illustrating part of the ejection member2and the flow passage member3in the present embodiment. In order to facilitate viewing, the face cover4is not illustrated inFIG.4. The second flow passage ports223are opened over the entire region in the Y direction that is the arranging direction of the ejection ports211. This can achieve sufficient liquid supply performance also in the case where the high-viscosity liquid is used and the case where the printing is performed at high speed. Moreover, in the ejection member2and the flow passage member3, the ejection member joining surface32is bonded to the bottom surface plate226of the ejection member2over the entire region thereof by adhesive, and a sufficient joining width can be secured. Furthermore, since the second flow passage ports223are provided in side portions of the ejection member2, it is possible to suppress flow-in of the adhesive62used for joining of the ejection member2and the ejection member joining surface32.

As described above, according to the configuration of the present embodiment, it is possible to achieve a liquid ejection head having a high liquid supplying performance and high joining reliability.

Note that, in the case where the liquid is supplied from the side portion of the ejection member2, for example, it is conceivable to provide the flow passage ports on side surfaces of the ejection port formation member214that is in the ejection side region21. However, this is assumed to be unsuitable due to the following points. Specifically, the heights of the individual flow passages and the ejection ports greatly affect the ejection of the liquid, and the dimensions cannot be easily changed. In order to achieve the liquid supply performance corresponding to the high-viscosity liquid or the high-speed printing, it is necessary to secure a certain level of height of the flow passage ports. However, due to relationships with the height of the ejection ports, achieving such a level of height together with the ejection performance is difficult. Moreover, the flow passage needs to be sealed in a very thin region (region with small height), and there are great challenges in manufacturing. Accordingly, a configuration in which the second flow passage ports are provided in the back surface side region22as in the present invention is preferable.

As in the present embodiment, the second flow passage ports223aand223bare provided in the side portions of the ejection member2. This configuration can prevent the second flow passage ports from affecting the joining portion of the ejection member2even in the case where the width of an ejection element substrate is reduced, and also allows an increase in the number of flow passage ports to be easily handled.

As described above, according to the present embodiment, it is possible to join the ejection member2to the ejection member joining surface32with a sufficient joining area, and a liquid ejection head with high reliability can be obtained.

Modified Example 1

FIG.5is a perspective diagram illustrating an ejection member50in Modified Example 1 and its surroundings. Second flow passage ports51included in the ejection member50are not provided over the entire region of the ejection member50, but are provided while being divided into multiple ports, and a side wall52is provided between each adjacent two of the second flow passage ports51. Providing the side walls52can improve mechanical strength of the ejection member50. The number of installed second flow passage ports51and the dimensions thereof may be determined depending on a balance between the required liquid ejection performance and the required mechanical strength.

Modified Example 2

FIGS.6A to6Eare diagrams illustrating the ejection member2in Modified Example 2 and its surroundings. Second flow passage ports63inFIG.6Aare provided to extend from the side portions of the back surface side region22and to portions of a bottom surface plate64. In the case where a sufficient joining area for the bottom surface plate64can be secured, such a configuration may be used. Using such a configuration can achieve a high supply performance by securing the width of the second common flow passages as illustrated inFIG.6Bor can reduce the size of the head as a whole including the supply flow passages as illustrated inFIG.6C.

Moreover, inFIG.6D, assuming that the ejection direction is the upward direction, second flow passage ports65are provided to be shifted toward a bottom surface plate67(lower side) and, inFIG.6E, second flow passage ports66are provided to be shifted toward an ejection element plate68(upper side). In the case where the sealing member61or the adhesive62tends to enter the second flow passage ports65and66due to the dimensions of the parts or the physical properties of the material, using these configurations can suppress the entering.

Modified Example 3

FIGS.7A to7Care cross-sectional diagrams illustrating the ejection member2in Modified Example 3 and its surroundings. As illustrated inFIG.7A, the configuration may be such that the face cover4is provided to partially cover an upper surface of the ejection member2, and the ejection member2and the face cover4are directly bonded to each other. Moreover, as illustrated inFIG.7B, the configuration may be such that a bonding film70is attached to the gap between the ejection member2and the face cover4to seal the gap between the ejection member2and the face cover4. Furthermore, as illustrated inFIG.7C, the configuration may be such that the face cover4receives a back surface of an ejection element plate71, and the ejection element plate71and the face cover4are directly bonded to each other.

Modified Example 4

FIGS.8A and8Bare diagrams for explaining a configuration in the case where there are two ejection element arrays, as Modified Example 4.FIG.8Ais a cross-sectional diagram illustrating the ejection member2and its surroundings, andFIG.8Bis a diagram illustrating the bottom surface plate226of the ejection member2.

In the present modified example, the liquid flowing from a second flow passage port223ainto a first common flow passage222aenters an individual liquid chamber213a, and is then collected into a common flow passage31bvia a common flow passage90aand a second flow passage port227a. Moreover, the liquid supplied from a common flow passage31cto an individual liquid chamber213bvia a second flow passage port227band a common flow passage90bis then collected from a second flow passage port223bvia a first common flow passage222b. As described above, the configuration of the present modified example is applied to provide the second flow passage port223aand the second flow passage port223bcorresponding to the outermost ejection element arrays in the side portions. This allows more second flow passage ports227to be installed than in the case where the flow passage ports corresponding to all ejection element arrays are provided in the bottom surface plate226, and higher liquid supply performance can be achieved.

FIGS.9A and9Bare diagrams illustrating comparative examples to Modified Example 4. These diagrams illustrate cases where the second flow passage ports corresponding to all ejection element arrays are provided as through-holes in the bottom surface plate.FIG.9Ais a diagram corresponding to two ejection element arrays, andFIG.9Bis a diagram corresponding to three ejection element arrays.

In the case where the second flow passage ports227corresponding to all ejection element arrays are provided in the bottom surface plate226, as the number of the ejection element arrays increases, the number of the second flow passage ports227arrangeable for each ejection element array decreases, from the viewpoint of securing the joining area. Moreover, the number of the second flow passage ports227arrangeable for each ejection element array in the case corresponding to the three ejection element arrays inFIG.9Bis even smaller than that in the case corresponding to the two ejection element arrays inFIG.9A.

FIG.10is a schematic diagram illustrating a liquid ejection apparatus10to which the present embodiment can be applied. The liquid ejection apparatus10includes the liquid ejection head1that ejects the liquid, a carriage12that is movable along guide rails11and in which the liquid ejection head1can be mounted, and a supply source14that supplies the liquid to the liquid ejection head1via supply tubes13. The liquid ejection head1performs printing on a medium15by ejecting the liquid to the medium15that is conveyed. The liquid ejection head1is provided with many ejection ports, and the liquid is ejected from the ejection ports by driving actuators such as heaters.

Second Embodiment

A second embodiment of the present invention is described below with reference to the drawings. Note that, since a basic configuration of the present embodiment is the same as that of the first embodiment, characteristic configurations are described below. The first embodiment has a configuration in which the liquid is circulated by passing the individual liquid chambers213, while the present embodiment has a configuration in which the liquid in the individual liquid chambers213is not collected and the liquid is not circulated.

FIG.11is a cross-sectional diagram illustrating the ejection member2in the present embodiment and its surroundings. One first common flow passage222and one second common flow passage31are provided for each of the two ejection element arrays. Different types of liquid are supplied to the two ejection element arrays, respectively, through routes of Fa and Fb. Also in the present embodiment, the second flow passage ports223aand223bare provided in the side portions of the ejection member2, and this allows the ejection member2and the flow passage member3to be joined to each other over the entire region of the bottom surface plate226.

This can achieve a liquid ejection head that can achieve both high joining reliability and a high liquid ejection performance even in the case where the size of the ejection member2is reduced.

Modified Example 5

FIGS.12A and12Bare each a cross-sectional diagram illustrating a liquid ejection head including three or more ejection element arrays in the configuration in which the liquid is not circulated. InFIG.12A, the liquid ejection head includes three ejection element arrays and, inFIG.12B, the liquid ejection head includes four ejection element arrays. In the case where the liquid ejection head includes three ejection element arrays as illustrated inFIG.12A, a second flow passage port110corresponding to the ejection element array located at the center is provided in the bottom surface plate226, and the second flow passage ports223aand223bcorresponding to the two ejection element arrays on the outer sides are provided in the side portions. The liquid to the second flow passage port110is supplied from a common flow passage31b.

Moreover, in the case where four ejection element arrays are provided as inFIG.12B, the liquid is supplied from second flow passage ports111and112provided in the bottom surface plate, to common flow passages222cand222dinterposed between the first common flow passages222aand222bon the outer sides. From the viewpoint of securing the joining area, the second flow passage ports111and112corresponding to the two ejection element arrays located at the center are arranged to be shifted toward the first common flow passages222aand222bon the outer sides, respectively. The liquid is supplied from the common flow passage31bto the common flow passage222cvia the second flow passage port111, and the liquid is supplied from the common flow passage31cto the common flow passage222dvia the second flow passage port112. This can secure a larger joining area than that in the case where the second flow passage ports corresponding to all arrays are provided in the bottom surface plate, and can achieve a liquid ejection head that can achieve both of high joining reliability and a high liquid supply performance.

Other Embodiments

The embodiments and modified examples described above can be carried out while being appropriately combined with one another as long as such a combination is possible.

This application claims the benefit of Japanese Patent Application No. 2022-132814 filed Aug. 23, 2022, which is hereby incorporated by reference wherein in its entirety.