Liquid ejecting head and liquid ejecting apparatus

Abstract

To provide: a liquid ejecting head in which deformation of a fixing plate is suppressed; and a liquid ejecting apparatus.SOLUTION: A liquid ejecting head includes: a plurality of first head chips each having a first nozzle that ejects a liquid; a fixing plate 40 to which the first head chips are fixed and which includes first exposure openings for exposing the plurality of first nozzles; a holder 30 that holds the first head chips between the fixing plate 40 and the holder 30; and a reinforcing plate 50 disposed between the holder 30 and the fixing plate 40. Therein the reinforcing plate 50 includes first openings surrounding respectively the first exposure openings, and through holes 54 at positions different from the first openings when viewed in the lamination direction of the fixing plate 40 and the reinforcing plate 50. Therein the through holes 54 are closed with a first adhesive 72.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a liquid ejection head that ejects liquid from nozzles and a liquid ejection apparatus. [Background technology]

[0002] 2. Description of the Related Art Liquid ejection apparatuses including a liquid ejection head that ejects liquid such as ink, such as ink jet printers, are known in the art.

[0003] The liquid ejection head includes a head chip provided with nozzles for ejecting liquid, a holder for holding the head chip, a fixed plate provided on the liquid ejection surface side of the head chip, and a reinforcing plate for reinforcing the fixed plate. The reinforcing plate is provided with through holes such as an insertion hole for inserting a protrusion for electrically connecting the holder and the fixed plate, and a sensor exposure hole for exposing a temperature sensor on the fixed plate side (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-185739 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a through hole is formed in the reinforcing plate as in the conventional technology, the strength of the portion of the fixed plate facing the through hole is reduced, and there is a risk that the fixed plate will deform when the medium collides with the fixed plate due to poor medium transport, etc. [Means for solving the problem]

[0006] An aspect of the present invention that solves the above problem is a liquid ejection head comprising: a first head chip having a plurality of first nozzles for ejecting liquid; a fixed plate to which the first head chip is fixed and having a first exposed opening for exposing the plurality of first nozzles; a holder that holds the first head chip between the fixed plate and the holder; and a reinforcing plate arranged between the holder and the fixed plate, wherein the reinforcing plate has, when viewed in the stacking direction of the fixed plate and the reinforcing plate, a first opening that surrounds the first exposed opening and a through hole at a position different from the first opening, and the through hole is blocked by a first adhesive.

[0007] Another aspect of the present invention is a liquid ejection apparatus comprising: the liquid ejection head described above; and a liquid storage section that stores liquid to be supplied to the liquid ejection head. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a liquid ejecting apparatus according to a first embodiment of the present invention. [Diagram 2] 1 is an exploded perspective view of a liquid jet head according to a first embodiment of the present invention. [Diagram 3] FIG. 2 is a plan view of a holder and a head chip according to the first embodiment of the present invention. [Figure 4] 1 is a cross-sectional view of a liquid jet head according to a first embodiment of the present invention. [Diagram 5] 1 is an enlarged cross-sectional view of a main part of a liquid jet head according to a first embodiment of the present invention. [Figure 6] 1 is a plan view of a main portion of a reinforcing plate according to a first embodiment of the present invention. [Figure 7] 6 is a cross-sectional view of a liquid jet head according to a second embodiment of the present invention. [Figure 8] 6 is an enlarged cross-sectional view of a main part of a liquid jet head according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention will be described in detail below based on an embodiment. However, the following description shows one aspect of the present invention and can be arbitrarily modified within the scope of the present invention. In each drawing, the same reference numerals indicate the same members, and the description is omitted as appropriate. In each drawing, X, Y, and Z represent three spatial axes that are mutually orthogonal. In this specification, the directions along these axes are defined as the X direction, the Y direction, and the Z direction. The direction in which the arrow in each drawing points is defined as the positive (+) direction, and the opposite direction to the arrow is defined as the negative (-) direction. In addition, the directions of the three spatial axes that are not limited to the positive and negative directions are defined as the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0010] (Embodiment 1) FIG. 1 is a diagram showing a schematic configuration of a liquid ejecting apparatus 1 according to a first embodiment of the present invention.

[0011] 1, the liquid ejecting device 1 is a so-called serial printer that includes a liquid ejecting head H and prints by ejecting liquid from the liquid ejecting head H toward the medium S in the +Z direction while transporting the medium S in the X-axis direction and reciprocating the liquid ejecting head H in the Y-axis direction. Note that the medium S can be made of any material, such as cloth, recording paper, or a resin film.

[0012] Such a liquid ejecting device 1 includes a liquid ejecting head H, a liquid storage section 3, a control unit 4 which is a control section, a transport mechanism 5 which feeds out the medium S, and a moving mechanism 6.

[0013] The liquid ejection head H ejects liquid supplied from a liquid storage unit 3 that stores the liquid as droplets in the +Z direction.

[0014] The liquid storage section 3 individually stores a plurality of types of liquids having different colors and components to be ejected from the liquid ejection head H. Examples of the liquid storage section 3 include a cartridge that can be attached to and detached from the liquid ejection device 1, a bag-shaped ink pack formed of a flexible film, and an ink tank that can be refilled with ink. FIG. 1 illustrates one liquid storage section 3. Incidentally, the liquid storage section 3 may be a liquid storage section 3 having separate chambers that individually store a plurality of types of liquid, or may be a plurality of liquid storage sections 3 that are individually provided according to the plurality of types of liquid. The liquid storage section 3 may be divided into a main tank and a sub-tank. The sub-tank may be connected to the liquid ejection head H, and the liquid consumed by ejecting droplets from the liquid ejection head H may be refilled from the main tank to the sub-tank.

[0015] The control unit 4 comprehensively controls each element of the liquid ejecting device 1, that is, the liquid ejecting head H, the transport mechanism 5, the moving mechanism 6, and the like.

[0016] The transport mechanism 5 transports the medium S in the X-axis direction and has a transport roller 5a. The transport mechanism 5 transports the medium S in the X-axis direction by rotating the transport roller 5a. The transport roller 5a rotates by driving a transport motor (not shown). The control unit 4 controls the transport of the medium S by controlling the driving of the medium transport motor. Note that the transport mechanism 5 that transports the medium S is not limited to one having the transport roller 5a, and may transport the medium S by, for example, a belt or a drum.

[0017] The movement mechanism 6 is a mechanism for reciprocating the liquid ejection head H in the Y-axis direction, and includes a holder 7 and a conveyor belt 8. The holder 7 is a so-called carriage that holds the liquid ejection head H, and is fixed to the conveyor belt 8. The conveyor belt 8 is an endless belt that is installed along the Y-axis direction. The conveyor belt 8 rotates by driving a conveyor motor (not shown). The control unit 4 controls the driving of the conveyor motor to rotate the conveyor belt 8, and moves the liquid ejection head H back and forth together with the holder 7 in the Y-axis direction. The holder 7 may be configured to mount a liquid storage unit 3 together with the liquid ejection head H.

[0018] The liquid ejection head H performs an ejection operation of ejecting the liquid supplied from the liquid storage section 3 as droplets from each of the multiple nozzles 21 (see FIG. 3) in the +Z direction under the control of the control unit 4. This ejection operation by the liquid ejection head H is performed in parallel with the transport of the medium S by the transport mechanism 5 and the reciprocating movement of the liquid ejection head H by the movement mechanism 6, thereby applying the liquid to the medium S, i.e., performing so-called printing.

[0019] FIG. 2 is an exploded perspective view of the liquid jet head H. FIG. 3 is a plan view of the holder 30 and the head chip Hc when viewed in the -Z direction. FIG. 4 is a cross-sectional view of the liquid jet head H corresponding to the line AA' in FIG. 3. FIG. 5 is an enlarged view of the main part of FIG. 4. FIG. 6 is a plan view of the reinforcing plate 50 when assembled in the liquid jet head H when viewed in the +Z direction. Each direction of the liquid jet head H will be described based on the direction when it is mounted on the liquid jet device 1, that is, the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0020] As shown in Figures 2 to 5, the liquid ejection head H includes multiple head chips Hc, four in this embodiment, a holder 30 that holds the multiple head chips Hc, a fixing plate 40 that fixes the multiple head chips Hc, a reinforcing plate 50 that reinforces the fixing plate 40, and a flow path member 60 that supplies ink to the head chips Hc.

[0021] The head chip Hc is long in the X-axis direction and short in the Y-axis direction. The head chip Hc has a nozzle row in which nozzles 21 that eject ink are arranged side by side along the X-axis direction. The head chip Hc has multiple nozzle rows in the Y-axis direction, two rows in this embodiment.

[0022] Inside such a head chip Hc (not shown), a flow path communicating with the nozzle 21 and a pressure generating means for generating a pressure change in the ink in the flow path are provided. The pressure generating means may be, for example, a piezoelectric actuator that changes the volume of the liquid flow path by deformation of a piezoelectric actuator having a piezoelectric material that exhibits an electromechanical conversion function, thereby generating a pressure change in the ink in the flow path and ejecting ink droplets from the nozzle 21. In addition, the pressure generating means may be, for example, a device that has a heating element disposed in the flow path and ejects ink droplets from the nozzle 21 by bubbles generated by heat generated by the heating element. In addition, the pressure generating means may be a so-called electrostatic actuator that generates an electrostatic force between a vibration plate and an electrode, and the electrostatic force deforms the vibration plate to eject ink droplets from the nozzle 21.

[0023] The holder 30 is made of a material such as metal or resin. The holder 30 has a storage section 31 having a concave shape that opens on a surface facing the +Z direction. The storage section 31 stores a plurality of head chips Hc fixed by a fixing plate 40. The opening of the storage section 31 is sealed by the fixing plate 40. That is, the head chips Hc are stored inside a space formed by the storage section 31 and the fixing plate 40. The storage section 31 may be provided for each head chip Hc, or may be provided continuously across the plurality of head chips Hc. In this embodiment, the storage section 31 is provided independently for each head chip Hc.

[0024] In such a holder 30, the head chips Hc are arranged in a staggered manner along the Y-axis direction. Here, arranging the head chips Hc in a staggered manner along the Y-axis direction means arranging the head chips Hc arranged in parallel in the Y-axis direction with a shift in the X-axis direction alternately. That is, two rows of head chips Hc arranged in parallel in the Y-axis direction are arranged in parallel in the X-axis direction, and the two rows of head chips Hc are arranged with a shift in the X-axis direction. By arranging the head chips Hc in a staggered manner along the Y-axis direction in this way, the nozzles 21 of the two head chips Hc can be partially overlapped in the X-axis direction to form a row of nozzles 21 that is continuous along the X-axis direction. By forming a long nozzle row along the X-axis direction using a plurality of head chips Hc in this way, the yield can be improved and the cost can be reduced compared to the case of forming a long nozzle row on one head chip Hc. The number of head chips Hc held by the holder 30 is not limited to four, and may be one or more than two.

[0025] In addition, the surface of the holder 30 facing the +Z direction where the storage section 31 opens is provided with a first recess 33 having a concave shape to which the reinforcing plate 50 and the fixing plate 40 are fixed. That is, the outer peripheral edge of the surface of the holder 30 facing the +Z direction is an edge 34 protruding toward the +Z direction, and this edge 34 forms the first recess 33. The reinforcing plate 50 and the fixing plate 40 are sequentially stacked on the bottom surface of the first recess 33, i.e., the surface facing the +Z direction. In this embodiment, the bottom surface of the first recess 33 of the holder 30 and the reinforcing plate 50 are bonded to each other by an adhesive 70, and the fixing plate 40 and the reinforcing plate 50 are bonded to each other by an adhesive 71. The adhesives 70 and 71 will be described in detail later. That is, the bottom surface of the first recess 33 of the holder 30 is bonded to the fixing plate 40 via the reinforcing plate 50.

[0026] Here, the fixed plate 40 is formed of a plate-like member such as a metal, such as stainless steel. The fixed plate 40 also has an exposure opening 41 that exposes the nozzle surface on which the nozzles 21 of each head chip Hc are formed. In this embodiment, the exposure opening 41 is provided independently for each head chip Hc. The exposure opening 41 has a shape that is long in the X-axis direction and short in the Y-axis direction when viewed in the Z-axis direction, in accordance with the shape of the head chip Hc. The fixed plate 40 is fixed to the nozzle surface side of the head chip Hc at the peripheral portion of the exposure opening 41.

[0027] Such a fixing plate 40 is fixed within the first recess 33 of the holder 30 via a reinforcing plate 50 so as to close the opening of the accommodation portion 31 of the holder 30 .

[0028] The reinforcing plate 50 is preferably made of a material having a higher strength than the fixed plate 40. In this embodiment, the reinforcing plate 50 is formed of a plate-shaped member that is made of the same material as the fixed plate 40 and is thicker in the Z-axis direction than the fixed plate 40. Of course, the reinforcing plate 50 may be made of a material different from that of the fixed plate 40. Also, the reinforcing plate 50 may be made of a material that is thinner in the Z-axis direction than the fixed plate 40.

[0029] The reinforcing plate 50 has a first surface 51 facing the +Z direction and fixed to the fixed plate 40, and a second surface 52 facing the side opposite to the first surface 51, that is, facing the -Z direction.

[0030] Further, the reinforcing plate 50 has an opening 53 surrounding the exposed opening 41 when viewed in the Z-axis direction. The opening 53 is provided penetrating the reinforcing plate 50 in the Z-axis direction. Here, the opening 53 surrounding the exposed opening 41 when viewed in the Z-axis direction means that the opening 53 is provided outside the periphery of the exposed opening 41 so that the periphery of the opening 53 surrounds the periphery of the exposed opening 41 in the Z-axis direction. That is, the opening 53 has a larger opening area than the exposed opening 41, and the opening 53 is disposed at a position that includes the exposed opening 41 when viewed in the Z-axis direction. Furthermore, the opening 53 has a larger opening area than the periphery of the head chip Hc when viewed in the Z-axis direction. The head chip Hc is inserted into the opening 53 of the reinforcing plate 50 and fixed to the surface of the fixing plate 40 facing the -Z direction. The head chip Hc and the fixing plate 40 are bonded to each other by an adhesive 75. Furthermore, in this embodiment, the opening 53 is provided independently for each exposed opening 41. Moreover, the opening 53 has a shape that matches the shape of the head chip Hc, that is, is long in the X-axis direction and short in the Y-axis direction when viewed in the Z-axis direction.

[0031] Further, the reinforcing plate 50 has a through hole 54 at a position different from the opening 53. Here, the through hole 54 at a position different from the opening 53 refers to a state in which the opening 53 and the through hole 54 are not in communication with each other. In this embodiment, the through holes 54 are provided on both sides of the opening 53 in the X-axis direction and on both sides of one of the two openings 53 arranged in the Y-axis direction, as viewed in the Z-axis direction. Among the through holes 54, those arranged on both sides of the opening 53 in the X-axis direction are referred to as through holes 54A, and among the two openings 53 arranged in the Y-axis direction, those arranged on both sides of one of the openings 53 in the Y-axis direction are referred to as through holes 54B. That is, the reinforcing plate 50 has a total of eight through holes 54A and a total of four through holes 54B. One of the two through holes 54A provided on both sides of one opening 53 in the X-axis direction is arranged between the two openings 53 in the X-axis direction. In addition, one of the two through holes 54B provided on both sides of one opening 53 in the Y-axis direction is disposed between the two openings 53 in the Y-axis direction. Such a through hole 54 functions as an adhesive escape groove into which excess adhesive 70 flows when the fixing plate 40 and the reinforcing plate 50 are bonded with the adhesive 70. That is, a part of the adhesive 70 is disposed in the through hole 54. In this way, by providing the through hole 54A between the two openings 53 in the X-axis direction and the through hole 54B between the two openings 53 in the Y-axis direction, the excess adhesive 70 flows into the through holes 54A and 54B, and the excess adhesive 70 can be prevented from flowing into the two openings 53 aligned in the X-axis direction and the two openings 53 aligned in the Y-axis direction. In particular, since the areas between openings 53 aligned in the Y-axis direction are relatively large, the amounts of adhesives 70 and 71 applied also increase, and there is a high risk that excess adhesive 70 will flow into openings 53, but by providing through holes 54B between openings 53 aligned in the Y-axis direction, the excess adhesive can be allowed to escape into through holes 54B, thereby preventing excess adhesive 70 from flowing out toward openings 53. Therefore, by preventing excess adhesive 70 from flowing into openings 53 and preventing adhesive 70 from interfering when fixing head chip Hc inserted through opening 53 to fixing plate 40, poor fixing between head chip Hc and fixing plate 40 can be prevented.

[0032] As described above, the opening 53 has a shape that is long in the X-axis direction and short in the Y-axis direction when viewed in the Z-axis direction. Therefore, the through holes 54B arranged in line with the opening 53 in the Y-axis direction have a shape that is long in the X-axis direction and short in the Y-axis direction in accordance with the shape of the opening 53. In contrast, the through holes 54A arranged in line with the opening 53 in the X-axis direction are shorter in length in the X-axis direction than the through holes 54B. Therefore, the through holes 54B have a larger opening area than the through holes 54A. Hereinafter, when the through holes 54A and 54B are not distinguished from each other, they are referred to as the through holes 54. The width d of the through holes 54B in the Y-axis direction is larger than the gap w between the opening 53 and the head chip Hc.

[0033] In this embodiment, the reinforcing plate 50 having such openings 53 and through holes 54 is formed by punching in a press process. By forming the reinforcing plate 50 by punching in a press process, the reinforcing plate 50 has burrs 50a protruding in the -Z direction on the periphery of the through holes 54 in the second surface 52. Note that, although only the burrs 50a on the through holes 54 are illustrated in Fig. 5, similar burrs are also formed on the periphery of the openings 53, the outer periphery of the reinforcing plate 50, and the like.

[0034] The holder 30 has a second recess 35 recessed toward the -Z direction on the surface facing the +Z direction fixed to the reinforcing plate 50. The second recess 35 surrounds the through hole 54 when viewed in the Z-axis direction. Here, the second recess 35 surrounding the through hole 54 is the same as the above-mentioned definition of the opening 53 surrounding the exposed opening 41. The second recess 35 is provided independently for each through hole 54. That is, the holder 30 has a total of 12 second recesses 35. By providing the second recess 35 in the holder 30 in this way, the holder 30 and the reinforcing plate 50 can be bonded to each other with the adhesive 71 without the burr 50a coming into contact with the surface of the holder 30 facing the +Z direction. In addition, by providing the second recess 35, excess adhesive 71 can be released to the second recess 35 when bonding the reinforcing plate 50 and the holder 30. Therefore, excess adhesive 71 is prevented from flowing into housing portion 31, and problems caused by adhesive 71 adhering to head chip Hc can be prevented.

[0035] The through-hole 54 of the reinforcement plate 50 has its opening in the +Z direction covered by the fixing plate 40. Then, the through-hole 54 is closed by the adhesive 72. Here, when it is said that the adhesive 72 closes the through-hole 54, as shown in FIG. 6, in the view in the Z-axis direction, it means a state where the adhesive 72 fills the inside of the through-hole 54 without any gaps. That is, the adhesive 72 includes those that are not filled in the through-hole 54 over the Z-axis direction. Also, in the cross-section along the Z-axis direction, it is preferable that the adhesive 72 closes 50% or more of the volume of the through-hole 54, and more preferably 80% or more. By closing the through-hole 54 with the adhesive 72 in this way, the strength of the reinforcement plate 50 can be increased, and the strength of the portion of the fixing plate 40 overlapping the through-hole 54 in the Z-axis direction can be increased. For this reason, when an external force such as the medium S coming into contact with the fixing plate 40 occurs due to a conveyance failure of the medium S in the liquid injection device 1, i.e., the occurrence of a so-called paper jam, deformation of the portion of the fixing plate 40 facing the through-hole 54 can be suppressed. Therefore, deformation of the fixing plate 40 can be suppressed, and destruction of the liquid injection head H such as the fixing plate 40 peeling from the reinforcement plate 50 or the fixing plate 40 and the reinforcement plate 50 peeling from the holder 30 can be suppressed. Also, by suppressing the application of stress to the head chip Hc in which the nozzles 21 are formed due to deformation of the fixing plate 40, deviation of the injection direction of the droplets injected from the nozzles 21, that is, deviation of the landing position of the droplets on the medium S can be suppressed, and deterioration of the printing quality can be suppressed. In particular, since the through-hole 54B has a larger opening area than the through-hole 54A, the portion of the fixing plate 40 facing the through-hole 54B in the Z-axis direction is easily deformed, but by closing the through-hole 54B with the adhesive 72, the strength of this portion of the fixing plate 40 can be increased, and deformation of the fixing plate 40 can be suppressed. Also, since the width d of the through-hole 54B in the Y-axis direction is larger than the gap w between the opening 53 and the head chip Hc, the portion of the fixing plate 40 facing the through-hole 54B in the Z-axis direction is easily deformed, but by closing the through-hole 54B with the adhesive 72, the strength of this portion of the fixing plate 40 can be increased.

[0036] Also, the adhesive 72 closes the through-hole 54 so as not to protrude from the opening of the through-hole 54 formed in the second surface 52. That is, the adhesive 72 does not exist in the -Z direction from the opening of the through-hole 54 on the second surface 52. By preventing the adhesive 72 from protruding from the opening of the through-hole 54 on the second surface 52 in this way, interference between the adhesive 72 and the holder 30 can be suppressed, and the reinforcing plate 50 and the holder 30 can be reliably adhered by the adhesive 71. In this embodiment, since the second recess 35 is provided, even if the adhesive 72 protrudes in the -Z direction from the opening of the through-hole 54 on the second surface 52, it does not interfere with the holder 30. However, if the adhesive 72 that has protruded from the through-hole 54 spreads wet on the second surface 52, the adhesive 72 on the second surface 52 may interfere when the holder 30 and the reinforcing plate 50 are adhered by the adhesive 71, which is not preferable.

[0037] Also, by providing the second recess 35 in the holder 30, the strength of the portion of the reinforcing plate 50 and the fixing plate 40 that overlaps the second recess 35 when viewed in the Z-axis direction is reduced. However, by closing the through-hole 54 with the adhesive 72, the strength of the portion of the fixing plate 40 and the reinforcing plate 50 that overlaps the second recess 35 when viewed in the Z-axis direction can be enhanced. Therefore, deformation of the fixing plate 40 and the reinforcing plate 50 can be suppressed, and destruction of the liquid ejection head H and deterioration of print quality can be suppressed.

[0038] Note that as the adhesive 72, a silicone-based adhesive, an epoxy-based adhesive, or the like is used. As the adhesive 70, it is generally preferable to use an epoxy-based thermosetting adhesive having a higher Young's modulus than a silicone-based adhesive. Note that an epoxy-based adhesive is an adhesive in which the main agent is an epoxy resin and the curing agent is, for example, an aliphatic amine, a polyamide resin, a polythiol resin, or the like. By using the adhesive 72 having a relatively high Young's modulus after curing in this way, deformation of the fixing plate 40 can be reliably suppressed.

[0039] Further, the reinforcing plate 50 and the fixing plate 40 are adhered to each other by the adhesive 70 as described above. After applying the adhesive 70 to the reinforcing plate 50, the reinforcing plate 50 and the fixing plate 40 are brought into contact with each other under a predetermined pressure and adhered. Therefore, the adhesive 70 is not provided so as to block the through hole 54. The through hole 54 allows the excess adhesive 70 to flow in when the reinforcing plate 50 and the fixing plate 40 are adhered. Thus, it is possible to suppress the excess adhesive 70 from flowing into the opening 53 side when the reinforcing plate 50 and the fixing plate 40 are adhered. Therefore, it is possible to suppress the occurrence of poor fixing between the head chip Hc and the fixing plate 40 due to the adhesive 70 flowing into the opening 53.

[0040] As the adhesive 70, a silicone-based adhesive, an epoxy-based adhesive, or the like is used. It is preferable to use an epoxy-based thermosetting adhesive having liquid resistance as the adhesive 70. Further, the adhesive 70 is a different type of adhesive from the adhesive 72. Here, the fact that the adhesive 70 and the adhesive 72 are different types of adhesives includes those having different main agents. Also, the fact that the adhesive 70 and the adhesive 72 are different types of adhesives includes those having the same main agent but different types of curing agents. Further, the fact that the adhesive 70 and the adhesive 72 are different types of adhesives includes those having the same types of main agent and curing agent, but different product model numbers and different Young's moduli, for example, due to different filler contents.

[0041] Also, after curing, the adhesive 72 preferably has a higher Young's modulus than the adhesive 70. By making the Young's modulus of the adhesive 72 higher than that of the adhesive 70 in this way, the strength of the fixing plate 40 at the position facing the through-hole 54 can be increased by the adhesive 72 in the through-hole 54. Therefore, the strength of the fixing plate 40 can be increased to suppress deformation at the position of the fixing plate 40 facing the through-hole 54. Note that the Young's modulus of the adhesive 70 is preferably 100 MPa or more higher than that of the adhesive 71. Thereby, the strength at the position of the fixing plate 40 facing the through-hole 54 can be more reliably increased. Also, generally, when the Young's modulus of an adhesive is high, the viscosity before curing tends to be high. For this reason, by using an adhesive 70 having a relatively low Young's modulus, it is easy to uniformly wet and spread over the first surface 51 of the reinforcing plate 50, and it is difficult to cause adhesion failures such as a region where the adhesive 70 is not applied or variations in the thickness of the adhesive 70.

[0042] As the adhesive 71 for bonding the reinforcing plate 50 and the holder 30, a silicone-based adhesive, an epoxy-based adhesive, or the like is used. It is preferable to use a silicone-based adhesive as the adhesive 71. A silicone-based adhesive generally cures at room temperature and has less heat-curing shrinkage than an epoxy-based adhesive. For this reason, by using a silicone-based adhesive as the adhesive 71, displacement between the holder 30 and the head chip Hc due to the curing shrinkage of the adhesive 71 can be suppressed. Also, by using a silicone-based adhesive having a relatively low Young's modulus as the adhesive 71, when the head chip Hc is fixed in the accommodation portion 31 of the holder 30 after bonding the fixing plate 40 and the reinforcing plate 50 to the head chip Hc with the adhesive 75, variations in the height of the head chip Hc with respect to the holder 30 can be absorbed by the adhesive 71.

[0043] In addition, in this embodiment, the adhesive 72 is an example of the "first adhesive", and the adhesive 70 is an example of the "second adhesive". Further, the second recess 35 is an example of the "recess". Also, any one of the four head chips Hc is an example of the "first head chip", and the nozzle 21 of this head chip Hc is an example of the "first nozzle". Further, one of the head chips Hc other than the first head chip is an example of the "second head chip", and the nozzle 21 of this head chip Hc is an example of the "second nozzle". Further, the exposure opening 41 that exposes the first nozzle among the four exposure openings 41 is an example of the "first exposure opening", and the exposure opening 41 that exposes the second nozzle is an example of the "second exposure opening". Further, the opening 53 surrounding the first exposure opening is an example of the "first opening", and the opening 53 surrounding the second exposure opening is an example of the "second opening". Further, the X-axis direction is an example of the "first direction", the Y-axis direction is an example of the "second direction", and is also an example of the "arrangement direction of the first head chip and the through hole".

[0044] The flow path member 60 is fixed to the surface of the holder 30 facing the -Z direction. Inside the flow path member 60 (not shown), a flow path for supplying ink to the head chip Hc is provided, and the ink supplied from the liquid storage unit 3 is supplied to each head chip Hc via the flow path member 60. Note that, in the flow path of the flow path member 60, a filter for removing foreign substances such as dust and bubbles contained in the ink, a pressure regulating valve that opens and closes according to the pressure of the downstream flow path, and the like may be provided.

[0045] In such a liquid ejection head H, ink is supplied from the liquid storage unit 3 via the flow path member 60, and ink droplets are ejected from the nozzle 21 by driving the pressure generating means in the head chip Hc based on a print signal from the control unit 4.

[0046] Such a liquid ejection head H is held alone or two or more are held by the holder 7.

[0047] (Embodiment 2) FIG. 7 is a cross-sectional view of a main part of the liquid ejection head H according to Embodiment 2 of the present invention. FIG. 8 is an enlarged view of the main part of FIG. 7. Note that the same members as those in the above-described embodiment are denoted by the same reference numerals, and redundant descriptions are omitted.

[0048] As shown in FIGS. 7 and 8, the through hole 54 of the reinforcing plate 50 is closed by the adhesive 71a. The adhesive 71a is constituted by a part of the adhesive 71 that adheres the reinforcing plate 50 and the holder 30. That is, by putting a part of the adhesive 71 used when adhering the reinforcing plate 50 and the holder 30 into the through hole 54, the through hole 54 can be closed with the adhesive 71a. Further, the adhesive 71 closes the second recess 35. Note that the fact that the adhesive 71a closes the through hole 54 has the same definition as the fact that the adhesive 72 in Embodiment 1 described above closes the through hole 54. Similarly, the fact that the adhesive 71 closes the second recess 35 has the same definition as the fact that the adhesive 72 in Embodiment 1 described above closes the through hole 54.

[0049] In order to close the second recess 35 and the through hole 54 with the adhesive 71, for example, when applying the uncured adhesive 71 to the surface of the holder 30 facing the +Z direction, the adhesive 71 is filled into the second recess 35 and the thickness of the adhesive 71 at the portion facing the through hole 54 is made thicker than other portions. Thereby, when the second surface 52 of the reinforcing plate 50 and the holder 30 are brought into contact with each other, a part of the adhesive 71 can be poured into the through hole 54, and the through hole 54 can be closed with the adhesive 71a and the inside of the second recess 35 can be closed with the adhesive 71. Incidentally, even if the excess adhesive 71 flows into the accommodating portion 31 side, since there is a gap between the peripheral wall of the accommodating portion 31 and the head chip Hc, when applying the adhesive 71 to the holder 30, it is not necessary to make only the portion facing the through hole 54 thick, and the whole may be made relatively thick.

[0050] Further, regarding the materials of the adhesive 70 and the adhesive 71, the same adhesives as those in Embodiment 1 described above can be used, and thus redundant descriptions are omitted.

[0051] Also, by closing the through hole 54 with the adhesive 71a which is a part of the adhesive 71 for bonding the reinforcing plate 50 and the holder 30 as described above, it is possible to increase the strength of the portion of the fixing plate 40 that overlaps the through hole 54 when viewed in the Z-axis direction.

[0052] Further, in the present embodiment, since the second recess 35 is closed with the adhesive 71, the strength of the portion of the reinforcing plate 50 that overlaps the second recess 35 when viewed in the Z-axis direction can be increased. Therefore, the strength of the portion of the fixing plate 40 that overlaps the through hole 54 when viewed in the Z-axis direction can be further increased, and deformation of the portion of the fixing plate 40 facing the through hole 54 can be suppressed.

[0053] (Other Embodiments) As described above, each embodiment of the present invention has been described, but the basic configuration of the present invention is not limited to what has been described above.

[0054] For example, in each of the above-described embodiments, the through hole 54 and the second recess 35 function as escape grooves for the adhesives 70 and 71, but are not particularly limited thereto. For example, a temperature sensor for detecting the temperature in the vicinity of the nozzle 21 may be provided in the second recess 35, and the through hole 54 may expose the fixing plate 40 toward the temperature sensor in order to detect the temperature of the fixing plate 40 by the temperature sensor. Also, the through hole 54 and the second recess 35 provided for other purposes may be used.

[0055] Also, in each of the above-described embodiments, since the reinforcing plate 50 has burrs 50a by forming the through hole 54 by punching with press working, the second recess 35 is provided in the holder 30, but is not particularly limited thereto. For example, the through hole 54 may be formed in the reinforcing plate 50 by laser processing or the like. Also, when burrs 50a are not formed on the reinforcing plate 50, or when the burrs 50a are of a size that can be ignored with respect to the thickness of the adhesive 71, the second recess 35 may not be provided in the holder 30.

[0056] In the above-described Embodiment 1, the reinforcing plate 50 and the holder 30 are adhered by the adhesive 71. However, the present invention is not particularly limited thereto, and welding or fastening with screws may be used instead.

[0057] (Appended Note) From the forms exemplified above, for example, the following configurations can be grasped.

[0058] The liquid ejection head according to Aspect 1, which is a preferred aspect, includes a first head chip having a plurality of first nozzles for ejecting liquid, a fixing plate to which the first head chip is fixed and which has a first exposure opening for exposing the plurality of first nozzles, a holder for holding the first head chip between the fixing plate, and a reinforcing plate disposed between the holder and the fixing plate. The reinforcing plate has a first opening surrounding the first exposure opening and a through hole at a position different from the first opening when viewed in the stacking direction of the fixing plate and the reinforcing plate. The through hole is closed by a first adhesive. According to this, by closing the through hole with the adhesive, the strength of the reinforcing plate can be increased, and the strength of the portion of the fixing plate facing the through hole can be increased. Therefore, deformation of the fixing plate due to an external force can be suppressed.

[0059] In Aspect 2, which is a specific example of Aspect 1, in a cross-section along the stacking direction of the fixing plate and the reinforcing plate, the first adhesive closes 50% or more of the through hole. According to this, the strength of the reinforcing plate and the fixing plate can be increased, and deformation of the fixing plate can be suppressed.

[0060] In Aspect 3, which is a specific example of Aspect 1, the fixing plate and the reinforcing plate are adhered to each other by a second adhesive, and a part of the second adhesive is disposed inside the through hole. According to this, a part of the second adhesive can be allowed to escape into the through hole so that the second adhesive does not flow out to other parts.

[0061] In Embodiment 4 which is a specific example of Embodiment 3, the first adhesive and the second adhesive are different types of adhesives. According to this, it is possible to use a first adhesive suitable for the purpose of increasing the strength of the reinforcing plate and the fixing plate, and a second adhesive suitable for adhering the reinforcing plate and the fixing plate.

[0062] In Embodiment 5 which is a specific example of Embodiment 4, the Young's modulus of the first adhesive is higher than that of the second adhesive. According to this, the strength of the fixing plate can be further increased by the first adhesive having a relatively high Young's modulus. In addition, since an adhesive is less likely to undergo curing shrinkage when its Young's modulus is high, by using a material with a high Young's modulus as the first adhesive, it is difficult for the fixing plate to deform when the first adhesive cures within the through hole. Also, since an adhesive is likely to have a high viscosity before curing when its Young's modulus is high, by using a material with a relatively low Young's modulus as the second adhesive, the second adhesive can be applied with a uniform thickness between the fixing plate and the reinforcing plate, and the occurrence of poor adhesion can be suppressed.

[0063] In Embodiment 6 which is a specific example of Embodiments 1 to 5, the first adhesive is an epoxy-based thermosetting adhesive. According to this, the strength of the fixing plate can be increased by using a relatively hard adhesive.

[0064] In Embodiment 7 which is a specific example of Embodiment 1, the reinforcing plate has a first surface fixed to the fixing plate and a second surface opposite to the first surface, and the first adhesive does not protrude from the opening of the through hole formed in the second surface. According to this, it is possible to suppress the interference between the first adhesive and the holder, and it is difficult for a fixing failure to occur between the reinforcing plate and the holder.

[0065] In Embodiment 8, which is a specific example of Embodiment 1, the reinforcing plate has a first surface fixed to the fixing plate and a second surface opposite to the first surface. A peripheral portion of the through hole on the second surface has a burr protruding in a direction from the first surface toward the second surface. A surface of the holder fixed to the reinforcing plate has a recess recessed in the direction from the first surface toward the second surface. The recess surrounds the through hole when viewed in the stacking direction. According to this, a through hole can be formed at low cost by punching by press working. Further, by providing a recess in the holder, it is possible to suppress the burr from interfering with the holder, and it is difficult for a fixing failure between the reinforcing plate and the holder to occur. Further, even if the strength of the reinforcing plate is reduced by the recess, the reduction in the strength of the reinforcing plate and the fixing plate can be suppressed by closing the through hole with the first adhesive.

[0066] In Embodiment 9, which is a specific example of Embodiment 1, a second head chip having a plurality of second nozzles for injecting a liquid is provided. The fixing plate has a second exposure opening for fixing the second head chip and exposing the plurality of second nozzles. The holder holds the second head chip between the holder and the fixing plate. The reinforcing plate has a second opening surrounding the second exposure opening when viewed in the stacking direction. According to this, by forming a long nozzle row with a plurality of head chips, the yield can be improved and the cost can be reduced compared to forming a long nozzle row with one head chip.

[0067] In Embodiment 10, which is a specific example of Embodiment 9, the through hole is disposed between the first opening and the second opening adjacent to each other. According to this, since the area between the adjacent first openings is large, the application amount of the adhesive also increases, and there is a high risk that the excess adhesive flows out to the first opening. However, by providing the through hole, the excess adhesive can be allowed to escape into the through hole, and it is possible to suppress the excess adhesive from flowing out to the first opening side.

[0068] In Embodiment 11, which is a specific example of Embodiment 1, the first head chip is long in a first direction orthogonal to the stacking direction, short in a second direction orthogonal to both the stacking direction and the first direction, the through hole is arranged in the second direction with respect to the first head chip, and is long in the first direction. Even with a through hole that is long in the first direction like this, by closing the through hole with the first adhesive, the strength of the reinforcing plate and the fixing plate can be increased to suppress deformation of the fixing plate.

[0069] In Embodiment 12, which is a specific example of Embodiment 1, in the arrangement direction of the first head chip and the through hole, the width of the through hole is larger than the gap between the first opening and the first head chip. Even when the width of the through hole is large like this, by closing the through hole with the first adhesive, the strength of the reinforcing plate and the fixing plate can be increased to suppress deformation of the fixing plate.

[0070] The liquid ejecting device according to Embodiment 13, which is a preferred embodiment, includes the liquid ejecting head described in Embodiment 1 and a liquid storage unit that stores the liquid supplied to the liquid ejecting head. According to this, it is possible to realize a liquid ejecting device that suppresses deformation of the fixing plate and suppresses breakage of the liquid ejecting head and deviation of the landing position of the liquid droplets on the medium.

Explanation of Reference Numerals

[0071] H... Liquid ejecting head, Hc... Head chip, S... Medium, 1... Liquid ejecting device, 3... Liquid storage unit, 4... Control unit, 5... Conveying mechanism, 5a... Conveying roller, 6... Moving mechanism, 7... Holding body, 8... Conveying belt, 21... Nozzle, 30... Holder, 31... Accommodating portion, 33... First recess, 34... Edge portion, 35... Second recess, 40... Fixing plate, 41... Exposed opening, 50... Reinforcing plate, 50a... Burr, 51... First surface, 52... Second surface, 53... Opening, 54, 54A, 54B... Through hole, 60... Flow path member, 70, 71, 71a, 72, 75... Adhesive.

Claims

1. A first head chip having a plurality of first nozzles for ejecting a liquid; A fixing plate to which the first head chip is fixed and having a first exposure opening for exposing the plurality of first nozzles; A holder for holding the first head chip between the fixing plate; A reinforcing plate disposed between the holder and the fixing plate; Comprising; The reinforcing plate has a first opening surrounding the first exposure opening and a through hole at a position different from the first opening when viewed in the stacking direction of the fixing plate and the reinforcing plate; The through hole is closed by a first adhesive; A liquid ejecting head, characterized in that.

2. In a cross section along the stacking direction of the fixing plate and the reinforcing plate, 50% or more of the through hole is closed by the first adhesive. The liquid ejecting head according to Claim 1.

3. The fixing plate and the reinforcing plate are adhered to each other by a second adhesive; A part of the second adhesive is disposed inside the through hole; The liquid ejecting head according to Claim 1, characterized in that.

4. The first adhesive and the second adhesive are different types of adhesives; The liquid ejecting head according to Claim 3, characterized in that.

5. The Young's modulus of the first adhesive is higher than the Young's modulus of the second adhesive; The liquid ejecting head according to Claim 4, characterized in that.

6. The first adhesive is an epoxy-based thermosetting adhesive; The liquid ejecting head according to any one of Claims 1 to 5, characterized in that.

7. The reinforcing plate has a first surface fixed to the fixing plate and a second surface opposite to the first surface; The first adhesive does not protrude from the opening of the through hole formed on the second surface; The liquid ejecting head according to Claim 1, characterized in that.

8. The reinforcing plate has a first surface fixed to the fixing plate and a second surface opposite to the first surface; A peripheral portion of the through hole on the second surface has a burr protruding in a direction from the first surface toward the second surface; A surface of the holder fixed to the reinforcing plate has a recess recessed in the direction from the first surface toward the second surface; The recess surrounds the through hole when viewed in the stacking direction; The liquid ejecting head according to Claim 1, characterized in that.

9. Comprising a second head chip having a plurality of second nozzles for ejecting a liquid; The fixed plate has a second exposure opening for fixing the second head chip and exposing the plurality of second nozzles. The holder holds the second head chip between the holder and the fixed plate. The reinforcing plate has a second opening surrounding the second exposure opening when viewed in the stacking direction. The liquid ejection head according to claim 1, characterized in that.

10. The through hole is disposed between the first opening and the second opening adjacent to each other. The liquid ejection head according to claim 9, characterized in that.

11. The first head chip is long in a first direction orthogonal to the stacking direction and short in a second direction orthogonal to both the stacking direction and the first direction. The through hole is disposed in the second direction with respect to the first head chip and is long in the first direction. The liquid ejection head according to claim 1, characterized in that.

12. In the arrangement direction of the first head chip and the through hole, the width of the through hole is larger than the gap between the first opening and the first head chip. The liquid ejection head according to claim 1, characterized in that.

13. The liquid ejection head according to claim 1, A liquid storage section for storing liquid to be supplied to the liquid ejection head, A liquid ejection device characterized by comprising.

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