Liquid discharge head and recording apparatus

Abstract

To provide a liquid discharge head which is excellent in liquid entry prevention into a head and in impact resistance.SOLUTION: An ink head 2B as a liquid discharge head comprises: a first flow channel member 3 which has a short direction and a longitudinal direction and discharges liquid; a second flow channel member 4 which is stacked over the first flow channel member 3, has the same width as the short direction of the first flow channel member 3, and supplies liquid to the first flow channel member 3; and a flat circuit component 5B which sends a signal for discharging liquid to the first flow channel member 3. The circuit component 5B includes a part which penetrates the second flow channel member 4 in a vertical direction. The second flow channel member 4 has a solid cross section along the short direction in a center area of the longitudinal direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a liquid ejection head capable of ejecting a liquid, and a recording apparatus using the liquid ejection head.

Background Art

[0002] There are apparatuses that use a liquid ejection head for ejecting a small amount of liquid. For example, a recording apparatus such as an inkjet printer includes an ink head that ejects ink for image formation toward a recording medium. The ink head includes a first flow path member having an ink ejection port, and a second flow path member that supplies liquid to the first flow path member. On the upper surface of the first flow path member, a pressurizing portion such as a piezoelectric actuator substrate is disposed, and circuit components for applying an electrical signal to the pressurizing portion are attached. The second flow path member is stacked on the first flow path member, and the circuit components are drawn out along the side surface of the second flow path member (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a liquid ejection head such as the above-described ink head, it is required to prevent the intrusion of liquid from the outside into the head. Further, resistance when an impact is applied to the liquid ejection head from the outside is required. For example, it is required that the stacked state of the first flow path member and the second flow path member is not disturbed as much as possible by an external impact. Furthermore, it is necessary to devise the drawing-out mode of the circuit components so as to ensure prevention of liquid intrusion and impact resistance.

[0005] An object of the present disclosure is to provide a liquid ejection head that can suppress liquid intrusion into the head and has excellent impact resistance, and a recording apparatus using the liquid ejection head.

Means for Solving the Problems

[0006] A liquid ejection head according to one aspect of the present disclosure has a short side direction and a long side direction, and includes a first flow path member that ejects liquid, a second flow path member that is stacked on the first flow path member and has a width equivalent to the short side direction of the first flow path member and supplies liquid to the first flow path member, and a flat circuit component that sends a signal for liquid ejection to the first flow path member. The circuit component includes a portion that penetrates the second flow path member in the vertical direction, and the second flow path member has a solid cross section along the short side direction in the central region in the long side direction.

[0007] A recording apparatus according to another aspect of the present disclosure includes the above-described liquid ejection head, a recording medium that lands the liquid ejected from the liquid ejection head, and a moving unit that relatively moves the recording medium and the liquid ejection head.

Effects of the Invention

[0008] According to the present disclosure, it is possible to provide a liquid ejection head that can suppress liquid intrusion into the head and has excellent impact resistance, and a recording apparatus using the liquid ejection head.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

[0010] Hereinafter, with reference to the drawings, a liquid ejection head and a recording apparatus according to an embodiment of the present disclosure will be described. The liquid ejection head has a function of ejecting a liquid. Examples of the liquid include printing ink, conductive liquid for printing a wiring pattern, and liquid containing a chemical agent. The recording apparatus is an apparatus that ejects ink, a processing liquid, or the like from the liquid ejection head onto a workpiece. In the following embodiments, an inkjet printer that is a recording apparatus including an ink head as the liquid ejection head will be exemplified. The inkjet printer prints an image such as characters or patterns on a workpiece such as a paper sheet, a resin sheet, or a fabric such as a woven or knitted fabric by an inkjet method.

[0011] [Overall Configuration of Printer] FIG. 1 is a side view of an inkjet printer 1 according to the present embodiment, and FIG. 2 is a plan view of the inkjet printer 1. The printer 1 includes an ink head 2, a moving unit 7, and a control unit 9. The ink head 2 is an example of a liquid ejection head according to the present disclosure, and ejects ink onto a work W as a recording medium. The moving unit 7 relatively moves the work W with respect to the ink head 2. The control unit 9 controls the ink head 2 based on image print data, ejects ink toward the work W moved by the moving unit 7, and lands ink droplets on the work W to perform recording such as printing on the work W.

[0012] The printer 1 exemplified in the present embodiment is a so-called line printer in which the ink head 2 is fixed to a head mounting frame 12 disposed in the head chamber 11. As another embodiment of the printer 1, there is a so-called serial printer that reciprocates the ink head 2 in a direction intersecting the conveyance direction of the work W and alternately performs an operation of ejecting ink from the ink head 2 and an operation of conveying the work W.

[0013] Four flat head mounting frames 12 are disposed in the head chamber 11. Each head mounting frame 12 is mounted with a head group 20 including five ink heads 2. The printer 1 has four head groups 20 and a total of 20 ink heads 2 are mounted.

[0014] The ink head 2 has an elongated shape that is slender in one direction. The ink head 2 is mounted on the head mounting frame 12 such that the ink ejection site faces the printing surface of the work W from above, and its longitudinal direction is parallel to the direction orthogonal to the conveyance direction of the work W. Within one head group 20, three ink heads 2 are arranged along the direction orthogonal to the conveyance direction of the work W. The other two ink heads 2 are each arranged one by one between the three ink heads 2 at positions shifted along the conveyance direction. In one head group 20, the ink heads 2 are arranged such that the printable range of each ink head 2 is connected in the width direction of the work W, that is, the direction orthogonal to the conveyance direction of the work W. With such an arrangement, printing without gaps in the width direction of the work W is possible based on the ink ejection from each ink head 2.

[0015] Four head groups 20 are arranged along the conveyance direction of the work W. The same color ink is supplied to each ink head 2 belonging to one head group 20. Four colors of ink can be printed with the four head groups 20. The colors of the ink are, for example, magenta (M), yellow (Y), cyan (C), and black (BK).

[0016] The moving unit 7 includes a supply roller 71 and a supply adjustment roller 72 arranged upstream in the conveyance direction of the work W with respect to the head chamber 11, a conveyance roller 73 arranged in the head chamber 11, and a first recovery adjustment roller 74, a second recovery adjustment roller 75, and a recovery roller 76 arranged downstream in the conveyance direction of the work W with respect to the head chamber 11. The supply roller 71 sends out the work W toward the head chamber 11. The supply adjustment roller 72 guides the work W sent out by the supply roller 71 into the head chamber 11. The conveyance roller 73 conveys the work W introduced into the head chamber 11 so as to pass under the ink head 2. The first recovery adjustment roller 74 and the second recovery adjustment roller 75 guide the work W conveyed by the conveyance roller 73 outside the head chamber 11. The recovery roller 76 recovers the work W guided outside the head chamber 11 by winding it up.

[0017] The printer 1 further includes an application unit 81 disposed between the supply adjustment roller 72 and the head chamber 11 in the conveyance direction of the workpiece W, a drying unit 82 disposed between the first recovery adjustment roller 74 and the second recovery adjustment roller 75, and an imaging unit 83 disposed between the second recovery adjustment roller 75 and the recovery roller 76.

[0018] The application unit 81 applies a coating agent to the workpiece W before it is introduced into the head chamber 11. Examples of the coating agent include an agent for forming an ink receiving layer to enhance the fixing property of the ink, or an agent for forming an ink penetration suppressing layer to suppress bleeding of the ink. The drying unit 82 dries the ink adhering to the workpiece W before it is recovered by the recovery roller 76. Examples of the ink drying method employed in the drying unit 82 include a method of blowing hot air, a method of irradiating infrared rays, and a method of bringing a heated roller into contact. The imaging unit 83 images the workpiece W after drying by the drying unit 82 and acquires imaging data for confirming the printing state of the ink on the workpiece W. The imaging data acquired by the imaging unit 83 is input to the control unit 9. The control unit 9 evaluates the printing state of the ink on the workpiece W based on the imaging data.

[0019] [Premise Configuration of Ink Head] Next, with reference to FIGS. 3 and 4, the ink head 2 having the configuration that is the premise of the present embodiment will be described. FIG. 3(A) is a perspective view of the ink head 2, FIG. 3(B) is a cross-sectional view taken along line IIIB-IIIB of FIG. 3(A), and FIG. 4 is an exploded perspective view of the ink head 2. As described above, the ink head 2 has an elongated shape that is slender in one direction. Among the XYZ direction indicators attached to the drawings below FIG. 3, the X direction represents the longitudinal direction of the ink head 2, the Y direction represents the short side direction, and the Z direction represents the height direction. The Z direction will be mainly described as the vertical direction.

[0020] The ink head 2 includes a first flow path member 3, a second flow path member 4, and circuit components 5. The first flow path member 3 is a member in which a flow path for discharging ink is formed. The first flow path member 3 is a flat plate-shaped member having a short side direction and a long side direction in the planar direction. The first flow path member 3 has a lower surface 31 on which a large number of ink discharge holes are arranged, and an upper surface 32 that serves as a joint surface with the second flow path member 4. The first flow path member 3 is composed of a laminate of a plurality of thin plates having individual flow paths connected to the discharge holes respectively and openings that serve as common flow paths for supplying ink to the individual flow paths. A piezoelectric substrate 33 as a pressurizing part is arranged on the upper surface 32.

[0021] The ink head 2 may further include a housing that covers a part of the upper surface of the second flow path member 4, and a control substrate 90 (FIG. 9) electrically connected to the circuit components 5. The housing may have, for example, a rectangular parallelepiped shape with one side open. The housing is superposed and joined to the second flow path member 4 such that the open side covers a through hole 4H described later. A connector electrically connected to the control unit 9 may be arranged on the surface of the housing. The control substrate 90 is housed inside the housing and is electrically connected to the connector from the inside of the housing.

[0022] The piezoelectric substrate 33 is a substrate for electrically causing an ink discharge operation from the discharge holes on the lower surface 31 and includes piezoelectric elements. When the piezoelectric substrate 33 is driven by the control unit 9 and a volume change of the pressurizing chamber occurs due to the displacement of the piezoelectric elements, ink is discharged from the discharge holes. The arrangement range of the piezoelectric substrate 33 is a rectangular region excluding the vicinity of the periphery of the upper surface 32. The pressurizing part may not be a member separate from the first flow path member 3 such as the piezoelectric substrate 33, and may be configured in such a manner that piezoelectric elements are arranged for each pressurizing chamber. Instead of the piezoelectric substrate 33, a substrate or the like constituting a pressurizing part of a thermal method or an electrostatic method may be arranged.

[0023] The second flow path member 4 is a reservoir that is stacked on the first flow path member 3 and has a function of supplying ink to the first flow path member 3. The second flow path member 4 includes a frame portion 41 and a main body portion 42 stacked on the frame portion 41. The frame portion 41 has the same longitudinal and lateral sizes as the first flow path member 3. The frame portion 41 has a rectangular opening 41H, and short side pieces 411 and long side pieces 412 that partition the opening 41H. The opening 41H has longitudinal and lateral sizes larger than those of the piezoelectric substrate 33. That is, the opening 41H has a size that can surround the outer peripheral edge of the piezoelectric substrate 33 with a gap by a frame composed of the short side pieces 411 and the long side pieces 412. The lower surface of the frame portion 41 becomes a bonding region with the first flow path member 3. The second flow path member 4 is bonded to the first flow path member 3 in a state where the frame portion 41 and the main body portion 42 are previously bonded. Therefore, the bonding region becomes a bonding region between the first flow path member 3 and the second flow path member 4. Examples of the above bonding include adhesion using an adhesive, welding by ultrasonic waves or heat, etc.

[0024] The main body portion 42 includes a flow path 4P inside which ink flows. The main body portion 42 is composed of a laminate of a plurality of thin plates provided with openings for forming the flow path 4P. As shown in FIG. 6 to be described later, the main body portion 42 includes a flow path portion 42a, a lower cover plate 42b, and an upper cover plate 42c, and may further include an upper surface plate 42d. Grooves that become the main flow path 4P are formed on the upper and lower surfaces of the flow path portion 42a. The lower cover plate 42b is laminated on the lower surface of the flow path portion 42a and closes the grooves formed on the lower surface of the flow path portion 42a to constitute the flow path 4P. The upper cover plate 42c is laminated on the upper surface of the flow path portion 42a and closes the grooves formed on the upper and lower surfaces of the flow path portion 42a to constitute the flow path 4P. The upper surface plate 42d is laminated on the upper cover plate 42c.

[0025] The flow path 4P includes a supply flow path that receives ink from an external ink tank and supplies it to the first flow path member 3, a recovery flow path through which the ink recovered from the first flow path member 3 flows, and the like. The main body portion 42 is provided with a pair of through holes 4H each formed of a long hole extending in the longitudinal direction. The through holes 4H are disposed in the vicinity of one end (+Y end) and the other end (-Y end) in the short-side direction, and penetrate the main body portion 42 in the height direction. That is, the pair of through holes 4H are long holes extending parallel to the X direction and linearly penetrate the main body portion 42 in the Z direction respectively.

[0026] The main body portion 42 includes a thin-wall portion 43 and a thick-wall portion 44 continuously provided above the thin-wall portion 43. The thin-wall portion 43 has the same size as the first flow path member 3 and the frame portion 41. The thick-wall portion 44 has a slightly larger longitudinal width and short-side width than the thin-wall portion 43. Referring to FIG. 3(B), here, "thin wall" and "thick wall" are based on the wall thickness on the outer side in the Y direction that partitions the through hole 4H. For the +Y side through hole 4H, it means whether the wall thickness in the Y direction between the +Y side inner wall of the through hole 4H and the +Y outer surface of the main body portion 42, and for the -Y side through hole 4H, between the -Y side inner wall of the through hole 4H and the -Y outer surface of the main body portion 42 is thin or thick.

[0027] The thin-wall portion 43 is a portion where the length from the through hole 4H to the +Y·-Y outer surfaces, that is, the short-side width is the same as the short-side width of the longitudinal piece 412 of the frame portion 41. In other words, the width in the short direction of the joining region between the first flow path member 3 and the second flow path member 4 (hereinafter referred to as the joining width) is the same as the length from the through hole 4H of the thin-wall portion 43 to the outer surface. The thick-wall portion 44 is a portion where the short-side width from the through hole 4H to the +Y·-Y outer surfaces is longer than the joining width.

[0028] The widths of the first flow path member 3 and the second flow path member 4 in the short direction may be the same, or may be different within a range that can be treated as equivalent. FIG. 3(B) is an example of "equivalent", and in the thick wall portion 44 above the main body portion 42, the second flow path member 4 is slightly wider than the first flow path member 3. Instead of this, the width of the second flow path member 4 in the short direction may be the same as that of the first flow path member 3 over the entire height. The width of the second flow path member 4 in the short direction may be slightly narrower or slightly longer than that of the first flow path member 3 over the entire height. Alternatively, the widths of the frame portion 41 and the thin wall portion 43 in the short direction may be slightly shorter or slightly longer than the width of the first flow path member 3 in the short direction. The range of "equivalent" can be exemplified by the length A2 of the protrusion or recession in the Y direction on the +Y or -Y outer surface of the second flow path member 4 with respect to the width A1 of the first flow path member 3 in the short direction. For example, A2 is -0.1·A1 or more and 0.5·A1 or less, preferably A2 is -0.05·A1 or more and 0.25·A1 or less, and more preferably A2 is 0.0·A1 or more and 0.1·A1 or less.

[0029] The circuit component 5 sends a signal for ink ejection to the piezoelectric substrate 33 of the first flow path member 3. The circuit component 5 is a flat and flexible signal transmission substrate such as an FFC (Flexible Flat Cable). The circuit component 5 includes a contact portion that makes electrical contact with the piezoelectric substrate 33 and a through portion that penetrates the second flow path member 4 in the vertical direction. There is a bent portion upward in the vertical direction between the contact portion and the through portion. In the present embodiment, the through portion is a portion where the circuit component 5 is drawn out above the second flow path member 4 through the through hole 4H. The longitudinal width of the through hole 4H is set to be slightly longer than the width of the circuit component 5 in the X direction, and the width in the short direction is set to be sufficiently larger than the thickness of the circuit component 5.

[0030] When assembling the ink head 2, the first flow path member 3 and the second flow path member 4 are individually assembled, and the two are joined with the circuit component 5 sandwiched therebetween. The lower surface of the frame portion 41 of the second flow path member 4 and the peripheral edge portion of the upper surface 32 of the first flow path member 3 form a joining region. The first flow path member 3 and the second flow path member 4 are joined in such a manner that the piezoelectric substrate 33 as a pressurizing portion fits into the inside of the opening 41H of the frame portion 41. The pair of through holes 4H are also located within the region of the opening 41H. That is, the first flow path member 3 and the second flow path member 4 are joined in a region surrounding the outside of the through hole 4H and outside the arrangement range of the piezoelectric substrate 33. The circuit component 5 has the contact portion pre-overlapped on the piezoelectric substrate 33 of the first flow path member 3, and the through portion is inserted into the through hole 4H and pulled upward during the joining.

[0031] The ink head 2 described above has a frame structure in which the first flow path member 3 and the second flow path member 4 are joined via the frame portion 41. This frame structure has an advantage that it can suppress the intrusion of ink from the outside into the arrangement region of the piezoelectric substrate 33 as compared with a casing structure in which the first flow path member 3 and the second flow path member 4 are overlapped and the first flow path member 3 is covered with a case. That is, since the arrangement region of the piezoelectric substrate 33 is surrounded by the frame portion 41, it is easy to prevent the intrusion of ink into the region.

[0032] On the other hand, if a frame structure is adopted, there is a concern that the resistance of the ink head 2 to external impacts may decrease. For example, when an external impact is applied to the ink head 2 during a jam of the work W or the like, there is a risk that the joint state between the first flow path member 3 and the second flow path member 4 may be broken. This is because the frame portion 41 having the piezoelectric substrate 33 and the opening 41H that can surround the through hole 4H bears the joint region between the first flow path member 3 and the second flow path member 4. The longitudinal piece 412 of the frame portion 41 adjacent to the through hole 4H that is long in the X direction should be narrow from the viewpoint of suppressing the width of the ink head 2 in the short side direction. Therefore, the joint width becomes short, and there is a tendency to be brittle against external impacts. If the joint width is widened, the joint strength between the first flow path member 3 and the second flow path member 4 can be increased, and the impact resistance can be improved. However, in this case, the width of the ink head 2 in the short side direction becomes large, and the high-density arrangement of the ink head 2 in the printer 1 is hindered. Hereinafter, embodiments of an ink head having excellent impact resistance while adopting the frame structure will be described.

[0033] [First Embodiment] FIG. 5(A) is a perspective view of the ink head 2A according to the first embodiment, and FIG. 5(B) is a perspective view showing the circuit component 5A and the first flow path member 3 according to the first embodiment. FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5(A). The circuit components 5A are arranged in a pair so as to face each other in the Y direction, similar to the circuit components 5 in FIG. 4, but only one circuit component 5A is drawn in FIGS. 5 and 6. The same applies to the joint portion 6 described later.

[0034] The ink head 2A includes a first flow path member 3, a second flow path member 4 stacked on the first flow path member 3, a flat circuit component 5A, a pressing plate 56, and a joint portion 6. Since the configurations of the first flow path member 3 and the second flow path member 4 have been described above based on FIGS. 3 and 4, the description thereof will be omitted here. The differences between the ink head 2A of the present embodiment and the above-described ink head 2 are the shape of the circuit component 5A, the arrangement of the pressing plate 56, and the arrangement of the joint portion 6 in the through hole 4H. Hereinafter, these differences will be mainly described.

[0035] The circuit component 5A includes a contact portion 51, a through portion 52, a bent portion 53, a slit 54, and a connector mounting portion 55. The contact portion 51 is a flat plate portion extending in the Y direction and overlaps on the piezoelectric substrate 33 disposed on the upper surface 32 of the first flow path member 3. On the lower surface of the contact portion 51, the terminal electrodes of a plurality of circuit wirings included in the circuit component 5A are exposed. On the other hand, on the upper surface of the piezoelectric substrate 33, the connection terminals drawn from the individual electrodes for driving the piezoelectric element are exposed. The individual electrodes are disposed for each of the pressure chambers provided corresponding to the respective discharge holes of the first flow path member 3. The contact portion 51 is stacked on the piezoelectric substrate 33 such that the terminal electrodes contact the connection terminals.

[0036] The through portion 52 is continuous with the contact portion 51 via the bent portion 53 and is a flat plate portion extending upward. That is, the circuit component 5A is bent vertically upward at the bent portion 53 and has an L-shaped shape in the X-direction view with the contact portion 51 extending in the Y direction and the through portion 52 extending in the Z direction. The through portion 52 vertically penetrates the through hole 4H.

[0037] The slit 54 is a portion formed by notching the central portion of the through portion 52 in the X direction. In FIG. 5, an inverted U-shaped slit 54 that is long in the vertical direction is illustrated. The bottom side of the slit 54 is at a position substantially equal to the position of the bent portion 53. The upper end of the slit 54 is located slightly below the upper end of the through portion 52. Due to the formation of the slit 54, the portion excluding the vicinity of the upper end of the through portion 52 has a bifurcated shape portion 501 divided into two wiring paths. The connector mounting portion 55 is located at the upper end of the through portion 52. A connector for connecting to the control board of the ink head 2A is mounted on the connector mounting portion 55.

[0038] Referring to FIG. 5(B), ejection holes of the ink are arranged on the lower surface 31 of the first flow path member 3. FIG. 5(B) shows the arrangement width 31A of the ejection holes in the longitudinal direction. The arrangement range in the longitudinal direction of the connection terminals connected to the individual electrodes of the piezoelectric substrate 33 described above is substantially the same as the arrangement width 31A of the ejection holes. Therefore, the width in the longitudinal direction where the contact portion 51 of the circuit component 5A and the piezoelectric substrate 33 come into contact is also substantially the same as the arrangement width 31A of the ejection holes.

[0039] In addition to the circuit wiring, the circuit component 5A requires a wiring area for the ground wiring and also needs to secure an insulating area at the edge portion. For this reason, the longitudinal width of the circuit component 5A is slightly longer than the arrangement width 31A of the ejection holes. The longitudinal width of the through hole 4H also needs to be slightly longer than the longitudinal width of the circuit component 5A in order to penetrate the circuit component 5A. Thus, the through hole 4H needs to be opened substantially with a longitudinal width longer than the arrangement width 31A of the ejection holes. As a result, the through hole 4H extends over most of the longitudinal width of the second flow path member 4, which may cause a decrease in the mechanical strength of the ink head 2A.

[0040] Referring to FIG. 6, the pressing plate 56 is composed of a rectangular flat plate having the same size as the arrangement range of the piezoelectric substrate 33. The pressing plate 56 is disposed between the upper surface of the contact portion 51 of the circuit component 5A and the second flow path member 4. The pressing plate 56 is provided to press the contact portion 51 from above. That is, the contact portion 51 is in contact with the piezoelectric substrate 33 while being pressed by the pressing plate 56. By arranging the pressing plate 56, the contact state between the piezoelectric substrate 33 and the contact portion 51 can be stabilized.

[0041] The joint portion 6 is disposed in the central region in the longitudinal direction of the through hole 4H and is a member that connects the opposing side walls of the through hole 4H in the short direction. The joint portion 6 can be formed, for example, by fitting a spacer-like member having a length corresponding to the short-side width of the through hole 4H into the central region in the longitudinal direction of the through hole 4H. Another preferred example of forming the joint portion 6 is a method of potting a thermosetting resin in the central region of the through hole 4H and then heating and curing the potted resin. By connecting the central region in the longitudinal direction of the through hole 4H with the joint portion 6, the amount of deflection when an external load is applied to the second flow path member 4 is significantly suppressed. Therefore, even when an external impact acts on the ink head 2A, the distortion force applied to the joint portion between the first flow path member 3 and the second flow path member 4 can be suppressed. This contributes to maintaining the joint state between the first flow path member 3 and the second flow path member 4.

[0042] The circuit component 5A is drawn out to the outside through the through hole 4H in a region other than the joint portion 6. The slit 54 of the circuit component 5A is disposed at a position corresponding to the joint portion 6 in a state where it is incorporated into the ink head 2A. The bifurcated shape portion 501 penetrates the through hole 4H with the joint portion 6 interposed therebetween. When assembling the ink head 2A, the first flow path member 3 and the second flow path member 4 are joined while passing the circuit component 5A through the through hole 4H, and the joint portion 6 is formed at the position of the slit 54.

[0043] As a result of the joint portion 6 being disposed, as shown in FIG. 6, the second flow path member 4 has a solid cross-section along the short direction in the central region in its longitudinal direction. The "solid" here means that at least a part of the through hole 4H is filled with a filler or a constituent material of the second flow path member 4. The presence of the flow path 4P or the like necessary for the second flow path member 4 to perform its original function in the short-direction cross-section does not impede the meaning of "solid".

[0044] In FIG. 6, an example is shown in which the through-hole 4H on the -Y side is filled with a joint portion 6 having a length extending over the entire vertical length of the through-hole 4H. The through-hole 4H on the +Y side is also entirely filled with the joint portion 6, but the description thereof is omitted in FIG. 6. The joint portion 6 only needs to connect the side walls facing each other in the short-side direction of the through-hole 4H at at least a part of the through-hole 4H, preferably at a part or all of the thin-wall portion 43, and does not necessarily need to fill the entire vertical length of the through-hole 4H. This point will be described later with reference to FIG. 10.

[0045] According to the ink head 2A of the first embodiment, the second flow path member 4 has a through-hole 4H that penetrates the circuit component 5A in the vertical direction, and has a solid short-side cross section in the central region in the longitudinal direction. Therefore, the strength of the second flow path member 4 against external impacts that may be applied to the ink head 2A can be increased. Accordingly, the influence on the stacked state of the first flow path member 3 and the second flow path member 4, that is, the joint state of the first flow path member 3 and the second flow path member 4, can be suppressed. As a result, the entry of liquid from the outside into the ink head 2A through the joint portion between the first flow path member 3 and the second flow path member 4 can be suppressed.

[0046] [Second Embodiment] FIG. 7(A) is a perspective view of the ink head 2B of the second embodiment, and FIG. 7(B) is a perspective view showing the circuit component 5B and the first flow path member 3 of the second embodiment. FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 7(A). The circuit components 5B are arranged in a pair so as to face each other in the Y direction, but only one of the circuit components 5B is depicted in FIGS. 7 and 8.

[0047] The ink head 2B includes a first flow path member 3, a second flow path member 4 stacked on the first flow path member 3, a flat circuit component 5B, a pressing plate 56, and a joint portion 6A. Since the first flow path member 3, the second flow path member 4, and the pressing plate 56 are as described above, the description thereof is omitted here. The circuit component 5B of the second embodiment is of a separated type in which the circuit is separated into two, and the joint portion 6A is a mode of previously dividing the through-hole 4H into two.

[0048] The circuit component 5B includes a contact portion 51, a first through portion 52A, a second through portion 52B, a bent portion 53, a separation portion 540, a first connector mounting portion 55A, and a second connector mounting portion 55B. The contact portion 51 is a flat plate portion extending in the Y direction, and is superimposed on the piezoelectric substrate 33 disposed on the upper surface 32 of the first flow path member 3. The contact portion 51 is pressed by a pressing plate 56.

[0049] The first through portion 52A and the second through portion 52B are respectively connected to the contact portion 51 via the bent portion 53, and are flat plate portions extending upward. The first through portion 52A and the second through portion 52B are arranged side by side with the separation portion 540 interposed therebetween in the X direction. The first through portion 52A and the second through portion 52B are composed of a rectangular lower portion and a trapezoidal upper portion that becomes narrower upward. The first through portion 52A and the second through portion 52B penetrate the through hole 4H in the vertical direction.

[0050] The separation portion 540 is a notch portion that divides the region of the circuit component 5B excluding the contact portion 51 into two. Due to the formation of the separation portion 540, the circuit component 5B has a bifurcated shape portion 502 in which the wiring path is divided into two, the first through portion 52A and the second through portion 52B. The first connector mounting portion 55A is located at the upper end of the first through portion 52A. The second connector mounting portion 55B is located at the upper end of the second through portion 52B. Connectors for connecting to the control board of the ink head 2B are respectively mounted on the connector mounting portions 55A and 55B.

[0051] Referring to the enlarged view of FIG. 8 (the joining portion 6A is omitted), the bent portion 53 is bent upward along the side of the pressing plate 56. The base portion of the separation portion 540, that is, the starting point 541 of the bifurcated shape portion 502, is located in the region of the contact portion 51. The bent portion 53 is a portion where the circuit component 5B is bent at a right angle near the base of the first through portion 52A and the second through portion 52B. In other words, the circuit component 5B has a bifurcated shape at the contact portion 51 before reaching the bent portion 53, and the bifurcated shape portion 502 is located at the bent portion 53. Therefore, the bent portion 53 can be easily formed as compared with the case of bending at the starting point 541 of the bifurcated shape portion 502 or in the region before branching into a bifurcated shape.

[0052] The joint portion 6A is disposed in the central region in the longitudinal direction of the through hole 4H and connects the opposing side walls of the through hole 4H in the short direction, which is the same as the joint portion 6 of the first embodiment. The joint portion 6A is different from the joint portion 6 of the first embodiment in that it is not attached to the through hole 4H retrospectively, but is provided in advance in a manner of dividing the through hole 4H at the central portion in the longitudinal direction. The joint portion 6A is made of the constituent material of the second flow path member 4 and bridges the opposing side walls of the through hole 4H. The joint portion 6A can be formed, for example, by using a plate material in which two long holes are drilled on the -Y side and the +Y side with the central region in the longitudinal direction interposed therebetween as the constituent material of the second flow path member 4. In this case, the central region becomes the joint portion 6A, and the two long holes become the through hole 4H.

[0053] The circuit component 5B is drawn out to the outside through the through hole 4H in a region other than the joint portion 6A. The separation portion 540 of the circuit component 5B is disposed at a position corresponding to the joint portion 6A in a state of being incorporated into the ink head 2B. The bifurcated shape portion 502 penetrates the through hole 4H with the joint portion 6A interposed therebetween. When assembling the ink head 2B, it becomes a working procedure of joining the first flow path member 3 and the second flow path member 4 while passing the circuit component 5B through the through hole 4H.

[0054] In the second embodiment, the through hole 4H is not a single long hole extending in the X direction, but is composed of two relatively short long holes divided by the joint portion 6A. Due to the intervention of the joint portion 6A, the amount of deflection when an external load is applied to the second flow path member 4 from the outside is significantly suppressed. Therefore, the impact resistance of the ink head 2B can be improved. As a result of the joint portion 6A being disposed, as shown in FIG. 8, the second flow path member 4 has a solid cross section in the short direction except for the portion of the cross section along the short direction in the central region in the longitudinal direction. Therefore, the strength of the second flow path member 4 against an external impact that may be applied to the ink head 2B can be increased.

[0055] [Connection mode of circuit components to the control board] The circuit components 5A and 5B illustrated in the above embodiments are connected to a control board that controls the operations of the ink heads 2A and 2B. FIGS. 9(A) to 9(C) are schematic diagrams showing examples of the connection modes of the circuit components 5A and 5B to the control board 90.

[0056] FIG. 9(A) shows the connection mode of the circuit component 5A with the slit 54 illustrated in the first embodiment. A connector 91 is attached to the connector mounting portion 55 of the circuit component 5A. The connector 91 is connected to a connection port provided on the control board 90. FIG. 9(B) shows the connection mode of the circuit component 5B with the separation portion 540 illustrated in the second embodiment. A first connector 91A is attached to the first connector mounting portion 55A of the circuit component 5B, and a second connector 91B is attached to the second connector mounting portion 55B. The first connector 91A and the second connector 91B are respectively connected to two connection ports provided on the control board 90.

[0057] FIG. 9(C) shows another example of the connection mode of the circuit component 5B. In this example, a relay board 92 is interposed between the circuit component 5B and the control board 90. The relay board 92 includes two connection ports to which the first connector 91A and the second connector 91B are connected. The relay board 92 further includes a relay circuit component 93 for connection to the control board 90. A third connector 94 is attached to the relay circuit component 93. The control board 90 has a connection port to which the third connector 94 is connected. By using the relay board 92, the control board 90 can be shared by both the circuit component 5A and the circuit component 5B.

[0058] [Various Embodiments of the Joint Portion] Next, various aspects of the joint portion of the through hole 4H will be described. FIG. 10 is a cross-sectional view in the short side direction of the ink head 2B of the second embodiment, showing the same cross-section as FIG. 8 mentioned above. The second flow path member 4 of the ink head 2B includes a thick wall portion 44, a thin wall portion 43, and a frame portion 41 as a lower region in this order from above. The frame portion 41 is between a first surface 41A that is joined to the first flow path member 3 and a second surface 41B that is located above the first surface 41A and has the lower end of the opening of the through hole 4H. The width in the short side direction of the first surface 41A of the frame portion 41 is the joining width W0 between the first flow path member 3 and the second flow path member 4.

[0059] The thick wall portion 44 and the thin wall portion 43 are walls that partition the through hole 4H. The thick wall portion 44 is a region with a length W1 from the through hole 4H to the outer surface of the second flow path member 4, that is, the outer surface orthogonal to the Y short side direction. The thin wall portion 43 is a region with a length W2 from the through hole 4H to the outer surface, and the relationship is W1>W2. The length W2 may be set to be equal to or less than the joining width W0. In this embodiment, W2 = W0 is illustrated. On the other hand, the length W1 is set to be longer than the joining width W0.

[0060] In FIG. 10, an example is shown where the joint portion 6A exists over the entire length in the vertical direction of the through hole 4H, but the joint portion 6A may be formed based on the following criteria. When the length from the upper surface 32 of the first flow path member 3 to the upper surface 4U of the second flow path member 4 is L1, the length L3 in the vertical direction where the joint portion 6A is formed is set to be half or more of L1 (L3≧L1 / 2). The region other than the length L3 may be a cavity or may be filled with grease or a gel-like substance. According to this aspect, in the second flow path member 4, the joint portion 6A of the through hole 4H occupies more than half of the length in the vertical direction of the second flow path member 4. Therefore, the strength of the second flow path member 4 can be increased.

[0061] Other criteria are as follows. Let the length from the first surface 41A to the second surface 41B of the frame portion 41 as the lower region be L2. In the vertical range D2 where the thin-walled portion 43 exists, set the vertical length where the joint portion 6A exists to be longer than L2. The short-side length W2 of the thin-walled portion 43 is relatively short and is a portion that easily bends when an external impact is applied. According to this aspect, the vertical width where the joint portion 6A exists in the thin-walled portion 43 is longer than L2, which is the vertical width of the frame portion 41 responsible for joining with the first flow path member 3. For this reason, the region where the joint portion 6A exists in the thin-walled portion 43 becomes dominant, and thus the strength of the second flow path member 4 is enhanced. Of course, it is desirable to form the joint portion 6A over the entire vertical length of the thin-walled portion 43.

[0062] Still another criterion is as follows. When setting the region from the lower surface 31 of the first flow path member 3 to the upper end of the thin-walled portion 43 as L4 in the vertical direction for the joint portion 6A, arrange it at a position including the vertical midpoint CP of the region L4. According to this aspect, due to the formation of the through hole 4H, in the region L3 from the lower surface 31 of the first flow path member 3, which is likely to have low strength, to the upper end of the thin-walled portion 43, the joint portion 6A is arranged at a position including the midpoint CP of the region L3. That is, since the joint portion 6A is disposed at the midpoint CP of the region that is likely to be a weak point in terms of strength, the strength of the second flow path member 4 and the joint region between the first flow path member 3 and the second flow path member 4 can be enhanced.

[0063] FIG. 11 is a diagram for explaining a desirable aspect of the joint portion 6A. It is desirable that the longitudinal width a1 of the joint portion 6A be wider than the short-side width a2 of the region where the first flow path member 3 and the second flow path member 4 are joined. The width a2 is the longitudinal piece 413 corresponding to the short-side width of the longitudinal piece 412 of the frame portion 41, that is, the joining width W0. According to this aspect, while enhancing the strength of the joint portion 6A itself, a structure is formed in which the relatively narrow longitudinal piece 413 is supported by the relatively wide joint portion 6A serving as a beam. Therefore, the strength of the second flow path member 4 can be enhanced.

[0064] FIG. 12 is a diagram for explaining the aspect of the through hole 4H. In the ink head 2B of the second embodiment, the ratio of the longitudinal width a3 of one of the two divided parts of the through hole 4H at the joint 6A to the lateral width a2 of the longitudinal piece 413 corresponding to the joint width W0 can be selected in the range of a2:a3 = 1:1 or more and 50 or less.

[0065] [Summary of the Present Disclosure] The specific embodiments described above include the following disclosures.

[0066] A liquid ejection head according to one aspect of the present disclosure has a lateral direction and a longitudinal direction, and includes a first flow path member that ejects liquid, a second flow path member that is stacked on the first flow path member, has a width equivalent to the lateral direction of the first flow path member, and supplies liquid to the first flow path member, and a flat circuit component that sends a signal for liquid ejection to the first flow path member. The circuit component includes a portion that penetrates the second flow path member in the vertical direction, and the second flow path member has a solid cross-section along the lateral direction in the central region in the longitudinal direction.

[0067] According to this aspect, the second flow path member has a solid lateral cross-section in the central region in the longitudinal direction while including a portion that allows the circuit component to penetrate in the vertical direction. Therefore, the strength of the second flow path member against an external impact that may be applied to the liquid ejection head can be increased. Accordingly, the influence on the stacked state of the first flow path member and the second flow path member, for example, the joint state between the first flow path member and the second flow path member, can be suppressed. As a result, the entry of liquid from the outside into the liquid ejection head through the stacked region of the first flow path member and the second flow path member can be suppressed.

[0068] In the above liquid ejection head, the second flow path member includes a through hole formed by a long hole extending in the longitudinal direction, and a joint portion that connects the opposing side walls of the through hole is provided in the central region in the longitudinal direction of the through hole. The circuit component may penetrate the through hole in a region other than the joint portion.

[0069] According to this aspect, although the through-hole for drawing out the circuit component is provided in the second flow path member, a joint portion for realizing the above-described "solid" structure is provided in the central region in the longitudinal direction of the through-hole. Therefore, the impact resistance of the second flow path member can be increased.

[0070] In the above liquid discharge head, the circuit component may include a bifurcated portion that penetrates the through-hole with the joint portion interposed therebetween.

[0071] According to this aspect, even if the joint portion exists in the central region in the longitudinal direction of the through-hole, the circuit component can be drawn out from the through-hole while avoiding the joint portion.

[0072] In the above liquid discharge head, the first flow path member includes a pressurizing portion disposed above the first flow path member and disposed within a rectangular arrangement range for electrically performing a liquid discharge operation. The liquid discharge head includes a pressing plate having a size equivalent to the arrangement range of the pressurizing portion. The circuit component includes a contact portion that abuts against the pressurizing portion while being pressed from above by the pressing plate, a bent portion that continues from the contact portion and is bent along the side of the pressing plate, and a penetrating portion that continues from the bent portion and penetrates the through-hole. The starting point of the bifurcated portion may be located at the contact portion.

[0073] According to this aspect, the arrangement of the pressing plate can stabilize the contact state between the pressurizing portion and the contact portion of the circuit component. Further, the portion where the circuit component has a bifurcated shape is located at the contact portion. That is, the circuit component becomes bifurcated at the contact portion before reaching the bent portion, and the bifurcated portion is located at the bent portion. For this reason, the bent portion can be easily formed as compared with the case of bending at the starting point of the bifurcated portion or in the region before branching into the bifurcated shape.

[0074] In the above-described liquid ejection head, the first flow path member is disposed above the first flow path member and includes a pressurizing portion for electrically performing the liquid ejection operation. The circuit component is disposed to send the signal to the pressurizing portion. The first flow path member and the second flow path member may be joined in a region surrounding the outside of the through hole and outside the arrangement range of the pressurizing portion.

[0075] According to this aspect, the first flow path member and the second flow path member are joined in a region surrounding the pressurizing portion. For this reason, it is possible to easily increase the joining strength between the first flow path member and the second flow path member, and to form a structure in which it is difficult for liquid to enter the pressurizing portion from the outside.

[0076] In the above-described liquid ejection head, it is desirable that the length in the vertical direction in which the joint portion is formed is at least half of the length from the upper surface of the first flow path member to the upper surface of the second flow path member.

[0077] According to this aspect, the joint portion of the through hole in the second flow path member occupies at least half of the length in the vertical direction of the second flow path member. Therefore, the strength of the second flow path member can be increased.

[0078] In the above-described liquid ejection head, when the width in the short side direction of the liquid ejection head of the joint region between the first flow path member and the second flow path member is defined as the joint width, the second flow path member includes a lower region between a first surface joined to the first flow path member and a second surface located above the first surface and having the through hole opened therein, and a thin wall portion having a length from the through hole to the outer surface of the second flow path member of not more than the joint width as a wall partitioning the through hole. The length in the vertical direction in which the joint portion exists can be made longer than the length in the vertical direction in which the thin wall portion exists within the range from the first surface to the second surface.

[0079] According to this aspect, the vertical width in which the joint exists in the thin-wall portion of the second flow path member is longer than the vertical width of the lower region responsible for joining with the first flow path member. Therefore, the region where the joint exists becomes dominant, and the strength of the second flow path member is increased.

[0080] In the above liquid ejection head, the second flow path member may have a thick-wall portion on the thin-wall portion, the length from the through hole to the outer surface of the second flow path member being longer than the joint width.

[0081] According to this aspect, the strength of the second flow path member can be further increased by the arrangement of the thick-wall portion.

[0082] In the above liquid ejection head, when the width in the short direction of the liquid ejection head in the joint region between the first flow path member and the second flow path member is defined as the joint width, the second flow path member has, as a wall partitioning the through hole, a thin-wall portion with a length from the through hole to the outer surface of the second flow path member being equal to or less than the joint width, and the joint may be arranged at a position including the midpoint from the lower surface of the first flow path member to the upper end of the thin-wall portion in the vertical direction.

[0083] According to this aspect, due to the formation of the through hole, in the region from the lower surface of the first flow path member, which is likely to have low strength, to the upper end of the thin-wall portion, the joint is arranged at a position including the midpoint of the region. That is, since the joint is arranged at the midpoint portion of the region that is likely to be a weak point in terms of strength, the strength of the second flow path member and the joint region between the first flow path member and the second flow path member can be increased.

[0084] Also in this liquid ejection head, the second flow path member may have a thick-wall portion on the thin-wall portion, the length from the through hole to the outer surface of the second flow path member being longer than the joint width. The strength of the second flow path member can be further increased by the arrangement of the thick-wall portion.

[0085] In the above liquid ejection head, the width of the joint in the longitudinal direction may be made wider than the width in the short direction of the region where the joint is made.

[0086] According to this aspect, the strength of the joint itself can be increased, and thus the strength of the second flow path member having the through hole can be increased.

[0087] A recording apparatus according to another aspect of the present disclosure includes the above-described liquid ejection head, a recording medium on which the liquid ejected from the liquid ejection head lands, and a moving unit that relatively moves the recording medium and the liquid ejection head.

[0088] According to this aspect, a recording apparatus can be provided that can suppress the intrusion of liquid from the outside into the liquid ejection head.

Explanation of Reference Numerals

[0089] 1 Inkjet Printer (Recording Apparatus) 2, 2A, 2B Ink Head (Liquid Ejection Head) 3 First Flow Path Member 31 Lower Surface 32 Upper Surface 33 Piezoelectric Substrate (Pressurizing Portion) 4 Second Flow Path Member 4H Through Hole 4U Upper Surface 41 Frame Portion (Lower Region) 41A, 41B First Surface, Second Surface 43 Thin Wall Portion 44 Thick Wall Portion 5, 5A, 5B Circuit Components 501, 502 Binary Shape Portion 56 Pressing Plate 51 Contact Portion 52 Through Portion 53 Bending Portion 6, 6A Joint Portion 7 Moving Unit CP Midpoint W Workpiece (Recording Medium) W0 Joint Width W1 Length from the Through Hole to the Outer Surface of the Thick Wall Portion W2 Length from the Through Hole to the Outer Surface of the Thin Wall Portion L1 Length from the Upper Surface of the First Flow Path Member to the Upper Surface of the Second Flow Path Member Length from the first surface to the second surface of L2 Length in the vertical direction where the joint is formed of L3

Claims

1. A first flow path member having a short-side direction and a long-side direction and discharging a liquid, a second flow path member stacked on the first flow path member, having a width equivalent to the short-side direction of the first flow path member, and supplying the liquid to the first flow path member, and a flat circuit component that sends a signal for liquid discharge to the first flow path member, wherein the circuit component includes a portion that penetrates the second flow path member in the vertical direction, and the second flow path member has a solid cross-section along the short-side direction in a central region in the long-side direction, the liquid discharge head.

2. In the liquid discharge head according to Claim 1, the second flow path member includes a through hole formed by a long hole extending in the long-side direction, a joint portion connecting opposite side walls of the through hole is provided in a central region in the long-side direction of the through hole, and the circuit component penetrates the through hole in a region other than the joint portion, the liquid discharge head.

3. In the liquid discharge head according to Claim 2, the circuit component includes a bifurcated portion that penetrates the through hole with the joint portion interposed therebetween, the liquid discharge head.

4. In the liquid discharge head according to Claim 3, the first flow path member includes a pressurizing portion disposed above the first flow path member and disposed within a rectangular arrangement range for electrically performing a liquid discharge operation, the liquid discharge head includes a pressing plate having a size equivalent to the arrangement range of the pressurizing portion, the circuit component includes a contact portion that contacts the pressurizing portion while being pressed from above by the pressing plate, a bent portion that is continuous with the contact portion and bent along a side of the pressing plate, and a penetrating portion that is continuous from the bent portion and penetrates the through hole, and a starting point of the bifurcated portion is located at the contact portion, the liquid discharge head.

5. In the liquid discharge head according to Claim 2, the first flow path member includes a pressurizing portion disposed above the first flow path member for electrically performing a liquid discharge operation, the circuit component is disposed to send the signal to the pressurizing portion, and the first flow path member and the second flow path member are joined in a region surrounding the outside of the through hole and outside the arrangement range of the pressurizing portion, the liquid discharge head.

6. In the liquid discharge head according to Claim 5, a vertical length in which the joint portion is formed is half or more of a length from an upper surface of the first flow path member to an upper surface of the second flow path member, the liquid discharge head.

7. In the liquid discharge head according to claim 5, when the width in the short direction of the liquid discharge head in the joining region between the first flow path member and the second flow path member is defined as the joining width, the second flow path member has a lower region between a first surface joined to the first flow path member and a second surface located above the first surface and having the through hole opened therein, and has, as a wall partitioning the through hole, a thin wall portion in which the length from the through hole to the outer surface of the second flow path member is equal to or less than the joining width, a liquid discharge head in which the length in the vertical direction where the joining portion exists is longer than the length from the first surface to the second surface within the vertical range where the thin wall portion exists.

8. In the liquid discharge head according to claim 7, the second flow path member has, above the thin wall portion, a thick wall portion in which the length from the through hole to the outer surface of the second flow path member is longer than the joining width, the liquid discharge head.

9. In the liquid discharge head according to claim 5, when the width in the short direction of the liquid discharge head in the joining region between the first flow path member and the second flow path member is defined as the joining width, the second flow path member has, as a wall partitioning the through hole, a thin wall portion in which the length from the through hole to the outer surface of the second flow path member is equal to or less than the joining width, and the joining portion is arranged at a position including the midpoint from the lower surface of the first flow path member to the upper end of the thin wall portion in the vertical direction, the liquid discharge head.

10. In the liquid discharge head according to claim 9, the second flow path member has, above the thin wall portion, a thick wall portion in which the length from the through hole to the outer surface of the second flow path member is longer than the joining width, the liquid discharge head.

11. In the liquid discharge head according to claim 5, the width in the longitudinal direction of the joining portion is wider than the width in the short direction of the region where the joining is performed, the liquid discharge head.

12. A recording apparatus comprising the liquid discharge head according to claims 1 to 11, a recording medium for landing the liquid discharged from the liquid discharge head, and a moving unit for relatively moving the recording medium and the liquid discharge head.

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