Liquid ejection head

Abstract

To determine whether a first head chip can be reused.SOLUTION: A liquid ejection head includes a first head chip having: a plurality of nozzles that eject a liquid; and a common liquid chamber that communicates with the plurality of nozzles. The first head chip includes: a filter that divides the common liquid chamber into an upstream chamber and a downstream chamber and allows the liquid to pass therethrough; a first flow passage member that defines the downstream chamber; and a second flow passage member that defines the upstream chamber. The filter is disposed between the first flow passage member and the second flow passage member, and each of the first flow passage member and the second flow passage member is formed of a translucent material.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a liquid jet head. [Background technology]

[0002] Inkjet printers and other devices generally include a liquid jet head that jets liquid such as ink. The liquid jet head described in Patent Document 1 includes a head chip having a filter that divides a common liquid chamber, which communicates with a plurality of nozzles, into an upstream common liquid chamber and a downstream common liquid chamber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-098016 Summary of the Invention [Problem to be solved by the invention]

[0004] It is desirable to recycle liquid jet heads by reusing head chips extracted from used liquid jet heads. However, in the past, it was not possible to determine the degree of clogging of the filters arranged in the head chips, which meant that it was unclear whether the used head chips could be reused. [Means for solving the problem]

[0005] In order to solve the above problems, a liquid jet head according to a preferred embodiment of the present disclosure is a liquid jet head including a first head chip having a plurality of nozzles for ejecting liquid and a common liquid chamber communicating with the plurality of nozzles, wherein the first head chip includes a filter that divides the common liquid chamber into an upstream chamber and a downstream chamber and allows liquid to pass through, a first flow path member that defines the downstream chamber, and a second flow path member that defines the upstream chamber, the filter being disposed between the first flow path member and the second flow path member, and each of the first flow path member and the second flow path member being made of a light-transmitting material. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a schematic diagram illustrating an example of the configuration of a liquid jet apparatus including a liquid jet head according to an embodiment. [Figure 2] FIG. 2 is a perspective view of a liquid jet head and a support according to the embodiment. [Figure 3] FIG. 1 is an exploded perspective view of a liquid jet head according to an embodiment. [Figure 4] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 5] FIG. 2 is an exploded perspective view of a head chip. [Figure 6] FIG. 2 is a cross-sectional view of a head chip. DETAILED DESCRIPTION OF THE INVENTION

[0007] Preferred embodiments of the present disclosure will be described below with reference to the accompanying drawings. Note that the dimensions and scale of each part in the drawings may differ from the actual dimensions and are shown schematically to facilitate understanding. Furthermore, the scope of the present disclosure is not limited to these embodiments unless otherwise specified in the following description to the effect that the present disclosure is limited.

[0008] For convenience, the following description will use the mutually intersecting X-axis, Y-axis, and Z-axis as appropriate. In the following, one direction along the X-axis is the X1 direction, and the direction opposite the X1 direction is the X2 direction. Similarly, the opposite directions along the Y-axis are the Y1 direction and the Y2 direction. Furthermore, the opposite directions along the Z-axis are the Z1 direction and the Z2 direction. The Z2 direction is an example of a "first direction," and the Z1 direction is an example of a "second direction."

[0009] Typically, the Z axis is a vertical axis, and the Z2 direction corresponds to the downward direction in the vertical direction. However, the Z axis does not have to be a vertical axis. Furthermore, the X axis, Y axis, and Z axis are typically perpendicular to each other, but are not limited to this. For example, they may intersect at an angle between 80° and 100°.

[0010] 1. Embodiment 1-1. Schematic configuration of the liquid ejection device FIG. 1 is a schematic diagram showing an example of the configuration of a liquid ejection device 100 including a liquid ejection head 50 according to an embodiment. The liquid ejection device 100 is an inkjet printing device that ejects ink, which is an example of a "liquid," as droplets onto a medium M. The medium M is typically printing paper. Note that the medium M is not limited to printing paper, and may be a printing target made of any material, such as a resin film or fabric.

[0011] As shown in FIG. 1, the liquid ejecting device 100 includes a liquid storage section 10, a control unit 20, a transport mechanism 30, a movement mechanism 40, and a liquid ejecting head 50.

[0012] The liquid storage unit 10 is a container that stores ink. Specific examples of the liquid storage unit 10 include a cartridge that is detachable from the liquid ejection device 100, a bag-shaped ink pack made of a flexible film, and a container such as an ink tank that can be refilled with ink.

[0013] Although not shown, the liquid storage unit 10 has multiple containers that store different types of ink. The inks stored in the multiple containers are not particularly limited, but include, for example, cyan ink, magenta ink, yellow ink, black ink, clear ink, white ink, and treatment liquid, and a combination of two or more of these is used. The composition of the ink is not particularly limited, and may be, for example, a water-based ink in which a coloring material such as a dye or pigment is dissolved in a water-based solvent, a solvent-based ink in which a coloring material is dissolved in an organic solvent, or a UV-curable ink.

[0014] The control unit 20 controls the operation of each element of the liquid ejection device 100. For example, the control unit 20 includes a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage circuit such as a semiconductor memory. The control unit 20 outputs a drive signal D and a control signal S to the liquid ejection head 50. The drive signal D is a signal including a drive pulse that drives a drive element of the liquid ejection head 50. The control signal S is a signal that specifies whether or not to supply the drive signal D to the drive element.

[0015] The transport mechanism 30 transports the medium M in a transport direction DM under the control of the control unit 20. In the example shown in FIG. 1, the transport direction DM is the Y1 direction. The movement mechanism 40 reciprocates the liquid ejection head 50 in the X1 direction and the X2 direction under the control of the control unit 20. In the example shown in FIG. 1, the movement mechanism 40 has a substantially box-shaped support 41 called a carriage that houses the liquid ejection head 50, and a transport belt 42 to which the support 41 is fixed. The support 41 supports the liquid ejection head 50 and is made of a metal material. In addition to the liquid ejection head 50, the aforementioned liquid storage unit 10 may also be mounted on the support 41.

[0016] The liquid jet head 50 includes a plurality of head chips 54, and under the control of the control unit 20, ejects ink supplied from the liquid storage section 10 from each of the plurality of nozzles of each head chip 54 in the Z2 direction toward the medium M. This ejection is performed in parallel with the transport of the medium M by the transport mechanism 30 and the reciprocating movement of the liquid jet head 50 by the movement mechanism 40, thereby forming a predetermined image in ink on the surface of the medium M. Of the plurality of head chips 54, any one of the head chips 54 is an example of a "first head chip," and any other one of the head chips 54 is an example of a "second head chip."

[0017] The liquid storage unit 10 may be connected to the liquid jet head 50 via a circulation mechanism. The circulation mechanism supplies ink to the liquid jet head 50 and recovers ink discharged from the liquid jet head 50 for resupply to the liquid jet head 50. The operation of the circulation mechanism can suppress an increase in the viscosity of the ink and reduce the accumulation of air bubbles in the ink.

[0018] 1-2. Liquid jet head installation status 2 is a perspective view of a liquid jet head 50 and a support 41 according to an embodiment. As shown in FIG. 2, the liquid jet head 50 is supported by the support 41. The support 41 is a member that supports the liquid jet head 50, and as described above, in this embodiment, is a substantially box-shaped carriage. The support 41 is made of a metal material such as stainless steel, aluminum, titanium, or a magnesium alloy.

[0019] Here, the support body 41 is provided with an opening 41a and a plurality of screw holes 41b. In this embodiment, the support body 41 is substantially box-shaped with a plate-like bottom, and, for example, the opening 41a and the plurality of screw holes 41b are provided in the bottom. The liquid jet head 50 is inserted into the opening 41a and fixed to the support body 41 by screws using the plurality of screw holes 41b. As described above, the liquid jet head 50 is attached to the support body 41.

[0020] 2, one liquid jet head 50 is attached to the support 41. However, the number of liquid jet heads 50 attached to the support 41 may be two or more. In this case, the arrangement and orientation of the multiple liquid jet heads 50 are set appropriately according to the specifications of the liquid jet device 100 and are arbitrary, and the support 41 is provided with openings 41a of, for example, the number or shape corresponding to the number.

[0021] 1-3. Liquid jet head configuration Fig. 3 is an exploded perspective view of the liquid jet head 50 according to the embodiment. Fig. 4 is a cross-sectional view taken along line AA in Fig. 2. For convenience, each part of the liquid jet head 50 is shown in an appropriately simplified manner in Figs. 3 and 4.

[0022] As shown in FIG. 3, the liquid jet head 50 includes a flow path structure 51, a substrate unit 52, a holder 53, four head chips 54-1 to 54-4, a fixing plate 55, a heater 56, a heat transfer member 57, and a cover 58.

[0023] Each of head chips 54-1 to 54-4 is head chip 54 shown in Fig. 1. Here, head chip 54-1 is an example of a "first head chip," and head chip 54-2 is an example of a "second head chip." Hereinafter, when head chips 54-1 to 54-4 are not to be distinguished from one another, each of these chips will be referred to as head chip 54.

[0024] The cover 58, the substrate unit 52, the flow path structure 51, the heat transfer member 57, the heater 56, the holder 53, the four head chips 54-1 to 54-4, and the fixing plate 55 are arranged in this order in the Z2 direction. Each part of the liquid jet head 50 will be described below in order.

[0025] The flow path structure 51 is a structure in which a flow path is provided inside for supplying the ink stored in the liquid storage portion 10 to the four head chips 54. The flow path structure 51 has a flow path member 51a and eight connection pipes 51b.

[0026] Although not shown, the flow path member 51a is provided with four supply flow paths, one for each of the four ink types, and four discharge flow paths, one for each of the four ink types. Each of the four supply flow paths has one inlet for receiving a supply of ink and two outlets for discharging the ink. Each of the four discharge flow paths has two inlet ports for receiving a supply of ink and one outlet port for discharging the ink. The inlet ports of each supply flow path and the outlet ports of each discharge flow path are provided on a surface of the flow path member 51a facing the Z1 direction. In contrast, the outlet ports of each supply flow path and the inlet ports of each discharge flow path are provided on a surface of the flow path member 51a facing the Z2 direction.

[0027] Furthermore, the flow path member 51a is provided with a plurality of wiring holes 51c. Each of the plurality of wiring holes 51c is a hole through which a wiring substrate 54i (described later) of the head chip 54 is passed toward the substrate unit 52. The flow path member 51a is also provided with holes (not shown), and is fixed to the holder 53 by screws using the holes.

[0028] Although not shown, the flow path member 51a is composed of a laminate of multiple substrates stacked in the direction along the Z axis. Grooves and holes for the aforementioned supply and discharge flow paths are appropriately formed in each of the multiple substrates. The multiple substrates are joined to each other, for example, by adhesive, brazing, welding, or screw fastening. If necessary, a sheet-like sealing member made of a rubber material or the like may be appropriately disposed between the multiple substrates. The number and thickness of the substrates constituting the flow path member 51a are determined depending on the shape and other aspects of the supply and discharge flow paths, and are not particularly limited and are arbitrary. Each of the multiple substrates is composed of a metal material such as stainless steel, titanium, or magnesium alloy, or a ceramic material such as silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet, or yttria.

[0029] Each of the eight connecting pipes 51b is a pipe protruding from the surface of the flow path member 51a facing the Z1 direction. The eight connecting pipes 51b correspond to the four supply flow paths and four discharge flow paths described above, and are connected to the inlets of the corresponding supply flow paths or the outlets of the corresponding discharge flow paths. Each connecting pipe 51b is made of a metal material such as stainless steel, titanium, or magnesium alloy, or a ceramic material such as silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet, or yttria.

[0030] Of the eight connection tubes 51b, four connection tubes 51b corresponding to the four supply flow paths are connected to the liquid storage unit 10 so as to receive different types of ink. On the other hand, of the eight connection tubes 51b, four connection tubes 51b corresponding to the four discharge flow paths are connected to a discharge container for discharging ink at a predetermined time, such as when the liquid jet head 50 is initially filled with ink, or to a sub-tank or the like that is disposed between the liquid storage unit 10 and the liquid jet head 50 and is capable of holding liquid. During normal times, such as during printing, the four connection tubes 51b corresponding to the four discharge flow paths are closed with a sealing body such as a cap. Note that when the liquid storage unit 10 is connected to the liquid jet head 50 via a circulation mechanism, the four connection tubes 51b corresponding to the four discharge flow paths are normally connected to a flow path for recovering ink in the circulation mechanism.

[0031] The substrate unit 52 is an assembly having mounted components for electrically connecting the liquid jet head 50 to the control unit 20. The substrate unit 52 has a circuit board 52a, a connector 52b, and a support plate 52c.

[0032] The circuit board 52a is a printed wiring board such as a rigid wiring board having wiring for electrically connecting each head chip 54 and the connector 52b. The circuit board 52a is disposed on the flow path structure 51 via a support plate 52c, and the connector 52b is disposed on the surface of the circuit board 52a facing the Z1 direction.

[0033] The connector 52b is a connecting part for electrically connecting the liquid jet head 50 and the control unit 20. The support plate 52c is a plate-shaped member for attaching the circuit board 52a to the flow path structure 51. The circuit board 52a is placed on one surface of the support plate 52c, and the circuit board 52a is fixed to the support plate 52c by screwing or the like. The other surface of the support plate 52c is in contact with the flow path structure 51, and in this state, the support plate 52c is fixed to the flow path structure 51 by screwing or the like.

[0034] Here, the support plate 52c not only supports the circuit board 52a as described above, but also ensures electrical insulation between the circuit board 52a and the flow path structure 51 and provides thermal insulation between the heater 56 and the circuit board 52a. To optimally perform these functions, the constituent material of the support plate 52c is preferably a material with excellent insulating and thermal insulation properties. Specifically, for example, a resin material such as a modified polyphenylene ether resin such as Zylon, a polyphenylene sulfide resin, or a polypropylene resin is preferred. Zylon is a registered trademark. The constituent material of the support plate 52c may include, in addition to the resin material, a fiber base material such as glass fiber, or a filler such as alumina particles.

[0035] The holder 53 is a structure that houses and supports the four head chips 54. The holder 53 is made of, for example, a metal material such as stainless steel, titanium, or magnesium alloy, or a ceramic material such as silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet, or yttria. This allows heat from the heater 56 to be efficiently transferred to each head chip 54 via the holder 53. The holder 53 may also be made of a resin composition containing resin.

[0036] The holder 53 is generally tray-shaped. The holder 53 is rectangular or generally rectangular in plan view. The shape of the holder 53 in plan view is not limited to the example shown in the drawing, and may be any shape.

[0037] The holder 53 has a recess 53a, multiple ink holes 53b, multiple wiring holes 53c, multiple recesses 53d, multiple screw holes 53i, and multiple screw holes 53k. The recess 53a opens in the Z1 direction and is a space in which the laminate of the flow path member 51a, the heater 56, and the heat transfer member 57 is disposed. Each of the multiple ink holes 53b is a flow path that allows ink to circulate between the head chip 54 and the flow path structure 51. Each of the multiple wiring holes 53c is a hole through which a wiring substrate 54i of the head chip 54 is inserted toward the substrate unit 52. Each of the multiple recesses 53d opens in the Z2 direction and is a space in which the head chip 54 is disposed. The multiple screw holes 53i are screw holes for screwing the holder 53 to the support body 41. The multiple screw holes 53k are screw holes for screwing a cover 58 to the holder 53.

[0038] Each head chip 54 ejects ink. More specifically, each head chip 54 has a nozzle surface FN. Although not shown in FIG. 3, the nozzle surface FN is provided with a plurality of nozzles that eject a first ink and a plurality of nozzles that eject a second ink that is different from the first ink. Here, the first ink and the second ink are two of the four types of ink mentioned above. For example, head chip 54-1 and head chip 54-2 each use two of the four types of ink as the first ink and the second ink. Then, head chip 54-3 and head chip 54-4 each use the remaining two of the four types of ink. Each head chip 54 is provided with a wiring substrate 54i. Note that FIG. 3 shows a simplified configuration of each head chip 54. The configuration of the head chip 54 will be described in detail later with reference to FIGS. 5 and 6.

[0039] Fixing plate 55 is a plate-like member to which four head chips 54 and holder 53 are fixed. Specifically, fixing plate 55 is arranged so that four head chips 54 are sandwiched between fixing plate 55 and holder 53, and each head chip 54 and holder 53 are fixed with an adhesive or the like. In this manner, head chips 54-1 to 54-4 are fixed to fixing plate 55.

[0040] The fixing plate 55 is provided with a plurality of openings 55a that expose the nozzle surfaces FN of the four head chips 54. In the example shown in FIG. 3, the plurality of openings 55a are individually provided for each head chip 54. The fixing plate 55 may be made of a metal material such as stainless steel, titanium, or magnesium alloy, but is preferably made of a light-transmitting material such as glass or resin. By making the fixing plate 55 of a light-transmitting material, the first flow path member 54d (described below) of each head chip 54 can be visually confirmed without removing the fixing plate 55 from the holder 53. The fixing plate 55 may be formed by combining a plate-shaped member made of a metal material with a plate-shaped member made of a glass or resin material. The openings 55a may also be shared by two or more head chips 54.

[0041] The heater 56 is a planar heater disposed between the flow path structure 51 and the holder 53. The heater 56 is, for example, a film heater having a thin-film substrate, an insulating film, and a heating resistor sandwiched between the substrate and the film.

[0042] The heater 56 is provided with a plurality of holes 56a and a plurality of holes 56b. Each of the plurality of holes 56a is a hole through which the wiring board 54i of the head chip 54 and the tubular protrusion in which the ink hole 53b of the holder 53 opens are passed. Each of the plurality of holes 56b is a hole for fastening the heater 56 to the holder 53 with a screw. The shape of the heater 56 is not limited to the example shown in the figure and is arbitrary. The heater 56 may be provided as needed or may be omitted.

[0043] The heat transfer member 57 is a plate-like member having thermal conductivity and disposed between the flow path structure 51 and the heater 56. The heat transfer member 57 has the function of transferring heat in both the thickness direction and the surface direction. Due to this function, heat from the heater 56 is efficiently transferred to the flow path structure 51 via the heat transfer member 57.

[0044] To optimally perform the above-described functions, the heat transfer member 57 is made of a thermally conductive material such as a metal material or ceramics. Examples of the metal material include stainless steel, aluminum, titanium, and magnesium alloys. Examples of the ceramic material include silicon carbide, aluminum nitride, sapphire, alumina, silicon nitride, cermet, and yttria.

[0045] The heat transfer member 57 is provided with a plurality of holes 57a, a plurality of wiring holes 57b, and a plurality of holes 57c. Each of the plurality of holes 57a is a hole through which a tubular protrusion, which opens into the ink hole 53b of the holder 53, is inserted. Each of the plurality of wiring holes 57b is a hole through which the wiring substrate 54i of the head chip 54 is passed toward the substrate unit 52. The plurality of holes 57c are holes for screwing the heat transfer member 57 to the holder 53. In this embodiment, two of the plurality of holes 57c are used to fasten the heater 56 and the heat transfer member 57 to the holder 53 by tightening them together. The heat transfer member 57 may be provided as needed and may be omitted.

[0046] The cover 58 is a box-shaped member that houses the board unit 52. The cover 58 is made of a resin material such as modified polyphenylene ether resin, polyphenylene sulfide resin, or polypropylene resin, similar to the support plate 52c described above.

[0047] Eight through holes 58a and an opening 58b are provided in the cover 58. The eight through holes 58a correspond to the eight connecting pipes 51b of the flow path structure 51, and the corresponding connecting pipes 51b are inserted into each through hole 58a. The aforementioned connector 52b is passed through the opening 58b from the inside to the outside of the cover 58.

[0048] 1-4.Head chip configuration Fig. 5 is an exploded perspective view of head chip 54. Fig. 6 is a cross-sectional view of head chip 54 taken along line VI-VI in Fig. 5. In this embodiment, head chips 54-1 to 54-4 have a common configuration, and each of head chips 54-1 to 54-4 has the configuration described below.

[0049] 5 and 6, the head chip 54 has a plurality of nozzles N arranged in the direction along the Y axis. The plurality of nozzles N are divided into a first row L1 and a second row L2 arranged at intervals in the direction along the X axis. Each of the first row L1 and the second row L2 is a collection of a plurality of nozzles N arranged linearly in the direction along the Y axis.

[0050] The head chips 54 are configured to be approximately symmetrical with respect to each other in the direction along the X-axis. However, the positions of the multiple nozzles N in the first row L1 and the multiple nozzles N in the second row L2 in the direction along the Y-axis may or may not match. Figures 5 and 6 show an example of a configuration in which the positions of the multiple nozzles N in the first row L1 and the multiple nozzles N in the second row L2 in the direction along the Y-axis match each other.

[0051] As shown in Figures 5 and 6, the head chip 54 has a flow path substrate 54a, a pressure chamber substrate 54b, a nozzle plate 54c, a first flow path member 54d, a vibration plate 54e, multiple piezoelectric elements 54f, a protective plate 54g, a second flow path member 54h, a wiring substrate 54i, a drive circuit 54j, and a filter F.

[0052] The flow path substrate 54a and the pressure chamber substrate 54b are stacked in this order in the Z1 direction to form a flow path for supplying ink to the multiple nozzles N. A vibration plate 54e, multiple piezoelectric elements 54f, a protective plate 54g, a second flow path member 54h, a wiring substrate 54i, and a drive circuit 54j are installed in an area located further in the Z1 direction than the stack of the flow path substrate 54a and the pressure chamber substrate 54b. A filter F is disposed between the flow path substrate 54a and the second flow path member 54h. Meanwhile, a nozzle plate 54c and a first flow path member 54d are installed in an area located further in the Z2 direction than the stack. Each element of the head chip 54 is generally a plate-like member elongated in the Y direction and joined to each other, for example, with an adhesive. Each element of the head chip 54 will be described below in order.

[0053] The nozzle plate 54c is a plate-like member having a plurality of nozzles N arranged in a first row L1 and a second row L2. Therefore, the head chip 54 has a plurality of nozzles N that eject liquid. Each of the nozzles N is a through-hole that allows ink to pass through. As described below, the ink is ejected in response to pressure changes in the pressure chambers C caused by deformation of the vibration plate 54e due to driving of the piezoelectric element 54f. The surface of the nozzle plate 54c facing the Z2 direction is the nozzle surface FN. The nozzle plate 54c is manufactured by processing a silicon single crystal substrate using semiconductor manufacturing techniques, such as dry etching or wet etching. However, other known methods and materials may also be used to manufacture the nozzle plate 54c. The cross-sectional shape of the nozzle is typically circular, but is not limited thereto and may be non-circular, such as polygonal or elliptical.

[0054] The flow path substrate 54a is provided with a downstream chamber R1, a plurality of supply flow paths Ra, and a plurality of communication flow paths Na for each of the first row L1 and the second row L2. The downstream chamber R1 is an elongated opening extending in the direction along the Y axis in a plan view seen in the direction along the Z axis. Each of the supply flow paths Ra and the communication flow paths Na is a through hole formed for each nozzle N. Each supply flow path Ra communicates with the downstream chamber R1.

[0055] The pressure chamber substrate 54b is a plate-like member in which a plurality of pressure chambers C, called cavities, are provided in each of a first row L1 and a second row L2. The plurality of pressure chambers C are arranged in a direction along the Y axis. Each pressure chamber C is formed for each nozzle N and is an elongated space extending in a direction along the X axis in a plan view. Like the nozzle plate 54c described above, the flow path substrate 54a and the pressure chamber substrate 54b are each manufactured by processing a silicon single crystal substrate using semiconductor manufacturing technology, for example. However, other known methods and materials may also be used as appropriate to manufacture the flow path substrate 54a and the pressure chamber substrate 54b.

[0056] The pressure chambers C are spaces located between the flow path substrate 54a and the vibration plate 54e. A plurality of pressure chambers C are arranged in the direction along the Y axis in each of the first row L1 and the second row L2. The pressure chambers C are also connected to the communication flow path Na and the supply flow path Ra. Therefore, the pressure chambers C are connected to the nozzle N via the communication flow path Na and to the downstream chamber R1 via the supply flow path Ra.

[0057] A diaphragm 54e is disposed on the surface of the pressure chamber substrate 54b facing the Z1 direction. The diaphragm 54e is a plate-like member that can elastically vibrate. The diaphragm 54e has, for example, a first layer and a second layer, which are stacked in this order in the Z1 direction. The first layer is, for example, an elastic film made of silicon oxide (SiO2). The elastic film is formed, for example, by thermally oxidizing one surface of a silicon single crystal substrate. The second layer is, for example, an insulating film made of zirconium oxide (ZrO2). The insulating film is formed, for example, by forming a zirconium layer by sputtering and then thermally oxidizing the layer. Note that the diaphragm 54e is not limited to the configuration of the stacked first and second layers described above, and may be, for example, a single layer or three or more layers.

[0058] On the surface of the vibration plate 54e facing the Z1 direction, a plurality of piezoelectric elements 54f corresponding to the nozzles N are arranged as drive elements in each of the first row L1 and the second row L2. Each piezoelectric element 54f is a passive element that deforms when a drive signal is supplied. Each piezoelectric element 54f has an elongated shape extending in the direction along the X-axis in a plan view. The plurality of piezoelectric elements 54f are arranged in the direction along the Y-axis so as to correspond to the plurality of pressure chambers C. The piezoelectric elements 54f overlap the pressure chambers C in a plan view.

[0059] Although not shown, each piezoelectric element 54f has a first electrode, a piezoelectric layer, and a second electrode, which are stacked in this order in the Z1 direction. One of the first and second electrodes is an individual electrode spaced apart from each other for each piezoelectric element 54f, and a drive signal is applied to that electrode. The other of the first and second electrodes is a strip-shaped common electrode extending continuously along the Y-axis across the plurality of piezoelectric elements 54f, and a predetermined reference potential is supplied to that other electrode. Examples of metal materials for these electrodes include platinum (Pt), aluminum (Al), nickel (Ni), gold (Au), and copper (Cu). These metals can be used singly or in combination of two or more in the form of an alloy or a laminate. The piezoelectric layer is made of a piezoelectric material such as lead zirconate titanate (Pb(Zr,Ti)O3) and has, for example, a strip shape extending continuously along the Y-axis across the plurality of piezoelectric elements 54f. However, the piezoelectric layer may be integral across the plurality of piezoelectric elements 54f. In this case, through-holes are provided in the piezoelectric layer extending along the X-axis in areas corresponding in plan view to the gaps between adjacent pressure chambers C. When the vibration plate 54e vibrates in conjunction with the deformation of the piezoelectric elements 54f, the pressure in the pressure chambers C fluctuates, causing ink to be ejected from the nozzles N. Note that instead of the piezoelectric elements 54f, a heating element that heats the ink in the pressure chambers C may be used as the driving element.

[0060] The wiring board 54i is mounted on the surface of the diaphragm 54e facing the Z1 direction and is a mounting component for electrically connecting the control unit 20 and the head chip 54. The wiring board 54i is a flexible wiring board such as a COF (Chip On Film), an FPC (Flexible Printed Circuit), or an FFC (Flexible Flat Cable). In this embodiment, a drive circuit 54j for supplying a drive voltage to each piezoelectric element 54f is mounted on the wiring board 54i. The drive circuit 54j is a circuit including a switching element that switches whether or not at least a portion of the waveform included in the drive signal D is supplied as a drive pulse to the drive element based on the control signal S.

[0061] The protective plate 54g is a plate-like member installed on the surface of the diaphragm 54e facing the Z1 direction, and protects the multiple piezoelectric elements 54f and reinforces the mechanical strength of the diaphragm 54e. The multiple piezoelectric elements 54f are housed between the protective plate 54g and the diaphragm 54e. The protective plate 54g is made of, for example, a resin material.

[0062] The second flow path member 54h is a case for storing ink to be supplied to the multiple pressure chambers C and defines an upstream chamber R2. The second flow path member 54h is made of, for example, a resin material. The second flow path member 54h has an upstream chamber R2 for each of the first row L1 and the second row L2. The upstream chamber R2 is a space that communicates with the downstream chamber R1 and, together with the downstream chamber R1, functions as a common liquid chamber R that stores ink to be supplied to the multiple pressure chambers C. The second flow path member 54h has an inlet HL for supplying ink to each common liquid chamber R. That is, the second flow path member 54h has an inlet HL for introducing ink into the upstream chamber R2. This allows liquid to be introduced into the upstream chamber R2 through the inlet HL. The ink in each common liquid chamber R is supplied to the pressure chamber C via each supply flow path Ra. In this way, the head chip 54 has a common liquid chamber R that communicates with the multiple nozzles N. In the example shown in Figure 5, there are two inlet ports HL provided for one common liquid chamber R, but this is not limited to this, and for example, there may be one inlet port HL provided for one common liquid chamber R.

[0063] The second flow path member 54h is made of a light-transmitting material. This allows the second flow path member 54h to transmit light inside and outside the upstream chamber R2. Therefore, light LL can be irradiated from outside the head chip 54 toward the filter F through the second flow path member 54h. Here, the second flow path member 54h defines at least a portion of the upper surface of the head chip 54. Therefore, light LL is irradiated from the upper surface toward the lower surface of the head chip 54. The "upper surface" refers to the surface facing one side and the other side in the thickness direction of the filter F that faces away from the liquid ejection direction from the head chip 54-1. The "lower surface" refers to the surface facing one side and the other side in the thickness direction of the filter F that faces the liquid ejection direction from the head chip 54-1.

[0064] The specific material constituting the second flow path member 54h is not particularly limited as long as it is a material that is translucent and resistant to ink, but examples include resin materials such as acrylic resin or cycloolefin copolymer (COC). Here, from the viewpoint of enhancing translucency, it is preferable that the resin material does not substantially contain a black or dark coloring agent. Furthermore, from the viewpoint of enhancing translucency and increasing the mechanical strength of the second flow path member 54h, it is preferable that the resin material contains an inorganic filler such as glass filler. Note that the second flow path member 54h does not have to be transparent and may be colored as long as it is translucent.

[0065] A filter F is provided in each common liquid chamber R. The filter F is a member that allows ink to pass through while capturing foreign matter moving toward the nozzle N. The filter F divides the common liquid chamber R into an upstream chamber R2 and a downstream chamber R1 and allows ink to pass through. The filter F is interposed between the flow path substrate 54a and the second flow path member 54h and is bonded to the flow path substrate 54a and the second flow path member 54h. As described above, the filter F is disposed between the first flow path member 54d and the second flow path member 54h. The filter F is made of a metal such as NiPd and manufactured by electroforming. Note that the manufacturing method of the filter F is not limited to electroforming and may be, for example, a method using etching. Two filters F may be connected to each other to form a frame. Furthermore, the constituent material of the filter F is not limited to metal and may be, for example, single crystal silicon or resin.

[0066] The first flow path member 54d is a compliance film made of a flexible film that forms the wall surface of the common liquid chamber R and defines the downstream chamber R1. The first flow path member 54d absorbs pressure fluctuations of the ink in the common liquid chamber R. The surface of the first flow path member 54d facing the Z1 direction is bonded to the flow path substrate 54a with an adhesive or the like. On the other hand, a frame 54k is bonded to the surface of the first flow path member 54d facing the Z2 direction with an adhesive or the like. The frame 54k is a frame-shaped member that fits along the outer periphery of the first flow path member 54d and comes into contact with the fixing plate 55 described above. Here, the frame 54k is made of a metal material such as stainless steel, aluminum, titanium, or a magnesium alloy.

[0067] The first flow path member 54d is made of a light-transmitting material. As a result, with light LL irradiated from the outside of the head chip 54 toward the filter F via the second flow path member 54h as described above, the presence or degree of clogging of the filter F can be observed from the outside of the head chip 54 via the first flow path member 54d, as indicated by the arrow OR in FIG. 6. Here, the first flow path member 54d defines at least a portion of the lower surface of the head chip 54. Therefore, with light LL irradiated from the upper surface of the head chip 54 toward the lower surface, the filter F can be observed from the lower surface of the head chip 54 toward the upper surface via the first flow path member 54d.

[0068] In this way, by irradiating light from one of the first flow path member 54d and the second flow path member 54h toward the other, it is possible to observe from the outside of the head chip 54-1 whether or not the filter F is clogged, and the degree of clogging. This makes it possible to determine whether the head chip 54-1 can be reused. Note that even if the filter F is clogged, the head chip 54-1 may be reused by cleaning the inside of the head chip 54-1. In this way, determining whether the head chip 54-1 can be reused includes identifying the head chip 54-1 to be cleaned.

[0069] The presence or degree of clogging of the filter F may be observed visually, but from the viewpoint of increasing the accuracy of determining whether the head chip 54-1 can be reused, it is preferable to calculate the clogging rate of the filter F by analyzing image data obtained by capturing an image using an optical device such as a camera using image recognition technology or the like. Note that the optical device may be a device provided as part of the liquid ejection device 100, or may be a device separate from the liquid ejection device 100. Furthermore, the determination of whether the head chip 54-1 can be reused may be made based on the number of light-transmitting holes in the filter F and the amount of light transmitted through the filter F, instead of the clogging rate.

[0070] A specific material for forming the first flow path member 54d is, from the viewpoints of resistance to ink and transparency for favorable visual recognition of the filter F, a resin such as polyphenylene sulfide (PPS) or polyaramid.

[0071] As described above, the first flow path member 54d is a flexible thin film. Therefore, the first flow path member 54d can be used as a compliance film. Furthermore, because the first flow path member 54d is a thin film, there is an advantage in that the state of the filter F can be easily visually confirmed through the first flow path member 54d. Here, the thickness of the first flow path member 54d is preferably, for example, 3 μm or more and 5 μm or less, from the viewpoint of ensuring transparency for favorable visual confirmation of the filter F while favorably functioning as a compliance film.

[0072] As described above, each of head chips 54-1 to 54-4 includes nozzle plate 54c, first flow path member 54d, filter F, and second flow path member 54h. Therefore, for each of head chips 54-1 to 54-4, it is possible to observe from the outside whether or not the filter F is clogged, and to what extent.

[0073] When viewed in the direction in which the filter F and the first flow path member 54d overlap, the fixing plate 55 overlaps the filter F. Therefore, if the fixing plate 55 is not transparent, it is necessary to remove the fixing plate 55 in order to observe the filter F through the first flow path member 54d. However, the head chip 54 may remain attached to the holder 53, or may be removed from the holder 53.

[0074] The fixing plate 55 may be made of a light-transmitting material. In this case, the state of the filter F in each head chip 54 can be observed without disassembling the fixing plate 55 and the head chip 54. If light is introduced from the side of the holder 53 that holds these head chips 54 using an opening in the housing of the liquid ejection head 50, the state of the filter F can be suitably observed even without disassembling the fixing plate 55 and the head chip.

[0075] As described above, in the liquid ejection head 50, the first flow path member 54d and the second flow path member 54h are each made of a light-transmitting material, so that by observing the presence or degree of clogging of the filter F from the outside of the head chip 54-1, it is possible to determine whether the head chip 54-1 can be reused.

[0076] 2. Variations The above-described exemplary embodiments can be modified in various ways. Specific modified embodiments that can be applied to the above-described embodiments are exemplified below. Two or more embodiments arbitrarily selected from the following examples can be combined as appropriate to the extent that they are not mutually contradictory.

[0077] 2-1. Variation 1 In the above-described embodiment, an example is given in which the first flow path member 54d is a compliance film and the second flow path member 54h is a case, but this is not limiting. The "first flow path member" may be any element that is located in the Z2 direction relative to the filter F among the elements that make up the head chip 54. For example, if a sealing plate is used instead of a compliance film, it may be the sealing plate. Furthermore, the "second flow path member" may be any element that is located in the Z1 direction relative to the filter F among the elements that make up the head chip 54. For example, if the case is made up of multiple members, it may be any one of the multiple members.

[0078] 2-2. Variation 2 In the above-described embodiment, an example is given in which the liquid jet head has four head chips, but this is not the only possible embodiment, and the number of head chips that the liquid jet head has may be three or less, or five or more. Furthermore, when the liquid jet head has multiple head chips, the arrangement and orientation of the multiple head chips are not limited to those in the above-described embodiment and are arbitrary. Furthermore, the shape of the liquid jet head is also not limited to those in the above-described embodiment and is arbitrary.

[0079] 2-3. Variation 3 In the above-described embodiment, a serial type liquid ejection device 100 was exemplified in which a support 41 carrying a liquid ejection head 1 is moved back and forth in the width direction of the medium M, but the liquid ejection device may also be a line type in which multiple nozzles N are distributed across the entire width of the medium M.

[0080] 2-4. Variation 4 The liquid ejection apparatus exemplified in the above-described embodiment can be employed in various devices such as facsimile machines and copiers, in addition to devices dedicated to printing. However, the uses of the liquid ejection apparatus are not limited to printing. For example, a liquid ejection apparatus that ejects a solution of a coloring material is used as a manufacturing apparatus for forming color filters for display devices such as liquid crystal display panels. Furthermore, a liquid ejection apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus for forming wiring and electrodes on a wiring board. Furthermore, a liquid ejection apparatus that ejects a solution of an organic substance related to a living body is used as a manufacturing apparatus for manufacturing biochips, for example.

[0081] 3. Notes A summary of this disclosure is provided below.

[0082] (Appendix 1) A first aspect, which is a preferred example of the liquid jet head of the present disclosure, is a liquid jet head comprising a first head chip having a plurality of nozzles for ejecting liquid and a common liquid chamber communicating with the plurality of nozzles, wherein the first head chip includes a filter that divides the common liquid chamber into an upstream chamber and a downstream chamber and allows liquid to pass through, a first flow path member that defines the downstream chamber, and a second flow path member that defines the upstream chamber, the filter being disposed between the first flow path member and the second flow path member, and each of the first flow path member and the second flow path member being made of a light-transmitting material.

[0083] In the above-described embodiment, by irradiating light from one of the first flow path member and the second flow path member toward the other, it is possible to observe from the outside of the first head chip whether or not the filter is clogged, and the degree of clogging. This makes it possible to determine whether the first head chip can be reused. Note that even if the filter is clogged, the first head chip may be reused by cleaning the inside of the first head chip. In this way, determining whether the first head chip can be reused includes identifying the first head chip to be cleaned.

[0084] (Supplementary Note 2) In a second aspect that is a preferred example of the first aspect, the first flow path member defines at least a part of the lower surface of the first head chip, and the second flow path member defines at least a part of the upper surface of the first head chip. In the above aspect, with light irradiated from one of the upper and lower surfaces of the first head chip toward the other, the presence or degree of clogging of the filter can be observed from outside the first head chip by irradiating the light from the other toward the one.

[0085] (Note 3) In a third aspect, which is a preferred example of the first or second aspect, the first flow path member is a flexible thin film. In the above aspects, a compliance film can be used as the first flow path member. In addition, because the first flow path member is a thin film, there is an advantage that the state of the filter can be easily visually confirmed through the first flow path member.

[0086] (Supplementary Note 4) In a fourth aspect which is a preferred example of any of the first to third aspects, the second flow path member has an inlet for introducing a liquid into the upstream chamber. In the above aspects, the liquid is introduced into the upstream chamber through the inlet.

[0087] (Supplementary Note 5) In a fifth aspect which is a suitable example of any of the first to fourth aspects, the liquid jet head further includes a second head chip, and each of the first head chip and the second head chip includes a nozzle plate having the plurality of nozzles, the first flow path member, the filter, and the second flow path member. In the above aspect, the presence or absence of clogging of the filter of each of the first head chip and the second head chip can be observed from the outside.

[0088] (Supplementary Note 6) In a sixth aspect, which is a preferred example of the fifth aspect, the liquid jet head further includes a fixing plate to which the first head chip and the second head chip are fixed, the fixing plate having a plurality of openings for exposing the nozzle plates of the first head chip and the second head chip to the outside, the fixing plate being made of a light-transmitting material. In the above aspect, since the fixing plate is made of a light-transmitting material, it is possible to observe the state of the filter in each head chip without disassembling the fixing plate and the head chips. Note that by introducing light from the holder side that holds these head chips using an opening in the housing of the liquid jet head, it is possible to preferably observe the state of the filter even without disassembling the fixing plate and the head chips. [Explanation of symbols]

[0089] 1...liquid jet head, 54-1...head chip (first head chip), 54-2...head chip (second head chip), 54c...nozzle plate, 54d...first flow path member, 54h...second flow path member, 55...fixing plate, 55a...opening, F...filter, HL...inlet, N...nozzle, R...common liquid chamber, R1...downstream chamber, R2...upstream chamber.

Claims

1. A liquid jet head including a first head chip having a plurality of nozzles for jetting liquid and a common liquid chamber communicating with the plurality of nozzles, The first head chip a filter that divides the common liquid chamber into an upstream chamber and a downstream chamber and allows liquid to pass through; a first flow path member defining the downstream chamber; a second flow path member defining the upstream chamber; the filter is disposed between the first flow path member and the second flow path member, Each of the first flow path member and the second flow path member is made of a light-transmitting material. A liquid jet head characterized by:

2. the first flow path member defines at least a portion of a lower surface of the first head chip; the second flow path member defines at least a portion of an upper surface of the first head chip; The liquid jet head according to claim 1 .

3. The first flow path member is a flexible thin film. The liquid jet head according to claim 2 .

4. The second flow path member has an inlet for introducing a liquid into the upstream chamber. The liquid jet head according to claim 2 .

5. Further comprising a second head chip, Each of the first head chip and the second head chip includes: a nozzle plate having the plurality of nozzles; The first flow path member; the filter; The second flow path member, The liquid jet head according to claim 1 .

6. a fixing plate to which the first head chip and the second head chip are fixed, the fixing plate having a plurality of openings for exposing the nozzle plates of the first head chip and the second head chip to the outside, The fixing plate is made of a light-transmitting material. The liquid jet head according to claim 5 .

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