The present application is based on, and claims priority from, JP Application Serial Number 2018-137108, filed Jul. 20, 2018, the disclosure of which is hereby incorporated by reference herein in its entirety.
The present disclosure relates to a liquid ejecting apparatus and a liquid ejecting head.
A liquid ejecting head that ejects an ink in a pressure chamber from a nozzle by changing the capacity of the pressure chamber by a piezoelectric element has been proposed. Since there is no need to heat an ink in a configuration using a piezoelectric element, various types of inks can be used. Specifically, various reactive inks such as a solvent ink containing an organic solvent are used as well as a water-based ink and an oil-based ink.
A reactive ink tends to be highly aggressive to other members formed of an organic material or the like. JP-A-2012-183669 discloses an improvement in an adhesive used for a liquid ejecting head that ejects an ink having high aggressiveness.
However, the reactive ink may affect elements other than the adhesive, for example, a member constituting a channel or a connection portion between terminals. With the configuration that ejects a very small amount of an ink, since an atomized ink electrically charged by the Lenard effect adheres to a wire, a problem in the case of using the reactive ink is particularly significant. In view of the above-described circumstances, even when the adhesive is improved by the technique disclosed in JP-A-2012-183669, various failures due to the reactive ink cannot be sufficiently addressed.
To address the above-described problem, a liquid ejecting apparatus according to a desirable aspect of the present disclosure includes a liquid ejecting unit including at least one pressure chamber filled with a reactive ink, at least one nozzle communicating with the pressure chamber, a supply channel through which the reactive ink is supplied to the pressure chamber, and an elastic compliance film forming a portion of the supply channel; a piezoelectric element that changes a capacity of the pressure chamber when an electric signal is supplied to the piezoelectric element; and a flexible wiring substrate at which a signal wire for supplying the electric signal to a connection terminal of the piezoelectric element is formed. The elastic compliance film is formed of a para-aramid resin. The connection terminal and the signal wire are electrically connected to each other by solder.
A liquid ejecting head according to another desirable aspect of the present disclosure includes a liquid ejecting unit including at least one pressure chamber filled with a reactive ink, at least one nozzle communicating with the pressure chamber, a supply channel through which the reactive ink is supplied to the pressure chamber, and an elastic compliance film forming a portion of the supply channel; a piezoelectric element that changes a capacity of the pressure chamber when an electric signal is supplied to the piezoelectric element; and a flexible wiring substrate at which a signal wire for supplying the electric signal to a connection terminal of the piezoelectric element is formed. The elastic compliance film is formed of a para-aramid resin. The connection terminal and the signal wire are electrically connected to each other by solder.
The liquid ejecting apparatus 100 according to the first embodiment ejects a reactive ink onto the medium 12. Typical examples of the reactive ink include a solvent ink in which a coloring material such as a pigment or a dye is dispersed in one of various solvents, such as an oil-based solvent or a water-based solvent; or a photoreactive ink whose characteristics are changed by irradiation with light. Examples of the photoreactive ink include an ultraviolet curable ink which is cured by irradiation with ultraviolet rays. A solvent ink is disclosed in, for example, JP-A-2014-80539, and a photoreactive ink is disclosed in, for example, JP-A-2015-174077. In addition to the solvent ink and the photoreactive ink exemplified above, a textile printing ink suitable for textile printing on a fabric or a pretreatment ink previously ejected to a fabric as a pretreatment of textile printing is also an example of the reactive ink. A textile printing ink is disclosed in, for example, JP-A-2017-222943, and a pretreatment ink is disclosed in JP-A-2004-143621. A reactive ink tends to be more aggressive to an organic material than a water-based ink.
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The movement mechanism 24 reciprocates the liquid ejecting head 26 in the X direction under the control of the control unit 20. The X direction is a direction orthogonal to the Y direction in which the medium 12 is transported. The movement mechanism 24 according to the first embodiment includes a substantially box-shaped transport body 242 (carriage) that houses the liquid ejecting head 26, and a transport belt 244 to which the transport body 242 is fixed. Alternatively, a configuration in which a plurality of liquid ejecting heads 26 are mounted at the transport body 242 or a configuration in which the liquid container 14 is mounted at the transport body 242 together with the liquid ejecting head 26 may also be employed.
The liquid ejecting head 26 ejects the reactive ink supplied from the liquid container 14 onto the medium 12 from a plurality of nozzles (that is, ejection holes) under the control of the control unit 20. The liquid ejecting head 26 ejects the reactive ink onto the medium 12 in synchronization with the transport of the medium 12 by the transport mechanism 22 and the repetitive reciprocation of the transport body 242. Thus, a desirable image is formed on a surface of the medium 12.
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The channel substrate 32 is a plate-shaped member for forming a channel of the reactive ink. As illustrated in
The housing 42 is a structure manufactured by, for example, injection molding using a resin material, and is fixed to the surface on the negative side in the Z direction of the channel substrate 32. As illustrated in
The vibration absorber 48 absorbs a pressure fluctuation in the liquid storage chamber R. The vibration absorber 48 of the first embodiment includes an elastic compliance film 481 and a support body 482. The elastic compliance film 481 is an elastically deformable film. As illustrated in
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The vibrating plate 36 is disposed at a surface of the pressure chamber substrate 34, on the side opposite to the channel substrate 32. The vibrating plate 36 is an elastically deformable plate-shaped member. The vibrating plate 36 is constituted of, for example, a lamination of an elastic film formed of silicon oxide (SiO2) and an insulating film formed of zirconium oxide (ZrO2).
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As understood from the above description, a channel (hereinafter referred to as “supply channel”) 60 for supplying the reactive ink to the plurality of pressure chambers C is formed in the liquid ejecting unit 30. The supply channel 60 of the first embodiment is a channel in which the inlet 424, the liquid storage chamber R (the housing portion 422 and the opening 322), the relay channel 328, and the first channels 324 are coupled to one another in that order from the inlet 424 side. The elastic compliance film 481 constitutes a portion of the supply channel 60. Accordingly, the reactive ink stored in the liquid storage chamber R comes into contact with the elastic compliance film 481. Based on the above-described configuration, the inventors of the present application have studied a material of the elastic compliance film 481 which is suitable from the viewpoint of the combination with the reactive ink.
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The piezoelectric layer 382 is formed on a surface of the first electrode 381 by using, for example, a ferroelectric piezoelectric material such as lead zirconate titanate (PZT). The second electrode 383 is formed on the surface of the piezoelectric layer 382. The second electrode 383 of the first embodiment is a band-shaped common electrode that is continuous over the plurality of piezoelectric elements 38. A predetermined reference voltage is applied to the second electrode 383.
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In a configuration (hereinafter referred to as “comparative example”) in which the signal wire 56 and the connection terminal 384 are electrically connected to each other by a conductive adhesive, the adhesive is dissolved or deteriorated due to the adhesion of the mist of the reactive ink. Therefore, a failure, such as peeling-off of the wiring substrate 50 or defective connection of the signal wire 56, may occur. In contrast to the comparative example, in the first embodiment, the signal wire 56 of the wiring substrate and the connection terminal 384 of the piezoelectric element 38 are electrically connected to each other by the solder 58. The solder 58 is hardly melted or deteriorated even when the mist of the reactive ink adheres to the solder 58. Therefore, according to the first embodiment, there is an advantage that it is possible to suppress a failure due to the adhesion of the reactive ink, such as peeling-off of the wiring substrate 50 or defective connection of the signal wire 56.
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As described above, according to the first embodiment, the elastic compliance film 481 is formed of a para-aramid resin. Therefore, for example, as compared with a configuration in which the elastic compliance film 481 is formed of polyphenylene sulfide (PPS) or the like, it is possible to suppress a failure such as dissolution or peeling-off of the elastic compliance film 481 due to the adhesion of the reactive ink. Further, the signal wire 56 and the connection terminal 384 are electrically connected to each other by the solder 58. Accordingly, as compared with a configuration in which the signal wire 56 and the connection terminal 384 are connected by a conductive adhesive, it is possible to suppress a failure such as peeling-off of the wiring substrate 50 due to the adhesion of the reactive ink.
A second embodiment of the present disclosure is described. Note that, for the elements in the following examples having functions similar to those in the first embodiment, the reference numerals used in the description of the first embodiment are used and the detailed description thereof is omitted.
The liquid ejecting unit 70 includes a channel substrate 71, a nozzle plate 72, a vibrating plate 73, a housing 74, and a fixed plate 75. The nozzle plate 72 is bonded to a surface on the positive side in the Z direction of the channel substrate 71, and the vibrating plate 73 is bonded to a surface on the negative side in the Z direction of the channel substrate 71. A plurality of nozzles N arranged in the Y direction are formed in the nozzle plate 72.
A liquid storage chamber R, a first channel 712, a pressure chamber C, and a second channel 713 are formed in the channel substrate 71. The liquid storage chamber R is a common liquid chamber that is continuous over the plurality of nozzles N. The first channel 712, the second channel 713, and the pressure chamber C are formed for each nozzle N. The first channel 712 is a contraction channel that causes the pressure chamber C to communicate with the liquid storage chamber R. The liquid storage chamber R and the first channel 712 function as a supply channel 78 through which the reactive ink is supplied to the pressure chamber C. The second channel 713 causes the pressure chamber C to communicate with the nozzle N.
The vibrating plate 73 includes an elastic film 731 and a support plate 732. The elastic film 731 is bonded to the surface of the channel substrate 71, and the support plate 732 is stacked on the elastic film 731. The elastic film 731 is formed of, for example, a para-aramid resin, and the support plate 732 is formed of, for example, stainless steel. The support plate 732 is partially removed to form an island portion 733 that overlaps the pressure chamber C. The region of the vibrating plate 73 overlapping the liquid storage chamber R is formed of a single layer of the elastic film 731 by the removal of the support plate 732, and functions as an elastic compliance film 734. Therefore, in the second embodiment as well, similarly to the first embodiment, the elastic compliance film 734 is formed of a para-aramid resin. Similarly to the first embodiment, the elastic compliance film 734 constitutes a portion of the supply channel 78, and absorbs a pressure fluctuation in the liquid storage chamber R. Specifically, the elastic compliance film 734 constitutes the upper surface of the liquid storage chamber R.
The housing 74 is bonded to a surface of the vibrating plate 73 opposite to the channel substrate 71, and the fixed plate 75 is fixed to the housing 74. The piezoelectric element 80 is a length-extension vibration driving element in which a piezoelectric layer and an electrode layer are alternately stacked, and a tip portion thereof is in contact with the island portion 733. When the island portion 733 vibrates together with the elastic film 731 in conjunction with the deformation of the piezoelectric element 80, the reactive ink filled in the pressure chamber C is ejected through the second channel 713 and the nozzle N. Similarly to the first embodiment, the liquid ejecting head 26 according to the second embodiment can eject the reactive ink by 5 pl (picoliters) or less from the nozzle N. However, the ejection amount of the reactive ink is not limited to the above-described example. A connection terminal 801 is formed at a side surface of the piezoelectric element 80.
Similarly to the first embodiment, the wiring substrate 82 includes a base member 822 at which a drive circuit 821 is mounted, and a plurality of signal wires 823. Each of the signal wires 823 of the wiring substrate 82 and the connection terminal 801 of corresponding one of the piezoelectric elements 80 are electrically connected to each other by solder 84. That is, in the first embodiment, the signal wire 56 is connected to the connection terminal 384 formed at the liquid ejecting unit 30. In contrast, in the second embodiment, the signal wire 823 is connected to the connection terminal 801 formed at the piezoelectric element 80.
Similarly to the first embodiment, the solder 84 is formed of a Sn—Pb-based alloy, a Sn—Zn-based alloy, a Sn—Cu-based alloy, a Sn—Ag-based alloy, or a Sn—Bi-based alloy. In a further desirable embodiment, lead-free solder such as a Sn—Cu-based alloy, a Sn—Ag-based alloy, or a Sn—Bi-based alloy is employed as a material for the solder 84. As described above, the elastic compliance film 734 according to the second embodiment is formed of a para-aramid resin, similarly to the first embodiment. Therefore, also in the second embodiment, advantageous effects similar to those of the first embodiment can be attained.
The embodiments described above may be modified in various ways. Specific modifications which can be applied to the above-described embodiments are exemplified below. Two or more embodiments desirably selected from the following examples may be appropriately combined within a range in which the selected embodiments do not conflict with one another.
(1) In the first embodiment, the configuration in which the first electrode 381 is an individual electrode and the second electrode 383 is a common electrode is exemplified; however, the first electrode 381 may be a common electrode that continues over the plurality of piezoelectric elements 38, and the second electrode 383 may be a separate individual electrode for each piezoelectric element 38. Further, both of the first electrode 381 and the second electrode 383 may serve as individual electrodes.
(2) In the above-described embodiments, the serial liquid ejecting apparatus 100 in which the transport body 242 at which the liquid ejecting head 26 is mounted reciprocates is exemplified; however, the present disclosure can also be applied to a line liquid ejecting apparatus in which a plurality of nozzles N are distributed over the entire width of a medium 12.
(3) The liquid ejecting apparatus 100 exemplified in each of the above-described embodiments may be employed in various apparatuses such as facsimile apparatuses and copying machines in addition to apparatuses dedicated to printing. Note that the use of the liquid ejecting apparatus of the present disclosure is not limited to printing. For example, a liquid ejecting apparatus that ejects a solution of a coloring material is used as a manufacturing apparatus that forms a color filter of a liquid crystal display device. Moreover, a liquid ejecting apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus that forms wires or electrodes of a wiring substrate.
Number | Date | Country | Kind |
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2018-137108 | Jul 2018 | JP | national |