The entire disclosures of Japanese Patent Application No. 2018-116136, filed Jun. 19, 2018 and 2019-014211, filed Jan. 30, 2019 are expressly incorporated by reference herein.
The present disclosure relates to a technique for ejecting a liquid such as ink.
For example, JP-A-2016-000488 discloses a liquid ejecting head that ejects a liquid such as ink from a plurality of nozzles. A drive IC that drives piezoelectric elements that eject ink from the nozzles is mounted in the liquid ejection head.
In a technique of JP-A-2016-000488, the drive IC generates heat by driving of the piezoelectric elements and the temperature inside a liquid ejection head increases, and, accordingly, viscosity of the ink is changed. Accordingly, there is a problem that an error in ink ejection characteristics occurs.
In order to overcome the above issue, a liquid ejecting head according to a suitable aspect of the present disclosure includes a head unit including a liquid ejecting unit that ejects a liquid from a nozzle, a drive circuit that drives the liquid ejecting unit, a containing body in which a space that stores the liquid is formed; a fixing plate which contacts the head unit on a nozzle side of the head unit; and a support that contacts the fixing plate and that supports the head unit, in which the support is formed of a material having a thermal conductivity higher than that of the containing body.
As illustrated as an example in
The moving mechanism 24 reciprocates head units 261 in an X direction under the control of the control unit 20. The X direction is a direction intersecting (typically, orthogonal) to the Y direction in which the medium 12 is transported. The moving mechanism 24 of the first embodiment includes a substantially box-shaped transport body 242 (a carriage) that houses the head units 261 and a transport belt 244 to which the transport body 242 is fixed. Note that a configuration in which a plurality of head units 261 are mounted in the transport body 242 or a configuration in which the liquid container 14 is mounted in the transport body 242 together with the head units 261 can be adopted.
The liquid ejecting head 26 includes the plurality of head units 261. Each head unit 261 ejects ink, which has been supplied from the liquid container 14, to the medium 12 through a plurality of nozzles (in other words, ejection holes) under the control of the control unit 20. Concurrently with the transportation of the medium 12 performed with the transport mechanism 22 and the repetitive reciprocation of the transport body 242, the head units 261 eject ink onto the medium 12 to form a desired image on a surface of the medium 12. Note that a direction perpendicular to an XY plane is hereinafter referred to as a Z direction. The ink ejection direction of each head unit 261 corresponds to the Z direction. The XY plane is, for example, a plane parallel to the surface of the medium 12. The Z direction is typically the vertical direction.
As illustrated as an example in
The liquid ejecting unit 50 includes a flow path structure 30 in which pressure chambers C that communicate with the nozzles N are formed, piezoelectric elements 44 that change pressures of the pressure chambers C, and a wiring substrate 46 on and in which wiring that electrically connects the drive circuit 80 and the piezoelectric elements 44 to each other is formed. The piezoelectric elements 44 are each an example of a driving element.
The flow path structure 30 is a structure that forms flow paths that supply ink to the plurality of nozzles N. The flow path structure 30 of the first embodiment includes a flow path substrate 32, a pressure chamber substrate 34, a diaphragm 42, a nozzle plate 62, and vibration absorbers 64. Each member constituting the flow path structure 30 is a plate-shaped member elongated in the Y direction. The containing body 90 and the pressure chamber substrate 34 are mounted on a surface of the flow path substrate 32 on the negative side in the Z direction. On the other hand, the nozzle plate 62 and the vibration absorbers 64 are mounted on a surface of the flow path substrate 32 on the positive side in the Z direction. Each member is fixed with an adhesive agent, for example.
The nozzle plate 62 is a plate-shaped member having the plurality of nozzles N formed therein. Each of the plurality of nozzles N is a circular through hole through which ink passes. In the nozzle plate 62 of the first embodiment, the plurality of nozzles N constituting the first line L1 and the plurality of nozzles N constituting the second line L2 are formed. The nozzle plate 62 is fabricated by processing a single crystal substrate formed of silicon (Si) using a semiconductor manufacturing technique (for example, a processing technique such as dry etching or wet etching), for example. However, any known materials and any manufacturing methods can be adopted to manufacture the nozzle plate 62.
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The wiring substrate 46 in
The containing body 90 is a case for storing the ink supplied to the plurality of pressure chambers C. A surface of the containing body 90 on the positive side in the Z direction is bonded to the flow path substrate 32 with, for example, an adhesive agent. As illustrated as an example in
The vibration absorbers 64 are elements that absorb pressure fluctuations of the ink in the liquid storage chambers R. The vibration absorbers 64 of the first embodiment each includes an elastic film 641 and a support plate 643. The elastic film 641 is a flexible member formed in a film shape. The elastic film 641 of the first embodiment is installed on a surface of the flow path substrate 32 so as to close the space Ra, the connection flow path 326 and the supply flow path 322, and constitutes the bottom of the common liquid chamber R. The support plate 643 is a flat plate formed of a material with high rigidity such as stainless steel, and supports the elastic film 641 on the surface of the flow path substrate 32 so that the opening formed in the flow path substrate 32 is closed by the elastic film 641. The pressure fluctuation in the liquid storage chamber R is suppressed by deforming the elastic film 641 according to the pressure of the ink in the storage chamber R.
The wiring substrate 46 includes a base portion 70 and a plurality of lengths of wire 72. The base portion 70 is an insulating plate-shaped member elongated in the Y direction, and is positioned between the flow path structure 30 and the drive circuit 80. The base portion 70 is fabricated by processing a single crystal substrate formed of silicon using a semiconductor manufacturing technique, for example. However, any known materials and any manufacturing methods can be adopted to manufacture the base portion 70. The lengths of wire 72 transmits, for example, a drive signal. The plurality of lengths of wire 72 are positioned at an end portion of a first surface F1 of the base portion 70 on the negative side in the Y direction.
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The fixing plate 263 is a member formed of, for example, a highly rigid metal, and each head unit 261 is fixed to the fixing plate 263. For example, the fixing plate 263 is formed of stainless steel. As illustrated in
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The support 265 is a box-shaped structure including a flat portion 653 and a frame-shaped sidewall portion protruding from the periphery of the flat portion 653 towards the positive side in the Z direction. As illustrated in
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The support 265 is formed of a material having a thermal conductivity higher than that of the containing body 90 and the fixing plate 263 of each head unit 261. For example, the support 265 is formed of a metal such as aluminum or copper. In the first embodiment, the entire support 265 is formed of metal. By forming the support 265 with a material having a thermal conductivity higher than that of the containing body 90 and the fixing plate 263, the heat generated inside the head units 261 is released to the support 265 through the fixing plate 263 in contact with the head units 261. Specifically, the heat generated in the drive circuit 80 of each head unit 261 is transmitted to the fixing plate 263 in contact with the support plate 643 of the corresponding vibration absorber 64 through the containing body 90 and the flow path structure 30 positioned in the vicinity of the drive circuit 80. The heat transmitted to the fixing plate 263 is radiated to the outside air through the support 265 in contact with the fixing plate 263. Accordingly, an increase in temperature inside each head unit 261 can be suppressed.
For example, in a configuration (hereinafter referred to as a “comparative example”) in which the support 265 is formed of a material having a thermal conductivity lower than those of the containing body 90 and the fixing plate 263, the heat generated by the drive circuit 80 is not easily transmitted to the outside of the head unit 261 and a problem occurs in that the temperature inside the head unit 261 rises. On the other hand, compared with the comparative example, in the configuration of the first embodiment in which the support 265 is formed of a material having a thermal conductivity higher than those of the containing body 90 of each head unit 261 and the fixing plate 263, the heat generated in the drive circuit 80 is efficiently released from the fixing plate 263 through the support 265. Specifically, since the area that can be used to release heat is larger than that of the comparative example, the increase in temperature inside each head unit 261 can be suppressed. Accordingly, an error in ink ejection characteristics caused by an increase in the temperature inside the head unit 261 can be reduced.
The configuration of the first embodiment in which the support 265 is formed of metal has an advantage in the heat releasing efficiency of the heat generated in each drive circuit 80. Furthermore, in the first embodiment, since the support 265 contacts the fixing plate 263 at the outer periphery of the fixing plate 263, the heat of the drive circuit 80 can be released through the outer periphery of the fixing plate 263.
A second embodiment of the present disclosure will be described. Note that in the following examples, elements having functions similar to those of the first embodiment will be denoted by applying the reference numerals used in the description of the first embodiment, and detailed description of the elements will be omitted appropriately.
As illustrated as an example in
A configuration in which a first head unit 261a, a second head unit 261b, and a third head unit 261c are fixed to the fixing plate 263 is assumed. A contact portion 654a contacts the fixing plate 263 at a portion between the first head unit 261a and the second head unit 261b. Similarly, a contact portion 654b contacts the fixing plate 263 at a portion between the second head unit 261b and the third head unit 261c. End portions of the contact portions 654 (654a and 654b) in the Z direction are joined to the surface of the fixing plate 263 with, for example, an adhesive agent. One of the first head unit 261a and the second head unit 261b is an example of a first head unit, and the other is an example of a second head unit. Furthermore, one of the second head unit 261b and the third head unit 261c is an example of the first head unit, and the other is an example of the second head unit.
In the second embodiment, the support 265 includes the first sidewall portion 651 and the second sidewall portion 652 contacting the outer periphery of the fixing plate 263, and the contact portions 654 contacting the fixing plate 263 at portions between the first sidewall portion 651 and the second sidewall portion 652; accordingly, in addition to the outer periphery of the fixing plate 263, the heat of the drive circuit 80 can be released from between the first sidewall portion 651 and the second sidewall portion 652. Heat is particularly likely to be accumulated between the head units 261 (261a, 261b, and 261c). In the second embodiment, since the support 265 includes the contact portions 654 in contact with the fixing plate 263 at portions between the head units 261, there is an advantage in that the heat accumulated between the head units 261 can be efficiently released.
Each of the configurations described above illustrated as examples can be modified in various ways. Specific modification modes that can be applied to the embodiments described above will be exemplified below. Two or more modes optionally selected from the following examples may be combined appropriately as long as they do not contradict each other.
(1) The configurations of the support 265 are not limited to the example configurations described above. The shape of the support 265 may be any shape that includes a portion in which the support 265 is in contact with the fixing plate 263. For example, a configuration in which the support 265 includes elements other than the sidewall portion and the contact portions 654 or a configuration in which the support 265 does not include the flat portion 653 may be adopted. Portions of the fixing plate 263 in contact with the support 265 may be appropriately changed according to the configuration of the support 265. In other words, the portions of the fixing plate 263 in contact with the support 265 are not limited to the outer periphery of the fixing plate 263 or the portion between the first sidewall portion 651 and the second sidewall portion 652.
(2) In the configurations described above, the fixing plate 263 is constituted by the fixing portion 631 and the peripheral portions 633; however, the shape of the fixing plate 263 is not limited to the example described above. For example, the peripheral portions 633 may be omitted. However, the area in which the fixing plate 263 and the support 265 contact each other is large in the configuration in which the fixing plate 263 includes the peripheral portions 633 and the fixing portion 631, compared with the configuration in which the fixing plate 263 does not include the peripheral portions 633. Accordingly, the heat generated from each drive circuit 80 can be efficiently released from the support 265 through the fixing plate 263. Furthermore, the fixing plate 263 may include an element other than the fixing portion 631 and the peripheral portions 633.
(3) In the configurations described above, the support 265 is formed of a material having a thermal conductivity higher than those of the containing body 90 and the fixing plate 263; however, the support 265 does not necessarily have to be formed of a material having a thermal conductivity higher than that of the fixing plate 263. When the support 265 is formed of a material having a thermal conductivity higher than that of the containing body 90, the above-described effect in which the heat generated in each drive circuit 80 is released from the fixing plate 263 through the support 265 can be achieved. However, with the configuration in which the support 265 is formed of a material having a thermal conductivity higher than that of the fixing plate 263, the heat transmitted from each drive circuit 80 to the fixing plate 263 is easily transmitted to the support 265. Accordingly, compared with a configuration in which the support 265 has a thermal conductivity lower than that of the fixing plate 263, there is an advantage that the heat of each drive circuit 80 can be released efficiently.
(4) In the configurations described above, the entire support 265 is formed of a metal material having a thermal conductivity higher than that of the containing body 90; however, a portion of the support 265 may be formed of a material having a thermal conductivity higher than that of the containing body 90. For example, the sidewall portion in contact with the fixing plate 263 may be formed of a material having a thermal conductivity higher than that of the containing body 90, and the other portions may be formed of a material having a thermal conductivity lower than that of the containing body 90. Note that in the second embodiment, the contact portions 654 may be formed of a material having a thermal conductivity higher than that of the containing body 90.
(5) In the configurations described above, in each vibration absorber 64, the support plate 643 is in contact with the fixing plate 263; however, the portion in the flow path structure 30 in contact with the fixing plate 263 is not limited to the support 265. For example, when the support plate 643 is omitted in the vibration absorber 64, the elastic film 641 contacts the fixing plate 263. Furthermore, when the vibration absorbers 64 are omitted in the flow path structure 30, the flow path substrate 32 contacts the fixing plate 263. As described above, according to the configuration of the flow path structure 30, the portion of the flow path structure 30 in contact with the fixing plate 263 is appropriately changed. Furthermore, the configuration of the flow path structure 30 is not limited to the example configurations described above.
(6) In the configurations described above, the support 265 is formed of metal; however, the material of the support 265 may be any material that has a thermal conductivity higher than that of the containing body 90. For example, the support 265 may be formed of a highly heat-conductive resin.
(7) In the configurations described above, a configuration is adopted in which each drive circuit 80 is mounted on the surface of the wiring substrate 46 on the side opposite the flow path structure 30; however, the position at which each drive circuit 80 is mounted is not limited to the example described above. For example, as illustrated in
(8) The driving elements that eject the ink in the pressure chambers C through the nozzles N are not limited to the piezoelectric elements 44 exemplified in the embodiments described above. For example, heating elements that generate air bubbles inside the pressure chambers C through heating to change the pressure therein may be used as the driving elements. As it can be understood from the examples described above, the driving elements are expressed comprehensively as elements that eject the liquid in the pressure chambers C through the nozzles N, and the operation system (piezoelectric system/thermal system) and the specific configuration of the driving elements do not matter.
(9) In the configurations described above, the liquid ejecting apparatus 100 of a serial type in which the transport body 242 on which the head units 261 are mounted is reciprocated is described as an example; however, the present disclosure can be applied to a liquid ejecting apparatus of a line type in which a plurality of nozzles N are distributed across an entire width of a medium 12. In the line-type liquid ejecting apparatus, the liquid ejecting head is a line head and includes a casing in contact with the support and to which the liquid ejecting head is fixed. With the above configuration, since the support 265 is in contact with the casing to which the liquid ejecting head is fixed, there is an advantage that the heat of the head unit can be released through the casing.
(10) The liquid ejecting apparatuses 100 described as examples in each of the configurations described above may be employed in various apparatuses other than an apparatus dedicated to printing, such as a facsimile machine and a copier. Note that the application of the liquid ejecting apparatus of the present disclosure is not limited to printing. For example, a liquid ejecting apparatus that ejects a coloring material solution is used as a manufacturing apparatus that forms a color filter of a display device such as a liquid crystal display panel. Furthermore, a liquid ejecting apparatus that ejects a conductive material solution is used as a manufacturing apparatus that forms wiring and electrodes of a wiring substrate. Furthermore, a liquid ejecting apparatus that ejects a solution of an organic matter related to a living body is used, for example, as a manufacturing apparatus that manufactures a biochip.
Number | Date | Country | Kind |
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2018-116136 | Jun 2018 | JP | national |
2019-014211 | Jan 2019 | JP | national |
Number | Name | Date | Kind |
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20150267868 | Yoshida | Sep 2015 | A1 |
20160347055 | Yamaguchi | Dec 2016 | A1 |
20180029395 | Sugiura | Feb 2018 | A1 |
Number | Date | Country |
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2016-000488 | Jan 2016 | JP |
Number | Date | Country | |
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20190381794 A1 | Dec 2019 | US |