Patent Application
20230173808
The present application is based on, and claims priority from JP Application Serial Number 2021-196716, filed Dec. 3, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety.
The present disclosure relates to a liquid ejecting head and a liquid ejecting apparatus.
A liquid ejecting head described in JP-A-2021-3827 includes nozzles that eject a liquid, pressure chambers that communicate with the nozzles, and piezoelectric elements that provide the liquid in the piezoelectric elements with pressure variations. The piezoelectric elements include individual electrodes provided to the respective pressure chambers, a common electrode provided to the individual electrodes in common, and piezoelectric bodies each disposed between the corresponding individual electrode and the common electrode. The liquid ejecting head also includes a wiring board for supplying voltages to the individual electrodes and the common electrode.
The liquid ejecting head includes wiring that electrically couples the common electrode to the wiring board. According to the liquid ejecting head of the related art, the wiring that electrically couples the common electrode to the wiring board is provided above a pressure chamber substrate in which the pressure chambers are formed. The liquid ejecting head of the related art has a problem of large resistance of the wiring that is coupled to the common electrode.
A liquid ejecting head according to an aspect of the present disclosure includes: a nozzle substrate including a first nozzle configured to eject a liquid and a second nozzle provided at a position adjacent to the first nozzle and configured to eject a liquid; a pressure chamber substrate provided above the nozzle substrate and including a first pressure chamber that communicates with the first nozzle and a second pressure chamber that communicates with the second nozzle; a first piezoelectric element formed from a common electrode, a first piezoelectric body, and a first individual electrode and configured to apply a pressure to a liquid in the first pressure chamber; a second piezoelectric element formed from the common electrode, a second piezoelectric body, and a second individual electrode and configured to apply a pressure to a liquid in the second pressure chamber; a sealing substrate provided above the pressure chamber substrate in such a way as to cover the first piezoelectric element and the second piezoelectric element; a wiring board configured to apply a voltage to the common electrode, the first individual electrode, and the second individual electrode; a first wiring portion provided above the pressure chamber substrate and configured to electrically couple the common electrode to the wiring board; a second wiring portion provided at a lower surface of the sealing substrate and configured to electrically couple the common electrode to the wiring board; and a third wiring portion provided between the first piezoelectric element and the second piezoelectric element and configured to electrically couple the first wiring portion to the second wiring portion.
A liquid ejecting apparatus of the present disclosure includes the liquid ejecting head and a control unit that controls an operation of ejection from the liquid ejecting head.
Modes for carrying out the present disclosure will be described below with reference to the drawings. It is to be noted, however, that dimensions and scales of components in the drawings are different from those of actual components as needed. The embodiments described below represent specific preferred examples and are therefore provided with various desirable limitations. The scope of the present disclosure is, however, not limited to these embodiments unless the following description expressly states the specific limitations of the present disclosure.
In the following description, three directions intersecting one another may be explained as x-axis direction, y-axis direction, and z-axis direction. The x-axis direction includes x1 direction and x2 direction which are mutually opposite directions. The y-axis direction includes y1 direction and y2 direction which are mutually opposite directions. The z-axis direction includes z1 direction and z2 direction which are mutually opposite directions. The x-axis direction, the y-axis direction, and the z-axis direction are orthogonal to one another. The “z1 direction” may be described as a “lower side” or “below” and the “z2 direction” may be described as an “upper side” or “above”.
A liquid ejecting head 10 according to Embodiment 1 will be described with reference to
As illustrated in
As illustrated in
A thickness direction of each of the nozzle substrate 21, the compliance substrates 23, the communication plate 24, the pressure chamber substrate 25, the vibration plate 26, the sealing plate 27, and the casing 28 extends in the z-axis direction. The nozzle substrate 21 and the compliance substrates 23 are disposed at a bottom portion of the liquid ejecting head 10. The communication plate 24 is disposed in the z2 direction relative to the nozzle substrate 21 and the compliance substrates 23. The pressure chamber substrate 25 is disposed in the z2 direction relative to the communication plate 24. The vibration plate 26 is disposed in the z2 direction relative to the pressure chamber substrate 25. The piezoelectric elements 50A and 50B are formed on the vibration plate 26. The sealing plate 27 is disposed in the z2 direction relative to the vibration plate 26. The sealing plate 27 covers the piezoelectric elements 50. The casing 28 is disposed above the communication plate 24. The piezoelectric elements 50A are provided corresponding to the pressure chambers CA. The piezoelectric elements 50B are provided corresponding to the pressure chambers CB. Illustration of wiring portions 72 and 73 to be described later is omitted in
Next, a description will be given of a flow channel 40 in which the ink flows. The liquid ejecting head 10 is provided with the flow channel 40 in which the ink flows. The flow channel 40 includes a supply port 42A, a discharge port 42B, the common liquid chambers RA and RB, relay flow channels 43A and 43B, the pressure chambers CA and CB, communication flow channels 45A to 45C, and nozzles N.
The flow channel 40 includes individual flow channels 41. The individual flow channels 41 are each provided corresponding to the nozzles N. The individual flow channels 41 include individual flow channels 41A and individual flow channels 41B. Each individual flow channel 41A includes the relay flow channel 43A, the pressure chamber CA, the communication flow channel 45A, and part of the communication flow channel 45C. The common liquid chamber RA communicates with the individual flow channels 41A in common and supplies the ink to the individual flow channels 41A. Each individual flow channel 41A is a portion of the individual flow channel 41 located upstream of the corresponding nozzle N.
Each individual flow channel 41B includes the relay flow channel 43B, the pressure chamber CB, the communication flow channel 45B, and part of the communication flow channel 45C. The common liquid chamber RB communicates with the individual flow channels 41B in common. The ink is discharged from the individual flow channels 41B to the common liquid chamber RB. The common liquid chamber RB discharges the ink from the individual flow channels 41B.
The liquid ejecting head 10 adopts a circulation system designed to circulate the ink that flows in the pressure chambers CA and CB. As illustrated in
The ink in the liquid container 2 is transferred by the pump 83. The ink flows in the supply flow channel 81, passes through the supply port 42A, and flows into the common liquid chamber RA. A portion of the common liquid chamber RA is formed in the communication plate 24 and another portion of the common liquid chamber RA is formed in the casing 28. The ink in the common liquid chamber RA passes through the relay flow channel 43A and is supplied to the pressure chamber CA. The ink in the pressure chamber CA passes through the communication flow channel 45A and the communication flow channel 45C and is ejected from the nozzle N.
The ink not ejected from the nozzle N passes through the communication flow channel 45C and the communication flow channel 45B and flows into the pressure chamber CB. The ink in the pressure chamber CB passes through the relay flow channel 43B, and is discharged to the common liquid chamber RB. The ink in the common liquid chamber RB flows into the collection flow channel 82 through the discharge port 42B and is collected by the liquid container 2. In the liquid ejecting head 10, the ink is circulated as described above.
Next, a structure of the liquid ejecting head 10 will be described. The nozzle substrate 21 illustrated in
The compliance substrates 23 are disposed on two sides in the x-axis direction of the nozzle substrate 21. Each compliance substrate 23 includes a flexible film. The compliance substrates 23 constitute bottom surfaces of the common liquid chambers RA and RB. The compliance substrates 23 are deformable by receiving a pressure of the ink. The compliance substrates 23 are deformed by the pressure of the ink and can absorb a variation in pressure of the ink in the liquid ejecting head 10.
The communication plate 24 is provided with portions of the common liquid chambers RA and RB, the relay flow channels 43A and 43B, and the communication flow channels 45A to 45C. The communication plate 24 is provided with through holes, grooves or recesses, and so forth. The portions of the common liquid chambers RA and RB, the relay flow channels 43, and the communication flow channels 45 are formed by these through holes, grooves or recesses, and so forth.
The common liquid chambers RA and RB are elongated in the y-axis direction. The common liquid chambers RA and RB correspond to the layout of the nozzles N in the y-axis direction. As illustrated in
The relay flow channel 43A establishes communication between the pressure chamber CA and the common liquid chamber RA. The relay flow channel 43A is provided to each of the pressure chambers CA. The relay flow channels 43A are disposed at given intervals in the y-axis direction. The relay flow channel 43B establishes communication between the pressure chamber CB and the common liquid chamber RB. The relay flow channel 43B is provided to each of the pressure chambers CB. The relay flow channels 43B are disposed at given intervals in the y-axis direction.
The communication flow channel 45A communicates with the pressure chamber CA and extends in the z-axis direction. The communication flow channel 45A is provided to each of the pressure chambers CA. The communication flow channel 45B communicates with the pressure chamber CB and extends in the z-axis direction. The communication flow channel 45B is provided to each of the pressure chambers CB.
The communication flow channels 45A and 45B penetrate the communication plate 24 in the z-axis direction. The communication flow channels 45A and 45B are located away from one another in the x-axis direction. Each communication flow channel 45A is disposed at a position overlapping the pressure chamber CA when viewed in the z-axis direction. Each communication flow channel 45B is disposed at a position overlapping the pressure chamber CB when viewed in the z-axis direction. Each communication flow channel 45C extends in the x-axis direction and establishes communication between the communication flow channel 45A and the communication flow channel 45B. The communication flow channel 45C is a groove which is recessed from a bottom surface of the communication plate 24. The communication flow channel 45C communicates with the corresponding nozzle N. The communication flow channels 45A to 45C are disposed at given intervals in the y-axis direction. The nozzle substrate 21 is disposed in such a way as to cover the communication flow channels 45A to 45C from below. Each pressure chamber CA and the corresponding pressure chamber CB communicate with each other by using the communication flow channels 45A to 45C.
The pressure chamber substrate 25 is provided with the pressure chambers CA and CB. The pressure chambers CA and CB penetrate the pressure chamber substrate 25 in the z-axis direction. Each of the pressure chambers CA and CB has a predetermined volume. The pressure chambers CA and CB are located away from each other in the x-axis direction. The pressure chambers CA are each provided corresponding to the nozzles N. The pressure chambers CA are disposed at given intervals in the y-axis direction. The pressure chambers CB are each provided corresponding to the nozzles N. The pressure chambers CB are disposed at given intervals in the y-axis direction. As described above, the line of pressure chambers CAL includes the pressure chambers CA. The pressure chamber substrate 25 can be produced from a single-crystalline substrate of silicon, for example. The pressure chamber substrate 25 may be produced from other materials.
The vibration plate 26 is disposed at an upper surface of the pressure chamber substrate 25. The vibration plate 26 covers openings of the pressure chamber substrate 25. Of the vibration plate 26, portions covering the openings of the pressure chamber substrate 25 constitute upper wall surface of the pressure chamber C.
The vibration plate 26 includes an elastic layer 26a and an insulating layer 26b. The elastic layer 26a is made of silicon dioxide (SiO2), for example. The insulating layer 26b is made of zirconium dioxide (ZrO2), for example. The elastic layer 26a is formed on the pressure chamber substrate 25 and the insulating layer 26b is formed on the elastic layer 26a.
The piezoelectric elements 50A and 50B are formed on the vibration plate 26. The piezoelectric elements 50A illustrated in
The vibration plate 26 is driven by the piezoelectric elements 50A and 50B and vibrates in the z-axis direction. A portion of the vibration plate 26 constituting the upper wall surface of each pressure chamber CA is driven by the piezoelectric element 50A above the pressure chamber CA. A portion of the vibration plate 26 constituting the upper wall surface of each pressure chamber CB is driven by the piezoelectric element 50B above the pressure chamber CB. A total thickness of the vibration plate 26 is equal to or below 2 μm, for example. The total thickness of the vibration plate 26 may be equal to or below 15 μm, or equal to or below 40 μm, or equal to or below 100 μm. When the total thickness of the vibration plate 26 is equal to or below 15 μm, for example, the vibration plate 26 may include a resin layer. The vibration plate 26 may be formed from a metal. Examples of the metal include stainless steel, nickel, and the like. When the vibration plate 26 is made of the metal, a plate thickness of the vibration plate 26 may be equal to or above 15 μm and equal to or below 100 μm.
As illustrated in
As illustrated in
As illustrated in
Each piezoelectric element 501 includes an individual electrode 511, a common electrode 521, and a piezoelectric body 531. Each piezoelectric element 502 includes an individual electrode 512, a common electrode 522, and a piezoelectric body 532. The piezoelectric elements 501 and 502 have the same structure. The “piezoelectric element 501” or the “piezoelectric element 502” may be referred to as the piezoelectric element 50 when the “piezoelectric element 501” and the “piezoelectric element 502” need not be distinguished from each other. Likewise, the “individual electrode 511” and the “individual electrode 512” may be referred to as the “individual electrode 51” when the “individual electrode 511” and the “individual electrode 512” need not be distinguished from each other. The “individual electrode 511” represents an example of a “first individual electrode”. The “individual electrode 512” represents an example of a “second individual electrode”.
The “common electrode 521” or the “common electrode 522” may be referred to as the common electrode 52 when the “common electrode 521” and the “common electrode 522” need not be distinguished from each other. The common electrode 521 includes a portion disposed above the individual electrode 511. The common electrode 522 includes a portion disposed above the individual electrode 512. The “piezoelectric body 531” or the “piezoelectric body 532” may be referred to as the piezoelectric body 53 when the “piezoelectric body 531” and the “piezoelectric body 532” need not be distinguished from each other. The “piezoelectric body 531” represents an example of a “first piezoelectric body”. The “piezoelectric body 532” represents an example of a “second piezoelectric body”.
The individual electrode 51, the piezoelectric body 53, and the common electrode 52 are stacked in this order above the vibration plate 26. The individual electrode 511, the piezoelectric body 531, and the common electrode 521 are located above the pressure chamber C1. The individual electrode 512, the piezoelectric body 532, and the common electrode 522 are located above the pressure chamber C2. The piezoelectric body 53 is sandwiched between the individual electrode 51 and the common electrode 52. The piezoelectric body 531 is sandwiched between the individual electrode 511 and the common electrode 521. The piezoelectric body 532 is sandwiched between the individual electrode 512 and the common electrode 522.
As illustrated in
Each common electrode 52 takes on a strip shape and extends in the y-axis direction. The common electrode 52 is continuously provided in such a way as to cover the individual electrodes 511 and 512. Of the common electrode 52 extending in the y-axis direction, a portion located above the individual electrode 511 may be defined as the common electrode 521 and a portion located above the individual electrode 512 may be defined as the common electrode 522.
The individual electrode 51 includes a foundation layer and an electrode layer. The foundation layer includes titanium (Ti), for example. The electrode layer includes, for example, a low-resistance conductive material, such as platinum (Pt) or iridium (Ir). The electrode layer may be formed from an oxide, such as strontium ruthenate (SrRuO3) and lanthanum nickel oxide (LaNiO3). The piezoelectric body 53 is formed from a known piezoelectric material, such as lead zirconate titanate (Pb(Zr,Ti)O3) or ceramics.
Each common electrode 52 includes a foundation layer and an electrode layer. The foundation layer includes titanium, for example. The electrode layer includes a low-resistance conductive material, such as platinum or iridium. The electrode layer may be formed from an oxide, such as strontium ruthenate and lanthanum nickel oxide. A region of the piezoelectric body 53 located between the individual electrode 51 and the common electrode 52 serves as a driving region. A region of the piezoelectric body 531 located between the individual electrode 511 and the common electrode 521 serves as the driving region. A region of the piezoelectric body 532 located between the individual electrode 512 and the common electrode 522 serves as the driving region. The driving regions of the piezoelectric bodies 53 are each formed above the corresponding pressure chambers C. Portions, other than the driving regions, of the piezoelectric bodies 531 and 532 may be coupled to each other.
A prescribed reference voltage is applied to the common electrodes 52. The reference voltage is a constant voltage, which is set to a voltage higher than a ground voltage, for example. A retention signal at a constant voltage is applied to the common electrodes 52, for example. Driving signals at variable voltages are applied to the individual electrodes 51. A voltage corresponding to a difference between the reference voltage to be applied to the common electrodes 52 and the driving signal to be applied to the individual electrodes 51 is applied to the piezoelectric bodies 53. A voltage corresponding to the difference between the reference voltage to be applied to the common electrode 521 and the driving signal to be applied to the individual electrode 511 is applied to the piezoelectric body 531. A voltage corresponding to the difference between the reference voltage to be applied to the common electrode 522 and the driving signal to be applied to the individual electrode 512 is applied to the piezoelectric body 532. The driving signal corresponds to an amount of ejection of the liquid to be ejected from the nozzle N.
As a consequence of deformation of the piezoelectric body 531 along with the application of the voltage between the individual electrode 51 and the common electrode 521, the piezoelectric element 501 creates energy for flexurally deforming the vibration plate 26. Likewise, as a consequence of deformation of the piezoelectric body 532 along with the application of the voltage between the individual electrode 512 and the common electrode 522, the piezoelectric element 502 creates energy for flexurally deforming the vibration plate 26.
The vibration of the vibration plate 26 with the energy generated by the piezoelectric element 501 changes the pressure of the liquid in the pressure chamber C1, whereby the liquid in the pressure chamber C1 is ejected from the nozzle N1. The vibration of the vibration plate 26 with the energy generated by the piezoelectric element 502 changes the pressure of the liquid in the pressure chamber C2, whereby the liquid in the pressure chamber C2 is ejected from the nozzle N2.
The sealing plate 27 is formed into a rectangular shape when viewed in the z-axis direction. The sealing plate 27 protects the piezoelectric elements 50 and reinforces mechanical strengths of the pressure chamber substrate 25 and the vibration plate 26. The sealing plate 27 is attached to the vibration plate 26 by using an adhesive, for example. The sealing plate 27 is fixed to the pressure chamber substrate 25 with the vibration plate 26 in between. The wiring portion 72 is formed at lower surfaces 27c, 27d, and 27e of the sealing plate 27. Details will be described later.
As illustrated in
As illustrated in
The driving circuit 62 is mounted on the flexible wiring board 61. The driving circuit 62 includes a switching element for driving the piezoelectric elements 50. The driving circuit 62 is electrically coupled to a control unit 30 illustrated in
As illustrated in
The COM lines 54 extend in the x-axis direction and are drawn into an opening 27a in the sealing plate 27. The opening 27a is illustrated in
As illustrated in
The COM lines 54 are electrically coupled to the flexible wiring board 61 via a COF mounting portion 64 illustrated in
As illustrated in
As illustrated in
As illustrated in
As illustrated in
As illustrated in
The sealing plate 27 includes protruding portions 27g which protrude in the z1 direction from the lower surface 27c (in other words, which are convex in the z1 direction beyond the lower surface 27c). The protruding portions 27g protrude from the lower surface 27c toward the pressure chamber substrate 25. The protruding portions 27g extend in the x-axis direction. The protruding portions 27g are disposed at given intervals in the y-axis direction.
Each protruding portion 27g includes the lower surfaces 27e, 27f, and 27d. The lower surfaces 27e and 27d define inclined surfaces of the protruding portion 27g. The lower surfaces 27e and 27d are inclined relative to the lower surface 27c. The lower surfaces 27e and 27d are inclined relative to XY plane. The XY plane is a plane extending in the x-axis direction and the y-axis direction. The lower surfaces 27e and 27d are inclined relative to an upper surface 25a of the pressure chamber substrate 25. The lower surface 27e is adjacent to the lower surface 27c in the y2 direction. The lower surface 27d is adjacent to the lower surface 27c in the y1 direction.
The lower surface 27f defines a bottom surface of the protruding portion 27g. The lower surface 27f is located between the lower surface 27e and the lower surface 27d in the y-axis direction. The lower surface 27f extends in the XY plane. The lower surface 27f is disposed at a position different from the lower surface 27c in the z-axis direction. The lower surface 27f is located between the pressure chamber C1 and the pressure chamber C2 in the y-axis direction.
The wiring portion 72 is disposed along the lower surfaces 27c, 27d, 27e, and 27f of the sealing plate 27 as described above. The wiring portion 72 includes a conductive layer. The wiring portion 72 has a prescribed thickness. The wiring portion 72 is disposed in such a way as to overlap the piezoelectric elements 50 when viewed in the z-axis direction. The wiring portion 72 and the VBS line 55 are located away from each other in the z-axis direction. The wiring portion 72 is formed in such a way as to cover the lower surfaces 27c, 27d, 27e, and 27f from below.
The wiring portion 72 includes portions 72c, 72d, 72e, and 72f. These portions 72c, 72d, 72e, and 72f are continuously provided in the y-axis direction. The portion 72c is formed in such a way as to cover the 27c of the sealing plate 27. The portion 72d is formed in such a way as to cover the lower surface 27d of the sealing plate 27. The portion 72d is inclined relative to the portion 72c. The portion 72e is formed in such a way as to cover the lower surface 27e of the sealing plate 27. The portion 72e is inclined relative to the portion 72c. The portion 72f is formed in such a way as to cover the lower surface 27f of the sealing plate 27. The portions 72d, 72e, and 72f are formed in such a way as to cover the protruding portion 27g.
As mentioned above, the wiring portion 73 electrically couples the VBS line 55 to the wiring portion 72. The wiring portion 73 is provided between the piezoelectric elements 50 in the y-axis direction. The wiring portion 73 is located between the piezoelectric element 501 and the piezoelectric element 502 in the y-axis direction. The wiring portion 73 is electrically coupled to the portion 72f of the wiring portion 72. The wiring portion 73 couples the wiring portion 72 to the VBS line 55 in the z-axis direction.
The pressure chamber substrate 25 includes partition walls 25c that define the pressure chambers C in the y-axis direction. Each partition wall 25c is located between the pressure chamber C1 and the pressure chamber C2 in the y-axis direction. The protruding portion 27g of the sealing plate 27 is disposed in such a way as to overlap the partition wall 25c when viewed in the z-axis direction. The lower surface 27f of the protruding portion 27g is disposed in such a way as to overlap the partition wall 25c when viewed in the z-axis direction.
The wiring portion 73 is disposed in such a way as to overlap the partition wall 25c when viewed in the z-axis direction. The wiring portion 73 is disposed above the partition wall 25c. The wiring portion 73 is electrically coupled to the VBS line 55 at a position above the partition wall 25c.
A thickness t3 of the wiring portion 73 is larger than the thickness t1 of the VBS line 55. The thickness t3 of the wiring portion 73 is larger than the thickness t2 of the wiring portion 72. The thickness t3 of the wiring portion 73 is a thickness thereof in the z-axis direction. The thickness t3 of the wiring portion 73 may be a thickness obtained by subtracting the thickness t1 from a thickness t4. The thickness t4 corresponds to a length in the z-axis direction between the lower surface 27f of the protruding portion 27g and the VBS line 55. The thickness t4 is larger than the thickness t1.
A width W2 of the wiring portion 73 is smaller than a width W1 of the partition wall 25c between the pressure chambers C. The width W2 of the wiring portion 73 is equivalent to a length thereof in the y-axis direction. The partition wall 25c has a length in the y-axis direction. The wiring portion 73 is disposed within the width W1 of the partition wall 25c when viewed in the z-axis direction. The width W2 of the wiring portion 73 may be substantially equal to a width in the y-axis direction of the lower surface 27f of the protruding portion 27g.
The wiring portion 72 and the wiring portion 73 are made of the same material, for example. The wiring portion 72 and the wiring portion 73 are made of gold, for instance. The VBS line 55 as well as the wiring portions 72 and 73 are made of the same material, such as gold. The VBS line 55 as well as the wiring portions 72 and 73 may be made of a metal other than gold. The VBS line 55 as well as the wiring portions 72 and 73 need not be made of the same material. Bonding quality is improved when the VBS line 55 as well as the wiring portions 72 and 73 are made of the same material. A junction between the VBS line 55 and the wiring portion 73 is disposed at a position overlapping the partition wall 25c when viewed in the z-axis direction.
According to the above-described liquid ejecting head 10, it is possible to supply a voltage to the common electrode 52 via the VBS line 55. Since the liquid ejecting head 10 includes the wiring portion 72 and the wiring portion 73 electrically coupled to the VBS line 55, the voltage can be supplied to the common electrode 52 via the wiring portion 72 and the wiring portion 73. In the liquid ejecting head 10, the voltage can be supplied to the common electrode 52 via the COF 60, the wiring portion 72, the wiring portion 73, and the VBS line 55. In the liquid ejecting head 10, the voltage can be supplied to the common electrode 52 by using the wiring portion 72 and the wiring portion 73 in addition to the VBS line 55. Accordingly, it is possible to reduce the resistance of wiring coupled to the common electrode 52. The liquid ejecting head 10 can suppress an effect of a voltage drop to be supplied to the common electrode 52. The liquid ejecting head 10 can suppress a delay of a current to the common electrode 52.
Since the liquid ejecting head 10 includes the wiring portion 72 and the wiring portion 73, it is possible to reduce the resistance in the VBS line 55 while avoiding an increase in the thickness t1 of the VBS line 55. The related art has a difficulty in further increasing the thickness t1 of the VBS line 55, for example. There is also a difficulty in accurately cutting the VBS line 55 when the VBS line 55 is made excessively thick. It is therefore not easy to reduce electric resistance by increasing the thickness of the VBS line 55. In the liquid ejecting head 10, the wiring portion 72 and the wiring portion 73 are formed along the lower surface of the sealing plate 27. Accordingly, it is possible to reduce the resistance of the VBS line 55 while avoiding the increase in thickness of the VBS line 55.
In the liquid ejecting head 10, the sealing plate 27 is fixed to the pressure chamber substrate 25 and to the vibration plate 26 by using the adhesive 59 as illustrated in
As illustrated in
Since the amount of use of the adhesive 59 is maintained at an appropriate level, the liquid ejecting head 10 reduces the amount of the adhesive that permeates the vibration plate 26. For example, an increase in amount of the adhesive that permeates the vibration plate 26 above the pressure chambers C reduces vibration of the vibration plate 26. Since the amount of the adhesive that permeates the vibration plate 26 is suppressed in the liquid ejecting head 10, the vibration of the vibration plate 26 is not disturbed. As a consequence, reliability of the performance of the liquid ejecting head 10 to eject the liquid is improved.
In the liquid ejecting head 10, the protruding portion 27g of the sealing plate 27 and the wiring portion 73 are disposed above each partition wall 25c between the pressure chambers C. The protruding portion 27g and the wiring portion 73 can press the partition wall 25c as well as the vibration plate 26 above the partition wall 25c. This suppresses deflection of the partition wall 25c. An increase in deflection of the partition wall 25c may affect the performance to eject the liquid from each pressure chamber C. The liquid ejecting head 10 can improve accuracy of the performance to eject the liquid since the deflection of the partition wall 25c is suppressed.
Next, a liquid ejecting head 10B according to Embodiment 2 will be described.
The liquid ejecting head 10B includes the pressure chambers C. The pressure chambers C include the pressure chambers C1 to C3. The pressure chambers C1 to C3 are disposed at given intervals in the y-axis direction. The pressure chambers C1 to C3 are arranged in this order. The pressure chamber C2 is located between the pressure chamber C1 and the pressure chamber C3 in the y-axis direction. The “pressure chamber C3” represents an example of a “third pressure chamber”.
The pressure chamber substrate 25 is provided with the nozzles N arranged in the y-axis direction. The nozzles N include nozzles N1 to N3. A line of nozzles NL includes the nozzles N1 to N3. The nozzles N1 to N3 are arranged in this order. The nozzle N2 is located between the nozzle N1 and the nozzle N3 in the y-axis direction. The “nozzle N3” represents an example of a “third nozzle”. The nozzle N3 communicates with the pressure chamber C3. The liquid in the pressure chamber C3 is ejected from the nozzle N3.
The liquid ejecting head 10B includes the piezoelectric elements 50 arranged in the y-axis direction. The piezoelectric elements 50 include the piezoelectric element 501, the piezoelectric element 502, and a piezoelectric element 503. The piezoelectric elements 501 to 503 are arranged in this order. The piezoelectric element 502 is located between the piezoelectric element 501 and the piezoelectric element 503 in the y-axis direction. The “piezoelectric element 503” represents an example of a “third piezoelectric element”.
Each piezoelectric element 50 includes the individual electrode 51, the common electrode 52, and the piezoelectric body 53. The piezoelectric element 503 includes the individual electrode 51, the common electrode 52, and the piezoelectric body 53. The piezoelectric element 503 is disposed at a position overlapping the pressure chamber C3 when viewed in the z-axis direction. The individual electrode 51 of the piezoelectric element 503 represents an example of a “third individual electrode”. The piezoelectric body 53 of the piezoelectric element 503 represents an example of a “third piezoelectric element”.
Each wiring portion 73 electrically couples the wiring portion 72 to the VBS line 55. Each wiring portion 73 is provided between the piezoelectric elements 50. One wiring portion 73 is located between the piezoelectric element 501 and the piezoelectric element 502. Another wiring portion 73 is located between the piezoelectric element 502 and the piezoelectric element 503. The wiring portion 73 located between the piezoelectric element 502 and the piezoelectric element 503 represents an example of a “fourth wiring portion”. The wiring portion 73 may be provided at every space between the piezoelectric elements 50.
The above-described liquid ejecting head 10B according to the Embodiment 2 is also acceptable. In the liquid ejecting head 10B including the piezoelectric elements 501 to 503, the wiring portion 73 may be provided between the piezoelectric element 501 and the piezoelectric element 502 and the wiring portion 73 may be provided between the piezoelectric element 502 and the piezoelectric element 503. The above-described liquid ejecting head 10B according to the Embodiment 2 also has the same operation and effects as those of the above-described liquid ejecting head 10 according to the Embodiment 1.
Next, a liquid ejecting head 10C according to Embodiment 3 will be described.
As mentioned above, the wiring portions 73 do not always have to be provided on two sides of each piezoelectric element 50. The configuration in which the wiring portion 73 is provided on one side in the y-axis direction of the piezoelectric element 50 is also acceptable. In the liquid ejecting head 10C, the wiring portion 73 is provided between the piezoelectric element 501 and the piezoelectric element 502 but the wiring portion 73 is not provided between the piezoelectric element 502 and the piezoelectric element 503.
Likewise, in the liquid ejecting head 10C, the protruding portion 27g is provided between the piezoelectric element 501 and the piezoelectric element 502 but the protruding portion 27g is not provided between the piezoelectric element 502 and the piezoelectric element 503.
Next, a liquid ejecting head 10D according to Embodiment 4 will be described.
The lower surface 27f of the protruding portion 27g illustrated in
A length in the z-axis direction of the wiring portion 73D of the liquid ejecting head 10D is smaller than the length in the z-axis direction of the wiring portion 73 of the liquid ejecting head 10.
As described above, in the liquid ejecting head 10D, the protruding portion 27g of the sealing plate 27 is disposed at a position closer to the upper surface 25a of the pressure chamber substrate 25. This makes it possible to reduce the length in the z-axis direction of the wiring portion 73D.
Next, a liquid ejecting head 10E according to Embodiment 5 will be described.
As illustrated in
The common electrode 52 is disposed above the piezoelectric body 53. The position of the upper surface of the common electrode 52 is constant in the z-axis direction. For example, the position of the upper surface of the common electrode 52 above the individual electrode 51 is substantially the same as the position of the upper surface of the common electrode 52 above the partition wall 25c. The upper surface of the common electrode 52 is a surface located closer to the VBS line 55 in the z-axis direction, and a lower surface of the common electrode 52 is a surface located closer to the piezoelectric body 53.
The VBS line 55 is disposed above the common electrode 52. The position of the upper surface of the VBS line 55 is constant in the z-axis direction. For example, the position of the upper surface of the VBS line 55 above the individual electrode 51 is substantially the same as the position of the upper surface of the VBS line 55 above the partition wall 25c. The upper surface of the VBS line 55 is a surface located closer to the sealed space in the z-axis direction, and a lower surface of the VBS line 55 is a surface located closer to the common electrode 52.
The thickness of the sealing plate 27 is constant above the piezoelectric elements 50. The position of the lower surface 27c of the sealing plate 27 is constant in the z-axis direction above the piezoelectric elements 50. As mentioned earlier, the sealing plate 27 is not provided with the protruding portions 27g.
The liquid ejecting head 10E includes the wiring portion 72E and the wiring portions 73E. The wiring portion 73E is provided between the VBS line 55 and the wiring portion 72E and electrically couples the VBS line 55 to the wiring portion 72E. The “wiring portion 72E” represents an example of the “second wiring portion” and the “wiring portion 73E” represents an example of the “third wiring portion”. The wiring portion 72E is provided at the lower surface 27c of the sealing plate 27. The wiring portion 72E extends in the y-axis direction along the lower surface 27c of the sealing plate 27.
The wiring portion 73E electrically couples the wiring portion 72E to the VBS line 55 in the z-axis direction. The wiring portion 73E is located above the partition wall 25c. A length in the x-axis direction of the wiring portion 72E may be substantially equal to a length in the x-axis direction of the common electrode 52, for example. The wiring portion 73E may be a block body.
The above-described liquid ejecting head 10E according to the Embodiment 5 also has the same operation and effects as those of the liquid ejecting head 10 according to the Embodiment 1. The liquid ejecting head 10E may have a configuration that includes the sealing plate 27 not provided with the protruding portions 27g. Since the piezoelectric body 53 is present below the wiring portion 73E, it is possible to dispose the VBS line 55 at a position located away from the pressure chamber substrate 25, and thus to reduce the length in the x-axis direction of the wiring portion 73E. Thus, an increase in wiring resistance is avoided. Since the common electrode 52 and the VBS line 55 are linearly formed when viewed in the x-axis direction, it is possible to reduce the lengths of the common electrode 52 and the VBS line 55. Thus, the increase in wiring resistance is avoided.
Next, a liquid ejecting head 10F according to Embodiment 6 will be described.
The liquid ejecting head 10F includes the pressure chamber substrate 25F. In
The liquid ejecting head 10F includes lines of nozzles NAL and NBL. The line of nozzles NAL and the line of nozzles NBL are located away from each other in the x-axis direction. The line of nozzles NAL includes the nozzles NA arranged in the y-axis direction. The line of nozzles NBL includes the nozzles NB arranged in the y-axis direction. The nozzles NA and the nozzles NB are disposed at positions different from one another in the y-axis direction.
The line of pressure chambers CAL includes a pressure chamber CA1 and a pressure chamber CA2. The “pressure chamber CA1” represents an example of the “first pressure chamber”. The “pressure chamber CA2” represents an example of the “second pressure chamber”. Each pressure chamber CB is disposed between two pressure chambers CA when viewed in the x-axis direction. In other words, each pressure chamber CA is disposed between two pressure chambers CB when viewed in the x-axis direction. Each pressure chamber CA communicates with the corresponding nozzle NA. Each pressure chamber CB communicates with the corresponding nozzle NB. No pressure chambers CB communicate with the nozzles NA. No pressure chambers CA communicate with the nozzles NB.
The liquid ejecting head 10F includes the wiring portions 73FA and the wiring portions 73FB. Each wiring portion 73FA represents an example of the “third wiring portion”. Each wiring portion 73FB represents another example of the “third wiring portion”. Each wiring portion 73FA is disposed between two pressure chambers CA in the y-axis direction. Each wiring portion 73FB is disposed between two pressure chambers CB in the y-axis direction.
Each wiring portion 73FA is electrically coupled to the VBS line 55 that supplies a voltage to the common electrode 52 of the piezoelectric element 50A corresponding to the pressure chamber CA. The wiring portion 73FA is electrically coupled to the wiring portion 72 and the VBS line 55 on a line A side. The “line A side” includes the constituents concerning the pressure chambers CA.
Each wiring portion 73FB is electrically coupled to the VBS line 55 that supplies a voltage to the common electrode 52 of the piezoelectric element 50B corresponding to the pressure chamber CB. The wiring portion 73FB is electrically coupled to the wiring portion 72 and the VBS line 55 on a line B side. The “line B side” includes the constituents concerning the pressure chambers CB.
As described above, in the liquid ejecting head 10F, the pressure chambers CA on the line A side and the pressure chambers CB on the line B side are disposed at the positions different from one another in the y-axis direction. The pressure chambers CA and CB need not be disposed at the same positions in the y-axis direction. In the liquid ejecting head 10F, the wiring portions 73FA on the line A side and the wiring portions 73FB on the line B side are disposed at positions different from one another in the y-axis direction. The wiring portions 73FA and 73FB need not be disposed at the same positions in the y-axis direction.
Next, a liquid ejecting apparatus 1 including the liquid ejecting head 10 will be described with reference to
The liquid ejecting apparatus 1 is an ink jet type printing apparatus that ejects an ink in the form of droplets, which represents an example of a “liquid”, onto a medium PA. The liquid ejecting apparatus 1 is a serial type printing apparatus. The medium PA is typically a sheet of printing paper. The medium PA is not limited to the printing paper and may be a printing target of a desired material, such as a resin film and a cloth.
The liquid ejecting apparatus 1 includes the liquid ejecting head 10 that ejects inks, the liquid containers 2 that store inks, a carriage 3 on which the liquid ejecting head 10 is mounted, a carriage transportation mechanism 4 that transports the carriage 3, a medium transportation mechanism 5 that transports the medium PA, and the control unit 30. The control unit 30 is a control unit that controls ejection of the liquids.
Examples of specific aspects of the liquid container 2 include a cartridge attachable to and detachable from the liquid ejecting apparatus 1, an ink pack in the form of a bag formed from a flexible film, and an ink-refillable ink tank. Any type of the ink may be stored in the liquid container 2. The liquid ejecting apparatus 1 includes multiple liquid containers 2 corresponding to inks of four colors, for instance. Examples of the inks of four colors include cyan, magenta, yellow, and black inks. The liquid containers 2 may be mounted on the carriage 3.
The liquid ejecting apparatus 1 includes the circulation mechanism 8 that circulates the inks. The circulation mechanism 8 includes the supply flow channels 81 that supply the inks to the liquid ejecting head 10, the collection flow channels 82 that collect the inks discharged from the liquid ejecting head 10, and the pumps 83 that transfer the inks.
The carriage transportation mechanism 4 includes a transportation belt 4a for transporting the carriage 3, and a motor. The medium transportation mechanism 5 includes a transportation roller 5a and a motor for transporting the medium PA. The carriage transportation mechanism 4 and the medium transportation mechanism 5 are controlled by the control unit 30. The liquid ejecting apparatus 1 causes the carriage transportation mechanism 4 to transport the carriage 3 while causing the medium transportation mechanism 5 to transport the medium PA, and performs printing by ejecting the ink droplets onto the medium PA.
As illustrated in
The control unit 30 includes one or more CPUs 31. The control unit 30 may include an FPGA instead of or in addition to the CPUs 31. The control unit 30 includes a storage unit 35. The storage unit 35 includes a ROM 36 and a RAM 37, for example. The storage unit 35 may include an EEPROM or a PROM. The storage unit 35 can store print data Img supplied from a host computer. The storage unit 35 stores a control program for the liquid ejecting apparatus 1.
CPU stands for a central processing unit. FPGA stands for a field-programmable gate array. RAM stands for random access memory. ROM stands for read only memory. EEPROM stands for electrically erasable programmable read only memory. PROM stands for a programmable ROM.
The control unit 30 generates signals for controlling operations of the respective units in the liquid ejecting apparatus 1. The control unit 30 can generate a print signal SI and a waveform designation signal dCom. The print signal SI is a digital signal for defining a type of an operation of the liquid ejecting head 10. The print signal SI can designate whether or not to supply the driving signal Com to each piezoelectric element 50. The waveform designation signal dCom is a digital signal that defines a waveform of the driving signal Com. The driving signal Com is an analog signal for driving the piezoelectric element 50.
The liquid ejecting apparatus 1 includes the driving signal generation circuit 32. The driving signal generation circuit 32 is electrically coupled to the control unit 30. The driving signal generation circuit 32 includes a DA converter circuit. The driving signal generation circuit 32 generates the driving signal Com having the waveform defined by the waveform designation signal dCom. When the control unit 30 receives the encoder signal from the linear encoder 6, the control unit 30 outputs a timing signal PTS to the driving signal generation circuit 32. The timing signal PTS defines timing to generate the driving signal Com. The driving signal generation circuit 32 outputs the driving signal Com every time the driving signal generation circuit 32 receives the timing signal PTS.
The driving circuit 62 is electrically coupled to the control unit 30 and to the driving signal generation circuit 32. The driving circuit 62 switches, based on the print signal SI, whether or not to supply the driving signal Com to the piezoelectric element 50. The driving circuit 62 can select the piezoelectric element 50, to which the driving signal Com is supplied, based on the print signal SI, a latch signal LAT, and a change signal CH that are supplied from the control unit 30. The latch signal LAT defines timing to latch the print data Img. The change signal CH defines timing to select a driving pulse included in the driving signal Com.
The control unit 30 controls an ink ejection operation by the liquid ejecting head 10. As described above, the control unit 30 drives the piezoelectric element 50 to change the pressure of the ink inside the pressure chamber C, thereby ejecting the ink from the nozzle N. The control unit 30 controls the ejection operation when performing a printing operation.
The above-described liquid ejecting head 10 can be applied to the liquid ejecting apparatus 1. The liquid ejecting apparatus 1 including the liquid ejecting head 10 can reduce the wiring resistance in the VBS line 55 since the wiring portions 72 and 73 are provided therein. The liquid ejecting apparatus 1 suppresses the delay of the current to the common electrode 52. Since the protruding portion 27g of the sealing plate 27 and the wiring portion 73 are provided above the partition wall 25c, the partition wall 25c is pressed from above and kept from deformation. Thus, the deflection of the partition wall 25c is suppressed.
In the above-described liquid ejecting head 10 according to the Embodiment 1, the protruding portion 27g of the sealing plate 27 is designed to protrude downward. Instead, the piezoelectric body 53 may be disposed above the partition wall 25c, and the piezoelectric body 53 above the partition wall 25c may be designed to protrude upward. In this way, the common electrode 52 and the VBS line 55 above the partition wall 25c are located at positions close to the sealing plate 27. Alternatively, the protruding portion 27g of the sealing plate 27 may be designed to protrude downward and the piezoelectric body 53 above the partition wall 25c may be designed to protrude upward.
The above-described Embodiments merely demonstrate representative examples of the present disclosure. The present disclosure is not limited to the above-described Embodiments, and various modifications and additions are possible within the range not departing from the gist of the present disclosure.
The above-described Embodiment 1 shows the example of the liquid ejecting head 10 configured to circulate the liquid. However, the present disclosure is also applicable to a liquid ejecting head 10 not configured to circulate the liquid.
The above-described Embodiment 1 exemplifies the case where two pressure chambers in total, namely, one first pressure chamber CA and one second pressure chamber CB communicate with one nozzle N. Instead, four pressure chambers in total, namely, two first pressure chambers CA adjacent to each other in the y-axis direction and two second pressure chambers CB adjacent to each other in the y-axis direction may communicate with one nozzle N.
The above-described Embodiments shows the example of the serial type liquid ejecting apparatus that reciprocates the carriage, on which the liquid ejecting head 10 is mounted, in the width direction of the medium PA. Instead, the present disclosure is also applicable to a line type liquid ejecting apparatus 1 provided with a line head on which multiple liquid ejecting heads 10 are mounted.
The liquid ejecting apparatus 1 shown as the example in any of the above-described Embodiments can be adopted to various apparatuses, such as a facsimile apparatus and a copier in addition to the apparatus dedicated for printing. The use of the liquid ejecting apparatus of the present disclosure is not limited to the printing. For example, a liquid ejecting apparatus configured to eject a solution of a coloring material is used as a manufacturing apparatus for forming color filters of display devices, such as liquid crystal display panels. A liquid ejecting apparatus configured to eject a solution of a conductive material is used as a manufacturing apparatus for forming wiring and electrodes on wiring boards. A liquid ejecting apparatus configured to eject a solution of a biological organic substance is used as a manufacturing apparatus for manufacturing biochips, for example.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-196716 | Dec 2021 | JP | national |
