Liquid dispensing head and recording device

Abstract

This liquid discharge head comprises a nozzle plate, a pressure chamber plate, and an actuator. The nozzle plate has a nozzle. The pressure chamber plate is positioned above the nozzle plate and has a pressure chamber that connects to the nozzle. The actuator is positioned above the pressure chamber plate. The nozzle plate is a single plate. The pressure chamber plate is a single plate. The nozzle is a through hole that passes through the single nozzle plate. The pressure chamber is a through hole that passes through the single pressure chamber plate. The thickness of the nozzle plate is greater than the thickness of the pressure chamber plate.

Description

Technical Field

[0001] The present disclosure relates to a liquid ejection head and a recording apparatus.

Background Art

[0002] Patent Document 1 and Patent Document 2 disclose a liquid ejection head including a nozzle plate having nozzles, a pressure chamber plate located on the nozzle plate and having pressure chambers connected to the nozzles, and an actuator located on the pressure chamber plate. In this liquid ejection head, a pressure wave is generated in the pressure chamber due to the displacement of the actuator. Then, this pressure wave travels toward the nozzles, and liquid is ejected from the nozzles.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

[0004] A liquid ejection head according to an aspect of the present disclosure includes a nozzle plate, a pressure chamber plate, and an actuator. The nozzle plate has nozzles. The pressure chamber plate is located on the nozzle plate and has pressure chambers connected to the nozzles. The actuator is located on the pressure chamber plate. The nozzle plate is a single plate. The pressure chamber plate is a single plate. The nozzles are through-holes penetrating the single nozzle plate. The pressure chambers are through-holes penetrating the single pressure chamber plate. The thickness of the nozzle plate is thicker than the thickness of the pressure chamber plate.

Brief Description of the Drawings

[0005] <了 [Figure 1]Figure 1 is a schematic side view showing a printer according to an embodiment. [Figure 2] Figure 2 is a schematic plan view showing a printer according to this embodiment. [Figure 3] Figure 3 is a schematic plan view showing a liquid dispensing head according to an embodiment. [Figure 4] Figure 4 is a side view of the liquid dispensing head shown in Figure 3, as seen from point A. [Figure 5] Figure 5 is an enlarged view of region I shown in Figure 3. [Figure 6] Figure 6 is a cross-sectional view along the line II-II shown in Figure 5. [Figure 7] Figure 7 is a cross-sectional view along the line III-III shown in Figure 5. [Modes for carrying out the invention]

[0006] For example, in a liquid discharge head like the one in Patent Document 1, through holes are made in each of several plates, and then the plates are laminated and bonded together to form the pressure chamber and nozzle. Therefore, there was a possibility that processing errors would occur in the pressure chamber and nozzle due to misalignment of the plate lamination. Also, in a liquid discharge head like the one in Patent Document 2, the thickness of the plate with the nozzle is thinner than the thickness of the plate with the pressure chamber, which could cause the direction of liquid flow velocity to vary, potentially resulting in low accuracy of liquid targeting.

[0007] Therefore, there is a need for technology that can reduce machining errors in the nozzle and pressure chamber while improving the accuracy of liquid targeting.

[0008] The embodiments of this disclosure will be described below with reference to the drawings.

[0009] Please note that the diagrams used in the following explanation are schematic, and the dimensions and ratios shown in the drawings do not necessarily correspond to reality. Even among multiple drawings showing the same configuration, the dimensions and ratios may not match each other in order to exaggerate the shape.

[0010] The configuration of the printer 10 according to this embodiment will be described with reference to Figures 1 and 2.

[0011] Figure 1 is a schematic side view showing the printer 10 according to the embodiment. Figure 2 is a schematic top view showing the printer 10 according to the embodiment. The printer 10 is, for example, a color inkjet printer. For the sake of clarity, Figure 1 shows a three-dimensional Cartesian coordinate system including the X-axis, where the right direction of the paper is positive, and the Y-axis, where the back direction of the paper is positive. Such a Cartesian coordinate system is also shown in other drawings used in the explanation below.

[0012] Furthermore, in the following explanation, for convenience, the positive Z-axis direction may be referred to as "up." The X-axis direction is the direction in which the printing paper P is transported. Also, "viewing from above" means viewing from the Z-axis direction.

[0013] The printer 10 includes a paper feed roller 101, a guide roller 102, a transport roller 103, a recovery roller 104, a head case 105, a frame 106, a liquid discharge head 1, a dryer 107, a sensor unit 108, and a control unit 109.

[0014] The control unit 109 controls the operation of the paper feed roller 101, guide roller 102, transport roller 103, recovery roller 104, head case 105, frame 106, liquid discharge head 1, dryer 107, and sensor unit 108.

[0015] The paper feed roller 101, guide roller 102, transport roller 103, and recovery roller 104 constitute a moving section that moves the printing paper P and the liquid discharge head 1 relative to each other. The printing paper P is an example of a recording medium. The moving section is controlled by the control unit 109. The printing paper P is transported from the paper feed roller 101, through two guide rollers 102A, onto a plurality of transport rollers 103. After that, the printing paper P is transported through two guide rollers 102B and two guide rollers 102C to the recovery roller 104.

[0016] The head case 105 houses the conveyance roller 103, the frame 106, and the liquid ejection head 1. The head case 105 is connected to the outside in part such as the part where the printing paper P enters and exits, but the other part is a space isolated from the outside. The internal space of the head case 105 may be configured to control control factors such as temperature, humidity, and air pressure by the control unit 109 as needed.

[0017] The frame 106 is flat and is located close to the upper side of the printing paper P conveyed by the conveyance roller 103. Four frames 106 are located in the head case 105 at predetermined intervals along the conveyance direction of the printing paper P. The number of frames 106 mounted on the printer 10 can be appropriately changed according to the printing target or printing conditions.

[0018] The liquid ejection head 1 has an elongated shape that is slender in the Y-axis direction. As shown in FIG. 2, five liquid ejection heads 1 are mounted on each frame 106. In each frame 106, three liquid ejection heads 1 are arranged along the direction intersecting the conveyance direction of the printing paper P, and the other two liquid ejection heads 1 are arranged at positions shifted along the conveyance direction, one by one between the three liquid ejection heads 1. In each frame 106, each liquid ejection head 1 is arranged so as to overlap in the conveyance direction of the printing paper P. The number of liquid ejection heads 1 included in one frame 106 can be appropriately changed according to the printing target or printing conditions.

[0019] The liquid ejection head 1 according to the present embodiment is fixed to the printer 10, and the printer 10 is a so-called line printer. Note that the printer 10 is not limited to a line printer, and may be a so-called serial printer that alternately performs an operation of ejecting liquid while moving the liquid ejection head 1 in a direction intersecting the conveyance direction of the printing paper P and conveyance of the printing paper P.

[0020] The liquid ejection head 1 is controlled by the control unit 109 based on data such as images or characters, and ejects liquid toward the printing paper P. The distance between the liquid ejection head 1 and the printing paper P may be, for example, about 0.5 mm to 20 mm.

[0021] The liquid ejection heads 1 belonging to one frame 106 are supplied with liquid of the same color, and four colors of liquid can be printed with the four frames 106. The color of the liquid ejected from the liquid ejection heads 1 of each frame 106 may be, for example, magenta, yellow, cyan, and black. By landing such liquid on the printing paper P, a color image can be printed. Note that the types of liquid colors can be changed as appropriate. Also, in the liquid ejection heads 1 belonging to one frame 106, a configuration in which several types of color liquids are supplied and several types of color liquids can be printed with one frame 106 may be adopted.

[0022] The dryer 107 dries the printing paper P. After passing through the two guide rollers 102B, the printing paper P is dried by the dryer 107. By drying with the dryer 107, it becomes difficult for the printing papers P wound up overlapping each other to adhere or for the undried liquid to be rubbed off at the recovery roller 104.

[0023] The sensor unit 108 may include a position sensor, a speed sensor, a temperature sensor, etc. The control unit 109 can control each part of the printer 10 based on the information from each sensor.

[0024] The printer 10 may include a cleaning unit for cleaning the liquid ejection head 1.

[0025] The recording medium may be anything other than printing paper P, such as a roll of cloth. The printer 10 may also transport the recording medium on a conveyor belt. The recording medium may be a single sheet of paper, cut cloth, wood, or tiles. Furthermore, the printer 10 may print wiring patterns for electronic devices by ejecting a liquid containing conductive particles from the liquid ejection head 1.

[0026] The configuration of the liquid discharge head 1 according to this embodiment will be described with reference to Figures 3 and 4. Figure 3 is a schematic plan view showing the liquid discharge head 1 according to this embodiment. Figure 4 is a side view of the liquid discharge head 1 shown in Figure 3 as seen from A. The two wavy lines shown in the vertical direction of Figure 3 represent omitted lines.

[0027] The liquid discharge head 1 comprises a nozzle plate 2, a flow path member 3, a supply path plate 4, and a liquid supply member 5.

[0028] The nozzle plate 2 comprises a plurality of nozzles 21. The nozzle plate 2 is made of a single-crystal silicon substrate. The plurality of nozzles 21 are through holes that penetrate the single-crystal silicon substrate in the Z-axis direction. The plurality of nozzles 21 are located along the Y-axis direction and form a nozzle group. The nozzle plate 2 according to this embodiment has two nozzle groups: a nozzle group on the positive X-axis side and a nozzle group on the negative X-axis side. Although the nozzle plate 2 according to this embodiment has two nozzle groups, it may have only one nozzle group or three or more nozzle groups. The two nozzle groups according to this embodiment may be configured parallel to each other. The distance between the nozzles 21 in each nozzle group may be 84.6 μm. In other words, the resolution of the nozzles 21 in the nozzle group may be 300 dpi. The nozzles 21 of the nozzle group on the positive X-axis side are each located between the nozzles 21 of the nozzle group on the negative X-axis side in the Y-axis direction. In other words, the nozzles 21 of the nozzle group on the positive X-axis side and the nozzles 21 of the nozzle group on the negative X-axis side are offset from each other in the Y-axis direction, and the resolution of the combined nozzles 21 of the two nozzle groups may be 600 dpi. The spacing between the nozzles 21 of each nozzle group may be set appropriately according to the resolution.

[0029] The flow path member 3 comprises a pressure chamber plate 30, a diaphragm 31, and a plurality of piezoelectric elements 32. The pressure chamber plate 30 is located on the nozzle plate 2. The diaphragm 31 is located on the pressure chamber plate 30. The plurality of piezoelectric elements 32 are located on the diaphragm 31. A plurality of pressure chambers 33 are formed in the pressure chamber plate 30. The pressure chamber plate 30 is made of a single-crystal silicon substrate. In this embodiment, the flow path member 3 may have substantially the same shape as the nozzle plate 2 when viewed from above.

[0030] Each of the multiple pressure chambers 33 is a through-hole that penetrates the pressure chamber plate 30 in the Z-axis direction and may be connected to each of the multiple nozzles 21. The multiple pressure chambers 33 are located along the Y-axis direction. Also, when viewed from above, the multiple pressure chambers 33 have their longitudinal direction along the X-axis direction and their transverse direction along the Y-axis direction. Liquid is stored inside the pressure chambers 33.

[0031] The pressure chamber 33 may have a first portion 331 and a second portion 332 connected to the first portion 331. In this embodiment, the first portion 331 is rectangular in shape when viewed from above. The second portion 332 gradually narrows in width when viewed from above, starting from the portion connected to the first portion 331, and includes a rectangular portion smaller than the width of the first portion 331. Therefore, the second portion 332 functions as a constrictor.

[0032] The diaphragm 31 is located on the pressure chamber plate 30. The diaphragm 31 is also located on multiple pressure chambers 33. Examples of materials for the diaphragm 31 include Si and SiO2. The thickness of the diaphragm 31 may be between 1 μm and 2 μm.

[0033] Multiple piezoelectric elements 32 are located on diaphragms 31 corresponding to multiple pressure chambers 33. Specifically, multiple piezoelectric elements 32 are located on diaphragms 31 corresponding to multiple first parts 331. Multiple piezoelectric elements 32 may be provided in a 1:1 relationship with multiple pressure chambers 33. By applying a voltage to the piezoelectric elements 32, the piezoelectric elements 32 are displaced. As the piezoelectric elements 32 are displaced, the diaphragms 31 located on the pressure chambers 33 are also displaced. As a result, pressure is applied to the liquid in the pressure chambers 33. This causes the liquid to be discharged from the pressure chambers 33 through the nozzles 21.

[0034] The supply path plate 4 is located on the flow path member 3. The supply path plate 4 may be made of a single-crystal silicon substrate. The supply path plate 4 has a predetermined thickness that is thicker than the flow path member 3 in the Z-axis direction and has the function of supporting the flow path member 3. The supply path plate 4 is provided with a plurality of supply paths 41.

[0035] Each of the multiple supply passages 41 is a through-hole that penetrates the supply passage plate 4 in the Z-axis direction and is connected to each of the multiple second parts 332. Each of the multiple supply passages 41 is connected to each of the multiple first parts 331 via the multiple second parts 332. The supply passages 41 function as so-called constrictions, similar to the second parts 332. Furthermore, when viewed from above, the multiple supply passages 41 are located in the center of the supply passage plate 4 in the X-axis direction.

[0036] The liquid supply member 5 is located on the supply path plate 4. In plan view, the liquid supply member 5 has substantially the same shape as the supply path plate 4. The liquid supply member 5 includes a common flow path 51. The liquid supply member 5 may be made of resin.

[0037] The common channel 51, when viewed from above, may be located in the center of the liquid supply member 5 in the X-axis direction and may be configured along the Y-axis direction. Therefore, the common channel 51 is located on and connected to multiple supply passages 41. Thus, the common channel 51 according to this embodiment can supply liquid to each of the multiple supply passages 41.

[0038] When liquid is discharged from the liquid discharge head 1 onto the printing paper P, the pressure chamber 33, the supply passage 41, and the common passage 51 are filled with liquid. In this case, when a voltage is applied to the piezoelectric element 32, the piezoelectric element 32 applies pressure to the pressure chamber 33. When pressure is applied to the pressure chamber 33, liquid is supplied from the pressure chamber 33 to the nozzle 21, and the liquid is discharged from the nozzle 21. Liquid is also supplied to the pressure chamber 33 from the common passage 51 via the supply passage 41.

[0039] Figures 3 and 4 show an example of the configuration of the liquid discharge head 1, and may include other components besides those shown in Figures 3 and 4.

[0040] The configuration of the nozzle 21 and the area around the pressure chamber 33 according to this embodiment will be described in detail with reference to Figures 5, 6, and 7. Figure 5 is an enlarged view of area I shown in Figure 3. Figure 6 is a cross-sectional view along the line II-II shown in Figure 5. Figure 7 is a cross-sectional view along the line III-III shown in Figure 5. Note that the liquid supply member 5 is omitted from Figures 5, 6, and 7 for the sake of clarity of explanation.

[0041] The piezoelectric element 32 comprises a common electrode 321, a piezoelectric body 322, and individual electrodes 323. In this embodiment, the piezoelectric element 32 has the common electrode 321 located on the diaphragm 31, the piezoelectric body 322 located on the common electrode 321, and the individual electrodes 323 located on the piezoelectric body 322, but is not limited to this arrangement. For example, the order of the common electrode 321 and the individual electrodes 323 relative to the diaphragm 31 may be reversed. Furthermore, the piezoelectric element 32 may have an adhesion layer such as Ti between the common electrode 321 and the diaphragm 31. In addition, the piezoelectric element 32 may have an adhesion layer such as LaNiO3 between the common electrode 321 and the piezoelectric body 322, and between the piezoelectric body 322 and the individual electrodes 323.

[0042] The common electrode 321 according to this embodiment is provided in common to multiple pressure chambers 33. The thickness of the common electrode 321 according to this embodiment may be 0.05 μm or more and 1 μm or less. The constituent material of the common electrode 321 may be a metallic material such as Pt.

[0043] In this embodiment, the piezoelectric element 322 is provided individually corresponding to each pressure chamber 33, but is not limited to this. For example, the piezoelectric element 322 may be provided across multiple pressure chambers 33 in a plan view. The thickness of the piezoelectric element 322 may be 0.5 μm or more and 5 μm or less. The constituent material of the piezoelectric element 322 may be, for example, Pb(Zr,Ti)O3 system, NaNbO3 system, BaTiO3 system, (BiNa)NbO3 system, BiNaNB5O 15 Examples include ferroelectric ceramic materials such as those found in the iodine system.

[0044] Individual electrodes 323 are provided individually, corresponding to each pressure chamber 33. The thickness of the individual electrodes 323 may be between 0.05 μm and 1 μm. The constituent material of the individual electrodes 323 may be a metallic material such as Pt.

[0045] In this embodiment, the liquid ejection head 1 has a diaphragm 31 and a piezoelectric element 32 that correspond to actuators. The actuator may also be a heating element. That is, the liquid ejection head 1 may eject ink using a piezoelectric method as in this embodiment. Alternatively, if the actuator of the liquid ejection head 1 is a heating element, the ink may be ejected using a thermal method.

[0046] In this embodiment, the liquid discharge head 1 generates a pressure wave in the pressure chamber 33 due to the displacement of the actuator. This pressure wave then moves towards the nozzle 21, causing the liquid to be discharged from the nozzle 21.

[0047] Furthermore, in the liquid discharge head 1 according to this embodiment, the nozzle plate 2 is a single plate, and the nozzle 21 is a through hole that penetrates the single nozzle plate 2. Therefore, compared to a configuration in which through holes are provided in each of multiple plates and then the multiple plates are laminated and bonded together to provide the nozzle, the liquid discharge head 1 according to this embodiment can reduce the processing error of the nozzle 21 because there is no misalignment in the lamination of the plates.

[0048] Furthermore, in the liquid discharge head 1 according to this embodiment, the pressure chamber plate 30 is a single plate, and the pressure chamber 33 is a through hole that penetrates the single pressure chamber plate 30. Therefore, compared to an embodiment in which through holes are provided in each of multiple plates and then the multiple plates are laminated and bonded together to form the pressure chamber 33, the liquid discharge head 1 according to this embodiment can reduce the processing error of the pressure chamber 33 because there is no misalignment in the lamination of the plates.

[0049] In the liquid discharge head 1 according to this embodiment, the thickness 2Z of the nozzle plate 2 is greater than the thickness 30Z of the pressure chamber plate 30. The thickness 2Z of the nozzle plate 2 may be, for example, 50 μm to 100 μm. The thickness 30Z of the pressure chamber plate 30 may be, for example, 50 μm to 100 μm. In the liquid discharge head 1 according to this embodiment, the thickness 2Z of the nozzle plate 2 may be 80 μm, and the thickness 30Z of the pressure chamber plate 30 may be 70 μm. Therefore, in the liquid discharge head 1 according to this embodiment, the height of the nozzle 21 is increased due to the thickness 2Z of the nozzle plate 2, so the nozzle 21 can align the direction of the liquid flow velocity to the negative Z-axis side. Therefore, the liquid discharge head 1 according to this embodiment can improve the accuracy of the liquid's impact when discharged from the nozzle 21.

[0050] In this embodiment, the thickness 2Z of the nozzle plate 2 may be the arithmetic mean of the thickness measurements taken at at least three or more points on the nozzle plate 2. Similarly, the thickness 30Z of the pressure chamber plate 30 may be the arithmetic mean of the thickness measurements taken at at least three or more points on the pressure chamber plate 30. Furthermore, in this embodiment, the height of the nozzle 21 is substantially the same as the thickness 2Z of the nozzle plate 2, and the height of the pressure chamber 33 is substantially the same as the thickness 30Z of the pressure chamber plate 30. Note that "substantially the same" means that even if they differ due to manufacturing tolerances, etc., they are still the same.

[0051] In the liquid discharge head 1 according to this embodiment, the pressure chamber plate 30 has a plurality of pressure chambers 33. In the liquid discharge head 1 according to this embodiment, when the thickness 2Z of the nozzle plate 2 is A (μm) and the thickness 30Z of the pressure chamber plate 30 is B (μm),

[0052] The liquid discharge head 1 according to this embodiment is 1

[0053] ​​ Incidentally, adjacent pressure chambers 33 influence each other through the portion of the pressure chamber plate 30 located between the adjacent pressure chambers 33. In other words, so-called crosstalk occurs. This crosstalk increases as the thickness of the pressure chamber plate 30 decreases. In this embodiment, the liquid discharge head 1 can reduce the possibility of increased crosstalk if the relationship A / B ≤ 2 is satisfied.

[0054] As described above, in the liquid discharge head 1 according to this embodiment, if the relationship in (Equation 1) above is satisfied, the accuracy of the liquid's impact can be improved, and the possibility of crosstalk can be reduced.

[0055] Furthermore, the liquid discharge head 1 according to this embodiment is 1

[0056] ​In this embodiment, the liquid discharge head 1 may have a nozzle plate 2 and a pressure chamber plate 30 joined to each other via an amorphous silicon layer 20. Amorphous silicon has excellent chemical stability, and its degradation due to the influence of liquid is slower than, for example, resins used in resin adhesives. Here, degradation due to the influence of liquid includes, for example, degradation due to hydrolysis, elution, or swelling. Also, since resins have lower thermal stability than amorphous silicon, the possibility of degradation due to hydrolysis, elution, or swelling increases as the liquid temperature rises. Therefore, in this embodiment, if the liquid discharge head 1 has the nozzle plate 2 and the pressure chamber plate 30 joined via an amorphous silicon layer 20 which has excellent chemical and thermal stability, the possibility of degradation occurring at the joint between the nozzle plate 2 and the pressure chamber plate 30 due to the influence of the supplied liquid can be reduced. In addition, amorphous silicon is less susceptible to degradation due to oxidation than metals used in metal joining. Therefore, in this embodiment, the liquid discharge head 1 can also reduce the possibility of degradation due to oxidation at the joint between the nozzle plate 2 and the pressure chamber plate 30.

[0057] In this embodiment, the liquid discharge head 1 has an activated amorphous silicon layer 20 formed by irradiating a nozzle plate 2 and a pressure chamber plate 30, which are made of single-crystal silicon, with an Ar ion beam under high vacuum. Here, high vacuum means 10 -5 This refers to a vacuum level of Pa or less. Furthermore, "activated" means that silicon atoms have unbonded hands. In this embodiment, the liquid discharge head 1 is joined to the nozzle plate 2 and the pressure chamber plate 30 by bringing the activated portions of single-crystal silicon into contact with each other. The nozzle plate 2 and the pressure chamber plate 30 can be joined at room temperature. Here, room temperature is defined as 5°C to 35°C, and in this embodiment, the liquid discharge head 1 is joined to the nozzle plate 2 and the pressure chamber plate 30 at 25°C.

[0058] In the liquid discharge head 1 according to this embodiment, the nozzle plate 2 and the pressure chamber plate 30 are joined to each other via an amorphous silicon layer 20, but they may also be joined to each other via a resin adhesive. In other words, the method of joining the nozzle plate 2 and the pressure chamber plate 30 is not limited to direct joining, but may also be indirect joining.

[0059] The liquid discharge head 1 according to this embodiment is located on the pressure chamber plate 30 and may further include a supply passage plate 4 having a supply passage 41 connected to the pressure chamber 33. As a result, the liquid discharge head 1 according to this embodiment is supplied with liquid from the supply passage 41 to the pressure chamber 33. Here, "on top of" the pressure chamber plate 30 does not necessarily mean directly "on top" of the pressure chamber plate 30, but may be, for example, "on top of" the diaphragm 31, or "on top of" another layer located on the diaphragm 31. In addition, in the liquid discharge head 1 according to this embodiment, the pressure chamber plate 30 and the supply passage plate 4 may be joined to each other via an amorphous silicon layer 40. Furthermore, in addition to the amorphous silicon layer 40, other layers such as the diaphragm 31 and a common electrode 321 may be included between the pressure chamber plate 30 and the supply passage plate 4. This reduces the possibility of deterioration occurring at the joint between the pressure chamber plate 30 and the supply passage plate 4 due to the influence of the supplied liquid. Moreover, amorphous silicon is less susceptible to deterioration due to oxidation compared to metals used in metal joining. Therefore, the liquid discharge head 1 according to this embodiment can also reduce the possibility of deterioration due to oxidation at the joint between the pressure chamber plate 30 and the supply passage plate 4.

[0060] In this embodiment, the liquid discharge head 1 may have an amorphous silicon layer 40 formed on the common electrode 321 by irradiating the common electrode 321, located on the pressure chamber plate 30, with an Ar ion beam to scatter silicon atoms onto the common electrode 321. In this embodiment, the amorphous silicon layer 40 is formed on the common electrode 321, but the amorphous silicon layer 40 is not limited to being located on the common electrode 321, but may be located on other layers (for example, insulating films or protective films not shown). Furthermore, the supply path plate 4 may have an activated amorphous silicon layer 40 formed on it by irradiating the supply path plate 4, which is made of single-crystal silicon, with an Ar ion beam under high vacuum. In this embodiment, the liquid discharge head 1 may have the pressure chamber plate 30 and the supply path plate 4 joined by bringing the activated portion of the supply path plate 4 into contact with the activated amorphous silicon layer 40 provided on the common electrode 321. The pressure chamber plate 30 and the supply path plate 4 can be joined at room temperature.

[0061] In this embodiment, the liquid discharge head 1 may have a single supply passage plate 4, and the supply passage 41 may be a through-hole that penetrates the single supply passage plate 4. Therefore, compared to an embodiment in which through-holes are provided in each of a plurality of plates and then the plurality of plates are laminated and bonded together to provide the supply passage 41, the liquid discharge head 1 in this embodiment can reduce the processing error of the supply passage 41 because there is no misalignment in the lamination of the plates.

[0062] In this embodiment, the thickness 4Z of the supply path plate 4 may be, for example, 200 μm to 400 μm. The thickness 4Z of the supply path plate 4 may be greater than the sum of the thickness 2Z of the nozzle plate 2 and the thickness 30Z of the pressure chamber plate 30. Specifically, in the liquid discharge head 1 according to this embodiment, the thickness 2Z of the nozzle plate 2 may be 80 μm, the thickness 30Z of the pressure chamber plate 30 may be 70 μm, and the thickness 4Z of the supply path plate 4 may be 300 μm.

[0063] Generally speaking, a thicker plate increases its rigidity. On the other hand, a thicker plate reduces the machining accuracy of the flow channels that penetrate it. Specifically, a thicker plate increases the amount of material removed by etching, making etching control more difficult and resulting in lower machining accuracy.

[0064] In this embodiment, the liquid discharge head 1 generates a pressure wave in the pressure chamber 33 due to the displacement of the actuator. This pressure wave is directed towards the nozzle 21, and liquid is discharged from the nozzle 21. In other words, the machining accuracy of the pressure chamber 33 and the nozzle 21 is required to be higher than that of the supply passage 41. This is because the pressure chamber 33 and the nozzle 21 have a greater impact on the discharge characteristics than the supply passage 41.

[0065] In the liquid discharge head 1 according to this embodiment, the thickness 4Z of the supply passage plate 4 may be greater than the sum of the thickness 2Z of the nozzle plate 2 and the thickness 30Z of the pressure chamber plate 30. Therefore, in the liquid discharge head 1 according to this embodiment, the thickness 2Z of the nozzle plate 2 and the thickness 30Z of the pressure chamber plate 30 are thinner than the thickness 4Z of the supply passage plate 4, resulting in higher machining accuracy of the nozzle 21 and the pressure chamber 33, and reducing the impact on the liquid discharge characteristics. Furthermore, in the liquid discharge head 1 according to this embodiment, the rigidity can be increased by increasing the thickness 4Z of the supply passage plate 4. Therefore, in the liquid discharge head 1 according to this embodiment, the possibility of damage can be reduced even if, for example, a printing medium comes into contact with it. Also, since the machining accuracy of the supply passage 41 has little impact on the discharge characteristics, increasing the thickness 4Z of the supply passage plate 4 has little impact on the discharge characteristics.

[0066] Here, the thickness 4Z of the supply path plate 4 may be the arithmetic mean of the thickness measured at at least three or more points on the supply path plate 4. In this embodiment, the height of the supply path 41 may also be the same as the thickness 4Z of the supply path plate 4.

[0067] As described above, the pressure chamber 33 may have a first portion 331 and a second portion 332. The second portion 332 may gradually narrow in width when viewed in plan from the portion connected to the first portion 331, and may include a rectangular portion smaller in width than the width of the first portion 331. In the present embodiment, when viewed in plan, the minimum width 332Y of the second portion 332 may be 20 μm, the width 331Y of the first portion 331 may be 70 μm, and the width 41X of the supply passage 41 may be 52 μm. Note that the supply passage 41 may be circular when viewed in plan, and its diameter may be 52 μm.

[0068] Therefore, in the liquid ejection head 1 according to the present embodiment, the flow path resistance of the second portion 332 becomes larger than that of the first portion 331, and the low processing accuracy of the second portion 332 greatly affects the liquid ejection characteristics. That is, in the liquid ejection head 1 according to the present embodiment, the influence of the processing accuracy of the supply passage 41 on the ejection characteristics becomes relatively small.

[0069] Thus, in the liquid ejection head 1 according to the present embodiment, even if the thickness 4Z of the supply passage plate 4 is made thicker than the total thickness of the thickness 2Z of the nozzle plate 2 and the thickness 30Z of the pressure chamber plate 30, the influence on the ejection characteristics is small. Also, in the liquid ejection head 1 according to the present embodiment, when viewed in plan, the minimum width 332Y of the second portion 332 may be smaller than half of the width 41Y of the supply passage 41. For this reason, in the liquid ejection head 1 according to the present embodiment, since the flow path resistance of the second portion 332 becomes larger, the influence of the processing accuracy of the supply passage 41 on the ejection characteristics becomes relatively smaller. Also, in the liquid ejection head 1 according to the present embodiment, the length 332X in the X-axis direction of the second portion 332 may be 500 μm, and the length 331X in the X-axis direction of the first portion 331 may be 240 μm.

[0070] In the liquid ejection head 1 according to the present embodiment, when the thickness 4Z of the supply passage plate 4 is C (μm), the relationship 1 < C / (A + B) ≤ 3 (hereinafter, referred to as (Equation 3)) may be satisfied.

[0071] Since the liquid ejection head 1 according to the present embodiment satisfies the formula 1 < C / (A + B), as described above, it is possible to reduce the influence on the liquid ejection characteristics and increase the rigidity.

[0072] Here, if the thickness 4Z of the supply path plate 4 is too thick, the low processing accuracy of the supply path 41 will affect the ejection characteristics. In the liquid ejection head 1 according to the present embodiment, since the relationship C / (A + B) ≤ 3 is satisfied, the thickness 4Z of the supply path plate 4 is not more than three times the total thickness of the thickness 2Z of the nozzle plate 2 and the thickness 30Z of the pressure chamber plate 30. For this reason, in the liquid ejection head 1 according to the present embodiment, compared with a liquid ejection head in which the thickness of the supply path plate is more than three times the total thickness of the thickness of the nozzle plate and the thickness of the pressure chamber plate, the possibility that the processing accuracy of the supply path 41 becomes low can be reduced. For this reason, the liquid ejection head 1 according to the present embodiment can reduce the influence of the low processing accuracy of the supply path 41 on the ejection characteristics.

[0073] Therefore, since the liquid ejection head 1 according to the present embodiment satisfies the above relationship (Formula 3), it is possible to further reduce the influence on the liquid ejection characteristics and increase the rigidity.

[0074] The nozzle plate 2 of the liquid ejection head 1 according to the present embodiment may be made of single crystal silicon. Further, the pressure chamber plate 30 of the liquid ejection head 1 according to the present embodiment may be made of single crystal silicon. In this case, the linear expansion coefficients of the nozzle plate 2 and the pressure chamber plate 30 become equal, and the expansion or contraction of the plates due to temperature changes becomes almost uniform. For this reason, the liquid ejection head 1 according to the present embodiment can reduce the possibility that these plates are damaged even if expansion or contraction occurs in the nozzle plate 2 and the pressure chamber plate 30.

[0075] Furthermore, single-crystal silicon has a lower thermal conductivity compared to metals such as SUS. Therefore, in the liquid discharge head 1 according to this embodiment, the temperature change of the liquid in the nozzle 21 and the liquid in the pressure chamber 33 due to external temperature changes is smaller compared to a liquid discharge head in which the nozzle plate 2 and pressure chamber plate 30 are made of metal. Therefore, in the liquid discharge head 1 according to this embodiment, the influence of temperature changes in the liquid in the nozzle 21 and the liquid in the pressure chamber 33 on the discharge characteristics can be reduced.

[0076] Furthermore, the liquid discharge head 1 according to this embodiment may have a supply passage plate 4 made of single-crystal silicon. Therefore, even if the pressure chamber plate 30 and supply passage plate 4, which are made of single-crystal silicon, expand or contract, the liquid discharge head 1 according to this embodiment can reduce the possibility of damage to these plates. In addition, the liquid discharge head 1 according to this embodiment experiences less temperature change of the liquid in the supply passage 41 due to external temperature changes compared to a liquid discharge head in which the supply passage plate is made of metal. Therefore, the liquid discharge head 1 according to this embodiment can reduce the impact of temperature changes of the liquid in the supply passage 41 on the discharge characteristics.

[0077] Finally, the manufacturing method of the liquid dispensing head 1 will be described.

[0078] First, the manufacturing method of the nozzle plate 2 will be described. The nozzle plate 2 can be manufactured by etching a single-crystal silicon substrate to form a nozzle 21. The single-crystal silicon substrate may be a single plate. That is, the nozzle 21 may be a through-hole penetrating a single nozzle plate 2.

[0079] Next, the manufacturing method of the flow channel member 3 will be described. The flow channel member 3 can be manufactured by sequentially depositing and etching various films onto a single-crystal silicon substrate. The pressure chamber plate 30 can be manufactured by etching the single-crystal silicon substrate to form a pressure chamber 33. The single-crystal silicon substrate may be a single plate. That is, the pressure chamber 33 may be a through-hole penetrating a single pressure chamber plate 30. In addition, the diaphragm 31 and piezoelectric element 32 may be formed on the single-crystal silicon substrate by sputtering, sol-gel method, CVD method, or thermal oxidation method.

[0080] Next, a method for manufacturing the supply path plate 4 will be described. The supply path plate 4 can be manufactured by etching a single-crystal silicon substrate to form supply paths 41. The single-crystal silicon substrate may be a single plate. That is, the supply paths 41 may be through holes penetrating a single supply path plate 4.

[0081] The liquid discharge head 1 can be manufactured by joining a supply path plate 4 onto a flow path member 3, then joining a nozzle plate 2 below the flow path member 3, and finally joining a liquid supply member 5 onto the supply path plate 4. The order of joining is not limited. Examples of joining methods include room temperature joining and metal joining for joining the nozzle plate 2 to the flow path member 3, and joining the flow path member 3 to the supply path plate 4. Examples of joining methods include joining the supply path plate 4 to the liquid supply member 5 using an adhesive. The joining method is also not limited.

[0082] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. Indeed, the embodiments described above can be embodied in a variety of forms. Furthermore, the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0083] 1. Liquid dispensing head 2 Nozzle Plates 2Z (Nozzle plate) thickness 3 Flow channel members 4. Supply path plate 4Z (thickness of the supply path plate) 10. Printer (storage device) 20,40 Amorphous silicon layer 21 nozzles 30 Pressure chamber plate 30Z (thickness of the pressure chamber plate) 31. Diaphragm (actuator) 32 Piezoelectric elements (actuators) 33 Pressure Chamber 41 Supply route 331 Part 1 332 Part 2

Claims

1. A nozzle plate having a nozzle, A pressure chamber plate located on the nozzle plate and having a pressure chamber connected to the nozzle, An actuator located on the pressure chamber plate, Equipped with, The nozzle plate is a single plate, The pressure chamber plate is a single plate, The nozzle is a through-hole that penetrates a single nozzle plate, The pressure chamber is a through-hole that penetrates a single pressure chamber plate. The thickness of the nozzle plate is greater than the thickness of the pressure chamber plate. Liquid dispensing head.

2. The aforementioned pressure chamber has multiple chambers, When the thickness of the nozzle plate is A (μm) and the thickness of the pressure chamber plate is B (μm), The relationship shown in (Equation 1) below is satisfied. The liquid dispensing head according to claim 1. 1<A / B≦2 (Formula 1)

3. The nozzle plate and the pressure chamber plate are joined to each other via an amorphous silicon layer. The liquid dispensing head according to claim 1.

4. The supply path plate further comprises a supply path having a supply path configured to supply liquid to the pressure chamber, The supply path plate is a single plate, The supply path is a through hole that penetrates a single supply path plate, The thickness of the supply path plate is greater than the sum of the thickness of the nozzle plate and the thickness of the pressure chamber plate. The liquid dispensing head according to claim 1.

5. The pressure chamber has a first section and a second section, The second part is connected to the first part and is also connected to the supply path. The width of the second portion is smaller than the width of the first portion and the width of the supply channel. The liquid dispensing head according to claim 4.

6. When the thickness of the nozzle plate is A (μm), the thickness of the pressure chamber plate is B (μm), and the thickness of the supply path plate is C (μm), The relationship shown in (Equation 3) below is satisfied. The liquid dispensing head according to claim 4. 1<C / (A+B)≦3 (Formula 3)

7. The pressure chamber plate and the supply channel plate are joined to each other via an amorphous silicon layer. The liquid dispensing head according to claim 4.

8. The nozzle plate is made of single-crystal silicon, The pressure chamber plate is made of single-crystal silicon. The liquid dispensing head according to claim 1.

9. A liquid dispensing head according to any one of claims 1 to 8, A moving unit that moves the liquid discharge head and the recording medium relative to each other, The system includes a control unit that controls the moving part. Recording device.

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