Liquid discharge 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

Liquid ejection head and recording apparatus

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

[0002] Patent Documents 1 and 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 displacement of the actuator. This pressure wave then travels toward the nozzles, ejecting liquid from the nozzles.

[0003] JP 2005-254659 A JP 2009-44031 A

[0004] A liquid ejection head according to one 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 that penetrate the single nozzle plate. The pressure chambers are through-holes that penetrate the single pressure chamber plate. The thickness of the nozzle plate is greater than the thickness of the pressure chamber plate.

[0005] FIG. 1 is a side view that schematically shows a printer according to an embodiment. FIG. 2 is a plan view that schematically shows a printer according to an embodiment. FIG. 3 is a plan view that schematically shows a liquid ejection head according to an embodiment. FIG. 4 is a side view of the liquid ejection head shown in FIG. 3 as seen from A. FIG. 5 is an enlarged view of region I shown in FIG. 3. FIG. 6 is a cross-sectional view taken along line II-II shown in FIG. 5. FIG. 7 is a cross-sectional view taken along line III-III shown in FIG. 5.

[0006] For example, in a liquid ejection head such as that disclosed in Patent Document 1, pressure chambers and nozzles are formed by laminating and bonding multiple plates together after forming through holes in each of the multiple plates, which can lead to processing errors in the pressure chambers and nozzles due to misalignment of the plates. Also, in a liquid ejection head such as that disclosed in Patent Document 2, the thickness of the plate having the nozzles is thinner than the thickness of the plate having the pressure chambers, which can lead to variations in the direction of the liquid flow velocity and reduced accuracy in landing of the liquid.

[0007] Therefore, there is a need for a technology that can reduce the processing errors of the nozzles and pressure chambers while improving the landing accuracy of the liquid.

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0009] Please note that the drawings used in the following explanation are schematic, and the dimensional ratios in the drawings do not necessarily correspond to the actual ones. Even among multiple drawings showing the same configuration, the dimensional ratios may not correspond to each other because the shapes and the like are exaggerated.

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

[0011] FIG. 1 is a side view that schematically illustrates a printer 10 according to an embodiment. FIG. 2 is a plan view that schematically illustrates the printer 10 according to an embodiment. The printer 10 is, for example, a color inkjet printer. For ease of understanding, FIG. 1 illustrates a three-dimensional Cartesian coordinate system that includes an X-axis with the positive direction toward the right of the page and a Y-axis with the positive direction toward the back of the page. This Cartesian coordinate system is also shown in other drawings used in the following description.

[0012] In the following description, for convenience, the positive Z-axis direction may be referred to as "upper." The X-axis direction is the transport direction of the printing paper P. In addition, "planar view" refers to a view 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 ejection head 1 , a dryer 107 , a sensor unit 108 , and a control unit 109 .

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

[0015] The paper feed roller 101, guide roller 102, transport roller 103, and recovery roller 104 constitute a moving unit that moves the print paper P and the liquid ejection head 1 relative to one another. The print paper P is an example of a recording medium. The moving unit is controlled by a control unit 109. The print paper P passes from the paper feed roller 101 between two guide rollers 102A and is transported onto multiple transport rollers 103. The print paper P then passes between two guide rollers 102B and two guide rollers 102C and is transported to the recovery roller 104.

[0016] The head case 105 houses the transport roller 103, the frame 106, and the liquid ejection head 1. The head case 105 is connected to the outside in some areas, such as the area where the printing paper P enters and leaves, but the rest of the head case 105 is a space isolated from the outside. The internal space of the head case 105 may be configured so that control factors such as temperature, humidity, and air pressure can be controlled by a control unit 109 as necessary.

[0017] The frame 106 is flat and positioned close to and above the print paper P being transported by the transport rollers 103. There are four frames 106 inside the head case 105, positioned at predetermined intervals along the transport direction of the print paper P. The number of frames 106 mounted on the printer 10 can be changed as appropriate depending on the object to be printed or the printing conditions.

[0018] Each liquid ejection head 1 has an elongated shape that is long and narrow in the Y-axis direction. As shown in FIG. 2 , five liquid ejection heads 1 are mounted on each frame 106. Within each frame 106, three liquid ejection heads 1 are aligned in a direction intersecting the transport direction of the print paper P, and the other two liquid ejection heads 1 are aligned one between the three liquid ejection heads 1 at positions offset along the transport direction. Within each frame 106, the liquid ejection heads 1 are arranged so that they overlap in the transport direction of the print paper P. The number of liquid ejection heads 1 included in one frame 106 can be changed as appropriate depending on the object to be printed or the printing conditions.

[0019] The liquid ejection head 1 according to this embodiment is fixed to the printer 10, which is a so-called line printer. Note that the printer 10 is not limited to a line printer, but may be a so-called serial printer in which the liquid ejection head 1 is moved in a direction intersecting the transport direction of the printing paper P to alternate between ejecting liquid and transporting 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, approximately 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 using four frames 106. The colors of liquid ejected from the liquid ejection heads 1 of each frame 106 may be, for example, magenta, yellow, cyan, and black. By causing such liquid to land on the printing paper P, a color image can be printed. The type of liquid color can be changed as appropriate. Alternatively, several colors of liquid can be supplied to the liquid ejection heads 1 belonging to one frame 106, and one frame 106 can be configured to print several colors of liquid.

[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 in the dryer 107, it becomes less likely that overlapping printing paper P wound up on the collection roller 104 will stick to each other, or that undried liquid will rub against each other.

[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 information from each sensor.

[0024] The printer 10 may be provided with a cleaning unit that cleans the liquid ejection head 1 .

[0025] The recording medium may be a roll of cloth or the like in addition to printing paper P. The printer 10 may also transport the recording medium on a transport belt. The recording medium may be a sheet of paper, cut cloth, wood, tile, or the like. Furthermore, the printer 10 may print wiring patterns for electronic devices by ejecting liquid containing conductive particles from the liquid ejection head 1.

[0026] The configuration of the liquid ejection head 1 according to this embodiment will be described with reference to Figures 3 and 4. Figure 3 is a plan view schematically showing the liquid ejection head 1 according to this embodiment. Figure 4 is a side view of the liquid ejection head 1 shown in Figure 3, as viewed from A. Note that the two wavy lines drawn in the vertical direction on the paper surface of Figure 3 represent omission lines.

[0027] The liquid ejection head 1 includes 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 includes 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 positioned along the Y-axis direction to form nozzle groups. The nozzle plate 2 according to this embodiment has two nozzle groups: a nozzle group on the positive X-axis direction side and a nozzle group on the negative X-axis direction 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. Furthermore, 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 in the nozzle group on the positive X-axis direction side are respectively positioned between the nozzles 21 in the nozzle group on the negative X-axis direction side in the Y-axis direction. In other words, the nozzles 21 in the nozzle group on the positive side of the X axis and the nozzles 21 in the nozzle group on the negative side of the X axis are offset from each other in the Y axis direction, and the combined resolution of the nozzles 21 in the two nozzle groups may be 600 dpi. Note that the spacing between the nozzles 21 in each nozzle group may be set appropriately depending on the resolution.

[0029] The flow path member 3 includes a pressure chamber plate 30, a vibration plate 31, and a plurality of piezoelectric elements 32. The pressure chamber plate 30 is located on the nozzle plate 2. The vibration plate 31 is located on the pressure chamber plate 30. The plurality of piezoelectric elements 32 are located on the vibration plate 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. The flow path member 3 according to this embodiment may have substantially the same shape as the nozzle plate 2 in a plan view.

[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. In plan view, the longitudinal direction of the multiple pressure chambers 33 is along the X-axis direction, and the lateral direction of the multiple pressure chambers 33 is 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 has a rectangular shape in a plan view. The second portion 332 gradually narrows in width in a plan view from the portion connected to the first portion 331, and includes a rectangular portion that is smaller in width than the first portion 331. Therefore, the second portion 332 functions as a restriction.

[0032] The vibration plate 31 is located on the pressure chamber plate 30. The vibration plate 31 is also located on a plurality of pressure chambers 33. The vibration plate 31 is made of a material such as Si or SiO. ２ The thickness of the diaphragm 31 may be set to 1 μm or more and 2 μm or less.

[0033] The plurality of piezoelectric elements 32 are positioned on the vibration plate 31 corresponding to the plurality of pressure chambers 33. Specifically, the plurality of piezoelectric elements 32 are positioned on the vibration plate 31 corresponding to the plurality of first portions 331. The plurality of piezoelectric elements 32 may be provided in a one-to-one relationship with the plurality of pressure chambers 33. By applying a voltage to the piezoelectric elements 32, the piezoelectric elements 32 are displaced. In accordance with the displacement of the piezoelectric elements 32, the vibration plate 31 positioned above the pressure chambers 33 is also displaced. As a result, pressure is applied to the liquid in the pressure chambers 33. This causes the liquid to be ejected 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 in the Z-axis direction than the flow path member 3, and functions to support the flow path member 3. The supply path plate 4 includes a plurality of supply paths 41.

[0035] Each of the plurality of supply paths 41 is a through-hole that penetrates the supply path plate 4 in the Z-axis direction, and is connected to each of the plurality of second portions 332. Each of the plurality of supply paths 41 is connected to each of the plurality of first portions 331 via the plurality of second portions 332. The supply paths 41 function as a so-called restriction, similar to the second portions 332. Furthermore, the plurality of supply paths 41 are located at the center of the supply path plate 4 in the X-axis direction when viewed in a plan view.

[0036] The liquid supply member 5 is located on the supply path plate 4. In a 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 flow path 51 may be located at the center of the liquid supply member 5 in the X-axis direction in a plan view, and may be configured along the Y-axis direction. Therefore, the common flow path 51 is located above the plurality of supply paths 41 and is connected to the plurality of supply paths 41. Therefore, the common flow path 51 according to this embodiment can supply liquid to each of the plurality of supply paths 41.

[0038] When liquid is ejected from the liquid ejection head 1 onto the printing paper P, the pressure chambers 33, the supply paths 41, and the common flow paths 51 are filled with liquid. In this case, when a voltage is applied to the piezoelectric elements 32, the piezoelectric elements 32 apply pressure to the pressure chambers 33. When pressure is applied to the pressure chambers 33, liquid is supplied from the pressure chambers 33 to the nozzles 21, and the liquid is ejected from the nozzles 21. Furthermore, liquid is supplied to the pressure chambers 33 from the common flow paths 51 via the supply paths 41.

[0039] 3 and 4 show an example of the configuration of the liquid ejection head 1, and the liquid ejection head 1 may further include members other than those shown in FIGS.

[0040] The configuration of the nozzle 21 and 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 region I shown in Figure 3. Figure 6 is a cross-sectional view taken along line II-II in Figure 5. Figure 7 is a cross-sectional view taken along line III-III in Figure 5. Note that in Figures 5, 6, and 7, the liquid supply member 5 is omitted from illustration in order to make the description easier to understand.

[0041] The piezoelectric element 32 includes a common electrode 321, a piezoelectric body 322, and an individual electrode 323. In the piezoelectric element 32 according to this embodiment, the common electrode 321 is located on the vibration plate 31, the piezoelectric body 322 is located on the common electrode 321, and the individual electrode 323 is located on the piezoelectric body 322, but this is not limiting. For example, the order of the common electrode 321 and the individual electrode 323 from the vibration plate 31 may be reversed. Furthermore, the piezoelectric element 32 may have an adhesive layer such as Ti between the common electrode 321 and the vibration plate 31. In addition, the piezoelectric element 32 may have a LaNiO layer between the common electrode 321 and the piezoelectric body 322 and between the piezoelectric body 322 and the individual electrode 323. ３ The adhesive layer may have an adhesive layer such as the above.

[0042] The common electrode 321 according to this embodiment is provided in common to the plurality of pressure chambers 33. The thickness of the common electrode 321 according to this embodiment may be set to 0.05 μm or more and 1 μm or less. The common electrode 321 may be made of a metal material such as Pt, for example.

[0043] The piezoelectric bodies 322 according to this embodiment are individually provided corresponding to each pressure chamber 33, but this is not limiting. For example, the piezoelectric bodies 322 may be provided across a plurality of pressure chambers 33 in plan view. The thickness of the piezoelectric bodies 322 may be 0.5 μm or more and 5 μm or less. The constituent material of the piezoelectric bodies 322 may be, for example, Pb(Zr,Ti)O ３ system, NaNbO ３ system, BaTiO ３ system, (BiNa)NbO ３ system, BiNaNB ５ O １５ Examples of suitable materials include ceramic materials having ferroelectricity such as ferroelectric ceramics.

[0044] The individual electrodes 323 are individually provided corresponding to the respective pressure chambers 33. The thickness of the individual electrodes 323 may be set to 0.05 μm or more and 1 μm or less. The individual electrodes 323 may be made of a metal material such as Pt, for example.

[0045] In the liquid ejection head 1 according to this embodiment, the vibration plate 31 and the piezoelectric element 32 correspond to the actuator. The actuator may be a heat generating element. That is, the liquid ejection head 1 may eject ink by a piezoelectric method as in this embodiment. Furthermore, if the actuator is a heat generating element, the liquid ejection head 1 may eject ink by a thermal method.

[0046] In the liquid ejection head 1 according to this embodiment, a pressure wave is generated in the pressure chamber 33 due to the displacement of the actuator. Then, this pressure wave is directed toward the nozzle 21, and liquid is ejected from the nozzle 21.

[0047] Furthermore, in the liquid ejection head 1 according to this embodiment, the nozzle plate 2 is a single plate, and the nozzles 21 are through-holes that penetrate the single nozzle plate 2. Therefore, in the liquid ejection head 1 according to this embodiment, there is no misalignment in the plates, and therefore processing errors in the nozzles 21 can be reduced, compared to a configuration in which through-holes are formed in each of a plurality of plates, and then the plurality of plates are laminated and bonded together to form nozzles.

[0048] Furthermore, in the liquid ejection head 1 according to this embodiment, the pressure chamber plate 30 is a single plate, and the pressure chambers 33 are through-holes that penetrate the single pressure chamber plate 30. Therefore, in the liquid ejection head 1 according to this embodiment, there is no misalignment in the plates, and therefore processing errors in the pressure chambers 33 can be reduced compared to an embodiment in which through-holes are formed in each of a plurality of plates and then the plurality of plates are laminated and bonded together to form the pressure chambers 33.

[0049] In the liquid ejection head 1 according to this embodiment, the thickness 2Z of the nozzle plate 2 is thicker 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 ejection 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 ejection head 1 according to this embodiment, the height of the nozzle 21 is increased due to the increased thickness 2Z of the nozzle plate 2, and the nozzle 21 can align the flow velocity direction of the liquid in the negative direction of the Z axis. Therefore, the liquid ejection head 1 according to this embodiment can improve the landing accuracy of the liquid ejected from the nozzle 21.

[0050] In this embodiment, the thickness 2Z of the nozzle plate 2 may be determined by measuring the thickness at at least three or more points on the nozzle plate 2 and calculating the arithmetic average of these measured values. Furthermore, the thickness 30Z of the pressure chamber plate 30 may be determined by measuring the thickness at at least three or more points on the pressure chamber plate 30 and calculating the arithmetic average of these measured values. 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 they are the same even if they differ due to manufacturing errors, etc.

[0051] In the liquid ejection head 1 according to this embodiment, the pressure chamber plate 30 has a plurality of pressure chambers 33. The liquid ejection head 1 according to this embodiment may satisfy the relationship 1<A / B≦2 (hereinafter referred to as (Formula 1)), where A (μm) is the thickness 2Z of the nozzle plate 2 and B (μm) is the thickness 30Z of the pressure chamber plate 30.

[0052] If the liquid ejection head 1 according to this embodiment satisfies the relationship 1<A / B, it is possible to improve the landing accuracy of the liquid ejected from the nozzles 21, as described above.

[0053] Adjacent pressure chambers 33 affect each other via the portions of the pressure chamber plate 30 that are 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 the liquid ejection head 1 according to this embodiment, if the relationship A / B≦2 is satisfied, the possibility of increased crosstalk can be reduced.

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

[0055] Furthermore, it is preferable that the liquid ejection head 1 according to this embodiment satisfies the relationship 1<A / B≦1.5 (hereinafter referred to as (Equation 2)). From the above (Equation 2), the relationship 1 / 2A≦B can be derived. Furthermore, from the above (Equation 2), the relationship 2 / 3A≦B can also be derived. In a liquid ejection head 1 that satisfies the relationship of (Equation 2) above, the thickness 30Z of the pressure chamber plate 30 can be made thicker than in a liquid ejection head 1 that satisfies the relationship of (Equation 1) above, thereby further reducing the possibility of increased crosstalk. Therefore, it can be said that it is more preferable that the liquid ejection head 1 according to this embodiment satisfies the relationship of (Equation 2) above.

[0056] In the liquid ejection head 1 according to this embodiment, the nozzle plate 2 and the pressure chamber plate 30 may be bonded to each other via an amorphous silicon layer 20. Amorphous silicon has excellent chemical stability and deteriorates more slowly due to the influence of liquid than, for example, resins used in resin adhesives. Examples of deterioration due to the influence of liquid include deterioration due to hydrolysis, elution, or swelling. Furthermore, resins have lower thermal stability than amorphous silicon, so as the temperature of the liquid increases, the possibility of deterioration due to hydrolysis, elution, or swelling increases. Therefore, in the liquid ejection head 1 according to this embodiment, if the nozzle plate 2 and the pressure chamber plate 30 are bonded to each other via an amorphous silicon layer 20 that has excellent chemical and thermal stability, the possibility of deterioration at the bonded portion between the nozzle plate 2 and the pressure chamber plate 30 due to the influence of the supplied liquid can be reduced. Furthermore, amorphous silicon is less susceptible to deterioration due to oxidation than metals used in metal bonding. Therefore, the liquid ejection head 1 according to this embodiment can also reduce the possibility of deterioration at the bonded portion between the nozzle plate 2 and the pressure chamber plate 30 due to oxidation.

[0057] In the liquid ejection head 1 according to this embodiment, an activated amorphous silicon layer 20 is formed by irradiating an Ar ion beam on the nozzle plate 2 and the pressure chamber plate 30 made of single crystal silicon under high vacuum. －５ This refers to a vacuum level of 0.1 Pa or less. Furthermore, being activated means that the silicon atoms have dangling bonds. In the liquid ejection head 1 according to this embodiment, the nozzle plate 2 and the pressure chamber plate 30 are bonded together by bringing activated portions of the single crystal silicon into contact with each other. The nozzle plate 2 and the pressure chamber plate 30 can be bonded together at room temperature. Here, room temperature refers to 5°C to 35°C, and in the liquid ejection head 1 according to this embodiment, the nozzle plate 2 and the pressure chamber plate 30 are bonded together at 25°C.

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

[0059] The liquid ejection head 1 according to this embodiment may further include a supply channel plate 4 located on the pressure chamber plate 30 and having supply channels 41 connecting to the pressure chambers 33. As a result, in the liquid ejection head 1 according to this embodiment, liquid is supplied to the pressure chambers 33 from the supply channels 41. Here, "above" the pressure chamber plate 30 does not necessarily mean being located directly "above" the pressure chamber plate 30. For example, it may mean "above" the diaphragm 31 or "above" another layer located on the diaphragm 31. Furthermore, in the liquid ejection head 1 according to this embodiment, the pressure chamber plate 30 and the supply channel plate 4 may be bonded 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 channel plate 4. This reduces the possibility of deterioration at the joint between the pressure chamber plate 30 and the supply channel plate 4 due to the influence of the supplied liquid. Furthermore, amorphous silicon is less susceptible to deterioration due to oxidation than metals used in metal bonding. Therefore, the liquid ejection head 1 according to this embodiment can also reduce the possibility that the joint between the pressure chamber plate 30 and the supply path plate 4 will deteriorate due to oxidation.

[0060] In the liquid ejection head 1 according to this embodiment, the amorphous silicon layer 40 may be formed on the common electrode 321 located on the pressure chamber plate 30 by irradiating the common electrode 321 with an Ar ion beam to scatter silicon atoms onto the common electrode 321. In the liquid ejection head 1 according to this embodiment, the amorphous silicon layer 40 is formed on the common electrode 321. However, the amorphous silicon layer 40 is not limited to being located on the common electrode 321 and may be located on another layer (e.g., an insulating film or protective film, not shown). Furthermore, the supply channel plate 4 may be formed by irradiating the supply channel plate 4 made of single-crystal silicon with an Ar ion beam under high vacuum to form an activated amorphous silicon layer 40. In the liquid ejection head 1 according to this embodiment, the pressure chamber plate 30 and the supply channel plate 4 may be bonded to each other by bringing the activated portion of the supply channel 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 channel plate 4 can be bonded to each other at room temperature.

[0061] In the liquid ejection head 1 according to this embodiment, the supply path plate 4 may be a single plate, and the supply path 41 may be a through-hole that penetrates the single supply path plate 4. Therefore, in the liquid ejection head 1 according to this embodiment, there is no misalignment of the plates, and therefore processing errors in the supply path 41 can be reduced compared to a configuration in which a through-hole is formed in each of a plurality of plates, and then the plurality of plates are laminated and bonded to form the supply path 41.

[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 thicker than the total thickness of the thickness 2Z of the nozzle plate 2 and the thickness 30Z of the pressure chamber plate 30. Specifically, in the liquid ejection 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, the thicker the plate, the greater the rigidity of the plate. On the other hand, the thicker the plate, the lower the processing accuracy of the flow path that penetrates the plate. Specifically, if the plate is thick, for example, the amount of material removed by etching increases, making it difficult to control the etching and resulting in lower processing accuracy.

[0064] In the liquid ejection head 1 according to this embodiment, a pressure wave is generated in the pressure chamber 33 due to displacement of the actuator, and this pressure wave is directed toward the nozzle 21, causing liquid to be ejected from the nozzle 21. In other words, the processing precision of the pressure chamber 33 and the nozzle 21 must be higher than the processing precision of the supply path 41. This is because the pressure chamber 33 and the nozzle 21 are parts that have a greater effect on the ejection characteristics than the supply path 41.

[0065] In the liquid ejection head 1 according to this embodiment, 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. Therefore, in the liquid ejection 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 path plate 4. This increases the machining accuracy of the nozzles 21 and the pressure chambers 33, thereby minimizing the impact on the liquid ejection characteristics. Furthermore, in the liquid ejection head 1 according to this embodiment, increasing the thickness 4Z of the supply path plate 4 increases rigidity. Therefore, the liquid ejection head 1 according to this embodiment can reduce the possibility of damage even if it comes into contact with a print medium, for example. Furthermore, because the machining accuracy of the supply paths 41 has little impact on the ejection characteristics, increasing the thickness 4Z of the supply path plate 4 also has little impact on the ejection characteristics.

[0066] Here, the thickness 4Z of the supply path plate 4 may be determined by measuring the thickness at at least three or more points on the supply path plate 4 and calculating the arithmetic mean of these measured values. In addition, in this embodiment, the height of the supply path 41 may 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 include a rectangular portion whose width gradually narrows in plan view from the portion connected to the first portion 331 and is smaller than the width of the first portion 331. In this embodiment, in plan view, 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 channel 41 may be 52 μm. Note that the supply channel 41 may be circular in plan view and may have a diameter of 52 μm.

[0068] For this reason, in the liquid ejection head 1 according to this embodiment, the flow path resistance of the second portion 332 is greater than that of the first portion 331, and the low processing accuracy of the second portion 332 has a significant effect on the ejection characteristics of the liquid. In other words, in the liquid ejection head 1 according to this embodiment, the effect that the processing accuracy of the supply path 41 has on the ejection characteristics is relatively small.

[0069] As described above, in the liquid ejection head 1 according to this embodiment, even if the thickness 4Z of the supply path plate 4 is greater than the total thickness of the thickness 2Z of the nozzle plate 2 and the thickness 30Z of the pressure chamber plate 30, the effect on the ejection characteristics is small. Furthermore, in the liquid ejection head 1 according to this embodiment, the minimum width 332Y of the second portion 332 may be smaller than half the width 41Y of the supply path 41 in a plan view. Therefore, in the liquid ejection head 1 according to this embodiment, the flow path resistance of the second portion 332 is greater, and the effect of the processing accuracy of the supply path 41 on the ejection characteristics is relatively smaller. Furthermore, in the liquid ejection head 1 according to this embodiment, the length 332X of the second portion 332 in the X-axis direction may be 500 μm, and the length 331X of the first portion 331 in the X-axis direction may be 240 μm.

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

[0071] The liquid ejection head 1 according to this embodiment satisfies the formula 1<C / (A+B), and therefore, as described above, can increase rigidity while reducing the effect on the liquid ejection characteristics.

[0072] Here, if the thickness 4Z of the supply path plate 4 is too thick, low processing accuracy of the supply paths 41 will affect the ejection characteristics. In the liquid ejection head 1 according to this embodiment, the relationship C / (A+B)≦3 is satisfied, and therefore the thickness 4Z of the supply path plate 4 is no 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. Therefore, in the liquid ejection head 1 according to this embodiment, the possibility of low processing accuracy of the supply paths 41 can be reduced compared to a liquid ejection head in which the thickness of the supply path plate is more than three times the total thickness of the nozzle plate and the pressure chamber plate. Therefore, the liquid ejection head 1 according to this embodiment can reduce the impact of low processing accuracy of the supply paths 41 on the ejection characteristics.

[0073] Therefore, the liquid ejection head 1 according to this embodiment satisfies the relationship of (Equation 3) above, and therefore can increase rigidity while further reducing the effect on the liquid ejection characteristics.

[0074] In the liquid ejection head 1 according to this embodiment, the nozzle plate 2 may be made of single crystal silicon. Also, in the liquid ejection head 1 according to this embodiment, the pressure chamber plate 30 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 are equivalent, and the expansion or contraction of the plates due to temperature changes is approximately uniform. Therefore, in the liquid ejection head 1 according to this embodiment, even if expansion or contraction occurs in the nozzle plate 2 and the pressure chamber plate 30, the possibility of these plates being damaged can be reduced.

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

[0076] Furthermore, in the liquid ejection head 1 according to this embodiment, the supply path plate 4 may be made of single crystal silicon. Therefore, in the liquid ejection head 1 according to this embodiment, even if the pressure chamber plate 30 and the supply path plate 4 made of single crystal silicon expand or contract, the possibility of these plates being damaged can be reduced. Furthermore, in the liquid ejection head 1 according to this embodiment, changes in temperature of the liquid in the supply path 41 due to changes in external temperature are smaller than in a liquid ejection head whose supply path plate is made of metal. Therefore, in the liquid ejection head 1 according to this embodiment, the effect on the ejection characteristics of changes in temperature of the liquid in the supply path 41 can be reduced.

[0077] Finally, a method for manufacturing the liquid ejection head 1 will be described.

[0078] First, a method for manufacturing the nozzle plate 2 will be described. The nozzle plate 2 can be manufactured by etching a single crystal silicon substrate to form the nozzles 21. The single crystal silicon substrate may be a single plate. In other words, the nozzles 21 may be through-holes that penetrate the single nozzle plate 2.

[0079] Next, a method for manufacturing the flow path member 3 will be described. The flow path member 3 can be manufactured by sequentially depositing and etching various films on a single crystal silicon substrate. The pressure chamber plate 30 can be manufactured by etching the single crystal silicon substrate to form the pressure chambers 33. The single crystal silicon substrate may be a single plate. In other words, the pressure chambers 33 may be through-holes that penetrate a single pressure chamber plate 30. Furthermore, the vibration plate 31 and the piezoelectric elements 32 may be formed on the single crystal silicon substrate by sputtering, a sol-gel method, a CVD method, or a thermal oxidation method.

[0080] Next, a method for manufacturing the supply channel plate 4 will be described. The supply channel plate 4 can be manufactured by etching a single crystal silicon substrate to form the supply channels 41. The single crystal silicon substrate may be a single plate. In other words, the supply channels 41 may be through-holes that penetrate the single supply channel plate 4.

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

[0082] The disclosed embodiments should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0083] REFERENCE SIGNS LIST 1 Liquid ejection head 2 Nozzle plate 2Z (Nozzle plate) thickness 3 Flow path member 4 Supply path plate 4Z (Supply path plate) thickness 10 Printer (recording device) 20, 40 Amorphous silicon layer 21 Nozzle 30 Pressure chamber plate 30Z (Pressure chamber plate) thickness 31 Vibration plate (actuator) 32 Piezoelectric element (actuator) 33 Pressure chamber 41 Supply path 331 First portion 332 Second portion

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.