Liquid ejection head and liquid ejection substrate

Abstract

To provide a liquid ejection head capable of stably performing normal ejection operations. [Solution] A liquid ejection head comprising a plurality of ejection ports for ejecting liquid, a plurality of pressure chambers each corresponding to the ejection ports and containing liquid to be ejected from the ejection ports, a first common flow path commonly connected to a first number of pressure chambers, a first damper area for reducing pressure fluctuations in the first common flow path, a second common flow path commonly connected to a second number of pressure chambers smaller than the first number, and a second damper area for reducing pressure fluctuations in the second common flow path, wherein the first damper area is larger than the second damper area.

Description

[Technical Field]

[0001] The present disclosure relates to a liquid ejection head and a liquid ejection substrate. [Background technology]

[0002] In a liquid ejection head, pressure fluctuations occur within a pressure chamber as the liquid is ejected, and these pressure fluctuations can propagate to other pressure chambers via the liquid flow path, resulting in so-called crosstalk, which affects the ejection characteristics. When crosstalk occurs, the ejection speed or ejection amount of each ejection element becomes unstable, which can adversely affect the image.

[0003] Patent Document 1 discloses a configuration in which a damper is provided in a liquid flow path that is commonly connected to a plurality of pressure chambers, thereby absorbing pressure fluctuations from the pressure chambers and suppressing crosstalk. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-155909 Summary of the Invention [Problem to be solved by the invention]

[0005] The effectiveness of a damper in suppressing pressure fluctuations depends on the number of pressure chambers that communicate with that damper. However, in the configuration of Patent Document 1, although multiple dampers of the same size are provided, the number of pressure chambers connected to each damper is not constant. As a result, depending on the ejection element, the crosstalk suppression effect is not sufficient, and there are cases where the entire liquid ejection head is unable to perform normal ejection operations stably.

[0006] Therefore, an object of the present disclosure is to provide a liquid ejection head that is capable of performing normal ejection operations stably. [Means for solving the problem]

[0007] A liquid ejection head according to one aspect of the present disclosure is a liquid ejection head comprising a plurality of ejection ports for ejecting liquid, a plurality of pressure chambers each corresponding to the ejection ports and containing liquid to be ejected from the ejection ports, a first common flow path commonly connected to a first number of pressure chambers, a first damper region for reducing pressure fluctuations in the first common flow path, a second common flow path commonly connected to a second number of pressure chambers that is smaller than the first number, and a second damper region for reducing pressure fluctuations in the second common flow path, wherein the first damper region is larger than the second damper region. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a liquid ejection head that is capable of performing normal ejection operations stably. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram schematically illustrating a recording apparatus. [Figure 2] FIG. 2 is a diagram illustrating a liquid ejection head. [Figure 3] FIG. 2 is a diagram illustrating a liquid ejection substrate according to the first embodiment. [Figure 4] 10A and 10B are diagrams illustrating a liquid ejection substrate according to a second embodiment. [Figure 5] 10A and 10B are diagrams illustrating a liquid ejection substrate according to a third embodiment. [Figure 6] 10A and 10B are diagrams illustrating a liquid ejection substrate according to a fourth embodiment. [Figure 7] FIG. 2 is a plan view of each substrate constituting the liquid ejection substrate. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the present disclosure, and not all combinations of features described in the following embodiments are necessarily essential to the solution of the present disclosure.

[0011] (First embodiment) A liquid ejection head and a liquid ejection device according to the present embodiment will be described below with reference to the drawings. In the present embodiment, a liquid ejection head and an inkjet recording device that eject ink will be described as an example, but the present invention is not limited to this example. The liquid ejection head and the liquid ejection device according to the present disclosure can be applied to devices such as printers, copiers, facsimiles with communication systems, word processors with printer units, and industrial recording devices combined with various processing devices. For example, the liquid ejection head and the liquid ejection device can also be used for applications such as biochip production or electronic circuit printing. Furthermore, the liquid ejected is not limited to ink.

[0012] <Outline of the recording device> FIG. 1 is a schematic diagram illustrating a recording apparatus 101, an example of a liquid ejection apparatus according to this embodiment. The recording apparatus 101 is a one-pass type recording apparatus that moves a recording medium 11 in the direction of arrow A relative to a liquid ejection head module 1 (hereinafter referred to as the liquid ejection head 1) to print an image on the recording medium 11. The liquid ejection head 1 has ejection openings (also referred to as nozzles) arranged in the X direction across an area corresponding to the width of the recording medium 11. The liquid ejection head 1 according to this embodiment is a head corresponding to four colors: cyan (C), magenta (M), yellow (Y), and black (K). More specifically, the liquid ejection head 1 includes liquid ejection heads 1Ca and 1Cb corresponding to cyan (C) ink, and liquid ejection heads 1Ma and 1Mb corresponding to magenta (M) ink. The liquid ejection head 1 also includes liquid ejection heads 1Ya and 1Yb corresponding to yellow (Y) ink, and liquid ejection heads 1Ka and 1Kb corresponding to black (K) ink. 1 is an example, and may be configured to be able to mount any type of liquid ejection head 1. For example, the recording apparatus 101 may have only one type of liquid ejection head, or may have multiple types of liquid ejection heads other than four types.

[0013] <Configuration of liquid ejection head> 2(a) to 2(c) are diagrams illustrating a liquid ejection head 1 according to this embodiment. FIG. 2(a) is a perspective view of the liquid ejection head 1 for any one of the colors shown in FIG. 1. The liquid ejection head 1 has a plurality of liquid ejection substrates 2 and a head main body 4. A plurality of liquid ejection substrates 2 are arranged on the head main body 4 (four liquid ejection substrates 2 are arranged in this figure). A plurality of ejection ports 3 are formed on each liquid ejection substrate 2. Ink ejected from the liquid ejection head 1 is supplied to the liquid ejection substrate 2 from an ink tank (not shown) via a common supply port (not shown) of the head main body 4. The liquid ejection substrate 2 is arranged so that the ends of the ejection ports 3 arranged in the X direction overlap in the Y direction. By arranging the liquid ejection substrates 2 in this manner, recording can be performed using a long array of ejection ports.

[0014] 2(b) is a view of the liquid ejection substrate 2 as viewed from the surface on which the ejection ports 3 are arranged. FIG. 2(c) is a view of the liquid ejection substrate 2 as viewed from the opposite side to the surface on which the ejection ports 3 are arranged. The liquid ejection substrate 2 is constructed using a plurality of substrates. As shown in FIG. 2(b), the liquid ejection substrate 2 includes an ejection port-forming substrate 201. The ejection ports 3 are formed in the ejection port-forming substrate 201, and a plurality of the ejection ports 3 are arranged along the longitudinal direction (X direction, first direction) of the liquid ejection substrate 2 (ejection port-forming substrate 201) to form a single ejection port array. In addition, the ejection port-forming substrate 201 has a plurality of ejection port arrays extending in the longitudinal direction of the substrate, arranged in a direction intersecting the direction along the ejection port array, i.e., in the lateral direction of the substrate (Y direction, second direction).

[0015] As shown in FIG. 2(c), a flow path forming substrate 204 is provided on the surface of the liquid ejection substrate 2 opposite to the surface on which the ejection ports 3 are formed. A plurality of connection ports 15 are formed in the flow path forming substrate 204. The liquid ejection head 1 of this embodiment is configured to circulate ink. Ink is supplied to the liquid ejection substrate 2 and liquid is recovered from the liquid ejection substrate 2 via the connection ports 15 formed in the flow path forming substrate 204. The ink supplied to the liquid ejection substrate 2 passes through flow paths inside the substrate, and is ejected from the ejection ports 3 in response to an ejection signal and applied to the recording medium 11.

[0016] An electric board (not shown) is arranged on the head main body 4 to supply the power and signals required to eject ink from the ejection ports 3, and is connected to the terminals 200 of each liquid ejection substrate 2 by wiring 205 (see FIG. 7(b)). Note that the example described in FIG. 2 is merely one example of this embodiment, and the liquid ejection head 1 can be configured in any desired form.

[0017] <Configuration of Liquid Ejection Substrate> Figures 3(a) to 3(c) are diagrams for explaining the liquid ejection substrate 2 of this embodiment in comparison with a comparative example. Figures 3(a) and 3(b) are cross-sectional views taken along line III-III in Figure 2(b). Figure 3(a) shows a conventional configuration in which crosstalk is difficult to suppress as a comparative example, while Figure 3(b) shows the configuration of this embodiment in which crosstalk is suppressed. Figure 3(c) is a perspective cross-sectional view taken along line III-III in Figure 2(b).

[0018] 3(a) to 3(c), the liquid ejection substrate 2 of this embodiment is formed by a laminated structure of multiple substrates. Specifically, the liquid ejection substrate 2 includes an ejection port forming substrate 201, a vibration substrate 202, a liquid supply substrate 203, a flow path forming substrate 204, and a damper member 300. The ejection port forming substrate 201, the vibration substrate 202, the liquid supply substrate 203, and the flow path forming substrate 204 can each be formed from a silicon substrate or the like. In this embodiment, an example will be described in which each of these is a separate substrate, but this is not limited to separate substrates.

[0019] The damper member 300 is made of an elastic material, and may be made of a resin material such as polyimide or polyamide. Dry etching can be used as a method for forming the openings in the damper member 300. In addition, if the damper member is made of a photosensitive resin, it may be patterned by exposure to light.

[0020] A case where a conventional general configuration is adopted for the liquid ejection substrate 2 of this embodiment will be described with reference to Fig. 3(a) In Fig. 3(a), the arrow in the drawing indicates the direction of liquid flow.

[0021] An ejection port 3 is formed in the ejection port forming substrate 201. A pressure chamber 5 communicating with the ejection port 3 is formed in the vibration substrate 202. A piezoelectric element 6 is provided in a portion of the vibration substrate 202 facing the ejection port 3. The piezoelectric element 6 deforms when a voltage is applied, pressurizing the liquid in the pressure chamber 5 and causing ink to be ejected from the ejection port 3. One pressure chamber 5 and one piezoelectric element 6 correspond to one ejection port 3. For convenience, this set of ejection port 3, pressure chamber 5, and piezoelectric element 6 will be referred to as an "ejection element" in this disclosure.

[0022] A plurality of ejection elements are arranged in the X direction to form one ejection element array. In this embodiment, two such ejection element arrays are arranged in parallel in the Y direction. For convenience, the ejection element array on the left side of the drawing will be referred to as the first ejection element array, and the ejection element array on the right side will be referred to as the second ejection element array. Wiring 205 for supplying power to the plurality of piezoelectric elements 6 is also formed on the vibration substrate 202 (see FIG. 7(b)).

[0023] The liquid supply substrate 203 is formed with a first common supply channel 17 for commonly supplying ink to the plurality of pressure chambers 5 of the first ejection element array, and a second common supply channel 19 for commonly supplying ink to the plurality of pressure chambers 5 of the second ejection element array. The liquid supply substrate 203 also is formed with a common recovery channel 18 for commonly recovering ink from the plurality of pressure chambers 5 of the first ejection element array and the second ejection element array. The first common supply channel 17, the second common supply channel 19, and the common recovery channel 18 extend in the X direction across the array area of ​​the ejection elements.

[0024] The liquid supply substrate 203 is formed with a first individual supply flow path 7 for individually supplying ink to the plurality of pressure chambers 5 of the first ejection element array, and a second individual supply flow path 9 for individually supplying ink to the plurality of pressure chambers 5 of the second ejection element array. The liquid supply substrate 203 also is formed with a first individual recovery flow path 8 for individually recovering ink from the plurality of pressure chambers 5 of the first ejection element array, and a second individual recovery flow path 10 for individually recovering ink from the plurality of pressure chambers 5 of the second ejection element array.

[0025] The flow path forming substrate 204 is formed with a first supply port 27 for supplying ink to the first common supply flow path 17, a second supply port 29 for supplying ink to the second common supply flow path 19, and a common recovery port 28 for recovering ink from the common recovery flow path 18. These correspond to the connection port 15 described in FIG. 2(c).

[0026] The flow path forming substrate 204 has a concave first damper chamber 301, a second damper chamber 302, and a third damper chamber 303 formed at positions corresponding to the first common supply flow path 17, the common recovery flow path 18, and the second common supply flow path 19. The first damper chamber 301, the second damper chamber 302, and the third damper chamber 303 extend in the X direction and face the first common supply flow path 17, the common recovery flow path 18, and the second common supply flow path 19, respectively, via a flexible film-like damper member 300.

[0027] With the above configuration, ink supplied from the first supply port 27 is supplied to the pressure chamber 5 of the first ejection element array via the first common supply channel 17 and the first individual supply channel 7. Ink that is not ejected from the pressure chamber 5 is recovered to the outside from the common recovery port 28 via the first individual recovery channel 8 and the common recovery channel 18. On the other hand, ink supplied from the second supply port 29 is supplied to the pressure chamber 5 of the second ejection element array via the second common supply channel 19 and the second individual supply channel 9. Ink that is not ejected from the pressure chamber 5 is recovered to the outside from the common recovery port 28 via the second individual recovery channel 10 and the common recovery channel 18.

[0028] As described above, in the liquid ejection head of this embodiment, one common flow path and one damper chamber for the supply system are provided for each of the two ejection element arrays. On the other hand, one common flow path and one damper chamber for the recovery system are provided in common for the two ejection element arrays. By sharing the common flow path for the recovery system between the first and second ejection element arrays, the first and second ejection element arrays can be brought closer to each other in the Y direction. As a result, the size of the liquid ejection substrate 2 can be reduced, and the liquid ejection head 1, and therefore the entire liquid ejection device 101, can be made smaller.

[0029] When a voltage is applied to the piezoelectric element 6 and ink in the pressure chamber 5 is ejected from the ejection port 3, a pressure wave is generated in the pressure chamber 5. This pressure wave propagates to the first common supply flow path 17 or the second common supply flow path 19, and the common recovery flow path 18, and is absorbed by the damper member 300 deforming toward the damper chamber.

[0030] Specifically, pressure waves propagated to the first common supply flow path 17 are absorbed by the damper member 300 deforming toward the first damper chamber 301. Pressure waves propagated to the second common supply flow path 19 are absorbed by the damper member 300 deforming toward the third damper chamber 303. Pressure waves propagated to the common recovery flow path 18 are absorbed by the damper member 300 deforming toward the second damper chamber 302. In the present disclosure, a set of one damper chamber and damper member 300 is referred to as a damper region.

[0031] Here, in the configuration of this embodiment, pressure waves from one row of ejection element arrays propagate to the first common supply flow path 17 and the second common supply flow path 19, but pressure waves from two rows of ejection element arrays propagate to the common recovery flow path 18. Therefore, in the case of the comparative example shown in Fig. 3(a), even if the damping effect of the first damper chamber 301 and the third damper chamber 303, which receive pressure waves from one row of ejection element arrays, is sufficient, there is a risk that a sufficient damping effect cannot be obtained in the second damper chamber 302, which receives pressure waves from two rows of ejection element arrays.

[0032] In addition, it has been confirmed that pressure fluctuations due to discharge tend to propagate more easily to the recovery flow path than to the supply flow path in the circulation flow path. Therefore, the second damper chamber 302 of the comparative example shown in Figure 3(a) does not have a sufficient damping effect, making it difficult to suppress crosstalk, and there are concerns about the impact on discharge.

[0033] In consideration of this situation, the liquid ejection head of this embodiment employs the configuration shown in FIG. 3(b). This differs from the comparative example shown in FIG. 3(a) in that the width Wb of the second damper chamber 302 is greater than the width Wa of the first damper chamber 301 and the third damper chamber 303 in the Y direction, which intersects with the direction in which the ejection elements are arranged (the X direction). That is, the volume of the second damper chamber 302, which corresponds to the common recovery channel 18, which communicates with a larger number of pressure chambers 5, is larger than that of the first common supply channel 17 and the second common supply channel 19. This widens the movable range of the film-like damper member 300, thereby enhancing the damping effect compared to the comparative example. As a result, even in a recovery channel that receives pressure waves from two rows of ejection elements, a sufficient damping effect is obtained, suppressing crosstalk and enabling normal and stable ejection throughout the entire liquid ejection head.

[0034] Figures 7(a) and (b) are plan views showing the substrates constituting the liquid ejection substrate 2 of this embodiment. Figure 7(a) shows a plan view of the ejection port forming substrate 201, the vibration substrate 202, the liquid supply substrate 203, and the flow path forming substrate 204, as viewed from the ink ejection direction. Figure 7(b) is a perspective view showing the back surfaces of the ejection port forming substrate 201, the vibration substrate 202, the liquid supply substrate 203, and the flow path forming substrate 204, as viewed from the same direction.

[0035] As shown in FIG. 7(a), in the flow path forming substrate 204, the width Wb in the Y direction of the second damper chamber 302 is larger than the width Wa in the Y direction of the first damper chamber 301 and the third damper chamber 303 (Wb>Wa).

[0036] According to the present embodiment described above, the damper chamber of the recovery flow path, which receives pressure waves from two rows of ejection elements, is made larger than the damper chamber of the supply flow path, which receives pressure waves from one row of ejection elements. This makes it possible to provide a liquid ejection head that is compact in size yet capable of stable, normal ejection.

[0037] In FIG. 3(b), the central common flow channel, which has a large number of communicating pressure chambers 5, is used as the common recovery flow channel 18 for recovery. However, this flow channel may also be used as a common supply flow channel for supplying ink to both the first and second ejection element arrays. That is, the ink circulation direction may be reversed compared to FIG. 3(b). Even in this case, by making the damper chamber of the common flow channel that receives pressure waves from two ejection element arrays larger than the damper chamber of the common flow channel that receives pressure waves from one ejection element array, crosstalk can be suppressed, enabling stable, normal ejection. Furthermore, by using the common flow channel corresponding to two ejection element arrays as a common supply flow channel that is less susceptible to pressure waves, the width of the second damper chamber 302 can be made smaller than in FIG. 3(b).

[0038] Second Embodiment 4(a) and 4(b) are diagrams illustrating a liquid ejection substrate according to a second embodiment. FIG. 4(a) is a cross-sectional view of a liquid ejection substrate 2 according to the second embodiment. FIG. 4(a) shows three ejection port arrays. For convenience, the ejection element array on the left side of the figure is referred to as the first ejection element array, the central ejection element array as the second ejection element array, and the ejection element array on the right side as the third ejection element array. The common flow path that supplies ink to the first ejection element array is referred to as a first common supply flow path 41, and the common flow path that recovers ink from the first and second ejection element arrays is referred to as a first common recovery flow path 42. The common flow path that supplies ink to the second and third ejection element arrays is referred to as a second common supply flow path 43, and the common flow path that recovers ink from the third ejection element array is referred to as a second common recovery flow path 44. Furthermore, the damper chambers formed at positions corresponding to the first common supply flow path 41, the first common recovery flow path 42, the second common supply flow path 43, and the second common recovery flow path 44 are called the first damper chamber 401, the second damper chamber 402, the third damper chamber 403, and the fourth damper chamber 404, respectively.

[0039] In this embodiment, the width Wd of the second damper chamber 402 and the third damper chamber 403 is made larger than the width We of the first damper chamber 401 and the fourth damper chamber 404. That is, the volumes of the second damper chamber 402 and the third damper chamber 403, which correspond to the first common recovery flow path 42 and the second common supply flow path 43, which communicate with a relatively large number of pressure chambers 5, are made larger than the first damper chamber 401 and the fourth damper chamber 404. This widens the movable range of the film-like damper member 300 in the common flow path that receives pressure waves from two rows of ejection elements, thereby achieving a sufficient damping effect. That is, it is possible to achieve normal and stable ejection throughout the entire liquid ejection head while achieving a compact size.

[0040] FIG. 4(b) is a diagram showing a modified example of the second embodiment. Compared to FIG. 4(a), the width of the third damper chamber 403 has been changed from Wd to Wc. As previously explained, pressure fluctuations due to ejection are more likely to propagate toward the recovery channel than toward the supply channel. This is because, in a circulation head, the internal pressure of the recovery channel is set lower than that of the supply channel, generating a circulation flow from the supply channel toward the recovery channel. This means that the pressure from the pressure chamber 5 is more likely to propagate toward the lower-pressure recovery channel. In other words, even though the second common supply channel 43 is connected to two rows of ejection element arrays, because it is located on the supply side of the pressure chamber 5, the impact of pressure fluctuations may not be as significant compared to the first common recovery channel 42, which is also connected to two rows of ejection element arrays. In such cases, as shown in FIG. 4(b), the width of the third damper chamber 403 may be set to Wc, prioritizing compactness over damping effect.

[0041] On the other hand, if the effect of pressure fluctuations in the first common recovery passage 42 is considerably large, further improvement of the damping effect may be prioritized over miniaturization, and the first common recovery passage 42 may be enlarged by the amount corresponding to the miniaturization of the second common supply passage 43. In any case, the size of each common passage may be adjusted appropriately between the magnitude of the pressure fluctuations that the common passage is subjected to and the demand for miniaturization.

[0042] Third Embodiment 5(a) to 5(c) are diagrams illustrating a third embodiment. FIG. 5(a) is a cross-sectional view of a liquid ejection substrate 2. In the third embodiment, as shown in FIG. 5(a), there are four ejection port arrays. For convenience, these will be referred to as the first ejection element array, the second ejection element array, the third ejection element array, and the fourth ejection element array, starting from the left in the figure. The common flow channel that supplies ink to the first ejection element array is referred to as the first common supply flow channel 51, the common flow channel that recovers ink from the first and second ejection element arrays is referred to as the first common recovery flow channel 52, and the common flow channel that supplies ink to the second and third ejection element arrays is referred to as the second common supply flow channel 53. The common flow channel that recovers ink from the third and fourth ejection element arrays is referred to as the second common recovery flow channel 54, and the common flow channel that supplies ink to the fourth ejection element array is referred to as the third common supply flow channel 55. Furthermore, the damper chambers formed at positions corresponding to the first common supply flow path 51, the first common recovery flow path 52, and the second common supply flow path 53 are referred to as a first damper chamber 501, a second damper chamber 502, and a third damper chamber 503, respectively. Furthermore, the damper chambers formed at positions corresponding to the second common recovery flow path 54 and the third common supply flow path 55 are referred to as a fourth damper chamber 504 and a fifth damper chamber 505, respectively.

[0043] In this embodiment, the width Wf of the second damper chamber 502, the third damper chamber 503, and the fourth damper chamber 504 is set larger than the width We of the first damper chamber 501 and the fifth damper chamber 505. That is, the volumes of the second damper chamber 502, the third damper chamber 503, and the fourth damper chamber 504, which correspond to the first common recovery flow path 52, the second common supply flow path 53, and the second common recovery flow path 54, which communicate with a large number of pressure chambers 5, are set larger than the first damper chamber 501 and the fifth damper chamber 505. This increases the movable range of the film-like damper member 300, thereby enhancing the damping effect. As a result, a sufficient damping effect can be achieved in the common flow path that receives pressure waves from two ejection element arrays. That is, a liquid ejection substrate 2 having four ejection element arrays can be miniaturized while still performing normal and stable ejection.

[0044] FIG. 5(b) is a diagram showing a first modification of the third embodiment. Compared with FIG. 5(a), the width of the third damper chamber 503 is changed from Wf to We. Since the second common supply passage 53 is located on the supply side with respect to the pressure chamber 5, the influence of pressure fluctuations may not appear as significantly as in the first common recovery passage 52 and the second common recovery passage 54. In such a case, as shown in FIG. 5(b), priority may be given to miniaturization rather than the damping effect, and the width of the third damper chamber 503 may be made smaller than Wf.

[0045] FIG. 5(c) is a diagram showing a second modification of the third embodiment. The circulation direction of the ink is reversed with respect to FIG. 5(a). In this case, the common passage of the recovery system communicating with the discharge element rows for two rows is only the central common passage that was the second common supply passage 53 in FIGS. 5(a) and (b). Therefore, in this modification, only the third damper chamber 503 corresponding to the central common passage where pressure fluctuations are most concerning has its width set to Wf, and the widths of the other four damper chambers are set to We (<Wf). Thereby, while realizing preferable damping performance, a liquid discharge substrate 2 of a smaller size can be realized compared with FIGS. 5(a) and (b).

[0046] <Fourth Embodiment> FIGS. 6(a) to (c) are diagrams for explaining the fourth embodiment. FIG. 6(a) is a cross-sectional view of the liquid discharge substrate 2. FIG. 6(b) is a cross-sectional perspective view of the liquid discharge substrate 2. FIG. 6(c) shows a plan view of the vibration substrate 202 as seen from the back side (the direction opposite to the direction in which the ink is discharged).

[0047] In this embodiment, eight ejection port arrays are arranged in parallel in the Y direction. When there are such a large number of ejection port arrays, terminals 200 for receiving signals and power supplied to each ejection element array may be provided at both ends (both ends in the Y direction) of the liquid ejection substrate 2, as shown in FIG. 6(c). The temperature sensor 20 for acquiring the average temperature within the liquid ejection substrate 2 is preferably disposed in the center of the liquid ejection substrate 2 so as not to interfere with other wiring. In this case, the distance between the two ejection element arrays located in the center of the liquid ejection substrate 2 is wider than the distance between the other ejection element arrays. In FIGS. 6(a) and 6(b), these two ejection element arrays are shown as a first ejection element array 13 and a second ejection element array 23.

[0048] In such a liquid ejection substrate 2, the common flow path shared by the first ejection element array 13 and the second ejection element array 23 is structurally easier to ensure a width in the Y direction than other common flow paths. Therefore, in this embodiment, the ink circulation direction is controlled so that the common flow path shared by the first ejection element array 13 and the second ejection element array 23 becomes a common recovery flow path for the first ejection element array 13 and the second ejection element array 23. The ink circulation direction is shown in Figure 6(a).

[0049] In this way, by setting a flow path that can secure a structurally large damper space as a common recovery flow path for two rows of ejection elements, it is possible to perform normal ejection stably while preventing the liquid ejection substrate 2, which has many ejection element rows, from becoming larger.

[0050] <Other embodiments> In the above-described embodiment, a circulation-type liquid ejection head having a common supply flow path and a common recovery flow path has been described as an example. However, the liquid ejection substrate of the present disclosure is not limited to this configuration. Even if a recovery flow path is not provided and all flow paths are supply flow paths, the effects of the present disclosure can be achieved by, for example, making the damper chamber of the common supply flow path shared by two rows of ejection elements larger than the damper chamber of the common supply flow path corresponding to one row of ejection elements. In other words, a damping effect appropriate to the magnitude of pressure fluctuations can be obtained in each common supply flow path, enabling normal and stable ejection throughout the entire liquid ejection head.

[0051] The disclosure of this embodiment includes the following liquid ejection head and liquid ejection substrate examples.

[0052] <Configuration 1> a plurality of discharge ports for discharging liquid; a plurality of pressure chambers provided corresponding to the ejection ports, each of which contains liquid to be ejected from the ejection ports; a first common flow channel that is in common communication with a first number of the pressure chambers; a first damper region for reducing pressure fluctuations in the first common flow path; a second common flow channel that is in communication with a second number of the pressure chambers that is smaller than the first number; a second damper region for reducing pressure fluctuations in the second common flow path; A liquid ejection head comprising: A liquid ejection head, wherein the first damper area is larger than the second damper area.

[0053] <Configuration 2> The liquid ejection head includes: a first ejection element array in which ejection elements including the ejection ports and the pressure chambers are arranged in a first direction; a second ejection element array arranged in a second direction intersecting the first direction with respect to the first ejection element array, the second ejection element array including the ejection elements arranged in the first direction; Including, A liquid ejection head according to configuration 1, wherein the first common flow path is commonly connected to the pressure chambers included in the first ejection element array and the second ejection element array, and the second common flow path is commonly connected to the pressure chambers of either the first ejection element array or the second ejection element array.

[0054] <Configuration 3> 3. The liquid ejection head according to configuration 2, wherein the width of the first damper region is greater than the width of the second damper region in the second direction.

[0055] <Configuration 4> A liquid ejection head according to configuration 2 or 3, wherein the first common flow path is a flow path for commonly recovering liquid from the pressure chambers included in the first ejection element array and the second ejection element array, and the second common flow path is a flow path for commonly supplying liquid to the pressure chambers of either the first ejection element array or the second ejection element array.

[0056] <Configuration 5> A liquid ejection head according to configuration 2 or 3, wherein the first common flow path is a flow path for commonly supplying liquid to the pressure chambers included in the first ejection element array and the second ejection element array, and the second common flow path is a flow path for commonly recovering liquid from the pressure chambers of either the first ejection element array or the second ejection element array.

[0057] <Configuration 6> A liquid ejection head according to configuration 2 or 3, wherein the first ejection element array and the second ejection element array are provided on a liquid ejection substrate, terminals for driving the ejection elements are arranged at both ends of the liquid ejection substrate in the second direction, and a sensor for detecting the temperature of the liquid ejection substrate is arranged between the first ejection element array and the second ejection element array at a position corresponding to the first common flow path.

[0058] <Configuration 7> The liquid ejection substrate is a first substrate in which the pressure chamber is formed; a second substrate on which the first common flow path, the second common flow path, and individual flow paths that individually connect the first common flow path and the second common flow path to each of the pressure chambers are formed; are stacked, 7. The liquid ejection head according to configuration 6, wherein the first common flow path and the second common flow path are formed on the surface of the second substrate opposite to the surface connected to the pressure chamber.

[0059] <Configuration 8> A liquid ejection head described in any one of configurations 1 to 7, wherein the first damper region is composed of a hollow first damper chamber and a flexible damper member, and the second damper region is composed of a second damper chamber having a larger volume than the first damper chamber and a flexible damper member.

[0060] <Configuration 9> 9. The liquid ejection head according to any one of configurations 1 to 8, wherein the liquid ejection head is an inkjet recording head that ejects ink to record an image on a recording medium.

[0061] <Configuration 10> a first substrate having a plurality of ejection ports formed thereon for ejecting liquid; a second substrate in which a plurality of pressure chambers are formed, the pressure chambers corresponding to the respective ejection ports and containing liquid to be ejected from the ejection ports; a third substrate on which a first common flow path communicating with a first number of the pressure chambers and a second common flow path communicating with a second number of the pressure chambers, the second number being smaller than the first number, are formed; a fourth substrate on which a first damper region for reducing pressure fluctuations in the first common flow path and a second damper region for reducing pressure fluctuations in the second common flow path are formed; A liquid ejection substrate formed by laminating A liquid ejection substrate, wherein the first damper area is larger than the second damper area. [Explanation of symbols]

[0062] 2 Liquid discharge board 3 outlet 17 First common supply channel 18 Common recovery channel 19 Second common supply channel 16 Atmospheric vent 300 Damper member 301 First Damper Room 302 Second damper chamber

Claims

1. a plurality of discharge ports for discharging liquid; a plurality of pressure chambers provided corresponding to the ejection ports, each of which contains liquid to be ejected from the ejection ports; a first common flow channel that is in common communication with a first number of the pressure chambers; a first damper region for reducing pressure fluctuations in the first common flow path; a second common flow channel that is in communication with a second number of the pressure chambers that is smaller than the first number; a second damper region for reducing pressure fluctuations in the second common flow path; A liquid ejection head comprising: A liquid ejection head, wherein the first damper area is larger than the second damper area.

2. The liquid ejection head includes: a first ejection element array in which ejection elements including the ejection ports and the pressure chambers are arranged in a first direction; a second ejection element array arranged in a second direction intersecting the first direction with respect to the first ejection element array, the second ejection element array including the ejection elements arranged in the first direction; Including, 2. A liquid ejection head according to claim 1, wherein the first common flow path is commonly connected to the pressure chambers included in the first ejection element array and the second ejection element array, and the second common flow path is commonly connected to the pressure chambers of either the first ejection element array or the second ejection element array.

3. The liquid ejection head according to claim 2 , wherein the width of the first damper region is greater than the width of the second damper region in the second direction.

4. 3. The liquid ejection head according to claim 2, wherein the first common flow path is a flow path for recovering liquid in common from the pressure chambers included in the first ejection element array and the second ejection element array, and the second common flow path is a flow path for supplying liquid in common to the pressure chambers of either the first ejection element array or the second ejection element array.

5. 3. The liquid ejection head according to claim 2, wherein the first common flow path is a flow path for commonly supplying liquid to the pressure chambers included in the first ejection element array and the second ejection element array, and the second common flow path is a flow path for commonly recovering liquid from the pressure chambers of either the first ejection element array or the second ejection element array.

6. 3. A liquid ejection head as described in claim 2, wherein the first ejection element array and the second ejection element array are provided on a liquid ejection substrate, terminals for driving the ejection elements are arranged at both ends of the liquid ejection substrate in the second direction, and a sensor for detecting the temperature of the liquid ejection substrate is arranged between the first ejection element array and the second ejection element array at a position corresponding to the first common flow path.

7. The liquid ejection substrate is a first substrate in which the pressure chamber is formed; a second substrate on which the first common flow path, the second common flow path, and individual flow paths that individually connect the first common flow path and the second common flow path to each of the pressure chambers are formed; are stacked, The liquid ejection head according to claim 6 , wherein the first common flow path and the second common flow path are formed on a surface of the second substrate opposite to a surface connected to the pressure chamber.

8. A liquid ejection head as described in claim 1, wherein the first damper region is composed of a hollow first damper chamber and a flexible damper member, and the second damper region is composed of a second damper chamber having a larger volume than the first damper chamber and a flexible damper member.

9. 2. The liquid ejection head according to claim 1, wherein the liquid ejection head is an ink jet recording head that ejects ink to record an image on a recording medium.

10. a first substrate having a plurality of ejection ports formed thereon for ejecting liquid; a second substrate in which a plurality of pressure chambers are formed, the pressure chambers corresponding to the respective ejection ports and containing liquid to be ejected from the ejection ports; a third substrate on which a first common flow path communicating with a first number of the pressure chambers and a second common flow path communicating with a second number of the pressure chambers, the second number being smaller than the first number, are formed; a fourth substrate on which a first damper region for reducing pressure fluctuations in the first common flow path and a second damper region for reducing pressure fluctuations in the second common flow path are formed; A liquid ejection substrate formed by laminating A liquid ejection substrate, wherein the first damper area is larger than the second damper area.

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