Liquid ejection head, liquid ejection unit, and liquid ejection device

Abstract

To provide a liquid discharge head configured such that when a joined member joined using two or more kinds of adhesives is used, the different kinds of adhesives are suppressed from mixing each other in a joining region.SOLUTION: A liquid discharge head comprises a first member 11 and a second member 12 joined to the first member with adhesives. The first member has a plurality of protruding parts (21 and 22) protruding toward the second member, where the plurality of protruding parts are formed of two or more kinds of protruding parts having different heights. In the second member, the heights of portions joined to the plurality of protruding parts are different depending on the heights of the protruding parts. The adhesives are two or more kinds of adhesives (31, 32 and 33).SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head, a liquid ejection unit, and an apparatus for ejecting liquid. [Background technology]

[0002] Known liquid ejection heads include, for example, a nozzle plate having multiple nozzles, a liquid chamber member having a liquid chamber connected to the nozzles, an actuator member including a piezoelectric element and an electrode portion, a holding substrate joined to the actuator member, and a frame member having a common liquid chamber that supplies liquid to the liquid chambers.

[0003] Adhesives are often used to bond the components of a liquid ejection head, and various types of adhesives and application methods are being investigated. Patent Document 1 discloses that the electrostatic actuator unit and the head frame are joined with an elastic adhesive. The purpose of Patent Document 1 is to improve reliability during joining and reduce costs, and it claims that this can prevent the nozzle plate and the substrates in the electrostatic actuator unit from peeling off. Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, the frame member is bonded to the actuator member and the holding substrate with an adhesive, and is sealed to prevent ink from entering. Furthermore, epoxy adhesive and UV adhesive are often used to bond the frame members, and the UV adhesive can fix the adhesive in place. In this way, when bonding components, multiple types of adhesives with different hardening speeds may be used, for example, to prevent misalignment of the bond.

[0005] However, in conventional technology, when different types of adhesives are used, the different types of adhesives may mix in the bonding area, and mixing of the adhesives in the bonding area can cause problems such as poor curing of epoxy adhesives.

[0006] Therefore, an object of the present invention is to provide a liquid ejection head in which, when a joining member joined using two or more types of adhesive is used, mixing of different types of adhesive in the joining area is suppressed. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the liquid ejection head of the present invention is a liquid ejection head having a first member and a second member bonded to the first member with an adhesive, wherein the first member has a plurality of convex portions that are convex toward the second member, the plurality of convex portions being composed of two or more types of convex portions with different heights, the height of the second member at the portion bonded to the plurality of convex portions differs depending on the height of the convex portions, and the adhesive is two or more types. The first member has a rectangular shape having long sides and short sides in a plan view, the plurality of convex portions have at least a first convex portion and a second convex portion having different heights, the first convex portions are provided at four corners of the first member, and the second convex portions are provided along edges of the long sides of the first member. It is characterized by: [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a liquid ejection head in which, when a joining member joined using two or more types of adhesive is used, mixing of different types of adhesive in the joining region is suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective schematic view showing an example of a first member. [Figure 2] FIG. 2 is a schematic plan view illustrating an example of a first member. [Figure 3] FIG. 4 is a schematic side view showing an example of joining a first member and a second member. [Figure 4] FIG. 10 is another schematic side view of an example of joining the first member and the second member. [Figure 5] 1A is a schematic plan view showing another example of joining a first member and a second member, FIG. 1B is a schematic cross-sectional view taken along line AA, and FIG. 1C is a schematic cross-sectional view taken along line BB. [Figure 6] 1A is a schematic side view and FIG. 1B is a schematic cross-sectional view showing an example of a concave shape of a first member and a convex shape of a second member. [Figure 7]1A is a schematic plan view, FIG. 1B is a schematic side view, and FIG. 1C is a schematic CC cross-sectional view of Comparative Example 1. FIG. [Figure 8] 1A is a schematic plan view, FIG. 1B is a schematic DD cross-sectional view, and FIG. 1C is a schematic EE cross-sectional view in Reference Example 1. FIG. [Figure 9] 1 is a schematic cross-sectional view showing an example of a liquid ejection head according to the present invention. [Figure 10] 1 is a schematic perspective view showing an example of a liquid ejection device according to the present invention. [Figure 11] 1 is a schematic side view showing an example of a liquid ejection device according to the present invention. [Figure 12] FIG. 10 is a schematic view showing another example of the device for discharging liquid according to the present invention. [Figure 13] FIG. 10 is a schematic view showing another example of the device for discharging liquid according to the present invention. [Figure 14] FIG. 2 is a schematic diagram illustrating an example of a liquid ejection unit. [Figure 15] FIG. 10 is a schematic diagram illustrating another example of the liquid ejection unit. DETAILED DESCRIPTION OF THE INVENTION

[0010] A liquid ejection head, a liquid ejection unit, and a liquid ejection device according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the following embodiments, and other modifications, additions, corrections, deletions, and other changes can be made within the scope of what a person skilled in the art can conceive. Any aspect that achieves the functions and effects of the present invention is within the scope of the present invention.

[0011] (liquid ejection head) The liquid ejection head of the present invention is a liquid ejection head having a first member and a second member bonded to the first member with an adhesive, wherein the first member has a plurality of convex portions that are convex toward the second member, the plurality of convex portions consisting of two or more types of convex portions with different heights, the height of the second member's portion that bonds to the plurality of convex portions varies depending on the height of the convex portions, and the adhesive is of two or more types.

[0012] An embodiment of the present invention will now be described. The first member and the second member joined together are also referred to as a joined member. The mixing of adhesives is sometimes referred to as color mixing.

[0013] Fig. 1 is a schematic perspective view of a first member 11 included in the liquid ejection head of this embodiment. Fig. 2 is a schematic plan view of the first member 11 included in the liquid ejection head of this embodiment, and is a top view when viewed from the direction a in Fig. 1.

[0014] The first member 11 in this embodiment has a plurality of convex portions, for example, a first convex portion 21 and a second convex portion 22. The plurality of convex portions have heights corresponding to the height of the joining region of the second member with the first member, for example, the second convex portion 22 is taller than the first convex portion 21. While this can be selected as appropriate, in the example shown, the first convex portions 21 are provided at the four corners of the first member 11, and the second convex portions 22 are provided along the edges of the longer sides of the first member 11.

[0015] 1 and 2 are examples in which the first member 11 is a frame member 70 in a liquid ejection head. The first member 11 is preferably a frame member, but is not limited to this. Although the reference numerals 11 and 70 are separate, in this example the first member is a frame member. The frame member 70 has, for example, a common flow path 16 formed therein for supplying liquid to the liquid chambers.

[0016] Fig. 3 is a schematic side view of the joining member in this embodiment, illustrating the first member 11 when viewed from direction b in Fig. 2. Fig. 4 is another schematic side view of the joining member in this embodiment, illustrating the first member 11 when viewed from direction c in Fig. 2. Note that the first member 11 in this embodiment has a rectangular shape having long and short sides in a plan view (Fig. 2), and Fig. 3 corresponds to a side view of the long side, and Fig. 4 corresponds to a side view of the short side.

[0017] 3 and 4 is an example in which the second member 12 is made up of an actuator substrate 53 and a holding substrate 55 bonded to the actuator substrate 53. The actuator substrate 53 includes, for example, a nozzle plate having a plurality of nozzles, a liquid chamber member having a liquid chamber communicating with the nozzles, and an actuator member having a piezoelectric element and an electrode portion.

[0018] As shown in Fig. 3, the first member 11 has a plurality of convex portions that are convex toward the second member 12, and in this example, the plurality of convex portions are provided as first convex portions 21 and second convex portions 22. In Fig. 3, i.e., a longitudinal side view, two first convex portions 21 are provided on the end sides, and a second convex portion 22 is provided on the central side.

[0019] The plurality of convex portions are made up of two or more types of convex portions with different heights, and as shown in Fig. 3, the first convex portions 21 and the second convex portions 22 have different heights. In the example shown here, the first convex portions 21 are lower than the second convex portions 22.

[0020] The region between the first convex portion 21 and the second convex portion 22 is also referred to as a groove portion 23. It can be said that the first convex portion 21 and the second convex portion 22 are not formed continuously, but are formed intermittently with the groove portion 23 interposed therebetween.

[0021] The height of the multiple convex portions can be selected as appropriate. For example, in the illustrated example, the height of the first convex portion 21 is approximately 500 μm and the height of the second convex portion 22 is approximately 1000 μm compared to the smooth portion (a portion other than the convex portions) of the first member 11. The smooth portion of the first member 11 can be, for example, the bottom of the groove portion 23.

[0022] In this embodiment, the heights of the portions of the second member 12 that join with the multiple protrusions vary depending on the heights of the protrusions. For example, as shown in Fig. 3, the height of the portions of the second member 12 that join with the protrusions is higher at the portion that joins with the first protrusion 21, and is lower at the portion that joins with the second protrusion 22.

[0023] In this embodiment, two or more types of adhesives are used to bond the first member 11 and the second member 12. Using two or more types of adhesives enables, for example, the use of multiple types of adhesives with different curing speeds to prevent misalignment of the bond. For example, by using an epoxy adhesive and a photocurable adhesive (e.g., a UV-curable adhesive), the photocurable adhesive can provide a temporary bonding function in a short time.

[0024] In this embodiment, for example, the first adhesive 31, which is a UV adhesive, is used in the bonding area of ​​the first convex portion 21, and the second adhesive 32, which is an epoxy adhesive, is used in the bonding area of ​​the second convex portion 22.

[0025] In this embodiment, the first member 11 is provided with a plurality of convex portions of different heights, and the heights of the portions of the second member 12 that bond to the plurality of convex portions vary depending on the height of the convex portions. As a result, in bonded members bonded using two or more types of adhesive, the adhesives are applied at different heights, allowing the application areas of each adhesive to be isolated and preventing mixing of different types of adhesive in the bonded area. Furthermore, in this embodiment, even when different types of adhesive are applied to adjacent areas, mixing of different types of adhesive in the bonded area can be prevented. According to this embodiment, preventing mixing of adhesive in the bonded area can prevent poor curing of the adhesive, resulting in a good bonded state and preventing misalignment of the bond.

[0026] In this embodiment, a groove 23 is provided between the first convex portion 21 and the second convex portion 23. For example, in the example shown in Fig. 3, if excess first adhesive 31 and second adhesive 32 occurs when members are bonded together, the excess adhesive flows into the groove 23 between the first convex portion 21 and the second convex portion 22 and does not flow into adjacent bonding regions. This makes it possible to further prevent different types of adhesives from mixing in the bonding regions.

[0027] Here, a supplementary explanation will be given regarding the holding substrate 55 in Fig. 3. In Fig. 3, the symbol for the holding substrate 55 is shown in parentheses. This indicates that the holding substrate 55 is not between the first convex portion 21 and the second convex portion 22, but rather that the holding substrate 55 is visible through the grooves 23 when viewed from the side. Therefore, grooves 23 are provided by not forming continuous convex portions, and the adhesive that flows out can be held between the convex portions (grooves 23), further suppressing mixing of the adhesive in the bonding area.

[0028] In this embodiment, it is preferable that the same type of adhesive is used for convex portions of the same height among the plurality of convex portions, and different types of adhesive are used for convex portions of different heights. For example, as in this embodiment, the same first adhesive 31 is used for first convex portions 21 of the same height (two first convex portions on the longitudinal end sides). Furthermore, a second adhesive 32 of a different type from the first adhesive 31 is used for second convex portions 22 of a different height from the first convex portions 21. This can further prevent different types of adhesives from mixing in the bonding region.

[0029] As described above, the first member 11 in this embodiment has a rectangular shape having long and short sides in a plan view (see FIG. 2 ), and the multiple convex portions include at least the first convex portions 21 and the second convex portions 22 that are different in height, with the first convex portions 21 being provided at the four corners of the first member 11 and the second convex portions 22 being provided along the edges of the long sides of the first member 11. This configuration can prevent different types of adhesives from mixing in the bonding region, and can also appropriately select the bonding region between the first member 11 and the second member 12, thereby improving the bonding strength. It also makes it easier to use a temporary adhesive for the first convex portions 21.

[0030] In this embodiment, a groove 23 is provided between the first convex portion 21 and the second convex portion. By providing the groove 23, the adhesive that flows out between the convex portions can be retained, and mixing of the adhesive in the bonding area can be further suppressed.

[0031] 4, it is preferable that the portions of the first member 11 other than the first convex portions 21 and the second convex portions 22 are bonded with a third adhesive 33 different from the first adhesive 31 and the second adhesive 32. In this embodiment, it is preferable that there are at least three types of adhesives, the first convex portions 21 are bonded with the photocurable first adhesive 31, the second convex portions 22 are bonded with the non-photocurable second adhesive 32, and the portions of the first member 11 other than the first convex portions 21 and the second convex portions 22 are bonded with the third adhesive 33 different from the first adhesive 31 and the second adhesive 32.

[0032] In this case, temporary bonding can be achieved in a short time by using a light-curing adhesive, such as a UV adhesive, as the first adhesive 31. Also, adhesives with a moderate reinforcing effect can be selected for the second adhesive 32 and the third adhesive 33, thereby improving the bonding strength. Although not particularly limited, in this case, it is preferable to use, for example, an epoxy adhesive as the second adhesive 32, and it is preferable to use, for example, a different type of epoxy adhesive from the second adhesive 32 as the third adhesive 33.

[0033] The thickness of the adhesive can be selected as appropriate. The thickness of the adhesive may be the same for all convex portions, but it is preferable to vary it depending on the convex portion. For example, in this embodiment, it is preferable that convex portions of the same height among the multiple convex portions have the same adhesive thickness, and convex portions of different heights have different adhesive thicknesses. By varying the thickness of the adhesive in this way, it is possible to further prevent different types of adhesive from mixing in the bonding area.

[0034] In this embodiment, the approximate thickness of each adhesive when bonded is 100 μm for the first adhesive 31, 150 μm for the second adhesive 32, and 50 μm for the third adhesive 33. The thickness of the adhesives other than the third adhesive 33 may be adjusted as described above, but is not necessarily required to be adjusted. By providing multiple protrusions of different heights on the first member 11, the gap (the distance between the first member 11 and the second member 12) in each bonding region differs, and as a result, the thickness of the adhesive changes. In this case, the thickness of the first adhesive 31 and the second adhesive 32 is the same as the gap in each bonding region.

[0035] The thickness of the third adhesive 33 can be selected as appropriate. Because it is provided between the frame member 70 and the holding substrate 55, it is preferable that the thickness be such that it does not affect the ejection performance. As described above, if the thickness is about 50 μm, it is preferable because it is unlikely to affect the ejection performance. If a foreign object is caught between the frame member 70 and the holding substrate 55 during bonding, ejection defects will occur. By applying an adhesive thicker than the height of the foreign object before bonding, the foreign object will be buried in the adhesive, and ejection defects can be prevented. If the thickness of the third adhesive is about 50 μm as described above, the above defects can be prevented.

[0036] The liquid ejection head of this embodiment can prevent mixing of adhesives and curing defects, thereby improving quality and ejection performance. Furthermore, since different types of adhesives do not mix, the adhesives can demonstrate their inherent capabilities and ink erosion can be suppressed.

[0037] When the first member 11 and the second member 12 are used in the liquid ejection head, it is possible to appropriately select which members in the liquid ejection head are used as the first member 11 and the second member 12. For example, as in the above example, the first member 11 is preferably a frame member having a common flow path that supplies ink to the liquid chambers, and the second member 12 is preferably made up of an actuator substrate 53 and a holding substrate 55 bonded to the actuator substrate 53. The actuator substrate 53 includes, for example, a nozzle plate having a plurality of nozzles, a liquid chamber member having liquid chambers that communicate with the nozzles, and an actuator member having a piezoelectric element and an electrode portion.

[0038] In this embodiment, the first member 11 and the second member 12 in the liquid ejection head are not limited to the above configurations. For example, the first member 11 may be the actuator substrate 53, and multiple convex portions may be provided on the actuator substrate 53 side. In this case, the second member 12 may be the frame member 70, and the height of the joining point may be varied depending on the height of the convex portions. From the viewpoint of member fabrication and preventing ink penetration, it is preferable that the first member 11 is the frame member 70, and the second member 12 is preferably composed of the actuator substrate 53 and the holding substrate 55.

[0039] The holding substrate 55 is bonded to the actuator substrate 53 and has, for example, a driving area for a piezoelectric element. Note that the piezoelectric element and the driving area for the piezoelectric element are not shown in Figures 3 and 4.

[0040] The side view of Fig. 3 shows an electrode portion 52a of the actuator member. As shown in Fig. 5 and Fig. 9, the electrode portion 52a is, for example, a region that does not face the holding substrate 55 and that comes into contact with the wiring member. In the drawing, the electrode portion 52a is indicated by a dashed line. Although the electrode portion 52a is illustrated as being provided from one end to the other in the thickness direction of the actuator substrate 53, this is merely a schematic illustration. For example, as shown in Fig. 9 described below, the electrode portion 52a is included in the actuator member, and in this example, the electrode portion 52a does not include the liquid chamber member or the nozzle substrate.

[0041] Next, another example of this embodiment will be described with reference to FIG. Fig. 5(a) is a schematic plan view of the first member 11 in this example. As in the above example, the first member 11 is a frame member 70. Figs. 5(b) and 5(c) are schematic cross-sectional views of the joining member in this example. Fig. 5(b) is a cross-sectional view taken along line AA in Fig. 5(a), and Fig. 5(c) is a cross-sectional view taken along line BB in Fig. 5(a).

[0042] Figure 5(a) is substantially the same as Figure 3. Figure 5(b) shows a configuration similar to the above example. That is, the first member 11 is provided with a plurality of convex portions (first convex portion 21, second convex portion 22) of different heights, and the heights of the portions of the second member 12 that join with the plurality of convex portions vary depending on the height of the convex portions.

[0043] The second member 12 in this example is made up of an actuator substrate 53 and a holding substrate 55. The liquid ejection head in this example also has a wiring member 57 that supplies a drive signal to the piezoelectric element. In this example, the actuator substrate 53 includes an actuator member having a piezoelectric element and an electrode portion, and the electrode portion 52a in this example is an area that does not face the holding substrate 55 and is an area that comes into contact with the wiring member 57. The electrode portion 52a is also bonded to a convex portion (e.g., second convex portion 22) of the first member 11 via the wiring member 57 and an adhesive. Note that the reference numerals for the actuator member and piezoelectric element are omitted in FIG. 5.

[0044] The thickness of the electrode portion 52a can be selected as appropriate, but is the thinnest among the actuator members. In this example, the thickness of the electrode portion 52a is set to, for example, 75 μm.

[0045] In this example, as shown in FIG. 5(c), the second adhesive 32 is filled without any gaps between the wiring member 57 and the second convex portion 22. This ensures the strength of the electrode portion 52a, which is the thinnest in the actuator member 52. The adhesive provided between the electrode portion 52a and the second convex portion 22 functions as a reinforcing agent and ensures the strength of the electrode portion 52a, thereby preventing damage to the electrode portion 52a. If there are gaps in the adhesive between the electrode portion 52a and the convex portion, the electrode portion 52a may be affected by external forces and may be damaged during assembly, for example.

[0046] The adhesive provided between the electrode portion 52a and the protrusion can be selected as appropriate, but epoxy adhesive is preferable, as it functions well as a reinforcing agent and is likely to prevent damage to the electrode portion 52a.

[0047] In this embodiment, the first member 11 preferably has a concave shape formed by two convex portions on at least one of its cross section and side surface, and the second member 12 preferably has a convex shape that fits into the concave shape. In this case, the bonding state between the first member 11 and the second member 12 can be further improved.

[0048] FIG. 6 shows a diagram for explaining an example of the concave and convex shapes. FIG. 6(a) is a schematic side view of a state in which the first member 11 and the second member 12 are not bonded, and corresponds to the schematic side view of FIG. 4. In this example, two first convex portions 21 in the first member 11 form a concave shape 27 (indicated by a dashed line in the figure). In addition, in this example, the second member 12 is made up of an actuator substrate 53 and a holding substrate 55, and forms a convex shape 28 (indicated by a dashed line in the figure). When the first member 11 and the second member 12 are bonded, the concave shape 27 and the convex shape 28 fit together. This can further improve the bond between the first member 11 and the second member 12.

[0049] FIG. 6(b) is a schematic cross-sectional view of a state in which the first member 11 and the second member 12 are not bonded together, and corresponds to, for example, a schematic cross-sectional view of a state in which the line BB in the BB cross section of FIG. 5(a) is further extended. In this example, two second convex portions 22 in the first member 11 form a concave shape 27 (indicated by a dashed line in the figure). In addition, in this example, the second member 12 is made up of an actuator substrate 53 and a holding substrate 55, and forms a convex shape 28 (indicated by a dashed line in the figure). When the first member 11 and the second member 12 are bonded together, the concave shape 27 and the convex shape 28 fit together. This can further improve the bond between the first member 11 and the second member 12. The two convex portions forming the concave shape 27 may have the same height or different heights. The convex portion of the convex shape 28 may be formed of a member other than the holding substrate 55.

[0050] Next, Comparative Example 1, which is not included in the present invention, will be described with reference to Fig. 7. Comparative Example 1 is the same as this embodiment except that the frame member is not provided with convex portions of different heights. Fig. 7(a) is a schematic plan view of a frame member 71 in Comparative Example 1. Fig. 7(b) is a schematic side view of the joining member in Comparative Example 1, illustrating the frame member 71 when viewed from direction d in Fig. 7(a). Fig. 7(c) is a schematic cross-sectional view of the joining member in Comparative Example 1, which is a cross-sectional view taken along CC in Fig. 7(a).

[0051] The frame member 71 in Comparative Example 1 does not have convex portions of different heights. The frame member 71 and the actuator substrate 53 are bonded with a first adhesive 31 and a second adhesive 32. The frame member 71 and the holding substrate 55 are bonded with a third adhesive 33.

[0052] In Comparative Example 1, the adhesive application height is consistent across the entire frame member 71, so when the bonding member in Comparative Example 1 is fabricated in this manner, all of the adjacent adhesives end up mixing together. More specifically, (1) the first adhesive 31 and the second adhesive 32, (2) the first adhesive 31 and the third adhesive 33, and (3) the second adhesive 32 and the third adhesive 33 end up mixing together. This results in poor curing, and in Comparative Example 1, the frame member 71 could not be bonded to the actuator substrate 53 and the holding substrate 55.

[0053] Furthermore, in Comparative Example 1, an attempt was made to reduce the amount of each adhesive applied to prevent adjacent adhesives from mixing. However, when attempting to bond by reducing the amount of each adhesive applied, unbonded areas were created in each bonded region, and a good bond was not achieved. Furthermore, when the bonded member obtained in this manner was used in a liquid ejection head, leakage defects occurred. The frame member 71 was not sealed to the actuator substrate 53 and the holding substrate 55, allowing ink to enter, and the function of the liquid ejection head could not be ensured.

[0054] From the above, it can be seen that the present embodiment, in which a plurality of convex portions of different heights are provided on the first member, is advantageous in order to prevent different types of adhesive from mixing in the bonding area.

[0055] Next, a first reference example will be described with reference to FIG. Figure 8 is a view corresponding to Figure 5. Figure 8(a) is a schematic plan view of the first member 11 (frame member 70) in Reference Example 1, and is the same first member 11 as in Figure 5. Figures 8(b) and 8(c) are schematic cross-sectional views of the joining member in Reference Example 1. Figure 8(b) is a DD cross-sectional view of Figure 8(a), and Figure 8(c) is an EE cross-sectional view of Figure 8(a).

[0056] Reference example 1 is an example in which the second adhesive 32 is not used. As shown in Fig. 8(b), the second adhesive 32 is not used between the actuator substrate 53 and the second convex portion 22, and as shown in Fig. 8(c), the second adhesive 32 is not used between the wiring member 57 and the second convex portion 22.

[0057] In Reference Example 1, the thinnest electrode portion 52a (e.g., 75 μm thick) in the actuator member was not protected, and a gap (space) of about 150 μm was generated between the electrode portion 52a and the second convex portion 22. As a result, the electrode portion 52a was damaged during assembly. From the above results, in order to reinforce the electrode portion 52a, it is preferable to use a second adhesive as a reinforcing agent between the electrode portion 52a and the convex portion, filling the gap without any gaps.

[0058] Next, the liquid ejection head of this embodiment will be further described using other figures. The liquid ejection head of this example is shown in Figure 9. Figure 9 is a schematic cross-sectional view of the liquid ejection head 1 of this example, and corresponds to, for example, a schematic cross-sectional view in which line BB in the BB cross section of Figure 5(a) is further extended. This example also shows a cross-sectional view where there is no common liquid chamber.

[0059] The liquid ejection head of this example has a frame member 70, an actuator substrate 53, and a holding substrate 55. The frame member 70 has a common flow channel 16 and supplies liquid (e.g., ink). The liquid supplied from the common flow channel 16 is supplied to the individual liquid chambers 6 through the flow channel.

[0060] The actuator substrate 53 has, for example, a nozzle plate 50, a liquid chamber member 51, and an actuator member 52. The nozzle plate 50 has a plurality of nozzles 4 and ejects liquid. The liquid chamber member 51 has liquid chambers (individual liquid chambers 6) that communicate with the nozzles. The actuator member 52 has a piezoelectric element 61 and an electrode portion 52a.

[0061] The holding substrate 55 has a driving region 62 for the piezoelectric element 61. The holding substrate 55 is bonded to a frame member 70 and also to the actuator substrate 53.

[0062] In the liquid ejection head of this embodiment, pressure is applied to the liquid in the individual liquid chambers 6 by the piezoelectric elements 61, and the liquid is ejected from the nozzles 4.

[0063] In this example, the frame member 70 serving as the first member 11 has a second convex portion 22, and the second convex portion 22 is bonded to the actuator substrate 53 with a second adhesive 32. In addition, the frame member 70 is bonded to the holding substrate 55 with a third adhesive 33.

[0064] The electrode portion 52a in this example is an area that does not face the holding substrate 55 and is in contact with the wiring member 57, and is joined to the second convex portion 22 via the wiring member 57 and the second adhesive 32. The electrode portion 52a has the smallest thickness in the actuator member 52, and the second adhesive 32 is filled without any gaps between the electrode portion 52a and the second convex portion 22. In other words, this example is a liquid ejection head with a preferred configuration.

[0065] (liquid ejection device, liquid ejection unit) Next, an example of an apparatus for ejecting liquid according to this embodiment will be described using an inkjet recording apparatus as an example. Figures 10 and 11 show an inkjet recording apparatus 90 according to this embodiment. This inkjet recording device 90 has, for example, a carriage 98, a liquid ejection head 1, a printing mechanism 91, etc. The carriage 98 is movable in the scanning direction inside the device body. The liquid ejection head 1 can be the liquid ejection head of the present embodiment described above, and is mounted on the carriage 98, for example. The printing mechanism 91 is made up of, for example, an ink cartridge 99 that supplies ink to the liquid ejection head 1.

[0066] A paper feed cassette 93 (or a paper feed tray) capable of holding a large number of sheets of paper 92 is attached to the lower part of the device body so as to be freely inserted and removed from the front side. The device may also have a manual feed tray 94 that opens to allow paper 92 to be manually fed. Paper 92 fed from the paper feed cassette 93 or manual feed tray 94 is taken in, and the required image is recorded by the printing mechanism 91. The paper is then ejected to an ejection tray 95 attached to the rear side.

[0067] The printing mechanism 91 holds a main guide rod 96 and a sub guide rod 97, which are guide members that are mounted horizontally on left and right side plates (not shown), and a carriage 98 so that they can slide freely in the main scanning direction. This carriage 98 is equipped with a liquid ejection head 1 that ejects ink droplets of each color (yellow (Y), cyan (C), magenta (M), and black (Bk)) with multiple ink ejection ports (nozzles) arranged in a direction intersecting the main scanning direction and with the ink droplet ejection direction facing downward. Furthermore, each ink cartridge 99 for supplying ink of each color to the liquid ejection head 1 is replaceably mounted on the carriage 98.

[0068] The ink cartridge 99 has an air port at the top that communicates with the atmosphere, and a supply port at the bottom that supplies ink to the liquid ejection head 1. The ink cartridge 99 has a porous body filled with ink inside, and the ink supplied to the liquid ejection head 1 is maintained at a slight negative pressure by the capillary force of the porous body.

[0069] Although the liquid ejection head 1 is used for each color, it may be possible to use a single liquid ejection head having nozzles for ejecting ink droplets of each color.

[0070] The rear side (downstream side of paper transport) of the carriage 98 is slidably fitted on a main guide rod 96, and the front side (upstream side of paper transport) is slidably mounted on a slave guide rod 97. In order to move the carriage 98 in the main scanning direction, a timing belt 104 is stretched between a drive pulley 102 and a slave pulley 103, which are driven to rotate by a main scanning motor 101. The timing belt 104 is fixed to the carriage 98, and the carriage 98 is driven to reciprocate by the forward and reverse rotation of the main scanning motor 101.

[0071] The device in this example has a paper feed roller 105, a friction pad 106, a guide member 107, a transport roller 108, and a tip roller 110 to transport paper 92 set in a paper feed cassette 93 downward toward the liquid ejection head 1.

[0072] The paper feed roller 105 and friction pad 106 separate and feed the paper 92 from the paper feed cassette 93. The guide member 107 guides the paper 92. The transport roller 108 reverses and transports the fed paper 92. The tip roller 110 regulates the angle at which the transport roller 109 is pressed against the circumferential surface of the transport roller 108 and the paper 92 is sent out from the transport roller 108. The transport roller 108 is rotated by a sub-scanning motor via a gear train.

[0073] The device of this example has a print receiving member 111, which is a paper guide member. The print receiving member 111 guides the paper 92 sent out from the transport roller 108 below the liquid ejection head 1 in accordance with the range of movement of the carriage 98 in the main scanning direction.

[0074] On the downstream side of the print receiving member 111 in the paper transport direction, there are provided a transport roller 112 and a spur 113 that are driven to rotate and that feed the paper 92 in the paper discharge direction. In addition, there are provided a paper discharge roller 114 and a spur 115 that feed the paper 92 to the paper discharge tray 95, and guide members 116 and 117 that form the paper discharge path.

[0075] When recording with this inkjet recording device 90, the liquid ejection head 1 is driven in response to an image signal while the carriage 98 is moving. For example, ink is ejected onto a stationary sheet of paper 92 to record one line, and then the sheet 92 is transported a predetermined distance before recording the next line. Upon receiving a recording end signal or a signal indicating that the rear end of the sheet 92 has reached the recording area, the recording operation is terminated and the sheet 92 is ejected.

[0076] A recovery device 117 for recovering from discharge defects of the liquid discharge head 1 is located at a position outside the recording area on the right end side of the carriage 98 in the movement direction. The recovery device 117 has capping means, suction means, and cleaning means. The carriage 98 is moved toward this recovery device 117 when waiting to print. Then, by capping the liquid discharge head 1 with a capping means to keep the discharge ports moist, discharge defects due to dried ink are prevented. In addition, by discharging ink unrelated to recording during recording, the viscosity of ink at all discharge ports is kept constant and a stable discharge state is maintained.

[0077] In the event of an ejection failure, the capping means seals the ejection outlet (nozzle) of the liquid ejection head 1, and the suction means sucks out the ink and air bubbles from the ejection outlet through a tube. This allows the cleaning means to remove ink and debris adhering to the ejection outlet surface, and the ejection failure is resolved. The sucked ink is then discharged into a waste ink reservoir located at the bottom of the main body, where it is absorbed and held by an ink absorber inside the waste ink reservoir.

[0078] Since this inkjet recording apparatus 90 is equipped with the liquid ejection head 1 of this embodiment, stable ink ejection characteristics are obtained and image quality is improved. In the above, a case where the liquid ejection head 1 is used in the inkjet recording apparatus 90 has been described, but the liquid ejection head 1 may also be applied to an apparatus that ejects droplets other than ink, for example, a liquid resist for patterning.

[0079] Next, another embodiment of the liquid ejecting apparatus of the present invention will be described, taking a recording apparatus as an example of the liquid ejecting apparatus of the present invention. The liquid ejection head of the present invention can be used in various recording devices using the inkjet recording method, such as printers, facsimile machines, copying machines, printer / fax / multifunction machines, three-dimensional modeling devices, and bioprinters.

[0080] In the present invention, the term "recording apparatus" and "recording method" refer to an apparatus capable of ejecting ink or various treatment liquids onto a recording medium, and a method of recording using the apparatus. The term "recording medium" refers to an object onto which ink or various treatment liquids can be attached, even if only temporarily.

[0081] This recording device can include not only the head portion that ejects ink, but also means related to feeding, transporting, and discharging the recording medium, as well as other devices called pre-processing devices and post-processing devices.

[0082] The recording apparatus and recording method may have a heating means used in the heating step and a drying means used in the drying step. The heating means and drying means include, for example, means for heating and drying the printed surface and back surface of the recording medium. The heating means and drying means are not particularly limited, but for example, a hot air heater or an infrared heater can be used. Heating and drying can be carried out before, during, or after printing.

[0083] Furthermore, the recording device and recording method are not limited to those that visualize meaningful images such as letters and figures using ink. For example, they also include those that form patterns such as geometric shapes and those that create three-dimensional images. Furthermore, unless otherwise specified, the recording device includes both serial-type devices that move a liquid ejection head and line-type devices that do not move an ejection head. Furthermore, this recording device also includes not only desktop types, but also wide-format recording devices that can print on A0-sized recording media, and continuous-feed printers that can use, for example, continuous paper wound into a roll as a recording medium.

[0084] Next, another example of a liquid ejection device according to the present invention will be described with reference to Figures 12 and 13. Figure 12 is an explanatory plan view of the main parts of the device, and Figure 13 is an explanatory side view of the main parts of the device.

[0085] This device is a serial type device, and a carriage 403 is moved back and forth in the main scanning direction by a main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, etc. The guide member 401 is hung between left and right side plates 491A and 491B, and movably holds the carriage 403. The main scanning motor 405 then moves the carriage 403 back and forth in the main scanning direction via a timing belt 408 hung between a drive pulley 406 and a driven pulley 407.

[0086] This carriage 403 is equipped with a liquid ejection unit 440 that integrates a liquid ejection head 404 according to the present invention and a head tank 441. The liquid ejection head 404 of the liquid ejection unit 440 ejects liquid of each color, for example, yellow (Y), cyan (C), magenta (M), and black (K). The liquid ejection head 404 is mounted with a nozzle row made up of multiple nozzles 4 arranged in a sub-scanning direction perpendicular to the main scanning direction, and the ejection direction facing downward.

[0087] The liquid stored in the liquid cartridge 450 is supplied to the head tank 441 by a supply mechanism 494 for supplying the liquid stored outside the liquid ejection head 404 to the liquid ejection head 404 .

[0088] The supply mechanism 494 is composed of a cartridge holder 451 which is a filling section to which the liquid cartridge 450 is attached, a tube 456, a liquid delivery unit 452 including a liquid delivery pump, etc. The liquid cartridge 450 is detachably attached to the cartridge holder 451. The liquid is delivered from the liquid cartridge 450 to the head tank 441 by the liquid delivery unit 452 via the tube 456.

[0089] This device is provided with a transport mechanism 495 for transporting paper 410. The transport mechanism 495 includes a transport belt 412, which is a transport means, and a sub-scanning motor 416 for driving the transport belt 412.

[0090] The conveyor belt 412 attracts the paper 410 and conveys it at a position facing the liquid ejection head 404. The conveyor belt 412 is an endless belt that is stretched between a conveyor roller 413 and a tension roller 414. The paper can be attracted by electrostatic attraction or air suction.

[0091] The conveyor belt 412 moves in a circular motion in the sub-scanning direction as the conveyor roller 413 is rotationally driven by a sub-scanning motor 416 via a timing belt 417 and a timing pulley 418 .

[0092] Furthermore, a maintenance and recovery mechanism 420 for performing maintenance and recovery of the liquid ejection head 404 is disposed on one side of the conveyor belt 412 on one side of the carriage 403 in the main scanning direction.

[0093] The maintenance and recovery mechanism 420 is made up of, for example, a cap member 421 that caps the nozzle surface (the surface on which the nozzles 4 are formed) of the liquid ejection head 404, a wiper member 422 that wipes the nozzle surface, and the like.

[0094] The main scanning movement mechanism 493, the supply mechanism 494, the maintenance and recovery mechanism 420, and the transport mechanism 495 are attached to a housing including side plates 491A and 491B and a back plate 491C.

[0095] In this device configured as described above, a sheet of paper 410 is fed onto and attracted to the conveyor belt 412, and the sheet of paper 410 is conveyed in the sub-scanning direction by the circular movement of the conveyor belt 412.

[0096] Therefore, by driving the liquid ejection head 404 in accordance with an image signal while moving the carriage 403 in the main scanning direction, liquid is ejected onto the stationary paper 410 to form an image.

[0097] As described above, this device is equipped with the liquid ejection head according to the present invention, and therefore can stably form high-quality images.

[0098] Next, another example of a liquid discharge unit according to the present invention will be described with reference to Fig. 14. Fig. 14 is an explanatory plan view of the main part of the unit.

[0099] This liquid ejection unit is composed of the components that make up the device for ejecting the liquid, including a housing portion consisting of side plates 491A, 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a liquid ejection head 404.

[0100] It is also possible to configure a liquid discharge unit in which at least one of the maintenance and recovery mechanism 420 and the supply mechanism 494 described above is further attached to, for example, the side plate 491B of this liquid discharge unit.

[0101] Next, still another example of a liquid discharge unit according to the present invention will be described with reference to Fig. 15. Fig. 15 is an explanatory front view of the unit.

[0102] This liquid ejection unit is composed of a liquid ejection head 404 to which a flow path part 444 is attached, and a tube 456 connected to the flow path part 444 .

[0103] The flow path part 444 is disposed inside the cover 442. A head tank 441 may be included instead of the flow path part 444. A connector 443 for electrically connecting the flow path part 444 to the liquid ejection head 404 is provided on the upper part of the flow path part 444.

[0104] In this application, a "liquid ejecting device" is a device that includes a liquid ejection head or a liquid ejection unit and ejects liquid by driving the liquid ejection head. Liquid ejecting devices include not only devices that can eject liquid onto objects to which the liquid can adhere, but also devices that eject liquid into air or liquid.

[0105] This "liquid ejecting device" can also include means for feeding, transporting, and discharging items onto which liquid can be attached, as well as pre-processing devices and post-processing devices.

[0106] For example, examples of "liquid ejecting devices" include image forming devices that eject ink to form images on paper, and three-dimensional modeling devices (three-dimensional modeling devices) that eject modeling liquid onto a powder layer formed from layers of powder in order to create a three-dimensional object (a three-dimensional model).

[0107] In addition, the "liquid ejection device" is a device that ejects liquid to produce meaningful images such as letters and figures. However, the present invention is not limited to visualization of the object. For example, it also includes the formation of patterns that have no meaning in themselves, and the formation of three-dimensional images.

[0108] The above-mentioned "object onto which a liquid can adhere" means an object onto which a liquid can adhere at least temporarily, an object onto which the liquid can adhere and stick, an object onto which the liquid can penetrate, etc. Specific examples include media such as paper, recording paper, film, and cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all objects onto which a liquid can adhere.

[0109] The material of the above-mentioned "object to which a liquid can adhere" may be any material to which a liquid can adhere, even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, building materials such as wallpaper and flooring, and textiles for clothing.

[0110] "Liquid" also includes ink, processing liquid, DNA sample, resist, pattern material, binder, modeling liquid, or solutions and dispersions containing amino acids, proteins, calcium, and the like.

[0111] Furthermore, the "liquid ejection device" may be a device in which a liquid ejection head and an object onto which liquid can be attached move relatively, but is not limited to this. Specific examples include a serial type device in which a liquid ejection head moves, and a line type device in which a liquid ejection head does not move.

[0112] Other examples of "liquid ejecting devices" include a treatment liquid application device that ejects a treatment liquid onto paper to apply the treatment liquid to the surface of the paper for purposes such as modifying the surface of the paper, and an injection granulation device that ejects a composition liquid in which raw materials are dispersed through a nozzle to granulate fine particles of the raw materials.

[0113] A "liquid ejection unit" is a collection of components related to the ejection of liquid, integrating functional parts and mechanisms with a liquid ejection head. For example, a "liquid ejection unit" includes a combination of a liquid ejection head and at least one of the following components: a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, and a main scanning movement mechanism.

[0114] Here, "integrated" includes, for example, a liquid ejection head and a functional part or mechanism that are fixed to each other by fastening, bonding, engaging, etc., or one that is held movably relative to the other. The liquid ejection head, functional part, or mechanism may also be configured to be detachable from each other.

[0115] For example, some liquid ejection units have a liquid ejection head and a head tank integrated together, such as liquid ejection unit 440 shown in Fig. 13. Other liquid ejection units have a liquid ejection head and a head tank integrated together by being connected to each other by a tube or the like. Here, a unit including a filter can be added between the head tank and the liquid ejection head of these liquid ejection units.

[0116] Furthermore, there is a liquid ejection unit in which the liquid ejection head and the carriage are integrated.

[0117] In some liquid ejection units, the liquid ejection head is movably held by a guide member that constitutes part of the scanning movement mechanism, and the liquid ejection head and the scanning movement mechanism are integrated together. In other liquid ejection units, as shown in Figure 14, the liquid ejection head, carriage, and main scanning movement mechanism are integrated together.

[0118] Furthermore, there is a liquid ejection unit in which a cap member, which is part of the maintenance and recovery mechanism, is fixed to a carriage on which a liquid ejection head is attached, thereby integrating the liquid ejection head, carriage, and maintenance and recovery mechanism.

[0119] As shown in FIG. 15, there is also a liquid ejection unit in which a tube is connected to a liquid ejection head to which a head tank or flow path components are attached, and the liquid ejection head and a supply mechanism are integrated.

[0120] The main scanning movement mechanism includes the guide member alone, and the supply mechanism includes the tube alone and the loading unit alone.

[0121] Furthermore, the pressure generating means used in the "liquid ejection head" is not limited. For example, in addition to the piezoelectric actuator (which may use a laminated piezoelectric element) as described in the above embodiment, a thermal actuator using an electrothermal conversion element such as a heating resistor, or an electrostatic actuator consisting of a vibration plate and an opposing electrode may also be used.

[0122] In addition, in the present application, the terms image formation, recording, printing, copying, printing, modeling, etc. are all synonymous. [Explanation of symbols]

[0123] 4 nozzles 6 individual liquid chambers 11 First member 12 Second member 16 Common flow path 21 First convex part 22 Second convex part 23 Groove 31 First Adhesive 32 Second Adhesive 33 Third Adhesive 50 nozzle plate 51 Liquid chamber member 52 Actuator member 52a Electrode section 53 Actuator board 55 Holding board 57 Wiring materials 61 Piezoelectric element 62 Driving Area 70 Frame members [Prior art documents] [Patent documents]

[0124] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-240303

Claims

1. A liquid ejection head having a first member and a second member bonded to the first member with an adhesive, the first member has a plurality of convex portions that are convex toward the second member, the plurality of convex portions are composed of two or more types of convex portions having different heights, the second member has a portion where the second member is joined to the plurality of protruding portions, the portion having a height that varies depending on the height of the protruding portions; The adhesive is two or more types, the first member has a rectangular shape having long sides and short sides in a plan view, the plurality of protrusions include at least a first protrusion and a second protrusion having different heights; the first convex portions are provided at four corners of the first member, The liquid ejection head is characterized in that the second convex portion is provided along an edge of a longitudinal side of the first member.

2. 2. The liquid ejection head according to claim 1, wherein the same type of adhesive is used for convex portions of the same height among the plurality of convex portions, and different types of adhesive are used for convex portions of different heights.

3. The adhesive is at least three types, the first convex portion is bonded with a photocurable first adhesive; the second convex portion is bonded by a second adhesive that is not photocurable, A liquid ejection head as described in claim 1, characterized in that the portion of the first member other than the first convex portion and the second convex portion is bonded with a third adhesive different from the first adhesive and the second adhesive.

4. A liquid ejection head as described in any one of claims 1 to 3, characterized in that convex portions of the plurality of convex portions having the same height have the same thickness of the adhesive, and convex portions of different heights have different thicknesses of the adhesive.

5. the first member is a frame member having a common flow path for supplying ink to the liquid chambers, the second member includes an actuator substrate and a holding substrate bonded to the actuator substrate, A liquid ejection head as described in any one of claims 1 to 4, characterized in that the actuator substrate includes a nozzle plate having a plurality of nozzles, a liquid chamber member having a liquid chamber communicating with the nozzles, and an actuator member having a piezoelectric element and an electrode portion.

6. a wiring member for supplying a drive signal to the piezoelectric element; the electrode portion is a region that does not face the holding substrate and is in contact with the wiring member, and is joined to the convex portion via the wiring member and the adhesive, The thickness of the electrode portion is the thinnest among the thicknesses of the actuator member, 6. The liquid ejection head according to claim 5, wherein the adhesive is filled between the electrode portion and the protrusion without leaving any gaps.

7. the first member has a concave shape formed by the two convex portions in at least one of a cross section and a side surface, 7. The liquid ejection head according to claim 1, wherein the second member has a convex shape that fits into the concave shape.

8. A liquid ejection unit comprising the liquid ejection head according to any one of claims 1 to 7.

9. The liquid ejection unit described in claim 8, characterized in that the liquid ejection head is integrated with at least one of a head tank that stores liquid to be supplied to the liquid ejection head, a carriage that mounts the liquid ejection head, a supply mechanism that supplies liquid to the liquid ejection head, a maintenance and recovery mechanism that maintains and recovers the liquid ejection head, and a main scanning movement mechanism that moves the liquid ejection head in the main scanning direction.

10. 10. A liquid ejection device comprising the liquid ejection head according to claim 1, or the liquid ejection unit according to claim 8 or 9.

Images