Liquid dispensing head and device for dispensing liquid

Abstract

The present invention provides a liquid dispensing head and a liquid dispensing device that can suppress variations in the amount of liquid dispensed from a nozzle. [Solution] The liquid discharge head comprises a nozzle plate 110 having a plurality of nozzles 2 for discharging liquid, a pressure chamber substrate 100 having a plurality of pressure chambers 4 communicating with each of the plurality of nozzles 2, a plurality of piezoelectric elements 5 such as actuators provided for each of the plurality of pressure chambers 4, and a common liquid chamber substrate 140 having a common liquid chamber 3 communicating with each of the plurality of pressure chambers 4. The liquid discharge head 1 also comprises a drive circuit 101 which is a heat generating member, and has an extension portion 120a that extends from a short-distance region in the common liquid chamber where the liquid receives a large amount of heat from the drive circuit 101 and is close to the drive circuit at both ends in the Y direction, to a long-distance region in the common liquid chamber where the liquid receives less heat from the drive circuit 101 and is farther from the drive circuit 101 at the center in the Y direction.

Description

Technical Field

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

Background Art

[0002] Conventionally, there is known a liquid ejection head including a nozzle plate having a plurality of nozzles for ejecting a liquid, a pressure chamber substrate having a plurality of pressure chambers respectively communicating with the plurality of nozzles, a plurality of actuators respectively provided for each of the plurality of pressure chambers, and a common liquid chamber substrate having a common liquid chamber respectively communicating with the plurality of pressure chambers, and driving the actuator to eject the liquid in the pressure chamber from the nozzle.

[0003] Patent Document 1 describes an apparatus in which a drive circuit for driving an actuator is provided at one end on the nozzle plate side of a pressure chamber substrate.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, there has been a possibility that variations occur in the ejection amounts of the liquid ejected from the respective nozzles.

Means for Solving the Problems

[0005] In order to solve the above-described problems, the present invention provides a liquid ejection head including a nozzle plate having a plurality of nozzles for ejecting a liquid, a pressure chamber substrate having a plurality of pressure chambers respectively communicating with the plurality of nozzles, a plurality of actuators respectively provided for each of the plurality of pressure chambers, and a common liquid chamber substrate having a common liquid chamber respectively communicating with the plurality of pressure chambers, and driving the actuator to eject the liquid in the pressure chamber from the nozzle, the liquid ejection head including a heat generating member, and having an extension portion extending from a region in the common liquid chamber where the amount of heat from the heat generating member received by the liquid is large to a region in the common liquid chamber where the amount of heat from the heat generating member received by the liquid is smaller than that in the region.

Effects of the Invention

[0006] According to the present invention, variations in the amount of liquid discharged from the nozzle can be suppressed. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic cross-sectional view showing the liquid dispensing head in the embodiment. [Figure 2] An enlarged cross-sectional view showing the peripheral configuration of one pressure chamber of the liquid discharge head. [Figure 3] This diagram illustrates the wiring section 102 connecting the drive circuit and piezoelectric element of the liquid discharge head. [Figure 4] An enlarged explanatory diagram showing the wiring section connecting the drive circuit and piezoelectric element of the liquid dispensing head. [Figure 5] A schematic exploded view of the liquid dispensing head. [Figure 6] A schematic cross-sectional view showing the liquid dispensing head of Modification 1. [Figure 7] A schematic exploded view of the liquid dispensing head in Modification 1. [Figure 8] A schematic cross-sectional view showing the liquid dispensing head of modified example 2. [Figure 9] A schematic exploded view of the liquid discharge head in modified example 2. [Figure 10] A schematic cross-sectional view showing the liquid dispensing head of the modified example 3. [Figure 11] A schematic exploded view of the liquid dispensing head in modified example 3. [Figure 12] A schematic diagram illustrating the liquid printing apparatus in one embodiment. [Figure 13] A plan view diagram of an example of a head unit of the printing apparatus. [Figure 14] Plan view diagram illustrating the main components of another printing device. [Figure 15] Side view of the main components of the printing apparatus in this example. [Figure 16] Plan view illustrating the main components of the liquid dispensing unit in this example. [Figure 17] Front view diagram of the liquid dispensing unit in this example. [Modes for carrying out the invention]

[0008] The following describes one embodiment in which the present invention is applied to a liquid dispensing head provided in a device for dispensing liquid. It should be noted that the present invention is not limited to the embodiments shown below, and can be modified, added, modified, or deleted to the extent that a person skilled in the art can conceive of other embodiments. Any embodiment that achieves the function and effect of the present invention is included within the scope of the present invention.

[0009] Figure 1 is a schematic cross-sectional view showing a liquid discharge head with a nozzle plate vibration type in an embodiment. In the following description, the longitudinal direction of the liquid discharge head 1 is referred to as the X direction, the short direction as the Y direction, and the height direction as the Z direction. The liquid discharge head 1 in this embodiment is a nozzle plate vibration type liquid discharge head that discharges liquid from the nozzle 2 by fluctuating the pressure in the pressure chamber 4 using a piezoelectric element 5, which is an actuator provided on the nozzle plate 110 (nozzle forming wall) having a nozzle. The nozzle plate vibration type has the advantage of being able to eject droplets with less force compared to a general unimorph type piezo head (which discharges liquid by vibrating the surface facing the wall portion (nozzle forming wall) through which the nozzles of the pressure chamber communicate), and can reduce the power consumption of the actuator.

[0010] The liquid discharge head 1 of this embodiment 1 comprises a nozzle plate 110, a pressure chamber substrate 100, a common liquid chamber substrate 120, and a frame portion 140. The nozzle plate 110 is thin-film in shape and comprises a plurality of nozzles 2 for discharging liquid, and piezoelectric elements 5, which are annular actuators and electromechanical conversion elements, arranged around the nozzles 2. The pressure chamber substrate 100 has a plurality of pressure chambers 4, each communicating with a plurality of nozzles 2. A nozzle 2 (vibrating membrane 103) is formed on one surface of each pressure chamber 4, and the opening 4a of the pressure chamber 4 is located on the side opposite to that surface. The common liquid chamber substrate 120 has a common liquid chamber 3 that communicates with the plurality of pressure chambers 4.

[0011] FIG. 2 is an enlarged cross-sectional view showing the peripheral configuration of one pressure chamber 4. The pressure chamber substrate 100 is a SOI (Silicon on Insulator) substrate. After the diaphragm 103 is formed, the drive circuit 101 as a heating member and the wiring portion 102 are arranged, and the drive circuit 101 and the wiring portion 102 are formed on the nozzle plate 110. Note that the diaphragm 103 may be formed after the drive circuit 101 and the wiring portion 102 are arranged, and the drive circuit 101 may be formed on the pressure chamber substrate 100. The drive circuit 101 is a CMOS circuit including transistors, resistors, and the like. The wiring portion 102 includes wiring for applying a drive waveform (drive signal) from the drive circuit 101 to the second electrode 53 (also referred to as the upper electrode).

[0012] The nozzle plate 110 has a nozzle forming portion (film) 111 in which a plurality of nozzles 2 are formed and which covers the piezoelectric element 5. A liquid repellent film 112 is formed on the nozzle surface of the nozzle forming portion 111. When the liquid discharge is continued, the mist generated simultaneously with the discharge adheres to the nozzle surface. If a large amount of this mist adheres to the nozzle surface, the liquid discharged from the nozzle 2 may be displaced from the desired landing position under the influence of the liquid adhering to the nozzle surface. By forming the liquid repellent film 112 on the nozzle surface, the adhesion of the liquid to the nozzle surface can be suppressed, and the influence of the liquid adhering to the nozzle surface on the liquid discharged from the nozzle 2 can be suppressed.

[0013] The piezoelectric element 5 of the nozzle plate 110 has a first electrode 51 (also referred to as the lower electrode), a piezoelectric film 52, and a second electrode 53 (also referred to as the upper electrode). The piezoelectric element 5 is covered with a first insulating film 8a. The first insulating film 8a is formed with a hole-shaped third contact 7d for electrically connecting to the first electrode 51 and a hole-shaped fourth contact 7e for electrically connecting to the second electrode 53.

[0014] Furthermore, a first lead wire 9a is formed in the first insulating film 8a, which electrically connects the first electrode 51 of the piezoelectric element 5 to the wiring portion 102 of the pressure chamber substrate 100. In addition, a second lead wire 9b is also formed in the first insulating film 8a, which electrically connects the second electrode 53 of the piezoelectric element 5 to the wiring portion 102 of the pressure chamber substrate 100.

[0015] The first lead wire 9a is electrically connected to the first electrode 51 via the third contact 7d and electrically connected to the wiring section 102 via the first contact 7a. The second lead wire 9b is electrically connected to the second electrode 53 via the fourth contact 7e and electrically connected to the wiring section 102 via the second contact 7b. The first lead wire 9a and the second lead wire 9b are covered by the second insulating film 8b. In this embodiment, the second insulating film 8b also covers the piezoelectric element 5 and has the function of protecting the piezoelectric element 5 by preventing moisture that has entered the nozzle forming section 111 made of resin from entering the piezoelectric element 5.

[0016] Alternatively, lead-out wiring sections may be provided on the first electrode 51 and the second electrode 53, respectively, and directly electrically connected to the wiring section 102 via contacts opened in the vibrating membrane. Furthermore, an adhesion-improving film may be formed on the second insulating film 8b to ensure adhesion with the nozzle forming section 111.

[0017] The liquid filling the liquid discharge head 1 enters the nozzle 2 and forms a meniscus within the nozzle. By applying a predetermined drive waveform from the drive circuit 101 to each electrode 51, 53 of the piezoelectric element 5, the piezoelectric film 52 is displaced (vibrates), and the vibrating film 103 vibrates vertically in Figure 3 so that the wall portion of the pressure chamber substrate 100 that partitions the pressure chambers 4 becomes the fixed end. The vibration of the vibrating film 103 causes a pressure change in the liquid in the pressure chamber, and the liquid is discharged from the nozzle 2.

[0018] Furthermore, in this embodiment, the liquid discharge head 1 has a protective film 11 formed on the inner circumferential surface of the nozzle 2, the inner circumferential surface of the pressure chamber 4, and the bottom surface of the common liquid chamber 3, which is hydrophilic to the liquid discharged by the liquid discharge head 1 and acts as a surface layer to prevent liquid erosion. In this embodiment, the liquid discharged by the liquid discharge head 1 is alkaline, and the pressure chamber substrate 100 and vibrating membrane 103 forming the pressure chamber 4 are made of silicon single crystal and silicon oxide. These materials are vulnerable to alkaline liquids and are dissolved and eroded by alkaline solutions. To prevent this, a liquid-resistant protective film 11 is formed to prevent liquid erosion, thereby protecting the pressure chamber substrate 100 and vibrating membrane 103 from the liquid.

[0019] Furthermore, the pressure chamber 4 and nozzle 2 are formed by dry etching. Because the dry etching gas contains fluorine, a fluorine-containing surface film is formed on the inner wall surface of the pressure chamber 4 and the inner circumferential surface of the nozzle 2 after etching, causing the inner wall surface of the pressure chamber 4 and the inner circumferential surface of the nozzle to become liquid-repellent. When the inner circumferential surface of the pressure chamber 4 is liquid-repellent, the liquid does not wet and spread across the inner circumferential surface of the pressure chamber 4 during filling, so the pressure chamber 4 is not properly filled with liquid, and air bubbles may form in the corners of the pressure chamber 4.

[0020] In this embodiment, a hydrophilic protective film 11 is formed on the inner circumferential surface of the pressure chamber 4 and the inner circumferential surface of the nozzle 2, thereby improving the wettability of the liquid to the inner circumferential surfaces of the pressure chamber 4 and the nozzle 2. The protective film 11 only needs to be more hydrophilic to the liquid than the film-forming surface (the lower layer surface of the protective film 11) of the pressure chamber 4 and the nozzle 2 on which the protective film 11 is formed. If the solvent of the liquid is water-based, a highly hydrophilic protective film can be formed, and if the solvent of the liquid is oil-based, a highly lipophilic protective film can be formed to create a highly hydrophilic protective film 11.

[0021] In this way, by forming a protective film 11 that is hydrophilic to the liquid filling the pressure chamber 4 on the inner surfaces of the nozzle 2 and the pressure chamber 4, the liquid spreads more easily to wet the inner surfaces of the pressure chamber 4 and the nozzle 2 during filling. As a result, the liquid filling performance can be improved, and the liquid can be well filled into the pressure chamber 4 and the nozzle 2 without pressurizing or suction during liquid filling. Therefore, it is possible to suppress the occurrence of cracks in the vibrating membrane 103 during liquid filling.

[0022] Since the solvent of the liquid in this embodiment is aqueous, by forming a protective film 11 that does not contain at least fluorine on the inner circumferential surface of the pressure chamber 4 and nozzle 2, the hydrophilicity can be improved compared to a surface film containing fluorine formed by dry etching. In addition to the above, since this film comes into direct contact with various liquids, it is desirable that the film be made of a liquid-resistant material, such as an oxide of a metal that forms a passivation state. As a further method to improve hydrophilicity, silicon dioxide (SiO2) can be mixed at the molecular level with the metal oxide that forms the passivation state. The SiO2 of the protective film 11 has hydrophilic OH groups where the O on its surface is substituted. This further imparts hydrophilicity to the protective film 11. Examples of metals for the metal oxide include tantalum (Ta), niobium (Nb), titanium (Ti), zirconium (Zr), hafnium (Hf), and tungsten (W), which have high compatibility with oxidation states. In particular, Zr and Hf, which have valencies similar to SOI2, or Ta, which have valencies around them, are especially desirable.

[0023] Alternatively, for example, the protective film 11 may have a two-layer structure consisting of a liquid-resistant film and a hydrophilic film. In this case, a liquid-resistant film is formed on the inner circumferential surface of the nozzle 2 and the pressure chamber 4, and then a hydrophilic film is formed on top of the liquid-resistant film.

[0024] In this embodiment, a hydrophilic protective film 11 is also formed on the surface of the pressure chamber substrate 100 that constitutes the bottom surface of the common liquid chamber 3, opposite to the surface on which the vibrating membrane 103 is film-deposited. However, the protective film 11 on this surface may only have liquid resistance. However, the process of forming the protective film 11 on the bottom surface of the common liquid chamber 3 would need to be provided separately from the process of forming a hydrophilic protective film on the inner surface of the nozzle and the wall surface of the pressure chamber, which may increase the manufacturing man-hours. Furthermore, forming the protective film 11 on the bottom surface of the common liquid chamber 3 makes it easier for the liquid to wet and spread on the bottom surface of the common liquid chamber 3, thus improving the liquid filling performance. For this reason, it is preferable to form a hydrophilic protective film 11 on the surface of the pressure chamber substrate 100 that constitutes the bottom surface of the common liquid chamber 3, opposite to the surface on which the vibrating membrane 103 is film-deposited.

[0025] The material for the vibrating membrane 103 can be any material that has at least insulating properties, such as SiO2, SiN, metal oxides, or resins. However, in order to increase the displacement, a material with a low Young's modulus is desirable, and considering the difference in the coefficient of linear expansion between it and the pressure chamber substrate 100, SiO2 (silicon dioxide), which has a relatively small difference, is the most desirable material for the vibrating membrane 103.

[0026] For the first electrode 51 and the second electrode 53, for example, a platinum film can be suitably used. As the piezoelectric material constituting the piezoelectric film 52, a piezoelectric material (a material mainly composed of AlN or ScAlN, etc.) manufactured through a heat treatment process at a temperature of less than 450°C is used.

[0027] Aluminum nitride piezoelectric materials are compounds of trivalent aluminum cations with trivalent nitrogen anions and have a hexagonal crystal structure. Substitutional materials include those in which trivalent aluminum is replaced with boron, scandium, yttrium, lanthanum, and lanthanide elements. Scandium-substituted materials include, for example, Al (1-x) ,Sc x Materials represented by N and substituted with Yb as a lanthanide element include, for example, Al (1-x) ,Yb x This is denoted by N.

[0028] As derivative materials of aluminum nitride, there are material designs that combine divalent and tetravalent elements to perform the same role as a trivalent element, and these have been reported to have superior piezoelectric properties compared to aluminum nitride. Specifically, examples include materials such as Mg0.5,Zr0.5N and Zn0.5,Hf0.5N. Other examples include hexagonal zinc oxide and magnesium zinc oxide.

[0029] Figure 3 is an explanatory diagram showing the wiring section 102 that connects the drive circuit 101 and the piezoelectric element 5 of the liquid discharge head 1 in this embodiment. Figure 4 is an enlarged explanatory diagram showing the wiring section 102 connecting the drive circuit 101 and the piezoelectric element 5 of the liquid discharge head 1 in this embodiment. In the example shown in Figure 3, one drive circuit 101 is connected to each of the second electrodes 53 (upper electrodes) of the five piezoelectric elements 5A to 5E. Specifically, the 10 rows of nozzles extending horizontally in the figure are wired from the top and bottom, with each row consisting of 5 nozzles.

[0030] In this embodiment, the nozzle pitch in the left-right direction (nozzle pitch within the same nozzle row) is set to 212 [μm], and the nozzle pitch in the up-down direction (nozzle pitch between adjacent nozzle rows) is set to 191 [μm]. This results in a liquid discharge head consisting of multiple rows of nozzles arranged so that the nozzle positions in the left-right direction are shifted by 21.2 [μm] between adjacent nozzle rows, achieving a high-density nozzle density of 1200 [npi].

[0031] As shown in Figure 2, by forming the drive circuit 101 on the nozzle plate 110 on which the piezoelectric elements 5 (5A to 5E) are formed, the wiring section 102 between the drive circuit 101 and the piezoelectric elements 5A to 5E can also be formed on the nozzle plate 110. This has the advantage of shortening the wiring length compared to when the drive circuit 101 is formed on the pressure chamber substrate 100 (on the pressure chamber substrate side, with the vibrating membrane 103 in between).

[0032] Figure 5 is a schematic exploded view of the liquid discharge head 1 in this embodiment, where Figure 5(a) shows the frame portion 140, Figure 5(b) shows the common liquid chamber substrate 120, and Figure 5(c) shows the drive substrate in which the pressure chamber substrate 100 and nozzle plate 110 are integrated.

[0033] As shown in Figure 5(c), the pressure chamber substrate 100 has multiple pressure chambers 4 arranged in a two-dimensional direction to correspond to the multiple nozzles 2 formed on the nozzle plate 110.

[0034] Although the pressure chamber 4 is described in an example where the cross-sectional shape parallel to the substrate plane is circular, its cross-sectional shape may be other shapes such as an elliptical column or a polygonal column. Furthermore, its cross-sectional shape does not need to be uniform across the substrate thickness.

[0035] The upper surface of the pressure chamber substrate 100 (the surface facing the common liquid chamber 3) has openings 4a for each pressure chamber 4, and the common liquid chamber 3 formed in the common liquid chamber substrate 120 is positioned to face the openings 4a of each pressure chamber 4. A fluid resistance section may be provided between the common liquid chamber 3 and each pressure chamber 4 to suppress crosstalk between the pressure chambers.

[0036] The common liquid chamber substrate 120 is provided with a plurality of extensions 120a that extend from one end in the Y direction (short side of the liquid discharge head) where one drive circuit 101 is located to the other end in the Y direction (short side of the liquid discharge head) where the other drive circuit 101 is located. In this embodiment, as shown in Figure 1, each extension 120a is provided so as to cross the opening 4a of each pressure chamber 4 in the Y direction, but is not limited to this.

[0037] A frame portion 140, as shown in Figure 5(a), is provided on the upper surface of the common liquid chamber substrate 120 (the surface opposite to the pressure chamber substrate 100). Liquid stored in an external liquid reservoir is supplied to the liquid discharge head 1 via a liquid supply port in the frame portion 140. The liquid supplied from this liquid supply port is then supplied from the supply liquid reservoir chamber 31 within the frame portion 140 to the common liquid chamber 3 of the common liquid chamber substrate 120. Subsequently, the liquid in the common liquid chamber 3 is supplied to each pressure chamber 4 of the pressure chamber substrate 100.

[0038] Generally, the liquids used in liquid dispensing heads 1 often have viscosity that changes with temperature. When the viscosity of the liquid changes, the amount of liquid dispensed from nozzle 2 fluctuates, making it difficult to dispense the desired amount of liquid. As a result, if there is a temperature difference between the liquids in the nozzles 2 of liquid dispensing head 1 (if there is a temperature difference between the liquids in the pressure chambers corresponding to each nozzle 2), variations in the amount of liquid dispensed will occur between the nozzles 2.

[0039] When a piezoelectric element with a high piezoelectric constant, such as PZT, is used as the piezoelectric element 5, the heat generated by the piezoelectric element is relatively large among the heat-generating components that can affect the temperature rise of the liquid in each pressure chamber, and the heat generated by the piezoelectric element is dominant in the temperature rise of the liquid in each pressure chamber 4. However, in this embodiment, as described above, the piezoelectric element 5 is made of a piezoelectric material with a low piezoelectric constant, mainly composed of AlN or ScAlN. Such a piezoelectric element 5 generates less heat during operation compared to a piezoelectric element made of a piezoelectric material with a high piezoelectric constant, such as PZT (for example, about 1 / 10). Therefore, the heat generated by the drive circuit 101, which is a heat-generating component other than the piezoelectric element, can affect the temperature rise of the liquid in each pressure chamber.

[0040] The liquid in each pressure chamber 4 experiences a temperature increase due to heat from the drive circuit 101 being conducted through the pressure chamber substrate 100. However, because the pressure chambers 4 are densely formed, the distant pressure chambers, which are located beyond a predetermined distance from the drive circuit 101, are less affected by the heat generated by the drive circuit 101. On the other hand, the short-range pressure chambers, which are located less than a predetermined distance from the drive circuit 101, are more susceptible to the heat generated by the drive circuit 101. As a result, the temperature difference between the liquid tends to be large between the distant and short-range pressure chambers, which are separated from the drive circuit 101 by different distances, causing variations in the liquid discharge volume between the nozzles 2 corresponding to the distant and short-range pressure chambers.

[0041] Furthermore, the heat from each drive circuit 101 is conducted to the liquid in the common liquid chamber formed on the pressure chamber substrate 100 via the pressure chamber substrate 100, heating the liquid on the drive circuit 101 side of the common liquid chamber. At this time, the liquid in the short-range regions on both sides in the Y direction of the common liquid chamber 3, which are close to the drive circuit 101, receives more heat from the drive circuit 101 than the liquid in the long-range region in the center of the common liquid chamber 3, which is farther from the drive circuit 101. Consequently, the temperature of the liquid in the short-range regions at both ends in the Y direction of the common liquid chamber 3 becomes higher than the temperature of the liquid in the long-range region in the center in the Y direction. As a result, the temperature of the liquid flowing from the common liquid chamber to the long-range pressure chamber in the center in the Y direction becomes lower than the temperature of the liquid flowing into the short-range pressure chamber at the ends in the Y direction, and the temperature difference between the liquids in the long-range and short-range pressure chambers becomes increasingly large. As a result, the variation in liquid discharge volume between the nozzles 2 corresponding to the long-range and short-range pressure chambers becomes larger.

[0042] Therefore, in this embodiment, as shown in Figure 5(b), a plurality of extensions 120a are provided that extend from one end of the common liquid chamber 3 in the Y direction (the short direction of the liquid discharge head) to the other end in the Y direction (the short direction of the liquid discharge head). This makes it possible to increase the amount of heat transferred in the Y direction compared to the amount of heat transferred in the X direction, which is the arrangement direction of the drive circuit 101 of the common liquid chamber substrate 120. As a result, heat exchange is actively carried out via the extensions 120a between the liquid in the short-range region, where the liquid at both ends of the common liquid chamber 3 receives a lot of heat from the drive circuit, and the liquid in the long-range region, which is in the center of the common liquid chamber in the Y direction, thereby making the temperature of the liquid in the common liquid chamber 3 more uniform. This reduces the temperature difference between the liquid flowing into the long-range pressure chamber on the center side of the Y direction and the liquid flowing into the short-range pressure chamber on the ends of the Y direction, and reduces the temperature difference between the liquid in the long-range pressure chamber and the liquid in the short-range pressure chamber. This makes it possible to suppress variations in the amount of liquid discharged between the nozzles 2 corresponding to the long-range pressure chamber and the short-range pressure chamber, respectively.

[0043] Furthermore, by providing the extended portion 120a, the contact area with the liquid in the common liquid chamber can be increased, allowing for efficient heat transfer of the liquid in the common liquid chamber. This makes it possible to achieve good temperature uniformity of the liquid in the common liquid chamber 3.

[0044] In this embodiment, the extension portion 120a extends from one end to the other in the Y direction (the short side direction of the liquid discharge head). However, for example, extension portions 120a extending from one end in the Y direction to the center in the Y direction and extension portions 120a extending from the other end in the Y direction to the center in the Y direction may be arranged alternately in the X direction. Even with such a configuration, heat exchange can be actively performed between the liquid at the Y-direction end of the common liquid chamber 3 and the liquid at the Y-direction center of the common liquid chamber 3 via the extension portion 120a, thereby achieving uniform temperature of the liquid in the common liquid chamber 3.

[0045] Furthermore, according to this embodiment, the common liquid chamber 3 formed in the common liquid chamber substrate 120 is partitioned by the extended portion 120a. As a result, the extended portion 120a prevents the pressure wave of the liquid in the pressure chamber 4, when the vibrating membrane 103 is vibrated by the piezoelectric element 5 of the nozzle plate 110, from propagating in the X direction through the common liquid chamber 3. This suppresses crosstalk.

[0046] Furthermore, in this embodiment, the extension portion 120a is provided so as to cross the opening 4a of each pressure chamber 4 in the Y direction. As a result, the liquid in each pressure chamber comes into contact with the extension portion 120a through the opening 4a. Therefore, heat exchange can be performed via the extension portion 120a between the liquid in the short-range pressure chamber at the Y-direction end, which is closer to the drive circuit 101, and the liquid in the long-range pressure chamber at the Y-direction center, which is further from the drive circuit 101, thereby suppressing the temperature difference between the liquid in the short-range pressure chamber at the Y-direction end and the liquid in the long-range pressure chamber at the Y-direction center.

[0047] [Example 1] Figure 6 is a schematic cross-sectional view of the liquid discharge head 1A of Modified Example 1, and Figure 7 is a schematic exploded view of the liquid discharge head 1A of Modified Example 1. This modified example 1 provides a common liquid chamber 3 with multiple common flow channels 3a separated from each other by extensions 120a. The common liquid chamber substrate 120 has a ceiling wall portion 120c that closes the frame portion 140 side of the common liquid chamber 3, and the extensions 120a extend in the Y direction so as to cross the openings 4a of each pressure chamber 4 of the pressure chamber substrate 100. The ceiling wall portion 120c and the extensions 120a form a common flow channel 3a in the common liquid chamber 3 through which liquid flows along the extensions 120a. In addition, supply openings 3b, which are liquid supply portions, are provided on both sides of the common liquid chamber substrate 120 in the X direction (longitudinal direction of the liquid discharge head), to which liquid is supplied from the supply liquid storage chamber 31 of the frame portion 140.

[0048] In this embodiment, during continuous operation, the liquid supplied from the supply liquid storage chamber 31 to the center side in the Y direction of the common liquid chamber 3 may not undergo sufficient heat exchange with the liquid at the end side in the Y direction via the extended portion 120a, and may flow into the distant pressure chamber on the center side in the Y direction.

[0049] On the other hand, in Modification 1, the liquid supplied to the common liquid chamber from the supply opening 3b flows from both sides in the Y direction of the common liquid chamber to the common flow channel 3a. Then, it flows through the common flow channel 3a toward the center and into the distant pressure chamber on the central side. In this way, in Modification 1, the liquid flowing into the distant pressure chamber is in contact with the extended section 120a for a long period of time and receives sufficient heat from the extended section 120a, so that its temperature can be made almost the same as the liquid in the short-range region on the Y-direction end side of the common liquid chamber. As a result, even during continuous operation, the temperature difference between the liquid in the short-range pressure chamber on the Y-direction end side and the liquid in the distant pressure chamber on the Y-direction center side can be effectively suppressed.

[0050] Furthermore, in the modified example 1, heat exchange can be performed between the liquid in the short-range region at the Y-direction end of the common liquid chamber 3 and the liquid in the long-range region at the Y-direction center of the common liquid chamber 3 via the ceiling wall portion 120c. This makes it possible to further equalize the temperature of the liquid in the common liquid chamber.

[0051] [Differentiation 2] Figure 8 is a schematic cross-sectional view of the liquid discharge head 1B of Modified Example 2, and Figure 9 is a schematic exploded view of the liquid discharge head 1B of Modified Example 2. In this modified version 2, the liquid inside the liquid dispensing head is circulated. In this modified example 2, the frame portion 140 has a supply liquid storage chamber 31 on one end in the X direction (longitudinal direction of the liquid discharge head) for supplying liquid to the common liquid chamber 3, and a discharge liquid storage chamber 35 on the other end in the X direction from which liquid is discharged from the common liquid chamber 3. A supply opening 3b, which is a liquid supply section, is provided on one end in the X direction of the common liquid chamber 3 from which liquid is supplied from the supply liquid storage chamber 31, and a discharge opening 3c, which is a liquid discharge section, is provided on the other end in the X direction for discharging liquid to the discharge liquid storage chamber 35. The other configurations are the same as in modified example 1.

[0052] In this modified example 2, the liquid supplied from the outside to the supply liquid storage chamber 31 of the frame section 140 is supplied into the common liquid chamber from the supply opening 3b, as shown by arrow C1 in Figure 8. The liquid supplied to the common liquid chamber 3 of the common liquid chamber substrate 120 flows to the pressure chamber 4 via the common flow path section 3a, in the same manner as in modified example 1. Furthermore, as liquid flows into the pressure chamber from one of the two common flow path sections 3a that communicate with the pressure chamber 4, the liquid in the pressure chamber is discharged to the other common flow path section 3a. Finally, the liquid flows from the discharge opening 3c to the discharge liquid storage chamber 35, and from the discharge liquid storage chamber 35, it is returned to the external liquid storage section via an external pump or the like. This circulates the liquid in the liquid discharge head 1. In this way, the circulation of the liquid within the liquid discharge head prevents the liquid from remaining in the pressure chamber 4 for a long period of time, equalizes the temperature of the liquid within the liquid discharge head, and reduces the temperature difference between the liquid in the far-range pressure chamber at the center in the Y direction and the liquid in the short-range pressure chamber at the end in the Y direction.

[0053] Furthermore, by circulating the liquid within the liquid discharge head, air bubbles present in the flow paths within the liquid discharge head 1, such as the common liquid chamber 3 and the pressure chamber 4, can be eliminated. In addition, when using a liquid with components that tend to settle, it is possible to suppress the settling of liquid components into the liquid chamber within the liquid discharge head 1.

[0054] [Difference 3] Figure 10 is a schematic cross-sectional view showing the liquid discharge head 1C of Modification 3, and Figure 11 is a schematic exploded view of the liquid discharge head 1C of Modification 3. This modified example 3 includes a common liquid chamber equipped with a common supply channel 3a1 for supplying liquid to each pressure chamber and a common discharge channel 3a2 for discharging liquid from each pressure chamber.

[0055] As shown in Figure 11(b), the supply common channel section 3a1 and the discharge common channel section 3a2 are each comb-shaped, and the comb-shaped portions of each are arranged to fit together.

[0056] The extensions 120a, which extend in the Y direction and are arranged at equal intervals in the X direction, have their ends in the Y direction connected to each other by a partition wall 120d. With this configuration, one of the spaces partitioned by the extensions 120a and the partition wall 120d constitutes a common supply channel 3a1, and the other constitutes a common discharge channel 3a2.

[0057] According to Modification 3, it is possible to create a flow that brings liquid into the opening 4a of the pressure chamber 4 from the supply common flow channel 3a1 and a flow that discharges liquid into the discharge common flow channel 3a2, thereby creating a flow that replaces the liquid in the pressure chamber 4. As a result, the movement of the liquid in the liquid discharge head can be made more active compared to Modification 2, and the accumulation of liquid in the common liquid chamber 3 and pressure chamber 4 can be effectively suppressed. As a result, the temperature of the liquid in the liquid discharge head can be made more uniform compared to Modification 2, and variations in the amount of liquid discharged between the nozzles 2 can be effectively suppressed.

[0058] In further modification 3, the movement of the liquid inside the pressure chamber 4 is activated, which moves the air bubbles inside the pressure chamber 4 and makes it easier to discharge them from the pressure chamber 4, thereby suppressing the occurrence of discharge failures.

[0059] Next, an example of a liquid dispensing apparatus according to the present invention will be described with reference to Figures 12 and 13. Figure 12 is a schematic diagram illustrating a printing apparatus, which is an inkjet recording apparatus that serves as an image forming apparatus for ejecting liquid in this embodiment. Figure 13 is a plan view illustrating an example of a head unit of the printing apparatus according to this embodiment.

[0060] The printing apparatus 500, which is a device that discharges this liquid, includes a loading means 501 for loading the continuous body 510, and a guiding and transporting means 503 for guiding and transporting the continuous body 510 loaded from the loading means 501 to the printing means 505. The printing apparatus 500 also includes a printing means 505 for printing an image by discharging liquid onto the continuous body 510, a drying means 507 for drying the continuous body 510, and an unloading means 509 for unloading the continuous body 510.

[0061] The continuous body 510 is fed out from the main winding roller 511 of the loading means 501, guided and transported by the rollers of the loading means 501, the guiding and transporting means 503, the drying means 507, and the unloading means 509, and then wound up by the winding roller 591 of the unloading means 509. In the printing means 505, this continuous body 510 is transported on the transport guide member 559 facing the head unit 550, and an image is printed by the liquid discharged from the head unit 550.

[0062] In the printing apparatus 500 of this embodiment, the head unit 550 is equipped with the two head modules 100A and 100B described above in this embodiment on a common base member 552.

[0063] Then, when the direction in which the liquid discharge heads 1 are arranged in a direction perpendicular to the transport direction of head modules 100A and 100B is defined as the head array direction, the head rows 1A1 and 1A2 of head module 100A discharge liquid of the same color. Similarly, the head rows 1B1 and 1B2 of head module 100A are paired, the head rows 1C1 and 1C2 of head module 100B are paired, and the head rows 1D1 and 1D2 are paired, and the required color liquid is discharged from each.

[0064] Next, other examples of printing apparatus as a liquid dispensing device according to the present invention will be described with reference to Figures 14 and 15. Figure 14 is a plan view illustrating the main components of the printing apparatus in this example. Figure 15 is a side view illustrating the main components of the printing apparatus in this example.

[0065] The printing apparatus 500 in this example is a serial type apparatus, and the carriage 403 reciprocates in the main scanning direction by the 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 stretched across the left and right side plates 491A and 491B and holds the carriage 403 in a movable position. The carriage 403 is then reciprocated in the main scanning direction by the main scanning motor 405 via the timing belt 408 stretched between the drive pulley 406 and the driven pulley 407.

[0066] The carriage 403 is equipped with a liquid discharge unit 440 that integrates a liquid discharge head 1 and a head tank 441 according to the present invention. The liquid discharge head 1 discharges liquids of various colors, such as yellow (Y), cyan (C), magenta (M), and black (K). The liquid discharge head 1 is also mounted with a nozzle row consisting of multiple nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and with the discharge direction facing downward. The liquid discharge head 1 is connected to a liquid circulation device, and the required color of liquid is circulated and supplied.

[0067] The printing apparatus 500 is equipped 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. The transport belt 412 picks up the paper 410 and transports it to a position facing the liquid discharge head 1. This transport belt 412 is an endless belt and is stretched between a transport roller 413 and a tension roller 414. Pickup can be performed by electrostatic attraction or air suction. The transport belt 412 moves in a circular motion in the sub-scanning direction as the transport roller 413 is rotationally driven by the sub-scanning motor 416 via a timing belt 417 and a timing pulley 418.

[0068] Furthermore, a maintenance and recovery mechanism 420 for maintaining and restoring the liquid discharge head 1 is positioned on one side of the carriage 403 in the main scanning direction, next to the transport belt 412. The maintenance and recovery mechanism 420 consists of, for example, a cap member 421 that caps the nozzle surface of the liquid discharge head 1, and a wiper member 422 that wipes the nozzle surface. The main scanning movement mechanism 493, the maintenance and recovery mechanism 420, and the transport mechanism 495 are mounted on a housing that includes side plates 491A, 491B, and a back plate 491C.

[0069] In the printing apparatus 500 configured in this way, the paper 410 is fed onto the transport belt 412 and held in place, and the paper 410 is transported in the sub-scanning direction by the circular movement of the transport belt 412. Then, by moving the carriage 403 in the main scanning direction and driving the liquid ejection head 1 in accordance with the image signal, liquid is ejected onto the stationary paper 410 to form an image.

[0070] Next, another example of the liquid dispensing unit according to the present invention will be described with reference to Figure 16. Figure 16 is a plan view illustrating the main components of the liquid dispensing unit in this example.

[0071] The liquid discharge unit 440 consists of a housing portion comprising side plates 491A, 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a liquid discharge head 1, which are components of the liquid discharge device.

[0072] Furthermore, a liquid dispensing unit can also be configured by attaching the aforementioned maintenance and recovery mechanism 420 to, for example, the side plate 491B of the liquid dispensing unit 440.

[0073] Next, yet another example of the liquid dispensing unit according to the present invention will be described with reference to Figure 17. Figure 17 is a front view of the liquid dispensing unit in this example.

[0074] This liquid discharge unit 440 consists of a liquid discharge head 1 to which a flow path component 444 is attached, and a tube 456 connected to the flow path component 444.

[0075] The flow path component 444 is located inside the cover 442. A head tank 441 can be included instead of the flow path component 444. Furthermore, a connector 443 for electrical connection to the liquid discharge head 1 is provided on the upper part of the flow path component 444.

[0076] In this application, the discharged liquid is not particularly limited as long as it has a viscosity and surface tension that can be discharged from the head, but it is preferable that its viscosity becomes 30 mPa·S or less at room temperature and atmospheric pressure, or when heated or cooled. More specifically, it is a solution, suspension, emulsion, or molten metal such as solder containing solvents such as water or organic solvents, colorants such as dyes or pigments, polymerizable compounds, resins, functional materials such as surfactants, biocompatible materials such as DNA, amino acids or proteins, calcium, or edible materials such as natural pigments. These can be used, for example, in inkjet inks, surface treatment liquids, liquids for forming components of electronic elements and light-emitting elements or electronic circuit resist patterns, liquids for forming solder bumps, and material liquids for 3D modeling.

[0077] A "liquid discharge unit" is a liquid discharge head with integrated functional components and mechanisms, and includes an assembly of parts related to liquid discharge. For example, a "liquid discharge unit" may include a combination of a liquid discharge head with at least one of the following components: a head tank, carriage, supply mechanism, maintenance and recovery mechanism, main scanning movement mechanism, and liquid circulation device.

[0078] Here, integration includes, for example, cases where the liquid dispensing head and functional components or mechanisms are fixed to each other by fastening, bonding, engaging, etc., or where one is held movably relative to the other. Furthermore, the liquid dispensing head and functional components or mechanisms may be configured to be detachable from each other.

[0079] For example, some liquid dispensing units have a liquid dispensing head and head tank integrated into one unit. Others have a liquid dispensing head and head tank integrated into one unit, connected to each other by tubes or similar means. In these liquid dispensing units, a unit including a filter can also be added between the head tank and the liquid dispensing head.

[0080] Additionally, some liquid dispensing units have an integrated liquid dispensing head and carriage.

[0081] Furthermore, some liquid dispensing units integrate the liquid dispensing head and the scanning mechanism by movably holding the liquid dispensing head in a guide member that constitutes part of the scanning mechanism. Others integrate the liquid dispensing head, carriage, and main scanning mechanism.

[0082] Furthermore, some liquid dispensing units integrate the liquid dispensing head, carriage, and maintenance / recovery mechanism by fixing a cap component, which is part of the maintenance / recovery mechanism, to a carriage to which the liquid dispensing head is attached.

[0083] Furthermore, some liquid discharge units have a head tank or a liquid discharge head to which a flow path component is attached, to which a tube is connected, integrating the liquid discharge head and the supply mechanism. Through this tube, the liquid from the liquid storage source is supplied to the liquid discharge head.

[0084] The main scanning movement mechanism shall include the guide member alone. The supply mechanism shall also include the tube alone and the loading section alone.

[0085] Here, the "liquid dispensing unit" is described in combination with a liquid dispensing head, but the "liquid dispensing unit" also includes a head module or head unit that includes the liquid dispensing head mentioned above, as well as the functional components and mechanisms described above, all integrated together.

[0086] "Liquid dispensing devices" include devices that have a liquid dispensing head, liquid dispensing unit, head module, head unit, etc., and drive the liquid dispensing head to dispense liquid. Liquid dispensing devices include not only devices that can dispense liquid onto surfaces to which liquid can adhere, but also devices that dispense liquid into air or into liquid.

[0087] This "liquid dispensing device" may also include means for feeding, transporting, and dispensing paper onto materials to which liquid can adhere, as well as pre-treatment devices, post-treatment devices, etc.

[0088] For example, "devices that dispense liquids" include image forming machines, which dispense ink to form images on paper, and three-dimensional molding machines, which dispense molding liquid into a powder layer formed in layers to create three-dimensional objects.

[0089] Furthermore, "devices that dispense liquid" are not limited to those that visualize meaningful images such as letters or figures through the dispensed liquid. For example, devices that form patterns that do not have meaning in themselves, or devices that create three-dimensional images, are also included.

[0090] The term "materials to which liquid can adhere" above refers to materials to which liquid can adhere, at least temporarily, including materials that adhere and solidify, or materials that adhere and penetrate. Specific examples include recording media such as paper, recording paper, film, and cloth; electronic components such as electronic circuit boards and piezoelectric elements; powder layers; organ models; and inspection cells. Unless otherwise specified, it includes all materials to which liquid can adhere.

[0091] The materials referred to as "materials to which liquid can adhere" above include paper, thread, fibers, fabrics, leather, metal, plastic, glass, wood, ceramics, etc., as long as liquid can adhere to them, even temporarily.

[0092] Furthermore, "liquid dispensing devices" include devices in which the liquid dispensing head and the surface to which the liquid can adhere move relative to each other, but are not limited to these. Specific examples include serial-type devices in which the liquid dispensing head moves, and line-type devices in which the liquid dispensing head does not move.

[0093] Furthermore, other types of "liquid dispensing devices" include processing liquid coating devices that dispense processing liquid onto the surface of paper for purposes such as modifying the paper's surface. There are also spray granulation devices that granulate fine particles of raw materials by spraying a compositional liquid, in which raw materials are dispersed in a solution, through a nozzle.

[0094] In this application, the terms image formation, recording, printing, copying, printing, and shaping are all considered synonymous.

[0095] The above is just one example; each of the following embodiments produces its own unique effects. (Aspect 1) A liquid discharge head 1 comprises a nozzle plate 110 having a plurality of nozzles 2 for discharging liquid, a pressure chamber substrate 100 having a plurality of pressure chambers 4 communicating with each of the plurality of nozzles 2, actuators such as a plurality of piezoelectric elements 5 provided for each of the plurality of pressure chambers 4, and a common liquid chamber substrate 120 having a common liquid chamber 3 communicating with each of the plurality of pressure chambers 4, wherein the actuators are driven to discharge the liquid in the pressure chamber from the nozzles 2, and the liquid discharge head 1 comprises a heat-generating element such as a drive circuit 101, and has an extension portion 120a that extends from a region in the common liquid chamber where the amount of heat received by the liquid from the heat-generating element is large (in this embodiment, this corresponds to the close-proximity region at both ends of the common liquid chamber in the Y direction, close to the drive circuit) to a region in the common liquid chamber where the amount of heat received by the liquid from the heat-generating element is smaller than that region (in this embodiment, this corresponds to the long-distance region at the center of the common liquid chamber in the Y direction, far from the drive circuit). The drive circuit generates heat when the actuator is driven. The heat from the drive circuit, which is a heat-generating component, is conducted to the liquid in the common liquid chamber via the pressure chamber substrate, heating the liquid in the common liquid chamber. At this time, the liquid in the short-range region of the common liquid chamber, which is close to the drive circuit, receives more heat from the drive circuit than the liquid in the long-range region of the common liquid chamber, and the temperature of the liquid in the short-range region of the common liquid chamber may become higher than the temperature of the liquid in the long-range region. As a result, there is a risk that a temperature difference will occur between the pressure chamber into which the liquid in the short-range region of the common liquid chamber flows and the pressure chamber into which the liquid in the long-range region flows. Generally, liquids such as ink used in liquid ejection heads have different viscosities depending on the temperature. Therefore, if the liquid temperature in the pressure chamber into which the liquid in the short-range region of the common liquid chamber flows and the liquid temperature in the pressure chamber into which the liquid in the long-range region flows are different, the viscosities of the liquids will differ, and there is a risk that the amount of liquid ejected from the nozzle will vary. In Embodiment 1, heat exchange can be actively performed via the extension between the liquid located in a region of the common liquid chamber where the liquid receives a large amount of heat from the heat-generating component and the liquid located in a region of the common liquid chamber where the liquid receives a small amount of heat from the heat-generating component, thereby achieving temperature uniformity of the liquid within the common liquid chamber. By achieving temperature uniformity of the liquid within the common liquid chamber in this way, temperature differences in the liquid flowing to each pressure chamber can be suppressed, and variations in the amount of liquid discharged from the nozzle can be suppressed.

[0096] (Aspect 2) In embodiment 1, the heat-generating element such as the drive circuit 101 is provided at one end of the pressure chamber substrate 100 or one end of the nozzle plate 110, and the extended portion 120a extends perpendicularly from at least the end of the heat-generating element in the common liquid chamber to the side wall portion 120b of the common liquid chamber 3 on the side where it is located. According to this, as described in the embodiment, heat can be actively exchanged via the extension portion 120a between the liquid on the side of the common liquid chamber 3 where the heat-generating element is located, such as the drive circuit 101, and the liquid in the common liquid chamber located at a predetermined distance in the vertical direction (Y direction) of the side wall portion 120b on the location side, in a region where the amount of heat received from the heat-generating element is small. This makes it possible to equalize the temperature of the liquid in the common liquid chamber.

[0097] (Aspect 3) In embodiment 1 or 2, the heat-generating components such as the drive circuit 101 are provided at both ends of the nozzle plate 110 or at both ends of the pressure chamber substrate 100, and the extension portion 120a extends from the side where one of the two heat-generating components is located to the side where the other heat-generating component is located. According to this, as described in the embodiment, heat can be actively exchanged via the extension portion 120a between the liquid on the side of the common liquid chamber 3 where the heat-generating element is located, such as the drive circuit 101, and the liquid in the common liquid chamber located at a predetermined distance in the vertical direction (Y direction) of the side wall portion 120b on the location side, in a region where the amount of heat received from the heat-generating element is small. This makes it possible to equalize the temperature of the liquid in the common liquid chamber.

[0098] (Aspect 4) In the liquid discharge head described in Embodiment 3, the common liquid chamber 3 faces each opening 4A of the plurality of pressure chambers 4 located on the side opposite to the nozzle forming wall of the plurality of pressure chambers 4, and the extended portion is arranged to straddle the pressure chambers 4. According to this, as described in the embodiment, the liquid in each pressure chamber 4 comes into contact with the extension portion 120a via the liquid at the opening 4a, and heat can be exchanged via the extension portion between the liquid in the nearby pressure chamber on the side where the heat-generating element such as the drive circuit 101 is located and the liquid in the far-field pressure chamber which is a predetermined distance away from the heat-generating element, thereby reducing the temperature difference between the liquid in the nearby pressure chamber and the liquid in the far-field pressure chamber.

[0099] (Aspect 5) In embodiment 3 or 4, the common liquid chamber 3 faces each opening 4a of the multiple pressure chambers 4 located on the side opposite to the nozzle forming wall of the multiple pressure chambers 4, and the common liquid chamber 3 is partitioned from each other by extensions 120a and is provided with multiple common flow channels 3a that allow liquid to flow along the extensions 120a. According to this, as explained in Modification 1, the liquid in the common liquid chamber enters the common flow path section 3a from the side where the heat-generating components such as the drive circuit 101 are located, moves along the extension section 120a within the common flow path section 3a, and then flows into the distant pressure chamber from the center in the Y direction, which is a predetermined distance from the heat-generating components such as the drive circuit 101. As a result, even during continuous operation, the liquid that has received heat from the extension section 120a for a long period of time and has risen to approximately the same temperature as the liquid on the side of the common liquid chamber 3 where the heat-generating components are located can flow into the distant pressure chamber. This makes it possible to suppress the temperature difference between the short-range pressure chamber and the distant pressure chamber during continuous operation, and to suppress variations in the liquid discharge amount between the nozzles 2.

[0100] (Aspect 6) In embodiment 5, the common flow channel section 3a has a ceiling wall section 120c that closes the side opposite to the opening 4a. According to this, as explained in Modification 1, heat exchange occurs in the liquid within the common liquid chamber via the ceiling wall section 120c, and the temperature of the liquid within the common liquid chamber can be made uniform.

[0101] (Aspect 7) In embodiment 5 or 6, the common liquid chamber substrate 120 has a liquid supply section, such as a supply opening 3b, for supplying liquid to the common liquid chamber 3, and a liquid discharge section, such as a discharge opening 3c, for discharging liquid from the common liquid chamber. According to this, as explained in Modification 2, the liquid in the liquid discharge head can be circulated, and the accumulation of liquid in the pressure chamber 4 and other areas can be suppressed. This makes it possible to equalize the temperature of the liquid in the liquid discharge head and suppress variations in the amount of liquid discharged between the nozzles 2. Furthermore, by circulating the liquid within the liquid discharge head, air bubbles present in the flow paths within the liquid discharge head 1, such as the common liquid chamber 3 and the pressure chamber 4, can be eliminated. In addition, when using a liquid with components that tend to settle, it is possible to suppress the settling of liquid components into the liquid chamber within the liquid discharge head 1.

[0102] (Pattern 8) In embodiment 7, the extension portion 120a is arranged to straddle the pressure chamber 4, and of the multiple common flow channels separated from each other by the extension portion 120a, some are supply common flow channels 3a1 that supply liquid to the pressure chamber 4, and the other are discharge common flow channels 3a2 that discharge liquid from the pressure chamber 4. According to this, as explained in Modification 3, it is possible to create a flow that brings liquid in from the supply common flow channel 3a1 to the opening 4a of the pressure chamber 4, and a flow that causes liquid to flow out to the discharge common flow channel 3a2, thereby creating a flow that replaces the liquid in the pressure chamber 4. This makes the movement of the liquid in the liquid discharge head more active and effectively suppresses the accumulation of liquid in the common liquid chamber 3 and the pressure chamber 4. As a result, the temperature of the liquid in the liquid discharge head can be made more uniform compared to Modification 2, and variations in the amount of liquid discharged between the nozzles 2 can be effectively suppressed.

[0103] (Aspect 9) A liquid discharge head 1 comprises a nozzle plate 110 having a plurality of nozzles 2 for discharging liquid, a pressure chamber substrate 100 having a plurality of pressure chambers 4 communicating with each of the plurality of nozzles 2, actuators such as a plurality of piezoelectric elements 5 provided for each of the plurality of pressure chambers 4, and a common liquid chamber substrate 120 having a common liquid chamber 3 communicating with each of the plurality of pressure chambers 4, wherein the actuators are driven to discharge the liquid in the pressure chambers from the nozzles 2, and a drive circuit 101 such as a plurality of heat-generating elements is arranged in a predetermined direction (X direction in this embodiment), and the amount of heat transferred in the orthogonal direction (Y direction in this embodiment) perpendicular to the arrangement direction of the heat-generating elements of the common liquid chamber substrate 120 is greater than the amount of heat transferred in the arrangement direction of the heat-generating elements (X direction). According to this, as described in the embodiment, the temperature deviation inside the common liquid chamber 3 increases in the orthogonal direction (Y direction) that is perpendicular to the arrangement direction of the heat-generating elements such as the drive circuit 101 of the common liquid chamber 3. In embodiment 8, since the amount of heat transferred is large in the orthogonal direction (Y direction) perpendicular to the arrangement direction, heat exchange of the liquid in the common liquid chamber is actively performed in the orthogonal direction (Y direction) via the common liquid chamber substrate, and the temperature of the liquid in the common liquid chamber 3 can be made uniform well.

[0104] (Aspect 10) In any of embodiments 1 to 9, the common liquid chamber substrate 120 is made of silicon. According to this, as described in the embodiment, microfabrication can be easily performed, high thermal conductivity can be obtained, heat exchange between liquids in the common liquid chamber can be efficiently carried out, and temperature uniformity in the common liquid chamber can be achieved well.

[0105] (Aspect 11) In any of embodiments 1 to 10, the heat-generating element is a drive circuit 101 that drives an actuator such as a piezoelectric element 5. According to this, it is possible to suppress variations in liquid discharge volume between nozzles 2 due to the heat generated by the drive circuit 101.

[0106] (Aspect 12) In embodiment 11, the drive circuit 101 drives actuators such as a plurality of piezoelectric elements 5. According to this, the number of drive circuits can be reduced compared to the case where the drive circuit 101 drives only one actuator.

[0107] (Aspect 13) In embodiment 11 or 12, the drive circuit 101 is provided on the nozzle plate 110 or the pressure chamber substrate 100. This allows for easy wiring to the actuator provided on the nozzle plate 110.

[0108] (Aspect 14) In a liquid dispensing device equipped with a liquid dispensing head 1, one of the liquid dispensing heads from embodiment 1 to 13 was used as the liquid dispensing head 1. This method makes it possible to equalize the liquid temperature within the common liquid chamber. [Explanation of Symbols]

[0109] 1: Liquid dispensing head 2: Nozzle 3: Common liquid chamber 3a: Common flow channel section 3a1: Common supply channel section 3a2: Common flow path for discharge 3b: Supply opening 3c: Discharge opening 4: Pressure chamber 4a: Opening 5: Piezoelectric element 31: Supply liquid storage chamber 35: Discharge liquid storage chamber 100: Pressure chamber substrate 101: Drive circuit 102:Wiring section 103: Vibrating membrane 110: Nozzle plate 111: Nozzle forming section 112: Liquid repellent film 120: Common liquid chamber substrate 120a: Extension part 120b: Side wall part 120c: Ceiling and wall section 120d: Partition wall 140: Frame part 440: Liquid Dispensing Unit 500:Printing device 550: Head Unit [Prior art documents] [Patent Documents]

[0110] [Patent Document 1] Japanese Patent Publication No. 2023-133007

Claims

1. A nozzle plate having multiple nozzles for discharging liquid, A pressure chamber substrate having a plurality of pressure chambers each communicating with the plurality of nozzles, A plurality of actuators are provided for each of the plurality of pressure chambers, The system comprises a common liquid chamber substrate having a common liquid chamber that communicates with each of the aforementioned multiple pressure chambers, A liquid discharge head that drives the actuator to discharge the liquid in the pressure chamber from the nozzle, Equipped with a heat-generating element, A liquid discharge head characterized by having an extension portion that extends from a region within the common liquid chamber where the liquid receives a large amount of heat from the heating element to a region within the common liquid chamber where the liquid receives less heat from the heating element than the region described above.

2. In the liquid discharge head according to claim 1, The heating element is provided at one end of the pressure chamber substrate or at one end of the nozzle plate. The liquid discharge head is characterized in that the extended portion extends at least from the end of the common liquid chamber on the side where the heat-generating member is located, perpendicular to the side wall of the common liquid chamber on the location side.

3. In the liquid discharge head according to claim 1, The heating element is provided at both ends of the pressure chamber substrate or at both ends of the nozzle plate. The liquid discharge head is characterized in that the extended portion extends from the side where one of the two heat-generating members is located to the side where the other heat-generating member is located.

4. In the liquid dispensing head according to claim 3, The common liquid chamber faces each opening of the plurality of pressure chambers, which is located on the side opposite to the nozzle forming wall of the plurality of pressure chambers. The liquid discharge head is characterized in that the extended portion is arranged to straddle the pressure chamber.

5. In the liquid dispensing head according to claim 3, The common liquid chamber faces the openings of the multiple pressure chambers located on the side opposite the nozzle forming wall of the multiple pressure chambers. The liquid discharge head is characterized in that the common liquid chambers are separated from each other by the extended portions, and a plurality of common flow paths are provided for the liquid to flow along the extended portions.

6. In the liquid dispensing head according to claim 5, A liquid discharge head characterized by having a ceiling wall portion that closes the side of the common flow path opposite to the opening.

7. In the liquid discharge head according to claim 5, The liquid discharge head is characterized in that the common liquid chamber substrate has a liquid supply unit for supplying the liquid to the common liquid chamber and a liquid discharge unit for discharging the liquid from the common liquid chamber.

8. In the liquid dispensing head according to claim 7, The aforementioned extension is arranged to straddle the pressure chamber, A liquid discharge head characterized in that some of the multiple common flow channels separated from each other by the extensions are supply common flow channels for supplying the liquid to the pressure chamber, and the other parts are discharge common flow channels for discharging the liquid from the pressure chamber.

9. A nozzle plate having multiple nozzles for discharging liquid, A pressure chamber substrate having a plurality of pressure chambers each communicating with the plurality of nozzles, A plurality of actuators are provided for each of the plurality of pressure chambers, The system comprises a common liquid chamber substrate having a common liquid chamber that communicates with each of the aforementioned multiple pressure chambers, A liquid discharge head that drives the actuator to discharge the liquid in the pressure chamber from the nozzle, Multiple heating elements are arranged in a predetermined direction. A liquid discharge head characterized in that the amount of heat transferred in the orthogonal direction perpendicular to the arrangement direction of the heat-generating elements of the common liquid chamber substrate is greater than the amount of heat transferred in the arrangement direction of the heat-generating elements.

10. In the liquid dispensing head according to claim 1 or 9, The liquid dispensing head is characterized in that the common liquid chamber substrate is made of silicon.

11. In the liquid dispensing head according to claim 1 or 9, The liquid dispensing head is characterized in that the heat-generating element is a drive circuit that drives the actuator.

12. In the liquid discharge head according to claim 11, The aforementioned drive circuit is a liquid dispensing head characterized by driving a plurality of actuators.

13. In the liquid discharge head according to claim 11, The liquid discharge head is characterized in that the drive circuit is provided on the nozzle plate or the pressure chamber substrate.

14. In a device for dispensing liquids equipped with a liquid dispensing head, A liquid dispensing device characterized in that the liquid dispensing head used is the liquid dispensing head described in claim 1 or 9.

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