Liquid discharge head, and liquid discharge device

Abstract

To provide a liquid discharge head that can make both improvement of reliability and downsizing compatible.SOLUTION: A liquid discharge head comprises an element substrate that discharges liquid, an electric wiring substrate electrically connected to the element substrate, and a liquid storage part that stores liquid which is supplied to the element substrate. An electrical component, which generates heat when controlling electric power inputted from the outside in order to discharge liquid, is provided on a first surface of the electric wiring substrate. The liquid storage part is provided on the first surface of the electric wiring substrate. When viewed from a direction perpendicular to the first surface, the electrical component and the liquid storage part are not arranged at positions facing each other.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] Patent Document 1 discloses a liquid ejection head in which a signal input section and a power input section to which high-potential power is input are disposed on opposite sides of a center line perpendicular to the longitudinal direction of an electric wiring board. According to the liquid ejection head of Patent Document 1, the wiring connected to the power input section and the wiring connected to the signal input section can be disposed at locations separate from each other, thereby reducing the effect of noise on the control signal.

[0003] Furthermore, liquid ejection heads capable of circulating liquid inside the head may be equipped with a negative pressure control unit for controlling the negative pressure when circulating the liquid. Under such circumstances, in order to reduce the size of the liquid ejection head, attempts have been made to place the power input section and the negative pressure control unit on the same side of the electrical wiring board. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-014110 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, if a specific component provided on the electric wiring board and the negative pressure control unit are arranged on the same side of the electric wiring board, there is a risk that the component and the negative pressure control unit will interfere with each other.

[0006] In view of the above, an object of the present disclosure is to provide a liquid ejection head that is capable of achieving both improved reliability and miniaturization. [Means for solving the problem]

[0007] The liquid ejection head of the present disclosure comprises an element substrate for ejecting liquid, an electric wiring board electrically connected to the element substrate, and a liquid storage section for storing liquid to be supplied to the element substrate, wherein a first surface of the electric wiring board is provided with electric components that generate heat when controlling power input from outside to eject liquid, the liquid storage section is provided on the first surface side of the electric wiring board, and when viewed from a direction perpendicular to the first surface, the electric components and the liquid storage section are not provided in positions facing each other. Effect of the Invention

[0008] According to the liquid ejection head of the present disclosure, it is possible to achieve both improved reliability and miniaturization. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a liquid ejection device according to an embodiment. [Diagram 2] FIG. 4 is a diagram showing an example of a circulation path according to an embodiment. [Diagram 3] FIG. 2 is an exploded perspective view of a liquid ejection head according to an embodiment. [Figure 4] FIG. 1 is a perspective view of a liquid ejection head according to an embodiment. [Diagram 5] FIG. 1 is a schematic cross-sectional view of a liquid ejection head according to an embodiment. [Figure 6] FIG. 4 is a schematic cross-sectional view of a liquid ejection head in a comparative example. [Figure 7] FIG. 2 is a perspective view of a liquid ejection head with a cover attached in one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [First embodiment] <Overall configuration of the recording device> FIG. 1 is a diagram showing a schematic configuration of a liquid ejection device 100. As shown in FIG.

[0011] The coordinate axes in the drawings will be described. In the drawings referred to in this specification, the X direction and the Y direction indicate two directions perpendicular to each other on a horizontal plane. The Z direction indicates the vertical direction. The +X direction indicates the rear of the liquid ejection head 103, the -X direction indicates the front, the +Y direction indicates the left, the -Y direction indicates the right, the +Z direction indicates the upper direction, and the -Z direction indicates the lower direction. The -X direction is also downstream in the conveying direction of the recording medium 101, and the +X direction is also upstream in the conveying direction of the recording medium 101. The X direction is appropriately called the conveying direction. The Y direction is the longitudinal direction (width direction) of the liquid ejection head 103, the X direction is the lateral direction (depth direction) of the liquid ejection head 103, and the Z direction is also the height direction of the liquid ejection head 103. In the following description, unless otherwise specified, the upper direction, the lower direction, and the left and right directions indicate the directions in the use posture in which the liquid ejection head 103 is normally used.

[0012] In this embodiment, the description will be made on the assumption that the "liquid" is ink. However, the liquid that can be used in this embodiment is not limited to ink. In other words, various recording liquids including a treatment liquid used for the purpose of improving the fixation of ink on a recording medium, reducing uneven gloss, or improving abrasion resistance may be used as the liquid.

[0013] "Recording" (also called "printing") does not only mean forming meaningful information such as letters and figures. "Recording" also means forming meaningless information such as images, designs, or patterns. Furthermore, "recording" does not matter whether it is something that is manifested so that humans can perceive it visually. In other words, "recording" also means forming a structure on a recording medium or processing the medium.

[0014] As shown in FIG. 1, a liquid ejection device 100 includes a transport unit 102 that transports a recording medium 101, and a line-type liquid ejection head 103 that is disposed substantially perpendicular to the transport direction of the recording medium 101.

[0015] In this embodiment, a line-type liquid ejection device 100 is used that performs continuous recording in one pass while continuously or intermittently conveying a plurality of recording media 101. Cut paper is used as the recording media 101. The recording media 101 is not limited to cut paper, and may be continuous rolled paper or a film. The liquid ejection device 100 includes four single-color liquid ejection heads 103 corresponding to four types of ink, namely, yellow, magenta, cyan, and black. Note that "Y", "M", "C", and "Bk" in FIG. 1 respectively indicate yellow, magenta, cyan, and black. In this manner, in this embodiment, the liquid ejection head 103 does not move, but the recording medium 101 moves under the liquid ejection head 103 to complete recording.

[0016] Furthermore, the liquid ejection device 100 is capable of circulating the ink inside the liquid ejection head 103. By circulating the ink inside the liquid ejection head 103, it is possible to prevent the ink from evaporating from the ejection port and becoming thicker, which can cause ejection defects.

[0017] <Liquid circulation path> Fig. 2 is a diagram showing an example of a circulation path that can be applied to this embodiment. In Fig. 2, in order to simplify the explanation, only a path through which ink of one of the four colors described above circulates is shown. However, the main body of the liquid ejection device 100 is provided with circulation paths for the above-mentioned four colors.

[0018] 2, the liquid ejection device 100 includes a main tank 201 capable of storing ink, a refill pump 202 capable of transporting ink, and a buffer tank 203 that functions as a sub-tank. The liquid ejection device 100 includes a first circulation pump 205 for recovering ink from the liquid ejection head 103 to the buffer tank 203, and a second circulation pump 204 for supplying ink from the buffer tank 203 to the liquid ejection head 103. The liquid ejection head 103 includes a liquid storage section 206 that can temporarily store liquid while circulating the liquid.

[0019] The liquid storage section 206 includes a liquid supply unit 207 capable of receiving ink from the second circulation pump 204, and a negative pressure control unit 208 capable of controlling negative pressure. The liquid supply unit 207 is a filter unit including an inlet 209 for introducing ink into the liquid ejection head 103, a filter 210 for removing foreign matter from the ink, and an outlet 211 for discharging the ink from the liquid ejection head 103.

[0020] The filter 210 is provided so as to allow liquid to pass from an inlet 209 provided on one side of the liquid supply unit 207 to a negative pressure control unit 208 arranged above the liquid supply unit 207. The filter 210 can prevent foreign matter such as dust from flowing downstream of the liquid supply unit 207.

[0021] The liquid ejection head 103 includes a liquid ejection unit 212 for ejecting ink. The liquid ejection unit 212 includes a common supply flow path 213 to which ink is supplied from the liquid storage portion 206, and a plurality of individual supply flow paths 214 connected to the single common supply flow path 213. The liquid ejection unit 212 includes a plurality of element substrates 215 connected to each of the multiple individual supply flow paths 214. The liquid ejection unit 212 includes a plurality of individual recovery flow paths 216 connected to each of the multiple element substrates 215, and one common recovery flow path 217 connected to each of the multiple individual recovery flow paths 216.

[0022] The first circulation pump 205 has a function of sucking liquid from the discharge port 211 of the liquid ejection unit 212 and returning it to the buffer tank 203. When the liquid ejection head 103 is driven, a constant amount of ink flows through the common recovery channel 217 by the first circulation pump 205.

[0023] A buffer tank 203 connected to the main tank 201 via a refill pump 202 is capable of storing ink. The buffer tank 203 has an atmosphere communication port (not shown) that passes atmosphere from the inside to the outside. The buffer tank 203 is capable of discharging air bubbles in the ink to the outside through the atmosphere communication port. The refill pump 202 transfers ink from the main tank 201 to the buffer tank 203 in an amount equivalent to the ink consumed by the liquid ejection head 103. For example, ink is consumed by ejecting ink from the ejection ports of the element substrate 215 during recording, suction recovery, and the like.

[0024] The negative pressure control unit 208 is provided between the second circulation pump 204 and the liquid discharge unit 212. The negative pressure control unit 208 is configured to be capable of performing pressure control for supplying the liquid that has passed through the filter 210 to the liquid discharge unit 212. The negative pressure control unit 208 has a function of operating to maintain the pressure downstream of the negative pressure control unit 208 (i.e., the liquid discharge unit 212 side) at a preset constant pressure even if the flow rate of the circulation system varies due to a difference in the duty for recording.

[0025] A first pressure adjustment mechanism 208H and a second pressure adjustment mechanism 208L are provided inside the negative pressure control unit 208. The first pressure adjustment mechanism 208H and the second pressure adjustment mechanism 208L are set to different control pressures. Each of the first pressure adjustment mechanism 208H and the second pressure adjustment mechanism 208L includes a pressure adjustment valve, a spring, and the like.

[0026] The pressure adjustment valve and the springs work to significantly attenuate pressure loss changes inside the supply system (the supply system upstream of the liquid ejection head 103) of the liquid ejection device 100 that occur with fluctuations in the liquid flow rate. This makes it possible to stabilize negative pressure changes downstream of the negative pressure control unit 208 (the liquid ejection unit 212 side) within a certain range.

[0027] The liquid ejection unit 212 is provided with a common supply flow path 213, a common recovery flow path 217, and individual supply flow paths 214 and individual recovery flow paths 216 connected to each of the multiple element substrates 215. The individual supply flow paths 214 and individual recovery flow paths 216 are connected to the common supply flow path 213 and the common recovery flow path 217.

[0028] The first pressure adjustment mechanism 208H is connected to the common supply flow path 213 via the liquid supply unit 207. The second pressure adjustment mechanism 208L is connected to the common recovery flow path 217 via the liquid supply unit 207. In this way, a pressure difference occurs between the two common flow paths, and thus a flow (a flow indicated by an arrow 218 in FIG. 2) occurs in which a portion of the ink flows from the common supply flow path 213 through a flow path provided inside the element substrate 215 to the common recovery flow path 217.

[0029] In this manner, in the liquid ejection unit 212, a flow of liquid passing through the inside of the common recovery channel 217 and a flow of liquid passing from the common supply channel 213 through the insides of each of the multiple element substrates 215 toward the common recovery channel 217 are generated. By utilizing this flow, heat generated by each of the multiple element substrates 215 can be discharged to the outside of the element substrate 215.

[0030] Furthermore, with this configuration, when the liquid ejection head 103 is performing printing, it is possible to generate ink flows in the ejection ports and pressure chambers in the element substrate 215 that are not performing printing. This makes it possible to suppress thickening of the ink in those ejection ports and pressure chambers. Then, it is possible to discharge the thickened ink and foreign matter in the ink into the common recovery flow path 217. This makes it possible for the liquid ejection head 103 to maintain its performance of performing high-speed, high-quality printing.

[0031] <Liquid ejection head 103> FIG. 3 is an exploded perspective view of the liquid ejection head 103. As shown in FIG.

[0032] 3, the liquid ejection head 103 includes a housing 301. A liquid ejection unit 212, a liquid supply unit 207, and an electric wiring board 302 are attached to the housing 301. The liquid supply unit 207 can supply liquid to the element substrate 215 through an opening provided in the housing 301.

[0033] The housing 301 includes a liquid ejection unit support part 303 that supports the liquid supply unit 207, and an electric wiring board support part 304 that supports the electric wiring board 302. The housing 301 supports the liquid ejection unit 212 and the electric wiring board 302, and ensures the rigidity of the liquid ejection head 103. The electric wiring board support part 304 is fixed to the liquid ejection unit support part 303 by screws.

[0034] The liquid discharge unit support part 303 is provided with a first opening 305 and a second opening 306. A joint rubber 307 is inserted into the first opening 305 and the second opening 306. The liquid supplied from the liquid supply unit 207 passes through an opening provided in the joint rubber 307 inserted into the second opening 306 and is guided to the liquid discharge unit 212. When the liquid is circulated, the liquid is returned from the liquid discharge unit 212 to the liquid supply unit 207 through an opening provided in the joint rubber 307 inserted into the first opening 305.

[0035] The liquid ejection unit 212 includes a flow path unit 308 and a plurality of ejection modules 309. The flow path unit 308 includes a first flow path member 310 and a second flow path member 311. The ejection module 309 includes an element substrate 215 and a flexible wiring substrate 312.

[0036] The element substrate 215 and the electric wiring substrate 302 are electrically connected by a flexible wiring substrate 312. An end of the flexible wiring substrate 312 is connected to the element substrate 215. The other end of the flexible wiring substrate 312 is connected to a terminal 313 provided on a contact surface of the electric wiring substrate 302.

[0037] The flow path unit 308 is formed by laminating a first flow path member 310 and a second flow path member 311. The flow path unit 308 can distribute the liquid supplied from the liquid supply unit 207 to each ejection module 309. The flow path unit 308 can also return the liquid circulating from the ejection module 309 to the liquid supply unit 207. The flow path unit 308 is fixed to the liquid ejection unit support part 303 by screwing. By being fixed in this manner, warping and deformation of the flow path unit 308 are suppressed.

[0038] In addition, a face cover 314 is attached to the liquid ejection unit 212. When the face cover 314 is attached to the liquid ejection unit 212, the element substrate 215 is exposed from an opening provided in the face cover 314. By attaching the face cover 314, the surface facing the recording medium 101 (see FIG. 1) is flattened, unevenness in the airflow caused by transport and ejection is reduced, and the landing accuracy of the liquid droplets is improved compared to when the face cover 314 is not present. By attaching the face cover 314, the airtightness is improved when a cap (not shown) is applied while printing is not being performed compared to when the face cover 314 is not present. By increasing the airtightness, it is possible to suppress the viscosity of the ink caused by the evaporation of moisture from the ejection port.

[0039] 4(a) and 4(b) are perspective views of a liquid ejection head 103 in this embodiment.

[0040] 4(a), this embodiment uses a page-wide type liquid ejection head 103 in which 17 element substrates 215 are arranged in-line along the longitudinal direction of the liquid ejection head 103. In addition, the electric wiring board support part 304 is fixed to the liquid ejection unit support part 303 by being screwed.

[0041] 4(b), electrical components used for controlling power input from the outside for discharging liquid are mounted on a first surface 400 of the electrical wiring board 302. A group of electrical components 405 including a capacitor 401, a transistor 402, a power supply terminal 403, and a signal input terminal 404 are mounted on the first surface 400.

[0042] The liquid storage portion 206 is provided on the first surface 400 side. However, the power supply terminal 403 and the liquid storage portion 206 are not provided at positions facing each other when viewed from a direction perpendicular to the first surface 400. The power supply terminal 403 is driven at a relatively high potential among the multiple electric components provided on the first surface 400. A voltage of, for example, 10 V (volts) or more is applied to the power supply terminal 403. The power supply terminal 403 is provided on the opposite side to the side on which the liquid storage portion 206 is provided, with the center of the electric wiring board 302 in the longitudinal direction as the boundary.

[0043] In the electric wiring board 302, the first surface 400 faces the opposite direction to the contact surface to which the flexible wiring board 312 (see FIG. 4(a)) is connected. A capacitor 401 for suppressing a voltage drop in the element substrate 215 is provided on the first surface 400. Specifically, an aluminum electrolytic capacitor is used as the capacitor 401.

[0044] Furthermore, a transistor 402 for controlling the capacitor 401 is provided on the first surface 400. Specifically, a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) is used as the transistor 402. A transistor (not shown) different from the transistor 402 is also provided on the first surface 400. A capacitor (not shown) different from the capacitor 401 for controlling the transistor (not shown) is also provided. In addition to these, a multiplexer for temperature control is provided on the electric wiring board 302. Furthermore, various other IC (Integrated Circuit) components are provided on the first surface 400. An operational amplifier is one example of an IC component.

[0045] Furthermore, the first surface 400 is provided with a power supply terminal 403 and a signal input terminal 404, which are connected to a flexible wiring board 312 (see FIG. 4(a)) via wiring provided inside the electric wiring board 302. A wiring for transmitting power required for ejection transmitted from a control unit (e.g., a CPU, not shown) provided in the main body of the liquid ejection device 100 (see FIG. 1) is connected to the power supply terminal 403. The power is supplied to the element substrate 215 via wiring provided inside the electric wiring board 302 and the flexible wiring board 312 (see FIG. 4(a)).

[0046] The element substrate 215 has a plurality of energy generating elements (e.g., heat generating elements such as heaters) that generate energy for ejecting liquid. Each of the plurality of energy generating elements is provided at a position corresponding to each of the plurality of ejection ports. When the energy generating elements are driven, droplets are ejected from the ejection ports. An electric signal (ejection signal) for driving the energy generating elements is generated by a control unit (e.g., a CPU, not shown) provided in the main body of the liquid ejection device 100. The ejection signal is transmitted from the main body of the liquid ejection device 100 to the electric wiring substrate 302 via an electric connection member (e.g., a flexible wiring substrate, not shown).

[0047] A wiring that transmits an electric signal (ejection signal) required for ejection transmitted from a control unit (e.g., a CPU, not shown) included in the main body of the liquid ejection device 100 (see FIG. 1) is connected to the signal input terminal 404. The ejection signal is supplied to the element substrate 215 via a wiring provided inside the electric wiring board 302 and the flexible wiring board 312 (see FIG. 4(a)).

[0048] The electric wiring board 302 is a rigid board. An example of a rigid board is a printed circuit board. Inside the electric wiring board 302, wiring is consolidated by an electric circuit. By consolidating the wiring in this manner, the number of power supply terminals 403 and signal input terminals 404 can be made smaller than the number of element substrates 215. Therefore, compared to the case where the numbers of power supply terminals 403, signal input terminals 404, and element substrates 215 are the same, the number of electrical connection parts required for attaching and detaching the liquid ejection head 103 to and from the liquid ejection device 100 (see FIG. 1) can be made smaller.

[0049] As described above, the liquid ejection head 103 is driven by power and electrical signals being input to the electric wiring board 302 from the power supply terminal 403 and the signal input terminal 404. Then, the wiring and circuits in the electric wiring board 302 control the drive signals and voltages, thereby driving the element substrate 215.

[0050] The circuits of the liquid ejection head 103 are divided into low-potential circuits and high-potential circuits. An example of a low-potential circuit is a logic circuit that operates at 3.3 V. An example of a high-potential circuit is a sub-heater that operates at 10 V or more, and a circuit for driving the heater.

[0051] The liquid ejection head 103 is driven by a voltage of about 10V to about 28V, and each component may consume several watts of power. Components that are driven by a high voltage of 10V or more, and components such as connectors through which a relatively large current flows, tend to generate more heat than other components. In particular, a large amount of heat may be generated near the base of a connector through which a relatively large current flows at a high potential of about 28V.

[0052] In this embodiment, a current of about 6 A (amperes) to about 10 A for driving three of the seventeen element substrates 215 flows through one of the relatively fine terminals included in the power supply terminal 403. Since the power supply terminal 403 has six such fine terminals, a current of about 30 A to about 60 A may flow near the power supply terminal 403. If such a relatively large current continues to flow through the power supply terminal 403, the power supply terminal 403 may generate heat, which may warm the surrounding atmosphere.

[0053] Under such circumstances, if the liquid storage section 206 is located near the power supply terminal 403, the ink temporarily stored inside the liquid storage section 206 may become warm and evaporate into the air accumulated inside, causing the ink to aggregate.

[0054] Therefore, in this embodiment, in order to suppress the aggregation of ink inside the liquid storage portion 206 , components that are likely to generate heat are not disposed between the liquid storage portion 206 and the electric wiring board 302 .

[0055] The negative pressure control unit 208 is disposed on the same side as the power supply terminal 403, across the electric wiring board 302, but in a position not facing the power supply terminal 403. The liquid storage portion 206 and the power supply terminal 403 are provided in areas on opposite sides of approximately the center in the longitudinal direction of the first surface 400. In other words, the power supply terminal 403 is provided in a position not facing the liquid storage portion 206.

[0056] With this arrangement, even if the power supply terminal 403 and the liquid storage portion 206 are arranged on the same side of the electric wiring board 302 , the liquid storage portion 206 can be located away from the power supply terminal 403 .

[0057] By locating the power supply terminal 403 as far away as possible from the liquid storage portion 206, even if the power supply terminal 403 generates heat, the heat is less likely to be transmitted to the liquid storage portion 206. In this manner, according to the configuration of this embodiment, the power supply terminal 403 and the liquid storage portion 206 are located at separate positions on the same side of the electric wiring board 302. This makes it possible to reduce the size of the liquid ejection head 103 while suppressing ink from coagulating inside the liquid storage portion 206.

[0058] On the first surface 400, it is preferable that components that operate at a relatively high potential are also provided as far away as possible from the liquid storage portion 206, regardless of the amount of power consumption (i.e., heat generation). For some reason, the liquid storage portion 206 may be damaged, causing ink to leak from the liquid storage portion 206. In this case, if ink adheres to a component that operates at a high potential, corrosion due to migration and current leakage may occur, which may result in burnout.

[0059] In this embodiment, the transistor 402 is used for switching the capacitor 401. The power consumption of the transistor 402 is relatively small, but it is driven at a relatively high potential. Therefore, even if the amount of heat generated by the transistor 402 is smaller than that of the power supply terminal 403, there is a risk of the transistor 402 being burned if ink adheres to the transistor 402. For this reason, like the power supply terminal 403, the transistor 402 is preferably provided in a position that does not face the liquid storage portion 206.

[0060] As described above, the liquid storage portion 206 is disposed at a position facing the region from approximately the center to one end in the longitudinal direction of the first surface 400. The transistor 402 is provided in a region from approximately the center to the other end in the longitudinal direction of the first surface 400. In other words, the transistor 402 is provided at a position not facing the liquid storage portion 206.

[0061] With this arrangement, even if the transistor 402 and the liquid storage portion 206 are arranged on the same side of the electric wiring board 302, it is possible to place the transistor 402 away from the liquid storage portion 206. By placing the transistor 402 as far away as possible from the liquid storage portion 206, it is possible to make it difficult for ink to adhere to the transistor 402, even if ink leaks from the liquid storage portion 206.

[0062] Therefore, according to the configuration of this embodiment, the transistor 402 and the liquid storage portion 206 are disposed on the same side of the electric wiring board 302, thereby making it possible to reduce the size of the liquid ejection head 103. Also, it is possible to prevent ink from adhering to the transistor 402.

[0063] If there is a risk that the capacitor 401 will also generate heat and cause the ink inside the liquid storage portion 206 to condense, it is preferable that the capacitor 401 be provided in a region from approximately the center in the longitudinal direction to the other end of the first surface 400. By placing the capacitor 401 as far away as possible from the liquid storage portion 206, it is possible to prevent the ink from condensing inside the liquid storage portion 206 even if the capacitor 401 generates heat.

[0064] It is also preferable that components having a relatively large size are not disposed between the liquid storage portion 206 and the electric wiring board 302 on the first surface 400. For example, when the capacitor 401 is attached to the electric wiring board 302, the main body of the capacitor 401 protrudes toward the side where the liquid storage portion 206 is disposed, with the electric wiring board 302 as the boundary. Therefore, it is preferable that the capacitor 401 (aluminum electrolytic capacitor) is not disposed between the liquid storage portion 206 and the electric wiring board 302.

[0065] Conventionally, the negative pressure control unit and the aluminum electrolytic capacitor have generally been arranged on opposite sides of the electrical wiring board, but such an arrangement may result in the liquid ejection head becoming larger in the depth direction (X direction), which hinders the miniaturization of the liquid ejection head.

[0066] When a relatively large component (capacitor 401) of electric wiring board 302 and liquid storage portion 206 are arranged on the same side across electric wiring board 302 as in this embodiment, their arrangement is important. On first surface 400, capacitor 401 is arranged so as not to face liquid storage portion 206. In this embodiment, liquid storage portion 206 is arranged on one side (right side in the figure) of the electric wiring board 302, approximately at the center in the longitudinal direction, and multiple capacitors 401 are arranged close to the opposite side (left side in the figure).

[0067] Fig. 5 is a cross-sectional view taken along line VV in Fig. 4(b). In Fig. 5, the liquid storage section 206 is about to be attached to the liquid discharge unit support section 303. "L2" in Fig. 5 indicates the length of the short side of the bottom surface of the liquid supply unit 207. "L3" indicates the height (length in the vertical direction) of the liquid discharge unit support section 303. "L4" indicates an arbitrary length extending vertically upward (in the +Z direction) from the upper end of the liquid discharge unit support section 303 along the first surface 400.

[0068] 5, the electric component group 405 includes an electric component 500 that has a relatively small protruding length from the first surface 400 toward the liquid storage portion 206. The protruding length of the electric component 500 from the first surface 400 toward the liquid storage portion 206 is equal to or less than the protruding length of the signal input terminal 404 from the first surface 400 toward the liquid storage portion 206. The amount of heat generated by the electric component 500 is approximately the same as the amount of heat generated by the signal input terminal 404, and does not affect the liquid stored inside the liquid storage portion 206. Examples of the electric component 500 include an aluminum electrolytic capacitor other than the capacitor 401 (see FIG. 4(b)) and a transistor other than the transistor 402 (see FIG. 4(b)).

[0069] Furthermore, the length in the depth direction of the liquid supply unit 207 is greater than the length in the depth direction of the negative pressure control unit 208. This is to prevent the pressure loss when the liquid flows from becoming too large. The length in the depth direction of the negative pressure control unit 208 is approximately the same as the length in the depth direction of the liquid discharge unit support part 303.

[0070] Here, the length of the short side of the bottom surface of the liquid supply unit 207 (length in the depth direction) is defined as L2. An arbitrary length extending vertically upward (in the +Z direction) from the upper end of the liquid discharge unit support part 303 (the upper end of the opening that houses the liquid supply unit 207) along the first surface 400 is defined as L4. Note that the protruding distance of the signal input terminal 404 from the first surface 400 in the X direction is, for example, 8 mm or more and 10 mm or less. In this case, if the signal input terminal 404 is provided at a position that satisfies the following formula 1, it is possible to attach the liquid storage part 206 to the liquid discharge unit support part 303 without contacting the signal input terminal 404.

[0071] (Formula 1)...L2 <L4

[0072] In this embodiment, the signal input terminal 404 is provided at a position vertically upward (+Z direction) from the upper end of the liquid ejection unit support portion 303, farther than the length L2 of the short side of the bottom surface of the liquid supply unit 207.

[0073] When formula 1 is satisfied, the liquid storage portion 206 can be attached to the liquid discharge unit support portion 303 so that the liquid supply unit 207 does not come into contact with the signal input terminal 404 that protrudes significantly (8 mm or more) in a direction away from the first surface 400. In other words, even if the signal input terminal 404 protrudes 8 mm or more from the electric wiring board 302, it is possible to prevent the liquid supply unit 207 from interfering with the signal input terminal 404 when attaching the liquid storage portion 206 to the liquid discharge unit support portion 303.

[0074] Then, after the liquid storage portion 206 is attached to the liquid discharge unit support portion 303, a sufficient clearance is created in the vertical direction (the longitudinal direction in the drawing) between the liquid supply unit 207 and the signal input terminal 404. Furthermore, it also becomes possible to provide an electric component 500 at a position facing the liquid storage portion 206.

[0075] As described above, the liquid storage portion 206 is provided at a position that does not face the capacitor 401 (see FIG. 4(b)). In this embodiment, the capacitor 401 (see FIG. 4(b)) protrudes from the electric wiring board 302 by approximately 10 mm. Therefore, compared to a case in which the liquid storage portion 206 and the capacitor 401 face each other, the liquid supply unit 207 does not come into contact with the capacitor 401 (see FIG. 4(b)), and the design freedom of the liquid supply unit 207 is improved.

[0076] When the electric component group 405 is disposed on the opposite side of the electric wiring board 302 from the liquid storage section 206, if the length of the element substrate in the transport direction (X direction) is about 15 mm, the length of the liquid ejection head in the transport direction (X direction) is about 90 mm. In contrast, when the electric component group 405 and the liquid storage section 206 are disposed on the same side of the electric wiring board 302 as in this embodiment, the length of the liquid ejection head 103 in the transport direction (X direction) is about 50 mm. In this way, according to the configuration of this embodiment, the liquid ejection head 103 is made smaller in size in the transport direction. With such a configuration, the greater the number of liquid ejection heads 103 disposed along the transport direction, the shorter the transport distance required for recording, and therefore the liquid ejection head 103 can be made smaller in size in the transport direction.

[0077] In the following, a hypothetical comparative example will be presented to facilitate understanding of the effects of this embodiment.

[0078] Fig. 6 is a schematic cross-sectional view of a liquid ejection head 600 in a comparative example. In Fig. 6, the liquid ejection head 600 is cut at the same position as line VV shown in Fig. 4(b). For configurations similar to or corresponding to this embodiment, the same names are used and explanations are omitted, and different configurations are mainly described.

[0079] 6, in this comparative example, a capacitor 603 is disposed between liquid storage portion 601 and electric wiring board 602. For this reason, there is a risk that liquid supply unit 605 will come into contact with capacitor 603 when attaching liquid storage portion 601 to liquid supply unit support portion 604. If liquid supply unit 605 comes into contact with capacitor 603, capacitor 603 may become detached from electric wiring board 602 and be damaged.

[0080] Furthermore, even if liquid supply unit 605 could be attached so as not to come into contact with capacitor 603, the depth (L1) of liquid supply unit 605 would have to be smaller than the depth (L2) (see FIG. 5) of liquid supply unit 207 (see FIG. 5). In such a configuration, the pressure loss that occurs when liquid is supplied would be greater than the pressure loss in this embodiment. Furthermore, in such a configuration, the design freedom of liquid storage section 206 would also be less than the design freedom in this embodiment.

[0081] The above is a description of the liquid ejection head 600 in the comparative example.

[0082] FIG. 7A is a perspective view of the liquid ejection head 103 to which a cover 700 according to this embodiment is attached.

[0083] 7A, the liquid ejection head 103 includes a resin cover 700 that covers the upper part of the housing 301. The cover 700 is configured to be detachable from the housing 301.

[0084] FIG. 7B is a perspective view of the liquid ejection head 103 to which a cover 700 according to this embodiment is attached.

[0085] 7(b), the interior of the cover 700 that covers the electric wiring board 302 is divided into a first space and a second space by a partition 701. Therefore, the liquid ejection head 103 with the cover 700 attached is also divided into a first space (-Y direction side) in which the power supply terminal 403 is provided, and a second space (-Y direction side) in which the liquid storage section 206 is provided. The first space is provided with a capacitor 401, a transistor 402, a power supply terminal 403, and a signal input terminal 404. The second space is provided with the liquid storage section 206.

[0086] In this embodiment, when the cover 700 is attached to the liquid ejection head 103, the cover 700 includes a partition 701 that divides the inside of the cover 700 into two spaces. When the cover 700 is attached to the liquid ejection head 103, the partition 401 is located near the center in the longitudinal direction of the electric wiring board 302. With this configuration, even if the power supply terminal 403 generates heat, the heat is blocked by the partition 401. That is, the heat can be prevented from moving toward the liquid storage unit 206 side beyond the partition 401. Therefore, compared to a case where the partition 401 is not present, it is possible to further prevent ink from coagulating inside the liquid storage unit 206.

[0087] Even if ink leaks from the liquid storage portion 206, it is possible to prevent the ink from moving toward the transistor 402 side from the partition 401. Therefore, compared to a case where the partition 401 is not provided, it is possible to further prevent the ink from adhering to the transistor 402.

[0088] As described above, in this embodiment, the capacitor 401, the transistor 402, the power supply terminal 403, the signal input terminal 404, and the liquid storage portion 206 are provided on the same side of the electric wiring board 302. This makes it possible to reduce the depth of the liquid ejection head 103 compared to the case where the liquid storage portion 206 is provided on the contact surface side of the electric wiring board 302.

[0089] Furthermore, on the first surface 400, the capacitor 401, the transistor 402, and the power supply terminal 403 are provided at positions that do not face the liquid storage portion 206. Therefore, reliability is improved compared to a case in which the liquid storage portion 206 faces the capacitor 401, the transistor 402, and the power supply terminal 403.

[0090] Therefore, according to the liquid ejection head 103 of the present embodiment, it is possible to improve the reliability while making it smaller than the conventional technology. That is, according to the liquid ejection head 103 of the present disclosure, it is possible to achieve both improved reliability and miniaturization.

[0091] [Other embodiments] The above description does not limit the scope of the present disclosure.

[0092] In the above embodiment, a thermal liquid ejection head that ejects liquid by generating bubbles using a heating element has been shown as an example, but the technology disclosed herein can also be applied to liquid ejection heads that employ a piezoelectric method and various other liquid ejection methods.

[0093] In the above embodiment, an example of a liquid ejection head in which liquid such as ink is circulated inside the liquid ejection head has been shown, but other configurations are also possible. For example, if liquid can be made to flow from the inlet side to the outlet side inside the liquid ejection head, the liquid does not need to be circulated.

[0094] In the above embodiment, the liquid flows from the inlet at the end of the liquid ejection head to the outlet at the opposite end. However, the liquid may flow from the inlet provided in the center of the liquid ejection head to the outlets provided at both ends.

[0095] In the above embodiment, an example of a so-called line type head having a length corresponding to the width of the recording medium is shown. However, the technology disclosed herein can also be applied to a so-called serial type liquid ejection head that performs printing while scanning the recording medium. An example of a serial type liquid ejection head is one that has one printing element each for black ink and color ink.

[0096] In addition, examples of serial type liquid ejection heads are not limited to the above. For example, a liquid ejection head may be used in which a short line head shorter than the width of the recording medium is created by arranging a plurality of recording elements so that the ejection ports overlap in the ejection port row direction, and the liquid ejection head is scanned across the recording medium. When liquid is supplied to a plurality of recording elements from the same inlet, such a liquid ejection head can be used.

[0097] Furthermore, in the above embodiment, a recording device is shown having a configuration in which one liquid ejection head ejects ink of multiple colors, but the recording device may also be configured such that one liquid ejection head ejects ink of a single color.

[0098] In addition, in the above embodiments, connectors, capacitors, and transistors are given as examples of electrical components, but the electrical components provided on the first surface of the electrical wiring board may be electrical components other than connectors, capacitors, and transistors.

[0099] The present disclosure includes the following configurations.

[0100] [Configuration 1] A liquid ejection head, An element substrate that ejects liquid; an electric wiring board electrically connected to the element substrate; a liquid storage section that stores a liquid to be supplied to the element substrate; Equipped with an electric component that generates heat when controlling power input from an external source for discharging liquid is provided on a first surface of the electric wiring board; the liquid storage portion is provided on a first surface side of the electric wiring board, When viewed from a direction perpendicular to the first surface, the electrical component and the liquid storage portion are not provided at positions facing each other. A liquid ejection head comprising:

[0101] [Configuration 2] the element substrate and the electrical wiring substrate are connected via a flexible wiring substrate; A liquid ejection head according to configuration 1.

[0102] [Configuration 3] The electrical wiring board is a rigid board. 3. The liquid ejection head according to configuration 1 or 2.

[0103] [Configuration 4] The electrical component is a component to which a voltage of 10 V or more is applied. 4. The liquid ejection head according to any one of configurations 1 to 3.

[0104] [Configuration 5] The electrical component is at least one of a connector, a transistor, or a capacitor. A liquid ejection head according to configuration 4.

[0105] [Configuration 6] In the longitudinal direction of the electric wiring board, the electric component is provided on the opposite side to the side on which the liquid storage portion is provided. 6. The liquid ejection head according to any one of configurations 1 to 5.

[0106] [Configuration 7] a cover for covering the electric wiring board and the liquid storage portion; The inside of the cover has a first space in which the electrical component is provided and a second space in which the liquid storage portion is provided, the first space being separated by a partition. The liquid ejection head according to any one of configurations 1 to 6.

[0107] [Configuration 8] A page-wide type in which a plurality of the element substrates are arranged, The liquid ejection head according to any one of configurations 1 to 7.

[0108] [Configuration 9] The electrical component includes a component that protrudes 8 mm or more in a direction away from the first surface. The liquid ejection head according to any one of configurations 1 to 8.

[0109] [Configuration 10] The liquid storage portion is a filter unit having a filter for removing foreign matter from the liquid; A pressure control unit that controls the pressure of the liquid that has passed through the filter. 10. The liquid ejection head according to any one of configurations 1 to 9.

[0110] [Configuration 11] A liquid ejection head, An element substrate that ejects liquid; an electric wiring board electrically connected to the element substrate; a liquid storage section that stores a liquid to be supplied to the element substrate; a support portion that supports the electric wiring board and the liquid storage portion; Equipped with an electrical component is provided on a first surface of the electrical wiring board, the electrical component protruding 8 mm or more in a direction away from the first surface; the liquid storage portion is provided on a first surface side of the electric wiring board, the electrical component is not provided at a position closer than the length of a short side of a bottom surface of the liquid storage portion in a vertically upward direction from an upper end of an opening in which the liquid storage portion is accommodated. A liquid ejection head comprising:

[0111] [Configuration 12] When viewed from a direction perpendicular to the first surface, the electrical component and the liquid storage portion are not provided at positions facing each other. A liquid ejection head according to configuration 11.

[0112] [Configuration 13] the element substrate and the electrical wiring substrate are connected via a flexible wiring substrate; 13. The liquid ejection head according to configuration 11 or 12.

[0113] [Configuration 14] The electrical wiring board is a rigid board. 14. The liquid ejection head according to any one of configurations 11 to 13.

[0114] [Configuration 15] The electrical component is at least one of a connector, a transistor, or a capacitor. 15. The liquid ejection head according to any one of configurations 11 to 14.

[0115] [Configuration 16] In the longitudinal direction of the electric wiring board, the electric component is provided on the side opposite to the side on which the liquid storage portion is provided. 16. The liquid ejection head according to any one of configurations 11 to 15.

[0116] [Configuration 17] A page-wide type in which a plurality of the element substrates are arranged, 17. The liquid ejection head according to any one of configurations 11 to 16.

[0117] [Configuration 18] The liquid storage portion is a filter unit having a filter for removing foreign matter from the liquid; A pressure control unit that controls the pressure of the liquid that has passed through the filter. 18. The liquid ejection head according to any one of configurations 11 to 17.

[0118] [Configuration 19] 19. A liquid ejection device comprising the liquid ejection head according to any one of configurations 1 to 18.

Claims

1. A liquid ejection head, An element substrate that ejects liquid; an electric wiring board electrically connected to the element substrate; a liquid storage section that stores a liquid to be supplied to the element substrate; Equipped with an electric component that generates heat when controlling power input from an outside source for discharging liquid is provided on a first surface of the electric wiring board; the liquid storage portion is provided on a first surface side of the electric wiring board, When viewed from a direction perpendicular to the first surface, the electrical component and the liquid storage portion are not provided at positions facing each other. A liquid ejection head comprising:

2. the element substrate and the electrical wiring substrate are connected via a flexible wiring substrate; The liquid ejection head according to claim 1 .

3. The electrical wiring board is a rigid board.

3. The liquid ejection head according to claim 1 or 2.

4. The electrical component is a component to which a voltage of 10 V or more is applied.

3. The liquid ejection head according to claim 1 or 2.

5. The electrical component is at least one of a connector, a transistor, or a capacitor.

5. The liquid ejection head according to claim 4.

6. In the longitudinal direction of the electric wiring board, the electric component is provided on the opposite side to the side on which the liquid storage portion is provided. The liquid ejection head according to claim 1 .

7. a cover for covering the electric wiring board and the liquid storage portion; The inside of the cover has a first space in which the electric component is provided and a second space in which the liquid storage portion is provided, the first space being divided by a partition. The liquid ejection head according to claim 1 .

8. A page-wide type in which a plurality of the element substrates are arranged, The liquid ejection head according to claim 1 .

9. The electrical component includes a component that protrudes 8 mm or more in a direction away from the first surface. The liquid ejection head according to claim 1 .

10. The liquid storage portion is a filter unit having a filter for removing foreign matter from the liquid; A pressure control unit that controls the pressure of the liquid that has passed through the filter. The liquid ejection head according to claim 1 .

11. A liquid ejection head, An element substrate that ejects liquid; an electric wiring board electrically connected to the element substrate; a liquid storage section that stores a liquid to be supplied to the element substrate; a support portion that supports the electric wiring board and the liquid storage portion; Equipped with an electrical component is provided on a first surface of the electrical wiring board, the electrical component protruding 8 mm or more in a direction away from the first surface; the liquid storage portion is provided on a first surface side of the electric wiring board, the electrical component is not provided at a position closer than the length of a short side of a bottom surface of the liquid storage portion in a vertically upward direction from an upper end of an opening in which the liquid storage portion is accommodated. A liquid ejection head comprising:

12. When viewed from a direction perpendicular to the first surface, the electrical component and the liquid storage portion are not provided at positions facing each other. The liquid ejection head according to claim 11.

13. the element substrate and the electrical wiring substrate are connected via a flexible wiring substrate; The liquid ejection head according to claim 11 or 12.

14. The electrical wiring board is a rigid board. The liquid ejection head according to claim 11 or 12.

15. The electrical component is at least one of a connector, a transistor, or a capacitor. The liquid ejection head according to claim 11 or 12.

16. In the longitudinal direction of the electric wiring board, the electric component is provided on the side opposite to the side on which the liquid storage portion is provided. The liquid ejection head according to claim 11 or 12.

17. A page-wide type in which a plurality of the element substrates are arranged, The liquid ejection head according to claim 11.

18. The liquid storage portion is a filter unit having a filter for removing foreign matter from the liquid; A pressure control unit that controls the pressure of the liquid that has passed through the filter. The liquid ejection head according to claim 11 or 12.

19. A liquid ejection apparatus comprising the liquid ejection head according to claim 1 .

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