Liquid discharge head, head unit, and liquid discharge apparatus

Abstract

A liquid discharge head includes a nozzle plate, a liquid chamber, a plurality of liquid supply channels, a valve, a piezoelectric body, and a circuit. The nozzle plate has a nozzle that discharges liquid. The liquid chamber communicates with the nozzle. The plurality of liquid supply channels communicate with the liquid chamber and supply liquid to the liquid chamber from different directions, respectively. The valve opens and closes the nozzle. The piezoelectric body moves the valve to open and close the nozzle. The circuit drives the piezoelectric body to move the valve toward the nozzle, thereby discharging liquid from the nozzle.

Description

Technical Field

[0001] Embodiments of this disclosure relate to a liquid discharge head, a head unit, and a liquid discharge device. Background Technology

[0002] In the prior art, there exist liquid discharge heads with a configuration in which a switching valve opens and closes the nozzle to discharge liquid from the nozzle. For example, Patent Document 1 discloses a configuration in which a plunger moves up and down via a solenoid coil to discharge ink (liquid) from the nozzle opening.

[0003] List of cited references

[0004] Patent documents

[0005] [PTL1] US Patent Application Publication US2012 / 0105522A1 Summary of the Invention

[0006] Technical issues

[0007] The liquid discharge head of Patent Document 1 may not be able to increase the discharge speed of liquid discharged from the nozzle, and may not be able to drive the discharge of liquid at a high frequency.

[0008] Solution to the problem

[0009] The purpose of this disclosure is to provide a liquid discharge head that discharges liquid by high-frequency drive.

[0010] According to embodiments of this disclosure, a liquid discharge head includes a nozzle plate, a liquid chamber, multiple liquid supply channels, a valve, a piezoelectric element, and a circuit. The nozzle plate has a nozzle for discharging liquid. The liquid chamber communicates with the nozzle. The multiple liquid supply channels communicate with the liquid chamber and supply liquid to the liquid chamber from different directions. The valve opens and closes the nozzle. The piezoelectric element moves the valve to open and close the nozzle. The circuit drives the piezoelectric element to move the valve toward the nozzle, thereby discharging liquid from the nozzle.

[0011] According to another embodiment of this disclosure, a liquid discharge head includes a nozzle plate, a liquid chamber, a valve, a piezoelectric element, and a circuit. The nozzle plate has a nozzle for discharging liquid. The liquid chamber communicates with the nozzle. The valve opens and closes the nozzle. The piezoelectric element moves the valve to open and close the nozzle. The circuit drives the piezoelectric element to cause the valve to move to a retracted position, in which the valve retracts from the nozzle to open the nozzle; to move the valve to a sealed position, in which the valve contacts the nozzle plate to close the nozzle; and to move the valve to a half-position between the retracted position and the sealed position, in which the valve does not close the nozzle.

[0012] Effects of the present invention

[0013] As a result, according to this disclosure, a liquid discharge head that discharges liquid by high-frequency drive can be provided. Attached Figure Description

[0014] A more complete understanding of the embodiments of the present disclosure and its many incidental advantages and features can be readily obtained and understood from the following detailed description with reference to the accompanying drawings.

[0015] [ Figure 1 ]

[0016] Figure 1 This is a perspective view of a liquid discharge device according to an embodiment of the present disclosure.

[0017] [ Figure 2A and 2B ]

[0018] Figure 2A and 2B This is a cross-sectional view of the liquid discharge head of the liquid discharge device according to this embodiment.

[0019] [ Figure 3 ]

[0020] Figure 3 It is a cross-sectional view of a head unit including a liquid discharge head, wherein a needle valve closes the nozzle.

[0021] [ Figure 4 ]

[0022] Figure 4 It is a cross-sectional view of the head unit including the liquid discharge head, wherein the needle valve opens the nozzle.

[0023] [ Figure 5 ]

[0024] Figure 5 It is a cross-sectional view of a head unit including a liquid discharge head, wherein a needle valve closes the nozzle to discharge ink from the nozzle.

[0025] [ Figure 6 ]

[0026] Figure 6 It is a cross-sectional view of a head unit including a liquid discharge head, wherein the needle valve is close to the nozzle.

[0027] The accompanying drawings are intended to illustrate embodiments of this disclosure and should not be construed as limiting its scope. Unless explicitly stated otherwise, the drawings should not be considered to be drawn to scale. Furthermore, throughout several views, the same or similar reference numerals denote the same or similar parts. Detailed Implementation

[0028] In describing the embodiments shown in the accompanying drawings, specific terminology has been used for clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology chosen, and it should be understood that each particular component includes all technical equivalents that have similar functionality, operate in a similar manner, and achieve similar results.

[0029] Hereinafter, embodiments of the invention will be described with reference to the accompanying drawings. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0030] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, a liquid discharge head for discharging ink as an example of liquid is given according to an embodiment of the present disclosure.

[0031] like Figure 1 As shown, the liquid discharge device 100 is mounted facing the object 200 on which an image is drawn. The liquid discharge device 100 includes an X-axis guide rail 101, a Y-axis guide rail 102 intersecting the X-axis guide rail 101, and a Z-axis guide rail 103 intersecting the X-axis guide rail 101 and the Y-axis guide rail 102.

[0032] Y-axis guide rail 102 holds X-axis guide rail 101, allowing X-axis guide rail 101 to move in the Y direction. X-axis guide rail 101 holds Z-axis guide rail 103, allowing Z-axis guide rail 103 to move in the X direction. Z-axis guide rail 103 holds carriage 1, allowing carriage 1 to move in the Z direction. Carriage 1 includes a liquid discharge head 10. Carriage 1 is an example of a head unit including a liquid discharge head.

[0033] Furthermore, the liquid discharge device 100 includes a first Z-direction actuator 92 and an X-direction actuator 72. The first Z-direction actuator 92 causes the carriage 1 to move in the Z-direction along the Z-axis guide rail 103. The X-direction actuator 72 causes the Z-axis guide rail 103 to move in the X-direction along the X-axis guide rail 101. The liquid discharge device 100 also includes a Y-direction actuator 82, causing the X-axis guide rail 101 to move in the Y-direction along the Y-axis guide rail 102. Additionally, the liquid discharge device 100 includes a second Z-direction actuator 93, causing the head holder 70 to move relative to the carriage 1 in the Z-direction.

[0034] Carriage 1 includes a head retainer 70. The head retainer 70 is an example of a retainer. Carriage 1 as... Figure 1 As shown, the head retainer 70 can move along the Z-axis guide rail 103 in the Z-direction direction by the power of the first Z-direction driver 92. Furthermore, the head retainer 70... Figure 1 As shown, the carriage 1 can be moved in the Z direction relative to the power of the second Z-direction drive 93.

[0035] The liquid discharge device 100 described above discharges ink, for example a liquid, from the liquid discharge head 10 to the object 200 while moving the carriage 1 along the X, Y, and Z axes. (Image shown). Here, the movement of the carriage 1 and the head holder 70 in the Z direction may not be parallel to the Z direction; it may be an inclined movement including at least a Z-direction component.

[0036] Although object 200 is Figure 1 The object 200 is represented as a plane, but it can have a nearly vertical surface shape or a curved surface with a large radius of curvature, such as the body of a car, truck, or airplane.

[0037] Figure 2A and 2B This is a schematic diagram of the liquid discharge head 10 of the present invention. Figure 2A This is an overall cross-sectional view of the liquid discharge head 10 according to an embodiment of the present invention. Figure 2B yes Figure 2A A magnified view of part B in the image.

[0038] The liquid discharge head 10 includes a housing 11. The housing 11 is made of metal or resin.

[0039] The liquid discharge head 10 includes a nozzle plate 15. The nozzle plate 15 is connected to the housing 11. The nozzle plate 15 includes nozzles 14 for discharging ink.

[0040] The liquid discharge head 10 includes a needle valve 17 and a piezoelectric element 18. The needle valve 17 in the housing 11 opens and closes the nozzle 14, and the piezoelectric element 18 drives (moves) the needle valve 17. A bearing portion 21 is disposed between the needle valve 17 and the housing 11. A seal 22, such as an O-ring, is disposed between the bearing portion 21 and the needle valve 17. The liquid discharge head 10 also includes a head controller 800 as a circuit for driving the piezoelectric element 18.

[0041] The piezoelectric element 18 is housed within a space 13 inside the housing 11. A retainer 23 holds the piezoelectric element 18 within a central space 23a. The piezoelectric element 18 and the needle valve 17 are connected via the front end 23b of the retainer 23, which is coaxial with each other. The front end 23b side of the retainer 23 is connected to the needle valve 17, and the rear end 23c side is fixed by a restraining member 19 mounted on the housing 11.

[0042] The needle valve 17 includes an elastic member 17a at its front end. When the elastic member 17a of the needle valve 17 is pressed against the nozzle plate 15, the elastic member 17a is compressed. As a result, the needle valve 17 reliably closes the nozzle 14.

[0043] Within the internal space of the housing 11, the portion of the space defined by the seal 22 in which the elastic member 17a of the needle valve 17 is disposed is an ink chamber 12 that serves as a liquid chamber for supplying ink to the nozzle 14.

[0044] The housing 11 includes a supply channel 16. The supply channel 16 is the path for supplying ink from the ink bottle (described later) to the ink chamber 12.

[0045] Casing 11 facing Figure 2A A limiting member 19 is provided at the upper end of the piezoelectric element 18. The limiting member 19 contacts the upper end of the piezoelectric element 18 to form a fixing point for the piezoelectric element 18.

[0046] Nozzle plate 15 is an example of an outlet forming component, needle valve 17 is an example of an on / off valve (also simply a valve), and piezoelectric element 18 is an example of a piezoelectric body.

[0047] The following describes the head unit 2 according to this embodiment, which is equipped with a liquid discharge head 10, and explains the process of discharging ink from the liquid discharge head 10.

[0048] like Figure 3 As shown, the head unit 2 includes a liquid discharge head 10, and a first ink supply bottle 31A and a second ink supply bottle 31B as liquid suppliers.

[0049] The first supply channel 16A and the second supply channel 16B serve as liquid supply channels, connected to the ink chamber 12 from two different directions to supply ink to the ink chamber from two different directions. The first ink supply bottle 31A and the second ink supply bottle 31B are respectively connected to the first supply channel 16A and the second supply channel 16B. The first ink supply bottle 31A and the second ink supply bottle 31B supply ink to the ink chamber 12, thereby filling the ink chamber 12 with ink. Alternatively, ink can be supplied to the ink chamber 12 from three or more different directions.

[0050] exist Figure 3 In the middle, the needle valve 17 contacts the nozzle plate 15 to seal (close) the opening 14a of the nozzle 14 facing the end of the needle valve 17.

[0051] In this embodiment, the ink in the ink chamber 12 is not pressurized even during the ink discharge operation, which will be described later. However, during the ink discharge operation, the ink in the ink chamber 12 can be pressurized by the pressurizing mechanism to a degree that does not affect the ink discharge operation.

[0052] During inkjet printing, voltage is applied to the piezoelectric element 18, causing it to contract. As a result, as... Figure 4 As shown, the needle valve 17 retracts from the nozzle 14, opening into an opening 14a at the end of the nozzle 14. Specifically, the head controller 800 drives the piezoelectric element 18 to move the needle valve 17 to the retracted position to open the nozzle 14. This reduces the pressure of the ink around the opening 14a, allowing ink to be supplied to the opening 14a. Ink is supplied to the nozzle 14 and the gap region 40 between the nozzle 14 and the needle valve 17.

[0053] From this state, the head controller 800 drives the piezoelectric element 18 to bring the needle valve 17 close to the nozzle 14 again, as... Figure 5 As shown, the needle valve 17 is moved until it seals (closes) the nozzle 14 (i.e., the sealed position). This causes the ink in the gap region 40 and within the nozzle 14 to be pushed by the needle valve 17, and ink 90 is discharged from the nozzle 14. Specifically, the head controller 800 drives the piezoelectric element 18 to move the needle valve 17 toward the nozzle 14, discharging ink 90.

[0054] In the ink discharge operation described above, according to this embodiment, since ink is supplied to the ink chamber from multiple directions, the speed of ink supply to the ink chamber and the ink discharge speed of the liquid discharge head 10 can be increased. Therefore, in the ink discharge operation, even though the ink in the ink chamber 12 is not pressurized, the ink can be discharged at a high frequency by opening and closing the needle valve 17.

[0055] Furthermore, the piezoelectric element 18 can respond to the application of voltage at high speed, thereby increasing the ink discharge speed of the liquid discharge head 10.

[0056] The following is a description of a liquid discharge head 10 (head unit 2) according to another embodiment of the present invention, which differs from the above embodiment and performs a different ink discharge action.

[0057] In this embodiment, the needle valve 17 is the same as in the embodiment described above. Figure 3 The sealing position (i.e., the sealing position) of the nozzle 14 shown is towards Figure 4 The nozzle 14 shown moves in the retraction direction (i.e., the retraction position). Specifically, the head controller 800 drives the piezoelectric element 18, causing the needle valve 17 to move from the sealed position to the retraction position. As a result, ink is supplied to the gap region 40 between the nozzle 14 and the needle valve 17.

[0058] Subsequently, needle valve 17 approaches nozzle 14, as... Figure 6 As shown, the needle valve 17 is moved to a position where it does not seal the nozzle 14 (i.e., the half position). Specifically, the head controller 800 drives the piezoelectric element 18 to move the needle valve 17 to the half position between the retracted position and the sealing position. Then, the needle valve 17 moves again in the direction of retraction from the nozzle 14, for example, to a position where it is aligned with the nozzle 14. Figure 4 At the same position. That is, the head controller 800 drives the piezoelectric element 18, causing the needle valve 17 to move back to the retracted position. Finally, the needle valve 17 approaches the nozzle 14 again, as... Figure 5 As shown, nozzle 14 is sealed (closed). That is, head controller 800 drives piezoelectric element 18 to move needle valve 17 to the sealed position. As a result, ink is discharged from nozzle 14, the same as in the embodiment described above.

[0059] As described above, in this embodiment, the needle valve 17 is pressed... Figure 3 , Figure 4 , Figure 6 , Figure 4 ,and Figure 5 The position sequence shown reciprocates twice in the opening and closing directions. In other words, the head controller 800 drives the piezoelectric element 18 to move the needle valve 17 from the sealing position to the retracted position, then from the retracted position to the half position, and finally to the sealing position. When the needle valve 17 moves from... Figure 4 The retreat position shown is moved to the position shown in the figure. Figure 6 When the nozzle 14 is in the unsealed position (i.e., half position), air bubbles inside or near the nozzle 14 are expelled to the outside. Furthermore, the reciprocating movement of the needle valve 17 increases the ink supply speed of the ink chamber 12 and the ink discharge speed of the liquid discharge head 10. Subsequently, the needle valve 17 opens and closes the nozzle 14, discharging ink from the nozzle 14 again. As a result, the amount of ink droplets discharged from the nozzle 14 can be increased. The position of the needle valve 17 when opening the nozzle 14 during the two reciprocating movements is not necessarily the same. Although for convenience, reference is made to the embodiment described above. Figures 3 to 5 This embodiment has been described, but the mechanisms and operations of the two embodiments are not necessarily the same. For example, the amount of movement of the needle valve 17 may not be the same. Figure 5 The amount of ink discharged from 90 shown may not be the same in the two embodiments.

[0060] Furthermore, the needle valve 17 can reciprocate more than three times. In this embodiment, the head controller 800 can change the number of reciprocating movements of the needle valve 17. As the number of reciprocating movements of the needle valve 17 increases, the amount of ink discharged from the nozzle 14 can be increased. That is, by changing the number of reciprocating movements of the needle valve 17, the desired amount of ink can be discharged from the nozzle 14.

[0061] In another embodiment described above, the liquid discharge head 10 may include only one liquid supply channel for supplying ink to the ink chamber 12.

[0062] The above embodiments are illustrative and do not limit this disclosure. Therefore, many additional modifications and variations are possible based on the above teachings. For example, within the scope of this disclosure, elements and / or features of different illustrative embodiments may be combined with and / or substituted for each other.

[0063] The term "liquid" includes not only ink but also paint.

[0064] In this disclosure, the term "liquid discharge device" refers to a device that includes a liquid discharge head or head unit and drives the liquid discharge head to discharge liquid. The liquid discharge device includes not only devices that can discharge liquid to objects that can adhere to liquid, but also devices that discharge liquid into a gas or liquid.

[0065] The "liquid discharge device" may include devices related to the supply, transport, and discharge of objects that can adhere to liquids, and may also include pretreatment devices, posttreatment devices, etc.

[0066] For example, as a "liquid discharge device", there is an image forming device that causes ink to be discharged to form an image on paper, and a three-dimensional modeling device that discharges modeling liquid to form a powder layer in order to model a three-dimensional object.

[0067] "Liquid dispensing device" is not limited to devices that visualize meaningful images such as letters or graphics by dispensing liquid. For example, liquid dispensing devices also include devices for forming patterns that are not meaningful on their own, or devices for creating three-dimensional images.

[0068] The term "liquid-adherable object" as used above refers to the object to which the liquid is applied, meaning an object to which the liquid can adhere at least temporarily, an object that adheres and solidifies, or an object that adheres and permeates. Specific examples include recording media such as paper, recording paper, film, and cloth; electronic components such as electronic substrates and piezoelectric elements; powder layers; organ models; and inspection units. Unless otherwise specified, this includes all objects to which the liquid adheres.

[0069] Examples of materials that can be "attached to liquids" include paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, and any material to which liquids can adhere, even temporarily.

[0070] A "liquid discharge device" is a device that allows relative movement between a liquid discharge head and an object to which the liquid can adhere, but is not limited to this. Specific examples include serial devices that move the liquid discharge head and linear devices that do not move the liquid discharge head.

[0071] In addition to the "liquid discharge device", there are also treatment liquid coating devices that discharge treatment liquid onto the paper surface for the purpose of modifying the paper surface, and spray granulation devices that granulate the raw material particles by spraying a combination liquid in which the raw material is dispersed in a solution through a nozzle.

[0072] In this disclosure, the terms “image formation,” “recording,” “character printing,” “image printing,” “printing,” and “modeling” are all synonyms.

[0073] The above embodiments are illustrative and do not limit the invention. Therefore, many additional modifications and variations are possible based on the above teachings. For example, within the scope of the invention, elements and / or features of different illustrative embodiments can be combined with and / or substituted for each other.

[0074] This invention can be implemented in any convenient form, such as using dedicated hardware or a combination of dedicated hardware and software. This invention can be implemented as computer software implemented by one or more networked processing devices. Processing devices include any suitably programmed device, such as a general-purpose computer, a personal digital assistant, a Wireless Application Protocol (WAP) or third-generation (3G) compatible mobile phone, etc. Since this invention can be implemented as software, each aspect of this invention includes computer software that can be implemented on a programmable device. The computer software can be provided to the programmable device using any conventional carrier medium (carrier device). Carrier media include transient carrier media, such as electrical, optical, microwave, acoustic, or radio frequency signals carrying computer code. An example of such a transient medium is Transmission Control Protocol / Internet Protocol (TCP / IP) signals carrying computer code over an IP network such as the Internet. Carrier media also include storage media for storing processor-readable code, such as floppy disks, hard disks, optical disc read-only memory (CD-ROM), magnetic tape devices, or solid-state storage devices.

[0075] The functions of the elements disclosed herein can be implemented using circuitry or processing circuitry, including general-purpose processors, application-specific processors, integrated circuits, application-specific integrated circuits (ASICs), digital signal processors (DSPs), field-programmable gate arrays (FPGAs), conventional circuitry, and / or combinations thereof, configured or programmed to perform the disclosed functions. Processors are considered processing circuitry or circuitry because they include transistors and other circuitry therein. In this disclosure, a circuit, unit, or device is hardware that performs or is programmed to perform the stated functions. The hardware can be any hardware disclosed herein or otherwise known, programmed or configured to perform the stated functions. When the hardware is a processor, it can be considered a type of circuit, and the circuit, device, or unit is a combination of hardware and software used to configure the hardware and / or processor.

[0076] This patent application is based on and claims priority to Japanese Patent Application No. 2022-031739, filed with the Japan Patent Office on March 2, 2022, the entire disclosure of which is incorporated herein by reference.

[0077] List of reference numerals

[0078] 2-head unit

[0079] 10 Liquid Discharge Head

[0080] 12 ink chambers (liquid chamber)

[0081] 14 nozzles

[0082] 15. Nozzle plate (exhaust port forming component)

[0083] 16A First Supply Channel (Liquid Supply Channel)

[0084] 16B Second Supply Channel (Liquid Supply Channel)

[0085] 17-needle valve (valve)

[0086] 18. Piezoelectric elements (piezoelectric bodies)

[0087] 31A First Ink Supply Bottle (Liquid Supply Unit)

[0088] 31B Second Ink Supply Bottle (Liquid Supply Unit)

[0089] 40 gap area

[0090] 100 Liquid Discharge Device

Claims

1. A liquid discharge head, comprising: Nozzle plate, with nozzles for discharging liquid; The liquid chamber is in communication with the nozzle; A plurality of liquid supply channels are connected to the liquid chamber, the plurality of liquid supply channels being configured to supply liquid to the liquid chamber from different directions, and the plurality of liquid supply channels being connected to different liquid supply chambers; A valve, configured to open and close the nozzle; A piezoelectric element configured to move the valve to open and close the nozzle; and A circuit configured to drive the piezoelectric element such that: The valve moves to a retracted position, in which the valve retracts from the nozzle to open the nozzle; The valve reciprocates at least once between the retracted position and a half-position between the retracted position and the sealing position, wherein, The valve does not close the nozzle in the half-position; as well as After the reciprocating movement, the valve moves from the retracted position to the sealed position and contacts the nozzle plate in the sealed position to close the nozzle, thereby discharging the liquid from the nozzle.

2. The liquid discharge head according to claim 1, in, The circuit is further configured to change the number of reciprocating movements of the valve from the retracted position to the half position.

3. A header unit, comprising: The liquid discharge head according to claim 1 or 2; and A carriage is mounted on the liquid discharge head and configured to move the liquid discharge head.

4. A liquid discharge device, comprising: The head unit according to claim 3; and A drive configured to move the carriage.

5. A liquid discharge head, comprising: Nozzle plate, with nozzles for discharging liquid; The liquid chamber is in communication with the nozzle; A valve, configured to open and close the nozzle; A piezoelectric element configured to move the valve to open and close the nozzle; and A circuit configured to drive the piezoelectric element such that: The valve moves to a retracted position, in which the valve retracts from the nozzle to open the nozzle; The valve reciprocates at least once between the retracted position and a half-position between the retracted position and the sealing position, wherein, The valve does not close the nozzle in the half-position; as well as After the reciprocating movement, the valve moves from the retracted position to the sealed position and contacts the nozzle plate in the sealed position to close the nozzle and discharge the liquid from the nozzle.

6. The liquid discharge head according to claim 5, in, The circuit is further configured to change the number of reciprocating movements of the valve from the retracted position to the half position.

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