JP2020049659A - Liquid ejection head, liquid ejection unit, and device for ejecting liquid - Google Patents

Abstract

To attenuate or hinder residual vibration resulting from liquid ejection.SOLUTION: A nozzle plate 1 with a nozzle 4 for ejecting a liquid, a channel plate 2 with a pressure chamber 6 communicating with the nozzle 4, and a vibration plate member 3 with a vibration area 30 forming a wall for the pressure chamber 6 are arranged in layers and joined. The vibration plate member 3 is provided with a vibration area 30 forming a displaceable wall for the pressure chamber 6. The vibration area 30 includes a first layer 3a, as a thin wall part, and a projection 30a. In the longitudinal direction of the pressure chamber 6, a thin wall part (a first layer 3a) forming the vibration area 30 has a relation of Ln>Li, in which Li is the length of the liquid supply side of the thin wall part with respect to the pressure chamber 6 and Ln is the length of the side opposite the liquid supply side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid discharge head, a liquid discharge unit, and a device for discharging liquid.

  In a liquid ejection head that ejects a liquid, ejection characteristics fluctuate due to residual vibrations that occur with ejection of the liquid.

  Conventionally, a thin portion is formed on the nozzle opening side and the ink supply port side to ensure compliance, and a diaphragm with an island portion in the center is provided, and pressure is generated by a piezoelectric vibrator through the island portion A recording head that compresses a chamber and discharges ink droplets from a nozzle opening. In order to apportion the compliance of the entire diaphragm so that the nozzle opening side and the ink supply port side are substantially the same, the nozzle opening side There is known a recording head in which a mass body is added to a thin portion of the recording medium or a thin portion on the ink supply port side (Patent Document 1).

JP-A-8-25632

  In the configuration disclosed in Patent Document 1, although it is possible to suppress the occurrence of residual vibration due to a difference in compliance between the nozzle opening side and the ink supply port side, residual vibration caused by liquid ejection is suppressed. There is a problem that cannot be done.

  The present invention has been made in view of the above problems, and has as its object to reduce fluctuations in liquid ejection characteristics.

In order to solve the above-described problems, the liquid ejection head according to the present invention includes:
A diaphragm member having a displaceable vibration region forming a wall surface of a pressure chamber communicating with a nozzle for discharging a liquid,
The vibration region includes a thin portion and a convex portion,
In the longitudinal direction of the pressure chamber, the thin portion forming the vibration region has a length Li on the supply side of the liquid with respect to the pressure chamber, and a length Ln on the side opposite to the supply side of the liquid with respect to the pressure chamber. In this case, the configuration is such that Ln> Li.

  ADVANTAGE OF THE INVENTION According to this invention, the fluctuation | variation of a liquid discharge characteristic can be reduced.

FIG. 2 is an explanatory cross-sectional view along a direction orthogonal to a nozzle arrangement direction of the liquid ejection head according to the first embodiment of the present invention. FIG. 2 is an explanatory cross-sectional view along a nozzle arrangement direction along line AA in FIG. 1. It is a plane explanatory view of each member similarly. FIG. 6 is an explanatory cross-sectional view along a nozzle arrangement direction of a liquid ejection head according to a second embodiment of the present invention. FIG. 11 is an explanatory cross-sectional view along a direction orthogonal to a nozzle arrangement direction of a liquid ejection head according to a third embodiment of the present invention. FIG. 14 is an explanatory cross-sectional view along a direction orthogonal to a nozzle arrangement direction of a liquid ejection head according to a fourth embodiment of the present invention. It is a plane explanatory view of a diaphragm member similarly. It is an external appearance perspective explanatory view of the liquid discharge head concerning a 6th embodiment of the present invention. FIG. 2 is a cross-sectional explanatory view along a direction orthogonal to a nozzle arrangement direction similar to FIG. 1. FIG. 1 is a schematic explanatory view of an example of an apparatus for discharging a liquid according to the present invention. FIG. 4 is an explanatory plan view of an example of a head unit of the device. It is a block explanatory view of an example of a liquid circulation device. FIG. 9 is an explanatory plan view of a main part of another example of the liquid ejection apparatus according to the present invention. It is a principal part side explanatory view of the same apparatus. FIG. 11 is an explanatory plan view of a main part of another example of the liquid ejection unit according to the present invention. FIG. 13 is a front explanatory view of still another example of the liquid ejection unit according to the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. A first embodiment of the present invention will be described with reference to FIGS. 1 is a cross-sectional explanatory view along a direction orthogonal to the nozzle arrangement direction of the liquid discharge head according to the embodiment, FIG. 2 is a cross-sectional explanatory view along the nozzle arrangement direction along the line AA in FIG. 1, and FIG. It is a plane explanatory view of each member similarly.

  In the liquid discharge head 100, a nozzle plate 1, a flow path plate 2, and a diaphragm member 3 as a wall member are laminated and joined. The piezoelectric actuator 11 includes a piezoelectric actuator 11 for displacing a vibration region (diaphragm) 30 of the diaphragm 3 and a common flow path member 20 also serving as a frame member of the head.

  The nozzle plate 1 has a nozzle row in which a plurality of nozzles 4 for discharging liquid are arranged.

  The flow path plate 2 includes a plurality of pressure chambers 6 that are a plurality of pressure chambers that communicate with the plurality of nozzles 4, a fluid resistance unit 7 that communicates with each pressure chamber 6, and one or a plurality of liquid introductions that communicate with one or more fluid resistance units 7. The part 8 is formed.

  In the present embodiment, the flow path plate 2 is configured by laminating plate members 2A and 2B. The plate-like member 2A is formed with through-grooves 6A, 7A, 8A forming the respective pressure chambers 6, the fluid resistance part 7, and the liquid introduction part 8, and the plate-like member 2B is formed with the respective pressure chambers 6. A through groove 6B and a through groove 8B that forms the liquid introducing section 8 are formed.

  The diaphragm member 3 has a plurality of displaceable diaphragms (vibration regions) 30 that form the wall surfaces of the pressure chambers 6 of the flow path plate 2. Here, the diaphragm member 3 has a two-layer structure (not limited), and includes a first layer 3a forming a thin portion and a second layer 3b forming a thick portion from the flow path plate 2 side.

  Then, a deformable vibration region 30 is formed in a portion corresponding to the pressure chamber 6 in the first layer 3a which is a thin portion. In the vibration region 30, a convex portion 30a which is a thick portion to be joined to the piezoelectric actuator 11 is formed in the second layer 3b. A thick portion 30c is formed by the second layer 3b around the first layer 3a which is a thin portion forming the vibration region 30. A portion corresponding to the partition 6a between the pressure chambers 6 in the thick portion 30c is defined as a protrusion 30b.

  A piezoelectric actuator 11 including an electromechanical transducer as driving means (actuator means, pressure generating means) for deforming the vibration region 30 of the diaphragm member 3 is arranged on the side of the diaphragm member 3 opposite to the pressure chamber 6. doing.

  In this piezoelectric actuator 11, a groove is formed in the piezoelectric member 12 bonded on the base member 13 by half-cut dicing, and a required number of columnar piezoelectric elements 12A and 12B are comb-shaped at predetermined intervals in the nozzle arrangement direction. Is formed.

  Further, the piezoelectric element 12A is joined to a thick portion 30a formed in the vibration region 30 of the vibration plate member 3. In addition, the piezoelectric element 12 </ b> B serving as a support is joined to the protrusion 30 b of the diaphragm member 3. On the piezoelectric element 12A, a projection 12c is formed at a portion joined to the projection 30a.

  The piezoelectric element 12 is obtained by alternately laminating a piezoelectric layer and an internal electrode. Each of the internal electrodes is drawn out to an end face and connected to an external electrode (end face electrode), and a flexible wiring member is connected to the external electrode. I have.

  The common flow path member 20 forms the common flow path 10. The common flow channel 10 communicates with the liquid introduction unit 8 via a filter unit 9 provided on the diaphragm member 3.

  In the liquid ejection head 100, for example, the voltage applied to the piezoelectric element 12A is reduced from the reference potential (intermediate potential), whereby the piezoelectric element 12A contracts, the vibration area 30 of the diaphragm member 3 is pulled, and the volume of the pressure chamber 6 is reduced. Expands, the liquid flows into the pressure chamber 6.

  Thereafter, the voltage applied to the piezoelectric element 12A is increased to extend the piezoelectric element 12A in the laminating direction, and to deform the vibration region 30 of the vibration plate member 3 in the direction toward the nozzle 4 to contract the volume of the pressure chamber 6. The liquid in the pressure chamber 6 is pressurized, and the liquid is discharged from the nozzle 4.

  The method of driving the head is not limited to the above-described example (pull-push), but pull-pull or push-push can be performed according to the drive waveform.

  Next, the configuration of the vibration region in the present embodiment will be described.

  The vibration region 30 that forms the wall surface of the pressure chamber 6 and is a region that can be displaced includes a first layer 3a that is a thin portion and a protrusion 30a. As shown in FIG. 3, in the longitudinal direction of the pressure chamber 6, the thin portion (the portion including only the first layer 3 a) forming the vibration region 30 has a length on the liquid supply side with respect to the pressure chamber 6. When Ln is the length of the side opposite to the supply side of Li and the liquid, Ln> Li.

  In this way, the length Ln of the thin portion (only the first layer 3a) forming the vibration region 30 on the side opposite to the liquid supply side is made longer than the length Li of the liquid supply side. Accordingly, in the longitudinal direction of the pressure chamber 6, the rigidity of the thin portion (only the first layer 3a) forming the vibration region 30 on the side opposite to the liquid supply side is lower than the rigidity on the liquid supply side. Become.

  Here, in the longitudinal direction of the pressure chamber 6, since the nozzle 4 is arranged on the side opposite to the liquid supply side, the compliance of the pressure chamber 6 in contact with the thin portion (only the first layer 3a) on the nozzle 4 side. Is larger than the compliance of the pressure chamber 6 in contact with the thin portion on the liquid supply side (only the first layer 3a).

  If the compliance of the pressure chamber 6 on the nozzle 4 side is large, the amplitude of the pressure wave becomes small before the pressure wave generated in the pressure chamber 6 after the discharge is transmitted to the meniscus formed in the nozzle 4, so that the meniscus remaining after the discharge is discharged. Vibration is reduced.

  If the compliance of the pressure chamber 6 on the nozzle 4 side is different from the compliance of the pressure chamber 6 on the liquid supply side, when a pressure wave is generated in the pressure chamber 6 after ejection, the supply of the thin portion on the nozzle 4 side and the liquid supply The thin portion on the side vibrates with a different vibration cycle.

  Therefore, since the vibration of the thin portion on the nozzle 4 side and the vibration of the thin portion on the liquid supply side cancel each other, the vibration is attenuated quickly, so that the pressure wave generated in the pressure chamber 6 after the discharge is also attenuated quickly, and the nozzle after the discharge is discharged. The meniscus residual vibration generated in No. 4 attenuates quickly.

  Thus, stable liquid ejection characteristics can be obtained, and variations in the liquid ejection characteristics can be reduced.

  Further, as shown in FIG. 1, a thin portion (portion of only the first layer 3a) forming the vibration region 30 and a thick portion formed by the second layer 3b provided around the thin portion. The boundary a is set inside the pressure chamber 6.

  Thereby, the area of the vibration region 30 becomes substantially the same between the plurality of pressure chambers 6, and variation in the discharge characteristics (discharge amount and discharge speed) among the plurality of nozzles 4 can be reduced.

  That is, for each pressure chamber 6, when the thin portion (the portion of only the first layer 3 a) of the vibration region 30 is applied to the partition wall outside the pressure chamber 6 or not, the thin portion is applied to the pressure chamber 6. In the pressure chamber 6 on the outer partition wall, the rigidity of the diaphragm does not decrease by the length of the thin wall partition wall. Therefore, the target amount of compliance increase cannot be obtained, and the thin wall portion of the pressure chamber 6 In the pressure chamber 6 that does not cover the outer partition wall, the target increase in compliance can be obtained.

  In this case, a difference in compliance occurs between the pressure chambers 6, and variations in the discharge speed and the discharge amount occur between the nozzles 4 of each pressure chamber 6.

  Therefore, the boundary a between the thin portion of only the first layer 3 a forming the vibration region 30 and the thick portion formed of the second layer 3 b provided around the thin portion is inside the pressure chamber 6. By doing so, the discharge characteristics can be varied.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is an explanatory cross-sectional view along a direction orthogonal to the nozzle arrangement direction of the liquid discharge head according to the embodiment.

  In the present embodiment, the diaphragm member 3 has a three-layer structure of a first layer 3a, a second layer 3b, and a third layer 3c. And the convex part 30a which joins with the piezoelectric element 12A is comprised by two layers of the 2nd layer 3b and the 3rd layer 3c.

  Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 is an explanatory cross-sectional view along a direction orthogonal to the nozzle arrangement direction of the liquid ejection head according to the embodiment.

  In the present embodiment, the diaphragm member 3 has a two-layer structure of a first layer 3a and a second layer 3b, similarly to the first embodiment, and has a flat joining surface with the projection 30a of the piezoelectric element 12A. .

  Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a cross-sectional explanatory view along a direction orthogonal to the nozzle arrangement direction of the liquid discharge head according to the embodiment, and FIG. 7 is a plan explanatory view similarly viewed from the diaphragm member side.

  In the present embodiment, the boundary a between the thin portion of only the first layer 3 a forming the vibration region 30 and the thick portion formed of the second layer 3 b provided around the thin portion is formed by the pressure chamber 6. So that it is on the outside.

  With this configuration, the size of the head can be reduced.

  Next, a fifth embodiment of the present invention will be described with reference to FIGS. FIG. 8 is an explanatory perspective view showing the appearance of the liquid delivery head according to the embodiment, and FIG. 9 is an explanatory sectional view taken along a direction orthogonal to the nozzle arrangement direction similar to FIG.

  The liquid discharge head 100 is a circulation type liquid discharge head, and has a nozzle plate 1, a flow path plate 2, and a diaphragm member 3 as a wall member that are laminated and joined. The piezoelectric actuator 11 includes a piezoelectric actuator 11 for displacing a vibration region (diaphragm) 30 of the diaphragm 3 and a common flow path member 20 also serving as a frame member of the head.

  The nozzle plate 1 has a plurality of nozzles 4 for discharging liquid.

  The flow path plate 2 includes a plurality of pressure chambers 6 communicating with the plurality of nozzles 4 via the nozzle communication passages 5, a plurality of supply-side fluid resistance portions 7 communicating with the plurality of pressure chambers 6, respectively, and one or more One or a plurality of liquid introduction parts 8 communicating with the fluid resistance part 7 on the supply side are formed. The liquid introduction unit 8 communicates with the supply-side common flow channel 10 through the supply-side opening 19 of the diaphragm member 3.

  In the present embodiment, the flow path plate 2 is configured by laminating a plurality of plate members 2A to 2E, but is not limited to this.

  The diaphragm member 3 has a plurality of deformable diaphragms (vibration regions) 30 that form the wall surfaces of the pressure chambers 6 of the flow path plate 2. Here, the diaphragm member 3 has a three-layer structure (not limited), and includes a first layer 3a forming a thin portion, a second layer 3b forming a thick portion, and a third layer 3c from the flow path plate 2 side. It is configured.

  Then, a deformable vibration region 30 is formed in a portion corresponding to the pressure chamber 6 in the first layer 3a which is a thin portion. In the vibration region 30, a convex portion 30a which is a thick portion to be joined to the piezoelectric actuator 11 is formed by the second layer 3b and the third layer 3c. Further, a thick portion 30c is formed by the second layer 3b around a thin portion (portion of only the first layer 3a) forming the vibration region 30.

  The flow path plate 2 includes a plurality of individual recovery flow paths 56 extending along the surface direction of the flow path plate 2 that communicate with the plurality of pressure chambers 6 via the nozzle communication path 5, respectively, and one or more individual recovery flow paths 56. One or a plurality of liquid lead-out portions 58 communicating with the liquid supply port are formed. The liquid lead-out portion 58 communicates with the recovery-side common flow channel 50 via the recovery-side opening 59 of the diaphragm member 3.

  The common flow path member 20 forms a supply-side common flow path 10 and a recovery-side common flow path 50. The common flow path 10 on the supply side communicates with the supply port 71, and the common flow path 50 on the collection side communicates with the collection port 72.

  In the liquid ejection head 100, for example, the voltage applied to the piezoelectric element 12A is reduced from the reference potential (intermediate potential), whereby the piezoelectric element 12A contracts, the vibration area 30 of the diaphragm member 3 is pulled, and the volume of the pressure chamber 6 is reduced. Expands, the liquid flows into the pressure chamber 6.

  Thereafter, the voltage applied to the piezoelectric element 12A is increased to extend the piezoelectric element 12A in the laminating direction, and to deform the vibration region 30 of the vibration plate member 3 in the direction toward the nozzle 4 to contract the volume of the pressure chamber 6. The liquid in the pressure chamber 6 is pressurized, and the liquid is discharged from the nozzle 4.

  The liquid that is not ejected from the nozzle 4 passes through the nozzle 4 and is collected from the individual collection channel 56 to the common channel 50 on the collection side. It is supplied to the road 10 again.

  The method of driving the head is not limited to the above-described example (pull-push), but pull-pull or push-push can be performed according to the drive waveform.

  Also in the present embodiment, in the longitudinal direction of the pressure chamber 6, the thin portion (only the first layer 3 a) forming the vibration region 30 has a length on the liquid supply side to the pressure chamber 6 equal to Li. When the length on the side opposite to the liquid supply side is Ln, there is a relationship of Ln> Li.

  Accordingly, the residual vibration of the pressure chamber 6 can be attenuated or suppressed, stable liquid ejection characteristics can be obtained, and variations in ejection characteristics can be reduced.

  Next, an example of an apparatus for ejecting liquid according to the present invention will be described with reference to FIGS. FIG. 10 is a schematic explanatory view of the apparatus, and FIG. 11 is a plan explanatory view of an example of a head unit of the apparatus.

  The printing apparatus 500 which discharges the liquid includes a loading unit 501 for loading the continuum 510, a guiding and conveying unit 503 for guiding and transporting the continuum 510 loaded from the loading unit 501 to the printing unit 505, The printing apparatus includes a printing unit 505 that performs printing to form an image by discharging a liquid to the 510, a drying unit 507 that dries the continuous body 510, and an unloading unit 509 that unloads the continuous body 510.

  The continuous body 510 is sent out from the original winding roller 511 of the carrying-in means 501, guided and carried by the carrying-in means 501, the guide carrying means 503, the drying means 507, and the carrying-out means 509, and the take-up roller 591 of the carrying-out means 509. Winded up at

  The continuum 510 is conveyed by the printing unit 505 on the conveyance guide member 559 so as to face the head unit 550 and the head unit 555, an image is formed by the liquid discharged from the head unit 550, and the continuum 510 is discharged from the head unit 555. Post-processing is performed with the processing solution to be performed.

  Here, the head unit 550 includes, for example, full-line head arrays 551A, 551B, 551C, and 551D for four colors from the upstream side in the transport direction (hereinafter, referred to as “head array 551” when no distinction is made between colors). Is arranged.

  Each of the head arrays 551 is a liquid ejection unit, and ejects black K, cyan C, magenta M, and yellow Y liquids to the continuous body 510 to be conveyed, respectively. Note that the type and number of colors are not limited to these.

  The head array 551 is, for example, one in which the liquid ejection heads (hereinafter, simply referred to as “heads”) 100 according to the present invention are arranged in a staggered manner on the base member 552, but are not limited thereto.

  Next, an example of the liquid circulation device will be described with reference to FIG. FIG. 12 is a block diagram of the circulation device. Although only one head is shown here, when a plurality of heads are arranged, a supply-side liquid path and a collection-side liquid path are respectively provided on the supply side and the collection side of the plurality of heads via a manifold or the like. Will be connected.

  The liquid circulation device 600 includes a supply tank 601, a recovery tank 602, a main tank 603, a first liquid supply pump 604, a second liquid supply pump 605, a compressor 611, a regulator 612, a vacuum pump 621, a regulator 622, and a supply side pressure sensor 631. , A recovery-side pressure sensor 632 and the like.

  Here, the compressor 611 and the vacuum pump 621 constitute a unit that generates a pressure difference between the pressure in the supply tank 601 and the pressure in the recovery tank 602.

  The supply side pressure sensor 631 is connected between the supply tank 601 and the head 100 and to a supply side liquid path connected to the supply port 71 of the head 100. The collection-side pressure sensor 632 is connected between the head 1 and the collection tank 602 and to a collection-side liquid path connected to the collection port 72 of the head 100.

  One of the recovery tanks 602 is connected to a supply tank 601 via a first liquid feed pump 604, and the other of the recovery tank 602 is connected to a main tank 603 via a second liquid feed pump 605.

  Thereby, the liquid flows into the head 100 from the supply tank 601 through the supply port 71, is collected from the collection port 72 to the collection tank 602, and the liquid is collected from the collection tank 602 to the supply tank 601 by the first liquid supply pump 604. By being sent, a circulation path for circulating the liquid is formed.

  Here, a compressor 611 is connected to the supply tank 601, and is controlled such that a predetermined positive pressure is detected by the supply-side pressure sensor 631. On the other hand, a vacuum pump 621 is connected to the collection tank 602, and is controlled so that a predetermined negative pressure is detected by the collection-side pressure sensor 632.

  Thus, the negative pressure of the meniscus can be kept constant while circulating the liquid through the inside of the head 100.

  Further, when the liquid is ejected from the nozzle 4 of the head 100, the liquid amount in the supply tank 601 and the recovery tank 602 decreases. Therefore, the liquid is replenished from the main tank 603 to the collection tank 602 by using the second liquid sending pump 605 as appropriate.

  The timing of liquid replenishment from the main tank 603 to the recovery tank 602 is set in the recovery tank 602, such as performing liquid replenishment when the liquid level in the recovery tank 602 falls below a predetermined height. It can be controlled by a detection result of a liquid level sensor or the like.

  Next, another example of a printing apparatus as an apparatus for ejecting liquid according to the present invention will be described with reference to FIGS. FIG. 13 is an explanatory plan view of a main part of the apparatus, and FIG. 14 is an explanatory side view of an essential part of the apparatus.

  The printing apparatus 500 is a serial type apparatus, and the carriage 403 reciprocates in the main scanning direction by the main scanning moving mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, and the like. The guide member 401 is bridged between the left and right side plates 491A and 491B, and movably holds the carriage 403. The carriage 403 is reciprocated in the main scanning direction by the main scanning motor 405 via a timing belt 408 spanned between the driving pulley 406 and the driven pulley 407.

  On the carriage 403, a liquid discharge unit 440 in which the liquid discharge head 100 and the head tank 441 according to the present invention are integrated is mounted. The liquid ejection head 100 of the liquid ejection unit 440 ejects, for example, liquids of each color of yellow (Y), cyan (C), magenta (M), and black (K). The liquid ejection head 100 has a nozzle row including a plurality of nozzles arranged in a sub-scanning direction orthogonal to the main scanning direction, and is mounted with the ejection direction facing downward.

  The liquid ejection head 100 is connected to the above-described liquid circulation device 600, and circulates and supplies a liquid of a required color.

  The printing apparatus 500 includes a transport mechanism 495 for transporting the sheet 410. The transport mechanism 495 includes a transport belt 412 as transport means, and a sub-scanning motor 416 for driving the transport belt 412.

  The transport belt 412 attracts the paper 410 and transports it at a position facing the liquid ejection head 100. The transport belt 412 is an endless belt, and is stretched between a transport roller 413 and a tension roller 414. Suction can be performed by electrostatic suction or air suction.

  The transport belt 412 is rotated in the sub-scanning direction by rotating the transport roller 413 via the timing belt 417 and the timing pulley 418 by the sub-scanning motor 416.

  Further, on one side of the carriage 403 in the main scanning direction, a maintenance / recovery mechanism 420 for maintaining and recovering the liquid ejection head 100 is disposed on the side of the transport belt 412.

  The maintenance and recovery mechanism 420 includes, for example, a cap member 421 for capping the nozzle surface (the surface on which the nozzle is formed) of the liquid ejection head 100, a wiper member 422 for wiping the nozzle surface, and the like.

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

  In the printing apparatus 500 configured as described above, the paper 410 is fed onto the transport belt 412 and is attracted, and the paper 410 is transported in the sub-scanning direction by the orbital movement of the transport belt 412.

Therefore, by driving the liquid ejection head 100 according to the image signal while moving the carriage 403 in the main scanning direction, the liquid is ejected to the stopped paper 410 to form an image.

  Next, another example of the liquid ejection unit according to the present invention will be described with reference to FIG. FIG. 15 is an explanatory plan view of a main part of the unit.

  The liquid discharge unit 440 includes, among members constituting the liquid discharge device, a housing portion including side plates 491A and 491B and a back plate 491C, a main scanning moving mechanism 493, a carriage 403, It is composed of a discharge head 100.

  Note that a liquid discharge unit in which the above-described maintenance and recovery mechanism 420 is further attached to, for example, the side plate 491B of the liquid discharge unit 440 may be configured.

  Next, still another example of the liquid ejection unit according to the present invention will be described with reference to FIG. FIG. 16 is an explanatory front view of the unit.

  The liquid discharge unit 440 includes the liquid discharge head 100 to which the flow path component 444 is attached, and a tube 456 connected to the flow path component 444.

  The flow path component 444 is disposed inside the cover 442. A head tank 441 may be included instead of the flow path component 444. Further, a connector 443 for making an electrical connection with the liquid ejection head 100 is provided above the flow path component 444.

  In the present application, the liquid to be discharged is not particularly limited as long as it has a viscosity and surface tension that can be discharged from the head, and the viscosity becomes 30 mPa · s or less at room temperature, under normal pressure, or by heating and cooling. Preferably, it is More specifically, solvents such as water and organic solvents, coloring agents such as dyes and pigments, functionalizing materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, and the like, solutions, suspensions, emulsions, and the like. These include, for example, ink-jet inks, surface treatment liquids, components of electronic elements and light-emitting elements, and formation of resist patterns for electronic circuits. Liquid, three-dimensional modeling material liquid, and the like.

  As the energy generation source for discharging liquid, piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators using electrothermal transducers such as heating resistors, and electrostatic actuators composed of a diaphragm and a counter electrode are used. Are included.

  The “liquid ejection unit” is a liquid ejection head in which functional components and mechanisms are integrated, and includes an assembly of components related to liquid ejection. For example, the “liquid ejection unit” includes a unit in which at least one of a configuration of a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, a main scanning movement mechanism, and a liquid circulation device is combined with a liquid ejection head.

  Here, the term “integration” means, for example, a case where the liquid ejection head and the functional component or mechanism are fixed to each other by fastening, bonding, engagement, or the like, or a case where one is movably held with respect to the other. Including. Further, the liquid ejection head, the functional component, and the mechanism may be configured to be detachable from each other.

  For example, there is a liquid discharge unit in which a liquid discharge head and a head tank are integrated. In some cases, the liquid ejection head and the head tank are integrated with each other by a tube or the like. Here, a unit including a filter can be added between the head tank and the liquid discharge head of these liquid discharge units.

  There is a liquid discharge unit in which a liquid discharge head and a carriage are integrated.

  Further, as a liquid discharge unit, there is a liquid discharge head in which a liquid ejection head is movably held by a guide member constituting a part of a scanning movement mechanism, and the liquid ejection head and the scanning movement mechanism are integrated. In some cases, a liquid discharge head, a carriage, and a main scanning moving mechanism are integrated.

  Further, as a liquid discharge unit, there is a liquid discharge head in which a cap member, which is a part of a maintenance and recovery mechanism, is fixed to a carriage to which a liquid discharge head is attached, and the liquid discharge head, the carriage, and the maintenance and recovery mechanism are integrated. .

  Further, as a liquid discharge unit, there is a liquid discharge head in which a tube is connected to a liquid discharge head to which a head tank or a flow path component is attached, and a liquid discharge head and a supply mechanism are integrated. The liquid in the liquid storage source is supplied to the liquid ejection head via this tube.

  The main scanning movement mechanism includes a guide member alone. The supply mechanism also includes a tube unit and a loading unit alone.

  The “device that discharges liquid” includes a device that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge liquid. The device that discharges liquid includes not only a device that can discharge liquid to an object to which liquid can be attached, but also a device that discharges liquid into the air or into the liquid.

  The “device for discharging liquid” may include a unit for feeding, transporting, and discharging paper to which liquid can be attached, as well as a pre-processing device and a post-processing device.

  For example, as a "device for ejecting liquid", an image forming apparatus that ejects ink to form an image on paper, and a powder is formed in layers to form a three-dimensional object (three-dimensional object) There is a three-dimensional modeling device (three-dimensional modeling device) that discharges a modeling liquid to the formed powder layer.

  Further, the “device for discharging liquid” is not limited to a device in which a significant image such as a character or a graphic is visualized by the discharged liquid. For example, those that form a pattern or the like that has no meaning in itself, and those that form a three-dimensional image are also included.

  The above-mentioned "thing to which a liquid can be attached" means a thing to which a liquid can be attached at least temporarily, such as a thing which is attached and fixed, a thing which is attached and penetrates, and the like. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth; electronic components such as electronic substrates and piezoelectric elements; powder layers (powder layers); organ models; and media such as inspection cells. Yes, unless otherwise specified, includes everything to which a liquid adheres.

  The material of the above-mentioned "thing to which the liquid can be attached" may be paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, etc. as long as the liquid can be attached even temporarily.

  In addition, the “device that discharges liquid” includes a device in which a liquid discharge head and a device to which liquid can be attached relatively move, but is not limited thereto. Specific examples include a serial device that moves the liquid ejection head, a line device that does not move the liquid ejection head, and the like.

  In addition, as the "device for discharging liquid", in addition, a processing liquid coating apparatus for discharging a processing liquid to the paper to apply the processing liquid to the surface of the paper for the purpose of modifying the surface of the paper, 2. Description of the Related Art There is an injection granulating apparatus in which a composition liquid in which a raw material is dispersed in a solution is sprayed through a nozzle to granulate fine particles of the raw material.

  Note that, in the terms of the present application, image formation, recording, printing, printing, printing, modeling, and the like are all synonyms.

DESCRIPTION OF SYMBOLS 1 Nozzle plate 4 Nozzle 2 Flow path plate 3 Vibration plate member 6 Pressure chamber 10 Common flow path 11 Piezoelectric actuator 20 Common flow path member 30 Vibration area 30a Convex part 30c Thick part 50 Common flow path 100 Liquid ejection head 403 Carriage 440 Liquid Discharge unit 500 Printing device (device for discharging liquid)
550 Head unit 600 Liquid circulation device

Claims (7)

A diaphragm member having a displaceable vibration region forming a wall surface of a pressure chamber communicating with a nozzle for discharging a liquid,
The vibration region includes a thin portion and a convex portion,
In the longitudinal direction of the pressure chamber, the thin portion forming the vibration region has a length Li on the supply side of the liquid with respect to the pressure chamber, and a length Ln on the side opposite to the supply side of the liquid with respect to the pressure chamber. A liquid discharge head, wherein Ln> Li. The liquid ejection head according to claim 1, wherein the nozzle is arranged on a side opposite to a side on which the liquid is supplied. A thick portion thicker than the thin portion is arranged around the thin portion forming the vibration region,
The liquid ejection head according to claim 1, wherein a boundary between the thin portion and the thick portion is located in the pressure chamber. A thick portion thicker than the thin portion is arranged around the thin portion forming the vibration region,
The liquid ejection head according to claim 1, wherein a boundary between the thin portion and the thick portion is located outside the pressure chamber.   A liquid discharge unit comprising the liquid discharge head according to claim 1. A head tank for storing liquid to be supplied to the liquid discharge head, a carriage on which the liquid discharge head is mounted, a supply mechanism for supplying liquid to the liquid discharge head, a maintenance and recovery mechanism for maintaining and recovering the liquid discharge head, and the liquid The liquid discharging unit according to claim 5, wherein at least one of a main scanning moving mechanism for moving the discharging head in the main scanning direction and the liquid discharging head are integrated.   An apparatus for discharging a liquid, comprising: the liquid discharge head according to claim 1; or a liquid discharge unit according to claim 5.

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