CN115107368A - Liquid ejection head and liquid ejection device - Google Patents

Abstract

The present invention provides a liquid ejection head and a liquid ejection device with high processability. The liquid ejection head according to one embodiment includes a base, a piezoelectric body, a top plate, and an orifice plate. The base is constructed of engineering ceramics. The piezoelectric body is disposed on one side in the first direction of the base, and is made of piezoelectric ceramics, and the piezoelectric body has a plurality of grooves that constitute pressure chambers. The top plate is disposed on one side of the piezoelectric body in the first direction, and is made of machinable ceramics. The orifice plate is arranged to face the end faces of the piezoelectric body and the top plate on one side in a second direction different from the first direction. The orifice plate has nozzles in communication with the pressure chambers. The end portion of the base on the orifice plate side is disposed at a position retreated from the orifice plate rather than the top plate and the end surface of the piezoelectric body.

Description

Liquid ejection head and liquid ejection device

technical field

Embodiments of the present invention relate to a liquid ejection head and a liquid ejection device.

Background technique

In a liquid ejection head such as a shear mode shared wall type ink jet head, a piezoelectric member having a plurality of grooves constituting a pressure chamber is laminated and joined to a bottom plate and a top plate that blocks one side of the grooves. For example, in an ink jet head, an orifice plate is bonded to an end surface of a laminate in which a piezoelectric member made of piezoelectric ceramics, a bottom plate, and a top plate are stacked and bonded. Since the bottom plate and the top plate constitute the joint surface to be joined to the orifice plate, it is necessary to form the same surface as that of the piezoelectric member which also constitutes the joint surface. Therefore, it is desirable that the processing characteristics of the bottom plate and the top plate be close to those of the piezoelectric component. On the other hand, if the base plate is made of piezoelectric ceramics, it is difficult to ensure necessary strength.

The technical problem to be solved by the present invention is to provide a liquid ejection head and a liquid ejection device with good workability.

SUMMARY OF THE INVENTION

The liquid ejection head according to one embodiment includes a base, a piezoelectric body, a top plate, and an orifice plate. The base is constructed of engineering ceramics. The piezoelectric body is disposed on one side of the base in the first direction, and is made of piezoelectric ceramics, and the piezoelectric body has a plurality of grooves that constitute pressure chambers. The top plate is disposed on one side of the piezoelectric body in the first direction, and is made of machinable ceramics. The orifice plate is arranged to face the end faces of the piezoelectric body and the top plate on one side in a second direction different from the first direction. The orifice plate has nozzles in communication with the pressure chambers. The end portion of the base on the orifice plate side is disposed at a position retreated from the orifice plate rather than the top plate and the end surface of the piezoelectric body.

Description of drawings

FIG. 1 is a perspective view showing a part of the ink jet head according to the first embodiment in a cutaway manner.

FIG. 2 is a cross-sectional view of the same ink jet head.

FIG. 3 is an explanatory diagram of the shape and operation of the same ink jet head.

FIG. 4 is an explanatory diagram showing a method of manufacturing the same ink jet head.

FIG. 5 is a table showing examples of machinable ceramics and thermal expansion coefficients.

FIG. 6 is an explanatory diagram showing an example of the material of the machinable ceramic and the amount of warpage.

Fig. 7 is an explanatory diagram showing the configuration of an ink jet printer according to a second embodiment using the same ink jet head.

FIG. 8 is an explanatory diagram showing a method of manufacturing an ink jet head according to another embodiment.

Description of reference numerals

1...inkjet recording device (liquid ejection device); 10...inkjet head (liquid ejection head); 20...base; 30...piezoelectric body; 33...groove; 331...first groove; 332...second 34...laminated piezoelectric element; 37...pressure chamber; 38...virtual chamber; 39...common chamber; 40...top plate; 50...cover; 60...orifice plate; 61...nozzle; 80...piezoelectric structure; 81... joint surface.

Detailed ways

Next, the configuration of the ink jet head 10 as the liquid jet head according to the first embodiment will be described with reference to Figs. 1 to 3 . Fig. 1 is a perspective view showing a part of the ink jet head according to the first embodiment in a cutaway view, and Fig. 2 is a cross-sectional view of the same ink jet head. Fig. 3 is an explanatory diagram of the shape and operation of the ink jet head. For convenience of explanation, the structures are appropriately enlarged, reduced, or omitted in each drawing and shown. In the figure, X, Y, and Z represent three directions that are orthogonal to each other. For example, the Z axis is along the first direction, the Y axis is along the second direction, and the X axis is along the third direction.

The inkjet head 10 of the present embodiment is, for example, a so-called shear mode shared wall type inkjet head.

As shown in FIGS. 1 to 3 , the ink jet head 10 includes a base 20 , a piezoelectric body 30 , a top plate 40 , a cover 50 , and an orifice plate 60 .

The base 20 is formed in, for example, a rectangular plate shape. The piezoelectric body 30 is arranged on one main surface in the first direction, which is the lamination direction of the susceptor 20 . In addition, a wiring pattern is formed in a predetermined region of one main surface of the base 20. As shown in FIG. As an example, the piezoelectric body 30 is arranged in the region 21 on one side of the one main surface, and the wiring pattern is formed in the region 22 on the other side. On the upper surface of the base 20, the driver circuit is connected to the wiring pattern through FPC or the like. The ink port 23 is formed at a predetermined position of the base 20, and can allow the ink to flow therethrough. The ink port 23 is a through hole penetrating the susceptor 20 in the thickness direction along the first direction, and serves as an inflow port for flowing ink into the common chamber 39 or a discharge port for discharging ink from the common chamber 39 .

As an example, the size of the susceptor 20 in the longitudinal direction along the arrangement direction of the nozzles 61 is larger than that of the piezoelectric body 30 . On the main surface of the base 20 on one side in the stacking direction, the piezoelectric body 30 is arranged and bonded to the region on the one side of the second direction perpendicular to the stacking direction in which the nozzles 61 are arranged. On the end face 24 on one side in the second direction of the susceptor 20 , the position where the piezoelectric bodies 30 are not arranged at both ends in the third direction, which is the nozzle arrangement direction, and the central portion in the third direction where the piezoelectric bodies 30 are arranged In contrast, it protrudes to one side in the second direction. That is, in the end face 24 on the one side in the second direction of the base 20, a predetermined area in the center including at least the portion where the piezoelectric body 30 is arranged is retracted more toward the other side in the second direction than the both ends. In addition, the end face 24 on the one side in the second direction is in a predetermined area in the center including at least the portion where the piezoelectric bodies 30 are stacked and arranged, compared with the end faces of the piezoelectric bodies 30 and the top plate 40 on the one side in the second direction. , and retreat to the other side of the second direction. It should be noted that the end surfaces of both end portions of the base 20 may be arranged on the same surface as the piezoelectric body 30 and the top plate 40.

The base 20 is made of engineering ceramic. The base 20 is composed of a material that is harder and more rigid than the piezoelectric member constituting the piezoelectric body 30 . For example, the thermal expansion coefficient of the engineering ceramic constituting the susceptor 20 is larger than that of the piezoelectric material constituting the piezoelectric body 30 . As the engineering ceramics constituting the susceptor 20, for example, alumina, zirconia, mullite, cordierite, forsterite, talc and the like are used. The coefficient of thermal expansion can be obtained in accordance with JISR1618 (“Method for measuring thermal expansion of fine ceramics by thermomechanical analysis”.

The piezoelectric body 30 is disposed on one side of the base 20, and is bonded to the base 20 via an adhesive layer. In the piezoelectric body 30, two piezoelectric members 31 and 32 having opposite polarization directions in the stacking direction are stacked, and are bonded to each other by an adhesive material layer. For example, as the adhesive, a thermal adhesive cured by heat bonding is used. The piezoelectric body 30 is formed into a predetermined shape and size by, for example, cutting, and is formed into a rectangular plate shape that is long in the third direction in which the nozzles 61 are arranged. The cross-sectional shape of the piezoelectric body 30 orthogonal to the third direction is formed into a trapezoid. One end face of the piezoelectric body 30 in the second direction constitutes a joint surface opposite to the orifice plate 60 , and the side face opposite to the joint face, that is, the other end face in the second direction constitutes a joint face opposite to the groove 33 . The extension direction of , that is, the tapered surface inclined in the second direction. That is, one side surface of the piezoelectric body 30 has a tapered surface from the bottom surface of the groove 33 to the main surface of the base 20 . As the piezoelectric material constituting the piezoelectric body 30 , for example, a piezoelectric ceramic material such as PZT (lead zirconate titanate) type or lead-free KNN (potassium sodium niobate) type is used.

The piezoelectric body 30 has a plurality of grooves 33 . The grooves 33 extend along the second direction of the piezoelectric body 30, and a plurality of grooves 33 are arranged side by side in the third direction. Each of the grooves 33 has an elongated shape whose longitudinal direction is along the second direction. The groove 33 is a bottomed slit opened on the one end side in the second direction where the orifice plate 60 is arranged and on the side in the first direction where the top plate 40 is arranged. A plurality of grooves 33 arranged in the third direction are formed in parallel with each other.

The plurality of grooves 33 are constituted by alternately arranged first grooves 331 and second grooves 332 . The first groove 331 constitutes the pressure chamber 37 that communicates with the nozzle 61 and the common chamber 39 . The second slot 332 constitutes an enclosed virtual chamber 38 .

The wall-shaped portion of the piezoelectric body 30 formed between the adjacent grooves 33 constitutes the laminated piezoelectric element 34 serving as the driving portion of the pressure generating unit. In the first direction, a plurality of laminated piezoelectric elements 34 and a plurality of grooves 33 are alternately arranged in the piezoelectric body 30 . The plurality of laminated piezoelectric elements 34 are continuous with each other through the piezoelectric member 32 constituting the bottom of the groove 33 . Each laminated piezoelectric element 34 is formed by laminating a pair of piezoelectric element portions 341 and 342 having opposite polarization directions in the lamination direction.

Electrodes 36 are formed on the inner surface and the inclined surface portion of the pressure chamber 37 constituted by the respective grooves 33 of the piezoelectric body 30 . The electrode 36 is led out from the inner surface of the groove 33 through the inclined surface portion, and is connected to the wiring pattern on the upper surface of the base 20 .

The electrode 36 is formed by, for example, a vacuum deposition method, an electroless nickel plating method, or the like. The electrodes 36 can be formed, for example, simultaneously with the wiring pattern by a method such as vacuum evaporation, electroless plating, or the like. The material of the electrode 36 is formed of a conductive material such as nickel, gold, and copper. The electrode 36 may be formed by laminating two or more types of conductive films.

The top plate 40 is formed of, for example, a square plate-like member. The top plate 40 is arranged to face the surface of the piezoelectric body 30 on one side in the stacking direction, and blocks the opening on one side of the groove 33 . The top plate 40 is made of machinable ceramic.

As will be described later, the end surface of the top plate 40 on the orifice plate 60 side and the end surface of the piezoelectric body 30 on the orifice plate 60 side are simultaneously cut and polished to form the same surface. The top plate 40 and the piezoelectric body 30 protrude toward the side of the orifice plate 60, that is, the side in the second direction, than the base 20. In other words, the susceptor 20 is retracted to the other side in the second direction so as to be farther away from the orifice plate 60 than the piezoelectric structure 80 in which the top plate 40 and the piezoelectric body 30 are stacked. That is, in the ink jet head 10, the end surface of the base 20 is arranged at a position on the other side of the second direction than the end surfaces of the piezoelectric body 30 and the top plate 40. In addition, the end surface of the base 20 may or may not be orthogonal to the bottom surface of the base 20, and may or may not be parallel to the joint surface 81 formed by the piezoelectric body 30 and the top plate 40. For example, the end face of the base 20 may also be inclined or curved.

FIG. 5 is a table showing thermal expansion coefficients of main machinable ceramics. The thermal expansion coefficient can be obtained according to JISR1618 (“Thermal-mechanical analysis and measurement method of thermal expansion of fine ceramics”. As shown in Fig. 5, Macerite HSP is 9.8×10 ^-6 /K, Macor is 9.3×10 ^-6 /K, Macerite SP is 9.2 × 10 ^-6 /K, Photoveel is 7.8 × 10 ^-6 /K, Photoveel L is 6.1 × 10 ^-6 /K, Macerite ET is 5.8 × 10 ^-6 /K, Macerite BT is 4.5 × 10 ^-6 /K, Macerite PN is 4.2×10 ^-6 /K. "Macerite" is a registered trademark of Krosaki Harima Corporation of Fukuoka, Japan for a machinable ceramic product, including fluorine-containing phlogopite. "Macor" is New York, USA A registered trademark of a machinable ceramic product of State Corning Corporation, which is a glass ceramic. "Photoveel" is a registered trademark of a machinable ceramic product of Ferrotec Holdings Corporation, Tokyo, Japan, and is a A glass composite in which fluorphlogopite and zirconia crystallites are uniformly precipitated.

For example, in the present embodiment, the top plate 40 is made of a material having a thermal expansion coefficient between 4 and 10×10 ⁻⁶ /K. Specifically, as the machinable ceramics constituting the top plate 40, Macerite, Macor, or Photoveel is used.

The top plate 40 is overlapped and bonded to the piezoelectric body 30 bonded to the base 20 . More preferably, as the material constituting the top plate 40 , machinable ceramics whose thermal expansion coefficient is a value between the thermal expansion coefficient of the engineering ceramics constituting the susceptor 20 and the thermal expansion coefficient of piezoelectric ceramics are used. For example, when the piezoelectric body 30 is made of PZT and the susceptor 20 is made of alumina, a thermal expansion coefficient of 2×10 ⁻⁶ /K or more and 7.2×10 ⁻⁶ /K or less is selected.

FIG. 6 shows that the piezoelectric body 30 is made of PZT, the base 20 is made of alumina, and the material of the top plate 40 is made of three types of PZT and two types of Macerite (ET, SP) with different thermal expansion coefficients. A table showing the amount of warpage of the assembly thermally bonded to the piezoelectric body 30 at a temperature of about 120°C. As shown in Fig. 6, the thermal expansion coefficient of alumina is 7.2 × 10 ^-6 /K, the thermal expansion coefficient of PZT is 2 × 10 ^-6 /K, the thermal expansion coefficient of Macerite SP is 9.2 × 10 ^-6 /K, and the thermal expansion coefficient of Macerite ET is 9.2 × 10 -6 /K. The coefficient of thermal expansion was 5.8×10 ⁻⁶ /K. When the top plate 40 is made of Macerite ET, the warpage amount is smaller than that of PZT and Macerite SP. Since the amount of warpage differs depending on the materials of the piezoelectric body 30 and the base 20 , the material of the top plate 40 is appropriately selected, for example, a material that reduces the warpage of the assembly may be selected.

The cover 50 is integrally provided with a rectangular cover plate 51 disposed opposite to one side in the stacking direction of the top plate 40, and a cover frame 52 extending from a side edge of the cover plate 51 toward the base 20. The cover plate 51 of the cover 50 is disposed on the top plate 40, and the end of the cover frame 52 is joined to one side of the base 20. The cover 50 covers a predetermined area of the base 20 on which the piezoelectric body 30 is disposed, and forms a common chamber 39 on the side of the piezoelectric body 30 . The common chamber 39 communicates with the ink port 23 formed in the susceptor 20 and the plurality of pressure chambers 37 of the piezoelectric body 30.

The orifice plate 60 is configured in a square plate shape with a thickness of about 10 μm to 100 μm. The orifice plate 60 is bonded to the bonding surface, which is one side surface of the laminated structure composed of the piezoelectric body 30 and the top plate 40 . The orifice plate 60 is formed with a plurality of nozzles 61 penetrating in the thickness direction. The nozzles 61 are provided at positions corresponding to the plurality of pressure chambers 37 arranged every other. That is, the orifice plate 60 has the nozzles 61 communicating with the pressure chamber 37 and blocks the side opening of the dummy chamber 38 .

It should be noted that a predetermined gap is formed between the orifice plate 60 and the end surface of the base 20 .

FIG. 4 is an explanatory diagram showing a method of manufacturing the ink jet head 10 . Here, as an example, an example in which the two piezoelectric structures 80 constituting the two ink jet heads 10 are integrated and then divided into two parts is shown. The manufacturing method of the ink jet head 10 according to the present embodiment includes piezoelectric body formation processing, bonding processing, trapezoidal processing processing, groove processing processing, electrode processing processing, and top plate bonding processing.

First, two plate-shaped piezoelectric members polarized in the plate thickness direction in advance are laminated so that the polarization directions are different from each other, and the laminated body is cut into desired widths and lengths to form two piezoelectric bodies 30 - Piezoelectric body part 300 which is integrally continuous (piezoelectric body forming process).

As the piezoelectric body bonding process, the piezoelectric body portion 300 is adhered to the base portion 200 (Act11), which is a plate-shaped member in which the two bases 20 are continuous, without gaps, using an adhesive or the like. In addition, in the base portion 200, two plate-shaped bases 20 are connected to both ends in the third direction, and a slit extending in the third direction and penetrating in the thickness direction is formed in the center portion of the third direction. Sew 201. The slit 201 has a width twice as large as the width of the step in the width direction, which is the second direction, and forms a step with the piezoelectric body 30 when it is divided into two bases 20 in a subsequent dividing step.

Next, as a trapezoidal processing process, the base portion 200 is processed into a trapezoidal shape to lead out the electrode 36 (Act12). In addition, as groove processing, a plurality of grooves 33 are formed on the surface of the base portion 200 including the piezoelectric body portion 300 by machining using a dicing saw, a scraper, or the like (Act 13 ).

Further, as an electrode processing treatment, conductive films such as electrodes 36 and wiring patterns are formed by a vacuum deposition method or the like (Act 13). After the electrodes are formed by plating, unnecessary electrodes are removed by etching, laser patterning, and desired electrode wirings connecting the pressure chamber and the end of the susceptor are formed.

Next, as a top plate bonding process, the upper surface of the piezoelectric body portion 300 is covered with the top plate portion 400 in which the two top plates 40 are integrally continuous and thermally bonded through an adhesive layer (Act 14).

After that, as a division process, the piezoelectric structure part 800 formed by laminating and bonding the base part 200 , the piezoelectric body part 300 and the top plate part 400 is divided into two parts by a cutting process, thereby completing the two piezoelectric structures 80 (Act15). In addition, the cut surface at the time of division becomes the nozzle joint surface 81 . The nozzle engaging surface 81 forms a right angle or a substantially right angle with the bottom surface of the base 20 as a reference. When the right angle achieved by only cutting is insufficient or the surface roughness is large, the cut surface may be further ground (Act16).

Each of the piezoelectric structures 80 configured as described above has a joint surface 81 formed by the top plate 40 and the end face of the piezoelectric body 30 . In the piezoelectric structure 80 , the end surface 24 of the base 20 is disposed at a position farther from the position where the orifice plate 60 is disposed in the second direction than the joint surface 81 formed by the top plate 40 and the side surface of the piezoelectric body 30 . . In other words, the bonding surface 81 to which the orifice plate 60 is bonded is formed by the side surfaces of the top plate 40 and the piezoelectric body 30, and does not include the surface of the base 20.

Then, the mounting hole plate 60 is bonded to the side surfaces of the top plate 40 and the piezoelectric body 30 . At this time, the nozzle 61 is arranged to face the first groove 331 constituting the pressure chamber 37, and the second groove 332 constituting the dummy chamber 38 is blocked.

In addition, the lid 50 is covered from one side of the piezoelectric structure 80, and the end face of the lid frame 52 of the lid 50 is attached to the surface of the base 20 by bonding. In the above manner, the ink jet head 10 shown in FIG. 1 is completed.

In the ink jet head 10 configured as described above, the pressure chamber is temporarily opened from the stationary state to allow ink to flow in, and then the pressure chamber is reduced to pressurize the ink and discharge it. Specifically, as shown in FIG. 3 , when the driving of the ejection of the material from the nozzle 61 is performed, a driving voltage is applied to the driving element via the wiring pattern formed on the base 20 by the driving circuit, thereby driving the pressure chamber 37 to be driven. The electrode 36 and the electrodes 36 of the two adjacent virtual chambers 38 impart a potential difference. Then, the pair of piezoelectric element portions 341, 342 of the laminated piezoelectric element 34 are deformed in opposite directions to each other, and by the deformation of the two piezoelectric elements, the driving element is bent and deformed. As an example, first, by deforming the driven pressure chamber 37 in the opening direction, the pressure inside the pressure chamber 37 becomes a negative pressure, and the ink is guided into the pressure chamber 37 (ink flows in). Next, by deforming the pressure chamber 37 in the closing direction to pressurize the pressure chamber 37 (ink pressurization), the ink droplet is ejected from the nozzle 61 and returned to the reference potential (the ink column is cut off).

According to the present embodiment, the inkjet head 10 with good workability can be provided. Since the wall of the pressure chamber, which is the joint surface of the orifice plate 60 having the nozzles 61, is composed of machinable ceramics and piezoelectric material, it can be easily processed, and the joint surface to which the orifice plate 60 is joined can be made the same surface by machining. That is, since the joining surface is constituted by the piezoelectric body 30 and the top plate 40 having the same processing characteristics, the processing conditions become easy, and the orifice plate 60 can be joined without omission. In addition, by making the material of the base 20 a lead-free material, the ink jet head 10 suitable for the environment can be provided.

For example, among the three materials used in this embodiment, since alumina is very hard and the machining conditions are different, if simultaneous machining is performed, the machined surface will become rough, or there will be problems such as many chips and burrs, which is difficult to carry out. processing. For example, for materials with different workability, a level difference is likely to occur during processing. That is, the soft material may be detached from the tool via the adhesive layer and recovered after machining, causing the layer of the soft material to protrude, or the soft material may be processed more, and the layer of the hard material may protrude. For example, even when a polishing process is performed, a level difference occurs due to a difference in the amount of polishing in the polishing process, and it is difficult to eliminate the level difference. From this, it can be seen that if a step is formed in the joint surface to be joined to the orifice plate 60, a gap is likely to be generated when the orifice plate 60 is joined. On the other hand, in the present embodiment, by using materials with similar processing characteristics for the top plate 40 and the piezoelectric body 30, and forming the joint surface by using these parts, it is difficult to generate a large level difference in the joint surface, and the joint surface can be formed without gaps. The orifice plate 60 is engaged. In addition, by withdrawing the end surface 24 of the base 20 from the joint surface 81, the restriction on material selection related to the workability of the base 20 can be eliminated, and the material selection of the base 20 can easily ensure the strength, so it is possible to achieve Thinning and miniaturization of the inkjet head 10 .

In addition, in the above-described embodiment, for example, by using machinable ceramics and selecting the thermal expansion coefficient between 4 and 10×10 ⁻⁶ /K, warpage and deformation after joining can be prevented. Therefore, even if a thermosetting adhesive is used, warpage and deformation after joining can be prevented, and it is easy to fix at the time of the cutting process, so that it is easy to process.

Furthermore, in the above-described embodiment, by appropriately selecting the thermal expansion coefficient of the machinable ceramics so as to minimize the warpage of the assembly, it is possible to enable adsorption to the device during machining and the like, and to achieve workability higher structure. For example, by selecting the material of the top plate 40 as a material between the thermal expansion coefficient of the piezoelectric body 30 and the thermal expansion coefficient of the base 20, the warpage of the assembly can be reduced.

In addition, for example, in the manufacturing process, in the method of forming a step on the base after bonding, if there is a lot of warpage, in order to cut off the alumina, a large amount of PZT is cut corresponding to the amount of warpage, which leads to holes. The joint surface of the plate is reduced, but in the above-mentioned embodiment, by setting the structure with a small warpage, the cutting amount of the PZT is reduced, and the joint surface of the orifice plate can be easily secured.

[Second Embodiment]

Next, the ink jet printer 100 as the liquid ejecting device will be described with reference to FIG. 7 . The inkjet printer 100 is a printer using the inkjet head 10 according to the first embodiment.

The inkjet printer 100 is an apparatus that performs various processes such as image formation while conveying, for example, paper P, which is a printing medium, along a predetermined conveying path. The inkjet recording apparatus 1 includes a casing 110, a paper feed cassette 111 as a paper supply portion, a paper discharge tray 112 as a discharge portion, a holding roller (drum) 113 as a support portion, a conveying device 114, and a reversing device 118.

The casing 110 constitutes the outer profile of the inkjet printer 100 . The paper feed cassette 111 is provided inside the casing 110. The paper discharge tray 112 is disposed on the upper part of the casing 110 . The holding roller (drum) 113 rotates while holding the sheet P on the outer surface. The conveying device 114 conveys the sheet P along a predetermined conveying path A formed from the sheet feeding cassette 111 through the outer periphery of the holding roller 113 to the sheet discharge tray 112. The inversion device 118 inverts the front and back surfaces of the paper P peeled from the holding roller 113 and feeds it onto the surface of the holding roller 113 again.

The conveyance device 114 includes a plurality of guide members 121 to 125 provided along the conveyance path A, and a plurality of conveyance rollers 126 to 131 . As the conveying rollers, a pickup roller, a pair of paper feed rollers, a pair of registration rollers, a pair of separation rollers, a pair of conveying rollers, and a pair of discharge rollers are provided. These conveying rollers 126 to 131 are driven and rotated by the conveying motor, so that the sheet P is conveyed to the downstream side along the conveying path A. As shown in FIG.

Sensors S etc. for monitoring the conveyance state of a sheet are arranged in various places of the conveyance path A. As shown in FIG.

The holding roller 113 conveys the paper P by rotating while holding the paper P on the surface thereof. The holding roller 113 supports the paper P, which is a printing medium, at a position facing the inkjet head 10 . Here, the holding roller 113 conveys the sheet P in the clockwise direction along the outer peripheral direction by rotating clockwise in Fig. 7 .

A holding device 115, an image forming device 116, a static elimination peeling device 117, and a cleaning device 119 are provided in this order from the upstream side toward the downstream side on the outer peripheral portion of the holding roller 113.

The holding device 115 includes a pressing roller 115a and a charging roller 115b. The pressing roller 115a is pressed against the outer surface of the holding roller 113. The charging roller 115b generates electrostatic force (charging) in a direction in which the sheet P is attracted to the outer surface of the holding roller 113 by being supplied with electric power. The sheet P is attracted to the holding roller 113 by this electrostatic force.

The image forming apparatus 116 includes four inkjet heads 10 corresponding to four colors of cyan, magenta, yellow, and black, respectively, as a plurality of (four colors) inkjet heads 10 arranged to face the outer surface of the holding roller 113. The four inkjet heads 10 eject ink onto the paper P from nozzles 61 provided at predetermined pitches, and form an image on the paper P held on the outer surface of the holding roller 113. As each ink jet head 10, the ink jet head 10 described in the first embodiment is used.

The static-removing peeling device 117 includes a static-removing roller for removing static electricity from the paper P, and a peeling claw for peeling the paper P from the holding roller 113 .

The cleaning device 119 includes a cleaning member that rotates while being in contact with the holding roller 113, thereby cleaning the holding roller 113.

The inversion device 118 inverts the sheet P peeled from the holding roller 113 and feeds the sheet P onto the surface of the holding roller 113 again. The reversing device 118 guides and conveys the paper P along a predetermined reversing path that reverses the paper P in the front-rear direction, for example, and turns the paper P over.

In addition, the inkjet printer 100 includes a CPU (Central Control Unit) as a controller, a ROM that stores various programs and the like, a RAM that temporarily stores various variable data, image data, and the like, and externally input or output data. I/F (interface).

For example, when the user instructs the printer to print, the CPU of the inkjet printer 100 outputs a print signal to the drive circuit of the inkjet head 10. Thereby, the ink jet head 10 is driven to form an image on the sheet P. As shown in FIG.

Also in the ink jet printer 100 configured as above, the same effects as those of the first embodiment described above can be obtained.

It should be noted that the present invention is not limited to the above-described embodiments as they are, and can be implemented by modifying constituent elements in an implementation stage without departing from the gist of the present invention.

For example, in the above-described embodiment, as a method of manufacturing the ink jet head 10, an example in which slits constituting a level difference are formed in advance in the base portion 200 is shown, but the present invention is not limited to this. For example, as shown in FIG. 8 , the base portion 200 may be formed in a continuous plate shape over the entire length without preliminarily having a slit. In this case, after the piezoelectric body portion 300 is pasted on the surface side of the center portion in the second direction of the base portion 200 , the base portion 200 is ground from the back side of the base portion 200 to a predetermined depth with a predetermined width, and the base is cut by cutting The portion 200 and a part of the piezoelectric body portion 300 are formed with grooves 83 having a depth greater than or equal to the thickness of the base portion 200 . Then, the piezoelectric structure portion 800 is cut into two at the line C passing through the center in the width direction of the groove 83 to form two piezoelectric structures having a level difference in which the end surface 24 of the base 20 is retracted from the joint surface 81 . Structure 80.

For example, the specific configuration of the inkjet head 10 , the shape of the flow path, the configuration and positional relationship of various components including the base 20 , the piezoelectric body 30 , the top plate 40 , the cover 50 , and the orifice plate 60 are not limited to the above-mentioned examples. , can be changed appropriately. In addition, the arrangement of the nozzles 61 and the pressure chambers 37 is not limited to the above. For example, two or more rows of nozzles 61 may be arranged. In addition, two or more dummy chambers 38 may be arranged between the plurality of pressure chambers 37.

For example, the liquid to be ejected is not limited to the ink for printing, and may be, for example, a device or the like that ejects a liquid containing conductive particles for forming a wiring pattern of a printed wiring board.

In addition, in the above-described embodiment, the inkjet head 10 is used for the liquid ejection device such as the inkjet recording device 1, but it is not limited to this, for example, it can also be used in a 3D printer, an industrial manufacturing machine, and a medical device. It is possible to achieve small size, light weight and cost reduction.

According to at least one of the embodiments described above, it is possible to provide a liquid ejection head and a liquid ejection device with good workability.

Further, although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments or modifications thereof are included in the scope and spirit of the invention, and are included in the invention described in the claims and the scope of equivalents thereof.

Claims (10)

1. A liquid ejection head includes:

a base composed of engineering ceramics;

a piezoelectric body which is arranged on one side of the base in the first direction and is made of a piezoelectric ceramic, the piezoelectric body having a plurality of grooves that constitute pressure chambers;

a top plate which is arranged on one side of the piezoelectric body in the first direction and is made of machinable ceramics; and

an orifice plate that is disposed so as to face end surfaces of the piezoelectric body and the top plate on one side in a second direction different from the first direction, and that has a nozzle that communicates with the pressure chamber,

the end portion of the base on the aperture plate side is disposed at a position retreated from the aperture plate than the end surfaces of the top plate and the piezoelectric body.

2. A liquid ejection head according to claim 1,

the thermal expansion rate of the machinable ceramic is a value between the thermal expansion rate of the engineered ceramic and the thermal expansion rate of the piezoelectric ceramic.

3. A liquid ejection head according to claim 1 or 2,

the piezoelectric body contains at least one of lead zirconate titanate and potassium sodium niobate,

the machinable ceramic comprises a thermal expansion coefficient of 4 x 10 ^－6 /K～10×10 ^－6 A material in the range of/K,

the engineering ceramic comprises at least any one of alumina, zirconia, mullite, cordierite, forsterite and talc.

4. A liquid ejection head according to claim 1,

the plurality of grooves are formed by alternately arranging first grooves and second grooves.

5. A liquid ejection head according to claim 4,

a common chamber is formed on a side of the piezoelectric body,

the first groove constitutes the pressure chamber communicating with the nozzle and the common chamber, and the second groove constitutes a closed dummy chamber.

6. A liquid ejection head according to claim 5,

the nozzle is disposed opposite to the first groove constituting the pressure chamber.

7. A liquid ejection head according to claim 1,

the wall-shaped portions of the piezoelectric body formed between the adjacent grooves constitute a laminated piezoelectric element serving as a driving section of the pressure generating unit.

8. A liquid ejection head according to claim 7,

the laminated piezoelectric element is formed by laminating a pair of piezoelectric element sections having opposite polarization directions in a lamination direction.

9. A liquid ejection head according to claim 1,

the thickness of the porous plate is 10-100 μm.

10. A liquid ejecting apparatus includes:

a liquid ejection head according to any one of claims 1 to 9; and

and a support portion that supports the printing medium at a position facing the liquid ejection head.

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