JP2010208036A - Liquid ejection head, head cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid ejection head, an ink cartridge and an image forming apparatus that can fulfill high density, high quality, high definition and cost reduction. <P>SOLUTION: The liquid ejection head has a nozzle substrate having nozzles for ejecting liquid; a liquid chamber unit provided with a liquid chamber for storing liquid, with which each nozzle communicates; a vibrating plate forming at least part of the wall surface of the liquid chamber; and a driving means for generating pressure for pressurizing the liquid in the liquid chamber. In the liquid ejection head, the liquid chamber unit is formed by laminating a first liquid chamber substrate formed by machining, and a flat second liquid chamber substrate having the same composition as the first liquid chamber substrate and formed by processing different from machining. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid discharge head, an ink cartridge, and an image forming apparatus, and more particularly, to a liquid discharge head that discharges liquid from a nozzle by displacing a diaphragm by a driving unit such as a piezoelectric element.

  An ink jet recording apparatus used as an image forming apparatus such as a printer, a facsimile machine, a copying apparatus, or a plotter has a nozzle that discharges droplets, a pressure chamber, a pressurized liquid chamber, a liquid chamber, an ink chamber, and a flow path that communicate with the nozzle. And the like, and an actuator means for generating energy to pressurize the liquid in the discharge chamber, and the actuator means is driven to pressurize the liquid in the discharge chamber and discharge droplets from the nozzles. Ink-on-demand systems, which eject droplets only when recording is necessary, are the mainstream.

  By the way, due to the demand for higher recording speed and higher recording density, a multi-nozzle head having a plurality of nozzles is used, and the required droplet size tends to be further reduced. Therefore, the liquid chamber tends to be made smaller. In order to make the nozzle pitch fine, it is necessary not only to shorten the width direction but also to shorten the length direction of the liquid chamber. This is because small droplets are ejected by increasing the pressure resonance frequency of the liquid chamber.

  Even if the liquid chamber is made small, it is necessary that the drive energy by the actuator element is sufficiently transmitted to the liquid chamber and that the drive energy is not transmitted to the partition walls separating the plurality of liquid chambers. Moreover, it is necessary to make the characteristics of droplets discharged from each nozzle uniform, and there is no difference in the volume and fluid resistance of liquid chambers such as pressure chambers, pressurized liquid chambers, discharge chambers, and ink chambers between heads. Therefore, high-precision machining and high-precision joining are essential.

  Therefore, according to Patent Document 1 as a conventional example, the liquid chamber and the diaphragm are processed and formed at the same time, so that it is not necessary to perform high-precision alignment for joining the liquid chamber and the diaphragm. It is difficult for etching processing to secure a liquid chamber with high accuracy. Pressing is used as a processing method for forming a liquid chamber in a highly accurate dimension. However, in press working, although it is possible to form a liquid chamber having a fine and highly accurate dimension, deformation in the thickness direction of the component becomes a problem. Regarding the dimensional variation in the thickness direction of such a component, Patent Document 2 describes that high-precision bonding is realized by processing a driving element having a variation in the thickness direction with high flatness.

  However, if it is a drive element like the said patent document 2, it is possible to cut an unnecessary part and process it to high flatness, but in the case of deformation | transformation of a liquid chamber board | substrate, the shape (thickness) of a liquid chamber is carried out by plane processing. The liquid chamber shape cannot be formed with high accuracy. Therefore, it is formed with high-density and high-accuracy dimensions, and even if there is deformation variation in the thickness direction, there is no variation between the liquid chambers, and the drive energy can be efficiently transmitted to the liquid. Joining is required.

  The present invention is to solve these problems, and provides a liquid discharge head, an ink cartridge, and an image forming apparatus that can satisfy high density, high quality, high image quality, and low cost. For the purpose.

  In order to solve the above problems, a liquid discharge head according to the present invention includes a nozzle substrate having a nozzle for discharging a liquid, a liquid chamber unit provided with a liquid chamber for storing a liquid communicated with each nozzle, and a liquid chamber. And a driving means for generating a pressure to pressurize the liquid in the liquid chamber. In the liquid discharge head according to the present invention, the liquid chamber unit includes a first liquid chamber substrate formed by a machining process, the same composition as the first liquid chamber substrate, and the machining process. It is characterized by being formed by laminating a flat second liquid chamber substrate formed by different processing. Therefore, the deformation of the first liquid chamber substrate is corrected to the second liquid chamber substrate side, and the other surface different from the bonding surface of the second liquid chamber substrate bonded to the first liquid chamber substrate is bonded. Since it is flat afterwards, uniform bonding is possible. Moreover, since the loss of energy given to the liquid chamber by the driving means can be prevented by the high-rigidity second liquid chamber substrate, a high-density liquid discharge head capable of realizing high quality and high reliability can be achieved. Can be provided. Further, since the first and second liquid chamber substrates are members having the same composition, the linear expansion coefficients are the same, and the warp due to the thermosetting temperature of the adhesive is eliminated. Further, since the hydrophilicity of the flow path member is the same in the liquid chamber unit, it is not difficult for bubbles to be easily removed due to a difference in the member (difference in hydrophilicity).

  In addition, since the area where the liquid chamber of the second liquid chamber substrate is processed is equal to or smaller than the area where the liquid chamber of the first liquid chamber substrate is processed, a highly reliable liquid ejection head with high rigidity is maintained. Can be provided.

  Further, the second liquid chamber substrate is bonded between the first liquid chamber substrate and the diaphragm. In addition, the second liquid chamber substrate is bonded between the first liquid chamber substrate and the nozzle substrate. Further, the second liquid chamber substrate is bonded between the first liquid chamber substrate and the nozzle substrate, and between the first liquid chamber substrate and the vibration plate. Therefore, it is possible to provide a highly reliable liquid ejection head that maintains high rigidity.

  In addition, by bonding a plurality of second liquid chamber substrates, it is possible to provide a highly reliable liquid discharge head that is further highly rigid.

  Furthermore, since the second liquid chamber substrate is formed by etching or laser processing, the processing surface is tapered, so that the flow of the adhesive is prevented from reaching the diaphragm portion of the diaphragm. Liquid discharge head can be provided.

  In addition, since the machining process for forming the first liquid chamber substrate is a press process, a liquid discharge head capable of forming a low-cost and high-accuracy liquid chamber and satisfying high image quality and low cost is provided. Can be provided.

  Furthermore, a head cartridge as another invention is characterized in that the above-described liquid discharge head is mounted. Therefore, it is possible to provide an ink cartridge that can satisfy high density, high quality, high image quality, and low cost.

  An image forming apparatus as another invention is characterized in that the above-described liquid discharge head is mounted. Therefore, an image forming apparatus that can satisfy high density, high quality, high image quality, and low cost can be provided.

  The liquid chamber unit in the liquid discharge head according to the present invention includes a first liquid chamber substrate formed by machining processing, and a processing process having the same composition as the first liquid chamber substrate and different from the machining processing. And a flat second liquid chamber substrate formed in (1). Therefore, high rigidity is maintained, and high density, high quality, high image quality, and low cost can be satisfied.

1 is a cross-sectional view illustrating a configuration of a liquid discharge head according to a first embodiment of the present invention. 1 is a cross-sectional view illustrating a configuration of a liquid discharge head according to a first embodiment of the present invention. 1 is a cross-sectional view illustrating a configuration of a liquid discharge head according to a first embodiment of the present invention. 1 is a cross-sectional view illustrating a configuration of a liquid discharge head according to a first embodiment of the present invention. It is sectional drawing which shows the structure of the liquid discharge head using the drive part of d31 piezoelectric direction. It is a figure which shows the liquid chamber board | substrate which formed the liquid chamber by the machining process. It is a figure which shows the prior art example which joined the liquid chamber board | substrate and diaphragm which performed the machining process. It is sectional drawing which shows the mode of the deformed diaphragm. 1 is a diagram illustrating a configuration of a liquid discharge head according to a first embodiment of the present invention. It is a figure which shows the structure of the liquid discharge head which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the liquid discharge head which concerns on the 3rd Embodiment of this invention. It is a figure which shows an example of another liquid chamber board | substrate formed by the etching process. It is a figure which shows another structure of the liquid discharge head of 1st Embodiment. It is a figure which shows another structure of the liquid discharge head of 1st Embodiment. It is a figure which shows another structure of the liquid discharge head of 1st Embodiment. It is a figure which shows another structure of the liquid discharge head of 2nd Embodiment. It is a figure which shows another structure of the liquid discharge head of 2nd Embodiment. It is a figure which shows another structure of the liquid discharge head of 3rd Embodiment. It is a side view which shows the whole structure of the image forming apparatus which concerns on another invention. It is a top view which shows the principal part structure of the image forming apparatus which concerns on another invention.

  1 to 4 are cross-sectional views showing the entire configuration of the liquid discharge head according to the first embodiment of the present invention. FIG. 1 is a cross-sectional view along the longitudinal direction of the liquid chamber, that is, the direction intersecting the nozzle arrangement direction. 2 and 3 are cross-sectional views along the minor axis direction of the liquid chamber, that is, along the nozzle arrangement direction. Note that the liquid to be ejected may not be ink. In addition, although the description will be made centering on the flat surface here, the surface of the member may have a plurality of irregularities.

  The liquid chamber substrate forming the liquid chamber 11 and the fluid resistance portion 12 of the liquid discharge head shown in FIGS. 1 and 2 is processed by processing different from the first liquid chamber substrate 10 formed by machining processing. The flat second liquid chamber substrate 70 is formed of two members. Further, a nozzle plate 20 that forms a nozzle 21 that discharges droplets bonded to the upper surface of the liquid chamber substrate 10, a vibration plate 30 that is bonded to the lower surface of the liquid chamber substrate 70 and has a diaphragm portion 31, and this vibration A laminated piezoelectric element 40 that is bonded to the plate 30 and is a pressure changing means that changes the pressure in the liquid chamber 11 and a base substrate 50 that fixes the laminated piezoelectric element 40 are provided. Each member is joined through an adhesive layer, but the adhesive layer is not shown in FIGS. 1 and 2 because it is thinner than other members. Moreover, the structure which provides the convex part 32 and the thick part 33 as shown in FIG.

  The laminated piezoelectric element 40 in the liquid discharge head includes a piezoelectric material layer, an electrode layer, and a piezoelectric material layer, as shown in FIG. 1B and an enlarged view of a broken line portion in FIG. Are laminated, and the liquid in the liquid chamber 11 is pressurized using displacement in the d33 direction as the piezoelectric direction of the laminated piezoelectric element 40. Also, as shown in FIGS. 2 and 3, the laminated piezoelectric element 40 is divided on the comb teeth by half-cut dicing, and each of them is used as a driving part 42 and a supporting member 43 that is a non-driving part of the piezoelectric element. use. This structure is called a bi-pitch structure. Since the flow path unit is supported by the support member 43, the liquid chamber substrate 10 is prevented from being lifted by a rise in the pressure of the liquid chamber 11, and is very effective in suppressing so-called mutual interference.

  As can be seen from FIG. 4 showing the structure in which the liquid chambers 11 are densified, the structure in which the driving member 42 of the laminated piezoelectric element 40 is the same as the nozzle pitch and the support member 43 is not formed (normal pitch structure). ) The material of the liquid chamber substrates 10 and 70 may be Si, Ni, 42 alloy, SUS304, or another SUS material. A liquid-resistant thin film made of an organic resin film such as a titanium nitride film or polyimide may be formed on the surface of the liquid chamber substrate 10 or 70 that comes into contact with the liquid. By forming such a liquid-resistant thin film, the material of the liquid chamber substrates 10 and 70 is less likely to elute from the liquid, and the wettability is improved, so that bubbles are less likely to stay and stable droplet ejection is achieved. It becomes possible. Here, “layer” and “film” are used to mean all substantially flat structures.

  1 and FIG. 2, the total thickness of the liquid chamber substrate 10 and the liquid chamber substrate 70 is 40 μm to 600 μm, the length of the liquid chamber 11 in the longitudinal direction is 400 μm to 1600 μm, and the liquid chamber 11 The width was set to 120 to 139 μm. The width of the flow path partition is about 15 to 50 μm (because the liquid chamber pitch is 150 dpi) at the joint surface with the diaphragm 30.

  Furthermore, the total thickness of the liquid chamber substrate 10 and the liquid chamber substrate 70 of the liquid discharge head shown in FIG. 4 is 100 μm to 600 μm, the length in the longitudinal direction of the liquid chamber 11 is 400 μm to 1200 μm, and the width of the liquid chamber 11 is 50. The structure may be ˜70 μm (because the liquid chamber pitch is 300 dpi). The nozzle plate 20 is formed of a metal material, for example, an Ni plating film formed by an electroforming method, and has a number of nozzles 21 that are fine discharge ports for causing droplets to fly. The internal shape (inner shape) of the nozzle 21 is formed in a horn shape (may be a substantially cylindrical shape or a substantially frustum shape). Further, the diameter of the nozzle 21 is about 15 to 35 μm on the droplet outlet side. The diameter of the nozzle 21 here was 18-24 μm. Further, the nozzle pitch of each row is 150 dpi / 300 dpi. A resin material may be used as the material of the nozzle plate 20.

  Further, a water repellent treatment layer (not shown) subjected to a water repellent surface treatment is provided on the liquid ejection surface (nozzle surface side) of the nozzle plate 20. Liquid physical properties such as PTFE-Ni eutectoid plating, electrodeposition coating of fluororesin, vapor-deposited fluororesin (for example, fluoride pitch), baking after solvent coating of silicon resin / fluorine resin, etc. A water repellent treatment film selected according to the above is provided to stabilize the liquid droplet shape and flight characteristics so that high-quality image quality can be obtained.

  As shown in FIG. 1, the liquid supply port 34 for supplying liquid from the outside and the frame 60 formed by the engraving that becomes the common liquid chamber 13 are formed by injection molding of epoxy resin. The resin material may be polyphenylene sulfite or the like.

  In the liquid ejection head having such a configuration, a displacement in the stacking direction occurs in the multilayer piezoelectric element 40 by applying a driving waveform (pulse voltage of 10 to 50 V) to the multilayer piezoelectric element 40 according to the recording signal. The liquid chamber 11 is pressurized through the vibration plate 30 to increase the pressure, and droplets are ejected from the nozzle 21. Thereafter, the liquid pressure in the liquid chamber 11 is reduced with the end of droplet discharge, and a negative pressure is generated in the liquid chamber 11 due to the inertia of the liquid flow and the discharge process of the driving pulse, and the liquid filling process is started. . At this time, the liquid supplied from the liquid tank flows into the common liquid chamber 13, passes from the common liquid chamber 13 through the liquid inflow port 34, passes through the fluid resistance portion 12, and is filled into the liquid chamber 11. The fluid resistance portion 12 is effective in damping the residual pressure vibration after ejection, but becomes resistant to refilling (refill) due to surface tension. By appropriately selecting the fluid resistance portion, it is possible to balance the attenuation of the residual pressure and the refill time, and to shorten the time (drive period) until shifting to the next droplet discharge operation.

Moreover, as shown in FIG. 1, the structure which made the member of the diaphragm the metal layer and the resin layer can be considered. By using a metal film, there is no concern about moisture permeation of the liquid. Ni, 42 alloy, and SUS304 can be considered as the metal member. Further, by forming a metal film such as SiO ₂ or Ti on the surface, there is no concern about moisture permeation of the liquid. Moreover, if the member of the diaphragm 30 is a resin layer, the rigidity of the diaphragm portion 31 is lower than that of the metal layer, so that the displacement efficiency of the laminated piezoelectric element 40 is not hindered. Further, when the liquid chamber substrates 10 and 70 are made of metal such as Ni, 42 alloy, SUS304 or the like, the bonding strength is increased as compared with the bonding between the metals.

  Furthermore, the resin layer may be a rolled film. As a result, even if the thickness is reduced, it is possible to provide a highly reliable product with almost no defects such as pinholes.

In addition, it is also conceivable to perform a process that shows affinity for the adhesive in the bonding region between the diaphragm 30 and the drive unit 42. Further, it is conceivable to form a hydroxyl group or a SiO ₂ thin film layer as a treatment showing affinity. The SiO ₂ thin film layer is formed by a method that can be formed at a temperature that is relatively not heated, that is, a temperature that does not cause thermal influence on the members of the diaphragm 30. Specifically, it can be said that sputtering, ion beam vapor deposition, ion plating, CVD (chemical vapor deposition), P-CVD (plasma vapor deposition) and the like are suitable. After sputtering of Si, the sputtered film is subjected to O ₂ treatment to generate a SiO ₂ film. From the viewpoint of process time and material cost, it is advantageous to set the thickness of the SiO ₂ thin film layer to the minimum necessary thickness within a range in which adhesion can be secured. The thickness of the SiO ₂ film is used in the range of 10 to 2000 mm. As for the water repellent treatment, a water repellent film is formed by a known method such as plating film or water repellent coating. As a water repellent treatment method, a spin coater, a roll coater, a screen printing, a spray coater, or the like can be used. In addition, a method of forming a film by vacuum deposition is also used. When this method is used, the adhesion of the water-repellent film is improved. The thickness of the thin portion is 2 to 6 μm. Moreover, the length of the thin part area | region of a liquid chamber short direction is 10-50 micrometers.

  In addition, polyphenylene sulfide (PPS) resin is used as the resin layer, but other stretchable polymer materials such as polyimide (PI) resin, polyetherimide (PEI) resin, polyamidoimide (PAI) resin, polybaraban Acid (PPA) resin, Borisulphone (PSF) resin, Polyethersulfone (PES) resin, Polyetherketone (PEK) resin, Polyetheretherketone (PEEK) resin, Polyolefin (APO) resin, Polyethylene naphthalate (PEN) Resins, aramid resins, polypropylene resins, vinylidene chloride resins, polycarbonate resins and the like can also be used.

  Further, not only the piezoelectric direction d33 direction of the piezoelectric element as the drive unit 42, but also the piezoelectric direction may be the d31 direction as shown in FIG. In FIG. 5, although the thickness of the adhesive is expressed as being thick, the coating thickness is about 1 to 10 μm.

  FIG. 6 is a view showing a liquid chamber substrate in which a liquid chamber is formed by machining. As shown in the figure, the length and width dimensions of the liquid chamber 11 and the fluid resistance portion 12 can be formed with high precision by machining, but it is a cross-sectional view taken along the line AA ′ of FIG. As shown in (b) of the figure, when viewed on the basis of a reference line indicated by a two-dot chain line, deformation occurs in the thickness direction. Particularly, when the density of the liquid chamber 11 is increased, the deformation in the thickness direction becomes remarkable.

  FIG. 7 is a view showing a conventional example in which a liquid chamber substrate subjected to machining processing and a diaphragm are joined. In the drawing, only the liquid chamber portion and the fluid resistance portion of the liquid chamber substrate 10 are indicated by dotted lines in order to show the positional relationship with the diaphragm. As shown in FIG. 7B, which is a cross-sectional view taken along the line BB ′ of FIG. 7A, the diaphragm 30 having the diaphragm portion 31 that performs elastic deformation and the liquid chamber substrate 10 in which the deformation has occurred. When bonded, the diaphragm 30 remains deformed following the liquid chamber substrate 10. If it joins with the drive part 42, leaving this deformation | transformation, it cannot join stably like FIG. In the joining example shown in FIG. 8A, the adhesive used for joining the convex portion 32 and the driving portion 42 is crushed and pushed out to the side surfaces of the driving portion 42 and the convex portion 32. It is. When the extruded adhesive reaches the diaphragm portion 31, the characteristics of the thin portion change, which affects ejection. In addition, the joining example shown in FIG. 8B is an example in which the joining of the drive unit 42 and the convex portion 32 is incomplete. Since the displacement of the drive unit 42 cannot be efficiently converted into pressure, a discharge abnormality occurs. Furthermore, the joining example shown in FIG. 8C is an example in which the projecting portion 32 and the driving portion 42 are not joined evenly and joined together by deforming the diaphragm portion 31. As a result of not being stably joined as shown in FIG. 8, the volume between the liquid chambers varies, and the tension of the diaphragm 31 also varies, resulting in a large variation in discharge characteristics.

  FIG. 9 is a diagram showing a configuration of the liquid discharge head according to the first embodiment of the present invention. The liquid discharge head shown in (b) of the figure, which is a cross-sectional view taken along the line CC ′ of (a) of the figure, is formed by a machined liquid chamber substrate 10 and a process other than machining, and the liquid chamber substrate A liquid chamber substrate 70 different from 10 is laminated, and the liquid chamber substrate 10 and the liquid chamber substrate 70 are bonded with an adhesive. As a result, the liquid chamber substrate 10 is corrected to the liquid chamber substrate 70, and the liquid chamber substrate 70 can be bonded in a state where the member is flat with the diaphragm 30. In order to increase the correction effect, it is desirable that the liquid chamber substrate 70 has rigidity higher than that of the liquid chamber substrate 10. However, the liquid chamber substrate 70 may have the same shape as the liquid chamber substrate 10. In addition, since the accuracy of parts cannot be ensured by machining, some variation may occur in the processed surface from the liquid chamber substrate 10. Furthermore, when the width of the liquid chamber 11 of the liquid chamber substrate 10 is narrower than the width of the liquid chamber 11 of the liquid chamber substrate 70, the adhesive used for joining the liquid chamber substrate 10 and the liquid chamber substrate 70 flows out. There is an advantage that it does not flow out to the diaphragm thin wall portion. Further, with such a configuration, since the processing width of the liquid chamber 11 of the liquid chamber substrate 70 is wide, it is easy to control accuracy even with a forming method other than mechanical processing such as etching, and stable quality can be maintained.

  FIG. 10 is a diagram showing the configuration of the liquid discharge head according to the second embodiment of the present invention. According to the liquid discharge head shown in (b) of the figure, which is a cross-sectional view taken along the line DD ′ of (a) of the figure, the place where the liquid chamber board 70 is joined is the liquid chamber board 10 and the nozzle plate ( (Not shown). Even in this configuration, the deformation in the thickness direction of the liquid chamber substrate 10 subjected to the machining process for forming the liquid chamber is corrected to the liquid chamber substrate 70.

  FIG. 11 is a diagram showing a configuration of a liquid discharge head according to the third embodiment of the present invention. According to the liquid discharge head shown in (b) of the figure, which is a cross-sectional view taken along the line EE ′ of (a) of the figure, between the nozzle substrate (not shown) and the liquid chamber substrate 10, the liquid chamber A liquid chamber substrate 70 is bonded to both the substrate 10 and the vibration plate 30. By sandwiching both of them with the flat liquid chamber substrate 70, the deformation of the liquid chamber substrate 10 can be corrected more efficiently, so that the thickness of the liquid chamber substrate 70 can be reduced and the processing accuracy of the liquid chamber substrate can be reduced. Can be raised. Here, there are an etching method and a laser processing method as processing methods different from machining.

  FIG. 12 is a view showing an example of another liquid chamber substrate formed by etching. Regarding the cross section of the processing surface of the liquid chamber substrate 70, FIG. 12B shows a tapered processing cross section formed by one-side etching, and FIG. 12C shows the processing cross section formed by double-side etching. Show. It is possible to prevent the adhesive used for bonding from flowing through the partition wall and flowing out to the nozzle and the diaphragm portion in either processed cross section. Specifically, in the configuration of FIG. 12B, the wide side (lower side in the figure) of the liquid chamber interval wall is joined to the liquid chamber substrate 10. Since the partition wall width of the bonding surface of the liquid chamber substrate 70 is wide, the adhesive that adheres the liquid chamber substrate 10 and the liquid chamber substrate 70 is dammed up at this portion, and the other is transmitted along the partition wall of the liquid chamber substrate 70. It can prevent flowing out to the member (for example, diaphragm). In the configuration of FIG. 12C, the adhesive produced by joining the liquid chamber substrate 10 and the liquid chamber substrate 70 flows out through the partition walls of the liquid chamber substrate 70, but the flow is stopped at the portion where the partition wall width is the widest. That is, it does not flow out to the back side. As a result, it is possible to prevent the adhesive from flowing out to other members as in the case of the component drawing 12B formed by one-side etching. Further, such a tapered processing cross section can be formed by laser processing.

  13 to 15 are diagrams showing another configuration of the liquid discharge head according to the first embodiment. 16 and 17 are diagrams illustrating another configuration of the liquid ejection head according to the second embodiment. In each figure, the liquid chamber substrate 70 is formed by laminating a plurality of members, and has a different processing shape. Here, the bonding position of the liquid chamber substrate 70 which is the same member as the liquid chamber substrate 10 may be either between the nozzle plate 20 and the liquid chamber substrate 10 or between the liquid chamber substrate 10 and the vibration plate 30. In addition, even when one sheet has lower rigidity than the liquid chamber substrate, the present embodiment includes a case where a plurality of sheets are stacked to show higher rigidity than the liquid chamber substrate.

  FIG. 18 is a diagram illustrating another configuration of the liquid ejection head according to the third embodiment. As shown in (b) of the figure, which is a cross-sectional view taken along line LL ′ of (a) of the same figure, between the nozzle plate (not shown) and the liquid chamber substrate 10, the liquid chamber substrate 10 and the vibration plate A plurality of liquid chamber substrates 70 formed between 30 are both stacked.

  In addition, the liquid chamber substrate 10 in the liquid discharge head of the present invention described above may be processed by pressing or may be processed by polishing.

  The ink jet head that can be used in the present invention may be an edge shooter type in which the shape from the ink flow path to the discharge port is linear, or a side shooter type in which the direction of the ink flow path and the direction of the discharge port are different. It may be.

  Next, an example of the image forming apparatus according to the present invention provided with the liquid ejection head or the droplet ejection apparatus according to the present invention will be described with reference to FIGS. FIG. 19 is a side view showing the overall configuration of the image forming apparatus according to the present invention, and FIG. 20 is a plan view showing the main configuration of the image forming apparatus according to the present invention.

  An image forming apparatus 100 according to the present invention holds a carriage 103 slidably in a main scanning direction by a guide rod 101 and a guide rail 102 that are horizontally mounted on left and right side plates (not shown). The moving scanning is performed in the direction indicated by the arrow (main scanning direction) in FIG. For example, a recording head 106 including four liquid discharge heads for discharging liquid droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk) is disposed on the carriage 103. The outlets are arranged in a direction crossing the main scanning direction, and are mounted with the droplet discharge direction facing downward. As the liquid discharge head constituting the recording head 106, a liquid ejection head using a piezoelectric actuator such as a piezoelectric element is used.

  Also, the carriage 103 is equipped with a sub-tank 107 for each color for supplying each color liquid to the recording head 106. The sub tank 107 is replenished with liquid from the ink cartridge of the present invention, which is the main tank, via a liquid supply tube (not shown). In this embodiment, the sub-tank 107 and the recording head 106 constitute a liquid droplet ejection device. However, the recording head 106 may be composed of the liquid ejection head according to the present invention, and the sub-tank 107 may be provided separately. Alternatively, the ink cartridge of the present invention can be mounted without using a sub tank.

  On the other hand, as a paper feeding unit for feeding the paper 110 stacked on the paper stacking unit (pressure plate) 109 such as the paper feeding cassette 108, a half-moon roller that separates and feeds the paper 110 one by one from the paper stacking unit 109. A sheet feeding roller 111 and a separation pad 112 made of a material having a large friction coefficient are provided opposite to the sheet feeding roller 111, and the separation pad 112 is urged toward the sheet feeding roller 111 side.

  Then, as a transport unit for transporting the paper 110 fed from such a paper feed unit below the recording head 106, a transport belt 113 for transporting the paper 110 by electrostatic adsorption, and a paper feed The counter roller 115 for transporting the paper 110 sent from the section via the guide 114 between the transport belt 113 and the paper 110 sent substantially vertically upward is changed by about 90 ° to be on the transport belt 113. A conveyance guide 116 for following the above and a tip pressure roller 118 urged toward the conveyance belt 113 by a pressing member 117. In addition, a charging roller 119 that is a charging unit for charging the surface of the conveyance belt 113 is provided.

  Here, the conveyance belt 113 is an endless belt, is stretched between the conveyance roller 120 and the tension roller 121, and is conveyed from the sub-scanning motor 122 via the timing belt 123 and the timing roller 124. Is rotated to rotate in the belt conveyance direction (sub-scanning direction) in FIG. A guide member 125 is disposed on the back side of the conveyor belt 113 in correspondence with the image forming area formed by the recording head 106.

  Further, as shown in FIG. 19, a slit disk 125 is attached to the shaft of the conveying roller 120, and the sensor 126 of FIG. 20 for detecting the slit of the slit disk 125 is provided, and these slit disks are provided. The encoder 127 is constituted by the sensor 125 and the sensor 126. Further, the charging roller 119 is arranged so as to come into contact with the surface layer of the conveyor belt 113 and rotate following the rotation of the conveyor belt 113, and 2.5N is applied to both ends of the shaft as a pressing force. Further, as shown in FIG. 20, an encoder scale 128 having slits is provided on the front side of the carriage 103, and an encoder sensor comprising a transmissive photosensor for detecting the slits of the encoder scale 128 on the front side of the carriage 103. The encoder 130 for detecting the position of the carriage 103 in the main scanning direction (position with respect to the home position) is configured.

  Further, as a paper discharge unit for discharging the paper 110 recorded by the recording head 106, a separation unit for separating the paper 110 from the conveying belt 113, a paper discharge roller 131 and a paper discharge roller 132, and paper discharge A paper discharge tray 133 for stocking the paper 110 to be stored.

  A double-sided paper feeding unit 134 is detachably attached to the back. The double-sided paper feeding unit 134 takes in the paper 110 returned by the reverse rotation of the transport belt 113, reverses it, and feeds it again between the counter roller 115 and the transport belt 113.

  In the image forming apparatus 100 of the present invention having such a configuration, the sheets 110 are separated and fed one by one from the sheet feeding unit, and the sheet 110 fed substantially vertically upward is guided by the guide 114 and is conveyed by the conveyance belt. 113 and the counter roller 115 are sandwiched and conveyed. Further, the leading end is guided by the conveying guide 116 and pressed against the conveying belt 113 by the leading end pressure roller 118, and the conveying direction is changed by approximately 90 °. At this time, a positive output and a negative output are alternately repeated from the high voltage power source to the charging roller 119 by a control circuit (not shown), that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 113 alternates, that is, a loop In the sub-scanning direction, which is the direction, plus and minus are alternately charged in a band shape with a predetermined width. When the sheet 110 is fed onto the conveyance belt 113 charged with this plus and minus alternately, the sheet 110 is attracted to the conveyance belt 113 by electrostatic force, and the sheet 110 is conveyed in the sub-scanning direction by the circular movement of the conveyance belt 113. Is done.

  Therefore, by driving the recording head 106 according to the image signal while moving the carriage 103, droplets are ejected onto the stopped sheet 110 to record one line, and after the sheet 110 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 110 reaches the recording area, the recording operation is finished, and the paper 110 is discharged onto the paper discharge tray 133.

  In the case of double-sided printing, when recording on the front surface (surface to be printed first) is completed, the recording belt 110 is fed into the double-sided paper feeding unit 134 by rotating the conveyor belt 113 in the reverse direction. The paper 110 is reversed (with the back surface being the printing surface), and is fed again between the counter roller 115 and the conveyor belt 113. The timing is controlled, and the sheet 110 is conveyed onto the conveyor bell 113 as described above. Then, after recording on the back surface, the paper is discharged onto the paper discharge tray 133.

  Note that the image forming apparatus according to the present invention can also be applied to a printer, a facsimile machine, a copying machine, a multi-function machine thereof, and the like. Further, the present invention can also be applied to a liquid discharge head or a droplet discharge device that discharges a liquid other than ink, such as a DNA sample, a resist, or a pattern material, or an image forming apparatus that includes these.

  Further, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications and substitutions are possible as long as the description is within the scope of the claims.

10, 70; liquid chamber substrate, 11; liquid chamber, 12; liquid resistance portion,
13; Common liquid chamber, 20; Nozzle plate, 21; Nozzle, 30;
31; Diaphragm part, 32; Convex part, 33; Thick part,
34; liquid supply port, 40; laminated piezoelectric element, 41; electrode laminated portion,
42; drive unit, 43; support member, 50; base substrate, 60; frame,
100: an image forming apparatus.

JP 09-290506 A Japanese Patent No. 3,114,771

Claims (11)

A nozzle substrate having a nozzle for discharging a liquid; a liquid chamber unit provided with a liquid chamber for storing a liquid communicating with each nozzle; a diaphragm forming at least a part of a wall surface of the liquid chamber; and the liquid chamber In a liquid discharge head having a driving means for generating a pressure to pressurize the liquid,
The liquid chamber unit includes a first liquid chamber substrate formed by a machining process, and a flat surface formed by a machining process having the same composition as the first liquid chamber substrate and different from the machining process. A liquid discharge head, wherein the second liquid chamber substrate is laminated.   The liquid discharge head according to claim 1, wherein an area where the liquid chamber of the second liquid chamber substrate is processed is equal to or smaller than an area where the liquid chamber of the first liquid chamber substrate is processed.   3. The liquid ejection head according to claim 1, wherein the second liquid chamber substrate is bonded between the first liquid chamber substrate and the vibration plate.   3. The liquid ejection head according to claim 1, wherein the second liquid chamber substrate is bonded between the first liquid chamber substrate and the nozzle substrate.   The second liquid chamber substrate is bonded between the first liquid chamber substrate and the nozzle substrate, and between the first liquid chamber substrate and the diaphragm. Liquid discharge head.   The liquid discharge head according to claim 3, wherein a plurality of the second liquid chamber substrates are bonded.   The liquid discharge head according to claim 1, wherein the second liquid chamber substrate is formed by etching.   The liquid discharge head according to claim 1, wherein the second liquid chamber substrate is formed by laser processing.   6. The liquid discharge head according to claim 1, wherein the machining process for forming the first liquid chamber substrate is a press process.   A head cartridge comprising the liquid discharge head according to claim 1.   An image forming apparatus comprising the liquid discharge head according to claim 1.

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