JP2012121199A - Liquid droplet delivering head, ink cartridge and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid droplet delivering head capable of easily and surely protecting an ink supply hole part with an ink-resistant film.SOLUTION: An actuator is produced by forming films of a vibration plate material and a piezoelectric element material on a silicon substrate 1. First, a silicon oxide film 5 is formed, and next, a polysilicon film 6 is formed ((a)). Then, a silicon nitride film 13 is formed, and after that, the polysilicon film 6 and the silicon nitride film 13 in a part working as an individual ink supply hole 24 are removed. A high temperature oxide film 7 is formed, and the laminated films are used as a vibration plate layer ((b)). Then, films of a lower electrode 8, a piezoelectric material layer 9, and an upper electrode 10 of the piezoelectric element are formed ((c)). Before forming a delivery chamber 14, the vibration plate laminated film in the part working as the individual ink supply hole 24 is patterned, and is protected by the silicon oxide films 5 and 7 with high ink-resistance, and thus, the vibration plate material with low ink-resistance can be protected from ink.

Description

The present invention relates to a droplet discharge head used for forming an image by discharging a liquid such as ink, an ink cartridge including the droplet discharge head, and an image forming apparatus.
The present invention can be applied to an inkjet recording apparatus, a three-dimensional molding technique using an inkjet technique, and the like.

The ink jet recording apparatus has many advantages such as extremely low noise during recording, high-speed printing, and use of inexpensive plain paper with a high degree of freedom of ink. Among them, a so-called ink-on-demand system that discharges ink droplets only when recording is necessary does not require collection of ink droplets that are not necessary for recording, and has become mainstream.
An inkjet head, which is a droplet discharge head used in an image recording apparatus such as a printer, a facsimile machine, or a copying apparatus, or an ink jet recording apparatus used as an image forming apparatus, includes a nozzle that discharges ink droplets, and a discharge chamber ( Pressure chamber, pressure chamber, ink flow path, etc.) and pressure generating means for generating pressure to pressurize the ink in the discharge chamber. The ink droplets are ejected from the nozzles by pressurizing the ink.

As such a droplet discharge head, a piezoelectric type that discharges ink droplets by deforming and displacing a diaphragm that forms the wall surface of the discharge chamber using an electromechanical conversion element such as a piezoelectric element as a pressure generating means. And a bubble type (thermal type) in which bubbles are generated by boiling an ink film using an electrothermal conversion element such as a heating resistor disposed in the discharge to discharge ink droplets.
Piezoelectric types include a longitudinal vibration type utilizing deformation in the d33 direction, a transverse vibration (bend mode) type utilizing deformation in the d31 direction, and a shear mode type utilizing shear deformation.
Among them, in recent years, with the progress of semiconductor processes and micromachining technology, patterning technology has been established, and an actuator configuration has been devised in which a pressure chamber and a piezoelectric element are directly formed on an inexpensive Si substrate.

In the liquid ejecting apparatus described in Patent Document 1, an ink supply hole is formed after bonding two substrates by direct bonding, anodic bonding, or the like, and then a liquid contact protective film for ensuring ink resistance at the bonding interface Is forming.
As the density of ink jet heads increases, the structure of the ink supply holes becomes finer, and the aspect of the supply holes becomes larger. It is difficult to form a dense protective film without unevenness after the supply holes are formed, and this is a factor that reduces reliability.
In the liquid ejecting apparatus described in Patent Document 2, a silicon carbide film is formed by a vapor phase growth method in a portion in contact with ink including a liquid chamber.
It is manufactured by attaching a glass substrate with through holes formed on a silicon substrate on which a piezoelectric element is formed, and then attaching a nozzle plate. Through holes are formed in the silicon substrate by RIE etching, and SiC is formed at the substrate bonding interface.
However, it is difficult to form a protective film uniformly on the inner wall of the through hole provided in the laminated substrate, which is a factor of reducing the reliability of the bonding interface.
In the liquid ejecting apparatus described in Patent Document 3, a configuration is disclosed in which the vibration plate is prevented from being bent by forming a corrosion-resistant film on the vibration plate. Ink is supplied from the surface of the nozzle plate, and no through hole is formed in the diaphragm.

Regardless of the method, the droplet discharge head requires ink resistance of the member in contact with ink, so in the various heads described above, ensure the ink resistance of all members in contact with ink. is important.
However, in recent actuator constructions in which the pressurization chamber and the piezo element are directly formed on the Si (silicon) substrate with the miniaturization of the head and the low cost by the micromachining technology, an ink-resistant member is used for all the ink contact portions. It is becoming difficult to use.
In addition, it is often difficult to form a protective film later in the flow path having a very complicated structure. In particular, it is very difficult to form a reliable protective film around the through hole for supplying ink, which is inevitable when ink is supplied from the back side of the substrate in order to reduce the size of the head.

  The present invention has been made in view of the above situation, and its main object is to provide a droplet discharge head capable of easily and reliably protecting an ink supply hole portion with an ink-resistant film.

  In order to achieve the above-mentioned object, the invention according to claim 1 includes a nozzle plate having a plurality of nozzle holes for discharging droplets, a discharge chamber partitioned by a partition wall and communicating with the nozzle holes, and the discharge chamber. A diaphragm substrate formed with a diaphragm, a diaphragm configured as at least one partition wall of the discharge chamber, and provided on one surface of the diaphragm, converts electrical energy into mechanical energy and applies the diaphragm to the diaphragm. In the liquid droplet ejection head provided with the electromechanical conversion element, the vibration plate is formed of a laminated film, and the side surface of the through hole as the liquid supply hole formed in the vibration plate forms any of the vibration plates. It is characterized by being covered with such a film.

According to a second aspect of the present invention, in the droplet discharge head according to the first aspect, the film covering the side surface of the through hole is either a silicon oxide film or a silicon nitride film. .
According to a third aspect of the present invention, in the liquid droplet ejection head according to the first aspect, the film covering the side surface of the through hole is a metal or a metal oxide.
According to a fourth aspect of the present invention, in the droplet discharge head according to the third aspect, the metal oxide is any one of TiN, Pt, PZT, LNO, SRO, and Al ₃ O _2. It is characterized by that.
According to a fifth aspect of the present invention, in the liquid droplet ejection head according to the first aspect, the film covering the side surface of the through hole is a resin.

According to a sixth aspect of the present invention, in the liquid droplet ejection head according to the fifth aspect, the resin is a photosensitive resin or an electrodeposited polyimide resin.
According to a seventh aspect of the present invention, there is provided an ink cartridge in which a droplet discharge head that discharges ink droplets and an ink tank that supplies ink to the droplet discharge head are integrated. It is a droplet discharge head described in any one of 1 to 6.
According to an eighth aspect of the present invention, in the image forming apparatus that forms an image by ejecting droplets from the droplet ejection head, the droplet ejection head is described in any one of the first to sixth aspects. It is characterized by being a droplet discharge head.

According to the present invention, since it is a structure that protects the side surface of a fine hole with a highly ink-resistant film before the pressure generating means (actuator) is built, a protective film that is difficult to form normally is formed by a simple method. It is possible to achieve a very high reliability at a low cost.
In the case of a structure that protects the side surface of fine holes with a highly ink-resistant film such as alumina or platinum that has high ink resistance, a protective film that is difficult to form normally can be formed by a simple method such as sputtering or CVD. It becomes possible to realize very high reliability at a cost.
In addition, a resin film with high ink resistance can be formed by a simple method such as spin coating or dipping in the previous stage where there are few steps on the substrate before the ink chamber is built, and fine ink supply holes can be formed. The side can be reliably protected. For this reason, it is possible to achieve very high reliability at low cost.
In the ink cartridge, since any one of the droplet discharge heads according to the present invention and the ink tank that supplies ink to the droplet discharge head are integrated, manufacturing defects can be reduced and the cost can be reduced.

1 is an exploded perspective view of a droplet discharge head according to a first embodiment of the present invention. 2A and 2B are cross-sectional views of the droplet discharge head, in which FIG. 1A is a schematic cross-sectional view taken along line X-X ′ of FIG. 1, and FIG. 2B is a schematic cross-sectional view taken along line Y-Y ′ of FIG. It is a figure which shows the manufacturing process of the droplet discharge head seen from Fig.2 (a) direction. It is a figure which shows the manufacturing process of the droplet discharge head seen from the FIG.2 (b) direction. It is a figure which shows the cross section of the droplet discharge head in 2nd Embodiment, and is a figure equivalent to FIG.2 (b). It is a figure which shows the manufacturing process of the droplet discharge head in 2nd Embodiment. It is a figure which shows the cross section of the droplet discharge head in 3rd Embodiment, and is a figure equivalent to FIG.2 (b). It is a figure which shows the manufacturing process of the droplet discharge head in 3rd Embodiment. FIG. 10 is a perspective view of an ink cartridge according to a fourth embodiment. It is a figure which shows 5th Embodiment and is a perspective view of an inkjet recording device. 2 is a schematic configuration diagram of the ink jet recording apparatus. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a first embodiment will be described with reference to FIGS. FIG. 1 is an exploded perspective view of a droplet discharge head in the present embodiment, which is a partial cross-sectional view. This droplet discharge head is a droplet discharge head using the actuator (vibrating plate) of the present invention, and is an example of a side shooter system that discharges ink droplets from nozzle holes provided on the surface of the substrate.
2 shows a cross-sectional view of the substrate 1 in FIG. 1. FIG. 2A is a cross-sectional view taken along the line XX ′ shown in FIG. 1, and only two discharge chambers 14 are shown for convenience.
FIG. 2B is a cross-sectional view taken along line YY ′ shown in FIG. As shown in FIG. 1, an inkjet head 95 as a droplet discharge head according to the present embodiment includes a nozzle substrate 2 having a plurality of nozzle holes 20 for discharging ink, and a liquid chamber substrate on which discharge chambers, vibration plates, and piezoelectric elements are formed. 1 and a three-layered structure in which a protective substrate 3 provided with a piezoelectric element protective space is stacked.
The liquid chamber substrate 1 and the protective substrate 3 constitute a partition substrate.

The liquid chamber substrate 1 as a first substrate forms a diaphragm layer by forming a thin film on a silicon substrate by pyro-oxidation, LPCVD, or the like, on which a Ti film and a platinum film 8 serving as a lower electrode, A piezoelectric material (PZT) 9 as a mechanical conversion element and an actuator (vibrating plate constituting one of the partition walls) composed of a multilayer structure of a platinum film 10 as an upper electrode are formed in a discharge chamber 14 formed by etching silicon. It is formed in the opposing region.
The nozzle substrate 2 as the second substrate is a nickel substrate formed to a thickness of 30 microns using a nickel high-speed electroforming method, and the nozzle substrate 2 communicates with the discharge chamber 14 with respect to the surface portion of the liquid chamber substrate 1. A hole 20 is provided.
The protective substrate 3 as a third substrate has a configuration in which a column 22 that supports the partition wall 4 is formed in order to increase the rigidity of the space 22 and the liquid chamber partition wall so as not to prevent the piezoelectric element 9 from being protected and displaced. .

The operation of the droplet discharge head 95 configured as described above will be described.
Ink is supplied from the common liquid chamber 24 into the discharge chambers 14 via the individual ink supply holes 18. A voltage is applied between the upper electrode 10 and the lower electrode 8 of the piezoelectric element 9 in a state where the discharge chamber 14 is filled with ink, whereby the piezoelectric element deformed in the transverse vibration mode contracts and vibrates in close contact with the piezoelectric element. The entire plate is deformed into a convex shape toward the discharge chamber 14 (left side in FIG. 2A).
The volume of the discharge chamber 14 decreases and the pressure in the discharge chamber 14 increases rapidly, and the ink droplets 21 are discharged toward the recording paper 40 from the nozzle holes 20.
Ink can be ejected continuously by applying and repeating the pulse voltage.

Next, a manufacturing method and a configuration will be described in detail with reference to examples.
This embodiment will be described with reference to FIGS. In this embodiment, an actuator is created by depositing a diaphragm material and a piezoelectric element material on a silicon substrate 1.
First, 0.6 μm of silicon oxide film 5 is formed on the surface of a <100> silicon substrate having a thickness of 400 μm by a pyro oxidation method, and 0.6 μm of polysilicon film 6 is further formed by LPCVD method (FIG. 3). (A), FIG. 4 (a)).
Further, a silicon nitride film 13 having a thickness of 0.3 μm is formed by LPCVD, and then the polysilicon 6 and the silicon nitride film 13 which become the individual ink supply holes 24 are removed by using a lithoetch method. Thereafter, a high-temperature oxide film (HTO film) 7 is formed to a thickness of 0.6 μm by the LPCVD method, and these laminated films are used as the vibration plate layer (= vibration plate) (FIGS. 3B and 4B).

Thereafter, a Ti and Pt layer to be the lower electrode 8 of the piezoelectric element are formed by sputtering, respectively, with a thickness of 0.05 μm and 0.2 μm. Further, a piezoelectric material layer 9 is formed with a thickness of 2 μm by sputtering, and the upper electrode 10 is further reduced to 0 1 μm is formed (FIGS. 3C and 4C). Thereafter, the upper electrode 10 and the piezoelectric material layer 9 are patterned by lithoetching, and the lower electrode 8 is further patterned by lithoetching (FIGS. 3D and 4D).
Further, the partial silicon oxide films 5 and 7 to be the individual ink supply holes 24 are removed by lithoetching. Thereafter, an interlayer insulating film 11 for insulating and separating the actuator upper and lower electrodes 8 and 10 from the wiring layer and a passivation film 12 for protecting the device including the wiring film are formed and patterned (FIG. 3E). 4 (e)) is a first substrate on which an actuator is formed by forming recesses to be the discharge chamber 14, the fluid resistance portion 15, and the individual ink supply holes 24 on the opposite surface of the silicon substrate 1 by ICP dry etching. The liquid chamber substrate 1 is completed (FIGS. 3 (f) and 4 (f)).

Here, before the liquid chamber is formed, a portion of the diaphragm laminated film that becomes the individual ink supply hole 24 is patterned, and protected by the silicon oxide films 5 and 7 having high ink resistance, so that the diaphragm material having low ink resistance is obtained. Can be protected from ink.
Thereafter, the nozzle substrate 2 manufactured separately by high-speed electroforming in a sulfamic acid bath is bonded to the discharge chamber 14 side of the liquid chamber substrate 1, and finally, a recess 22 is formed on the silicon substrate by a lithoetch method. 3 is bonded to the surface of the piezoelectric element of the liquid chamber substrate 1 (FIGS. 3 (g) and 4 (g)). Although not shown, the wiring portions of the upper electrode 10 and the lower electrode 8 of the piezoelectric element are used as a drive circuit. By connecting, the droplet discharge head of this embodiment is completed (FIG. 3 (h), FIG. 4 (h)).

The protective substrate 3 may be a <110> silicon substrate processed by wet etching using an alkaline etching solution such as TMAH or KOH, or a substrate in which grooves are formed on a glass substrate by blasting.
Molded parts such as resin molds and metal injection molds may be used.
When the driver circuit is integrally formed on the actuator substrate (liquid chamber substrate) 1, the oxide film formed by the pyro oxidation method is formed by the LOCOS oxidation method, and the region where the oxide film is formed is selected, so that the drive circuit is the same. It can also be formed on a substrate.
The film given in the present embodiment as a material for the laminated diaphragm is exemplified by a film generally used in a semiconductor factory. For example, the silicon nitride film 13 is a film having a tensile stress. It is not limited.
In this embodiment, the side surfaces of the individual ink supply holes 24 formed in the diaphragm are protected by a silicon oxide film having high ink resistance.
For the diaphragm formed by CVD method, materials with low ink resistance may be used to design the diaphragm by combining film rigidity and stress. It is very difficult to form a protective film uniformly after forming the liquid chamber in the hole portion or after joining the common liquid chamber substrate, and it is difficult to ensure reliability. It is possible to achieve high reliability by protecting the side surface of a fine hole with a film having high ink resistance before the actuator is built.

As described above, in the droplet discharge head of the present invention, the side surfaces of the individual ink supply holes formed in the vibration plate are protected by the silicon oxide film having high ink resistance. In a droplet discharge head that forms a diaphragm by forming a laminated film, a desired diaphragm is formed by combining the rigidity and stress of various films in order to form the diaphragm. At that time, since a material with low ink resistance exists, it is necessary to form a protective film on the portion in contact with the ink. However, it is very difficult to form a protective film uniformly after forming a liquid chamber or joining a common liquid chamber substrate to the fine ink supply holes of the high-density head, and it is very difficult to ensure reliability. It is difficult.
Since the structure of the present invention protects the side surfaces of fine holes with a highly ink-resistant film before the actuator is built, a protective film that is difficult to form normally can be formed by a simple construction method, and the cost is low. Therefore, it is possible to achieve very high reliability.

The second embodiment will be described with reference to FIGS. Note that the same parts as those in the above embodiment are denoted by the same reference numerals, and unless otherwise specified, description of the configuration and functions already described is omitted, and only the main part will be described (the same applies to other embodiments below). 5 corresponds to FIG. 2B of the above embodiment, and FIG. 6 corresponds to FIG.
As in the first embodiment, an actuator is created by depositing a diaphragm material and a piezoelectric element material on the silicon substrate 1.
A silicon oxide film 5 and a polysilicon film 6 are respectively formed on the surface of the silicon substrate by 0.6 μm (FIG. 6A). Further, a silicon nitride film 13 having a thickness of 0.3 μm is formed, and thereafter, the polysilicon 6 and the silicon nitride film 13 which become the individual ink supply holes 24 are removed by using a lithoetch method.
Thereafter, an alumina film (Al ₂ O ₃ ) 16 having a thickness of 0.1 μm is formed by a sputtering method, and the laminated film is used as a diaphragm layer (FIG. 6B).
Thereafter, as in the first embodiment, the lower electrode 8, the piezoelectric material layer 9, and the upper electrode 10 are respectively formed (FIG. 6C), and the upper electrode 10 and the piezoelectric material layer 9 are patterned by a lithoetch method. Further, the lower electrode 8, the partial silicon oxide film 5 and the alumina film (Al ₂ O ₃ ) 16 to be the individual ink supply holes 24 are removed by the lithoetch method (FIG. 6D). Thereafter, an alumina film 17 and a passivation film 12 are formed and patterned as an interlayer insulating film (FIG. 6E). Similarly to the first embodiment, the discharge chamber 14, the fluid resistance unit 15, the individual ink supply holes 24, The first substrate (liquid chamber substrate) 1 on which the actuator is formed is completed by forming the concave portion (FIG. 6F).
Thereafter, the nozzle substrate 2 and the protective substrate 3 are bonded together to complete the droplet discharge head of this embodiment (FIG. 6G).

In this embodiment, the alumina film 16 that is a metal oxide is applied to the diaphragm material. The alumina film has a larger linear expansion coefficient than that of the silicon substrate, and the internal residual stress can be brought into a tension state depending on the film formation conditions, so that the flexure of the laminated diaphragm can be adjusted, and other than the individual ink supply holes in the process. By covering this material with the alumina film 16, a protective film having high ink resistance can be formed.
Since it is very difficult to protect the fine individual ink supply holes after completion of the head, reliability can be improved by protecting them during the manufacturing process.
Also, the alumina film can block the hydrogen component diffusing from other diaphragm materials to the piezoelectric element, and can prevent deterioration of the characteristics of the piezoelectric element due to hydrogen reduction. Therefore, the alumina film 17 as an interlayer insulating film is used. In addition, a highly reliable actuator can be created by sandwiching the piezoelectric element from above and below with an alumina film.

A third embodiment will be described with reference to FIGS.
As in the second embodiment, a silicon oxide film 5, a polysilicon 6, a silicon nitride film 13, and an alumina film 16 are sequentially formed on the silicon substrate 1, and portions of the polysilicon 6 and silicon nitride that become individual ink supply holes are formed. The film 13 and the alumina film 16 are removed by lithoetching (FIG. 8A).
Thereafter, similarly to the first embodiment, the lower electrode 8, the piezoelectric material layer 9, and the upper electrode 10 are formed, and the upper electrode 10, the piezoelectric material layer 9, and the lower electrode 8 are patterned by a lithoetch method (FIG. 8). (B)). Thereafter, an alumina curtain 17 is formed and patterned as a passivation film (FIG. 8C), and a polyimide resin 19 is applied by a spin coating method and baked at an appropriate temperature (FIG. 8D).
Thereafter, the polyimide resin 19 and the silicon oxide film 5 in the individual ink supply holes are removed by etching using a lithoetch method (FIG. 8E). Thereafter, as in the first embodiment, the first substrate (liquid chamber substrate) 1 on which the actuator is formed by forming the recesses to be the discharge chamber 14, the fluid resistance portion 15, and the individual ink supply holes 24 by ICP dry etching is provided. Completed (FIG. 8F).
Further, the nozzle substrate 2 and the protective substrate 3 are bonded together to complete the droplet discharge head of the present embodiment (FIG. 8G).

Since the polyimide resin has high chemical resistance and low film rigidity, even if a thick film is formed on the vibration plate surface, it does not adversely affect the vibration plate operation of the droplet discharge head. By thickening, defects due to pinholes can be reduced and ink resistance of the individual ink supply holes can be sufficiently secured, so that a highly reliable head can be built.
A polyimide having a photosensitivity may be used, or a film type may be attached. The same effect can be obtained even if a film is formed by spray coating or electrodeposition.

Next, an ink cartridge according to the present invention (fourth embodiment) will be described with reference to FIG.
This ink cartridge is obtained by integrating the ink jet head 61 according to any of the above embodiments having the nozzle 20 and the like, and the ink tank 62 for supplying ink to the ink jet head 61.
In this way, in the case of an ink tank integrated head, the cost reduction and reliability improvement of the head immediately lead to the cost reduction and reliability improvement of the entire ink cartridge. Therefore, as described above, the cost reduction and high reliability are achieved. By reducing the manufacturing defects, the yield and reliability of the ink cartridge can be improved, and the cost of the head-integrated ink cartridge can be reduced.

Next, an example of an ink jet recording apparatus (fifth embodiment) equipped with the ink jet head according to the present invention will be described with reference to FIGS. 10 is a perspective explanatory view of the recording apparatus, and FIG. 11 is a side explanatory view of a mechanism portion of the recording apparatus.
This ink jet recording apparatus includes a carriage movable in the main scanning direction inside the recording apparatus main body 81, a recording head composed of an ink jet head embodying the present invention mounted on the carriage, an ink cartridge for supplying ink to the recording head, and the like. A sheet feeding cassette (or a sheet feeding tray) 84 on which a large number of sheets 83 can be stacked from the front side is detachably attached to the lower part of the apparatus main body 81. It is possible to be.
Further, the manual feed tray 85 for manually feeding the paper 83 can be opened, the paper 83 fed from the paper feed cassette 84 or the manual feed tray 85 is taken in, and a required image is displayed by the printing mechanism unit 82. After recording, the paper is discharged to a paper discharge tray 86 mounted on the rear side.

The printing mechanism 82 holds a carriage 93 slidably in the main scanning direction by a main guide rod 91 and a sub guide rod 92 which are guide members horizontally mounted on left and right side plates (not shown). (Y), cyan (C), magenta (M), black (Bk) A head 94 comprising an ink jet head according to the present invention for ejecting ink droplets of each color has a plurality of ink ejection openings (nozzles) as the main scanning direction. They are arranged in the intersecting direction and mounted with the ink droplet ejection direction facing downward.
Each ink cartridge 95 for supplying ink of each color to the head 94 is replaceably mounted on the carriage 93.
The ink cartridge 95 has an air port that communicates with the atmosphere upward, a supply port that supplies ink to the inkjet head below, and a porous body filled with ink inside, and the capillary force of the porous body. Thus, the ink supplied to the inkjet head is maintained at a slight negative pressure.

Here, the heads 94 of the respective colors are used as the recording heads, but a single head having nozzles for ejecting ink droplets of the respective colors may be used.
Here, the carriage 93 is slidably fitted to the main guide rod 91 on the rear side (downstream side in the paper conveyance direction), and is slidably mounted on the sub guide rod 92 on the front side (upstream side in the paper conveyance direction). is doing. In order to move and scan the carriage 93 in the main scanning direction, a timing belt 100 is stretched between a driving pulley 98 and a driven pulley 99 that are rotationally driven by a main scanning motor 97, and the timing belt 100 is moved to the carriage 93. The carriage 93 is driven to reciprocate by forward and reverse rotation of the main scanning motor 97.
On the other hand, in order to convey the paper 83 set in the paper feed cassette 84 to the lower side of the head 94, the paper feed roller 101 and the friction pad 102 for separating and feeding the paper 83 from the paper feed cassette 84 and the paper 83 are guided. A guide member 103, a transport roller 104 that reverses and transports the fed paper 83, a transport roller 105 that is pressed against the peripheral surface of the transport roller 104, and a leading end that defines a feed angle of the paper 83 from the transport roller 104 A roller 106 is provided.

The transport roller 104 is rotationally driven by a sub-scanning motor 107 through a gear train.
Corresponding to the range of movement of the carriage 93 in the main scanning direction, there is provided a printing receiving member 109 which is a sheet guide member for guiding the sheet 83 fed from the conveying roller 104 below the recording head 94. A conveyance roller 111 and a spur 112 that are rotationally driven to send the paper 83 in the paper discharge direction are provided on the downstream side of the printing receiving member 109 in the paper conveyance direction, and the paper 83 is further delivered to the paper discharge tray 86. A roller 113 and a spur 114, and guide members 115 and 116 that form a paper discharge path are disposed.
At the time of recording, the recording head 94 is driven according to the image signal while moving the carriage 93, thereby ejecting ink onto the stopped sheet 83 to record one line. Record the line.
Upon receiving a recording end signal or a signal that the trailing edge of the paper 83 has reached the recording area, the recording operation is terminated and the paper 83 is discharged.

A recovery device 117 for recovering defective ejection of the head 94 is disposed at a position outside the recording area on the right end side in the movement direction of the carriage 93. The recovery device 117 includes a cap unit, a suction unit, and a cleaning unit. The carriage 93 is moved to the recovery device 117 side during printing standby and the head 94 is capped by the capping means, and the ejection port portion is kept in a wet state to prevent ejection failure due to ink drying.
By ejecting ink that is not related to recording during recording or the like, the ink viscosity of all the ejection ports is made constant and stable ejection performance is maintained. When a discharge failure occurs, the discharge port (nozzle) of the head 94 is sealed with a capping unit, and bubbles and the like are sucked out from the discharge port with the suction unit through the tube. Is removed by the cleaning means to recover the ejection failure.
The sucked ink is discharged to a waste ink reservoir (not shown) installed at the lower part of the main body and absorbed and held by an ink absorber inside the waste ink reservoir.

As described above, since the inkjet head embodying the present invention is mounted in this inkjet recording apparatus, there is no ink droplet ejection failure due to vibration plate drive failure, stable ink droplet ejection characteristics are obtained, and image quality is improved. improves.
The numerical values such as film thickness and materials described in the above embodiments are not limited to these.

DESCRIPTION OF SYMBOLS 1 Liquid chamber board | substrate as one element of a partition board | substrate 2 Nozzle plate 9 Piezoelectric material as an electromechanical conversion element 14 Discharge chamber 20 Nozzle hole 21 Droplet 95 Head as a droplet discharge head

JP 2002-160361 A JP 2007-175902 A JP 2002-113866 A

Claims (8)

A nozzle plate having a plurality of nozzle holes for discharging droplets;
A discharge chamber partitioned by a partition wall and communicating with the nozzle hole;
A partition substrate on which the discharge chamber is formed;
A diaphragm configured as at least one partition wall of the discharge chamber;
An electromechanical transducer that is provided on one surface of the diaphragm and converts electrical energy into mechanical energy to be applied to the diaphragm;
In a droplet discharge head equipped with
The droplet is characterized in that the diaphragm is a laminated film, and a side surface of a through hole as a liquid supply hole formed in the diaphragm is covered with any film forming the diaphragm. Discharge head. The droplet discharge head according to claim 1,
The liquid droplet ejection head according to claim 1, wherein the film covering the side surface of the through hole is either a silicon oxide film or a silicon nitride film. The droplet discharge head according to claim 1,
The liquid droplet ejection head, wherein the film covering the side surface of the through hole is a metal or a metal oxide. The droplet discharge head according to claim 3,
The liquid droplet ejection head, wherein the metal oxide is any one of TiN, Pt, PZT, LNO, SRO, and Al ₃ O ₂ . The droplet discharge head according to claim 1,
A liquid droplet ejection head, wherein the film covering the side surface of the through hole is made of resin. The droplet discharge head according to claim 5,
A droplet discharge head, wherein the resin is a photosensitive resin or an electrodeposited polyimide resin. In an ink cartridge in which a droplet discharge head that discharges ink droplets and an ink tank that supplies ink to the droplet discharge head are integrated,
An ink cartridge, wherein the droplet discharge head is the droplet discharge head according to any one of claims 1 to 6. In an image forming apparatus for forming an image by discharging droplets from a droplet discharge head,
An image forming apparatus, wherein the droplet discharge head is the droplet discharge head according to claim 1.

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