JP2016165853A - Droplet discharge head, liquid cartridge, and image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an adhesive from flowing out to an actuator part.SOLUTION: A droplet discharge head includes: a nozzle substrate 300 having a nozzle hole 16; an actuator substrate 100 having a passage formation layer, which has a liquid chamber 15 communicating with the nozzle hole 16 and a liquid chamber division wall 14, a diaphragm 13 forming a part of a wall surface of the liquid chamber 15, and a piezoelectric element 12 disposed at a surface of the diaphragm 13 which is opposite to the liquid chamber 15; and a support substrate 200 which includes an air gap formed in a portion facing the piezoelectric element 12 and is joined to the actuator substrate 100 by an adhesive 49. The actuator substrate 100 and the support substrate 200 have joint parts 47, 48 which are jointed to or contact with each other. A joint part of the actuator substrate 100 comprises two or more joint parts 47a, 48a having different heights from the diaphragm 13.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a droplet discharge head, a liquid cartridge, and an image forming apparatus.

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, or a multifunction machine of these, an apparatus including a droplet discharge head is used, and a recording medium (hereinafter also referred to as paper, but the material is not limited; While recording media, recording paper, transfer materials, recording paper, etc. are used in the same way), image formation (recording, printing, printing, printing is also synonymous) with ink as a liquid (recording liquid) attached to the paper A so-called ink jet type image forming apparatus (also referred to as an ink jet recording apparatus) is known.

  In recent years, inkjet recording apparatuses have become widespread due to advances in printing speed, image quality, price reduction, and miniaturization. A droplet discharge head used in such an ink jet recording apparatus generally has a plurality of nozzle rows, a plurality of individual liquid chambers (pressure chambers) communicating with the nozzle rows, and the plurality of individual liquid chambers. In general, a common liquid chamber having a relatively large volume is communicated. By selectively applying energy to the individual liquid chamber, the individual liquid chamber can be deformed, and droplets can be ejected to form an arbitrary image on demand. As energy application media (also referred to as drive means or actuators), for example, piezoelectric elements, heater chips, and the like are known.

  Droplet discharge heads used in inkjet recording devices are required to output higher quality images at higher printing speeds (higher printing speed and higher image quality), and demand for higher image quality. However, the number of nozzles tends to be increased to increase the density.

  In the actuator substrate on which the actuator used for the droplet discharge head is mounted, the height of the liquid chamber is, for example, about 100 [um], but if the actuator substrate is thinned to the height of the liquid chamber, handling in the subsequent steps (inside the processing apparatus) The actuator substrate is easily cracked during the transfer and the transfer between processes, and stable production cannot be performed. Therefore, before thinning the actuator substrate, the support substrate on which the liquid flow path and the like are formed is joined with an adhesive to reinforce the actuator substrate.

  Here, since the actuator part (diaphragm and piezoelectric element) of the actuator board is a movable part, when the actuator board and the support board are joined, the actuator part is not in contact with the support board directly. Is provided with a convex joint.

  However, an adhesive having a thickness of about 1 to 4 [um] is formed on the support substrate side using a thin film transfer technique, and then joined to the convex portion of the actuator substrate when joined to the actuator substrate by a general joining technique. The adhesive may protrude from the joint surface and solidify at the actuator portion. When the adhesive is solidified in the actuator portion, the displacement of the diaphragm is suppressed, the original characteristics cannot be obtained, and the characteristics vary among the actuators.

  As a technique for controlling the flow of such an adhesive, for example, in Patent Document 1, the flow of the adhesive is prevented by providing a recess on the support substrate side of the joint.

  Moreover, in patent document 2, the bank for preventing an adhesive agent is provided in the actuator board | substrate side, and the flow-out of an adhesive agent is prevented.

  However, as in Patent Document 1, in the structure in which the concave portion is provided on the support substrate side of the joint portion, the joint area is reduced and the joint strength is lowered. Further, it is necessary to pattern the support at least twice, which increases the cost.

  Further, in the method of providing a dike for damming the adhesive on the actuator substrate side as in Patent Document 2, an extra structure is required on the substrate, so that the nozzle density per unit area is reduced. It may become an obstacle to the improvement of quality and image quality. On the other hand, if the pattern is too thin, the pattern collapses and becomes defective.

  Therefore, an object of the present invention is to provide a droplet discharge head that can prevent an adhesive from flowing out to an actuator portion.

  In order to achieve such an object, a liquid droplet ejection head according to the present invention includes a nozzle substrate having nozzle holes, a liquid channel communicating with the nozzle holes, a flow path forming layer having a liquid chamber partition wall, and a wall surface of the liquid chamber. And an actuator substrate having a piezoelectric element disposed on a surface opposite to the liquid chamber of the diaphragm, and a gap is formed in a portion facing the piezoelectric element, and an adhesive is formed on the actuator substrate. And the actuator substrate and the support substrate have joint portions that are joined or in contact with each other, and the joint portions of the actuator substrate have two or more different heights from the diaphragm It consists of a joint part.

  According to the present invention, it is possible to prevent the adhesive from flowing out to the actuator portion.

It is sectional drawing of the liquid chamber short direction in (a) a part without a piezoelectric element of a droplet discharge head, and (b) a part with a piezoelectric element. It is sectional drawing of the liquid chamber longitudinal direction of a droplet discharge head. FIG. 4 is a cross-sectional view in the lateral direction of the liquid chamber in the portion (a) where there is no piezoelectric element and (b) the portion where there is a piezoelectric element of the liquid droplet ejection head according to Example 1. FIG. 6 is a cross-sectional view in the lateral direction of the liquid chamber in a portion (a) where there is no piezoelectric element and (b) a portion where there is a piezoelectric element of a droplet discharge head according to Example 2. FIG. 6 is a cross-sectional view in the lateral direction of the liquid chamber in a portion (a) where there is no piezoelectric element and (b) a portion where there is a piezoelectric element of a droplet discharge head according to Example 3. FIG. 6A is a cross-sectional view (1) in a lateral direction of a liquid chamber at a portion (a) without a piezoelectric element and (b) a portion with a piezoelectric element of a droplet discharge head according to Example 4. Sectional view (2) in the short direction of the liquid chamber in the portion (a) where there is no piezoelectric element and (b) the portion where the piezoelectric element is provided in the case where a plurality of recesses are provided on the support substrate of the droplet discharge head according to Example 4. ). FIG. 10 is a cross-sectional view (3) in the lateral direction of the liquid chamber in a portion (a) where there is no piezoelectric element and (b) a portion where there is a piezoelectric element when a recess has a multi-stage structure. FIG. 7A is a cross-sectional view of a liquid droplet ejection head according to Example 5 in a lateral direction of a liquid chamber in a portion where (a) a piezoelectric element is not present and (b) a portion where a piezoelectric element is present. 2 is a perspective view of a recording apparatus equipped with a droplet discharge head. FIG. FIG. 6 is a side cross-sectional view illustrating a configuration of a mechanism unit of a recording apparatus equipped with a droplet discharge head.

(Droplet ejection head)
The droplet discharge head according to this embodiment includes a nozzle substrate (300) having nozzle holes (16), a flow path forming layer having a liquid chamber (15) and a liquid chamber partition wall (14) communicating with the nozzle holes (16). An actuator substrate having a diaphragm (13) constituting a part of the wall surface of the liquid chamber (15) and a piezoelectric element (12) disposed on the surface of the diaphragm (13) opposite to the liquid chamber (15). 100) and a support substrate (200) in which a gap is formed in a portion facing the piezoelectric element (12) and bonded to the actuator substrate (100) with an adhesive (49), the actuator substrate (100) and The support substrate (200) has joints (47, 48) that join or contact each other, and the joint of the actuator substrate (100) has two or more joints (height from the diaphragm (13) ( 47a, 4 Consisting of a). In addition, the code | symbol in embodiment and the example of application are shown in a parenthesis.

  That is, by making a difference in the height of the joint (including the case of contact), it is possible to suppress the excess adhesive from protruding into the diaphragm region. Therefore, it is possible to prevent variation in vibration displacement due to the protrusion of the adhesive to the diaphragm, and to realize a highly accurate and reliable droplet discharge head, and thus a droplet discharge device.

  Hereinafter, the configuration according to this embodiment will be described in detail based on the embodiment shown in FIGS.

  FIGS. 1A, 1B and 2 are cross-sectional views of a droplet discharge head 1 having a piezoelectric actuator of this embodiment. FIG. 1A is a cross-sectional view in the short direction of the liquid chamber where no piezoelectric element is disposed and there is no liquid chamber, and FIG. FIG. 2 is a sectional view in the longitudinal direction of the liquid chamber.

  As shown in FIGS. 1A, 1B and 2, the droplet discharge head 1 discharges the recording liquid in the liquid chamber 15 to the recording medium through the nozzle holes 16. The liquid chamber 15 is formed by the actuator substrate 100 and the nozzle substrate 300, and is partitioned by the liquid chamber partition wall 14. The diaphragm 13 is located on the opposite surface of the nozzle substrate 300, and the piezoelectric element 12 sandwiched between the common electrode 10 (lower electrode) and the individual electrode 11 (upper electrode) is disposed on the opposite surface of the diaphragm 13 to the liquid chamber 15. Is installed. The piezoelectric element 12 is sandwiched between the common electrode 10 and the individual electrode 11, and a wiring layer is laminated on each electrode layer to apply a voltage. In this embodiment, the lower electrode is a common electrode and the upper electrode is an individual electrode. However, the lower electrode may be an individual electrode and the upper electrode may be a common electrode.

  The actuator substrate 100 and the support substrate 200 have bonding portions 47 and 48 that are bonded to or in contact with the counterpart substrate, respectively. The joint portion of the actuator substrate 100 includes a joint portion 48a (first joint portion) in a peripheral portion where the piezoelectric element 12 is installed, and a joint portion 47a (second joint portion) in the other portion. The joint part on the support substrate 200 side facing the joint part 48a is called a joint part 48b, and the joint part on the support substrate 200 side facing the joint part 47a is called a joint part 47b. An adhesive 49 is formed at each joint location. Therefore, the joint portion 47 includes the joint portion 47a, the adhesive 49, and the joint portion 47b, and the joint portion 48 includes the joint portion 48a, the adhesive 49, and the joint portion 48b.

  In the example of FIG. 1, the joint portions 47 a and 48 a are formed by the interlayer insulating film 45, the wiring layer 42, and the passivation film 50.

  The droplet discharge head 1 is formed by bonding the actuator substrate 100, the support substrate 200, and the nozzle substrate 300.

  In the droplet discharge head 1, when a signal from the control unit based on image data is received in a state where each liquid chamber 15 is filled with recording liquid (ink), the piezoelectric element 12 receives, for example, 20 [V]. The pulse voltage is applied.

  When a voltage pulse is applied to the piezoelectric element 12, the piezoelectric element 12 contracts in a direction parallel to the diaphragm 13 due to an electrostrictive effect, and the diaphragm 13 bends in the direction of the liquid chamber 15. As a result, the pressure in the liquid chamber 15 rapidly increases, and the recording liquid is ejected from the nozzle holes 16 communicating with the liquid chamber 15.

  After applying the pulse voltage, the contracted piezoelectric element 12 returns to its original state. Then, since the deflected diaphragm 13 returns to the original position, the liquid chamber 15 has a negative pressure compared to the common liquid chamber, and the recording liquid supplied from the outside via the droplet supply port 66 is the common liquid. The liquid is supplied from the droplet supply path 19 and the common liquid chamber 18 to the liquid chamber 15 via the fluid resistance portion 17. By repeating the application of the voltage pulse at an arbitrary timing, the droplets are ejected to the target location of the recording medium, and an image is formed on the recording medium disposed facing the droplet ejection head 1.

  The pulse voltage is applied to the individual electrode 11 corresponding to the nozzle hole 16 from which the recording liquid is to be ejected by the oscillation circuit through the wiring layer 42 (lead-out wiring) and the connection hole formed in the interlayer insulating film 45. Is done.

<Example 1>
Hereinafter, examples and comparative examples of the droplet discharge head according to the present invention will be described.

  FIG. 3 is a cross-sectional view of the actuator substrate 100 of the droplet discharge head according to the first embodiment in the lateral direction of the liquid chamber. The production method is shown below.

  As the actuator substrate 100, for example, the diaphragm 13 is formed on a silicon single crystal substrate (for example, a plate thickness of 400 [μm]) having a plane orientation (110). The diaphragm 13 may be either a single layer or a laminated film as long as the function as the diaphragm and the later process consistency are ensured.

For example, as the material of the diaphragm 13, a silicon oxide film, a polysilicon film, an amorphous silicon film, or a silicon nitride film is used by a LP-CVD method (Low Pressure-Chemical Vapor Deposition). A film is formed on the laminate so that the diaphragm has rigidity. In view of process consistency, diaphragm rigidity, and stress of the entire diaphragm 13, the number of stacked layers is preferably about 3 to 7 layers. In order to ensure adhesion with the later common electrode 10, the uppermost layer of the diaphragm 13 is a silicon oxide film formed by LP-CVD. Thereafter, the common electrode 10 is formed by sputtering, for example, by 20 [nm] and 160 [nm], respectively. Examples of the layer configuration of the common electrode 10 include titanium dioxide (TiO ₂ ) as an insulating protective film and platinum (Pt) and iridium (Ir) as conductor layers.

For example, the insulating protective film TiO ₂ is formed as follows. After Ti is formed by sputtering, the formed titanium film is thermally oxidized using an RTA (Rapid Thermal Annealing) apparatus to form a titanium oxide film. The conditions for thermal oxidation are, for example, a temperature in the range of 650 [° C.] to 800 [° C.], a treatment time in the range of 1 [min] to 30 [min], and an O ₂ atmosphere. To form the titanium oxide film, reactive sputtering may be used, but thermal oxidation of the titanium film at a high temperature is desirable.

  Next, lead zirconate titanate (PZT) is formed on the common electrode 10 as a piezoelectric element 12 in a plurality of times, for example, by spin coating, and finally a film having a thickness of 2 [μm] is formed. Next, an individual electrode 11 made of strontium ruthenate (SRO) and Pt is formed by sputtering to a thickness of 40 [nm] and 100 [nm], respectively. Ir or the like may be used as the individual electrode 11. Here, the film forming method of the piezoelectric element 12 is not limited to the spin coating method, and may be formed by, for example, a sputtering method, an ion plating method, an air sol method, a sol gel method, an ink jet method, or the like. The piezoelectric element 12 is not limited to PZT, and for example, lead lanthanum zirconate titanate (PLZT) to which elements other than Pb, Zr, and Ti are added may be used. Then, the piezoelectric element 12 and the individual electrode 11 are formed at a position corresponding to the liquid chamber 15 to be formed later by a pattern formation method (lithoetch method) using a photolithography technique and an etching technique.

  In the present embodiment, the piezoelectric element 12 is formed at a position corresponding to the joint portion 48a (details will be described later).

Next, an interlayer insulating film 45 is formed to insulate the common electrode 10 and the piezoelectric element 12 from the wiring layer 42 to be formed later. As the interlayer insulating film 45, a silicon dioxide (SiO ₂ ) film having a thickness of 1000 nm is formed by, for example, a plasma CVD method (plasma-enhanced chemical vapor deposition). The interlayer insulating film 45 may be a film other than the SiO _{2 of the} plasma CVD method as long as it does not affect the piezoelectric element 12 and the electrode material and has an insulating property.

  Next, the connection hole 30 for connecting the individual electrode 11 and the wiring layer 42 is formed by a lithoetch method. In the case where the common electrode 10 is connected to the wiring layer 42, a connection hole is similarly formed.

  Next, as the wiring layer 42, for example, titanium nitride (TiN) / aluminum (Al) is formed in a thickness of 30 [nm] / 3 [um] by sputtering. TiN is alloyed in the thermal history of the subsequent process by Pt, which is the material of the individual electrode 11 or the common electrode 10, and Al, which is the material of the wiring layer 42, at the bottom of the connection hole 30. It is applied as a barrier layer to prevent alloying in order to prevent film peeling and the like due to stress caused by the above. Further, the wiring layer 42 is also formed at a location that becomes the joint 47a.

  Next, as the passivation film 50, a silicon nitride film having a thickness of 1000 nm is formed by plasma CVD, for example. By forming the passivation film 50, the wiring layer 42 is covered with an insulator, and for example, inexpensive Al or an alloy material containing Al as a main component can be used as the electrode material. As a result, a low-cost and highly reliable droplet discharge head (inkjet head) can be obtained.

  Thereafter, the lead-out wiring pad portion of the wiring layer 42, the piezoelectric element 12 portion, and the common droplet channel 19 are also opened by the lithoetch method.

  Next, the diaphragm 13 is removed by the litho-etching method at the location that becomes the common liquid chamber flow path 19 and the later common liquid chamber 18.

  Next, the support substrate 200 in which the counterbore 67 is formed at a position corresponding to the piezoelectric element 12 and the actuator substrate 100 are bonded with an adhesive via the bonding portions 47 and 48. In this embodiment, the adhesive is applied to the support substrate 200 side by a thickness of about 2 to 4 [um] by a general thin film transfer device. In the present embodiment, the height of the joint 47a from the diaphragm 13 is 4 [um], the height of the joint 48a from the diaphragm 13 is 3 [um], and the joint 47a is made higher. Yes.

  Therefore, when bonding is performed with sufficient pressure at the time of bonding, the gap between the support substrate 200 and the diaphragm 13 is defined by the height of the bonding portion 47, and the adhesive 49 is not excessively pressurized at the bonding portion 48. The protrusion of 49 is suppressed.

  At this time, since the piezoelectric element 12 is not disposed around the joint portion 47, the protrusion of the adhesive 49 is not a problem. Thereafter, in order to form the liquid chamber 15, the common liquid chamber 18, and the fluid resistance portion 17, the actuator substrate 100 is polished by a known technique so as to have a desired thickness t (for example, a thickness of 80 [μm]). Etching may be used in addition to the polishing method. Note that the heights of the joint portions 47 and 48 are not particularly limited as long as the above relationship (the height from the vibration plate 13 satisfies the joint portion 47a> 48a) is satisfied. Moreover, the thickness etc. which apply | coat an adhesive agent are not specifically limited.

  Next, a partition wall portion other than the liquid chamber 15, the common liquid chamber 18, and the fluid resistance portion 17 is covered with a resist by lithography. Thereafter, anisotropic wet etching is performed with an alkaline solution (potassium hydroxide (KOH) solution or tetramethylammonium hydroxide (TMAH) solution) to form the liquid chamber 15, the common liquid chamber 18, and the fluid resistance portion 17. The liquid chamber 15, the common liquid chamber 18, and the fluid resistance portion 17 may be formed by dry etching using an ICP (inductive coupling type) etcher other than anisotropic etching using an alkaline solution.

  Next, the nozzle substrate 300 having the nozzle holes 16 opened at positions corresponding to the separately formed liquid chambers 15 is joined to the actuator substrate 100 to complete the droplet discharge head 1.

  As described above, in the first embodiment, when the joint portions 47 and 48 are compared, the joint portion 48a on the actuator substrate 100 side has a lower height from the diaphragm 13 than the joint portion 47a. It has become. Here, since the joint portions 47b and 48b on the support substrate 200 side have the same height, the thickness of the adhesive 49 in the joint portion 48 is defined by the joint portion height of the joint portion 47a. Regardless of the in-plane pressure difference, the adhesive film thickness at the joint 48 is constant. Accordingly, the adhesive 49 is prevented from protruding to the diaphragm 13 in the region where the piezoelectric element 12 of the diaphragm 13 is provided due to excessive pressure applied to the joint portion 48 during joining. On the other hand, even if the adhesive 49 protrudes from the joint portion 47 corresponding to a position other than the drive portion, a problem hardly occurs.

  Therefore, it is possible to eliminate the drive variation due to the flow of the adhesive 49 to the drive region (actuator portion) of the piezoelectric element 12 positioned around the joint portion 48, and to stably drive the droplet discharge head with high reliability and stability. 1 can be realized with a high yield.

  Here, the joint portions 47 and 48 may be patterned by film formation and etching to form the joint portions 47 and 48, but the layers originally used in the actuator substrate 100 (piezoelectric element 12, interlayer layers). By using the members of the insulating film 45, the wiring layer 42 (wiring member), the wiring protective film, etc.), the flow amount of the adhesive can be suppressed without increasing the process and cost. For example, the piezoelectric element 12 (piezoelectric layer) and the passivation layer 50 are used in the bonding portion 48a, and the wiring layer 42 and the passivation layer 50 are used in the bonding portion 47a. The layer configuration of the joint portions 47a and 48a is not particularly limited as long as the height can be varied.

  By doing in this way, it can be realized only by changing the mask in order to make joints having different heights. In addition, the height itself has a degree of freedom in which the level can be adjusted according to the joining conditions. Therefore, it is possible to obtain a highly reliable droplet discharge head and droplet discharge device that can suppress the variation between bits without increasing the manufacturing cost.

  The droplet discharge head 1 described so far has two types of joints having different heights, but may have three or more types of joints having different heights.

  Further, the droplet discharge head 1 according to the first embodiment can be provided by being incorporated in the incorporated ink cartridge 99 or the inkjet recording apparatus 90.

<Example 2>
The configuration of Example 2 is shown in FIG. In Example 2, in the configuration of Example 1, a plurality of grooves 46 for absorbing the protruding adhesive 49 were provided in the joint portion 47b on the support substrate 200 side. Thereby, since the thickness of the adhesive 49 can be sufficiently reduced in the joint portion 47, the accuracy of the height of the joint portion 47 at the time of adhesion can be increased, and as a result, the support substrate 200 and the actuator substrate can be more stably provided. One hundred gaps could be defined. In addition, the amount of the adhesive 49 protruding from the joint portion 47 could be suppressed. The shape of the groove 46 is not limited to the square groove as shown in FIG. 4, but may be, for example, a V-shape or a U-shape, and the number and position thereof are not particularly limited.

<Example 3>
The configuration of Example 3 is shown in FIG. In Example 3, in the configuration of Example 1, a round shape was provided in a portion that is bonded to the adhesive 49 in the joint portion 48b on the support substrate 200 side. A gray scale mask was applied to the round part, and a pattern was obtained by a lithoetch method. Thereby, the protrusion amount of the adhesive 49 could be further suppressed. The shape to be applied is not limited to the round shape, and may be, for example, a tapered shape as long as the adhesive 49 is allowed to escape. Further, a structure for releasing the adhesive 49 may be provided in the joint portion 48a on the actuator substrate 100 side. Moreover, you may provide in both the junction part 48a and the junction part 48b.

<Example 4>
The configuration of Example 4 is shown in FIG. In the fourth embodiment, in the configuration of the first embodiment, the concave portion 61 is provided in a portion to be bonded to the adhesive 49 in the joint portion 48b on the support substrate 200 side. Thereby, the protrusion amount of the adhesive 49 could be further suppressed. The shape to be applied is not limited to the simple concave shape 61, and may be a concave shape 61a having a plurality of recesses as shown in FIG. 7, or a concave shape 61b having a step in the recess as shown in FIG. . Further, the shape may be provided in the joint portion 48a on the actuator substrate 100 side. Moreover, you may provide in both the junction part 48a and the junction part 48b.

<Example 5>
The configuration of the fifth embodiment is shown in FIG. In this embodiment, in the configuration of the first embodiment, the contact portion where the support substrate 200 and the actuator substrate 100 are in direct contact with each other is not bonded with the adhesive 49 in the portion corresponding to the bonding portion 47 in FIG. . As a result, the gap between the support substrate 200 and the actuator substrate 100 can be defined at the height of the contact portion 47 regardless of the adhesive thickness at the joint portion 47, and a stable pressure can be applied to the joint portion 48. Therefore, the protruding amount of the adhesive 49 could be further suppressed. An example of a method for applying the adhesive 49 is a gravure offset method. In addition, according to the gravure offset method, it is possible to apply | coat an adhesive agent only to a specific site | part.

  Note that the present invention can also be applied to other than the actuator substrate 100 described in the above embodiment. For example, the present invention can also be applied to an actuator substrate configured only by the piezoelectric element 12, the common electrode 10, the individual electrode 11, and the passivation film 50.

(Inkjet recording device)
An example of an ink jet recording apparatus equipped with the droplet discharge head 1 will be described with reference to a perspective view of FIG. 10 and a side view showing a configuration of a mechanism portion of FIG.

  The ink jet recording apparatus 90 includes a carriage 98 that can move in the scanning direction inside the apparatus main body, a droplet discharge head 1 mounted on the carriage 98, an ink cartridge 99 that supplies ink to the droplet discharge head 1, and the like. A mechanism 91 or the like is housed, and a paper feed cassette (or a paper feed tray) 93 capable of stacking a large number of sheets 92 from the front side is detachably mounted on the lower part of the apparatus main body. Further, it has a manual feed tray 94 that is opened to manually feed the paper 92, takes in the paper 92 fed from the paper feed cassette 93 or the manual feed tray 94, and records a required image by the printing mechanism 91. Thereafter, the paper is discharged to a paper discharge tray 95 mounted on the rear side.

  A printing machine rear portion 91 in FIG. 11 holds a carriage 98 slidably in a main scanning direction along a main guide rod 96 and a sub guide rod 97 which are guide members horizontally mounted on left and right side plates. Is a droplet discharge head 1 that discharges yellow (Y), cyan (C), magenta (M), and black (Bk) ink droplets across a plurality of ink discharge ports (nozzles) in the main scanning direction. The ink droplets are mounted with the ink droplet discharge direction facing downward. In addition, each ink cartridge 99 for supplying ink of each color to the droplet discharge head 1 is replaceably mounted on the carriage 98.

  The ink cartridge 99 is provided with an air opening communicating with the atmosphere above, a supply opening for supplying ink to the droplet discharge head 1 below, and a porous body filled with ink inside. The ink supplied to the droplet discharge head 1 is maintained at a slight negative pressure by the capillary force of the porous body. Further, although the droplet discharge head 1 of each color is used as the droplet discharge head 1, a single liquid discharge head having nozzles for discharging ink droplets of each color may be used. In the ink cartridge 99, the droplet discharge head 1 and an ink tank that supplies ink to the droplet discharge head 1 are integrated.

  Here, the carriage 98 is slidably fitted to the main guide rod 96 on the rear side (sheet conveyance downstream side), and the front side (sheet conveyance upstream side) is slidably mounted on the sub guide rod 97. Yes. In order to move and scan the carriage 98 in the main scanning direction, a timing belt 104 is stretched between a driving pulley 102 and a driven pulley 103 that are rotationally driven by the main scanning motor 101, and the timing belt 104 is moved to the carriage 98. The carriage 98 is reciprocally driven by forward and reverse rotations of the main scanning motor 101.

  On the other hand, in order to convey the paper 92 set in the paper feed cassette 93 downward to the droplet discharge head 1, the paper feed roller 105 and the friction pad 106 for separating and feeding the paper 92 from the paper feed cassette 93, and the paper 92 A guide member 107 that guides the sheet 92, a conveyance roller 108 that reverses and conveys the fed paper 92, a conveyance roller 109 that is pressed against the circumferential surface of the conveyance roller 108, and a feeding angle of the sheet 92 from the conveyance roller 108. And a tip roller 110 for defining. The transport roller 108 is rotationally driven through a gear train by a sub-scanning motor.

  In addition, a printing receiving member 111 that is a paper guide member is provided to guide the paper 92 sent out from the transport roller 108 corresponding to the movement range of the carriage 98 in the main scanning direction on the lower side of the droplet discharge head 1. Yes. A conveyance roller 112 and a spur 113 that are rotationally driven to send the paper 92 in the paper discharge direction are provided on the downstream side of the printing receiving member 111 in the paper conveyance direction, and the paper 92 is further discharged to the paper discharge tray 95. A roller 114, a spur 115, and guide members 116 and 117 that form a paper discharge path are disposed.

  When recording with the inkjet recording apparatus 90, the droplet discharge head 1 is driven in accordance with the image signal while moving the carriage 98, thereby discharging ink onto the stopped sheet 92 to record one line. Thereafter, after the sheet 92 is conveyed by a predetermined amount, the next line is recorded. Upon receiving a recording end signal or a signal that the trailing edge of the paper 92 reaches the recording area, the recording operation is terminated and the paper 92 is discharged.

  Further, a recovery device for recovering the ejection failure of the droplet ejection head 1 is disposed at a position outside the recording area on the right end side in the movement direction of the carriage 98. The recovery device has cap means, suction means, and cleaning means. During printing standby, the carriage 98 is moved to the recovery device side, and the droplet discharge head 1 is capped by the capping means to keep the discharge port portion in a wet state, thereby preventing discharge failure due to ink drying. Further, 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 a stable ejection state is maintained.

  Further, when a discharge failure occurs, the discharge outlet (nozzle) of the liquid droplet discharge head 1 is sealed with a capping unit, and bubbles with ink are sucked out from the discharge port by a suction unit through the tube. Ink, dust, etc. adhering to the ink are removed by the cleaning means, and the ejection failure is recovered. The sucked ink is discharged to a waste ink reservoir installed at the lower part of the main body, and is absorbed and held by an ink absorber inside the waste ink reservoir.

  As described above, since the above-described droplet discharge head 1 is mounted in the inkjet recording apparatus 90, stable ink discharge characteristics can be obtained, and image quality can be improved.

  The droplet discharge head 1 may be applied not only to the case where the droplet discharge head 1 is used in the ink jet recording apparatus 90 but also to an apparatus that discharges droplets other than ink, for example, a liquid resist for patterning.

DESCRIPTION OF SYMBOLS 1 Droplet discharge head 10 Common electrode 11 Individual electrode 12 Piezoelectric element 13 Diaphragm 14 Liquid chamber partition 15 Liquid chamber 16 Nozzle hole 17 Fluid resistance part 18 Common liquid chamber 19 Common liquid chamber flow path 30 Connection hole 42 Wiring layer 45 Interlayer insulation Film 46 Grooves 47, 47a, 47b Joint portions 48, 48a, 48b Joint portion 49 Adhesive 50 Passivation film 61 Concave shape 66 Droplet supply port 67 Counterbore 90 Inkjet recording device 91 Printing mechanism portion 92 Recording medium (paper)
93 Paper feed cassette 94 Manual feed tray 95 Paper discharge tray 96 Main guide rod 97 Subordinate guide rod 98 Carriage 99 Ink cartridge 100 Actuator substrate 101 Main scanning motor 102 Drive pulley 103 Driven pulley 104 Timing belt 105 Paper feed roller 106 Friction pad 107 Guide member 108 Conveying roller 109 Conveying roller 110 End roller 111 Printing receiving member 112 Conveying roller 113 Spur 114 Discharge roller 115 Spur 116,117 Guide member 200 Support substrate 300 Nozzle substrate

JP2013-163341A JP 2014-151537 A

Claims (10)

A nozzle substrate having nozzle holes;
A flow path forming layer having a liquid chamber and a liquid chamber partition wall communicating with the nozzle hole, a vibration plate constituting a part of the wall surface of the liquid chamber, and a piezoelectric element disposed on the surface of the vibration plate opposite to the liquid chamber An actuator substrate having
A gap is formed in a portion facing the piezoelectric element, and a support substrate bonded to the actuator substrate by an adhesive, and
The actuator substrate and the support substrate have joints that join or contact each other;
The droplet discharge head, wherein the joint portion of the actuator substrate includes two or more joint portions having different heights from the diaphragm.   The droplet discharge head according to claim 1, wherein the joint portion of the actuator substrate is made of the same layer as a part or all of the layers formed on the actuator substrate. The joint portion of the actuator substrate includes a first joint portion that is a peripheral portion where the piezoelectric element is installed, and a second joint portion that is another portion,
The droplet discharge head according to claim 1, wherein a height of the first joint portion from the diaphragm is lower than a height of the second joint portion from the diaphragm.   4. The droplet discharge head according to claim 3, wherein the first joint portion is thicker than the second joint portion.   The droplet discharge head according to claim 3, wherein an adhesive is not applied to the second joint portion.   The liquid droplet ejection head according to claim 3, wherein one or more grooves are provided in a joint portion of the support substrate facing the second joint portion.   The liquid according to any one of claims 3 to 6, wherein the first joint portion and / or the joint portion of the support substrate facing the first joint portion has a tapered shape or a round shape. Drop ejection head.   The liquid droplet according to any one of claims 3 to 7, wherein a concave portion is provided in the first joint portion and / or the joint portion of the support substrate facing the first joint portion. Discharge head. A droplet discharge head;
In a liquid cartridge integrated with an ink tank for supplying a recording liquid to the droplet discharge head,
A liquid cartridge, wherein the droplet discharge head is the droplet discharge head according to claim 1.   An image forming apparatus comprising the liquid droplet ejection head according to claim 1 or the liquid cartridge according to claim 9.