JP2012061704A - Liquid droplet ejection head, head cartridge, image forming apparatus, and micro pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently cool a driver IC by bringing the driver IC into direct contact with a cooling medium.SOLUTION: A liquid droplet ejection head includes: a nozzle plate having a plurality of nozzle holes for ejecting liquid droplets; an individual liquid chamber substrate in which a pressure chamber and an actuator are formed corresponding to each of nozzle holes; a driver IC for output of driving signals for driving the actuator; and a common liquid chamber substrate in which a common liquid chamber and a supply port for supplying the liquid droplets to the pressure chamber are provided. The driver IC is arranged immediately above the individual liquid chamber substrate and is cooled by coming into direct contact with the cooling medium.

Description

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

  An ink jet recording apparatus used as an image forming apparatus (image recording apparatus) such as a printer, a facsimile machine, a copying apparatus, etc. uses plain paper with extremely low noise during recording, high-speed printing, high degree of freedom of ink, and low cost. It has many advantages such as being usable. Also, among ink jet recording devices, the ink-on-demand method, which ejects ink droplets only when recording is necessary, does not require the collection of ink droplets that are not necessary for recording, and has now become mainstream. Yes.

  Such an ink jet recording apparatus adds a nozzle that discharges ink droplets, a discharge chamber (also referred to as a pressurized liquid chamber, a pressure chamber, an ink flow path, and the like) that communicates with the nozzle, and ink in the discharge chamber. A droplet discharge head including pressure generating means for generating pressure to be pressed is mounted. The droplet discharge head discharges ink droplets from the nozzles by pressurizing the ink in the discharge chamber with the pressure generated by the pressure generating means.

  The droplet discharge head uses a piezoelectric type that discharges ink droplets by deforming and displacing the diaphragm forming the wall surface of the discharge chamber using an electromechanical transducer element such as a piezoelectric element as a pressure generating means, There is known 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 a room and ink droplets are ejected. In addition, the piezoelectric type includes a longitudinal mode, a lateral mode (bend mode) type, and a shear mode type using shear deformation. Among them, in recent years, with the advance of semiconductor processes and micromachining technology, patterning technology has been established, and the configuration of an actuator that directly forms a discharge chamber and a piezoelectric element on a low-cost Si substrate has been studied.

  Further, in order to realize high integration for the purpose of downsizing the droplet discharge head, a driver IC (Integrated Circuit) that supplies a drive signal for vibrating the actuator is provided with an individual liquid in which the above-described discharge chamber and actuator are formed. A droplet discharge head mounted directly on a chamber substrate has been studied. However, the driver IC is driven by an actuator that ejects ink droplets, so that the temperature rises and the amount of heat generated per unit area increases. Therefore, the driver IC needs to be cooled.

  Therefore, conventionally, for example, a method is known in which a portion of the driver board where the circulation flow path is routed is cooled by drawing a circulation flow path connecting the discharge port of the head and the recovery tank to the driver board (for example, , See Patent Document 1).

  Further, the cooling medium flow path is provided so as to abut the periphery of a support plate that supports a recording element substrate having a discharge port that discharges the liquid and a recording element that generates discharge energy for discharging the liquid from the discharge port. A method of forming and cooling the recording head is known (for example, see Patent Document 2).

  However, in the method of Patent Document 1 described above, the circulation flow path is configured to be routed around the driver board on which the driver IC is disposed, but the circulation flow path is close to the periphery of the driver IC. Since it is only provided, the driver IC cannot be cooled efficiently. Further, the above-described method of Patent Document 2 does not directly cool the driver IC, but only cools the support plate.

  The present invention has been made in view of the above problems, and includes a droplet discharge head, a head cartridge, an image forming apparatus, and a micropump that efficiently cool a driver IC by directly contacting the cooling medium with the driver IC. The purpose is to provide.

  In order to achieve the above object, the present invention provides a nozzle plate having a plurality of nozzle holes for discharging droplets, and an individual liquid chamber provided with a pressure chamber and an actuator formed corresponding to each of the nozzle holes. A droplet discharge head comprising a substrate, a driver IC that outputs a drive signal for driving the actuator, and a common liquid chamber substrate provided with a supply port for supplying droplets to the pressure chamber and a common liquid chamber. The driver IC is disposed immediately above the center of the individual liquid chamber substrate and is cooled by being in direct contact with a cooling medium.

  According to another aspect of the present invention, there is provided a head cartridge comprising the above-described droplet discharge head and an ink tank that supplies ink to the droplet discharge head. According to another aspect of the present invention, there is provided an image forming apparatus including the above-described droplet discharge head.

  According to another aspect of the present invention, there is provided a micropump including the above-described droplet discharge head and transporting the droplet by deformation of the diaphragm.

  According to the present invention, the driver IC can be efficiently cooled by directly contacting the cooling medium.

It is the figure which looked at the droplet discharge head concerning a 1st embodiment of the present invention from right above. FIG. 2 is a cross-sectional view taken along the line AA ′ of the droplet discharge head of FIG. 1. It is sectional drawing along BB 'of the droplet discharge head of FIG. FIG. 4 is a process diagram in a cross section taken along the line BB ′ of FIG. It is sectional drawing along AA 'of the droplet discharge head which concerns on 2nd Embodiment of this invention. FIG. 6 is an exploded perspective view of a frame of a droplet discharge head and a common liquid chamber substrate according to a second embodiment of the present invention. It is sectional drawing along AA 'of the droplet discharge head which concerns on 3rd Embodiment of this invention. It is a perspective view of the head cartridge which concerns on 4th Embodiment of this invention. It is a perspective view which shows an example of the inkjet recording device which concerns on 5th Embodiment of this invention. It is a side view which shows an example of the inkjet recording device which concerns on 5th Embodiment of this invention. It is sectional drawing of the micropump which concerns on 6th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail.

<First Embodiment: Droplet Discharge Head 1>
FIG. 1 is a view of a droplet discharge head according to the first embodiment of the present invention as viewed from directly above. FIG. 1 is a perspective top view of the nozzle plate, the individual liquid chamber substrate, and the driver IC. 2 is a cross-sectional view taken along the line AA ′ of the droplet discharge head of FIG. 3 is a cross-sectional view taken along the line BB ′ of the droplet discharge head of FIG.

  Here, FIGS. 2 and 3 show only main components for the sake of convenience in order to clearly describe the shape and operation of the droplet discharge head 1 according to the present embodiment, and FIG. 3 shows only one pressure chamber. Show. The droplet discharge head 1 shown in FIGS. 1 to 3 is a side shooter type that discharges ink droplets from nozzle holes provided in a nozzle substrate, and is of a type driven by a piezoelectric actuator. .

  The droplet discharge head 1 according to the first embodiment shown in FIGS. 1 to 3 is configured to have three substrates, a common liquid chamber substrate 10, an individual liquid chamber substrate 20, and a nozzle substrate 30. The common liquid chamber substrate 10 is bonded to one side of the individual liquid chamber substrate 20, and the nozzle plate 30 is bonded to the other side of the individual liquid chamber substrate 20.

  As shown in FIG. 1, a driver IC (Integrated Circuit) 40 for supplying a signal for driving the piezoelectric actuator is provided immediately above the individual liquid chamber substrate 20 at a position substantially in the center of the individual liquid chamber substrate 20. Yes. As shown in FIG. 2, the droplet discharge head 1 has a frame 50 having ink liquid and cooling medium supply ports and discharge ports, and the frame 50 is joined to the common liquid chamber substrate 10. Yes.

  The common liquid chamber substrate 10 includes a common liquid chamber 11, a through hole 12 for supplying ink liquid (recording liquid) to the pressure chamber 22, a space 13 for securing and protecting an operation area of a piezoelectric actuator described later, A cooling medium flow path 14 serving as a cooling medium flow path is provided.

  The individual liquid chamber substrate 20 is formed corresponding to the vibration plate 21 that can vibrate and the nozzle hole 31, and is formed on the side facing the pressure chamber 22 through the vibration plate 21 and the pressure chamber 22 that stores the ink liquid. And a piezoelectric actuator 23 that vibrates the vibration plate 21 to apply pressure to the ink liquid in the pressure chamber 22, a fluid resistance portion 24 that communicates with the pressure chamber 22, and a partition wall 25 that partitions each pressure chamber 22. Has been.

  The pressure chamber 22 communicates with the through hole 12 of the common liquid chamber substrate 10 through the fluid resistance portion 24, and ink is supplied from the through hole 12. As shown in FIG. 3, the piezoelectric actuator 23 is formed by a common electrode 26, a piezoelectric body 27, and an individual electrode 28. Further, the nozzle substrate 30 has a plurality of nozzle holes 31 for ejecting ink droplets.

  As shown in FIGS. 1 to 3, the pressure chambers 22 have an elongated rectangular parallelepiped shape, and are arranged in, for example, two rows along the main scanning direction in the individual liquid chamber substrate 20 and along the sub-scanning direction. For example, they are arranged in a plurality of columns at a resolution of 300 dpi.

  In the first embodiment, as shown in FIG. 1, the output terminal of the driver IC 40 arranged on the individual liquid chamber substrate 20 is bump-bonded with the input terminal of the individual electrode 28 drawn from the piezoelectric actuator 23. The individual liquid chamber substrate 20 is formed with an input wiring for taking in electric power for driving the piezoelectric actuator 23 from the outside, and an input terminal of the driver IC 40 is a terminal for inputting electric power from this input wiring. Etc. are bump-bonded.

  In addition, as shown in FIG. 2, the common liquid chamber substrate 10 has a driver IC 40 disposed almost directly above the center of the individual liquid chamber substrate 20 as described above, and when the common liquid chamber substrate 10 is viewed from directly above, The common liquid chamber substrate 10 is through-processed so that the driver IC 40 is exposed. Therefore, the cooling medium flow path 14 formed by bonding the common liquid chamber substrate 10 to the individual liquid chamber substrate 20 and the frame 50 has a part of the inner wall formed by a part of the surface of the driver IC 40. .

  In the first embodiment, by having the above-described configuration, the driver IC 40 is cooled by heat exchange by directly contacting the cooling medium circulating in the cooling medium flow path 14. Thereby, it is possible to cool the heat generated in the droplet discharge head 1 due to high integration, and to stabilize the electrical characteristics of the driver IC 40. Further, the printing speed can be improved by downsizing the chip.

  Note that the same liquid as the ink droplets can be used as the cooling medium. As a result, the supply pump and the supply tank can be shared to reduce the cost.

<Operation of Droplet Discharge Head 1>
Next, the operation of the droplet discharge head 1 configured as described above will be described. The ink liquid is supplied from the through hole 12 to each pressure chamber 22 via the common liquid chamber 11. Each pressure chamber 22 applies a voltage pulse from the driver IC 40 to the individual electrode 28 in a state where the ink liquid is filled.

  As a result, the piezoelectric body 27 contracts in a direction parallel to the vibration plate 21, and the entire vibration plate 21 in close contact with the piezoelectric actuator 23 is bent toward the pressure chamber 22. The volume in the pressure chamber 22 decreases, the pressure in the pressure chamber 22 rises rapidly, and ink droplets are ejected from the nozzle holes 31 communicating with the pressure chamber 22.

  After the voltage pulse is applied, the contracted piezoelectric body 27 returns to the original position, so that the deflected diaphragm 21 returns to the original position. Therefore, the pressure chamber 22 has a negative pressure as compared with the common liquid chamber 11. Ink liquid is supplied from the common liquid chamber 11 to the pressure chamber 22 through the fluid resistance portion 24.

  By continuously applying this pulse voltage, it becomes possible to discharge ink liquid continuously from the nozzle hole 31 and an image is formed on a recording medium such as a sheet disposed opposite to the droplet discharge head 1. Is done.

<Method for Manufacturing Droplet Discharge Head 1>
Next, a manufacturing method of the droplet discharge head according to the first embodiment will be described with reference to FIG. FIG. 4 shows a process chart in a cross section taken along the line BB ′ of FIG. In the first embodiment, an actuator is created by depositing a diaphragm material and a piezoelectric element material on a silicon substrate 110.

As shown in FIG. 4A, a silicon oxide film 21-1 made of silicon oxide (SiO ₂ ) as an insulating film is formed on one surface of a <100> silicon substrate 110 having a thickness of about 250 [μm]. An SOI (Silicon on Insulator) substrate in which about 1.0 [μm] is bonded to about 0.5 [μm] and single crystal silicon 21-2 that is a material for forming the diaphragm 21 is used. A silicon oxide film 29 made of silicon oxide (SiO ₂ ) is formed on the opposite surface of the silicon substrate 110.

Next, by forming a silicon oxide film 21-3 of about 0.6 [μm] made of silicon oxide (SiO ₂ ) on the surface of the SOI substrate by a pyro oxidation method, the diaphragm 21 is formed. Form.

  Next, as shown in FIG. 4B, a platinum (Pt) layer to be the common electrode 26 of the piezoelectric element is formed to a thickness of about 0.1 [μm] by sputtering and patterned by lithoetch. Further, a piezoelectric material 27 made of lead zirconate titanate (PZT) is formed in a thickness of about 1.0 [μm] by a sputtering method, and a platinum (Pt) layer serving as an individual electrode 28 is formed on the piezoelectric material 27 by a sputtering method. 1 [μm] film is formed.

  Next, as shown in FIG. 4C, the above-described layers to be the piezoelectric material 27 and the individual electrodes 28 are patterned by the lithoetch method using the same mask. As a result, the piezoelectric actuator 23 is formed in a region of the diaphragm 21 that faces the pressure chamber 22.

  Next, as shown in FIG. 4D, the silicon oxide film 29 formed on the opposite surface of the silicon substrate 110 simultaneously with the silicon oxide film 21-1 in FIG. Using the pattern of the silicon oxide film 29 as a mask, the silicon substrate 110 is etched by ICP dry etching to form the pressure chamber 22, the fluid resistance portion 24, and a recess that becomes a part of the common liquid chamber 11.

  Next, as shown in FIG. 4E, the nozzle substrate 30 produced by high-speed electroforming in a sulfamic acid bath is bonded to the pressure chamber 22 side of the individual liquid chamber substrate 20.

  Next, the output terminal and the like of the driver IC 40 are bump-bonded to the input terminal and the like drawn from the individual electrode 28 of the piezoelectric actuator 23. Further, as shown in FIG. 4F, the common liquid chamber in which the common liquid chamber 11, the space 13, the concave portions to be the cooling medium flow path 14, and the like are formed by the lithoetch method using the silicon substrate 110 separately. The substrate 10 is bonded to the surface of the individual liquid chamber substrate 20 on which the piezoelectric element is formed.

  As described above, when the common liquid chamber substrate 10 is formed, as shown in FIG. 2 and the like, for example, a recess, an opening, and the like serving as the cooling medium flow path 14 in direct contact with the cooling medium are formed in the driver IC 40. .

  The common liquid chamber substrate 10 may be a <110> silicon substrate 110 processed by wet etching using an alkaline etching solution such as TMAH or KOH, or may be a molded part such as a resin mold or a metal injection mold.

  Finally, as shown in FIG. 4G, a frame 50 having ink droplets, a cooling medium supply port and a discharge port is joined. Thereby, the droplet discharge head 1 according to the first embodiment is completed.

<Second Embodiment: Droplet Discharge Head>
Next, a liquid droplet ejection head according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a cross-sectional view taken along the line AA ′ of the droplet discharge head according to the second embodiment of the present invention. FIG. 6 is an exploded perspective view of the frame of the droplet discharge head and the common liquid chamber substrate according to the second embodiment of the present invention.

  Compared with the droplet discharge head 1 according to the first embodiment shown in FIG. 2, the droplet discharge head according to the second embodiment shown in FIG. It is different from the shape of the cooling medium flow path 14 of the droplet discharge head 1.

  That is, as shown in FIG. 5, the cooling medium flow path 15 of the droplet discharge head includes a part of the upper surface of the driver IC 40 (the surface facing the frame 50) and a common liquid that constitutes the cooling medium flow path 15. The chamber substrate 10 is configured to be joined to a partial region of the side surface (wall surface). Specifically, as shown in FIG. 5A, the side surface of the common liquid chamber substrate 10 constituting the cooling medium flow path 15 has a convex shape so as to come into contact with the upper surface of the driver IC 40. A convex surface facing the chamber substrate 20 is joined so as to overlap the upper surface of the driver IC 40.

  Here, for example, an adhesive having a cooling medium wettability may be used for a joint portion between the upper surface of the driver IC 40 and the side surface of the common liquid chamber substrate 10 constituting the cooling medium flow path 15.

  As described above, in the second embodiment, after the driver IC 40 is bump-bonded, the common liquid chamber substrate 10 that is penetrated so as to look into the upper surface portion of the driver IC 40 is bonded to the individual liquid chamber substrate 20, and the common liquid chamber The frame 50 is bonded to the substrate 10. As a result, the cooling medium flow path 15 is formed, and the cooling medium flowing through the cooling medium flow path 15 can directly contact the driver IC 40 for heat exchange, so that the heat dissipation effect of the driver IC 40 can be enhanced. It becomes possible.

  As shown in FIG. 6, the frame 50 joined to the common liquid chamber substrate 10 is configured to have a cooling medium supply port 51-1 and a cooling medium discharge port 51-2. Therefore, by joining the frame 50 to the common liquid chamber substrate 10, it is possible to form the cooling medium flow path 15 through which the cooling medium circulates.

  Further, the frame 50 is configured to have ink liquid supply ports 52-1 to 52-2 and ink liquid discharge ports 52-3 to 52-4. Therefore, as described above, the cooling medium flow path 15 formed by using the cooling medium supply port 51-1 and the cooling medium discharge port 51-2 is in parallel with the common liquid chamber 11 in which the ink liquid is supplied and discharged. A flow path can be formed.

  Thus, by forming the cooling medium flow path 15 in parallel with the common liquid chamber 11, for example, the cooling medium flow path 15 has a vibration plate rather than forming the cooling medium flow path 15 in series with the common liquid chamber 11. 21 is less susceptible to pressure fluctuations and ink liquid flow fluctuations. As a result, the cooling medium channel 15 can be supplied with an optimal flow rate for cooling without being significantly affected by the consumption of the discharged liquid.

<Third Embodiment: Droplet Discharge Head>
Next, a droplet discharge head according to a third embodiment of the present invention will be described with reference to FIG. FIG. 7 is a cross-sectional view taken along the line AA ′ of the droplet discharge head according to the third embodiment of the present invention.

  Compared with the droplet discharge heads according to the first embodiment and the second embodiment, the droplet discharge head according to the third embodiment shown in FIG. 7 has an uneven surface on the surface of the driver IC 40 that directly contacts the cooling medium. is doing.

  That is, as shown in FIG. 7B, the surface of the driver IC 40 that is in direct contact with the cooling medium is subjected to uneven processing. Therefore, it is possible to increase the area where the driver IC 40 directly contacts the cooling medium flowing through the cooling medium flow path 16 of the droplet discharge head.

  As a result, the cooling medium flowing through the cooling medium flow path 16 is in direct contact with the driver IC 40 to perform heat exchange, whereby the heat dissipation effect of the driver IC 40 can be enhanced. In addition, the uneven shape in the third embodiment is not particularly limited as long as the area in which the cooling medium and the driver IC 40 are in direct contact with each other is increased as compared with the planar contact.

<Fourth Embodiment: Head Cartridge>
Next, a head cartridge (liquid cartridge: ink tank integrated head) according to a fourth embodiment to which the above-described droplet discharge head of the present invention can be applied will be described with reference to FIG. FIG. 8 is a perspective view of a head cartridge according to the fourth embodiment of the present invention.

  In the fourth embodiment, an ink tank that supplies ink to the droplet discharge head of any of the above-described embodiments is integrated.

  A head cartridge 60 according to the fourth embodiment shown in FIG. 8 includes an inkjet head 61 that is a droplet discharge head according to any of the above-described embodiments having the nozzle holes 31 and the like, and ink that supplies ink to the inkjet head 61. The tank 62 is integrated.

  That is, in the fourth embodiment, any of the droplet discharge heads shown in the above-described embodiments is used for the head cartridge 60 shown in FIG.

  As described above, since the driver IC 40 can be efficiently cooled by using the droplet discharge head according to each of the above-described embodiments, the electrical characteristics of the driver IC 40 are stabilized, and the droplet discharge characteristics vary. Thus, it is possible to improve the reliability and obtain the head cartridge 60 capable of high-quality recording. Further, since the head cartridge 60 is an ink jet head 61 integrated with an ink tank 62, it is possible to reduce the cost while ensuring the reliability of the product.

<Fifth embodiment: inkjet recording apparatus>
Next, an example of an ink jet recording apparatus according to a fifth embodiment to which the above-described droplet discharge head of the present invention can be applied will be described with reference to FIGS. FIG. 9 is a perspective view showing an example of an ink jet recording apparatus according to the fifth embodiment of the present invention, and FIG. 10 is a side view showing an example of the ink jet recording apparatus according to the fifth embodiment of the present invention.

  In the fifth embodiment, an inkjet head that is a droplet discharge head according to the present invention is mounted on an inkjet recording apparatus that is an image forming apparatus.

  An ink jet recording apparatus 70 according to the fifth embodiment shown in FIG. 9 has a carriage movable in the main scanning direction inside a recording apparatus main body 71, a recording head comprising the ink jet head according to the present invention mounted on the carriage, and a recording head. A printing mechanism 72 including an ink cartridge for supplying ink and the like are accommodated. In addition, a sheet feeding cassette (or a sheet feeding tray) 74 on which a large number of sheets 73 can be stacked from the front side can be detachably attached to the lower part of the apparatus main body 71.

  Further, the ink jet recording apparatus 70 opens the manual feed tray 75 for manually feeding the paper 73 and takes in the paper 73 fed from the paper feed cassette 74 or the manual feed tray 75, and the printing mechanism unit 72 performs the required operation. After the image is recorded, it is discharged to a discharge tray 76 mounted on the rear side.

  The printing mechanism 72 holds the carriage 83 slidably in the main scanning direction by a main guide rod 81 and a sub guide rod 82 which are guide members horizontally mounted on left and right side plates (not shown). Further, the carriage 83 is a recording composed of an ink jet head which is a droplet discharge head according to the present invention for discharging ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). The head 84 is mounted with a plurality of ink discharge ports (nozzles) arranged in a direction crossing the main scanning direction, and the ink droplet discharge direction is directed downward.

  In addition, each ink cartridge 85 for supplying ink of each color to the recording head 84 is replaceably mounted on the carriage 83. In the present embodiment, the above-described head cartridge (ink cartridge) according to the present invention may be mounted.

  The ink cartridge 85 has an atmosphere port communicating with the atmosphere above, a supply port for supplying ink to the inkjet head below, and a porous body filled with ink inside, and a capillary tube for the porous body. The ink supplied to the inkjet head is maintained at a slight negative pressure by force. Further, here, the recording heads 84 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 83 is slidably fitted to the main guide rod 81 on the rear side (downstream side in the paper conveyance direction), and slidably mounted on the secondary guide rod 82 on the front side (upstream side in the paper conveyance direction). It is location. In order to move and scan the carriage 83 in the main scanning direction, a timing belt 90 is stretched between a driving pulley 88 and a driven pulley 89 that are rotationally driven by a main scanning motor 87, and the timing belt 90 is fixed to the carriage 83. The carriage 83 is reciprocated by forward and reverse rotation of the main scanning motor 87.

  On the other hand, in order to convey the paper 73 set in the paper feed cassette 74 to the lower side of the recording head 84, the paper feed roller 91 and the friction pad 92 for separating and feeding the paper 73 from the paper feed cassette 74 and the paper 73 are guided. Guide member 93, a conveyance roller 94 that reverses and conveys the fed paper 73, a conveyance roller 95 that is pressed against the peripheral surface of the conveyance roller 94, and a tip that defines a feeding angle of the paper 73 from the conveyance roller 94 A roller 96 is provided. The transport roller 94 is rotationally driven by a sub-scanning motor 97 through a gear train.

  Corresponding to the range of movement of the carriage 83 in the main scanning direction, there is provided a printing receiving member 99 which is a sheet guide member for guiding the sheet 73 fed from the conveying roller 94 below the recording head 84.

  A conveyance roller 101 and a spur 102 that are rotationally driven to send out the paper 73 in the paper discharge direction are provided on the downstream side of the printing receiving member 99 in the paper conveyance direction, and a paper discharge roller that sends out the paper 73 to the paper discharge tray 76. 103, a spur 104, and guide members 105 and 106 that form a paper discharge path are disposed.

  At the time of recording, the recording head 84 is driven according to the image signal while moving the carriage 83 to eject ink onto the stopped sheet 73 to record one line, and after conveying the sheet 73 by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 73 has reached the recording area, the recording operation is terminated and the sheet 73 is discharged.

  Further, a recovery device 107 for recovering defective ejection of the recording head 84 is disposed at a position outside the recording area on the right end side in the moving direction of the carriage 83. The recovery device 107 includes a cap unit, a suction unit, and a cleaning unit.

  The carriage 83 moves to the recovery device 107 side during printing standby, capping the recording head 84 by the capping unit, and keeps the ejection port portion in a wet state to prevent ejection 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 stable ejection performance is maintained.

  When a discharge failure occurs, the discharge port (nozzle) of the recording head 84 is sealed by the capping unit, and bubbles and the like are sucked out from the discharge port by the suction unit through the tube. Etc. are 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, in the fifth embodiment, the driver IC 40 can be efficiently cooled by applying any one of the above-described droplet discharge heads to the recording head 84 of the inkjet recording apparatus 70. It becomes. As a result, it is possible to stabilize the electrical characteristics of the driver IC 40 and to obtain an image forming apparatus capable of recording a high-quality image with little variation in droplet discharge characteristics.

  In addition, although the droplet discharge head has been used as an example of each embodiment described above, the piezoelectric actuator according to the present invention can be used as an optical device such as an optical scanning mirror or an optical valve.

<Sixth Embodiment: Micro Pump>
Next, a micro pump 120 according to a sixth embodiment to which the above-described configuration of the present invention is applied will be described with reference to FIG. It is sectional drawing of the micropump which concerns on 6th Embodiment of this invention.

  In the micropump 120 according to the sixth embodiment shown in FIG. 11, the pressure generation chamber and the gap are opposed to each other with a diaphragm 121 including a piezoelectric element sandwiched between electrodes, and a plurality of combinations of these are provided. Yes. The diaphragm 121 has a laminated structure in which a piezoelectric material is sandwiched between an individual electrode 122 and a common electrode 123 and sandwiched between insulating films. In addition, a fluid flows through the flow path 124.

  The fluid in the flow path 124 flows in the direction of the arrow in FIG. 11 when the diaphragm 121 including the piezoelectric element is sequentially driven from the right side in the drawing. Thus, the micropump 120 can transport a fluid. In the sixth embodiment, an example in which a plurality of diaphragms 121 are provided is shown, but only one diaphragm 121 may be provided.

  As described above, the operation principle of the sixth embodiment has been briefly described. However, by applying the configuration and manufacturing method of the first embodiment to the sixth embodiment, a large flow rate of liquid can be efficiently fed. It is possible to obtain a micropump 120 having a high driving force (transport force).

  In the sixth embodiment, the driver IC 125 can be efficiently cooled by including the droplet discharge heads or head cartridges according to the above-described embodiments. As a result, the electrical characteristics of the driver IC 125 can be stabilized, there is little variation in the droplet ejection characteristics, the reliability can be improved, the cost can be reduced, and the micropump 120 capable of high-quality recording can be obtained. It becomes. In addition, the structure of this invention is applicable also to a liquid transport device.

  As described above, according to the present embodiment, the driver IC can be efficiently cooled by directly contacting the cooling medium.

The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to that described in the above embodiments, and various modifications can be made without departing from the scope of the invention. Is possible.

DESCRIPTION OF SYMBOLS 1 Droplet discharge head 10 Common liquid chamber board | substrate 11 Common liquid chamber 12 Through-hole 13 Spaces 14-16 Cooling medium flow path 20 Individual liquid chamber board | substrate 21 Diaphragm 21-1, 21-3, 29 Silicon oxide film 21-2 Single Crystalline silicon 22 Pressure chamber 23 Piezoelectric actuator 24 Fluid resistance portion 25 Partition 26 Common electrode 27 Piezoelectric body 28 Individual electrode 30 Nozzle substrate 31 Nozzle hole 40 Driver IC
50 Frame 51-1 Cooling medium supply port 51-2 Cooling medium discharge port 52-1 to 52-2 Ink liquid supply port 52-3 to 52-4 Ink liquid discharge port 60 Head cartridge 61 Inkjet head 62 Ink tank 70 Inkjet recording Device 71 recording device main body 72 printing mechanism 73 paper 74 paper feed cassette 75 manual feed tray 76 paper discharge tray 81 main guide rod 82 sub guide rod 83 carriage 84 recording head 85 ink cartridge 87 main scanning motor 88 driving pulley 89 driven pulley 90 timing Belt 91 Feed roller 92 Friction pad 93 Guide member 94 Transport roller 95 Transport roller 96 End roller 97 Sub-scanning motor 99 Printing receiving member 101 Transport roller 102, 104 Spur 103 Discharge roller 105, 106 Guide member 107 times Recovery device 110 Silicon substrate 120 Micro pump 121 Diaphragm 122 Individual electrode 123 Common electrode 124 Flow path 125 Driver IC

JP 2009-241316 A JP 2009-132095 A

Claims (8)

A nozzle plate having a plurality of nozzle holes for discharging droplets, an individual liquid chamber substrate provided with a pressure chamber and an actuator corresponding to each of the nozzle holes, and a drive signal for driving the actuator are output. A droplet discharge head comprising a driver IC for performing the operation, a supply port for supplying droplets to the pressure chamber, and a common liquid chamber substrate provided with a common liquid chamber,
The liquid droplet ejection head, wherein the driver IC is disposed immediately above the center of the individual liquid chamber substrate and is cooled by being in direct contact with a cooling medium.   The droplet discharge head according to claim 1, wherein the surface of the driver IC that is in direct contact with the cooling medium has an uneven shape.   The droplet discharge head according to claim 1, wherein an output terminal of the driver IC is bump-bonded to an input terminal drawn out from the actuator.   The droplet discharge head according to claim 1, wherein the same liquid as the discharge droplet is used for the cooling medium.   The droplet discharge head according to claim 1, wherein a cooling medium flow path through which the cooling medium flows is formed in parallel with the common liquid chamber.   6. A head cartridge comprising: the droplet discharge head according to claim 1; and an ink tank that supplies ink to the droplet discharge head.   An image forming apparatus comprising the droplet discharge head according to claim 1.   A micropump comprising the droplet discharge head according to any one of claims 1 to 5, wherein the liquid is transported by deformation of the diaphragm.

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