JP2017193128A - Liquid discharge head, liquid discharge unit and device for discharging liquid - Google Patents

Abstract

Provided is a liquid discharge head capable of improving heat dissipation efficiency. An ink jet recording having a pressure generating chamber 22 communicating with a nozzle 31 for discharging a liquid, a laminated piezoelectric element 5 causing a pressure change in the pressure generating chamber 22, and an FPC 8 connected to the laminated piezoelectric element 5. In the head 10, an exposed portion 81 a exposed from an insulating material covering the FPC 8 is provided on at least a part of the FPC 8, and the exposed portion 81 a is a part (frame) of the inkjet recording head 10 via the heat conductive member 85. 1) is in contact. [Selection] Figure 10

Description

  The present invention relates to a liquid discharge head, a liquid discharge unit, and an apparatus for discharging liquid.

  In general, as a printer, a fax machine, a plotter, or an image forming apparatus that combines a plurality of these functions, for example, a liquid including a liquid discharge head that discharges a recording liquid (liquid) droplet (ink droplet) is discharged. Some apparatuses use an apparatus to form an image by attaching a recording liquid to the medium while conveying the medium.

  Liquid discharge heads are roughly classified into several types according to the type of actuator means for discharging liquid. For example, a part of the wall of the liquid chamber is formed as a thin diaphragm, and a piezoelectric element (piezo element) as an electromechanical conversion element is arranged corresponding to the thin diaphragm, and the diaphragm is deformed by the deformation of the piezoelectric element that occurs when voltage is applied. This is a piezo type that changes the pressure in the pressurized liquid chamber by changing the pressure and discharges ink droplets. A heating element is placed inside the liquid chamber, and bubbles are generated by heating the heating element by energization. A bubble jet (registered trademark) system is known in which ink droplets are ejected by the pressure of the pressure. In addition, an electrostatic force generated by applying an electric field between the diaphragm and the electrode, including a diaphragm that forms a wall surface of the liquid chamber and an individual electrode outside the liquid chamber that is disposed to face the diaphragm. There has also been proposed an electrostatic type in which an ink droplet is ejected from a nozzle by changing the pressure / volume in the liquid chamber by deforming the diaphragm.

  As a piezo-type liquid ejection head, a configuration in which a driving circuit (driving IC) for driving a piezoelectric element is arranged on a flexible printed circuit (FPC) and is electrically connected to the piezoelectric element is known. ing.

  In the configuration in which the driving IC is disposed on the flexible printed circuit board, it is important to efficiently dissipate heat generated by the piezoelectric element and heat generated by the driving IC. In this regard, for example, Patent Document 1 includes a piezoelectric member, a base member on which the piezoelectric member is fixedly disposed, a piezoelectric actuator including an FPC (wiring member) that transmits a drive signal to the piezoelectric member, and a frame member. The FPC and the frame member are connected by a film-like heat conducting member, and a liquid discharge head that releases heat generated by the driver IC and heat accumulated in the base member to the frame member via the FPC and the film-like heat conducting member is provided. It is disclosed.

  However, in the above technique, since heat conduction is performed to the head casing through the insulating member of the wiring member, the heat dissipation efficiency is low, and there is room for study to improve the heat dissipation efficiency.

  SUMMARY An advantage of some aspects of the invention is that it provides a liquid discharge head capable of improving heat dissipation efficiency.

  In order to achieve such an object, a liquid discharge head according to the present invention includes a pressure generation chamber that communicates with a nozzle that discharges liquid, a pressure generation unit that causes a pressure change in the pressure generation chamber, and a connection to the pressure generation unit. A liquid ejection head having an exposed wiring member, wherein at least a part of the wiring member is provided with an exposed portion exposed from an insulating material covering the wiring member, and the exposed portion is interposed through a heat conducting member. In contact with a part of the liquid discharge head.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid discharge head which can improve heat dissipation efficiency can be provided.

It is sectional drawing which follows the liquid chamber longitudinal direction of an inkjet recording head. It is sectional drawing which follows the liquid chamber short direction of an inkjet recording head. It is a block diagram which shows the outline | summary of the control part of an inkjet recording device. FIG. 3 is a block diagram illustrating details of a print control unit and a head driver. It is a schematic block diagram explaining the whole structure of a serial type inkjet recording device. 1 is a schematic plan view of a serial type ink jet recording apparatus. It is a schematic block diagram explaining the whole structure of an inkjet recording device. 1 is a schematic plan view of an ink jet recording apparatus. It is sectional drawing which follows the liquid chamber longitudinal direction of an inkjet recording head. FIG. 3 is a cross-sectional view taken along the longitudinal direction of the liquid chamber of the ink jet recording head according to the first embodiment. 1A is a schematic top view of an inkjet recording head according to the first embodiment, and FIG. 1B is a schematic plan view of the inkjet recording head. It is a schematic sectional drawing in alignment with the liquid chamber longitudinal direction of the inkjet recording head which concerns on 2nd Embodiment. FIG. 5 is a schematic top view of an ink jet recording head according to a second embodiment. It is a schematic sectional drawing in alignment with the liquid chamber longitudinal direction of the inkjet recording head which concerns on 3rd Embodiment. It is a schematic sectional drawing in alignment with the liquid chamber longitudinal direction of the inkjet recording head which concerns on 4th Embodiment. FIG. 6 is a schematic top view of an ink jet recording head according to a fourth embodiment. It is a schematic sectional drawing of the flame | frame of the inkjet recording head which concerns on 4th Embodiment.

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

(Basic configuration of inkjet recording head)
First, a basic configuration of an ink jet recording head which is an embodiment of a liquid discharge head will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a cross-sectional view of the ink jet recording head 10 along the longitudinal direction of the liquid chamber. FIG. 2 is a cross-sectional view of the inkjet recording head 10 along the lateral direction of the liquid chamber.

  The ink jet recording head 10 includes an ink supply port, a frame 1 (housing portion) formed with an engraving serving as a common liquid chamber 12, a communication port communicating with the engraving and nozzle 31 serving as a fluid resistance portion 21 and a pressure generating chamber 22. 23, the nozzle plate 3 forming the nozzle 31, the diaphragm 6 having the island-shaped convex portion 61, the diaphragm portion 62, and the ink inlet 63, and the vibration plate 6 with the adhesive layer 7 interposed therebetween. And a base 4 to which the laminated piezoelectric element 5 is fixed.

  The base 4 is made of a barium titanate ceramic, and the laminated piezoelectric elements 5 are arranged in two rows and joined. The laminated piezoelectric element 5 is composed of a lead zirconate titanate (PZT) piezoelectric layer having a thickness of 10 to 50 μm / layer and an internal electrode layer made of silver and palladium (AgPd) having a thickness of several μm / layer alternately. Are stacked. The internal electrode layer is connected to the individual electrode 54 at both ends. The laminated piezoelectric element 5 is divided into comb teeth by half-cut dicing and used as a drive unit 56 and a support unit 57 (non-drive unit) one by one. The length of the outer electrode is limited by cutting or the like so as to be divided by half-cut dicing, and these become a plurality of individual electrodes 54. The other is not divided in the dicing process and is conductive and becomes the common electrode 55.

  The ink jet recording head 10 is configured to use the laminated piezoelectric element 5 of the d33 method which is displacement in the thickness direction, and the pressure generating chamber 22 is contracted and expanded by expansion and contraction of the laminated piezoelectric element 5. When the drive signal is applied to the laminated piezoelectric element 5 and charging is performed, the piezoelectric element expands. When the charge charged in the laminated piezoelectric element 5 is discharged, the piezoelectric element contracts in the opposite direction.

  An FPC (flexible printed circuit) 8 is soldered to the individual electrode 54 of the drive unit 56. In addition, the common electrode 55 is provided with an electrode layer at the end of the laminated piezoelectric element 5 and is wound around to join the Gnd electrode of the FPC 8. A driving IC is mounted on the FPC 8, thereby controlling application of a driving voltage to the driving unit 56.

  The diaphragm 6 is joined to the frame 1 with a thin film diaphragm 62, an island-shaped convex part (island part) 61 that joins the laminated piezoelectric element 5 to be the driving part 56 formed at the center of the diaphragm 62. A thick film portion including a beam and an opening serving as an ink inflow port 63 are formed by stacking two Ni plating films by an electroforming method. The thickness of the diaphragm 62 is, for example, 3 μm and the width is 35 μm (one side). The island-shaped convex portion 61 of the diaphragm 6 and the driving unit 56 of the laminated piezoelectric element 5 and the coupling of the diaphragm 6 and the frame 1 are bonded by patterning the adhesive layer 7 including a gap material.

  The flow path plate 2 is formed using a silicon single crystal substrate by patterning the engraving that becomes the fluid resistance portion 21 and the pressure generation chamber 22 and the through-hole that becomes the communication port 23 at a position relative to the nozzle 31 by an etching method. . The portion left by etching becomes the partition wall 24 of the pressure generating chamber 22. Further, a portion for narrowing the etching width was provided, and this was used as the fluid resistance portion 21.

  The nozzle plate 3 is formed of a metal material, for example, an Ni plating film by an electroforming method, and has a large number of nozzles 31 that are fine discharge ports for flying ink droplets. The internal shape (inner shape) of the nozzle 31 is formed in a horn shape (may be a substantially cylindrical shape or a substantially frustum shape). The diameter of the nozzle 31 is, for example, about 20 to 35 μm on the ink droplet outlet side. The nozzle pitch of each row is, for example, 150 dpi.

  The ink ejection surface (nozzle surface side) of the nozzle plate 3 is provided with a water repellent treatment layer 32 subjected to a water repellent surface treatment. Ink physical properties such as PTFE-Ni eutectoid plating, electrodeposition coating of fluororesin, vapor-deposited fluororesin (for example, fluorinated pitch), baking after solvent application of silicon resin / fluorine resin, etc. A water-repellent treatment film selected according to the above is provided to stabilize the ink droplet shape and flight characteristics so that high-quality image quality can be obtained.

  The frame 1 that forms the engraving that becomes the ink supply port 11 and the common liquid chamber 12 is manufactured by resin molding.

  In the ink jet recording head 10 configured as described above, a driving waveform (pulse voltage of 10 to 50 V) configured by a driving pulse (that is, a driving signal) is applied to the driving unit 56 in accordance with a recording signal, thereby driving the driving unit. A displacement in the stacking direction occurs at 56, the pressure generating chamber 22 is pressurized through the diaphragm 6, the pressure rises, and an ink droplet is ejected from the nozzle 31.

  Thereafter, the ink pressure in the pressure generation chamber 22 decreases with the end of ink droplet ejection, and negative pressure is generated in the pressure generation chamber 22 due to the inertia of the ink flow and the discharge process of the drive voltage (drive pulse). The process proceeds to the ink filling process. At this time, the ink supplied from the ink tank flows into the common liquid chamber 12, passes from the common liquid chamber 12 through the ink inlet 63, passes through the fluid resistance portion 21, and is filled into the pressure generation chamber 22.

  The fluid resistance portion 21 is effective in damping the residual pressure vibration after ejection, but becomes resistant to the maximum filling (refill) due to surface tension. By appropriately selecting the fluid resistance portion 21, it is possible to balance the attenuation of the residual pressure and the refill time, and to shorten the time (drive cycle) until shifting to the next ink droplet ejection operation.

  In the ink jet recording head 10 configured as described above, a method of discharging a plurality of types of ink droplets having different ink amounts from the same nozzle 31 has been performed in order to achieve both high speed printing operation and high image quality. By selectively applying a drive signal from one cycle drive signal, small dots to large dots are formed. In many cases, a maximum of 2 bits (4 gradations) is controlled.

(Inkjet recording device)
Next, an ink jet recording apparatus (image forming apparatus) which is an embodiment of an apparatus for ejecting liquid according to the present invention will be described.

[Control unit]
An overview of the control unit of the inkjet recording apparatus 200 will be described with reference to FIG. FIG. 3 is a block diagram illustrating an outline of the control unit 100 of the inkjet recording apparatus 200.

  The control unit 100 includes a CPU 101 that controls the entire inkjet recording apparatus 20, a ROM 102 that stores programs executed by the CPU 101 and other fixed data, a RAM 103 that temporarily stores image data and the like, and a power source for the inkjet recording apparatus 200. A rewritable NVRAM (non-volatile memory) 104 for holding data even while shut off, image processing for performing various signal processing and rearrangement on image data, and other input / output signals for controlling the entire apparatus And an ASIC 105 for processing.

  Further, the control unit 100 includes a data transfer means for driving and controlling the ink jet recording head 10 and a drive signal generating means, and a head driver (driver IC for driving the ink jet recording head 10 provided on the carriage 130 side). ) Motor driving such as driving the printing control unit 108 for controlling 109, the main scanning motor 131 for moving and scanning the carriage 130, the sub-scanning motor 132 for rotating the conveyor belt, and the maintenance and recovery motor 133 of the maintenance and recovery mechanism An AC bias supply unit 111 that supplies an AC bias to the unit 110 and the charging roller 134. The control unit 100 is connected to an operation panel 114 for inputting and displaying information necessary for the apparatus.

The control unit 100 is a host interface (hereinafter referred to as a host I / F) for transmitting and receiving data and signals to and from a host side such as an information processing device such as a personal computer, an image reading device such as an image scanner, and an imaging device such as a digital camera. The output signal is received by the host I / F 106 from the host 120 side via a cable or a network.
The CPU 101 of the control unit 100 reads and analyzes the print data in the reception buffer included in the host I / F 106, performs necessary image processing, data rearrangement processing, and the like in the ASIC 105, and outputs the image data to the print control unit. The data is transferred from 108 to the head driver 109. Note that the generation of dot pattern data for image output is performed by the printer driver 121 on the host 120 side.

  The print control unit 108 transfers the above-described image data as serial data, and outputs a transfer clock, a latch signal, a control signal, and the like necessary for transferring the image data and confirming the transfer to the head driver 109. In addition to performing the above operation, the print control unit 108 performs a drive signal waveform unit that includes a D / A converter, a voltage amplifier, a current amplifier, and the like that perform D / A conversion on drive pulse pattern data stored in the ROM 102. And a drive signal composed of one or a plurality of drive pulses is output to the head driver 109.

  The head driver 109 drives the ink jet recording head 10 based on image data corresponding to one line of the ink jet recording head 10 serially input from the print control unit 108. That is, the head driver 109 applies a drive pulse that constitutes a drive signal given from the print control unit 108 to a drive element (here, the laminated piezoelectric element 5) that generates energy for ejecting droplets of the inkjet recording head 10. The ink jet recording head 10 is driven by selectively applying the ink.

  The head driver 109 can select dots having different sizes, such as large droplets, medium droplets, and small droplets, in the inkjet recording head 10 by selecting a drive pulse that constitutes a drive signal.

  An I / O (input / output) unit 113 acquires information from various sensor groups 115 mounted on the apparatus, extracts information necessary for controlling the printer, the print control unit 108, the motor drive unit 110, and the like. The processing for the control is performed.

  The sensor group 115 includes an optical sensor for detecting the position of the paper, a thermistor for monitoring the temperature in the machine, a humidity sensor for monitoring the humidity in the machine, a sensor for monitoring the voltage of the charging belt, and opening and closing of the cover. An I / O unit 113 can perform the above-described processing on various sensor information.

  FIG. 4 is a block diagram illustrating details of the print control unit 108 and the head driver 109. As described above, the print control unit 108 generates and outputs a drive waveform (common drive waveform) composed of a plurality of drive pulses (that is, drive signals) within one printing cycle at the time of image formation. A drive waveform generation unit 201 that generates and outputs a drive waveform (common drive waveform) composed of a plurality of drive pulses (drive signals) within one idle ejection cycle during operation, and 2-bit image data corresponding to a print image (Gradation signals 0 and 1), and a data transfer unit 202 that outputs a transfer clock, a latch signal (LAT), and droplet control signals M0 to M3. The droplet control signals M0 to M3 are 2-bit signals for instructing opening / closing of an analog switch 215, which will be described later, of the head driver 109 for each droplet, and are waveforms to be selected in accordance with the printing cycle of the drive waveform. The state transitions to H level (ON), and when the drive waveform is not selected, the state transitions to L level (OFF).

  The head driver 109 receives a transfer clock (shift clock) and image data (gradation data: 2 bits / 1 channel (1 nozzle)) from the data transfer unit 202, and each register value of the shift register 211. Is latched by a latch signal from the data transfer unit 202, a decoder 213 that decodes gradation data and droplet control signals M0 to M3 and outputs a result, and a logic level voltage signal of the decoder 213 is analog. A level shifter 214 that converts the level of the switch 215 to an operable level, and an analog switch 215 that is turned on / off (opened / closed) by the output of the decoder 213 provided through the level shifter 214 are provided.

  The analog switch 215 is connected to the individual electrode 54 of each laminated piezoelectric element 5 and receives a drive waveform from the drive waveform generation unit 201. Therefore, the analog switch 215 is turned on in accordance with the result of decoding the serially transferred image data (grayscale data) and the droplet control signals M0 to M3 by the decoder 213, so that a required drive signal constituting the drive waveform is obtained. Passing (selected) is applied to the laminated piezoelectric element 5.

[Configuration example 1 of ink jet recording apparatus (serial type)]
An example of a serial type ink jet recording apparatus will be described with reference to FIGS. FIG. 5 is a schematic configuration diagram illustrating the overall configuration of the inkjet recording apparatus 200A, and FIG. 6 is a schematic plan view of the inkjet recording apparatus 200A.

  The ink jet recording apparatus 200A is a serial type ink jet recording apparatus, and the carriage 130 is slidable in the main scanning direction by a main guide rod 231 and a sub guide rod 232 which are guide members horizontally mounted on the left and right side plates 221A and 221B. Hold. The main scanning motor 131 moves and scans in the direction indicated by the arrow (carriage main scanning direction) via the timing belt. The carriage 130 is equipped with a liquid discharge unit for discharging ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K).

  The carriage 130 has a nozzle array composed of a plurality of nozzles for inkjet recording heads 10a and 10b for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K). They are arranged in the sub-scanning direction orthogonal to the main scanning direction, and are mounted with the ink droplet ejection direction facing downward.

  Each of the inkjet recording heads 10 has two nozzle rows, and one nozzle row of the inkjet recording head 10a performs black (K) droplets, and the other nozzle row provides cyan (C) droplets. One nozzle row of the head 10b discharges magenta (M) droplets, and the other nozzle row discharges yellow (Y) droplets.

  The carriage 130 is also equipped with sub tanks 235a and 235b (referred to as “sub tank 235” when not distinguished) for supplying ink of each color corresponding to the nozzle rows of the inkjet recording head 10.

  The sub tank 235 is supplementarily supplied with ink of each color from the ink cartridges 210k, 210c, 210m, 210y of each color via the supply tube 236 of each color.

  On the other hand, as a paper feeding unit for feeding the paper P stacked on the paper stacking unit (pressure plate) 241 of the paper feed tray 242, a half-moon roller (feeding) that separates and feeds the paper P one by one from the paper stacking unit 241. A separation pad 244 made of a material having a large coefficient of friction is provided opposite to the sheet roller 243 and the sheet feeding roller 243, and the separation pad 244 is urged toward the sheet feeding roller 243 side.

  In order to feed the sheet P fed from the sheet feeding unit to the lower side of the ink jet recording head 10, a guide member 245 for guiding the sheet P, a counter roller 246, a transport guide member 247, and a tip pressurization. A pressing member 248 having a roller 249 and a conveying belt 251 that is a conveying unit for electrostatically adsorbing the fed paper P and conveying it at a position facing the inkjet recording head 10 are provided.

  The conveyor belt 251 is an endless belt, and is configured to wrap around the conveyor roller 252 and the tension roller 253 so as to circulate in the belt conveyance direction (sub-scanning direction).

  Further, a charging roller 134 which is a charging unit for charging the surface of the transport belt 251 is provided. The charging roller 134 is disposed so as to come into contact with the surface layer of the conveyor belt 251 and to rotate following the rotation of the conveyor belt 251.

  The transport belt 251 rotates in the belt transport direction when the transport roller 252 is rotationally driven by the sub-scanning motor 132 through timing.

  Further, as a paper discharge unit for discharging the paper P recorded by the inkjet recording head 10, a separation claw 261 for separating the paper P from the transport belt 251, a paper discharge roller 262 and a paper discharge roller 263 are provided. In addition, a paper discharge tray 203 is provided below the paper discharge roller 262.

  A double-sided unit 271 is detachably attached to the back surface of the apparatus main body. The duplex unit 271 takes in the paper P returned by the reverse rotation of the transport belt 251, reverses it, and feeds it again between the counter roller 246 and the transport belt 251. The upper surface of the duplex unit 271 is a manual feed tray 272.

  Further, a maintenance / recovery mechanism 281 for maintaining and recovering the nozzle state of the inkjet recording head 10 is disposed in a non-printing area on one side of the carriage 130 in the scanning direction. The maintenance / recovery mechanism 281 includes cap members (hereinafter referred to as “caps”) 282a and 282b (hereinafter referred to as “caps 282” when not distinguished) for capping each nozzle surface of the inkjet recording head 10 and nozzles. A wiper blade 283 which is a blade member for wiping the surface, and an empty discharge receiver 284 for receiving droplets when performing empty discharge for discharging droplets that do not contribute to recording in order to discharge the thickened recording liquid. I have.

  In addition, in the non-printing area on the other side of the carriage 130 in the scanning direction, the liquid that receives liquid droplets when performing idle ejection that ejects liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. An ink collection unit (empty discharge receptacle) 288 that is a collection container is disposed, and the ink collection unit 288 includes an opening 289 along the nozzle row direction of the inkjet recording head 10 and the like.

  In the ink jet recording apparatus 200A configured as described above, the paper P is separated and fed one by one from the paper feed tray 242, and the paper P fed substantially vertically upward is guided by the guide member 245, and the transport belt 251. And the counter roller 246, and further, the front end is guided by the transport guide 237 and pressed against the transport belt 251 by the front end pressure roller 249, and the transport direction is changed by approximately 90 °.

  At this time, a positive output and a negative output are alternately repeated with respect to the charging roller 134, that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 251 alternates, that is, in the sub-scanning direction that is the circumferential direction. , Plus and minus are alternately charged in a band shape with a predetermined width.

  When the sheet P is fed onto the conveyance belt 251 charged alternately with plus and minus, the sheet P is attracted to the conveyance belt 251, and the sheet P is conveyed in the sub-scanning direction by the circular movement of the conveyance belt 251.

  Therefore, by driving the inkjet recording head 10 in accordance with the image signal while moving the carriage 130, ink droplets are ejected onto the stopped paper P to record one line, and the paper P is conveyed by a predetermined amount. Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper P reaches the recording area, the recording operation is finished, and the paper P is discharged onto the paper discharge tray 203.

[Configuration example 2 of ink jet recording apparatus (line type)]
An example of a line type ink jet recording apparatus will be described with reference to FIGS. FIG. 7 is a schematic configuration diagram for explaining the overall configuration of the inkjet recording apparatus 200B, and FIG. 8 is a schematic plan view of the inkjet recording apparatus 200B.

  The apparatus main body 301, a paper feed tray 302 that stacks and feeds paper P, a paper discharge tray 303 that discharges and stacks printed paper P, and paper P is conveyed from the paper feed tray 302 to the paper discharge tray 303. The transport unit 304, the image forming unit 305 that discharges and prints droplets on the paper P transported by the transport unit 304, and the maintenance recovery that performs the maintenance recovery of each head of the image forming unit 305 after completion of printing or at a required timing. And a cleaning device 306 which is a mechanism.

  The apparatus main body 301 is composed of front and rear side plates, stays, and the like, and the paper P stacked on the paper feed tray 302 is fed one by one to the transport unit 304 by the separation roller 321 and the paper feed roller 322. .

  The transport unit 304 includes a transport drive roller 341A, a transport driven roller 341B, and an endless transport belt 343 wound around these rollers 341A and 341B. A plurality of holes are formed on the surface of the transport belt 343, and a suction fan 344 that sucks the paper P is disposed below the transport belt 343. Further, conveyance guide rollers 342A and 342B are held by the guides on the conveyance driving roller 341A and the conveyance driven roller 341B, respectively, and are in contact with the conveyance belt 343 by their own weight.

  The conveyance driving roller 341 </ b> A is rotated by a motor to rotate the conveyance belt 343, and the paper P is sucked onto the conveyance belt 343 by the suction fan 344 and conveyed by the circular movement of the conveyance belt 343. The transport driven roller 341B and the transport guide rollers 342A and 42B are rotated by the transport belt 343.

  An image forming unit 305 serving as an ink jet recording head composed of a plurality of head units that discharge droplets to be printed on the paper P is disposed above the transport unit 304 so as to be movable in the arrow A direction. The image forming unit 305 moves to above the cleaning device 306 during the maintenance / recovery operation (during cleaning).

  The image forming unit 305 includes a recording head unit 350 in which head modules 351A, 351B, 351C, and 351D are arranged on the array base member 352 along the sheet conveyance direction. Here, one of the two nozzle rows of the head modules 351A and 351B ejects yellow (Y) droplets and the other of the magenta (M) droplets, and the two nozzle rows of the head modules 351C and 351D. On the other hand, cyan (C) droplets are discharged, and on the other hand, black (K) droplets are discharged.

  That is, in the recording head unit 350 of the image forming unit 305, two head modules 351 that discharge droplets of the same color are arranged side by side in the paper transport direction, and the two head modules 351 correspond to one row corresponding to the paper width. The nozzle array is configured.

  An ink tank 381 of an ink tank unit 308 (only one ink tank is provided with a reference numeral) is disposed on the upstream side of the image forming unit 305, and is supplied to each head module 351 through a supply tube 382. Due to the water head difference between the ink tank 381 and the head module 351, a negative pressure is formed on each head of the head module 351.

  The ink tank unit 308 is disposed so as to be movable in the direction of arrow A together with the image forming unit 305. Note that the supply tube 382 from the ink tank 381 to the head module 351 is shown connected from above the head module 351 for easy understanding, but in reality, the longitudinal direction of the head module 351 (perpendicular to the paper conveyance direction). Connected to the end in the direction of

  Further, a main tank unit 309 is disposed on the upstream side of the ink tank 381, and ink is supplied from the main tank 391 to the ink tank 381 through the supply tube 392.

  On the downstream side of the transport unit 304, a transport guide unit 307 that discharges the paper P to the paper discharge tray 303 is provided. The sheet P guided and conveyed by the conveyance guide unit 307 is discharged to the sheet discharge tray 3. The paper discharge tray 303 includes a pair of side fences 331 that regulate the width direction of the paper P and an end fence 332 that regulates the front end of the paper P.

  The maintenance / recovery mechanism (cleaning device) 306 includes four rows of cleaning units 361A to 361D corresponding to each head module 351 of the image forming unit 305, and one cleaning unit 361 is provided for each head of the head module 351. A corresponding cap member 362 and a wiper member are formed. The cap member 362 of each cleaning means 361 can be moved up and down independently in each row. Further, below the cleaning unit 361, suction pumps 363A to 363D for sucking ink from the nozzles in a state where the nozzle surface of the head module 351 is capped by the cap member 362 are arranged.

  Further, in this image forming apparatus, after the printing is finished, when ink is sucked from the nozzles with the nozzle surface of each head of the head module 351 that discharges droplets being capped by the cleaning unit 361, or in the head module 351 When the ink adhering to the nozzle surface of each head is cleaned with a wiping member, as shown in FIG. 7, after printing is stopped, the entire transport unit 304 rotates in the direction of arrow B with the transport driven roller 341B as a fulcrum. By making the space between the image forming unit 305 larger than that at the time of image formation, a space for moving the image forming unit 305 is secured. At this time, the conveyance guide portion 307 disposed above the cleaning device 306 is also rotated upward in the direction of the arrow C at the fulcrum 371 and the upper portion of the cleaning device 306 is opened.

  Then, after the transport unit 304 and the transport guide portion 307 are released (released), the image forming unit 305 moves in the paper passing direction (arrow A direction), stops above the cleaning device 306, and is cleaned. Rises to shift to the cleaning operation (maintenance recovery operation) of each head module 351.

[First Embodiment]
Next, the ink jet recording head 10 which is an embodiment of the liquid discharge head according to the present invention will be described.

  First, a basic configuration example of the inkjet recording head 10 will be described. FIG. 9 is a sectional view taken along the longitudinal direction of the liquid chamber of the inkjet recording head 10. The description of the points described with reference to FIG. 1 is omitted.

  As shown in FIG. 9, the FPC 8 is bonded to the laminated piezoelectric element 5, and a drive IC 9 (driving means) that drives the laminated piezoelectric element 5 is provided on the other end side of the FPC 8. In the FPC 8, a wiring member 81 that is a conductor is formed on a base material 80 that is an insulating material, and the wiring member 81 is covered with a resist material 82 that is an insulating material.

  In such a configuration, the laminated piezoelectric element 5 and the drive IC 9 serve as heat generation sources, which may cause a rise in the temperature of the pressure chamber liquid and a failure of the drive IC 9. For this reason, as shown in FIG. 9, it is known to include a cooling means for cooling the drive IC 9. For example, it is known to include the heat sink 13 in the drive IC 9. By adopting the heat dissipation structure by the heat sink 13, the temperature rise caused by the laminated piezoelectric element 5 and the drive IC 9 is suppressed.

  However, when the heat sink 13 is provided, it is necessary to provide a space for disposing the heat sink 13 in the ink jet recording head 10, which becomes a barrier to downsizing the ink jet recording head 10.

  Therefore, the ink jet recording head 10 according to the present embodiment includes a pressure generation chamber (pressure generation chamber 22) communicating with a nozzle (nozzle 31) that discharges liquid, and a pressure generation unit (lamination) that causes a pressure change in the pressure generation chamber. A liquid discharge head (inkjet recording head 10) having a piezoelectric element 5) and a wiring member (FPC 8) connected to a pressure generating means, wherein at least a part of the wiring member is made of an insulating material covering the wiring member An exposed exposed portion (exposed portion 81a) is provided, and the exposed portion is in contact with a part of the liquid discharge head via a heat conductive member (heat conductive member 85).

  FIG. 10 is a schematic cross-sectional view along the longitudinal direction of the liquid chamber of the ink jet recording head 10 according to the first embodiment. 11A is a schematic top view as seen from the direction of arrow A in the figure, and FIG. 11B is a schematic plan view as seen from the direction of arrow B in the figure.

  The inkjet recording head 10 according to the present embodiment has an exposed portion 81a where at least a part of the wiring material 81 of the FPC 8 is exposed without being covered with an insulating material (here, the base material 80).

  For example, as shown in FIG. 10, the wiring material 81 is exposed on a part of the wiring material 81 on the base material 80 side (frame 1 side) without applying a resist, and the wiring material 81 in the FPC 8 is The exposed part is called an exposed part 81a. The FPC 8 is configured to be in contact with the frame 1 that is a conductor through the heat conducting member 85 that is a conductor at the exposed portion 81a. As the FPC 8, for example, a double-sided FPC in which the wiring material 81 is exposed on both sides connected by vias can be used.

  The material of the heat conducting member 85 is not particularly limited, but for example, it is preferable to use silicon resin or acrylic resin. Moreover, the connection form of the heat conductive member 85 and the frame 1 is not particularly limited, but it is preferable that the heat conductive member 85 and the frame 1 are bonded via an adhesive layer formed of, for example, a heat conductive epoxy adhesive.

  Thereby, the heat generation of the laminated piezoelectric element 5 and the driving IC 9 is conducted from the exposed portion 81a of the wiring member 81 of the FPC 8 to the heat conducting member 85 and from the heat conducting member 85 to the frame 1.

  Thereby, compared with the structure shown in FIG. 9, it becomes possible to improve heat dissipation efficiency. Therefore, without providing a cooling means such as the heat sink 13, the temperature rise of the pressure chamber liquid and the temperature rise of the drive IC 9 can be suppressed, and the change in the ejection characteristics and the occurrence of the malfunction of the drive IC 9 can be suppressed. Further, the space for providing the cooling means is not required, and the ink jet recording head 10 can be miniaturized. Also, in the case where the cooling unit is provided, it is possible to use a small cooling unit (such as the heat sink 13) that has a cooling performance lower than that of the conventional one, so that the ink jet recording head 10 can be downsized accordingly. it can.

[Second Embodiment]
Hereinafter, other embodiments of the inkjet recording head 10 will be described. In addition, the description about the same point as the said embodiment is abbreviate | omitted suitably.

  In the first embodiment, the exposed portion 81a of the FPC 8 is arranged between the FPC 8 and the frame 1 at a wiring portion in the middle of the FPC 8 on one end side to which the laminated piezoelectric element 5 is connected and the other end side on which the drive IC 9 is provided. Although the example which connects to the heat conduction member 85 provided in between and conducts heat conduction in the order of the exposed portion 81a, the heat conduction member 85, and the frame 1 from the wiring member 81 of the FPC 8 has been described, the exposed portion 81a It is only necessary that the heat can be released by being coupled to each other, and the connection form is not limited to the example of FIG. Other examples will be described below.

  FIG. 12 is a schematic cross-sectional view along the longitudinal direction of the liquid chamber of the ink jet recording head 10 according to the second embodiment. FIG. 13 is a schematic top view as seen from the direction of arrow A in the figure.

  In the second embodiment, an example in which the exposed portion 81a of the wiring member 81 and the heat conducting member 85 are provided at the position where the drive IC 9 is provided in the FPC 8 is shown. For example, a heat radiating pad is disposed on the back surface of the drive IC 9 and a pattern (exposed portion 81a) is provided on the back surface of the FPC 8 so as to be electrically connected to the heat radiating pad. Then, by dissipating heat from the exposed portion 81a to the frame 1 via the heat conducting member 85, it is possible to dissipate the heat of the drive IC 9 with a smaller thermal resistance compared to the configuration of the first embodiment. is there.

  In the second embodiment, in particular, the heat dissipation efficiency of the drive IC 9 can be improved, the temperature rise of the drive IC 9 and the pressure chamber liquid can be suppressed, and the occurrence of defects in the drive IC 9 and the change in the discharge characteristics can be suppressed. Can do.

[Third Embodiment]
FIG. 14 is a schematic cross-sectional view along the longitudinal direction of the liquid chamber of the inkjet recording head 10 according to the third embodiment.

  In the third embodiment, in the FPC 8, an example in which the exposed portion 81a of the wiring member 81 and the heat conducting member 85 are provided at the position of the connecting portion between the laminated piezoelectric element 5 (individual electrode 54) and the FPC 8 is shown. Heat can be radiated from the exposed portion 81a to the frame 1 through the heat conducting member 85. Further, as shown in FIG. 14, the metal member 86 as a conductor is sandwiched between the heat conducting members 85, so that the exposed portion 81 a passes through the heat conducting member 85, the metal member 86, and the heat conducting member 85 to the frame 1. It may be made to dissipate heat.

  In the third embodiment, in particular, the heat dissipation efficiency of the multilayer piezoelectric element 5 can be improved to suppress the temperature rise of the drive IC 9 and the pressure chamber liquid, and the occurrence of defects in the drive IC 9 and the change in the discharge characteristics are suppressed. can do.

  In the first to third embodiments, an example of connecting to the frame 1 at an intermediate position of the wiring of the FPC 8, an example of connecting to the frame 1 at a position where the driving IC 9 on one end side of the FPC 8 is provided, and the other end side of the FPC 8 Although the example of connecting to the frame 1 at the position where the laminated piezoelectric element 5 is provided has been described, the position where the exposed portion 81a is formed in the FPC 8 is not limited to the above example. Alternatively, two or more exposed portions 81a may be provided, and the heat conducting member 85 may be provided at each location. Moreover, when providing the some exposed part 81, the exposed part 81a may be provided in the both surfaces side of FPC8. Further, the connection destination via the heat conducting member 85 may be connected to another part (conductor) of the inkjet recording head 10, and the connection destination is not limited to the frame 1.

[Fourth Embodiment]
FIG. 15 is a schematic cross-sectional view along the longitudinal direction of the liquid chamber of the inkjet recording head 10 according to the fourth embodiment. FIG. 16 is a schematic top view of the inkjet recording head 10 according to the fourth embodiment as viewed from the direction of arrow A in FIG. 17, and FIG. 17 is a schematic cross section of the frame 1 at a portion where the flow path of the coolant 87 is formed. FIG.

  In the fourth embodiment, the flow path of the coolant 87 is provided in the frame 1, and the frame 1 that is thermally coupled to the FPC 8 is cooled by a water cooling method using the coolant 87. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  For example, the cooling liquid 87 is supplied from the cooling liquid supply port 88 to the circulation path provided in the frame 1, that is, circulates in the frame 1 and is discharged from the cooling liquid discharge port 89. Yes. As a cooling mechanism for cooling the cooling liquid 87, for example, a known cooling mechanism such as a chiller or a radiator may be used, and it is not essential to cool the cooling liquid 87 in the inkjet recording head 10.

  According to the fourth embodiment, it is possible to suppress the temperature rise of the drive IC 9 and the pressure chamber liquid without providing a cooling means such as the heat sink 13, and to suppress the occurrence of problems in the drive IC 9 and the change in the discharge characteristics. be able to. Further, the space for providing the cooling means is not required, and the ink jet recording head 10 can be miniaturized.

  The above-described embodiment is a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

  A “liquid ejection head” is a functional component that ejects and ejects liquid from a nozzle. The “liquid discharge head” is not limited to the pressure generating means to be used. For example, in addition to the piezoelectric actuator as described in the above embodiment (a multilayer piezoelectric element may be used), a thermal actuator using an electrothermal conversion element such as a heating resistor, a diaphragm and a counter electrode are included. An electrostatic actuator or the like may be used.

  In addition, the terms “image formation”, “recording”, “printing”, “printing”, “printing”, “modeling” and the like in the terms of the present application are all synonymous.

  Further, the “liquid discharge unit” is an assembly of other functional parts and mechanisms integrated with the liquid discharge head, and is an assembly of parts related to the function of discharging liquid. For example, the “liquid discharge unit” includes a combination of at least one of a head tank, a carriage, a supply mechanism, a maintenance / recovery mechanism, and a main scanning movement mechanism with a liquid discharge head.

  Here, the term “integrated” refers to, for example, a liquid discharge head, a functional component, and a mechanism that are fixed to each other by fastening, adhesion, engagement, etc., and one that is held movably with respect to the other. Including. Further, the liquid discharge head, the functional component, and the mechanism may be configured to be detachable from each other.

  For example, there is a liquid discharge unit in which a liquid discharge head and a head tank are integrated. Also, there are some in which the liquid discharge head and the head tank are integrated by being connected to each other by a tube or the like. Here, a unit including a filter may be added between the head tank and the liquid discharge head of these liquid discharge units.

  In addition, there is a liquid discharge unit in which a liquid discharge head and a carriage are integrated.

  In addition, there is a liquid discharge unit in which the liquid discharge head and the scanning movement mechanism are integrated by holding the liquid discharge head movably on a guide member that constitutes a part of the scanning movement mechanism. In some cases, a liquid discharge head, a carriage, and a main scanning movement mechanism are integrated.

  Also, there is a liquid discharge unit in which a cap member that is a part of the maintenance / recovery mechanism is fixed to a carriage to which the liquid discharge head is attached, and the liquid discharge head, the carriage, and the maintenance / recovery mechanism are integrated. .

  In addition, there is a liquid discharge unit in which a tube is connected to a liquid discharge head to which a head tank or a flow path component is attached, and the liquid discharge head and a supply mechanism are integrated. The liquid from the liquid storage source is supplied to the liquid discharge head via this tube.

  The main scanning movement mechanism includes a guide member alone. The supply mechanism includes a single tube and a single loading unit.

  Further, the “apparatus that discharges liquid” is an apparatus that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge the liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid.

  This “apparatus for discharging liquid” may include means for feeding, transporting, and discharging a liquid to which liquid can adhere, as well as a pre-processing apparatus and a post-processing apparatus.

  For example, as a “liquid ejecting device”, an image forming device that forms an image on paper by ejecting ink, a powder is formed in layers to form a three-dimensional model (three-dimensional model) There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid onto the powder layer.

  Further, the “apparatus for ejecting liquid” is not limited to an apparatus in which significant images such as characters and figures are visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

  The above-mentioned “applicable liquid” means that the liquid can be attached at least temporarily and adheres and adheres, or adheres and penetrates. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic parts such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and test cells. Yes, unless specifically limited, includes everything that the liquid adheres to.

  The material of the above-mentioned “material to which liquid can adhere” is not limited as long as liquid such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics can be adhered even temporarily.

  The “liquid” is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head, and the viscosity is 30 mPa · s or less at room temperature, normal pressure, or by heating and cooling. Preferably there is. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, solutions, suspensions, emulsions, and the like. These include, for example, inkjet inks, surface treatment liquids, components of electronic devices and light emitting devices, and formation of electronic circuit resist patterns. It can be used in applications such as liquids for use, three-dimensional modeling material liquids, and the like.

  In addition, the “device for ejecting liquid” includes a device in which the liquid ejection head and the device to which the liquid can adhere move relatively, but is not limited thereto. Specific examples include a serial type apparatus that moves the liquid discharge head, a line type apparatus that does not move the liquid discharge head, and the like.

  In addition to the “device for discharging liquid”, a processing liquid coating apparatus for discharging a processing liquid onto a sheet for applying a processing liquid to the surface of the sheet for the purpose of modifying the surface of the sheet, or a raw material There is an injection granulating apparatus or the like that granulates fine particles of a raw material by spraying a composition liquid in which a solution is dispersed in a solution through a nozzle.

DESCRIPTION OF SYMBOLS 1 Frame 2 Flow path board 3 Nozzle board 4 Base 5 Laminated piezoelectric element 6 Diaphragm 7 Adhesion layer 8 FPC (flexible printed circuit)
9 Drive IC
10, 10a, 10b Inkjet recording head 11 Ink supply port 12 Common liquid chamber 13 Heat sink 21 Fluid resistance portion 22 Pressure generating chamber 23 Communication port 24 Partition 31 Nozzle 32 Water repellent treatment layer 54 Individual electrode 55 Common electrode 56 Drive portion 57 Support portion 61 Island-shaped convex part 62 Diaphragm part 63 Ink inlet 80 Base material 81 Wiring material 81a Exposed part 82 Resist material 85 Thermal conduction member 86 Metal member 87 Coolant 88 Coolant supply port 89 Coolant outlet 100 Controller 101 CPU
102 ROM
103 RAM
104 NVRAM (nonvolatile memory)
105 ASIC
106 Host I / F
108 Print Control Unit 109 Head Driver 110 Motor Drive Unit 111 AC Bias Supply Unit 113 I / O Unit 114 Operation Panel 115 Sensor Group 120 Host 121 Printer Driver 130 Carriage 131 Main Scanning Motor 132 Sub-Scanning Motor 133 Maintenance / Recovery Motor 134 Charging Roller 200 , 200A, 200B Inkjet recording apparatus 201 Drive waveform generation unit 202 Data transfer unit 203 Paper discharge tray 210k, 210c, 210m, 210y Ink cartridge 211 Shift register 212 Latch circuit 213 Decoder 214 Level shifter 215 Analog switch 221A, 221B Side plate 231 Main guide rod 232 Sub guide rods 235a, 235b Sub tank 236 Supply tube 241 Paper stacking section (pressure plate)
242 Paper Tray 243 Half Moon Roll (Feed Roll)
244 Separation pad 245 Guide member 246 Counter roller 247 Conveying guide member 248 Holding member 249 Tip pressure roller 251 Conveying belt 252 Conveying roller 253 Tension roller 261 Separating claw 262 Discharging roller 263 Discharging roller 271 Duplex unit 272 Manual tray 281 Maintenance recovery Mechanisms 282a and 282b Cap member 283 Wiper blade 284 Empty discharge receptacle 288 Ink recovery unit 289 Opening 301 Device main body 302 Paper feed tray 303 Paper discharge tray 304 Transport unit 305 Image forming unit 306 Cleaning device 307 Transport guide unit 308 Ink tank unit 309 Main tank unit 321 Separation roller 322 Paper feed roller 331 Side fence 332 End fence 341A Transport drive roller 341B Driven roller 342A, 342B conveying guide rollers 343 transport belt 344 suction fan 350 recording head unit 351A, 351B, 351C, 351D head module 352 array base member 361A~361D cleaning unit 362 cap member 363A~363D suction pump
371 Support point 381 Ink tank 382 Supply tube 391 Main tank 392 Supply tube P Paper

JP2013-63555A

Claims (9)

A pressure generating chamber communicating with a nozzle for discharging liquid;
Pressure generating means for causing a pressure change in the pressure generating chamber;
A liquid discharge head having a wiring member connected to the pressure generating means,
At least a part of the wiring member is provided with an exposed portion exposed from an insulating material covering the wiring member, and
The liquid ejection head, wherein the exposed portion is in contact with a part of the liquid ejection head via a heat conducting member.   The wiring member is provided with two or more exposed portions, and the plurality of exposed portions are in contact with a part of the liquid ejection head via the corresponding heat conducting members. Item 2. The liquid discharge head according to Item 1.   The liquid discharge head according to claim 1, wherein the heat conducting member is in contact with a housing portion of the liquid discharge head. The wiring member is connected to the pressure generating means on one end side, and connected to a driving means for driving the pressure generating means on the other end side,
4. The liquid ejection head according to claim 1, wherein the exposed portion of the wiring member is provided at any position excluding both end portions. 5. The wiring member is connected to driving means for driving the pressure generating means,
The liquid ejection head according to claim 1, wherein the exposed portion of the wiring member is provided in the vicinity of a connection position with the driving unit.   The liquid ejection head according to claim 1, wherein the exposed portion of the wiring member is provided in the vicinity of a connection position with the pressure generating unit.   The liquid discharge head according to claim 3, wherein a circulation path for a cooling liquid is provided in the casing.   A liquid discharge unit for discharging a liquid, comprising the liquid discharge head according to claim 1.   An apparatus for ejecting liquid, comprising the liquid ejection head according to claim 1 or the liquid ejection unit according to claim 8.