JP5398171B2 - Droplet discharge head, droplet discharge unit, and droplet discharge device - Google Patents

Description

  The present invention relates to a droplet discharge head, a droplet discharge unit, and a droplet discharge device.

  2. Description of the Related Art In recent years, so-called paper width printing type ink jet printers that perform printing by stopping a long print head extending over the entire width of a recording medium such as recording paper or film and continuously conveying the recording medium have been widely used. .

As such a paper width printing type ink jet printer, for example, an ink jet recording apparatus that records on a recording medium by discharging ink from nozzles, and has a nozzle surface on which nozzles are arranged over the entire width of the recording medium. Including a plurality of line heads and a plurality of line cleaning means for cleaning the nozzle face in close contact with the nozzle face, wherein the plurality of line cleaning means are arranged outwardly in the width direction with respect to the recording medium. Corresponding to the line head in the conveying direction of the recording medium, and the line head moves in the width direction of the recording medium so that the recording position on the recording medium and the line cleaning means There is an ink jet recording apparatus (Patent Document 1) in which the position is mutually changed to the cleaning position.
Japanese Patent Laying-Open No. 2005-074764

  As an operation peculiar to the ink jet printer, there is a recovery operation of the print head. In the recovery operation, depending on which one of the print head and the paper transport system is to be retracted, a print head retract type for retracting the print head and a paper transport system retract type for retracting the paper transport system are roughly classified. .

  In an ink jet printer, a print head retract type and a paper transport system retract type can be arbitrarily selected. For example, in an ink jet printer configured to transport paper with a belt, the paper transport system is retracted by retracting the paper transport belt. The formula can be adopted. In this case, since it is not necessary to retract the print head, a print head with high rigidity can be configured by individually fixing the print unit, the ink supply unit, and the drive circuit unit constituting the print head to the frame.

  On the other hand, in an ink jet printer in which a sheet is conveyed by a drum, it is practical to select a print head retracting type.

  Furthermore, since an inkjet printer normally has a plurality of print heads, in a print head retractable inkjet printer, whether the plurality of print heads are retracted collectively in relation to the operation of the recovery unit. It is necessary to select whether to evacuate individually.

  In addition, the print head is provided with a back pressure control mechanism for controlling the back pressure applied to the ink so that the meniscus formed on the nozzle surface is not destroyed, and the entire print head extends over the entire width of the recording medium. It is necessary to supply ink to the printer. Therefore, when the print head retracting method is selected in the paper width printing type ink jet printer, the print head having the ink supply unit, the drive circuit unit, and the printing unit tends to be large in both volume and mass.

  In order to obtain good print quality in the print head, it is necessary to position the print portion with high accuracy with respect to the recording medium at least during printing. Therefore, it is necessary to prevent the mass or distortion of the ink supply unit from affecting the printing unit.

  The present invention has been made to solve the above problems, and in a droplet discharge head having a mechanism portion such as an ink supply portion and a droplet discharge portion such as a printing portion, the mass and distortion of the mechanism portion are reduced. An object of the present invention is to provide a droplet discharge head capable of suppressing the influence on the droplet discharge portion.

According to a first aspect of the present invention, there is provided a droplet discharge portion that extends over the entire width of the recording medium and discharges droplets onto the recording medium, and supplies liquid to be discharged as droplets to the droplet discharge portion. as well as a mechanism for the droplet ejecting sections are resiliently coupled, is secured to the mechanism, e Bei and a driving circuit unit for driving the droplet ejecting section, suspended in the mechanism portion The suspended portion is provided with a suspended portion at the droplet discharge portion, and the droplet discharge portion is suspended from the suspended portion of the mechanism portion at the suspended portion, and the suspended portion is suspended. The present invention relates to a droplet discharge head in which a spring is interposed between a portion and a suspended portion .

  According to a second aspect of the present invention, in the liquid droplet ejection head according to the first aspect, the mechanism unit includes a liquid supply unit that supplies liquid to the liquid droplet ejection unit, and the liquid supply unit and the liquid droplet ejection. And a temperature control unit that adjusts the temperature of the liquid supplied from the liquid supply unit to the droplet discharge unit.

  According to a third aspect of the present invention, in the liquid droplet ejection head according to the first or second aspect, the liquid droplet ejection unit has a plurality of liquid droplet ejection modules, and the liquid supply unit temporarily stores liquid. A temporary storage tank, a reflux path that is provided for each droplet discharge module, circulates liquid between the temporary storage tank and the droplet discharge module, and a fluid element that opens and closes the liquid flow path. It relates to what is provided.

  According to a fourth aspect of the present invention, in the liquid droplet ejection head according to the third aspect, the inlet side end portion into which the liquid flows from the temporary storage tank of the annular flow path and the liquid circulated through the reflux path are supplied to the temporary storage tank. The present invention relates to an inlet side manifold and an outlet side manifold in which the return outlet side ends are integrated.

  According to a fifth aspect of the present invention, in the liquid droplet ejection head according to the fourth aspect, the liquid supply unit further controls the back pressure of the liquid in the inlet side manifold and the outlet side manifold in the reflux path. The present invention relates to a device including a pressure control unit.

  According to a sixth aspect of the present invention, in the liquid droplet ejection head according to any one of the first to fifth aspects, the drive circuit unit moves the mechanism unit on both sides along the longitudinal direction of the liquid droplet ejection unit. It is related with what is provided so that it may pinch.

  A seventh aspect of the present invention relates to the liquid droplet ejection head according to any one of the first to sixth aspects, wherein the drive circuit unit includes a cooling unit that cools the drive circuit.

  The invention according to an eighth aspect relates to the liquid droplet ejection head according to any one of the first to seventh aspects, wherein the ink is ejected as the liquid.

  A ninth aspect of the present invention relates to the liquid droplet ejection head according to any one of the first to eighth aspects, wherein the mechanism portion has a detachable handle.

  A tenth aspect of the present invention is a liquid comprising: the liquid droplet ejection head according to any one of the first to ninth aspects; and a support base on which the liquid droplet ejection head is detachably mounted. The present invention relates to a droplet discharge unit.

  The invention described in claim 11 is a recording medium transport unit that transports the recording medium in a predetermined direction, and a droplet discharge unit according to claim 10, which discharges droplets to the recording medium transported by the recording medium transport unit. And a droplet discharge device.

  According to the first aspect of the present invention, since the droplet discharge portion is elastically coupled to the mechanism portion, the rigidity of the mechanism portion is higher than that of a droplet discharge head in which the droplet discharge portion is rigidly coupled to the mechanism portion. A liquid droplet ejection head that can significantly reduce the influence on the liquid droplet ejection section and can therefore position the liquid droplet ejection section with high accuracy is provided.

  According to the second aspect of the present invention, the liquid led out from the liquid supply unit is adjusted to a predetermined liquid temperature by the temperature control unit and then supplied to the droplet discharge section. By setting the temperature at which appropriate droplet discharge can be performed, a droplet discharge head capable of properly discharging droplets regardless of the environmental temperature is provided.

  According to the invention of claim 3, by opening and closing the fluid element, a recovery operation can be performed for each droplet discharge module, and in the recovery operation, other than the fluid device communicating with the droplet discharge module in which clogging or bubbles are generated By closing the fluid element, there is provided a droplet discharge head capable of effectively removing clogging and bubbles by supplying liquid intensively to the droplet discharge module.

  According to the invention of claim 4, the circulation path is formed between the temporary storage tank, the reflux path, and the droplet discharge module by connecting the inlet side manifold and the outlet side manifold to the temporary storage tank. An easy-to-use droplet discharge head is provided.

  According to the invention of claim 5, the back pressure control unit controls the back pressure between the inlet side manifold and the outlet side manifold in the reflux path, thereby effectively preventing meniscus destruction on the nozzle surface in the droplet discharge module. A liquid droplet ejection head is provided.

  According to the invention of claim 6, since the drive circuit section is provided so as to sandwich the mechanism section from both sides, the wiring between the drive circuit section and the droplet discharge head can be shortened, and the drive Provided is a droplet discharge head that allows easy inspection and replacement of a circuit portion.

  According to the seventh aspect of the present invention, even if the load on the drive circuit unit increases due to the fact that the drive circuit unit is cooled by the cooling means and a high-density image signal is input for a long time, etc. A droplet discharge head that does not overheat is provided.

  According to invention of Claim 8, the droplet discharge head used suitably as a print head in an inkjet printer is provided.

  According to the ninth aspect of the present invention, there is provided a liquid droplet ejection head that is easier to carry, attach to and remove from a support base, as compared with those without a handle.

  According to the invention of claim 10, in a state where the droplet discharge head is mounted on the support base, the droplet discharge portion is distorted by the rigidity of the mechanism portion of the droplet discharge head, and the nozzle surface of the droplet discharge portion to the recording medium. It is possible to provide a droplet discharge unit capable of minimizing a change in the distance of the droplet.

  According to the invention of claim 11, in the droplet discharge unit, the droplet discharge portion is distorted by the rigidity of the mechanism portion of the droplet discharge head, and the distance from the nozzle surface of the droplet discharge portion to the recording medium is changed to change the recording medium. As a result, it is possible to effectively prevent a change in the size of the discharged droplets, and as a result, it is possible to provide a droplet discharge device that can obtain good print quality.

  An ink jet recording apparatus that is an example of a liquid droplet ejection apparatus according to the present invention and an ink jet recording head that is an example of the liquid droplet ejection head of the present invention and that is included in the ink jet recording apparatus will be described.

[Constitution]
As shown in FIG. 1, the inkjet recording apparatus 10 records an image on a sheet feeding unit 12 that stores a recording sheet P before an image is recorded, and a recording sheet P supplied from the sheet feeding unit 12. An image recording unit, a conveying unit that conveys the recording paper P to the image recording unit, and a paper discharge unit that accommodates the recording paper P after the image is recorded by the image recording unit. Yes.

  The image recording unit 14 includes an inkjet recording head 20, and the inkjet recording head 20 includes a nozzle surface 22 on which a plurality of nozzles (not shown) are formed. The nozzle surface 22 is an example of the recording medium of the present invention, and has a recordable area that is about the same as or larger than the maximum width of the recording paper P on which an image is formed by the inkjet recording apparatus 10.

  The inkjet recording head 20 is arranged in parallel in the order of yellow (Y), magenta (M), cyan (C), and black (K) from the downstream side with respect to the conveyance direction of the recording paper P. The ink droplets are ejected by a known means such as a method or a piezoelectric method. As the ink, various inks such as water-based ink, oil-based ink, and solvent-based ink can be used. The ink-jet recording apparatus 10 is provided with an ink tank (not shown) that supplies ink to each of the ink-jet recording heads 20Y to 20K. ) Is arranged.

  The transport unit 16 transports the recording paper P to the pickup drum 24 that picks up (picks up) the recording paper P in the paper feeding unit 12 one by one and the inkjet recording head 20 of the image recording unit 14, and prints the surface (surface). ) To the ink jet recording head 20 and a transport drum 26 as a transport body, and a delivery drum 28 that feeds the recording paper P on which an image is recorded to the paper discharge unit 18. The pickup drum 24, the transport drum 26, and the delivery drum 28 are each configured such that the recording paper P is held on the peripheral surface thereof by an electrostatic suction means or a non-electrostatic suction means such as suction or adhesion. ing.

  The pickup drum 24, the transport drum 26, and the delivery drum 28 are provided with, for example, two sets of grippers 30 as holding means for holding the downstream end of the recording paper P in the transport direction. Each of the three drums 24, 26, and 28 is configured to be able to hold a recording sheet P on its peripheral surface, in this case up to two sheets. And the gripper 30 is provided in the recessed part 24A, 26A, 28A formed in the circumferential surface of each drum 24,26,28 2 each.

  That is, a rotation shaft 34 is mounted in parallel with the rotation shaft 32 of each drum 24, 26, 28 at a predetermined position in the recess 24 A, 26 A, 28 A of each drum 24, 26, 28. A plurality of grippers 30 are fixed to 34 at predetermined intervals in the axial direction (for example, at equal intervals). Therefore, when the rotary shaft 34 is rotated in both forward and reverse directions by an actuator (not shown), the gripper 30 is rotated in both forward and reverse directions along the substantially circumferential direction of each drum 24, 26, 28, and the recording paper P is transported downstream in the conveyance direction. The side end portion can be held and separated.

  In other words, the gripper 30 is rotated so that the front end thereof slightly protrudes from the peripheral surfaces of the drums 24, 26, and 28, so that the peripheral surface of the pickup drum 24 and the peripheral surface of the transport drum 26 face each other. 36, the recording paper P can be transferred from the gripper 30 of the pickup drum 24 to the gripper 30 of the transport drum 26, and transported at a transfer position 38 where the peripheral surface of the transport drum 26 and the peripheral surface of the delivery drum 28 face each other. The recording paper P can be transferred from the gripper 30 of the drum 26 to the gripper 30 of the delivery drum 28.

  Although not shown, the ink jet recording apparatus 10 determines the ink droplet ejection timing and the nozzle to be used according to the image signal, and applies control signals to the ink jet recording head 20 for applying a drive signal to the nozzle. System control means for controlling the operation of the entire recording apparatus 10 is provided.

  Hereinafter, the configuration of the inkjet recording head 20 will be described in detail.

  2 and 3, the inkjet recording head 20 extends over the entire width of the recording paper P along the width direction of the recording paper P and ejects ink droplets onto the recording paper P. 200, a mechanism unit 202 that supplies ink to be ejected to the inkjet recording unit 200, and a drive circuit unit 204 that is fixed to both surfaces of the mechanism unit 202 and drives the inkjet recording unit 200. The ink jet recording unit 200 corresponds to a droplet discharge unit in the present invention.

  As shown in FIGS. 2 to 7, the inkjet recording unit 200 includes 17 inkjet recording modules 205, a module holding block 206 that holds the inkjet recording module 205, and a suspended suspension that is fixed to both ends of the module holding block 206. Unit 207.

  The ink jet recording unit 200 is elastically suspended below the mechanism unit 202 in the suspended unit 207.

  The ink jet recording module 205 corresponds to the droplet discharge module of the present invention, and a nozzle surface 22 is formed on the lower surface as shown in FIG. 2 and nozzle holes (not shown) are formed on the nozzle surface 22 at a predetermined pitch. Z.) is formed. The nozzle holes may be arranged in a staggered pattern or a grid pattern. Piezoelectric elements (not shown) such as piezo elements are provided corresponding to the nozzle holes, and each piezoelectric element is a recording module in the drive circuit unit 204 via a printed wiring (not shown). It is connected to the drive circuit 204A.

  As shown in FIG. 2, the mechanism unit 202 includes a temporary storage tank 208 that temporarily stores the ink supplied from the ink tank, and a reflux path that circulates the ink between the temporary storage tank 208 and each inkjet recording module 205. 209, fluid elements 210 and 211 that intermittently connect the reflux path 209, a back pressure control unit 212 that controls the back pressure on the inlet side and the outlet side of the reflux path 209, and the temperature of ink flowing through the reflux path 209. The temperature control unit 214 includes a temporary storage tank 208, a reflux path 209, fluid elements 210 and 211, a back pressure control unit 212, and a frame body 216 that holds the temperature control unit 214 in a predetermined position.

  The temporary storage tank 208 and the back pressure control unit 212 are provided above the frame body 216, and the fluid elements 210 and 211 and the reflux path 209 are provided inside the frame body 216. The temperature adjustment unit 214 is provided inside the frame that forms the lower edge of the frame 216.

  The reflux path 209 is provided for each ink jet recording module 205, and supplies ink from the temporary storage tank 208 to each ink jet recording module 205, and returns the ink from each ink jet recording module 205 to the temporary storage tank 208. The return channel 209B is divided. The fluid element 210 interrupts the supply-side flow path 209A, and the fluid element 211 interrupts the return-side flow path 209B. The inlet side end of the supply side channel 209A is integrated to form an inlet side manifold (not shown). Similarly, the outlet side end portions of the return side channel 209B are integrated to form an outlet side manifold (not shown). The back pressure control unit 212 is connected to the inlet side manifold and the outlet side manifold.

  The temperature control unit 14 is also provided for each ink jet recording module 205 similarly to the reflux path 209, and is connected to the temperature control circuit 204B in the drive circuit unit 204 by a printed wiring 215 as shown in FIG.

  As shown in FIGS. 2 to 7, a suspension part 217 for suspending the inkjet recording part 200 from both ends of the lower edge part of the frame 216 toward the outside is provided. In addition, arm mounting portions 218 protrude outward from the frame forming both side edges of the frame body 216. As shown in FIG. 5, an arm-shaped handle arm 220 is detachably mounted on the arm mounting portion 218. A rod-shaped handle main body 222 is attached to the handle arm portion 220, and the handle arm portion 220 and the handle main body 222 form a handle as a whole.

  As shown in FIG. 3, a cooling fan 204C for cooling various circuits such as a recording module drive circuit 204A and a temperature control circuit 204B is provided at the upper end of the drive circuit unit 204. As shown in FIGS. 4 and 5, the drive circuit unit 204 is covered with a protective cover 204D. The upper end of the protective cover 204D is a protective cover 204E that covers the cooling fan 204C. In addition, the temporary storage tank 208 and the back pressure control unit 212 in the mechanism unit 202 are also covered with a protective cover 219.

  Hereinafter, how the inkjet recording unit 200 is suspended below the mechanism unit 202 will be described in detail.

  As shown in FIGS. 6 and 7, a pin 207 </ b> A extending along the vertical direction is implanted on the upper surface of the suspended portion 207 in the inkjet recording unit 200. And pin 207A is penetrated by the opening part provided in the suspension part 217 in the mechanism part 202. As shown in FIG. The tip of the pin 207A bulges outward to form a bulging portion 207B that functions as a spring seat. A coil spring 224 is interposed between the bulging portion 207B and the suspension portion 217 in the pin 207A. Instead of interposing the coil spring 224 between the bulging part 207B and the suspension part 217 of the pin 207A, a rubber spring or a leaf spring is provided between the lower surface of the suspension part 217 and the upper surface of the suspended part 207. You may interpose.

[Action]
Hereinafter, the operation of the inkjet recording apparatus 10 according to the first embodiment will be described.

  Next, the operation of the inkjet recording apparatus 10 configured as described above will be described. The recording paper P picked up and held one by one by the gripper 30 of the pickup drum 24 from the paper supply unit 12 is conveyed while being attracted to the peripheral surface of the pickup drum 24, and at the delivery position 36, the gripper 30 of the pickup drum 24. To the gripper 30 of the transport drum 26.

  The recording paper P held by the gripper 30 of the transport drum 26 is transported to the image recording position of the ink jet recording head 20 while being attracted to the transport drum 26, and the printing surface is printed by ink droplets ejected from the ink jet recording head 20. An image is formed.

  The recording paper P on which an image is formed on the printing surface is delivered from the gripper 30 of the transport drum 26 to the gripper 30 of the delivery drum 28 at the delivery position 38. The recording paper P held by the gripper 30 of the delivery drum 28 is conveyed while being attracted to the delivery drum 28 and supplied to the paper discharge unit 18. In this way, a series of image formation is completed.

  Here, when the ink jet recording head 20 is replaced, the handle arm portion 220 is attached to the arm attachment portion 218 and the handle main body 222 is inserted into the handle arm portion 220 as shown in FIG. By grasping the grip formed in this manner, the ink jet recording head 20 can be easily detached from the image recording unit 14.

  As described above, in each ink jet recording head 20, the ink jet recording unit 200 is elastically suspended from the mechanism unit 202 by the coil spring 224. Therefore, when the ink jet recording head 20 is attached to the image recording unit 14, the mechanism unit The deformation stress that the inkjet recording unit 200 receives due to the rigidity of 202 can be greatly reduced. Therefore, since the ink jet recording unit 200 can be positioned with high accuracy, the fluctuation in the position of the ink jet recording unit 200 when the ink jet recording head 20 is attached to and detached from the image recording unit 14, in other words, the fluctuation in the position of the nozzle surface 22 is minimized. To the limit.

  As described above, the example in which the liquid droplet ejection head of the present invention is used as a print head of an ink jet printer type liquid droplet ejection apparatus has been described, but the liquid droplet ejection head of the present invention is not limited to performing image formation by ejecting ink. For example, it is also used to form a circuit pattern by discharging a suspension of fine particles of metal such as copper or aluminum or conductive oxide such as ITO in an organic solvent or water onto a substrate or film. can do.

FIG. 1 is a schematic diagram illustrating an overall configuration of the ink jet recording apparatus according to the first embodiment. FIG. 2 is a perspective view showing a configuration in which the drive circuit unit is removed from the ink jet recording head provided in the ink jet recording apparatus shown in FIG. FIG. 3 is a perspective view showing the relative positional relationship of the drive circuit unit with respect to the inkjet recording unit and the mechanism unit in the inkjet recording head. FIG. 4 is a perspective view showing a place where a protective cover is put on the drive circuit portion in the ink jet recording head. FIG. 5 is a view showing a position where a handle arm portion is provided in the ink jet recording head. FIG. 6 is a perspective view showing details of a mechanism for elastically suspending the ink jet recording unit from the mechanism unit in the ink jet recording head. FIG. 7 is a perspective view showing details of a mechanism for elastically suspending the ink jet recording unit from the mechanism unit in the ink jet recording head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inkjet recording device 12 Paper supply part 14 Image recording part 16 Conveying means 18 Paper discharge part 20 Inkjet recording head 20Y Inkjet recording head 20M Inkjet recording head 20C Inkjet recording head 20K Inkjet recording head 22 Nozzle surface 200 Inkjet recording part 202 Mechanism part 204 Drive circuit portion 204A Recording module drive circuit 204B Temperature control circuit 204C Cooling fan 204D Protective cover 204E Protective cover 205 Inkjet recording module 206 Module holding block 207 Suspended suspended portion 207A Pin 207B Swelling portion 208 Temporary storage tank 209 Reflux path 209A Supply side Channel 209B Return side channel 210 Fluid element 211 Fluid element 212 Back pressure control unit 214 Temperature control unit 215 Print wiring 216 Frame 217 Suspension part 218 Arm mounting part 219 Protective cover 220 Handle arm part 222 Handle body 224 Coil spring

Claims (11)

A droplet discharge section that extends over the entire width of the recording medium and discharges droplets onto the recording medium;
Supplying a liquid to be discharged as droplets to the droplet discharge unit, and a mechanism unit in which the droplet discharge unit is elastically coupled;
A drive circuit unit fixed to the mechanism unit and driving the droplet discharge unit;
With
The mechanism portion is provided with a suspension portion, and the droplet discharge portion is provided with a suspended portion. The droplet discharge portion is suspended from the suspension portion of the mechanism portion in the suspended portion. And a spring is interposed between the suspended portion and the suspended suspended portion.   The mechanism unit is located between a liquid supply unit that supplies liquid to the droplet discharge unit, and between the liquid supply unit and the droplet discharge, and the temperature of the liquid supplied from the liquid supply unit to the droplet discharge unit A droplet discharge head according to claim 1, further comprising a temperature control unit that adjusts the temperature. The droplet discharge unit has a plurality of droplet discharge modules,
The liquid supply unit includes a temporary storage tank in which liquid is temporarily stored, a reflux path that is provided for each droplet discharge module, and circulates the liquid between the temporary storage tank and the droplet discharge module, and the reflux The liquid droplet ejection head according to claim 2 , further comprising a fluid element that opens and closes the path.   The reflux path is integrated with an inlet side end portion and an outlet side manifold, where an inlet side end portion into which liquid flows from the temporary storage tank and an outlet side end portion where the liquid circulated through the reflux path returns to the temporary storage tank are integrated. The droplet discharge head according to claim 3.   The droplet discharge head according to claim 4, wherein the liquid supply unit further includes a back pressure control unit that controls a back pressure of the liquid in the inlet side manifold and the outlet side manifold in the reflux path.   6. The droplet discharge head according to claim 1, wherein the drive circuit unit is provided so as to sandwich the mechanism unit from both sides along a longitudinal direction of the droplet discharge unit.   The liquid droplet ejection head according to claim 1, wherein the drive circuit unit includes a cooling unit that cools the drive circuit.   The liquid droplet ejection head according to claim 1, wherein ink is ejected as the liquid.   The liquid droplet ejection head according to claim 1, wherein the mechanism portion has a detachable handle.   A droplet discharge unit comprising: the droplet discharge head according to any one of claims 1 to 9; and a support base on which one or a plurality of the droplet discharge heads are detachably mounted.   A liquid droplet ejection apparatus comprising: a recording medium conveyance unit that conveys a recording medium in a predetermined direction; and a liquid droplet ejection unit according to claim 10 that ejects liquid droplets onto a recording medium conveyed by the recording medium conveyance unit.

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