JP2010158646A - Droplet discharge apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the deposition or non-deposition of droplets to a material to be applied at a low voltage. <P>SOLUTION: The pathway of the droplet is changed by statically charging the droplets to cause mutual action between the droplets discharged from a nozzle 24A and droplets discharged from a nozzle 24B by the electrostatic force due to the static charge. The mutual action of the static force of the charged droplets is used to change the pathway of the droplets without applying a structure for forming deflection electric field to deflect the charged droplets. As a result, the control for the deposition or non-deposition of the droplets on the material to be applied 12 is carried out at a lower voltage in comparison with the structure for forming deflection electric field to deflect the charged droplets, because, for example, the deflection voltage requires 1 kv but the charging voltage is only about 50V. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a droplet discharge device.

  As a droplet discharge device, a functional material coating device disclosed in Patent Literature 1 and an ink jet recording device disclosed in Patent Literature 2 are known.

  The functional material coating apparatus disclosed in Patent Document 1 pressurizes the functional material coating liquid 14 continuously to eject the liquid columnar coating liquid 14 from the nozzle 121 of the ejection head 12, and the ejected liquid. The columnar coating liquid 14 is formed into droplets and applied to the object 10 to be coated. In this way, since the coating liquid 14 is discharged under continuous pressure, even a high-viscosity coating liquid (for example, a coating having a viscosity of about 3 mPa · s or less close to water to a coating having a viscosity of about 300 mPa · s) is stable. Then, the coating liquid 14 can be discharged and applied to the article 10 to be coated.

The ink jet recording apparatus disclosed in Patent Document 2 is an ink jet system in which landing on a recording paper is turned on / off depending on whether or not a droplet is charged, and the charging signal generating means includes charged ink particles and uncharged ink particles. Considering in advance the positional deviation of the ink particles caused by electrical repulsion with each other, a charging signal for applying a constant charge to the ink particles is generated. When this charge signal is applied to the ink particles, the amount of charge is corrected by this charge signal, so that the particles that have been charged with a certain amount of charge scatter to the regular position on the recording medium. Become.
JP 2007-325993 A (FIG. 2) Japanese Patent Laid-Open No. 01-159254

  An object of the present invention is to make it possible to control the landing and non-landing of a droplet on an object to be discharged with a lower voltage than a configuration in which a deflection electric field for deflecting a charged droplet is formed. .

  A droplet discharge device according to claim 1 of the present invention has a nozzle set including a plurality of nozzles formed on a nozzle surface, and a droplet discharge head that continuously discharges droplets from the nozzle set; A counter member disposed opposite to the nozzle surface and formed with a passage hole through which the liquid droplets discharged from the nozzle set can pass, and the liquid droplets discharged from the nozzle set are charged, and the electrostatic force generated by the charging And a charging electrode that interacts between droplets ejected from each nozzle of the nozzle set to change the course of the droplets.

  According to a second aspect of the present invention, there is provided the liquid droplet ejection apparatus according to the first aspect, wherein the liquid droplet ejection head is arranged in the other direction along the ejection direction of the liquid droplets ejected from one nozzle of the nozzle set. A droplet is discharged from the nozzle.

  According to a third aspect of the present invention, there is provided the liquid droplet ejection apparatus according to the first or second aspect, wherein the liquid droplet ejection head is configured such that the liquid droplets pass through the passage hole when the charging electrode is in an uncharged operation state. Thus, the droplets are ejected, and the charging electrodes charge the droplets and repel each other, thereby changing the course of the droplets and colliding with the opposing member.

  According to a fourth aspect of the present invention, in the liquid droplet ejection device according to the third aspect, the passage hole is formed at a position other than on the path changed by the repulsion of the liquid droplets.

  According to a fifth aspect of the present invention, there is provided the droplet discharge device according to any one of the first to fourth aspects, wherein the droplet discharged from the droplet discharge head and landed by the droplet passing through the passage hole is landed. And a moving mechanism for moving the discharge object relative to the droplet discharge head in the direction of the rotation axis of the rotation mechanism. The droplet discharge head has an arrangement of the nozzles. A plurality of nozzle sets that are the same are arranged at a constant interval along the rotation axis direction, and the moving mechanism is configured so that the rotation mechanism rotates the discharge target object one or more times while the rotation mechanism rotates the discharge object one or more times. The object to be discharged is moved relatively.

  A droplet discharge device according to a sixth aspect of the present invention is the discharge target according to any one of the first to fourth aspects, wherein a droplet discharged from the droplet discharge head and landed through the passage hole is landed. The charging electrode is controlled to be charged / non-charged based on a signal generated by the rotation position of the discharged object.

  According to a seventh aspect of the present invention, in the configuration of any one of the first to sixth aspects, the opposing member has a recovery mechanism for recovering the droplet that has collided with the opposing member. .

  According to the configuration of the first aspect of the present invention, it is possible to control the landing and non-landing of the droplet on the discharged object with a lower voltage than the configuration in which the deflection electric field for deflecting the charged droplet is formed. .

  According to the configuration of the second aspect of the present invention, it is possible to control the landing and non-landing of the droplet on the discharged object with a lower voltage than in the case where the configuration is not provided.

  According to the configuration of the third aspect of the present invention, it is possible to easily control the landing and non-landing of the droplet on the discharged object as compared with the configuration of passing the passage hole when the path of the droplet is changed.

  According to the structure of Claim 4 of this invention, compared with the case where it does not have this structure, it can suppress that the droplet which should collide with an opposing member passes a passage hole accidentally.

  According to the configuration of the fifth aspect of the present invention, it is possible to mesh the droplets that have landed on the discharge start side and the discharge end side as compared with the case where the configuration is not provided.

  According to the configuration of the sixth aspect of the present invention, the charging operation / non-charging operation of the charging electrode can be easily controlled as compared with the case where the configuration is not provided.

  According to the structure of Claim 7 of this invention, compared with the case where this structure is not provided, the dripping of the droplet which collided with the opposing member can be suppressed.

  Below, an example of an embodiment concerning the present invention is described based on a drawing.

  In this embodiment, as an example of a droplet discharge device that discharges droplets, a liquid coating device that applies a coating liquid of a functional material to an object to be coated will be described.

  The droplet discharge device is not limited to this liquid application device. Examples of the droplet discharge device include an ink jet recording device that discharges ink droplets to record an image on a recording medium, a color filter manufacturing device that discharges ink or the like on a film or glass, and a dissolved state. A device for forming bumps for component mounting by discharging solder onto a substrate, a device for forming a wiring pattern by discharging a liquid containing metal, and various film forming devices for forming a film by discharging droplets It may be present as long as it ejects droplets.

(Overall configuration of liquid application apparatus according to this embodiment)
First, the overall configuration of the liquid coating apparatus according to this embodiment will be described. 1 and 2 are schematic perspective views showing the overall configuration of the liquid coating apparatus according to the present embodiment.

  The liquid application apparatus 10 according to the present embodiment is an apparatus that applies a coating liquid to an object to be applied 12 as an example of an object to be discharged that receives liquid droplets. As shown in FIGS. 1 and 2, the liquid coating apparatus 10 includes a coating object support portion 14 that supports the coating object 12.

  The article support 14 is formed in a plate shape, for example, and is provided upright on the substrate 16. The coated object support portions 14 are respectively disposed at both ends of the coated object 12, and rotatably support the rotating shaft 18 </ b> A to which the coated object 12 is attached at both ends of the coated object 12.

  For example, a photosensitive drum is used as the coating object 12. Note that the object to be coated 12 is not limited to the photosensitive drum. For example, other electrophotographic members (functional belt (intermediate transfer member), transfer roll, charging roll, etc.), and other industrial products (for example, liquid crystal) Display, plasma display, semiconductor product) may be used.

  Further, the shape of the article to be coated 12 is not limited to a cylindrical shape, and may be other shapes such as a columnar shape and a rectangular tube shape.

  The liquid coating apparatus 10 includes a rotation device 18 that rotationally drives the object 12 supported by the object support 14 as an example of a rotation mechanism that rotates the object to be discharged. The rotating device 18 includes a rotating shaft 18A to which the workpiece 12 is attached, an endless belt 18B connected to a gear portion disposed at one axial end of the rotating shaft 18A, and the workpiece through the belt 18B. And a drive motor 18 </ b> C that applies a rotational force to 12.

  The rotating shaft 18A of the rotating device 18 is provided with an encoder 29 for detecting the rotational position of the rotating shaft 18A. The encoder 29 counts the rotation angle of the rotary shaft 18A.

  The rotating mechanism is not limited to the rotating device 18 and may be a rotating mechanism configured by other mechanical elements as long as the rotating mechanism rotates the workpiece 12.

  The liquid coating apparatus 10 includes, as an example of a droplet discharge head that continuously discharges droplets, a discharge head 20 that continuously discharges a functional material coating liquid onto an object 12 supported by an object support 14. ing. In the ejection head 20, the nozzle 24 is disposed along the rotation axis direction of the workpiece 12 (see FIG. 3).

  As the application liquid of the functional material discharged from the discharge head 20, for example, a charge transport layer solution in which a resin and a charge transport agent used in a photoreceptor are dissolved in an organic solvent is used.

  Further, the liquid coating apparatus 10 includes a coating liquid tank 30 that stores a coating liquid discharged from the discharge head 20. One end of a coating solution supply pipe 32 for supplying the coating solution stored in the coating solution tank 30 to the ejection head 20 is connected to the coating solution tank 30. The other end of the coating liquid supply pipe 32 is connected to one end of the ejection head 20.

  One end of a coating liquid discharge pipe 34 for discharging the coating liquid from the discharging head 20 to the coating liquid tank 30 is connected to the other end of the discharge head 20. The other end of the coating liquid discharge pipe 34 is connected to the coating liquid tank 30.

  The coating liquid tank 30 is provided with a pump 36 for sending the coating liquid from the coating liquid tank 30 to the ejection head 20 through the coating liquid supply pipe 32. The pump 36 continuously pressurizes and sends the coating liquid from the coating liquid tank 30 to the discharge head 20, and the coating liquid sent to the discharge head 20 is continuously discharged from the nozzles 24 of the discharge head 20. .

  The ejection head 20 is provided with a piezoelectric element 33 (see FIG. 4). By this piezoelectric element 33, vibration is applied to the coating liquid in the ejection head 20, and the coating liquid discharged from the nozzle 24 is made into droplets. Although not shown, the piezoelectric element 33 generates a vibration (sound wave) by applying a high frequency voltage from an electrode to a PZT ceramic film, for example, and transmits this vibration to the coating liquid in the ejection head 20.

  In the present embodiment, the pump 36 has a function of ejecting the coating liquid from the nozzle 24 in a liquid column shape, and the piezoelectric element 33 has a function of making the liquid columnar coating liquid into droplets. That is, the pump 36 and the piezoelectric element 33 cooperate to discharge the coating liquid from the discharge head 20 as droplets.

  The application liquid droplet forming means for forming the application liquid into droplets is not limited to a configuration using a piezoelectric element, and a system in which the application liquid is heated and formed into droplets by the fluctuation of the heat may be used.

  In addition, the liquid coating apparatus 10 is an object to be coated supported by the object support 14 as an example of a moving mechanism that moves the object to be ejected relative to the droplet discharge head in the rotation axis direction of the rotation mechanism. A moving device 28 for moving the object 12 in the axial direction is provided.

  The moving device 28 includes a rail 28A disposed between the coating object support portions 14, a moving body 28B supported on the rail 28A so as to be reciprocally movable along the rotation axis direction of the coating object 12, and a moving body 28B. A drive unit (not shown) for moving the body 28B along the rail 28A is provided.

  The moving body 28B is provided with a connecting portion 28C that is connected to the rotating shaft 18A of the rotating device 18. The connecting portion 28C extends from the moving body 28B in an arm shape, and the tip end is fixed to the rotating shaft 18A.

  As a result, the moving body 28B moves along the rail 28A in the direction of the rotation axis of the workpiece 12, whereby the rotation shaft 18A of the rotating device 18 moves in the axial direction, and the workpiece 12 moves in the axial direction. Moving.

  The moving mechanism is not limited to the moving device 28, and may be a moving mechanism configured by other mechanical elements as long as it is a moving mechanism that moves the workpiece 12 in the axial direction.

  As described above, the coating object 12 is rotated by the rotating device 18, and the coating object 12 is moved in the rotation axis direction by the moving device 28. The coating liquid is applied to the object to be coated 12 in a spiral manner.

  In the liquid coating apparatus 10, the rotation shaft 18 </ b> A generates an application start signal at a predetermined rotation position of the rotation shaft 18 </ b> A detected by the encoder 29, and the rotation shaft 18 </ b> A completes application to the coating object 12 from the rotation position. An application end signal is generated when a plurality of rounds are made.

  For example, when the ejection head 20 can apply all of the application area in the rotation axis direction of the application object 12 at a time, the application object 12 is applied without moving in the rotation axis direction. It may be. In this case, an application start signal is generated at a predetermined rotational position of the rotary shaft 18A detected by the encoder 29, and the rotary shaft 18A that completes application to the coating object 12 is rotated once from the rotational position. When this is done, an application end signal is generated.

(Configuration for controlling landing / non-landing of droplets on the object 12)
Next, a configuration for controlling the landing / non-landing of droplets on the coating object 12 will be described.

  As shown in FIGS. 3 and 5A, the discharge head 20 has a nozzle set 26 including a plurality of nozzles 24 formed on the nozzle surface 20A.

  In the present embodiment, the nozzle set 26 includes nozzles 24A and 24B that are adjacent nozzles. In the present specification, the nozzle 24A and the nozzle 24B are not distinguished from each other, and are referred to as a nozzle 24 when indicating a nozzle.

  The nozzles 24 </ b> A and 24 </ b> B are arranged obliquely with respect to the longitudinal direction (axial direction) of the ejection head 20. Specifically, when viewed from the nozzle 24A, the nozzle 24B is disposed on one side in the longitudinal direction of the nozzle surface 20A of the ejection head 20 (on the left side in FIG. 5A) in the lateral direction of the nozzle surface 20A of the ejection head 20. They are arranged shifted to one side (the lower side in FIG. 5A).

  The longitudinal direction of the nozzle surface 20A of the ejection head 20 is a relative movement direction in which the ejection head 20 moves relative to the object 12 by the moving device 28, and the plurality of nozzles 24 as a whole are arranged. It is also the direction of arrangement.

  Further, the short direction of the nozzle surface 20A of the discharge head 20 is a relative rotation direction in which the discharge head 20 rotates relative to the workpiece 12 by the rotating device 18, and the longitudinal direction of the nozzle surface 20A. It is also the direction orthogonal to

  Further, as will be described later, since the electrostatic force acts between the droplets discharged from the nozzle 24A and the nozzle 24B, the nozzle 24A is kept to such an extent that the droplets maintain a distance at which the electrostatic force acts on each other. And the nozzle 24B are close to each other.

  Further, the nozzle hole of the nozzle 24A is formed along the nozzle hole of the nozzle 24B, and the droplet is discharged from the nozzle 24A along the droplet discharged from the nozzle 24B. Thereby, the time for making an electrostatic force act mutually between the droplets discharged from the nozzle 24A and the nozzle 24B is ensured.

  More specifically, it is desirable that the nozzle holes of the nozzles 24A and 24B are formed in parallel, and the droplets discharged from the nozzles 24A and 24B are parallel.

  Since the nozzle set 26 includes two nozzles 24A and 24B, the droplets ejected from the nozzle 24A are subjected to the repulsive force of only the droplets ejected from the nozzle 24B, and are ejected from the nozzle 24B. The repelled force of only the liquid droplets discharged from the nozzle 24 </ b> A acts on the liquid droplets that have been discharged.

  As shown in FIGS. 6A and 6B, in the configuration in which three or more nozzles 24 are arranged in a straight line, droplets from the nozzles 24 sandwiched between them are nozzles on both sides. When the repulsive force is received from the droplets from 24, the repulsive force is canceled out, and the course of the droplets discharged from the nozzles 24 sandwiched therebetween is difficult to change. Therefore, a nozzle arrangement in which three or more nozzles 24 are arranged in a straight line is not desirable.

  5 and 6, the solid line arrows indicate the repulsive force (electrostatic force) of the droplets, and the dotted arrows indicate the direction of repulsion of the droplets. Further, the number of nozzles in the nozzle set 26 is not limited to two, and may be three or more as shown in FIGS. 5 (B) and 5 (C).

  In the configuration shown in FIG. 5B, the nozzles 24 are arranged in a zigzag shape, and the distances between the centers of the adjacent nozzles 24 are equal. For this reason, a repulsive force is applied from the droplets ejected from the nozzles 24 adjacent on both sides in the longitudinal direction of the nozzle surface 20A of the ejection head 20. As a result, a combined repulsive force is generated from the droplets ejected from the nozzles 24 adjacent on both sides.

  In the configuration shown in FIG. 5C, the nozzle set 26 includes three nozzles 24. One nozzle 24 generates a combined repulsive force from the droplets discharged from the other two nozzles 24.

  In addition, the configuration shown in FIG. 5C includes nozzle sets 26 in which the arrangement of the nozzles 24 is different. Specifically, the nozzle set 26 includes two types, and includes a nozzle set 26A and a nozzle set 26B.

  In the nozzle set 26A, two nozzles 24 are disposed on one side (upper side in FIG. 5C) of the nozzle surface 20A of the ejection head 20, and the other side (FIG. 5) of the nozzle surface 20A. One nozzle 24 is arranged on the lower side in (C).

  In the nozzle set 26B, one nozzle 24 is arranged on one side (upper side in FIG. 5C) of the nozzle surface 20A of the ejection head 20, and the other side (FIG. 5) of the nozzle surface 20A. Two nozzles 24 are arranged on the lower side in (C).

  As described above, in the configuration having the nozzle sets 26 in which the arrangement of the nozzles 24 is different, when the droplets land on the workpiece 12 in a spiral shape and the droplets landed from the different nozzles 24 are joined together, the joint is considered. There is a need to.

  For example, as shown in FIG. 7, when the application start side of the droplets landed from the nozzle set 26A and the application end side of the liquid droplets landed from the nozzle set 26B are connected, the nozzle set 26A and the nozzle Since the arrangement of the nozzles 24 is different from the set 26B, the landed droplets do not mesh.

  Therefore, as shown in FIG. 8, the coating object 12 is axially aligned so that the application start side of the liquid droplets landed from the nozzle set 26A and the application end side of the liquid droplets landed from the nozzle set 26A are connected. The droplets need to be moved in a spiral manner. In the example shown in FIG. 8, nozzle sets 26 </ b> A and nozzle sets 26 </ b> B are alternately arranged, and a plurality of nozzle sets 26 </ b> A are arranged at regular intervals along the rotation axis direction of the workpiece 12.

  In this embodiment, while the rotating device 18 rotates the coating object 12 one or more times, the droplets landed from the nozzle set 26 </ b> A by moving the coating object 12 in the axial direction by the interval. And the application end side of the droplets landed from the nozzle set 26A are joined together.

  Further, as shown in FIGS. 3 and 4, the liquid coating apparatus 10 is disposed to face the nozzle surface 20 </ b> A of the ejection head 20, and a passage hole 40 </ b> A through which droplets ejected from the nozzle set 26 can pass is formed. The opposed member 40 is provided. The facing member 40 is disposed between the coating object 12 supported by the coating object support 14 and the ejection head 20. Moreover, the opposing member 40 is comprised with the plate body formed in plate shape, and the both ends are supported by the support part (illustration omitted).

  The passage hole 40A is formed to be at least larger than the droplets ejected from the ejection head 20. Since the diameter of the droplets ejected from the ejection head 20 is defined by the nozzle diameter of the ejection head 20, the diameter of the passage hole 40 </ b> A is made larger than the nozzle diameter of the ejection head 20.

  The passage hole 40A is formed in the ejection direction in which the ejection head 20 ejects droplets. Thereby, when the charging electrode 42 is in the non-charging operation state, the droplets discharged from the discharge head 20 pass through the passage hole 40A.

  The passage holes 40A are configured in the same number as the nozzles 24A and 24B, and are arranged in the same shape as the nozzles 24A and 24B.

  Further, as shown in FIG. 9A, the passage hole 40A is formed at a position other than on the course where the droplets repel each other and changed. Thereby, it is difficult for the droplet whose course has been changed to pass through the other passage hole 40A.

  When the nozzles 24 are arranged in a zigzag shape as shown in FIG. 5B, the passage holes 40A are also arranged in a zigzag shape as shown in FIG. 9B. Also in this case, the passage hole 40A is formed at a position other than on the course changed by the droplets repelling each other.

  Further, as shown in FIG. 5 (C), when the nozzle set 26 is composed of three nozzles 24, as shown in FIG. The Also in this case, the passage hole 40A is formed at a position other than on the course changed by the droplets repelling each other.

  As shown in FIGS. 10A and 10B, when the passage hole 40A is formed on the route changed by the repulsion of the droplets, the droplet whose route has been changed passes through another passage. There is a risk of passing through the hole 40A. In FIGS. 9 and 10, the solid line arrows indicate the repulsive force (electrostatic force) of the droplets, and the dotted arrows indicate the direction of repulsion of the droplets.

  The nozzle diameter of the nozzle is, for example, 30 μm, and the nozzle interval at the center of the nozzle is, for example, 100 μm. In this case, the passage hole 40A has, for example, a hole diameter of 70 μm, and an interval at the hole center of, for example, 100 μm. In this case, if the path of the liquid droplet is changed by 50 μm before reaching the counter member 40, the liquid droplet collides with the counter member 40 without passing through the passage hole 40A.

  In addition, the liquid application apparatus 10 includes a funnel 46 as an example of a recovery mechanism for recovering droplets that have landed on the opposing member 40. The funnel 46 has a shape in which a cone is flattened, and the mouth portion 46 </ b> A side is supported by the article support portion 14.

  The funnel 46 flows the liquid flowing in from the upper opening 46 </ b> A to the lower part and discharges the liquid from the lower discharge opening to the discharge tank 48. The facing member 40 extends from the edge of the mouth portion 46 </ b> A of the funnel 46 and is provided integrally with the funnel 46. The funnel 46 is connected to the ground. As a result, the funnel has an unnecessary potential, and the path of the charged droplet is prevented from being changed unintentionally.

  Note that the facing member 40 may be provided separately from the funnel 46.

  Between the opposing member 40 and the ejection head 20, a charging electrode 42 for charging the droplets ejected from the nozzle set 26 is disposed. The charging electrode 42 has a gap between the facing member 40 and the ejection head 20, and is provided separately from the facing member 40 and the ejection head 20.

  In the present embodiment, two charging electrodes 42 are provided, and are configured by a charging electrode 42A and a charging electrode 42B. In the present specification, the charging electrode 42A and the charging electrode 42B are referred to as the charging electrode 42 when showing the charging electrode without distinguishing them.

  The charging electrode 42 </ b> A is arranged in the vicinity of one nozzle 24 </ b> A (the upper nozzle in FIGS. 3 and 5) of the nozzle set 26. The charging electrode 42 </ b> B is arranged in the vicinity of the other nozzle 24 </ b> B (the lower nozzle in FIGS. 3 and 5) of the nozzle set 26.

  The charging electrode 42A is connected to a power source 50 and a circuit 52 (see FIG. 12) for applying a charging voltage between the charging electrode 42A and the nozzle 24A. By applying a charging voltage between the charging electrode 42A and the nozzle 24A, a charging electric field is formed between the charging electrode 42A and the nozzle 24A to charge the droplets discharged from the nozzle 24A.

  The charging electrode 42B is connected to a power source (not shown) and a circuit (not shown) for applying a charging voltage between the charging electrode 42B and the nozzle 24B. By applying a charging voltage between the charging electrode 42B and the nozzle 24B, a charging electric field is formed between the charging electrode 42B and the nozzle 24B to charge the droplets discharged from the nozzle 24B.

  The charging electric field formed between the charging electrode 42A and the nozzle 24A and the charging electric field formed between the charging electrode 42B and the nozzle 24B have the same polarity (for example, positive electrode).

  The droplets ejected from the nozzle 24A and the nozzle 24B are charged by passing through a charging electric field, and the electrostatic force due to this charging interacts between the droplets ejected from the nozzle 24A and the nozzle 24B, The course of those droplets is changed.

  Specifically, since the droplets discharged from the nozzle 24A and the nozzle 24B have the same polarity, they repel each other and change their path to the outside of the passage hole 40A.

  The charging electrode 42A and the charging electrode 42B enter a charging operation state in which a charging electric field is formed by an application start signal generated by the rotation position of the object to be applied 12, and stop by an application end signal to enter a non-charging operation state. .

  The shape of the charging electrode need not be a flat plate shape, and may be any shape such as a cylindrical shape or a donut shape as long as the droplet can be charged satisfactorily.

(Operation of the liquid coating apparatus according to this embodiment)
Next, the operation of the liquid coating apparatus according to this embodiment will be described.

  In the liquid coating apparatus 10, when a start command for starting coating is acquired, first, as shown in FIG. 11, in step 102, the pump 36 starts feeding the coating liquid to the ejection head 20, and the rotating device 18. Starts to rotate the workpiece 12. When feeding of the coating liquid is started by the pump 36, the coating liquid starts to be gradually discharged from the discharge head 20, and the coating liquid starts to fly from the discharge head 20.

  Next, in step 104, charging by the charging electrode 42 is started before the coating liquid flies. Thereby, as shown in FIGS. 12A and 12B, the droplets discharged from the nozzle 24A and the nozzle 24B repel each other and collide with the opposing member 40. For this reason, the droplets discharged from the nozzle 24 </ b> A and the nozzle 24 </ b> B do not reach the coating object 12.

  Next, in step 106, an application start signal generated by the rotational position of the application object 12 detected by the encoder 29 is acquired, and charging by the charging electrode 42 is completed. As a result, as shown in FIGS. 13A and 13B, the droplets discharged from the nozzle 24A and the nozzle 24B pass through the passage hole 40A and land on the object 12 to be applied. Application to 12 is started.

  When the application to the application object 12 is started, the application object 12 is gradually moved in the direction of the rotation axis while rotating the application object 12, and the liquid droplets discharged from the nozzles 24 </ b> A and 24 </ b> B are discharged to the outer periphery of the application object 12. The surface is spirally landed and applied to the outer peripheral surface of the object to be coated 12, and a coating film is formed on the outer peripheral surface of the object to be coated 12.

  Next, in step 108, an application end signal generated by the number of revolutions of the workpiece 12 detected by the encoder 29 is acquired, and charging by the charging electrode 42 is started. Thereby, the droplets discharged from the nozzle 24A and the nozzle 24B repel each other and collide with the facing member 40. For this reason, the droplets discharged from the nozzle 24A and the nozzle 24B do not reach the application object 12, and the application to the application object 12 is completed.

  Next, in step 110, the pump 36 finishes feeding the coating liquid to the ejection head 20, and the rotating device 18 finishes the rotation of the coating object 12.

  Next, in step 112, the charging by the charging electrode 42 is finished, and the coating operation on the coating object 12 is finished.

  As described above, in the present embodiment, the droplets are charged, and the electrostatic force due to this charging interacts between the droplets discharged from the nozzle 24A and the nozzle 24B, and the path of these droplets is determined. Be changed.

  For this reason, landing / non-landing of the droplets discharged from the plurality of nozzles 24 at a time onto the object to be coated 12 is controlled. Further, in order to change the course of the droplet, the electrostatic force of the charged droplet is interacted with each other, and the deflection electric field for deflecting the charged droplet is not formed. For example, a charging voltage of about 50 V is sufficient as compared with the case where the deflection voltage is required to be 1 kv. Landing / non-landing is controlled.

  The charging voltage shown here is an example, and changes depending on the type of liquid and the interval between the charging electrode and the nozzle. As long as the droplets can be charged satisfactorily, the values described in this embodiment are not particular.

  As described above, the ejection head 20 ejects droplets from the nozzle 24A along the droplets ejected from the nozzle 24B. However, ejection of droplets from the nozzle 24A and the nozzle 24B is performed. The direction is not limited to this. For example, as shown in FIG. 14A, when viewed from above, the droplet ejection trajectory from the nozzle 24A intersects with the droplet ejection trajectory from the nozzle 24B (see FIG. 14B). ) When viewed from the lateral direction, the droplet ejection trajectory from the nozzle 24A and the droplet ejection trajectory from the nozzle 24B are parallel to each other (see FIG. 14C), and the nozzle 24A and the nozzle You may set the discharge direction of the droplet from 24B.

  The droplets ejected from the nozzle 24A and the nozzle 24B can fly over a distance at which the electrostatic force can act on each other, and the distance can be maintained for a time during which the electrostatic force can act on each other. As such, the direction in which the droplets are ejected may be set.

  Further, as shown in FIGS. 15A and 15B, the droplets discharged from the nozzle 24B are used for application to the coating object 12, and the droplets from the nozzle 24A are applied to the coating object 12. The structure may be used only for applying an electrostatic force to the droplet discharged from the nozzle 24 </ b> A without being used for the coating.

  In the configuration shown in FIGS. 15A and 15B, the counter member 40 is not formed with the passage hole 40 </ b> A for allowing the liquid droplets discharged from the nozzle 24 </ b> A to pass therethrough. In the non-charging operation state of the charging electrode 42, as shown in FIG. 15A, the liquid droplet ejected from the nozzle 24B passes through the passage hole 40A, while the liquid droplet ejected from the nozzle 24A is a counter member. Collide with 40.

  In the charging operation state of the charging electrode 42, as shown in FIG. 15B, the droplets discharged from the nozzle 24A and the nozzle 24B repel each other and collide with the opposing member 40.

  In the configuration of the present embodiment, as shown in FIGS. 12 and 13, when the charging electrode 42 is in the non-charging operation state, the droplet passes through the passage hole 40 </ b> A, and when the charging electrode 42 is in the charging operation state, the droplet However, as shown in FIGS. 16 and 17, when the charging electrode 42 is in the charging operation state, the droplets pass through the passage hole 40A. In the non-charging operation state of the charging electrode 42, the droplet may collide with the facing member 40 without passing through the passage hole 40A.

  In this configuration, as shown in FIGS. 16A and 16B, the counter member 40 is not formed with a passage hole 40A in the ejection direction in which droplets are ejected from the ejection head 20, and charging is performed. In the non-charging operation state of the electrode 42, the liquid droplet ejected from the ejection head 20 travels straight and collides with the opposing member 40, and does not reach the coating object 12.

  As shown in FIGS. 17A and 17B, the opposing member 40 is formed with a passage hole 40A on the path changed by the droplets ejected from the ejection head 20 repelling each other. ing. For this reason, in the charging operation state of the charging electrode 42, the droplets ejected from the ejection head 20 pass through the passage hole 40 </ b> A and reach the coating object 12.

  Further, in the configuration of the present embodiment, as shown in FIG. 12, in the charging operation state of the charging electrode 42, the droplets repel each other to change the course, but as shown in FIG. 18, In a charging operation state of the charging electrode 42, a configuration in which droplets are attracted to each other to change the course may be employed.

  The charging electric field formed between the charging electrode 42A and the nozzle 24A and the charging electric field formed between the charging electrode 42B and the nozzle 24B have opposite polarities.

  The droplets ejected from the nozzle 24A and the nozzle 24B are charged by passing through the charging electric field, and the droplets ejected from the nozzle 24A and the nozzle 24B are attracted to each other by the electrostatic force due to the charging. The course of the droplet is changed. The droplet whose course has been changed does not pass through the passage hole 40A and collides with the opposing member 40, and does not reach the coating object 12.

  In the liquid coating apparatus 10, the ejection head 20, the charging electrode 42, and the opposing member 40 are provided separately. However, as shown in FIG. 19, the ejection head 20, the charging electrode 42, and the opposing member 40 are integrated. The discharge head unit 100 may be provided. In this configuration, the charging electrode 42 is attached to the nozzle surface 20 </ b> A side of the ejection head 20 via the insulating member 43. The facing member 40 is attached to the charging electrode 42 via the insulating member 44, and is provided on the ejection head 20 via the charging electrode 42 and the insulating member 43.

  The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made.

FIG. 1 is a schematic perspective view showing the overall configuration of the liquid coating apparatus according to the present embodiment. FIG. 2 is a schematic perspective view showing the overall configuration of the liquid coating apparatus according to the present embodiment, and is a view of the apparatus viewed from the side opposite to FIG. FIG. 3 is a schematic perspective view illustrating the configuration of the ejection head, the charging electrode, and the opposing member according to the present embodiment. FIG. 4 is a schematic perspective view illustrating the configuration of the ejection head, the charging electrode, and the facing member according to the present embodiment, and is a view of the ejection head and the like viewed from the side opposite to FIG. FIG. 5 is a schematic diagram illustrating a configuration of a nozzle or a passage hole according to the present embodiment. FIG. 6 is a schematic diagram showing a configuration of an undesirable nozzle or passage hole. FIG. 7 is a schematic diagram showing a case where the application start and the application end are not meshed in a configuration having nozzle sets with different nozzle arrangements. FIG. 8 is a schematic diagram showing a case where the application start and the application end are engaged in a configuration having nozzle sets with different nozzle arrangements. FIG. 9 is a schematic view showing the configuration of the passage hole according to the present embodiment. FIG. 10 is a schematic diagram showing a configuration of an undesired passage hole. FIG. 11 is a diagram illustrating a coating procedure for an object to be coated in the liquid coating apparatus according to the present embodiment. 12A and 12B are schematic views showing the operation of the liquid droplet in the charging operation state of the charging electrode according to the present embodiment, FIG. 12A is a perspective view, and FIG. 12B is a side view. 13A and 13B are schematic views showing the operation of the droplets in the non-charging operation state of the charging electrode according to the present embodiment, FIG. 13A is a perspective view, and FIG. 13B is a side view. FIG. 14A is a schematic diagram showing a configuration in which the ejection trajectories of droplets ejected from two nozzles intersect when viewed from above, and FIG. 14B shows the liquid when viewed from above. FIG. 14C shows the droplet ejection trajectory when viewed from the lateral direction. FIG. 15 is a schematic diagram showing a configuration in which droplets ejected from one nozzle are used only for applying an electrostatic force to droplets ejected from the other nozzle, and FIG. It is the schematic which shows operation | movement of the droplet in a non-charging operation state, (B) is the schematic which shows operation | movement of the droplet in the charging operation state of a charging electrode. FIG. 16 is a schematic diagram illustrating a configuration in which a droplet collides with a counter member in a non-charging operation state of the charging electrode, (A) is a perspective view, and (B) is a side view. FIG. 17 is a schematic diagram illustrating a configuration in which a droplet passes through a passage hole and lands on an object to be coated in a charging operation state of the charging electrode, (A) is a perspective view, and (B) is a perspective view. It is a side view. 18A and 18B are schematic views showing a configuration in which droplets are mutually sucked to change their course, wherein FIG. 18A is a perspective view and FIG. 18B is a side view. FIG. 19 is a schematic diagram illustrating a configuration of a droplet discharge head unit in which a droplet discharge head, a charging electrode, and a counter member are integrated.

10 Liquid applicator (droplet discharge head)
12 Object to be coated (Subject to be discharged)
18 Rotating device (rotating mechanism)
20A Nozzle surface 20 Discharge head (droplet discharge head)
24 Nozzle 26 Nozzle set 28 Moving device (moving mechanism)
40 Opposing member 40A Passing hole 42 Charging electrode 46 Funnel (recovery mechanism)
100 Discharge head unit

Claims (7)

A droplet discharge head that has a nozzle set composed of a plurality of nozzles formed on the nozzle surface, and continuously discharges droplets from the nozzle set;
An opposing member that is disposed to face the nozzle surface and has a passage hole through which liquid droplets discharged from the nozzle set can pass;
A charging electrode that charges droplets discharged from the nozzle set and causes the electrostatic force generated by the charging to interact between the droplets discharged from the nozzles of the nozzle set to change the path of the droplets. When,
A droplet discharge device comprising:   The droplet ejection apparatus according to claim 1, wherein the droplet ejection head ejects droplets from the other nozzle along the ejection direction of droplets ejected from one nozzle of the nozzle set. The droplet discharge head discharges the droplet so that the droplet passes through the passage hole in a non-charging operation state of the charging electrode,
3. The droplet discharge device according to claim 1, wherein the charging electrode charges the droplets and repels each other, thereby changing a path of the droplets to collide with the opposing member.   The droplet ejection device according to claim 3, wherein the passage hole is formed at a position other than on a course changed by the droplets repelling each other. A rotating mechanism for rotating a discharged object discharged from the droplet discharge head and landed by a droplet passing through the passage hole;
A moving mechanism for moving the discharge object relative to the droplet discharge head in the rotation axis direction of the rotation mechanism;
With
In the droplet discharge head, a plurality of nozzle sets having the same nozzle arrangement are arranged at regular intervals along the rotation axis direction.
The droplet according to any one of claims 1 to 4, wherein the moving mechanism relatively moves the discharged object by the interval while the rotating mechanism rotates the discharged object one or more times. Discharge device. A rotation mechanism for rotating a discharge object discharged from the droplet discharge head and landed by a droplet passing through the passage port;
5. The droplet discharge device according to claim 1, wherein the charging electrode is controlled to perform a charging operation or a non-charging operation based on a signal generated by a rotation position of the discharge target.   The droplet discharge device according to claim 1, wherein the facing member has a recovery mechanism for recovering a droplet that has collided with the facing member.

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