JP2011051209A - Liquid droplet discharging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid droplet discharging device that effectively removes bubble and foreign substances in a nozzle channel groove by a small amount of cleaning liquid not deaerated enough and that can clean a nozzle formation surface. <P>SOLUTION: The liquid droplet discharging device includes: an inkjet head that discharges liquid droplets from a nozzle; a pressure reducing means that decompresses in the inkjet head; a wiping head that has a wipe blade for wiping out the nozzle formation surface of the inkjet head; and a moving means that relatively moves the wipe blade to the nozzle formation surface. The liquid droplet discharging device also includes a liquid reservoir for reserving liquid in an upper part of the wiping head. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a droplet discharge device.

  Conventionally, a droplet discharge device is a device that discharges droplets, which is simple and easy by discharging droplets of ink (a dye or pigment diluted with a solvent or the like and liquefied) toward an object. Since the apparatus can perform vivid color printing and has a low running cost, it is generally widely used as a printer. Therefore, it is generally called “inkjet device”. Further, in recent years, the droplet discharge device is used not only for general printing performed on paper, but also for the field of precision industrial applications such as manufacturing fine pixel display structures such as liquid crystal display modules and organic EL display modules. The field of use is expanding.

  When precision printing is performed using a droplet discharge device, an inkjet head (the droplet discharge device is not limited to one that discharges ink, but the droplet discharge head of the droplet discharge device is referred to as an “inkjet head”. In this specification, the term “inkjet head” is used, but the droplets ejected by the “inkjet head” are not limited to ink, but liquid (including solids in the liquid). It is particularly important that the liquid droplets be ejected with high accuracy as long as it is acceptable.

  However, as the inkjet head continues to be used, the ink (dye or pigment) in the droplets adheres to the nozzle forming surface of the inkjet head or foreign matter adheres to it. It becomes a cause that it becomes impossible to discharge a droplet to this position. In order to continue discharging liquid droplets stably and accurately for a long time, it is necessary to periodically clean the nozzle forming surface to remove dyes or pigments adhering to the nozzle forming surface and attached foreign substances.

  As a method for cleaning the nozzle formation surface, a method of wiping the nozzle formation surface with a plate-like wipe blade made of an elastic body is generally used.

  Patent Document 1 discloses a cleaning method in which ink is used as a cleaning liquid when a nozzle forming surface is wiped with a wipe blade. Specifically, a method for cleaning a nozzle forming surface is disclosed in which the inside of an inkjet head is pressurized to ooze ink from the nozzles to wet the wipe blade, and the head drive unit slides on the nozzle surface while microvibrating. Yes.

  In addition, if bubbles or foreign substances are mixed in the nozzle channel groove in the ink jet head, it may cause a defective discharge of the liquid droplet or a liquid droplet that cannot be discharged to a desired position. Therefore, in order to continuously discharge liquid droplets stably for a long time, it is necessary to periodically remove bubbles and foreign matters in the nozzle channel grooves of the inkjet head.

  As a method for removing bubbles and foreign matters in the nozzle channel groove, a method is generally used in which the nozzle surface of the inkjet head is capped and suctioned with a negative pressure inside the cap.

  Patent Document 2 discloses a method in which pressure (positive pressure and negative pressure) is generated by a pressure generation unit in an inkjet head in a state where the nozzle is immersed in a cleaning liquid, and bubbles and foreign matters are removed from the nozzle channel groove. ing.

  Further, in Patent Document 3, in order to prevent bubbles from being mixed in the nozzle channel groove and to remove the bubbles, the degassed cleaning liquid is supplied to the vicinity of the nozzle, and the ink jet head nozzle formation surface is wiped with a wipe blade. Technology is disclosed. In Patent Document 3, bubbles in the nozzle channel groove are removed by supplying the cleaning liquid degassed in the nozzle forming surface cleaning method described in Patent Document 1 to the nozzle forming surface.

In this specification, cleaning of the nozzle forming surface and removal of bubbles and foreign matters in the nozzle channel groove are referred to as “inkjet head maintenance” or simply “maintenance”.
JP 2008-49535 A (published March 6, 2008) JP 2006-150937 A (released on June 15, 2006) Japanese Unexamined Patent Publication No. 2007-261088 (released on October 11, 2007)

  By the way, since the cleaning method of the nozzle formation surface described in patent document 1 is a method of removing the foreign material and ink on a nozzle formation surface, the bubble and foreign material in a nozzle channel groove cannot be removed.

  In general, if there are bubbles in the nozzle channel groove of the ink jet head, droplets cannot be discharged from the nozzle or unstable discharge is performed. As the state of bubbles in the nozzle channel groove, the state shown in FIG. 15 (a) or (b) is expected. FIG. 15 is a cross-sectional view illustrating a state in which the bubbles 26 remain in the nozzle channel grooves in the inkjet head 9. A nozzle plate 9d is attached as a bottom surface of the nozzle channel groove, and a nozzle 9a which is a through hole is formed in the nozzle plate 9d.

  FIG. 15A shows a state in which large bubbles 26 remain so as to block the nozzle channel groove. When the ink used is difficult to degas or when the ink jet head 9 is initially filled with ink, bubbles as shown in FIG. In this case, even if the ejection driving voltage is applied to the partition wall 9c and the piezoelectric element is vibrated, the pressure fluctuation hardly propagates to the nozzle, and even if a meniscus is formed, the vibration is merely ejected and no ejection occurs.

  On the other hand, FIG. 15B shows a state where minute bubbles 26 having a diameter smaller than that of the nozzle channel groove cross section remain in the partition wall. At this time, if the ejection drive voltage is applied in the same manner, ejection can be performed, but accurate ejection cannot be performed in terms of ejection volume, ejection speed, and landing accuracy.

  When removing the large bubbles 26 that block the nozzle channel groove as shown in FIG. 15A by cap suction operation or discard discharge operation, it cannot be surely removed by one removal operation. Can be executed multiple times to increase the probability of removal. Since the same removal process is performed a plurality of times, there is a problem that the amount of ink consumed is large and not economical.

  The method for removing bubbles and foreign matters described in Patent Document 2 requires a cleaning tank for immersing the nozzle forming surface in the cleaning liquid. Moreover, since it is necessary to fill the cleaning tank with the cleaning liquid, the amount of the cleaning liquid used is large. In addition, after cleaning, the nozzle formation surface becomes wet with a mixture of cleaning liquid and ink, so that these may later dry and solidify, resulting in liquid droplet ejection failure and inability to eject liquid droplets at desired positions There were problems such as becoming.

  With the method for removing bubbles described in Patent Document 3, it is impossible to remove the large bubbles 26 that block the inside of the nozzle flow path as shown in FIG. Further, since a means for degassing the cleaning liquid and supplying it to the wipe blade is required, there are problems such as an increase in manufacturing cost of the droplet discharge device and an increase in the size of the device.

  The present invention has been made in view of the above problems, and its object is to effectively remove bubbles and foreign matters in the nozzle channel groove with a small amount of cleaning liquid that has not been sufficiently deaerated, and to form a nozzle. An object of the present invention is to provide a droplet discharge device capable of cleaning a surface.

  In order to solve the above problems, a droplet discharge device according to the present invention wipes an inkjet head that discharges droplets from a nozzle, a decompression unit that decompresses the interior of the inkjet head, and a nozzle formation surface of the inkjet head. A droplet discharge apparatus comprising a wiping head having a wiping blade and a moving means for moving the wiping blade relative to the nozzle formation surface, wherein a liquid reservoir for storing liquid is provided on an upper portion of the wiping head. This is a droplet discharge device.

  The liquid droplet ejection apparatus according to the present invention is a liquid droplet ejection apparatus characterized in that the liquid reservoir is a groove.

  The wiping head includes a blade portion formed by stacking a rear member, an intermediate member, and a front member, and an upper surface of the intermediate member is disposed below an upper end of the rear member and an upper end of the front member. The upper part of the rear member functions as the wipe blade, and the upper part of the rear member, the upper surface of the intermediate member, and the upper part of the front member integrally form a liquid reservoir.

  In addition, the droplet discharge device according to the present invention is a droplet discharge device characterized by having a notch between the wipe blade and the bottom of the liquid reservoir.

  In addition, the droplet discharge device according to the present invention is a droplet discharge device including a cleaning liquid supply unit that can supply a liquid different from the liquid to be discharged to the liquid reservoir.

  Further, the liquid reservoir is a liquid droplet ejection apparatus comprising a cleaning liquid supply port for supplying liquid droplets to be discharged and liquid supplied from the cleaning liquid supply means to the liquid reservoir.

  The liquid droplet ejection apparatus is configured such that a plurality of the nozzles correspond to the liquid reservoir.

  According to the present invention, the liquid accumulated in the liquid reservoir using the moving means can be brought into contact with the nozzle forming surface, and the pressure in the nozzle channel groove can be reduced using the pressure reducing means. The liquid stored in the reservoir can pass through the nozzle and flow into the nozzle channel groove, and the large bubbles blocking the nozzle channel groove can be removed with the liquid that has not been sufficiently deaerated.

  Further, according to the present invention, the liquid accumulated in the liquid reservoir can be supplied to the adjacent wipe blade. The nozzle forming surface can be cleaned with a small amount of liquid by moving the wipe blade using the moving means so that the wipe blade wipes the nozzle forming surface while the wipe blade is wet.

It is a three-view figure (top view, side sectional view, front view) of the wiping head. It is a perspective view which shows the flow of the washing | cleaning liquid in a wiping head. It is side sectional drawing which shows the wiping head in a wiping process. FIG. 3 is a three-side view (a top view, a side sectional view, and a front view) showing a component configuration of the wiping head. It is a perspective view of a wiping device. It is a schematic diagram which shows the structure of a cleaning liquid supply means and a cleaning liquid discharge means. It is a schematic diagram which shows the structure of a droplet discharge apparatus. It is the schematic diagram which showed the structure of the nozzle and nozzle channel groove | channel. It is an exploded view of an inkjet head. It is a flowchart of a maintenance method. It is side sectional drawing which shows the inkjet head and wiping head in a bubble removal process. It is a front view which shows the wiping head of the state which overflowed the cleaning liquid, the cleaning liquid supply means, and the cleaning liquid discharge means. It is a perspective view of a wiping device. It is a side sectional view showing a wiping head and a cleaning liquid supply port in a process of supplying a cleaning liquid to the wiping head. It is sectional drawing which shows the state in which a bubble stays in a nozzle channel groove | channel.

  Embodiments of the present invention will be described below with reference to FIGS.

  The liquid droplet ejection apparatus according to the present embodiment includes an inkjet head that ejects droplets from nozzles, a decompression unit that decompresses the interior of the inkjet head, and a wipe blade that wipes the nozzle formation surface of the inkjet head. And a moving means for moving the wipe blade relative to the nozzle forming surface, wherein a liquid reservoir for storing liquid is provided on the upper portion of the wiper head. A droplet discharge device.

  The wiping head includes a blade portion configured by laminating a rear member, an intermediate member, and a front member, and the upper surface of the intermediate member is disposed below the upper end of the rear member and the upper end of the front member. The upper part of the rear member functions as a wipe blade, and the upper part of the rear member, the upper surface of the intermediate member, and the upper part of the front member form a liquid reservoir.

  In addition, a slit is formed between the wipe blade and the bottom of the liquid reservoir.

  According to the present embodiment, the liquid stored in the liquid reservoir is brought into contact with the nozzle by the moving unit, and the pressure reducing unit reduces the pressure in the nozzle channel groove, so that the liquid stored in the liquid reservoir passes through the nozzle. The large bubbles that flow into the nozzle channel groove and block the nozzle channel can be removed.

  In addition, after removing air bubbles and foreign matter in the nozzle channel groove, the liquid is supplied to the adjacent wipe blade, and the wiper blade wipes the nozzle forming surface while the wipe blade is wetted. Therefore, it is possible to remove bubbles and clean the nozzle forming surface with a small amount of liquid.

  (Description of Wiping Head) First, the schematic configuration of the wiping head 30 provided in the droplet discharge device of the present invention will be described with reference to FIGS. The wiping head 30 is a member that performs wiping in the wiping device. FIG. 1A is a top view showing a wiping head 30 in this embodiment, and FIG. 1B is a cross-sectional view (side cross-sectional view) taken along the line AA of FIG. (C) is a front view. Moreover, FIG.1 (d) is the elements on larger scale of B of FIG.1 (b). In the following description, when the wiping head performs the wiping operation, the direction in which the nozzle forming surface exists (not shown) is viewed from the wiping head 30, the wiping operation direction of the wiping head is the front, the direction orthogonal to the front, and the front Is the side (right and left). Moreover, the figure seen from the top is a top view, the figure seen from the front is a front view, and the figure seen from the side is a side view.

  FIG. 2 is a perspective view showing a flow of the cleaning liquid in the wiping head 30, and an arrow in the figure indicates a direction in which the cleaning liquid flows.

  As shown in FIGS. 1A to 1D, the wiping head 30 includes a blade portion 30a and a base portion 30b. The blade part 30a is a part that contacts the inkjet head and performs maintenance. The base portion 30b is a support portion that supports the entire wiping head 30, and is an attachment portion for the wiping device.

  The wipe blade 1 and the liquid reservoir portion 2 are provided adjacent to the upper portion of the blade portion 30. The wipe blade 1 is a part that is brought into contact with the nozzle forming surface and wiped off the nozzle forming surface during maintenance, and is generally formed in a plate shape having a plate thickness in the front-rear direction by a material having an elastic body.

  The liquid reservoir 2 is a recess or groove for storing liquid. In FIG. 1, as shown in FIG. 1 (d), the liquid reservoir 2 has a liquid reservoir bottom 2 a as the “bottom”, and the liquid reservoir front wall 2 b and the liquid reservoir rear wall 2 c are separated from the front and rear “standing walls”. It is a groove | channel (elongated hollow) which has a cross section called "."

  The upper end of the wipe blade 1 is higher than the upper end of the liquid reservoir front wall 2b and is fixed to the blade portion 30a at the lower end. Specifically, as shown in 1a of FIG. 1 (d), there is a notch 1a between the wipe blade 1 and the liquid reservoir bottom 2a, and the notch 1a is bent independently from the front part. The deformable range is the wipe blade 1. When there is no notch 1a, the wiper blade 1 is the rear part of the liquid reservoir bottom 2a and the upper part. In this embodiment, the term “cut” means “a mating surface that is not fixed and can be opened”, and has a meaning in the production process that a “cut” is made with a cutting tool or the like. Although it does not have, it may be the surface created by making “cut”.

  Further, the wiping head 30 includes a cleaning liquid supply channel 3 that supplies the cleaning liquid to the liquid reservoir 2. The cleaning liquid supply channel 3 is a through-hole penetrating the base 30b and the blade part 30a, and the cleaning liquid supplied from the base 30b side flows out from the cleaning liquid supply port 3a provided in the liquid reservoir bottom 2a, and the liquid reservoir 2 It is the composition which accumulates in. As shown in FIG. 1 (a), the cleaning liquid supply port 3a may be an opening that is long in the longitudinal direction (that is, the left-right direction of the front view) opened in the liquid reservoir bottom 2a, or may be a plurality of small A plurality of holes may be arranged side by side in the left-right direction of the front view.

  Further, the wiping head 30 includes a cleaning liquid discharge channel 4 for discharging the cleaning liquid. The cleaning liquid supply flow path 3 includes a cleaning liquid recovery port 4a which is a hole opened on the left and right sides of the liquid reservoir bottom 2a and on the base 30b, and an absorber that temporarily absorbs and holds the cleaning liquid recovered from the cleaning liquid recovery port 4a. 4b and a discharge path for discharging the cleaning liquid that cannot be held by the absorber 4b to the outside of the wiping head 30.

  When a supply pump (not shown) for supplying the cleaning liquid is operated to the wiping head 30 having the above-described configuration, the cleaning liquid is supplied from the cleaning liquid inlet 6 through the cleaning liquid inlet 6 as indicated by an arrow in FIG. It flows into the passage 3 and overflows from the cleaning liquid supply port 3a provided in the liquid reservoir bottom 2a. The cleaning liquid flows right and left in the liquid reservoir 2 and flows down from both left and right ends of the liquid reservoir bottom 2a. Thereafter, the cleaning liquid flows into the cleaning liquid recovery port 4a, is absorbed by the absorber 4b (not shown), and is discharged from the cleaning liquid discharge channel 4 (not shown).

  In this embodiment, the liquid reservoir 2 is a groove, and has a structure in which a certain amount of cleaning liquid is accumulated in the liquid reservoir 2 due to the lyophilicity of the members constituting the liquid reservoir 2 with respect to the cleaning liquid and capillary action. In addition, when a large amount of cleaning liquid is supplied to the liquid reservoir 2 beyond the predetermined amount, the cleaning liquid that exceeds the amount that can be stored in the liquid reservoir 2 flows down from the left and right ends of the liquid reservoir bottom 2a. The amount of cleaning liquid stored in the liquid reservoir 2 is kept constant. When the cleaning liquid stored in the liquid reservoir 2 is contaminated and becomes unsuitable for cleaning, the contaminated cleaning liquid is washed away by supplying the cleaning liquid of a certain amount or more to the liquid reservoir 2 so that the cleaning liquid is clean. The cleaning liquid can be stored in the liquid reservoir 2.

  When the wipe blade 1 is brought into contact with the nozzle forming surface 9b in a state where the cleaning liquid is stored in the liquid reservoir 2, the nozzle 9a is covered with the cleaning liquid as shown in FIG. Further, in wet wiping (described later), the liquid reservoir 2 is preferably adjacent to the wipe blade 1 in order to supply the cleaning liquid to the wipe blade 1, and specifically, the liquid reservoir 2 as in this embodiment. A shape in which the liquid reservoir rear wall 2c, which is a rear standing wall for holding the liquid, is the wipe blade 1 can be considered. A portion of the wipe blade 1 that contacts the nozzle forming surface 9b is referred to as a contact portion (edge portion) of the wipe blade 1.

  Moreover, when the several nozzle is formed in a line on the nozzle formation surface, it is preferable that the liquid reservoir part 2 is a groove | channel. The liquid reservoir 2 which is a groove can collectively maintain a plurality of nozzles arranged in a straight line with a small amount of cleaning liquid. Further, by utilizing the capillary phenomenon, the amount of the cleaning liquid stored in the liquid reservoir 2 can be made constant, thereby enabling stable maintenance.

  The cross-sectional shape of the liquid reservoir 2 may be any shape as long as it is a shape capable of storing liquid, such as a concave shape, a U shape, and a V shape.

  The height of the wipe blade 1 (the length from the upper end of the wipe blade 1 to the bottom of the cut 1a when there is a cut 1a, and the length from the upper end of the wipe blade 1 to the bottom 2a of the liquid reservoir when there is no cut 1a. Is preferably 2.5 times or more the thickness of the wipe blade 1. At the time of wiping (when the wiping head 30 is brought into contact with the nozzle and moved in the forward direction relative to the nozzle), the cut 1a is opened as shown in FIG. 3A, and only the wipe blade 1 is bent backward, Wipe out. According to this configuration, the wipe blade 1 can be greatly bent backward with a small force.

  The nozzle 9a is a precise and delicate component, and fails due to slight scratches or deformation. If excessive pressure is applied to the nozzle 9a by the wipe blade 1 at the time of wiping, it may cause a failure, so a large pressure should not be applied. For wiping, the wipe blade 1 needs to maintain a close contact state with the nozzle forming surface 9b, but solid matter (solidified dye or pigment solidified by foreign matter or discharged droplets on the nozzle forming surface 9b). Etc.) may be attached to form protrusions on the nozzle forming surface 9b. If it is possible to bend largely backward with a small force as in the present invention, the wipe blade 1 can be greatly bent backward with a small force even if there is a protrusion on the forming surface 9b. A close contact state can be maintained without applying a large pressure to the surface 9b, and liquids such as foreign matter and ink on the nozzle forming surface 9b can be wiped without causing the nozzle 9a to fail.

  The force required for the bending operation (ie, bending deformation) is inversely proportional to the Young's modulus of the wiping blade and proportional to the square of the thickness. When the material of the wiping blade is rubber, elastomer or the like (both are materials often used as the material of the wiping blade), the Young's modulus is about 1 to 20 MPa, so the thickness is 1/10 to 1 of the height. /2.5 is preferable. When a material having a higher Young's modulus is used, it is desirable to make the wiping blade thinner. Further, in order to accurately derive a suitable thickness of the wiping blade having a non-uniform thickness, it is necessary to perform a complicated bending deformation simulation calculation. However, it may be easily obtained by approximating the average thickness. .

  Further, since the notch 1a is provided, the distance between the liquid reservoir bottom 2a and the nozzle forming surface 9b can be reduced while ensuring the height of the wipe blade 1, and the amount of cleaning liquid that must be accumulated in the liquid reservoir 2 Can be reduced, and the consumption of the cleaning liquid can be reduced.

  Next, the wiping process will be described with reference to FIG. 3A and 3B are side sectional views showing the wiping head 30 in the wiping process.

  The wiping head 30 in the present embodiment can perform two types of wiping when wiping the nozzle forming surface. That is, wet wiping and dry wiping.

  First, wet wiping will be described. As shown in FIG. 3A, during the wiping operation of the wiping head 30, the wipe blade 1 contacts the nozzle forming surface 9b while being bent by the contact pressure with the nozzle forming surface 9b. Before the wipe blade 1 reaches the head nozzle 9a, the cleaning liquid 7 is supplied from the cleaning liquid supply channel 3. The supplied cleaning liquid 7 spreads between the contact portion of the wipe blade 1 and the nozzle forming surface 9b, and the contact portion of the wipe blade 1 becomes wet. The wipe blade 1 moves in the direction of the hollow arrow in FIG. 3A and wipes the nozzle forming surface 9b in a wet state.

  In the wet wiping of the present embodiment, since the nozzle forming surface 9b is filled with the cleaning liquid, the dye or pigment solidified on the nozzle forming surface 9b or the wipe blade 1 can be remelted and solidified without damaging the nozzle 9a. Dyes or pigments can be removed.

  On the other hand, dry wiping is wiping performed without using a cleaning liquid. This will be described with reference to FIG. During the wiping operation of the wiping head 30, the wipe blade 1 contacts the nozzle forming surface 9b while being bent by the contact pressure with the nozzle forming surface 9b. The wipe blade 1 wipes the nozzle forming surface 9b in the direction of the hollow arrow in FIG.

  After the wet wiping, when the cleaning liquid remains on the nozzle forming surface 9b, the cleaning liquid can be removed by performing dry wiping. If no solidified dye or pigment or foreign matter is attached to the nozzle forming surface 9b, the nozzle forming surface 9b can be cleaned by dry wiping instead of wet wiping.

  The liquid reservoir front wall 2b may be changed to a second wiping blade. In this case, the wiping blade 1 or the second wiping blade may be used for wiping, and the wiping unit 30 can be wiped by moving in any direction.

  4A to 4C show an example of a component configuration of the wiping head 30. FIG. 4A is a top view, FIG. 4B is a cross-sectional view (side cross-sectional view) of the AA cross section of FIG. 4A, and FIG. 4C is a front view. The blade part 30 a is composed of a rear member 71, an intermediate member 72, and a front member 73. The base 30b is mainly composed of a blade holder 75 and includes an absorber 4b. The rear member 71, the intermediate member 72, and the front member 73 are each in the form of a thin plate, and are stacked and disposed so that the front-back direction of the wiping head 30 is the plate thickness direction. In front of the rear member 71, an intermediate member 72 having a cleaning liquid supply port 3a which is a through hole in the upper and lower direction is adjacent. A front member 73 is adjacent to the front of the intermediate member 72. The rear member 71, the intermediate member 72, and the front member 73 are positioned in a rectangular hole provided on the upper surface of the blade holder 75 by a pin or a contact surface. In this component configuration, the upper part of the rear member 71 functions as a wipe blade. Further, the upper part of the rear member 71, the upper surface of the intermediate member 72, and the upper part of the front member 73 constitute the liquid reservoir 2 as a unit. Specifically, the upper surface of the intermediate member 72 functions as the liquid reservoir bottom 2a, and the portion of the front member 73 above the upper surface of the intermediate member 72 functions as the liquid reservoir front wall 2b. The upper part of the rear member 71 functions as the liquid reservoir rear wall 2c.

  An absorber 4b is disposed below the rear member 71 and the front member 73. The blade holder 75 is provided with a supply channel 75b, which is a through hole, as a part of the cleaning liquid supply channel 3 and is connected to the cleaning liquid supply port 3a. Further, since the intermediate member 72 is slightly shorter in the left-right direction than the rear member 71 and the front member 73, if the laminated member of the rear member 71, the intermediate member 72, and the front member 73 is disposed in a rectangular hole on the upper surface of the blade holder 75, the blade On the upper surface of the holder 75, slits leading to the absorber 4b are formed on the left and right of the intermediate member 72. The slit functions as a cleaning liquid recovery port 4a. Further, the blade holder 75 is formed with a discharge flow path 75a connected to the absorber 4b as a cleaning liquid discharge flow path. The supply channel 75b is connected to a cleaning liquid inlet (not shown). An O-ring is provided at each of the connecting part between the cleaning liquid supply port 3a and the supply flow path 75b and the connecting part between the cleaning liquid inlet and the supply flow path 75b to prevent the cleaning liquid from leaking from the connection part to the outside. Is desirable.

  The rear member 71 is preferably formed of a material made of an elastic body. Examples of such materials include rubber and elastomer. In particular, the rear member 71 is preferably formed of a material having chemical resistance such as perfluoro rubber (Perflo (registered trademark: Daikin Industries)).

  The upper surface of the intermediate member 72 is disposed below the upper end of the rear member 71 and the upper end of the front member 73. The intermediate member 72 is not particularly limited with respect to the material thereof, but may be formed of resin or metal. A cleaning liquid supply port 3 a for supplying a cleaning liquid is formed on the upper surface of the intermediate member 72.

  The upper end of the front member 73 is disposed below the upper end of the rear member 71 and above the upper surface of the intermediate member 72. Further, like the rear member 71, the front member 73 is preferably formed of a material made of an elastic body. The reason for this is to prevent the front member 73 from coming into contact with the nozzle forming surface 9b and damaging the nozzle forming surface 9b due to a malfunction or the like when the wiping head 30 is moved upward with respect to the ink jet head 9. is there. If the front member 73 is an elastic body, even if the front member 73 and the nozzle forming surface 9b come into contact with each other, the nozzle forming surface 9b is not damaged.

  As described above, when the rear member 71, the intermediate member 72, and the front member 73 are stacked and positioned on the blade holder 75, the rear member 71, the intermediate member 72, and the front member 73 are formed in a simple rectangular plate shape. Manufacturing is easy. Further, since the mounting position can be easily changed at the stage of positioning on the blade holder 75, the effect can be confirmed after the operation of the apparatus of the present invention, and the position can be changed to the optimum position.

  Further, since the rear member is a member for wiping the nozzle forming surface, there is a high possibility that the rear member will collide with a solidified dye or pigment or a foreign substance, and it is easily worn or damaged. If the rear member 71 is separate from other members as in this embodiment, the worn or damaged rear member 71 can be easily replaced with another rear member, and the replacement cost is low.

  Furthermore, by using the rear member 71, the intermediate member 72, and the front member 73 as separate members, as described above, a material suitable for each purpose can be selected.

  The intermediate member 72 may be formed as an integral member with the blade holder 75, the intermediate member 72 may be formed as an integral member with the rear member 71, and the intermediate member 72 is integral with the front member 73. It may be formed as a member. When the components are integrally formed, the number of components is reduced, so that the manufacturing cost can be reduced and the reliability of the droplet discharge device of the present invention is improved. If a suitable positional relationship among the rear member 71, the intermediate member 72, the front member 73, and the blade holder 75 is known in advance before designing, it is more stable by forming the members as one body so as to be in the positional relationship. The effect (removal of bubbles, liquid such as ink, solidified dye or pigment, or foreign matter) can be expected, and defects due to liquid leakage or foreign matter clogging between the parts can be prevented.

  The absorbent body 4b only needs to be configured to quickly absorb and permeate the used cleaning liquid and discharge it from the discharge flow path 75a. The absorbent body 4b may be porous, such as sponge, and has a hollow inside such as absorbent cotton. Or a simple space.

  The blade holder 75 positions and holds the rear member 71, the intermediate member 72, and the front member 73. The front member 73 is positioned so as not to contact the nozzle forming surface 9b when the rear member 71 contacts the nozzle forming surface 9b for the wiping operation.

  (Description of Wipe Unit) Next, the wiping device 40 is shown in FIG. FIG. 5 is a perspective view schematically showing the wiping device 40 and shows wiping. Although the ink jet head is not a component of the wiping device 40, the outer edge of the ink jet head 9 is indicated by a broken line in FIG. The wiping device 40 functions as a first moving unit that moves the wipe blade 1 relative to the nozzle forming surface 9b.

  As shown in FIG. 5, the wipe unit 13 includes a plurality of wiping heads 30. The wipe unit 13 is engaged by motion conversion means (for example, a combination of a worm gear and a pinion gear) that converts the rotational motion of the drive shaft 10 into motion in the wiping direction of the wiping head 30. By rotating 10, the wipe unit 13 moves along the guide rail 12 in the wiping direction of the wiping head 30.

  In the movement of the wipe unit 13, an origin sensor and a limit sensor (not shown) are attached to the side of the guide rail 12. Signals from the sensors are input to a control unit (not shown), and the control unit controls the operation of the motor 11 based on the signals and the like. The control unit grasps the state of the wipe unit 13 by receiving a signal from each sensor, and performs different specific operations (supply of cleaning liquid, movement of the wipe unit 13 and the like) depending on the state according to a built-in program. For transmitting a command signal to the operation unit such as a motor for executing the operation and each display unit.

  During the origin return operation, the origin sensor generates a signal. A signal from the origin sensor is input to the control unit, whereby the control unit can detect that the wipe unit 13 is at the origin.

  In addition, when the motor 11 is operated and the wipe unit 13 is moved, a pulse signal is generated by a sensor (not shown) attached to the motor 11 or the guide rail 12, and the control unit receives a signal from the origin sensor. Thereafter, the received pulse signals are counted, and the distance from the origin, that is, the current position of the wipe unit 13 can be detected by converting the counted number of signals into a distance.

  On the other hand, the limit sensors are respectively attached to the upper limit side and the lower limit side of the movement direction of the wipe unit 13. By receiving a signal from the limit sensor, the control unit can detect that the wipe unit 13 has moved to the upper limit side or the lower limit side end. Therefore, when the signal is detected, a control program such as stopping the motor 11 is executed. By incorporating it in the control unit, it is possible to prevent the wipe unit 13 from moving beyond the upper limit or the lower limit.

  Although not shown in FIG. 5, the wiping device 40 has a moving means for moving the wipe unit 13 up and down. The moving means may be a means for moving the wiping unit 13 up and down on the wiping device 40, or a method for moving the entire wiping device 40 shown in FIG. 5 up and down. As the moving means, similarly to the movement in the front-rear direction described above, the motor, a mechanism for converting the movement of the motor into a vertical movement and transmitting it to the wiping unit 13, a guide rail, a sensor, and a control unit are combined. Can be configured in a timely manner.

  Next, a cleaning liquid supply unit that can supply a liquid different from the liquid discharged to the wipe unit 13 and a cleaning liquid discharge unit that discharges the used cleaning liquid will be described with reference to FIG. FIG. 6 is a schematic diagram showing the configuration of the cleaning liquid supply means and the cleaning liquid discharge means.

  In addition, in a part of the description of the present embodiment, the description has been made using ink (a liquid obtained by diluting a dye, pigment, or the like with a solvent) as “liquid to be discharged”. In the apparatus, the “liquid to be discharged” may be any liquid (which may contain a solid content in the liquid or may be a jelly-like substance). The present invention is not limited by the composition and characteristics.

  Examples of the “liquid to be ejected” in the present embodiment include liquefied resin (thermoplastic resin, thermosetting resin, photocurable resin, etc.), melted liquid (solder, etc.), solvent (alcohol) in addition to ink. , Petroleum, water, etc.), adhesives, reaction solutions that cause certain chemical reactions (acids, etc.), catalyst solutions that promote certain chemical reactions, pharmaceuticals, proteins, RNA, DNA, It may be a liquid containing any of microorganisms such as vaccines, antibodies, viruses, and cells. That is, in this embodiment, “ink” may be read as “liquid to be ejected” or the liquid exemplified above.

  In the cleaning liquid supply means, as shown in FIG. 6, the cleaning liquid tank 17 and each of the cleaning liquid supply flow paths 3 of the plurality of wiping heads 30 are connected via a supply pipe 19 in which a supply pump 15 is arranged in the middle. . The cleaning liquid tank 17 is a tank that stores the cleaning liquid. When the supply pump 15 is driven, the cleaning liquid 7 stored in the cleaning liquid tank 17 flows through the supply pipe 19 and is supplied from the cleaning liquid supply port 3a of the liquid reservoir bottom 2a of the wiping head 30 to the nozzle forming surface 9b. The

  When the remaining amount of the cleaning liquid 7 in the cleaning liquid tank 17 becomes small, the empty sensor 21 detects and warns a warning device (display, lamp, buzzer, etc.) (not shown) to replenish the cleaning liquid 7 to the user. Arouse. Examples of the empty sensor 21 that can be used here include those with specifications based on optical, electrostatic capacitance, and weight detection methods.

  In the case of a droplet discharge device that uses ink as a cleaning liquid, there is a disadvantage that the cleaning power is inferior to a method using a dedicated cleaning liquid having a high cleaning power for removing dyes or pigments and foreign matters. Also, since the ink adheres to the contact portion of the wipe blade with the nozzle forming surface and is dried and solidified, and the wiped blade to which the dried or solidified dye or pigment is attached wipes the nozzle forming surface, the solidified dye or pigment May damage the nozzle and shorten the usable time of the nozzle. In addition, since the solidified dye or pigment is mixed from the nozzle into the nozzle channel groove, the nozzle cannot be used stably for a long period of time, resulting in a failure.

  In this embodiment, since the cleaning liquid supply means is provided, the inkjet head can be maintained using a liquid different from the liquid to be discharged as the cleaning liquid. For example, if a liquid (for example, an ink solvent) having an action of re-dissolving solid matter solidified by the liquid to be discharged is used as the cleaning liquid, the solid matter solidified in the nozzle forming surface 9b or the nozzle channel groove is re-dissolved. Can be removed. In addition, if a liquid having a lower viscosity than the liquid to be discharged or a liquid having a low surface tension is used, the cleaning liquid can easily flow into every corner of the nozzle channel groove, and the bubbles are peeled off from the inner wall (partition wall) of the nozzle channel groove. The effect to do can be made larger. Further, since no ink is used as the cleaning liquid, the ink adheres to the wipe blade 1 and does not dry or solidify. Therefore, the nozzle surface is not damaged by wiping the nozzle surface with the wipe blade 1 to which the solidified dye or pigment is adhered. In addition, since the solid matter in which the discharged droplets are solidified does not enter the nozzle channel groove from the nozzle, the nozzle can be used stably for a long period of time.

The cleaning liquid 7 used in this example is IPA (iso-propyl alcohol), and the surface tension value is about 2.3 × 10 ⁻³ kg / m, which is a liquid having a lower surface tension value than the ink used. It is. In addition, as the other cleaning liquid, the main solvent of the ink can be used as the cleaning liquid.

  In addition, in accordance with the liquid to be discharged, there is an action of melting the solidified substance of the liquid, or it is easy to mix with the liquid, and by mixing, the viscosity is lowered or the surface tension is lowered. What is necessary is just to select suitably the liquid which has the effect | action which makes it act as a washing | cleaning liquid. In the droplet discharge device of the present invention, since the cleaning liquid is not a component of the invention, the invention is not limited by the composition or characteristics of the cleaning liquid.

  On the other hand, as the cleaning liquid discharging means for discharging the used cleaning liquid, the cleaning liquid discharge flow path 4 of the wiping head 30 is connected via the common discharge flow path in the wipe unit 13 and the waste liquid pipe 20 disposed in the middle of the waste liquid pump 16. A waste liquid tank 18 is connected. The used cleaning liquid overflowed by wet wiping by the wipe blade 1 is accommodated in the waste liquid tank 18 from the common discharge flow path in the wipe unit 13 through the waste liquid pipe 20 by driving the waste liquid pump 16. .

  When many parts of the waste liquid tank 18 are filled with the stored used cleaning liquid, first, a signal is transmitted from the full sensor 22 for warning. A warning device (display, lamp, buzzer, etc.) not shown alerts the user to replace the waste liquid tank 18 by warning that effect. The user who has received the warning may replace the waste liquid tank 18. In spite of the warning, when the operation of discharging the cleaning liquid is continued without replacing the waste liquid tank 18 and the waste liquid tank 18 is completely filled with the waste liquid, a signal is transmitted from the error full sensor 23. Is done. The control unit receives the signal, and the control unit issues a command signal for stopping the operation of each operation unit of the droplet discharge device, and the droplet discharge device stops its operation.

  (Description of Droplet Discharge Device) In the following description of the present embodiment, the case where the liquid to be discharged is ink will be described as an example. The configuration of the droplet discharge device 60 of this embodiment will be described with reference to FIG. As shown in FIG. 7, the carriage 50 includes an inkjet head 9, a head drive controller 9 c, an ink tank 41, a sub tank 42, a buffer tank 43, a negative pressure chamber 44, an upper waste liquid tank 45, a liquid feed pump 46, and a vacuum pump 47. , Pressure sensors 48a and 48b and a shut-off valve. Moreover, as a maintenance apparatus, the wiping apparatus 40, the cap part which is not shown in figure, an inspection part, etc. are provided. The inkjet head 9 is mounted on the carriage 50, and when the carriage 50 moves in the horizontal direction, the inkjet head 9 reaches an ejection position corresponding to a desired droplet deposition position on the print object, and the inkjet head 9 Is discharged.

  Instead of the configuration in which the carriage 50 moves in the horizontal direction (front-rear direction and / or left-right direction), a configuration in which the print target is moved horizontally may be used.

  The moving means for moving the wipe blade 1 relative to the nozzle forming surface 9b may be configured to move the inkjet head 9 instead of moving the wipe blade 1 as in this embodiment. That is, a moving means (not shown) that horizontally moves the carriage 50 may be used as a second moving means that moves the wipe blade 1 relative to the nozzle forming surface 9b. In this case, the wiping device 40 does not have to include means for horizontally moving the wiping unit 13 (the drive shaft 10, the motor 11, the guide rail 12, etc.).

  The ink tank 41 and the sub tank 42 are formed of a flexible material. As shown in FIG. 7, the sub tank 42 is disposed in a pressure chamber 44 that is highly airtight and pressure-controllable. A vacuum pump 47 is connected to the pressure chamber 44, and the atmospheric pressure in the pressure chamber 44 is adjusted by the vacuum pump 47.

  The sub tank 42 has an inflow port and an outflow port. The inflow port and the ink tank 41 are connected by an ink supply tube, and the outflow port and the inkjet head 9 are connected by an ink supply tube. The ink supply tube is preferably a tube that is chemically resistant to the solvent used. For example, a fluororesin tube, a polypropylene tube, and SUS (stainless steel) piping can be used. The ink is supplied from the ink tank 41 into the sub tank 42, and the ink in the sub tank 42 is supplied to the ink jet head 9 while maintaining the meniscus of the nozzles of the ink jet head 9 by appropriately controlling the pressure of the pressure chamber 44. .

  The sub tank 42 has a bag shape in which the periphery of two films facing each other is bonded by thermal welding. Each of the two films has flexibility and gas barrier properties. The film constituting the sub-tank 42 forms a layer of MDPE (medium density polyethylene), aluminum, and nylon from the inside of the sub-tank 42, and aluminum is deposited on each other. For this reason, an increase in the amount of dissolved air in the ink in the sub tank 42 is suppressed. In addition, each above-mentioned layer of a film is not limited to aluminum vapor deposition, You may laminate.

  The ink discharged from the inkjet head 9 passes through the buffer tank 43 and is discharged to the upper waste liquid tank 45 by the liquid feed pump 46. Since the buffer tank 43 suppresses the amplitude of the pressure fluctuation caused by the liquid feed pump 46, the ink can be sent stably to the upper waste liquid tank 45. Furthermore, by attaching the pressure sensor 48a and feeding back the pressure value acquired by the pressure sensor 48a to the operation of the liquid feed pump 46, the waste liquid can be discharged more stably.

  The upper waste liquid tank 45 is disposed in the carriage 50. Since a sponge-like sheet is contained inside the upper waste liquid tank 45, the ink can be held to some extent by capillary force. In addition, an air passage hole exists in the upper lid portion so that the internal pressure does not increase. As the liquid feed pump 43, a tube pump, a diaphragm pump, or the like is used.

  As described above, the vacuum pump 47, the pressure chamber 44, and the sub tank 42 function as the first decompression unit 51a that decompresses the interior of the inkjet head as a unit. The vacuum pump 47, the pressure chamber 44, and the sub tank 42 function as a first pressurizing unit 51b that pressurizes the inside of the ink jet head as a unit.

  Further, the liquid feed pump 46 and the buffer tank 43 function as a second decompression unit 52a that decompresses the interior of the inkjet head as a unit.

  (Description of Inkjet Head) The structure of the inkjet head 9 will be described with reference to FIGS.

  The inkjet head 9 is a share mode type inkjet head, and FIG. 8 is a schematic diagram showing the configuration of the nozzles and nozzle channel grooves. 8A and FIG. 8B are top views, and FIG. 8C is a cross-sectional view at the cross section C. FIG. FIG. 8A and FIG. 8B respectively show the form at a certain point during the operation of the inkjet head 9. As shown in FIG. 8C, a nozzle plate 9d in which nozzles 9a that are through holes are formed is disposed on the bottom surface of the inkjet head 9, and the lower surface of the nozzle plate 9d is a nozzle forming surface 9b. The inkjet head 9 has a plurality of partition walls 9c, and the partition wall 9c partitions the inkjet head 9 into a plurality of nozzle channel grooves. Each nozzle channel groove has one nozzle 9a as a hole communicating with the outside. When a voltage is applied to the partition wall 9c, the partition wall 9c undergoes shear deformation as shown in FIGS. 8A and 8B, the volume in the nozzle channel groove changes, and a droplet is ejected from the nozzle 9a.

  FIG. 9 shows an exploded view of the inkjet head 9. The configuration includes a nozzle plate 9d, a manifold 61, a filter 62, and a flow path substrate 64. An ink supply port 65 for supplying ink to the head and an ink discharge port 66 for discharging ink are connected to the manifold 61, and a common ink chamber 63 for temporarily storing ink is disposed. The flow path substrate 64 is formed with a common ink chamber overlapping the common ink chamber 63 and nozzle channel grooves corresponding to the number of nozzles.

  (Method for removing bubbles and foreign matter in nozzle channel groove) In the present invention, as shown in FIG. 15 (a), bubbles remain in the nozzle channel groove so as to block the bubbles with a simple configuration and method even when there is no discharge. Can be removed.

The maintenance method of the present embodiment will be described with reference to FIGS.
FIG. 10 shows a flow chart of the maintenance method in this embodiment, and FIG. 11 shows a side sectional view of the nozzle channel groove and the wiping head 30 when the bubbles in the nozzle channel groove are removed. . The removal method of the present invention can be executed in a short time as a series of operations together with wet wiping.

  First, in order to supply the cleaning liquid to the liquid reservoir 2 of the wiping head 30, the supply pump 15 is driven to store the cleaning liquid in the liquid reservoir 2, and the contact part of the wipe blade 1 is wetted with the cleaning liquid (S1). The wiping head 30 is moved by the wiping device 40 (S2). When the liquid reservoir 2 is located immediately below the nozzle, the wiping head 30 is stopped, the cleaning liquid is brought into contact with the nozzle 9a, and the nozzle 9a is immersed in the cleaning liquid (S3). ).

  Next, the bubbles in the head channel groove are removed while the nozzle 9a is immersed in the cleaning liquid. There are three main bubble removal methods, and any one of the removal methods (S41, S42, or S43) is performed. 11A, 11B, and 11C are side sectional views of the inkjet head 9 and the wiping head 30 in the bubble removing process.

  FIG. 11A shows that the common ink chamber 63 in the head is set to a negative pressure, the capillary force of the cleaning liquid is used, the cleaning liquid is introduced from the nozzle 9a, and the bubbles 26 are peeled off from the partition walls 9c of the nozzle channel. A removal method is shown in which the bubbles 26 are carried to the common ink chamber 63 by buoyancy and negative pressure acting on the nozzles 26 to remove the bubbles staying in the inkjet head 9 (S41). At this time, as a method for setting the common ink chamber 63 to a negative pressure, there are a first pressure reducing means 51a and a second pressure reducing means 52a. According to this removal method, since the entire nozzle 9a of the inkjet head 9 is immersed in the cleaning liquid, the cleaning liquid similarly flows into the nozzle channel groove where the bubbles 26 do not exist, and the cleaning liquid is mixed into the ejected ink. If there is a problem if the cleaning liquid is mixed in the ink to be discharged, it is necessary to remove the cleaning liquid from the ink jet by performing a cap suction operation or a discard discharge operation on the ink jet head 9 in a later step S5.

  Further, when there is a problem if the cleaning liquid is mixed in the ink to be discharged, it is necessary to prevent the ink in the common ink chamber 63 from flowing into the sub tank 42 in order to avoid discharging the ink mixed with the cleaning liquid onto the discharge target. is there. Therefore, it is desirable to use the second decompression means 52a as the decompression means for decompressing the inside of the inkjet head 9. However, if there is no problem even if the cleaning liquid is mixed into the ink because the cleaning liquid is the same as the ink stored in the ink tank 41 and the sub tank 42, the above problem does not occur. As the means, the first pressure reducing means 51a may be used. In this case, ink can be supplied from the common ink chamber 63 to the sub tank 42, and the ink supplied to the sub tank 42 can be reused, so that the ink consumption is reduced. be able to.

  FIG. 11B shows a removal method in which the partition wall 9c is driven to cause the nozzle channel groove to act as a pump to allow the cleaning liquid to flow from the nozzle 9a, and the bubbles are peeled off due to fluctuations in the partition wall 9c (S42). That is, in this step, the partition wall 9c is used as a third decompression unit. Thereafter, maintenance such as cap suction and discard discharge operation is performed, and the bubbles 26 are removed from the ink jet head 9. At this time, if the partition wall 9c is made larger and fluctuated faster, the bubbles are more easily peeled off. Therefore, it is desirable to make the driving voltage and driving frequency of the head larger than that during ejection. In the case of the present embodiment, the driving frequency of the head is set to three-phase 100 kHz.

  FIG. 11 (c) is a method for executing the removal method shown in FIG. 11 (a) and the removal method shown in FIG. 11 (b) simultaneously or successively, and FIG. 11 (a) and FIG. 11 (b). More or larger bubbles can be removed faster than the method shown in ().

  As described above, the liquid droplet ejection apparatus according to the present embodiment includes the first to third total three pressure reducing means as the pressure reducing means for reducing the pressure inside the ink jet head, but any pressure reducing means may be used. Also, two or more of the three decompression means may be executed simultaneously or successively.

  According to this embodiment, since the liquid reservoir 2 serves as a cleaning tank, a separate cleaning tank is not required, and the amount of cleaning liquid used is less than that of the conventional technique using the cleaning tank.

  In the case of the present embodiment, the time for the liquid reservoir 2 of the wiping head 30 to stop immediately below the nozzle is about 30 seconds in total, that is, a standby time of 5 seconds, a bubble removal time of 20 seconds, and a standby time of 5 seconds.

  After the wet wiping is completed, the cap suction operation and the discard discharge operation described above are performed in order to remove bubbles and cleaning liquid staying in the inkjet head (S5).

  Next, in wet wiping (S6), the ink, the cleaning liquid, and the like attached to the nozzle forming surface 9b in the steps S41, S42, S43, and S5 are removed. At the end of the steps S41, S42, and S43, since the remaining cleaning liquid used to remove bubbles remains in the liquid reservoir 2, the wiping head 30 is moved by the wiping device 40, and the wiper blade 1 moves the nozzle surface 9b. If wiping is performed (S5), the remaining cleaning liquid is supplied to the wipe blade 1, the wipe blade 1 is in a wet state, and wet wiping can be performed. Therefore, it is possible to remove bubbles and clean the nozzle forming surface with a small amount of cleaning liquid.

  In order to prevent the cleaning liquid from flowing into the nozzle channel during wet wiping, it is desirable that the nozzle channel is in a more pressurized state than usual. As the means for pressurization, either the first pressurizing means or the second pressurizing means may be used. Further, instead of the first pressurizing means and the second pressurizing means, the inside of the nozzle channel groove may be pressurized by driving the partition wall 9c so that the nozzle channel groove serves as a pump. That is, the partition wall 9c may be used as the third pressurizing means in this step. Two or more of the first pressurizing unit, the second pressurizing unit, and the third pressurizing unit may be used simultaneously or successively.

  With the series of steps from S3 to S6 described above, it is possible to remove bubbles and foreign matters in the nozzle channel groove and wet wiping the nozzle forming surface 9b. If there is no cleaning liquid in the liquid reservoir 2 at the timing of starting the wet wiping, the supply pump 15 is driven as shown in FIG. 12, and the cleaning liquid stored in the cleaning liquid tank 17 is supplied to the wipe blade 1 to supply the cleaning liquid. What is necessary is just to move the wiping head 30 after making it overflow. According to this embodiment, the liquid reservoir 2 includes the cleaning liquid supply port 3a for supplying the liquid supplied by the cleaning liquid supply means to the liquid reservoir 2, so that the wipe blade 1 is in contact with the nozzle forming surface 9b. The cleaning liquid can be supplied as it is, and it can be avoided that the cleaning liquid becomes insufficient in the liquid reservoir 2 during the maintenance.

  Finally, it is inspected whether the inkjet head 9 is discharging normally (S7). If NG, the wiping head 30 is returned to the initial position once more, the cleaning liquid is supplied, and the steps from S1 to S7 are repeated.

  According to the present embodiment, the cleaning liquid collected in the liquid reservoir 2 is brought into contact with the nozzle by the moving means, and the pressure reducing means reduces the pressure in the nozzle channel groove so that the cleaning liquid accumulated in the liquid reservoir 2 is removed from the nozzle. 9, the air bubbles 26 are allowed to flow into the nozzle channel groove, so that the large bubbles 26 that block the nozzle flow path can be removed.

  In addition, after removing bubbles and foreign matters in the nozzle channel groove, the remaining cleaning liquid used is supplied to the adjacent wipe blade 1, and the wipe blade 1 wipes the nozzle forming surface in a state where the wipe blade 1 is wet. Since the moving means moves the wipe blade 1 as described above, it is possible to remove the bubbles 26 and clean the nozzle forming surface 9b with a small amount of cleaning liquid.

  Since the present embodiment has many parts that are common to the configuration of the first embodiment, description of the common parts is omitted, and only different parts are described.

FIG. 13 is a perspective view of the wiping device 140 of the droplet discharge device according to the present invention.
A wiping device 140 illustrated in FIG. 13 includes a cleaning liquid supply unit 8 in addition to the wiping device 40 illustrated in FIG. 5. The cleaning liquid supply unit 8 includes an injection needle-shaped cleaning liquid supply port 8a. A cleaning liquid supply means (not shown) capable of supplying a liquid different from the liquid to be discharged is connected to the cleaning liquid supply port 8a. The cleaning liquid supply means includes a supply pipe having a supply pump disposed in the middle and a cleaning liquid tank. The cleaning liquid tank is a tank that stores the cleaning liquid. When the supply pump is driven, the cleaning liquid stored in the cleaning liquid tank is supplied to the cleaning liquid supply port 8a via the supply pipe and dripped from the cleaning liquid supply port 8a.

  In the present embodiment, the wipe unit 13 may not have a function of supplying the cleaning liquid. That is, the cleaning liquid supply port 3 a does not have to exist in the liquid reservoir 2 of the wiping head 30, and the cleaning liquid inlet 6 and the cleaning liquid supply flow channel 3, which are channels for supplying the cleaning liquid to the cleaning liquid supply port 3 a of the wiping head 30. May not be present.

  Next, the removal method by the droplet discharge device of this embodiment and the flow of wet wiping will be described. The difference between the removal method by the droplet discharge device of this embodiment and the flow of wet wiping and the flow of Embodiment 1 is the step S1 shown in FIG.

  FIG. 14 is a side sectional view in the step of supplying the cleaning liquid to the wiping head 30 from the cleaning liquid supply port. In the supply of the cleaning liquid (S1) in this embodiment, first, the wipe unit 13 is moved directly below the cleaning liquid supply unit 8 and positioned so that the liquid reservoir 2 of the wiping head 30 comes directly below the cleaning liquid supply port. As shown in FIG. 14, the supply pump is then driven to supply the cleaning liquid from the cleaning liquid tank to the cleaning liquid supply port 8 a, the cleaning liquid 7 is dropped from the cleaning liquid supply port 8 a, and the cleaning liquid is stored in the liquid reservoir 2. Thus, the contact portion of the wipe blade 1 is wetted with the cleaning liquid (S1). Since the flow after S2 is the same as that of the first embodiment, the description thereof is omitted.

  In the present embodiment, since the wiping head 30 does not need to have a structure for supplying the cleaning liquid, the structure of the wiping head 30 can be simplified and downsized. Therefore, reduction of manufacturing cost and improvement of reliability related to the wiping head 30 can be expected.

  Example 3 is an embodiment that is possible when ink is used as the cleaning liquid. Since the present embodiment has many parts that are common to the configuration of the first embodiment, description of the common parts is omitted, and only different parts are described.

  In the present embodiment, the wipe unit 13 may not have the function of supplying the cleaning liquid. That is, the cleaning liquid supply port 3 a does not have to exist in the liquid reservoir 2 of the wiping head 30, and the cleaning liquid inlet 6 and the cleaning liquid supply flow channel 3, which are channels for supplying the cleaning liquid to the cleaning liquid supply port 3 a of the wiping head 30. May not be present. Further, there is no need for cleaning liquid supply means for supplying a liquid different from the liquid to be discharged.

  Next, the removal method by the droplet discharge device of this embodiment and the flow of wet wiping will be described. The step of S1 shown in FIG. 10 is different from the flow of the first embodiment in the removal method and wet wiping flow by the droplet discharge device of the present embodiment.

  In the supply of the cleaning liquid (S1) in this embodiment, first, the wiping unit 13 or the ink jet head 9 is moved, and the liquid reservoir 2 of the wiping head 30 moves in the droplet discharge direction (usually directly below the nozzle 9a). Position to come. Next, liquid droplets are discharged from the nozzle 9a, and the discharged liquid is stored in the liquid reservoir 2. The droplet discharge device according to the present embodiment is characterized in that a plurality of nozzles correspond to the liquid reservoir. Specifically, there are a plurality of nozzles 9 a, and the plurality of nozzles 9 a are configured to be able to supply the liquid discharged to the same liquid reservoir 2. Even if the plurality of nozzles 9a include nozzles 9a that are in a non-dischargeable state, it is unlikely that all of the nozzles 9a can be discharged, and liquid can be discharged from the nozzles 9a that are in a dischargeable state. 2 can store liquid. Thus, the contact portion of the wipe blade 1 is wetted with the discharged liquid (S1). Since the flow after S2 is the same as that of the first embodiment, the description thereof is omitted.

  In this embodiment, it is not necessary to have a structure for supplying the cleaning liquid to the wiping head 30, and the cleaning liquid supply means 8 for supplying a liquid different from the liquid to be discharged is also unnecessary. Therefore, the apparatus can be simplified and downsized. Further, the manufacturing cost of the droplet discharge device can be reduced and the reliability of the wiping head 30 can be expected, and the failure risk associated with the cleaning liquid supply means is eliminated.

  The droplet discharge device according to the present invention can be suitably used for a droplet discharge device that cleans an inkjet head nozzle formation surface with a wipe blade, for example.

  In the present embodiment, the present invention has been described by way of an example of a so-called ink jet apparatus that ejects ink. However, in the present invention, the liquid to be ejected is not limited to ink, and droplet ejection that ejects other liquids. It may be a device.

DESCRIPTION OF SYMBOLS 1 Wipe blade 2 Liquid storage part 3 Cleaning liquid supply flow path 8 Cleaning liquid supply means 9 Inkjet head 15 Supply pump 17 Cleaning liquid tank 30 Wiping head 40 Wiping apparatus 60 Droplet discharge apparatus 140 Wiping apparatus

Claims (7)

An inkjet head that discharges droplets from a nozzle; a decompression unit that depressurizes the interior of the inkjet head; a wiping head that includes a wipe blade that wipes a nozzle formation surface of the inkjet head; and the wipe blade with respect to the nozzle formation surface A droplet discharge device comprising a moving means for relatively moving, wherein a liquid reservoir for storing a liquid is provided above the wiping head. The droplet discharge device according to claim 1, wherein the liquid reservoir is a groove. The wiping head includes a blade portion configured by stacking a rear member, an intermediate member, and a front member, and an upper surface of the intermediate member is disposed below an upper end of the rear member and an upper end of the front member. 2. The upper portion of the rear member functions as a wipe blade, and the upper portion of the rear member, the upper surface of the intermediate member, and the upper portion of the front member integrally form a liquid reservoir. Droplet discharge device. The droplet discharge device according to claim 1, wherein a slit is formed between the wipe blade and the bottom of the liquid reservoir. The liquid droplet ejection apparatus according to claim 1, further comprising a cleaning liquid supply unit capable of supplying a liquid different from the liquid to be discharged to the liquid reservoir. 6. The droplet discharge device according to claim 5, wherein the liquid reservoir includes a cleaning liquid supply port that supplies the liquid supplied by the cleaning liquid supply unit to the liquid reservoir. 2. The liquid droplet ejection apparatus according to claim 1, wherein a plurality of the nozzles correspond to the liquid reservoir.