JP5928512B2 - Liquid ejection device - Google Patents

Description

  The present invention relates to a droplet discharge device and a liquid supply method.

  2. Description of the Related Art Conventionally, an ink supply system that supplies ink to an ejection head that can eject ink from an ink tank that contains ink via an ink supply pipe is known. When such an ink supply system is used, if ink is not supplied for a long time after ink is supplied to the ejection head, components contained in the ink remaining in the flow path of the ink supply pipe May settle. If the component contained in the ink settles, when supplying ink to the ejection head again, the ink may not be stably supplied to the ejection head, or ejection failure may occur.

  In particular, when an inorganic pigment (for example, titanium oxide) or a metal pigment (for example, aluminum) is included as an ink component, there is a problem that these pigments are liable to settle from the point of difference in specific gravity with respect to the solvent.

  For example, Patent Document 1 describes an ink supply system provided with a sub tank that always holds a certain amount of ink in an ink flow path. Japanese Patent Application Laid-Open No. H10-228561 describes that a stirring ball is provided in the sub tank in order to stir the ink in the sub tank. By providing such a subtank, sedimentation of components such as pigments contained in the ink can be reduced.

JP 2006-272648 A

  However, in the above-described conventional technology, when the ink supply is started after the ink supply system has been stopped for a long time, the liquid in the supernatant portion having a low pigment concentration in the ink flow path is supplied to the head via the sub tank, and the component composition In some cases, a liquid having a large variation in the ratio is discharged.

  One of the objects according to some aspects of the present invention is to provide a droplet discharge device capable of discharging droplets with little variation in component composition ratio by solving the above-described problems.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
One aspect of the droplet discharge device according to the present invention is:
A storage section for storing liquid;
A container connected to the housing part via a first pipe and supplied with the liquid from the housing part;
A head connected to the container to which the liquid is supplied from the container and ejecting the liquid to a medium to be ejected conveyed by a conveyance mechanism;
Stirring means for stirring the liquid in the container;
Control means for controlling a first operation for replacing the liquid in the container without discharging it to the medium to be discharged and a second operation for performing stirring in the container by the stirring means;
The control means causes the first action to be performed before the second action is performed when a predetermined time or more has elapsed after the stirring by the stirring means is completed.

  According to the invention described in the application example 1, when a predetermined time or more has elapsed after the stirring by the stirring unit is completed, the control unit performs control to perform the first operation before performing the second operation. Therefore, even if a sedimentation component is generated in the first pipe and the container, a liquid with a small variation in component composition ratio can be supplied to the head, and a liquid with a small variation in component composition ratio can be discharged from the head. .

[Application Example 2]
One aspect of the droplet discharge device according to the present invention is:
A storage section for storing liquid;
A container connected to the housing part via a first pipe and supplied with the liquid from the housing part;
A head connected to the container to which the liquid is supplied from the container and ejecting the liquid to a medium to be ejected conveyed by a conveyance mechanism;
Stirring means for stirring the liquid in the container;
Control means for controlling a first operation for replacing the liquid in the container without discharging it to the medium to be discharged and a second operation for performing stirring in the container by the stirring means;
The control means includes a mode in which the first operation is performed and the second operation is performed after the first operation.

  According to the invention described in the application example 2, the control unit performs control such that the first operation is performed and the second operation is performed after the first operation. As a result, a liquid with little variation in component composition ratio can be supplied to the head, so that a liquid with little variation in component composition ratio can be discharged from the head.

[Application Example 3]
In application example 1 or application example 2,
And a second pipe connecting the head and the container,
The control means can replace the liquid in the head and the second pipe by the first operation after performing the second operation.

  According to the invention described in the application example 3, since the liquid sufficiently stirred in the container can be supplied into the head and the second pipe, the component composition is used when the liquid is discharged from the head onto the discharge target medium. It is possible to discharge a liquid with further reduced variation in the ratio.

[Application Example 4]
In any one of Application Example 1 or Application Example 3,
In the first operation, a replacement amount of the liquid in the container may be not less than 0.4 times and not more than 1.0 times the volume of the first tube.

  According to the invention described in the application example 4, the liquid in the first pipe can be sufficiently supplied into the container by the replacement of the liquid in the container. Therefore, the second operation is performed after the first operation is performed. As a result, it is possible to supply a liquid with little variation in the component composition ratio to the head.

[Application Example 5]
In any one of Application Examples 1 to 3,
In the first operation, the amount of liquid replaced in the container may be not less than 0.8 times and not more than 1.0 times the volume of the first tube.

  According to the invention described in the fifth application example, a sufficient amount of the liquid in the first pipe can be supplied into the container by replacing the liquid in the container. Therefore, the second operation is performed after the first operation is performed. By performing the above, it is possible to supply a liquid with little variation in the component composition ratio to the head.

[Application Example 6]
In application example 1,
The liquid includes a component that can settle,
The predetermined time may be set to a time equal to or longer than a time until the components that can settle in the container and the first pipe completely settle.

  According to the invention described in the application example 6, in the first operation for replacing the liquid in the container, it is possible to prevent the component that has not settled from being replaced.

[Application Example 7]
One aspect of the liquid supply method according to the present invention is:
A container connected to the housing part via a pipe and supplied with the liquid from the housing part;
A head connected to the container to which the liquid is supplied from the container and ejecting the liquid to a medium to be ejected conveyed by a conveyance mechanism;
A liquid supply method using a droplet discharge device having a stirring means for stirring the liquid in the container,
A first step of replacing the liquid in the container without discharging it to the discharge medium when a predetermined time or more has elapsed after the stirring by the stirring means is completed;
The second step of stirring the container by the stirring means is performed in this order.

  According to the invention described in Application Example 7, since the first step and the second step are performed in this order when a predetermined time or more has elapsed after the stirring by the stirring means is completed, the sedimentation component is contained in the pipe and the container. Even if this occurs, a liquid with little variation in the component composition ratio can be supplied to the head.

The perspective view which shows typically the droplet discharge apparatus which concerns on this embodiment. FIG. 3 is a diagram illustrating functional blocks of a droplet discharge device according to the present embodiment. 6 is a flowchart showing control processing of the droplet discharge device according to the present embodiment. Explanatory drawing which shows typically the sedimentation state of the sedimentation component in the droplet discharge apparatus which concerns on this embodiment. 1 is a perspective view schematically showing an ink jet printer according to an embodiment. The figure which shows the density | concentration change of the titanium dioxide for every discharge amount of a white ink composition.

  Hereinafter, although embodiment of this invention is described, this invention is not restrict | limited to these.

1. Droplet discharge device A droplet discharge device according to the present invention includes a storage portion that stores a liquid, a container that is connected to the storage portion via a first pipe, and that is supplied with the liquid from the storage portion, and the container The liquid is supplied from the container and connected to the head, and the head discharges the liquid to the discharge target medium transported by the transport mechanism, the stirring means for stirring the liquid in the container, and the liquid in the container. Control means for controlling a first operation for replacing the discharge medium without discharging it and a second operation for performing stirring in the container by the stirring means.

  FIG. 1 is a perspective view schematically showing a droplet discharge device 100 according to the present embodiment. Hereinafter, the droplet discharge apparatus 100 according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, the droplet discharge device 100 according to the present embodiment includes a storage unit 10, a container 20, a first tube 30, a head 40, a carriage 50 </ b> A, and a control unit (not shown). Have. The container 20 and the head 40 are mounted on the carriage 50A. The container 20 includes a stirrer 15 therein. The carriage 50A can reciprocate in a predetermined direction (hereinafter also referred to as “main scanning direction”) MSD.

1.1. Accommodating portion The droplet discharge device in the present embodiment has an accommodating portion. The storage unit stores a liquid described later. In the example of FIG. 1, the accommodating portion 10 is connected to the container 20 via a tube 30. Thereby, the liquid can be supplied to the container 20.

  The container 10 is preferably configured to replenish consumed liquid, and more preferably configured to replenish liquid during operation of the droplet discharge device 100. By replenishing the container 10 with the dispersion without stopping the operation of the droplet discharge device 100, the working efficiency can be improved.

  In addition, the storage unit 10 may include a known stirring unit in the interior thereof, whereby a liquid with little variation in the component composition ratio can be supplied to the tube 30 and the container 20.

  The liquid in the present specification can include components that can settle, and examples thereof include dispersions such as suspensions and emulsions. For example, the liquid stored in the storage unit 10 may be an ink composition, an organic EL display material, a color filter material such as a liquid crystal display, an FED (surface emitting display) material, an electrode such as an electrophoretic display, or a color. Examples include filter materials and bioorganic materials used for biochip production.

  In addition, as a component that can settle, for example, a component having a high specific gravity with respect to a solvent, and the ink composition includes, for example, at least one selected from inorganic pigments, metal pigments, and hollow resin particles And can include components bound or adsorbed thereto. In addition, the sediment is obtained by sedimenting components that can settle, and can include at least one selected from inorganic pigments, metal pigments, and hollow resin particles, and includes components that are bound or adsorbed thereto. be able to.

  Examples of the inorganic pigment include titanium dioxide, silicon oxide, aluminum oxide, zinc oxide, iron oxide, and carbon black.

  Examples of the metal pigment include aluminum, gold, silver, copper, brass, titanium, and the like, or alloys thereof.

  Examples of the hollow resin particles include hollow resin particles described in specifications such as US Pat. No. 4,880,465 and Japanese Patent No. 3,562,754. The hollow resin particles are, for example, those having a cavity inside and an outer shell formed of a resin having liquid permeability. The hollow resin particles can be used as a white pigment.

  The liquid accommodated in the accommodating part 10 contains a solvent such as an organic solvent or water, and a composition having a specific gravity difference between the sediment and the solvent of 1 or more can be used. As described above, even if the specific gravity difference between the solvent in the liquid and the sediment component is large, the liquid and the sediment component can be sufficiently stirred by using the droplet discharge device 100 according to the present invention. A liquid with little variation can be discharged from the head.

  Hereinafter, the white ink composition typically used as the liquid stored in the storage unit 10 will be described. For example, in the white ink composition, the above-described titanium dioxide can be used as a white pigment. The content of titanium dioxide is preferably 5% by mass or more and 20% by mass or less, more preferably 8% by mass or more and 15% by mass or less with respect to the total mass of the white ink composition. If the content of titanium dioxide exceeds the above range, clogging of the ejection head 40 may occur. Moreover, when the content of titanium dioxide is less than the above range, whiteness may be insufficient.

  The white ink composition can include a resin for fixing the pigment. Examples of the resin include an acrylic resin (for example, Almatex (manufactured by Mitsui Chemicals)), a urethane resin (for example, WBR-022U (manufactured by Taisei Fine Chemical)), and the like. The content of the resin is preferably 0.5% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more and 3% by mass or less with respect to the total mass of the white ink composition.

  The white ink composition preferably contains at least one selected from alkanediols and glycol ethers. Alkanediol and glycol ether can increase the wettability of the surface to be ejected, such as the medium to be ejected, to increase the permeability of the ink.

  Examples of the alkanediol include 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, 1,2-octanediol, etc. , 2-alkanediol is preferred. Among these, 1,2-hexanediol, 1,2-heptanediol, and 1,2-octanediol having 6 to 8 carbon atoms are more preferable because of their particularly high permeability to the medium to be discharged.

  As glycol ethers, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol Mention may be made of lower alkyl ethers of polyhydric alcohols such as monomethyl ether, triethylene glycol monobutyl ether and tripropylene glycol monomethyl ether.

  The content of at least one selected from these alkanediols and glycol ethers is preferably 1% by mass or more and 20% by mass or less, more preferably 1% by mass or more, based on the total mass of the white ink composition. It is 10 mass% or less.

  The white ink composition preferably contains an acetylene glycol surfactant or a polysiloxane surfactant. The acetylene glycol surfactant or the polysiloxane surfactant can increase the wettability of the surface to be ejected such as the medium to be ejected to increase the ink permeability.

  Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3, Examples include 5-dimethyl-1-hexyn-3-ol, 2,4-dimethyl-5-hexyn-3-ol, and the like. Moreover, a commercial item can also be utilized for acetylene glycol type-surfactant, for example, Orphine E1010, STG, Y (above, Nissin Chemical Co., Ltd.), Surfinol 104, 82, 465, 485, TG (above , Air Products and Chemicals Inc.).

  Commercially available products can be used as the polysiloxane surfactant, and examples thereof include BYK-347, BYK-348 (manufactured by BYK Japan).

  Further, the white ink composition may contain other surfactants such as an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant.

  The content of the surfactant is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.1% by mass or more and 0.5% by mass or less, with respect to the total mass of the white ink composition. It is.

  The white ink composition preferably contains a polyhydric alcohol. For example, when the white ink composition is applied to an ink jet recording apparatus, the polyhydric alcohol can suppress ink drying and prevent clogging of the ink in the ink jet recording head portion.

  Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, thioglycol, hexylene glycol, glycerin, and trimethylolethane. And trimethylolpropane.

  The content of the polyhydric alcohol is preferably 0.1% by mass or more and 30% by mass or less, and more preferably 0.5% by mass or more and 20% by mass or less, with respect to the total mass of the white ink composition. .

  The white ink composition can contain water as a solvent. It is preferable to use pure water or ultrapure water such as ion exchange water, ultrafiltered water, reverse osmosis water, or distilled water. In particular, water obtained by sterilizing these waters by ultraviolet irradiation or addition of hydrogen peroxide is preferable because generation of mold and bacteria can be suppressed over a long period of time.

  Further, the white ink composition may be prepared by using a fixing agent such as water-soluble rosin, an antifungal agent / preservative such as sodium benzoate, an antioxidant / ultraviolet absorber such as allophanate, a chelating agent, triethanol, as necessary. Additives such as pH adjusters such as amines and oxygen absorbers can be contained. These additives can be used alone or in combination of two or more.

  Although the water-based ink composition has been described as an example of the white ink composition, an ultraviolet curable ink or the like may be used. In the case of using an ultraviolet curable ink, examples of components that can settle include a photopolymerization initiator.

1.2. Tube The droplet discharge device according to the present embodiment has a first tube that connects the container and the container. A 1st pipe | tube supplies the liquid supplied from the accommodating part to a container. In the example of FIG. 1, the first tube 30 connects the housing unit 10 and the container 20.

  Although it does not specifically limit as a shape of the 1st pipe | tube 30, The following can be mentioned. For example, a straight line connecting the container 10 and the container 20 with a simple straight line, a sagging shape, a wave shape including a portion where locally high and low portions are alternately repeated, and a portion where a plurality of loops are connected The loop shape etc. which contain can be mentioned.

  A partition (not shown) that is twisted along the flow direction of the liquid may be provided inside the first tube 30. The partition portion has a function of stirring the liquid introduced into the first tube 30. The liquid introduced into the first pipe 30 travels through the first pipe 30 along the partition portion having a twisted structure, and is supplied to the container 20. Thereby, the liquid in the 1st pipe | tube 30 can fully be stirred.

  The material of the first tube 30 is not particularly limited as long as it has flexibility, and examples thereof include an elastomer. Examples of the elastomer include vulcanized rubber such as natural rubber and synthetic rubber, and elastomers such as vinyl chloride, styrene, olefin, silicone, and fluorine.

  The inner diameter of the first tube 30 is not particularly limited as long as the stirrer 15 does not move into the first tube 30. For example, when the droplet discharge device 100 is applied to an ink jet printer 300 described later, the inner diameter of the liquid supply tube 30 is preferably 2 mm or more and 5 mm or less, more preferably 2 mm or more and 4 mm or less.

  The volume of the first tube 30 is preferably equal to or less than the volume of the container 20. Thereby, it is possible to supply the liquid with a small variation in the component composition ratio to the head 40. On the other hand, if the volume of the first tube 30 is greater than or equal to the volume of the container 20, the supernatant liquid of the first tube 30 may be supplied to the head after a replacement operation described later. In the present specification, the volume of the first pipe 30 refers to the volume inside the first pipe 30 to which the liquid is supplied, and the volume of the container 20 refers to the volume inside the container 20 to which the liquid is supplied. I mean.

  In addition, as shown in FIG. 1, the droplet discharge device in this embodiment can include a second tube 32 that connects the container 20 and the head 40. The liquid stored in the storage unit 10 is supplied to the container 20 through the liquid supply pipe 30, stirred by the stirrer 15 in the container 20, then flows in the container 20, and passes through the pipe 32. It is supplied to the head 40. Since the second pipe 32 is the same as the first pipe 30 except that the container 20 and the head 40 are connected, description thereof is omitted.

  In the example of FIG. 1, the container 20 and the head 40 are connected via the second pipe 32, but the present invention is not limited to this, and the container 20 and the head 40 are directly connected without passing through the second pipe 32. May be.

1.3. Stirring Means The droplet discharge device according to the present embodiment includes a container connected to the storage unit via a tube and supplied with liquid from the storage unit. Further, the droplet discharge device of the present embodiment has a stirring means for stirring the liquid in the container. The stirring means for the container of the droplet discharge device in the present embodiment is not particularly limited, and examples thereof include those having the following mechanism.

  For example, as the agitation means, the container fixed to the moving device is moved by moving the moving device back and forth, right and left, the liquid inside the container is stirred, and the liquid in the container is vibrated and stirred by ultrasonic waves or the like. A mechanism that moves and stirs the liquid in the container by tilting the container; a mechanism that stirs the liquid in the container by moving the magnetic body arranged in the container by moving the magnet from the outside of the container; Examples include a mechanism for stirring the liquid in the container by sending air into the container using a pump or the like. If the stirring means has the mechanism as described above, the liquid in the container can be stirred regardless of whether the droplet discharge device has a line type head or a serial type head.

  Here, the line-type head is one in which the head is formed wider than the width of the medium to be ejected and a desired image is formed by ejecting liquid droplets onto the medium to be ejected without moving the head. In the case where the head provided in the droplet discharge device is a line-type head, the installation position of the container is not particularly limited. For example, the container can be installed at a position adjacent to the head.

  The serial type head is a type in which a head is mounted on a carriage movable in a predetermined direction, and a desired image is formed on a target medium by moving the head as the carriage moves. . In the case where the head provided in the droplet discharge device is a serial head, the installation position of the container is not particularly limited, and can be mounted on a carriage, for example.

  In the case where the droplet discharge device includes a serial type head, the stirring means other than the above include a mechanism in which a container is mounted on the carriage and the container is moved along with the movement of the carriage to stir the liquid in the container. It is done. Thus, when the container is mounted on the carriage, it is not necessary to provide a separate mechanism for stirring the liquid in the container, and the liquid in the container can be stirred using the carriage moving mechanism. For this reason, mounting the container on the carriage is excellent from the viewpoint of easily obtaining a droplet discharge device with excellent stirring efficiency. In the case of using the above-described stirring means in which the container is mounted on the carriage, it is preferable to place a stirring bar in the container in advance. As a result, the stirring bar moves along with the movement of the container in the movement of the carriage, so that the stirring efficiency of the liquid in the container can be improved.

  FIG. 1 shows a droplet discharge device 100 having a serial type head. Specifically, in the droplet discharge device 100 in FIG. 1, the container 20 is mounted on the carriage 50 </ b> A, and the stirrer 15 is disposed in the container 20 as a stirring means for the liquid in the container 20.

  In FIG. 1, the container 20 is connected to the accommodating portion 10 via the first tube 30. The connection part J1 of the container 20 and the first pipe 30 may be provided in any part of the container 20 as long as it is formed in a part other than J2 described later.

  In FIG. 1, the container 20 is connected to the head 40 via the second pipe 32. The connection part J2 of the container 20 and the pipe 30b may be provided in any part of the container 20 as long as it is formed in a part other than J1.

  The direction, angle, and the like of the container 20 are not particularly limited as long as the stirrer 15 moves based on the reciprocating motion of the carriage 50A.

  For example, when the container 20 is arranged so that the longitudinal direction thereof is parallel to the predetermined direction MSD, the stirrer 15 is easily moved along with the movement of the carriage 50A, so that the liquid stirring efficiency can be improved. Moreover, since the moving distance of the stirrer 15 becomes long, the stirring efficiency of the liquid can be improved.

  Further, when the longitudinal direction of the container 20 is arranged so as to be parallel to the predetermined direction MSD, the stirrer 15 is provided when the carriage 50A is installed so that the predetermined direction MSD is orthogonal to the vertical direction VD. However, it becomes easier to move as the carriage 50A moves. Thereby, the stirring efficiency of the liquid can be further improved.

  The shape of the container 20 of the droplet discharge device 100 according to the present embodiment is a cylindrical shape in the example of FIG. 1, but is not limited thereto, and may be, for example, a rectangular parallelepiped shape, an elliptic cylinder shape, or the like. Good.

  A plurality of containers 20 may be provided. By providing a plurality of containers 20, the liquid stirring efficiency can be improved. Further, the container 20 may include a plurality of stirring bars 15 therein. Thereby, the stirring efficiency of the liquid supplied to the container 20 can be improved.

  The stirrer 15 can move the inside of the container 20 based on the movement of the carriage 50 </ b> A in a predetermined direction MSD, and can stir the liquid and sediment supplied to the container 20. The trajectory and moving direction of the stirrer 15 are determined by the reciprocating motion of the carriage 50A, the amount of liquid supplied to the container 20, the direction and angle in which the container 20 is attached, the shape of the container, and the like.

  The shape of the stirrer 15 may be any shape that can move in the container 20, and examples thereof include a polyhedron, a sphere, an ellipsoid, a cylinder, and an elliptic cylinder. Among these, it is preferable that it is a sphere or an ellipsoid from a viewpoint that the movement efficiency is excellent irrespective of the shape of the container 20.

  The stirrer 15 is preferably made of a material having a specific gravity higher than the specific gravity of the liquid supplied to the container 20, and more preferably a material having a specific gravity of 2.5 or more. For example, as the material of the stirrer 15, glass mainly composed of silicate, aluminum oxide, zirconium oxide, metal (for example, aluminum, titanium, chromium, nickel, iron, and an alloy containing any of these) Etc. When the specific gravity of the stirrer 15 is higher than the specific gravity of the liquid supplied to the container 20, the sediment can be effectively stirred.

1.4. Head The droplet discharge device according to the present embodiment has a head that is connected to a container, is supplied with liquid from the container, and discharges the liquid onto the discharge medium transported by the transport mechanism. The head has a plurality of nozzle holes and can discharge liquid from the nozzle holes. The head included in the droplet discharge device according to the present embodiment may be the above-described line type head or a serial type head. In the example of FIG. 1, the head 40 is a serial head, is mounted on the carriage 50 </ b> A, and is connected to the container 20 via the second tube 32. The head 40 can eject the liquid supplied from the second tube 32.

  The liquid supplied to the head 40 has been sufficiently stirred in the container 20. Therefore, the head 40 can eject a liquid with little variation in the component composition ratio.

1.5. Conveying Mechanism The droplet discharge apparatus according to the present embodiment has a conveying mechanism (not shown) that conveys a medium to be ejected (not shown). The transport mechanism moves the medium to be ejected to a position where the liquid ejected from the head can land. Thereby, a desired image can be formed on the ejection target medium. The transport mechanism is not particularly limited as long as it includes a mechanism for moving the medium to be ejected, and may be constituted by, for example, a roller and a motor. In this case, the roller can be rotated by the driving force of the motor, and the discharged medium can be moved by the rotation of the roller. Further, the position where the transport mechanism is provided is not particularly limited, and can be provided, for example, at a position facing the ejection surface of the head 40.

  The discharge medium is not particularly limited, and examples thereof include plain paper, matte paper, glossy paper, glass, plastic films such as vinyl chloride, and films in which a base material is coated with plastic or a receiving layer. .

1.6. Carriage The droplet discharge device according to the present embodiment can have a carriage that moves in a predetermined direction. In FIG. 1, the carriage 50A can reciprocate in the main scanning direction MSD by the power of a carriage motor (not shown) serving as a drive source, for example. When the container 20 is mounted on the carriage 50A and the stirrer 15 is provided inside the container 20, the stirrer 15 in the container 20 mounted on the carriage 50A moves as the carriage 50A moves. The liquid in the container 20 can be stirred. When the head is a serial head mounted on the carriage, the liquid can be discharged from the head 40 as the carriage 50A moves, so that the liquid can be discharged to a desired position.

1.7. Substitution Unit The droplet ejection apparatus according to the present embodiment includes a substitution unit that substitutes the liquid in the container without ejecting the liquid onto the ejection target medium. As the replacement means, for example, suction means such as a vacuum pump and a tube pump can be used. For example, a mechanism described in FIG. 13 of Japanese Patent Application Laid-Open No. 2003-165231 can be used for suction of the liquid by the tube pump. Specifically, after the cap device is connected to the head and the liquid discharge surface of the head is sealed, the liquid is discharged by discharging the air in the hose (tube) by the pump roller connected to the cap device. Is.

  In the droplet discharge device 100 according to the present embodiment, when the liquid is sucked from the head 40, the liquid in the container 20 is discharged from the head 40 and the liquid in the first tube 30 is supplied into the container 20. . In this way, the inside of the container 20 is replaced with the liquid in the first tube 30. At this time, the liquid in the second tube 32 and the head 40 is discharged from the head, and the inside of the second tube 32 and the head 40 is replaced with the liquid supplied from the container.

  Further, the suction speed in the suction performed to replace the liquid in the container 20 is higher than the suction speed performed in order to eliminate clogging of the head 40 from the viewpoint of preventing the sediment in the container 20 from being sucked. Slower is preferable.

  The replacement means for replacing the liquid in the container is not particularly limited as long as the liquid in the container can be replaced without discharging the liquid onto the medium to be discharged, and the suction means using the above-described pump or the like. It is not limited. For example, as a replacement means for replacing the liquid in the container, a conventional means for performing maintenance of the nozzle holes of the head by discharging the liquid onto a liquid absorption pad (for example, non-woven fabric) (so-called flushing) Etc.

1.8. Control Unit The droplet discharge apparatus according to the present embodiment has a control unit. The control means can be configured using, for example, a computer having a CPU and a memory. FIG. 2 is a functional block diagram of the droplet discharge device 100 according to the present embodiment. In the example of FIG. 2, the droplet discharge device 100 is controlled by the control means 60.

  The control unit 60 receives an input signal from the input unit, and controls the operation of the housing unit 10, the head 40, the carriage 50A, the suction unit 80, and the like. Specifically, the control means 60 cooperates each means mentioned later according to the received command, and controls the order of execution.

  Examples of command input means for the control means 60 include operation buttons provided on the main body of the droplet discharge device 100, a PC connected to the droplet discharge device 100, and the like. When the user operates such an input means, an input signal is sent to the control means 60.

  Examples of the command input by the user include an in-pipe maintenance command and a discharge command. The maintenance instruction in the pipe refers to a maintenance work instruction for the droplet discharge device 100, and specifically, an instruction for supplying a liquid with a small component composition ratio variation to the head 40 of the droplet discharge device 100. That means. The ejection command refers to a command for creating an image by ejecting liquid onto the ejection target medium based on ejection data.

  The control unit 60 can include an instruction determination unit 110. The command determination unit 110 determines the type of command received by the control unit 60 and transmits the command content to the control unit 60.

  The control unit 60 can include a liquid supply operation control unit 120. The liquid supply operation control unit 120 controls the liquid supply timing, the liquid supply amount, and the like by supplying the liquid from the container 10 to the first tube 30 when the liquid is consumed by a replacement operation or a discharge operation described later. .

  The control unit 60 can include a liquid discharge operation control unit 130. When receiving the discharge command, the liquid discharge operation control means 130 determines the liquid discharge timing and the discharge amount according to the discharge data, and discharges the liquid from the head 40.

  The control means 60 includes first operation control means 140. When the first operation control unit 140 receives the maintenance command or the discharge command in the pipe, the first operation control unit 140 operates the suction unit 80 to discharge the liquid in the container 20 through the head 40, and the replacement amount of the liquid in the container 20, etc. To control. In the present specification, the “first operation” is also referred to as a “replacement operation”.

  The control means 60 has second operation control means 150. When receiving the maintenance command or the discharge command, the second operation control means 150 reciprocates the carriage 50A in a predetermined direction MSD, and controls the moving speed, the number of movements, and the like of the carriage 50A. When the carriage 50A reciprocates in a predetermined direction, the stirrer 15 moves in the container 20 as the carriage 50A moves, so that the liquid in the container 20 can be stirred. In the present specification, the “second operation” is also referred to as “stirring operation”.

  The control means 60 can include third operation control means 160. When receiving the ejection command, the third operation control means 160 moves the carriage 50A in a predetermined direction MSD based on the ejection data. The control unit 60 causes the third operation control unit 160 and the liquid ejection operation control unit 130 to cooperate to form an image based on the ejection data on the ejection target medium. In the present specification, the “third operation” is also referred to as “ejection operation”.

  The control means 60 can have time measuring means 170. The timer unit 170 is not particularly limited as long as it can record time, and a timer or the like can be used. The time measuring means 170 is preferably capable of measuring time even when the power of the droplet discharge device 100 is turned off. For example, a rechargeable battery may be incorporated. The start of timing in the timing unit 170, reset of the accumulated time, and the like can be controlled by the control unit 60.

  In addition to the above-described reset timer, the time counting means 170 counts the number of rotations of the gear using, for example, a device having a rotating gear, and correlates the number of rotations of the gear with the elapsed time. The thing which can measure elapsed time by can be used. Further, the time measuring means 170 has two or more timers, and one is used as a timer for storing the accumulated time from the time of shipment of the droplet discharge device or the like, and one is shipped of the droplet discharge device. The elapsed time may be determined from the difference between these accumulated times, using as a timer for storing the accumulated time from the time until the predetermined operation is completed.

  The control unit 60 can include a storage unit 180. The storage unit 180 can be provided with a memory function capable of storing various information, and can store a predetermined time, which will be described later, or can read and store the accumulated time measured by the time measuring unit 170.

1.9. Control Flow FIG. 3 is a flowchart showing a control process of the droplet discharge device 100 according to the present embodiment. Hereinafter, various control methods employed in the droplet discharge device 100 according to the present embodiment will be described with reference to the flowchart shown in FIG.

(1) Flow of Executing Discharge Instruction First, the control means 60 determines whether or not an input signal from the input means has been received (step S11). When the input signal is not received by the control means 60 (N in step S11), the droplet discharge device 100 is in a standby state until the input signal is received again. On the other hand, when the control means 60 receives an instruction from the input means (Y in step S11), the instruction determination means 110 determines the type of instruction (step S12).

When the determination of the type of the command by the command determination unit 110 is a discharge command (a command for causing the discharge medium to discharge based on the discharge data), the control unit 60 reads the time t ₁ from the storage unit 180. (Step S13). Time t ₁ is the time measured by the time measuring means 170, and indicates the time from when the stirring operation by the stirring means is completed until when the command is received.

Next, the control means 60 compares the time t ₁ with the times T1 and T2 stored in advance in the storage means 180 (step S14). When the time t ₁ is equal to or longer than the time T 1, the first operation control unit 140 does not discharge the liquid to the medium to be discharged, and at least part of the liquid in the container 20 is liquid in the first tube 30. The first operation (replacement operation) to be replaced is executed (step S15).

  Here, the time T1 indicates a time longer than the time T2, and corresponds to the predetermined time in the claims. The time T1 is preferably set as the time until the settled component contained in the liquid in the container 20 or the first pipe 30 is vigorously settled, and the container is used to prevent the non-precipitated component from being replaced. More preferably, it is set as the time until the sediment component contained in the liquid vigorously settles in 20 and the first pipe 30. In order to prevent substitution of components that have not settled, it is more preferable to set the time until the sedimented components contained in the liquid completely settle in the container 20 and the first pipe 30. The time T1 can be determined by the specific gravity or content of the sediment component contained in the liquid, and can be stored in the storage unit 180 in advance.

  Further, in the first operation, the amount of liquid to be replaced in the container 20 is preferably 0.4 times or more and 1.0 times or less of the volume of the first tube 30, and 0.8 times or more and 1.0 times. It is more preferable that the ratio is not more than twice. As a result, a liquid with little variation in the component composition ratio can be supplied to the head 40 by performing a second operation described later. On the other hand, if the amount of liquid to be replaced is less than the above range, the supernatant liquid in the first tube may be supplied to the head. Further, when the amount of liquid to be replaced exceeds the above range, after all the liquid in the first pipe is discharged, it is discharged to a liquid with little variation in the component composition ratio supplied from the storage unit 10 to the first pipe, The liquid in the storage unit 10 may be consumed wastefully.

  After the end of the first operation, the second operation control means 150 executes the second operation (stirring operation) (step S16) and ends this flow. When a droplet discharge device having a serial head is used, the second operation is a reciprocating operation of the carriage 50A in a predetermined direction MSD. Thereby, the liquid in the container 20 can be sufficiently stirred. Control conditions such as the number of reciprocating movements and the moving speed of the carriage 50A are not particularly limited, and can be determined based on the type of sedimentation component, time t1, and the like. In addition, although the stirring operation in the case of using the droplet discharge device provided with the serial type head in which the container is mounted on the carriage is shown, the present invention is not limited thereto, and the stirring operation is performed using the various stirring means described above. Can be executed.

  Next, after the end of the second operation, the third operation control unit 160 causes the third operation (discharge operation) to be executed based on the discharge data. As described above, the third operation control unit 160 is controlled by the control unit 60 so as to cooperate with the liquid ejection operation control unit 130. As a result, the liquid discharge operation control means 130 and the third operation control means 160 control the discharge amount and discharge timing of the liquid from the head 40, the movement of the carriage 50A in the predetermined direction MSD, and the like. It is possible to obtain a discharge medium on which data is discharged. In the third operation, the carriage 50A reciprocates in a predetermined direction MSD. Therefore, the liquid in the container 20 can be stirred. In addition, although the discharge operation | movement in the case of using the droplet discharge apparatus provided with the serial type head was shown, it is not limited to this, For example, discharge operation is performed using the droplet discharge apparatus provided with the line type head. It can be carried out.

  Note that after the second operation (stirring operation) is completed, the control unit 60 resets the measurement time of the time measuring unit 170 and starts counting again before the execution of the third operation (discharge operation).

Thus, if the time t ₁ is the time T1 or more, after the first operation, for performing the second operation will be described in detail with reference to FIG. FIG. 4 is an explanatory diagram schematically showing a sedimentation state of sedimentation components in the droplet discharge device 100 according to the present embodiment. FIG. 4A is a front view schematically showing the droplet discharge device 100 after the elapse of time T1. In addition, the front in FIG. 4 means the mounting surface of the container 20 of the carriage 50A in FIG.

  As shown in FIG. 4A, after the time T1 has elapsed, a sediment S1 and a supernatant liquid L1 are generated in the first tube 30, and a sediment S2 and a supernatant liquid L2 are generated in the container 20. At this time, when the supply of the liquid to the head 40 is started, the supernatant liquid L2 is supplied to the head 40. As a result, a liquid having a large variation in the component composition ratio is ejected.

  In addition, when the liquid in the container 20 is sufficiently stirred after the time T1 has elapsed and then the liquid is supplied to the head 40, the sufficiently mixed and stirred supernatant liquid L2 and sediment S2 are supplied to the head 40. . However, in the first pipe 30, the supernatant liquid L1 and the sediment S1 are hardly stirred. Therefore, the supernatant liquid L1 is supplied to the container 20, and the sediment S1 is hardly supplied. Accordingly, when the liquid in the container 20 is supplied to the head 40, there is a case where the supernatant liquid L1 is discharged from the head 40.

Therefore, when the time t ₁ is the time T1 or more, performs the first operation (replacement operation), while discharging the supernatant liquid L2 in the container 20 to replace the portion of the container 20 in the supernatant liquid L1 . Next, as illustrated in FIG. 4B, the liquid D <b> 1 is supplied from the storage unit 10 to the first tube 30. And by performing 2nd operation | movement (stirring operation | movement), as shown in FIG.4 (C), the supernatant liquid L1 and the sediment S2 in the container 20 are fully mixed and stirred, and the inside of the container 20 is liquid D2. Will be satisfied by. As a result, the head 40 can be supplied with the liquid D2 and the liquid D1 with little variation in the component composition ratio. The sediment S1 in the first pipe 30 is supplied into the container 20 little by little as the liquid D1 is supplied from the container 10 into the first pipe 30.

On the other hand, if the time t ₁ is less than the time T1 and not less than the time T2 in step S14 (T1> t ₁ ≧ T2), the second operation control is not performed without executing the first operation (replacement operation). The second operation (stirring operation) is executed by the means 150 (step S16), and this flow is finished. And after completion | finish of 2nd operation | movement (stirring operation | movement), the 3rd operation | movement control means 160 performs 3rd operation | movement (discharge operation | movement) based on discharge data. Note that after the second operation (stirring operation) is completed, the control unit 60 resets the measurement time of the time measuring unit 170 and starts counting again before the execution of the third operation (discharge operation).

  Here, the time T <b> 2 indicates a time until the sediment component contained in the liquid settles in the container 20 and the first pipe 30. Specifically, during the time T2, when the liquid is supplied from the storage unit 10 to the first pipe 30, the sediment in the first pipe 30 can sufficiently flow into the container 20, but the inside of the container 20 This is the time until the head 40 cannot be supplied with a liquid with little variation in component composition ratio unless the liquid is sufficiently stirred. The time T2 can be determined by the specific gravity, content, etc. of the sediment component contained in the liquid, and can be stored in the storage unit 180 in advance.

As described above, when the time t ₁ is less than the time T _{1 and} is equal to or longer than the time T 2, the component composition ratio varies by performing the second operation (stirring operation) without replacing the liquid in the container 20. Less liquid can be supplied to the head 40.

On the other hand, in step S14, in the case (T2> t ₁₎ time t ₁ is less than the time T2, without running the first operation (replacement operation) and a second operation (agitating operation), the flow ends Then, the third operation control unit 160 causes the third operation (discharge operation) to be executed. If the time t ₁ is less than the time T 2, there is almost no sediment in the first tube 30 and the container 20, so the components can be obtained without performing the first operation (replacement operation) or the second operation (stirring operation). A liquid with little variation in composition ratio can be supplied to the head 40. At this time, since the second operation (stirring operation) is not performed, the measurement time may not be reset.

  The third operation (discharge operation) is more preferably performed after removing the liquid in the second tube 32 and the head 40. For example, after the first operation is performed and the second operation is performed as described above, the control unit 60 further executes a flow for replacing the liquid in the head 40 and the second pipe 32 by the first operation. Can do. As a result, the liquid with a low component concentration in the second tube and the head 40 that has not been stirred or replaced is not discharged to the discharge medium, and a liquid having a sufficient concentration can be discharged.

(2) Execution flow of maintenance instruction in pipe Next, a flow in the case where the instruction determination by the instruction determining means (step S12) is a maintenance instruction in the pipe (hereinafter also simply referred to as “maintenance instruction”) will be described with reference to FIG. Will be described with reference to FIG. This flow is different from “(1) Discharge command execution flow” in that the third operation (stirring operation) is not mainly executed. In this flow, the same control means as those in “(1) Discharge command execution flow” are given the same names, and the description thereof is omitted.

When the instruction type determination by the instruction determination unit 110 is a maintenance instruction, the control unit 60 reads the time t ₁ from the storage unit 180 (step S21). The time t ₁ is the same as “(1) Discharge command execution flow”, and thus the description thereof is omitted.

Next, the control means 60 compares the time t ₁ with the times T1 and T2 stored in advance in the storage means 180 (step S22). When the time t ₁ is equal to or longer than the time T1 (t ₁ ≧ T1), the first operation control unit 140 replaces the liquid in the container 20 with the liquid in the first tube 30 (replacement operation). Is executed (step S23). Since the times T1 and T2 are the same as those in “(1) Flow of execution of discharge command”, description thereof is omitted. Further, the reason why the first operation (replacement operation) is performed when the time t ₁ is equal to or longer than the time T ₁ is the same as that in “(1) Flow of execution of discharge command”, and thus the description thereof is omitted.

  After the end of the first operation, the second operation control means 150 executes the second operation (stirring operation) (step S23).

On the other hand, in step S22, in the case (T1> t ₁ ≧ T2) is the time t ₁ is the time T2 or more and less than time T1, without executing the first operation (replacement operation), the second operation control The second operation (stirring operation) is executed by the means 150 (step S24). When the second operation (stirring operation) is performed without performing the first operation (replacement operation) when the time t ₁ is less than the time T1 and greater than or equal to the time T2, “(1) Discharge” Since this is the same as the “command execution flow”, its description is omitted.

  Then, after the end of the second operation, the control unit 60 resets the measurement time of the time measuring unit 170 and starts time measurement again (step S25), and the droplet discharge device 100 enters a standby state.

On the other hand, if the time t ₁ at step S22 is less than the time T2 (T2> t _1), the control unit 60 does not execute the first operation (replacement operation) and a second operation (agitating operation), and Then, the liquid droplet ejection device 100 is put into a standby state without resetting the measurement time of the time measuring means 170. In this case, since there is almost no sediment in the 1st pipe | tube 30 and the container 20, even if it does not perform 1st operation | movement (replacement operation | movement) and 2nd operation | movement (stirring operation | movement), there are few dispersion | variation in a component composition ratio. Liquid can be supplied to the head 40. Further, since the second operation (stirring operation) is not performed, it is not necessary to reset the measurement time of the time measuring unit 170.

(3) Initial Operation In the case of using the droplet discharge device 100 provided with a serial type head, the above control flow may include an initial operation. The initial operation refers to a positioning operation of the carriage 50A, for example. The initial operation is controlled by the control means 60 and can be performed by reciprocating the carriage 50A in a predetermined direction MSD.

  The timing at which the initial operation is performed is preferably performed after the first operation and before the third operation when a predetermined time (T1) or more has elapsed after the stirring by the stirring means is completed. As a result, a liquid with little variation in the component composition ratio can be supplied to the head 40.

  On the other hand, when a predetermined time (T1) or more has elapsed after the stirring by the stirring means has been completed, if the initial operation is performed before the first operation is performed, the sediment in the container 20 is removed by the movement of the carriage 50A. A part may be stirred and a part of sediment in a container may be discharged | emitted from the head 40 by 1st operation | movement. Thereby, since the supernatant liquid in the 1st pipe | tube 30 will be supplied in the container 20, the density | concentration of the sediment in the container 20 will fall. At this time, even if the liquid in the container 20 is stirred by the stirring operation, the head 40 may be supplied with a liquid having a varying component composition ratio. In addition, when a predetermined time (T1) or more has elapsed after the stirring by the stirring means has been completed, if the initial operation is performed after the third operation is performed, the carriage 50A can be placed at a desired position during the ejection operation. It may disappear.

(4) Others As described above, whether the control flow of FIG. 3, to obtain the t _1, performed with t _1, by comparing the T1 and T2, the second operation and subsequently performs a first operation Whether the second operation is performed without performing the first operation is determined. However, the control flow according to the present embodiment is not limited to the control flow of FIG.

For example, when a discharge command or a maintenance command is received, if t ₁ exceeds T2 and it is determined that the second operation is performed, the first operation is performed and the second operation is performed regardless of T1. May be performed. Further, when a discharge command or a maintenance command is received, the first operation and the second operation may be performed continuously regardless of T1 and T2. Further, the first operation may be performed and then the second operation may be performed under conditions other than the time t ₁ .

  In addition, the control means 60 causes the first operation to be performed when it is determined that t1 exceeds T1 even if a command such as a discharge command or a maintenance command is not input, and the first operation is performed after the first operation. Two operations may be performed. Thereby, even when the droplet discharge device is left for a long period of time, it is not necessary to perform maintenance operations such as the first operation and the second operation, and the discharge operation can be performed quickly.

1.10. Effects The droplet discharge device according to this embodiment is controlled by the control unit to perform the first operation and to perform the second operation after the first operation. As a result, a liquid with little variation in component composition ratio can be supplied to the head, so that a liquid with little variation in component composition ratio can be discharged from the head.

  Further, in the droplet discharge device according to the present embodiment, when a predetermined time or more elapses, the control unit performs control to perform the first operation before performing the second operation. For this reason, even if the sedimentation component settles in the pipe and the container, a liquid with a small variation in the component composition ratio can be supplied to the head, so that a liquid with a small variation in the component composition ratio can be discharged from the head.

2. Liquid Supply Method The liquid supply method according to the present embodiment is performed using the droplet discharge device 100 described above.

  In the liquid supply method according to the present embodiment, the liquid in the container 20 is not discharged onto the medium to be discharged when a predetermined time or more has elapsed after the stirring by the stirring means has been completed using the droplet discharge device 100. The first step (hereinafter also referred to as “replacement step”) and the second step (hereinafter also referred to as “stirring step”) in which the liquid in the container is stirred by the stirring means in this order. It is characterized by performing.

  The replacement process is the same as the first operation in “1.9. Control Flow” described above, and thus the description thereof is omitted. Moreover, since the stirring step is the same as the second operation in “1.9. Control flow” described above, the description thereof is omitted.

  When a predetermined time or more has elapsed after the stirring by the stirring means is completed, if the replacement step and the stirring step are performed in this order, the composition of the components in the head 40 is similar to the content described in “1.9. A liquid with little variation in the ratio can be supplied.

  The liquid supply method according to the present embodiment can further include a third step (hereinafter, also referred to as “discharge step”) in which liquid is discharged from the head 40 onto the discharge target medium. Since the discharge process is the same as the third operation in “1.9. Control flow” described above, the description thereof is omitted.

  The discharging step is preferably performed after the first step and the second step when a predetermined time or more has elapsed after the stirring by the stirring means is completed. As a result, similarly to the content described in “1.9. Control Flow”, it is possible to discharge liquid from the head 40 with little variation in the component composition ratio.

3. Inkjet Printer The droplet discharge device according to the present invention can be applied to an inkjet printer. In the present embodiment, an ink jet printer 300 including a serial head to which the droplet discharge device 100 is applied will be described. In addition, although the example which applied the droplet discharge apparatus which concerns on this invention to the inkjet printer provided with the serial type head was shown, it is not limited to this. The ink jet printer according to the present invention may be applied to, for example, an ink jet printer having a line type head.

  FIG. 5 is a perspective view schematically showing an inkjet printer 300 including the droplet discharge device 100. As shown in FIG. 5, the inkjet printer 300 according to the present embodiment includes a control unit 60, a storage unit 10, a first tube 30, a second tube 32, a drive unit 50, a paper feeding unit 70, A suction part 380.

  Since the container 10, the first tube 30, the second tube 32, and the liquid stored in the container 10 have been described in “1. Liquid droplet ejection device”, description thereof will be omitted.

  The control unit 360 can be shared with the control unit 60 used in the droplet discharge device, and can be configured using a computer having a CPU and a memory. The control unit 360 has a function of controlling the storage unit 10, the driving unit 50, the paper feeding unit 70, and the suction unit 380.

  The drive unit 50 can include a carriage 50A, a drive belt 50B, and a carriage motor 50C. The drive unit 50 is connected to the control unit 60 via the flexible cable 62 and is controlled by the control unit 360.

  The drive unit 50 has a function of reciprocating the carriage 50A in a predetermined direction MSD. Specifically, the driving belt 50B connected to the carriage 50A is driven by the power of the carriage motor 50C as a driving source of the carriage 50A, and the carriage 50A is reciprocated in a predetermined direction MSD.

  As described in “1. Liquid droplet ejection device”, the container 20 and the head 40 are mounted on the carriage 50A.

  Since the discharge onto the recording paper P is the same as that described in “1.8. Control Flow”, the description thereof is omitted.

  The head 40 can have a plurality of nozzles that eject droplets. Further, the method of discharging the droplets of the head 40 is not particularly limited, and for example, an inkjet discharge method can be used. As the inkjet discharge method, any conventionally known method can be used, and examples thereof include a piezo inkjet and a thermal jet inkjet.

  The paper feed unit 70 includes a paper feed motor (not shown) serving as a drive source thereof, and a paper feed roller 72 that rotates by the operation of the paper feed motor. The paper feeding unit 70 can transport the recording paper P in a direction that intersects the predetermined direction MSD. The paper feed unit 70 corresponds to the transport mechanism described in “1. Droplet Discharge Device”.

  The suction unit 380 can have the same configuration as the suction unit 80 in the droplet discharge device 100. Specifically, the suction unit 380 can include a cap device 382 and a tube pump (not shown). The suction unit 380 connects the cap device 382 to the head 40 to seal the liquid discharge surface of the head 40, and then in a tube (not shown) by a pump roller (not shown) connected to the cap device 382. By discharging the air, the liquid in the container 20 can be discharged through the head 40. The suction method by the suction unit 380 is not particularly limited as long as the liquid in the container 20 can be discharged.

  Since the ink jet printer 300 according to the present embodiment includes the droplet discharge device 100 described above, it is possible to supply a liquid with a small variation in component composition ratio to the head, and a liquid with a small variation in component composition ratio from the head. Drops can be ejected.

  In the present invention, the case where the droplet discharge apparatus 100 is applied to an image recording apparatus such as the ink jet printer 300 has been described. However, the present invention is not limited to this. For example, the droplet discharge device 100 is used for forming a color filter such as a color material ejecting device, an organic EL display, an FED (surface emitting display), and an electrophoretic display used for manufacturing a color filter such as a liquid crystal display. The present invention can also be applied to a liquid material ejecting apparatus or the like.

4). Examples Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these examples.

4.1. Preparation of white ink composition A white ink composition having the following composition was prepared.
Titanium dioxide (average particle size 360 nm, specific gravity 4.3): 10% by mass
Styrene-acrylic acid copolymer: 2% by mass
1,2-hexanediol: 5% by mass
Glycerin: 10% by mass
Triethanolamine: 0.9% by mass
BYK-348 (Bic Chemie Japan Co., Ltd.): 0.5% by mass
Ultrapure water: remaining 100% by mass

4.2. Apparatus For the preparation of the sample for evaluation, an apparatus in which an inkjet printer (product name “EPSON PX-G930”, manufactured by Seiko Epson Corporation) was modified so as to have the same configuration as in FIG. 5 was used. Specifically, the container was attached to the carriage of the ink jet printer so that the longitudinal direction of the container was parallel to the moving direction (horizontal direction) of the carriage, and the container and the container were connected by the first tube. Further, the container and the head were connected by a second tube. Further, the white ink composition prepared in “4.1. Preparation of white ink composition” was accommodated in the accommodating portion.

  The container used was a cylindrical shape (inner dimensions: diameter 1.5 cm × height 11.3 cm, capacity: 20 ml). The stirrer arranged inside the container was a sphere (diameter: 1.0 cm, specific gravity 7.9). A first tube having a diameter of 3 mm × length of 280 cm and a capacity of 20 ml was used. The total volume in the head and in the second tube was 3 ml.

4.3. Preparation of evaluation sample (1) Example 1
The ink jet printer is activated, the white ink composition is supplied from the container, the first tube and the container are filled with the white ink composition, and the second tube and the head are filled with the white ink composition. . Then, the ink jet printer was left for 30 days to allow the titanium oxide contained in the white ink composition to settle in the first tube and the container.

  After standing for 30 days, 3 ml of liquid in the second tube and the head were removed by a flushing operation. Next, 20 ml of the liquid in the container was discharged from the head, and the white ink composition was supplied from the container to the first pipe, whereby the supernatant liquid in the first pipe was supplied into the container (replacement operation). Next, the carriage is reciprocated 30 times at a distance of 23 cm at a speed of 46 cm / sec (stirring operation), and then the liquid is discharged from the head while supplying the liquid from the housing to the head through the first tube and the container. (Discharge operation).

  At this time, the liquid discharged from the head was stored in different sample bottles every 4 ml, and the sample for evaluation according to Example 1 was obtained.

(2) Example 2
An evaluation sample according to Example 2 was obtained in the same manner as in “(1) Example 1” except that the discharge amount of the liquid in the container in the replacement operation was 16 ml.

(3) Example 3
As in the case of “(1) Example 1”, the above-described inkjet printer is started, and the white ink composition is supplied from the container, and the first tube, the container, and the head are filled with the white ink composition. . Then, the ink jet printer was left for 30 days to allow the titanium oxide contained in the white ink composition to settle in the first tube and the container.

  After standing for 30 days, 3 ml of liquid in the second tube and the head were removed by a flushing operation. Next, an initial operation was executed (initial operation). The initial operation conditions were such that the carriage was reciprocated twice at a distance of 28 cm at a speed of 70 cm / second.

  Next, 20 ml of the liquid in the container was discharged from the head, and the white ink composition was supplied from the container to the first pipe, whereby the supernatant liquid in the first pipe was supplied into the container (replacement operation). Next, the carriage is reciprocated 30 times at a distance of 23 cm at a speed of 46 cm / sec (stirring operation), and then the liquid is discharged from the head while supplying the liquid from the housing to the head through the first tube and the container. (Discharge operation).

  At this time, the liquid discharged from the head was stored in a different sample bottle every 4 ml, and the sample for evaluation according to Example 3 was obtained.

(4) Example 4
An evaluation sample according to Example 4 was obtained in the same manner as in “(1) Example 1” except that the discharge amount of the liquid in the container in the replacement operation was 8 ml.

(5) Comparative Example 1
In the same manner as in “(1) Example 1”, the above-described inkjet printer was activated, the white ink composition was supplied from the container, and the first tube and the container were filled with the white ink composition. Then, the ink jet printer was left for 30 days to allow the titanium oxide contained in the white ink composition to settle in the first tube and the container.

  After standing for 30 days, 3 ml of liquid in the second tube and the head were removed by a flushing operation. Next, the carriage was reciprocated 30 times at a distance of 23 cm at a speed of 46 cm / sec (stirring operation). Next, the liquid was ejected from the head while the liquid was supplied from the container to the head via the first tube and the container (ejection operation).

  At this time, 0.8 ml of the liquid discharged from the head first was stored in a sample bottle, and then 3.2 ml of the liquid discharged from the head was stored in another sample bottle. Thereafter, the liquid discharged from the head was stored in different sample bottles every 4 ml. As described above, an evaluation sample according to Comparative Example 1 was obtained.

(6) Comparative Example 2
In the same manner as in “(1) Example 1”, the above-described inkjet printer was activated, the white ink composition was supplied from the container, and the first tube and the container were filled with the white ink composition. Then, the ink jet printer was left for 30 days to allow the titanium oxide contained in the white ink composition to settle in the first tube and the container.

  After standing for 30 days, 3 ml of liquid in the second tube and the head were removed by a flushing operation. Next, the carriage was reciprocated 30 times at a distance of 23 cm at a speed of 46 cm / sec (stirring operation). Next, 20 ml of the liquid in the container was discharged from the head, and the white ink composition was supplied from the container to the first pipe, whereby the supernatant liquid in the first pipe was supplied into the container (replacement operation). Next, the liquid was ejected from the head while the liquid was supplied from the container to the head via the first tube and the container (ejection operation).

  At this time, the liquid discharged from the head was stored in different sample bottles every 4 ml, and the evaluation sample according to Comparative Example 2 was obtained.

4.4. Evaluation Test For each sample of Examples 1 to 4 and Comparative Examples 1 to 2 obtained as described above, a spectrophotometer (product name “U-3300” manufactured by Hitachi, Ltd.) was used. Then, the concentration of titanium dioxide in the liquid was measured.

4.5. Evaluation Results The results of the evaluation test are shown in FIG. In FIG. 6, the horizontal axis indicates the total discharge amount of the white ink composition discharged from the head. The vertical axis indicates the concentration of titanium dioxide contained in the white ink composition for each discharge amount.

  In Examples 1 to 4, control is performed so that the stirring operation is performed after the suction operation is performed. Therefore, as shown in FIG. 6, it was shown that the decrease in the concentration of titanium dioxide is small from the initial stage of the discharge operation. Further, it was shown that when the discharge of the white ink composition is continued, the concentration of titanium dioxide is excellent in recovery. In Example 1, the value when the titanium dioxide concentration was the lowest was 9.2%. In Example 2, the value when the titanium dioxide concentration was the lowest was 7.58%. In Example 3, the value when the titanium dioxide concentration was the lowest was 6.9%. In Example 4, the value when the titanium dioxide concentration was the lowest was 5.1%.

  On the other hand, in Comparative Example 1, control is performed so that the discharge operation is performed after the stirring operation is performed without performing the suction operation. Therefore, as shown in FIG. 6, a rapid decrease in the concentration of titanium dioxide occurred from the initial stage of the discharge operation. Further, it was shown that a large amount of white ink composition was required until the titanium dioxide concentration was restored to the same level as in the examples. In Comparative Example 1, the value when the titanium dioxide concentration was the lowest was 3.6%.

  The change in the concentration of titanium dioxide in Comparative Example 1 will be specifically described. First, when discharge of the white ink composition is started from the head, the supernatant liquid in the first tube that has not been stirred by the stirring operation is supplied to the head. Therefore, as shown in FIG. 6, the concentration of titanium dioxide discharged from the head starts to decrease. When all the supernatant liquid in the first tube is supplied to the head, the concentration of titanium dioxide in the white ink composition discharged from the head is reduced to 3.6%. Accordingly, in order to increase the titanium dioxide concentration in the white ink composition supplied to the head, it is necessary to supply a large amount of the white ink composition.

  In Comparative Example 2, the suction operation is controlled after the stirring operation. Therefore, since the supernatant liquid in the first tube was supplied to the head, as shown in FIG. 6, a significant decrease in the titanium dioxide concentration was recognized from the initial stage of the ejection operation. This indicated that a large amount of white ink composition was required to increase the titanium dioxide concentration. In Comparative Example 2, the value when the titanium dioxide concentration was the lowest was 3.4%.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same purposes and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

  10 container, 15 stirrer, 20 container, 30 first tube, 32 second tube, 40 head, 50 drive unit, 50A carriage, 50B drive belt, 50C carriage motor, 60 control means, 62 flexible cable, 70 paper feed 72, paper feed roller, 80 suction means, 82 cap device, 100 droplet discharge device, 110 command determination means, 120 liquid supply operation control means, 130 liquid discharge operation control means, 140 first operation control means, 150 second Operation control means, 160 third operation control means, 170 timing means, 180 storage means, 300 ink jet printer, 360 control section, 380 suction section, 382 cap device.

Claims (4)

A storage section for storing liquid;
A container connected to the housing part via a first pipe and supplied with the liquid from the housing part;
A head connected to the container, supplied with the liquid from the container, and discharging the liquid to a discharge medium;
Stirring means for stirring the liquid in the container;
Control means for controlling a first operation for replacing the liquid in the container with the liquid in the container and a second operation for stirring the liquid in the container by the stirring means;
Inside the first tube, there is a partition portion twisted along the flow direction of the liquid,
The control means causes the first operation and the second operation to be performed when the head is not performing an ejection operation for ejecting the liquid onto the ejection target medium and forming an image based on ejection data. Discharge device. In claim 1,
A second pipe connecting the head and the container ;
A replacement device comprising a cap device connected to the head, and a suction device connected to the cap device;
Further comprising
The control means, after performing the second operation, controls the suction means to replace the liquid in the head and the second tube by the first action, and the suction means in the first action The droplet discharge device is implemented at a suction speed that is slower than a suction speed performed to eliminate clogging of the head . In claim 1 or claim 2,
In the first operation, the liquid replacement amount of the liquid in the container is not less than 0.4 times and not more than 1.0 times the volume of the first tube. In any one of Claims 1 thru | or 3,
In the first operation, the liquid replacement amount of the liquid in the container is not less than 0.8 times and not more than 1.0 times the volume of the first tube.